WorldWideScience

Sample records for prsa liquid hydrogen

  1. Power Reactant Storage Assembly (PRSA) (Space Shuttle). PRSA hydrogen and oxygen DVT tank refurbishment

    Science.gov (United States)

    1993-01-01

    The Power Reactant Storage Assembly (PRSA) liquid hydrogen Development Verification Test (H2 DVT) tank assembly (Beech Aircraft Corporation P/N 15548-0116-1, S/N 07399000SHT0001) and liquid oxygen (O2) DVT tank assembly (Beech Aircraft Corporation P/N 15548-0115-1, S/N 07399000SXT0001) were refurbished by Ball Electro-Optics and Cryogenics Division to provide NASA JSC, Propulsion and Power Division, the capability of performing engineering tests. The refurbishments incorporated the latest flight configuration hardware and avionics changes necessary to make the tanks function like flight articles. This final report summarizes these refurbishment activities. Also included are up-to-date records of the pressure time and cycle histories.

  2. Liquid hydrogen in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yasumi, S. [Iwatani Corp., Osaka (Japan). Dept. of Overseas Business Development

    2009-07-01

    Japan's Iwatani Corporation has focused its attention on hydrogen as the ultimate energy source in future. Unlike the United States, hydrogen use and delivery in liquid form is extremely limited in the European Union and in Japan. Iwatani Corporation broke through industry stereotypes by creating and building Hydro Edge Co. Ltd., Japan's largest liquid hydrogen plant. It was established in 2006 as a joint venture between Iwatani and Kansai Electric Power Group in Osaka. Hydro Edge is Japan's first combined liquid hydrogen and ASU plant, and is fully operational. Liquid oxygen, liquid nitrogen and liquid argon are separated from air using the cryogenic energy of liquefied natural gas fuel that is used for power generation. Liquid hydrogen is produced efficiently and simultaneously using liquid nitrogen. Approximately 12 times as much hydrogen in liquid form can be transported and supplied as pressurized hydrogen gas. This technology is a significant step forward in the dissemination and expansion of hydrogen in a hydrogen-based economy.

  3. Liquid hydrogen: back to basics

    Energy Technology Data Exchange (ETDEWEB)

    Sherif, S.A. [Dept. of Mechanical and Aerospace Engineering, Univ. of Florida, Florida (United States)

    2009-07-01

    'Full text': Liquid hydrogen is primarily used as a rocket fuel and is predestined for supersonic and hypersonic space vehicles to a large extent because it has the lowest boiling point density and the highest specific thrust of any known fuel. Its favorable characteristics include its high heating value per unit mass, its wide ignition range in hydrogen/oxygen or air mixtures, as well as its large flame speed and cooling capacity due to its high specific heat which permits very effective engine cooling and cooling the critical parts of the outer skin. Liquid hydrogen has some other important uses such as in high-energy nuclear physics and bubble chambers. The transport of hydrogen is vastly more economical when it is in liquid form even though cryogenic refrigeration and special Dewar vessels are required. Although liquid hydrogen can provide a lot of advantages, its uses are restricted in part because liquefying hydrogen by existing conventional methods consumes a large amount of energy (around 30% of its heating value). Liquefying 1 kg of hydrogen in a medium-size plant requires 10 to 13 kWh of electric energy. In addition, boil-off losses associated with the storage, transportation, and handling of liquid hydrogen can consume up to 40% of its available combustion energy. It is therefore important to search for ways that can improve the efficiency of the liquefiers and diminish the boil-off losses. This lecture gives an overview of the main issues associated with the production, storage, and handling of liquid hydrogen. Some discussion of promising ways of hydrogen liquefaction will also be presented. (author)

  4. Capacitive level meter for liquid hydrogen

    OpenAIRE

    Matsumoto, Koichi; Sobue, Masamitsu; Asamoto, Kai; Nishimura, Yuta; Abe, Satoshi; Numazawa, Takenori

    2011-01-01

    A capacitive level meter working at low temperatures was made to use in magnetic refrigerator for hydrogen liquefaction. The liquid level was measured from the capacitance between parallel electrodes immersed in the liquid. The meter was tested for liquid nitrogen, hydrogen, and helium. The operation was successful using an AC capacitance bridge. The estimated sensitivity of the meter is better than 0.2 mm for liquid hydrogen. The meter also worked with pressurized hydrogen. © 2010.

  5. Storage of liquid hydrogen in natural zeolite

    National Research Council Canada - National Science Library

    Pavol Rybár; Carsten Drebenstedt; Mário Molokáč; Ladislav Hvizdák; Ľubomír Štrba

    2015-01-01

    .... Therefore, the storage of hydrogen is relatively dangerous. A storage of liquid hydrogen in the natural zeolite, which is placed in large capacity battery, appears to be a suitable hydrogen storage method...

  6. Storage of liquid hydrogen in natural zeolite

    OpenAIRE

    Pavol Rybár; Carsten Drebenstedt; Mário Molokáč; Ladislav Hvizdák; Ľubomír Štrba

    2015-01-01

    When producing and utilizing hydrogen, its storage is one of the biggest problems. Hydrogen, as a gas, is extremely fluid with very low specific weight. Moreover, at a certain rate, the hydrogen-oxygen mixture is explosive. Therefore, the storage of hydrogen is relatively dangerous. A storage of liquid hydrogen in the natural zeolite, which is placed in large capacity battery, appears to be a suitable hydrogen storage method. Proposed and constructed pressure tank, large cap...

  7. Microscopic dynamics of liquid hydrogen

    CERN Document Server

    Zoppi, M; Celli, M

    2001-01-01

    We have measured the almost-pure incoherent scattering function of liquid parahydrogen using neutron inelastic scattering. The experiment was carried out on TOSCA, a time-of-flight, inverse geometry, crystal analyser spectrometer, operating on the pulsed- neutron source ISIS (UK). Since the instrument kinematic region is close to a line in the (k, E)-plane, we have actually measured the projection of S/sub inc/(k, w) on this line. The measured cross- section gives a direct experimental access to the microscopic dynamic of the centre-of-mass motion of molecular hydrogen. The data have been analysed using the Gaussian approximation and have been compared with the results of a novel Quantum Mechanical Molecular Dynamics simulation technique. The results are encouraging, but claim for further developments of the theoretical approach, as well as for more extensive experimental data. (14 refs).

  8. Storage of liquid hydrogen in natural zeolite

    Directory of Open Access Journals (Sweden)

    Pavol Rybár

    2015-10-01

    Full Text Available When producing and utilizing hydrogen, its storage is one of the biggest problems. Hydrogen, as a gas, is extremely fluid with very low specific weight. Moreover, at a certain rate, the hydrogen-oxygen mixture is explosive. Therefore, the storage of hydrogen is relatively dangerous. A storage of liquid hydrogen in the natural zeolite, which is placed in large capacity battery, appears to be a suitable hydrogen storage method. Proposed and constructed pressure tank, large capacity battery, allows long-term and safe storage of liquid hydrogen, with the possibility to change its state from liquid to gaseous or contrarily in real time. Natural zeolite is an inert material with large internal surface area and high thermal capacity. In the future, presented large capacity battery VAZEP can be a part of the system for production and storage of electric energy generated by photovoltaic modules from the sun.

  9. Novel developments in hydrogen storage, hydrogen activation and ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Doroodian, Amir

    2010-12-03

    This dissertation is divided into three chapters. Recently, metal-free hydrogen activation using phosphorous compounds has been reported in science magazine. We have investigated the interaction between hydrogen and phosphorous compounds in presence of strong Lewis acids (chapter one). A new generation of metal-free hydrogen activation, using amines and strong Lewis acids with sterically demanding nature, was already developed in our group. Shortage of high storage capacity using large substitution to improve sterical effect led us to explore the amine borane derivatives, which are explained in chapter two. Due to the high storage capacity of hydrogen in aminoborane derivatives, we have explored these materials to extend hydrogen release. These compounds store hydrogen as proton and hydride on adjacent atoms or ions. These investigations resulted in developing hydrogen storage based on ionic liquids containing methyl guanidinium cation. Then we have continued to develop ionic liquids based on methyl guanidinium cation with different anions, such as tetrafluoro borate (chapter three). We have replaced these anions with transition metal anions to investigate hydrogen bonding and catalytic activity of ionic liquids. This chapter illustrates the world of ionic liquid as a green solvent for organic, inorganic and catalytic reactions and combines the concept of catalysts and solvents based on ionic liquids. The catalytic activity is investigated particularly with respect to the interaction with CO{sub 2}. (orig.)

  10. The microscopic structure of the hydrogen liquids

    CERN Document Server

    Zoppi, M; Celli, M; Cuello, G J; Formisano, F; Guarini, E; Magli, R; Neumann, M

    2003-01-01

    We have measured the microscopic structure of liquid para-hydrogen by means of a neutron diffraction experiment on the D4C liquids diffractometer at Institute Laue-Langevin (Grenoble, France). This is the first direct neutron diffraction measurement of the static structure factor of hydrogen. The present determination of the microscopic structure of hydrogen is consistent with previous experimental determinations carried out on liquid deuterium and with path integral Monte Carlo simulations. The comparison with recent x-ray determinations is also satisfactory.

  11. Pad B Liquid Hydrogen Storage Tank

    Science.gov (United States)

    Hall, Felicia

    2007-01-01

    Kennedy Space Center is home to two liquid hydrogen storage tanks, one at each launch pad of Launch Complex 39. The liquid hydrogen storage tank at Launch Pad B has a significantly higher boil off rate that the liquid hydrogen storage tank at Launch Pad A. This research looks at various calculations concerning the at Launch Pad B in an attempt to develop a solution to the excess boil off rate. We will look at Perlite levels inside the tank, Boil off rates, conductive heat transfer, and radiant heat transfer through the tank. As a conclusion to the research, we will model the effects of placing an external insulation to the tank in order to reduce the boil off rate and increase the economic efficiency of the liquid hydrogen storage tanks.

  12. Hydrogen bonding in ionic liquids.

    Science.gov (United States)

    Hunt, Patricia A; Ashworth, Claire R; Matthews, Richard P

    2015-03-07

    Ionic liquids (IL) and hydrogen bonding (H-bonding) are two diverse fields for which there is a developing recognition of significant overlap. Doubly ionic H-bonds occur when a H-bond forms between a cation and anion, and are a key feature of ILs. Doubly ionic H-bonds represent a wide area of H-bonding which has yet to be fully recognised, characterised or explored. H-bonds in ILs (both protic and aprotic) are bifurcated and chelating, and unlike many molecular liquids a significant variety of distinct H-bonds are formed between different types and numbers of donor and acceptor sites within a given IL. Traditional more neutral H-bonds can also be formed in functionalised ILs, adding a further level of complexity. Ab initio computed parameters; association energies, partial charges, density descriptors as encompassed by the QTAIM methodology (ρBCP), qualitative molecular orbital theory and NBO analysis provide established and robust mechanisms for understanding and interpreting traditional neutral and ionic H-bonds. In this review the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored. Estimating the H-bonding energy is difficult because at a fundamental level the H-bond and ionic interaction are coupled. The NBO and QTAIM methodologies, unlike the total energy, are local descriptors and therefore can be used to directly compare neutral, ionic and doubly ionic H-bonds. The charged nature of the ions influences the ionic characteristics of the H-bond and vice versa, in addition the close association of the ions leads to enhanced orbital overlap and covalent contributions. The charge on the ions raises the energy of the Ylp and lowers the energy of the X-H σ* NBOs resulting in greater charge transfer, strengthening the H-bond. Using this range of parameters and comparing doubly ionic H-bonds to more traditional neutral and ionic H-bonds it is clear that doubly ionic H-bonds cover the full range of weak

  13. Liquid Metallic Hydrogen: A Building Block for the Liquid Sun

    OpenAIRE

    Robitaille P.-M.

    2011-01-01

    Liquid metallic hydrogen provides a compelling material for constructing a condensed matter model of the Sun and the photosphere. Like diamond, metallic hydrogen might have the potential to be a metastable substance requiring high pressures for forma- tion. Once created, it would remain stable even at lower pressures. The metallic form of hydrogen was initially conceived in 1935 by Eugene Wigner and Hillard B. Huntington who indirectly anticipated its elevated critical temper...

  14. Liquid Metallic Hydrogen: A Building Block for the Liquid Sun

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2011-07-01

    Full Text Available Liquid metallic hydrogen provides a compelling material for constructing a condensed matter model of the Sun and the photosphere. Like diamond, metallic hydrogen might have the potential to be a metastable substance requiring high pressures for forma- tion. Once created, it would remain stable even at lower pressures. The metallic form of hydrogen was initially conceived in 1935 by Eugene Wigner and Hillard B. Huntington who indirectly anticipated its elevated critical temperature for liquefaction (Wigner E. and Huntington H.B. On the possibility of a metallic modification of hydro- gen. J. Chem. Phys. , 1935, v.3, 764–770. At that time, solid metallic hydrogen was hypothesized to exist as a body centered cubic, although a more energetically accessible layered graphite-like lattice was also envisioned. Relative to solar emission, this struc- tural resemblance between graphite and layered metallic hydrogen should not be easily dismissed. In the laboratory, metallic hydrogen remains an elusive material. However, given the extensive observational evidence for a condensed Sun composed primarily of hydrogen, it is appropriate to consider metallic hydrogen as a solar building block. It is anticipated that solar liquid metallic hydrogen should possess at least some layered order. Since layered liquid metallic hydrogen would be essentially incompressible, its invocation as a solar constituent brings into question much of current stellar physics. The central proof of a liquid state remains the thermal spectrum of the Sun itself. Its proper understanding brings together all the great forces which shaped modern physics. Although other proofs exist for a liquid photosphere, our focus remains solidly on the generation of this light.

  15. Microwave plasma for hydrogen production from liquids

    Directory of Open Access Journals (Sweden)

    Czylkowski Dariusz

    2016-06-01

    Full Text Available The hydrogen production by conversion of liquid compounds containing hydrogen was investigated experimentally. The waveguide-supplied metal cylinder-based microwave plasma source (MPS operated at frequency of 915 MHz at atmospheric pressure was used. The decomposition of ethanol, isopropanol and kerosene was performed employing plasma dry reforming process. The liquid was introduced into the plasma in the form of vapour. The amount of vapour ranged from 0.4 to 2.4 kg/h. Carbon dioxide with the flow rate ranged from 1200 to 2700 NL/h was used as a working gas. The absorbed microwave power was up to 6 kW. The effect of absorbed microwave power, liquid composition, liquid flow rate and working gas fl ow rate was analysed. All these parameters have a clear influence on the hydrogen production efficiency, which was described with such parameters as the hydrogen production rate [NL(H2/h] and the energy yield of hydrogen production [NL(H2/kWh]. The best achieved experimental results showed that the hydrogen production rate was up to 1116 NL(H2/h and the energy yield was 223 NL(H2 per kWh of absorbed microwave energy. The results were obtained in the case of isopropanol dry reforming. The presented catalyst-free microwave plasma method can be adapted for hydrogen production not only from ethanol, isopropanol and kerosene, but also from different other liquid compounds containing hydrogen, like gasoline, heavy oils and biofuels.

  16. Development of Automotive Liquid Hydrogen Storage Systems

    Science.gov (United States)

    Krainz, G.; Bartlok, G.; Bodner, P.; Casapicola, P.; Doeller, Ch.; Hofmeister, F.; Neubacher, E.; Zieger, A.

    2004-06-01

    Liquid hydrogen (LH2) takes up less storage volume than gas but requires cryogenic vessels. State-of-the-art applications for passenger vehicles consist of double-wall cylindrical tanks that hold a hydrogen storage mass of up to 10 kg. The preferred shell material of the tanks is stainless steel, since it is very resistant against hydrogen brittleness and shows negligible hydrogen permeation. Therefore, the weight of the whole tank system including valves and heat exchanger is more than 100 kg. The space between the inner and outer vessel is mainly used for thermal super-insulation purposes. Several layers of insulation foils and high vacuums of 10-3 Pa reduce the heat entry. The support structures, which keep the inner tank in position to the outer tank, are made of materials with low thermal conductivity, e.g. glass or carbon fiber reinforced plastics. The remaining heat in-leak leads to a boil-off rate of 1 to 3 percent per day. Active cooling systems to increase the stand-by time before evaporation losses occur are being studied. Currently, the production of several liquid hydrogen tanks that fulfill the draft of regulations of the European Integrated Hydrogen Project (EIHP) is being prepared. New concepts of lightweight liquid hydrogen storage tanks will be investigated.

  17. Crash test of a liquid hydrogen automobile

    Science.gov (United States)

    Finegold, J. G.; Van Vorst, W. D.

    1976-01-01

    Details of the conversion of a U.S. Postal Service mail truck to hydrogen-fueled operation are given. Specific reference is made to design safety considerations. A traffic accident is described that caused the mail truck (mounted on a trailer) to turn on its side at approximately 20 mph and to finally slide to a stop and turn upside down. No one was injured, and there was essentially no damage to the liquid hydrogen fuel system. The mail truck was driven away from the scene of the accident. Suggestions to insure the safety of hydrogen-fueled experimental vehicles are made.

  18. Permeation Barrier for Lightweight Liquid Hydrogen Tanks

    OpenAIRE

    Schultheiß, Daniel

    2007-01-01

    For the future usage of hydrogen as an automotive fuel, its on-board storage is crucial. One approach is the storage of liquid hydrogen (LH2, 20 K) in double-walled, vacuum insulated tanks. The introduction of carbon fiber reinforced plastics (CFRP) as structural material enables a high potential of reducing the weight in comparison to the state-of-the-art stainless steel tanks. The generally high permeability of hydrogen through plastics, however, can lead to long-term degradation of the ins...

  19. Liquid Hydrogen Consumption During Space Shuttle Program

    Science.gov (United States)

    Partridge, Jonathan K.

    2011-01-01

    This slide presentation reviews the issue of liquid hydrogen consumption and the points of its loss in prior to the shuttle launch. It traces the movement of the fuel from the purchase to the on-board quantity and the loss that results in 54.6 of the purchased quantity being on board the Shuttle.

  20. Critical fields of liquid superconducting metallic hydrogen

    Science.gov (United States)

    Jaffe, J.; Ashcroft, N. W.

    1983-01-01

    Liquid metallic hydrogen, in a fully dissociated state, is predicted at certain densities to pass from dirty to clean and from type II to type I superconducting behavior as temperature is lowered. Previously announced in STAR as N82-29374

  1. Hydrogen production from glucose in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Assenbaum, D.W.; Taccardi, N.; Berger, M.E.M.; Boesmann, A.; Enzenberger, F.; Woelfel, R.; Wasserscheid, P. [Erlangen-Nuernberg Univ. (Germany). Lehrstuhl fuer chemische Reaktionstechnik

    2010-07-01

    technologies suffer from the fact that the overall reaction rates are often restricted by mass and heat transport problems. Lastly, there are severe limitations concerning the feedstock selection as for some important substrates, such as e.g. glucose, the process can only be operated in very diluted systems to avoid rapid tar formation [22,23,24]. In this contribution we describe for the first time a catalytic reaction system producing hydrogen from glucose in astonishingly high selectivities using a single reaction step under very mild conditions. The catalytic reaction system is characterized by its homogeneous nature and comprises a Ru-complex catalyst dissolved and stabilized in an ionic liquid medium. Ionic liquids are salts of melting points below 100 C [25]. These liquid materials have attracted much interest in the last decade as solvents for catalytic reactions [26] and separation technologies (extraction, distillation) [27,28,29,30,31,32]. Besides, these liquids have found industrial applications as process fluids for mechanic [33] and electrochemical applications [34]. Finally, from the pioneering work of Rogers and co-workers, it is known that ionic liquids are able to dissolve significant amounts of water-insoluble biopolymers (such as e.g. cellulose and chitin)[35] and even complex biopolymer mixtures, such as e.g. wood, have been completely dissolved in some ionic liquids [36]. In our specific application, the role of the ionic liquid is threefold: a) the ionic liquid dissolves the carbohydrate starting material thus expanding the range of applicable carbohydrate to water insoluble polymers; b) the ionic liquid provides a medium to dissolve and stabilize the catalyst; c) the ionic liquid dissolves hydrogen at a very low level, so inhibiting any possible collateral hydrogen-consuming process (detailed investigation of the hydrogen solubility in ionic liquids have been reported by e.g. Brennecke and coworkers [37]). (orig.)

  2. Thermal Analysis of Cryogenic Hydrogen Liquid Separator

    Science.gov (United States)

    Congiardo, Jared F.; Fortier, Craig R. (Editor)

    2014-01-01

    During launch for the new Space Launch System (SLS) liquid hydrogen is bleed through the engines during replenish, pre-press, and extended pre-press to condition the engines prior to launch. The predicted bleed flow rates are larger than for the shuttle program. A consequence of the increased flow rates is having liquif hydrogen in the vent system, which the facilities was never designed to handle. To remedy the problem a liquid separator is being designed in the system to accumulated the liquid propellant and protect the facility flare stack (which can only handle gas). The attached document is a presentation of the current thermalfluid analysis performed for the separator and will be presented at the Thermal and Fluid Analysis Workshop (NASA workshop) next week in Cleveland, Ohio.

