A study of alternative designs for a system to concentrate carbon dioxide in a hydrogen-depolarized cell

NASA Technical Reports Server (NTRS)

1973-01-01

Experimental results are presented on alternative designs for a hydrogen depolarized cell to concentrate CO2 in spacecraft atmospheric control systems. Data cover technical problems, methods for solving these problems, and the suitability of such a cell for CO2 removal and control of atmospheric humidity during the flight mode.

Evaluating different concentrations of hydrogen peroxide in an automated room disinfection system.

PubMed

Murdoch, L E; Bailey, L; Banham, E; Watson, F; Adams, N M T; Chewins, J

2016-09-01

A comparative study was made on the efficacy of 5, 10 and 35% weight by weight (w/w) hydrogen peroxide solutions when applied using an automated room disinfection system. Six-log biological indicators of methicillin-resistant Staphylococcus aureus (MRSA) and Geobacillus stearothermophilus were produced on stainless steel coupons and placed within a large, sealed, environmentally controlled enclosure. Five percent hydrogen peroxide was distributed throughout the enclosure using a Bioquell hydrogen peroxide vapour generator (BQ-50) for 40 min and left to reside for a further 200 min. Biological indicators were removed at 10-min intervals throughout the first 120 min of the process. The experiment was repeated for 10 and 35% hydrogen peroxide solutions. Five percent and 10% hydrogen peroxide solutions failed to achieve any reduction of MRSA, but achieved full kill of G. stearothermophilus spores at 70 and 40 min respectively. Thirty-five percent hydrogen peroxide achieved a 6-log reduction of MRSA after 30 min and full kill of G. stearothermophilus at 20 min. The concentration of 5% hydrogen peroxide within the enclosure after the 200-min dwell was measured at 9·0 ppm. This level exceeds the 15-min Short Term Exposure Limit (STEL) for hydrogen peroxide of 2·0 ppm. Users of automated hydrogen peroxide disinfection systems should review system efficacy and room re-entry protocols in light of these results. This research allows hospital infection control teams to consider the impact and risks of using low concentrations of hydrogen peroxide for disinfection within their facilities, and to question automated room disinfection system providers on the efficacy claims they make. The evidence that low concentration hydrogen peroxide solutions do not rapidly, autonomously break down, is in contradiction to the claims made by some hydrogen peroxide equipment providers and raises serious health and safety concerns. Facilities using hydrogen peroxide systems that claim autonomous break down of hydrogen peroxide should introduce monitoring procedures to ensure rooms are safe for re-entry and patient occupation. © 2016 The Society for Applied Microbiology.

Hydrogen Peroxide Probes Directed to Different Cellular Compartments

PubMed Central

Malinouski, Mikalai; Zhou, You; Belousov, Vsevolod V.; Hatfield, Dolph L.; Gladyshev, Vadim N.

2011-01-01

Background Controlled generation and removal of hydrogen peroxide play important roles in cellular redox homeostasis and signaling. We used a hydrogen peroxide biosensor HyPer, targeted to different compartments, to examine these processes in mammalian cells. Principal Findings Reversible responses were observed to various redox perturbations and signaling events. HyPer expressed in HEK 293 cells was found to sense low micromolar levels of hydrogen peroxide. When targeted to various cellular compartments, HyPer occurred in the reduced state in the nucleus, cytosol, peroxisomes, mitochondrial intermembrane space and mitochondrial matrix, but low levels of the oxidized form of the biosensor were also observed in each of these compartments, consistent with a low peroxide tone in mammalian cells. In contrast, HyPer was mostly oxidized in the endoplasmic reticulum. Using this system, we characterized control of hydrogen peroxide in various cell systems, such as cells deficient in thioredoxin reductase, sulfhydryl oxidases or subjected to selenium deficiency. Generation of hydrogen peroxide could also be monitored in various compartments following signaling events. Conclusions We found that HyPer can be used as a valuable tool to monitor hydrogen peroxide generated in different cellular compartments. The data also show that hydrogen peroxide generated in one compartment could translocate to other compartments. Our data provide information on compartmentalization, dynamics and homeostatic control of hydrogen peroxide in mammalian cells. PMID:21283738

Cold weather hydrogen generation system and method of operation

DOEpatents

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

2010-12-14

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

Hydrogen Research for Spaceport and Space-Based Applications: Hydrogen Sensors and Systems. Part 2

NASA Technical Reports Server (NTRS)

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. Sensor systems research was focused on hydrogen leak detection and smart sensors with adaptive feedback control for fuel cells. The goal was to integrate multifunction smart sensors, low-power high-efficiency wireless circuits, energy harvesting devices, and power management circuits in one module. Activities were focused on testing and demonstrating sensors in a realistic environment while also bringing them closer to production and commercial viability for eventual use in the actual operating environment.

Flight Hydrogen Sensor for use in the ISS Oxygen Generation Assembly

NASA Technical Reports Server (NTRS)

MSadoques, George, Jr.; Makel, Darby B.

2005-01-01

This paper provides a description of the hydrogen sensor Orbital Replacement Unit (ORU) used on the Oxygen Generation Assembly (OGA), to be operated on the International Space Station (ISS). The hydrogen sensor ORU is being provided by Makel Engineering, Inc. (MEI) to monitor the oxygen outlet for the presence of hydrogen. The hydrogen sensor ORU is a triple redundant design where each sensor converts raw measurements to actual hydrogen partial pressure that is reported to the OGA system controller. The signal outputs are utilized for system shutdown in the event that the hydrogen concentration in the oxygen outlet line exceeds the specified shutdown limit. Improvements have been made to the Micro-Electro-Mechanical Systems (MEMS) based sensing element, screening, and calibration process to meet OGA operating requirements. Two flight hydrogen sensor ORUs have successfully completed the acceptance test phase. This paper also describes the sensor s performance during acceptance testing, additional tests planned to extend the operational performance calibration cycle, and integration with the OGA system.

Room temperature micro-hydrogen-generator

NASA Astrophysics Data System (ADS)

Gervasio, Don; Tasic, Sonja; Zenhausern, Frederic

A new compact and cost-effective hydrogen-gas generator has been made that is well suited for supplying hydrogen to a fuel-cell for providing base electrical power to hand-carried appliances. This hydrogen-generator operates at room temperature, ambient pressure and is orientation-independent. The hydrogen-gas is generated by the heterogeneous catalytic hydrolysis of aqueous alkaline borohydride solution as it flows into a micro-reactor. This reactor has a membrane as one wall. Using the membrane keeps the liquid in the reactor, but allows the hydrogen-gas to pass out of the reactor to a fuel-cell anode. Aqueous alkaline 30 wt% borohydride solution is safe and promotes long application life, because this solution is non-toxic, non-flammable, and is a high energy-density (≥2200 W-h per liter or per kilogram) hydrogen-storage solution. The hydrogen is released from this storage-solution only when it passes over the solid catalyst surface in the reactor, so controlling the flow of the solution over the catalyst controls the rate of hydrogen-gas generation. This allows hydrogen generation to be matched to hydrogen consumption in the fuel-cell, so there is virtually no free hydrogen-gas during power generation. A hydrogen-generator scaled for a system to provide about 10 W electrical power is described here. However, the technology is expected to be scalable for systems providing power spanning from 1 W to kW levels.

Shuttle Gaseous Hydrogen Venting Risk from Flow Control Valve Failure

NASA Technical Reports Server (NTRS)

Drummond, J. Philip; Baurle, Robert A.; Gafney, Richard L.; Norris, Andrew T.; Pellett, Gerald L.; Rock, Kenneth E.

2009-01-01

This paper describes a series of studies to assess the potential risk associated with the failure of one of three gaseous hydrogen flow control valves in the orbiter's main propulsion system during the launch of Shuttle Endeavour (STS-126) in November 2008. The studies focused on critical issues associated with the possibility of combustion resulting from release of gaseous hydrogen from the external tank into the atmosphere during assent. The Shuttle Program currently assumes hydrogen venting from the external tank will result in a critical failure. The current effort was conducted to increase understanding of the risk associated with venting hydrogen given the flow control valve failure scenarios being considered in the Integrated In-Flight Anomaly Investigation being conducted by NASA.

Control of accidental releases of hydrogen selenide in vented storage cabinets

NASA Astrophysics Data System (ADS)

Fthenakis, V. M.; Moskowitz, P. D.; Sproull, R. D.

1988-07-01

Highly toxic hydrogen selenide and hydrogen sulfide gases are used in the production of copper-indium-diselenide photovoltaic cells by reactive sputtering. In the event of an accident, these gases may be released to the atmosphere and pose hazards to public and occupational safety and health. This paper outlines an approach for designing systems for the control of these releases given the uncertainty in release conditions and lack of data on the chemical systems involved. Accidental releases of these gases in storage cabinets can be controlled by either a venturi and packed-bed scrubber and carbon adsorption bed, or containment scrubbing equipment followed by carbon adsorption. These systems can effectively reduce toxic gas emissions to levels needed to protect public health. The costs of these controls (˜0.012/Wp) are samll in comparison with current (˜6/Wp) and projected (˜I/Wp) production costs.

Activation energy for diamond growth from the carbon-hydrogen gas system at low substrate temperatures

NASA Astrophysics Data System (ADS)

Stiegler, J.; Lang, T.; von Kaenel, Y.; Michler, J.; Blank, E.

1997-01-01

The growth kinetics of diamond films deposited at low substrate temperatures (600-400 °C) from the carbon-hydrogen gas system have been studied. When the substrate temperature alone was varied, independently of all other process parameters in the microwave plasma reactor, an activation energy in the order of 7 kcal/mol was observed. This value did not change with different carbon concentrations in hydrogen. It is supposed that growth kinetics in this temperature range are controlled by a single chemical reaction, probably the abstraction of surface bonded hydrogen by gas phase atomic hydrogen.

Space station propulsion test bed

NASA Technical Reports Server (NTRS)

Briley, G. L.; Evans, S. A.

1989-01-01

A test bed was fabricated to demonstrate hydrogen/oxygen propulsion technology readiness for the intital operating configuration (IOC) space station application. The test bed propulsion module and computer control system were delivered in December 1985, but activation was delayed until mid-1986 while the propulsion system baseline for the station was reexamined. A new baseline was selected with hydrogen/oxygen thruster modules supplied with gas produced by electrolysis of waste water from the space shuttle and space station. As a result, an electrolysis module was designed, fabricated, and added to the test bed to provide an end-to-end simulation of the baseline system. Subsequent testing of the test bed propulsion and electrolysis modules provided an end-to-end demonstration of the complete space station propulsion system, including thruster hot firings using the oxygen and hydrogen generated from electrolysis of water. Complete autonomous control and operation of all test bed components by the microprocessor control system designed and delivered during the program was demonstrated. The technical readiness of the system is now firmly established.

Efficacy of hydrogen peroxide in controlling mortality associated with saprolegniasis on walleye, white sucker, and paddlefish eggs

USGS Publications Warehouse

Gaikowski, M.P.; Rach, J.J.; Drobish, M.; Hamilton, J.; Harder, T.; Lee, L.A.; Moen, C.; Moore, A.

2003-01-01

The efficacy of hydrogen peroxide in controlling saprolegniasis on eggs of walleye Stizostedion vitreum, white sucker Catostomus commersoni, and paddlefish Polyodon spathula was evaluated at four private, state, and federal production hatcheries participating in an Investigational New Animal Drug efficacy study (experiment 1; walleyes) and in a laboratory-based miniature egg jar incubation system (experiment 2; walleyes, white suckers, and paddlefish). Naturally occurring fungal infestations (saprolegniasis) were observed on eggs in both experiments. Confirmatory diagnosis of infested eggs from one hatchery in experiment 1 identified the pathogen as Saprolegnia parasitica. During experiment 1, eggs were treated daily for 15 min with either 0, 500, or 750 mg/L of hydrogen peroxide, and one trial compared a 500-mg/L hydrogen peroxide treatment with a formalin treatment at 1,667 mg/L. Saprolegniasis infestation was observed in control egg jars, whereas treatment with either formalin or hydrogen peroxide virtually eliminated the infestation. Hydrogen peroxide treatments of 500 mg/L either increased egg hatch or were as effective as physical removal of infested eggs in controlling mortality. Although treatment with formalin at 1,667 mg/L significantly increased the percent eye-up of walleye eggs compared with that of those treated with hydrogen peroxide at 500 mg/L, the difference was only 1.9-2.6%. In experiment 2, noneyed eggs were treated for 15 min every other day with 0, 283, 565, or 1,130 mg/L of hydrogen peroxide until the viable eggs hatched. Saprolegniasis infestation engulfed most control eggs, whereas infestation of treated eggs was either reduced or not visible. Hydrogen peroxide significantly increased egg hatch for all three species tested in experiment 2. Although hydrogen peroxide treatments as low as 283 mg/L significantly increased walleye and white sucker hatch, treatments between 500 and 1,000 mg/L are more likely to be effective in production egg incubation systems.

New potentials for conventional aircraft when powered by hydrogen-enriched gasoline

NASA Technical Reports Server (NTRS)

Menard, W. A.; Moynihan, P. I.; Rupe, J. H.

1976-01-01

Hydrogen enrichment for aircraft piston engines is under study in a new NASA program. The objective of the program is to determine the feasibility of inflight injection of hydrogen in general aviation aircraft engines to reduce fuel consumption and to lower emission levels. A catalytic hydrogen generator will be incorporated as part of the air induction system of a Lycoming turbocharged engine and will generate hydrogen by breaking down small amounts of the aviation gasoline used in the normal propulsion system. This hydrogen will then be mixed with gasoline and compressed air from the turbocharger before entering the engine combustion chamber. The paper summarizes the results of a systems analysis study. Calculations assuming a Beech Duke aircraft indicate that fuel savings on the order of 20% are possible. An estimate of the potential for the utilization of hydrogen enrichment to control exhaust emissions indicates that it may be possible to meet the 1979 Federal emission standards.

Operational characteristics of the J-PARC cryogenic hydrogen system for a spallation neutron source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tatsumoto, Hideki; Ohtsu, Kiichi; Aso, Tomokazu

2014-01-29

The J-PARC cryogenic hydrogen system provides supercritical hydrogen with the para-hydrogen concentration of more than 99 % and the temperature of less than 20 K to three moderators so as to provide cold pulsed neutron beams of a higher neutronic performance. Furthermore, the temperature fluctuation of the feed hydrogen stream is required to be within ± 0.25 K. A stable 300-kW proton beam operation has been carried out since November 2012. The para-hydrogen concentrations were measured during the cool-down process. It is confirmed that para-hydrogen always exists in the equilibrium concentration because of the installation of an ortho-para hydrogen convertor.more » Propagation characteristics of temperature fluctuation were measured by temporarily changing the heater power under off-beam condition to clarify the effects of a heater control for thermal compensation on the feed temperature fluctuation. The experimental data gave an allowable temperature fluctuation of ± 1.05 K. It is clarified through a 286-kW and a 524-kW proton beam operations that the heater control would be applicable for the 1-MW proton beam operation by extrapolating from the experimental data.« less

Design of hydrogen vent line for the cryogenic hydrogen system in J-PARC

NASA Astrophysics Data System (ADS)

Tatsumoto, Hideki; Aso, Tomokazu; Kato, Takashi; Ohtsu, Kiichi; Hasegawa, Shoichi; Maekawa, Fujio; Futakawa, Masatoshi

2009-02-01

As one of the main experimental facilities in J-PARC, an intense spallation neutron source (JSNS) driven by a 1-MW proton beam selected supercritical hydrogen at a temperature of 20 K and a pressure of 1.5 MPa as a moderator material. Moderators are controlled by a cryogenic hydrogen system that has a hydrogen relief system, which consists of high and low pressure stage of manifolds, a hydrogen vent line and a stack, in order to release hydrogen to the outside safely. The design of the hydrogen vent line should be considered to prevent purge nitrogen gas in the vent line from freezing when releasing the cryogenic hydrogen, to prevent moisture in the stack placed in an outdoor location from freezing, and to inhibit large piping temperature reduction at a building wall penetration. In this work, temperature change behaviors in the hydrogen vent line were analyzed by using a CFD code, STAR-CD. We determined required sizes of the vent line based on the analytical results and its layout in the building.

Microfabricated Hydrogen Sensor Technology for Aerospace and Commercial Applications

NASA Technical Reports Server (NTRS)

Hunter, Gary W.; Bickford, R. L.; Jansa, E. D.; Makel, D. B.; Liu, C. C.; Wu, Q. H.; Powers, W. T.

1994-01-01

Leaks on the Space Shuttle while on the Launch Pad have generated interest in hydrogen leak monitoring technology. An effective leak monitoring system requires reliable hydrogen sensors, hardware, and software to monitor the sensors. The system should process the sensor outputs and provide real-time leak monitoring information to the operator. This paper discusses the progress in developing such a complete leak monitoring system. Advanced microfabricated hydrogen sensors are being fabricated at Case Western Reserve University (CWRU) and tested at NASA Lewis Research Center (LeRC) and Gencorp Aerojet (Aerojet). Changes in the hydrogen concentrations are detected using a PdAg on silicon Schottky diode structure. Sensor temperature control is achieved with a temperature sensor and heater fabricated onto the sensor chip. Results of the characterization of these sensors are presented. These sensors can detect low concentrations of hydrogen in inert environments with high sensitivity and quick response time. Aerojet is developing the hardware and software for a multipoint leak monitoring system designed to provide leak source and magnitude information in real time. The monitoring system processes data from the hydrogen sensors and presents the operator with a visual indication of the leak location and magnitude. Work has commenced on integrating the NASA LeRC-CWRU hydrogen sensors with the Aerojet designed monitoring system. Although the leak monitoring system was designed for hydrogen propulsion systems, the possible applications of this monitoring system are wide ranged. Possible commercialization of the system will also be discussed.

Phase-change composites TES for nickel-hydrogen batteries

NASA Technical Reports Server (NTRS)

Knowles, Timothy R.; Meyer, Richard A.

1993-01-01

Viewgraphs of a discussion on phase-change composites thermal energy storage (TES) for nickel-hydrogen batteries are presented. Topics covered include Ni-H2 thermal control problems; passive thermal control with TES; phase-change composites (PCC); candidate materials; design options; fabrication and freeze-melt cycling; thermal modeling; system benefits; and applications.

Photoproduction of hydrogen by marine blue-green algae. Progress report 15 August 80-14 February 81

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitsui, A.

The growth of Miami BG 7 (Oscillatoria sp.) in seawater was studied using 2.8 liters of Fernbach batch cultures, 14 liters of Carboy batch cultures, and 7 liters of a controlled environment system. In the batch culture tests, both 'instant ocean' and natural seawater from the local environment were used. The effects of adding supplemental nitrate and ammonia to the seawater bases were also examined. The 7-liter controlled environment culture system provides for the control and monitoring of physical and chemical parameters, and can be used for continuous culture experiments. Work on the comparative study of Anabaena cylindrica and Miamimore » BG 7 indicates that their hydrogen metabolism is quite different having a direct bearing on their applied potential. In particular, this study has shown that there is a strong uptake hydrogenase activity in Anabaena cylindrica in a closed system. This differs sharply with the high rates of production achieved by Anabaena cylindrica in 'flow through systems,' where hydrogen gas is continuously eliminated from the experimental chamber. In contrast, Miami BG 7 exhibits no uptake hydrogenase activity. Consequently, a high rate of hydrogen evolution is maintained.« less

Kinetic limitations of the Mg(2)Si system for reversible hydrogen storage.

PubMed

Kelly, Stephen T; Van Atta, Sky L; Vajo, John J; Olson, Gregory L; Clemens, B M

2009-05-20

Despite the promising thermodynamics and storage capacities of many destabilized metal hydride hydrogen storage material systems, they are often kinetically limited from achieving practical and reversible behavior. Such is the case with the Mg2Si system. We investigated the kinetic mechanisms responsible for limiting the reversibility of the MgH2+Si system using thin films as a controlled research platform. We observed that the reaction MgH2 + 1/2Mg2Si + H2 is limited by the mass transport of Mg and Si into separate phases. Hydrogen readily diffuses through the Mg2Si material and nucleating MgH2 phase growth does not result in reaction completion. By depositing and characterizing multilayer films of Mg2Si and Mg with varying Mg2Si layer thicknesses, we conclude that the hydrogenation reaction consumes no more than 1 nm of Mg2Si, making this system impractical for reversible hydrogen storage.

Controlling the Formation of Ionic-Liquid-based Aqueous Biphasic Systems by Changing the Hydrogen-Bonding Ability of Polyethylene Glycol End Groups.

PubMed

Pereira, Jorge F B; Kurnia, Kiki A; Freire, Mara G; Coutinho, João A P; Rogers, Robin D

2015-07-20

The formation of aqueous biphasic systems (ABS) when mixing aqueous solutions of polyethylene glycol (PEG) and an ionic liquid (IL) can be controlled by modifying the hydrogen-bond-donating/-accepting ability of the polymer end groups. It is shown that the miscibility/immiscibility in these systems stems from both the solvation of the ether groups in the oxygen chain and the ability of the PEG terminal groups to preferably hydrogen bond with water or the anion of the salt. The removal of even one hydrogen bond in PEG can noticeably affect the phase behavior, especially in the region of the phase diagram in which all the ethylene oxide (EO) units of the polymeric chain are completely solvated. In this region, removing or weakening the hydrogen-bond-donating ability of PEG results in greater immiscibility, and thus, in a higher ability to form ABS, as a result of the much weaker interactions between the IL anion and the PEG end groups. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adjustable ECR Ion Source Control System: Ion Source Hydrogen Positive Project

NASA Astrophysics Data System (ADS)

Arredondo, I.; Eguiraun, M.; Jugo, J.; Piso, D.; del Campo, M.; Poggi, T.; Varnasseri, S.; Feuchtwanger, J.; Bilbao, J.; Gonzalez, X.; Harper, G.; Muguira, L.; Miracoli, R.; Corres, J.; Belver, D.; Echevarria, P.; Garmendia, N.; Gonzalez, P.; Etxebarria, V.

2015-06-01

ISHP (Ion Source Hydrogen Positive) project consists of a highly versatile ECR type ion source. It has been built for several purposes, on the one hand, to serve as a workbench to test accelerator related technologies and validate in-house made developments, at the first stages. On the other hand, to design an ion source valid as the first step in an actual LINAC. Since this paper is focused on the control system of ISHP, besides the ion source, all the hardware and its control architecture is presented. Nowadays the ion source is able to generate a pulse of positive ions of Hydrogen from 2 μs to a few ms range with a repetition rate ranging from 1 Hz to 50 Hz with a maximum of 45 mA of current. Furthermore, the first experiments with White Rabbit (WR) synchronization system are presented.

Automated Hydrogen Gas Leak Detection System

NASA Technical Reports Server (NTRS)

1995-01-01

The Gencorp Aerojet Automated Hydrogen Gas Leak Detection System was developed through the cooperation of industry, academia, and the Government. Although the original purpose of the system was to detect leaks in the main engine of the space shuttle while on the launch pad, it also has significant commercial potential in applications for which there are no existing commercial systems. With high sensitivity, the system can detect hydrogen leaks at low concentrations in inert environments. The sensors are integrated with hardware and software to form a complete system. Several of these systems have already been purchased for use on the Ford Motor Company assembly line for natural gas vehicles. This system to detect trace hydrogen gas leaks from pressurized systems consists of a microprocessor-based control unit that operates a network of sensors. The sensors can be deployed around pipes, connectors, flanges, and tanks of pressurized systems where leaks may occur. The control unit monitors the sensors and provides the operator with a visual representation of the magnitude and locations of the leak as a function of time. The system can be customized to fit the user's needs; for example, it can monitor and display the condition of the flanges and fittings associated with the tank of a natural gas vehicle.

Ground operations demonstration unit for liquid hydrogen initial test results

NASA Astrophysics Data System (ADS)

Notardonato, W. U.; Johnson, W. L.; Swanger, A. M.; Tomsik, T.

2015-12-01

NASA operations for handling cryogens in ground support equipment have not changed substantially in 50 years, despite major technology advances in the field of cryogenics. NASA loses approximately 50% of the hydrogen purchased because of a continuous heat leak into ground and flight vessels, transient chill down of warm cryogenic equipment, liquid bleeds, and vent losses. NASA Kennedy Space Center (KSC) needs to develop energy-efficient cryogenic ground systems to minimize propellant losses, simplify operations, and reduce cost associated with hydrogen usage. The GODU LH2 project has designed, assembled, and started testing of a prototype storage and distribution system for liquid hydrogen that represents an advanced end-to-end cryogenic propellant system for a ground launch complex. The project has multiple objectives including zero loss storage and transfer, liquefaction of gaseous hydrogen, and densification of liquid hydrogen. The system is unique because it uses an integrated refrigeration and storage system (IRAS) to control the state of the fluid. This paper will present and discuss the results of the initial phase of testing of the GODU LH2 system.

Ground Operations Demonstration Unit for Liquid Hydrogen Initial Test Results

NASA Technical Reports Server (NTRS)

Notardonato, W. U.; Johnson, W. L.; Swanger, A. M.; Tomsik, T.

2015-01-01

NASA operations for handling cryogens in ground support equipment have not changed substantially in 50 years, despite major technology advances in the field of cryogenics. NASA loses approximately 50% of the hydrogen purchased because of a continuous heat leak into ground and flight vessels, transient chill down of warm cryogenic equipment, liquid bleeds, and vent losses. NASA Kennedy Space Center (KSC) needs to develop energy-efficient cryogenic ground systems to minimize propellant losses, simplify operations, and reduce cost associated with hydrogen usage. The GODU LH2 project has designed, assembled, and started testing of a prototype storage and distribution system for liquid hydrogen that represents an advanced end-to-end cryogenic propellant system for a ground launch complex. The project has multiple objectives including zero loss storage and transfer, liquefaction of gaseous hydrogen, and densification of liquid hydrogen. The system is unique because it uses an integrated refrigeration and storage system (IRAS) to control the state of the fluid. This paper will present and discuss the results of the initial phase of testing of the GODU LH2 system.

Anode reactive bleed and injector shift control strategy

DOEpatents

Cai, Jun [Rochester, NY; Chowdhury, Akbar [Pittsford, NY; Lerner, Seth E [Honeoye Falls, NY; Marley, William S [Rush, NY; Savage, David R [Rochester, NY; Leary, James K [Rochester, NY

2012-01-03

A system and method for correcting a large fuel cell voltage spread for a split sub-stack fuel cell system. The system includes a hydrogen source that provides hydrogen to each split sub-stack and bleed valves for bleeding the anode side of the sub-stacks. The system also includes a voltage measuring device for measuring the voltage of each cell in the split sub-stacks. The system provides two levels for correcting a large stack voltage spread problem. The first level includes sending fresh hydrogen to the weak sub-stack well before a normal reactive bleed would occur, and the second level includes sending fresh hydrogen to the weak sub-stack and opening the bleed valve of the other sub-stack when the cell voltage spread is close to stack failure.

Optimal control of fuel overpressure in a polymer electrolyte membrane fuel cell with hydrogen transfer leak during load change

NASA Astrophysics Data System (ADS)

Ebadighajari, Alireza; DeVaal, Jake; Golnaraghi, Farid

2017-02-01

Formation of membrane pinholes is a common defect in fuel cells, inflicting more cost and making less durable cells. This work focuses on mitigating this issue, and offers a continuous online treatment instead of attempting to dynamically model the hydrogen transfer leak rate. This is achieved by controlling the differential pressure between the anode and cathode compartments at the inlet side of the fuel cell stack, known as the fuel overpressure. The model predictive control approach is used to attain the objectives in a Ballard 9-cell Mk1100 polymer electrolyte membrane fuel cell (PEMFC) with inclusion of hydrogen transfer leak. Furthermore, the pneumatic modeling technique is used to model the entire anode side of a fuel cell station. The hydrogen transfer leak is embedded in the model in a novel way, and is considered as a disturbance during the controller design. Experimental results for different sizes of hydrogen transfer leaks are provided to show the benefits of fuel overpressure control system in alleviating the effects of membrane pinholes, which in turn increases membrane longevity, and reduces hydrogen emissions in the eventual presence of transfer leaks. Moreover, the model predictive controller provides an optimal control input while satisfying the problem constraints.

Optimization of the water chemistry of the primary coolant at nuclear power plants with VVER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barmin, L. F.; Kruglova, T. K.; Sinitsyn, V. P.

2005-01-15

Results of the use of automatic hydrogen-content meter for controlling the parameter of 'hydrogen' in the primary coolant circuit of the Kola nuclear power plant are presented. It is shown that the correlation between the 'hydrogen' parameter in the coolant and the 'hydrazine' parameter in the makeup water can be used for controlling the water chemistry of the primary coolant system, which should make it possible to optimize the water chemistry at different power levels.

Flow-Control Unit For Nitrogen And Hydrogen Gases

NASA Technical Reports Server (NTRS)

Chang, B. J.; Novak, D. W.

1990-01-01

Gas-flow-control unit installed and removed as one piece replaces system that included nine separately serviced components. Unit controls and monitors flows of nitrogen and hydrogen gases. Designed for connection via fluid-interface manifold plate, reducing number of mechanical fluid-interface connections from 18 to 1. Unit provides increasing reliability, safety, and ease of maintenance, and for reducing weight, volume, and power consumption.

Method and apparatus for controlling accidental releases of tritium

DOEpatents

Galloway, T.R.

1980-04-01

An improvement is described in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release. 1 fig.

Method and apparatus for controlling accidental releases of tritium

DOEpatents

Galloway, Terry R. [Berkeley, CA

1980-04-01

An improvement in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release.

Hydrogen considerations in light-water power reactons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keilholtz, G.W.

1976-02-01

A critical review of the literature now available on hydrogen considerations in light-water power reactors (LWRs) and a bibliography of that literature are presented. The subject matter includes mechanisms for the generation of hydrogen-oxygen mixtures, a description of the fundamental properties of such mixtures, and their spontaneous ignition in both static and dynamic systems. The limits for hydrogen flammability and flame propagation are examined in terms of the effects of pressure, temperature, and additives; the emphasis is on the effects of steam and water vapor. The containment systems for pressurized-water reactors (PWRs) and boiling-water reactors (BWRs) are compared, and methodsmore » to control hydrogen and oxygen under the conditions of both normal operation and postulated accidents are reviewed. It is concluded that hydrogen can be controlled so that serious complications from the production of hydrogen will not occur. The bibliography contains abstracts from the computerized files of the Nuclear Safety Information Center. Key-word, author, and permuted-title indexes are provided. The bibliography includes responses to questions asked by the U. S. Nuclear Regulatory Commission (NRC) which relate to hydrogen, as well as information on normal operations and postulated accidents including generation of hydrogen from core sprays. Other topics included in the ten sections of the bibliography are metal-water reactions, containment atmosphere, radiolytic gas, and recombiners.« less

New potentials for conventional aircraft when powered by hydrogen-enriched gasoline

NASA Technical Reports Server (NTRS)

Menard, W. A.; Moynihan, P. I.; Rupe, J. H.

1976-01-01

Hydrogen enrichment for aircraft piston engines is under study in a new NASA program. The objective of the program is to determine the feasibility of inflight injection of hydrogen in general aviation aircraft engines to reduce fuel consumption and to lower emission levels. A catalytic hydrogen generator will be incorporated as part of the air induction system of a Lycoming turbocharged engine and will generate hydrogen by breaking down small amounts of the aviation gasoline used in the normal propulsion system. This hydrogen will then be mixed with gasoline and compressed air from the turbocharger before entering the engine combustion chamber. The special properties of the hydrogen-enriched gasoline allow the engine to operate at ultralean fuel/air ratios, resulting in higher efficiencies and hence less fuel consumption. This paper summarizes the results of a systems analysis study. Calculations assuming a Beech Duke aircraft indicate that fuel savings on the order of 20% are possible. An estimate of the potential for the utilization of hydrogen enrichment to control exhaust emissions indicates that it may be possible to meet the 1979 Federal emission standards.

Enhanced Photoelectrochemical Behavior of H-TiO2 Nanorods Hydrogenated by Controlled and Local Rapid Thermal Annealing

NASA Astrophysics Data System (ADS)

Wang, Xiaodan; Estradé, Sonia; Lin, Yuanjing; Yu, Feng; Lopez-Conesa, Lluis; Zhou, Hao; Gurram, Sanjeev Kumar; Peiró, Francesca; Fan, Zhiyong; Shen, Hao; Schaefer, Lothar; Braeuer, Guenter; Waag, Andreas

2017-05-01

Recently, colored H-doped TiO2 (H-TiO2) has demonstrated enhanced photoelectrochemical (PEC) performance due to its unique crystalline core—disordered shell nanostructures and consequent enhanced conduction behaviors between the core-shell homo-interfaces. Although various hydrogenation approaches to obtain H-TiO2 have been developed, such as high temperature hydrogen furnace tube annealing, high pressure hydrogen annealing, hydrogen-plasma assisted reaction, aluminum reduction and electrochemical reduction etc., there is still a lack of a hydrogenation approach in a controlled manner where all processing parameters (temperature, time and hydrogen flux) were precisely controlled in order to improve the PEC performance of H-TiO2 and understand the physical insight of enhanced PEC performance. Here, we report for the first time a controlled and local rapid thermal annealing (RTA) approach to prepare hydrogenated core-shell H-TiO2 nanorods grown on F:SnO2 (FTO) substrate in order to address the degradation issue of FTO in the typical TiO2 nanorods/FTO system observed in the conventional non-RTA treated approaches. Without the FTO degradation in the RTA approach, we systematically studied the intrinsic relationship between the annealing temperature, structural, optical, and photoelectrochemical properties in order to understand the role of the disordered shell on the improved photoelectrochemical behavior of H-TiO2 nanorods. Our investigation shows that the improvement of PEC performance could be attributed to (i) band gap narrowing from 3.0 to 2.9 eV; (ii) improved optical absorption in the visible range induced by the three-dimensional (3D) morphology and rough surface of the disordered shell; (iii) increased proper donor density; (iv) enhanced electron-hole separation and injection efficiency due to the formation of disordered shell after hydrogenation. The RTA approach developed here can be used as a suitable hydrogenation process for TiO2 nanorods/FTO system for important applications such as photocatalysis, hydrogen generation from water splitting and solar energy conversion.

Enhanced Photoelectrochemical Behavior of H-TiO2 Nanorods Hydrogenated by Controlled and Local Rapid Thermal Annealing.

PubMed

Wang, Xiaodan; Estradé, Sonia; Lin, Yuanjing; Yu, Feng; Lopez-Conesa, Lluis; Zhou, Hao; Gurram, Sanjeev Kumar; Peiró, Francesca; Fan, Zhiyong; Shen, Hao; Schaefer, Lothar; Braeuer, Guenter; Waag, Andreas

2017-12-01

Recently, colored H-doped TiO 2 (H-TiO 2 ) has demonstrated enhanced photoelectrochemical (PEC) performance due to its unique crystalline core-disordered shell nanostructures and consequent enhanced conduction behaviors between the core-shell homo-interfaces. Although various hydrogenation approaches to obtain H-TiO 2 have been developed, such as high temperature hydrogen furnace tube annealing, high pressure hydrogen annealing, hydrogen-plasma assisted reaction, aluminum reduction and electrochemical reduction etc., there is still a lack of a hydrogenation approach in a controlled manner where all processing parameters (temperature, time and hydrogen flux) were precisely controlled in order to improve the PEC performance of H-TiO 2 and understand the physical insight of enhanced PEC performance. Here, we report for the first time a controlled and local rapid thermal annealing (RTA) approach to prepare hydrogenated core-shell H-TiO 2 nanorods grown on F:SnO 2 (FTO) substrate in order to address the degradation issue of FTO in the typical TiO 2 nanorods/FTO system observed in the conventional non-RTA treated approaches. Without the FTO degradation in the RTA approach, we systematically studied the intrinsic relationship between the annealing temperature, structural, optical, and photoelectrochemical properties in order to understand the role of the disordered shell on the improved photoelectrochemical behavior of H-TiO 2 nanorods. Our investigation shows that the improvement of PEC performance could be attributed to (i) band gap narrowing from 3.0 to 2.9 eV; (ii) improved optical absorption in the visible range induced by the three-dimensional (3D) morphology and rough surface of the disordered shell; (iii) increased proper donor density; (iv) enhanced electron-hole separation and injection efficiency due to the formation of disordered shell after hydrogenation. The RTA approach developed here can be used as a suitable hydrogenation process for TiO 2 nanorods/FTO system for important applications such as photocatalysis, hydrogen generation from water splitting and solar energy conversion.

Development of a sterilizing in-place application for a production machine using Vaporized Hydrogen Peroxide.

PubMed

Mau, T; Hartmann, V; Burmeister, J; Langguth, P; Häusler, H

2004-01-01

The use of steam in sterilization processes is limited by the implementation of heat-sensitive components inside the machines to be sterilized. Alternative low-temperature sterilization methods need to be found and their suitability evaluated. Vaporized Hydrogen Peroxide (VHP) technology was adapted for a production machine consisting of highly sensitive pressure sensors and thermo-labile air tube systems. This new kind of "cold" surface sterilization, known from the Barrier Isolator Technology, is based on the controlled release of hydrogen peroxide vapour into sealed enclosures. A mobile VHP generator was used to generate the hydrogen peroxide vapour. The unit was combined with the air conduction system of the production machine. Terminal vacuum pumps were installed to distribute the gas within the production machine and for its elimination. In order to control the sterilization process, different physical process monitors were incorporated. The validation of the process was based on biological indicators (Geobacillus stearothermophilus). The Limited Spearman Karber Method (LSKM) was used to statistically evaluate the sterilization process. The results show that it is possible to sterilize surfaces in a complex tube system with the use of gaseous hydrogen peroxide. A total microbial reduction of 6 log units was reached.

Hydrogen generation in CSP plants and maintenance of DPO/BP heat transfer fluids - A simulation approach

NASA Astrophysics Data System (ADS)

Kuckelkorn, Thomas; Jung, Christian; Gnädig, Tim; Lang, Christoph; Schall, Christina

2016-05-01

The ageing of diphenyl oxide/ biphenyl (DPO/BP) Heat Transfer Fluids (HTFs) implies challenging tasks for operators of parabolic trough power plants in order to find the economic optimum between plant performance and O&M costs. Focusing on the generation of hydrogen, which is effecting from the HTF ageing process, the balance of hydrogen pressure in the HTF is simulated for different operation scenarios. Accelerated build-up of hydrogen pressure in the HTF is causing increased permeation into the annular vacuum space of the installed receivers and must be avoided in order to maintain the performance of these components. Therefore, the effective hydrogen partial pressure in the HTF has to be controlled and limited according to the specified values so that the vacuum lifetime of the receivers and the overall plant performance can be ensured. In order to simulate and visualize the hydrogen balance of a typical parabolic trough plant, initially a simple model is used to calculate the balance of hydrogen in the system and this is described. As input data for the simulation, extrapolated hydrogen generation rates have been used, which were calculated from results of lab tests performed by DLR in Cologne, Germany. Hourly weather data, surface temperatures of the tubing system calculated by using the simulation tool from NREL, and hydrogen permeation rates for stainless steel and carbon steel grades taken from literature have been added to the model. In a first step the effect of HTF ageing, build-up of hydrogen pressure in the HTF and hydrogen loss rates through piping and receiver components have been modeled. In a second step a selective hydrogen removal process has been added to the model. The simulation results are confirming the need of active monitoring and controlling the effective hydrogen partial pressure in parabolic trough solar thermal power plants with DPO/BP HTF. Following the results of the simulation, the expected plant performance can only be achieved over lifetime, if the hydrogen partial pressure is actively controlled and limited.

Liquid Hydrogen Target Experience at SLAC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weisend, J.G.; Boyce, R.; Candia, A.

2005-08-29

Liquid hydrogen targets have played a vital role in the physics program at SLAC for the past 40 years. These targets have ranged from small ''beer can'' targets to the 1.5 m long E158 target that was capable of absorbing up to 800 W without any significant density changes. Successful use of these targets has required the development of thin wall designs, liquid hydrogen pumps, remote positioning and alignment systems, safety systems, control and data acquisition systems, cryogenic cooling circuits and heat exchangers. Detailed operating procedures have been created to ensure safety and operational reliability. This paper surveys the evolutionmore » of liquid hydrogen targets at SLAC and discusses advances in several of the enabling technologies that made these targets possible.« less

JF-104 ground testing reaction control system (RCS) jets

NASA Technical Reports Server (NTRS)

1961-01-01

JF-104A (formerly YF-104A, serial # 55-2961) was modifed with a hydrogen peroxide reaction control system (RCS). Following a zoom climb to altitudes in the vicinity of 80,000 feet, the RCS system gave the aircraft controllability in the thin upper atmosphere where conventional control surfaces are ineffective.

Peculiarities of the behavior of the W–Al{sub 2}O{sub 3} system in a controlled reducing atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kostomarov, D. V., E-mail: bagdasarov@ns.crys.ras.ru

2016-03-15

The W–Al{sub 2}O{sub 3} system at T = 2400 K and standard pressure (controlled Ar + H{sub 2} atmosphere) has been calculated by stochastic simulation. It is shown that the presence of hydrogen leads to the formation of aluminum hydrides, hydrogen oxides, and aluminum hydroxides; the compounds from the two latter groups (except for water) can interact directly with tungsten. The main chemical reactions occurring in the system are determined, based on which a conclusion about the cyclic character of the processes is drawn. Some recommendations on the composition and pressure of controlled atmosphere for growing sapphire crystals are given.

Integrated Renewable Hydrogen Utility System (IRHUS) business plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1999-03-01

This business plan is for a proposed legal entity named IRHUS, Inc. which is to be formed as a subsidiary of Energy Partners, L.C. (EP) of West Palm Beach, Florida. EP is a research and development company specializing in hydrogen proton exchange membrane (PEM) fuel cells and systems. A fuel cell is an engine with no moving parts that takes in hydrogen and produces electricity. The purpose of IRHUS, Inc. is to develop and manufacture a self-sufficient energy system based on the fuel cell and other new technology that produces hydrogen and electricity. The product is called the Integrated renewablemore » Hydrogen utility System (IRHUS). IRHUS, Inc. plans to start limited production of the IRHUS in 2002. The IRHUS is a unique product with an innovative concept in that it provides continuous electrical power in places with no electrical infrastructure, i.e., in remote and island locations. The IRHUS is a zero emissions, self-sufficient, hydrogen fuel generation system that produces electricity on a continuous basis by combining any renewable power source with hydrogen technology. Current plans are to produce a 10 kilowatt IRHUS MP (medium power). Future plans are to design and manufacture IRHUS models to provide power for a variety of power ranges for identified attractive market segments. The technological components of the IRHUS include an electrolyzer, hydrogen and oxygen storage subsystems, fuel cell system, and power control system. The IRHUS product is to be integrated with a variety of renewable energy technologies. 5 figs., 10 tabs.« less

Supplementary steam - A viable hydrogen power generation concept

NASA Technical Reports Server (NTRS)

Wright, D. E.; Lee, J. C.

1979-01-01

Technical and economic aspects of a supplementary steam generation for peaking power applications are discussed. Preliminary designs of the hydrogen/oxygen combustors to be used for such applications are described. The integration of the hydrogen/oxygen steam-generating equipment into a typical coal-fired steam station is studied. The basic steam generation system was designed as a 20 MW supplementary system to be added to the existing 160 MW system. An analysis of the operating and design requirements of the supplementary system is conducted. Estimates were made for additional steam and fuel supply lines and for additional control required to operate the combustors and to integrate the combustor system into the facility.

Sea water magnesium fuel cell power supply

NASA Astrophysics Data System (ADS)

Hahn, Robert; Mainert, Jan; Glaw, Fabian; Lang, K.-D.

2015-08-01

An environmentally friendly magnesium fuel cell system using seawater electrolyte and atmospheric oxygen was tested under practical considerations for use as maritime power supply. The hydrogen rate and therefore the power density of the system were increased by a factor of two by using hydrogen evolution cathodes with a gas separation membrane instead of submerged cathodes without gas separation. Commercial magnesium AZ31 rolled sheet anodes can be dissolved in seawater for hydrogen production, down to a thickness below 100 μm thickness, resulting in hydrogen generation efficiency of the anode of over 80%. A practical specific energy/energy density of the alloy of more than 1200 Wh/kg/3000 Wh/l was achieved when coupled to a fuel cell with atmospheric air breathing cathode. The performance of several AZ31 alloy anodes was tested as well as the influence of temperature, electrolyte concentration and anode - cathode separation. The excess hydrogen produced by the magnesium hydrogen evolving cell, due to the negative difference effect, is proportional to the cell current in case of the AZ31 alloys, which simplifies system control considerably. Stable long-term operation of the system was demonstrated at low pressures which can be maintained in an open-seawater-submerged hydrogen generator.

[Characteristics and operation of enhanced continuous bio-hydrogen production reactor using support carrier].

PubMed

Ren, Nan-qi; Tang, Jing; Gong, Man-li

2006-06-01

A kind of granular activated carbon, whose granular size is no more than 2mm and specific gravity is 1.54g/cm3, was used as the support carrier to allow retention of activated sludge within a continuous stirred-tank reactor (CSTR) using molasses wastewater as substrate for bio-hydrogen production. Continuous operation characteristics and operational controlling strategy of the enhanced continuous bio-hydrogen production system were investigated. It was indicated that, support carriers could expand the activity scope of hydrogen production bacteria, make the system fairly stable in response to organic load impact and low pH value (pH <3.8), and maintain high biomass concentration in the reactor at low HRT. The reactor with ethanol-type fermentation achieved an optimal hydrogen production rate of 0.37L/(g x d), while the pH value ranged from 3.8 to 4.4, and the hydrogen content was approximately 40% approximately 57% of biogas. It is effective to inhibit the methanogens by reducing the pH value of the bio-hydrogen production system, consequently accelerate the start-up of the reactor.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

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

DOEpatents

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

2015-08-11

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

Wind-To-Hydrogen Energy Pilot Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ron Rebenitsch; Randall Bush; Allen Boushee

2009-04-24

WIND-TO-HYDROGEN ENERGY PILOT PROJECT: BASIN ELECTRIC POWER COOPERATIVE In an effort to address the hurdles of wind-generated electricity (specifically wind's intermittency and transmission capacity limitations) and support development of electrolysis technology, Basin Electric Power Cooperative (BEPC) conducted a research project involving a wind-to-hydrogen system. Through this effort, BEPC, with the support of the Energy & Environmental Research Center at the University of North Dakota, evaluated the feasibility of dynamically scheduling wind energy to power an electrolysis-based hydrogen production system. The goal of this project was to research the application of hydrogen production from wind energy, allowing for continued wind energymore » development in remote wind-rich areas and mitigating the necessity for electrical transmission expansion. Prior to expending significant funding on equipment and site development, a feasibility study was performed. The primary objective of the feasibility study was to provide BEPC and The U.S. Department of Energy (DOE) with sufficient information to make a determination whether or not to proceed with Phase II of the project, which was equipment procurement, installation, and operation. Four modes of operation were considered in the feasibility report to evaluate technical and economic merits. Mode 1 - scaled wind, Mode 2 - scaled wind with off-peak, Mode 3 - full wind, and Mode 4 - full wind with off-peak In summary, the feasibility report, completed on August 11, 2005, found that the proposed hydrogen production system would produce between 8000 and 20,000 kg of hydrogen annually depending on the mode of operation. This estimate was based on actual wind energy production from one of the North Dakota (ND) wind farms of which BEPC is the electrical off-taker. The cost of the hydrogen produced ranged from $20 to $10 per kg (depending on the mode of operation). The economic sensitivity analysis performed as part of the feasibility study showed that several factors can greatly affect, both positively and negatively, the "per kg" cost of hydrogen. After a September 15, 2005, meeting to evaluate the advisability of funding Phase II of the project DOE concurred with BEPC that Phase I results did warrant a "go" recommendation to proceed with Phase II activities. The hydrogen production system was built by Hydrogenics and consisted of several main components: hydrogen production system, gas control panel, hydrogen storage assembly and hydrogen-fueling dispenser The hydrogen production system utilizes a bipolar alkaline electrolyzer nominally capable of producing 30 Nm3/h (2.7 kg/h). The hydrogen is compressed to 6000 psi and delivered to an on-site three-bank cascading storage assembly with 80 kg of storage capacity. Vehicle fueling is made possible through a Hydrogenics-provided gas control panel and dispenser able to fuel vehicles to 5000 psi. A key component of this project was the development of a dynamic scheduling system to control the wind energy's variable output to the electrolyzer cell stacks. The dynamic scheduling system received an output signal from the wind farm, processed this signal based on the operational mode, and dispatched the appropriate signal to the electrolyzer cell stacks. For the study BEPC chose to utilize output from the Wilton wind farm located in central ND. Site design was performed from May 2006 through August 2006. Site construction activities were from August to November 2006 which involved earthwork, infrastructure installation, and concrete slab construction. From April - October 2007, the system components were installed and connected. Beginning in November 2007, the system was operated in a start-up/shakedown mode. Because of numerous issues, the start-up/shakedown period essentially lasted until the end of January 2008, at which time a site acceptance test was performed. Official system operation began on February 14, 2008, and continued through the end of December 2008. Several issues continued to prevent consistent operation, resulting in operation of the system in fits and starts. During the operational period, three ramp tests were performed on the electrolyzer cell stacks to evaluate cell stack degradation, if present. In addition, from December 23 - 30 2008, the hydrogen system was operated using Mode 1 protocol. From February 14, 2008 - December 31, 2008, the system produced a total of just less than 26,000,000 liters (2320 kg), including approximately 3,300,000 liters (295 kg) of hydrogen during Mode 1 operation. Unfortunately, the chronic shutdown issues prevented consistent operation and, therefore, did not allow for any accurate economic analysis as originally intended. With that said, much valuable experience was gained in the form of "lessons learned," and the project served as an extremely valuable platform for educating the public.« less

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

NASA Astrophysics Data System (ADS)

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.

In-situ formation of solidified hydrogen thin-membrane targets using a pulse tube cryocooler

NASA Astrophysics Data System (ADS)

Astbury, S.; Bedacht, S.; Brummitt, P.; Carroll, D.; Clarke, R.; Crisp, S.; Hernandez-Gomez, C.; Holligan, P.; Hook, S.; Merchan, J. S.; Neely, D.; Ortner, A.; Rathbone, D.; Rice, P.; Schaumann, G.; Scott, G.; Spindloe, C.; Spurdle, S.; Tebartz, A.; Tomlinson, S.; Wagner, F.; Borghesi, M.; Roth, M.; Tolley, M. K.

2016-04-01

An account is given of the Central Laser Facility's work to produce a cryogenic hydrogen targetry system using a pulse tube cryocooler. Due to the increasing demand for low Z thin laser targets, CLF (in collaboration with TUD) have been developing a system which allows the production of solid hydrogen membranes by engineering a design which can achieve this remotely; enabling the gas injection, condensation and solidification of hydrogen without compromising the vacuum of the target chamber. A dynamic sealing mechanism was integrated which allows targets to be grown and then remotely exposed to open vacuum for laser interaction. Further research was conducted on the survivability of the cryogenic targets which concluded that a warm gas effect causes temperature spiking when exposing the solidified hydrogen to the outer vacuum. This effect was shown to be mitigated by improving the pumping capacity of the environment and reducing the minimum temperature obtainable on the target mount. This was achieved by developing a two-stage radiation shield encased with superinsulating blanketing; reducing the base temperature from 14 ± 0.5 K to 7.2 ± 0.2 K about the coldhead as well as improving temperature control stability following the installation of a high-performance temperature controller and sensor apparatus. The system was delivered experimentally and in July 2014 the first laser shots were taken upon hydrogen targets in the Vulcan TAP facility.

The Use of Cryogenically Cooled 5A Molecular Sieves for Large Volume Reduction of Tritiated Hydrogen Gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antoniazzi, A.B.; Bartoszek, F.E.; Sherlock, A.M.

2006-07-01

A commercial hydrogen isotope separation system based on gas chromatography (AGC-ISS) has been built. The system operates in two modes: stripping and volume reduction. The purpose of the stripping mode is to reduce a large volume of tritiated hydrogen gas to a small volume of tritium rich hydrogen gas. The results here illustrate the effectiveness of the AGC-ISS in the stripping and volume reduction phases. Column readiness for hydrogen isotope separation is confirmed by room temperature air separation tests. Production runs were initially carried out using natural levels of deuterium (110-160 ppm) in high purity hydrogen. After completion of themore » deuterium/hydrogen runs the system began operations with tritiated hydrogen. The paper presents details of the AGC-ISS design and results of tritium tests. The heart of the AGC-ISS consists of two packed columns (9 m long, 3.8 cm OD) containing 5A molecular sieve material of 40/60 mesh size. Each column has 5 individually controlled heaters along the length of the column and is coiled around an inverted inner dewar. The coiled column and inner dewar are both contained within an outer dewar. In this arrangement liquid nitrogen, used to cryogenically cool the columns, flows into and out off the annular space defined by the two dewars, allowing for alternate heating and cooling cycles. Tritiated hydrogen feed is injected in batch quantities. The batch size is variable with the maximum quantity restricted by the tritium concentration in the exhausted hydrogen. The stripping operations can be carried out in full automated mode or in full manual mode. The average cycle time between injections is about 75 minutes. To date, the maximum throughput achieved is 10.5 m{sup 3}/day. A total of 37.8 m{sup 3} of tritiated hydrogen has been processed during commissioning. The system has demonstrated that venting of >99.95% of the feed gas is possible while retaining 99.98% of the tritium. At a maximum tritium concentration of {approx}7 GBq/m{sup 3} (190 mCi/m{sup 3}), processing tritiated hydrogen gas at a rate of 8.1 m{sup 3} (NTP)/day results in an average tritium concentration in the process effluent line of 1.4 MBq/m{sup 3} (37 {mu}Ci/m{sup 3}). The average process exhaust flow, split between helium and hydrogen, is 10.6 litre/min. Product from the stripping phase is stored on a 5 kg depleted uranium bed. A 250 g depleted uranium bed is available for storage of enriched product. Several, ionization type, tritium sensors are located throughout the process to control emissions, control valve switching, and monitor evolution of tritiated species from the columns. (authors)« less

Surface Magnetism of Cobalt Nanoislands Controlled by Atomic Hydrogen

DOE PAGES

Park, Jewook; Park, Changwon; Yoon, Mina; ...

2016-12-01

Controlling the spin states of the surface and interface is key to spintronic applications of magnetic materials. We report the evolution of surface magnetism of Co nanoislands on Cu(111) upon hydrogen adsorption and desorption with the hope of realizing reversible control of spin-dependent tunneling. Spin-polarized scanning tunneling microscopy reveals three types of hydrogen-induced surface superstructures, 1H-(2 × 2), 2H-(2 × 2), and 6H-(3 × 3), with increasing H coverage. The prominent magnetic surface states of Co, while being preserved at low H coverage, become suppressed as the H coverage level increases, which can then be recovered by H desorption. First-principlesmore » calculations reveal the origin of the observed magnetic surface states by capturing the asymmetry between the spin-polarized surface states and identify the role of hydrogen in controlling the magnetic states. This study offers new insights into the chemical control of magnetism in low-dimensional systems.« less

Liquid Hydrogen Fill

NASA Image and Video Library

2016-08-03

Inside a control building at NASA's Kennedy Space Center in Florida, Adam Swinger, cryogenic research engineer in the Exploration Research and Technology Directorate, communicates with team members during a test of the Ground Operations Demo Unit for liquid hydrogen. The system includes a 33,000 gallon liquid hydrogen storage tank with an internal cold heat exchanger supplied from a cryogenic refrigerator. The primary goal of the testing is to achieve a liquid hydrogen zero boil-off capability. The system was designed, installed and tested by a team of civil servants and contractors from the center's Cryogenic Test Laboratory, with support from engineers at NASA's Glenn Research Center in Cleveland and Stennis Space Center in Mississippi. It may be applicable for use by the Ground Systems Development and Operations Program at Launch Pad 39B.

The Development of a Compact Refrigeration System using Metal Hydrides

NASA Astrophysics Data System (ADS)

Bae, Sang-Chul; Ogawa, Masahito; Katsuta, Masafumi

The MH refrigeration systems are regarded as important and compact ones for solving energy and environmental issues. Our purposes are to develop the compact refrigeration system for the vending machine and the show case using MH, and to attain a refrigeration temperature of 243K by using a heat source of 403∼423K. The kinetics of MH hydriding and dehydriding reactions is of importance relative to their practical use as a refrigerator system. The kinetics of the reaction between hydrogen and MHHigh (Ti0.18Zr0.84Cr1.0FeO.7Mn0.3CuO.057)has been followed in this paper. A relatively rapid absorption of hydrogen takes place for values of relative composition to about 0.3∼0.4. It is evident that a hydrogen diffusion plays a minor role during this stage, as that part of the metal not covered by hydride is always in contact with hydrogen. The direct chemical reaction between the hydrogen and the exposed metal surface is therefore postulated as the rate-controlling process. The rate of the reaction then decreases, and for values of relative composition above about 0.8, the reaction becomes slow. After the metal particles have been completely covered by a hydride layer, the transport of materials through the layer by diffusion becomes rate controlling process

Current Welding Consumables Research in the U. S. Navy

DTIC Science & Technology

1993-03-01

experimental alloy system has a lower C content than the MIL-120S wire and uses no chromium . These modifications are intended to improve resistance to hydrogen...120S system. Molybdemm is reportedly a more potent strengthener than chromium [Enis and Telford, 1%8], but has a less detrimental effect on hydrogen...carbon steel through the control of certain alloying elements such as manganese, chromium , and primarily carbon (Linnert, 1965]. This system can

Nonaqueous System of Iron-Based Ionic Liquid and DMF for the Oxidation of Hydrogen Sulfide and Regeneration by Electrolysis.

PubMed

Guo, Zhihui; Zhang, Tingting; Liu, Tiantian; Du, Jun; Jia, Bing; Gao, Shujing; Yu, Jiang

2015-05-05

To improve the hydrogen sulfide removal efficiency with the application of an iron-based imidazolium chloride ionic liquid (Fe(III)-IL) as desulfurizer, Fe(II) and N,N-dimethylformamide (DMF) are introduced to Fe(III)-IL to construct a new nonaqueous desulfurization system (Fe(III/II)-IL/DMF). Following desulfurization, the system can be regenerated using the controlled-potential electrolysis method. The addition of Fe(II) in Fe(III)-IL is beneficial for the hydrogen sulfide removal and the electrochemical regeneration of the desulfurizer. The addition of DMF in Fe(III/II)-IL does not change the structure of Fe(III/II)-IL but clearly decreases the acidity, increases the electrolytic current, and decreases the stability of the Fe-Cl bond in Fe(III/II)-IL. Fe(III/II)-IL/DMF can remove hydrogen sulfide and can be regenerated through an electrochemical method more efficiently than can Fe(III/II)-IL. After six cycles, the desulfurization efficiency remains higher than 98%, and the average conversion rate of Fe(II) is essentially unchanged. No sulfur peroxidation occurs, and the system remains stable. Therefore, this new nonaqueous system has considerable potential for removing H2S in pollution control applications.

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

PubMed

Lai, Lin; Barnard, Amanda S

2012-02-21

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

Development of a thermal-hydraulics experimental system for high Tc superconductors cooled by liquid hydrogen

NASA Astrophysics Data System (ADS)

Tatsumoto, H.; Shirai, Y.; Shiotsu, M.; Hata, K.; Kobayashi, H.; Naruo, Y.; Inatani, Y.; Kato, T.; Futakawa, M.; Kinoshita, K.

2010-06-01

A thermal-hydraulics experimental system of liquid hydrogen was developed in order to investigate the forced flow heat transfer characteristics in the various cooling channels for wide ranges of subcoolings, flow velocities, and pressures up to supercritical. A main tank is connected to a sub tank through a hydrogen transfer line with a control valve. A channel heater is located at one end of the transfer line in the main tank. Forced flow through the channel is produced by adjusting the pressure difference between the tanks and the valve opening. The mass flow rate is measured from the weight change of the main tank. For the explosion protection, electrical equipments are covered with a nitrogen gas blanket layer and a remote control system was established. The first cryogenic performance tests confirmed that the experimental system had satisfied with the required performances. The forced convection heat transfer characteristics was successfully measured at the pressure of 0.7 MPa for various flow velocities.

System Design Description for the SY-101 Hydrogen Mitigation Test Project Data Acquisition and Control System (DACS-1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

ERMI, A.M.

2000-01-24

This document describes the hardware and software of the computer subsystems for the Data Acquisition and Control System (DACS) used in mitigation tests conducted on waste tank 241-SY-101 at the Hanford Nuclear Reservation.

Pressure Response of Various Gases in a Pneumatic Resistance Capacitance System and Pipe

NASA Astrophysics Data System (ADS)

Peng, J.; Youn, C.; Tadano, K.; Kagawa, T.

2017-10-01

City gas, such as propane and methane, is widely used as a fuel in households and factories. Recently, hydrogen as a clean and efficient fuel has been proposed for fuel cell vehicles. However, few studies have investigated pressure control and response of gases considering their properties. This study investigated the static flow rate characteristics in an orifice with four gases—air, propane, methane, and hydrogen. Then, a pressure response experiment was performed using a pneumatic resistance capacitance system comprising an isothermal chamber and a nozzle flapper, and the time constant of the pressure response with various gases was analysed with a mathematical model. The simulation results agreed with the experimental data. Finally, the differences in pressure propagation in a pipe with various gases were explicated by a pressure response experiment. The results showed that the pressure response speed of hydrogen is faster than that of the other three gases because of its small molecular weight. Therefore, the pressure control equipment of hydrogen needs a high response speed.

Hydrogen Fuel System Design Trades for High-Altitude Long-Endurance Remotely- Operated Aircraft

NASA Technical Reports Server (NTRS)

Millis, Marc G.; Tornabene, Robert T.; Jurns, John M.; Guynn, Mark D.; Tomsik, Thomas M.; VanOverbeke, Thomas J.

2009-01-01

Preliminary design trades are presented for liquid hydrogen fuel systems for remotely-operated, high-altitude aircraft that accommodate three different propulsion options: internal combustion engines, and electric motors powered by either polymer electrolyte membrane fuel cells or solid oxide fuel cells. Mission goal is sustained cruise at 60,000 ft altitude, with duration-aloft a key parameter. The subject aircraft specifies an engine power of 143 to 148 hp, gross liftoff weight of 9270 to 9450 lb, payload of 440 lb, and a hydrogen fuel capacity of 2650 to 2755 lb stored in two spherical tanks (8.5 ft inside diameter), each with a dry mass goal of 316 lb. Hydrogen schematics for all three propulsion options are provided. Each employs vacuum-jacketed tanks with multilayer insulation, augmented with a helium pressurant system, and using electric motor driven hydrogen pumps. The most significant schematic differences involve the heat exchangers and hydrogen reclamation equipment. Heat balances indicate that mission durations of 10 to 16 days appear achievable. The dry mass for the hydrogen system is estimated to be 1900 lb, including 645 lb for each tank. This tank mass is roughly twice that of the advanced tanks assumed in the initial conceptual vehicle. Control strategies are not addressed, nor are procedures for filling and draining the tanks.