  3. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17...) § 179.102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated liquid must comply with the following special requirements: (a) The tank car must comply with...

  4. Organic liquids to storage the hydrogen; Des liquides organiques pour stocker l'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Lepetit, V.

    2003-09-01

    The research programs on the different possibilities to storage the hydrogen are presented: the methanol, the metallic alloys, the hybrid organic liquids and the carbon nano-tubes. A special interest is given to the organic liquids with the use of the naphthalene and the benzene. (A.L.B.)

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

    Science.gov (United States)

    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

  6. Liquid Metallic Hydrogen: Building Block of a Liquid Sun

    Science.gov (United States)

    Robitaille, Pierre-Marie

    2011-04-01

    The establishment by Andrews of critical temperatures (T. Andrews, Phil. Trans. 1869, v. 159, 575-590) soon became one of the great pillars in support of the gaseous models of the Sun. Gases above these temperatures simply could not be liquefied. Given that interior of the Sun was already hypothesized in the 19th century to be at temperatures well exceeding those achievable on Earth in ordinary furnaces, it became inconceivable to think of the solar interior as anything but gaseous. Hence, the models advanced by Secchi, Faye, Stoney, Lane, and Young, could easily gain acceptance. However, modern science is beginning to demonstrate that hydrogen (which under ordinary conditions has a critical point at ˜33 K) can become pressure ionized such that its electrons enter metallic conductions bands, given sufficiently elevated pressures, as the band gap is reduced from 15 eV to ˜0.3 eV. Liquid metallic hydrogen will possess a new critical temperature well above that of ordinary hydrogen. Already, experiments suggests that it can exist at temperatures of thousands of Kelvin and millions of atmospheres (S. T. Weir et al., Phys. Rev. Let. 1996, 76, 1860). The formation of liquid metallic hydrogen brings with it a new candidate for the interior of the Sun and the stars. Its existence shatters the great pillar of the gaseous models of the Sun which the critical point of ordinary gases had erected.

  7. Screen Channel Liquid Acquisition Device Outflow Tests in Liquid Hydrogen

    Science.gov (United States)

    Hartwig, Jason W.; Chato, David J.; McQuillen, J. B.; Vera, J.; Kudlac, M. T.; Quinn, F. D.

    2013-01-01

    This paper presents experimental design and test results of the recently concluded 1-g inverted vertical outflow testing of two 325x2300 full scale liquid acquisition device (LAD) channels in liquid hydrogen (LH2). One of the channels had a perforated plate and internal cooling from a thermodynamic vent system (TVS) to enhance performance. The LADs were mounted in a tank to simulate 1-g outflow over a wide range of LH2 temperatures (20.3 - 24.2 K), pressures (100 - 350 kPa), and flow rates (0.010 - 0.055 kg/s). Results indicate that the breakdown point is dominated by liquid temperature, with a second order dependence on mass flow rate through the LAD. The best performance is always achieved in the coldest liquid states for both channels, consistent with bubble point theory. Higher flow rates cause the standard channel to break down relatively earlier than the TVS cooled channel. Both the internal TVS heat exchanger and subcooling the liquid in the propellant tank are shown to significantly improve LAD performance.

  8. Hydrogenated liquids and hydrogen production by non-thermal plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Arabi, K.; Aubry, O.; Khacef, A.; Cormier, J.M. [Orleans Univ., Orleans Cedex (France). Centre national de la recherche scientifique, Polytech d' Orleans, Group for Research and Studies on Mediators of Inflamation

    2010-07-01

    In recent years, hydrogen (H{sub 2}) has been considered as a fuel for electricity generation and transportation purposes. H{sub 2} is a renewable energy source that does not contribute to the greenhouse effect. This paper reported on a comparative study of syngas production from alcohol, with particular reference to the plasma steam-reforming of ethanol, methanol, ammonia and vegetable oil. The H{sub 2} yields and energetic cost in function of hydrogen sources were presented. The non thermal plasma used in this study was a laboratory scale experimental device static discharge. An arc formed between two electrodes made of graphite. The efficiency of the process was determined through chemical diagnostics. Gas chromatography and Fourier transform infrared (FTIR) techniques were used to determine concentrations of H{sub 2}, carbon monoxide, carbon dioxide and carbon as functions of flow and inlet liquid mixture concentration parameters. This paper also presented the values of H{sub 2}/CO ratio and the composition of synthesis gas according to various operating conditions. 18 refs., 2 tabs., 8 figs.

  9. Ordered pairing in liquid metallic hydrogen

    Science.gov (United States)

    Carlsson, A. E.; Ashcroft, N. W.

    1983-01-01

    We study two possible types of pairing involving the protons of a proposed low-temperature liquid phase metallic hydrogen. Electron-proton pairing, which can result in an insulating phase, is investigated by using an approximate solution of an Eliashberg-type equation for the anomalous self-energy. A very low estimate of the transition temperature is obtained by including proton correlations in the effective interaction. For proton-proton pairing, we derive a new proton pair potential based on the Abrikosov wave function. This potential includes the electron-proton interaction to all orders and has a much larger well depth than is obtained with linear screening methods. This suggests the possibility of either a superfluid paired phase analogous to that in He-3, or alternatively a phase with true molecular pairing.

  10. Aircraft-Fuel-Tank Design for Liquid Hydrogen

    Science.gov (United States)

    Reynolds, T W

    1955-01-01

    Some of the considerations involved in the design of aircraft fuel tanks for liquid hydrogen are discussed herein. Several of the physical properties of metals and thermal insulators in the temperature range from ambient to liquid-hydrogen temperatures are assembled. Calculations based on these properties indicate that it is possible to build a large-size liquid-hydrogen fuel tank which (1) will weigh less then 15 percent of the fuel weight, (2) will have a hydrogen vaporization rate less than 30 percent of the cruise fuel-flow rate, and (3) can be held in a stand-by condition and readied for flight in a short time.

  11. Permeation barrier for lightweight liquid hydrogen tanks

    Energy Technology Data Exchange (ETDEWEB)

    Schultheiss, D.

    2007-04-16

    For the future usage of hydrogen as an automotive fuel, its on-board storage is crucial. One approach is the storage of liquid hydrogen (LH2, 20 K) in double-walled, vacuum insulated tanks. The introduction of carbon fiber reinforced plastics (CFRP) as structural material enables a high potential of reducing the weight in comparison to the state-of-the-art stainless steel tanks. The generally high permeability of hydrogen through plastics, however, can lead to long-term degradation of the insulating vacuum. The derived objective of this dissertation was to find and apply an adequate permeation barrier (liner) on CFRP. The investigated liners were either foils adhered on CFRP specimens or coatings deposited on CFRP specimens. The coatings were produced by means of thermal spraying, metal plating or physical vapor deposition (PVD). The materials of the liners included Al, Au, Cu, Ni and Sn as well as stainless steel and diamond-like carbon. The produced liners were tested for their permeation behavior, thermal shock resistance and adherence to the CFRP substrate. Additionally, SEM micrographs were used to characterize and qualify the liners. The foils, although being a good permeation barrier, adhered weakly to the substrate. Furthermore, leak-free joining of foil segments is a challenge still to be solved. The metal plating liners exhibited the best properties. For instance, no permeation could be detected through a 50 {mu}m thick Cu coating within the accuracy of the measuring apparatus. This corresponds to a reduction of the permeation gas flow by more than factor 7400 compared to uncoated CFRP. In addition, the metal platings revealed a high adherence and thermal shock resistance. The coatings produced by means of thermal spraying and PVD did not show a sufficient permeation barrier effect. After having investigated the specimens, a 170 liter CFRP tank was fully coated with 50 {mu}m Cu by means of metal plating. (orig.)

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

    Science.gov (United States)

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

    2015-04-17

    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.

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

    OpenAIRE

    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 hydro...

  14. Chemical utilization of hydrogen from fluctuating energy sources – Catalytic transfer hydrogenation from charged Liquid Organic Hydrogen Carrier systems

    OpenAIRE

    Geburtig, Denise; Preuster, Patrick; Bösmann, Andreas; Müller, Karsten; Wasserscheid, Peter

    2016-01-01

    Liquid Organic Hydrogen Carrier (LOHC) systems offer a very attractive way for storing and distributing hydrogen from electrolysis using excess energies from solar or wind power plants. In this contribution, an alternative, high-value utilization of such hydrogen is proposed namely its use in steady-state chemical hydrogenation processes. We here demonstrate that the hydrogen-rich form of the LOHC system dibenzyltoluene/perhydro-dibenzyltoluene can be directly applied as sole source of hydrog...

  15. A superconductor to superfluid phase transition in liquid metallic hydrogen.

    Science.gov (United States)

    Babaev, Egor; Sudbø, Asle; Ashcroft, N W

    2004-10-07

    Although hydrogen is the simplest of atoms, it does not form the simplest of solids or liquids. Quantum effects in these phases are considerable (a consequence of the light proton mass) and they have a demonstrable and often puzzling influence on many physical properties, including spatial order. To date, the structure of dense hydrogen remains experimentally elusive. Recent studies of the melting curve of hydrogen indicate that at high (but experimentally accessible) pressures, compressed hydrogen will adopt a liquid state, even at low temperatures. In reaching this phase, hydrogen is also projected to pass through an insulator-to-metal transition. This raises the possibility of new state of matter: a near ground-state liquid metal, and its ordered states in the quantum domain. Ordered quantum fluids are traditionally categorized as superconductors or superfluids; these respective systems feature dissipationless electrical currents or mass flow. Here we report a topological analysis of the projected phase of liquid metallic hydrogen, finding that it may represent a new type of ordered quantum fluid. Specifically, we show that liquid metallic hydrogen cannot be categorized exclusively as a superconductor or superfluid. We predict that, in the presence of a magnetic field, liquid metallic hydrogen will exhibit several phase transitions to ordered states, ranging from superconductors to superfluids.

  16. Fractional Consumption of Liquid Hydrogen and Liquid Oxygen During the Space Shuttle Program

    Science.gov (United States)

    Partridge, Jonathan K.

    2011-01-01

    The Space Shuttle uses the propellants, liquid hydrogen and liquid oxygen, to meet part of the propulsion requirements from ground to orbit. The Kennedy Space Center procured over 25 million kilograms of liquid hydrogen and over 250 million kilograms of liquid oxygen during the 3D-year Space Shuttle Program. Because of the cryogenic nature of the propellants, approximately 55% of the total purchased liquid hydrogen and 30% of the total purchased liquid oxygen were used in the Space Shuttle Main Engines. The balance of the propellants were vaporized during operations for various purposes. This paper dissects the total consumption of liqUid hydrogen and liqUid oxygen and determines the fraction attributable to each of the various processing and launch operations that occurred during the entire Space Shuttle Program at the Kennedy Space Center.

  17. Hydrogen engines based on liquid fuels, a review

    Science.gov (United States)

    Houseman, J.; Voecks, G. E.

    1981-01-01

    The concept of storing hydrogen as part of a liquid fuel, such as gasoline or methanol, and subsequent onboard generation of the hydrogen from such liquids, is reviewed. Hydrogen generation processes, such as steam reforming, partial oxidation, and thermal decomposition are evaluated in terms of theoretical potential and practical limitations, and a summary is presented on the major experimental work on conversion of gasoline and methanol. Results of experiments indicate that onboard hydrogen generation from methanol is technically feasible and will yield substantial improvements in fuel economy and emissions, especially if methanol decomposition is brought about by the use of engine exhaust heat; e.g., a methanol decomposition reactor of 3.8 provides hydrogen-rich gas for a 4 cylinder engine (1.952), and 80% of the methanol is converted, engine exhaust gas being the only heat supply. A preliminary outline of the development of a methanol-based hydrogen engine and a straight hydrogen engine is presented.

  18. Identification of Conserved and Species-Specific Functions of the Listeria monocytogenes PrsA2 Secretion Chaperone

    Science.gov (United States)

    Cahoon, Laty A.

    2015-01-01

    The Gram-positive bacterium Listeria monocytogenes is a facultative intracellular pathogen that relies on the regulated secretion and activity of a variety of proteins that sustain life within diverse environments. PrsA2 has recently been identified as a secreted peptidyl-prolyl cis/trans isomerase and chaperone that is dispensable for bacterial growth in broth culture but essential for L. monocytogenes virulence. Following host infection, PrsA2 contributes to the proper folding and activity of secreted proteins that are required for bacterial replication within the host cytosol and for bacterial spread to adjacent cells. PrsA2 is one member of a family of Gram-positive secretion chaperones that appear to play important roles in bacterial physiology; however, it is not known how these proteins recognize their substrate proteins or the degree to which their function is conserved across diverse Gram-positive species. We therefore examined PrsA proteins encoded by a variety of Gram-positive bacteria for functional complementation of L. monocytogenes mutants lacking prsA2. PrsA homologues encoded by Bacillus subtilis, Streptococcus pyogenes, Streptococcus pneumoniae, Streptococcus mutans, Staphylococcus aureus, and Lactococcus lactis were examined for functional complementation of a variety of L. monocytogenes PrsA2-associated phenotypes central to L. monocytogenes pathogenesis and bacterial cell physiology. Our results indicate that while selected aspects of PrsA2 function are broadly conserved among diverse Gram-positive bacteria, PrsA2 exhibits unique specificity for L. monocytogenes target proteins required for pathogenesis. The L. monocytogenes PrsA2 chaperone thus appears evolutionarily optimized for virulence factor secretion within the host cell cytosol while still maintaining aspects of activity relevant to more general features of Gram-positive protein translocation. PMID:26216425

  19. Liquid hydrogen as a propulsion fuel, 1945-1959

    Science.gov (United States)

    Sloop, J. L.

    1978-01-01

    A historical review is presented on the research and development of liquid hydrogen for use as a propulsion fuel. The document is divided into three parts: Part 1 (1945-1950); Part 2 (1950-1957); and Part 3 (1957-1958), encompassing eleven topics. Two appendixes are included. Hydrogen Technology Through World War 2; and Propulsion Primer, Performance Parameters and Units.

  20. Hydrogen Response in Liquid Propylene Polymerization : Towards a Generalized Model

    NARCIS (Netherlands)

    Al-haj Ali, M.; Betlem, B.; Roffel, B.; Weickert, G.

    2006-01-01

    Liquid propylene batch experiments in the absence of a gas phase have been carried out using a highly-active MgCl2/TiCl4/phthalate/silane/AlR3 catalyst at varying temperatures (60-80°C) and molar hydrogen-monomer ratios of 0-10 mmol/mol. With increasing hydrogen concentration the polymerization rate

  1. Structure and weak hydrogen bonds in liquid acetaldehyde

    Directory of Open Access Journals (Sweden)

    Cordeiro Maria A. M.

    2004-01-01

    Full Text Available Monte Carlo simulations have been performed to investigate the structure and hydrogen bonds formation in liquid acetaldehyde. An all atom model for the acetaldehyde have been optimized in the present work. Theoretical values obtained for heat of vaporisation and density of the liquid are in good agreement with experimental data. Graphics of radial distribution function indicate a well structured liquid compared to other similar dipolar organic liquids. Molecular mechanics minimization in gas phase leads to a trimer of very stable structure. The geometry of this complex is in very good agreement with the rdf. The shortest site-site correlation is between oxygen and the carbonyl hydrogen, suggesting that this correlation play a important role in the liquid structure and properties. The OxxxH average distance and the C-HxxxO angle obtained are characteristic of weak hydrogen bonds.

  2. Heat Analysis of Liquid piston Compressor for Hydrogen Applications

    DEFF Research Database (Denmark)

    Kermani, Nasrin Arjomand; Rokni, Masoud

    2014-01-01

    is developed based on the mass and energy balance of the hydrogen, liquid and the wall of the compression chamber at each time step and positional node with various compression ratios to calculate the temperature distribution of the system. The amount of heat extracted from hydrogen, directly at the interface......A new hydrogen compression technology using liquid as the compression piston is investigated from heat transfer point of view. A thermodynamic model, simulating a single compression stroke, is developed to investigate the heat transfer phenomena inside the compression chamber. The model...

  3. Measurements of capillary system degradation. [liquid hydrogen propellant retention capability

    Science.gov (United States)

    Warren, R. P.; Butz, J. R.; Maytum, C. D.; Fester, D. A.; Young, G. M.

    1975-01-01

    The effects of vibration, flow transients, and warm gas pressurization on capillary acquisition system performance were evaluated. The degradation observed under wide band random and high frequency sinusoidal vibration was of a substantially different nature from that obtained under low frequency sinusoidal vibration. With the former, ingestion of small gas bubbles into the liquid region was correlated by a hydrostatic model, while the capillary stability was destroyed and liquid was lost from the liquid region with the latter. No degradation was observed as a result of flow transients in a flight-type multichannel screen device, but it was observed in a transparent laboratory device. Liquid hydrogen outflow tests were conducted with a multilayer dual-screen-liner system with both helium and hydrogen pressurant gases. The tendency towards dryout of the device with hydrogen pressurant was found to increase with increasing pressurant temperature and length of prepressurization period. Dryout did not occur with helium pressurant.

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

    Science.gov (United States)

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

    2010-05-25

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

  5. Track formation in a liquid hydrogen ultrasonic bubble chamber

    CERN Document Server

    Brown, R C A; Jarman, P D

    1973-01-01

    Track sensitivity to minimum ionising particles has been demonstrated in liquid hydrogen using only an intense ultrasonic field. Carefully designed transducer systems are shown to be capable of producing pressure amplitudes >2.8 atm in a standing wave system in liquid hydrogen. The growth of bubbles to visible size (0.1 mm) in less than 0.2 ms, and their collapse in less than 15 ms, indicates that rapid cycling rates of 50-100 pulses per second may be feasible with this technique. (11 refs).

  6. Corrosion behavior of construction materials for ionic liquid hydrogen compressor

    DEFF Research Database (Denmark)

    Arjomand Kermani, Nasrin; Petrushina, Irina; Nikiforov, Aleksey Valerievich

    2016-01-01

    The corrosion behavior of various commercially available stainless steels and nickel-based alloys as possible construction materials for components which are in direct contact with one of five different ionic liquids was evaluated. The ionic liquids, namely: 1-ethyl-3-methylimidazolium triflate, 1...... liquid hydrogen compressor. An electrochemical cell was specially designed, and steady-state cyclic voltammetry was used to measure the corrosion resistance of the alloys in the ionic liquids at 23 °C, under atmospheric pressure. The results showed a very high corrosion resistance and high stability...... for all the alloys tested. The two stainless steels, AISI 316L and AISI 347 showed higher corrosion resistance compared to AISI 321 in all the ionic liquids tested. It was observed that small addition of molybdenum, tantalum, and niobium to the alloys increased the corrosion stability in the ionic liquids...

  7. Liquid oxygen/liquid hydrogen boost/vane pump for the advanced orbit transfer vehicles auxiliary propulsion system

    Science.gov (United States)

    Gluzek, F.; Mokadam, R. G.; To, I. H.; Stanitz, J. D.; Wollschlager, J.

    1979-01-01

    A rotating, positive displacement vane pump with an integral boost stage was designed to pump saturated liquid oxygen and liquid hydrogen for auxiliary propulsion system of orbit transfer vehicle. This unit is designed to ingest 10% vapor by volume, contamination free liquid oxygen and liquid hydrogen. The final pump configuration and the predicted performance are included.

  8. Comparison of alternate fuels for aircraft. [liquid hydrogen, liquid methane, and synthetic aviation kerosene

    Science.gov (United States)

    Witcofski, R. D.

    1979-01-01

    Liquid hydrogen, liquid methane, and synthetic aviation kerosene were assessed as alternate fuels for aircraft in terms of cost, capital requirements, and energy resource utilization. Fuel transmission and airport storage and distribution facilities are considered. Environmental emissions and safety aspects of fuel selection are discussed and detailed descriptions of various fuel production and liquefaction processes are given. Technological deficiencies are identified.

  9. Performance of a Small Gas Generator Using Liquid Hydrogen and Liquid Oxygen

    Science.gov (United States)

    Acker, Loren W.; Fenn, David B.; Dietrich, Marshall W.

    1961-01-01

    The performance and operating problems of a small hot-gas generator burning liquid hydrogen with liquid oxygen are presented. Two methods of ignition are discussed. Injector and combustion chamber design details based on rocket design criteria are also given. A carefully fabricated showerhead injector of simple design provided a gas generator that yielded combustion efficiencies of 93 and 96 percent.

  10. A liquid hydrogen target for the calibration of the MEG and MEG II liquid xenon calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Signorelli, G., E-mail: giovanni.signorelli@pi.infn.it [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Baldini, A.M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Bemporad, C.; Cei, F.; Nicolò, D. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Università di Pisa, Dipartimento di Fisica, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Galli, L.; Gallucci, G.; Grassi, M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Papa, A. [Paul Scherrer Institut, 5232 Villigen (Switzerland); Sergiampietri, F. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Venturini, M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy)

    2016-07-11

    We designed, built and operated a liquid hydrogen target for the calibration of the liquid xenon calorimeter of the MEG experiment. The target was used throughout the entire data taking period, from 2008 to 2013 and it is being refurbished and partly re-designed to be integrated and used in the MEG-II experiment.