Hydrogen Sensors Boost Hybrids; Today's Models Losing Gas?

NASA Technical Reports Server (NTRS)

2005-01-01

Advanced chemical sensors are used in aeronautic and space applications to provide safety monitoring, emission monitoring, and fire detection. In order to fully do their jobs, these sensors must be able to operate in a range of environments. NASA has developed sensor technologies addressing these needs with the intent of improving safety, optimizing combustion efficiencies, and controlling emissions. On the ground, the chemical sensors were developed by NASA engineers to detect potential hydrogen leaks during Space Shuttle launch operations. The Space Shuttle uses a combination of hydrogen and oxygen as fuel for its main engines. Liquid hydrogen is pumped to the external tank from a storage tank located several hundred feet away. Any hydrogen leak could potentially result in a hydrogen fire, which is invisible to the naked eye. It is important to detect the presence of a hydrogen fire in order to prevent a major accident. In the air, the same hydrogen-leak dangers are present. Stress and temperature changes can cause tiny cracks or holes to form in the tubes that line the Space Shuttle s main engine nozzle. Such defects could allow the hydrogen that is pumped through the nozzle during firing to escape. Responding to the challenges associated with pinpointing hydrogen leaks, NASA endeavored to improve propellant leak-detection capabilities during assembly, pre-launch operations, and flight. The objective was to reduce the operational cost of assembling and maintaining hydrogen delivery systems with automated detection systems. In particular, efforts have been focused on developing an automated hydrogen leak-detection system using multiple, networked hydrogen sensors that are operable in harsh conditions.

Smart Energy Management of Multiple Full Cell Powered Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

MOhammad S. Alam

2007-04-23

In this research project the University of South Alabama research team has been investigating smart energy management and control of multiple fuel cell power sources when subjected to varying demands of electrical and thermal loads together with demands of hydrogen production. This research has focused on finding the optimal schedule of the multiple fuel cell power plants in terms of electric, thermal and hydrogen energy. The optimal schedule is expected to yield the lowest operating cost. Our team is also investigating the possibility of generating hydrogen using photoelectrochemical (PEC) solar cells through finding materials for efficient light harvesting photoanodes. Themore » goal is to develop an efficient and cost effective PEC solar cell system for direct electrolysis of water. In addition, models for hydrogen production, purification, and storage will be developed. The results obtained and the data collected will be then used to develop a smart energy management algorithm whose function is to maximize energy conservation within a managed set of appliances, thereby lowering O/M costs of the Fuel Cell power plant (FCPP), and allowing more hydrogen generation opportunities. The Smart Energy Management and Control (SEMaC) software, developed earlier, controls electrical loads in an individual home to achieve load management objectives such that the total power consumption of a typical residential home remains below the available power generated from a fuel cell. In this project, the research team will leverage the SEMaC algorithm developed earlier to create a neighborhood level control system.« less

Hydrogen peroxide inhibits iodide uptake and iodine organification in cultured porcine thyroid follicles.

PubMed

Fukayama, H; Murakami, S; Nasu, M; Sugawara, M

1991-01-01

We investigated the effect of hydrogen peroxide on the process of thyroid hormone formation in a physiologic culture system of porcine thyroid follicles that we recently established. Porcine thyroid follicles cultured in medium containing 1 mU/mL TSH were exposed to 0 to 500 microM hydrogen peroxide in the presence of 0.1 microCi carrier-free Na125 and sodium iodide for 2 h. Iodide uptake and iodine organification were measured in this incubation system. The kinetics of iodide uptake were used to explain the action of hydrogen peroxide. In addition, cAMP content and Na+,K(+)-ATPase activity (an enzyme necessary for iodide uptake) were measured to investigate the mechanism of hydrogen peroxide action. Hydrogen peroxide at concentrations of 100, 200, and 500 microM inhibited iodide uptake in a dose-dependent manner. Iodide organification was inhibited only when the concentration of hydrogen peroxide was greater than 200 microM. The kinetics of iodide uptake indicated that hydrogen peroxide was a noncompetitive inhibitor with iodide. Inhibition of iodide uptake and iodine organification by hydrogen peroxide were not mediated by alteration of cAMP content of Na+,K(+)-ATPase activity, since exposure to even 500 microM hydrogen peroxide did not change these parameters in the follicle when compared with those of control samples. Our results suggest that the iodide transport system in the thyroid follicle is inhibited at 200 microM hydrogen peroxide or greater.

A Matlab-Based Graphical User Interface for Simulation and Control Design of a Hydrogen Mixer

NASA Technical Reports Server (NTRS)

Richter, Hanz; Figueroa, Fernando

2003-01-01

A Graphical User Interface (GUI) that facilitates prediction and control design tasks for a propellant mixer is described. The Hydrogen mixer is used in rocket test stand operations at the NASA John C. Stennis Space Center. The mixer injects gaseous hydrogen (GH2) into a stream of liquid hydrogen (LH2) to obtain a combined flow with desired thermodynamic properties. The flows of GH2 and LH2 into the mixer are regulated by two control valves, and a third control valve is installed at the exit of the mixer to regulate the combined flow. The three valves may be simultaneously operated in order to achieve any desired combination of total flow, exit temperature and mixer pressure within the range of operation. The mixer, thus, constitutes a three-input, three-output system. A mathematical model of the mixer has been obtained and validated with experimental data. The GUI presented here uses the model to predict mixer response under diverse conditions.

Electrolyzers Enhancing Flexibility in Electric Grids

DOE PAGES

Mohanpurkar, Manish; Luo, Yusheng; Terlip, Danny; ...

2017-11-10

This paper presents a real-time simulation with a hardware-in-the-loop (HIL)-based approach for verifying the performance of electrolyzer systems in providing grid support. Hydrogen refueling stations may use electrolyzer systems to generate hydrogen and are proposed to have the potential of becoming smarter loads that can proactively provide grid services. On the basis of experimental findings, electrolyzer systems with balance of plant are observed to have a high level of controllability and hence can add flexibility to the grid from the demand side. A generic front end controller (FEC) is proposed, which enables an optimal operation of the load on themore » basis of market and grid conditions. This controller has been simulated and tested in a real-time environment with electrolyzer hardware for a performance assessment. It can optimize the operation of electrolyzer systems on the basis of the information collected by a communication module. Real-time simulation tests are performed to verify the performance of the FEC-driven electrolyzers to provide grid support that enables flexibility, greater economic revenue, and grid support for hydrogen producers under dynamic conditions. In conclusion, the FEC proposed in this paper is tested with electrolyzers, however, it is proposed as a generic control topology that is applicable to any load.« less

Reversible hydrogen storage using CO2 and a proton-switchable iridium catalyst in aqueous media under mild temperatures and pressures.

PubMed

Hull, Jonathan F; Himeda, Yuichiro; Wang, Wan-Hui; Hashiguchi, Brian; Periana, Roy; Szalda, David J; Muckerman, James T; Fujita, Etsuko

2012-03-18

Green plants convert CO(2) to sugar for energy storage via photosynthesis. We report a novel catalyst that uses CO(2) and hydrogen to store energy in formic acid. Using a homogeneous iridium catalyst with a proton-responsive ligand, we show the first reversible and recyclable hydrogen storage system that operates under mild conditions using CO(2), formate and formic acid. This system is energy-efficient and green because it operates near ambient conditions, uses water as a solvent, produces high-pressure CO-free hydrogen, and uses pH to control hydrogen production or consumption. The extraordinary and switchable catalytic activity is attributed to the multifunctional ligand, which acts as a proton-relay and strong π-donor, and is rationalized by theoretical and experimental studies.

Slow positron studies of hydrogen activation/passivation on SiO2/Si(100) interfaces

NASA Astrophysics Data System (ADS)

Lynn, K. G.; Asoka-Kumar, P.

The hydrogen atoms are one of the most common impurity species found in semiconductor systems owing to its large diffusivity, and are easily incorporated either in a controlled process like in ion implantation or in an uncontrolled process like the one at the fabrication stage. Hydrogen can passivate dangling bonds and dislocations in these systems and hence can be used to enhance the electrical properties. In a SiO2/Si system, hydrogen can passivate electronic states at the interface and can alter the fixed or mobile charges in the oxide layer. Since hydrogen is present in almost all of the environments of SiO2/Si wafer fabrication, the activation energy of hydrogen atoms is of paramount importance to a proper understanding of SiO2/Si based devices and has not been measured on the technologically most important Si(100) face. There are no direct, nondestructive methods available to observe hydrogen injection into the oxide layer and subsequent diffusion. The positrons are used as a 'sensitive', nondestructive probe to observe hydrogen interaction in the oxide layer and the interface region. A new way is described of characterizing the changes in the density of the interface states under a low temperature annealing using positrons.

Evaluation of biological hydrogen sulfide oxidation coupled with two-stage upflow filtration for groundwater treatment.

PubMed

Levine, Audrey D; Raymer, Blake J; Jahn, Johna

2004-01-01

Hydrogen sulfide in groundwater can be oxidized by aerobic bacteria to form elemental sulfur and biomass. While this treatment approach is effective for conversion of hydrogen sulfide, it is important to have adequate control of the biomass exiting the biological treatment system to prevent release of elemental sulfur into the distribution system. Pilot scale tests were conducted on a Florida groundwater to evaluate the use of two-stage upflow filtration downstream of biological sulfur oxidation. The combined biological and filtration process was capable of excellent removal of hydrogen sulfide and associated turbidity. Additional benefits of this treatment approach include elimination of odor generation, reduction of chlorine demand, and improved stability of the finished water.

A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions

PubMed Central

Brack, Paul; Dann, Sandie; Wijayantha, K. G. Upul; Adcock, Paul; Foster, Simon

2016-01-01

There is a growing research interest in the development of portable systems which can deliver hydrogen on-demand to proton exchange membrane (PEM) hydrogen fuel cells. Researchers seeking to develop such systems require a method of measuring the generated hydrogen. Herein, we describe a simple, low-cost, and robust method to measure the hydrogen generated from the reaction of solids with aqueous solutions. The reactions are conducted in a conventional one-necked round-bottomed flask placed in a temperature controlled water bath. The hydrogen generated from the reaction in the flask is channeled through tubing into a water-filled inverted measuring cylinder. The water displaced from the measuring cylinder by the incoming gas is diverted into a beaker on a balance. The balance is connected to a computer, and the change in the mass reading of the balance over time is recorded using data collection and spreadsheet software programs. The data can then be approximately corrected for water vapor using the method described herein, and parameters such as the total hydrogen yield, the hydrogen generation rate, and the induction period can also be deduced. The size of the measuring cylinder and the resolution of the balance can be changed to adapt the setup to different hydrogen volumes and flow rates. PMID:27584581

Final test results for the ground operations demonstration unit for liquid hydrogen

NASA Astrophysics Data System (ADS)

Notardonato, W. U.; Swanger, A. M.; Fesmire, J. E.; Jumper, K. M.; Johnson, W. L.; Tomsik, T. M.

2017-12-01

Described herein is a comprehensive project-a large-scale test of an integrated refrigeration and storage system called the Ground Operations and Demonstration Unit for Liquid Hydrogen (GODU LH2), sponsored by the Advanced Exploration Systems Program and constructed at Kennedy Space Center. A commercial cryogenic refrigerator interfaced with a 125,000 l liquid hydrogen tank and auxiliary systems in a manner that enabled control of the propellant state by extracting heat via a closed loop Brayton cycle refrigerator coupled to a novel internal heat exchanger. Three primary objectives were demonstrating zero-loss storage and transfer, gaseous liquefaction, and propellant densification. Testing was performed at three different liquid hydrogen fill-levels. Data were collected on tank pressure, internal tank temperature profiles, mass flow in and out of the system, and refrigeration system performance. All test objectives were successfully achieved during approximately two years of testing. A summary of the final results is presented in this paper.

Control of malodorous hydrogen sulfide compounds using microbial fuel cell.

PubMed

Eaktasang, Numfon; Min, Hyeong-Sik; Kang, Christina; Kim, Han S

2013-10-01

In this study, a microbial fuel cell (MFC) was used to control malodorous hydrogen sulfide compounds generated from domestic wastewaters. The electricity production demonstrated a distinct pattern of a two-step increase during 170 h of system run: the first maximum current density was 118.6 ± 7.2 mA m⁻² followed by a rebound of current density increase, reaching the second maximum of 176.8 ± 9.4 mA m⁻². The behaviors of the redox potential and the sulfate level in the anode compartment indicated that the microbial production of hydrogen sulfide compounds was suppressed in the first stage, and the hydrogen sulfide compounds generated from the system were removed effectively as a result of their electrochemical oxidation, which contributed to the additional electricity production in the second stage. This was also directly supported by sulfur deposits formed on the anode surface, which was confirmed by analyses on those solids using a scanning electron microscope equipped with energy dispersive X-ray spectroscopy as well as an elemental analyzer. To this end, the overall reduction efficiencies for HS⁻ and H₂S(g) were as high as 67.5 and 96.4 %, respectively. The correlations among current density, redox potential, and sulfate level supported the idea that the electricity signal generated in the MFC can be utilized as a potential indicator of malodor control for the domestic wastewater system.

Computer system design description for SY-101 hydrogen mitigation test project data acquisition and control system (DACS-1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ermi, A.M.

1997-05-01

Description of the Proposed Activity/REPORTABLE OCCURRENCE or PIAB: This ECN changes the computer systems design description support document describing the computers system used to control, monitor and archive the processes and outputs associated with the Hydrogen Mitigation Test Pump installed in SY-101. There is no new activity or procedure associated with the updating of this reference document. The updating of this computer system design description maintains an agreed upon documentation program initiated within the test program and carried into operations at time of turnover to maintain configuration control as outlined by design authority practicing guidelines. There are no new crediblemore » failure modes associated with the updating of information in a support description document. The failure analysis of each change was reviewed at the time of implementation of the Systems Change Request for all the processes changed. This document simply provides a history of implementation and current system status.« less

Pressure and temperature fluctuation simulation of J-PARC cryogenic hydrogen system

NASA Astrophysics Data System (ADS)

Tatsumoto, H.; Ohtsu, K.; Aso, T.; Kawakami, Y.

2015-12-01

The J-PARC cryogenic hydrogen system provides supercritical cryogenic hydrogen to the moderators at a pressure of 1.5 MPa and temperature of 18 K and removes 3.8 kW of nuclear heat from the 1 MW proton beam operation. We prepared a heater for thermal compensation and an accumulator, with a bellows structure for volume control, to mitigate the pressure fluctuation caused by switching the proton beam on and off. In this study, a 1-D simulation code named DiSC-SH2 was developed to understand the propagation of pressure and temperature propagations through the hydrogen loop due to on and off switching of the proton beam. We confirmed that the simulated dynamic behaviors in the hydrogen loop for 300-kW and 500-kW proton beam operations agree well with the experimental data under the same conditions.

System configuration management plan for 101-SY Hydrogen Mitigation Test Project Mini-Data Acquisition and Control System of Tank Waste Remediation System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vargo, G.F. Jr.

1994-10-11

The DOE Standard defines the configuration management program by the five basic program elements of ``program management,`` ``design requirements,`` ``document control,`` ``change control,`` and ``assessments,`` and the two adjunct recovery programs of ``design reconstitution,`` and ``material condition and aging management. The C-M model of five elements and two adjunct programs strengthen the necessary technical and administrative control to establish and maintain a consistent technical relationship among the requirements, physical configuration, and documentation. Although the DOE Standard was originally developed for the operational phase of nuclear facilities, this plan has the flexibility to be adapted and applied to all life-cycle phasesmore » of both nuclear and non-nuclear facilities. The configuration management criteria presented in this plan endorses the DOE Standard and has been tailored specifically to address the technical relationship of requirements, physical configuration, and documentation during the full life-cycle of the 101-SY Hydrogen Mitigation Test Project Mini-Data Acquisition and Control System of Tank Waste Remediation System.« less

Controlling Gas-Flow Mass Ratios

NASA Technical Reports Server (NTRS)

Morris, Brian G.

1990-01-01

Proposed system automatically controls proportions of gases flowing in supply lines. Conceived for control of oxidizer-to-fuel ratio in new gaseous-propellant rocket engines. Gas-flow control system measures temperatures and pressures at various points. From data, calculates control voltages for electronic pressure regulators for oxygen and hydrogen. System includes commercially available components. Applicable to control of mass ratios in such gaseous industrial processes as chemical-vapor depostion of semiconductor materials and in automotive engines operating on compressed natural gas.

Automotive Stirling engine system component review

NASA Technical Reports Server (NTRS)

Hindes, Chip; Stotts, Robert

1987-01-01

The design and testing of the power and combustion control system for the basic Stirling engine, Mod II, are examined. The power control system is concerned with transparent operation, and the Mod II uses engine working gas pressure variation to control the power output of the engine. The main components of the power control system, the power control valve, the pump-down system, and the hydrogen stable system, are described. The combustion control system consists of a combustion air supply system and an air/fuel ratio control system, and the system is to maintain constant heater head temperature, and to maximize combustion efficiency and to minimize exhaust emissions.

Fuel Flexible Gas Turbine Combustor Flametube Facility Upgraded

NASA Technical Reports Server (NTRS)

Little, James E.; Nemets, Steve A.; Tornabene, Robert T.; Smith, Timothy D.; Frankenfeld, Bruce J.

2004-01-01

In fiscal year 2003, test cell 23 of the Research Combustion Laboratory (RCL 23) at the NASA Glenn Research Center was upgraded with the addition of gaseous hydrogen as a working propellant and the addition of a 450-psig air-supply system. Test flexibility was further enhanced by upgrades to the facility control systems. RCL 23 can now test with gaseous hydrogen flow rates up to 0.05 lbm/sec and jet fuel flow rates up to 0.62 lbm/sec. Research airflow rates up to 3 lbm/sec are possible with the 450-psig supply system over a range of inlet temperatures. Nonvitiated, heated air is supplied from a shell and tube heat exchanger. The maximum nonvitiated facility air temperature is 1100 F at 1.5 lbm/sec. Research-section exhaust temperatures are limited to 3200 F because of material and cooling capacity limits. A variety of support systems are available depending on the research hardware configuration. Test section ignition can be provided via either a hydrogen air torch system or an electronic spark system. Emissions measurements are obtained with either pneumatically or electromechanically actuated gas sample probes, and the electromechanical system allows for radial measurements at a user-specified axial location for measurement of emissions profiles. Gas analysis data can be obtained for a variety of species, including carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NO and NOx), oxygen (O2), unburnt hydrocarbons, and unburnt hydrogen. Facility control is accomplished with a programmable logic control system. Facility operations have been upgraded to a system based on graphical user interface control screens. A data system is available for real-time acquisition and monitoring of both measurements in engineering units and performance calculations. The upgrades have made RCL 23 a highly flexible facility for research into low emissions gas turbine combustor concepts, and the flame tube configuration inherently allows for a variety of fuel nozzle configurations to be tested in a cost-effective manner. RCL 23 is poised to be a leading facility for developing modern low-emission fuel nozzles for use with jet fuel and alternative fuels.

Uranium droplet core nuclear rocket

NASA Technical Reports Server (NTRS)

Anghaie, Samim

1991-01-01

Uranium droplet nuclear rocket is conceptually designed to utilize the broad temperature range ofthe liquid phase of metallic uranium in droplet configuration which maximizes the energy transfer area per unit fuel volume. In a baseline system dissociated hydrogen at 100 bar is heated to 6000 K, providing 2000 second of Isp. Fission fragments and intense radian field enhance the dissociation of molecular hydrogen beyond the equilibrium thermodynamic level. Uranium droplets in the core are confined and separated by an axisymmetric vortex flow generated by high velocity tangential injection of hydrogen in the mid-core regions. Droplet uranium flow to the core is controlled and adjusted by a twin flow nozzle injection system.

Emission control system

NASA Technical Reports Server (NTRS)

Parrish, Clyde F. (Inventor); Chung, J. Landy (Inventor)

2009-01-01

Methods and apparatus utilizing hydrogen peroxide are useful to reduce SOx and mercury (or other heavy metal) emissions from combustion flue gas streams. The methods and apparatus may further be modified to reduce NOx emissions. Continuous concentration of hydrogen peroxide to levels approaching or exceeding propellant-grade hydrogen peroxide facilitates increased system efficiency. In this manner, combustion flue gas streams can be treated for the removal of SOx and heavy metals, while isolating useful by-products streams of sulfuric acid as well as solids for the recovery of the heavy metals. Where removal of NOx emissions is included, nitric acid may also be isolated for use in fertilizer or other industrial applications.

Controlled-release Hydrogen Peroxide for On-site Treatment of Organic Pollutants in Urban Storm Runoff

NASA Astrophysics Data System (ADS)

Lee, E.; Sun, S.; Kim, Y.

2011-12-01

Nonpoint source (NPS) pollutants are the remaining cause of the environment problems, significantly impairing the hydrologic and biologic function of urban water systems and human health. Managing the NPS loads to urban aquatic systems remains a challenge because of ubiquitous contaminant sources and large pollutants loads in the first flush. Best management practices (BMPs) exist for reducing the NPS pollutants in urban storm waters, but the remedial efficiencies of these passive schemes are unpredictable. This study aims to develop a controlled-release system as part of an in situ chemical oxidation scheme designed for on-site treatment of organic pollutants in urban runoff. Controlled-release hydrogen peroxide (CR-HP) solids were manufactured by dispersing fine sodium percarbonate granules in paraffin wax matrices. Release kinetics and treatment efficiencies of CR-HP for BTEX and MTBE were investigated through a series of column tests. Release data indicated that the CR-HP could continually release hydrogen peroxide (H2O2) in flowing water at controlled rates over 276-1756 days, and the release rates could be adjusted by changing the mixing ratios of sodium percarbonate and wax matrices. Additional column tests and model calculations demonstrated that CR-HP/UV systems can provide low-cost, target-specific, and persistent source of oxidants for efficient treatment of organic compounds in urban storm runoff.

An experimental study of ammonia borane based hydrogen storage systems

NASA Astrophysics Data System (ADS)

Deshpande, Kedaresh A.

2011-12-01

Hydrogen is a promising fuel for the future, capable of meeting the demands of energy storage and low pollutant emission. Chemical hydrides are potential candidates for chemical hydrogen storage, especially for automobile applications. Ammonia borane (AB) is a chemical hydride being investigated widely for its potential to realize the hydrogen economy. In this work, the yield of hydrogen obtained during neat AB thermolysis was quantified using two reactor systems. First, an oil bath heated glass reactor system was used with AB batches of 0.13 gram (+/- 0.001 gram). The rates of hydrogen generation were measured. Based on these experimental data, an electrically heated steel reactor system was designed and constructed to handle up to 2 grams of AB per batch. A majority of components were made of stainless-steel. The system consisted of an AB reservoir and feeder, a heated reactor, a gas processing unit and a system control and monitoring unit. An electronic data acquisition system was used to record experimental data. The performance of the steel reactor system was evaluated experimentally through batch reactions of 30 minutes each, for reaction temperatures in the range from 373 K to 430 K. The experimental data showed exothermic decomposition of AB accompanied by rapid generation of hydrogen during the initial period of the reaction. 90% of the hydrogen was generated during the initial 120 seconds after addition of AB to the reactor. At 430 K, the reaction produced 12 wt.% of hydrogen. The heat diffusion in the reactor system and the process of exothermic decomposition of AB were coupled in a two-dimensional model. Neat AB thermolysis was modeled as a global first order reactions based on Arrhenius theory. The values of equation constants were derived from curve fit of experimental data. The pre-exponential constant and the activation energy were estimated to be 4 s-1 (+/- 0.4 s-1) and 13000 J mol -1 s-1 (+/- 1050 J mol-1 s -1) respectively. The model was solved in COMSOL Multiphysics. The model was capable of simulating the transient response of the system and captured the observed trends such as the decrease in reactor temperature upon addition of AB and exothermic decomposition.

Liquid Hydrogen Recirculation System for Forced Flow Cooling Test of Superconducting Conductors

NASA Astrophysics Data System (ADS)

Shirai, Y.; Kainuma, T.; Shigeta, H.; Shiotsu, M.; Tatsumoto, H.; Naruo, Y.; Kobayashi, H.; Nonaka, S.; Inatani, Y.; Yoshinaga, S.

2017-12-01

The knowledge of forced flow heat transfer characteristics of liquid hydrogen (LH2) is important and necessary for design and cooling analysis of high critical temperature superconducting devices. However, there are few test facilities available for LH2 forced flow cooling for superconductors. A test system to provide a LH2 forced flow (∼10 m/s) of a short period (less than 100 s) has been developed. The test system was composed of two LH2 tanks connected by a transfer line with a controllable valve, in which the forced flow rate and its period were limited by the storage capacity of tanks. In this paper, a liquid hydrogen recirculation system, which was designed and fabricated in order to study characteristics of superconducting cables in a stable forced flow of liquid hydrogen for longer period, was described. This LH2 loop system consists of a centrifugal pump with dynamic gas bearings, a heat exchanger which is immersed in a liquid hydrogen tank, and a buffer tank where a test section (superconducting wires or cables) is set. The buffer tank has LHe cooled superconducting magnet which can produce an external magnetic field (up to 7T) at the test section. A performance test was conducted. The maximum flow rate was 43.7 g/s. The lowest temperature was 22.5 K. It was confirmed that the liquid hydrogen can stably circulate for 7 hours.

Control of degreening in postharvest green sour citrus fruit by electrostatic atomized water particles.

PubMed

Yamauchi, Naoki; Takamura, Kohtaro; Shigyo, Masayoshi; Migita, Catharina Taiko; Masuda, Yukihiro; Maekawa, Tetsuya

2014-08-01

The effect of electrostatic atomized water particles (EAWP) on degreening of green sour citrus fruit during storage was determined. Superoxide anion and hydroxyl radicals included in EAWP were present on the surface of the fruit peel after the treatment. Hydrogen peroxide was formed from EAWP in an aqueous solution, which could indicate that a hydroxyl radical of EAWP turns to hydrogen peroxide in the fruit flavedo as well as in the aqueous solution. EAWP treatment effectively suppressed the degreening of green yuzu and Nagato-yuzukichi fruits during storage at 20°C. The enhancement in K+ ion leakage of both EAWP-treated fruits reduced in comparison with the control. In spite of EAWP treatment, total peroxide level in both fruits showed almost no changes during storage, suggesting that hydrogen peroxide formed by EAWP treatment could stimulate the activation of hydrogen peroxide scavenging system and control degreening of these fruits during storage. Copyright © 2014 Elsevier Ltd. All rights reserved.

Electrochemical hydrogenation of thiophene on SPE electrodes

NASA Astrophysics Data System (ADS)

Huang, Haiyan; Yuan, Penghui; Yu, Ying; Chung, Keng H.

2017-01-01

Electrochemical reduction desulfurization is a promising technology for petroleum refining which is environmental friendly, low cost and able to achieve a high degree of automation. Electrochemical hydrogenation of thiophene was performed in a three-electrode system which SPE electrode was the working electrode. The electrochemical desulfurization was studied by cyclic voltammetry and bulk electrolysis with coulometry (BEC) techniques. The results of cyclic voltammetry showed that the electrochemical hydrogenation reduction reaction occurred at -0.4V. The BEC results showed that the currents generated from thiophene hydrogenation reactions increased with temperature. According to Arrhenius equation, activation energy of thiophene electrolysis was calculated and lower activation energy value indicated it was diffusion controlled reaction. From the products of electrolytic reactions, the mechanisms of electrochemical hydrogenation of thiophene were proposed, consisting of two pathways: openingring followed by hydrogenation, and hydrogenation followed by ring opening.

Hydrogen peroxide mechanosynthesis in siloxane-hydrogel contact lenses.

PubMed

Tavazzi, Silvia; Ferraro, Lorenzo; Cozza, Federica; Pastori, Valentina; Lecchi, Marzia; Farris, Stefano; Borghesi, Alessandro

2014-11-26

Drug-loaded contact lenses are emerging as the preferred treatment method for several ocular diseases, and efforts are being directed to promote extended and controlled delivery. One strategy is based on delivery induced by environmental triggers. One of these triggers can be hydrogen peroxide, since many platforms based on drug-loaded nanoparticles were demonstrated to be hydrogen-peroxide responsive. This is particularly interesting when hydrogen peroxide is the result of a specific pathophysiological condition. Otherwise, an alternative route to induce drug delivery is here proposed, namely the mechano-synthesis. The present work represents the proof-of-concept of the mechanosynthesis of hydrogen peroxide in siloxane-hydrogel contact lenses as a consequence of the cleavage of siloxane bonds at the interface between the polymer and water in aqueous phase. Their spongy morphology makes contact lenses promising systems for mechanical-to-chemical energy conversion, since the amount of hydrogen peroxide is expected to scale with the interfacial area between the polymer and water. The eyelid pressure during wear is sufficient to induce the hydrogen peroxide synthesis with concentrations which are biocompatible and suitable to trigger the drug release through hydrogen-peroxide-responsive platforms. For possible delivery on demand, the integration of piezoelectric polymers in the siloxane-hydrogel contact lenses could be designed, whose mechanical deformation could be induced by an applied wireless-controlled voltage.

Amine-free reversible hydrogen storage in formate salts catalyzed by ruthenium pincer complex without pH control or solvent change.

PubMed

Kothandaraman, Jotheeswari; Czaun, Miklos; Goeppert, Alain; Haiges, Ralf; Jones, John-Paul; May, Robert B; Prakash, G K Surya; Olah, George A

2015-04-24

Due to the intermittent nature of most renewable energy sources, such as solar and wind, energy storage is increasingly required. Since electricity is difficult to store, hydrogen obtained by electrochemical water splitting has been proposed as an energy carrier. However, the handling and transportation of hydrogen in large quantities is in itself a challenge. We therefore present here a method for hydrogen storage based on a CO2 (HCO3 (-) )/H2 and formate equilibrium. This amine-free and efficient reversible system (>90 % yield in both directions) is catalyzed by well-defined and commercially available Ru pincer complexes. The formate dehydrogenation was triggered by simple pressure swing without requiring external pH control or the change of either the solvent or the catalyst. Up to six hydrogenation-dehydrogenation cycles were performed and the catalyst performance remained steady with high selectivity (CO free H2 /CO2 mixture was produced). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nondestructive detection and measurement of hydrogen embrittlement

DOEpatents

Alex, Franklin; Byrne, Joseph Gerald

1977-01-01

A nondestructive system and method for the determination of the presence and extent of hydrogen embrittlement in metals, alloys, and other crystalline structures subject thereto. Positron annihilation characteristics of the positron-electron annihilation within the tested material provide unique energy distribution curves for each type of material tested at each respective stage of hydrogen embrittlement. Gamma radiation resulting from such annihilation events is detected and statistically summarized by appropriate instrumentation to reveal the variations of electron activity within the tested material caused by hydrogen embrittlement therein. Such data from controlled tests provides a direct indication of the relative stages of hydrogen embrittlement in the form of unique energy distribution curves which may be utilized as calibration curves for future comparison with field tests to give on-site indication of progressive stages of hydrogen embrittlement.

Other Challenges in the Development of the Orbiter Environmental Control Hardware

NASA Technical Reports Server (NTRS)

Gibb, J. W.; Mcintosh, M. E.; Heinrich, S. R.; Thomas, E.; Steele, M.; Schubert, F.; Koszenski, E. P.; Wynveen, R. A.; Murray, R. W.; Schelkopf, J. D.

1985-01-01

Development of the Space Shuttle orbiter environmental control and life support system (ECLSS) included the identification and resolution of several interesting problems in several systems. Some of these problems occurred late in the program, including the flight phase. Problems and solutions related to the ammonia boiler system (ABS), smoke detector, water/hydrogen separator, and waste collector system (WCS) are addressed.

System and method for controlling hydrogen elimination during carbon nanotube synthesis from hydrocarbons

DOEpatents

Reilly, Peter T. A.

2010-03-23

A system and method for producing carbon nanotubes by chemical vapor deposition includes a catalyst support having first and second surfaces. The catalyst support is capable of hydrogen transport from the first to the second surface. A catalyst is provided on the first surface of the catalyst support. The catalyst is selected to catalyze the chemical vapor deposition formation of carbon nanotubes. A fuel source is provided for supplying fuel to the catalyst.

Fuel cell system logic for differentiating between rapid and normal shutdown commands

DOEpatents

Keskula, Donald H.; Doan, Tien M.; Clingerman, Bruce J.

2000-01-01

A method of controlling the operation of a fuel cell system wherein each shutdown command for the system is subjected to decision logic which determines whether the command should be a normal shutdown command or rapid shutdown command. If the logic determines that the shutdown command should be a normal shutdown command, then the system is shutdown in a normal step-by-step process in which the hydrogen stream is consumed within the system. If the logic determines that the shutdown command should be a rapid shutdown command, the hydrogen stream is removed from the system either by dumping to atmosphere or routing to storage.

Hydrogen storage systems based on magnesium hydride: from laboratory tests to fuel cell integration

NASA Astrophysics Data System (ADS)

de Rango, P.; Marty, P.; Fruchart, D.

2016-02-01

The paper reviews the state of the art of hydrogen storage systems based on magnesium hydride, emphasizing the role of thermal management, whose effectiveness depends on the effective thermal conductivity of the hydride, but also depends of other limiting factors such as wall contact resistance and convective exchanges with the heat transfer fluid. For daily cycles, the use of phase change material to store the heat of reaction appears to be the most effective solution. The integration with fuel cells (1 kWe proton exchange membrane fuel cell and solid oxide fuel cell) highlights the dynamic behaviour of these systems, which is related to the thermodynamic properties of MgH2. This allows for "self-adaptive" systems that do not require control of the hydrogen flow rate at the inlet of the fuel cell.

Metal membrane-type 25-kW methanol fuel processor for fuel-cell hybrid vehicle

NASA Astrophysics Data System (ADS)

Han, Jaesung; Lee, Seok-Min; Chang, Hyuksang

A 25-kW on-board methanol fuel processor has been developed. It consists of a methanol steam reformer, which converts methanol to hydrogen-rich gas mixture, and two metal membrane modules, which clean-up the gas mixture to high-purity hydrogen. It produces hydrogen at rates up to 25 N m 3/h and the purity of the product hydrogen is over 99.9995% with a CO content of less than 1 ppm. In this fuel processor, the operating condition of the reformer and the metal membrane modules is nearly the same, so that operation is simple and the overall system construction is compact by eliminating the extensive temperature control of the intermediate gas streams. The recovery of hydrogen in the metal membrane units is maintained at 70-75% by the control of the pressure in the system, and the remaining 25-30% hydrogen is recycled to a catalytic combustion zone to supply heat for the methanol steam-reforming reaction. The thermal efficiency of the fuel processor is about 75% and the inlet air pressure is as low as 4 psi. The fuel processor is currently being integrated with 25-kW polymer electrolyte membrane fuel-cell (PEMFC) stack developed by the Hyundai Motor Company. The stack exhibits the same performance as those with pure hydrogen, which proves that the maximum power output as well as the minimum stack degradation is possible with this fuel processor. This fuel-cell 'engine' is to be installed in a hybrid passenger vehicle for road testing.

Testing the Effects of Helium Pressurant on Thermodynamic Vent System Performance with Liquid Hydrogen

NASA Technical Reports Server (NTRS)

Flachbart, R. H.; Hastings, L. J.; Hedayat, A.; Nelson, S.; Tucker, S.

2006-01-01

In support of the development of a zero gravity pressure control capability for liquid hydrogen, testing was conducted at the Marshall Space Flight Center using the Multipurpose Hydrogen Test Bed (MHTB) to evaluate the effects of helium pressurant on the performance of a spray bar thermodynamic vent system (TVS). Fourteen days of testing was performed in August - September 2005, with an ambient heat leak of about 70-80 watts and tank fill levels of 90%, 50%, and 25%. The TVS successfully controlled the tank pressure within a +/- 3.45 kPa (+/- 0.5 psi) band with various helium concentration levels in the ullage. Relative to pressure control with an "all hydrogen" ullage, the helium presence resulted in 10 to 30 per cent longer pressure reduction durations, depending on the fill level, during the mixing/venting phase of the control cycle. Additionally, the automated control cycle was based on mixing alone for pressure reduction until the pressure versus time slope became positive, at which time the Joule-Thomson vent was opened. Testing was also conducted to evaluate thermodynamic venting without the mixer operating, first with liquid then with vapor at the recirculation line inlet. Although ullage stratification was present, the ullage pressure was successfully controlled without the mixer operating. Thus, if vapor surrounded the pump inlet in a reduced gravity situation, the ullage pressure can still be controlled by venting through the TVS Joule Thomson valve and heat exchanger. It was evident that the spray bar configuration, which extends almost the entire length of the tank, enabled significant thermal energy removal from the ullage even without the mixer operating. Details regarding the test setup and procedures are presented in the paper. 1

Chicken barn climate and hazardous volatile compounds control using simple linear regression and PID

NASA Astrophysics Data System (ADS)

Abdullah, A. H.; Bakar, M. A. A.; Shukor, S. A. A.; Saad, F. S. A.; Kamis, M. S.; Mustafa, M. H.; Khalid, N. S.

2016-07-01

The hazardous volatile compounds from chicken manure in chicken barn are potentially to be a health threat to the farm animals and workers. Ammonia (NH3) and hydrogen sulphide (H2S) produced in chicken barn are influenced by climate changes. The Electronic Nose (e-nose) is used for the barn's air, temperature and humidity data sampling. Simple Linear Regression is used to identify the correlation between temperature-humidity, humidity-ammonia and ammonia-hydrogen sulphide. MATLAB Simulink software was used for the sample data analysis using PID controller. Results shows that the performance of PID controller using the Ziegler-Nichols technique can improve the system controller to control climate in chicken barn.

Solid Hydrogen Experiments for Atomic Propellants: Image Analyses

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2002-01-01

This paper presents the results of detailed analyses of the images from experiments that were conducted on the formation of solid hydrogen particles in liquid helium. Solid particles of hydrogen were frozen in liquid helium, and observed with a video camera. The solid hydrogen particle sizes, their agglomerates, and the total mass of hydrogen particles were estimated. Particle sizes of 1.9 to 8 mm (0.075 to 0.315 in.) were measured. The particle agglomerate sizes and areas were measured, and the total mass of solid hydrogen was computed. A total mass of from 0.22 to 7.9 grams of hydrogen was frozen. Compaction and expansion of the agglomerate implied that the particles remain independent particles, and can be separated and controlled. These experiment image analyses are one of the first steps toward visually characterizing these particles, and allow designers to understand what issues must be addressed in atomic propellant feed system designs for future aerospace vehicles.

Development of satellite borne nickel hydrogen battery experiment equipment for ETS-6

NASA Astrophysics Data System (ADS)

Kuwashima, Saburou; Kamimori, Norimitsu; Kusawake, Hiroaki; Takahashi, Kazumichi

1992-08-01

An overview of the support rendered for the Engineering Test Satellite-6 (ETS-6) system integration test and protoflight test by the ETS-6 borne experimental nickel hydrogen battery development part is presented. Articles in the ETS-6 specifications and procedures related to the experimental battery were prepared or supported in preparation because of the battery's special characteristics such as its automatic control dependency on the bus voltage, thermal sensitivity equivalent to that of other batteries and so forth. System tests were witnessed and the acquired data were evaluated. Charging characteristics from 0 V were verified at trickle charging rate, using a flight scale model of Nickel Hydrogen (Ni-H2) Battery (NHB) after long term storage and an engineering model of the Ni-H2 Battery Controller (NHC). Requests for approval were submitted to the related self governing bodies in accordance with the Explosives Control Law when NHB's were charged and discharged. Installation and calibration data acquisition of the inner pressure sensors for the Ni-H2 battery cells for the flight model NHB were conducted and the battery assembly was started.

Hydrogen in thin Pd-based layers deposited on reticulated vitreous carbon-A new system for electrochemical capacitors

NASA Astrophysics Data System (ADS)

Łukaszewski, M.; Żurowski, A.; Czerwiński, A.

Reticulated vitreous carbon (RVC) has been used as a matrix for electrodeposition of thin layers of Pd and Pd-rich Pd-Rh alloys. It was found that RVC substrate does not affect qualitatively hydrogen absorption behavior of Pd-based deposits. Similarly to thin Pd or Pd alloy layers deposited on Au wires, the α-β phase transition controls the overall rate of hydrogen absorption and desorption into/from Pd-based/RVC electrodes. The possibility of the application of these materials as phase charging-discharging systems was investigated. The values of specific pseudocapacitance, specific power and specific energy were comparable with those for supercapacitors utilizing various redox reactions.

Prospects for hydrogen storage in graphene.

PubMed

Tozzini, Valentina; Pellegrini, Vittorio

2013-01-07

Hydrogen-based fuel cells are promising solutions for the efficient and clean delivery of electricity. Since hydrogen is an energy carrier, a key step for the development of a reliable hydrogen-based technology requires solving the issue of storage and transport of hydrogen. Several proposals based on the design of advanced materials such as metal hydrides and carbon structures have been made to overcome the limitations of the conventional solution of compressing or liquefying hydrogen in tanks. Nevertheless none of these systems are currently offering the required performances in terms of hydrogen storage capacity and control of adsorption/desorption processes. Therefore the problem of hydrogen storage remains so far unsolved and it continues to represent a significant bottleneck to the advancement and proliferation of fuel cell and hydrogen technologies. Recently, however, several studies on graphene, the one-atom-thick membrane of carbon atoms packed in a honeycomb lattice, have highlighted the potentialities of this material for hydrogen storage and raise new hopes for the development of an efficient solid-state hydrogen storage device. Here we review on-going efforts and studies on functionalized and nanostructured graphene for hydrogen storage and suggest possible developments for efficient storage/release of hydrogen under ambient conditions.

Hydrogen Purification and Recycling for an Integrated Oxygen Recovery System Architecture

NASA Technical Reports Server (NTRS)

Abney, Morgan B.; Greenwood, Zachary; Wall, Terry; Miller, Lee; Wheeler, Ray

2016-01-01

The United States Atmosphere Revitalization life support system on the International Space Station (ISS) performs several services for the crew including oxygen generation, trace contaminant control, carbon dioxide (CO2) removal, and oxygen recovery. Oxygen recovery is performed using a Sabatier reactor developed by Hamilton Sundstrand, wherein CO2 is reduced with hydrogen in a catalytic reactor to produce methane and water. The water product is purified in the Water Purification Assembly and recycled to the Oxygen Generation Assembly (OGA) to provide O2 to the crew. This architecture results in a theoretical maximum oxygen recovery from CO2 of approximately 54% due to the loss of reactant hydrogen in Sabatier-produced methane that is currently vented outside of ISS. Plasma Methane Pyrolysis technology (PPA), developed by Umpqua Research Company, provides the capability to further close the Atmosphere Revitalization oxygen loop by recovering hydrogen from Sabatier-produced methane. A key aspect of this technology approach is to purify the hydrogen from the PPA product stream which includes acetylene, unreacted methane and byproduct water and carbon monoxide. In 2015, four sub-scale hydrogen separation systems were delivered to NASA for evaluation. These included two electrolysis single-cell hydrogen purification cell stacks developed by Sustainable Innovations, LLC, a sorbent-based hydrogen purification unit using microwave power for sorbent regeneration developed by Umpqua Research Company, and a LaNi4.6Sn0.4 metal hydride produced by Hydrogen Consultants, Inc. Here we report the results of these evaluations, discuss potential architecture options, and propose future work.

Hydrogen Purification and Recycling for an Integrated Oxygen Recovery System Architecture

NASA Technical Reports Server (NTRS)

Abney, Morgan B.; Greenwood, Zachary; Wall, Terry; Nur, Mononita; Wheeler, Richard R., Jr.; Preston, Joshua; Molter, Trent

2016-01-01

The United States Atmosphere Revitalization life support system on the International Space Station (ISS) performs several services for the crew including oxygen generation, trace contaminant control, carbon dioxide (CO2) removal, and oxygen recovery. Oxygen recovery is performed using a Sabatier reactor developed by Hamilton Sundstrand, wherein CO2 is reduced with hydrogen in a catalytic reactor to produce methane and water. The water product is purified in the Water Purification Assembly and recycled to the Oxygen Generation Assembly (OGA) to provide O2 to the crew. This architecture results in a theoretical maximum oxygen recovery from CO2 of approx.54% due to the loss of reactant hydrogen in Sabatier-produced methane that is currently vented outside of ISS. Plasma Pyrolysis Assembly (PPA) technology, developed by Umpqua Research Company, provides the capability to further close the Atmosphere Revitalization oxygen loop by recovering hydrogen from Sabatier-produced methane. A key aspect of this technology approach is the need to purify the hydrogen from the PPA product stream which includes acetylene, unreacted methane and byproduct water and carbon monoxide. In 2015, four sub-scale hydrogen separation systems were delivered to NASA for evaluation. These included two electrolysis single-cell hydrogen purification cell stacks developed by Sustainable Innovations, LLC, a sorbent-based hydrogen purification unit using microwave power for sorbent regeneration developed by Umpqua Research Company, and a LaNi4.6Sn0.4 metal hydride produced by Hydrogen Consultants, Inc. Here we report the results of these evaluations to-date, discuss potential architecture options, and propose future work.

Improved apparatus for continuous culture of hydrogen-fixing bacteria

NASA Technical Reports Server (NTRS)

Foster, J. F.; Litchfield, J. H.

1970-01-01

Improved apparatus permits the continuous culture of Hydrogenomonas eutropha. System incorporates three essential subsystems - /1/ environmentally isolated culture vessel, /2/ analytical system with appropriate sensors and readout devices, /3/ control system with feedback responses to each analytical measurement.

Linear quadratic stochastic control of atomic hydrogen masers.

PubMed

Koppang, P; Leland, R

1999-01-01

Data are given showing the results of using the linear quadratic Gaussian (LQG) technique to steer remote hydrogen masers to Coordinated Universal Time (UTC) as given by the United States Naval Observatory (USNO) via two-way satellite time transfer and the Global Positioning System (GPS). Data also are shown from the results of steering a hydrogen maser to the real-time USNO mean. A general overview of the theory behind the LQG technique also is given. The LQG control is a technique that uses Kalman filtering to estimate time and frequency errors used as input into a control calculation. A discrete frequency steer is calculated by minimizing a quadratic cost function that is dependent on both the time and frequency errors and the control effort. Different penalties, chosen by the designer, are assessed by the controller as the time and frequency errors and control effort vary from zero. With this feature, controllers can be designed to force the time and frequency differences between two standards to zero, either more or less aggressively depending on the application.

Self pressuring HTP feed systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitehead, J.

1999-10-14

Hydrogen peroxide tanks can be pressurized with decomposed HTP (high test hydrogen peroxide) originating in the tank itself. In rocketry, this offers the advantage of eliminating bulky and heavy inert gas storage. Several prototype self-pressurizing HTP systems have recently been designed and tested. Both a differential piston tank and a small gas-driven pump have been tried to obtain the pressure boost needed for flow through a gas generator and back to the tank. Results include terrestrial maneuvering tests of a prototype microsatellite, including warm gas attitude control jets.

ISHN Ion Source Control System. First Steps Toward an EPICS Based ESS-Bilbao Accelerator Control System

NASA Astrophysics Data System (ADS)

Eguiraun, M.; Jugo, J.; Arredondo, I.; del Campo, M.; Feuchtwanger, J.; Etxebarria, V.; Bermejo, F. J.

2013-04-01

ISHN (Ion Source Hydrogen Negative) consists of a Penning type ion source in operation at ESS-Bilbao facilities. From the control point of view, this source is representative of the first steps and decisions taken towards the general control architecture of the whole accelerator to be built. The ISHN main control system is based on a PXI architecture, under a real-time controller which is programmed using LabVIEW. This system, with additional elements, is connected to the general control system. The whole system is based on EPICS for the control network, and the modularization of the communication layers of the accelerator plays an important role in the proposed control architecture.

Controls and measurements of KU engine test cells for biodiesel, SynGas, and assisted biodiesel combustion

NASA Astrophysics Data System (ADS)

Cecrle, Eric Daniel

This thesis is comprised of three unique data acquisition and controls (CDAQ) projects. Each of these projects differs from each other; however, they all include the concept of testing renewable or future fuel sources. The projects were the following: University of Kansas's Feedstock-to-Tailpipe Initiative's Synthesis Gas Reforming rig, Feedstock-to-Tailpipe Initiative's Biodiesel Single Cylinder Test Stand, and a unique Reformate Assisted Biodiesel Combustion architecture. The main responsibility of the author was to implement, develop and test CDAQ systems for the projects. For the Synthesis Gas Reforming rig, this thesis includes a report that summarizes the analysis and solution of building a controls and data acquisition system for this setup. It describes the purpose of the sensors selected along with their placement throughout the system. Moreover, it includes an explanation of the planned data collection system, along with two models describing the reforming process useful for system control. For the Biodiesel Single Cylinder Test Stand, the responsibility was to implement the CDAQ system for data collection. This project comprised a variety of different sensors that are being used collect the combustion characteristics of different biodiesel formulations. This project is currently being used by other graduates in order to complete their projects for subsequent publication. For the Reformate Assisted Biodiesel Combustion architecture, the author developed a reformate injection system to test different hydrogen and carbon monoxide mixtures as combustion augmentation. Hydrogen combustion has certain limiting factors, such as pre-ignition in spark ignition engines and inability to work as a singular fuel in compression ignition engines. To offset these issues, a dual-fuel methodology is utilized by injecting a hydrogen/carbon monoxide mixture into the intake stream of a diesel engine operating on biodiesel. While carbon monoxide does degrade some of the desirable properties of hydrogen, it acts partially like a diluent in order to prevent pre-ignition from occurring. The result of this mixture addition allows the engine to maintain power while reducing biodiesel fuel consumption with a minimal NOx emissions increase.

Japan's Sunshine Project

NASA Astrophysics Data System (ADS)

1992-07-01

A summary report is given on the results of hydrogen energy research and development achieved during 1991 under the Sunshine Project. In hydrogen manufacturing, regenerative cells that can also generate power as fuel cells were discussed by using solid macromolecular electrolytic films for the case where no electrolysis is carried out with water electrolysis. Yttria stabilized zirconia (YSZ), an oxide solid electrolyte was used for the basic research on high-temperature steam electrolysis. Compositions of hydrogen storage alloys and their deterioration mechanisms were investigated to develop hydrogen transportation and storage technologies. High-density hydrides were searched, and fluidization due to paraffin was discussed. Electrode materials and forming technologies were discussed to develop a hydrogen to power conversion system using hydrogen storage alloys as reversible electrodes. Hydrogen-oxygen combustion was studied in terms of reactive theories, and so was the control of ignition and combustion using ultraviolet ray ignition plasma. Studies were made on hydrogen brittlement in welds on materials in hydrogen utilization and its preventive measures. Surveys were given on technical movements and development problems in high-efficiency, pollution-free hydrogen combustion turbines.

A Hydrogen Peroxide Hot-Jet Simulator for Wind-Tunnel Tests of Turbojet-Exit Models

NASA Technical Reports Server (NTRS)

Runckel, Jack F.; Swihart, John M.

1959-01-01

A turbojet-engine-exhaust simulator which utilizes a hydrogen peroxide gas generator has been developed for powered-model testing in wind tunnels with air exchange. Catalytic decomposition of concentrated hydrogen peroxide provides a convenient and easily controlled method of providing a hot jet with characteristics that correspond closely to the jet of a gas turbine engine. The problems associated with simulation of jet exhausts in a transonic wind tunnel which led to the selection of a liquid monopropellant are discussed. The operation of the jet simulator consisting of a thrust balance, gas generator, exit nozzle, and auxiliary control system is described. Static-test data obtained with convergent nozzles are presented and shown to be in good agreement with ideal calculated values.

Safe Detection System for Hydrogen Leaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lieberman, Robert A.; Beshay, Manal

2012-02-29

Hydrogen is an "environmentally friendly" fuel for future transportation and other applications, since it produces only pure ("distilled") water when it is consumed. Thus, hydrogen-powered vehicles are beginning to proliferate, with the total number of such vehicles expected to rise to nearly 100,000 within the next few years. However, hydrogen is also an odorless, colorless, highly flammable gas. Because of this, there is an important need for hydrogen safety monitors that can warn of hazardous conditions in vehicles, storage facilities, and hydrogen production plants. To address this need, IOS has developed a unique intrinsically safe optical hydrogen sensing technology, andmore » has embodied it in detector systems specifically developed for safety applications. The challenge of using light to detect a colorless substance was met by creating chemically-sensitized optical materials whose color changes in the presence of hydrogen. This reversible reaction provides a sensitive, reliable, way of detecting hydrogen and measuring its concentration using light from low-cost LEDs. Hydrogen sensors based on this material were developed in three completely different optical formats: point sensors ("optrodes"), integrated optic sensors ("optical chips"), and optical fibers ("distributed sensors") whose entire length responds to hydrogen. After comparing performance, cost, time-to-market, and relative market need for these sensor types, the project focused on designing a compact optrode-based single-point hydrogen safety monitor. The project ended with the fabrication of fifteen prototype units, and the selection of two specific markets: fuel cell enclosure monitoring, and refueling/storage safety. Final testing and development of control software for these markets await future support.« less

Catalytic Combustion for Ultra-Low NOx Hydrogen Turbines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Etemad, Shahrokh; Baird, Benjamin; Alavandi, Sandeep

2011-06-30

Precision Combustion, Inc., (PCI) in close collaboration with Solar Turbines, Incorporated, has developed and demonstrated a combustion system for hydrogen fueled turbines that reduces NOx to low single digit level while maintaining or improving current levels of efficiency and eliminating emissions of carbon dioxide. Full scale Rich Catalytic Hydrogen (RCH1) injector was developed and successfully tested at Solar Turbines, Incorporated high pressure test facility demonstrating low single digit NOx emissions for hydrogen fuel in the range of 2200F-2750F. This development work was based on initial subscale development for faster turnaround and reduced cost. Subscale testing provided promising results for 42%more » and 52% H2 with NOx emissions of less than 2 ppm with improved flame stability. In addition, catalytic reactor element testing for substrate oxidation, thermal cyclic injector testing to simulate start-stop operation in a gas turbine environment, and steady state 15 atm. operation testing were performed successfully. The testing demonstrated stable and robust catalytic element component life for gas turbine conditions. The benefit of the catalytic hydrogen combustor technology includes capability of delivering near-zero NOx without costly post-combustion controls and without requirement for added sulfur control. In addition, reduced acoustics increase gas turbine component life. These advantages advances Department of Energy (DOE’s) objectives for achievement of low single digit NOx emissions, improvement in efficiency vs. postcombustion controls, fuel flexibility, a significant net reduction in Integrated Gasification Combined Cycle (IGCC) system net capital and operating costs, and a route to commercialization across the power generation field from micro turbines to industrial and utility turbines.« less

MONTANA PALLADIUM RESEARCH INITIATIVE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, John; McCloskey, Jay; Douglas, Trevor

2012-05-09

Project Objective: The overarching objective of the Montana Palladium Research Initiative is to perform scientific research on the properties and uses of palladium in the context of the U.S. Department of Energy's Hydrogen, Fuel Cells and Infrastructure Technologies Program. The purpose of the research will be to explore possible palladium as an alternative to platinum in hydrogen-economy applications. To achieve this objective, the Initiatives activities will focus on several cutting-edge research approaches across a range of disciplines, including metallurgy, biomimetics, instrumentation development, and systems analysis. Background: Platinum-group elements (PGEs) play significant roles in processing hydrogen, an element that shows highmore » potential to address this need in the U.S. and the world for inexpensive, reliable, clean energy. Platinum, however, is a very expensive component of current and planned systems, so less-expensive alternatives that have similar physical properties are being sought. To this end, several tasks have been defined under the rubric of the Montana Palladium Research Iniative. This broad swath of activities will allow progress on several fronts. The membrane-related activities of Task 1 employs state-of-the-art and leading-edge technologies to develop new, ceramic-substrate metallic membranes for the production of high-purity hydrogen, and develop techniques for the production of thin, defect-free platinum group element catalytic membranes for energy production and pollution control. The biomimetic work in Task 2 explores the use of substrate-attached hydrogen-producing enzymes and the encapsulation of palladium in virion-based protein coats to determine their utility for distributed hydrogen production. Task 3 work involves developing laser-induced breakdown spectroscopy (LIBS) as a real-time, in situ diagnostic technique to characterize PGEs nanoparticles for process monitoring and control. The systems engineering work in task 4 will determine how fuel cells taken as systems behave over periods of time that should show how their reformers and other subsystems deteriorate with time.« less

Air Force Science and Technology Plan

DTIC Science & Technology

2011-01-01

charged particles and guide high- power microwaves and radiofrequency waves in the air • Bioenergy – developing renewable biosolar hydrogen...Aeronautical sciences, control sciences, structures and integration Directed Energy High- power microwaves , lasers, beam control, space situational...Propulsion Turbine and rocket engines, advanced propulsion systems , system -level thermal management, and propulsion fuels and propellants Sensors Air

p-Type and n-type doping of ZnSe: Effects of hydrogen incorporation

NASA Astrophysics Data System (ADS)

Fisher, P. A.; Ho, E.; House, J. L.; Petrich, G. S.; Kolodziejski, L. A.; Walker, J.; Johnson, N. M.

1995-05-01

The hydrogenation behavior of p- and n-type ZnSe grown on GaAs by gas source molecular beam epitaxy (GSMBE) is presented. Recent advances in p-type doping, using a radio frequency (RF) plasma source with nitrogen, have led to the successful fabrication of blue/green light emitters based on the (Zn,Mg)(S,Se) material system grown by molecular beam epitaxy (MBE). GSMBE replaces the high vapor pressure group VI elements with hydride gases which are amenable to regulation using precision mass flow controllers, and has the potential to deliver improved compositional control and reproducibility. We have found that the presence of hydrogen does not affect the electrical conductivity of ZnSe:Cl grown by GSMBE. In contrast, nitrogen-doped ZnSe is speculated to be electrically passivated by hydrogen for certain growth conditions as evidenced by: (1) coherent tracking of the hydrogen concentration with variations in the nitrogen concentration, which is measured by secondary ion mass spectrometry (SIMS), and (2) indications of high resistivity determined by capacitance-voltage ( C-V) measurements. Conventional and rapid thermal annealing (RTA) have been investigated to modify the degree of hydrogen passivation.

Control of impurities in toroidal plasma devices

DOEpatents

Ohkawa, Tihiro

1980-01-01

A method and apparatus for plasma impurity control in closed flux plasma systems such as Tokamak reactors is disclosed. Local axisymmetrical injection of hydrogen gas is employed to reverse the normally inward flow of impurities into the plasma.

Hydrogen peroxide as a fungicide for fish culture

USGS Publications Warehouse

Dawson, V.K.; Rach, J.J.; Schreier, Theresa M.

1994-01-01

Antifungal agents are needed to maintain healthy stocks of fish in the intensive culture systems currently employed in fish hatcheries. Malachite green has been the most widely used antifungal agent; however, its potential for producing teratology in animals and fish precludes further use in fish culture. Preliminary studies at the National Fisheries Research Center, La Crosse, WI, USA (La Crosse Center) indicate that hydrogen peroxide is effective for control of Saprolegnia sp. fungus on incubating eggs of rainbow trout. It is also effective against a wide variety of other organisms such as bacteria, yeasts, viruses, and spores, and has been proposed as a treatment for sea lice on salmon. Hydrogen peroxide and its primary decomposition products, oxygen and water, are not systemic poisons and are considered environmentally compatible. In response to a petition from the La Crosse Center, the U.S. Food and Drug Administration (FDA) recently classified hydrogen peroxide as a 'low regulatory priority' when used for control of fungus on fish and fish eggs. Preliminary tests conducted at the La Crosse Center suggest that prophylactic treatments of 250 to 500 ppm (based on 100% active ingredient) for 15 minutes every other day will inhibit fungal infections on healthy rainbow trout (Oncorhynchus mykiss) eggs. This treatment regime also seems to inhibit fungal development and increase hatching success among infected eggs. Efficacy and safety of hydrogen peroxide as a fungicide for fish are currently being evaluated.

Theoretical Study of the Metal-Controlled Dehydrogenation Mechanism of MN2H3BH3 (M = Li, Na, K): A New Family of Hydrogen Storage Material.

PubMed

Li, Tong; Zhang, Jian-Guo

2018-02-08

Metal hydrazineboranes (MHBs), as a kind of new hydrogen storage materials, show excellent hydrogen storage performance and dehydrogenation properties. Herein, we designed multiple dehydrogenation pathways to compare the metal-controlled effect. Quantum chemistry theory is used to calculate the crystal structure for determining the molecular structure. With an increase of the metal radius, the energy difference of the isomers also increases. The dehydrogenation pathways of lithium hydrazineborane (path A) and sodium hydrazineborane (path B) appear totally similar to each other in the dehydrogenation process despite the energy barrier, as well as the comparison paths A' (for LiHB) and B' (for NaHB). In contrast with LiHB and NaHB, the tautomeric reaction occurs in the potassium hydrazineborane (KHB) first, and the following dehydrogenation path is similar to that of the LiHB and NaHB. It explores the hydrogen-release properties of the different metal hydrazineboranes and also indcates the affection of the metal in the metal hydrazineboranes hydrogen-storage system.

Materials Engineering and Scale Up of Fluid Phase Chemical Hydrogen Storage for Automotive Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westman, Matthew P.; Chun, Jaehun; Choi, Young Joon

Among candidates for chemical hydrogen storage in PEM fuel cell automotive applications, ammonia borane (AB, NH3BH3) is considered to be one of the most promising materials due to its high hydrogen content of 14-16 wt% below 200°C and high volumetric density. In our previous paper, we selected AB in silicone oil as a role model for a slurry hydrogen storage system. Materials engineering properties were optimized by increasing solid loading by using an ultra-sonic process. In this paper, we proceeded to scale up to liter size batches with solid loadings up to 50 wt% (8 wt% H2) with dynamic viscositiesmore » less than 1000cP at 25°C. The use of a non-ionic surfactant, Triton X-15, shows significant promise in controlling the level of foaming produced during the thermal dehydrogenation of the AB. Through the development of new and efficient processing techniques and the ability to adequately control the foaming, stable homogenous slurries of high solid loading have been demonstrated as a viable hydrogen delivery source.« less

Vehicle-scale investigation of a fluorine jet-pump liquid hydrogen tank pressurization system

NASA Technical Reports Server (NTRS)

Cady, E. C.; Kendle, D. W.

1972-01-01

A comprehensive analytical and experimental program was performed to evaluate the performance of a fluorine-hydrogen jet-pump injector for main tank injection (MTI) pressurization of a liquid hydrogen (LH2) tank. The injector performance during pressurization and LH2 expulsion was determined by a series of seven tests of a full-scale injector and MTI pressure control system in a 28.3 cu m (1000 cu ft) flight-weight LH2 tank. Although the injector did not effectively jet-pump LH2 continuously, it showed improved pressurization performance compared to straight-pipe injectors tested under the same conditions in a previous program. The MTI computer code was modified to allow performance prediction for the jet-pump injector.

COLD-SAT: An orbital cryogenic hydrogen technology experiment

NASA Technical Reports Server (NTRS)

Schuster, J. R.; Wachter, Joseph P.; Powers, Albert G.

1989-01-01

The COLD-SAT spacecraft will perform subcritical liquid hydrogen storage and transfer experiments under low-gravity conditions to provide engineering data for future space transportation missions. Consisting of an experiment module mated to a spacecraft bus, COLD-SAT will be placed in an initial 460 km circular orbit by an Atlas I commercial launch vehicle. After deployment, the three-axis-controlled spacecraft bus will provide electric power, experiment control and data management, communications, and attitude control along with propulsive acceleration levels ranging from 10(-6) to 10(-4)g. These accelerations are an important aspect of some of the experiments, as it is desired to know the effects that low gravity levels might have on the heat and mass transfer processes involved. The experiment module will contain the three liquid hydrogen tanks, valves, pressurization equipment, and instrumentation. At launch all the hydrogen will be in the largest tank, which has helium-purged MLI and is loaded and topped off by the hydrogen tanking system used for the Centaur upper stage of the Atlas. The two smaller tanks will be utilized in orbit for performing some of the experiments. The experiments are grouped into two classes on the basis of their priority, and include six regarded as enabling technology and nine regarded as enhancing technology.

Tuning the Hydrogen Storage in Magnesium Alloys

NASA Astrophysics Data System (ADS)

Er, Suleyman; de Wijs, Gilles A.; Brocks, Geert

2011-03-01

We investigate the hydrogen storage properties of promising magnesium alloys. Mg H2 (7.6 wt % H) would be a very useful storage material if the (de)hydrogenation kinetics can be improved and the desorption temperature is markedly lowered. Using first principles calculations, we show that hydrides of Mg-transition metal (TM) alloys adopt a structure that promotes faster (de)hydrogenation kinetics, as is also observed in experiment. Within the lightweight TMs, the most promising alloying element is titanium. Alloying Mg with Ti alone, however, is not sufficient to decrease the stability of the hydride phases, which is necessary to reduce the hydrogen desorption temperature. We find that adding aluminium or silicon markedly destabilizes Mg-Ti hydrides and stabilizes Mg-Ti alloys. Finally, we show that controlling the structure of Mg-Ti-Al(Si) system by growing it as multilayers, has a beneficial influence on the thermodynamic properties and makes it a stronger candidate for hydrogen storage.

Insight into hydrogenation of graphene: Effect of hydrogen plasma chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Felten, A.; Nittler, L.; Pireaux, J.-J.

2014-11-03

Plasma hydrogenation of graphene has been proposed as a tool to modify the properties of graphene. However, hydrogen plasma is a complex system and controlled hydrogenation of graphene suffers from a lack of understanding of the plasma chemistry. Here, we correlate the modifications induced on monolayer graphene studied by Raman spectroscopy with the hydrogen ions energy distributions obtained by mass spectrometry. We measure the energy distribution of H{sup +}, H{sub 2}{sup +}, and H{sub 3}{sup +} ions for different plasma conditions showing that their energy strongly depends on the sample position, pressure, and plasma power and can reach values asmore » high as 45 eV. Based on these measurements, we speculate that under specific plasma parameters, protons should possess enough energy to penetrate the graphene sheet. Therefore, a graphene membrane could become, under certain conditions, transparent to both protons and electrons.« less

Pressure control and analysis report: Hydrogen Thermal Test Article (HTTA)

NASA Technical Reports Server (NTRS)

1971-01-01

Tasks accomplished during the HTTA Program study period included: (1) performance of a literature review to provide system guidelines; (2) development of analytical procedures needed to predict system performance; (3) design and analysis of the HTTA pressurization system considering (a) future utilization of results in the design of a spacecraft maneuvering system propellant package, (b) ease of control and operation, (c) system safety, and (d) hardware cost; and (4) making conclusions and recommendations for systems design.

Hydrogen-Rich Water Intake Accelerates Oral Palatal Wound Healing via Activation of the Nrf2/Antioxidant Defense Pathways in a Rat Model

PubMed Central

Orihuela-Campos, Rita Cristina; Fukui, Makoto; Ito, Hiro-O

2016-01-01

The wound healing process attempts to restore the integrity and function of the injured tissue. Additionally, proinflammatory cytokines, growth factors, and oxidative stress play important roles in wound healing. The aim of this study was to determine whether hydrogen-rich water intake induces the activation of the Nrf2/antioxidant defense pathway in rat palatal tissue, thereby reducing systemic oxidative stress and proinflammatory cytokine levels and promoting healing-associated genes. A circular excisional wound was created in the oral palatal region, and the wound healing process was observed. The rats were divided into two experimental groups in which either hydrogen-rich water or distilled water was consumed. In the drinking hydrogen-rich water, the palatal wound healing process was accelerated compared to that in the control group. As molecular hydrogen upregulated the Nrf2 pathway, systemic oxidative stresses were decreased by the activation of antioxidant activity. Furthermore, hydrogen-rich water intake reduced proinflammatory cytokine levels and promoted the expression of healing-associated factors in rat palatal tissue. In conclusion, hydrogen-rich water intake exhibited multiple beneficial effects through activation of the Nrf2/antioxidant defense pathway. The results of this study support the hypothesis that oral administration of hydrogen-rich water benefits the wound healing process by decreasing oxidative stress and inflammatory responses. PMID:26798423

Hydrogen-Rich Water Intake Accelerates Oral Palatal Wound Healing via Activation of the Nrf2/Antioxidant Defense Pathways in a Rat Model.

PubMed

Tamaki, Naofumi; Orihuela-Campos, Rita Cristina; Fukui, Makoto; Ito, Hiro-O

2016-01-01

The wound healing process attempts to restore the integrity and function of the injured tissue. Additionally, proinflammatory cytokines, growth factors, and oxidative stress play important roles in wound healing. The aim of this study was to determine whether hydrogen-rich water intake induces the activation of the Nrf2/antioxidant defense pathway in rat palatal tissue, thereby reducing systemic oxidative stress and proinflammatory cytokine levels and promoting healing-associated genes. A circular excisional wound was created in the oral palatal region, and the wound healing process was observed. The rats were divided into two experimental groups in which either hydrogen-rich water or distilled water was consumed. In the drinking hydrogen-rich water, the palatal wound healing process was accelerated compared to that in the control group. As molecular hydrogen upregulated the Nrf2 pathway, systemic oxidative stresses were decreased by the activation of antioxidant activity. Furthermore, hydrogen-rich water intake reduced proinflammatory cytokine levels and promoted the expression of healing-associated factors in rat palatal tissue. In conclusion, hydrogen-rich water intake exhibited multiple beneficial effects through activation of the Nrf2/antioxidant defense pathway. The results of this study support the hypothesis that oral administration of hydrogen-rich water benefits the wound healing process by decreasing oxidative stress and inflammatory responses.

Proceedings of the DOE chemical energy storage and hydrogen energy systems contracts review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Sessions were held on electrolysis-based hydrogen storage systems, hydrogen production, hydrogen storage systems, hydrogen storage materials, end-use applications and system studies, chemical heat pump/chemical energy storage systems, systems studies and assessment, thermochemical hydrogen production cycles, advanced production concepts, and containment materials. (LHK)

Multidisciplinary approaches to solar hydrogen

PubMed Central

Bren, Kara L.

2015-01-01

This review summarizes three different approaches to engineering systems for the solar-driven evolution of hydrogen fuel from water: molecular, nanomaterials and biomolecular. Molecular systems have the advantage of being highly amenable to modification and detailed study and have provided great insight into photophysics, electron transfer and catalytic mechanism. However, they tend to display poor stability. Systems based on nanomaterials are more robust but also are more difficult to synthesize in a controlled manner and to modify and study in detail. Biomolecular systems share many properties with molecular systems and have the advantage of displaying inherently high efficiencies for light absorption, electron–hole separation and catalysis. However, biological systems must be engineered to couple modules that capture and convert solar photons to modules that produce hydrogen fuel. Furthermore, biological systems are prone to degradation when employed in vitro. Advances that use combinations of these three tactics also are described. Multidisciplinary approaches to this problem allow scientists to take advantage of the best features of biological, molecular and nanomaterials systems provided that the components can be coupled for efficient function. PMID:26052425

Integrated Refrigeration and Storage for Advanced Liquid Hydrogen Operations

NASA Technical Reports Server (NTRS)

Swanger, A. M.; Notardonato, W. U.; Johnson, W. L.; Tomsik, T. M.

2016-01-01

NASA has used liquefied hydrogen (LH2) on a large scale since the beginning of the space program as fuel for the Centaur and Apollo upper stages, and more recently to feed the three space shuttle main engines. The LH2 systems currently in place at the Kennedy Space Center (KSC) launch pads are aging and inefficient compared to the state-of-the-art. Therefore, the need exists to explore advanced technologies and operations that can drive commodity costs down, and provide increased capabilities. The Ground Operations Demonstration Unit for Liquid Hydrogen (GODU-LH2) was developed at KSC to pursue these goals by demonstrating active thermal control of the propellant state by direct removal of heat using a cryocooler. The project has multiple objectives including zero loss storage and transfer, liquefaction of gaseous hydrogen, and densification of liquid hydrogen. The key technology challenge was efficiently integrating the cryogenic refrigerator into the LH2 storage tank. A Linde LR1620 Brayton cycle refrigerator is used to produce up to 900W cooling at 20K, circulating approximately 22 g/s gaseous helium through the hydrogen via approximately 300 m of heat exchanger tubing. The GODU-LH2 system is fully operational, and is currently under test. This paper will discuss the design features of the refrigerator and storage system, as well as the current test results.

Preparation of ortho-para ratio controlled D2 gas for muon-catalyzed fusion.

PubMed

Imao, H; Ishida, K; Kawamura, N; Matsuzaki, T; Matsuda, Y; Toyoda, A; Strasser, P; Iwasaki, M; Nagamine, K

2008-05-01

A negative muon in hydrogen targets, e.g., D2 or D-T mixture, can catalyze nuclear fusions following a series of atomic processes involving muonic hydrogen molecular formation (muon-catalyzed fusion, muCF). The ortho-para state of D2 is a crucial parameter not only for enhancing the fusion rate but also to precisely investigate various muonic atom processes. We have developed a system for controlling and measuring the ortho-para ratio of D2 gas for muCF experiments. We successfully collected para-enriched D2 without using liquid-hydrogen coolant. Ortho-enriched D2 was also obtained by using a catalytic conversion method with a mixture of chromium oxide and alumina. The ortho-para ratio of D2 gas was measured with a compact Raman spectroscopy system. We produced large volume (5-30 l at STP), high-purity (less than ppm high-Z contaminant) D2 targets with a wide range of ortho-para ratios (ortho 20%-99%). By using the ortho-para controlled D2 in muCF experiments, we observed the dependence of muCF phenomena on the ortho-para ratio.

Preparation of ortho-para ratio controlled D{sub 2} gas for muon-catalyzed fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Imao, H.; Ishida, K.; Matsuzaki, T.

2008-05-15

A negative muon in hydrogen targets, e.g., D{sub 2} or D-T mixture, can catalyze nuclear fusions following a series of atomic processes involving muonic hydrogen molecular formation (muon-catalyzed fusion, {mu}CF). The ortho-para state of D{sub 2} is a crucial parameter not only for enhancing the fusion rate but also to precisely investigate various muonic atom processes. We have developed a system for controlling and measuring the ortho-para ratio of D{sub 2} gas for {mu}CF experiments. We successfully collected para-enriched D{sub 2} without using liquid-hydrogen coolant. Ortho-enriched D{sub 2} was also obtained by using a catalytic conversion method with a mixturemore » of chromium oxide and alumina. The ortho-para ratio of D{sub 2} gas was measured with a compact Raman spectroscopy system. We produced large volume (5-30 l at STP), high-purity (less than ppm high-Z contaminant) D{sub 2} targets with a wide range of ortho-para ratios (ortho 20%-99%). By using the ortho-para controlled D{sub 2} in {mu}CF experiments, we observed the dependence of {mu}CF phenomena on the ortho-para ratio.« less

Development of a Ground Operations Demonstration Unit for Liquid Hydrogen at Kennedy Space Center

NASA Astrophysics Data System (ADS)

Notardonato, W. U.

NASA operations for handling cryogens in ground support equipment have not changed substantially in 50 years, despite major technology advances in the field of cryogenics. NASA loses approximately 50% of the hydrogen purchased because of a continuous heat leak into ground and flight vessels, transient chill down of warm cryogenic equipment, liquid bleeds, and vent losses. NASA Kennedy Space Center (KSC) needs to develop energy-efficient cryogenic ground systems to minimize propellant losses, simplify operations, and reduce cost associated with hydrogen usage. The GODU LH2 project will design, assemble, and test a prototype storage and distribution system for liquid hydrogen that represents an advanced end-to-end cryogenic propellant system for a ground launch complex. The project has multiple objectives and will culminate with an operational demonstration of the loading of a simulated flight tank with densified propellants. The system will be unique because it uses an integrated refrigeration and storage system (IRAS) to control the state of the fluid. The integrated refrigerator is the critical feature enabling the testing of the following three functions: zero-loss storage and transfer, propellant densification/conditioning, and on-site liquefaction. This paper will discuss the test objectives, the design of the system, and the current status of the installation.

Simulation of Hydrogen Distribution in Ignalina NPP ALS Compartments During BDBA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babilas, Egidijus; Urbonavicius, Egidijus; Rimkevicius, Sigitas

2006-07-01

Accident Localisation System (ALS) of Ignalina NPP is a 'pressure suppression' type confinement, which protects the population, employees and environment from the radiation hazards. According to the Safety Analysis Report for Ignalina NPP {approx}110 m{sup 3} of hydrogen is released to ALS compartments during the Maximum Design Basis Accident. However in case of beyond design basis accident, when the oxidation of zirconium starts, the amount of generated hydrogen could be significantly higher. If the volume concentration of hydrogen in the compartment reaches 4%, there is a possibility for a combustible mixture to appear. To prevent the possible hydrogen accumulation inmore » the ALS of the Ignalina NPP during an accident the H{sub 2} control system is installed. The results of the performed analysis derived the places of the possible H{sub 2} accumulation in the ALS compartments during the transient processes and assessed the mixture combustibility in these places for a beyond design basis accident scenario. Such analysis of H{sub 2} distribution in the ALS of Ignalina NPP in case of BDBA was not performed before. (authors)« less

Thin-film metal hydrides.

PubMed

Remhof, Arndt; Borgschulte, Andreas

2008-12-01

The goal of the medieval alchemist, the chemical transformation of common metals into nobel metals, will forever be a dream. However, key characteristics of metals, such as their electronic band structure and, consequently, their electric, magnetic and optical properties, can be tailored by controlled hydrogen doping. Due to their morphology and well-defined geometry with flat, coplanar surfaces/interfaces, novel phenomena may be observed in thin films. Prominent examples are the eye-catching hydrogen switchable mirror effect, the visualization of solid-state diffusion and the formation of complex surface morphologies. Thin films do not suffer as much from embrittlement and/or decrepitation as bulk materials, allowing the study of cyclic absorption and desorption. Therefore, thin-metal hydride films are used as model systems to study metal-insulator transitions, for high throughput combinatorial research or they may be used as indicator layers to study hydrogen diffusion. They can be found in technological applications as hydrogen sensors, in electrochromic and thermochromic devices. In this review, we discuss the effect of hydrogen loading of thin niobium and yttrium films as archetypical examples of a transition metal and a rare earth metal, respectively. Our focus thereby lies on the hydrogen induced changes of the electronic structure and the morphology of the thin films, their optical properties, the visualization and the control of hydrogen diffusion and on the study of surface phenomena and catalysis.

Writing with ring currents: selectively hydrogenated polycyclic aromatics as finite models of graphene and graphane

PubMed Central

Fowler, Patrick W.; Gibson, Christopher M.; Bean, David E.

2014-01-01

Alternating partial hydrogenation of the interior region of a polycyclic aromatic hydrocarbon gives a finite model system representing systems on the pathway from graphene to the graphane modification of the graphene sheet. Calculations at the DFT and coupled Hartree–Fock levels confirm that sp2 cycles of bare carbon centres isolated by selective hydrogenation retain the essentially planar geometry and electron delocalization of the annulene that they mimic. Delocalization is diagnosed by the presence of ring currents, as detected by ipsocentric calculation and visualization of the current density induced in the π system by a perpendicular external magnetic field. These induced ‘ring’ currents have essentially the same sense, strength and orbital origin as in the free hydrocarbon. Subjected to the important experimental proviso of the need for atomic-scale control of hydrogenation, this finding predicts the possibility of writing single, multiple and concentric diatropic and/or paratropic ring currents on the graphene/graphane sheet. The implication is that pathways for free flow of ballistic current can be modelled in the same way. PMID:24611026

Method and System for Hydrogen Evolution and Storage

DOEpatents

Thorn, David L.; Tumas, William; Hay, P. Jeffrey; Schwarz, Daniel E.; Cameron, Thomas M.

2008-10-21

A method and system for storing and evolving hydrogen employ chemical compounds that can be hydrogenated to store hydrogen and dehydrogenated to evolve hydrogen. A catalyst lowers the energy required for storing and evolving hydrogen. The method and system can provide hydrogen for devices that consume hydrogen as fuel.

Integrated control and health management. Orbit transfer rocket engine technology program

NASA Technical Reports Server (NTRS)

Holzmann, Wilfried A.; Hayden, Warren R.

1988-01-01

To insure controllability of the baseline design for a 7500 pound thrust, 10:1 throttleable, dual expanded cycle, Hydrogen-Oxygen, orbit transfer rocket engine, an Integrated Controls and Health Monitoring concept was developed. This included: (1) Dynamic engine simulations using a TUTSIM derived computer code; (2) analysis of various control methods; (3) Failure Modes Analysis to identify critical sensors; (4) Survey of applicable sensors technology; and, (5) Study of Health Monitoring philosophies. The engine design was found to be controllable over the full throttling range by using 13 valves, including an oxygen turbine bypass valve to control mixture ratio, and a hydrogen turbine bypass valve, used in conjunction with the oxygen bypass to control thrust. Classic feedback control methods are proposed along with specific requirements for valves, sensors, and the controller. Expanding on the control system, a Health Monitoring system is proposed including suggested computing methods and the following recommended sensors: (1) Fiber optic and silicon bearing deflectometers; (2) Capacitive shaft displacement sensors; and (3) Hot spot thermocouple arrays. Further work is needed to refine and verify the dynamic simulations and control algorithms, to advance sensor capabilities, and to develop the Health Monitoring computational methods.

Apparatus for control of mercury

DOEpatents

Downs, William; Bailey, Ralph T.

2001-01-01

A method and apparatus for reducing mercury in industrial gases such as the flue gas produced by the combustion of fossil fuels such as coal adds hydrogen sulfide to the flue gas in or just before a scrubber of the industrial process which contains the wet scrubber. The method and apparatus of the present invention is applicable to installations employing either wet or dry scrubber flue gas desulfurization systems. The present invention uses kraft green liquor as a source for hydrogen sulfide and/or the injection of mineral acids into the green liquor to release vaporous hydrogen sulfide in order to form mercury sulfide solids.

Low cycle fatigue properties of MAR-M-246 Hf in hydrogen. [a cast nickel-base alloy

NASA Technical Reports Server (NTRS)

Warren, J. R.

1979-01-01

The transverse, low cycle fatigue properties were determined for directionally solidified and single crystal samples of a cast nickel-base alloy proposed for use in space propulsion systems in pure or partial high pressure hydrogen environments at elevated temperatures. The test temperature was 760 C (1400F) and the pressure of the gaseous hydrogen was 34.5 MPa (5000 psig). Low cycle fatique life was established by strain controlled testing using smooth specimens and a servohydraulic closed-loop test machine modified with a high pressure environmental chamber. Results and conclusions are discussed.

Control method for high-pressure hydrogen vehicle fueling station dispensers

DOEpatents

Kountz, Kenneth John; Kriha, Kenneth Robert; Liss, William E.

2006-06-13

A method for quick filling a vehicle hydrogen storage vessel with hydrogen, the key component of which is an algorithm used to control the fill process, which interacts with the hydrogen dispensing apparatus to determine the vehicle hydrogen storage vessel capacity.

Test Data Analysis of a Spray Bar Zero-Gravity Liquid Hydrogen Vent System for Upper Stages

NASA Technical Reports Server (NTRS)

Hedayat, A.; Bailey, J. W.; Hastings, L. J.; Flachbart, R. H.

2003-01-01

To support development of a zero-gravity pressure control capability for liquid hydrogen (LH2), a series of thermodynamic venting system (TVS) tests was conducted in 1996 and 1998 using the Marshall Space Flight Center (MSFC) multipurpose hydrogen test bed (MHTB). These tests were performed with ambient heat leaks =20 and 50 W for tank fill levels of 90%, 50%, and 25%. TVS performance testing revealed that the spray bar was highly effective in providing tank pressure control within a 7-kPa band (131-138 Wa), and complete destratification of the liquid and the ullage was achieved with all test conditions. Seven of the MHTB tests were correlated with the TVS performance analytical model. The tests were selected to encompass the range of tank fill levels, ambient heat leaks, operational modes, and ullage pressurants. The TVS model predicted ullage pressure and temperature and bulk liquid saturation pressure and temperature obtained from the TVS model were compared with the test data. During extended self-pressurization periods, following tank lockup, the model predicted faster pressure rise rates than were measured. However, once the system entered the cyclic mixing/venting operational mode, the modeled and measured data were quite similar.

Hydrogen peroxide propulsion for smaller satellites (SSC98-VIII-1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitehead, J C

1998-07-13

As satellite designs shrink, providing maneuvering and control capability falls outside the realm of available propulsion technology. While cold gas has been used on the smallest satellites, hydrogen peroxide propellant is suggested as the next step in performance and cost before hydrazine. Minimal toxicity and a small scale enable benchtop propellant preparation and development testing. Progress toward low-cost thrusters and self-pressurizing tank systems is described.

Spray Bar Zero-Gravity Vent System for On-Orbit Liquid Hydrogen Storage

NASA Technical Reports Server (NTRS)

Hastings, L. J.; Flachbart, R. H.; Martin, J. J.; Hedayat, A.; Fazah, M.; Lak, T.; Nguyen, H.; Bailey, J. W.

2003-01-01

During zero-gravity orbital cryogenic propulsion operations, a thermodynamic vent system (TVS) concept is expected to maintain tank pressure control without propellant resettling. In this case, a longitudinal spray bar mixer system, coupled with a Joule-Thompson (J-T) valve and heat exchanger, was evaluated in a series of TVS tests using the 18 cu m multipurpose hydrogen test bed. Tests performed at fill levels of 90, 50, and 25 percent, coupled with heat tank leaks of about 20 and 50 W, successfully demonstrated tank pressure control within a 7-kPa band. Based on limited testing, the presence of helium constrained the energy exchange between the gaseous and liquid hydrogen (LH2) during the mixing cycles. A transient analytical model, formulated to characterize TVS performance, was used to correlate the test data. During self-pressurization cycles following tank lockup, the model predicted faster pressure rise rates than were measured; however, once the system entered the cyclic self-pressurization/mixing/venting operational mode, the modeled and measured data were quite similar. During a special test at the 25-percent fill level, the J-T valve was allowed to remain open and successfully reduced the bulk LH2 saturation pressure from 133 to 70 kPa in 188 min.

Metal (Ag/Ti)-Containing Hydrogenated Amorphous Carbon Nanocomposite Films with Enhanced Nanoscratch Resistance: Hybrid PECVD/PVD System and Microstructural Characteristics.

PubMed

Constantinou, Marios; Nikolaou, Petros; Koutsokeras, Loukas; Avgeropoulos, Apostolos; Moschovas, Dimitrios; Varotsis, Constantinos; Patsalas, Panos; Kelires, Pantelis; Constantinides, Georgios

2018-03-30

This study aimed to develop hydrogenated amorphous carbon thin films with embedded metallic nanoparticles (a-C:H:Me) of controlled size and concentration. Towards this end, a novel hybrid deposition system is presented that uses a combination of Plasma Enhanced Chemical Vapor Deposition (PECVD) and Physical Vapor Deposition (PVD) technologies. The a-C:H matrix was deposited through the acceleration of carbon ions generated through a radio-frequency (RF) plasma source by cracking methane, whereas metallic nanoparticles were generated and deposited using terminated gas condensation (TGC) technology. The resulting material was a hydrogenated amorphous carbon film with controlled physical properties and evenly dispersed metallic nanoparticles (here Ag or Ti). The physical, chemical, morphological and mechanical characteristics of the films were investigated through X-ray reflectivity (XRR), Raman spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM) and nanoscratch testing. The resulting amorphous carbon metal nanocomposite films (a-C:H:Ag and a-C:H:Ti) exhibited enhanced nanoscratch resistance (up to +50%) and low values of friction coefficient (<0.05), properties desirable for protective coatings and/or solid lubricant applications. The ability to form nanocomposite structures with tunable coating performance by potentially controlling the carbon bonding, hydrogen content, and the type/size/percent of metallic nanoparticles opens new avenues for a broad range of applications in which mechanical, physical, biological and/or combinatorial properties are required.

NASA Orbit Transfer Rocket Engine Technology Program

NASA Technical Reports Server (NTRS)

1984-01-01

The advanced expander cycle engine with a 15,000 lb thrust level and a 6:1 mixture ratio and optimized performance was used as the baseline for a design study of the hydrogen/oxgyen propulsion system for the orbit transfer vehicle. The critical components of this engine are the thrust chamber, the turbomachinery, the extendible nozzle system, and the engine throttling system. Turbomachinery technology is examined for gears, bearing, seals, and rapid solidification rate turbopump shafts. Continuous throttling concepts are discussed. Components of the OTV engine described include the thrust chamber/nozzle assembly design, nozzles, the hydrogen regenerator, the gaseous oxygen heat exchanger, turbopumps, and the engine control valves.

Thermogravity system designed for use in dispersion strengthening studies

NASA Technical Reports Server (NTRS)

Herbell, T. P.

1972-01-01

A thermogravimetry system designed to study the reduction of oxides in metal and alloy powders to be used in dispersion strengthened materials is described. The apparatus was devised for use at high temperatures with controlled atmospheres. Experimental weight change and moisture evolution results for the thermal decomposition of calcium oxalate monohydrate in dry helium, and experimental weight change results for the reduction of nickel oxide in dry hydrogen and hydrogen containing 15,000 PPM water vapor are presented. The system is currently being successfully applied to the evaluation of the reduction characteristics and the removal of impurities from metals and alloys to be used for dispersion strengthening.

Thermogravimetry system designed for use in dispersion strengthening studies.

NASA Technical Reports Server (NTRS)

Herbell, T. P.

1972-01-01

A thermogravimetry system, designed to study the reduction of oxides in metal and alloy powders to be used in dispersion strengthened materials, is described. The apparatus was devised for use at high temperatures with controlled atmospheres. Experimental weight change and moisture evolution results for the thermal decomposition of calcium oxalate monohydrate in dry helium, and experimental weight change results for the reduction of nickel oxide in dry hydrogen and hydrogen containing 15,000 p.p.m. water vapor are presented. The system is currently being successfully applied to the evaluation of the reduction characteristics and the removal of impurities from metals and alloys to be used for dispersion strengthening.

System and process for upgrading hydrocarbons

DOEpatents

Bingham, Dennis N.; Klingler, Kerry M.; Smith, Joseph D.; Turner, Terry D.; Wilding, Bruce M.

2015-08-25

In one embodiment, a system for upgrading a hydrocarbon material may include a black wax upgrade subsystem and a molten salt gasification (MSG) subsystem. The black wax upgrade subsystem and the MSG subsystem may be located within a common pressure boundary, such as within a pressure vessel. Gaseous materials produced by the MSG subsystem may be used in the process carried out within the black wax upgrade subsystem. For example, hydrogen may pass through a gaseous transfer interface to interact with black wax feed material to hydrogenate such material during a cracking process. In one embodiment, the gaseous transfer interface may include one or more openings in a tube or conduit which is carrying the black wax material. A pressure differential may control the flow of hydrogen within the tube or conduit. Related methods are also disclosed.

Method and system for hydrogen evolution and storage

DOEpatents

Thorn, David L.; Tumas, William; Hay, P. Jeffrey; Schwarz, Daniel E.; Cameron, Thomas M.

2012-12-11

A method and system for storing and evolving hydrogen (H.sub.2) employ chemical compounds that can be hydrogenated to store hydrogen and dehydrogenated to evolve hydrogen. A catalyst lowers the energy required for storing and evolving hydrogen. The method and system can provide hydrogen for devices that consume hydrogen as fuel.

Crystal-liquid-vapor equilibrium experiments at high temperature (less than or equal to 1800 C) and low, controlled oxygen and hydrogen pressure (10(-1) to 10(-9) PA)

NASA Technical Reports Server (NTRS)

Mysen, B. O.

1987-01-01

Evidence from carbonaceous chrondrites points to refractory oxides in the system CaO-MgO-Al2O3-TiO2-SiO2-Fe-O as being among the earliest phases to condense from the solar nebula. It is necessary to establish the equilibrium relationships between the relevant crystalline and amorphous phases before the chemical constraints can be meaningfully applied to models of solar system history. Preliminary experiments on earth show that such experiments are feasible. Earth-based experiments suffer from several unavoidable problems. These problems can be overcome by experimentation in the Space Station where the experiments can be conducted under near static pressure conditions and where total pressure equals the sum of controlled hydrogen and oxygen pressures and can be controlled for periods exceeding several hours.

Testing and analysis of the impact on engine cycle parameters and control system modifications using hydrogen or methane as fuel in an industrial gas turbine

NASA Astrophysics Data System (ADS)

Funke, H. H.-W.; Keinz, J.; Börner, S.; Hendrick, P.; Elsing, R.

2016-07-01

The paper highlights the modification of the engine control software of the hydrogen (H2) converted gas turbine Auxiliary Power Unit (APU) GTCP 36-300 allowing safe and accurate methane (CH4) operation achieved without mechanical changes of the metering unit. The acceleration and deceleration characteristics of the engine controller from idle to maximum load are analyzed comparing H2 and CH4. Also, the paper presents the influence on the thermodynamic cycle of gas turbine resulting from the different fuels supported by a gas turbine cycle simulation of H2 and CH4 using the software GasTurb.

A dynamic system for the simulation of fasting luminal pH-gradients using hydrogen carbonate buffers for dissolution testing of ionisable compounds.

PubMed

Garbacz, Grzegorz; Kołodziej, Bartosz; Koziolek, Mirko; Weitschies, Werner; Klein, Sandra

2014-01-23

The hydrogen carbonate buffer is considered as the most biorelevant buffer system for the simulation of intestinal conditions and covers the physiological pH range of the luminal fluids from pH 5.5 to about pH 8.4. The pH value of a hydrogen carbonate buffer is the result of a complex and dynamic interplay of the concentration of hydrogen carbonate ions, carbonic acid, the concentration of dissolved and solvated carbon dioxide and its partial pressure above the solution. The complex equilibrium between the different ions results in a thermodynamic instability of hydrogen carbonate solutions. In order to use hydrogen carbonate buffers with pH gradients in the physiological range and with the dynamics observed in vivo without changing the ionic strength of the solution, we developed a device (pHysio-grad®) that provides both acidification of the dissolution medium by microcomputer controlled carbon dioxide influx and alkalisation by degassing. This enables a continuous pH control and adjustment during dissolution of ionisable compounds. The results of the pH adjustment indicate that the system can compensate even rapid pH changes after addition of a basic or acidic moiety in amounts corresponding up to 90% of the overall buffer capacity. The results of the dissolution tests performed for a model formulation containing ionizable compounds (Nexium 20mg mups) indicate that both the simulated fasting intraluminal pH-profiles and the buffer species can significantly affect the dissolution process by changing the lag time prior to initial drug release and the release rate of the model compound. A prediction of the in vivo release behaviour of this formulation is thus most likely strongly related to the test conditions such as pH and buffer species. Copyright © 2013 Elsevier B.V. All rights reserved.

KSC-2012-3731

NASA Image and Video Library

2012-07-09

CAPE CANAVERAL, Fla. – Near the Hypergolic Maintenance Facility at NASA’s Kennedy Space Center in Florida, a groundbreaking ceremony was held to mark the location of the Ground Operations Demonstration Unit Liquid Hydrogen, or GODU LH2, test site. From left, are Johnny Nguyen, Fluids Test and Technology Development branch chief Emily Watkins, engineering intern Jeff Walls, Engineering Services Contract, or ESC, Cryogenics Test Lab engineer Kelly Currin, systems engineer Stephen Huff and Rudy Werlink partially hidden, cryogenics engineers Angela Krenn, systems engineer Doug Hammond, command and control engineer in the electrical division William Notardonato, GODU LH2 project manager and Kevin Jumper, ESC Cryogenics Test Lab manager. The GODU LH2 test site is one of the projects in NASA’s Advanced Exploration Systems Program. The site will be used to demonstrate advanced liquid hydrogen systems that are cost and energy efficient ways to store and transfer liquid hydrogen during process, loading, launch and spaceflight. The main components of the site will be a storage tank and a cryogenic refrigerator. Photo credit: NASA/Dimitri Gerondidakis

KSC-2012-3732

NASA Image and Video Library

2012-07-09

CAPE CANAVERAL, Fla. – Near the Hypergolic Maintenance Facility at NASA’s Kennedy Space Center in Florida, a groundbreaking ceremony was held to mark the location of the Ground Operations Demonstration Unit Liquid Hydrogen, or GODU LH2, test site. From left, are Johnny Nguyen, Fluids Test and Technology Development branch chief Emily Watkins, engineering intern Jeff Walls, Engineering Services Contract, or ESC, Cryogenics Test Lab engineer Kelly Currin, systems engineer Stephen Huff and Rudy Werlink partially hidden, cryogenics engineers Angela Krenn, systems engineer Doug Hammond, command and control engineer in the electrical division William Notardonato, GODU LH2 project manager and Kevin Jumper, ESC Cryogenics Test Lab manager. The GODU LH2 test site is one of the projects in NASA’s Advanced Exploration Systems Program. The site will be used to demonstrate advanced liquid hydrogen systems that are cost and energy efficient ways to store and transfer liquid hydrogen during process, loading, launch and spaceflight. The main components of the site will be a storage tank and a cryogenic refrigerator. Photo credit: NASA/Dimitri Gerondidakis

Helium refrigeration system for hydrogen liquefaction applications

NASA Astrophysics Data System (ADS)

Nair, J. Kumar, Sr.; Menon, RS; Goyal, M.; Ansari, NA; Chakravarty, A.; Joemon, V.

2017-02-01

Liquid hydrogen around 20 K is used as cold moderator for generating “cold neutron beam” in nuclear research reactors. A cryogenic helium refrigeration system is the core upon which such hydrogen liquefaction applications are built. A thermodynamic process based on reversed Brayton cycle with two stage expansion using high speed cryogenic turboexpanders (TEX) along with a pair of compact high effectiveness process heat exchangers (HX), is well suited for such applications. An existing helium refrigeration system, which had earlier demonstrated a refrigeration capacity of 470 W at around 20 K, is modified based on past operational experiences and newer application requirements. Modifications include addition of a new heat exchanger to simulate cryogenic process load and two other heat exchangers for controlling the temperatures of helium streams leading out to the application system. To incorporate these changes, cryogenic piping inside the cold box is suitably modified. This paper presents process simulation, sizing of new heat exchangers as well as fabrication aspects of the modified cryogenic process piping.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Breault, R.W.; Rolfe, J.

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, Thermomore » 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.« less

Vectorial electron transfer for improved hydrogen evolution by mercaptopropionic-acid-regulated CdSe quantum-dots-TiO2 -Ni(OH)2 assembly.

PubMed

Yu, Shan; Li, Zhi-Jun; Fan, Xiang-Bing; Li, Jia-Xin; Zhan, Fei; Li, Xu-Bing; Tao, Ye; Tung, Chen-Ho; Wu, Li-Zhu

2015-02-01

A visible-light-induced hydrogen evolution system based on a CdSe quantum dots (QDs)-TiO2 -Ni(OH)2 ternary assembly has been constructed under an ambient environment, and a bifunctional molecular linker, mercaptopropionic acid, is used to facilitate the interaction between CdSe QDs and TiO2 . This hydrogen evolution system works effectively in a basic aqueous solution (pH 11.0) to achieve a hydrogen evolution rate of 10.1 mmol g(-1)  h(-1) for the assembly and a turnover frequency of 5140 h(-1) with respect to CdSe QDs (10 h); the latter is comparable with the highest value reported for QD systems in an acidic environment. X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and control experiments demonstrate that Ni(OH)2 is an efficient hydrogen evolution catalyst. In addition, inductively coupled plasma optical emission spectroscopy and the emission decay of the assembly combined with the hydrogen evolution experiments show that TiO2 functions mainly as the electron mediator; the vectorial electron transfer from CdSe QDs to TiO2 and then from TiO2 to Ni(OH)2 enhances the efficiency for hydrogen evolution. The assembly comprises light antenna CdSe QDs, electron mediator TiO2 , and catalytic Ni(OH)2 , which mimics the strategy of photosynthesis exploited in nature and takes us a step further towards artificial photosynthesis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanometer-scale hydrogen 'portals' for the control of magnesium hydride formation.

PubMed

Chung, Chia-Jung; Nivargi, Chinmay; Clemens, Bruce

2015-11-21

Magnesium and Mg-based material systems are attractive candidates for hydrogen storage but limited by unsuitable thermodynamic and kinetic properties. In particular, the kinetics are too slow at room temperature and atmospheric pressure. To study the hydride formation kinetics in a controlled way, we have designed a unique 'nanoportal' structure of Pd nanoparticles deposited on epitaxial Mg thin films, through which the hydride will nucleate only under Pd nanoparticles. We propose a growth mechanism for the hydrogenation reaction in the nanoportal structure, which is supported by scanning electron microscopy (SEM) images of hydrogenated samples exhibiting consistent results. Interestingly, the grain boundaries of Mg films play an important role in hydride nucleation and growth processes. Kinetic modeling based on the Johnson-Mehl-Avrami-Kolmogorov (JMAK) formalism seems to agree with the two-dimensional nucleation and growth mechanism hypothesized and the overall reaction rate is limited by hydrogen flux through the interface between the Pd nanoparticle and the underlying Mg film. The fact that in our structure Mg can be transformed completely into MgH2 with only a small percentage of Pd nanoparticles offers possibilities for future on-board storage applications.

Effects of hydrogenated TiO2 nanotube arrays on protein adsorption and compatibility with osteoblast-like cells.

PubMed

Lu, Ran; Wang, Caiyun; Wang, Xin; Wang, Yuji; Wang, Na; Chou, Joshua; Li, Tao; Zhang, Zhenting; Ling, Yunhan; Chen, Su

2018-01-01

Modified titanium (Ti) substrates with titanium dioxide (TiO 2 ) nanotubes have broad usage as implant surface treatments and as drug delivery systems. To improve drug-loading capacity and accelerate bone integration with titanium, in this study, we hydrogenated anodized titanium dioxide nanotubes (TNTs) by a thermal treatment. Three groups were examined, namely: hydrogenated TNTs (H 2 -TNTs, test), unmodified TNTs (air-TNTs, control), and Ti substrates (Ti, control). Our results showed that oxygen vacancies were present in all the nanotubes. The quantity of -OH groups greatly increased after hydrogenation. Furthermore, the protein adsorption and loading capacity of the H 2 -TNTs were considerably enhanced as compared with the properties of the air-TNTs ( P <0.05). Additionally, time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to investigate the interactions of TNTs with proteins. During the protein-loading process, the H 2 -TNTs not only enabled rapid protein adsorption, but also decreased the rate of protein elution compared with that of the air-TNTs. We found that the H 2 -TNTs exhibited better biocompatibility than the air-TNT and Ti groups. Both cell adhesion activity and alkaline phosphatase activity were significantly improved toward MG-63 human osteoblast-like cells as compared with the control groups ( P <0.05). We conclude that hydrogenated TNTs could greatly improve the loading capacity of bioactive molecules and MG-63 cell proliferation.

Renewable Molecular Flasks with NADH Models: Combination of Light-Driven Proton Reduction and Biomimetic Hydrogenation of Benzoxazinones.

PubMed

Zhao, Liang; Wei, Jianwei; Lu, Junhua; He, Cheng; Duan, Chunying

2017-07-17

Using small molecules with defined pockets to catalyze chemical transformations resulted in attractive catalytic syntheses that echo the remarkable properties of enzymes. By modulating the active site of a nicotinamide adenine dinucleotide (NADH) model in a redox-active molecular flask, we combined biomimetic hydrogenation with in situ regeneration of the active site in a one-pot transformation using light as a clean energy source. This molecular flask facilitates the encapsulation of benzoxazinones for biomimetic hydrogenation of the substrates within the inner space of the flask using the active sites of the NADH models. The redox-active metal centers provide an active hydrogen source by light-driven proton reduction outside the pocket, allowing the in situ regeneration of the NADH models under irradiation. This new synthetic platform, which offers control over the location of the redox events, provides a regenerating system that exhibits high selectivity and efficiency and is extendable to benzoxazinone and quinoxalinone systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Integrated hydrocarbon reforming system and controls

DOEpatents

Clawson, Lawrence G.; Dorson, Matthew H.; Mitchell, William L.; Nowicki, Brian J.; Thijssen, Johannes; Davis, Robert; Papile, Christopher; Rumsey, Jennifer W.; Longo, Nathan; Cross, III, James C.; Rizzo, Vincent; Kleeburg, Gunther; Rindone, Michael; Block, Stephen G.; Sun, Maria; Morriseau, Brian D.; Hagan, Mark R.; Bowers, Brian

2003-11-04

A hydrocarbon reformer system including a first reactor configured to generate hydrogen-rich reformate by carrying out at least one of a non-catalytic thermal partial oxidation, a catalytic partial oxidation, a steam reforming, and any combinations thereof, a second reactor in fluid communication with the first reactor to receive the hydrogen-rich reformate, and having a catalyst for promoting a water gas shift reaction in the hydrogen-rich reformate, and a heat exchanger having a first mass of two-phase water therein and configured to exchange heat between the two-phase water and the hydrogen-rich reformate in the second reactor, the heat exchanger being in fluid communication with the first reactor so as to supply steam to the first reactor as a reactant is disclosed. The disclosed reformer includes an auxiliary reactor configured to generate heated water/steam and being in fluid communication with the heat exchanger of the second reactor to supply the heated water/steam to the heat exchanger.

A DFT study and micro-kinetic analysis of acetylene selective hydrogenation on Pd-doped Cu(111) surfaces

NASA Astrophysics Data System (ADS)

Ma, Ling-Ling; Lv, Cun-Qin; Wang, Gui-Chang

2017-07-01

Semi-hydrogenation of acetylene in a hydrogen-rich stream is an industrially important process. Inspired by the recent experiments that Cu(111) surface doped by a small number of Pd atoms can exhibit excellent catalytic performance toward the dissociation of H2 molecule as well as the high selective hydrogenation of acetylene as compared with pure Cu and Pd metal alone at low-temperature, here we performed systematic first-principles calculations to investigate the corresponding reaction mechanism related to the acetylene hydrogenation processes on single atom alloys (SAAs) and monolayer Pd/Cu(111) (i.e.,1.00 ML Pd/Cu(111)) model catalysts in detail, and to explore the possible factors controlling the high selectivity on SAAs. Our results clearly demonstrate that the SAA catalyst has higher selectivity for the ethylene formation than that of 1.00 ML Pd/Cu(111), and lower activity for the acetylene conversion compared with that of 1.00 ML Pd/Cu(111). The relatively high selectivity on SAA is mainly due to the facile desorption of ethylene and moderate activity in the dissociation of molecular H2. The main factor which lowers the selectivity towards the ethylene formation on 1.00 ML Pd/Cu(111) is that this system has a higher capacity to promote the breaking of Csbnd H/Csbnd C bonds, which leads to the formation of carbonaceous deposits and polymers such as benzene, and thus reduces the selectivity for the ethylene formation. Meanwhile, it was found that the desorption energy of ethylene on these two surfaces was smaller than the energy barrier of further hydrogenation, which results in the absence of ethane on these two systems. Micro-kinetic model analysis provides a further valuable insight into the evidence for the key factors controlling the catalytic activity and selectivity towards the selective hydrogenation of acetylene. Our findings may help people to design a highly selective hydrogenation catalyst by controlling the balance between the H2 dissociation and Csbnd H/Csbnd C bond broken processes, and a good catalyst should be the one with the modest catalytic activity in the activation of molecular H2. At the same time, the present work provides an extremely significant mechanism of acetylene trimerization to form benzene and carbon formation.

Lessons Learned from the Space Shuttle Engine Hydrogen Flow Control Valve Poppet Breakage

NASA Technical Reports Server (NTRS)

Martinez, Hugo E.; Damico, Stephen; Brewer, John

2011-01-01

The Main Propulsion System (MPS) uses three Flow Control Valves (FCV) to modulate the flow of pressurant hydrogen gas from the Space Shuttle Main Engines (SSME) to the hydrogen External Tank (ET). This maintains pressure in the ullage volume as the liquid level drops, preserving ET structural integrity and assuring the engines receive a sufficient amount of head pressure. On Space Transportation System (STS)-126 (2009), with only a handful of International Space Station (ISS) assembly flights from the end of the Shuttle program, a portion of a single FCV?s poppet head broke off at about a minute and a half after liftoff. The risk of the poppet head failure is that the increased flow area through the FCV could result in excessive gaseous hydrogen flow back to the external tank, which could result in overboard venting of hydrogen ullage pressure. If the hydrogen venting were to occur in first stage (i.e., lower atmosphere), a flammability hazard exists that could lead to catastrophic loss of crew and vehicle. Other failure risks included particle impact damage to MPS downstream hardware. Although the FCV design had been plagued by contamination-related sluggish valve response problems prior to a redesign at STS-80 (1996), contamination was ruled out as the cause of the STS-126 failure. Employing a combination of enhanced hardware inspection and a better understanding of the consequences of a poppet failure, safe flight rationale for subsequent flights (STS-119 and later) was achieved. This paper deals with the technical lessons learned during the investigation and mitigation of this problem at a time when assembly flights were each in the critical path to Space Station success.

Extended temperature range ACPS thruster investigation

NASA Technical Reports Server (NTRS)

Blubaugh, A. L.; Schoenman, L.

1974-01-01

The successful hot fire demonstration of a pulsing liquid hydrogen/liquid oxygen and gaseous hydrogen/liquid oxygen attitude control propulsion system thruster is described. The test was the result of research to develop a simple, lightweight, and high performance reaction control system without the traditional requirements for extensive periods of engine thermal conditioning, or the use of complex equipment to convert both liquid propellants to gas prior to delivery to the engine. Significant departures from conventional injector design practice were employed to achieve an operable design. The work discussed includes thermal and injector manifold priming analyses, subscale injector chilldown tests, and 168 full scale and 550 N (1250 lbF) rocket engine tests. Ignition experiments, at propellant temperatures ranging from cryogenic to ambient, led to the generation of a universal spark ignition system which can reliably ignite an engine when supplied with liquid, two phase, or gaseous propellants. Electrical power requirements for spark igniter are very low.

Cryptosporidium-contaminated water disinfection by a novel Fenton process.

PubMed

Matavos-Aramyan, Sina; Moussavi, Mohsen; Matavos-Aramyan, Hedieh; Roozkhosh, Sara

2017-05-01

Three novel modified advanced oxidation process systems including ascorbic acid-, pro-oxidants- and ascorbic acid-pro-oxidants-modified Fenton system were utilized to study the disinfection efficiency on Cryptosporidium-contaminated drinking water samples. Different concentrations of divalent and trivalent iron ions, hydrogen peroxide, ascorbic acid and pro-oxidants at different exposure times were investigated. These novel systems were also compared to the classic Fenton system and to the control system which comprised of only hydrogen peroxide. The complete in vitro mechanism of the mentioned modified Fenton systems are also provided. The results pointed out that by considering the optimal parameter limitations, the ascorbic acid-modified Fenton system decreased the Cryptosporidium oocytes viability to 3.91%, while the pro-oxidant-modified and ascorbic acid-pro-oxidant-modified Fenton system achieved an oocytes viability equal to 1.66% and 0%, respectively. The efficiency of the classic Fenton at optimal condition was observed to be 20.12% of oocytes viability. The control system achieved 86.14% of oocytes viability. The optimum values of the operational parameters during this study are found to be 80mgL -1 for the divalent iron, 30mgL -1 for ascorbic acid, 30mmol for hydrogen peroxide, 25mgL -1 for pro-oxidants and an exposure time equal to 5min. The ascorbic acid-pro-oxidants-modified Fenton system achieved a promising complete water disinfection (0% viability) at the optimal conditions, leaving this method a feasible process for water disinfection or decontamination, even at industrial scales. Copyright © 2017 Elsevier Inc. All rights reserved.

Survey of current and emerging technologies for biological contamination control

NASA Astrophysics Data System (ADS)

Frick, Andreas; Mogul, Rakesh

2012-07-01

This study will survey current and emerging technologies for biological contamination control within the context of planetary protection. Using a systems analysis approach, our objective is to compare various implementation variables across tasks ranging from surface cleaning to full-system sterilization for spacecraft and spacecraft components. Methods reviewed include vapor-phase hydrogen peroxide, plasma-phase sterilants such as oxygen and hydrogen peroxide, dry heat, laser-based techniques, supercritical carbon dioxide-based methods, and advanced bio-barriers. These methods will be evaluated in relation to relevant mission architectures and will address aspects of sample return missions. Results from this study, therefore, will offer new insights into the present-day engineering capabilities and future developmental concerns for missions targeting icy satellites, Mars, and other locations of astrochemical and astrobiological significance.

Proton transfer in microbial electrolysis cells

DOE PAGES

Borole, Abhijeet P.; Lewis, Alex J.

2017-02-15

Proton transfer and electron transfer are of prime importance in the development of microbial electrochemical cells. While electron transfer is primarily controlled by biology, proton transfer is controlled by process engineering and cell design. To develop commercially feasible technologies around the concept of a bioelectrochemical cell, real feedstocks have to be explored and associated limitations have to be identified. Here in this study, the proton transfer rate was quantified for a microbial electrolysis cell (MEC) and its dependence on process parameters was investigated using a proton balance model. The reaction system consisted of a biomass-derived pyrolytic aqueous stream as amore » substrate producing hydrogen in a flow-through MEC. The proton transfer rate increased with anode flow rate and organic loading rate up to a maximum of 0.36 ± 0.01 moles per m 2 per h, equivalent to a hydrogen production rate of 9.08 L per L per day. Higher rates of hydrogen production, reaching 11.7 ± 0.2 L per L per day were achieved, when additional protons were provided via the cathode buffer. Electrochemical impedance spectroscopy shows that proton transfer was the dominant resistance in the production of hydrogen. The quantification of proton transfer rates for MECs with potential for biorefinery application and the demonstration of high hydrogen production rates approaching those required for commercial consideration indicate the strong potential of this technology for renewable hydrogen production. Understanding the transport phenomenon in bioelectrochemical cells is of great significance since these systems have potential for wide-ranging applications including energy production, bioremediation, chemical and nanomaterial synthesis, electro-fermentation, energy storage, desalination, and produced water treatment. Electron transfer in anode biofilms has been investigated extensively, but proton transfer studies are also important, since many cathodic half reactions require protons as the reactant. Determination of transport rates via proton balance was investigated in microbial electrolysis cells, which can be applied to other forms of microbial electrochemical systems. Lastly, these systems have a unique niche in the development of future biorefineries as a means of recovering energy from waste streams with potential for water recycle, making them an integral part of the water–energy nexus focus area.« less

Proton transfer in microbial electrolysis cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borole, Abhijeet P.; Lewis, Alex J.

Proton transfer and electron transfer are of prime importance in the development of microbial electrochemical cells. While electron transfer is primarily controlled by biology, proton transfer is controlled by process engineering and cell design. To develop commercially feasible technologies around the concept of a bioelectrochemical cell, real feedstocks have to be explored and associated limitations have to be identified. Here in this study, the proton transfer rate was quantified for a microbial electrolysis cell (MEC) and its dependence on process parameters was investigated using a proton balance model. The reaction system consisted of a biomass-derived pyrolytic aqueous stream as amore » substrate producing hydrogen in a flow-through MEC. The proton transfer rate increased with anode flow rate and organic loading rate up to a maximum of 0.36 ± 0.01 moles per m 2 per h, equivalent to a hydrogen production rate of 9.08 L per L per day. Higher rates of hydrogen production, reaching 11.7 ± 0.2 L per L per day were achieved, when additional protons were provided via the cathode buffer. Electrochemical impedance spectroscopy shows that proton transfer was the dominant resistance in the production of hydrogen. The quantification of proton transfer rates for MECs with potential for biorefinery application and the demonstration of high hydrogen production rates approaching those required for commercial consideration indicate the strong potential of this technology for renewable hydrogen production. Understanding the transport phenomenon in bioelectrochemical cells is of great significance since these systems have potential for wide-ranging applications including energy production, bioremediation, chemical and nanomaterial synthesis, electro-fermentation, energy storage, desalination, and produced water treatment. Electron transfer in anode biofilms has been investigated extensively, but proton transfer studies are also important, since many cathodic half reactions require protons as the reactant. Determination of transport rates via proton balance was investigated in microbial electrolysis cells, which can be applied to other forms of microbial electrochemical systems. Lastly, these systems have a unique niche in the development of future biorefineries as a means of recovering energy from waste streams with potential for water recycle, making them an integral part of the water–energy nexus focus area.« less

Modelling and simulation of fuel cell dynamics for electrical energy usage of Hercules airplanes.

PubMed

Radmanesh, Hamid; Heidari Yazdi, Seyed Saeid; Gharehpetian, G B; Fathi, S H

2014-01-01

Dynamics of proton exchange membrane fuel cells (PEMFC) with hydrogen storage system for generating part of Hercules airplanes electrical energy is presented. Feasibility of using fuel cell (FC) for this airplane is evaluated by means of simulations. Temperature change and dual layer capacity effect are considered in all simulations. Using a three-level 3-phase inverter, FC's output voltage is connected to the essential bus of the airplane. Moreover, it is possible to connect FC's output voltage to airplane DC bus alternatively. PID controller is presented to control flow of hydrogen and oxygen to FC and improve transient and steady state responses of the output voltage to load disturbances. FC's output voltage is regulated via an ultracapacitor. Simulations are carried out via MATLAB/SIMULINK and results show that the load tracking and output voltage regulation are acceptable. The proposed system utilizes an electrolyser to generate hydrogen and a tank for storage. Therefore, there is no need for batteries. Moreover, the generated oxygen could be used in other applications in airplane.

Modelling and Simulation of Fuel Cell Dynamics for Electrical Energy Usage of Hercules Airplanes

PubMed Central

Radmanesh, Hamid; Heidari Yazdi, Seyed Saeid; Gharehpetian, G. B.; Fathi, S. H.

2014-01-01

Dynamics of proton exchange membrane fuel cells (PEMFC) with hydrogen storage system for generating part of Hercules airplanes electrical energy is presented. Feasibility of using fuel cell (FC) for this airplane is evaluated by means of simulations. Temperature change and dual layer capacity effect are considered in all simulations. Using a three-level 3-phase inverter, FC's output voltage is connected to the essential bus of the airplane. Moreover, it is possible to connect FC's output voltage to airplane DC bus alternatively. PID controller is presented to control flow of hydrogen and oxygen to FC and improve transient and steady state responses of the output voltage to load disturbances. FC's output voltage is regulated via an ultracapacitor. Simulations are carried out via MATLAB/SIMULINK and results show that the load tracking and output voltage regulation are acceptable. The proposed system utilizes an electrolyser to generate hydrogen and a tank for storage. Therefore, there is no need for batteries. Moreover, the generated oxygen could be used in other applications in airplane. PMID:24782664

Integration and dynamics of a renewable regenerative hydrogen fuel cell system

NASA Astrophysics Data System (ADS)

Bergen, Alvin Peter

2008-10-01

This thesis explores the integration and dynamics of residential scale renewable-regenerative energy systems which employ hydrogen for energy buffering. The development of the Integrated Renewable Energy Experiment (IRENE) test-bed is presented. IRENE is a laboratory-scale distributed energy system with a modular structure which can be readily re-configured to test newly developed components for generic regenerative systems. Key aspects include renewable energy conversion, electrolysis, hydrogen and electricity storage, and fuel cells. A special design feature of this test bed is the ability to accept dynamic inputs from and provide dynamic loads to real devices as well as from simulated energy sources/sinks. The integration issues encountered while developing IRENE and innovative solutions devised to overcome these barriers are discussed. Renewable energy systems that employ a regenerative approach to enable intermittent energy sources to service time varying loads rely on the efficient transfer of energy through the storage media. Experiments were conducted to evaluate the performance of the hydrogen energy buffer under a range of dynamic operating conditions. Results indicate that the operating characteristics of the electrolyser under transient conditions limit the production of hydrogen from excess renewable input power. These characteristics must be considered when designing or modeling a renewable-regenerative system. Strategies to mitigate performance degradation due to interruptions in the renewable power supply are discussed. Experiments were conducted to determine the response of the IRENE system to operating conditions that are representative of a residential scale, solar based, renewable-regenerative system. A control algorithm, employing bus voltage constraints and device current limitations, was developed to guide system operation. Results for a two week operating period that indicate that the system response is very dynamic but repeatable are presented. The overall system energy balance reveals that the energy input from the renewable source was sufficient to meet the demand load and generate a net surplus of hydrogen. The energy loss associated with the various system components as well as a breakdown of the unused renewable energy input is presented. In general, the research indicates that the technical challenges associated with hydrogen energy buffing can be overcome, but the round trip efficiency for the current technologies is low at only 22 percent.

Bioelectrochemical ethanol production through mediated acetate reduction by mixed cultures.

PubMed

Steinbusch, Kirsten J J; Hamelers, Hubertus V M; Schaap, Joris D; Kampman, Christel; Buisman, Cees J N

2010-01-01

Biological acetate reduction with hydrogen is a potential method to convert wet biomass waste into ethanol. Since the ethanol concentration and reaction rates are low, this research studies the feasibility of using an electrode, in stead of hydrogen, as an electron donor for biological acetate reduction in conjunction of an electron mediator. Initially, the effect of three selected mediators on metabolic flows during acetate reduction with hydrogen was explored; subsequently, the best performing mediator was used in a bioelectrochemical system to stimulate acetate reduction at the cathode with mixed cultures at an applied cathode potential of -550 mV. In the batch test, methyl viologen (MV) was found to accelerate ethanol production 6-fold and increased ethanol concentration 2-fold to 13.5 +/- 0.7 mM compared to the control. Additionally, MV inhibited n-butyrate and methane formation, resulting in high ethanol production efficiency (74.6 +/- 6%). In the bioelectrochemical system, MV addition to an inoculated cathode led directly to ethanol production (1.82 mM). Hydrogen was coproduced at the cathode (0.0035 Nm(3) hydrogen m(-2) d(-1)), so it remained unclear whether acetate was reduced to ethanol by electrons supplied by the mediator or by hydrogen. As MV reacted irreversibly at the cathode, ethanol production stopped after 5 days.

Effect of the lactoperoxidase system on Listeria monocytogenes behavior in raw milk at refrigeration temperatures.

PubMed Central

Gaya, P; Medina, M; Nuñez, M

1991-01-01

Activity of raw milk lactoperoxidase-thiocyanate-hydrogen peroxide (LP) system on four Listeria monocytogenes strains at refrigeration temperatures after addition of 0.25 mM sodium thiocyanate and 0.25 mM hydrogen peroxide was studied. The LP system exhibited a bactericidal activity against L. monocytogenes at 4 and 8 degrees C; the activity was dependent on temperature, length of incubation, and strain of L. monocytogenes tested. D values in activated-LP system milk for the four strains tested ranged from 4.1 to 11.2 days at 4 degrees C and from 4.4 to 9.7 days at 8 degrees C. The lactoperoxidase level in raw milk declined during a 7-day incubation, the decrease being more pronounced at 8 degrees C than at 4 degrees C and in control milk than in activated-LP system milk. The thiocyanate concentration decreased considerably in activated-LP system milk at both temperatures during the first 8 h of incubation. LP system activation was shown to be a feasible procedure for controlling development of L. monocytogenes in raw milk at refrigeration temperatures. PMID:1781693

Probing hydrogen positions in hydrous compounds: information from parametric neutron powder diffraction studies.

PubMed

Ting, Valeska P; Henry, Paul F; Schmidtmann, Marc; Wilson, Chick C; Weller, Mark T

2012-05-21

We demonstrate the extent to which modern detector technology, coupled with a high flux constant wavelength neutron source, can be used to obtain high quality diffraction data from short data collections, allowing the refinement of the full structures (including hydrogen positions) of hydrous compounds from in situ neutron powder diffraction measurements. The in situ thermodiffractometry and controlled humidity studies reported here reveal that important information on the reorientations of structural water molecules with changing conditions can be easily extracted, providing insight into the effects of hydrogen bonding on bulk physical properties. Using crystalline BaCl2·2H2O as an example system, we analyse the structural changes in the compound and its dehydration intermediates with changing temperature and humidity levels to demonstrate the quality of the dynamic structural information on the hydrogen atoms and associated hydrogen bonding that can be obtained without resorting to sample deuteration.

Silane-Pyrolysis Reactor With Nonuniform Heating

NASA Technical Reports Server (NTRS)

Iya, Sridhar K.