  11. Ground Operations Demonstration Unit for Liquid Hydrogen Initial Test Results

    Science.gov (United States)

    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.

  12. Liquid oxygen/liquid hydrogen auxiliary power system thruster investigation

    Science.gov (United States)

    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.

  13. Penicillin-binding protein folding is dependent on the PrsA peptidyl-prolyl cis-trans isomerase in Bacillus subtilis.

    Science.gov (United States)

    Hyyryläinen, Hanne-Leena; Marciniak, Bogumila C; Dahncke, Kathleen; Pietiäinen, Milla; Courtin, Pascal; Vitikainen, Marika; Seppala, Raili; Otto, Andreas; Becher, Dörte; Chapot-Chartier, Marie-Pierre; Kuipers, Oscar P; Kontinen, Vesa P

    2010-07-01

    Summary The PrsA protein is a membrane-anchored peptidyl-prolyl cis-trans isomerase in Bacillus subtilis and most other Gram-positive bacteria. It catalyses the post-translocational folding of exported proteins and is essential for normal growth of B. subtilis. We studied the mechanism behind this indispensability. We could construct a viable prsA null mutant in the presence of a high concentration of magnesium. Various changes in cell morphology in the absence of PrsA suggested that PrsA is involved in the biosynthesis of the cylindrical lateral wall. Consistently, four penicillin-binding proteins (PBP2a, PBP2b, PBP3 and PBP4) were unstable in the absence of PrsA, while muropeptide analysis revealed a 2% decrease in the peptidoglycan cross-linkage index. Misfolded PBP2a was detected in PrsA-depleted cells, indicating that PrsA is required for the folding of this PBP either directly or indirectly. Furthermore, strongly increased uniform staining of cell wall with a fluorescent vancomycin was observed in the absence of PrsA. We also demonstrated that PrsA is a dimeric or oligomeric protein which is localized at distinct spots organized in a helical pattern along the cell membrane. These results suggest that PrsA is essential for normal growth most probably as PBP folding is dependent on this PPIase.

  14. Green oxidation of alkenes in ionic liquid solvent by hydrogen ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 3. Green oxidation of alkenes in ionic liquid solvent by hydrogen peroxide over high performance Fe(III) Schiff base complexes immobilized on MCM-41. Mohammad Taghi Goldani Ali Mohammadi Reza Sandaroos. Regular Articles Volume 126 Issue 3 May ...

  15. Silicon surface barrier detectors used for liquid hydrogen density measurement

    Science.gov (United States)

    James, D. T.; Milam, J. K.; Winslett, H. B.

    1968-01-01

    Multichannel system employing a radioisotope radiation source, strontium-90, radiation detector, and a silicon surface barrier detector, measures the local density of liquid hydrogen at various levels in a storage tank. The instrument contains electronic equipment for collecting the density information, and a data handling system for processing this information.

  16. The Concept Design of a Split Flow Liquid Hydrogen Turbopump

    Science.gov (United States)

    2008-03-01

    Advanced Expander Engine Cycle Schematic ................................................... 20 Figure 10 Component View of ALH Turbopump...21 Table 12 ALH Turbopump Performance Parameters ....................................................... 21 Table 13...Units C Absolute velocity ft/s ALH Advanced Liquid Hydrogen Al Aluminum AR Aspect Ratio AxLngth Axial Length inches Beta2b Blade exit angle

  17. Two-component Fermi-liquid theory - Equilibrium properties of liquid metallic hydrogen

    Science.gov (United States)

    Oliva, J.; Ashcroft, N. W.

    1981-01-01

    It is reported that the transition of condensed hydrogen from an insulating molecular crystal phase to a metallic liquid phase, at zero temperature and high pressure, appears possible. Liquid metallic hydrogen (LMH), comprising interpenetrating proton and electron fluids, would constitute a two-component Fermi liquid with both a very high component-mass ratio and long-range, species-dependent bare interactions. The low-temperature equilibrium properties of LMH are examined by means of a generalization to the case of two components of the phenomenological Landau Fermi-liquid theory, and the low-temperature specific heat, compressibility, thermal expansion coefficient and spin susceptibility are given. It is found that the specific heat and the thermal expansion coefficient are vastly greater in the liquid than in the corresponding solid, due to the presence of proton quasiparticle excitations in the liquid.

  18. Quantum simulation of low-temperature metallic liquid hydrogen.

    Science.gov (United States)

    Chen, Ji; Li, Xin-Zheng; Zhang, Qianfan; Probert, Matthew I J; Pickard, Chris J; Needs, Richard J; Michaelides, Angelos; Wang, Enge

    2013-01-01

    The melting temperature of solid hydrogen drops with pressure above ~65 GPa, suggesting that a liquid state might exist at low temperatures. It has also been suggested that this low-temperature liquid state might be non-molecular and metallic, although evidence for such behaviour is lacking. Here we report results for hydrogen at high pressures using ab initio methods, which include a description of the quantum motion of the protons. We determine the melting temperature as a function of pressure and find an atomic solid phase from 500 to 800 GPa, which melts at metallic atomic liquid is stable at temperatures as low as 50 K. The quantum motion of the protons is critical to the low melting temperature reported, as simulations with classical nuclei lead to considerably higher melting temperatures of ~300 K across the entire pressure range considered.

  19. Electrokinetic Hydrogen Generation from Liquid WaterMicrojets

    Energy Technology Data Exchange (ETDEWEB)

    Duffin, Andrew M.; Saykally, Richard J.

    2007-05-31

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

  20. Catalytic decomposition of carbon-based liquid-phase chemical hydrogen storage materials for hydrogen generation under mild conditions

    National Research Council Canada - National Science Library

    Sánchez, Felipe; Motta, Davide; Dimitratos, Nikolaos

    2016-01-01

    ... investment, and low potential risks. In this review, we survey the progress made in hydrogen generation from carbon-based liquid-phase chemical hydrogen storage materials, focusing mainly on the catalytic decomposition of formic acid...

  1. The liquid-liquid phase transition in dense hydrogen

    Science.gov (United States)

    Ceperley, David; Pierleoni, Carlo; Holzmann, Markus; Morales, Miguel

    The phase diagram of high pressure hydrogen is of great interest for fundamental research. A first-order phase transition in the fluid phase between a molecular insulating fluid and a monoatomic metallic fluid has been long anticipated. Recent experiments reported contrasting results about the location of the transition and theoretical results are very uncertain. We report highly accurate coupled electron-ion quantum Monte Carlo calculations of this transition, finding results that lie between the two experimental predictions, close to that measured in diamond anvil cell experiments but at 25-30 GPa higher pressure. The transition along an isotherm is signaled by a discontinuity in the specific volume, a sudden dissociation of the molecules, a jump in electrical conductivity and loss of electron localization. Funding from DOE NA DE-NA0001789 and DE-AC52-07NA27344. Computer time from PRACE and Blue Waters.

  2. Additive Manufacturing a Liquid Hydrogen Rocket Engine

    Science.gov (United States)

    Jones, Carl P.; Robertson, Elizabeth H.; Koelbl, Mary Beth; Singer, Chris

    2016-01-01

    Space Propulsion is a 5 day event being held from 2nd May to the 6th May 2016 at the Rome Marriott Park Hotel in Rome, Italy. This event showcases products like Propulsion sub-systems and components, Production and manufacturing issues, Liquid, Solid, Hybrid and Air-breathing Propulsion Systems for Launcher and Upper Stages, Overview of current programmes, AIV issues and tools, Flight testing and experience, Technology building blocks for Future Space Transportation Propulsion Systems : Launchers, Exploration platforms & Space Tourism, Green Propulsion for Space Transportation, New propellants, Rocket propulsion & global environment, Cost related aspects of Space Transportation propulsion, Modelling, Pressure-Thrust oscillations issues, Impact of new requirements and regulations on design etc. in the Automotive, Manufacturing, Fabrication, Repair & Maintenance industries.

  3. Integrated Refrigeration and Storage for Advanced Liquid Hydrogen Operations

    Science.gov (United States)

    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.

  4. Warm Pressurant Gas Effects on the Liquid Hydrogen Bubble Point

    Science.gov (United States)

    Hartwig, Jason W.; McQuillen, John B.; Chato, David J.

    2013-01-01

    This paper presents experimental results for the liquid hydrogen bubble point tests using warm pressurant gases conducted at the Cryogenic Components Cell 7 facility at the NASA Glenn Research Center in Cleveland, Ohio. The purpose of the test series was to determine the effect of elevating the temperature of the pressurant gas on the performance of a liquid acquisition device. Three fine mesh screen samples (325 x 2300, 450 x 2750, 510 x 3600) were tested in liquid hydrogen using cold and warm noncondensible (gaseous helium) and condensable (gaseous hydrogen) pressurization schemes. Gases were conditioned from 0 to 90 K above the liquid temperature. Results clearly indicate a degradation in bubble point pressure using warm gas, with a greater reduction in performance using condensable over noncondensible pressurization. Degradation in the bubble point pressure is inversely proportional to screen porosity, as the coarsest mesh demonstrated the highest degradation. Results here have implication on both pressurization and LAD system design for all future cryogenic propulsion systems. A detailed review of historical heated gas tests is also presented for comparison to current results.

  5. Concept for on orbit liquid hydrogen test bed

    Science.gov (United States)

    Frank, D.; Nast, T.; Mix, J.

    2012-04-01

    There is growing interest in the utilization of cryogenic propellants for future space missions. The utilization of these propellants for long duration in space presents substantial challenges in fluid management in the low g environment. Lockheed Martin (LM) is developing the concept for a space borne system for demonstration of long term storage, various fluid management tests involving control of tank pressure, location and identification of vapor and liquid phases, venting in low g, mass gauging, and extension of life with cryocoolers and location of liquid for transfer. In addition the concept includes autonomous coupling and hydrogen transfer from tank to tank. The concept is based on a flight qualified flight proven hydrogen Dewar design from a previous program The concept for this system is described.

  6. Bacillus subtilis PrsA is required in vivo as an extracytoplasmic chaperone for secretion of active enzymes synthesized either with or without pro-sequences

    DEFF Research Database (Denmark)

    Jacobs, M; Kontinen, V; Sarvas, M

    1993-01-01

    In prsA (protein secretion) mutants of Bacillus subtilis, decreased levels of exoproteins, including alpha-amylase and subtilisins, are found extracellularly. The effect of prsA on subtilisin secretion is elaborated here. Extracytoplasmic folding and secretion of active subtilisin is assisted...

  7. A Sensitivity Study for a MICE Liquid Hydrogen Absorber

    OpenAIRE

    Errede, D.; Rakhno, I.

    2004-01-01

    The International Muon Ionization Cooling Experiment (MICE) is devoted to a study of a muon cooling channel capable of giving the desired performance for a Neutrino Factory. One of the goals is achieving an absolute accuracy of measurements of emittance reduction as high as 0.1%. The paper describes results of a Monte Carlo study on allowed density variations of liquid hydrogen corresponding to the desired accuracy of the measurements.

  8. Heat transfer analysis of liquid piston compressor for hydrogen applications

    DEFF Research Database (Denmark)

    Kermani, Nasrin Arjomand; Rokni, Masoud

    2015-01-01

    A hydrogen compression technology using liquid as the compression piston is investigated from heat transfer point of view. A thermodynamic model, simulating a single compression stroke, is developed to investigate the heat transfer phenomena inside the compression chamber. The model is developed...... and through the walls, is investigated and compared with the adiabatic case. The results show that depending on heat transfer correlation, the hydrogen temperature reduces slightly between 0.2% and 0.4% compared to the adiabatic case, at 500bar, due to the large wall resistance and small contact area...... at the interface. Moreover, the results of the sensitivity analysis illustrates that increasing the total heat transfer coefficients at the interface and the wall, together with compression time, play key roles in reducing the hydrogen temperature. Increasing the total heat transfer coefficient at the interface...

  9. Glass Bubbles Insulation for Liquid Hydrogen Storage Tanks

    Science.gov (United States)

    Sass, J. P.; SaintCyr, W. W.; Barrett, T. M.; Baumgartner, R. G.; Lott, J. W.; Fesmire, J. E.

    2009-01-01

    A full-scale field application of glass bubbles insulation has been demonstrated in a 218,000 L liquid hydrogen storage tank. This work is the evolution of extensive materials testing, laboratory scale testing, and system studies leading to the use of glass bubbles insulation as a cost efficient and high performance alternative in cryogenic storage tanks of any size. The tank utilized is part of a rocket propulsion test complex at the NASA Stennis Space Center and is a 1960's vintage spherical double wall tank with an evacuated annulus. The original perlite that was removed from the annulus was in pristine condition and showed no signs of deterioration or compaction. Test results show a significant reduction in liquid hydrogen boiloff when compared to recent baseline data prior to removal of the perlite insulation. The data also validates the previous laboratory scale testing (1000 L) and full-scale numerical modeling (3,200,000 L) of boiloff in spherical cryogenic storage tanks. The performance of the tank will continue to be monitored during operation of the tank over the coming years. KEYWORDS: Glass bubble, perlite, insulation, liquid hydrogen, storage tank.

  10. Time-resolved crystallization of deeply cooled liquid hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Kuehnel, Matthias

    2014-02-15

    This thesis serves two main purposes: 1. The introduction of a novel experimental method to investigate phase change dynamics of supercooled liquids 2. First-time measurements for the crystallization behaviour for hydrogen isotopes under various conditions (1) The new method is established by the synergy of a liquid microjet of ∼ 5 μm diameter and a scattering technique with high spatial resolution, here linear Raman spectroscopy. Due to the high directional stability and the known velocity of the liquid filament, its traveling axis corresponds to a time axis static in space. Utilizing evaporative cooling in a vacuum environment, the propagating liquid cools down rapidly and eventually experiences a phase transition to the crystalline state. This temporal evolution is probed along the filament axis, ultimately resulting in a time resolution of 10 ns. The feasibility of this approach is proven successfully within the following experiments. (2) A main object of study are para-hydrogen liquid filaments. Raman spectra reveal a temperature gradient of the liquid across the filament. This behaviour can quantitatively be reconstructed by numerical simulations using a layered model and is rooted in the effectiveness of evaporative cooling on the surface and a finite thermal conductivity. The deepest supercoolings achieved are ∼ 30% below the melting point, at which the filament starts to solidify from the surface towards the core. With a crystal growth velocity extracted from the data the appropriate growth mechanism is identified. The crystal structure that initially forms is metastable and probably the result of Ostwald's rule of stages. Indications for a transition within the solid towards the stable equilibrium phase support this interpretation. The analog isotope ortho-deuterium is evidenced to behave qualitatively similar with quantitative differences being mass related. In further measurements, isotopic mixtures of para-hydrogen and ortho-deuterium are

  11. Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

    Directory of Open Access Journals (Sweden)

    Eero eSalminen

    2014-02-01

    Full Text Available The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat benzalkonium [ADBA] (alkyldimethylbenzylammonium was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs. Typically, a SILCA contains metal nanoparticles, enzymes or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC. The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70 % molar yield towards citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide.

  12. Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

    Science.gov (United States)

    Salminen, Eero; Virtanen, Pasi; Mikkola, Jyri-Pekka

    2014-02-01

    The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat) benzalkonium [ADBA] (alkyldimethylbenzylammonium) was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs). Typically, a SILCA contains metal nanoparticles, enzymes or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC). The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70 % molar yield towards citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide.

  13. Performance Gains of Propellant Management Devices for Liquid Hydrogen Depots

    Science.gov (United States)

    Hartwig, Jason W.; McQuillen, John B.; Chato, David J.

    2013-01-01

    This paper presents background, experimental design, and preliminary experimental results for the liquid hydrogen bubble point tests conducted at the Cryogenic Components Cell 7 facility at the NASA Glenn Research Center in Cleveland, Ohio. The purpose of the test series was to investigate the parameters that affect liquid acquisition device (LAD) performance in a liquid hydrogen (LH2) propellant tank, to mitigate risk in the final design of the LAD for the Cryogenic Propellant Storage and Transfer Technology Demonstration Mission, and to provide insight into optimal LAD operation for future LH2 depots. Preliminary test results show an increase in performance and screen retention over the low reference LH2 bubble point value for a 325 2300 screen in three separate ways, thus improving fundamental LH2 LAD performance. By using a finer mesh screen, operating at a colder liquid temperature, and pressurizing with a noncondensible pressurant gas, a significant increase in margin is achieved in bubble point pressure for LH2 screen channel LADs.

  14. Minimum energy, liquid hydrogen supersonic cruise vehicle study

    Science.gov (United States)

    Brewer, G. D.; Morris, R. E.

    1975-01-01

    The potential was examined of hydrogen-fueled supersonic vehicles designed for cruise at Mach 2.7 and at Mach 2.2. The aerodynamic, weight, and propulsion characteristics of a previously established design of a LH2 fueled, Mach 2.7 supersonic cruise vehicle (SCV) were critically reviewed and updated. The design of a Mach 2.2 SCV was established on a corresponding basis. These baseline designs were then studied to determine the potential of minimizing energy expenditure in performing their design mission, and to explore the effect of fuel price and noise restriction on their design and operating performance. The baseline designs of LH2 fueled aircraft were than compared with equivalent designs of jet A (conventional hydrocarbon) fueled SCV's. Use of liquid hydrogen for fuel for the subject aircraft provides significant advantages in performance, cost, noise, pollution, sonic boom, and energy utilization.

  15. An experiment to evaluate liquid hydrogen storage in space

    Science.gov (United States)

    Eberhardt, R. N.; Fester, D. A.; Johns, W. A.; Marino, J. S.

    1981-01-01

    The design and verification of a Cryogenic Fluid Management Experiment for orbital operation on the Shuttle is described. The experiment will furnish engineering data to establish design criteria for storage and supply of cryogenic fluids, mainly hydrogen, for use in low gravity environments. The apparatus comprises an LAD (liquid acquisition device) and a TVS (thermodynamic vent system). The hydrogen will be either vented or forced out by injected helium and the flow rates will be monitored. The data will be compared with ground-based simulations to determine optimal flow rates for the pressurizing gas and the release of the cryogenic fluid. It is noted that tests on a one-g, one-third size LAD system are under way.

  16. Aerogel Insulation Applications for Liquid Hydrogen Launch Vehicle Tanks

    Science.gov (United States)

    Fesmire, J. E.; Sass, J.

    2007-01-01

    Aerogel based insulation systems for ambient pressure environments were developed for liquid hydrogen (LH2) tank applications. Solutions to thermal insulation problems were demonstrated for the Space Shuttle External Tank (ET) through extensive testing at the Cryogenics Test Laboratory. Demonstration testing was performed using a 1/10th scale ET LH2 intertank unit and liquid helium as the coolant to provide the 20 K cold boundary temperature. Cryopumping tests in the range of 20K were performed using both constant mass and constant pressure methods. Long-duration tests (up to 10 hours) showed that the nitrogen mass taken up inside the intertank is reduced by a factor of nearly three for the aerogel insulated case as compared to the un-insulated (bare metal flight configuration) case. Test results including thermal stabilization, heat transfer effectiveness, and cryopumping confirm that the aerogel system eliminates free liquid nitrogen within the intertank. Physisorption (or adsorption) of liquid nitrogen within the fine pore structure of aerogel materials was also investigated. Results of a mass uptake method show that the sorption ratio (liquid nitrogen to aerogel beads) is about 62 percent by volume. A novel liquid nitrogen production method of testing the liquid nitrogen physical adsorption capacity of aerogel beads was also performed to more closely approximate the actual launch vehicle cooldown and thermal stabilization effects within the aerogel material. The extraordinary insulating effectiveness of the aerogel material shows that cryopumping is not an open-cell mass transport issue but is strictly driven by thermal communication between warm and cold surfaces. The new aerogel insulation technology is useful to solve heat transfer problem areas and to augment existing thermal protection systems on launch vehicles. Examples are given and potential benefits for producing launch systems that are more reliable, robust, reusable, and efficient are outlined.

  17. Liquid crystal nanocomposites produced by mixtures of hydrogen bonded achiral liquid crystals and functionalized carbon nanotubes

    Science.gov (United States)

    Katranchev, B.; Petrov, M.; Keskinova, E.; Naradikian, H.; Rafailov, P. M.; Dettlaff-Weglikowska, U.; Spassov, T.

    2014-12-01

    The liquid crystalline (LC) nature of alkyloxybenzoic acids is preserved after adding of any mesogenic or non-mesogenic compound through hydrogen bonding. However, this noncovalent interaction provokes a sizable effect on the physical properties as, e. g. melting point and mesomorphic states. In the present work we investigate nanocomposites, prepared by mixture of the eighth homologue of p-n-alkyloxybenzoic acids (8OBA) with single-walled carbon nanotubes (SWCNT) with the purpose to modify the optical properties of the liquid crystal. We exercise optical control on the LC system by inserting SWCNT specially functionalized by carboxylic groups. Since the liquid crystalline state combines order and mobility at the molecular (nanoscale) level, molecular modification can lead to different macroscopical nanocomposite symmetry. The thermal properties of the functionalized nanocomposite are confirmed by DSC analyses. The mechanism of the interaction between surface-treated nanoparticles (functionalized nanotubes) and the liquid crystal 8OBA bent- dimer molecules is briefly discussed.

  18. Hydrogen-bond acidity of ionic liquids: an extended scale.

    Science.gov (United States)

    Kurnia, Kiki A; Lima, Filipa; Cláudio, Ana Filipa M; Coutinho, João A P; Freire, Mara G

    2015-07-15

    One of the main drawbacks comprising an appropriate selection of ionic liquids (ILs) for a target application is related to the lack of an extended and well-established polarity scale for these neoteric fluids. Albeit considerable progress has been made on identifying chemical structures and factors that influence the polarity of ILs, there still exists a high inconsistency in the experimental values reported by different authors. Furthermore, due to the extremely large number of possible ILs that can be synthesized, the experimental characterization of their polarity is a major limitation when envisaging the choice of an IL with a desired polarity. Therefore, it is of crucial relevance to develop correlation schemes and a priori predictive methods able to forecast the polarity of new (or not yet synthesized) fluids. In this context, and aiming at broadening the experimental polarity scale available for ILs, the solvatochromic Kamlet-Taft parameters of a broad range of bis(trifluoromethylsulfonyl)imide-([NTf2](-))-based fluids were determined. The impact of the IL cation structure on the hydrogen-bond donating ability of the fluid was comprehensively addressed. Based on the large amount of novel experimental values obtained, we then evaluated COSMO-RS, COnductor-like Screening MOdel for Real Solvents, as an alternative tool to estimate the hydrogen-bond acidity of ILs. A three-parameter model based on the cation-anion interaction energies was found to adequately describe the experimental hydrogen-bond acidity or hydrogen-bond donating ability of ILs. The proposed three-parameter model is also shown to present a predictive capacity and to provide novel molecular-level insights into the chemical structure characteristics that influence the acidity of a given IL. It is shown that although the equimolar cation-anion hydrogen-bonding energies (EHB) play the major role, the electrostatic-misfit interactions (EMF) and van der Waals forces (EvdW) also contribute

  19. Hydrogen-bond acidity of ionic liquids: an extended scale†

    Science.gov (United States)

    Kurnia, Kiki A.; Lima, Filipa; Cláudio, Ana Filipa M.; Coutinho, João A. P.; Freire, Mara G.

    2015-01-01

    One of the main drawbacks comprising an appropriate selection of ionic liquids (ILs) for a target application is related to the lack of an extended and well-established polarity scale for these neoteric fluids. Albeit considerable progress has been made on identifying chemical structures and factors that influence the polarity of ILs, there still exists a high inconsistency in the experimental values reported by different authors. Furthermore, due to the extremely large number of possible ILs that can be synthesized, the experimental characterization of their polarity is a major limitation when envisaging the choice of an IL with a desired polarity. Therefore, it is of crucial relevance to develop correlation schemes and a priori predictive methods able to forecast the polarity of new (or not yet synthesized) fluids. In this context, and aiming at broadening the experimental polarity scale available for ILs, the solvatochromic Kamlet–Taft parameters of a broad range of bis(trifluoromethylsulfonyl)imide-([NTf2]−)-based fluids were determined. The impact of the IL cation structure on the hydrogen-bond donating ability of the fluid was comprehensively addressed. Based on the large amount of novel experimental values obtained, we then evaluated COSMO-RS, COnductor-like Screening MOdel for Real Solvents, as an alternative tool to estimate the hydrogen-bond acidity of ILs. A three-parameter model based on the cation–anion interaction energies was found to adequately describe the experimental hydrogen-bond acidity or hydrogen-bond donating ability of ILs. The proposed three-parameter model is also shown to present a predictive capacity and to provide novel molecular-level insights into the chemical structure characteristics that influence the acidity of a given IL. It is shown that although the equimolar cation–anion hydrogen-bonding energies (EHB) play the major role, the electrostatic-misfit interactions (EMF) and van der Waals forces (EvdW) also contribute

  20. A Drude polarizable model for liquid hydrogen sulfide.

    Science.gov (United States)

    Riahi, Saleh; Rowley, Christopher N

    2013-05-02

    A polarizable force field for liquid hydrogen sulfide (H2S) has been developed based on the Drude oscillator model. This force field has been designed to be analogous to the SWM4-NDP water model; the model is rigid with point charges assigned to the H and S atoms and a lone pair on the bisector of ∠HSH in the molecular plane. Positions of the lone pair and the charges have been defined such that the model has a static dipole moment of 0.98 D, equal to the experimental value. Polarizability is incorporated by a charged (Drude) particle attached to the S atom through a harmonic potential. Intermolecular nonbonded forces are included by use of a Lennard-Jones potential between S atoms. The model was parametrized to reproduce the density, enthalpy of vaporization, and dielectric constant of pure H2S at 212 K and 1 atm. The calculated density, enthalpy of vaporization, shear viscosity coefficient, and self-diffusion coefficient are in good agreement with experiment over the temperature range 212-298 K along the liquid-vapor coexistence curve of liquid H2S. The radial distribution function calculated from this model is in good agreement with experimental diffraction data and ab initio molecular dynamics simulations.

  1. RF gauging efforts with liquid hydrogen and liquid oxygen as applicable to subcritical space vehicle systems

    Science.gov (United States)

    Thompson, H. E.; Ott, W.; Stanley, N.

    1974-01-01

    The RF gauging concept is based on the interaction between a fluid dielectric medium in an enclosed metallic cavity and electromagnetic fields set up within that cavity. In RF gauging systems, the fundamental measurement relies on the interpretation of changes in the resonant RF frequencies of an enclosed tank as the mass of the propellant contained in the tank is changed. In addition to a discussion of the basic principles of operation of these systems, the study presents a description of the current breadboard implementation with typical test arrangements, along with supporting test data. The experimental testing of the RF gauging technique for liquid cryogen mass gauging indicates that this technique is a feasible approach to liquid oxygen and liquid hydrogen gauging under all attitude or reduced gravity environments.

  2. Transport properties of liquid metal hydrogen under high pressures

    Science.gov (United States)

    Brown, R. C.; March, N. H.

    1972-01-01

    A theory is developed for the compressibility and transport properties of liquid metallic hydrogen, near to its melting point and under high pressure. The interionic force law is assumed to be of the screened Coulomb type, because hydrogen has no core electrons. The random phase approximation is used to obtain the structure factor S(k) of the system in terms of the Fourier transform of this force law. The long wavelenth limit of the structure factor S(o) is related to the compressibility, which is much lower than that of alkali metals at their melting points. The diffusion constant at the melting point is obtained in terms of the Debye frequency, using a frequency spectrum analogous with the phonon spectrum of a solid. A similar argument is used to obtain the combined shear and bulk viscosities, but these depend also on S(o). The transport coefficients are found to be about the same size as those of alkali metals at their melting points.

  3. Annular Air Leaks in a liquid hydrogen storage tank

    Science.gov (United States)

    Krenn, AG; Youngquist, RC; Starr, SO

    2017-12-01

    Large liquid hydrogen (LH2) storage tanks are vital infrastructure for NASA, the DOD, and industrial users. Over time, air may leak into the evacuated, perlite filled annular region of these tanks. Once inside, the extremely low temperatures will cause most of the air to freeze. If a significant mass of air is allowed to accumulate, severe damage can result from nominal draining operations. Collection of liquid air on the outer shell may chill it below its ductility range, resulting in fracture. Testing and analysis to quantify the thermal conductivity of perlite that has nitrogen frozen into its interstitial spaces and to determine the void fraction of frozen nitrogen within a perlite/frozen nitrogen mixture is presented. General equations to evaluate methods for removing frozen air, while avoiding fracture, are developed. A hypothetical leak is imposed on an existing tank geometry and a full analysis of that leak is detailed. This analysis includes a thermal model of the tank and a time-to-failure calculation. Approaches to safely remove the frozen air are analyzed, leading to the conclusion that the most feasible approach is to allow the frozen air to melt and to use a water stream to prevent the outer shell from chilling.

  4. Acoustic Emission Monitoring of the DC-XA Composite Liquid Hydrogen Tank During Structural Testing

    Science.gov (United States)

    Wilkerson, C.

    1996-01-01

    The results of acoustic emission (AE) monitoring of the DC-XA composite liquid hydrogen tank are presented in this report. The tank was subjected to pressurization, tensile, and compressive loads at ambient temperatures and also while full of liquid nitrogen. The tank was also pressurized with liquid hydrogen. AE was used to monitor the tank for signs of structural defects developing during the test.

  5. Refining effect of the liquid phase (in coal hydrogenation)

    Energy Technology Data Exchange (ETDEWEB)

    Hupfer; Leonhardt

    1942-11-07

    Experiments were run in a 10-liter oven at 600 atm. on various starting materials to determine what percentage of the original content of nitrogen, oxygen, and sulfur impurities were removed during liquid-phase processing. It was determined that the liquid phase removed most of these impurities, with nitrogen being affected to a lesser extent than the other two. In general, the raw materials which could most easily be hydrogenated had the greatest percentage of impurities removed. Also, in general, the more drastic the processing, the more effective the impurity-removal, especially in the case of nitrogen. Removal of oxygen as oxides of carbon happened in the case of brown coal to about twice the extent that it did in the case of bituminous coal, and happened to an even greater extent in the case of high-temperature tar. In the case of sulfur, the following percentages were removed in the following processes: 79% in processing low-temperature-carbonization tar to heavy oil, 75% to 87% in processing high-temperature-carbonization tar to heavy oil, 82% to 92% in processing high-temperature-carbonization tar to gasoline and middle oil, 80% to 97% in processing bituminous coal to gasoline and middle oil, and 86% to 89% in processing brown coal to gasoline and middle oil. In the case of oxygen, the corresponding figures (in the same order) were 73%, 36% to 70%, 44% to 70%, 86% to 91%, and 89% to 92%. In the case of nitrogen, they were 56%, 38% to 51%, 53% to 73%, 60% to 67%, and 64% to 79%. 1 table.

  6. Diagnosis of a Poorly Performing Liquid Hydrogen Bulk Storage Sphere

    Science.gov (United States)

    Krenn, Angela G.

    2011-01-01

    There are two 850,000 gallon Liquid Hydrogen (LH2) storage spheres used to support the Space Shuttle Program; one residing at Launch Pad A and the other at Launch Pad B. The LH2 Sphere at Pad B has had a high boiloff rate since being brought into service in the 1960's. The daily commodity loss was estimated to be approximately double that of the Pad A sphere, and well above the minimum required by the sphere's specification. Additionally, after being re-painted in the late 1990's a "cold spot" appeared on the outer sphere which resulted in a poor paint bond, and mold formation. Thermography was used to characterize the area, and the boiloff rate was continually evaluated. All evidence suggested that the high boiloff rate was caused by an excessive heat leak into the inner sphere due to an insulation void in the annulus. Pad B was recently taken out of Space Shuttle program service which provided a unique opportunity to diagnose the sphere's poor performance. The sphere was drained and inerted, and then opened from the annular relief device on the top where a series of boroscoping operations were accomplished. Boroscoping revealed a large Perlite insulation void in the region of the sphere where the cold spot was apparent. Perlite was then trucked in and off-loaded into the annular void region until the annulus was full. The sphere has not yet been brought back into service.

  7. Solar Thermal Upper Stage Liquid Hydrogen Pressure Control Testing

    Science.gov (United States)

    Moore, J. D.; Otto, J. M.; Cody, J. C.; Hastings, L. J.; Bryant, C. B.; Gautney, T. T.

    2015-01-01

    High-energy cryogenic propellant is an essential element in future space exploration programs. Therefore, NASA and its industrial partners are committed to an advanced development/technology program that will broaden the experience base for the entire cryogenic fluid management community. Furthermore, the high cost of microgravity experiments has motivated NASA to establish government/aerospace industry teams to aggressively explore combinations of ground testing and analytical modeling to the greatest extent possible, thereby benefitting both industry and government entities. One such team consisting of ManTech SRS, Inc., Edwards Air Force Base, and Marshall Space Flight Center (MSFC) was formed to pursue a technology project designed to demonstrate technology readiness for an SRS liquid hydrogen (LH2) in-space propellant management concept. The subject testing was cooperatively performed June 21-30, 2000, through a partially reimbursable Space Act Agreement between SRS, MSFC, and the Air Force Research Laboratory. The joint statement of work used to guide the technical activity is presented in appendix A. The key elements of the SRS concept consisted of an LH2 storage and supply system that used all of the vented H2 for solar engine thrusting, accommodated pressure control without a thermodynamic vent system (TVS), and minimized or eliminated the need for a capillary liquid acquisition device (LAD). The strategy was to balance the LH2 storage tank pressure control requirements with the engine thrusting requirements to selectively provide either liquid or vapor H2 at a controlled rate to a solar thermal engine in the low-gravity environment of space operations. The overall test objective was to verify that the proposed concept could enable simultaneous control of LH2 tank pressure and feed system flow to the thruster without necessitating a TVS and a capillary LAD. The primary program objectives were designed to demonstrate technology readiness of the SRS concept

  8. EDU liquid acquisition device outflow tests in liquid hydrogen: Experiments and analytical modeling

    Science.gov (United States)

    Hartwig, J. W.; Darr, S. R.; Meyerhofer, P.; Garces, R.

    2017-10-01

    This paper presents experiments and modeling of the most recent set of liquid acquisition device (LAD) vertical outflow tests conducted in liquid hydrogen. The Engineering Development Unit (EDU) was a relatively large tank (4.25 m3) used to mimic a storage tank for a cryogenic storage and transfer flight demonstration test. Six 1-g propellant tank outflow tests were conducted with a standard 325 × 2300 rectangular cross-section curved LAD channel conformal to the tank walls over a range of tank pressure (158-221 kPa), ullage temperature (22-39 K), and mass flow rate (0.0103-0.0187 kg/s) per arm. An analytical LAD channel solver, an exact solution to the Navier-Stokes equations, is used to model propellant outflow for the LAD channel. Results shows that the breakdown height of the LAD is dominated by liquid and ullage gas temperatures, with a secondary effect of flow rate. The best performance is always obtained by exposing the channel to cold pressurant gas and low flow rates, consistent with the cryogenic bubble point model. The model tracks the trends in the data and shows that the contribution of flow-through-screen pressure drop is minimized for bottom outflow in 1-g, versus the standard inverted outflow.

  9. A Liquid Hydrogen Cooler with a Cooling Capacity of 20 Watts Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For the future spaceport and long-term storage of liquid hydrogen NASA requires cryocoolers that can provide cooling power in the range of 20 watts at 20 K. The...

  10. Hydrogen Production Using Reduced-Iron Nanoparticles by Laser Ablation in Liquids

    OpenAIRE

    Okada, Takehiro; Saiki, Taku; Taniguchi, Seiji; Ueda, Tsuyoshi; Nakamura, Kazuhiro; Nishikawa, Yusuke; Iida, Yukio

    2013-01-01

    A recyclable energy cycle using a pulsed laser and base-metal nanoparticles is proposed. In this energy cycle, iron nanoparticles reduced from iron oxides by laser ablation in liquid are used for hydrogen generation. The laser energy can be stored in the base-metal nanoparticles as the difference between the chemical energies of iron oxide and iron. According to the results of an experiment on hydrogen production using the reduced iron nanoparticles, the reaction efficiency of the hydrogen ge...

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

    Science.gov (United States)

    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.

  12. The use of infrared absorption to determine density of liquid hydrogen.

    Science.gov (United States)

    Unland, H. D.; Timmerhaus, K. D.; Kropschot, R. H.

    1972-01-01

    Experimental evaluation of the use of infrared absorption for determining the density of liquid hydrogen, and discussion of the feasibility of an airborne densitometer based on this concept. The results indicate that infrared absorption of liquid hydrogen is highly sensitive to the density of hydrogen, and, under the operating limitations of the equipment and experimental techniques used, the determined values proved to be repeatable to an accuracy of 2.7%. The desiderata and limitations of an in-flight density-determining device are outlined, and some of the feasibility problems are defined.

  13. Simulation of Liquid Level, Temperature and Pressure Inside a 2000 Liter Liquid Hydrogen Tank During Truck Transportation

    Science.gov (United States)

    Takeda, Minoru; Nara, Hiroyuki; Maekawa, Kazuma; Fujikawa, Shizuichi; Matsuno, Yu; Kuroda, Tsuneo; Kumakura, Hiroaki

    Hydrogen is an ultimate energy source because only water is produced after the chemical reaction of hydrogen and oxygen. In the near future, a large amount of hydrogen, produced using sustainable/renewable energy, is expected to be consumed. Since liquid hydrogen (LH2) has the advantage of high storage efficiency, it is expected to be the ultimate medium for the worldwide storage and transportation of large amounts of hydrogen. To make a simulation model of the sloshing of LH2 inside a 2000 liter tank, simulation analyses of LH2 surface oscillation, temperature and pressure inside the tank during a truck transportation have been carried out using a multipurpose software ANSYS CFX. Numerical results are discussed in comparison with experimental results.

  14. Topological hydrogen-bond definition to characterize the structure and dynamics of liquid water.

    Science.gov (United States)

    Henchman, Richard H; Irudayam, Sheeba Jem

    2010-12-23

    A definition that equates a hydrogen bond topologically with a local energy well in the potential energy surface is used to study the structure and dynamics of liquid water. We demonstrate the robustness of this hydrogen-bond definition versus the many other definitions which use fixed, arbitrary parameters, do not account for variable molecular environments, and cannot effectively resolve transition states. Our topology definition unambiguously shows that most water molecules are double acceptors but sizable proportions are single or triple acceptors. Almost all hydrogens are found to take part in hydrogen bonds. Broken hydrogen bonds only form when two molecules try to form two hydrogen bonds between them. The double acceptors have tetrahedral geometry, lower potential energy, entropy, and density, and slower dynamics. The single and triple acceptors have trigonal and trigonal bipyramidal geometry and when considered together have higher density, potential energy, and entropy, faster dynamics, and a tendency to cluster. These calculations use an extended theory for the entropy of liquid water that takes into account the variable number of hydrogen bonds. Hydrogen-bond switching is shown to depend explicitly on the variable number of hydrogen bonds accepted and the presence of interstitial water molecules. Transition state theory indicates that the switching of hydrogen bonds is a mildly activated process, requiring only a moderate distortion of hydrogen bonds. Three main types of switching events are observed depending on whether the donor and acceptor are already sharing a hydrogen bond. The switch may proceed with no intermediate or via a bifurcated-oxygen or cyclic dimer, both of which have a broken hydrogen bond and symmetric and asymmetric forms. Switching is found to be strongly coupled to whole-molecule vibration, particularly for the more mobile single and triple acceptors. Our analysis suggests that even though water is heterogeneous in terms of the

  15. Hydrogen-Bond Dynamics in a Protic Ionic Liquid: Evidence of Large-Angle Jumps.

    Science.gov (United States)

    Hunger, Johannes; Sonnleitner, Thomas; Liu, Liyuan; Buchner, Richard; Bonn, Mischa; Bakker, Huib J

    2012-10-18

    We study the molecular rotation of the protic room-temperature ionic liquid ethylammonium nitrate with dielectric relaxation spectroscopy and femtosecond-infrared spectroscopy (fs-IR) of the ammonium N-H vibrations. The results suggest that the rotation of ethylammonium ion takes place via large angular jumps. Such nondiffusive reorientational dynamics is unique to strongly hydrogen-bonded liquids such as water and indicates that the intermolecular interaction is highly directional in this class of ionic liquids.

  16. Continuous process for the pressure hydrogenation of coals, tars, and mineral oils in liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    1943-05-25

    In the continuous pressure hydrogenation of coals, tars, and mineral oils in liquid phase as, for example, of coal or oil pastes, the liquid together with the hydrogen required for the reaction was, at the time of this report, preheated under pressure in a special preheater and brought to the reaction temperature. At this temperature, the mixture then entered the reaction vessel. Here, due to the absorption of hydrogen by the hydrogenation feed, so much heat was generated that in practical operations, cooling had to be provided for. This report dealt with an investigation that solved this problem. In this process hydrogenation feed, together with hydrogen, entered at the bottom of one section of a reaction vessel which was divided by separating walls into two vertical sections, which were connected with each other at the top and the bottom, so that hydrogenation feed was given a circulating motion between the two sections of the vessel, whereby the greatest part of the hydrogen mass, together with the vaporous mass, and as a rule, also a part of the liquid, was drawn off at the top. A description of the operation and the equipment involved was given. A sketch containing six figures was also included showing the flow of the materials.