1991-01-01

Improved reactor serves as last stage in system processing metallurgical-grade silicon feedstock into silicon powder of ultrahigh purity. Silane pyrolized to silicon powder and hydrogen gas via homogeneous decomposition reaction in free space. Features set of individually adjustable electrical heaters and purge flow of hydrogen to improve control of pyrolysis conditions. Power supplied to each heater set in conjunction with flow in reactor to obtain desired distribution of temperature as function of position along reactor.

A 4-cylinder Stirling engine computer program with dynamic energy equations

NASA Technical Reports Server (NTRS)

Daniele, C. J.; Lorenzo, C. F.

1983-01-01

A computer program for simulating the steady state and transient performance of a four cylinder Stirling engine is presented. The thermodynamic model includes both continuity and energy equations and linear momentum terms (flow resistance). Each working space between the pistons is broken into seven control volumes. Drive dynamics and vehicle load effects are included. The model contains 70 state variables. Also included in the model are piston rod seal leakage effects. The computer program includes a model of a hydrogen supply system, from which hydrogen may be added to the system to accelerate the engine. Flow charts are provided.

Significant Quantum Effects in Hydrogen Activation

DOE PAGES

Kyriakou, Georgios; Davidson, Erlend R. M.; Peng, Guowen; ...

2014-03-31

Dissociation of molecular hydrogen is an important step in a wide variety of chemical, biological, and physical processes. Due to the light mass of hydrogen, it is recognized that quantum effects are often important to its reactivity. However, understanding how quantum effects impact the reactivity of hydrogen is still in its infancy. Here, we examine this issue using a well-defined Pd/Cu(111) alloy that allows the activation of hydrogen and deuterium molecules to be examined at individual Pd atom surface sites over a wide range of temperatures. Experiments comparing the uptake of hydrogen and deuterium as a function of temperature revealmore » completely different behavior of the two species. The rate of hydrogen activation increases at lower sample temperature, whereas deuterium activation slows as the temperature is lowered. Density functional theory simulations in which quantum nuclear effects are accounted for reveal that tunneling through the dissociation barrier is prevalent for H 2 up to ~190 K and for D 2 up to ~140 K. Kinetic Monte Carlo simulations indicate that the effective barrier to H 2 dissociation is so low that hydrogen uptake on the surface is limited merely by thermodynamics, whereas the D 2 dissociation process is controlled by kinetics. These data illustrate the complexity and inherent quantum nature of this ubiquitous and seemingly simple chemical process. Here, examining these effects in other systems with a similar range of approaches may uncover temperature regimes where quantum effects can be harnessed, yielding greater control of bond-breaking processes at surfaces and uncovering useful chemistries such as selective bond activation or isotope separation.« less

Strategies to diagnose and control microbial souring in natural gas storage reservoirs and produced water systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morris, E.A.; Derr, R.M.; Pope, D.H.

1995-12-31

Hydrogen sulfide production (souring) in natural gas storage reservoirs and produced water systems is a safety and environmental problem that can lead to operational shutdown when local hydrogen sulfide standards are exceeded. Systems affected by microbial souring have historically been treated using biocides that target the general microbial community. However, requirements for more environmentally friendly solutions have led to treatment strategies in which sulfide production can be controlled with minimal impact to the system and environment. Some of these strategies are based on microbial and/or nutritional augmentation of the sour environment. Through research sponsored by the Gas Research Institute (GRI)more » in Chicago, Illinois, methods have been developed for early detection of microbial souring in natural gas storage reservoirs, and a variety of mitigation strategies have been evaluated. The effectiveness of traditional biocide treatment in gas storage reservoirs was shown to depend heavily on the methods by which the chemical is applied. An innovative strategy using nitrate was tested and proved ideal for produced water and wastewater systems. Another strategy using elemental iodine was effective for sulfide control in evaporation ponds and is currently being tested in microbially sour natural gas storage wells.« less

Role of Hot Water System Design on Factors Influential to Pathogen Regrowth: Temperature, Chlorine Residual, Hydrogen Evolution, and Sediment

PubMed Central

Brazeau, Randi H.; Edwards, Marc A.

2013-01-01

Abstract Residential water heating is linked to growth of pathogens in premise plumbing, which is the primary source of waterborne disease in the United States. Temperature and disinfectant residual are critical factors controlling increased concentration of pathogens, but understanding of how each factor varies in different water heater configurations is lacking. A direct comparative study of electric water heater systems was conducted to evaluate temporal variations in temperature and water quality parameters including dissolved oxygen levels, hydrogen evolution, total and soluble metal concentrations, and disinfectant decay. Recirculation tanks had much greater volumes of water at temperature ranges with potential for increased pathogen growth when set at 49°C compared with standard tank systems without recirculation. In contrast, when set at the higher end of acceptable ranges (i.e., 60°C), this relationship was reversed and recirculation systems had less volume of water at risk for pathogen growth compared with conventional systems. Recirculation tanks also tended to have much lower levels of disinfectant residual (standard systems had 40–600% higher residual), 4–6 times as much hydrogen, and 3–20 times more sediment compared with standard tanks without recirculation. On demand tankless systems had very small volumes of water at risk and relatively high levels of disinfectant residual. Recirculation systems may have distinct advantages in controlling pathogens via thermal disinfection if set at 60°C, but these systems have lower levels of disinfectant residual and greater volumes at risk if set at lower temperatures. PMID:24170969

New insights into designing metallacarborane based room temperature hydrogen storage media.

PubMed

Bora, Pankaj Lochan; Singh, Abhishek K

2013-10-28

Metallacarboranes are promising towards realizing room temperature hydrogen storage media because of the presence of both transition metal and carbon atoms. In metallacarborane clusters, the transition metal adsorbs hydrogen molecules and carbon can link these clusters to form metal organic framework, which can serve as a complete storage medium. Using first principles density functional calculations, we chalk out the underlying principles of designing an efficient metallacarborane based hydrogen storage media. The storage capacity of hydrogen depends upon the number of available transition metal d-orbitals, number of carbons, and dopant atoms in the cluster. These factors control the amount of charge transfer from metal to the cluster, thereby affecting the number of adsorbed hydrogen molecules. This correlation between the charge transfer and storage capacity is general in nature, and can be applied to designing efficient hydrogen storage systems. Following this strategy, a search for the best metallacarborane was carried out in which Sc based monocarborane was found to be the most promising H2 sorbent material with a 9 wt.% of reversible storage at ambient pressure and temperature.

Ocular response to hydrogen peroxide.

PubMed

Paugh, J R; Brennan, N A; Efron, N

1988-02-01

A controlled, randomized, double-masked study was conducted on eight human subjects to determine the threshold level of hydrogen peroxide, which is toxic when introduced into the eye via a high water content (75%; Durasoft 4) hydrogel contact lens. Subjective comfort, conjunctival hyperemia, corneal and conjunctival epithelial staining, and corneal oxygen uptake were assessed in response to 5-min wear of lenses that were presoaked in isotonic saline solutions of physiologic pH containing 0, 25, 50, 100, 200, 400, and 800 parts per million (ppm) hydrogen peroxide. Higher levels of hydrogen peroxide were associated with greater discomfort (p less than 0.05) and increased conjunctival hyperemia (p less than 0.001). The highest level of hydrogen peroxide tested (800 ppm) did not induce significant corneal or conjunctival epithelial staining or alter the corneal aerobic response. We conclude that residual concentrations of hydrogen peroxide in contact lens care systems should not exceed 100 ppm. Practitioners can use these data to estimate the level of residual hydrogen peroxide to which a patient may have been exposed upon lens application after neutralization.

New insights into designing metallacarborane based room temperature hydrogen storage media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bora, Pankaj Lochan; Singh, Abhishek K.

Metallacarboranes are promising towards realizing room temperature hydrogen storage media because of the presence of both transition metal and carbon atoms. In metallacarborane clusters, the transition metal adsorbs hydrogen molecules and carbon can link these clusters to form metal organic framework, which can serve as a complete storage medium. Using first principles density functional calculations, we chalk out the underlying principles of designing an efficient metallacarborane based hydrogen storage media. The storage capacity of hydrogen depends upon the number of available transition metal d-orbitals, number of carbons, and dopant atoms in the cluster. These factors control the amount of chargemore » transfer from metal to the cluster, thereby affecting the number of adsorbed hydrogen molecules. This correlation between the charge transfer and storage capacity is general in nature, and can be applied to designing efficient hydrogen storage systems. Following this strategy, a search for the best metallacarborane was carried out in which Sc based monocarborane was found to be the most promising H{sub 2} sorbent material with a 9 wt.% of reversible storage at ambient pressure and temperature.« less

Isotope composition and volume of Earth's early oceans.

PubMed

Pope, Emily C; Bird, Dennis K; Rosing, Minik T

2012-03-20

Oxygen and hydrogen isotope compositions of Earth's seawater are controlled by volatile fluxes among mantle, lithospheric (oceanic and continental crust), and atmospheric reservoirs. Throughout geologic time the oxygen mass budget was likely conserved within these Earth system reservoirs, but hydrogen's was not, as it can escape to space. Isotopic properties of serpentine from the approximately 3.8 Ga Isua Supracrustal Belt in West Greenland are used to characterize hydrogen and oxygen isotope compositions of ancient seawater. Archaean oceans were depleted in deuterium [expressed as δD relative to Vienna standard mean ocean water (VSMOW)] by at most 25 ± 5‰, but oxygen isotope ratios were comparable to modern oceans. Mass balance of the global hydrogen budget constrains the contribution of continental growth and planetary hydrogen loss to the secular evolution of hydrogen isotope ratios in Earth's oceans. Our calculations predict that the oceans of early Earth were up to 26% more voluminous, and atmospheric CH(4) and CO(2) concentrations determined from limits on hydrogen escape to space are consistent with clement conditions on Archaean Earth.

The 1973 GSFC battery workshop, second day. [technology transfer

NASA Technical Reports Server (NTRS)

1973-01-01

Technological progress in the development, testing, and manufacturing of nickel-cadmium battery cells as well as hydrogen cells is presented. The following major topics were discussed: (1) carbonate analysis; (2) nickel-cadmium memory effect; (3) use of batteries in an automatic acquisition and control system; (4) accelerated testing; (5) formulation of a mathematical odel for a nickel-cadmium cell; (6) development of a light weight nickel-cadmium battery capable of delivering 20 watt hours per pound; (7) magnetic testing of nickel-cadmium cells; (8) design and performance characteristics of nickel-hydrogen and silver-hydrogen cells; and (9) development of a semiprismatic cell design. For Vol. 1, see N75-15152.

Controlling Internal Organization of Multilayer Poly(methacrylic acid) Hydrogels with Polymer Molecular Weight

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozlovskaya, Veronika; Zavgorodnya, Oleksandra; Ankner, John F.

Here, we report on tailoring the internal architecture of multilayer-derived poly(methacrylic acid) (PMAA) hydrogels by controlling the molecular weight of poly(N-vinylpyrrolidone) (PVPON) in hydrogen-bonded (PMAA/PVPON) layer-by-layer precursor films. The hydrogels are produced by cross-linking PMAA in the spin-assisted multilayers followed by PVPON release. We found that the thickness, morphology, and architecture of hydrogen-bonded films and the corresponding hydrogels are significantly affected by PVPON chain length. For all systems, an increase in PVPON molecular weight from M w = 2.5 to 1300 kDa resulted in increased total film thickness. We also show that increasing polymer M w smooths the hydrogen-bonded filmmore » surfaces but roughens those of the hydrogels. Using deuterated dPMAA marker layers in neutron reflectometry measurements, we found that hydrogen-bonded films reveal a high degree of stratification which is preserved in the cross-linked films. We observed dPMAA to be distributed more widely in the hydrogen-bonded films prepared with small M w PVPON due to the greater mobility of short-chain PVPON. Furthermore, these variations in the distribution of PMAA are erased after cross-linking, resulting in a distribution of dPMAA over about two bilayers for all M w but being somewhat more widely distributed in the films templated with higher M w PVPON. Finally, our results yield new insights into controlling the organization of nanostructured polymer networks using polymer molecular weight and open opportunities for fabrication of thin films with well-organized architecture and controllable function.« less

Controlling Internal Organization of Multilayer Poly(methacrylic acid) Hydrogels with Polymer Molecular Weight

DOE PAGES

Kozlovskaya, Veronika; Zavgorodnya, Oleksandra; Ankner, John F.; ...

2015-11-16

Here, we report on tailoring the internal architecture of multilayer-derived poly(methacrylic acid) (PMAA) hydrogels by controlling the molecular weight of poly(N-vinylpyrrolidone) (PVPON) in hydrogen-bonded (PMAA/PVPON) layer-by-layer precursor films. The hydrogels are produced by cross-linking PMAA in the spin-assisted multilayers followed by PVPON release. We found that the thickness, morphology, and architecture of hydrogen-bonded films and the corresponding hydrogels are significantly affected by PVPON chain length. For all systems, an increase in PVPON molecular weight from M w = 2.5 to 1300 kDa resulted in increased total film thickness. We also show that increasing polymer M w smooths the hydrogen-bonded filmmore » surfaces but roughens those of the hydrogels. Using deuterated dPMAA marker layers in neutron reflectometry measurements, we found that hydrogen-bonded films reveal a high degree of stratification which is preserved in the cross-linked films. We observed dPMAA to be distributed more widely in the hydrogen-bonded films prepared with small M w PVPON due to the greater mobility of short-chain PVPON. Furthermore, these variations in the distribution of PMAA are erased after cross-linking, resulting in a distribution of dPMAA over about two bilayers for all M w but being somewhat more widely distributed in the films templated with higher M w PVPON. Finally, our results yield new insights into controlling the organization of nanostructured polymer networks using polymer molecular weight and open opportunities for fabrication of thin films with well-organized architecture and controllable function.« less

Linear Aerospike SR-71 Experiment (LASRE): Aerospace Propulsion Hazard Mitigation Systems

NASA Technical Reports Server (NTRS)

Mizukami, Masashi; Corpening, Griffin P.; Ray, Ronald J.; Hass, Neal; Ennix, Kimberly A.; Lazaroff, Scott M.

1998-01-01

A major hazard posed by the propulsion system of hypersonic and space vehicles is the possibility of fire or explosion in the vehicle environment. The hazard is mitigated by minimizing or detecting, in the vehicle environment, the three ingredients essential to producing fire: fuel, oxidizer, and an ignition source. The Linear Aerospike SR-71 Experiment (LASRE) consisted of a linear aerospike rocket engine integrated into one-half of an X-33-like lifting body shape, carried on top of an SR-71 aircraft. Gaseous hydrogen and liquid oxygen were used as propellants. Although LASRE is a one-of-a-kind experimental system, it must be rated for piloted flight, so this test presented a unique challenge. To help meet safety requirements, the following propulsion hazard mitigation systems were incorporated into the experiment: pod inert purge, oxygen sensors, a hydrogen leak detection algorithm, hydrogen sensors, fire detection and pod temperature thermocouples, water misting, and control room displays. These systems are described, and their development discussed. Analyses, ground test, and flight test results are presented, as are findings and lessons learned.

Status and Design Concepts for the Hydrogen On-Orbit Storage and Supply Experiment

NASA Technical Reports Server (NTRS)

Chato, David J.; VanDyke, Melissa; Batty, J. Clair; Schick, Scott

1998-01-01

This paper studies concepts for the Hydrogen On-Orbit Storage and Supply Experiment (HOSS). HOSS is a space flight experiment whose objectives are: Show stable gas supply for storage and direct gain solar-thermal thruster designs; and evaluate and compare low-g performance of active and passive pressure control via a thermodynamic vent system (TVS) suitable for solar-thermal upper stages. This paper shows that the necessary experimental equipment for HOSS can be accommodated in a small hydrogen dewar of 36 to 80 liter. Thermal designs for these dewars which meet the on-orbit storage requirements can be achieved. Furthermore ground hold insulation and shielding concepts are achieved which enable storing initially subcooled liquid hydrogen in these small dewars without venting in excess of 144 hours.

Design, fabrication, assembly, and test of a liquid hydrogen acquisition subsystem

NASA Technical Reports Server (NTRS)

Blackman, J. B.

1974-01-01

The development of a cryogenic fluid system to supply liquid hydrogen to a turbopump at flowrates up to 7.5 pounds per second for a period of approximately 5 seconds before refill, is discussed. Refill is accomplished in less than 10 seconds, during which a constant flowrate can be maintained to the pumps. Diagrams are provided to show the configuration of the system. Subsystem acceptance and functional tests, including acquisition subsystem expulsion, pressurization, and refill were performed. The tests included: (1) thermodynamic vent system operation, (2) warm-gas pressurization effects, (3) hydraulic pressure surge effects, (4) screen device operational limitations, (5) feedline vapor control, and (6) two-phase refill.

Reactivity, characterization, equilibrium thermodynamics and hetero-bimetallic studies of tridentate and tetradentate complexes relevant to syngas catalysis

NASA Astrophysics Data System (ADS)

Imler, Gregory H.

The unifying objective of this work is the study of model systems that will assist in the development of new metal catalysts capable of converting carbon monoxide and hydrogen (syngas) into organic oxygenates at mild temperature and pressure. The selective catalytic transformation of carbon monoxide and hydrogen to liquid fuels and chemical feedstocks represents a major "Grand Challenge" of catalysis science. A core objective is the study of a macrocycle that is related to a porphyrin ligand in order to circumvent some of the disadvantages of utilizing porphyrins in catalysis. The rhodium complex of the macrocycle dibenzotetramethylaza[14]annulene ([(tmtaa)Rh]2]) was reacted with a series of small molecules relevant to CO reduction and hydrogenation. Several complexes were formed that demonstrated the ability to partially reduce and hydrogenate carbon monoxide, including the dirhodium ketone (Rh-C(O)-Rh) and an example of a thermodynamically favorable metal formyl complex ((tmtaa)Rh-C(O)H). An important feature of this work is the measurement of thermodynamic data to provide experimental benchmarks for obtaining key species in CO reduction and hydrogenation. A thorough study of the (tmtaa)Rh system will help in identifying structural features that assist or hinder CO hydrogenation. All reactions are monitored by 1H NMR which permits determination of solution thermodynamics from equilibrium constants obtained by NMR peak integrations. DFT calculations have supplemented experimental results by providing estimates to compare with the experimentally determined thermodynamic data. These computations also provide insight into the structures and thermodynamics of species that cannot be observed directly such as short lived intermediates and thermodynamically unfavorable products. Heterobimetallic complexes of (tmtaa)Rh• with a second metal radical have been utilized to attempt to convert CO to organic products. Reactivity with CO and H2 has been accomplished, with most of these metal systems providing (tmtaa)Rh-C(O)H and M-H as final products. These systems are now ideally set up for catalysis in which M-H can deliver hydrogen to reduce and hydrogenate the rhodium formyl unit. Performing these reactions at high pressures of CO/H2 or with a more sterically hindered analog of tmtaa may provide the conditions necessary for catalysis. Reactivity, thermodynamic and computational studies have been used to analyze and compare bond energies in this current work with previous studies accomplished in the Wayland group. These comparisons permit further understanding into the factors that control bond strength, guiding future studies and allowing tuning of bond strengths based on choice of conditions for a catalytic process. This research has resulted in a more complete understanding of the factors that control the favorability of various intermediates in CO reduction and hydrogenation and the application of these results can be used to guide the next generation of metal ligand systems that will yield organic oxygenates at mild conditions.

Controlling the Local Electronic Properties of Si(553)-Au through Hydrogen Doping

NASA Astrophysics Data System (ADS)

Hogan, C.; Speiser, E.; Chandola, S.; Suchkova, S.; Aulbach, J.; Schäfer, J.; Meyer, S.; Claessen, R.; Esser, N.

2018-04-01

We propose a quantitative and reversible method for tuning the charge localization of Au-stabilized stepped Si surfaces by site-specific hydrogenation. This is demonstrated for Si(553)-Au as a model system by combining density functional theory simulations and reflectance anisotropy spectroscopy experiments. We find that controlled H passivation is a two-step process: step-edge adsorption drives excess charge into the conducting metal chain "reservoir" and renders it insulating, while surplus H recovers metallic behavior. Our approach illustrates a route towards microscopic manipulation of the local surface charge distribution and establishes a reversible switch of site-specific chemical reactivity and magnetic properties on vicinal surfaces.

SAIDE: A Semi-Automated Interface for Hydrogen/Deuterium Exchange Mass Spectrometry.

PubMed

Villar, Maria T; Miller, Danny E; Fenton, Aron W; Artigues, Antonio

2010-01-01

Deuterium/hydrogen exchange in combination with mass spectrometry (DH MS) is a sensitive technique for detection of changes in protein conformation and dynamics. Since temperature, pH and timing control are the key elements for reliable and efficient measurement of hydrogen/deuterium content in proteins and peptides, we have developed a small, semiautomatic interface for deuterium exchange that interfaces the HPLC pumps with a mass spectrometer. This interface is relatively inexpensive to build, and provides efficient temperature and timing control in all stages of enzyme digestion, HPLC separation and mass analysis of the resulting peptides. We have tested this system with a series of standard tryptic peptides reconstituted in a solvent containing increasing concentration of deuterium. Our results demonstrate the use of this interface results in minimal loss of deuterium due to back exchange during HPLC desalting and separation. For peptides reconstituted in a buffer containing 100% deuterium, and assuming that all amide linkages have exchanged hydrogen with deuterium, the maximum loss of deuterium content is only 17% of the label, indicating the loss of only one deuterium molecule per peptide.

SAIDE: A Semi-Automated Interface for Hydrogen/Deuterium Exchange Mass Spectrometry

PubMed Central

Villar, Maria T.; Miller, Danny E.; Fenton, Aron W.; Artigues, Antonio

2011-01-01

Deuterium/hydrogen exchange in combination with mass spectrometry (DH MS) is a sensitive technique for detection of changes in protein conformation and dynamics. Since temperature, pH and timing control are the key elements for reliable and efficient measurement of hydrogen/deuterium content in proteins and peptides, we have developed a small, semiautomatic interface for deuterium exchange that interfaces the HPLC pumps with a mass spectrometer. This interface is relatively inexpensive to build, and provides efficient temperature and timing control in all stages of enzyme digestion, HPLC separation and mass analysis of the resulting peptides. We have tested this system with a series of standard tryptic peptides reconstituted in a solvent containing increasing concentration of deuterium. Our results demonstrate the use of this interface results in minimal loss of deuterium due to back exchange during HPLC desalting and separation. For peptides reconstituted in a buffer containing 100% deuterium, and assuming that all amide linkages have exchanged hydrogen with deuterium, the maximum loss of deuterium content is only 17% of the label, indicating the loss of only one deuterium molecule per peptide. PMID:25309638

Liquid oxygen/liquid hydrogen auxiliary power system thruster investigation

NASA Technical Reports Server (NTRS)

Eberle, E. E.; Kusak, L.

1979-01-01

The design, fabrication, and demonstration of a 111 newton (25 lb) thrust, integrated auxiliary propulsion system (IAPS) thruster for use with LH2/LO2 propellants is described. Hydrogen was supplied at a temperature range of 22 to 33 K (40 to 60 R), and oxygen from 89 to 122 K (160 to 220 R). The thruster was designed to operate in both pulse mode and steady-state modes for vehicle attitude control, space maneuvering, and as an abort backup in the event of failure of the main propulsion system. A dual-sleeve, tri-axial injection system was designed that utilizes a primary injector/combustor where 100 percent of the oxygen and 8 percent of the hydrogen is introduced; a secondary injector/combustor where 45 percent of the hydrogen is introduced to mix with the primary combustor gases; and a boundary layer injector that uses the remaining 45 percent of the hydrogen to cool the thrust throat/nozzle design. Hot-fire evaluation of this thruster with a BLC injection distance of 2.79 cm (1.10 in.) indicated that a specific impulse value of 390 sec can be attained using a coated molybdenum thrust chamber. Pulse mode tests indicated that a chamber pressure buildup to 90 percent thrust can be achieved in a time on the order of 48 msec. Some problems were encountered in achieving ignition of each pulse during pulse trains. This was interpreted to indicate that a higher delivered spark energy level ( 100 mJ) would be required to maintain ignition reliability of the plasma torch ignition system under the extra 'cold' conditions resulting during pulsing.

Engineering bacterial motility towards hydrogen-peroxide.

PubMed

Virgile, Chelsea; Hauk, Pricila; Wu, Hsuan-Chen; Shang, Wu; Tsao, Chen-Yu; Payne, Gregory F; Bentley, William E

2018-01-01

Synthetic biologists construct innovative genetic/biological systems to treat environmental, energy, and health problems. Many systems employ rewired cells for non-native product synthesis, while a few have employed the rewired cells as 'smart' devices with programmable function. Building on the latter, we developed a genetic construct to control and direct bacterial motility towards hydrogen peroxide, one of the body's immune response signaling molecules. A motivation for this work is the creation of cells that can target and autonomously treat disease, the latter signaled by hydrogen peroxide release. Bacteria naturally move towards a variety of molecular cues (e.g., nutrients) in the process of chemotaxis. In this work, we engineered bacteria to recognize and move towards hydrogen peroxide, a non-native chemoattractant and potential toxin. Our system exploits oxyRS, the native oxidative stress regulon of E. coli. We first demonstrated H2O2-mediated upregulation motility regulator, CheZ. Using transwell assays, we showed a two-fold increase in net motility towards H2O2. Then, using a 2D cell tracking system, we quantified bacterial motility descriptors including velocity, % running (of tumble/run motions), and a dynamic net directionality towards the molecular cue. In CheZ mutants, we found that increased H2O2 concentration (0-200 μM) and induction time resulted in increased running speeds, ultimately reaching the native E. coli wild-type speed of ~22 μm/s with a ~45-65% ratio of running to tumbling. Finally, using a microfluidic device with stable H2O2 gradients, we characterized responses and the potential for "programmed" directionality towards H2O2 in quiescent fluids. Overall, the synthetic biology framework and tracking analysis in this work will provide a framework for investigating controlled motility of E. coli and other 'smart' probiotics for signal-directed treatment.

Isothermal vapor-liquid equilibria for the systems 1-chloro-1,1-difluoroethane + hydrogen fluoride, 1,1-dichloro-1-fluoroethane + hydrogen fluoride, and chlorodifluoromethane + hydrogen fluoride

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Y.W.; Lee, Y.Y.

1997-03-01

Isothermal vapor-liquid equilibria for the three binary systems (1-chloro-1,1-difluoroethane + hydrogen fluoride, 1,1-dichloro-1-fluoroethane + hydrogen fluoride, and chlorodifluoromethane + hydrogen fluoride) have been measured. The experimental data for the binary systems are correlated with the NRTL equation with the vapor-phase association model for the mixtures containing hydrogen fluoride, and the relevant parameters are presented. All of the systems form minimum boiling heterogeneous azeotropes.

Potential structural material problems in a hydrogen energy system

NASA Technical Reports Server (NTRS)

Gray, H. R.; Nelson, H. G.; Johnson, R. E.; Mcpherson, B.; Howard, F. S.; Swisher, J. H.

1975-01-01

Potential structural material problems that may be encountered in the three components of a hydrogen energy system - production, transmission/storage, and utilization - were identified. Hydrogen embrittlement, corrosion, oxidation, and erosion may occur during the production of hydrogen. Hydrogen embrittlement is of major concern during both transmission and utilization of hydrogen. Specific materials research and development programs necessary to support a hydrogen energy system are described.

A Novel Approach for Modeling Chemical Reaction in Generalized Fluid System Simulation Program

NASA Technical Reports Server (NTRS)

Sozen, Mehmet; Majumdar, Alok

2002-01-01

The Generalized Fluid System Simulation Program (GFSSP) is a computer code developed at NASA Marshall Space Flight Center for analyzing steady state and transient flow rates, pressures, temperatures, and concentrations in a complex flow network. The code, which performs system level simulation, can handle compressible and incompressible flows as well as phase change and mixture thermodynamics. Thermodynamic and thermophysical property programs, GASP, WASP and GASPAK provide the necessary data for fluids such as helium, methane, neon, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide, fluorine, hydrogen, water, a hydrogen, isobutane, butane, deuterium, ethane, ethylene, hydrogen sulfide, krypton, propane, xenon, several refrigerants, nitrogen trifluoride and ammonia. The program which was developed out of need for an easy to use system level simulation tool for complex flow networks, has been used for the following purposes to name a few: Space Shuttle Main Engine (SSME) High Pressure Oxidizer Turbopump Secondary Flow Circuits, Axial Thrust Balance of the Fastrac Engine Turbopump, Pressurized Propellant Feed System for the Propulsion Test Article at Stennis Space Center, X-34 Main Propulsion System, X-33 Reaction Control System and Thermal Protection System, and International Space Station Environmental Control and Life Support System design. There has been an increasing demand for implementing a combustion simulation capability into GFSSP in order to increase its system level simulation capability of a liquid rocket propulsion system starting from the propellant tanks up to the thruster nozzle for spacecraft as well as launch vehicles. The present work was undertaken for addressing this need. The chemical equilibrium equations derived from the second law of thermodynamics and the energy conservation equation derived from the first law of thermodynamics are solved simultaneously by a Newton-Raphson method. The numerical scheme was implemented as a User Subroutine in GFSSP.

Low temperature fluid blender

NASA Technical Reports Server (NTRS)

Repas, G. A.

1971-01-01

Blender supplies hydrogen at temperatures from 289 deg K to 367 deg K. Hydrogen temperature is controlled by using blender to combine flow from liquid hydrogen tank /276 deg K/ and gaseous hydrogen cylinder /550 deg K/. Blenders are applicable where flow of controlled low-temperature fluid is desired.

PROPULSE 980: A Hydrogen Peroxide Enrichment System

NASA Technical Reports Server (NTRS)

Boxwell, Robert; Bromley, G.; Wanger, Robert; Pauls, Dan; Maynard, Bryon; McNeal, Curtis; Dumbacher, D. L. (Technical Monitor)

2000-01-01

The PROPULSE 980 unit is a transportable processing plant that enriches aerospace grade hydrogen peroxide from 90% to 98% final concentration. The unit was developed by Degussa-H Is, in cooperation with Orbital, NASA Marshall Space Center, and NASA Stennis Space Center. The system is a self-contained unit that houses all of the process equipment, instrumentation and controls to perform the concentration operation nearly autonomously. It is designed to produce non-bulk quantities of 98% hydrogen peroxide. The enrichment unit design also maintains system, personnel and environmental safety during all aspects of the enrichment process and final product storage. As part of the Propulse 980 checkout and final buyoff, it will be disassembled at the Degussa-H Is Corporation plant in Theodore, AL, transported to the Stennis Space Center, reassembled and subjected to a series of checkout tests to verify design objectives have been met. This paper will summarize the basic project elements and provide an update on the present status of the project.

Hydrogen purification systems for PEM fuel cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

System for exchange of hydrogen between liquid and solid phases

DOEpatents

Reilly, James J.; Grohse, Edward W.; Johnson, John R.; Winsche, deceased, Warren E.

1988-01-01

The reversible reaction M+x/2 H.sub.2 .rarw..fwdarw.MH.sub.x, wherein M is a reversible metal hydride former that forms a hydride MH.sub.x in the presence of H.sub.2, generally used to store and recall H.sub.2, is found to proceed under an inert liquid, thereby reducing contamination, providing better temperature control, providing in situ mobility of the reactants, and increasing flexibility in process design. Thus, a slurry of particles of a metal hydride former with an inert solvent is subjected to a temperature and pressure controlled atmosphere containing H.sub.2, to store hydrogen and to release previously stored hydrogen. The direction of the flow of the H.sub.2 through the liquid is dependent upon the H.sub.2 pressure in the gas phase at a given temperature. When the actual H.sub.2 pressure is above the equilibrium absorption pressure of the respective hydride the reaction proceeds to the right, i.e., the metal hydride is formed and hydrogen is stored in the solid particles. When the actual pressure in the gas phase is below the equilibrium dissociation pressure of the respective hydride the reaction proceeds to the left, the metal hydride is decomposed and hydrogen is released into the gas phase.

System for exchange of hydrogen between liquid and solid phases

DOEpatents

Reilly, J.J.; Grohse, E.W.; Johnson, J.R.; Winsche, W.E.

1985-02-22

The reversible reaction M + x/2 H/sub 2/ reversible MH/sub x/, wherein M is a reversible metal hydride former that forms a hydride MH/sub x/ in the presence of H/sub 2/, generally used to store and recall H/sub 2/, is found to proceed under an inert liquid, thereby reducing contamination, providing better temperature control, providing in situ mobility of the reactants, and increasing flexibility in process design. Thus, a slurry of particles of a metal hydride former with an inert solvent is subjected to a temperature and pressure controlled atmosphere containing H/sub 2/, to store hydrogen and to release previously stored hydrogen. The direction of the flow of the H/sub 2/ through the liquid is dependent upon the H/sub 2/ pressure in the gas phase at a given temperature. When the actual H/sub 2/ pressure is above the equilibrium absorption pressure of the respective hydride the reaction proceeds to the right, i.e., the metal hydride is formed and hydrogen is stored in the solid particle. When the actual pressure in the gas phase is below the equilibrium dissociation pressure of the respective hydride the reaction proceeds to the left, the metal hydride is decomposed and hydrogen is released into the gas phase.

Fuel cell using a hydrogen generation system

DOEpatents

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.

Hydrogen storage and generation system

DOEpatents

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

2010-08-24

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

Hydrogen-water vapor mixtures: Control of hydrothermal atmospheres by hydrogen osmosis

USGS Publications Warehouse

Shaw, H.R.

1963-01-01

Experiments at 700??C and 800 bars total pressure demonstrate positive deviations from ideality for mixtures of hydrogen and H2O gases. The deviations are greater than predicted with Stockmayer's method. The composition of the mixture and the fugacity of hydrogen are controlled by diffusing hydrogen through metallic membranes. The results give the fugacities of both H 2O and oxygen.

Technology readiness assessment of advanced space engine integrated controls and health monitoring

NASA Technical Reports Server (NTRS)

Millis, Marc G.

1991-01-01

An evaluation is given for an integrated control and health monitoring system (ICHM) system that is designed to be used with hydrogen-oxygen rocket engines. The minimum required ICHM functions, system elements, technology readiness, and system cost are assessed for a system which permits the operation of H-O engines that are space-based, reusable, and descent throttleable. Based on the evaluation of the H-O ICHM, it is estimated that the minimum system requirements for demonstration on an engine system testbed will require an investment of 30 to 45 million dollars over six years.

Moisture contamination and welding parameter effects on flux cored arc welding diffusible hydrogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiefer, J.J.

1994-12-31

Gas metal arc (GMAW) and flux cored arc (FCAW) welding are gas shielded semiautomatic processes widely used for achieving high productivity in steel fabrication. Contamination of the shielding has can occur due to poorly maintained gas distribution systems. Moisture entering as a gas contaminant is a source of hydrogen that can cause delayed cold cracking in welds. Limiting heat-affected zone hardness is one method of controlling cracking. Even this is based on some assumptions about the hydrogen levels in the weld. A study was conducted to investigate the effect of shielding gas moisture contamination and welding parameters on the diffusiblemore » hydrogen content of gas shielded flux cored arc welding. The total wire hydrogen of various electrodes was also tested and compared to the diffusible weld hydrogen. An empirical equation has been developed that estimates the diffusible hydrogen in weld metal for gas shielded flux cored arc welding. The equation is suitable for small diameter electrodes and welding parameter ranges commonly used for out-of-position welding. by combining this with the results from the total wire hydrogen tests, it is possible to estimate diffusible hydrogen directly from measured welding parameters, shielding gas dew point, and total hydrogen of the consumable. These equations are also useful for evaluating the effect of welding procedure variations from known baseline conditions.« less

Thin-film fiber optic hydrogen and temperature sensor system

DOEpatents

Nave, Stanley E.

1998-01-01

The invention discloses a sensor probe device for monitoring of hydrogen gas concentrations and temperatures by the same sensor probe. The sensor probe is constructed using thin-film deposition methods for the placement of a multitude of layers of materials sensitive to hydrogen concentrations and temperature on the end of a light transparent lens located within the sensor probe. The end of the lens within the sensor probe contains a lens containing a layer of hydrogen permeable material which excludes other reactive gases, a layer of reflective metal material that forms a metal hydride upon absorbing hydrogen, and a layer of semi-conducting solid that is transparent above a temperature dependent minimum wavelength for temperature detection. The three layers of materials are located at the distal end of the lens located within the sensor probe. The lens focuses light generated by broad-band light generator and connected by fiber-optics to the sensor probe, onto a reflective metal material layer, which passes through the semi-conducting solid layer, onto two optical fibers located at the base of the sensor probe. The reflected light is transmitted over fiberoptic cables to a spectrometer and system controller. The absence of electrical signals and electrical wires in the sensor probe provides for an elimination of the potential for spark sources when monitoring in hydrogen rich environments, and provides a sensor free from electrical interferences.

Thin-film fiber optic hydrogen and temperature sensor system

DOEpatents

Nave, S.E.

1998-07-21

The invention discloses a sensor probe device for monitoring of hydrogen gas concentrations and temperatures by the same sensor probe. The sensor probe is constructed using thin-film deposition methods for the placement of a multitude of layers of materials sensitive to hydrogen concentrations and temperature on the end of a light transparent lens located within the sensor probe. The end of the lens within the sensor probe contains a lens containing a layer of hydrogen permeable material which excludes other reactive gases, a layer of reflective metal material that forms a metal hydride upon absorbing hydrogen, and a layer of semi-conducting solid that is transparent above a temperature dependent minimum wavelength for temperature detection. The three layers of materials are located at the distal end of the lens located within the sensor probe. The lens focuses light generated by broad-band light generator and connected by fiber-optics to the sensor probe, onto a reflective metal material layer, which passes through the semi-conducting solid layer, onto two optical fibers located at the base of the sensor probe. The reflected light is transmitted over fiber optic cables to a spectrometer and system controller. The absence of electrical signals and electrical wires in the sensor probe provides for an elimination of the potential for spark sources when monitoring in hydrogen rich environments, and provides a sensor free from electrical interferences. 3 figs.

Hydrogen Storage Properties of New Hydrogen-Rich BH3NH3-Metal Hydride (TiH2, ZrH2, MgH2, and/or CaH2) Composite Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Young Joon; Xu, Yimin; Shaw, Wendy J.

2012-04-19

Ammonia borane (AB = NH3BH3) is one of the most attractive materials for chemical hydrogen storage due to its high hydrogen contents of 19.6 wt.%, however, impurity levels of borazine, ammonia and diborane in conjunction with foaming and exothermic hydrogen release calls for finding ways to mitigate the decomposition reactions. In this paper we present a solution by mixing AB with metal hydrides (TiH2, ZrH2, MgH2 and CaH2) which have endothermic hydrogen release in order to control the heat release and impurity levels from AB upon decomposition. The composite materials were prepared by mechanical ball milling, and their H2 releasemore » properties were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The formation of volatile products from decomposition side reactions, such as borazine (N3B3H6) was determined by mass spectrometry (MS). Sieverts type pressure-composition-temperature (PCT) gas-solid reaction instrument was adopted to observe the kinetics of the H2 release reactions of the combined systems and neat AB. In situ 11B MAS-NMR revealed a destabilized decomposition pathway. We found that by adding specific metal hydrides to AB we can eliminate the impurities and mitigate the heat release.« less

Cryogenic target system for hydrogen layering

DOE PAGES

Parham, T.; Kozioziemski, B.; Atkinson, D.; ...

2015-11-24

Here, a cryogenic target positioning system was designed and installed on the National Ignition Facility (NIF) target chamber. This instrument incorporates the ability to fill, form, and characterize the NIF targets with hydrogen isotopes needed for ignition experiments inside the NIF target bay then transport and position them in the target chamber. This effort brought to fruition years of research in growing and metrologizing high-quality hydrogen fuel layers and landed it in an especially demanding operations environment in the NIF facility. D-T (deuterium-tritium) layers for NIF ignition experiments have extremely tight specifications and must be grown in a very highlymore » constrained environment: a NIF ignition target inside a cryogenic target positioner inside the NIF target bay. Exquisite control of temperature, pressure, contaminant level, and thermal uniformity are necessary throughout seed formation and layer growth to create an essentially-groove-free single crystal layer.« less

High-Capacity Hydrogen-Based Green-Energy Storage Solutions For The Grid Balancing

NASA Astrophysics Data System (ADS)

D'Errico, F.; Screnci, A.

One of the current main challenges in green-power storage and smart grids is the lack of effective solutions for accommodating the unbalance between renewable energy sources, that offer intermittent electricity supply, and a variable electricity demand. Energy management systems have to be foreseen for the near future, while they still represent a major challenge. Integrating intermittent renewable energy sources, by safe and cost-effective energy storage systems based on solid state hydrogen is today achievable thanks to recently some technology breakthroughs. Optimized solid storage method made of magnesium-based hydrides guarantees a very rapid absorption and desorption kinetics. Coupled with electrolyzer technology, high-capacity storage of green-hydrogen is therefore practicable. Besides these aspects, magnesium has been emerging as environmentally friend energy storage method to sustain integration, monitoring and control of large quantity of GWh from high capacity renewable generation in the EU.

High-Capacity Hydrogen-Based Green-Energy Storage Solutions for the Grid Balancing

NASA Astrophysics Data System (ADS)

D'Errico, F.; Screnci, A.

One of the current main challenges in green-power storage and smart grids is the lack of effective solutions for accommodating the unbalance between renewable energy sources, that offer intermittent electricity supply, and a variable electricity demand. Energy management systems have to be foreseen for the near future, while they still represent a major challenge. Integrating intermittent renewable energy sources, by safe and cost-effective energy storage systems based on solid state hydrogen is today achievable thanks to recently some technology breakthroughs. Optimized solid storage method made of magnesium-based hydrides guarantees a very rapid absorption and desorption kinetics. Coupled with electrolyzer technology, high-capacity storage of green-hydrogen is therefore practicable. Besides these aspects, magnesium has been emerging as environmentally friend energy storage method to sustain integration, monitoring and control of large quantity of GWh from high capacity renewable generation in the EU.

Systems and methods for selective hydrogen transport and measurement

DOEpatents

Glatzmaier, Gregory C

2013-10-29

Systems and methods for selectively removing hydrogen gas from a hydrogen-containing fluid volume are disclosed. An exemplary system includes a proton exchange membrane (PEM) selectively permeable to hydrogen by exclusively conducting hydrogen ions. The system also includes metal deposited as layers onto opposite sides or faces of the PEM to form a membrane-electrode assembly (MEA), each layer functioning as an electrode so that the MEA functions as an electrochemical cell in which the ionic conductors are hydrogen ions, and the MEA functioning as a hydrogen selective membrane (HSM) when located at the boundary between a hydrogen-containing fluid volume and a second fluid.

Selection of combined water electrolysis and resistojet propulsion for Space Station Freedom

NASA Technical Reports Server (NTRS)

Schmidt, George R.

1988-01-01

An analytical rationale is presented for the configuration of the NASA Space Station's two-element propulsion system, and attention is given to the cost benefits accruing to this system over the Space Station's service life. The principal system element uses gaseous oxygen and hydrogen obtained through water electrolysis to furnish attitude control, backup attitude control, and contingency maneuvering. The secondary element uses resistojets to augment Space Station reboost through the acceleration of waste gases in the direction opposite the Station's flight path.

Design manual: Oxygen Thermal Test Article (OTTA)

NASA Technical Reports Server (NTRS)

Chronic, W. L.; Baese, C. L.; Conder, R. L.

1974-01-01

The characteristics of a cryogenic tank for storing liquid hydrogen, nitrogen, oxygen, methane, or helium for an extended period of time with minimum losses are discussed. A description of the tank and control module, assembly drawings and details of major subassemblies, specific requirements controlling development of the system, thermal concept considerations, thermal analysis methods, and a record of test results are provided. The oxygen thermal test article thermal protection system has proven that the insulation system for cryogenic vessels is effective.

A hydrogen energy carrier. Volume 2: Systems analysis

NASA Technical Reports Server (NTRS)

Savage, R. L. (Editor); Blank, L. (Editor); Cady, T. (Editor); Cox, K. (Editor); Murray, R. (Editor); Williams, R. D. (Editor)

1973-01-01

A systems analysis of hydrogen as an energy carrier in the United States indicated that it is feasible to use hydrogen in all energy use areas, except some types of transportation. These use areas are industrial, residential and commercial, and electric power generation. Saturation concept and conservation concept forecasts of future total energy demands were made. Projected costs of producing hydrogen from coal or from nuclear heat combined with thermochemical decomposition of water are in the range $1.00 to $1.50 per million Btu of hydrogen produced. Other methods are estimated to be more costly. The use of hydrogen as a fuel will require the development of large-scale transmission and storage systems. A pipeline system similar to the existing natural gas pipeline system appears practical, if design factors are included to avoid hydrogen environment embrittlement of pipeline metals. Conclusions from the examination of the safety, legal, environmental, economic, political and societal aspects of hydrogen fuel are that a hydrogen energy carrier system would be compatible with American values and the existing energy system.

Software Architecture to Support the Evolution of the ISRU RESOLVE Engineering Breadboard Unit 2 (EBU2)

NASA Technical Reports Server (NTRS)

Moss, Thomas; Nurge, Mark; Perusich, Stephen

2011-01-01

The In-Situ Resource Utilization (ISRU) Regolith & Environmental Science and Oxygen & Lunar Volatiles Extraction (RESOLVE) software provides operation of the physical plant from a remote location with a high-level interface that can access and control the data from external software applications of other subsystems. This software allows autonomous control over the entire system with manual computer control of individual system/process components. It gives non-programmer operators the capability to easily modify the high-level autonomous sequencing while the software is in operation, as well as the ability to modify the low-level, file-based sequences prior to the system operation. Local automated control in a distributed system is also enabled where component control is maintained during the loss of network connectivity with the remote workstation. This innovation also minimizes network traffic. The software architecture commands and controls the latest generation of RESOLVE processes used to obtain, process, and quantify lunar regolith. The system is grouped into six sub-processes: Drill, Crush, Reactor, Lunar Water Resource Demonstration (LWRD), Regolith Volatiles Characterization (RVC) (see example), and Regolith Oxygen Extraction (ROE). Some processes are independent, some are dependent on other processes, and some are independent but run concurrently with other processes. The first goal is to analyze the volatiles emanating from lunar regolith, such as water, carbon monoxide, carbon dioxide, ammonia, hydrogen, and others. This is done by heating the soil and analyzing and capturing the volatilized product. The second goal is to produce water by reducing the soil at high temperatures with hydrogen. This is done by raising the reactor temperature in the range of 800 to 900 C, causing the reaction to progress by adding hydrogen, and then capturing the water product in a desiccant bed. The software needs to run the entire unit and all sub-processes; however, throughout testing, many variables and parameters need to be changed as more is learned about the system operation. The Master Events Controller (MEC) is run on a standard laptop PC using Windows XP. This PC runs in parallel to another laptop that monitors the GC, and a third PC that monitors the drilling/ crushing operation. These three PCs interface to the process through a CompactRIO, OPC Servers, and modems.

Assessing microbial competition in a hydrogen-based membrane biofilm reactor (MBfR) using multidimensional modeling.

PubMed

Martin, Kelly J; Picioreanu, Cristian; Nerenberg, Robert

2015-09-01

The membrane biofilm reactor (MBfR) is a novel technology that safely delivers hydrogen to the base of a denitrifying biofilm via gas-supplying membranes. While hydrogen is an effective electron donor for denitrifying bacteria (DNB), it also supports sulfate-reducing bacteria (SRB) and methanogens (MET), which consume hydrogen and create undesirable by-products. SRB and MET are only competitive for hydrogen when local nitrate concentrations are low, therefore SRB and MET primarily grow near the base of the biofilm. In an MBfR, hydrogen concentrations are greatest at the base of the biofilm, making SRB and MET more likely to proliferate in an MBfR system than a conventional biofilm reactor. Modeling results showed that because of this, control of the hydrogen concentration via the intramembrane pressure was a key tool for limiting SRB and MET development. Another means is biofilm management, which supported both sloughing and erosive detachment. For the conditions simulated, maintaining thinner biofilms promoted higher denitrification fluxes and limited the presence of SRB and MET. The 2-d modeling showed that periodic biofilm sloughing helped control slow-growing SRB and MET. Moreover, the rough (non-flat) membrane assembly in the 2-d model provided a special niche for SRB and MET that was not represented in the 1-d model. This study compared 1-d and 2-d biofilm model applicability for simulating competition in counter-diffusional biofilms. Although more computationally expensive, the 2-d model captured important mechanisms unseen in the 1-d model. © 2015 Wiley Periodicals, Inc.

Methanol partial oxidation reformer

DOEpatents

Ahmed, Shabbir; Kumar, Romesh; Krumpelt, Michael

1999-01-01

A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

Methanol partial oxidation reformer

DOEpatents

Ahmed, S.; Kumar, R.; Krumpelt, M.

1999-08-17

A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

Methanol partial oxidation reformer

DOEpatents

Ahmed, S.; Kumar, R.; Krumpelt, M.

1999-08-24

A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

Methanol partial oxidation reformer

DOEpatents

Ahmed, Shabbir; Kumar, Romesh; Krumpelt, Michael

2001-01-01

A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

The E-3 Test Facility at Stennis Space Center: Research and Development Testing for Cryogenic and Storable Propellant Combustion Systems

NASA Technical Reports Server (NTRS)

Pazos, John T.; Chandler, Craig A.; Raines, Nickey G.

2009-01-01

This paper will provide the reader a broad overview of the current upgraded capabilities of NASA's John C. Stennis Space Center E-3 Test Facility to perform testing for rocket engine combustion systems and components using liquid and gaseous oxygen, gaseous and liquid methane, gaseous hydrogen, hydrocarbon based fuels, hydrogen peroxide, high pressure water and various inert fluids. Details of propellant system capabilities will be highlighted as well as their application to recent test programs and accomplishments. Data acquisition and control, test monitoring, systems engineering and test processes will be discussed as part of the total capability of E-3 to provide affordable alternatives for subscale to full scale testing for many different requirements in the propulsion community.

Liquid propellant thermal conditioning system test program

NASA Technical Reports Server (NTRS)

Bullard, B. R.

1972-01-01

Results are presented from more than 1500 hours of testing on a liquid hydrogen thermal conditioning unit. Test parameters included: mixer and vent flow rates; tank size; ullage volume; pressurant gas; pressurant temperature; pressure level; and heat rate. Gaseous hydrogen and helium were used as pressurants. Analytical models were developed to correlate the test data and relate the performance to that anticipated in zero gravity. Experimental and theoretical results are presented which relate the variables controlling vapor condensation at a moving interface.

Magnetocaloric properties of distilled gadolinium: Effects of structural inhomogeneity and hydrogen impurity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burkhanov, G. S.; Kolchugina, N. B.; Chzhan, V. B.

2014-06-16

High-purity Gd prepared by distillation is a structurally inhomogeneous system consisting of needle-shaped crystals of cross section 0.5–2.5 μm with near-c-axis orientation embedded in a matrix of nanosized (30–100 nm) grains. By measuring the magnetocaloric effect (MCE) directly, we find that the MCE values differ markedly for the plate-shaped samples cut out of a distillate along and perpendicular to the crystals. The effect of small controlled amounts of impurity (hydrogen) on the properties of distilled Gd is further studied. We observe opposite trends in the MCE response to hydrogen charging with respect to the crystal's orientation within the samples and discuss mechanismsmore » interrelating the unique structural morphology with the impurity behavior. As an overall assessment, the Curie temperatures of α-GdH{sub x} solid solutions increase from 291 K up to 294 K when increasing hydrogen concentration x from 0 to 0.15. Hydrogenation is found to broaden the ferromagnetic-to-paramagnetic phase transition. Hydrogen-containing specimens demonstrate reversibility of MCE at these temperatures.« less

Isotope composition and volume of Earth’s early oceans

PubMed Central

Pope, Emily C.; Bird, Dennis K.; Rosing, Minik T.

2012-01-01

Oxygen and hydrogen isotope compositions of Earth’s seawater are controlled by volatile fluxes among mantle, lithospheric (oceanic and continental crust), and atmospheric reservoirs. Throughout geologic time the oxygen mass budget was likely conserved within these Earth system reservoirs, but hydrogen’s was not, as it can escape to space. Isotopic properties of serpentine from the approximately 3.8 Ga Isua Supracrustal Belt in West Greenland are used to characterize hydrogen and oxygen isotope compositions of ancient seawater. Archaean oceans were depleted in deuterium [expressed as δD relative to Vienna standard mean ocean water (VSMOW)] by at most 25 ± 5‰, but oxygen isotope ratios were comparable to modern oceans. Mass balance of the global hydrogen budget constrains the contribution of continental growth and planetary hydrogen loss to the secular evolution of hydrogen isotope ratios in Earth’s oceans. Our calculations predict that the oceans of early Earth were up to 26% more voluminous, and atmospheric CH4 and CO2 concentrations determined from limits on hydrogen escape to space are consistent with clement conditions on Archaean Earth. PMID:22392985

Gas-controlled dynamic vacuum insulation with gas gate

DOEpatents

Benson, David K.; Potter, Thomas F.

1994-06-07

Disclosed is a dynamic vacuum insulation comprising sidewalls enclosing an evacuated chamber and gas control means for releasing hydrogen gas into a chamber to increase gas molecule conduction of heat across the chamber and retrieving hydrogen gas from the chamber. The gas control means includes a metal hydride that absorbs and retains hydrogen gas at cooler temperatures and releases hydrogen gas at hotter temperatures; a hydride heating means for selectively heating the metal hydride to temperatures high enough to release hydrogen gas from the metal hydride; and gate means positioned between the metal hydride and the chamber for selectively allowing hydrogen to flow or not to flow between said metal hydride and said chamber.

Gas-controlled dynamic vacuum insulation with gas gate

DOEpatents

Benson, D.K.; Potter, T.F.

1994-06-07

Disclosed is a dynamic vacuum insulation comprising sidewalls enclosing an evacuated chamber and gas control means for releasing hydrogen gas into a chamber to increase gas molecule conduction of heat across the chamber and retrieving hydrogen gas from the chamber. The gas control means includes a metal hydride that absorbs and retains hydrogen gas at cooler temperatures and releases hydrogen gas at hotter temperatures; a hydride heating means for selectively heating the metal hydride to temperatures high enough to release hydrogen gas from the metal hydride; and gate means positioned between the metal hydride and the chamber for selectively allowing hydrogen to flow or not to flow between said metal hydride and said chamber. 25 figs.

Recent developments in nickel hydrogen technology

NASA Astrophysics Data System (ADS)

Beauchamp, R. L.; Dunlop, J. D.

1988-05-01

A program to design and develop a multikilowatt-hour nickel hydrogen battery for storing electricity from photovoltaic or other power sources is continuing under a cost sharing contract with Sandia National Laboratories. The challenge has been to dramatically reduce the first cost of the battery to make it economically competitive, on a life-cycle cost basis, with other energy storage batteries used in terrestrial applications. The advantages offered by nickel hydrogen batteries are: (1) long cycle life, (2) no maintenance, and (3) a high tolerance to abuse. The last being the most important, implying that there is no need for a charge controller between the solar array and the battery. This would have a beneficial effect on the installation's long term reliability and cost. It also means that one can take full advantage of the maximum output of the solar array, in contrast to systems where the controller isolates the battery during times of maximum insolation. Couple this to the battery's excellent energy efficiency and there can be a significant reduction in the size of the array. In addition, since the state-of-charge is directly related to pressure, the battery can be used as a load management system.

Feasibility Studies of Vortex Flow Impact On the Proliferation of Algae in Hydrogen Production for Fuel Cell Applications

NASA Astrophysics Data System (ADS)

Miskon, Azizi; A/L Thanakodi, Suresh; Shiema Moh Nazar, Nazatul; Kit Chong, Marcus Wai; Sobri Takriff, Mohd; Fakir Kamarudin, Kamrul; Aziz Norzali, Abdul; Nooraya Mohd Tawil, Siti

2016-11-01

The instability of crude oil price in global market as well as the sensitivity towards green energy increases, more research works being carried out to find alternative energy replacing the depleting of fossil fuels. Photobiological hydrogen production system using algae is one of the promising alternative energy source. However, the yield of hydrogen utilizing the current photobioreactor (PBR) is still low for commercial application due to restricted light penetration into the deeper regions of the reactor. Therefore, this paper studies the feasibility of vortex flow impact utilizing magnetic stirring in hydrogen production for fuel cell applications. For comparison of results, a magnetic stirrer is placed under a PBR of algae to stir the algae to obtain an even distribution of sunlight to the algae while the controlled PBR of algae kept in static. The produced hydrogen level was measured using hydrogen sensor circuit and the data collected were communicated to laptop using Arduino Uno. The results showed more cell counts and hydrogen produced in the PBR under the influence of magnetic stirring compared to static PBR by an average of 8 percent in 4 days.

Development of an experimental system for characterization of high-temperature superconductors cooled by liquid hydrogen under the external magnetic field

NASA Astrophysics Data System (ADS)

Tatsumoto, H.; Shirai, Y.; Shiotsu, M.; Naruo, Y.; Kobayashi, H.; Inatani, Y.

2014-05-01

An experimental system has been developed to investigate electro-magnetic properties of high-Tc superconductors cooled by liquid hydrogen under the external magnetic field of up to 7 T. A LH2 cryostat is concentrically mounted on the inside of a LHe cryostat to cool a NbTi superconducting magnet. The experimental system is installed in an explosion-proof room. Explosion proof electrical devices are used and current leads are covered with an enclosure filled with nitrogen gas. A remote control system has been developed. Furthermore, the effects of stray magnetic field on the existing and the new devices are investigated and electro-magnetic shielding panels and enclosure made of iron were designed. It is confirmed through the cryogenic test that the experimental system meets the design requirements.

Study of liquid oxygen/liquid hydrogen auxiliary propulsion systems for the space tug

NASA Technical Reports Server (NTRS)

Nichols, J. F.

1975-01-01

Design concepts are considered that permit use of a liquid-liquid (as opposed to gas-gas) oxygen/hydrogen thrust chamber for attitude control and auxiliary propulsion thrusters on the space tug. The best of the auxiliary propulsion system concepts are defined and their principal characteristics, including cost as well as operational capabilities, are established. Design requirements for each of the major components of the systems, including thrusters, are developed at the conceptual level. The competitive concepts considered use both dedicated (separate tanks) and integrated (propellant from main propulsion tanks) propellant supply. The integrated concept is selected as best for the space tug after comparative evaluation against both cryogenic and storable propellant dedicated systems. A preliminary design of the selected system is established and recommendations for supporting research and technology to further the concept are presented.

Hydrogenated amorphous silicon formation by flux control and hydrogen effects on the growth mechanism

NASA Astrophysics Data System (ADS)

Toyoda, H.; Sugai, H.; Kato, K.; Yoshida, A.; Okuda, T.

1986-06-01

The composition of particle flux to deposit hydrogenated amorphous silicon films in a glow discharge is controlled by a combined electrostatic-magnetic deflection technique. As a result, the films are formed firstly without hydrogen ion flux, secondly by neutral flux only, and thirdly by all species fluxes. Comparison of these films reveals the significant role of hydrogen in the surface reactions. Hydrogen breaks the Si-Si bond, decreases the sticking probability of the Si atom, and replaces the SiH bond by a SiH2 bond to increase the hydrogen content of the films.

Space Shuttle Program (SSP) Orbiter Main Propulsion System (MPS) Gaseous Hydrogen (GH2) Flow Control Valve (FCV) Poppet Eddy Current (EC) Inspection Probability of Detection (POD) Study. Volume 1

NASA Technical Reports Server (NTRS)

Piascik, Robert S.; Prosser, William H.

2011-01-01

The Director of the NASA Engineering and Safety Center (NESC), requested an independent assessment of the anomalous gaseous hydrogen (GH2) flow incident on the Space Shuttle Program (SSP) Orbiter Vehicle (OV)-105 during the Space Transportation System (STS)-126 mission. The main propulsion system (MPS) engine #2 GH2 flow control valve (FCV) LV-57 transition from low towards high flow position without being commanded. Post-flight examination revealed that the FCV LV-57 poppet had experienced a fatigue failure that liberated a section of the poppet flange. The NESC assessment provided a peer review of the computational fluid dynamics (CFD), stress analysis, and impact testing. A probability of detection (POD) study was requested by the SSP Orbiter Project for the eddy current (EC) nondestructive evaluation (NDE) techniques that were developed to inspect the flight FCV poppets. This report contains the findings and recommendations from the NESC assessment.

Space Shuttle Program (SSP) Orbiter Main Propulsion System (MPS) Gaseous Hydrogen (GH2) Flow Control Valve (FCV) Poppet Eddy Current (EC) Inspection Probability of Detection (POD) Study. Volume 2; Appendices

NASA Technical Reports Server (NTRS)

Piascik, Robert S.; Prosser, William H.

2011-01-01

The Director of the NASA Engineering and Safety Center (NESC), requested an independent assessment of the anomalous gaseous hydrogen (GH2) flow incident on the Space Shuttle Program (SSP) Orbiter Vehicle (OV)-105 during the Space Transportation System (STS)-126 mission. The main propulsion system (MPS) engine #2 GH2 flow control valve (FCV) LV-57 transition from low towards high flow position without being commanded. Post-flight examination revealed that the FCV LV-57 poppet had experienced a fatigue failure that liberated a section of the poppet flange. The NESC assessment provided a peer review of the computational fluid dynamics (CFD), stress analysis, and impact testing. A probability of detection (POD) study was requested by the SSP Orbiter Project for the eddy current (EC) nondestructive evaluation (NDE) techniques that were developed to inspect the flight FCV poppets. This report contains the Appendices to the main report.

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

PubMed

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

2013-11-14

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

Chemical hydrogen storage material property guidelines for automotive applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Semelsberger, Troy; Brooks, Kriston P.