  17. Active Oxidation of Liquid Silicon in the Presence of Hydrogen: Extension of the Ratto Model

    Science.gov (United States)

    Vadon, Mathieu; Delannoy, Yves; Chichignoud, Guy

    2017-06-01

    The rate of oxidation of silicon has been studied in the presence of hydrogen, in order to predict the rate of boron removal from liquid silicon in liquid/gas processes where a chemical equilibrium exists at the surface. A new 1D model for the reactive boundary layer above liquid silicon has been developed from existing literature, adding two gaseous species H2 and H2O. The classical model (O2 only) gives a layer of silica aerosol just above the surface, for oxygen pressures above some pascals. Adding some hydrogen, this layer is displaced away from the silicon and vanishes if the hydrogen ratio is sufficient. We applied this model on liquid silicon oxidation experiments with theoretically predicted mass boundary layer thicknesses for impinging jets. The needed thickness to reproduce the experimental purification rate on our plasma process is compatible with our model.

  18. Liquid Acquisition Device Hydrogen Outflow Testing on the Cryogenic Propellant Storage and Transfer Engineering Design Unit

    Science.gov (United States)

    Zimmerli, Greg; Statham, Geoff; Garces, Rachel; Cartagena, Will

    2015-01-01

    As part of the NASA Cryogenic Propellant Storage and Transfer (CPST) Engineering Design Unit (EDU) testing with liquid hydrogen, screen-channel liquid acquisition devices (LADs) were tested during liquid hydrogen outflow from the EDU tank. A stainless steel screen mesh (325x2300 Dutch T will weave) was welded to a rectangular cross-section channel to form the basic LAD channel. Three LAD channels were tested, each having unique variations in the basic design. The LADs fed a common outflow sump at the aft end of the 151 cu. ft. volume aluminum tank, and included a curved section along the aft end and a straight section along the barrel section of the tank. Wet-dry sensors were mounted inside the LAD channels to detect when vapor was ingested into the LADs during outflow. The use of warm helium pressurant during liquid hydrogen outflow, supplied through a diffuser at the top of the tank, always led to early breakdown of the liquid column. When the tank was pressurized through an aft diffuser, resulting in cold helium in the ullage, LAD column hold-times as long as 60 minutes were achieved, which was the longest duration tested. The highest liquid column height at breakdown was 58 cm, which is 23 less than the isothermal bubble-point model value of 75 cm. This paper discusses details of the design, construction, operation and analysis of LAD test data from the CPST EDU liquid hydrogen test.

  19. Mechanisms of hydrogen bond formation between ionic liquids and cellulose and the influence of water content.

    Science.gov (United States)

    Rabideau, Brooks D; Ismail, Ahmed E

    2015-02-28

    We study the dynamics of the formation of multiple hydrogen bonds between ionic liquid anions and cellulose using molecular dynamics simulations. We examine fifteen different ionic liquids composed of 1-alkyl-3-methylimidazolium cations ([Cnmim], n = 1, 2, 3, 4, 5) paired with either chloride, acetate or dimethylphosphate. We map the transitions of anions hydrogen bonded to cellulose into different bonding states. We find that increased tail length in the ionic liquids has only a very minor effect on these transitions, tending to slow the dynamics of the transitions and increasing the hydrogen bond lifetimes. Each anion can form up to four hydrogen bonds with cellulose. We find that this hydrogen bond "redundancy" leads to multiply bonded anions having lifetimes three to four times that of singly bound anions. Such redundant hydrogen bonds account for roughly half of all anion-cellulose hydrogen bonds. Additional simulations for [C2mim]Cl, [C2mim]Ac and [C2mim]DMP were performed at different water concentrations between 70 mol% and 90 mol%. It was found that water crowds the hydrogen bond-accepting sites of the anions, preventing interactions with cellulose. The more water that is present in the system, the more crowded these sites become. Thus, if a hydrogen bond between an anion and cellulose breaks, the likelihood that it will be replaced by a nearby water molecule increases as well. We show that the formation of these "redundant" hydrogen bonding states is greatly affected by the presence of water, leading to steep drops in hydrogen bonding between the anions and cellulose.

  20. Acoustically Forced Coaxial Hydrogen/Liquid Oxygen Jet Flames

    Science.gov (United States)

    2016-05-15

    propellants be stored in condensed form – e.g., kerosene, liquid oxygen in rockets • Combustion systems can no longer be designed to meet modern...of the reactants – e.g., liquid rockets, future gas turbines • When the combustion systems are for propulsion, limited tankage dictates that on-board...Symmetric recirculation zones Low-speed liquid O2 High-speed gaseous H2 Asymmetric recirculation zones Combustion case Results show large oxygen-side

  1. Commentary on the Liquid Metallic Hydrogen Model of the Sun III. Insight into Solar Lithium Abundances

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-04-01

    Full Text Available The apparent depletion of lithium represents one of the grea test challenges to modern gaseous solar models. As a result, lithium has been hypothes ized to undergo nuclear burning deep within the Sun. Conversely, extremely low lith ium abundances can be easily accounted for within the liquid metallic hydrogen mo del, as lithium has been hypothesized to greatly stabilize the formation of metalli c hydrogen (E. Zurek et al. A little bit of lithium does a lot for hydrogen. Proc. Nat. Acad. Sci. USA , 2009, v. 106, no. 42, 17640–17643. Hence, the abundances of lithium on th e solar surface can be explained, not by requiring the nuclear burning of this elem ent, but rather, by suggesting that the Sun is retaining lithium within the solar body in ord er to help stabilize its liquid metallic hydrogen lattice. Unlike lithium, many of t he other elements synthesized within the Sun should experience powerful lattice exclusio nary forces as they are driven out of the intercalate regions between the layered liquid me tallic hydrogen hexagonal planes (Robitaille J.C. and Robitaille P.M. Liquid Metalli c Hydrogen III. Intercalation and Lattice Exclusion Versus Gravitational Settling and Th eir Consequences Relative to Internal Structure, Surface Activity, and Solar Winds in the Sun. Progr. Phys ., 2013, v. 2, in press. As for lithium, its stabilizing role within t he solar interior helps to account for the lack of this element on the surface of the Sun.

  2. FINAL REPORT: Room Temperature Hydrogen Storage in Nano-Confined Liquids

    Energy Technology Data Exchange (ETDEWEB)

    VAJO, JOHN

    2014-06-12

    DOE continues to seek solid-state hydrogen storage materials with hydrogen densities of ≥6 wt% and ≥50 g/L that can deliver hydrogen and be recharged at room temperature and moderate pressures enabling widespread use in transportation applications. Meanwhile, development including vehicle engineering and delivery infrastructure continues for compressed-gas hydrogen storage systems. Although compressed gas storage avoids the materials-based issues associated with solid-state storage, achieving acceptable volumetric densities has been a persistent challenge. This project examined the possibility of developing storage materials that would be compatible with compressed gas storage technology based on enhanced hydrogen solubility in nano-confined liquid solvents. These materials would store hydrogen in molecular form eliminating many limitations of current solid-state materials while increasing the volumetric capacity of compressed hydrogen storage vessels. Experimental methods were developed to study hydrogen solubility in nano-confined liquids. These methods included 1) fabrication of composites comprised of volatile liquid solvents for hydrogen confined within the nano-sized pore volume of nanoporous scaffolds and 2) measuring the hydrogen uptake capacity of these composites without altering the composite composition. The hydrogen storage capacities of these nano-confined solvent/scaffold composites were compared with bulk solvents and with empty scaffolds. The solvents and scaffolds were varied to optimize the enhancement in hydrogen solubility that accompanies confinement of the solvent. In addition, computational simulations were performed to study the molecular-scale structure of liquid solvent when confined within an atomically realistic nano-sized pore of a model scaffold. Confined solvent was compared with similar simulations of bulk solvent. The results from the simulations were used to formulate a mechanism for the enhanced solubility and to guide the

  3. Collective Excitations in Liquid Hydrogen Observed by Coherent Neutron Scattering

    DEFF Research Database (Denmark)

    da Costa Carneiro, Kim; Nielsen, M.; McTague, J. P.

    1973-01-01

    Coherent scattering of neutrons by liquid parahydrogen shows the existence of well-defined collective excitations in this liquid. Qualitative similarity with the scattering from liquid helium is found. Furthermore, in the range of observed wave vectors, 0.7 Å-1 ≤κ≤3.1 Å-1, extending from the firs...... through the third Brillouin zones in the solid, S(κ,ω) is remarkably similar to the scattering law expected from a polycrystal. For κ≤2.3 Å-1 the observed spectra satisfy the one-phonon sum rule with mean square displacement 〈u2〉=1.0 Å2....

  4. Informing hazardous zones for on-board maritime hydrogen liquid and gas systems

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, Myra L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Pratt, Joseph William [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bran Anleu, Gabriela A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Proctor, Camron [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2018-01-01

    The significantly higher buoyancy of hydrogen compared to natural gas means that hazardous zones defined in the IGF code may be inaccurate if applied to hydrogen. This could place undue burden on ship design or could lead to situations that are unknowingly unsafe. We present dispersion analyses to examine three vessel case studies: (1) abnormal external vents of full blowdown of a liquid hydrogen tank due to a failed relief device in still air and with crosswind; (2) vents due to naturally-occurring boil-off of liquid within the tank; and (3) a leak from the pipes leading into the fuel cell room. The size of the hydrogen plumes resulting from a blowdown of the tank depend greatly on the wind conditions. It was also found that for normal operations releasing a small amount of "boil- off" gas to regulate the pressure in the tank does not create flammable concentrations.

  5. Hydrogen bonding in the protic ionic liquid triethylammonium nitrate explored by density functional tight binding simulations.

    Science.gov (United States)

    Zentel, Tobias; Kühn, Oliver

    2016-12-21

    The applicability of the density functional based tight binding (DFTB) method to the description of hydrogen bond dynamics and infrared (IR) spectroscopy is addressed for the exemplary protic ionic liquid triethylammonium nitrate. Potential energy curves for proton transfer in gas and liquid phases are shown to be comparable to the high level coupled cluster theory in the thermally accessible range of bond lengths. Geometric correlations in the hydrogen bond dynamics are analyzed for a cluster of six ion pairs. Comparing DFTB and DFT data lends further support for the reliability of the DFTB method. Therefore, DFTB bulk simulations are performed to quantify the extent of geometric correlations in terms of Pauling's bond order model. Further, IR absorption spectra are obtained using DFTB and analyzed putting emphasis on the signatures of hydrogen bonding in the NH-stretching and far IR hydrogen bond range.

  6. Hydrogen bonding in the protic ionic liquid triethylammonium nitrate explored by density functional tight binding simulations

    CERN Document Server

    Zentel, Tobias

    2016-01-01

    The applicability of the density functional based tight binding (DFTB) method to the description of hydrogen bond dynamics and infrared spectroscopy is addressed for the exemplary protic ionic liquid triethylammonium nitrate. Potential energy curves for proton transfer in gas and liquid phase are shown to be comparable to high level coupled cluster theory in the thermally accessible range of bond lengths. Geometric correlations in the hydrogen bond dynamics are analyzed for a cluster of six ion pairs. Comparing DFTB and regular DFT data lends further support for the reliability of the DFTB method. Therefore, DFTB bulk simulations are performed to quantify the extent of geometric correlations in terms of Pauling's bond order model. Further, infrared (IR) absorption spectra are obtained and analyzed putting emphasis on the signatures of hydrogen bonding in the NH-stretching and far IR hydrogen bond range.

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

    Science.gov (United States)

    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.

  8. Molecular catalytic hydrogenation of aromatic hydrocarbons and hydrotreating of coal liquids.

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shiyong; Stock, L.M.

    1996-05-01

    This report presents the results of research on the development of new catalytic pathways for the hydrogenation of multiring aromatic hydrocarbons and the hydrotreating of coal liquids at The University of Chicago under DOE Contract No. DE-AC22-91PC91056. The work, which is described in three parts, is primarily concerned with the research on the development of new catalytic systems for the hydrogenation of aromatic hydrocarbons and for the improvement of the quality of coal liquids by the addition of dihydrogen. Part A discusses the activation of dihydrogen by very basic molecular reagents to form adducts that can facilitate the reduction of multiring aromatic hydrocarbons. Part B examines the hydrotreating of coal liquids catalyzed by the same base-activated dihydrogen complexes. Part C concerns studies of molecular organometallic catalysts for the hydrogenation of monocyclic aromatic hydrocarbons under mild conditions.

  9. Performance of a 10-kJ SMES model cooled by liquid hydrogen thermo-siphon flow for ASPCS study

    Science.gov (United States)

    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.

  10. Evidence of a liquid–liquid phase transition in hot dense hydrogen

    OpenAIRE

    Dzyabura, Vasily; Zaghoo, Mohamed; Silvera, Isaac F.

    2013-01-01

    We use pulsed-laser heating of hydrogen at static pressures in the megabar pressure region to search for the plasma phase transition to liquid atomic metallic hydrogen. We heat our samples substantially above the melting line and observe a plateau in a temperature vs. laser power curve that otherwise increases with power. This anomaly in the heating curve appears correlated with theoretical predictions for the plasma phase transition.

  11. Technical Assessment of Organic Liquid Carrier Hydrogen Storage Systems for Automotive Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ahluwalia, R. K. [Argonne National Lab. (ANL), Argonne, IL (United States); Hua, T. Q. [Argonne National Lab. (ANL), Argonne, IL (United States); Peng, J. -K [Argonne National Lab. (ANL), Argonne, IL (United States); Kromer, M. [TIAX LLC, Lexington, MA (United States); Lasher, S. [TIAX LLC, Lexington, MA (United States); McKenney, K. [TIAX LLC, Lexington, MA (United States); Law, K. [TIAX LLC, Lexington, MA (United States); Sinha, J. [TIAX LLC, Lexington, MA (United States)

    2011-06-21

    In 2007-2009, the DOE Hydrogen Program conducted a technical assessment of organic liquid carrier based hydrogen storage systems for automotive applications, consistent with the Program’s Multiyear Research, Development, and Demonstration Plan. This joint performance (ANL) and cost analysis (TIAX) report summarizes the results of this assessment. These results should be considered only in conjunction with the assumptions used in selecting, evaluating, and costing the systems discussed here and in the Appendices.

  12. Environmental and health impact assessment of Liquid Organic Hydrogen Carrier (LOHC) systems – challenges and preliminary results

    OpenAIRE

    Markiewicz, M.; Y. Q. Zhang; Bösmann, A.; Brückner, N. (Nadine); Thöming, J.; Wasserscheid, P.; Stolte, S.

    2015-01-01

    Liquid Organic Hydrogen Carrier (LOHC) systems offer a very attractive way to store and transport hydrogen, a technical feature that is highly desirable to link unsteady energy production from renewables with the vision of a sustainable, CO2-free, hydrogen-based energy system. LOHCs can be charged and discharged with considerable amounts of hydrogen in cyclic, catalytic hydrogenation and dehydrogenation processes. As their physico-chemical properties are very similar to diesel, today's infras...

  13. Penicillin-binding protein folding is dependent on the PrsA peptidyl-prolyl cis-trans isomerase in Bacillus subtilis

    NARCIS (Netherlands)

    Hyyrylainen, Hanne-Leena; Marciniak, Bogumila C.; Dahncke, Kathleen; Pietiainen, Milla; Courtin, Pascal; Vitikainen, Marika; Seppala, Raili; Otto, Andreas; Becher, Doerte; Chapot-Chartier, Marie-Pierre; Kuipers, Oscar P.; Kontinen, Vesa P.; Hyyryläinen, Hanne-Leena; Pietiäinen, Milla

    P>The PrsA protein is a membrane-anchored peptidyl-prolyl cis-trans isomerase in Bacillus subtilis and most other Gram-positive bacteria. It catalyses the post-translocational folding of exported proteins and is essential for normal growth of B. subtilis. We studied the mechanism behind this

  14. Power generation in fuel cells using liquid methanol and hydrogen peroxide

    Science.gov (United States)

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

    2002-01-01

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

  15. Unexpectedly high pressure for molecular dissociation in liquid hydrogen by electronic simulation.

    Science.gov (United States)

    Mazzola, Guglielmo; Yunoki, Seiji; Sorella, Sandro

    2014-03-19

    The study of the high pressure phase diagram of hydrogen has continued with renewed effort for about one century as it remains a fundamental challenge for experimental and theoretical techniques. Here we employ an efficient molecular dynamics based on the quantum Monte Carlo method, which can describe accurately the electronic correlation and treat a large number of hydrogen atoms, allowing a realistic and reliable prediction of thermodynamic properties. We find that the molecular liquid phase is unexpectedly stable, and the transition towards a fully atomic liquid phase occurs at much higher pressure than previously believed. The old standing problem of low-temperature atomization is, therefore, still far from experimental reach.

  16. Modeling the effects of dissolved helium pressurant on a liquid hydrogen rocket propellant tank

    Science.gov (United States)

    Richardson, I. A.; Leachman, J. W.

    2017-12-01

    A model was developed using NASA’s Generalized Fluid System Simulation Program (GFSSP) for the self-pressurization of a liquid hydrogen propellant tank due to boil-off to determine the significance of mixture non-idealities. The GFSSP model compared the tank performance for the traditional model that assumes no helium pressurant dissolves into the liquid hydrogen propellant to an updated model that accounts for dissolved helium pressurant. Traditional NASA models have been unable to account for this dissolved helium due to a lack of fundamental property information. Recent measurements of parahydrogen-helium mixtures enabled the development of the first multi-phase Equation Of State (EOS) for parahydrogen-helium mixtures. The self-pressurization GFSSP model was run assuming that the liquid propellant was pure liquid hydrogen and assuming helium dissolved into the liquid utilizing the new helium-hydrogen EOS. The analysis shows that having dissolved helium in the propellant does not have a significant effect on the tank pressurization rate for typical tank conditions (-423 °F and 30 psia).

  17. Electrochemical behaviour of hydrogen in low-viscosity phosphonium ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Matsumiya, M. [Yokohama National Univ. (Japan). Graduate School of Environment and Information Sciences; Tsunashima, K. [Wakayama National College of Technology (Japan). Dept. of Materials Science; Kodama, S. [Nippon Chemical Industrial Co., Ltd., Tokyo (Japan)

    2011-10-15

    The electrochemical and diffusive properties of hydrogen in low-viscosity phosphonium ionic liquids were investigated by the electrochemical methods such as cyclic voltammetry and chronoamperometry. The hydrogen redox reactions were concluded to be a quasi-reversible system in phosphonium-based ionic liquids. The diffusion coefficients of hydrogen in these ionic liquids were of the order of 10{sup -10} m{sup 2} s{sup -1} at 25 C. Additionally, the obtained activation energy of the diffusion process for hydrogen was 11.2-15.9 kJ mol{sup -1} estimated from the temperature dependence of the diffusion coefficients. A new type of proton conducting medium such as triethylphosphonium bis(trifluoromethylsulfonyl)amide was synthesized by the neutralization reaction, because the trialkylphosphine-based ionic liquids with good stability at higher temperature and high conductivity were appropriate candidates. This proton conducting membrane containing the ionic liquids with trialkylphosphine-based cations and the polyvinylidenefluoride-co-hexafluoropropylene has been fabricated in the present study. The proton conducting membrane exhibits relatively high ionic conductivity along with good mechanical stability. (orig.)

  18. Hugoniot and temperature measurements of liquid hydrogen by laser-shock compression

    Energy Technology Data Exchange (ETDEWEB)

    Sano, T; Shigemori, K; Shiroshita, A; Hironaka, Y; Kadono, T; Nakai, M [Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Ozaki, N; Kimura, T; Miyanishi, K; Endo, T; Jitsui, T [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Sakaiya, T; Takahashi, H; Kondo, T [Department of Earth and Space Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Ikoma, M; Hori, Y [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8551 (Japan); Iwamoto, A [National Institute of Fusion Science, Toki, Gifu 509-5292 (Japan); Okuchi, T [Institute for Study of the Earth' s Interior, Okayama University, Misasa, Tottori 682-0193 (Japan); Otani, K [Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Shimizu, K, E-mail: sano@ile.osaka-u.ac.j [KYOKUGEN, Center for Quantum Science and Technology under Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531 (Japan)

    2010-08-01

    Hydrogen at high pressure in the fluid state is of great interest for target design of inertial confinement fusion and understanding the interior structure of gas giant planets. In this work, we successfully obtained the Hugoniot data for liquid hydrogen up to 55 GPa under laser-driven shock loading using impedance matching to a quartz standard. The shocked temperature was determined simultaneously by the brightness temperature. The compression and temperature along the principal Hugoniot are in good agreement with theoretical models. High reflectivity of hydrogen was observed at 40 GPa, which suggests the fluid becomes conducting.

  19. Catalytic polymer membranes for high temperature hydrogenation of viscous liquids

    Energy Technology Data Exchange (ETDEWEB)

    Fritsch, D.; Bengtson, G. [GKSS Research Centre Geesthacht GmbH, Institute of Polymer Research, Max-Planck-Str. 1, 21502 Geesthacht (Germany)

    2006-05-15

    Polymeric membranes with high oil fluxes were developed and catalytically activated by a new route of direct calcination of polymeric membranes charged by Pd or Pt catalyst precursors. High concentrations of citric acid mixed with the precursors afforded a decrease of the calcination temperature to 175 C. Membrane reactor tests in the flow through contactor mode displayed high reactivities for sunflower oil hydrogenation. Pt showed a similar activity to Pd catalysts as measured by iodine value and generated about 13% less trans-isomers but 5% more stearic acid at an iodine value of 90. By means of alumina supported catalysts tests of methyl oleate (cis-C18:1) and methyl elaidate (trans-C18:1) hydrogenation exhibited a different pathway of reaction by either isomerization followed by reduction (Pd) or primarily direct reduction to methyl stearate (Pt). (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  20. Liquid Hydrogen Fuel System for Small Unmanned Air Vehicles

    Science.gov (United States)

    2013-01-07

    the Office of Naval Research for support of this research. VII. References 1 R. Stroman, J.C. Kellogg, K. Swider-Lyons, “Testing of a PEM Fuel Cell ...energy storage system. The Naval Research Laboratory has been extending the duration of electric UAVs through the use of hydrogen fuel cells , which...take advantage of both the high energy of H2 fuel in combination with the high efficiency (~50%) of polymer fuel cells . In this paper, we describe

  1. Evaluation of the nonrandom hydrogen bonding (NRHB) theory and the simplified perturbed-chain-statistical associating fluid theory (sPC-SAFT). 2. Liquid-liquid equilibria and prediction of monomer fraction in hydrogen bonding systems

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Grenner, Andreas; Economou, Ioannis

    2008-01-01

    Two statistical thermodynamic models, the nonrandom hydrogen bonding (NRHB) theory, which is a compressible lattice model, and the simplified perturbed-chain-statistical associating fluid theory (sPC-SAFT), which is based on Wertheim's perturbation theory, were used to model liquid-liquid equilib...... for the treatment of hydrogen bonding, yielded similar predictions for the fraction of non-hydrogen bonded molecules (monomer fraction) in pure 1-alkanols and in 1-alkanol-n-hexane mixtures....

  2. Hydrogen bonding in protic ionic liquids: structural correlations, vibrational spectroscopy, and rotational dynamics of liquid ethylammonium nitrate

    Science.gov (United States)

    Zentel, Tobias; Overbeck, Viviane; Michalik, Dirk; Kühn, Oliver; Ludwig, Ralf

    2018-02-01

    The properties of the hydrogen bonds in ethylammonium nitrate (EAN) are analyzed by using molecular dynamics simulations and infrared as well as nuclear magnetic resonance experiments. EAN features a flexible three-dimensional network of hydrogen bonds with moderate strengths, which makes it distinct from related triethylammonium-based ionic liquids. First, the network’s flexibility is manifested in a not very pronounced correlation of the hydrogen bond geometries, which is caused by rapid interchanges of bonding partners. The large flexibility of the network also leads to a substantial broadening of the mid-IR absorption band, with the contributions due to N–H stretching motions ranging from 2800 to 3250 cm‑1. Finally, the different dynamics are also seen in the rotational correlation of the N–H bond vector, where a correlation time as short as 16.1 ps is observed.

  3. Comment on "Protonium annihilation into $\\pi^{0} \\pi^{0}$ at rest in a liquid hydrogen target"

    CERN Document Server

    Amsler, Claude; Barnett, B M; Batty, C J; Benayoun, M; Blüm, P; Braune, K; Bugg, D V; Case, T; Credé, V; Crowe, K M; Doser, Michael; Dünnweber, W; Engelhardt, D; Faessler, M A; Haddock, R P; Heinsius, F H; Heinzelmann, M; Hessey, N P; Hidas, P; Jamnik, D; Kalinowsky, H; Kammel, P; Kisiel, J; Klempt, E; Koch, H; Kunze, M; Kurilla, U; Landua, Rolf; Matthäy, H; Meyer, C A; Meyer-Wildhagen, F; Ouared, R; Peters, K; Pick, B; Ratajczak, M; Regenfus, C; Reinnarth, J; Röthel, W; Sarantsev, A V; Spanier, S; Strohbusch, U; Suffert, Martin; Suh, J S; Thoma, U; Uman, I; Wallis-Plachner, S; Walther, D; Wiedner, U; Wittmack, K; Zou, B S

    2002-01-01

    We comment on the recent paper published by the Obelix Collaboration on protonium annihilation into pi /sup 0/ pi /sup 0/ at rest in a liquid hydrogen target ÝPhys. Rev. D 65, 012001 (2002)¿, with particular reference to the discrepancy with the results obtained by the Crystal Barrel Collaboration.

  4. Covalency of hydrogen bonds in liquid water can be probed by proton nuclear magnetic resonance experiments.

    Science.gov (United States)

    Elgabarty, Hossam; Khaliullin, Rustam Z; Kühne, Thomas D

    2015-09-15

    The concept of covalency is widely used to describe the nature of intermolecular bonds, to explain their spectroscopic features and to rationalize their chemical behaviour. Unfortunately, the degree of covalency of an intermolecular bond cannot be directly measured in an experiment. Here we established a simple quantitative relationship between the calculated covalency of hydrogen bonds in liquid water and the anisotropy of the proton magnetic shielding tensor that can be measured experimentally. This relationship enabled us to quantify the degree of covalency of hydrogen bonds in liquid water using the experimentally measured anisotropy. We estimated that the amount of electron density transferred between molecules is on the order of 10  m while the stabilization energy due to this charge transfer is ∼15 kJ mol(-1). The physical insight into the fundamental nature of hydrogen bonding provided in this work will facilitate new studies of intermolecular bonding in a variety of molecular systems.

  5. Self-pressurization of a spherical liquid hydrogen storage tank in a microgravity environment

    Science.gov (United States)

    Lin, C. S.; Hasan, M. M.

    1992-01-01

    Thermal stratification and self-pressurization of partially filled liquid hydrogen (LH2) storage tanks under microgravity condition is studied theoretically. A spherical tank is subjected to a uniform and constant wall heat flux. It is assumed that a vapor bubble is located in the tank center such that the liquid-vapor interface and tank wall form two concentric spheres. This vapor bubble represents an idealized configuration of a wetting fluid in microgravity conditions. Dimensionless mass and energy conservation equations for both vapor and liquid regions are numerically solved. Coordinate transformation is used to capture the interface location which changes due to liquid thermal expansion, vapor compression, and mass transfer at liquid-vapor interface. The effects of tank size, liquid fill level, and wall heat flux on the pressure rise and thermal stratification are studied. Liquid thermal expansion tends to cause vapor condensation and wall heat flux tends to cause liquid evaporation at the interface. The combined effects determine the direction of mass transfer at the interface. Liquid superheat increases with increasing wall heat flux and liquid fill level and approaches an asymptotic value.

  6. Green Hypergolic Bipropellants: H202/Hydrogen-Rich Ionic Liquids

    Science.gov (United States)

    2011-03-04

    unsaturated salts featuring imidazolium, triazolium, pyridinium and other common IL cations, are reduced by BH4-,[6] negatively affecting their thermal...trihexyl-tetradecyl- phosphonium (THTDP) cation has been used to transform fullerenes into RTILs and forms liquids with BH3Cl-.[12, 13] THTDP Cl is also...can lead to serious injuries! General. Starting materials, trihexyltetradecyl- phosphonium chloride, sodium borohydride (≥99%), lithium borohydride

  7. Progress on the Liquid Hydrogen Absorber for the MICE Cooling Channel

    CERN Document Server

    Cummings, M A C

    2005-01-01

    This report describes the progress made on the design of the liquid hydrogen absorber for the international Muon Ionization Cooling Experiment (MICE). The absorber consists of a 21-liter vessel that contains liquid hydrogen (1.5 kg) or liquid helium (2.63 kg). The cryogen vessel is within the warm bore of the superconducting focusing magnet for the MICE. The purpose of the magnet is to provide a low beam beta region within the absorber. For safety reasons, the vacuum vessel for the hydrogen absorber is separated from the vacuum vessel for the superconducting magnet and the vacuum that surrounds the RF cavities or the detector. The absorber has two 300 mm-diameter thin aluminum windows. The vacuum vessel around the absorber has a pair of thin aluminum windows that separate the absorber vacuum space from adjacent vacuum spaces. The absorber will be cooled down using a heat exchanger that is built into the absorber walls. Liquid nitrogen is used to cool the absorber to 80 K. Liquid helium completes the absorber ...

  8. Experimental Investigation of Jet-Induced Mixing of a Large Liquid Hydrogen Storage Tank

    Science.gov (United States)

    Lin, C. S.; Hasan, M. M.; Vandresar, N. T.

    1994-01-01

    Experiments have been conducted to investigate the effect of fluid mixing on the depressurization of a large liquid hydrogen storage tank. The test tank is approximately ellipsoidal, having a volume of 4.89 m(exp 3) and an average wall heat flux of 4.2 W/m(exp 2) due to external heat input. A mixer unit was installed near the bottom of the tank to generate an upward directed axial jet flow normal to the liquid-vapor interface. Mixing tests were initiated after achieving thermally stratified conditions in the tank either by the introduction of hydrogen gas into the tank or by self-pressurization due to ambient heat leak through the tank wall. The subcooled liquid jet directed towards the liquid-vapor interface by the mixer induced vapor condensation and caused a reduction in tank pressure. Tests were conducted at two jet submergence depths for jet Reynolds numbers from 80,000 to 495,000 and Richardson numbers from 0.014 to 0.52. Results show that the rate of tank pressure change is controlled by the competing effects of subcooled jet flow and the free convection boundary layer flow due to external tank wall heating. It is shown that existing correlations for mixing time and vapor condensation rate based on small scale tanks may not be applicable to large scale liquid hydrogen systems.

  9. Development of the ReaxFFCBN reactive force field for the improved design of liquid CBN hydrogen storage materials.

    Science.gov (United States)

    Pai, Sung Jin; Yeo, Byung Chul; Han, Sang Soo

    2016-01-21

    Liquid CBN (carbon-boron-nitrogen) hydrogen-storage materials such as 3-methyl-1,2-BN-cyclopentane have the advantage of being easily accessible for use in current liquid-fuel infrastructure. To develop practical liquid CBN hydrogen-storage materials, it is of great importance to understand the reaction pathways of hydrogenation/dehydrogenation in the liquid phase, which are difficult to discover by experimental methods. Herein, we developed a reactive force field (ReaxFFCBN) from quantum mechanical (QM) calculations based on density functional theory for the storage of hydrogen in BN-substituted cyclic hydrocarbon materials. The developed ReaxFFCBN provides similar dehydrogenation pathways and energetics to those predicted by QM calculations. Moreover, molecular dynamics (MD) simulations with the developed ReaxFFCBN can predict the stability and dehydrogenation behavior of various liquid CBN hydrogen-storage materials. Our simulations reveal that a unimolecular dehydrogenation mechanism is preferred in liquid CBN hydrogen-storage materials. However, as the temperature in the simulation increases, the contribution of a bimolecular dehydrogenation mechanism also increases. Moreover, our ReaxFF MD simulations show that in terms of thermal stability and dehydrogenation kinetics, liquid CBN materials with a hexagonal structure are more suitable materials than those with a pentagonal structure. We expect that the developed ReaxFFCBN could be a useful protocol in developing novel liquid CBN hydrogen-storage materials.

  10. Ultrafast conversions between hydrogen bonded structures in liquid water observed by femtosecond x-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Haidan; Huse, Nils; Schoenlein, Robert W.; Lindenberg, Aaron M.

    2010-05-01

    We present the first femtosecond soft x-ray spectroscopy in liquids, enabling the observation of changes in hydrogen bond structures in water via core-hole excitation. The oxygen K-edge of vibrationally excited water is probed with femtosecond soft x-ray pulses, exploiting the relation between different water structures and distinct x-ray spectral features. After excitation of the intramolecular OH stretching vibration, characteristic x-ray absorption changes monitor the conversion of strongly hydrogen-bonded water structures to more disordered structures with weaker hydrogen-bonding described by a single subpicosecond time constant. The latter describes the thermalization time of vibrational excitations and defines the characteristic maximum rate with which nonequilibrium populations of more strongly hydrogen-bonded water structures convert to less-bonded ones. On short time scales, the relaxation of vibrational excitations leads to a transient high-pressure state and a transient absorption spectrum different from that of statically heated water.

  11. Study of thermal insulation for airborne liquid hydrogen fuel tanks

    Science.gov (United States)

    Ruccia, F. E.; Lindstrom, R. S.; Lucas, R. M.

    1978-01-01

    A concept for a fail-safe thermal protection system was developed. From screening tests, approximately 30 foams, adhesives, and reinforcing fibers using 0.3-meter square liquid nitrogen cold plate, CPR 452 and Stafoam AA1602, both reinforced with 10 percent by weight of 1/16 inch milled OCF Style 701 Fiberglas, were selected for further tests. Cyclic tests with these materials in 2-inch thicknesses bonded on a 0.6-meter square cold plate with Crest 7410 adhesive systems, were successful. Zero permeability gas barriers were identified and found to be compatible with the insulating concept.

  12. The calculation of transport properties in quantum liquids using the maximum entropy numerical analytic continuation method: Application to liquid para-hydrogen

    OpenAIRE

    Rabani, Eran; Reichman, David R.; Krilov, Goran; Berne, Bruce J.

    2002-01-01

    We present a method based on augmenting an exact relation between a frequency-dependent diffusion constant and the imaginary time velocity autocorrelation function, combined with the maximum entropy numerical analytic continuation approach to study transport properties in quantum liquids. The method is applied to the case of liquid para-hydrogen at two thermodynamic state points: a liquid near the triple point and a high-temperature liquid. Good agreement for the self-diffusion constant and f...

  13. C1 Chemistry for the Production of Ultra-Clean Liquid Transportation Fuels and Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Gerald P. Huffman

    2006-03-30

    Professors and graduate students from five universities--the University of Kentucky, University of Pittsburgh, University of Utah, West Virginia University, and Auburn University--are collaborating in a research program to develop C1 chemistry processes to produce ultra-clean liquid transportation fuels and hydrogen, the zero-emissions transportation fuel of the future. The feedstocks contain one carbon atom per molecular unit. They include synthesis gas (syngas), a mixture of carbon monoxide and hydrogen produced by coal gasification or reforming of natural gas, methane, methanol, carbon dioxide, and carbon monoxide. An important objective is to develop C1 technology for the production of liquid transportation fuel and hydrogen from domestically plentiful resources such as coal, coalbed methane, and hydrocarbon gases and liquids produced from coal. An Advisory Board with representatives from Chevron-Texaco, Eastman Chemical, Conoco-Phillips, the Air Force Research Laboratory, the U.S. Army National Automotive Center, and Tier Associates provides guidance on the practicality of the research. The current report summarizes the results obtained in this program during the period October 1, 2002 through March 31, 2006. The results are presented in detailed reports on 16 research projects headed by professors at each of the five CFFS Universities and an Executive Summary. Some of the highlights from these results are: (1) Small ({approx}1%) additions of acetylene or other alkynes to the Fischer-Tropsch (F-T) reaction increases its yield, causes chain initiation, and promotes oxygenate formation. (2) The addition of Mo to Fe-Cu-K/AC F-T catalysts improves catalyst lifetime and activity. (3) The use of gas phase deposition to place highly dispersed metal catalysts on silica or ceria aerogels offers promise for both the F-T and the water-gas shift WGS reactions. (4) Improved activity and selectivity are exhibited by Co F-T catalysts in supercritical hexane. (5) Binary Fe

  14. Phonon-like Hydrogen-Bond Modes in Protic Ionic Liquids.

    Science.gov (United States)

    Reichenbach, Judith; Ruddell, Stuart A; González-Jiménez, Mario; Lemes, Julio; Turton, David A; France, David J; Wynne, Klaas

    2017-05-31

    Gigahertz- to terahertz-frequency infrared and Raman spectra contain a wealth of information concerning the structure, intermolecular forces, and dynamics of ionic liquids. However, these spectra generally have a large number of contributions ranging from slow diffusional modes to underdamped librations and intramolecular vibrational modes. This makes it difficult to isolate effects such as the role of Coulombic and hydrogen-bonding interactions. We have applied far-infrared and ultrafast optical Kerr effect spectroscopies on carefully selected ions with a greater or lesser degree of symmetry in order to isolate spectral signals of interest. This has allowed us to demonstrate the presence of longitudinal and transverse optical phonon modes and a great similarity of alkylammonium-based protic ionic liquids to liquid water. The data show that such phonon modes will be present in all ionic liquids, requiring a reinterpretation of their spectra.

  15. Characterization of the Escherichia coli prsA1-encoded mutant phosphoribosylpyrophosphate synthetase identifies a divalent cation-nucleotide binding site

    DEFF Research Database (Denmark)

    Bower, Stanley G.; Harlow, Kenneth W.; Switzer, Robert L.

    1989-01-01

    by chemical determination of the amino acid sequence of a tryptic peptide derived from the purified mutant enzyme. The mutation lies at the N-terminal end of a 16 residue sequence that is highly conserved in E. coli, Bacillus subtilis, and rat PRPP synthetases and has the following consensus sequence......The prsA1 allele, specifying a mutant Escherichia coli phosphoribosylpyrophosphate (PRPP) synthetase, has been cloned. The mutation was shown by nucleotide sequence analysis to result from substitution of Asp-128 (GAT) in the wild type by Ala (GCT) in prsA1. This alteration was confirmed......: DLHAXQIQGFFDI/VPI/VD. There was little alteration in the Km for ribose 5-phosphate. The Km for ATP of the mutant enzyme was increased 27-fold when Mg2+ was the activating cation but only 5-fold when Mn2+ was used. Maximal velocities of the wild type and mutant enzymes were the same. The mutant enzyme has a 6...

  16. Sticking probability for hydrogen atoms on the surface of liquid /sup 4/He

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, D.S.; Berlinsky, A.J.

    1983-03-01

    A calculation is presented of the sticking probability for hydrogen atoms colliding with a liquid /sup 4/He surface. The calculation is based on a model potential for the H-liquid /sup 4/He interaction which is used to derive both bound and free atom wave function and the linear H atom-ripplon coupling. Results are presented in terms of the energy and angle dependent sticking probability s(E,THETA) and the thermally averaged probability s(T), and comparison is made to the experimental results s(T)=0.035 +-0.00 for 0.18 < T < 0.27 K.

  17. Thermo-physical performance prediction of the KSC Ground Operation Demonstration Unit for liquid hydrogen

    Science.gov (United States)

    Baik, J. H.; Notardonato, W. U.; Karng, S. W.; Oh, I.

    2015-12-01

    NASA Kennedy Space Center (KSC) researchers have been working on enhanced and modernized cryogenic liquid propellant handling techniques to reduce life cycle costs of propellant management system for the unique KSC application. The KSC Ground Operation Demonstration Unit (GODU) for liquid hydrogen (LH2) plans to demonstrate integrated refrigeration, zero-loss flexible term storage of LH2, and densified hydrogen handling techniques. The Florida Solar Energy Center (FSEC) has partnered with the KSC researchers to develop thermal performance prediction model of the GODU for LH2. The model includes integrated refrigeration cooling performance, thermal losses in the tank and distribution lines, transient system characteristics during chilling and loading, and long term steady-state propellant storage. This paper will discuss recent experimental data of the GODU for LH2 system and modeling results.

  18. Solid Catalyst with Ionic Liquid Layer (SCILL). A concept to improve the selectivity of selective hydrogenations

    Energy Technology Data Exchange (ETDEWEB)

    Jess, A.; Korth, W. [Bayreuth Univ. (Germany). Chair of Chemical Engineering

    2011-07-01

    Catalytic hydrogenations are important for refinery processes, petrochemical applications as well as for numerous processes of the fine chemicals industry. In some cases, hydrogenations consist of a sequence of consecutive reactions, and the desired product is the intermediate. An important goal is then a high yield and selectivity to the intermediate, if possible at a high conversion degree. The selectivity to an intermediate primarily depends on the chemical nature of the catalyst, but may also be influenced by diffusion processes. Ionic liquids (ILs) are low melting salts (< 100 C) and represent a promising solvent class. This paper focuses on the concept of a Solid Catalyst with Ionic Liquid Layer (SCILL), where the solid catalyst is coated with a thin IL layer to improve the selectivity. (orig.)