2015-04-01

Chemical hydrogen storage is the sought after hydrogen storage media for automotive applications because of the expected low pressure operation (<20 atm), moderate temperature operation (<200 C), system gravimetric capacities (>0.05 kg H2/kg system), and system volumetric capacities (>0.05 kg H2/L system). Currently, the primary shortcomings of chemical hydrogen storage are regeneration efficiency, fuel cost and fuel phase (i.e., solid or slurry phase). Understanding the required material properties to meet the DOE Technical Targets for Onboard Hydrogen Storage Systems is a critical knowledge gap in the hydrogen storage research community. This study presents a set of fluid-phase chemical hydrogen storagemore » material property guidelines for automotive applications meeting the 2017 DOE technical targets. Viable material properties were determined using a boiler-plate automotive system design. The fluid phase chemical hydrogen storage media considered in this study were neat liquids, solutions, and non-settling homogeneous slurries. Material properties examined include kinetics, heats of reaction, fuel-cell impurities, gravimetric and volumetric hydrogen storage capacities, and regeneration efficiency. The material properties, although not exhaustive, are an essential first step in identifying viable chemical hydrogen storage material propertiesdand most important, their implications on system mass, system volume and system performance.« less

Fermentative hydrogen production from liquid swine manure with glucose supplement using an anaerobic sequencing batch reactor

NASA Astrophysics Data System (ADS)

Wu, Xiao

2009-12-01

The idea of coupling renewable energy production and agricultural waste management inspired this thesis. The production of an important future fuel---hydrogen gas---from high strength waste stream-liquid swine manure---using anaerobic treatment processes makes the most sustainable sense for both wastewater utilization and energy generation. The objectives of this thesis were to develop a fermentation process for converting liquid swine manure to hydrogen and to maximize hydrogen productivity. Anaerobic sequencing batch reactor (ASBR) systems were constructed to carry out this fermentation process, and seed sludge obtained from a dairy manure anaerobic digester and pretreated by nutrient acclimation, heat and pH treatment was used as inoculum. High system stability was indicated by a short startup period of 12 days followed by stable hydrogen production, and successful sludge granulation occurred within 23 days of startup at a hydraulic retention time (HRT) of 24 hours. Operation at a progressively decreasing HRT from 24 to 8h gave rise to an increasing biogas production rate from 15.2-34.4L/d, while good linear relationships were observed between both total biogas and hydrogen production rates correlated to HRT, with R2 values of 0.993 and 0.997, respectively. The maximum hydrogen yield of 1.63 mol-H 2/mol-hexose-feed occurred at HRT of 16h, while the HRT of 12h was highly suggested to achieve both high production rate and efficient yield. Hexose utilization efficiencies over 98%, considerable hydrogen production rate up to 14.3 L/d and hydrogen percentage of off-gas up to 43% (i.e., a CO 2/H2 ratio of 1.2) with the absence of CH4 production throughout the whole course of experiment at a pH of 5.0 strongly validated the feasibility of the fermentative H2 production from liquid swine manure using an ASBR system. Ethanol as well as acetic, butyric and valeric acids were produced in the system accompanying the hydrogen production, with acetic acid being the dominant one, which contributed to 56-58% of the total soluble metabolite production, indicative of an acetic acid fermentation system, and acetate-to-butyrate ratio was found to be closely related to hydrogen yield. pH level influenced every aspect of the ASBR performance for hydrogen production. ASBR operation at five pHs ranging from 4.4 to 5.6 (4.4, 4.7, 5.0, 5.3, 5.6) showed distinct dynamic profiles of both biogas production and the changes of H2 and CH4 percentage in the biogas during a running period of 22 days. The H2 content in biogas, H 2 production rate and H2 yield were all pH-dependent, in the range of 5.1-36.9 %, 0.71-8.97 L/d and 0.12-1.50 mol-H2/mol-glucose, respectively, and maximum values for all three responses were simultaneously achieved at pH 5.0. Methanogens appeared to be significantly activated at pH of 5.3 or higher since significant CH4 evolution and concurrent reduction in H2 production was observed at pH 5.3 and 5.6. Acetate, propionate, butyrate, valerate, and ethanol were main aqueous products in all pH tests and their distribution was influenced by pH. Analysis of kinetic models developed from modified Gompertz equations for batch experiments showed that pH had a profound effect on all kinetic parameters for hydrogen production including hydrogen potential, maximum hydrogen production rate and the length of the lag phase, as well as the maximum substrate utilization rate. The low pH of 4.4 gave the highest hydrogen production potential but with the lowest hydrogen production rate. A contrast experiment was conducted with an initial pH of 5.3 but not controlled, came up with a rapid pH decline, leading to a low hexose degradation efficiency of 33.2% and a significantly suppressed H2 production, indicating the importance of pH control and the effect of pH on H2 production and substrate consumption. pH 5.0 was verified as the optimal for the proposed fermentation system by kinetic models. An extremely linear relationship (R2= 0.993) between the maximum H2 production rate and the maximum hexose degradation rate suggested that the pH inhibition on H2 production was a result of the suppression on the bacterial activity for substrate utilization due to an unfavorable pH level. System optimization was realized through experiments conducted according to a response surface methodology, with a central composite design and empirical quadratic response equations obtained for three responses including the hydrogen content in the biogas, hydrogen evolution rate and hydrogen yield, against three independent variables, pH (4.4-5.6), HRT (8-24h) and substrate glucose concentrations (Cg, 0-20 g/L). Contour plots revealed that all three responses were significantly impacted by the variable and squared pH. Furthermore, pH and Cg had a significant interaction effect on H2 production rate, while HRT and glucose concentration were interdependent, or they had a mildly significant interaction effect on H2 production rate. The hydrogen content decreased when pH was greater than 5.0 or less than 4.6 and a largest value of 42.7% could be obtained at pH 4.8, HRT 8 h, and Cg of 18.7 g/L. The highest hydrogen production rate of 26.1 L/d happened under a pH of 4.6, HRT of 8h, and Cg of 20 g/L; Lower HRT and higher Cg was found to benefit the H2 production rate because they provide elevated organic loading and food to microorganism ratio for the system. HRT shorter than 17h resulted in declined hydrogen yield, while the glucose concentration up to 20 g/L did not cause suppression on hydrogen yield. The revised optimal condition of pH 4.8, HRT 11h, and Cg of 20 g/L, which could achieve 85% of the maximum values of all three hydrogen productivity responses, was determined by surface response methodology. Highly reproducible results from confirming experiments at the optimal condition indicated that the results modeled in this study possessed a high reliability, while the results of H2 content, H2 production rate and yield were obtained as 40.3%, 23.16 L/d, and 1.36mol H2/mol hexose, respectively. Results obtained in this study indicated that ASBR system using swine manure based substrate had significant potential of fermentative hydrogen production. Key words: biohydrogen production, hydrogen fermentation, liquid swine manure, anaerobic sequencing batch reactor (ASBR), hydrogen content, hydrogen production rate, hydrogen yield

Hydrogen storage properties of Mg xFe (x: 2, 3 and 15) compounds produced by reactive ball milling

NASA Astrophysics Data System (ADS)

Puszkiel, J. A.; Arneodo Larochette, P.; Gennari, F. C.

This work deals with the assessment of the thermo-kinetic properties of Mg-Fe based materials for hydrogen storage. Samples are prepared from Mg xFe (x: 2, 3 and 15) elemental powder mixtures via low energy ball milling under hydrogen atmosphere at room temperature. The highest yield is obtained with Mg 15Fe after 150 h of milling (90 wt% of MgH 2). The thermodynamic characterization carried out between 523 and 673 K shows that the obtained Mg-Fe-H hydride systems have similar thermodynamic parameters, i.e. enthalpy and entropy. However, in equilibrium conditions, Mg 15Fe has higher hydrogen capacity and small hysteresis. In dynamic conditions, Mg 15Fe also shows better hydrogen capacity (4.85 wt% at 623 K absorbed in less than 10 min and after 100 absorption/desorption cycles), reasonably good absorption/desorption times and cycling stability in comparison to the other studied compositions. From hydrogen uptake rate measurements performed at 573 and 623 K, the rate-limiting step of the hydrogen uptake reaction is determined by fitting particle kinetic models. According to our results, the hydrogen uptake is diffusion controlled, and this mechanism does not change with the Mg-Fe proportion and temperature.

Solar thermal propulsion for planetary spacecraft

NASA Technical Reports Server (NTRS)

Sercel, J. C.

1985-01-01

Previous studies have shown that many desirable planetary exploration missions require large injection delta-V. Solar Thermal Rocket (STR) propulsion, under study for orbit-raising applications may enhance or enable such high-energy missions. The required technology of thermal control for liquid hydrogen propellant is available for the required storage duration. Self-deploying, inflatable solar concentrators are under study. The mass penalty for passive cryogenic thermal control, liquid hydrogen tanks and solar concentrators does not compromise the specific impulse advantage afforded by the STR as compared to chemical propulsion systems. An STR injection module is characterized and performance is evaluated by comparison to electric propulsion options for the Saturn Orbiter Titan Probe (SOTP) and Uranus Flyby Uranus Probe (UFUP) missions.

Hydrogen Infrastructure Testing and Research Facility Animation | Hydrogen

Science.gov Websites

at full pressure. This system provides hydrogen to fill fuel cell forklifts and feeds the high pressure compressor. View Photos High Pressure Storage The high pressure hydrogen storage system consists full pressure. This system provides hydrogen to high pressure research projects and for fuel cell

Hydrogen Infrastructure Testing and Research Facility | Energy Systems

Science.gov Websites

hydrogen production through renewable electrolysis, fuel cell manufacturing and testing, high-pressure system provides hydrogen to fill fuel cell forklifts and feeds the high pressure compressor. View Photos High Pressure Storage The high pressure hydrogen storage system consists of four Type II hydrogen tanks

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

NASA Technical Reports Server (NTRS)

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.

TARA MARSHALL AND MIKE NICHOLS AT TEST STAND 4693

NASA Image and Video Library

2016-12-14

TARA MARSHALL, LEFT, A MARSHALL ENGINEER, TALKS ABOUT THE INSTALLATION OF A PRESSURIZATION CONTROL PANEL AT TEST STAND 4693 WITH MIKE NICHOLS, LEAD TEST ENGINEER FOR THE SPACE LAUNCH SYSTEM LIQUID HYDROGEN TANK STRUCTURAL TEST ARTICLE.

Chemical hydrogen storage material property guidelines for automotive applications

NASA Astrophysics Data System (ADS)

Semelsberger, Troy A.; Brooks, Kriston P.

2015-04-01

Chemical hydrogen storage is the sought after hydrogen storage media for automotive applications because of the expected low pressure operation (<20 atm), moderate temperature operation (<200 °C), system gravimetric capacities (>0.05 kg H2/kgsystem), and system volumetric capacities (>0.05 kg H2/Lsystem). Currently, the primary shortcomings of chemical hydrogen storage are regeneration efficiency, fuel cost and fuel phase (i.e., solid or slurry phase). Understanding the required material properties to meet the DOE Technical Targets for Onboard Hydrogen Storage Systems is a critical knowledge gap in the hydrogen storage research community. This study presents a set of fluid-phase chemical hydrogen storage material property guidelines for automotive applications meeting the 2017 DOE technical targets. Viable material properties were determined using a boiler-plate automotive system design. The fluid-phase chemical hydrogen storage media considered in this study were neat liquids, solutions, and non-settling homogeneous slurries. Material properties examined include kinetics, heats of reaction, fuel-cell impurities, gravimetric and volumetric hydrogen storage capacities, and regeneration efficiency. The material properties, although not exhaustive, are an essential first step in identifying viable chemical hydrogen storage material properties-and most important, their implications on system mass, system volume and system performance.

Hydrogen detection study. [for environmental control/life support systems

NASA Technical Reports Server (NTRS)

Shumar, J. W.; Powell, J. D.

1974-01-01

The effectiveness was assessed of a hydrogen (H2) detection concept for regenerative environmental control life support systems (EC/LSS). The concept evaluated was that utilized for the electrochemical depolarized concentrator (EDC) design, constructed, and tested for the EC/LSS space station prototype program. The EDC contains combustible gas detectors (CGDs) which were evaluated with H2. The CGDs were evaluated for linearity, position sensitivity, reproducibility, ambient effects, repeatability, speed of response, recovery time, and interchangeability. The effectiveness of CGDs located within the EDC for sensing H2 leaks at various line replaceable units in the subsystem was determined. The effects of H2 leak rate, H2 concentration of leaking gas and air currents in the vicinity of the EDC were determined. Proposed improvements for the H2 detection concept were documented and alternative H2 detection approaches were identified and analyzed.

Development of the HyStEP Device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Terry A.; Ainscough, Christopher; Terlip, Danny

2016-04-05

With the introduction of more fuel cell electric vehicles (FCEVs) on U.S. roadways, especially in California, the need for available hydrogen refueling stations is growing. While funding from the California Energy Commission is helping to solve this problem, solutions need to be developed and implemented to help reduce the time to commission a hydrogen station. The current practice of hydrogen station acceptance can take months because each vehicle manufacturer conducts their own testing and evaluation. This process is not practical or sufficient to support the timely development of a hydrogen fueling station network. To address this issue, as part ofmore » the Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) Project Sandia National Laboratories and the National Renewable Energy Laboratory along with a team of stakeholders and contractor Powertech Labs has developed the Hydrogen Station Equipment Performance (HyStEP) Device. The HyStEP Device is intended to be a surrogate for FCEVs that can be used to collect data on hydrogen station fueling performance. The device includes three Type IV 70 MPa tanks capable of storing a total of 9 kg H2 that are instrumented with pressure and temperature sensors. The tanks can be used individually or in parallel to simulate small, medium, and large fuel systems. The tanks are connected to a 70 MPa receptacle equipped with pressure and temperature sensor as well as infrared communications integrated with a data acquisition, analysis, and control system. The HyStEP Device is capable of performing tests defined in the test method standard CSA HGV 4.3 and providing the data needed to ensure that hydrogen stations meet the fueling protocol standard SAE J2601-2014. These include IrDA communication tests, fault detection tests, and communication and non-communication fueling.« less

Experimental study of catalytic hydrogenation by using an in-situ hydrogen measuring technique. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiang, S.H.; Klinzing, G.E.; Cheng, Y.S.

1984-12-01

An in-situ technique for measuring hydrogen concentration (partial pressure) had been previously used to measure static properties (hydrogen solubilities, vapor pressures of hydrocarbons, etc.). Because of its good precision (2% relative error) and relatively short respond time (9.7 to 2.0 seconds at 589 to 728K), the technique was successfully applied to a dynamic study of hydrogenation reactions in this work. Furthermore, the technique is to be tested for industrial uses. Hydrogen/1-methylnaphthalene system was experimentally investigated in a one-liter autoclave equipped with a magnetically driven stirrer and temperature controlling devices. Catalytic hydrogenation of 1-methylnaphthalene was studied in the presence of sulfidedmore » Co-Mo-Al2O3 catalyst. In addition, the vapor/liquid equilibrium relationship was determined by using this technique. Hydrogenation reaction runs were performed at temperatures of 644.1, 658.0 and 672.0K and pressures up to 9.0 MPa. The ring hydrogenation, resulting in 1- and 5-methyltetralin, was found to be the dominant reaction. This is in agreement with cited literature. Effects of hydrogen partial pressure, operating temperature, as well as presulfided catalyst are also investigated and discussed in this work. The vapor pressure of 1-methylnaphthalene was measured over a temperature range of 555.2 to 672.0K. The results are in good agreement with literature data. Measurements for hydrogen solubility in 1-methylnaphthalene were conducted over temperature and pressure range of 598 to 670K and 5.2 to 8.8 MPa, respectively. Similar to previously reported results, the hydrogen solubility increases with increasing temperature when total pressure is held constant. A linear relation is found between the hydrogen solubility and hydrogen partial pressure. 21 refs., 13 figs., 10 tabs.« less

Cooling by Para-to-Ortho-Hydrogen Conversion

NASA Technical Reports Server (NTRS)

Sherman, A.; Nast, T.

1983-01-01

Catalyst speeds conversion, increasing capacity of solid hydrogen cooling system. In radial-flow catalytic converter, para-hydrogen is converted to equilibrium mixture of para-hydrogen and ortho-hydrogen as it passes through porous cylinder of catalyst. Addition of catalyst increases capacity of hydrogen sublimation cooling systems for radiation detectors.

LH2 tank pressure control by thermodynamic vent system (TVS) at zero gravity

NASA Astrophysics Data System (ADS)

Wang, B.; Huang, Y. H.; Chen, Z. C.; Wu, J. Y.; Li, P.; Sun, P. J.

2017-02-01

Thermodynamic vent system (TVS) is employed for pressure control of propellant tanks at zero gravity. An analytical lumped parameter model is developed to predict pressure variation in an 18.09 m3 liquid hydrogen tank equipped with TVS. Mathematical simulations are carried out assuming tank is filled up to 75% volume (liquid mass equals to 945 kg) and is subjected to heat flux of 0.76 W/m2. Tank pressure controls at 165.5-172.4, 165.5-179.3 and 165.5-182.2 kPa are compared with reference to number of vent cycles, vent duration per cycle and loss of hydrogen. Analysis results indicate that the number of vent cycles significantly decreases from 62 to 21 when tank pressure control increases from 6.9 to 20.4 kPa. Also, duration of vent cycle increases from 63 to 152 and cycle duration decreases from 3920 to 3200 s. Further, the analysis result suggests that LH2 evaporation loss per day decreases from 0.17 to 0.14%. Based on the results of analysis, TVS is found effective in controlling the propellant tank pressure in zero gravity.

Zero boil-off methods for large-scale liquid hydrogen tanks using integrated refrigeration and storage

NASA Astrophysics Data System (ADS)

Notardonato, W. U.; Swanger, A. M.; E Fesmire, J.; Jumper, K. M.; Johnson, W. L.; Tomsik, T. M.

2017-12-01

NASA has completed a series of tests at the Kennedy Space Center to demonstrate the capability of using integrated refrigeration and storage (IRAS) to remove energy from a liquid hydrogen (LH2) tank and control the state of the propellant. A primary test objective was the keeping and storing of the liquid in a zero boil-off state, so that the total heat leak entering the tank is removed by a cryogenic refrigerator with an internal heat exchanger. The LH2 is therefore stored and kept with zero losses for an indefinite period of time. The LH2 tank is a horizontal cylindrical geometry with a vacuum-jacketed, multilayer insulation system and a capacity of 125,000 liters. The closed-loop helium refrigeration system was a Linde LR1620 capable of 390W cooling at 20K (without any liquid nitrogen pre-cooling). Three different control methods were used to obtain zero boil-off: temperature control of the helium refrigerant, refrigerator control using the tank pressure sensor, and duty cycling (on/off) of the refrigerator as needed. Summarized are the IRAS design approach, zero boil-off control methods, and results of the series of zero boil-off tests.

Zero Boil-Off Methods for Large Scale Liquid Hydrogen Tanks Using Integrated Refrigeration and Storage

NASA Technical Reports Server (NTRS)

Notardonato, W. U.; Swanger, A. M.; Fesmire, J. E.; Jumper, K. M.; Johnson, W. L.; Tomsik, T. M.

2017-01-01

NASA has completed a series of tests at the Kennedy Space Center to demonstrate the capability of using integrated refrigeration and storage (IRAS) to remove energy from a liquid hydrogen (LH2) tank and control the state of the propellant. A primary test objective was the keeping and storing of the liquid in a zero boil-off state, so that the total heat leak entering the tank is removed by a cryogenic refrigerator with an internal heat exchanger. The LH2 is therefore stored and kept with zero losses for an indefinite period of time. The LH2 tank is a horizontal cylindrical geometry with a vacuum-jacketed, multi-layer insulation system and a capacity of 125,000 liters. The closed-loop helium refrigeration system was a Linde LR1620 capable of 390W cooling at 20K (without any liquid nitrogen pre-cooling). Three different control methods were used to obtain zero boil-off: temperature control of the helium refrigerant, refrigerator control using the tank pressure sensor, and duty cycling (on/off) of the refrigerator as needed. Summarized are the IRAS design approach, zero boil-off control methods, and results of the series of zero boil-off tests.

Auxiliary propulsion technology for advanced Earth-to-orbit vehicles

NASA Technical Reports Server (NTRS)

Schneider, Steven J.

1987-01-01

The payload which can be delivered to orbit by advanced Earth-to-Orbit vehicles is significantly increased by advanced subsystem technology. Any weight which can be saved by advanced subsystem design can be converted to payload at Main Engine Cut Off (MECO) given the same launch vehicle performance. The auxiliary propulsion subsystem and the impetus for the current hydrogen/oxygen technology program is examined. A review of the auxiliary propulsion requirements of advanced Earth-to-Orbit (ETO) vehicles and their proposed missions is given first. Then the performance benefits of hydrogen/oxygen auxiliary propulsion are illustrated using current shuttle data. The proposed auxiliary propulsion subsystem implementation includes liquid hydrogen/liquid oxygen (LH2/LO2) primary Reaction Control System (RCS) engines and gaseous hydrogen/gaseous oxygen (GH2/GO2) vernier RCS engines. A distribution system for the liquid cryogens to the engines is outlined. The possibility of providing one dual-phase engine that can operate on either liquid or gaseous propellants is being explored, as well as the simultaneous firing of redundant primary RCS thrusters to provide Orbital Maneuvering System (OMS) level impulse. Scavenging of propellants from integral main engine tankage is proposed to utilize main engine tank residuals and to combine launch vehicle and subsystem reserves.

Importance of analytically verifying chemical treatments

USGS Publications Warehouse

Rach, J.J.; Gaikowski, M.P.; Olson, J.J.

1997-01-01

Hydrogen peroxide is considered a low regulatory priority compound by the U.S. Food and Drug Administration. It is used to control fungal infections on fish eggs. We studied the treatment profiles of hydrogen peroxide in Heath, McDonald egg jar, and Clark-Williamson incubators during treatments intended to deliver an effective regimen of at least 500 ??L hydrogen peroxide/L (i.e., treatments of 500 and 1,000 ??L/L) for 15 min. Hydrogen peroxide concentrations decreased with increasing distance from the influent water in both Heath and Clark-Williamson incubators. The top treatment tray (tray 2) of the Heath incubator received more than 90% of the intended regimen during the 500 ??L/L treatment, whereas at 1,000 ??L/L, all trays had hydrogen peroxide concentrations at or above 500 ??L/L for 15 min. None of the compartments in the Clark-Williamson incubator received the intended therapeutic regimen when treated at 500 ??L/L. The McDonald egg jar system distributed the intended concentration for the designated treatment period in all jars, except those located directly below the influent water. Our results indicate that dilution of therapeutants applied through certain egg incubation systems significantly decreases the efficacy of treatments and may render them ineffective. The dilution characteristics of egg incubation systems should be assessed in order to ensure proper delivery of all intended chemical concentrations and exposure regimens. Suggestions for maintaining the minimum effective concentrations in evaluated incubators are included.

Physics Simulation Software for Autonomous Propellant Loading and Gas House Autonomous System Monitoring

NASA Technical Reports Server (NTRS)

Regalado Reyes, Bjorn Constant

2015-01-01

1. Kennedy Space Center (KSC) is developing a mobile launching system with autonomous propellant loading capabilities for liquid-fueled rockets. An autonomous system will be responsible for monitoring and controlling the storage, loading and transferring of cryogenic propellants. The Physics Simulation Software will reproduce the sensor data seen during the delivery of cryogenic fluids including valve positions, pressures, temperatures and flow rates. The simulator will provide insight into the functionality of the propellant systems and demonstrate the effects of potential faults. This will provide verification of the communications protocols and the autonomous system control. 2. The High Pressure Gas Facility (HPGF) stores and distributes hydrogen, nitrogen, helium and high pressure air. The hydrogen and nitrogen are stored in cryogenic liquid state. The cryogenic fluids pose several hazards to operators and the storage and transfer equipment. Constant monitoring of pressures, temperatures and flow rates are required in order to maintain the safety of personnel and equipment during the handling and storage of these commodities. The Gas House Autonomous System Monitoring software will be responsible for constantly observing and recording sensor data, identifying and predicting faults and relaying hazard and operational information to the operators.

Effect of the self-pumped limiter concept on the tritium fuel cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finn, P.A.; Sze, D.K.; Hassanein, A.

1988-01-01

The self-pumped limiter concept for impurity control of the plasma of a fusion reactor has a major impact on the design of the tritium systems. To achieve a sustained burn, conventional limiters and divertors remove large quantities of unburnt tritium and deuterium from the plasma which must be then recycled using a plasma processing system. The self-pumped limiter which does not remove the hydrogen species, does not require any plasma processing equipment. The blanket system and the coolant processing systems acquire greater importance with the use of this unconventional impurity control system. 3 refs., 2 figs.

Hydrogen Research for Spaceport and Space-Based Applications: Hydrogen Production, Storage, and Transport. Part 3

NASA Technical Reports Server (NTRS)

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. Hydrogen storage and in-space hydrogen transport research focused on developing and verifying design concepts for efficient, safe, lightweight liquid hydrogen cryogenic storage systems. Research into hydrogen production had a specific goal of further advancing proton conducting membrane technology in the laboratory at a larger scale. System and process trade studies evaluated the proton conducting membrane technology, specifically, scale-up issues.

Nanostructured materials for hydrogen storage

DOEpatents

Williamson, Andrew J.; Reboredo, Fernando A.

2007-12-04

A system for hydrogen storage comprising a porous nano-structured material with hydrogen absorbed on the surfaces of the porous nano-structured material. The system of hydrogen storage comprises absorbing hydrogen on the surfaces of a porous nano-structured semiconductor material.

Nonequilibrium phase coexistence and criticality near the second explosion limit of hydrogen combustion

NASA Astrophysics Data System (ADS)

Newcomb, Lucas B.; Alaghemandi, Mohammad; Green, Jason R.

2017-07-01

While hydrogen is a promising source of clean energy, the safety and optimization of hydrogen technologies rely on controlling ignition through explosion limits: pressure-temperature boundaries separating explosive behavior from comparatively slow burning. Here, we show that the emergent nonequilibrium chemistry of combustible mixtures can exhibit the quantitative features of a phase transition. With stochastic simulations of the chemical kinetics for a model mechanism of hydrogen combustion, we show that the boundaries marking explosive domains of kinetic behavior are nonequilibrium critical points. Near the pressure of the second explosion limit, these critical points terminate the transient coexistence of dynamical phases—one that autoignites and another that progresses slowly. Below the critical point temperature, the chemistry of these phases is indistinguishable. In the large system limit, the pseudo-critical temperature converges to the temperature of the second explosion limit derived from mass-action kinetics.

Efficient direct solar-to-hydrogen conversion by in situ interface transformation of a tandem structure

NASA Astrophysics Data System (ADS)

May, Matthias M.; Lewerenz, Hans-Joachim; Lackner, David; Dimroth, Frank; Hannappel, Thomas

2015-09-01

Photosynthesis is nature's route to convert intermittent solar irradiation into storable energy, while its use for an industrial energy supply is impaired by low efficiency. Artificial photosynthesis provides a promising alternative for efficient robust carbon-neutral renewable energy generation. The approach of direct hydrogen generation by photoelectrochemical water splitting utilizes customized tandem absorber structures to mimic the Z-scheme of natural photosynthesis. Here a combined chemical surface transformation of a tandem structure and catalyst deposition at ambient temperature yields photocurrents approaching the theoretical limit of the absorber and results in a solar-to-hydrogen efficiency of 14%. The potentiostatically assisted photoelectrode efficiency is 17%. Present benchmarks for integrated systems are clearly exceeded. Details of the in situ interface transformation, the electronic improvement and chemical passivation are presented. The surface functionalization procedure is widely applicable and can be precisely controlled, allowing further developments of high-efficiency robust hydrogen generators.

Design Concepts Studied for the Hydrogen On-Orbit Storage and Supply Experiment

NASA Technical Reports Server (NTRS)

Chato, David J.

1998-01-01

The NASA Lewis Research Center, in conjunction with the Utah State University Space Dynamics Laboratory, studied concepts for the Hydrogen On-Orbit Storage and Supply Experiment (HOSS). HOSS is a space flight experiment whose objectives are (1) to show stable gas supply for solar-thermal thruster designs by using both storage and direct-gain approaches and (2) to evaluate and compare the low-gravity performance of active and passive pressure control via a thermodynamic vent system (TVS) suitable for solar-thermal upper stages. This study showed that the necessary experimental equipment for HOSS can be accommodated in a small hydrogen Dewar (36 to 80 liter). Thermal designs can be achieved that meet the on-orbit storage requirements for these Dewars. Furthermore, ground hold insulation concepts are easily achieved that can store liquid hydrogen in these small Dewars for more than 144 hr without venting.

Efficient direct solar-to-hydrogen conversion by in situ interface transformation of a tandem structure

PubMed Central

May, Matthias M.; Lewerenz, Hans-Joachim; Lackner, David; Dimroth, Frank; Hannappel, Thomas

2015-01-01

Photosynthesis is nature's route to convert intermittent solar irradiation into storable energy, while its use for an industrial energy supply is impaired by low efficiency. Artificial photosynthesis provides a promising alternative for efficient robust carbon-neutral renewable energy generation. The approach of direct hydrogen generation by photoelectrochemical water splitting utilizes customized tandem absorber structures to mimic the Z-scheme of natural photosynthesis. Here a combined chemical surface transformation of a tandem structure and catalyst deposition at ambient temperature yields photocurrents approaching the theoretical limit of the absorber and results in a solar-to-hydrogen efficiency of 14%. The potentiostatically assisted photoelectrode efficiency is 17%. Present benchmarks for integrated systems are clearly exceeded. Details of the in situ interface transformation, the electronic improvement and chemical passivation are presented. The surface functionalization procedure is widely applicable and can be precisely controlled, allowing further developments of high-efficiency robust hydrogen generators. PMID:26369620

Hydrogen separation process

DOEpatents

Mundschau, Michael [Longmont, CO; Xie, Xiaobing [Foster City, CA; Evenson, IV, Carl; Grimmer, Paul [Longmont, CO; Wright, Harold [Longmont, CO

2011-05-24

A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

Efficacy of Intravenous Cobinamide Versus Hydroxocobalamin or Control for Treatment of Severe Hydrogen Sulfide Toxicity in a Swine

DTIC Science & Technology

2016-05-18

Hydroxocobalamin or Control for Treatment of Severe Hydrogen Sulfide Toxicity In A Swine presented at/published to SURF Conference, San Antonio, TX 20 May 2016...approval.) Intravenous versus intramuscular cobinamide compared to intravenous sal ine (control) in the treatment of acute, survivable, hydrogen ...severe hydrogen sulfide toxici ty in a swine (Sus Sci 7. FUNDING RECEIVED FOR THIS STUDY? IZJ YES 0 NO FUNDING SOURCE:59th CRD O&M Funds 8. DO YOU NEED

Activity of a dry mist hydrogen peroxide system against environmental Clostridium difficile contamination in elderly care wards.

PubMed

Shapey, S; Machin, K; Levi, K; Boswell, T C

2008-10-01

Clostridium difficile causes serious healthcare-associated infections. Infection control is difficult, due in part to environmental contamination with C. difficile spores. These spores are relatively resistant to cleaning and disinfection. The activity of a dry mist hydrogen peroxide decontamination system (Sterinis) against environmental C. difficile contamination was assessed in three elderly care wards. Initial sampling for C. difficile was performed in 16 rooms across a variety of wards and specialties, using Brazier's CCEY (cycloserine-cefoxitin-egg yolk) agar. Ten rooms for elderly patients (eight isolation and two sluice rooms) were then resampled following dry mist hydrogen peroxide decontamination. Representative isolates of C. difficile were typed by polymerase chain reaction ribotyping. C. difficile was recovered from 3%, 11% and 26% of samples from low, medium and high risk rooms, respectively. In 10 high risk elderly care rooms, 24% (48/203) of samples were positive for C. difficile, with a mean of 6.8 colony-forming units (cfu) per 10 samples prior to hydrogen peroxide decontamination. Ribotyping identified the presence of the three main UK epidemic strains (ribotypes 001, 027 and 106) and four rooms contained mixed strains. After a single cycle of hydrogen peroxide decontamination, only 3% (7/203) of samples were positive (P<0.001), with a mean of 0.4 cfu per 10 samples ( approximately 94% reduction). The Sterinis hydrogen peroxide system significantly reduced the extent of environmental contamination with C. difficile in these elderly care rooms. This relatively quick and user-friendly technology might be a more reliable method of terminally disinfecting isolation rooms, following detergent cleaning, compared to the manual application of other disinfectants.

Hydrous pyrolysis of polycyclic aromatic hydrocarbons and implications for the origin of PAH in hydrothermal petroleum

NASA Technical Reports Server (NTRS)

McCollom, T. M.; Simoneit, B. R.; Shock, E. L.

1999-01-01

Polycyclic aromatic hydrocarbons (PAH) are found at high concentrations in thermally altered organic matter and hydrothermally generated petroleum from sediment-covered seafloor hydro-thermal systems. To better understand the factors controlling the occurrence of PAH in thermally altered environments, the reactivities of two PAH, phenanthrene and anthracene, were investigated in hydrothermal experiments. The compounds were heated with water at 330 degrees C in sealed reaction vessels for durations ranging from 1 to 17 days. Iron oxide and sulfide minerals, formic acid, or sodium for-mate were included in some experiments to vary conditions within the reaction vessel. Phenanthrene was unreactive both in water alone and in the presence of minerals for up to 17 days, while anthracene was partially hydrogenated (5-10%) to di- and tetrahydroanthracene. In the presence of 6-21 vol % formic acid, both phenanthrene and anthracene reacted extensively to form hydrogenated and minor methylated derivatives, with the degree of hydrogenation and methylation increasing with the amount of formic acid. Phenanthrene was slightly hydrogenated in sodium formate solutions. The hydrogenation reactions could be readily reversed; heating a mixture of polysaturated phenanthrenes resulted in extensive dehydrogenation (aromatization) after 3 days at 330 degrees C. While the experiments demonstrate that reaction pathways for the hydrogenation of PAH under hydrothermal conditions exist, the reactions apparently require higher concentrations of H2 than are typical of geologic settings. The experiments provide additional evidence that PAH may be generated in hydrothermal systems from progressive aromatization and dealkylation of biologically derived polycyclic precursors such as steroids and terpenoids. Furthermore, the results indicate that PAH initially present in sediments or formed within hydrothermal systems are resistant to further thermal degradation during hydrothermal alteration.

Cryogenic On-Orbit Liquid Depot Storage, Acquisition, and Transfer Satellite (COLD-SAT)

NASA Technical Reports Server (NTRS)

Schuster, John R.; Russ, Edwin J.; Wachter, Joseph P.

1990-01-01

The Cryogenic On-Orbit Liquid Depot Storage, Acquisition, and Transfer Satellite (COLD-SAT) will perform subcritical liquid hydrogen handling experiments under low gravity conditions to provide engineering data for future space transportation missions. Comprising the four Class 1 enabling experiments are tank press control, tank chilldown, tank no-vent fill, and liquid acquisition device fill/refill. The nine Class 2 enhancing experiments are tanker thermal performance, pressurization, low-gravity setting and outflow, liquid acquisition device performance, transfer line chilldown, outflow subcooling, low-gravity vented fill, fluid dumping, and advanced instrumentation. Consisting of an experiment module mated to a spacecraft bus, COLD-SAT will be placed in an initial 1300 km circular orbit by an Atlas commercial launch vehicle, and will perform experiments in a semi-autonomous mode for a period of up to six months. The three-axis controlled spacecraft bus provides electric power, control and data management, communications, and attitude control along with propulsive acceleration levels ranging from 10(exp -6) to 10(exp -4) g. It is desired to understand the effects that low acceleration levels might have on the heat and mass transfer processes involved in some of the experiments. The experiment module contains the three liquid hydrogen tanks, valves, pressurization and pumping equipment, and instrumentation. Within the highly insulated tanks are specialized fluid management equipment that might be used in future space transportation systems. At launch all the liquid hydrogen for the experiments is contained in the largest tank, which has helium-purged insulation to prevent cryo-pumping of air on the launch pad. The tank is loaded by the hydrogen tanking system used for the Centaur upper stage of the Atlas. After reaching orbit the two smaller tanks become receivers for fluid transfers, and when tanked, become the vessels for performing many of the experiments.

The 1982 Goddard Space Flight Center Battery Workshop

NASA Technical Reports Server (NTRS)

Halpert, G. (Editor)

1983-01-01

Various topics concerned with advanced battery technology are addressed including lithium cell and battery safety developments, mathematical modelling, charge control of aerospace power systems, and the application of nickel hydrogen cells/batteries vis-a-vis nickel cadmium cells/batteries.

Hydrogen inhibits cytotrophoblast cells apoptosis in hypertensive disorders complicating pregnancy.

PubMed

Guo, L; Guan, Z; Li, H; Yang, X

2016-05-30

Hypertensive disorders complicating pregnancy (HDCP) is one of the most serious medical disorders during pregnancy. Hydrogen is a therapeutic antioxidant and used to treat HDCP effectively. However, the molecular mechanism about the effect of hydrogen on HDCP still remains unclear. In this study, we found ROS content in HDCP group was significantly higher than that in the control and was reduced markedly in the presence of 100μmol/L hydrogen. IL6, Caspase3, Bax1, P-JAK2, P-Stat3 and P-p38 expression was much higher than the control, and was notably decreasedby the application of 100μmol/L hydrogen. Bcl2 expression in HDCP group was notably lower than the control and was increased by 100 μmol/L hydrogen. The apoptosis rate of cytotrophoblast cells was decreased, andratio of cytotrophoblast cells at G1 and G2 phase was increased and decreased by hydrogen, respectively. All those data indicated a potential molecular mechanism of hydrogen-mediated treatment in HDCP.

Innovative Airbreathing Propulsion Concepts for Access to Space

NASA Technical Reports Server (NTRS)

Whitlow, Jr., Woodrow; Blech, Richard A.; Blankson, Isaiah M.

2001-01-01

This paper will present technologies and concepts for novel aeropropulsion systems. These technologies will enhance the safety of operations, reduce life cycle costs, and contribute to reduced costs of air travel and access to space. One of the goals of the NASA program is to reduce the carbon-dioxide emissions of aircraft engines. Engine concepts that use highly efficient fuel cell/electric drive technologies in hydrogen-fueled engines will be presented in the proposed paper. Carbon-dioxide emissions will be eliminated by replacing hydrocarbon fuel with hydrogen, and reduce NOx emissions through better combustion process control. A revolutionary exoskeletal engine concept, in which the engine drum is rotated, will be shown. This concept has the potential to allow a propulsion system that can be used for subsonic through hypersonic flight. Dual fan concepts that have ultra-high bypass ratios, low noise, and low drag will be presented. Flow-controlled turbofans and control-configured turbofans also will be discussed. To increase efficiency, a system of microengines distributed along lifting surfaces and on the fuselage is being investigated. This concept will be presented in the paper. Small propulsion systems for affordable, safe personal transportation vehicles will be discussed. These low-oil/oilless systems use technologies that enable significant cost and weight reductions. Pulse detonation engine-based hybrid-cycle and combined-cycle propulsion systems for aviation and space access will be presented.

Energy Systems Integration Laboratory | Energy Systems Integration Facility

Science.gov Websites

systems test hub includes a Class 1, Division 2 space for performing tests of high-pressure hydrogen Laboratory offers the following capabilities. High-Pressure Hydrogen Systems The high-pressure hydrogen infrastructure. Key Infrastructure Robotic arm; high-pressure hydrogen; natural gas supply; standalone SCADA

Slush Hydrogen Technology Program

NASA Technical Reports Server (NTRS)

Cady, Edwin C.

1994-01-01

A slush hydrogen (SH2) technology facility (STF) was designed, fabricated, and assembled by a contractor team of McDonnell Douglas Aerospace (MDA), Martin Marietta Aerospace Group (MMAG), and Air Products and Chemicals, Inc. (APCI). The STF consists of a slush generator which uses the freeze-thaw production process, a vacuum subsystem, a test tank which simulates the NASP vehicle, a triple point hydrogen receiver tank, a transfer subsystem, a sample bottle, a pressurization system, and a complete instrumentation and control subsystem. The STF was fabricated, checked-out, and made ready for testing under this contract. The actual SH2 testing was performed under the NASP consortium following NASP teaming. Pre-STF testing verified SH2 production methods, validated special SH2 instrumentation, and performed limited SH2 pressurization and expulsion tests which demonstrated the need for gaseous helium pre-pressurized of SH2 to control pressure collapse. The STF represents cutting-edge technology development by an effective Government-Industry team under very tight cost and schedule constraints.

Catalytic dehydrogenation of amine borane complexes

NASA Technical Reports Server (NTRS)

Mohajeri, Nahid (Inventor); Tabatabaie-Raissi, Ali (Inventor)

2007-01-01

A method of generating hydrogen includes the steps of providing an amine borane (AB) complex, at least one hydrogen generation catalyst, and a solvent, and mixing these components. Hydrogen is generated. The hydrogen produced is high purity hydrogen suitable for PEM fuel cells. A hydrolytic in-situ hydrogen generator includes a first compartment that contains an amine borane (AB) complex, a second container including at least one hydrogen generation catalyst, wherein the first or second compartment includes water or other hydroxyl group containing solvent. A connecting network permits mixing contents in the first compartment with contents in the second compartment, wherein high purity hydrogen is generated upon mixing. At least one flow controller is provided for controlling a flow rate of the catalyst or AB complex.

Catalytic dehydrogenation of amine borane complexes

NASA Technical Reports Server (NTRS)

Tabatabaie-Raissi, Ali (Inventor); Mohajeri, Nahid (Inventor); Bokerman, Gary (Inventor)

2009-01-01

A method of generating hydrogen includes the steps of providing an amine borane (AB) complex, at least one hydrogen generation catalyst, and a solvent, and mixing these components Hydrogen is generated. The hydrogen produced is high purity hydrogen suitable for PEM fuel cells. A hydrolytic in-situ hydrogen generator includes a first compartment that contains an amine borane (AB) complex, a second container including at least one hydrogen generation catalyst, wherein the first or second compartment includes water or other hydroxyl group containing solvent. A connecting network permits mixing contents in the first compartment with contents in the second compartment, wherein high purity hydrogen is generated upon mixing. At least one flow controller is provided for controlling a flow rate of the catalyst or AB complex.

Diffusional interaction behavior of NSAIDs in lipid bilayer membrane using molecular dynamics (MD) simulation: Aspirin and Ibuprofen.

PubMed

Sodeifian, Gholamhossein; Razmimanesh, Fariba

2018-05-10

In this research, for the first time, molecular dynamics (MD) method was used to simulate aspirin and ibuprofen at various concentrations and in neutral and charged states. Effects of the concentration (dosage), charge state, and existence of an integral protein in the membrane on the diffusion rate of drug molecules into lipid bilayer membrane were investigated on 11 systems, for which the parameters indicating diffusion rate and those affecting the rate were evaluated. Considering the diffusion rate, a suitable score was assigned to each system, based on which, analysis of variance (ANOVA) was performed. By calculating the effect size of the indicative parameters and total scores, an optimum system with the highest diffusion rate was determined. Consequently, diffusion rate controlling parameters were obtained: the drug-water hydrogen bond in protein-free systems and protein-drug hydrogen bond in the systems containing protein.

Test of an orbiting hydrogen maser clock system using laser time transfer

NASA Technical Reports Server (NTRS)

Vessot, Robert F. C.; Mattison, Edward M.; Nystrom, G. U.; Decher, Rudolph

1992-01-01

We describe a joint Smithsonian Astrophysical Laboratory/National Aeronautics and Space Administration (SAO/NASA) program for flight testing a atomic hydrogen maser clock system designed for long-term operation in space. The clock system will be carried by a shuttle-launched EURECA spacecraft. Comparisons with earth clocks to measure the clock's long-term frequency stability (tau = 10(exp 4) seconds) will be made using laser time transfer from existing NASA laser tracking stations. We describe the design of the maser clock and its control systems, and the laser timing technique. We describe the precision of station time synchronization and the limitations in the comparison between the earth and space time scales owing to gravitational and relativistic effects. We will explore the implications of determining the spacecraft's location by an on-board Global Position System (GPS) receiver, and of using microwave techniques for time and frequency transfer.

Design progress of cryogenic hydrogen system for China Spallation Neutron Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G. P.; Zhang, Y.; Xiao, J.

2014-01-29

China Spallation Neutron Source (CSNS) is a large proton accelerator research facility with 100 kW beam power. Construction started in October 2011 and is expected to last 6.5 years. The cryogenic hydrogen circulation is cooled by a helium refrigerator with cooling capacity of 2200 W at 20 K and provides supercritical hydrogen to neutron moderating system. Important progresses of CSNS cryogenic system were concluded as follows. Firstly, process design of cryogenic system has been completed including helium refrigerator, hydrogen loop, gas distribution, and safety interlock. Secondly, an accumulator prototype was designed to mitigate pressure fluctuation caused by dynamic heat loadmore » from neutron moderation. Performance test of the accumulator has been carried out at room and liquid nitrogen temperature. Results show the accumulator with welding bellows regulates hydrogen pressure well. Parameters of key equipment have been identified. The contract for the helium refrigerator has been signed. Mechanical design of the hydrogen cold box has been completed, and the hydrogen pump, ortho-para hydrogen convertor, helium-hydrogen heat exchanger, hydrogen heater, and cryogenic valves are in procurement. Finally, Hydrogen safety interlock has been finished as well, including the logic of gas distribution, vacuum, hydrogen leakage and ventilation. Generally, design and construction of CSNS cryogenic system is conducted as expected.« less

Solar-hydrogen energy system for Pakistan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lutfi, N.

1990-01-01

A solar-hydrogen energy system has been proposed for Pakistan as the best replacement for the present fossil fuel based energy system. It has been suggested to produce hydrogen via photovoltaic-electrolysis, utilizing the available non-agricultural sunny terrain in Baluchistan region. There will be a desalination plant for sea water desalination. The area under the photovoltaic panels with the availability of water would provide suitable environment for growing some cash crops. This would change the cast useless desert land into green productive farms. In order to show the quantitative benefits of the proposed system, future trends of important energy and economical parametersmore » have been studied with and without hydrogen introduction. The following parameters have been included: population, energy demand (fossil + hydrogen), energy production (fossil + hydrogen), gross national product, fossil energy imports, world energy prices, air pollution, quality of life, environmental savings due to hydrogen introduction, savings due to the higher utilization efficiency of hydrogen, by-product credit, agricultural income, income from hydrogen sale, photovoltaic cell area, total land area, water desalination plant capacity, capital investment, operating and maintenance cost, and total income from the system. The results indicate that adopting the solar-hydrogen energy system would eliminate the import dependency of fossil fuels, increase gross product per capita, reduce pollution, improve quality of life and establish a permanent and clean energy system. The total annual expenditure on the proposed system is less than the total income from the proposed system. The availability of water, the cash crop production, electricity and hydrogen would result in rapid development of Baluchistan, the largest province of Pakistan.« less

Phase-controlled synthesis of polymorphic tungsten diphosphide with hybridization of monoclinic and orthorhombic phases as a novel electrocatalyst for efficient hydrogen evolution

NASA Astrophysics Data System (ADS)

Pi, Mingyu; Wu, Tianli; Guo, Weimeng; Wang, Xiaodeng; Zhang, Dingke; Wang, Shuxia; Chen, Shijian

2017-05-01

The design and development of high-efficiency and non-noble-metal hydrogen evolution reaction (HER) electrocatalysts for future clean and renewable energy system has excited significant research interests over the recent years. In this communication, the polymorphic tungsten diphosphide (p-WP2) nanoparticles with mixed monoclinic (α-) and orthorhombic (β-) phases are synthesized by phase-controlled phosphidation route via vacuum capsulation and explored as a novel efficient electrocatalyst towards HER. The p-WP2 catalyst delivers superior performance with excellent stability under both acidic and alkaline conditions over its single phases of α-WP2 and β-WP2. This finding demonstrates that a highly efficient hybrid electrocatalyst can be achieved via precise composition controlling and may open up exciting opportunities for their practical applications toward energy conversion.

Analytical methods development for supramolecular design in solar hydrogen production

NASA Astrophysics Data System (ADS)

Brown, J. R.; Elvington, M.; Mongelli, M. T.; Zigler, D. F.; Brewer, K. J.

2006-08-01

In the investigation of alternative energy sources, specifically, solar hydrogen production from water, the ability to perform experiments with a consistent and reproducible light source is key to meaningful photochemistry. The design, construction, and evaluation of a series of LED array photolysis systems for high throughput photochemistry have been performed. Three array systems of increasing sophistication are evaluated using calorimetric measurements and potassium tris(oxalato)ferrate(II) chemical actinometry and compared with a traditional 1000 W Xe arc lamp source. The results are analyzed using descriptive statistics and analysis of variance (ANOVA). The third generation array is modular, and controllable in design. Furthermore, the third generation array system is shown to be comparable in both precision and photonic output to a 1000 W Xe arc lamp.

Apparatus for material tests using an internal loading system in high-pressure gas at room temperature.

PubMed

Imade, M; Fukuyama, S; Yokogawa, K

2008-07-01

A new type of apparatus for material tests using an internal loading system in high-pressure gas up to 100 MPa at room temperature without conventional material testing equipment was developed. The apparatus consists of a high-pressure control system and a pressure vessel, in which a piston is installed in the cylinder of the pressure vessel. The load caused by the pressure difference between spaces separated by the piston in the vessel cylinder is applied on the specimen connected to the piston in the vessel cylinder. The actual load on the specimen is directly measured by an external load cell and the displacement of the specimen is also measured by an external extensometer. As an example of the application of the apparatus, a tensile test on SUS316 stainless steel the Japanese Industrial Standard (JIS) G4303, which is comparable to the type 316 stainless steel ASTM A276, was conducted in 90 MPa hydrogen and argon. Hydrogen showed a marked effect on the tensile property of the material. The hydrogen gas embrittlement of the material was briefly discussed.

Apparatus for material tests using an internal loading system in high-pressure gas at room temperature

NASA Astrophysics Data System (ADS)

Imade, M.; Fukuyama, S.; Yokogawa, K.

2008-07-01

A new type of apparatus for material tests using an internal loading system in high-pressure gas up to 100MPa at room temperature without conventional material testing equipment was developed. The apparatus consists of a high-pressure control system and a pressure vessel, in which a piston is installed in the cylinder of the pressure vessel. The load caused by the pressure difference between spaces separated by the piston in the vessel cylinder is applied on the specimen connected to the piston in the vessel cylinder. The actual load on the specimen is directly measured by an external load cell and the displacement of the specimen is also measured by an external extensometer. As an example of the application of the apparatus, a tensile test on SUS316 stainless steel the Japanese Industrial Standard (JIS) G4303, which is comparable to the type 316 stainless steel ASTM A276, was conducted in 90MPa hydrogen and argon. Hydrogen showed a marked effect on the tensile property of the material. The hydrogen gas embrittlement of the material was briefly discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ewan, Mitch; Rocheleau, Richard; Swider-Lyons, Karen

The Hawai‘i Natural Energy Institute (HNEI) is conducting research to assess the technical potential of using an electrolyzer-based hydrogen (H2) production and storage system as a grid demand response tool using battery data from a 200 MW grid to show the kind of response required. The hydrogen produced by the electrolyzer is used for transportation. A 65 kg/day hydrogen energy system (HES) consisting of a PEM electrolyzer, 35 bar buffer tank, 450 bar compressor, and associated chiller systems was purchased and installed at the Hawaii Natural Energy Laboratory Hawaii Authority (NELHA) to demonstrate long-term durability of the electrolyzer under cyclicmore » operation required for frequency regulation on an island grid system. The excess hydrogen was stored for use by three fuel-cell buses to be operated at Hawai‘i Volcanoes National Park (HAVO) and by the County of Hawai‘i Mass Transit Agency (MTA). This paper describes the site selection and equipment commissioning, plus a comprehensive test plan that was developed to characterize the performance and durability of the electrolyzer under dynamic load conditions. The controls were modified for the operating envelope and dynamic limits of the electrolyzer. While the data showed these modifications significantly improved the system response time, it is not fast enough to match a BESS response time for grid frequency management. The electrolyzer can only be used for slower acting changes (1 to 0.5 Hz). A potential solution is to design an electrolyzer/BESS hybrid system and develop a modeling program to find the optimum mix of battery and electrolyzer to provide the maximum grid regulation services at minimum cost.« less

Bridging the Gap: From Model Surfaces to Nanoparticle Analogs for Selective Oxidation and Steam Reforming of Methanol and Selective Hydrogenation Catalysis

NASA Astrophysics Data System (ADS)

Boucher, Matthew B.

Most industrial catalysts are very complex, comprising of non-uniform materials with varying structures, impurities, and interaction between the active metal and supporting substrate. A large portion of the ongoing research in heterogeneous catalysis focuses on understanding structure-function relationships in catalytic materials. In parallel, there is a large area of surface science research focused on studying model catalytic systems for which structural parameters can be tuned and measured with high precision. It is commonly argued, however, that these systems are oversimplified, and that observations made in model systems do not translate to robust catalysts operating in practical environments; this discontinuity is often referred to as a "gap." The focus of this thesis is to explore the mutual benefits of surface science and catalysis, or "bridge the gap," by studying two catalytic systems in both ultra-high vacuum (UHV) and near ambient-environments. The first reaction is the catalytic steam reforming of methanol (SRM) to hydrogen and carbon dioxide. The SRM reaction is a promising route for on-demand hydrogen production. For this catalytic system, the central hypothesis in this thesis is that a balance between redox capability and weak binding of reaction intermediates is necessary for high SRM activity and selectivity to carbon dioxide. As such, a new catalyst for the SRM reaction is developed which incorporates very small amounts of gold (<1 atomic %) supported on zinc oxide nanoparticles with controlled crystal structures. The performance of these catalysts was studied in a fixed-bed micro-reactor system at ambient pressures, and their structure was characterized by high-resolution microscopic and spectroscopic techniques. Pre-existing oxygen defects in zinc oxide {0001} surfaces, and those created by a perturbation of the defect equilibrium by addition of gold, provide an anchoring site for highly dispersed gold species. By utilizing shape control of zinc oxide supports, it is found that highly dispersed gold, capable of low-temperature redox behavior is most prominent on zinc oxide {0001} surfaces and leads to high SRM activity and selectivity to carbon dioxide. Like other Group IB metal catalysts the SRM over gold-zinc oxide proceeds through the formation and weak binding of formaldehyde, and subsequent coupling with methoxy to produce methyl formate. Mechanistic clarification of this point was achieved by studying the interaction methanol-water mixtures with model catalyst surfaces. Model catalysts were studied in a UHV chamber where the base pressure was maintained at 10-10 mbar. High resolutions surface science techniques show that hydrogen-bonded networks of water are capable of deprotonating methanol to methoxy on low index surfaces in the absence of atomic oxygen. These UHV studies show that adsorbates, other than oxygen, are capable of activating methanol on Group IB metal surfaces. The second reaction involves the selective hydrogenation of alkynes to alkenes. Selective hydrogenations of carbon-carbon multiple bonds are important for a wide range of industrial processes. The governing hypothesis for this reaction system is that cooperation between a minority metal with a low barrier for hydrogen dissociation, and a less-reactive host metal capable of hydrogen uptake via spillover will lead to high alkene selectivity. A strategy for the preparation of such a catalyst is developed using model catalyst studied in a UHV chamber. The model catalyst features isolated palladium atoms in a copper(111) surface, termed single atom alloy (SAA). Individual, isolated palladium atoms act as sites for hydrogen uptake, dissociation, and spillover onto an otherwise inert copper(111) host. Weak binding offered by copper provides a surface where selective hydrogenation reactions can take place. Palladium-copper SAA model catalysts are highly selective to the partial hydrogenation of acetylene, whereas surfaces containing larger palladium ensembles facilitate complete hydrogenation and decomposition. Nanoparticle analogs of palladium-copper SAAs were prepared to investigate the feasibility of this strategy for practical application. Very small amounts of palladium (<0.2 atomic %) on the surface of copper nanoparticles are highly active and selective catalysts for the partial hydrogenation of phenylacetylene to styrene. The performance of these catalysts was studied in a liquid-phase, stirred-tank batch reactor under a hydrogen head pressure of approximately 7 bar. Palladium alloyed into the surface of otherwise inactive copper nanoparticles shows a marked improvement in selectivity when compared to monometallic palladium catalysts with the same metal loading. This effect is attributed hydrogen spillover onto the copper surface. In summary, the development of new, highly active and selective catalysts for the methanol steam reforming reaction and for the partial hydrogenation of alkynes to alkenes was accomplished by the use of state-of-the-art techniques in both surface science and heterogeneous catalysis. The implications of this work can be extended to a wide variety of catalytic systems.

A Hydrogen Leak Detection System for Aerospace and Commercial Applications

NASA Technical Reports Server (NTRS)

Hunter, Gary W.; Makel, D. B.; Jansa, E. D.; Patterson, G.; Cova, P. J.; Liu, C. C.; Wu, Q. H.; Powers, W. T.

1995-01-01

Leaks on the space shuttle while on the launch pad have generated interest in hydrogen leak monitoring technology. Microfabricated hydrogen sensors are being fabricated at Case Western Reserve University (CWRU) and tested at NASA Lewis Research Center (LeRC). These sensors have been integrated into hardware and software designed by Aerojet. This complete system allows for multipoint leak monitoring designed to provide leak source and magnitude information in real time. The monitoring system processes data from the hydrogen sensors and presents the operator with a visual indication of the leak location and magnitude. Although the leak monitoring system was designed for hydrogen propulsion systems, the possible applications of this monitoring system are wide ranged. This system is in operation in an automotive application which requires high sensitivity to hydrogen.

Light-activated regulation of cofilin dynamics using a photocaged hydrogen peroxide generator.

PubMed

Miller, Evan W; Taulet, Nicolas; Onak, Carl S; New, Elizabeth J; Lanselle, Julie K; Smelick, Gillian S; Chang, Christopher J

2010-12-08

Hydrogen peroxide (H2O2) can exert diverse signaling and stress responses within living systems depending on its spatial and temporal dynamics. Here we report a new small-molecule probe for producing H2O2 on demand upon photoactivation and its application for optical regulation of cofilin-actin rod formation in living cells. This chemical method offers many potential opportunities for dissecting biological roles for H2O2 as well as remote control of cell behavior via H2O2-mediated pathways.

Competitive Adsorption-Assisted Formation of One-Dimensional Cobalt Nanochains with High CO Hydrogenation Activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Xin; Ren, Zhibo; Zhu, Xiaolin

In the present work, cobalt nanochains have been successfully synthesized by a novel co assisted self-assembling formation strategy. A dramatic morphology transformation from cobalt nanoparticles to nanochains are observed when co molecules were introduced into the synthetic system. DFT calculations further confirm that competitive co-adsorbed co and oleylamine over the cobalt nanoparticles facilitates the formation of cobalt nanochains, which show higher co hydrogenation performance. The present work provides a new strategic and promising method for controllable synthesis of catalyst nanomaterials with the preferred surface structure and morphology.

Measuring Hydrogen Concentrations in Metals

NASA Technical Reports Server (NTRS)

Danford, M. D.

1985-01-01

Commercial corrosion-measurement system adapted to electrochemical determination of hydrogen concentrations in metals. New technique based on diffusion of hydrogen through foil specimen of metal. In sample holder, hydrogen produced on one side of foil, either by corrosion reaction or by cathodic current. Hydrogen diffused through foil removed on other side by constant anode potential, which leads to oxidation of hydrogen to water. Anode current is measure of concentration of hydrogen diffusing through foil. System used to study hydrogen uptake, hydrogen elimination by baking, effect of heat treatment, and effect of electroplating on high-strength steels.

A novel atmospheric tritium sampling system

NASA Astrophysics Data System (ADS)

Qin, Lailai; Xia, Zhenghai; Gu, Shaozhong; Zhang, Dongxun; Bao, Guangliang; Han, Xingbo; Ma, Yuhua; Deng, Ke; Liu, Jiayu; Zhang, Qin; Ma, Zhaowei; Yang, Guo; Liu, Wei; Liu, Guimin

2018-06-01

The health hazard of tritium is related to its chemical form. Sampling different chemical forms of tritium simultaneously becomes significant. Here a novel atmospheric tritium sampling system (TS-212) was developed to collect the tritiated water (HTO), tritiated hydrogen (HT) and tritiated methane (CH3T) simultaneously. It consisted of an air inlet system, three parallel connected sampling channels, a hydrogen supply module, a methane supply module and a remote control system. It worked at air flow rate of 1 L/min to 5 L/min, with temperature of catalyst furnace at 200 °C for HT sampling and 400 °C for CH3T sampling. Conversion rates of both HT and CH3T to HTO were larger than 99%. The collecting efficiency of the two-stage trap sets for HTO was larger than 96% in 12 h working-time without being blocked. Therefore, the collected efficiencies of TS-212 are larger than 95% for tritium with different chemical forms in environment. Besides, the remote control system made sampling more intelligent, reducing the operator's work intensity. Based on the performance parameters described above, the TS-212 can be used to sample atmospheric tritium in different chemical forms.

Advanced space engine powerhead breadboard assembly system study

NASA Technical Reports Server (NTRS)

Campbell, R. G.

1978-01-01

The objective of this study was to establish a preliminary design of a Powerhead Breadboard Assembly (PBA) for an 88 964-Newton (20,000-pound) thrust oxygen/hydrogen staged combustion cycle engine for use in orbital transfer vehicle propulsion. Existing turbopump, preburner, and thrust chamber components were integrated with interconnecting ducting, a heat exchanger, and a control system to complete the PBA design. Cycle studies were conducted to define starting transients and steady-state balances for the completed design. Specifications were developed for all valve applications and the conditions required for the control system integration with the facility for system test were defined.

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

NASA Astrophysics Data System (ADS)

Georgis, Dimitrios

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

Catalytic Hydrogenation and Hydrodeoxygenation of Furfural over Pt(111): A Model System for the Rational Design and Operation of Practical Biomass Conversion Catalysts.

PubMed

Taylor, Martin J; Jiang, Li; Reichert, Joachim; Papageorgiou, Anthoula C; Beaumont, Simon K; Wilson, Karen; Lee, Adam F; Barth, Johannes V; Kyriakou, Georgios

2017-04-20

Furfural is a key bioderived platform chemical whose reactivity under hydrogen atmospheres affords diverse chemical intermediates. Here, temperature-programmed reaction spectrometry and complementary scanning tunneling microscopy (STM) are employed to investigate furfural adsorption and reactivity over a Pt(111) model catalyst. Furfural decarbonylation to furan is highly sensitive to reaction conditions, in particular, surface crowding and associated changes in the adsorption geometry: furfural adopts a planar geometry on clean Pt(111) at low coverage, tilting at higher coverage to form a densely packed furfural adlayer. This switch in adsorption geometry strongly influences product selectivity. STM reveals the formation of hydrogen-bonded networks for planar furfural, which favor decarbonylation on clean Pt(111) and hydrogenolysis in the presence of coadsorbed hydrogen. Preadsorbed hydrogen promotes furfural hydrogenation to furfuryl alcohol and its subsequent hydrogenolysis to methyl furan, while suppressing residual surface carbon. Furfural chemistry over Pt is markedly different from that over Pd, with weaker adsorption over the former affording a simpler product distribution than the latter; Pd catalyzes a wider range of chemistry, including ring-opening to form propene. Insight into the role of molecular orientation in controlling product selectivity will guide the design and operation of more selective and stable Pt catalysts for furfural hydrogenation.