  19. A 2.5m long liquid hydrogen target for COMPASS

    CERN Document Server

    Bielert, E; Doshita, N; Geyer, R; Hashimoto, R; Horikawa, N; Ishimoto, S; Iwata, T; Kondo, K; Mallot, G K; Matsuda, H; Matsuda, T; Miyachi, Y; Nukazuka, G; Pirotte, O; Suzuki, H; Suzuki, S; Vullierme, B

    2014-01-01

    A 2.5 m long liquid hydrogen target has been developed for the COMPASS experiment at CERN to investigate the nucleon spin structure via the Deeply Virtual Compton Scattering (DVCS) process. To recognize exclusive DVCS events, produced photons and slow protons need to be detected. In order to do so, the material budget around the target has to be minimal. A 0.125 mm thick Kapton s target cell and a 1 mm thick carbon fi ber vacuum chamber with a Mylar s window have been constructed and tested. Finally, the target system was successfully employed during the DVCS pilot run in COMPASS at the end of 2012. The objective of this paper is to give a detailed description of this newly developed liquid hydrogen target apparatus

  20. Synthesis of liquid menthol by hydrogenation of dementholized peppermint oil over Ni catalysts

    Directory of Open Access Journals (Sweden)

    Debora L. Manuale

    2010-01-01

    Full Text Available Hydrogenation of (--menthone and (+-isomenthone was studied at 2.7 MPa and 100 ºC. The objective was to produce a liquid menthol mixture rich in (--menthol from dementholized peppermint oil. Ni-based catalysts were tested and compared for this reaction: a 6 and 12% Ni dispersed into a nonstoichiometric magnesium aluminate (Ni-Mg-Al with spinel structure; b Ni-Raney catalyst. Both types of catalysts were active for (--menthone and (+-isomenthone hydrogenation. Lower conversion but higher selectivity to (--menthol was obtained with Ni-Mg-Al catalysts. However, they rapidly lost their activity. Instead Ni-Raney catalysts kept its original activity even after several hydrogenation runs.

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

    Science.gov (United States)

    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

  2. Design of a Helium Vapor Shroud for Liquid Hydrogen Fueling of an Unmanned Aerial Vehicle (UAV)

    Science.gov (United States)

    Cavender, K.; Evans, C.; Haney, J.; Leachman, J.

    2017-12-01

    Filling a vehicular liquid hydrogen fuel tank presents the potential for flammable mixtures due to oxygen concentration from liquid air condensation. Current liquid hydrogen tank designs utilize insulating paradigms such as aerogel/fiberglass materials, vacuum jackets, or inert gas purge systems to keep the outer surface from reaching the condensation temperature of air. This work examines the heat transfer at the refuelling connection of the tank to identify potential areas of condensation, as well as the surface temperature gradient. A shrouded inert gas purge was designed to minimize vehicle weight and refuelling time. The design of a shrouded inert gas purge system is presented to displace air preventing air condensation. The design investigates 3D printed materials for an inert gas shroud, as well as low-temperature sealing designs. Shroud designs and temperature profiles were measured and tested by running liquid nitrogen through the filling manifold. Materials for the inert gas shroud are discussed and experimental results are compared to analytical model predictions. Suggestions for future design improvements are made.

  3. Simultaneous photon absorption as a probe of molecular interaction and hydrogen-bond cooperativity in liquids.

    Science.gov (United States)

    Woutersen, Sander

    2007-10-21

    We have investigated the simultaneous absorption of near-infrared photons by pairs of neighboring molecules in liquid methanol. Simultaneous absorption by two OH-stretching modes is found to occur at an energy higher than the sum of the two absorbing modes. This frequency shift arises from interaction between the modes, and its value has been used to determine the average coupling between neighboring methanol molecules. We find a rms coupling strength of 46+/-1 cm(-1), larger than can be explained from a transition-dipole coupling mechanism, suggesting that hydrogen-bond mediated interactions also contribute to the coupling. The most important aspect of simultaneous vibrational absorption is that it allows for a quantitative investigation of hydrogen-bond cooperativity. We derive the extent to which the hydrogen-bond strengths of neighboring molecules are correlated by comparing the line shape of the absorption band caused by simultaneous absorption with that of the fundamental transition. Surprisingly, neighboring hydrogen bonds in methanol are found to be strongly correlated, and from the data we obtain an estimate for the hydrogen-bond correlation coefficient of 0.69+/-0.12.

  4. Pressurization of a Flightweight, Liquid Hydrogen Tank: Evaporation & Condensation at a Liquid/Vapor Interface

    Science.gov (United States)

    Stewart, Mark E. M.

    2017-01-01

    This paper presents an analysis and simulation of evaporation and condensation at a motionless liquid/vapor interface. A 1-D model equation, emphasizing heat and mass transfer at the interface, is solved in two ways, and incorporated into a subgrid interface model within a CFD simulation. Simulation predictions are compared with experimental data from the CPST Engineering Design Unit tank, a cryogenic fluid management test tank in 1-g. The numerical challenge here is the physics of the liquid/vapor interface; pressurizing the ullage heats it by several degrees, and sets up an interfacial temperature gradient that transfers heat to the liquid phase-the rate limiting step of condensation is heat conducted through the liquid and vapor. This physics occurs in thin thermal layers O(1 mm) on either side of the interface which is resolved by the subgrid interface model. An accommodation coefficient of 1.0 is used in the simulations which is consistent with theory and measurements. This model is predictive of evaporation/condensation rates, that is, there is no parameter tuning.

  5. Commentary on the Liquid Metallic Hydrogen Model of the Sun: Insight Relative to Coronal Holes, Sunspots, and Solar Activity

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-04-01

    Full Text Available While mankind will always remain unable to sample the interior of the Sun, the presence of sunspots and coronal holes can provide clues as to its subsurface structure. Insight relative to the solar body can also be gained by recognizing that the Sun must exist in the condensed state and support a discrete lattice structure, as required for the production of its continuous spectrum. In this regard, the layered liquid metallic hydrogen lattice advanced as a condensed model of the Sun (Robitaille P.M. Liquid Metallic Hydrogen: A Building Block for the Liquid Sun. Progr. Phys ., 2011, v. 3, 60–74; Robitaille P.M. Liquid Metallic Hydrogen II: A Critical Assessment of Current and Primordial Helium Levels in Sun. Progr. Phys ., 2013, v. 2, 35–47; Robitaille J.C. and Robitaille P.M. Liquid Metallic Hydrogen III. Intercalation and Lattice Exclusion Versus Gravitational Settling and Their Consequences Relative to Internal Structure, Surface Activity, and Solar Winds in the Sun. Progr. Phys ., 2013, v. 2, in press provides the ability to add structure to the solar interior. This constitutes a significant advantage over the gaseous solar models. In fact, a layered liquid metallic hydrogen lattice and the associated intercalation of non-hydrogen elements can help to account for the position of sunspots and coronal holes. At the same time, this model provides a greater understanding of the mechanisms which drive solar winds and activity.

  6. Hydrogen and carbon vapour pressure isotope effects in liquid fluoroform studied by density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Oi, Takao; Mitome, Ryota; Yanase, Satoshi [Sophia Univ., Tokyo (Japan). Faculty of Science and Technology

    2017-06-01

    H/D and {sup 12}C/{sup 13}C vapour pressure isotope effects (VPIEs) in liquid fluoroform (CHF{sub 3}) were studied at the MPW1PW91/6-31 ++ G(d) level of theory. The CHF{sub 3} monomer and CHF{sub 3} molecules surrounded by other CHF{sub 3} molecules in every direction in CHF{sub 3} clusters were used as model molecules of vapour and liquid CHF{sub 3}. Although experimental results in which the vapour pressure of liquid {sup 12}CHF{sub 3} is higher than that of liquid {sup 12}CDF{sub 3} and the vapour pressure of liquid {sup 13}CHF{sub 3} is higher than that of liquid {sup 12}CHF{sub 3} between 125 and 212 K were qualitatively reproduced, the present calculations overestimated the H/D VPIE and underestimated the {sup 12}C/{sup 13}C VPIE. Temperature-dependent intermolecular interactions between hydrogen and fluorine atoms of neighbouring molecules were required to explain the temperature dependences of both H/D and {sup 12}C/{sup 13}C VPIEs.

  7. Hydrogen bonding in asphaltenes and coal liquids. Quarterly report, 1 February-30 April 1981

    Energy Technology Data Exchange (ETDEWEB)

    Li, N. C.; Jones, L.; Yaggi, N. F.

    1981-01-01

    The objective of this project is to investigate the nature and strength of hydrogen bonding and other molecular interactions in coal liquids and their fractions. Determinations are made of the molecular interactions involving the preasphaltene, asphaltent and oil, together with their separated fractions, obtained from coal liquids after hydroprocessing under different processing conditions and accelerated aging. NMR, IR, GC/MS, calorimetric, GPC, ESR, viscosity methods are used to determine structural changes caused by upgrading and aging of coal liquids. The upgraded coal liquids, derived from catalytic hydroprocessing of a 30 to 70 weight percent blend of solid solvent refined coal product (SRC-I) with liquid solvent-refined coal product (SRC-II) were analyzed as a function of contact time and temperature, and the observed variations of structural parameters were correlated with the physical properties of the liquid products. The oxidative degradation of a SRC-II middle distillate, which is an oil, free of asphaltenes and benzene-insolubles, was investigated to determine the molecular types of compounds responsible for the viscosity change and postulate mechanisms. Since the middle distillate is relatively stable to oxidative degradation, copper shavings were added to accelerate the process. Results and discussion are presented in detail.

  8. Quantum cluster equilibrium theory treatment of hydrogen-bonded liquids: water, methanol and ethanol

    Science.gov (United States)

    Borowski, Piotr; Jaroniec, Justyna; Janowski, Tomasz; Woliński, Krzysztof

    2003-01-01

    The quantum cluster equilibrium (QCE) theory was used in order to predict the composition of the hydrogen bonded liquids: water, methanol and ethanol. The calculations were based on high accuracy theoretical data obtained at the DFT/B3LYP/6-311G(d,p) level of theory. All investigated liquids are predicted to be composed of big clusters: hexamers in the case of water, tetramers, pentamers, hexamers and heptamers in the case of methanol and pentamers in the case of ethanol. The content of big clusters in a liquid phase as predicted by QCE is overestimated. We have found two confirmations of this. First of all, the behaviour of the liquid water isobar clearly demonstrates that there should be a substantial amount of small clusters in order to obtain the correct temperature dependence of the molar volume. Indeed, the theoretical molar volume close to the boiling point is by about 0.6 cm3 lower than the experimental one. The molar volume is too low due to the overestimated population of big clusters resulting in too high a liquid density. Second, the temperature dependence of the chemical shift of the hydroxyl protons in liquid methanol and ethanol, obtained as the population weighted average of the chemical shift of individual clusters, is shifted down field as compared to experiment by as much as 2 ppm. This is because big clusters with strongly deshielded hydroxyl protons contribute too much to the weighted average. Possible shortcomings of the QCE approach are discussed.

  9. Vacuum Surface Science Meets Heterogeneous Catalysis: Dehydrogenation of a Liquid Organic Hydrogen Carrier in the Liquid State.

    Science.gov (United States)

    Matsuda, Takashi; Taccardi, Nicola; Schwegler, Johannes; Wasserscheid, Peter; Steinrück, Hans-Peter; Maier, Florian

    2015-06-22

    Ultrahigh vacuum (UHV) surface science techniques are used to study the heterogeneous catalytic dehydrogenation of a liquid organic hydrogen carrier in its liquid state close to the conditions of real catalysis. For this purpose, perhydrocarbazole (PH), otherwise volatile under UHV, is covalently linked as functional group to an imidazolium cation, forming a non-volatile ionic liquid (IL). The catalysed dehydrogenation of the PH unit as a function of temperature is investigated for a Pt foil covered by a macroscopically thick PH-IL film and for Pd particles suspended in the PH-IL film, and for PH-IL on Au as inert support. X-ray photoelectron spectroscopy and thermal desorption spectroscopy allows us to follow in situ the catalysed transition of perhydrocarbazole to carbazole at technical reaction temperatures. The data demonstrate the crucial role of the Pt and Pd catalysts in order to shift the dehydrogenation temperature below the critical temperature of thermal decomposition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Hazards Induced by Breach of Liquid Rocket Fuel Tanks: Conditions and Risks of Cryogenic Liquid Hydrogen-Oxygen Mixture Explosions

    Science.gov (United States)

    Osipov, Viatcheslav; Muratov, Cyrill; Hafiychuk, Halyna; Ponizovskya-Devine, Ekaterina; Smelyanskiy, Vadim; Mathias, Donovan; Lawrence, Scott; Werkheiser, Mary

    2011-01-01

    We analyze the data of purposeful rupture experiments with LOx and LH2 tanks, the Hydrogen-Oxygen Vertical Impact (HOVI) tests that were performed to clarify the ignition mechanisms, the explosive power of cryogenic H2/Ox mixtures under different conditions, and to elucidate the puzzling source of the initial formation of flames near the intertank section during the Challenger disaster. We carry out a physics-based analysis of general explosions scenarios for cryogenic gaseous H2/Ox mixtures and determine their realizability conditions, using the well-established simplified models from the detonation and deflagration theory. We study the features of aerosol H2/Ox mixture combustion and show, in particular, that aerosols intensify the deflagration flames and can induce detonation for any ignition mechanism. We propose a cavitation-induced mechanism of self-ignition of cryogenic H2/Ox mixtures that may be realized when gaseous H2 and Ox flows are mixed with a liquid Ox turbulent stream, as occurred in all HOVI tests. We present an overview of the HOVI tests to make conclusion on the risk of strong explosions in possible liquid rocket incidents and provide a semi-quantitative interpretation of the HOVI data based on aerosol combustion. We uncover the most dangerous situations and discuss the foreseeable risks which can arise in space missions and lead to tragic outcomes. Our analysis relates to only unconfined mixtures that are likely to arise as a result of liquid propellant space vehicle incidents.

  11. 40 CFR Table 3 to Subpart IIIii of... - Work Practice Standards-Required Actions for Liquid Mercury Spills and Accumulations and Hydrogen...

    Science.gov (United States)

    2010-07-01

    ... Actions for Liquid Mercury Spills and Accumulations and Hydrogen and Mercury Vapor Leaks 3 Table 3 to... Standards—Required Actions for Liquid Mercury Spills and Accumulations and Hydrogen and Mercury Vapor Leaks... cell back into service until the leaking equipment is repaired. 3. A decomposer or hydrogen system...

  12. Liquid Metallic Hydrogen II. A Critical Assessment of Current and Primordial Helium Levels in the Sun

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-04-01

    Full Text Available Before a solar model becomes viable in astrophysics, one mus t consider how the ele- mental constitution of the Sun was ascertained, especially relative to its principle com- ponents: hydrogen and helium. Liquid metallic hydrogen has been proposed as a solar structural material for models based on condensed matter (e .g. Robitaille P.-M. Liq- uid Metallic Hydrogen: A Building Block for the Liquid Sun. Progr. Phys. , 2011, v. 3, 60–74. There can be little doubt that hydrogen plays a d ominant role in the uni- verse and in the stars; the massive abundance of hydrogen in t he Sun was established long ago. Today, it can be demonstrated that the near isointe nse nature of the Sun’s Balmer lines provides strong confirmatory evidence for a dis tinct solar surface. The situation relative to helium remains less conclusive. Stil l, helium occupies a prominent role in astronomy, both as an element associated with cosmol ogy and as a byproduct of nuclear energy generation, though its abundances within the Sun cannot be reliably estimated using theoretical approaches. With respect to th e determination of helium lev- els, the element remains spectroscopically silent at the le vel of the photosphere. While helium can be monitored with ease in the chromosphere and the prominences of the corona using spectroscopic methods, these measures are hig hly variable and responsive to elevated solar activity and nuclear fragmentation. Dire ct assays of the solar winds are currently viewed as incapable of providing definitive in formation regarding solar helium abundances. As a result, insight relative to helium r emains strictly based on the- oretical estimates which couple helioseismological appro aches to metrics derived from solar models. Despite their “state of the art” nature, heliu m estimates based on solar models and helioseismology are suspect on several fronts, i ncluding their reliance on solar opacities. The best knowledge can only come from the so

  13. C1 CHEMISTRY FOR THE PRODUCTION OF ULTRA-CLEAN LIQUID TRANSPORTATION FUELS AND HYDROGEN

    Energy Technology Data Exchange (ETDEWEB)

    Gerald P. Huffman

    2004-03-31

    Faculty and students from five universities--the University of Kentucky, University of Pittsburgh, University of Utah, West Virginia University, and Auburn University--are collaborating in a research program to develop C1 chemistry processes to produce ultra-clean liquid transportation fuels and hydrogen, the zero-emissions transportation fuel of the future. The feedstocks contain one carbon atom per molecular unit. They include synthesis gas (syngas), a mixture of carbon monoxide and hydrogen produced by coal gasification or reforming of natural gas, methane, methanol, carbon dioxide, and carbon monoxide. An important objective is to develop C1 technology for the production of liquid transportation fuel and hydrogen from domestically plentiful resources such as coal, coalbed methane, and natural gas. An Industrial Advisory Board with representatives from Chevron-Texaco, Eastman Chemical, Conoco-Phillips, the Air Force Research Laboratory, the U.S. Army National Automotive Center (Tank & Automotive Command--TACOM), and Tier Associates provides guidance on the practicality of the research. The current report presents results obtained in this research program during the six months of the subject contract from October 1, 2002 through March 31, 2003. The results are presented in thirteen detailed reports on research projects headed by various faculty members at each of the five CFFS Universities. Additionally, an Executive Summary has been prepared that summarizes the principal results of all of these projects during the six-month reporting period.

  14. Influence of heat transfer rates on pressurization of liquid/slush hydrogen propellant tanks

    Science.gov (United States)

    Sasmal, G. P.; Hochstein, J. I.; Hardy, T. L.

    1993-01-01

    A multi-dimensional computational model of the pressurization process in liquid/slush hydrogen tank is developed and used to study the influence of heat flux rates at the ullage boundaries on the process. The new model computes these rates and performs an energy balance for the tank wall whereas previous multi-dimensional models required a priori specification of the boundary heat flux rates. Analyses of both liquid hydrogen and slush hydrogen pressurization were performed to expose differences between the two processes. Graphical displays are presented to establish the dependence of pressurization time, pressurant mass required, and other parameters of interest on ullage boundary heat flux rates and pressurant mass flow rate. Detailed velocity fields and temperature distributions are presented for selected cases to further illuminate the details of the pressurization process. It is demonstrated that ullage boundary heat flux rates do significantly effect the pressurization process and that minimizing heat loss from the ullage and maximizing pressurant flow rate minimizes the mass of pressurant gas required to pressurize the tank. It is further demonstrated that proper dimensionless scaling of pressure and time permit all the pressure histories examined during this study to be displayed as a single curve.

  15. Conductivity and dissociation in liquid metallic hydrogen and implications for planetary interiors.

    Science.gov (United States)

    Zaghoo, Mohamed; Silvera, Isaac F

    2017-11-07

    Liquid metallic hydrogen (LMH) is the most abundant form of condensed matter in our solar planetary structure. The electronic and thermal transport properties of this metallic fluid are of fundamental interest to understanding hydrogen's mechanism of conduction, atomic or pairing structure, as well as the key input for the magnetic dynamo action and thermal models of gas giants. Here, we report spectrally resolved measurements of the optical reflectance of LMH in the pressure region of 1.4-1.7 Mbar. We analyze the data, as well as previously reported measurements, using the free-electron model. Fitting the energy dependence of the reflectance data yields a dissociation fraction of 65 ± 15%, supporting theoretical models that LMH is an atomic metallic liquid. We determine the optical conductivity of LMH and find metallic hydrogen's static electrical conductivity to be 11,000-15,000 S/cm, substantially higher than the only earlier reported experimental values. The higher electrical conductivity implies that the Jovian and Saturnian dynamo are likely to operate out to shallower depths than previously assumed, while the inferred thermal conductivity should provide a crucial experimental constraint to heat transport models. Published under the PNAS license.

  16. C1 Chemistry for the Production of Ultra-Clean Liquid Transportation Fuels and Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Gerald P. Huffman

    2005-03-31

    Faculty and students from five universities--the University of Kentucky, University of Pittsburgh, University of Utah, West Virginia University, and Auburn University--are collaborating in a research program to develop C1 chemistry processes to produce ultra-clean liquid transportation fuels and hydrogen, the zero-emissions transportation fuel of the future. The feedstocks contain one carbon atom per molecular unit. They include synthesis gas (syngas), a mixture of carbon monoxide and hydrogen produced by coal gasification or reforming of natural gas, methane, methanol, carbon dioxide, and carbon monoxide. An important objective is to develop C1 technology for the production of liquid transportation fuel and hydrogen from domestically plentiful resources such as coal, coalbed methane, and natural gas. An Industrial Advisory Board with representatives from Chevron-Texaco, Eastman Chemical, Conoco-Phillips, the Air Force Research Laboratory, the U.S. Army National Automotive Center (Tank & Automotive Command--TACOM), and Tier Associates provides guidance on the practicality of the research. The current report presents results obtained in this research program during the six months of the subject contract from October 1, 2002 through March 31, 2003. The results are presented in thirteen detailed reports on research projects headed by various faculty members at each of the five CFFS Universities. Additionally, an Executive Summary has been prepared that summarizes the principal results of all of these projects during the six-month reporting period.

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

    Science.gov (United States)

    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.