Catalytic Hydrogenation and Hydrodeoxygenation of Furfural over Pt(111): A Model System for the Rational Design and Operation of Practical Biomass Conversion Catalysts

PubMed Central

2017-01-01

Furfural is a key bioderived platform chemical whose reactivity under hydrogen atmospheres affords diverse chemical intermediates. Here, temperature-programmed reaction spectrometry and complementary scanning tunneling microscopy (STM) are employed to investigate furfural adsorption and reactivity over a Pt(111) model catalyst. Furfural decarbonylation to furan is highly sensitive to reaction conditions, in particular, surface crowding and associated changes in the adsorption geometry: furfural adopts a planar geometry on clean Pt(111) at low coverage, tilting at higher coverage to form a densely packed furfural adlayer. This switch in adsorption geometry strongly influences product selectivity. STM reveals the formation of hydrogen-bonded networks for planar furfural, which favor decarbonylation on clean Pt(111) and hydrogenolysis in the presence of coadsorbed hydrogen. Preadsorbed hydrogen promotes furfural hydrogenation to furfuryl alcohol and its subsequent hydrogenolysis to methyl furan, while suppressing residual surface carbon. Furfural chemistry over Pt is markedly different from that over Pd, with weaker adsorption over the former affording a simpler product distribution than the latter; Pd catalyzes a wider range of chemistry, including ring-opening to form propene. Insight into the role of molecular orientation in controlling product selectivity will guide the design and operation of more selective and stable Pt catalysts for furfural hydrogenation. PMID:29225721

Practical achievements on biomass steam gasification in a rotary tubular coiled-downdraft reactor.

PubMed

Andrew, Renny; Gokak, D T; Sharma, Pankaj; Gupta, Shalini

2016-12-01

Today, the impending stringent environmental norms and concerns about the depletion of fossil fuel reserves have added impetus on development of cutting edge technologies for production of alternative fuels from renewable sources, like biomass. The concept of biomass pyro-gasification offers a platform for production of (a) hydrogen, (b) hydrocarbons and (c) value added chemicals, etc. In this context, there exists potential for hydrogen production from biomass by superheated steam gasification. Apart from H 2 , gaseous products of biomass steam gasification contain CO, CH 4 and other hydrocarbons that can be converted to hydrogen through cracking, steam reforming and water gas shift reactions. In the present work, the characteristics of biomass steam gasification in an indigenously designed rotary tubular coiled-downdraft reactor for high value gaseous fuel production from rice husk was studied through a series of experiments. The robust reactor system enhances biomass conversion to gaseous products by improved mass and heat transfer within the system induced by a coiled flow pattern with increased heat transfer area. Also, the system has improved upon the reliability of operation and offered greater continuity of the process and easier control in comparison with a conventional process by making use of an innovative gas cooler assembly and efficient venturi-mixing system for biomass and steam. Subsequently, the effects of reactor temperature, steam-to-biomass ratio and residence time on overall product gas yield and hydrogen yield were investigated. From the experimental results, it can be deduced that an optimum reactor temperature of 750 °C, steam-to-biomass ratio of 2.0 and a residence time of 3.0 min contributed highest gas yield (1.252 Nm 3  kg -1 moisture-free biomass). Based on the obtained experimental results, a projected potential hydrogen yield of 8.6 wt% of the moisture-free biomass could be achieved, and is also practical for production of pure hydrogen. © The Author(s) 2016.

Process models vs empirical models

USDA-ARS?s Scientific Manuscript database

The dairy industry is rapidly expanding in the western and south-central U.S., with a trend towards larger, high-density, intensive production systems. Increased production intensity creates challenges for effective management of nutrients and control of emissions of ammonia, hydrogen sulfide, green...

Microscale Enhancement of Heat and Mass Transfer for Hydrogen Energy Storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drost, Kevin; Jovanovic, Goran; Paul, Brian

2015-09-30

The document summarized the technical progress associated with OSU’s involvement in the Hydrogen Storage Engineering Center of Excellence. OSU focused on the development of microscale enhancement technologies for improving heat and mass transfer in automotive hydrogen storage systems. OSU’s key contributions included the development of an extremely compact microchannel combustion system for discharging hydrogen storage systems and a thermal management system for adsorption based hydrogen storage using microchannel cooling (the Modular Adsorption Tank Insert or MATI).

Structural and kinetic studies of metal hydride hydrogen storage materials using thin film deposition and characterization techniques

NASA Astrophysics Data System (ADS)

Kelly, Stephen Thomas

Hydrogen makes an attractive energy carrier for many reasons. It is an abundant chemical fuel that can be produced from a wide variety of sources and stored for very long periods of time. When used in a fuel cell, hydrogen emits only water at the point of use, making it very attractive for mobile applications such as in an automobile. Metal hydrides are promising candidates for on-board reversible hydrogen storage in mobile applications due to their very high volumetric storage capacities---in most cases exceeding even that of liquid hydrogen. The United States Department of Energy (DOE) has set fuel system targets for an automotive hydrogen storage system, but as of yet no single material meets all the requirements. In particular, slow reaction kinetics and/or inappropriate thermodynamics plague many metal hydride hydrogen storage materials. In order to engineer a practical material that meets the DOE targets, we need a detailed understanding of the kinetic and thermodynamic properties of these materials during the phase change. In this work I employed sputter deposited thin films as a platform to study materials with highly controlled chemistry, microstructure and catalyst placement using thin film characterization techniques such as in situ x-ray diffraction (XRD) and neutron reflectivity. I observed kinetic limitations in the destabilized Mg2Si system due to the slow diffusion of the host Mg and Si atoms while forming separate MgH2 and Si phases. Conversely, I observed that the presence of Al in the Mg/Al system inhibits hydrogen diffusion while the host Mg and Al atoms interdiffuse readily, allowing the material to fall into a kinetic and/or thermodynamic trap by forming intermetallic compounds such as Mg17Al 12. By using in situ XRD to analyze epitaxial Mg films grown on (001) oriented Al2O3 substrates I observed hydride growth consistent with a model of a planar hydride layer growing into an existing metal layer. Subsequent film cycling changes the hydrogen absorption and desorption kinetics and degrades the material texture. Cycling the films to greater hydrogen loading accelerates the changes to the kinetics and material texture. In addition to in situ XRD experiments, in situ neutron reflectivity experiments on epitaxial Mg films exposed to hydrogen gas reveal details about the microstructural development of the growing hydride layer as the film absorbs and releases hydrogen. Small (10 wt%) additions of Ti to epitaxial Mg films during growth result in metastable solid solution films of Ti in Mg that deposit epitaxially on (001) Al2O3 substrates with epitaxy similar to the pure Mg films. These metastable alloy films absorb hydrogen faster than pure Mg films under identical conditions. Subsequent film cycling results in altered reaction kinetics and a transition to a different kinetic mechanism during desorption than for pure Mg films.

Glutathione-capped gold nanoclusters as photosensitizers. Visible light-induced hydrogen generation in neutral water.

PubMed

Chen, Yong-Siou; Kamat, Prashant V

2014-04-23

Glutathione-capped metal nanoclusters (Aux-GSH NCs) which exhibit molecular-like properties are employed as a photosensitizer for hydrogen generation in a photoelectrochemical cell (PEC) and a photocatalytic slurry reactor. The reversible reduction (E(0) = -0.63 V vs RHE) and oxidation (E(0) = 0.97 and 1.51 V vs RHE) potentials of these metal nanoclusters make them suitable for driving the water-splitting reaction. When a mesoscopic TiO2 film sensitized by Aux-GSH NCs is used as the photoanode with a Pt counter electrode in aqueous buffer solution (pH = 7), we observe significant photocurrent activity under visible light (400-500 nm) excitation. Additionally, sensitizing Pt/TiO2 nanoparticles with Aux-GSH NCs in an aqueous slurry system and irradiating with visible light produce H2 at a rate of 0.3 mmol of hydrogen/h/g of Aux-GSH NCs. The rate of H2 evolution is significantly enhanced (∼5 times) when a sacrificial donor, such as EDTA, is introduced into the system. Using metal nanoclusters as a photosensitizer for hydrogen generation lays the foundation for the future exploration of other metal nanoclusters with well-controlled numbers of metal atoms and capping ligands.

Tokamak experimental power reactor conceptual design. Volume II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1976-08-01

Volume II contains the following appendices: (1) summary of EPR design parameters, (2) impurity control, (3) plasma computational models, (4) structural support system, (5) materials considerations for the primary energy conversion system, (6) magnetics, (7) neutronics penetration analysis, (8) first wall stress analysis, (9) enrichment of isotopes of hydrogen by cryogenic distillation, and (10) noncircular plasma considerations. (MOW)

Bioengineering and Coordination of Regulatory Networks and Intracellular Complexes to Maximize Hydrogen Production by Phototrophic Microorganisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tabita, F. Robert

2013-07-30

In this study, the Principal Investigator, F.R. Tabita has teamed up with J. C. Liao from UCLA. This project's main goal is to manipulate regulatory networks in phototrophic bacteria to affect and maximize the production of large amounts of hydrogen gas under conditions where wild-type organisms are constrained by inherent regulatory mechanisms from allowing this to occur. Unrestrained production of hydrogen has been achieved and this will allow for the potential utilization of waste materials as a feed stock to support hydrogen production. By further understanding the means by which regulatory networks interact, this study will seek to maximize themore » ability of currently available “unrestrained” organisms to produce hydrogen. The organisms to be utilized in this study, phototrophic microorganisms, in particular nonsulfur purple (NSP) bacteria, catalyze many significant processes including the assimilation of carbon dioxide into organic carbon, nitrogen fixation, sulfur oxidation, aromatic acid degradation, and hydrogen oxidation/evolution. Moreover, due to their great metabolic versatility, such organisms highly regulate these processes in the cell and since virtually all such capabilities are dispensable, excellent experimental systems to study aspects of molecular control and biochemistry/physiology are available.« less

Hot hydrogen testing of metallic turbo pump materials

NASA Technical Reports Server (NTRS)

Zee, Ralph; Chin, Bryan; Inamdar, Rohit

1993-01-01

The objectives of this investigation are to expose heat resistant alloys to hydrogen at elevated temperatures and to use various microstructural and analytical techniques to determine the chemical and rate process involved in degradation of these materials due to hydrogen environment. Inconel 718 and NASA-23 (wrought and cast) are candidate materials. The degradation of these materials in the presence of 1 to 5 atmospheric pressure of hydrogen from 450 C to 1100 C was examined. The hydrogen facility at Auburn University was used for this purpose. Control experiments were also conducted wherein the samples were exposed to vacuum so that a direct comparison of the results would separate the thermal contribution from the hydrogen effects. The samples were analyzed prior to and after exposure. A residual gas collection system was used to determine the gaseous species produced by any chemical reaction that may have occurred during the exposure. Analysis of this gas sample shows only the presence of H2 as expected. Analyses of the samples were conducted using optical microscopy, x-ray diffraction, scanning electron microscopy, and weight change. There appears to be no change in weight of the samples as a result of hydrogen exposure. In addition no visible change on the surface structure was detected. This indicates that the materials of interest do not have strong interaction with hot hydrogen. This is consistent with the microstructure results.

System for operating solid oxide fuel cell generator on diesel fuel

NASA Technical Reports Server (NTRS)

Singh, Prabhu (Inventor); George, Raymond A. (Inventor)

1997-01-01

A system is provided for operating a solid oxide fuel cell generator on diesel fuel. The system includes a hydrodesulfurizer which reduces the sulfur content of commercial and military grade diesel fuel to an acceptable level. Hydrogen which has been previously separated from the process stream is mixed with diesel fuel at low pressure. The diesel/hydrogen mixture is then pressurized and introduced into the hydrodesulfurizer. The hydrodesulfurizer comprises a metal oxide such as ZnO which reacts with hydrogen sulfide in the presence of a metal catalyst to form a metal sulfide and water. After desulfurization, the diesel fuel is reformed and delivered to a hydrogen separator which removes most of the hydrogen from the reformed fuel prior to introduction into a solid oxide fuel cell generator. The separated hydrogen is then selectively delivered to the diesel/hydrogen mixer or to a hydrogen storage unit. The hydrogen storage unit preferably comprises a metal hydride which stores hydrogen in solid form at low pressure. Hydrogen may be discharged from the metal hydride to the diesel/hydrogen mixture at low pressure upon demand, particularly during start-up and shut-down of the system.

Highly hydrogen-sensitive thermal desorption spectroscopy system for quantitative analysis of low hydrogen concentration (˜1 × 1016 atoms/cm3) in thin-film samples

NASA Astrophysics Data System (ADS)

Hanna, Taku; Hiramatsu, Hidenori; Sakaguchi, Isao; Hosono, Hideo

2017-05-01

We developed a highly hydrogen-sensitive thermal desorption spectroscopy (HHS-TDS) system to detect and quantitatively analyze low hydrogen concentrations in thin films. The system was connected to an in situ sample-transfer chamber system, manipulators, and an rf magnetron sputtering thin-film deposition chamber under an ultra-high-vacuum (UHV) atmosphere of ˜10-8 Pa. The following key requirements were proposed in developing the HHS-TDS: (i) a low hydrogen residual partial pressure, (ii) a low hydrogen exhaust velocity, and (iii) minimization of hydrogen thermal desorption except from the bulk region of the thin films. To satisfy these requirements, appropriate materials and components were selected, and the system was constructed to extract the maximum performance from each component. Consequently, ˜2000 times higher sensitivity to hydrogen than that of a commercially available UHV-TDS system was achieved using H+-implanted Si samples. Quantitative analysis of an amorphous oxide semiconductor InGaZnO4 thin film (1 cm × 1 cm × 1 μm thickness, hydrogen concentration of 4.5 × 1017 atoms/cm3) was demonstrated using the HHS-TDS system. This concentration level cannot be detected using UHV-TDS or secondary ion mass spectroscopy (SIMS) systems. The hydrogen detection limit of the HHS-TDS system was estimated to be ˜1 × 1016 atoms/cm3, which implies ˜2 orders of magnitude higher sensitivity than that of SIMS and resonance nuclear reaction systems (˜1018 atoms/cm3).

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

A novel liquid organic hydrogen carrier system based on catalytic peptide formation and hydrogenation

PubMed Central

Hu, Peng; Fogler, Eran; Diskin-Posner, Yael; Iron, Mark A.; Milstein, David

2015-01-01

Hydrogen is an efficient green fuel, but its low energy density when stored under high pressure or cryogenically, and safety issues, presents significant disadvantages; hence finding efficient and safe hydrogen carriers is a major challenge. Of special interest are liquid organic hydrogen carriers (LOHCs), which can be readily loaded and unloaded with considerable amounts of hydrogen. However, disadvantages include high hydrogen pressure requirements, high reaction temperatures for both hydrogenation and dehydrogenation steps, which require different catalysts, and high LOHC cost. Here we present a readily reversible LOHC system based on catalytic peptide formation and hydrogenation, using an inexpensive, safe and abundant organic compound with high potential capacity to store and release hydrogen, applying the same catalyst for loading and unloading hydrogen under relatively mild conditions. Mechanistic insight of the catalytic reaction is provided. We believe that these findings may lead to the development of an inexpensive, safe and clean liquid hydrogen carrier system. PMID:25882348

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

NASA Astrophysics Data System (ADS)

Patki, Gauri Dilip

Hydrogen is a promising energy carrier, for use in fuel cells, engines, and turbines for transportation or mobile applications. Hydrogen is desirable as an energy carrier, because its oxidation by air releases substantial energy (thermally or electrochemically) and produces only water as a product. In contrast, hydrocarbon energy carriers inevitably produce CO2, contributing to global warming. While CO2 capture may prove feasible in large stationary applications, implementing it in transportation and mobile applications is a daunting challenge. Thus a zero-emission energy carrier like hydrogen is especially needed in these cases. Use of H2 as an energy carrier also brings new challenges such as safe handling of compressed hydrogen and implementation of new transport, storage, and delivery processes and infrastructure. With current storage technologies, hydrogen's energy per volume is very low compared to other automobile fuels. High density storage of compressed hydrogen requires combinations of high pressure and/or low temperature that are not very practical. An alternative for storage is use of solid light weight hydrogenous material systems which have long durability, good adsorption properties and high activity. Substantial research has been conducted on carbon materials like activated carbon, carbon nanofibers, and carbon nanotubes due to their high theoretical hydrogen capacities. However, the theoretical values have not been achieved, and hydrogen uptake capacities in these materials are below 10 wt. %. In this thesis we investigated the use of silicon for hydrogen generation. Hydrogen generation via water oxidation of silicon had been ignored due to slow reaction kinetics. We hypothesized that the hydrogen generation rate could be improved by using high surface area silicon nanoparticles. Our laser-pyrolysis-produced nanoparticles showed surprisingly rapid hydrogen generation and high hydrogen yield, exceeding the theoretical maximum of two moles of H2 per mole of Si. We compare our silicon nanoparticles (˜10nm diameter) with commercial silicon nanopowder (<100nm diameter) and ball-milled silicon powder (325 mesh). The increase in rate upon decreasing the particle size to 10 nm was even greater than would be expected based upon the increase in surface area. While specific surface area increased by a factor of 6 in going from <100 nm to ˜10 nm particles, the hydrogen production rate increased by a factor of 150. However, in all cases, silicon requires a base (e.g. NaOH, KOH, hydrazine) to catalyze its reaction with water. Metal hydrides are also promising hydrogen storage materials. The optimum metal hydride would possess high hydrogen storage density at moderate temperature and pressure, release hydrogen safely and controllably, and be stable in air. Alkali metal hydrides have high hydrogen storage density, but exhibit high uncontrollable reactivity with water. In an attempt to control this explosive nature while maintaining high storage capacity, we mixed our silicon nanoparticles with the hydrides. This has dual benefits: (1) the hydride- water reaction produces the alkali hydroxide needed for base-catalyzed silicon oxidation, and (2) dilution with 10nm coating by, the silicon may temper the reactivity of the hydride, making the process more controllable. Initially, we analyzed hydrolysis of pure alkali metal hydrides and alkaline earth metal hydrides. Lithium hydride has particularly high hydrogen gravimetric density, along with faster reaction kinetics than sodium hydride or magnesium hydride. On analysis of hydrogen production we found higher hydrogen yield from the silicon nanoparticle—metal hydride mixture than from pure hydride hydrolysis. The silicon-hydride mixtures using our 10nm silicon nanoparticles produced high hydrogen yield, exceeding the theoretical yield. Some evidence of slowing of the hydride reaction rate upon addition of silicon nanoparticles was observed.

FY17 Transportation and Hydrogen Systems Center Journal Publication Highlights

DOE Office of Scientific and Technical Information (OSTI.GOV)

NREL's Transportation and Hydrogen Systems Center published 39 journal articles in fiscal year 2017 highlighting recent research in advanced vehicle technology, alternative fuels, and hydrogen systems.

In-line calibration of Raman systems for analysis of gas mixtures of hydrogen isotopologues with sub-percent accuracy.

PubMed

Schlösser, Magnus; Seitz, Hendrik; Rupp, Simone; Herwig, Philipp; Alecu, Catalin Gabriel; Sturm, Michael; Bornschein, Beate

2013-03-05

Highly accurate, in-line, and real-time composition measurements of gases are mandatory in many processing applications. The quantitative analysis of mixtures of hydrogen isotopologues (H2, D2, T2, HD, HT, and DT) is of high importance in such fields as DT fusion, neutrino mass measurements using tritium β-decay or photonuclear experiments where HD targets are used. Raman spectroscopy is a favorable method for these tasks. In this publication we present a method for the in-line calibration of Raman systems for the nonradioactive hydrogen isotopologues. It is based on precise volumetric gas mixing of the homonuclear species H2/D2 and a controlled catalytic production of the heteronuclear species HD. Systematic effects like spurious exchange reactions with wall materials and others are considered with care during the procedure. A detailed discussion of statistical and systematic uncertainties is presented which finally yields a calibration accuracy of better than 0.4%.

Effects of Hydrogen Peroxide on Dental Unit Biofilms and Treatment Water Contamination

PubMed Central

Lin, Shih-Ming; Svoboda, Kathy K.H.; Giletto, Anthony; Seibert, Jeff; Puttaiah, Raghunath

2011-01-01

Objectives: To study effects of various concentrations of hydrogen peroxide on mature waterline biofilms and in controlling planktonic (free-floating) organisms in simulated dental treatment water systems; and to study in vitro the effects of 2%, 3%, and 7% hydrogen peroxide on the removal of mature biofilms and inorganic compounds in dental waterlines. Methods: Four units of an automated dental unit water system simulation device was used for 12 weeks. All units were initially cleaned to control biofilms and inorganic deposits. H2O2 at concentrations of 1%, 2%, 3% was used weekly for periodic cleaning in three treatment group units (units 1, 2 & 3), with 0.05%, 0.15% and 0.25% H2O2 in municipal water used as irrigant respectively. The control unit (unit 4) did not have weekly cleanings and used municipal water as irrigant. Laser Scanning Confocal Microscopy and Scanning Electron Microscopy were used to study deposits on lines, and weekly heterotrophic plate counts done to study effluent water contamination. A 24 hour in vitro challenge test with 7%, 3% and 2% H2O2 on mature biofilms was conducted using harvested waterlines to study biofilm and inorganic deposit removal. Results: Heterotrophic plate counts of effluent water showed that the control unit reached contamination levels in excess of 400,000 CFU/mL while all treatment units showed contamination levels <500 CFU/mL through most of the 12 weeks. All treatment units showed varying levels of biofilm and inorganic deposit control in this short 12 week study. The in vitro challenge test showed although there was biofilm control, there was no eradication even when 7% H2O2 was used for 24 hours. Conclusions: 2% H2O2 used as a periodic cleaner, and diluted to 0.05% in municipal water for irrigation was beneficial in controlling biofilm and planktonic contamination in dental unit water systems. However, to remove well established biofilms, it may take more than 2 months when initial and multiple periodic cleanings are performed using H2O2. PMID:21228956

Hydrogen-rich saline prevents bone loss in diabetic rats induced by streptozotocin.

PubMed

Guo, Jialiang; Dong, Weichong; Jin, Lin; Wang, Pengcheng; Hou, Zhiyong; Zhang, Yingze

2017-10-01

As an antioxidant molecule, hydrogen has been received much more attention and reported to be used as the treatment strategy for various diseases. In this study, we hypothesize that systemic delivery of hydrogen saline water may improve the reservation of bone tissue in the tibias and femurs of osteoporotic rats caused by diabetes mellitus (DM), which is characterized by increased levels of oxidative stress and overproducing reactive oxygen species (ROS). The animals were divided into three groups of 12 animals and lavaged with normal saline (normal control and DM), or hydrogen saline water (DM + HRS). General status, blood glucose level, tibial and femoral mechanical strength, and micro-CT scans of the proximal tibia were recorded and analyzed. After 12 weeks, the glucose level was significantly decreased in the DM + HRS group compared with that of the DM group. Micro-CT scans showed that bone volume/total volume, connectivity density, trabecular thickness, and trabecular number were significantly increased compared with the DM group. Mechanical results of energy, stiffness and elastic modulus in the DM + HRS group were significantly higher than in the other groups for the tibia and femur. The results indicate that the systemic delivery of hydrogen saline water, which is safe and well tolerated, preserves bone volume and decreases fracture risks in streptozotocin-induced diabetic status rats, whose bone structure or inherent material properties of bone tissues are changed.

Chronic toxicity of hydrogen peroxide to Daphnia magna in a continuous exposure, flow-through test system

USGS Publications Warehouse

Meinertz, J.R.; Greseth, Shari L.; Gaikowski, M.P.; Schmidt, L.J.

2008-01-01

A flow-through, continuous exposure test system was developed to expose Daphnia magna to an unstable compound. 35% Perox-Aid?? is a specially formulated hydrogen peroxide (a highly oxidative chemical) product approved for use in U.S. aquaculture and therefore has the potential to be released from aquaculture facilities and pose a risk to aquatic invertebrates. The study objective was to assess the effects of 35% Perox-Aid?? on an aquatic invertebrate by evaluating the survival, growth, production, and gender ratio of progeny from a representative aquatic invertebrate continuously exposed to 35% Perox-Aid??. The study design consisted of 6 treatment groups (10 test chambers each) with target hydrogen peroxide concentrations of 0.0, 0.32, 0.63, 1.25, 2.5, and 5.0??mg L- 1. The study was initiated with < 24-h-old Daphnia (1 daphnid per chamber) that were exposed to hydrogen peroxide for 21??days. Hydrogen peroxide concentrations ??? 1.25??mg L- 1 had no significant effect on Daphnia time to death compared to controls and no significant effect on the time to first brood production and the number of broods produced. Concentrations ??? 0.63??mg L- 1 had no significant effect on the total number of young produced. Concentrations ??? 0.32??mg L- 1 had a negative effect on Daphnia growth. Hydrogen peroxide had no significant effect on the gender ratio of young produced. All second generation Daphnia were female. A continuous discharge of hydrogen peroxide into aquatic ecosystems is not likely to affect cladocerans if the concentration is maintained at ??? 0.63??mg L- 1 for less than 21??days.

Economic Assessment of Hydrogen Technologies Participating in California Electricity Markets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eichman, Joshua; Townsend, Aaron; Melaina, Marc

As the electric sector evolves and increasing amounts of variable renewable generation are installed on the system, there are greater needs for system flexibility and sufficient capacity, and greater concern for overgeneration from renewable sources not well matched in time with electric loads. Hydrogen systems have the potential to support the grid in each of these areas. However, limited information is available about the economic competitiveness of hydrogen system configurations. This paper quantifies the value for hydrogen energy storage and demand response systems to participate in select California wholesale electricity markets using 2012 data. For hydrogen systems and conventional storagemore » systems (e.g., pumped hydro, batteries), the yearly revenues from energy, ancillary service, and capacity markets are compared to the yearly cost to establish economic competitiveness. Hydrogen systems can present a positive value proposition for current markets. Three main findings include: (1) For hydrogen systems participating in California electricity markets, producing and selling hydrogen was found to be much more valuable than producing and storing hydrogen to later produce electricity; therefore systems should focus on producing and selling hydrogen and opportunistically providing ancillary services and arbitrage. (2) Tighter integration with electricity markets generates greater revenues (i.e., systems that participate in multiple markets receive the highest revenue). (3) More storage capacity, in excess of what is required to provide diurnal shifting, does not increase competitiveness in current California wholesale energy markets. As more variable renewable generation is installed, the importance of long duration storage may become apparent in the energy price or through additional markets, but currently, there is not a sufficiently large price differential between days to generate enough revenue to offset the cost of additional storage. Future work will involve expanding to consider later year data and multiple regions to establish more generalized results.« less

Nickel-hydrogen bipolar battery systems

NASA Technical Reports Server (NTRS)

Thaller, L. H.

1982-01-01

Nickel-hydrogen cells are currently being manufactured on a semi-experimental basis. Rechargeable nickel-hydrogen systems are described that more closely resemble a fuel cell system than a traditional nickel-cadmium battery pack. This has been stimulated by the currently emerging requirements related to large manned and unmanned low earth orbit applications. The resultant nickel-hydrogen battery system should have a number of features that would lead to improved reliability, reduced costs as well as superior energy density and cycle lives as compared to battery systems constructed from the current state-of-the-art nickel-hydrogen individual pressure vessel cells.

Solar/hydrogen systems assessment. Volume 1: Solar/hydrogen systems for the 1985 - 2000 time frame

NASA Technical Reports Server (NTRS)

Foster, R. W.; Tison, R. R.; Escher, W. J. D.; Hanson, J. A.

1980-01-01

Opportunities for commercialization of systems capable of producing hydrogen from solar energy were studied. The hydrogen product costs that might be achieved by the four selected candidate systems was compared with the pricing structure and practices of the commodity gas market. Subsequently, product cost and market price match was noted to exist in the small user sector of the hydrogen marketplace. Barriers to and historical time lags in, commercialization of new technologies are reviewed. Recommendations for development and demonstration programs designed to accelerate the commercialization of the candidate systems are presented.

Solar/hydrogen systems assessment. Volume 1: Solar/hydrogen systems for the 1985 - 2000 time frame

NASA Astrophysics Data System (ADS)

Foster, R. W.; Tison, R. R.; Escher, W. J. D.; Hanson, J. A.

1980-06-01

Opportunities for commercialization of systems capable of producing hydrogen from solar energy were studied. The hydrogen product costs that might be achieved by the four selected candidate systems was compared with the pricing structure and practices of the commodity gas market. Subsequently, product cost and market price match was noted to exist in the small user sector of the hydrogen marketplace. Barriers to and historical time lags in, commercialization of new technologies are reviewed. Recommendations for development and demonstration programs designed to accelerate the commercialization of the candidate systems are presented.

Reversible Interconversion between 2,5-Dimethylpyrazine and 2,5-Dimethylpiperazine by Iridium-Catalyzed Hydrogenation/Dehydrogenation for Efficient Hydrogen Storage.

PubMed

Fujita, Ken-Ichi; Wada, Tomokatsu; Shiraishi, Takumi

2017-08-28

A new hydrogen storage system based on the hydrogenation and dehydrogenation of nitrogen heterocyclic compounds, employing a single iridium catalyst, has been developed. Efficient hydrogen storage using relatively small amounts of solvent compared with previous systems was achieved by this new system. Reversible transformations between 2,5-dimethylpyrazine and 2,5-dimethylpiperazine, accompanied by the uptake and release of three equivalents of hydrogen, could be repeated almost quantitatively at least four times without any loss of efficiency. Furthermore, hydrogen storage under solvent-free conditions was also accomplished. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Making a Splash in Homogeneous CO₂ Hydrogenation: Elucidating the Impact of Solvent on Catalytic Mechanisms.

PubMed

Wiedner, Eric; Linehan, John

2018-06-06

Molecular catalysts for hydrogenation of CO₂ are widely studied as a means of chemical hydrogen storage. Catalysts are traditionally designed from the perspective of controlling the ligands bound to the metal. In recent years, studies have shown that the solvent can also play a key role in the mechanism of CO₂ hydrogenation. A prominent example is the impact of the solvent on the thermodynamic hydride donor ability, or hydricity, of metal hydride complexes relative to the hydride acceptor ability of CO₂. In some cases, simply changing from an organic solvent to water can reverse the direction of hydride transfer between a metal hydride and CO₂. Additionally, the solvent can impact catalysis by converting CO₂ into carbonate species, as well as activate intermediate products for hydrogenation to more reduced products. By understanding the substrate and product speciation, as well as the reactivity of the catalyst towards the substrate, the solvent can be used as a central design component for the rational development of new catalytic systems. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

PNNL Development and Analysis of Material-Based Hydrogen Storage Systems for the Hydrogen Storage Engineering Center of Excellence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brooks, Kriston P.; Alvine, Kyle J.; Johnson, Kenneth I.

The Hydrogen Storage Engineering Center of Excellence is a team of universities, industrial corporations, and federal laboratories with the mandate to develop lower-pressure, materials-based, hydrogen storage systems for hydrogen fuel cell light-duty vehicles. Although not engaged in the development of new hydrogen storage materials themselves, it is an engineering center that addresses engineering challenges associated with the currently available hydrogen storage materials. Three material-based approaches to hydrogen storage are being researched: 1) chemical hydrogen storage materials 2) cryo-adsorbents, and 3) metal hydrides. As a member of this Center, Pacific Northwest National Laboratory (PNNL) has been involved in the design andmore » evaluation of systems developed with each of these three hydrogen storage materials. This report is a compilation of the work performed by PNNL for this Center.« less

40 CFR 62.15390 - What equations must I use?

Code of Federal Regulations, 2011 CFR

2011-07-01

... reduction in potential hydrogen chloride emissions. Calculate the percent reduction in potential hydrogen... of the potential hydrogen chloride emissions Ei = hydrogen chloride emission concentration as measured at the air pollution control device inlet, corrected to 7 percent oxygen, dry basis Eo = hydrogen...

40 CFR 62.15390 - What equations must I use?

Code of Federal Regulations, 2010 CFR

2010-07-01

... reduction in potential hydrogen chloride emissions. Calculate the percent reduction in potential hydrogen... of the potential hydrogen chloride emissions Ei = hydrogen chloride emission concentration as measured at the air pollution control device inlet, corrected to 7 percent oxygen, dry basis Eo = hydrogen...

Effect of disinfectants on glucose monitors.

PubMed

Mahoney, John J; Lim, Christine G

2012-01-01

Monitoring blood glucose levels is an integral part of routine diabetes management. To minimize the risk of transmission of bloodborne pathogens during monitoring, the Centers for Disease Control and Prevention (CDC) recommends that glucose meters be disinfected after each use whenever they are used to test multiple patients. The objective of this study is to assess the compatibility of some common disinfectants with certain blood glucose meter systems. We tested six disinfectants for adverse impact on meter performance or the exterior meter surfaces. The disinfectants tested were 0.525% sodium hypochlorite, 20% 2-propanol and 10% ethanol, 17.2% isopropanol, 55% isopropanol, 70% isopropanol, and hydrogen peroxide. To assess meter performance, we tested OneTouch® Ultra® blood glucose monitoring systems with control solution before and after application of either water or disinfectant. To assess the effect on exterior meter surfaces, we performed a soaking test to simulate long-term exposure to disinfectant. Paired t-test results showed that the control solution data associated with disinfectant and with water application were not significantly different for each meter type. However, most of the meter types were adversely affected by hydrogen peroxide and/or by the higher concentrations of alcohol-based disinfectants. Although none of the six disinfectants affected meter performance, hydrogen peroxide and isopropanol >20% adversely affected the exterior surfaces of the tested meters. When complying with CDC instructions for meter disinfection, users should use caution and choose disinfectants that have been validated by the meter manufacturer. © 2012 Diabetes Technology Society.

Effect of Disinfectants on Glucose Monitors

PubMed Central

Mahoney, John J; Lim, Christine G

2012-01-01

Background Monitoring blood glucose levels is an integral part of routine diabetes management. To minimize the risk of transmission of bloodborne pathogens during monitoring, the Centers for Disease Control and Prevention (CDC) recommends that glucose meters be disinfected after each use whenever they are used to test multiple patients. The objective of this study is to assess the compatibility of some common disinfectants with certain blood glucose meter systems. Methods We tested six disinfectants for adverse impact on meter performance or the exterior meter surfaces. The disinfectants tested were 0.525% sodium hypochlorite, 20% 2-propanol and 10% ethanol, 17.2% isopropanol, 55% isopropanol, 70% isopropanol, and hydrogen peroxide. To assess meter performance, we tested OneTouch® Ultra® blood glucose monitoring systems with control solution before and after application of either water or disinfectant. To assess the effect on exterior meter surfaces, we performed a soaking test to simulate long-term exposure to disinfectant. Results Paired t-test results showed that the control solution data associated with disinfectant and with water application were not significantly different for each meter type. However, most of the meter types were adversely affected by hydrogen peroxide and/or by the higher concentrations of alcohol-based disinfectants. Conclusions Although none of the six disinfectants affected meter performance, hydrogen peroxide and isopropanol >20% adversely affected the exterior surfaces of the tested meters. When complying with CDC instructions for meter disinfection, users should use caution and choose disinfectants that have been validated by the meter manufacturer. PMID:22401326

Cryogenic Fluid Management Technology Development for Nuclear Thermal Propulsion

NASA Technical Reports Server (NTRS)

Taylor, Brian; Caffrey, Jarvis; Hedayat, Ali; Stephens, Jonathan; Polsgrove, Robert

2015-01-01

The purpose of this paper is to investigate, facilitate a discussion and determine a path forward for technology development of cryogenic fluid management technology that is necessary for long duration deep space missions utilizing nuclear thermal propulsion systems. There are a number of challenges in managing cryogenic liquids that must be addressed before long durations missions into deep space, such as a trip to Mars can be successful. The leakage rate of hydrogen from pressure vessels, seals, lines and valves is a critical factor that must be controlled and minimized. For long duration missions, hydrogen leakage amounts to large increases in hydrogen and therefore vehicle mass. The size of a deep space vehicle, such as a mars transfer vehicle, must be kept small to control cost and the logistics of a multi launch, assembled in orbit vehicle. The boil off control of the cryogenic fluid is an additional obstacle to long duration missions. The boil off caused by heat absorption results in the growth of the propellant needs of the vehicle and therefore vehicle mass. This is a significant problem for a vehicle using nuclear (fission) propulsion systems. Radiation from the engines deposits large quantities of heat into the cryogenic fluid, greatly increasing boil off beyond that caused by environmental heat leakage. Addressing and resolving these challenges is critical to successful long duration space exploration. This paper discusses the state of the technology needed to address these challenges and discuss the path forward needed in technology development.

Preliminary design of an auxiliary power unit for the space shuttle: Component and system configuration screening analysis

NASA Technical Reports Server (NTRS)

Binsley, R. L.; Maddox, J. P.; Marcy, R. D.; Siegler, R. S.; Spies, R.

1971-01-01

The auxiliary power unit (APU) for the space shuttle is required to provide hydraulic and electrical power on board the booster and orbiter vehicles. Five systems and their associated components, which utilize hot gas turbines to supply horsepower at gearbox output pads, were studied. Hydrogen-oxygen and storable propellants were considered for the hot gas supply. All APU's were required to be self-contained with respect to dissipating internally generated heat. These five systems were evaluated relative to a consistent criteria. The system supplied with high pressure gaseous hydrogen and oxygen was recommended as the best approach. It included a two-stage pressure-compounded partial-admission turbine, a propellant conditioning system with recuperation, a control system, and a gearbox. The gearbox output used was 240 hp. At the close of the study a 400 hp level was considered more appropriate for meeting the prime shuttle vehicle needs, and an in-depth analysis of the system at the 400 hp output level was recommended.

A systematic computational study of electronic effects on hydrogen sensitivity of olefin polymerization catalysts (abstract only).

PubMed

Coussens, Betty B; Budzelaar, Peter H M; Friederichs, Nic

2008-02-13

One of the important product parameters of polyolefins is their molecular weight (distribution). A common way to control this parameter is to add molecular hydrogen during the polymerization, which then acts as a chain transfer agent. The factors governing the hydrogen sensitivity of olefin polymerization catalysts are poorly understood and have attracted little attention from computational chemists. To explore the electronic factors determining hydrogen sensitivity we performed density functional calculations on a wide range of simple model systems including some metallocenes and a few basic models of heterogeneous catalysts. As a quantitative measure for hydrogen sensitivity we used the ratio of (i) the rate constant for chain transfer to hydrogen to (ii) the rate constant for ethene insertion, k(h)/k(p) (see the scheme below), and as a measure of electrophilicity we used the energy of complexation to the probe molecule ammonia. [Formula: see text] For isolated species in the gas phase, complexation energies appear to dominate the chemistry. Ethene complexes more strongly than hydrogen and with increasing electrophilicity of the metal centre this difference grows; the hydrogen sensitivity decreases accordingly. Although many factors (like catalyst dormancy and deactivation issues) complicate the comparison with experiment, this result seems to agree both in broad terms with the experimental lower hydrogen sensitivity of heterogeneous catalysts, and more specifically with the increased hydrogen sensitivity of highly alkylated or fused metallocenes. The opposite conclusion reached by Blom (see Blom et al 2002 Macromol. Chem. Phys. 203 381-7) is due to the use of a very different measure of electrophilicity, rather than to different experimental data.

Sensitive hydrogen leak detector

DOEpatents

Myneni, Ganapati Rao

1999-01-01

A sensitive hydrogen leak detector system using passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor.

A Technical and Economic Review of Solar Hydrogen Production Technologies

ERIC Educational Resources Information Center

Wilhelm, Erik; Fowler, Michael

2006-01-01

Hydrogen energy systems are being developed to replace fossil fuels-based systems for transportation and stationary application. One of the challenges facing the widespread adoption of hydrogen as an energy vector is the lack of an efficient, economical, and sustainable method of hydrogen production. In the short term, hydrogen produced from…

Hydrogen-bromine fuel cell advance component development

NASA Technical Reports Server (NTRS)

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.

Ford/BASF/UM Activities in Support of the Hydrogen Storage Engineering Center of Excellence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veenstra, Mike; Purewal, Justin; Xu, Chunchuan

Widespread adoption of hydrogen as a vehicular fuel depends critically on the development of low-cost, on-board hydrogen storage technologies capable of achieving high energy densities and fast kinetics for hydrogen uptake and release. As present-day technologies -- which rely on physical storage methods such as compressed hydrogen -- are incapable of attaining established Department of Energy (DOE) targets, development of materials-based approaches for storing hydrogen have garnered increasing attention. Material-based storage technologies have potential to store hydrogen beyond twice the density of liquid hydrogen. To hasten development of these ‘hydride’ materials, the DOE previously established three centers of excellence formore » materials storage R&D associated with the key classes of materials: metal hydrides, chemical hydrogen, and adsorbents. While these centers made progress in identifying new storage materials, the challenges associated with the engineering of the system around a candidate storage material are in need of further advancement. In 2009 the DOE established the Hydrogen Storage Engineering Center of Excellence with the objective of developing innovative engineering concepts for materials-based hydrogen storage systems. As a partner in the Hydrogen Storage Engineering Center of Excellence, the Ford-UM-BASF team conducted a multi-faceted research program that addresses key engineering challenges associated with the development of materials-based hydrogen storage systems. First, we developed a novel framework that allowed for a material-based hydrogen storage system to be modeled and operated within a virtual fuel cell vehicle. This effort resulted in the ability to assess dynamic operating parameters and interactions between the storage system and fuel cell power plant, including the evaluation of performance throughout various drive cycles. Second, we engaged in cost modeling of various incarnations of the storage systems. This analysis revealed cost gaps and opportunities that identified a storage system that was lower cost than a 700 bar compressed system. Finally, we led the HSECoE efforts devoted to characterizing and enhancing metal organic framework (MOF) storage materials. This report serves as a final documentation of the Ford-UM-BASF project contributions to the HSECoE during the 6-year timeframe of the Center. The activities of the HSECoE have impacted the broader goals of the DOE-EERE and USDRIVE, leading to improved understanding in the engineering of materials-based hydrogen storage systems. This knowledge is a prerequisite to the development of a commercially-viable hydrogen storage system.« less

Low Cost Embedded Controlled Full Bridge LC Parallel Resonant Converter

NASA Astrophysics Data System (ADS)

Chandrasekhar, P.; Reddy, S.

2009-01-01

In this paper the converter requirements for an optimum control of an electrolyser linked with a DC bus are analyzed and discussed. An electrolyser is a part of renewable energy system which generates hydrogen from water electrolysis. The hydrogen generating device is part of a complex system constituted by a supplying photovoltaic plant, the grid and a fuel cell battery. The characterization in several operative conditions of an actual industrial electrolyser is carried out in order to design and optimize the DC/DC converter. A dedicated zero voltage switching DC/DC converter is presented and simulated inside the context of the distributed energy production and storage system. The proposed supplying converter gives a stable output voltage and high circuit efficiency in all the proposed simulated scenarios. The adopted DC/DC converter is realized in a full-bridge topology technique in order to achieve zero voltage switching for the power switches and to regulate the output voltage. This converter has advantages like high power density, low EMI and reduced switching stresses. The simulation results are verified with the experimental results.

Systems and methods for generation of hydrogen peroxide vapor

DOEpatents

Love, Adam H; Eckels, Joel Del; Vu, Alexander K; Alcaraz, Armando; Reynolds, John G

2014-12-02

A system according to one embodiment includes a moisture trap for drying air; at least one of a first container and a second container; and a mechanism for at least one of: bubbling dried air from the moisture trap through a hydrogen peroxide solution in the first container for producing a hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above a hydrogen peroxide solution in the second container for producing a hydrogen peroxide vapor. A method according one embodiment includes at least one of bubbling dried air through a hydrogen peroxide solution in a container for producing a first hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above the hydrogen peroxide solution in a container for producing a second hydrogen peroxide vapor. Additional systems and methods are also presented.

Coordination nano-space as stage of hydrogen ortho-para conversion.

PubMed

Kosone, Takashi; Hori, Akihiro; Nishibori, Eiji; Kubota, Yoshiki; Mishima, Akio; Ohba, Masaaki; Tanaka, Hiroshi; Kato, Kenichi; Kim, Jungeun; Real, José Antonio; Kitagawa, Susumu; Takata, Masaki

2015-07-01

The ability to design and control properties of nano-sized space in porous coordination polymers (PCPs) would provide us with an ideal stage for fascinating physical and chemical phenomena. We found an interconversion of nuclear-spin isomers for hydrogen molecule H2 adsorbed in a Hofmann-type PCP, {Fe(pz)[Pd(CN)4]} (pz=pyrazine), by the temperature dependence of Raman spectra. The ortho (o)-para (p) conversion process of H2 is forbidden for an isolated molecule. The charge density study using synchrotron radiation X-ray diffraction reveals the electric field generated in coordination nano-space. The present results corroborate similar findings observed on different systems and confirm that o-p conversion can occur on non-magnetic solids and that electric field can induce the catalytic hydrogen o-p conversion.

Feasibility analysis of a hydrogen backup power system for Russian telecom market

NASA Astrophysics Data System (ADS)

Borzenko, V. I.; Dunikov, D. O.

2017-11-01

We performed feasibility analysis of 10 kW hydrogen backup power system (H2BS) consisting of a water electrolyzer, a metal hydride hydrogen storage and a fuel cell. Capital investments in H2BS are mostly determined by the costs of the PEM electrolyzer, the fuel cell and solid state hydrogen storage materials, for single unit or small series manufacture the cost of AB5-type intermetallic compound can reach 50% of total system cost. Today the capital investments in H2BS are 3 times higher than in conventional lead-acid system of the same capacity. Wide distribution of fuel cell hydrogen vehicles, development of hydrogen infrastructure, and mass production of hydrogen power systems will for sure lower capital investments in fuel cell backup power. Operational expenditures for H2BS is only 15% from the expenditures for lead acid systems, and after 4-5 years of exploitation the total cost of ownership will become lower than for batteries.

Study on Introduction of CO2 Free Energy to Japan with Liquid Hydrogen

NASA Astrophysics Data System (ADS)

Kamiya, Shoji; Nishimura, Motohiko; Harada, Eichi

In Japan, both CO2(Carbon dioxide) emission reduction and energy security are the very important social issues after Fukushima Daiichi accident. On the other hand, FCV (Fuel Cell Vehicle)using hydrogen will be on the market in 2015. Introducing large mass hydrogen energy is being expected as expanding hydrogen applications, or solution to energy issues of Japan.And then,the Japanese government announced the road map for introducing hydrogen energy supply chain in this June,2014. Under these circumstances, imported CO2 free hydrogen will be one of the solutions for energy security and CO2 reduction, if the hydrogen price is affordable. To achieve this, Kawasaki Heavy Industries, Ltd. (KHI) performed a feasibility studyon CO2-free hydrogen energy supply chainfrom Australian brown coal linked with CCS (Carbon dioxide Capture and Storage) to Japan. In the study, hydrogen production systems utilizing brown coal gasificationandLH2 (liquid hydrogen)systems as storing and transporting hydrogen are examined.This paper shows the possibilityof realizingthe CO2 free hydrogen supply chain, the cost breakdown of imported hydrogen cost, its cost competitiveness with conventionalfossil, andLH2systems as key technologies of the hydrogen energy chain.

Liquid Organic Hydrogen Carriers (LOHCs): Toward a Hydrogen-free Hydrogen Economy.

PubMed

Preuster, Patrick; Papp, Christian; Wasserscheid, Peter

2017-01-17

The need to drastically reduce CO 2 emissions will lead to the transformation of our current, carbon-based energy system to a more sustainable, renewable-based one. In this process, hydrogen will gain increasing importance as secondary energy vector. Energy storage requirements on the TWh scale (to bridge extended times of low wind and sun harvest) and global logistics of renewable energy equivalents will create additional driving forces toward a future hydrogen economy. However, the nature of hydrogen requires dedicated infrastructures, and this has prevented so far the introduction of elemental hydrogen into the energy sector to a large extent. Recent scientific and technological progress in handling hydrogen in chemically bound form as liquid organic hydrogen carrier (LOHC) supports the technological vision that a future hydrogen economy may work without handling large amounts of elemental hydrogen. LOHC systems are composed of pairs of hydrogen-lean and hydrogen-rich organic compounds that store hydrogen by repeated catalytic hydrogenation and dehydrogenation cycles. While hydrogen handling in the form of LOHCs allows for using the existing infrastructure for fuels, it also builds on the existing public confidence in dealing with liquid energy carriers. In contrast to hydrogen storage by hydrogenation of gases, such as CO 2 or N 2 , hydrogen release from LOHC systems produces pure hydrogen after condensation of the high-boiling carrier compounds. This Account highlights the current state-of-the-art in hydrogen storage using LOHC systems. It first introduces fundamental aspects of a future hydrogen economy and derives therefrom requirements for suitable LOHC compounds. Molecular structures that have been successfully applied in the literature are presented, and their property profiles are discussed. Fundamental and applied aspects of the involved hydrogenation and dehydrogenation catalysis are discussed, characteristic differences for the catalytic conversion of pure hydrocarbon and nitrogen-containing LOHC compounds are derived from the literature, and attractive future research directions are highlighted. Finally, applications of the LOHC technology are presented. This part covers stationary energy storage (on-grid and off-grid), hydrogen logistics, and on-board hydrogen production for mobile applications. Technology readiness of these fields is very different. For stationary energy storage systems, the feasibility of the LOHC technology has been recently proven in commercial demonstrators, and cost aspects will decide on their further commercial success. For other highly attractive options, such as, hydrogen delivery to hydrogen filling stations or direct-LOHC-fuel cell applications, significant efforts in fundamental and applied research are still needed and, hopefully, encouraged by this Account.

KEA-144: Final Results of the Ground Operations Demonstration Unit for Liquid Hydrogen (GODU-LH2) Project

NASA Technical Reports Server (NTRS)

Notardonato, William; Fesmire, James; Swanger, Adam; Jumper, Kevin; Johnson, Wesley; Tomsik, Thomas

2017-01-01

GODU-LH2 system has successfully met all test objectives at the 33%, 67%, and 100% tank fill level. Complete control over the state of the fluid has been demonstrated using Integrated Refrigeration and Storage (IRAS). Almost any desired point along the H2saturation curve can essentially be "dialed in" and maintained indefinitely. System can also be used to produce densified hydrogen in large quantities to the triple point. Exploring multiple technology infusion paths. Studying implementation of IRAS technology into new LH2sphere for EM-2 at LC39B. Technical interchange also occurring with STMD, LSP, ULA, DoE, KIST, Kawasaki, Shell Oil, SpaceX, US Coast Guard, and Virgin Galactic.

Solar/hydrogen systems for the 1985-2000 time frame - A review and assessment

NASA Technical Reports Server (NTRS)

Hanson, J. A.; Foster, R. W.; Escher, W. J. D.; Tison, R. R.

1982-01-01

A comprehensive state-of-the-art review of solar/hydrogen technologies has been conducted. From this, solar/hydrogen production systems which could be commercialized by the year 2000 have been characterized technically and economically. Incentives and disincentives for the early commercialization of four solar/hydrogen systems have been explored, conclusions drawn and recommendations made.

Release and control of hydrogen sulfide during sludge thermal drying.

PubMed

Weng, Huanxin; Dai, Zhixi; Ji, Zhongqiang; Gao, Caixia; Liu, Chongxuan

2015-10-15

The release of hydrogen sulfide (H2S) during sludge drying is a major environmental problem because of its toxicity to human health. A series of experiments were performed to investigate the mechanisms and factors controlling the H2S release. Results of this study show that: (1) the biomass and activity of sulfate-reducing bacteria (SRB) in sludge were the major factors controlling the amount of H2S release, (2) the sludge drying temperature had an important effect on both the extent and the timing of H2S release from the sludge, and (3) decreasing sludge pH increased the H2S release. Based on the findings from this study, a new system that integrates sludge drying and H2S gas treatment was developed, by which 97.5% of H2S and 99.7% of smoke released from sludge treatments was eliminated. Copyright © 2015 Elsevier B.V. All rights reserved.

Release and control of hydrogen sulfide during sludge thermal drying

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weng, Huanxin; Dai, Zhixin; Ji, Zhongqiang

2015-04-15

The release of hydrogen sulfide (H2S) during sludge drying is a major environmental problem because of its toxicity to human health. A series of experiments were performed to investigate the mechanisms and factors controlling the H2S release. Results of this study show that: 1) the biomass and activity of sulfate-reducing bacteria (SRB) in sludge were the major factors controlling the amount of H2S release, 2) the sludge drying temperature had an important effect on both the extent and the timing of H2S release from the sludge, and 3) decreasing sludge pH increased the H2S release. Based on the findings frommore » this study, a new system that integrates sludge drying and H2S gas treatment was developed to reduce the amount of H2S released from sludge treatments.« less

Handling Procedures of Vegetable Crops

NASA Technical Reports Server (NTRS)

Perchonok, Michele; French, Stephen J.

2004-01-01

The National Aeronautics and Space Administration (NASA) is working towards future long duration manned space flights beyond low earth orbit. The duration of these missions may be as long as 2.5 years and will likely include a stay on a lunar or planetary surface. The primary goal of the Advanced Food System in these long duration exploratory missions is to provide the crew with a palatable, nutritious, and safe food system while minimizing volume, mass, and waste. Vegetable crops can provide the crew with added nutrition and variety. These crops do not require any cooking or food processing prior to consumption. The vegetable crops, unlike prepackaged foods, will provide bright colors, textures (crispy), and fresh aromas. Ten vegetable crops have been identified for possible use in long duration missions. They are lettuce, spinach, carrot, tomato, green onion, radish, bell pepper, strawberries, fresh herbs, and cabbage. Whether these crops are grown on a transit vehicle (e.g., International Space Station) or on the lunar or planetary surface, it will be necessary to determine how to safely handle the vegetables while maintaining acceptability. Since hydrogen peroxide degrades into water and oxygen and is generally recognized as safe (GRAS), hydrogen peroxide has been recommended as the sanitizer. The objective of th is research is to determine the required effective concentration of hydrogen peroxide. In addition, it will be determined whether the use of hydrogen peroxide, although a viable sanitizer, adversely affects the quality of the vegetables. Vegetables will be dipped in 1 % hydrogen peroxide, 3% hydrogen peroxide, or 5% hydrogen peroxide. Treated produce and controls will be stored in plastic bags at 5 C for up to 14 days. Sensory, color, texture, and total plate count will be measured. The effect on several vegetables including lettuce, radish, tomato and strawberries has been completed. Although each vegetable reacts to hydrogen peroxide differently, the data suggest that 5% hydrogen peroxide reduces the shelf life of the vegetable. A dip of either 1 % or 3% hydrogen peroxide helps reduce the microbial total count while not adversely affecting the quality of the vegetable.

Space shuttle auxiliary propulsion system design study. Phase D report: Oxygen-hydrogen special RCS studies

NASA Technical Reports Server (NTRS)

Baumann, T. L.; Pattern, T. C.; Mckee, H. B.

1972-01-01

Two alternate oxygen-hydrogen auxiliary propulsion system concepts for use with the space shuttle vehicle were evaluated. The two concepts considered were: (1) gaseous oxygen-hydrogen systems with electric or hydraulic motor driven pumps to provide system pressure and (2) liquid oxygen-hydrogen systems which delivered propellants to the engines in a liquid state without the need for pumps. The various means of implementing each of the concepts are compared on the basis of weight, technology requirements, and operational considerations. It was determined that the liquid oxygen-hydrogen system concepts have the potential to produce substantial weight reductions in the space shuttle orbiter total impulse range.

Hydrogen embrittlement of structural alloys. A technology survey

NASA Technical Reports Server (NTRS)

Carpenter, J. L., Jr.; Stuhrke, W. F.

1976-01-01

Technical abstracts for about 90 significant documents relating to hydrogen embrittlement of structural metals and alloys are reviewed. Particular note was taken of documents regarding hydrogen effects in rocket propulsion, aircraft propulsion and hydrogen energy systems, including storage and transfer systems.

Hydrogen energy systems studies. Final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogden, J.M.; Kreutz, T.; Kartha, S.

1996-08-13

The results of previous studies suggest that the use of hydrogen from natural gas might be an important first step toward a hydrogen economy based on renewables. Because of infrastructure considerations (the difficulty and cost of storing, transmitting and distributing hydrogen), hydrogen produced from natural gas at the end-user`s site could be a key feature in the early development of hydrogen energy systems. In the first chapter of this report, the authors assess the technical and economic prospects for small scale technologies for producing hydrogen from natural gas (steam reformers, autothermal reformers and partial oxidation systems), addressing the following questions:more » (1) What are the performance, cost and emissions of small scale steam reformer technology now on the market? How does this compare to partial oxidation and autothermal systems? (2) How do the performance and cost of reformer technologies depend on scale? What critical technologies limit cost and performance of small scale hydrogen production systems? What are the prospects for potential cost reductions and performance improvements as these technologies advance? (3) How would reductions in the reformer capital cost impact the delivered cost of hydrogen transportation fuel? In the second chapter of this report the authors estimate the potential demand for hydrogen transportation fuel in Southern California.« less

Intravenous versus intramuscular cobinamide compared to intravenous saline (control) in the treatment of acute, survivable, hydrogen sulfide toxicity in swine (Sus Scrofa).

DTIC Science & Technology

2017-11-09

FWH20140070A, “Intravenous versus intramuscular // compared to intravenous saline ( control ) in the treatment of acute, survivable, hydrogen sulfide toxicity... control ) in the treatment of acute, survivable, hydrogen sulfide toxicity in swine (Sus Scrofa). 4. Principal Investigator (PI): Name Rank Date...remainder of the study. Animals were treated with IV HOC, IV Cobinamide or control (no treatment) 1 minute post apnea. There were no significant

[Protective effect of hydrogen against hyperoxia-induced type II alveolar epithelial cell injury].

PubMed

Yao, Lan; Xu, Feng; Luo, Chong; Yu, Pan; Dong, Xinxin; Sun, Xuejun; Liu, Chengjun

2013-02-01

To investigate the protective effect of hydrogen against hyperoxia-induced oxidative stress injury in premature rat type II alveolar epithelial cells (AECs). The type II AECs isolated from premature rats were randomly divided into air (21% oxygen) control group, hyperoxia (95% oxygen) control group, air + hydrogen group, and hyperoxia+ hydrogen group. The cells with hydrogen treatment were cultured in the presence of rich hydrogen. After the corresponding exposure for 24 h, the cell morphology was observed microscopically. MTT assay was used to evaluated the cell proliferation ability, and JC-1 fluorescence probe was used to detect the mitochondrial membrane potential (δφ) changes of the type II AECs. The concentration of maleic dialdehyde (MDA) and superoxide dismutase (SOD) activity in the cell supernatant were detected using colorimetric method. No significant differences were found in cell growth or measurements between air control and air + hydrogen groups. Compared with air control group, the cells exposed to hyperoxia showed significantly suppressed proliferation, reduced mitochondrial membrane potential, increased MDA content, and decreased SOD activity. Intervention with hydrogen resulted in significantly increased cell proliferation and SOD activity and lowered MDA content, and restored the mitochondrial membrane potential in the cells with hyperoxia exposure (P<0.05). Hydrogen can significantly reduce hyperoxia-induced oxidative stress injury in premature rat type II AECs, improve the cellular antioxidant capacity, stabilize the mitochondrial membrane potential, and reduce the inhibitory effect of hyperoxia on cell proliferation.

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

NASA Astrophysics Data System (ADS)

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.

Evaluation of a hydrogen peroxide-based system for high-level disinfection of vaginal ultrasound probes.

PubMed

Johnson, Stephen; Proctor, Matthew; Bluth, Edward; Smetherman, Dana; Baumgarten, Katherine; Troxclair, Laurie; Bienvenu, Michele

2013-10-01

Because of the complex process and the risk of errors associated with the glutaraldehyde-based solutions previously used at our institution for disinfection, our department has implemented a new method for high-level disinfection of vaginal ultrasound probes: the hydrogen peroxide-based Trophon system (Nanosonics, Alexandria, New South Wales, Australia). The aim of this study was to compare the time difference, safety, and sonographers' satisfaction between the glutaraldehyde-based Cidex (CIVCO Medical Solutions, Kalona, IA) and the hydrogen peroxide-based Trophon disinfection systems. The Institutional Review Board approved a 14-question survey administered to the 13 sonographers in our department. Survey questions addressed a variety of aspects of the disinfection processes with graded responses over a standardized 5-point scale. A process diagram was developed for each disinfection method with segmental timing analysis, and a cost analysis was performed. Nonvariegated analysis of the survey data with the Wilcoxon signed rank test showed a statistical difference in survey responses in favor of the hydrogen peroxide-based system over the glutaraldehyde-based system regarding efficiency (P = .0013), ease of use (P = .0013), ability to maintain work flow (P = .026), safety (P = .0026), fixing problems (P = .0158), time (P = .0011), and overall satisfaction (P = .0018). The glutaraldehyde-based system took 32 minutes versus 14 minutes for the hydrogen peroxide-based system; the hydrogen peroxide-based system saved on average 7.5 hours per week. The cost of the hydrogen peroxide-based system and weekly maintenance pays for itself if 1.5 more ultrasound examinations are performed each week. The hydrogen peroxide-based disinfection system was proven to be more efficient and viewed to be easier and safer to use than the glutaraldehyde-based system. The adoption of the hydrogen peroxide-based system led to higher satisfaction among sonographers.

Cystathionine γ-Lyase-Produced Hydrogen Sulfide Controls Endothelial NO Bioavailability and Blood Pressure.

PubMed

Szijártó, István András; Markó, Lajos; Filipovic, Milos R; Miljkovic, Jan Lj; Tabeling, Christoph; Tsvetkov, Dmitry; Wang, Ning; Rabelo, Luiza A; Witzenrath, Martin; Diedrich, André; Tank, Jens; Akahoshi, Noriyuki; Kamata, Shotaro; Ishii, Isao; Gollasch, Maik

2018-06-01

Hydrogen sulfide (H 2 S) and NO are important gasotransmitters, but how endogenous H 2 S affects the circulatory system has remained incompletely understood. Here, we show that CTH or CSE (cystathionine γ-lyase)-produced H 2 S scavenges vascular NO and controls its endogenous levels in peripheral arteries, which contribute to blood pressure regulation. Furthermore, eNOS (endothelial NO synthase) and phospho-eNOS protein levels were unaffected, but levels of nitroxyl were low in CTH-deficient arteries, demonstrating reduced direct chemical interaction between H 2 S and NO. Pretreatment of arterial rings from CTH-deficient mice with exogenous H 2 S donor rescued the endothelial vasorelaxant response and decreased tissue NO levels. Our discovery that CTH-produced H 2 S inhibits endogenous endothelial NO bioavailability and vascular tone is novel and fundamentally important for understanding how regulation of vascular tone is tailored for endogenous H 2 S to contribute to systemic blood pressure function. © 2018 American Heart Association, Inc.

Iron-catalyzed hydrogenation of bicarbonates and carbon dioxide to formates.

PubMed

Zhu, Fengxiang; Zhu-Ge, Ling; Yang, Guangfu; Zhou, Shaolin

2015-02-01

The catalytic hydrogenation of carbon dioxide and bicarbonate to formate has been explored extensively. The vast majority of the known active catalyst systems are based on precious metals. Herein, we describe an effective, phosphine-free, air- and moisture-tolerant catalyst system based on Knölker's iron complex for the hydrogenation of bicarbonate and carbon dioxide to formate. The catalyst system can hydrogenate bicarbonate at remarkably low hydrogen pressures (1-5 bar). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lunar true polar wander inferred from polar hydrogen.

PubMed

Siegler, M A; Miller, R S; Keane, J T; Laneuville, M; Paige, D A; Matsuyama, I; Lawrence, D J; Crotts, A; Poston, M J

2016-03-24

The earliest dynamic and thermal history of the Moon is not well understood. The hydrogen content of deposits near the lunar poles may yield insight into this history, because these deposits (which are probably composed of water ice) survive only if they remain in permanent shadow. If the orientation of the Moon has changed, then the locations of the shadowed regions will also have changed. The polar hydrogen deposits have been mapped by orbiting neutron spectrometers, and their observed spatial distribution does not match the expected distribution of water ice inferred from present-day lunar temperatures. This finding is in contrast to the distribution of volatiles observed in similar thermal environments at Mercury's poles. Here we show that polar hydrogen preserves evidence that the spin axis of the Moon has shifted: the hydrogen deposits are antipodal and displaced equally from each pole along opposite longitudes. From the direction and magnitude of the inferred reorientation, and from analysis of the moments of inertia of the Moon, we hypothesize that this change in the spin axis, known as true polar wander, was caused by a low-density thermal anomaly beneath the Procellarum region. Radiogenic heating within this region resulted in the bulk of lunar mare volcanism and altered the density structure of the Moon, changing its moments of inertia. This resulted in true polar wander consistent with the observed remnant polar hydrogen. This thermal anomaly still exists and, in part, controls the current orientation of the Moon. The Procellarum region was most geologically active early in lunar history, which implies that polar wander initiated billions of years ago and that a large portion of the measured polar hydrogen is ancient, recording early delivery of water to the inner Solar System. Our hypothesis provides an explanation for the antipodal distribution of lunar polar hydrogen, and connects polar volatiles to the geologic and geophysical evolution of the Moon and the bombardment history of the early Solar System.

Linear Test Bed. Volume 2: Test Bed No. 2. [linear aerospike test bed for thrust vector control

NASA Technical Reports Server (NTRS)

1974-01-01

Test bed No. 2 consists of 10 combustors welded in banks of 5 to 2 symmetrical tubular nozzle assemblies, an upper stationary thrust frame, a lower thrust frame which can be hinged, a power package, a triaxial combustion wave ignition system, a pneumatic control system, pneumatically actuated propellant valves, a purge and drain system, and an electrical control system. The power package consists of the Mark 29-F fuel turbopump, the Mark 29-0 oxidizer turbopump, a gas generator assembly, and propellant ducting. The system, designated as a linear aerospike system, was designed to demonstrate the feasibility of the concept and to explore technology related to thrust vector control, thrust vector optimization, improved sequencing and control, and advanced ignition systems. The propellants are liquid oxygen/liquid hydrogen. The system was designed to operate at 1200-psia chamber pressure at an engine mixture ratio of 5.5. With 10 combustors, the sea level thrust is 95,000 pounds.

Sensitive hydrogen leak detector

DOEpatents

Myneni, G.R.

1999-08-03

A sensitive hydrogen leak detector system is described which uses passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor. 1 fig.

Nickel-hydrogen bipolar battery system

NASA Technical Reports Server (NTRS)

Thaller, L. H.

1982-01-01

Rechargeable nickel-hydrogen systems are described that more closely resemble a fuel cell system than a traditional nickel-cadmium battery pack. This was stimulated by the currently emerging requirements related to large manned and unmanned low Earth orbit applications. The resultant nickel-hydrogen battery system should have a number of features that would lead to improved reliability, reduced costs as well as superior energy density and cycle lives as compared to battery systems constructed from the current state-of-the-art nickel-hydrogen individual pressure vessel cells.

Chemical Stockpile Disposal Program. Monitoring Concept Plan

DTIC Science & Technology

1987-09-10

Government Owned Contractor Operated GPL General Population Limit H Bis (2-chloroethyl) sulfide or Levinstein Mustard (75% purity) P HCI Hydrogen Chloride... government agencies, will provide technical expertise and equipment necessary to monitor affected areas and resources. 2-25 SECTIO 3 PROCESS CONTROL AND...conditions and to issue correct emergency response notifications, if required. The process sensors work in conjunction with the process control system and

Reduction of liquid hydrogen boiloff: Optimal reliquefaction system design and cost study

NASA Technical Reports Server (NTRS)

1978-01-01

A preliminary design and economic analysis of candidate hydrogen reliquefaction systems was performed. All candidate systems are of the same general type; differences and size, compressor arrangement, and amount of hydrogen venting. The potential application of the hydrogen reliquefaction will be to reduce the boil-off from the 850,000 gallon storage dewars at LC-39.

University coal research/historically black colleges and universities and other minority institutions contractors review meeting

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2006-07-01

A variety of papers/posters were presented on topics concerning power generation, including solid oxide fuel cells, hydrogen production, mercury as a combustion product, carbon dioxide separation from flue gas. A total of 31 presentations in slide/overview/viewgraph form and with a separate abstract are available online (one in abstract form only) and 24 poster papers (text). In addition 41 abstracts only are available. Papers of particular interest include: Hydrogen production from hydrogen sulfide in IGCC power plants; Oxidation of mercury in products of coal combustion; Computer aided design of advanced turbine aerofoil alloys for industrial gas turbines in coal fired environments;more » Developing engineered fuel using flyash and biomass; Conversion of hydrogen sulfide in coal gases to elemental sulfur with monolithic catalysts; Intelligent control via wireless sensor networks for advanced coal combustion systems; and Investment of fly ash and activated carbon obtained from pulverized coal boilers (poster).« less

On the Extraction of Aromatic Compounds from Hydrocarbons by Imidazolium Ionic Liquids

PubMed Central

Cassol, Cláudia C.; Umpierre, Alexandre P.; Ebeling, Günter; Ferrera, Bauer; Chiaro, Sandra S. X.; Dupont, Jairton

2007-01-01

The liquid-liquid equilibrium for the ternary system formed by n-octane and aromatic (alkylbenzenes) and heteroaromatic compounds (nitrogen and sulfur containing heterocyles) and 1-alkyl-3-methylimidazolium ionic liquids (ILs) associated with various anions has been investigated. The selectivity on the extraction of a specific aromatic compound is influenced by anion volume, hydrogen bond strength between the anion and the imidazolium cation and the length of the 1-methyl-3-alkylimidazolium alkyl side chain. The interaction of alkylbenzenes and sulfur heterocyles with the IL is preferentially through CH-π hydrogen bonds and the quantity of these aromatics in the IL phase decreases with the increase of the steric hindrance imposed by the substituents on the aromatic nucleus. In the case of nitrogen heterocycles the interaction occurs preferentially through N(heteroaromatic)-H(imidazolium) hydrogen bonds and the extraction process is largely controlled by the nitrogen heterocycle pKa. Competitive extraction experiments suggest that benzene, pyridine and dibenzothiophene do not compete for the same hydrogen bond sites of the IL.

KSC-2009-1949

NASA Image and Video Library

2009-03-03

CAPE CANAVERAL, Fla. – One of the three thoroughly inspected gaseous hydrogen flow control valves is shown after its arrival at NASA's Kennedy Space Center in Florida. Technicians installed and retested them in space shuttle Discovery. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have worked to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Space Shuttle Program managers decided to replace Discovery's valves with others that have undergone a detailed eddy current inspection. Program managers will review the testing and determine whether to meet on March 6 for the Flight Readiness Review for the STS-119 mission. Launch of Discovery tentatively is targeted for March 12. Photo credit: NASA/Chris Rhodes

KSC-2009-1950

NASA Image and Video Library

2009-03-03

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians prepare to install three gaseous hydrogen flow control valves on space shuttle Discovery. The valves were retested after installation. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have worked to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Space Shuttle Program managers decided to replace Discovery's valves with others that have undergone a detailed eddy current inspection. Program managers will review the testing and determine whether to meet on March 6 for the Flight Readiness Review for the STS-119 mission. Launch of Discovery tentatively is targeted for March 12. Photo credit: NASA/Chris Rhodes

KSC-2009-1951

NASA Image and Video Library

2009-03-03

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians install three gaseous hydrogen flow control valves on space shuttle Discovery. The valves were retested after installation. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have worked to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Space Shuttle Program managers decided to replace Discovery's valves with others that have undergone a detailed eddy current inspection. Program managers will review the testing and determine whether to meet on March 6 for the Flight Readiness Review for the STS-119 mission. Launch of Discovery tentatively is targeted for March 12. Photo credit: NASA/Chris Rhodes

KSC-2009-1948

NASA Image and Video Library

2009-03-03

CAPE CANAVERAL, Fla. – One of the three thoroughly inspected gaseous hydrogen flow control valves is shown after its arrival at NASA's Kennedy Space Center in Florida. Technicians installed and retested them in space shuttle Discovery. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have worked to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Space Shuttle Program managers decided to replace Discovery's valves with others that have undergone a detailed eddy current inspection. Program managers will review the testing and determine whether to meet on March 6 for the Flight Readiness Review for the STS-119 mission. Launch of Discovery tentatively is targeted for March 12. Photo credit: NASA/Chris Rhodes

Structural active cooling applications for the Space Shuttle.

NASA Technical Reports Server (NTRS)

Masek, R. V.; Niblock, G. A.; Huneidi, F.

1972-01-01

Analytic and experimental studies have been conducted to evaluate a number of active cooling approaches to structural thermal protection for the Space Shuttle. The primary emphasis was directed toward the thermal protection system. Trade study results are presented for various heat shield material and TPS arrangements. Both metallic and reusable surface insulation (RSI) concepts were considered. Active systems heat sinks consisted of hydrogen, phase change materials, and expendable water. If consideration is given only to controlling the surface temperature, passive TPS was found to provide the most efficient system. Use of active cooling which incorporates some interior temperature control made the thermally less efficient RSI system more attractive.

Evaluation of Lighting Systems, Carbon Sources, and Bacteria Cultures on Photofermentative Hydrogen Production.

PubMed

Hu, Chengcheng; Choy, Sing-Ying; Giannis, Apostolos

2018-05-01

Fluorescent and incandescent lighting systems were applied for batch photofermentative hydrogen production by four purple non-sulfur photosynthetic bacteria (PNSB). The hydrogen production efficiency of Rhodopseudomonas palustris, Rhodobacter sphaeroides, Rhodobacter capsulatus, and Rhodospirillum rubrum was evaluated using different carbon sources (acetate, butyrate, lactate, and malate). Incandescent light was found to be more effective for bacteria cell growth and hydrogen production. It was observed that PNSB followed substrate selection criteria for hydrogen production. Only R. palustris was able to produce hydrogen using most carbon sources. Cell density was almost constant, but cell growth rate and hydrogen production were significantly varied under the different lighting systems. The kinetics study suggested that initial substrate concentration had a positive correlation with lag phase duration. Among the PNSB, R. palustris grew faster and had higher hydrogen yields of 1.58, 4.92, and 2.57 mol H 2 /mol using acetate, butyrate, and lactate, respectively. In the integrative approach with dark fermentation effluents rich in organic acids, R. palustris should be enriched in the phototrophic microbial consortium of the continuous hydrogen production system.

New potentials for conventional aircraft when powered by hydrogen-enriched gasoline

NASA Technical Reports Server (NTRS)

Menard, W. A.; Moynihan, P. I.; Rupe, J. H.

1976-01-01

Overall system efficiency and performance of a Beech Model 20 Duke aircraft was studied to provide analytical representations of an aircraft piston engine system, including all essential components required for onboard hydrogen generation. Lower emission levels and a 20% reduction in fuel consumption may be obtained by using a catalytic hydrogen generator, incorporated as part of the air induction system, to generate hydrogen by breaking down small amounts of the aviation gasoline used in the normal propulsion system. This hydrogen is then mixed with gasoline and compressed air from the turbocharger before entering the engine combustion chamber. The special properties of the hydrogen-enriched gasoline allow the engine to operate at ultra lean fuel/air ratios, resulting in higher efficiencies.

Hydrogen isotope exchange in a metal hydride tube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, David B.

2014-09-01

This report describes a model of the displacement of one hydrogen isotope within a metal hydride tube by a different isotope in the gas phase that is blown through the tube. The model incorporates only the most basic parameters to make a clear connection to the theory of open-tube gas chromatography, and to provide a simple description of how the behavior of the system scales with controllable parameters such as gas velocity and tube radius. A single tube can be seen as a building block for more complex architectures that provide higher molar flow rates or other advanced design goals.

Hydropyrolysis process

DOEpatents

Ullman, Alan Z.; Silverman, Jacob; Friedman, Joseph

1986-01-01

An improved process for producing a methane-enriched gas wherein a hydrogen-deficient carbonaceous material is treated with a hydrogen-containing pyrolysis gas at an elevated temperature and pressure to produce a product gas mixture including methane, carbon monoxide and hydrogen. The improvement comprises passing the product gas mixture sequentially through a water-gas shift reaction zone and a gas separation zone to provide separate gas streams of methane and of a recycle gas comprising hydrogen, carbon monoxide and methane for recycle to the process. A controlled amount of steam also is provided which when combined with the recycle gas provides a pyrolysis gas for treatment of additional hydrogen-deficient carbonaceous material. The amount of steam used and the conditions within the water-gas shift reaction zone and gas separation zone are controlled to obtain a steady-state composition of pyrolysis gas which will comprise hydrogen as the principal constituent and a minor amount of carbon monoxide, steam and methane so that no external source of hydrogen is needed to supply the hydrogen requirements of the process. In accordance with a particularly preferred embodiment, conditions are controlled such that there also is produced a significant quantity of benzene as a valuable coproduct.

Carbon Dioxide-Free Hydrogen Production with Integrated Hydrogen Separation and Storage.

PubMed

Dürr, Stefan; Müller, Michael; Jorschick, Holger; Helmin, Marta; Bösmann, Andreas; Palkovits, Regina; Wasserscheid, Peter

2017-01-10

An integration of CO 2 -free hydrogen generation through methane decomposition coupled with hydrogen/methane separation and chemical hydrogen storage through liquid organic hydrogen carrier (LOHC) systems is demonstrated. A potential, very interesting application is the upgrading of stranded gas, for example, gas from a remote gas field or associated gas from off-shore oil drilling. Stranded gas can be effectively converted in a catalytic process by methane decomposition into solid carbon and a hydrogen/methane mixture that can be directly fed to a hydrogenation unit to load a LOHC with hydrogen. This allows for a straight-forward separation of hydrogen from CH 4 and conversion of hydrogen to a hydrogen-rich LOHC material. Both, the hydrogen-rich LOHC material and the generated carbon on metal can easily be transported to destinations of further industrial use by established transport systems, like ships or trucks. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Borazine-boron nitride hybrid hydrogen storage system

DOEpatents

Narula, Chaitanya K [Knoxville, TN; Simonson, J Michael [Knoxville, TN; Maya, Leon [Knoxville, TN; Paine, Robert T [Albuquerque, NM

2008-04-22

A hybrid hydrogen storage composition includes a first phase and a second phase adsorbed on the first phase, the first phase including BN for storing hydrogen by physisorption and the second phase including a borazane-borazine system for storing hydrogen in combined form as a hydride.

Biological removal of air loaded with a hydrogen sulfide and ammonia mixture.

PubMed

Chen, Ying-xu; Yin, Jun; Fang, Shi

2004-01-01

The nuisance impact of air pollutant emissions from wastewater pumping stations is a major issue of concern to China. Hydrogen sulfide and ammonia are commonly the primary odor and are important targets for removal. An alternative control technology, biofiltration, was studied. The aim of this study is to investigate the potential of unit systems packed with compost in terms of ammonia and hydrogen sulfide emissions treatment, and to establish optimal operating conditions for a full-scale conceptual design. The laboratory scale biofilter packed with compost was continuously supplied with hydrogen sulfide and ammonia gas mixtures. A volumetric load of less than 150 gH2S/(m3 x d) and 230 gNH3/(m3 x d) was applied for about fifteen weeks. Hydrogen sulfide and ammonia elimination occurred in the biofilter simultaneously. The removal efficiency, removal capacity and removal kinetics in the biofilter were studied. The hydrogen sulfide removal efficiency reached was very high above 99%, and ammonia removal efficiency was about 80%. Hydrogen sulfide was oxidized into sulphate. The ammonia oxidation products were nitrite and nitrate. Ammonia in the biofilter was mainly removed by adsorption onto the carrier material and by absorption into the water fraction of the carrier material. High percentages of hydrogen sulfide or ammonia were oxidized in the first section of the column. Through kinetics analysis, the presence of ammonia did not hinder the hydrogen sulfide removal. According to the relationship between pressure drop and gas velocity for the biofilter and Reynolds number, non-Darcy flow can be assumed to represent the flow in the medium.

Genetically encoded proton sensors reveal activity-dependent pH changes in neurons.

PubMed

Raimondo, Joseph V; Irkle, Agnese; Wefelmeyer, Winnie; Newey, Sarah E; Akerman, Colin J

2012-01-01

The regulation of hydrogen ion concentration (pH) is fundamental to cell viability, metabolism, and enzymatic function. Within the nervous system, the control of pH is also involved in diverse and dynamic processes including development, synaptic transmission, and the control of network excitability. As pH affects neuronal activity, and can also itself be altered by neuronal activity, the existence of tools to accurately measure hydrogen ion fluctuations is important for understanding the role pH plays under physiological and pathological conditions. Outside of their use as a marker of synaptic release, genetically encoded pH sensors have not been utilized to study hydrogen ion fluxes associated with network activity. By combining whole-cell patch clamp with simultaneous two-photon or confocal imaging, we quantified the amplitude and time course of neuronal, intracellular, acidic transients evoked by epileptiform activity in two separate in vitro models of temporal lobe epilepsy. In doing so, we demonstrate the suitability of three genetically encoded pH sensors: deGFP4, E(2)GFP, and Cl-sensor for investigating activity-dependent pH changes at the level of single neurons.

Final Environmental Impact Statement (EIS) for the Space Nuclear Thermal Propulsion (SNTP) program

NASA Astrophysics Data System (ADS)

1991-09-01

A program has been proposed to develop the technology and demonstrate the feasibility of a high-temperature particle bed reactor (PBR) propulsion system to be used to power an advanced second stage nuclear rocket engine. The purpose of this Final Environmental Impact Statement (FEIS) is to assess the potential environmental impacts of component development and testing, construction of ground test facilities, and ground testing. Major issues and goals of the program include the achievement and control of predicted nuclear power levels; the development of materials that can withstand the extremely high operating temperatures and hydrogen flow environments; and the reliable control of cryogenic hydrogen and hot gaseous hydrogen propellant. The testing process is designed to minimize radiation exposure to the environment. Environmental impact and mitigation planning are included for the following areas of concern: (1) Population and economy; (2) Land use and infrastructure; (3) Noise; (4) Cultural resources; (5) Safety (non-nuclear); (6) Waste; (7) Topography; (8) Geology; (9) Seismic activity; (10) Water resources; (11) Meteorology/Air quality; (12) Biological resources; (13) Radiological normal operations; (14) Radiological accidents; (15) Soils; and (16) Wildlife habitats.

Hydrogen Energy Storage and Power-to-Gas: Establishing Criteria for Successful Business Cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eichman, Joshua; Melaina, Marc

As the electric sector evolves and increasing amounts of variable generation are installed on the system, there are greater needs for system flexibility, sufficient capacity and greater concern for overgeneration. As a result there is growing interest in exploring the role of energy storage and demand response technologies to support grid needs. Hydrogen is a versatile feedstock that can be used in a variety of applications including chemical and industrial processes, as well as a transportation fuel and heating fuel. Traditionally, hydrogen technologies focus on providing services to a single sector; however, participating in multiple sectors has the potential tomore » provide benefits to each sector and increase the revenue for hydrogen technologies. The goal of this work is to explore promising system configurations for hydrogen systems and the conditions that will make for successful business cases in a renewable, low-carbon future. Current electricity market data, electric and gas infrastructure data and credit and incentive information are used to perform a techno-economic analysis to identify promising criteria and locations for successful hydrogen energy storage and power-to-gas projects. Infrastructure data will be assessed using geographic information system applications. An operation optimization model is used to co-optimizes participation in energy and ancillary service markets as well as the sale of hydrogen. From previous work we recognize the great opportunity that energy storage and power-to-gas but there is a lack of information about the economic favorability of such systems. This work explores criteria for selecting locations and compares the system cost and potential revenue to establish competitiveness for a variety of equipment configurations. Hydrogen technologies offer unique system flexibility that can enable interactions between multiple energy sectors including electric, transport, heating fuel and industrial. Previous research established that hydrogen technologies, and in particular electrolyzers, can respond fast enough and for sufficient duration to participate in electricity markets. This work recognizes that participation in electricity markets and integration with the gas system can enhance the revenue streams available for hydrogen storage systems and quantifies the economic competitiveness and of these systems. A few of the key results include 1) the most valuable revenue stream for hydrogen systems is to sell the produced hydrogen, 2) participation in both energy and ancillary service markets yields the greatest revenue and 3) electrolyzers acting as demand response devices are particularly favorable.« less

Fuzzy logic controller versus classical logic controller for residential hybrid solar-wind-storage energy system

NASA Astrophysics Data System (ADS)

Derrouazin, A.; Aillerie, M.; Mekkakia-Maaza, N.; Charles, J. P.

2016-07-01

Several researches for management of diverse hybrid energy systems and many techniques have been proposed for robustness, savings and environmental purpose. In this work we aim to make a comparative study between two supervision and control techniques: fuzzy and classic logics to manage the hybrid energy system applied for typical housing fed by solar and wind power, with rack of batteries for storage. The system is assisted by the electric grid during energy drop moments. A hydrogen production device is integrated into the system to retrieve surplus energy production from renewable sources for the household purposes, intending the maximum exploitation of these sources over years. The models have been achieved and generated signals for electronic switches command of proposed both techniques are presented and discussed in this paper.

Current Status of Study on Hydrogen Production with Space Solar Power Systems (SSPS)

NASA Astrophysics Data System (ADS)

Mori, M.; Kagawa, H.; Nagayama, H.; Saito, Y.

2004-12-01

Japan Aerospace Exploration Agency (JAXA) has been conducting studies on Space Solar Power Systems (SSPS) using microwave and laser beams for years since FY1998 organizing a special committee and working groups. The microwave based SSPS are huge solar power systems that generate GW power by solar cells. The electric power is transmitted via microwave from the SSPS to the ground. In the laser based SSPS, a solar condenser equipped with lenses or mirrors and laser-generator would be put into orbit. A laser beam would be sent to Earth-based hydrogen generating device. We are proposing a roadmap that consists of a stepwise approach to achieve commercial SSPS in 20-30 years. The first step is 50kW class Technology Demonstration Satellite to demonstrate microwave power transmission. The second step is to demonstrate robotic assembly of 10MW class large scale flexible structure in space on ISS co-orbit. The third step is to build a prototype SSPS in GEO. The final step is to build commercial SSPS in GEO. We continue the study of SSPS concepts and architectures, technology flight demonstration and major technology development. System design of tens of kW class Technology Demonstration Satellite and conceptual study of 10MW class demonstration system on ISS co-orbit are also conducted. Several key technologies which are needed to be developed in appropriate R&D roadmap, such as high-voltage solar cell array, fiber type of direct solar pumping solid-state laser, high efficiency magnetron, thermal control technology and control technology of large scale flexible structure etc. are also investigated. In the study of concept design of commercial SSPS mentioned above, we have studied some configurations of both microwave based SSPS and laser based SSPS. In case of microwave based SSPS, the solar energy must be converted to electricity and then converted to a microwave beam. The on-ground rectifying antenna will collect the microwave beam and convert it to electricity to connect to commercial power grids. From the past experiences of the conceptual design of the1GW class SSPS, it is clear that system with the mirrors and modularized unit which integrated solar cells and microwave power transmitters is promising. In this type of SSPS, the solar lights are directed to the energy conversion unit integrated solar cells and microwave power transmitters using mirrors. The key factor in designing systems is feasibility of thermal system. Considering above these factors, some reference models are being considered now. FY2003 reference model is the model for formation flight without the center truss which connect to primary mirrors to energy conversion unit. Using this model as basis, we are carrying out examination from various viewpoints aiming at the cost minimum to build and maintain the systems. In case of laser based SSPS, the laser beam would be directly produced from the solar light using the direct solar pumping solid-state laser device. This laser beams would be collected on ground and used to produce hydrogen from seawater. The receiving / energy conversion station is settled on an ocean, and producing hydrogen can be stored and transported by ships to consumers. In designing laser based SSPS, conversion efficiency of the direct solar pumping solid-state laser and feasibility of thermal system are critical factors. Since magnification of solar concentrator is very high, improvement of thermal control system is important. Feasibility of its ground facilities and production technology of hydrogen using laser beams has been also studied. Both hydrogen generating systems with photo-catalyst device and electrolytic ones have been examined. From the past experiences of this study, high efficient electric power generating technology using the solar cell which suited the wavelength of laser is promising. The life cycle cost model of laser based SSPS was created and evaluated its validity. Sensitivity analysis of laser based SSPS are also continued aiming at hydrogen generating cost of around 20 cent per Nm3 . This paper presents a summary of studies on SSPS that JAXA has examined.

Performance of a 10-kJ SMES model cooled by liquid hydrogen thermo-siphon flow for ASPCS study

NASA Astrophysics Data System (ADS)

Makida, Y.; Shintomi, T.; Hamajima, T.; Ota, N.; Katsura, M.; Ando, K.; Takao, T.; Tsuda, M.; Miyagi, D.; Tsujigami, H.; Fujikawa, S.; Hirose, J.; Iwaki, K.; Komagome, T.

2015-12-01

We propose a new electrical power storage and stabilization system, called an Advanced Superconducting Power Conditioning System (ASPCS), which consists of superconducting magnetic energy storage (SMES) and hydrogen energy storage, converged on a liquid hydrogen station for fuel cell vehicles. A small 10- kJ SMES system, in which a BSCCO coil cooled by liquid hydrogen was installed, was developed to create an experimental model of an ASPCS. The SMES coil is conductively cooled by liquid hydrogen flow through a thermo-siphon line under a liquid hydrogen buffer tank. After fabrication of the system, cooldown tests were carried out using liquid hydrogen. The SMES coil was successfully charged up to a nominal current of 200 A. An eddy current loss, which was mainly induced in pure aluminum plates pasted onto each pancake coils for conduction cooling, was also measured.

Renewable Electrolysis | Hydrogen and Fuel Cells | NREL

Science.gov Websites

variable-input power conditions Designing and developing shared power-electronics packages and controllers Development NREL develops power electronics interfaces for renewable electrolysis systems to characterize and constant voltage DC bus and power electronics to regulate power output and to convert wild alternating

Hydrogen storage container

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jy-An John; Feng, Zhili; Zhang, Wei

An apparatus and system is described for storing high-pressure fluids such as hydrogen. An inner tank and pre-stressed concrete pressure vessel share the structural and/or pressure load on the inner tank. The system and apparatus provide a high performance and low cost container while mitigating hydrogen embrittlement of the metal tank. System is useful for distributing hydrogen to a power grid or to a vehicle refueling station.

Large-capacity pump vaporizer for liquid hydrogen and nitrogen

NASA Technical Reports Server (NTRS)

Hauser, J. A.

1970-01-01

Pump vaporizer system delivers 500 standard cubic feet per minute of hydrogen or nitrogen, one system delivers both gases. Vacuum-jacketed pump discharges liquid hydrogen or liquid nitrogen into vaporizing system heated by ambient air. Principal characteristics of the flow and discharge system, pump, and vaporizer are given.

Liquid Hydrogen Zero-Boiloff Testing and Analysis for Long-Term Orbital Storage

NASA Astrophysics Data System (ADS)

Hastings, L. J.; Hedayat, A.; Bryant, C. B.; Flachbart, R. H.

2004-06-01

Advancement of cryocooler and passive insulation technologies in recent years has improved the prospects for zero-boiloff (ZBO) storage of cryogenic fluids. The ZBO concept involves the use of a cryocooler/radiator system to balance storage system incoming and extracted energy such that zero boiloff (no venting) occurs. A large-scale demonstration of the ZBO concept was conducted using the Marshall Space Flight Center (MSFC) multipurpose hydrogen test bed (MHTB) along with a commercial cryocooler unit. The liquid hydrogen (LH2) was withdrawn from the tank, passed through the cryocooler heat exchanger, and then the chilled liquid was sprayed back into the tank through a spray bar. The spray bar recirculation system was designed to provide destratification independent of ullage and liquid positions in a zero-gravity environment. The insulated MHTB tank, combined with the vacuum chamber conditions, enabled orbital storage simulation. ZBO was demonstrated for fill levels of 95%, 50%, and 25%. At each fill level, a steady-state boiloff test was performed prior to operating the cryocooler to establish the baseline heat leak. Control system logic based on real-time thermal data and ullage pressure response was implemented to automatically provide a constant tank pressure. A comparison of test data and analytical results is presented in this paper.

Hydrogen desorption using honeycomb finned heat exchangers integrated in adsorbent storage systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corgnale, Claudio; Hardy, Bruce; Chahine, Richard

One of the main technical hurdles associated with adsorbent based hydrogen storage systems is relative to their ability to discharge hydrogen effectively, as dictated by fuel cell requirements. In this study, a new honeycomb finned heat exchanger concept was examined to evaluate its potential as a heat transfer system for hydrogen desorption. A bench scale 0.5 L vessel was equipped with the proposed heat exchanger, filled with MOF-5® adsorbent material. The heating power, required to desorb hydrogen, was provided by a 100 W electric heater placed in the center of the honeycomb structure. Two desorption tests, at room temperature andmore » under cryogenic temperatures, were carried out to evaluate the hydrogen desorption performance of the proposed system under different operating conditions. The bench scale vessel performance was verified from both an experimental and a modeling point of view, demonstrating the ability to desorb about 45% of the adsorbed hydrogen in reduced time and applying low heating power. Further modeling analyses were also carried out showing the potential of the proposed system to reach high hydrogen discharging rates at cryogenic temperature conditions and operating pressures between 100 bar and 5 bar. The proposed adsorption system also demonstrated to be able to discharge all the available hydrogen in less than 500 s operating at cryogenic conditions and with a nominal heating power of 100 W.« less

Hydrogen desorption using honeycomb finned heat exchangers integrated in adsorbent storage systems

DOE PAGES

Corgnale, Claudio; Hardy, Bruce; Chahine, Richard; ...

2018-03-01

One of the main technical hurdles associated with adsorbent based hydrogen storage systems is relative to their ability to discharge hydrogen effectively, as dictated by fuel cell requirements. In this study, a new honeycomb finned heat exchanger concept was examined to evaluate its potential as a heat transfer system for hydrogen desorption. A bench scale 0.5 L vessel was equipped with the proposed heat exchanger, filled with MOF-5® adsorbent material. The heating power, required to desorb hydrogen, was provided by a 100 W electric heater placed in the center of the honeycomb structure. Two desorption tests, at room temperature andmore » under cryogenic temperatures, were carried out to evaluate the hydrogen desorption performance of the proposed system under different operating conditions. The bench scale vessel performance was verified from both an experimental and a modeling point of view, demonstrating the ability to desorb about 45% of the adsorbed hydrogen in reduced time and applying low heating power. Further modeling analyses were also carried out showing the potential of the proposed system to reach high hydrogen discharging rates at cryogenic temperature conditions and operating pressures between 100 bar and 5 bar. The proposed adsorption system also demonstrated to be able to discharge all the available hydrogen in less than 500 s operating at cryogenic conditions and with a nominal heating power of 100 W.« less

In situ study at high pressure and temperature of the environment of water in hydrous Na and Ca aluminosilicate melts and coexisting aqueous fluids

NASA Astrophysics Data System (ADS)

Le Losq, Charles; Dalou, Célia; Mysen, Bjorn O.

2017-07-01

The bonding and speciation of water dissolved in Na silicate and Na and Ca aluminosilicate melts were inferred from in situ Raman spectroscopy of the samples, in hydrothermal diamond anvil cells, while at crustal temperature and pressure conditions. Raman data were also acquired on Na silicate and Na and Ca aluminosilicate glasses, quenched from hydrous melts equilibrated at high temperature and pressure in a piston cylinder apparatus. In the hydrous melts, temperature strongly influences O-H stretching ν(O-H) signals, reflecting its control on the bonding of protons between different molecular complexes. Pressure and melt composition effects are much smaller and difficult to discriminate with the present data. However, the chemical composition of the melt + fluid system influences the differences between the ν(O-H) signals from the melts and the fluids and, hence, between their hydrogen partition functions. Quenching modifies the O-H stretching signals: strong hydrogen bonds form in the glasses below the glass transition temperature Tg, and this phenomenon depends on glass composition. Therefore, glasses do not necessarily record the O-H stretching signal shape in melts near Tg. The melt hydrogen partition function thus cannot be assessed with certainty using O-H stretching vibration data from glasses. From the present results, the ratio of the hydrogen partition functions of hydrous silicate melts and aqueous fluids mostly depends on temperature and the bulk melt + fluid system chemical composition. This implies that the fractionation of hydrogen isotopes between magmas and aqueous fluids in water-saturated magmatic systems with differences in temperature and bulk chemical composition will be different.

29 CFR 1910.103 - Hydrogen.

Code of Federal Regulations, 2011 CFR

2011-07-01

... containers, pressure regulators, safety relief devices, manifolds, interconnecting piping and controls. The... against physical damage and against tampering. (d) Cabinets or housings containing hydrogen control or... valve shall be of the remote control type with no connections, flanges, or other appurtenances (other...

29 CFR 1910.103 - Hydrogen.

Code of Federal Regulations, 2012 CFR

2012-07-01

... containers, pressure regulators, safety relief devices, manifolds, interconnecting piping and controls. The... against physical damage and against tampering. (d) Cabinets or housings containing hydrogen control or... valve shall be of the remote control type with no connections, flanges, or other appurtenances (other...

Overview of the U.S. DOE Hydrogen Safety, Codes and Standards Program. Part 4: Hydrogen Sensors; Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buttner, William J.; Rivkin, Carl; Burgess, Robert

Hydrogen sensors are recognized as a critical element in the safety design for any hydrogen system. In this role, sensors can perform several important functions including indication of unintended hydrogen releases, activation of mitigation strategies to preclude the development of dangerous situations, activation of alarm systems and communication to first responders, and to initiate system shutdown. The functionality of hydrogen sensors in this capacity is decoupled from the system being monitored, thereby providing an independent safety component that is not affected by the system itself. The importance of hydrogen sensors has been recognized by DOE and by the Fuel Cellmore » Technologies Office's Safety and Codes Standards (SCS) program in particular, which has for several years supported hydrogen safety sensor research and development. The SCS hydrogen sensor programs are currently led by the National Renewable Energy Laboratory, Los Alamos National Laboratory, and Lawrence Livermore National Laboratory. The current SCS sensor program encompasses the full range of issues related to safety sensors, including development of advance sensor platforms with exemplary performance, development of sensor-related code and standards, outreach to stakeholders on the role sensors play in facilitating deployment, technology evaluation, and support on the proper selection and use of sensors.« less

Effectiveness of ultraviolet devices and hydrogen peroxide systems for terminal room decontamination: Focus on clinical trials.

PubMed

Weber, David J; Rutala, William A; Anderson, Deverick J; Chen, Luke F; Sickbert-Bennett, Emily E; Boyce, John M

2016-05-02

Over the last decade, substantial scientific evidence has accumulated that indicates contamination of environmental surfaces in hospital rooms plays an important role in the transmission of key health care-associated pathogens (eg, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridium difficile, Acinetobacter spp). For example, a patient admitted to a room previously occupied by a patient colonized or infected with one of these pathogens has a higher risk for acquiring one of these pathogens than a patient admitted to a room whose previous occupant was not colonized or infected. This risk is not surprising because multiple studies have demonstrated that surfaces in hospital rooms are poorly cleaned during terminal cleaning. To reduce surface contamination after terminal cleaning, no touch methods of room disinfection have been developed. This article will review the no touch methods, ultraviolet light devices, and hydrogen peroxide systems, with a focus on clinical trials which have used patient colonization or infection as an outcome. Multiple studies have demonstrated that ultraviolet light devices and hydrogen peroxide systems have been shown to inactivate microbes experimentally plated on carrier materials and placed in hospital rooms and to decontaminate surfaces in hospital rooms naturally contaminated with multidrug-resistant pathogens. A growing number of clinical studies have demonstrated that ultraviolet devices and hydrogen peroxide systems when used for terminal disinfection can reduce colonization or health care-associated infections in patients admitted to these hospital rooms. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Combination of cupric ion with hydroxylamine and hydrogen peroxide for the control of bacterial biofilms on RO membranes.

PubMed

Lee, Hye-Jin; Kim, Hyung-Eun; Lee, Changha

2017-03-01

Combinations of Cu(II) with hydroxylamine (HA) and hydrogen peroxide (H 2 O 2 ) (i.e., Cu(II)/HA, Cu(II)/H 2 O 2 , and Cu(II)/HA/H 2 O 2 systems) were investigated for the control of P. aeruginosa biofilms on reverse osmosis (RO) membranes. These Cu(II)-based disinfection systems effectively inactivated P. aeruginosa cells, exhibiting different behaviors depending on the state of bacterial cells (planktonic or biofilm) and the condition of biofilm growth and treatment (normal or pressurized condition). The Cu(II)/HA and Cu(II)/HA/H 2 O 2 systems were the most effective reagents for the inactivation of planktonic cells. However, these systems were not effective in inactivating cells in biofilms on the RO membranes possibly due to the interactions of Cu(I) with extracellular polymeric substances (EPS), where biofilms were grown and treated in center for disease control (CDC) reactors. Different from the results using CDC reactors, in a pressurized cross-flow RO filtration unit, the Cu(II)/HA/H 2 O 2 treatment significantly inactivated biofilm cells formed on the RO membranes, successfully recovering the permeate flux reduced by the biofouling. The pretreatment of feed solutions by Cu(II)/HA and Cu(II)/HA/H 2 O 2 systems (applied before the biofilm formation) effectively mitigated the permeate flux decline by preventing the biofilm growth on the RO membranes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Coordination nano-space as stage of hydrogen ortho–para conversion

PubMed Central

Kosone, Takashi; Hori, Akihiro; Nishibori, Eiji; Kubota, Yoshiki; Mishima, Akio; Ohba, Masaaki; Tanaka, Hiroshi; Kato, Kenichi; Kim, Jungeun; Real, José Antonio; Kitagawa, Susumu; Takata, Masaki

2015-01-01

The ability to design and control properties of nano-sized space in porous coordination polymers (PCPs) would provide us with an ideal stage for fascinating physical and chemical phenomena. We found an interconversion of nuclear-spin isomers for hydrogen molecule H2 adsorbed in a Hofmann-type PCP, {Fe(pz)[Pd(CN)4]} (pz=pyrazine), by the temperature dependence of Raman spectra. The ortho (o)–para (p) conversion process of H2 is forbidden for an isolated molecule. The charge density study using synchrotron radiation X-ray diffraction reveals the electric field generated in coordination nano-space. The present results corroborate similar findings observed on different systems and confirm that o–p conversion can occur on non-magnetic solids and that electric field can induce the catalytic hydrogen o–p conversion. PMID:26587262

Novel Anaerobic Wastewater Treatment System for Energy Generation at Forward Operating Bases

DTIC Science & Technology

2016-08-01

AnMBR) technology with clinoptilolite ion exchange and GreenBox™ ammonia electrolysis. The system generates both methane and hydrogen fuels...experimental setup. ................................................ 21 Figure 10. Methane phase semi batch experimental setup, a total of three reactors were...set up for PS + solid, Bioc and ADS methane phase reactors. .................... 21 Figure 11. Dried PS solid for the control, Bioc blend for the

The control system of the polarized internal target of ANKE at COSY

NASA Astrophysics Data System (ADS)

Kleines, H.; Sarkadi, J.; Zwoll, K.; Engels, R.; Grigoryev, K.; Mikirtychyants, M.; Nekipelov, M.; Rathmann, F.; Seyfarth, H.; Kravtsov, P.; Vasilyev, A.

2006-05-01

The polarized internal target for the ANKE experiment at the Cooler Synchrotron COSY of the Forschungszentrum Jülich utilizes a polarized atomic beam source to feed a storage cell with polarized hydrogen or deuterium atoms. The nuclear polarization is measured with a Lamb-shift polarimeter. For common control of the two systems, industrial equipment was selected providing reliable, long-term support and remote control of the target as well as measurement and optimization of its operating parameters. The interlock system has been implemented on the basis of SIEMENS SIMATIC S7-300 family of programmable logic controllers. In order to unify the interfacing to the control computer, all front-end equipment is connected via the PROFIBUS DP fieldbus. The process control software was implemented using the Windows-based WinCC toolkit from SIEMENS. The variety of components, to be controlled, and the logical structure of the control and interlock system are described. Finally, a number of applications derived from the present development to other, new installations are briefly mentioned.

Effects of hydrogen-rich water on aging periodontal tissues in rats

PubMed Central

Tomofuji, Takaaki; Kawabata, Yuya; Kasuyama, Kenta; Endo, Yasumasa; Yoneda, Toshiki; Yamane, Mayu; Azuma, Tetsuji; Ekuni, Daisuke; Morita, Manabu

2014-01-01

Oxidative damage is involved in age-related inflammatory reactions. The anti-oxidative effects of hydrogen-rich water suppress oxidative damage, which may aid in inhibiting age-related inflammatory reactions. We investigated the effects of drinking hydrogen-rich water on aging periodontal tissues in healthy rats. Four-month-old male Fischer 344 rats (n = 12) were divided into two groups: the experimental group (hydrogen-rich water treatment) and the control group (distilled water treatment). The rats consumed hydrogen-rich water or distilled water until 16 months of age. The experimental group exhibited lower periodontal oxidative damage at 16 months of age than the control group. Although protein expression of interleukin-1β did not differ, gene expression of Nod-like receptor protein 3 inflammasomes was activated in periodontal tissues from the experimental group as compared with the control group. Drinking hydrogen-rich water is proposed to have anti-aging effects on periodontal oxidative damage, but not on inflammatory reactions in healthy rats. PMID:24985521

Hydrogen: Its Future Role in the Nation's Energy Economy.

PubMed

Winsche, W E; Hoffman, K C; Salzano, F J

1973-06-29

In examining the potential role of hydrogen in the energy economy of the future, we take an optimistic view. All the technology required for implementation is feasible but a great deal of development and refinement is necessary. A pessimistic approach would obviously discourage further thinking about an important and perhaps the most reasonable alternative for the future. We have considered a limited number of alternative energy systems involving hydrogen and have shown that hydrogen could be a viable secondary source of energy derived from nuclear power; for the immediate future, hydrogen could be derived from coal. A hydrogen supply system could have greater flexibility and be competitive with a more conventional all-electric delivery system. Technological improvements could make hydrogen as an energy source an economic reality. The systems examined in this article show how hydrogen can serve as a general-purpose fuel for residential and automotive applications. Aside from being a source of heat and motive power, hydrogen could also supply the electrical needs of the household via fuel cells (19), turbines, or conventional "total energy systems." The total cost of energy to a residence supplied with hydrogen fuel depends on the ratio of the requirements for direct fuel use to the requirements for electrical use. A greater direct use of hydrogen as a fuel without conversion to electricity reduces the overall cost of energy supplied to the household because of the greater expense of electrical transmission and distribution. Hydrogen fuel is especially attractive for use in domestic residential applications where the bulk of the energy requirement is for thermal energy. Although a considerable amount of research is required before any hydrogen energy delivery system can be implemented, the necessary developments are within the capability of present-day technology and the system could be made attractive economically .Techniques for producing hydrogen from water by electrolysis, from coal, and directly from thermal energy could be found that are less expensive than those now available; inexpensive fuel cells could be developed, and high-temperature turbines could be used for the efficient conversion of hydrogen (and oxygen) to electricity. The use of hydrogen as an automotive fuel would be a key factor in the development of a hydrogen energy economy, and safe storage techniques for carrying sufficient quantities of hydrogen in automotive systems can certainly be developed. The use of hydrogen in automobiles would significantly reduce urban pollution because the dispersed fossil fuel emissions would be replaced by radioactive wastes generated at large central stations. The conversion of internal or external combustion engines for combustion of hydrogen fuel would probably have less economic impact on the automotive industry than the mass introduction of electric automobiles. However, this is a subject that requires more detailed study. All of the safety aspects of hydrogen utilization will have to be examined, especially the problems of safety in the domestic use and the long distance transport of hydrogen in pipelines at high pressures. It is our opinion that the various energy planning agencies should now begin to outline the mode of implementing hydrogen energy delivery systems in the energy economy. The initial transition to hydrogen energy derived from available fossil fuels such as coal should be considered together with the long range view of all the hydrogen being derived eventually from nuclear energy. By the year 1985 when petroleum imports may be in excess of the domestic supply, these plans could set the stage for the transition period from fossil to a predominantly nuclear energy economy able to supply abundant synthetic fuels such as hydrogen. Synthetic fuels will obviously be more expensive than fuels now derived from petroleum; however, there may be no other viable choice. Thus, it is essential that the analysis and technological feasibility of a hydrogen energy system be considered now. It is of vital importance to the nation to develop some general-purpose fuel that can be Produced from a variety of domestic energy sources and reduce our dependence on imported oil.

Achieving ethanol-type fermentation for hydrogen production in a granular sludge system by aeration.

PubMed

Zhang, Song; Liu, Min; Chen, Ying; Pan, Yu-Ting

2017-01-01

To investigate the effects of aeration on hydrogen-producing granular system, experiments were performed in two laboratory-scale anaerobic internal circulation hydrogen production (AICHP) reactors. The preliminary experiment of Reactor 1 showed that direct aeration was beneficial to enhancing hydrogen production. After the direct aeration was implied in Reactor 2, hydrogen production rate (HPR) and hydrogen content were increased by 100% and 60%, respectively. In addition, mixed-acid fermentation was transformed into typical ethanol-type fermentation (ETF). Illumina MiSeq sequencing shows that the direct aeration did not change the species of hydrogen-producing bacteria but altered their abundance. Hydrogen-producing bacteria and ethanol-type fermentative bacteria were increased by 24.5% and 146.3%, respectively. Ethanoligenens sp. sharply increased by 162.2% and turned into predominant bacteria in the system. These findings indicated that appropriate direct aeration might be a novel and promising way to obtain ETF and enhance hydrogen production in practical use. Copyright © 2016 Elsevier Ltd. All rights reserved.

Remote network control plasma diagnostic system for Tokamak T-10

NASA Astrophysics Data System (ADS)

Troynov, V. I.; Zimin, A. M.; Krupin, V. A.; Notkin, G. E.; Nurgaliev, M. R.

2016-09-01

The parameters of molecular plasma in closed magnetic trap is studied in this paper. Using the system of molecular diagnostics, which was designed by the authors on the «Tokamak T-10» facility, the radiation of hydrogen isotopes at the plasma edge is investigated. The scheme of optical radiation registration within visible spectrum is described. For visualization, identification and processing of registered molecular spectra a new software is developed using MatLab environment. The software also includes electronic atlas of electronic-vibrational-rotational transitions for molecules of protium and deuterium. To register radiation from limiter cross-section a network control system is designed using the means of the Internet/Intranet. Remote control system diagram and methods are given. The examples of web-interfaces for working out equipment control scenarios and viewing of results are provided. After test run in Intranet, the remote diagnostic system will be accessible through Internet.

Development of a solid electrolyte carbon dioxide and water reduction system for oxygen recovery

NASA Technical Reports Server (NTRS)

Elikan, L.; Morris, J. P.; Wu, C. K.

1972-01-01

A 1/4-man solid electrolyte oxygen regeneration system, consisting of an electrolyzer, a carbon deposition reactor, and palladium membranes for separating hydrogen, was operated continuously in a 180-day test. Oxygen recovery from the carbon dioxide-water feed was 95%. One percent of the oxygen was lost to vacuum with the hydrogen off-gas. In a space cabin, the remaining 4% would have been recycled to the cabin and recovered. None of the electrolysis cells used in the 180-day test failed. Electrolysis power rose 20% during the test; the average power was 283.5 watts/man. Crew time was limited to 18 min/day of which 12 min/day was used for removing carbon. The success achieved in operating the system can be attributed to an extensive component development program, which is described. Stability of operation, ease of control, and flexibility in feed composition were demonstrated by the life test.

Carbon Dioxide Reduction Systems

NASA Technical Reports Server (NTRS)

Burghardt, Stanley I.; Chandler, Horace W.; Taylor, T. I.; Walden, George

1961-01-01

The Methoxy system for regenerating oxygen from carbon dioxide was studied. Experiments indicate that the reaction between carbon dioxide and hydrogen can be carried out with ease in an efficient manner and with excellent heat conservation. A small reactor capable of handling the C02 expired by three men has been built and operated. The decomposition of methane by therma1,arc and catalytic processes was studied. Both the arc and catalytic processes gave encouraging results with over 90 percent of the methane being decomposed to carbon and hydrogen in some of the catalytic processes. Control of the carbon deposition in both the catalytic and arc processes is of great importance to prevent catalyst deactivation and short circuiting of electrical equipment. Sensitive analytical techniques have been developed for all of the components present in the reactor effluent streams.

Multimodal nanoporous silica nanoparticles functionalized with aminopropyl groups for improving loading and controlled release of doxorubicin hydrochloride.

PubMed

Wang, Xin; Li, Chang; Fan, Na; Li, Jing; He, Zhonggui; Sun, Jin

2017-09-01

The purpose of this study was to develop amino modified multimodal nanoporous silica nanoparticles (M-NSNs-NH 2 ) loaded with doxorubicin hydrochloride (DOX), intended to enhance the drug loading capacity and to achieve controlled release effect. M-NSNs were functionalized with aminopropyl groups through post-synthesis. The contribution of large pore sizes and surface chemical groups on DOX loading and release were systemically studied using transmission electron microscope (TEM), nitrogen adsorption/desorption measurement, Fourier transform infrared spectroscopy (FTIR), zeta potential analysis, X-ray photoelectron spectroscopy (XPS) and ultraviolet spectrophotometer (UV). The results demonstrated that the NSNs were functionalized with aminopropyl successfully and the DOX molecules were adsorbed inside the nanopores by the hydrogen bonding. The release performance indicated that DOX loaded M-NSNs significantly controlled DOX release, furthermore DOX loaded M-NSNs-NH 2 performed slower controlled release, which was mainly attributed to its stronger hydrogen bonding forces. As expected, we developed a novel carrier with high drug loading capacity and controlled release for DOX. Copyright © 2017 Elsevier B.V. All rights reserved.

Cryogenic Pressure Control Modeling for Ellipsoidal Space Tanks in Reduced Gravity

NASA Technical Reports Server (NTRS)

Hedayat, Ali; Lopez, Alfredo; Grayson, Gary D.; Chandler, Frank O.; Hastings, Leon J.

2008-01-01

A computational fluid dynamics (CFD) model is developed to simulate pressure control of an ellipsoidal-shaped liquid hydrogen tank under external heating in low gravity. Pressure control is provided by an axial jet thermodynamic vent system (TVS) centered within the vessel that injects cooler liquid into the tank, mixing the contents and reducing tank pressure. The two-phase cryogenic tank model considers liquid hydrogen in its own vapor with liquid density varying with temperature only and a fully compressible ullage. The axisymmetric model is developed using a custom version of the commercially available FLOW-3D software and simulates low gravity extrapolations of engineering checkout tests performed at Marshall Space Flight Center in 1999 in support of the Solar Thermal Upper Stage Technology Demonstrator (STUSTD) program. Model results illustrate that stable low gravity liquid-gas interfaces are maintained during all phases of the pressure control cycle. Steady and relatively smooth ullage pressurization rates are predicted. This work advances current low gravity CFD modeling capabilities for cryogenic pressure control and aids the development of a low cost CFD-based design process for space hardware.

Advanced oxidation and disinfection processes for onsite net-zero greywater reuse: A review.

PubMed

Gassie, Lucien W; Englehardt, James D

2017-11-15

Net-zero greywater (NZGW) reuse, or nearly closed-loop recycle of greywater for all original uses, can recover both water and its attendant hot-water thermal energy, while avoiding the installation and maintenance of a separate greywater sewer in residential areas. Such a system, if portable, could also provide wash water for remote emergency health care units. However, such greywater reuse engenders human contact with the recycled water, and hence superior treatment. The purpose of this paper is to review processes applicable to the mineralization of organics, including control of oxidative byproducts such as bromate, and maintenance of disinfection consistent with potable reuse guidelines, in NZGW systems. Specifically, TiO 2 -UV, UV-hydrogen peroxide, hydrogen peroxide-ozone, ozone-UV advanced oxidation processes, and UV, ozone, hydrogen peroxide, filtration, and chlorine disinfection processes were reviewed for performance, energy demand, environmental impact, and operational simplicity. Based on the literature reviewed, peroxone is the most energy-efficient process for organics mineralization. However, in portable applications where delivery of chemicals to the site is a concern, the UV-ozone process appears promising, at higher energy demand. In either case, reverse osmosis, nanofiltration, or ED may be useful in controlling the bromide precursor in make-up water, and a minor side-stream of ozone may be used to prevent microbial regrowth in the treated water. Where energy is not paramount, UV-hydrogen peroxide and UV-TiO 2 can be used to mineralize organics while avoiding bromate formation, but may require a secondary process to prevent microbial regrowth. Chlorine and ozone may be useful for maintenance of disinfection residual. Copyright © 2017 Elsevier Ltd. All rights reserved.

Water reactive hydrogen fuel cell power system

DOEpatents

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.

Water reactive hydrogen fuel cell power system

DOEpatents

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

2014-11-25

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 the fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

Future long-range transports - Prospects for improved fuel efficiency

NASA Technical Reports Server (NTRS)

Nagel, A. L.; Alford, W. J., Jr.; Dugan, J. F., Jr.

1975-01-01

A status report is provided on current thinking concerning potential improvements in fuel efficiency and possible alternate fuels. Topics reviewed are: historical trends in airplane efficiency; technological opportunities including supercritical aerodynamics, vortex diffusers, composite materials, propulsion systems, active controls, and terminal-area operations; unconventional design concepts, and hydrogen-fueled airplane.

A new process and equipment for waste minimization: Conversion of NO(x) scrubber liquor to fertilizer

NASA Technical Reports Server (NTRS)

Parrish, Clyde F.; Barile, Ronald G.; Gamble, Paul H.; Lueck, Dale E.; Young, Rebecca C.

1995-01-01

A new emissions control system for the oxidizer scrubbers that eliminates the current oxidizer liquor waste and lowers the NO(x) emissions is described. Since fueling and deservicing spacecraft constitute the primary operations in which environmental emissions occur, this will eliminate the second largest waste stream at KSC. This effort is in accord with Executive Order No. 12856 (Federal Compliance with Right-to-Know Laws and Pollution Prevention Requirements, data 6 Aug. 1993) and Executive Order No. 12873 (Federal Acquisition, Recycling, and Waste Prevention, dated 20 Oct. 1993). A recent study found that the efficiencies of the oxidizer scrubbers during normal operations ranged from 70 percent to 99 percent. The new scrubber liquor starts with 1% hydrogen peroxide at a pH of 7 and the process control system adds hydrogen peroxide and potassium hydroxide to the scrubber liquor to maintain those initial conditions. The result is the formation of a solution of potassium nitrate, which is sold as a fertilizer. This report describes the equipment and procedures used to monitor and control the conversion of the scrubber liquor to fertilizer, while reducing the scrubber emissions.

Environment control system

DOEpatents

Sammarone, Dino G.

1978-01-01

A system for controlling the environment of an enclosed area in nuclear reactor installations. The system permits the changing of the environment from nitrogen to air, or from air to nitrogen, without the release of any radioactivity or process gas to the outside atmosphere. In changing from a nitrogen to an air environment, oxygen is inserted into the enclosed area at the same rate which the nitrogen-oxygen gas mixture is removed from the enclosed area. The nitrogen-oxygen gas mixture removed from the enclosed area is mixed with hydrogen, the hydrogen recombining with the oxygen present in the gas to form water. The water is then removed from the system and, if it contains any radioactive products, can be utilized to form concrete, which can then be transferred to a licensed burial site. The process gas is purified further by stripping it of carbon dioxide and then distilling it to remove any xenon, krypton, and other fission or non-condensable gases. The pure nitrogen is stored as either a cryogenic liquid or a gas. In changing from an air to nitrogen environment, the gas is removed from the enclosed area, mixed with hydrogen to remove the oxygen present, dried, passed through adsorption beds to remove any fission gases, and reinserted into the enclosed area. Additionally, the nitrogen stored during the nitrogen to air change, is inserted into the enclosed area, the nitrogen from both sources being inserted into the enclosed area at the same rate as the removal of the gas from the containment area. As designed, the amount of nitrogen stored during the nitrogen to air change substantially equals that required to replace oxygen removed during an air to nitrogen change.

Despin System for Hydrogen Tank in the Propulsion Systems Laboratory

NASA Image and Video Library

1962-04-21

Mechanic Howard Wine inspects the setup of a spin isolator in Cell 2 of the Propulsion Systems Laboratory at the National Aeronautics and Space Administration (NASA) Lewis Research Center. Photographer Al Jecko filmed the proceedings. This test was unique in that the chamber’s altitude system was used, but not its inlet air flow. The test was in preparation for an upcoming launch of modified liquid hydrogen propellant tank on a sounding rocket. This Weightlessness Analysis Sounding Probe (WASP) was part of Lewis investigation into methods for controlling partially filled liquid hydrogen fuel tanks during flight. Second-stage rockets, the Centaur in particular, were designed to stop their engines and coast, then restart them when needed. During this coast period, the propellant often shifted inside the tank. This movement could throw the rocket off course or result in the sloshing of fuel away from the fuel pump. Wine was one of only three journeymen mechanics at Lewis when he was hired in January 1954. He spent his first decade in the Propulsion Systems Laboratory and was soon named a section head. Wine went on to serve as Assistant Division Chief and later served as an assistant to the director. Jecko joined the center in 1947 as a photographer and artist. He studied at the Cleveland School or Art and was known for his cartoon drawing. He worked at the center for 26 years.

29 CFR 1910.103 - Hydrogen.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., trailers, mobile supply trucks, or tank cars. (ii) Liquefied hydrogen systems. (a) Paragraph (c) of this... refilling portable containers, trailers, mobile supply trucks, or tank cars. (b) Gaseous hydrogen systems—(1... be located above ground. (c) Systems shall not be located beneath electric power lines. (d) Systems...

29 CFR 1910.103 - Hydrogen.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., trailers, mobile supply trucks, or tank cars. (ii) Liquefied hydrogen systems. (a) Paragraph (c) of this... refilling portable containers, trailers, mobile supply trucks, or tank cars. (b) Gaseous hydrogen systems—(1... be located above ground. (c) Systems shall not be located beneath electric power lines. (d) Systems...

Simultaneous hydrogen utilization and in situ biogas upgrading in an anaerobic reactor.

PubMed

Luo, Gang; Johansson, Sara; Boe, Kanokwan; Xie, Li; Zhou, Qi; Angelidaki, Irini

2012-04-01

The possibility of converting hydrogen to methane and simultaneous upgrading of biogas was investigated in both batch tests and fully mixed biogas reactor, simultaneously fed with manure and hydrogen. Batch experiments showed that hydrogen could be converted to methane by hydrogenotrophic methanogenesis with conversion of more than 90% of the consumed hydrogen to methane. The hydrogen consumption rates were affected by both P(H₂) (hydrogen partial pressure) and mixing intensity. Inhibition of propionate and butyrate degradation by hydrogen (1 atm) was only observed under high mixing intensity (shaking speed 300 rpm). Continuous addition of hydrogen (flow rate of 28.6 mL/(L/h)) to an anaerobic reactor fed with manure, showed that more than 80% of the hydrogen was utilized. The propionate and butyrate level in the reactor was not significantly affected by the hydrogen addition. The methane production rate of the reactor with H₂ addition was 22% higher, compared to the control reactor only fed with manure. The CO₂ content in the produced biogas was only 15%, while it was 38% in the control reactor. However, the addition of hydrogen resulted in increase of pH (from 8.0 to 8.3) due to the consumption of bicarbonate, which subsequently caused slight inhibition of methanogenesis. Copyright © 2011 Wiley Periodicals, Inc.

Thermal Design for Extra-Terrestrial Regenerative Fuel Cell System

NASA Technical Reports Server (NTRS)

Gilligan, R.; Guzik, M.; Jakupca, I.; Bennett, W.; Smith, P.; Fincannon, J.

2017-01-01

The Advanced Exploration Systems (AES) Advanced Modular Power Systems (AMPS) Project is investigating different power systems for various lunar and Martian mission concepts. The AMPS Fuel Cell (FC) team has created two system-level models to evaluate the performance of regenerative fuel cell (RFC) systems employing different fuel cell chemistries. Proton Exchange Membrane fuel cells PEMFCs contain a polymer electrolyte membrane that separates the hydrogen and oxygen cavities and conducts hydrogen cations (protons) across the cell. Solid Oxide fuel cells (SOFCs) operate at high temperatures, using a zirconia-based solid ceramic electrolyte to conduct oxygen anions across the cell. The purpose of the modeling effort is to down select one fuel cell chemistry for a more detailed design effort. Figures of merit include the system mass, volume, round trip efficiency, and electrolyzer charge power required. PEMFCs operate at around 60 C versus SOFCs which operate at temperatures greater than 700 C. Due to the drastically different operating temperatures of the two chemistries the thermal control systems (TCS) differ. The PEM TCS is less complex and is characterized by a single pump cooling loop that uses deionized water coolant and rejects heat generated by the system to the environment via a radiator. The solid oxide TCS has its own unique challenges including the requirement to reject high quality heat and to condense the steam produced in the reaction. This paper discusses the modeling of thermal control systems for an extraterrestrial RFC that utilizes either a PEM or solid oxide fuel cell.

A fuzzy logic approach to control anaerobic digestion.

PubMed

Domnanovich, A M; Strik, D P; Zani, L; Pfeiffer, B; Karlovits, M; Braun, R; Holubar, P

2003-01-01

One of the goals of the EU-Project AMONCO (Advanced Prediction, Monitoring and Controlling of Anaerobic Digestion Process Behaviour towards Biogas Usage in Fuel Cells) is to create a control tool for the anaerobic digestion process, which predicts the volumetric organic loading rate (Bv) for the next day, to obtain a high biogas quality and production. The biogas should contain a high methane concentration (over 50%) and a low concentration of components toxic for fuel cells, e.g. hydrogen sulphide, siloxanes, ammonia and mercaptanes. For producing data to test the control tool, four 20 l anaerobic Continuously Stirred Tank Reactors (CSTR) are operated. For controlling two systems were investigated: a pure fuzzy logic system and a hybrid-system which contains a fuzzy based reactor condition calculation and a hierachial neural net in a cascade of optimisation algorithms.

Nickel-hydrogen component development

NASA Technical Reports Server (NTRS)

Charleston, J. A.

1983-01-01

Light weight energy storage systems for future space missions are investigated. One of the systems being studied is the nickel hydrogen battery. This battery is designed to achieve longer life, improve performance, and higher energy densities for space applications. The nickel hydrogen component development is discussed. Test data from polarization measurements of the hydrogen electrode component is presented.

Real time charge efficiency monitoring for nickel electrodes in NICD and NIH2 cells

NASA Astrophysics Data System (ADS)

Zimmerman, A. H.

1987-09-01

The charge efficiency of nickel-cadmium and nickel-hydrogen battery cells is critical in spacecraft applications for determining the amount of time required for a battery to reach a full state of charge. As the nickel-cadmium or nickel-hydrogen batteries approach about 90 percent state of charge, the charge efficiency begins to drop towards zero, making estimation of the total amount of stored charge uncertain. Charge efficiency estimates are typically based on prior history of available capacity following standardized conditions for charge and discharge. These methods work well as long as performance does not change significantly. A relatively simple method for determining charge efficiencies during real time operation for these battery cells would be a tremendous advantage. Such a method was explored and appears to be quite well suited for application to nickel-cadmium and nickel-hydrogen battery cells. The charge efficiency is monitored in real time, using only voltage measurements as inputs. With further evaluation such a method may provide a means to better manage charge control of batteries, particularly in systems where a high degree of autonomy or system intelligence is required.

Real time charge efficiency monitoring for nickel electrodes in NICD and NIH2 cells

NASA Technical Reports Server (NTRS)

Zimmerman, A. H.

1987-01-01

The charge efficiency of nickel-cadmium and nickel-hydrogen battery cells is critical in spacecraft applications for determining the amount of time required for a battery to reach a full state of charge. As the nickel-cadmium or nickel-hydrogen batteries approach about 90 percent state of charge, the charge efficiency begins to drop towards zero, making estimation of the total amount of stored charge uncertain. Charge efficiency estimates are typically based on prior history of available capacity following standardized conditions for charge and discharge. These methods work well as long as performance does not change significantly. A relatively simple method for determining charge efficiencies during real time operation for these battery cells would be a tremendous advantage. Such a method was explored and appears to be quite well suited for application to nickel-cadmium and nickel-hydrogen battery cells. The charge efficiency is monitored in real time, using only voltage measurements as inputs. With further evaluation such a method may provide a means to better manage charge control of batteries, particularly in systems where a high degree of autonomy or system intelligence is required.

Tuning Solvatochromism of Azo Dyes with Intramolecular Hydrogen Bonding in Solution and on Titanium Dioxide Nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Lei; Cole, Jacqueline M.; Liu, Xiaogang

2013-11-25

“Smart tuning” of optical properties in three azo dyes containing intramolecular hydrogen bonding is realized by the judicious control of solvents, when the dyes are in solution or adsorbed onto titanium dioxide nanoparticles. In solution, certain solvents destabilizing intramolecular hydrogen bonding induce a distinctive ≈70 nm “blue-shifted” absorption peak, compared with other solvents. In parallel, the optical properties of azo dye/TiO2 nanocomposites can be tuned using solvents with different hydrogen-bond accepting/donating abilities, giving insights into smart materials and dye-sensitized solar cell device design. It is proposed that intramolecular hydrogen bonding alone plays the leading role in such phenomena, which ismore » fundamentally different to other mechanisms, such as tautomerism and cis–trans isomerization, that explain the optical control of azo dyes. Hybrid density functional theory (DFT) is employed in order to trace the origin of this optical control, and these calculations support the mechanism involving intramolecular hydrogen bonding. Two complementary studies are also reported: 1H NMR spectroscopy is conducted in order to further understand the solvent effects on intramolecular hydrogen bonding; crystal structure analysis from associated research indicates the importance of intramolecular hydrogen bonding on intramolecular charge transfer.« less

The role of pH control on biohydrogen production by single stage hybrid dark- and photo-fermentation.

PubMed

Zagrodnik, R; Laniecki, M

2015-10-01

The role of pH control on biohydrogen production by co-culture of dark-fermentative Clostridium acetobutylicum and photofermentative Rhodobacter sphaeroides was studied. Single stage dark fermentation, photofermentation and hybrid co-culture systems were studied at different values of controlled and uncontrolled pH. Increasing pH during dark fermentation resulted in lower hydrogen production rate (HPR) and longer lag time for both controlled and uncontrolled conditions. However, it only slightly affected cumulative H2 volume. Results have shown that pH control at pH 7.5 increased photofermentative hydrogen production from 0.966 to 2.502 L H2/L(medium) when compared to uncontrolled process. Fixed pH value has proven to be an important control strategy also for the hybrid process and resulted in obtaining balanced co-culture of dark and photofermentative bacteria. Control of pH at 7.0 was found optimum for bacteria cooperation in the co-culture what resulted in obtaining 2.533 L H2/L(medium) and H2 yield of 6.22 mol H2/mol glucose. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of a Novel Efficient Solid-Oxide Hybrid for Co-generation of Hydrogen and Electricity Using Nearby Resources for Local Application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, Greg, G.; Virkar, Anil, V.; Bandopadhyay, Sukumar

2009-06-30

Developing safe, reliable, cost-effective, and efficient hydrogen-electricity co-generation systems is an important step in the quest for national energy security and minimized reliance on foreign oil. This project aimed to, through materials research, develop a cost-effective advanced technology cogenerating hydrogen and electricity directly from distributed natural gas and/or coal-derived fuels. This advanced technology was built upon a novel hybrid module composed of solid-oxide fuel-assisted electrolysis cells (SOFECs) and solid-oxide fuel cells (SOFCs), both of which were in planar, anode-supported designs. A SOFEC is an electrochemical device, in which an oxidizable fuel and steam are fed to the anode and cathode,more » respectively. Steam on the cathode is split into oxygen ions that are transported through an oxygen ion-conducting electrolyte (i.e. YSZ) to oxidize the anode fuel. The dissociated hydrogen and residual steam are exhausted from the SOFEC cathode and then separated by condensation of the steam to produce pure hydrogen. The rationale was that in such an approach fuel provides a chemical potential replacing the external power conventionally used to drive electrolysis cells (i.e. solid oxide electrolysis cells). A SOFC is similar to the SOFEC by replacing cathode steam with air for power generation. To fulfill the cogeneration objective, a hybrid module comprising reversible SOFEC stacks and SOFC stacks was designed that planar SOFECs and SOFCs were manifolded in such a way that the anodes of both the SOFCs and the SOFECs were fed the same fuel, (i.e. natural gas or coal-derived fuel). Hydrogen was produced by SOFECs and electricity was generated by SOFCs within the same hybrid system. A stand-alone 5 kW system comprising three SOFEC-SOFC hybrid modules and three dedicated SOFC stacks, balance-of-plant components (including a tailgas-fired steam generator and tailgas-fired process heaters), and electronic controls was designed, though an overall integrated system assembly was not completed because of limited resources. An inexpensive metallic interconnects fabrication process was developed in-house. BOP components were fabricated and evaluated under the forecasted operating conditions. Proof-of-concept demonstration of cogenerating hydrogen and electricity was performed, and demonstrated SOFEC operational stability over 360 hours with no significant degradation. Cost analysis was performed for providing an economic assessment of the cost of hydrogen production using the targeted hybrid technology, and for guiding future research and development.« less

Cryogenic propellant thermal control system design considerations, analyses, and concepts applied to a Mars human exploration mission

NASA Technical Reports Server (NTRS)

Plachta, David W.; Tucker, Stephen; Hoffman, David J.

1993-01-01

This paper analyzes, defines, and sizes cryogenic storage thermal control systems that meet the requirements of future NASA Mars human exploration missions. The design issues of this system include the projection of the existing Multilayer Insulation data base for cryogenic storage to much thicker (10 cm or more) insulation systems, the unknown heat leak from mechanical interfaces, and the thermal and structural performance effects of the large tank sizes required for a Mars mission. Acknowledging these unknown effects, heat loss projections are made based on extrapolation of the existing data base. The results indicate that hydrogen, methane, and oxygen are feasible propellants, and that the best suited thermal control sytems are 'thick' MLI, thermodynamic vent sytems, cryocoolers, and vacuum jackets.

Enhancement of hydrogen production during waste activated sludge anaerobic fermentation by carbohydrate substrate addition and pH control.

PubMed

Chen, Yinguang; Xiao, Naidong; Zhao, Yuxiao; Mu, Hui

2012-06-01

The effects of carbohydrate/protein ratio (CH/Pr) and pH on hydrogen production from waste activated sludge (WAS) were investigated. Firstly, the optimal pH value for hydrogen production was influenced by the CH/Pr ratio, which was pH 10, 9, 8, 8, 8 and 6 at the CH/Pr ratio (COD based) of 0.2 (sole sludge), 1, 2.4, 3.8, 5 and 6.6, respectively. The maximal hydrogen production (100.6 mL/g-COD) was achieved at CH/Pr of 5 and pH 8, which was due to the synergistic effect of carbohydrate addition on hydrogen production, the enhancement of sludge protein degradation and protease and amylase activities, and the suitable fermentation pathway for hydrogen production. As hydrogen consumption was observed at pH 8, in order to further increase hydrogen production a two-step pH control strategy (pH 8+pH 10) was developed and the hydrogen production was further improved by 17.6%. Copyright © 2012 Elsevier Ltd. All rights reserved.

Clean energy and the hydrogen economy.

PubMed

Brandon, N P; Kurban, Z

2017-07-28

In recent years, new-found interest in the hydrogen economy from both industry and academia has helped to shed light on its potential. Hydrogen can enable an energy revolution by providing much needed flexibility in renewable energy systems. As a clean energy carrier, hydrogen offers a range of benefits for simultaneously decarbonizing the transport, residential, commercial and industrial sectors. Hydrogen is shown here to have synergies with other low-carbon alternatives, and can enable a more cost-effective transition to de-carbonized and cleaner energy systems. This paper presents the opportunities for the use of hydrogen in key sectors of the economy and identifies the benefits and challenges within the hydrogen supply chain for power-to-gas, power-to-power and gas-to-gas supply pathways. While industry players have already started the market introduction of hydrogen fuel cell systems, including fuel cell electric vehicles and micro-combined heat and power devices, the use of hydrogen at grid scale requires the challenges of clean hydrogen production, bulk storage and distribution to be resolved. Ultimately, greater government support, in partnership with industry and academia, is still needed to realize hydrogen's potential across all economic sectors.This article is part of the themed issue 'The challenges of hydrogen and metals'. © 2017 The Author(s).

Future production of hydrogen from solar energy and water - A summary and assessment of U.S. developments

NASA Technical Reports Server (NTRS)

Hanson, J. A.; Escher, W. J. D.

1979-01-01

The paper examines technologies of hydrogen production. Its delivery, distribution, and end-use systems are reviewed, and a classification of solar energy and hydrogen production methods is suggested. The operation of photoelectric processes, biophotolysis, photocatalysis, photoelectrolysis, and of photovoltaic systems are reviewed, with comments on their possible hydrogen production potential. It is concluded that solar hydrogen derived from wind energy, photovoltaic technology, solar thermal electric technology, and hydropower could supply some of the hydrogen for air transport by the middle of the next century.

KSC-2009-1873

NASA Image and Video Library

2009-02-25

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians have removed space shuttle Discovery's three gaseous hydrogen flow control valves, two of which will undergo detailed inspection. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have been working to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Approximately 4,000 images of each valve removed will be reviewed for evidence of cracks. Valves that have flown fewer times will be installed in Discovery. NASA's Space Shuttle Program has established a plan that could support shuttle Discovery's launch to the International Space Station, tentatively targeted for March 12. An exact target launch date will be determined as work on the valves progresses. Photo credit: NASA/Dimitri Gerondidakis

Object-oriented model-driven control

NASA Technical Reports Server (NTRS)

Drysdale, A.; Mcroberts, M.; Sager, J.; Wheeler, R.

1994-01-01

A monitoring and control subsystem architecture has been developed that capitalizes on the use of modeldriven monitoring and predictive control, knowledge-based data representation, and artificial reasoning in an operator support mode. We have developed an object-oriented model of a Controlled Ecological Life Support System (CELSS). The model based on the NASA Kennedy Space Center CELSS breadboard data, tracks carbon, hydrogen, and oxygen, carbodioxide, and water. It estimates and tracks resorce-related parameters such as mass, energy, and manpower measurements such as growing area required for balance. We are developing an interface with the breadboard systems that is compatible with artificial reasoning. Initial work is being done on use of expert systems and user interface development. This paper presents an approach to defining universally applicable CELSS monitor and control issues, and implementing appropriate monitor and control capability for a particular instance: the KSC CELSS Breadboard Facility.

Solar-hydrogen energy system model for Libya

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eljrushi, G.S.

1987-01-01

A solar-hydrogen energy-system model for Libya was developed, obtaining relationships for and between the main energy and energy related parameters of Libya and the world. The parameters included are: population, energy demand, fossil-fuel production, fossil-fuel resources, hydrogen production, hydrogen introduction rates, energy prices, gross domestic product, pollution and quality of life. The trends of these parameters with and without hydrogen introduction were investigated over a period of time - through the year 2100. The results indicate that the fossil-fuel resources in Libya could be exhausted, due to production for local and export demands, within three to four decades unless seriousmore » measures for reducing production are taken. The results indicate that adopting solar-hydrogen energy system would extend the availability of fossil-fuel resources for a longer time period, reduce pollution, improve quality of life and establish a permanent energy system for Libya. It also shows that eventually Libya could export hydrogen in lieu of oil and natural gas.« less

From flavoenzymes to devices: The role of electronic effects in recognition

NASA Astrophysics Data System (ADS)

Deans, Robert

Acylated aminopyridines provide models for specific flavoenzyme-cofactor interactions, allowing isolation and observation of the effects of hydrogen bonding on flavin NMR. To determine the relative hydrogen bond affinities of O(2) and O(4) of the flavin, a 2-aminopyridine based receptor was investigated. Additionally, this receptor allowed the effects of hydrogen bonding at O(2) and O(4) on the electron distribution in the flavin nucleus to be determined using sp{13}C NMR. A new family of receptors for flavins based on 6-aryl-2,4-(acyldiamino)-s-triazines was synthesized. In these synthetic hosts, systematic variation of the spatially remote substituents on the 6-aryl ring altered the hydrogen bond donating abilities of the amide functionality and the hydrogen bond accepting properties of the triazine N(3). This variation resulted in a strong modulation of the efficiency of flavin binding, with association constants for the receptor flavin complexes ranging over an 8-fold range. In addition, the communication of electronic information over extended distances was also investigated. Polymers can provide relevant media for the modeling of biological processes, including molecular recognition. To explore this possibility, a diaminotriazine-functionalized polymer was synthesized, starting from Merrifield's peptide resin. This polymer selectively bound a flavin derivative through hydrogen bonding, efficiently extracting it from a chloroform solution, as monitored by UV-vis extraction studies. The temperature profile of this polymer-flavin binding was also investigated and compared to the analogous solution-phase triazine-flavin dyad. Hydrogen bonding and aromatic stacking are fundamental interactions in molecular recognition. These interactions are sensitive to the redox states of the components of the host-guest complex. To explore the interplay of recognition and redox processes, a system consisting of two hosts and one guest, where guest binding interactions (hydrogen bonding and aromatic stacking) were modulated via choice of redox state was examined. Proper choice of receptors then provided a device where the competition between the two hosts was controlled by the redox state of the guest. The efficient reversal of host preference in this assembly provided an electrochemically-controlled three-component, two-pole, molecular switch.

Triple-Shape Memory Polymers Based on Self-Complementary Hydrogen Bonding

PubMed Central

Ware, Taylor; Hearon, Keith; Lonnecker, Alexander; Wooley, Karen L.; Maitland, Duncan J.; Voit, Walter

2012-01-01

Triple shape memory polymers (TSMPs) are a growing subset of a class of smart materials known as shape memory polymers, which are capable of changing shape and stiffness in response to a stimulus. A TSMP can change shapes twice and can fix two metastable shapes in addition to its permanent shape. In this work, a novel TSMP system comprised of both permanent covalent cross-links and supramolecular hydrogen bonding cross-links has been synthesized via a one-pot method. Triple shape properties arise from the combination of the glass transition of (meth)acrylate copolymers and the dissociation of self-complementary hydrogen bonding moieties, enabling broad and independent control of both glass transition temperature (Tg) and cross-link density. Specifically, ureidopyrimidone methacrylate and a novel monomer, ureidopyrimidone acrylate, were copolymerized with various alkyl acrylates and bisphenol A ethoxylate diacrylate. Control of Tg from 0 to 60 °C is demonstrated: concentration of hydrogen bonding moieties is varied from 0 to 40 wt %; concentration of the diacrylate is varied from 0 to 30 wt %. Toughness ranges from 0.06 to 0.14 MPa and is found to peak near 20 wt % of the supramolecular cross-linker. A widely tunable class of amorphous triple-shape memory polymers has been developed and characterized through dynamic and quasi-static thermomechanical testing to gain insights into the dynamics of supramolecular networks. PMID:22287811

Hydrogen Generation from Biomass-Derived Surgar Alcohols via the Aqueous-Phase Carbohydrate Reforming (ACR) Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Randy Cortright

2006-06-30

This project involved the investigation and development of catalysts and reactor systems that will be cost-effective to generate hydrogen from potential sorbitol streams. The intention was to identify the required catalysts and reactors systems as well as the design, construction, and operation of a 300 grams per hour hydrogen system. Virent was able to accomplish this objective with a system that generates 2.2 kgs an hour of gas containing both hydrogen and alkanes that relied directly on the work performed under this grant. This system, funded in part by the local Madison utility, Madison, Gas & Electric (MGE), is describedmore » further in the report. The design and development of this system should provide the necessary scale-up information for the generation of hydrogen from corn-derived sorbitol.« less

Hydrogen Storage Performance in Pd/Graphene Nanocomposites.

PubMed

Zhou, Chunyu; Szpunar, Jerzy A

2016-10-05

We have developed a Pd-graphene nanocomposite for hydrogen storage. The spherically shaped Pd nanoparticles of 5-45 nm in size are homogeneously distributed over the graphene matrix. This new hydrogen storage system has favorable features like desirable hydrogen storage capacity, ambient conditions of hydrogen uptake, and low temperature of hydrogen release. At a hydrogen charging pressure of 50 bar, the material could yield a gravimetric density of 6.7 wt % in the 1% Pd/graphene nanocomposite. As we increased the applied pressure to 60 bar, the hydrogen uptake capacity reached 8.67 wt % in the 1% Pd/graphene nanocomposite and 7.16 wt % in the 5% Pd/graphene nanocomposite. This system allows storage of hydrogen in amounts that exceed the capacity of the gravimetric target announced by the U.S. Department of Energy (DOE).

A Review of Fatigue Crack Growth for Pipeline Steels Exposed to Hydrogen

PubMed Central

Nanninga, N.; Slifka, A.; Levy, Y.; White, C.

2010-01-01

Hydrogen pipeline systems offer an economical means of storing and transporting energy in the form of hydrogen gas. Pipelines can be used to transport hydrogen that has been generated at solar and wind farms to and from salt cavern storage locations. In addition, pipeline transportation systems will be essential before widespread hydrogen fuel cell vehicle technology becomes a reality. Since hydrogen pipeline use is expected to grow, the mechanical integrity of these pipelines will need to be validated under the presence of pressurized hydrogen. This paper focuses on a review of the fatigue crack growth response of pipeline steels when exposed to gaseous hydrogen environments. Because of defect-tolerant design principles in pipeline structures, it is essential that designers consider hydrogen-assisted fatigue crack growth behavior in these applications. PMID:27134796

Improvement of the efficiency of a space oxygen-hydrogen electrochemical generator

NASA Astrophysics Data System (ADS)

Glukhikh, I. N.; Shcherbakov, A. N.; Chelyaev, V. F.

2014-12-01

This paper describes the method used for cooling of an on-board oxygen-hydrogen electrochemical generator (ECG). Apart from electric power, such a unit produces water of reaction and heat; the latter is an additional load on the thermal control system of a space vehicle. This load is undesirable in long-duration space flights, when specific energy characteristics of on-board systems are the determining factors. It is suggested to partially compensate the energy consumption by the thermal control system of a space vehicle required for cooling of the electrochemical generator through evaporation of water of reaction from the generator into a vacuum (or through ice sublimation if the pressure in the ambient space is lower than that in the triple point of water.) Such method of cooling of an electrochemical generator improves specific energy parameters of an on-board electric power supply system, and, due to the presence of the negative feedback, it makes the operation of this system more stable. Estimates suggest that it is possible to compensate approximately one half of heat released from the generator through evaporation of its water of reaction at the electrical efficiency of the electrochemical generator equal to 60%. In this case, even minor increase in the efficiency of the generator would result in a considerable increase in the efficiency of the evaporative system intended for its cooling.

Hydrogen Fuel Cell Electric Vehicle Learning Demonstration | Hydrogen and

Science.gov Websites

Fuel Cells | NREL Fuel Cell Electric Vehicle Learning Demonstration Hydrogen Fuel Cell Electric Vehicle Learning Demonstration Initiated in 2004, DOE's Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project-later dubbed the Fuel Cell Electric Vehicle (FCEV) Learning Demonstration

Hydrogen Doping into MoO3 Supports toward Modulated Metal-Support Interactions and Efficient Furfural Hydrogenation on Iridium Nanocatalysts.

PubMed

Xie, Lifang; Chen, Ting; Chan, Hang Cheong; Shu, Yijin; Gao, Qingsheng

2018-03-16

As promising supports, reducible metal oxides afford strong metal-support interactions to achieve efficient catalysis, which relies on their band states and surface stoichiometry. In this study, in situ and controlled hydrogen doping (H doping) by means of H 2 spillover was employed to engineer the metal-support interactions in hydrogenated MoO x -supported Ir (Ir/H-MoO x ) catalysts and thus promote furfural hydrogenation to furfuryl alcohol. By easily varying the reduction temperature, the resulting H doping in a controlled manner tailors low-valence Mo species (Mo 5+ and Mo 4+ ) on H-MoO x supports, thereby promoting charge redistribution on Ir and H-MoO x interfaces. This further leads to clear differences in H 2 chemisorption on Ir, which illustrates its potential for catalytic hydrogenation. As expected, the optimal Ir/H-MoO x with controlled H doping afforded high activity (turnover frequency: 4.62 min -1 ) and selectivity (>99 %) in furfural hydrogenation under mild conditions (T=30 °C, PH2 =2 MPa), which means it performs among the best of current catalysts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dechlorination of chloropicrin and 1,3-dichloropropene by hydrogen sulfide species: redox and nucleophilic substitution reactions.

PubMed

Zheng, Wei; Yates, Scott R; Papiernik, Sharon K; Guo, Mingxin; Gan, Jianying

2006-03-22

The chlorinated fumigants chloropicrin (trichloronitromethane) and 1,3-dichloropropene (1,3-D) are extensively used in agricultural production for the control of soilborne pests. The reaction of these two fumigants with hydrogen sulfide species (H2S and HS-) was examined in well-defined anoxic aqueous solutions. Chloropicrin underwent an extremely rapid redox reaction in the hydrogen sulfide solution. Transformation products indicated reductive dechlorination of chloropicrin by hydrogen sulfide species to produce dichloro- and chloronitromethane. The transformation of chloropicrin in hydrogen sulfide solution significantly increased with increasing pH, indicating that H2S is less reactive toward chloropicrin than HS- is. For both 1,3-D isomers, kinetics and transformation products analysis revealed that the reaction between 1,3-D and hydrogen sulfide species is an S(N)2 nucleophilic substitution process, in which the chlorine at C3 of 1,3-D is substituted by the sulfur nucleophile to form corresponding mercaptans. The 50% disappearance time (DT50) of 1,3-D decreased with increasing hydrogen sulfide species concentration at a constant pH. Transformation of 1,3-D was more rapid at high pH, suggesting that the reactivity of hydrogen sulfide species in the experimental system stems primarily from HS-. Because of the relatively low smell threshold values and potential environmental persistence of organic sulfur products yielded by the reaction of 1,3-D and HS-, the effects of reduced sulfide species should be considered in the development of alternative fumigation practices, especially in the integrated application of sulfur-containing fertilizers.

Elucidation of metal-ion accumulation induced by hydrogen bonds on protein surfaces by using porous lysozyme crystals containing Rh(III) ions as the model surfaces.

PubMed

Ueno, Takafumi; Abe, Satoshi; Koshiyama, Tomomi; Ohki, Takahiro; Hikage, Tatsuo; Watanabe, Yoshihito

2010-03-01

Metal-ion accumulation on protein surfaces is a crucial step in the initiation of small-metal clusters and the formation of inorganic materials in nature. This event is expected to control the nucleation, growth, and position of the materials. There remain many unknowns, as to how proteins affect the initial process at the atomic level, although multistep assembly processes of the materials formation by both native and model systems have been clarified at the macroscopic level. Herein the cooperative effects of amino acids and hydrogen bonds promoting metal accumulation reactions are clarified by using porous hen egg white lysozyme (HEWL) crystals containing Rh(III) ions, as model protein surfaces for the reactions. The experimental results reveal noteworthy implications for initiation of metal accumulation, which involve highly cooperative dynamics of amino acids and hydrogen bonds: i) Disruption of hydrogen bonds can induce conformational changes of amino-acid residues to capture Rh(III) ions. ii) Water molecules pre-organized by hydrogen bonds can stabilize Rh(III) coordination as aqua ligands. iii) Water molecules participating in hydrogen bonds with amino-acid residues can be replaced by Rh(III) ions to form polynuclear structures with the residues. iv) Rh(III) aqua complexes are retained on amino-acid residues through stabilizing hydrogen bonds even at low pH (approximately 2). These metal-protein interactions including hydrogen bonds may promote native metal accumulation reactions and also may be useful in the preparation of new inorganic materials that incorporate proteins.

Fuel Cell and Hydrogen Technology Validation | Hydrogen and Fuel Cells |

Science.gov Websites

NREL Fuel Cell and Hydrogen Technology Validation Fuel Cell and Hydrogen Technology Validation The NREL technology validation team works on validating hydrogen fuel cell electric vehicles; hydrogen fueling infrastructure; hydrogen system components; and fuel cell use in early market applications such as

The development of a solid-state hydrogen sensor for rocket engine leakage detection

NASA Technical Reports Server (NTRS)

Liu, Chung-Chiun

1994-01-01

Hydrogen propellant leakage poses significant operational problems in the rocket propulsion industry as well as for space exploratory applications. Vigorous efforts have been devoted to minimizing hydrogen leakage in assembly, test, and launch operations related to hydrogen propellant. The objective has been to reduce the operational cost of assembling and maintaining hydrogen delivery systems. Specifically, efforts have been made to develop a hydrogen leak detection system for point-contact measurement. Under the auspices of Lewis Research Center, the Electronics Design Center at Case Western Reserve University, Cleveland, Ohio, has undertaken the development of a point-contact hydrogen gas sensor with potential applications to the hydrogen propellant industry. We envision a sensor array consisting of numbers of discrete hydrogen sensors that can be located in potential leak sites. Silicon-based microfabrication and micromachining techniques are used in the fabrication of these sensor prototypes. Evaluations of the sensor are carried out in-house at Case Western Reserve University as well as at Lewis Research Center and GenCorp Aerojet, Sacramento, California. The hydrogen gas sensor is not only applicable in a hydrogen propulsion system, but also usable in many other civilian and industrial settings. This includes vehicles or facility use, or in the production of hydrogen gas. Dual space and commercial uses of these point-contacted hydrogen sensors are feasible and will directly meet the needs and objectives of NASA as well as various industrial segments.

The development of a solid-state hydrogen sensor for rocket engine leakage detection

NASA Astrophysics Data System (ADS)

Liu, Chung-Chiun

Hydrogen propellant leakage poses significant operational problems in the rocket propulsion industry as well as for space exploratory applications. Vigorous efforts have been devoted to minimizing hydrogen leakage in assembly, test, and launch operations related to hydrogen propellant. The objective has been to reduce the operational cost of assembling and maintaining hydrogen delivery systems. Specifically, efforts have been made to develop a hydrogen leak detection system for point-contact measurement. Under the auspices of Lewis Research Center, the Electronics Design Center at Case Western Reserve University, Cleveland, Ohio, has undertaken the development of a point-contact hydrogen gas sensor with potential applications to the hydrogen propellant industry. We envision a sensor array consisting of numbers of discrete hydrogen sensors that can be located in potential leak sites. Silicon-based microfabrication and micromachining techniques are used in the fabrication of these sensor prototypes. Evaluations of the sensor are carried out in-house at Case Western Reserve University as well as at Lewis Research Center and GenCorp Aerojet, Sacramento, California. The hydrogen gas sensor is not only applicable in a hydrogen propulsion system, but also usable in many other civilian and industrial settings. This includes vehicles or facility use, or in the production of hydrogen gas. Dual space and commercial uses of these point-contacted hydrogen sensors are feasible and will directly meet the needs and objectives of NASA as well as various industrial segments.

Fuzzy logic controller versus classical logic controller for residential hybrid solar-wind-storage energy system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Derrouazin, A., E-mail: derrsid@gmail.com; Université de Lorraine, LMOPS, EA 4423, 57070 Metz; CentraleSupélec, LMOPS, 57070 Metz

Several researches for management of diverse hybrid energy systems and many techniques have been proposed for robustness, savings and environmental purpose. In this work we aim to make a comparative study between two supervision and control techniques: fuzzy and classic logics to manage the hybrid energy system applied for typical housing fed by solar and wind power, with rack of batteries for storage. The system is assisted by the electric grid during energy drop moments. A hydrogen production device is integrated into the system to retrieve surplus energy production from renewable sources for the household purposes, intending the maximum exploitationmore » of these sources over years. The models have been achieved and generated signals for electronic switches command of proposed both techniques are presented and discussed in this paper.« less

40 CFR 63.8184 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2014 CFR

2014-07-01

... in the manufacture of product chlorine, product caustic, and by-product hydrogen at a plant site. This subpart covers mercury emissions from by-product hydrogen streams, end box ventilation system vents, and fugitive emission sources associated with cell rooms, hydrogen systems, caustic systems, and...

40 CFR 63.8184 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2011 CFR

2011-07-01

... in the manufacture of product chlorine, product caustic, and by-product hydrogen at a plant site. This subpart covers mercury emissions from by-product hydrogen streams, end box ventilation system vents, and fugitive emission sources associated with cell rooms, hydrogen systems, caustic systems, and...

40 CFR 63.8184 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2012 CFR

2012-07-01

... in the manufacture of product chlorine, product caustic, and by-product hydrogen at a plant site. This subpart covers mercury emissions from by-product hydrogen streams, end box ventilation system vents, and fugitive emission sources associated with cell rooms, hydrogen systems, caustic systems, and...

40 CFR 63.8184 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2013 CFR

2013-07-01

... in the manufacture of product chlorine, product caustic, and by-product hydrogen at a plant site. This subpart covers mercury emissions from by-product hydrogen streams, end box ventilation system vents, and fugitive emission sources associated with cell rooms, hydrogen systems, caustic systems, and...

Liquid Hydrogen Fill

NASA Image and Video Library

2016-08-03

Technicians with Praxair pressurize the hydrogen trailer before offloading liquid hydrogen during a test of the Ground Operations Demo Unit for liquid hydrogen at NASA's Kennedy Space Center in Florida. The system includes a 33,000 gallon liquid hydrogen storage tank with an internal cold heat exchanger supplied from a cryogenic refrigerator. The primary goal of the testing is to achieve a liquid hydrogen zero boil-off capability. The system was designed, installed and tested by a team of civil servants and contractors from the center's Cryogenic Test Laboratory, with support from engineers at NASA's Glenn Research Center in Cleveland and Stennis Space Center in Mississippi. It may be applicable for use by the Ground Systems Development and Operations Program at Launch Pad 39B.

Efficacy, efficiency and safety aspects of hydrogen peroxide vapour and aerosolized hydrogen peroxide room disinfection systems.

PubMed

Fu, T Y; Gent, P; Kumar, V

2012-03-01

This was a head-to-head comparison of two hydrogen-peroxide-based room decontamination systems. To compare the efficacy, efficiency and safety of hydrogen peroxide vapour (HPV; Clarus R, Bioquell, Andover, U.K.) and aerosolized hydrogen peroxide (aHP; SR2, Sterinis, now supplied as Glosair, Advanced Sterilization Products (ASP), Johnson & Johnson Medical Ltd, Wokingham, U.K.) room disinfection systems. Efficacy was tested using 4- and 6-log Geobacillus stearothermophilus biological indicators (BIs) and in-house prepared test discs containing approximately 10(6) meticillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile and Acinetobacter baumannii. Safety was assessed by detecting leakage of hydrogen peroxide using a hand-held detector. Efficiency was assessed by measuring the level of hydrogen peroxide using a hand-held sensor at three locations inside the room, 2 h after the start of the cycles. HPV generally achieved a 6-log reduction, whereas aHP generally achieved less than a 4-log reduction on the BIs and in-house prepared test discs. Uneven distribution was evident for the aHP system but not the HPV system. Hydrogen peroxide leakage during aHP cycles with the door unsealed, as per the manufacturer's operating manual, exceeded the short-term exposure limit (2 ppm) for more than 2 h. When the door was sealed with tape, as per the HPV system, hydrogen peroxide leakage was <1 ppm for both systems. The mean concentration of hydrogen peroxide in the room 2 h after the cycle started was 1.3 [standard deviation (SD) 0.4] ppm and 2.8 (SD 0.8) ppm for the four HPV and aHP cycles, respectively. None of the readings were <2 ppm for the aHP cycles. The HPV system was safer, faster and more effective for biological inactivation. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Hydrogen turbine power conversion system assessment

NASA Technical Reports Server (NTRS)

Wright, D. E.; Lucci, A. D.; Campbell, J.; Lee, J. C.

1978-01-01

A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three most promising candidates: (1) Ericsson Cycle, (2) gas turbine, and (3) direct steam injection system for fossil fuel as well as nuclear powerplants. A technical and economic evaluation was performed on the three systems from which the direct injection system (fossil fuel only) was selected for a preliminary conceptual design of an integrated hydrogen-fired power conversion system.

Comparative experimental study of gas evolution and gas consumption reactions in sealed Ni-Cd and Ni-MH cells

NASA Astrophysics Data System (ADS)

Cha, Chuansin; Yu, Jingxian; Zhang, Jixiao

The behavior of the sealed Ni-Cd and Ni-MH systems are compared experimentally with regard to their ability to consume gaseous products generated during the overcharge stage of these systems. It was found that the Ni-Cd system could only consume oxygen, while the Ni-MH system possesses the additional ability to adsorb hydrogen and to catalyze the recombination reaction of hydrogen and oxygen. The internal pressure within both sealed Ni-Cd cells and sealed Ni-MH cells can be kept well under control during the charge/overcharge processes if the rate of overcharge is not too high and if there is sufficient surplus of charging capacity at the negative electrodes. However, the internal pressure can rise to dangerously high levels if the rate of overcharge is too high or there is a deficiency of the charging capacity at the negative electrodes. The various factors that may affect the surplus of charging capacity of the negative electrodes are also discussed.

Method for controlled hydrogen charging of metals

DOEpatents

Cheng, Bo-Ching; Adamson, Ronald B.

1984-05-29

A method for controlling hydrogen charging of hydride forming metals through a window of a superimposed layer of a non-hydriding metal overlying the portion of the hydride forming metals to be charged.

Innovation and reliability of atomic standards for PTTI applications

NASA Technical Reports Server (NTRS)

Kern, R.

1981-01-01

Innovation and reliability in hyperfine frequency standards and clock systems are discussed. Hyperfine standards are defined as those precision frequency sources and clocks which use a hyperfine atomic transition for frequency control and which have realized significant commercial production and acceptance (cesium, hydrogen, and rubidium atoms). References to other systems such as thallium and ammonia are excluded since these atomic standards have not been commercially exploited in this country.

Compact hydrogen production systems for solid polymer fuel cells

NASA Astrophysics Data System (ADS)

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.

21 CFR 178.1005 - Hydrogen peroxide solution.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric food...

21 CFR 178.1005 - Hydrogen peroxide solution.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric food...

21 CFR 178.1005 - Hydrogen peroxide solution.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric food...

21 CFR 178.1005 - Hydrogen peroxide solution.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric food...

Hydrogen and water reactor safety: proceedings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1982-01-01

Separate abstracts were prepared for papers presented in the following areas of interest: 1) hydrogen research programs; 2) hydrogen behavior during light water reactor accidents; 3) combustible gas generation; 4) hydrogen transport and mixing; 5) combustion modeling and experiments; 6) accelerated flames and detonations; 7) combustion mitigation and control; and 8) equipment survivability.

Enhanced biohydrogen production from corn stover by the combination of Clostridium cellulolyticum and hydrogen fermentation bacteria.

PubMed

Zhang, Shou-Chi; Lai, Qi-Heng; Lu, Yuan; Liu, Zhi-Dan; Wang, Tian-Min; Zhang, Chong; Xing, Xin-Hui

2016-10-01

Hydrogen was produced from steam-exploded corn stover by using a combination of the cellulolytic bacterium Clostridium cellulolyticum and non-cellulolytic hydrogen-producing bacteria. The highest hydrogen yield of the co-culture system with C. cellulolyticum and Citrobacter amalonaticus reached 51.9 L H2/kg total solid (TS). The metabolites from the co-culture system were significantly different from those of the mono-culture systems. Formate, which inhibits the growth of C. cellulolyticum, could be consumed by the hydrogen-evolving bacteria, and transformed into hydrogen. Glucose and xylose were released from corn stover via hydrolysis by C. cellulolyticum and were quickly utilized in dark fermentation with the co-cultured hydrogen-producing bacteria. Because the hydrolysis of corn stover by C. cellulolyticum was much slower than the utilization of glucose and xylose by the hydrogen-evolving bacteria, the sugar concentrations were always maintained at low levels, which favored a high hydrogen molar yield. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2015-11-01

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

Hydrogen peroxide oxidant fuel cell systems for ultra-portable applications

NASA Technical Reports Server (NTRS)

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.

Li-Decorated β12-Borophene as Potential Candidates for Hydrogen Storage: A First-Principle Study.

PubMed

Liu, Tingting; Chen, Yuhong; Wang, Haifeng; Zhang, Meiling; Yuan, Lihua; Zhang, Cairong

2017-12-07

The hydrogen storage properties of pristine β 12 -borophene and Li-decorated β 12 -borophene are systemically investigated by means of first-principles calculations based on density functional theory. The adsorption sites, adsorption energies, electronic structures, and hydrogen storage performance of pristine β 12 -borophene/H₂ and Li- β 12 -borophene/H₂ systems are discussed in detail. The results show that H₂ is dissociated into Two H atoms that are then chemisorbed on β 12 -borophene via strong covalent bonds. Then, we use Li atom to improve the hydrogen storage performance and modify the hydrogen storage capacity of β 12 -borophene. Our numerical calculation shows that Li- β 12 -borophene system can adsorb up to 7 H₂ molecules; while 2Li- β 12 -borophene system can adsorb up to 14 H₂ molecules and the hydrogen storage capacity up to 10.85 wt %.

Optimizing investments in coupled offshore wind -electrolytic hydrogen storage systems in Denmark

NASA Astrophysics Data System (ADS)

Hou, Peng; Enevoldsen, Peter; Eichman, Joshua; Hu, Weihao; Jacobson, Mark Z.; Chen, Zhe

2017-08-01

In response to electricity markets with growing levels of wind energy production and varying electricity prices, this research examines incentives for investments in integrated renewable energy power systems. A strategy for using optimization methods for a power system consisting of wind turbines, electrolyzers, and hydrogen fuel cells is explored. This research reveals the investment potential of coupling offshore wind farms with different hydrogen systems. The benefits in terms of a return on investment are demonstrated with data from the Danish electricity markets. This research also investigates the tradeoffs between selling the hydrogen directly to customers or using it as a storage medium to re-generate electricity at a time when it is more valuable. This research finds that the most beneficial configuration is to produce hydrogen at a time that complements the wind farm and sell the hydrogen directly to end users.

Antifungal effects of peroxidase systems.

PubMed

Lehrer, R I

1969-08-01

In the presence of hydrogen peroxide and either potassium iodide, sodium chloride, or potassium bromide, purified human myeloperoxidase was rapidly lethal to several species of Candida. Its candidacidal activity was inhibited by cyanide, fluoride, and azide, and by heat inactivation of the enzyme. A hydrogen peroxidegenerating system consisting of d-amino acid oxidase, flavine-adenine dinucleotide, and d-alanine could replace hydrogen peroxide in the candidacidal system. Horseradish peroxidase and human eosinophil granules also exerted candidacidal activity in the presence of iodide and hydrogen peroxide; however, unlike myeloperoxidase or neutrophil granules, these peroxidase sources were inactive when chloride replaced iodide. Cells of Saccharomyces, Geotrichum, and Rhodotorula species, and spores of Aspergillus fumigatus and A. niger were also killed by the combination of myeloperoxidase, iodide, and hydrogen peroxide. Peroxidases, functionally linked to hydrogen peroxide-generating systems, could provide phagocytic cells with the ability to kill many fungal species.

Optimizing investments in coupled offshore wind-electrolytic hydrogen storage systems in Denmark

DOE PAGES

Hou, Peng; Enevoldsen, Peter; Eichman, Joshua; ...

2017-05-25

In response to electricity markets with growing levels of wind energy production and varying electricity prices, this research examines incentives for investments in integrated renewable energy power systems. A strategy for using optimization methods for a power system consisting of wind turbines, electrolyzers, and hydrogen fuel cells is explored. This research reveals the investment potential of coupling offshore wind farms with different hydrogen systems. The benefits in terms of a return on investment are demonstrated with data from the Danish electricity markets. This research also investigates the tradeoffs between selling the hydrogen directly to customers or using it as amore » storage medium to re-generate electricity at a time when it is more valuable. Finally, this research finds that the most beneficial configuration is to produce hydrogen at a time that complements the wind farm and sell the hydrogen directly to end users.« less

Plasmatron-catalyst system

DOEpatents

Bromberg, Leslie; Cohn, Daniel R.; Rabinovich, Alexander; Alexeev, Nikolai

2004-09-21

A plasmatron-catalyst system. The system generates hydrogen-rich gas and comprises a plasmatron and at least one catalyst for receiving an output from the plasmatron to produce hydrogen-rich gas. In a preferred embodiment, the plasmatron receives as an input air, fuel and water/steam for use in the reforming process. The system increases the hydrogen yield and decreases the amount of carbon monoxide.

Plasmatron-catalyst system

DOEpatents

Bromberg, Leslie; Cohn, Daniel R.; Rabinovich, Alexander; Alexeev, Nikolai

2007-10-09

A plasmatron-catalyst system. The system generates hydrogen-rich gas and comprises a plasmatron and at least one catalyst for receiving an output from the plasmatron to produce hydrogen-rich gas. In a preferred embodiment, the plasmatron receives as an input air, fuel and water/steam for use in the reforming process. The system increases the hydrogen yield and decreases the amount of carbon monoxide.

System for the co-production of electricity and hydrogen

DOEpatents

Pham, Ai Quoc; Anderson, Brian Lee

2007-10-02

Described herein is a system for the co-generation of hydrogen gas and electricity, wherein the proportion of hydrogen to electricity can be adjusted from 0% to 100%. The system integrates fuel cell technology for power generation with fuel-assisted steam-electrolysis. A hydrocarbon fuel, a reformed hydrocarbon fuel, or a partially reformed hydrocarbon fuel can be fed into the system.

Hydrogen Data | Geospatial Data Science | NREL

Science.gov Websites

Hydrogen Data Hydrogen Data This hydrogen data estimates the potential for producing hydrogen from Coordinate System Name: GCS_North_American_1983 Coverage File Last Updated Metadata KMZ File Hydrogen Zip of hydrogen could be produced annually from wind, solar, and biomass resources in the United States

Liquid Fuel Production from Biomass via High Temperature Steam Electrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant L. Hawkes; Michael G. McKellar

2009-11-01

A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Hydrogen from electrolysis allows a high utilization of the biomass carbon for syngas production. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-fed biomass gasifier. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon monoxide and hydrogen). Assuming the thermal efficiency of the powermore » cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K. Parametric studies of system pressure, biomass moisture content and low temperature alkaline electrolysis are also presented.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Dongseok; Young, James L.; Lim, Haneol

Despite their excellent photophysical properties and record-high solar-to-hydrogen conversion efficiency, the high cost and limited stability of III-V compound semiconductors prohibit their practical application in solar-driven photoelectrochemical water splitting. Here in this paper we present a strategy for III-V photocatalysis that can circumvent these difficulties via printed assemblies of epitaxially grown compound semiconductors. A thin film stack of GaAs-based epitaxial materials is released from the growth wafer and printed onto a non-native transparent substrate to form an integrated photocatalytic electrode for solar hydrogen generation. The heterogeneously integrated electrode configuration together with specialized epitaxial design serve to decouple the material interfacesmore » for illumination and electrocatalysis. Subsequently, this allows independent control and optimization of light absorption, carrier transport, charge transfer, and material stability. Using this approach, we construct a series-connected wireless tandem system of GaAs photoelectrodes and demonstrate 13.1% solar-to-hydrogen conversion efficiency of unassisted-mode water splitting.« less

Hydrogen Bond Induces Hierarchical Self-Assembly in Liquid-Crystalline Block Copolymers.

PubMed

Huang, Shuai; Pang, Linlin; Chen, Yuxuan; Zhou, Liming; Fang, Shaoming; Yu, Haifeng

2018-03-01

Microphase-separated structures of block copolymers (BCs) with a size of sub-10 nm are usually obtained by hydrogen-bond-induced self-assembly of BCs through doping with small molecules as functional additives. Here, fabrication of hierarchically self-assembled sub-10 nm structures upon microphase separation of amphiphilic liquid-crystalline BCs (LCBCs) at the existence of hydrogen bonds but without any dopants is reported. The newly introduced urethane groups in the side chain of the hydrophobic block of LCBCs interact with the ether groups of the hydrophilic poly(ethylene oxide) (PEO) block, leading to imperfect crystallization of the PEO blocks. Both crystalline and amorphous domains coexist in the separated PEO phase, enabling a lamellar structure to appear inside the PEO nanocylinders. This provides an elegant method to fabricate controllable sub-10 nm microstructures in well-defined polymer systems without the introduction of any dopants. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

On the nature of hydrogen bonding between the phosphatidylcholine head group and water and dimethylsulfoxide

NASA Astrophysics Data System (ADS)

Dabkowska, Aleksandra P.; Lawrence, M. Jayne; McLain, Sylvia E.; Lorenz, Christian D.

2013-01-01

Molecular dynamics simulations are used to provide a detailed investigation of the hydrogen bond networks around the phosphatidylcholine (PC) head group in 1,2-dipropionyl-sn-glycero-3-phosphocholine in pure water, 10 mol.% and 30 mol.% dimethylsulfoxide (DMSO)-water solutions. Specifically, it is observed that DMSO replaces those water molecules that are within the first solvation shell of the choline, phosphate and ester groups of the PC head group, but are not hydrogen-bonded to the group. The effect of the presence of DMSO on the hydrogen bond network around the PC head groups of the lipid changes with the concentration of DMSO. In comparison to the hydrogen bond network observed in the pure water system, the number of hydrogen-bonded chains of solvent molecules increases slightly for the 10 mol.% DMSO system, while, in the 30 mol.% DMSO system, the number of hydrogen-bonded chains of solvent molecules decreases.

Design and fabrication of miniaturized PEM fuel cell combined microreactor with self-regulated hydrogen mechanism

NASA Astrophysics Data System (ADS)

Balakrishnan, A.; Frei, M.; Kerzenmacher, S.; Reinecke, H.; Mueller, C.

2015-12-01

In this work we present the design and fabrication of the miniaturized PEM fuel cell combined microreactor system with hydrogen regulation mechanism and testing of prototype microreactor. The system consists of two components (i) fuel cell component and (ii) microreactor component. The fuel cell component represents the miniaturized PEM fuel cell system (combination of screen printed fuel cell assembly and an on-board hydrogen storage medium). Hydrogen production based on catalytic hydrolysis of chemical hydride takes place in the microreactor component. The self-regulated hydrogen mechanism based on the gaseous hydrogen produced from the catalytic hydrolysis of sodium borohydride (NaBH4) gets accumulated as bubbles at the vicinity of the hydrophobic coated hydrogen exhaust holes. When the built up hydrogen bubbles pressure exceeds the burst pressure at the hydrogen exhaust holes the bubble collapses. This collapse causes a surge of fresh NaBH4 solution onto the catalyst surface leading to the removal of the reaction by-products formed at the active sites of the catalyst. The catalyst used in the system is platinum deposited on a base substrate. Nickel foam, carbon porous medium (CPM) and ceramic plate were selected as candidates for base substrate for developing a robust catalyst surface. For the first time the platinum layer fabricated by pulsed electrodeposition and dealloying (EPDD) technique is used for hydrolysis of NaBH4. The major advantages of such platinum catalyst layers are its high surface area and their mechanical stability. Prototype microreactor system with self-regulated hydrogen mechanism is demonstrated.

Tuning selectivity in catalysis by controlling particle shape

NASA Astrophysics Data System (ADS)

Lee, Ilkeun; Delbecq, Françoise; Morales, Ricardo; Albiter, Manuel A.; Zaera, Francisco

2009-02-01

A catalytic process for the selective formation of cis olefins would help minimize the production of unhealthy trans fats during the partial hydrogenation of edible oils. Here we report on the design of such a process on the basis of studies with model systems. Temperature programmed desorption data on single crystals showed that the isomerization of trans olefins to their cis counterparts is promoted by (111) facets of platinum, and that such selectivity is reversed on more open surfaces. Quantum mechanics calculations suggested that the extra stability of cis olefins seen on hydrogen-saturated Pt(111) surfaces may be due to a lesser degree of surface reconstruction, a factor found to be significant in the adsorption on close-packed platinum surfaces. Kinetic data using catalysts made out of dispersed tetrahedral Pt nanoparticles corroborated the selective promotion of the trans-to-cis isomerization on the (111) facets of the metal. Our work provides an example for how catalytic selectivity may be controlled by controlling the shape of the catalytic particles.

Recent progress in the NASA-Goddard Space Flight Center atomic hydrogen standards program

NASA Technical Reports Server (NTRS)

Reinhardt, V. S.

1981-01-01

At NASA Goddard Space Flight Center and through associated contractors, a broad spectrum of work is being carried out to develop improved hydrogen maser frequency standards for field use, improved experimental hydrogen maser frequency standards, and improved frequency and time distribution and measurement systems for hydrogen maser use. Recent progress in the following areas is reported: results on the Nr masers built by the Applied Physics Laboratory of Johns Hopkins University, the development of a low cost hydrogen maser at Goddard Space Flight Center, and work on a low noise phase comparison system and digitally phase locked crystal oscillator called the distribution and measurement system.

Use of Hydrogen Peroxide to Disinfect Hydroponic Plant Growth Systems

NASA Technical Reports Server (NTRS)

Barta, Daniel J.; Henderson, Keith

2000-01-01

Hydrogen peroxide was studied as an alternative to conventional bleach and rinsing methods to disinfect hydroponic plant growth systems. A concentration of 0.5% hydrogen peroxide was found to be effective. Residual hydrogen peroxide can be removed from the system by repeated rinsing or by flowing the solution through a platinum on aluminum catalyst. Microbial populations were reduced to near zero immediately after treatment but returned to pre-disinfection levels 2 days after treatment. Treating nutrient solution with hydrogen peroxide and planting directly into trays being watered with the nutrient solution without replenishment, was found to be detrimental to lettuce germination and growth.

Advantages of cryopumping with liquid hydrogen instead of helium refrigerators

NASA Technical Reports Server (NTRS)

Anderson, J. W.; Tueller, J. E.

1972-01-01

Open loop hydrogen vaporizers and helium refrigerators are compared for operational complexity, installation and operating cost, and safety requirements. Data from two vacuum chambers using helium refrigerators are used to provide comparative data. In general, the use of hydrogen is attractive in the larger systems, even when extra safety precautions are taken. Emotional resistance to the use of hydrogen because of safety requirements is considered great. However, the experience gained in the handling of large quantities of cryogenics, particularly hydrogen and liquefied natural gases, should be considered in the design of open loop hydrogen cooling systems.

NASA Hydrogen Research for Spaceport and Space Based Applications

NASA Technical Reports Server (NTRS)

Anderson, Tim

2006-01-01

The activities presented are a broad based approach to advancing key hydrogen related technologies in areas such as hydrogen production, distributed sensors for hydrogen-leak detection, laser instrumentation for hydrogen-leak detection, and cryogenic transport and storage. Presented are the results form 15 research projects, education, and outreach activities, system and trade studies, and project management. 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.

Polymers for hydrogen infrastructure and vehicle fuel systems :

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barth, Rachel Reina; Simmons, Kevin L.; San Marchi, Christopher W.

2013-10-01

This document addresses polymer materials for use in hydrogen service. Section 1 summarizes the applications of polymers in hydrogen infrastructure and vehicle fuel systems and identifies polymers used in these applications. Section 2 reviews the properties of polymer materials exposed to hydrogen and/or high-pressure environments, using information obtained from published, peer-reviewed literature. The effect of high pressure on physical and mechanical properties of polymers is emphasized in this section along with a summary of hydrogen transport through polymers. Section 3 identifies areas in which fuller characterization is needed in order to assess material suitability for hydrogen service.

Onboard fuel reformers for fuel cell vehicles: Equilibrium, kinetic and system modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kreutz, T.G.; Steinbugler, M.M.; Ogden, J.M.

1996-12-31

On-board reforming of liquid fuels to hydrogen for use in proton exchange membrane (PEM) fuel cell electric vehicles (FCEVs) has been the subject of numerous investigations. In many respects, liquid fuels represent a more attractive method of carrying hydrogen than compressed hydrogen itself, promising greater vehicle range, shorter refilling times, increased safety, and perhaps most importantly, utilization of the current fuel distribution infrastructure. The drawbacks of on-board reformers include their inherent complexity [for example a POX reactor includes: a fuel vaporizer, a reformer, water-gas shift reactors, a preferential oxidation (PROX) unit for CO cleanup, heat exchangers for thermal integration, sensorsmore » and controls, etc.], weight, and expense relative to compressed H{sub 2}, as well as degraded fuel cell performance due to the presence of inert gases and impurities in the reformate. Partial oxidation (POX) of automotive fuels is another alternative for hydrogen production. This paper provides an analysis of POX reformers and a fuel economy comparison of vehicles powered by on-board POX and SRM fuel processors.« less

Equilibrium and diffusion studies of metal-hydrogen systems

NASA Astrophysics Data System (ADS)

Maroevic, Petar

Several new methods and models have been developed pertaining to equilibrium properties of hydrogen in random binary substitutional alloys at room and lower temperatures, describing both statistics and kinetics of hydrogen in them. They represent a solution to the problem of the complete Fermi-Dirac description which is physically appropriate for these systems. Hydrogen diffusion which proceeds via lattice assisted quantum tunneling at room and lower temperatures requires a new and different description from the one based on the thermal hopping picture, which pertains only to relatively high temperatures. It is also shown that the analogs of the solution to the Fermi-Dirac problem of hydrogen can be successfully applied to the description of vacancies in a hydrogenated system, a phenomena known to occur due to high hydrogen-vacancy binding energies and the creation of hydrogen-vacancy clusters. The solution based on this model applies to much lower temperatures and higher concentrations than the tradition alone. This methodology has also been applied to the surface problem where very large vacancy and hydrogen concentrations occur. This is of special importance since mechanical properties are known to be greatly affected by the surface. As another consequence of hydrogen induced vacancies, hydrogen induced lattice migration (HILM) occurs. This has been demonstrated in our electrical resistivity study of palladium wires where recrystallization and annealing effects were observed upon hydrogen-heat-treatment (HHT).

Hydrogen interactions with metals

NASA Technical Reports Server (NTRS)

Mclellan, R. B.; Harkins, C. G.

1975-01-01

Review of the literature on the nature and extent of hydrogen interactions with metals and the role of hydrogen in metal failure. The classification of hydrogen-containing systems is discussed, including such categories as covalent hydrides, volatile hydrides, polymeric hydrides, and transition metal hydride complexes. The use of electronegativity as a correlating parameter in determining hydride type is evaluated. A detailed study is made of the thermodynamics of metal-hydrogen systems, touching upon such aspects as hydrogen solubility, the positions occupied by hydrogen atoms within the solvent metal lattice, the derivation of thermodynamic functions of solid solutions from solubility data, and the construction of statistical models for hydrogen-metal solutions. A number of theories of hydrogen-metal bonding are reviewed, including the rigid-band model, the screened-proton model, and an approach employing the augmented plane wave method to solve the one-electron energy band problem. Finally, the mechanism of hydrogen embrittlement is investigated on the basis of literature data concerning stress effects and the kinetics of hydrogen transport to critical sites.

Solar hydrogen production: renewable hydrogen production by dry fuel reforming

NASA Astrophysics Data System (ADS)

Bakos, Jamie; Miyamoto, Henry K.

2006-09-01

SHEC LABS - Solar Hydrogen Energy Corporation constructed a pilot-plant to demonstrate a Dry Fuel Reforming (DFR) system that is heated primarily by sunlight focusing-mirrors. The pilot-plant consists of: 1) a solar mirror array and solar concentrator and shutter system; and 2) two thermo-catalytic reactors to convert Methane, Carbon Dioxide, and Water into Hydrogen. Results from the pilot study show that solar Hydrogen generation is feasible and cost-competitive with traditional Hydrogen production. More than 95% of Hydrogen commercially produced today is by the Steam Methane Reformation (SMR) of natural gas, a process that liberates Carbon Dioxide to the atmosphere. The SMR process provides a net energy loss of 30 to 35% when converting from Methane to Hydrogen. Solar Hydrogen production provides a 14% net energy gain when converting Methane into Hydrogen since the energy used to drive the process is from the sun. The environmental benefits of generating Hydrogen using renewable energy include significant greenhouse gas and criteria air contaminant reductions.

EVermont Renewable Hydrogen Production and Transportation Fueling System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garabedian, Harold T.

2008-03-30

A great deal of research funding is being devoted to the use of hydrogen for transportation fuel, particularly in the development of fuel cell vehicles. When this research bears fruit in the form of consumer-ready vehicles, will the fueling infrastructure be ready? Will the required fueling systems work in cold climates as well as they do in warm areas? Will we be sure that production of hydrogen as the energy carrier of choice for our transit system is the most energy efficient and environmentally friendly option? Will consumers understand this fuel and how to handle it? Those are questions addressedmore » by the EVermont Wind to Wheels Hydrogen Project: Sustainable Transportation. The hydrogen fueling infrastructure consists of three primary subcomponents: a hydrogen generator (electrolyzer), a compression and storage system, and a dispenser. The generated fuel is then used to provide transportation as a motor fuel. EVermont Inc., started in 1993 by then governor Howard Dean, is a public-private partnership of entities interested in documenting and advancing the performance of advanced technology vehicles that are sustainable and less burdensome on the environment, especially in areas of cold climates, hilly terrain and with rural settlement patterns. EVermont has developed a demonstration wind powered hydrogen fuel producing filling system that uses electrolysis, compression to 5000 psi and a hydrogen burning vehicle that functions reliably in cold climates. And that fuel is then used to meet transportation needs in a hybrid electric vehicle whose internal combustion engine has been converted to operate on hydrogen Sponsored by the DOE EERE Hydrogen, Fuel Cells & Infrastructure Technologies (HFC&IT) Program, the purpose of the project is to test the viability of sustainably produced hydrogen for use as a transportation fuel in a cold climate with hilly terrain and rural settlement patterns. Specifically, the project addresses the challenge of building a renewable transportation energy capable system. The prime energy for this project comes from an agreement with a wind turbine operator.« less

Final Technical Report for GO15056 Millennium Cell: Development of an Advanced Chemical Hydrogen Storage and Generation System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno, Oscar

The objectives of this project are to increase system storage capacity by improving hydrogen generation from concentrated sodium borohydride, with emphasis on reactor and system engineering; to complete a conceptual system design based on sodium borohydride that will include key technology improvements to enable a hydrogen fuel system that will meet the systembased storage capacity of 1.2 kWh/L (36 g H2/L) and 1.5 kWh/kg (45 g H2/kg), by the end of FY 2007; and to utilize engineering expertise to guide Center research in both off-board chemical hydride regeneration and on-board hydrogen generation systems.

Hydrogen production by recombinant Escherichia coli strains

PubMed Central

Maeda, Toshinari; Sanchez‐Torres, Viviana; Wood, Thomas K.

2012-01-01

Summary The production of hydrogen via microbial biotechnology is an active field of research. Given its ease of manipulation, the best‐studied bacterium Escherichia coli has become a workhorse for enhanced hydrogen production through metabolic engineering, heterologous gene expression, adaptive evolution, and protein engineering. Herein, the utility of E. coli strains to produce hydrogen, via native hydrogenases or heterologous ones, is reviewed. In addition, potential strategies for increasing hydrogen production are outlined and whole‐cell systems and cell‐free systems are compared. PMID:21895995