  18. Evaluation of industrially applied heat-transfer fluids as liquid organic hydrogen carrier systems.

    Science.gov (United States)

    Brückner, Nicole; Obesser, Katharina; Bösmann, Andreas; Teichmann, Daniel; Arlt, Wolfgang; Dungs, Jennifer; Wasserscheid, Peter

    2014-01-01

    Liquid organic hydrogen carrier (LOHC) systems offer a very attractive method for the decentralized storage of renewable excess energy. In this contribution, industrially well-established heat-transfer oils (typically sold under trade names, e.g., Marlotherm) are proposed as a new class of LOHC systems. It is demonstrated that the liquid mixture of isomeric dibenzyltoluenes (m.p. -39 to -34 °C, b.p. 390 °C) can be readily hydrogenated to the corresponding mixture of perhydrogenated analogues by binding 6.2 wt% of H2. The liquid H2 -rich form can be stored and transported similarly to diesel fuel. It readily undergoes catalytic dehydrogenation at temperatures above 260 °C, which proves its applicability as a reversible H2 carrier. The presented LOHC systems are further characterized by their excellent technical availability at comparably low prices, full registration of the H2 -lean forms, and excellent thermal stabilities. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Alternative probe for the determination of the hydrogen-bond acidity of ionic liquids and their aqueous solutions.

    Science.gov (United States)

    Madeira, Pedro P; Passos, Helena; Gomes, Joana; Coutinho, João A P; Freire, Mara G

    2017-05-10

    Although highly relevant to a priori select adequate solvents for a given application, the determination of the hydrogen-bond acidity or proton donor ability of aqueous solutions of ionic liquids is a difficult task due to the poor solubility of the commonly used probes in aqueous media. In this work, we demonstrate the applicability of the pyridine-N-oxide probe to determine the hydrogen-bond acidity of both neat ionic liquids and their aqueous solutions, based on 13C NMR chemical shifts, and the suitability of these values to appraise the ability of ionic liquids to form aqueous two-phase systems.

  20. About the process improvement of adsorptive desulphurisation by adding hydrogen donators as additives in liquid fuels

    Science.gov (United States)

    van Rheinberg, Oliver; Lucka, Klaus; Köhne, Heinrich

    For the use in fuel cell system commercial fuels, like diesel or domestic heating oil, have to be desulphurised to ultra deep sulphur levels of below 1 mg kg -1. To reach this goal the adsorptive desulphurisation using a nickel-based sorbent has been identified. The evaluation of the reaction mechanism reveals in principle the same route as that of the hydrodesulphurisation (HDS) whereas the sulphur is adsorbed by the sorbent instead of being converted to hydrogen sulphide. The required hydrogen for the process is provided out of the fuel itself and not by an external supply of hydrogen. This analysis leads to an easy applicable enhancement of the process by adding a hydrogen donator as an additive to the liquid fuel. In correlation to the mass fraction of the donator the reaction rates and sorbent capacities are improved significantly. Furthermore the influence of aromatic compounds has been investigated, which exhibit similar molecular structures and chemical properties than comparable high refractory sulphur species. This leads to side reactions especially of di- and tri-aromatics which influence the sulphur adsorption. A shift of the aromatic fraction from mono- to di- and tri-aromatic compounds has been observed as well as the alkylation of di- and tri-aromatics.

  1. Extended scale for the hydrogen-bond basicity of ionic liquids.

    Science.gov (United States)

    Cláudio, Ana Filipa M; Swift, Lorna; Hallett, Jason P; Welton, Tom; Coutinho, João A P; Freire, Mara G

    2014-04-14

    In the past decade, ionic liquids (ILs) have been the focus of intensive research regarding their use as potential and alternative solvents in many chemical applications. Targeting their effectiveness, recent investigations have attempted to establish polarity scales capable of ranking ILs according to their chemical behaviours. However, some major drawbacks have been found since polarity scales only report relative ranks because they depend on the set of probe dyes used, and they are sensitive to measurement conditions, such as purity levels of the ILs and procedures employed. Due to all these difficulties it is of crucial importance to find alternative and/or predictive methods and to evaluate them as a priori approaches capable of providing the chemical properties of ILs. Furthermore, the large number of ILs available makes their experimental characterization, usually achieved by a trial and error methodology, burdensome. In this context, we firstly evaluated COSMO-RS, COnductor-like Screening MOdel for Real Solvents, as an alternative tool to estimate the hydrogen-bond basicity of ILs. After demonstrating a straight-line correlation between the experimental hydrogen-bond basicity values and the COSMO-RS hydrogen-bonding energies in equimolar cation-anion pairs, an extended scale for the hydrogen-bond accepting ability of IL anions is proposed here. This new ranking of the ILs' chemical properties opens the possibility to pre-screen appropriate ILs (even those not yet synthesized) for a given task or application.

  2. Correlation between hydrogen bond basicity and acetylene solubility in room temperature ionic liquids.

    Science.gov (United States)

    Palgunadi, Jelliarko; Hong, Sung Yun; Lee, Jin Kyu; Lee, Hyunjoo; Lee, Sang Deuk; Cheong, Minserk; Kim, Hoon Sik

    2011-02-10

    Room temperature ionic liquids (RTILs) are proposed as the alternative solvents for the acetylene separation in ethylene generated from the naphtha cracking process. The solubility behavior of acetylene in RTILs was examined using a linear solvation energy relationship based on Kamlet-Taft solvent parameters including the hydrogen-bond acidity or donor ability (α), the hydrogen-bond basicity or acceptor ability (β), and the polarity/polarizability (π*). It is found that the solubility of acetylene linearly correlates with β value and is almost independent of α or π*. The solubility of acetylene in RTILs increases with increasing hydrogen-bond acceptor (HBA) ability of the anion, but is little affected by the nature of the cation. Quantum mechanical calculations demonstrate that the acidic proton of acetylene specifically forms hydrogen bond with a basic oxygen atom on the anion of a RTIL. On the other hand, although C-H···π interaction is plausible, all optimized structures indicate that the acidic protons on the cation do not specifically associate with the π cloud of acetylene. Thermodynamic analysis agrees well with the proposed correlation: the higher the β value of a RTIL is, the more negative the enthalpy of acetylene absorption in the RTIL is.

  3. Insights into hydrogen bond donor promoted fixation of carbon dioxide with epoxides catalyzed by ionic liquids.

    Science.gov (United States)

    Liu, Mengshuai; Gao, Kunqi; Liang, Lin; Wang, Fangxiao; Shi, Lei; Sheng, Li; Sun, Jianmin

    2015-02-28

    Catalytic coupling of carbon dioxide with epoxides to obtain cyclic carbonates is an important reaction that has been receiving renewed interest. In this contribution, the cycloaddition reaction in the presence of various hydrogen bond donors (HBDs) catalyzed by hydroxyl/carboxyl task-specific ionic liquids (ILs) is studied in detail. It was found that the activity of ILs could be significantly enhanced in the presence of ethylene glycol (EG), and EG/HEBimBr were the most efficient catalysts for the CO2 cycloaddition to propylene oxide. Moreover, the binary catalysts were also efficiently versatile for the CO2 cycloaddition to less active epoxides such as styrene oxide and cyclohexene oxide. Besides, the minimum energy paths for this hydrogen bond-promoted catalytic reaction were calculated using the density functional theory (DFT) method. The DFT results suggested that the ring-closing reaction was the rate-determining step in the HEBimBr-catalyzed cycloaddition reaction but the EG addition could remarkably reduce its energy barrier as the formation of a hydrogen bond between EG and the oxygen atom of epoxides led this process along the standard SN2 mechanism. As a result, the ring-opening reaction became the rate-determining step in the EG/HEBimBr-catalyzed cycloaddition reaction. The work reported herein helped the understanding and design of catalysts for efficient fixation of CO2 to epoxides via hydrogen bond activation.

  4. Ethylene glycol revisited: Molecular dynamics simulations and visualization of the liquid and its hydrogen-bond network.

    Science.gov (United States)

    Kaiser, Alexander; Ismailova, Oksana; Koskela, Antti; Huber, Stefan E; Ritter, Marcel; Cosenza, Biagio; Benger, Werner; Nazmutdinov, Renat; Probst, Michael

    2014-01-01

    Molecular dynamics simulations of liquid ethylene glycol described by the OPLS-AA force field were performed to gain insight into its hydrogen-bond structure. We use the population correlation function as a statistical measure for the hydrogen-bond lifetime. In an attempt to understand the complicated hydrogen-bonding, we developed new molecular visualization tools within the Vish Visualization shell and used it to visualize the life of each individual hydrogen-bond. With this tool hydrogen-bond formation and breaking as well as clustering and chain formation in hydrogen-bonded liquids can be observed directly. Liquid ethylene glycol at room temperature does not show significant clustering or chain building. The hydrogen-bonds break often due to the rotational and vibrational motions of the molecules leading to an H-bond half-life time of approximately 1.5 ps. However, most of the H-bonds are reformed again so that after 50 ps only 40% of these H-bonds are irreversibly broken due to diffusional motion. This hydrogen-bond half-life time due to diffusional motion is 80.3 ps. The work was preceded by a careful check of various OPLS-based force fields used in the literature. It was found that they lead to quite different angular and H-bond distributions.

  5. Liquid hydrogen for Europe - the Linde plant at Ingolstadt. Fluessigwasserstoff fuer Europa - die Linde-Anlage in Ingolstadt

    Energy Technology Data Exchange (ETDEWEB)

    Gross, R.; Otto, W.; Patzelt, A.; Wanner, M.

    1994-01-01

    In view of the increasing demand for liquid hydrogen on the European market in Industrial Gases Division of Linde AG invested a pure hydrogen production facility with a capacity of 4.4 tons/day which has been in operation at Ingolstadt since 1992. The plant uses raw gas from a refinery. After prification, the hydrogen gas can either be liquefied or delivered as high-pressure gas. In addition to liquefaction the facility comprises liquid hydrogen storage and filling stations. The following article highlights the commitment of the Linde Group supporting the introduction and use of this environmental friendly energy medium in Europe. The concept of the facility and the individual processes are described as well as the main components of this pure hydrogen plant. (orig.)

  6. C1 CHEMISTRY FOR THE PRODUCTION OF ULTRA-CLEAN LIQUID TRANSPORTATION FUELS AND HYDROGEN

    Energy Technology Data Exchange (ETDEWEB)

    Gerald P. Huffman

    2004-09-30

    The Consortium for Fossil Fuel Science (CFFS) is a research consortium with participants from the University of Kentucky, University of Pittsburgh, West Virginia University, University of Utah, and Auburn University. The CFFS is conducting a research program to develop C1 chemistry technology for the production of clean transportation fuel from resources such as coal and natural gas, which are more plentiful domestically than petroleum. The processes under development will convert feedstocks containing one carbon atom per molecular unit into ultra clean liquid transportation fuels (gasoline, diesel, and jet fuel) and hydrogen, which many believe will be the transportation fuel of the future. Feedstocks include synthesis gas, a mixture of carbon monoxide and hydrogen produced by coal gasification, coalbed methane, light products produced by Fischer-Tropsch (FT) synthesis, methanol, and natural gas.

  7. Density functional theory study on the ionic liquid pyridinium hydrogen sulfate

    Science.gov (United States)

    Tankov, Ivaylo; Yankova, Rumyana; Genieva, Svetlana; Mitkova, Magdalena; Stratiev, Dicho

    2017-07-01

    The geometry, electronic structure and chemical reactivity of a pyridinium-based ionic liquid, pyridinium hydrogen sulfate ([H-Pyr]+[HSO4]-), have been discussed on the basis of quantum chemical density functional theory calculations using B3LYP/6-311+G(d,p) and B3LYP/6-311++G(2d,2p) approaches. The calculations indicated that [H-Pyr]+[HSO4]- exists in the form of an ion pair. A large electropositive potential was found on the pyridinium ring, while the regions of a negative electrostatic potential is linked with the lone pair of electronegative oxygen atoms in hydrogen sulfate anion ([HSO4]-). Electron transfer both within the anion, and between the anion and cation of an ion pair were described using natural bond orbital theory. The energy values of -7.1375 and -2.8801 eV were related to HOMO and LUMO orbitals, respectively.

  8. Diketopyrrolopyrrole Columnar Liquid-Crystalline Assembly Directed by Quadruple Hydrogen Bonds.

    Science.gov (United States)

    Soberats, Bartolome; Hecht, Markus; Würthner, Frank

    2017-08-28

    A diketopyrrolopyrrole (DPP) dye self-assembles via a unique hydrogen-bonding motif into an unprecedented columnar liquid-crystalline (LC) structure. X-ray and polarized FTIR experiments reveal that the DPPs organize into a one-dimensional assembly with the chromophores oriented parallel to the columnar axis. This columnar structure is composed of two π-π-stacked DPP dimers with mirror-image configurations that stack alternately through quadruple hydrogen bonding by 90° rotation. This exotic packing is dictated by the complementarity between H-bonds and the steric demands of the wedge-shaped groups attached at the core. This novel LC supramolecular material opens a new avenue of research on DPP dye assemblies with photofunctional properties tailored by H-bonding networks. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Superconducting characteristics of short MgB2 wires of long level sensor for liquid hydrogen

    Science.gov (United States)

    Takeda, M.; Inoue, Y.; Maekawa, K.; Matsuno, Y.; Fujikawa, S.; Kumakura, H.

    2015-12-01

    To establish the worldwide storage and marine transport of hydrogen, it is important to develop a high-precision and long level sensor, such as a superconducting magnesium diboride (MgB2) level sensor for large liquid hydrogen (LH2) tanks on board ships. Three 1.7- m-long MgB2 wires were fabricated by an in situ method, and the superconducting characteristics of twenty-four 20-mm-long MgB2 wires on the 1.7-m-long wires were studied. In addition, the static level-detecting characteristics of five 500-mm-long MgB2 level sensors were evaluated under atmospheric pressure.

  10. Catalytic pressurization of liquid hydrogen fuel tanks for unmanned aerial vehicles

    Science.gov (United States)

    Leachman, Jacob; Street, Melissa Jean; Graham, Teira

    2012-06-01

    As the use and applications of Unmanned Aerial Vehicles (UAV) expand, the need for a lighter weight fuel allowing for longer duration flights has become the primary limiting factor in the advancement of these vehicles. To extend the operational envelope of UAV, onboard condensed hydrogen storage for missions exceeding one week is necessary. Currently, large spherical liquid hydrogen tanks that are pressurized with external helium tanks or electronic heating elements are utilized for this purpose. However, the mass, size, and power consumption of the fuel storage tank and fuel pressurization system significantly limit the flight envelope of UAV. In an effort to alleviate these issues, this paper investigates the technological feasibility of orthohydrogen-parahydrogen catalysis as a method of fuel pressurization. Typical pressurization requirements for takeoff, cruise, and landing are reviewed. Calculations of the catalyst system mass and response time are presented.

  11. Liquid-phase oxidation of hydrogen sulfide in presence of native and modified petroleum porphyrins

    Energy Technology Data Exchange (ETDEWEB)

    Zemtseva, L.I.; Antipenko, V.R.; Vil' danov, A.F.; Mazgarov, A.M.

    1988-09-10

    An important property of the porphyrin and phthalocyanine metal complexes is their ability to catalyze the oxidation of hydrogen sulfide by molecular oxygen in certain organic solvents. The highest reaction rate is observed in a dimethylformamide (DMFA) medium. To study the possible use of native and modified petroleum porphyrins for the catalysis of the oxidation reaction of H/sub 2/S in a DMFA medium, they compared the catalytic activities of vanadyl complexes of petroleum porphyrins, and the products of their transmetallation by cobalt and iron salts, and also the corresponding metal complexes of etioporphyrins and di- and tetrasulfophthalocyanines. Their investigations thus showed that the iron complex obtained from a concentrate of petroleum porphyrins can, in principle, be used as an effective catalyst of the liquid phase oxidation of hydrogen sulfide in a dimethylformamide medium.

  12. Processes of the formation of large unconfined clouds following a massive spillage of liquid hydrogen on the ground

    OpenAIRE

    Proust, Christophe; Lacome, Jean-Marc; Jamois, Didier; Perrette, Lionel

    2007-01-01

    International audience; Because of hydrogen low volumetric energy content under its gaseous form, transport and storage of liquid hydrogen will certainly play a major role in any future hydrogen economy. One of the obstacles to the expected development use of hydrogen is the poor state of knowledge on explosion risks in the event of an extensive spillage. INERIS set up a large-scale experiment to study the mechanisms of the formation of the gas cloud resulting from such a spillage and the ass...

  13. Assessment of liquid hydrogen cooled MgB2 conductors for magnetically confined fusion

    Science.gov (United States)

    Glowacki, B. A.; Nuttall, W. J.

    2008-02-01

    Importantly environmental factors are not the only policy-driver for the hydrogen economy. Over the timescale of the development of fusion energy systems, energy security issues are likely to motivate a shift towards both hydrogen production and fusion as an energy source. These technologies combine local control of the system with the collaborative research interests of the major energy users in the global economy. A concept Fusion Island Reactor that might be used to generate H2 (rather than electricity) is presented. Exploitation of produced hydrogen as a coolant and as a fuel is proposed in conjunction with MgB2 conductors for the tokomak magnets windings, and electrotechnical devices for Fusion Island's infrastructure. The benefits of using MgB2 over the Nb-based conductors during construction, operation and decommissioning of the Fusion Island Reactor are presented. The comparison of Nb3Sn strands for ITER fusion magnet with newly developed high field composite MgB2 PIT conductors has shown that at 14 Tesla MgB2 possesses better properties than any of the Nb3Sn conductors produced. In this paper the potential of MgB2 conductors is examined for tokamaks of both the conventional ITER type and a Spherical Tokamak geometry. In each case MgB2 is considered as a conductor for a range of field coil applications and the potential for operation at both liquid helium and liquid hydrogen temperatures is considered. Further research plans concerning the application of MgB2 conductors for Fusion Island are also considered.

  14. Taming Liquid Hydrogen: The Centaur Upper Stage Rocket, 1958-2002

    Science.gov (United States)

    Dawson, Virginia P.; Bowles, Mark D.

    2004-01-01

    During its maiden voyage in May 1962, a Centaur upper stage rocket, mated to an Atlas booster, exploded 54 seconds after launch, engulfing the rocket in a huge fireball. Investigation revealed that Centaur's light, stainless-steel tank had split open, spilling its liquid-hydrogen fuel down its sides, where the flame of the rocket exhaust immediately ignited it. Coming less than a year after President Kennedy had made landing human beings on the Moon a national priority, the loss of Centaur was regarded as a serious setback for the National Aeronautics and Space Administration (NASA). During the failure investigation, Homer Newell, Director of Space Sciences, ruefully declared: "Taming liquid hydrogen to the point where expensive operational space missions can be committed to it has turned out to be more difficult than anyone supposed at the outset." After this failure, Centaur critics, led by Wernher von Braun, mounted a campaign to cancel the program. In addition to the unknowns associated with liquid hydrogen, he objected to the unusual design of Centaur. Like the Atlas rocket, Centaur depended on pressure to keep its paper-thin, stainless-steel shell from collapsing. It was literally inflated with its propellants like a football or balloon and needed no internal structure to give it added strength and stability. The so-called "pressure-stabilized structure" of Centaur, coupled with the light weight of its high- energy cryogenic propellants, made Centaur lighter and more powerful than upper stages that used conventional fuel. But, the critics argued, it would never become the reliable rocket that the United States needed.

  15. The calculation of transport properties in quantum liquids using the maximum entropy numerical analytic continuation method: application to liquid para-hydrogen.

    Science.gov (United States)

    Rabani, Eran; Reichman, David R; Krilov, Goran; Berne, Bruce J

    2002-02-05

    We present a method based on augmenting an exact relation between a frequency-dependent diffusion constant and the imaginary time velocity autocorrelation function, combined with the maximum entropy numerical analytic continuation approach to study transport properties in quantum liquids. The method is applied to the case of liquid para-hydrogen at two thermodynamic state points: a liquid near the triple point and a high-temperature liquid. Good agreement for the self-diffusion constant and for the real-time velocity autocorrelation function is obtained in comparison to experimental measurements and other theoretical predictions. Improvement of the methodology and future applications are discussed.

  16. The impact of iron on the bleaching efficacy of hydrogen peroxide in liquid whey systems.

    Science.gov (United States)

    Jervis, Suzanne M; Drake, MaryAnne

    2013-02-01

    Whey is a value-added product that is utilized in many food and beverage applications for its nutritional and functional properties. Whey and whey products are generally utilized in dried ingredient applications. One of the primary sources of whey is from colored Cheddar cheese manufacture that contains the pigment annatto resulting in a characteristic yellow colored Cheddar cheese. The colorant is also present in the liquid cheese whey and must be bleached so that it can be used in ingredient applications without imparting a color. Hydrogen peroxide and benzoyl peroxide are 2 commercially approved chemical bleaching agents for liquid whey. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have been previously reported for whey bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how bleaching can impact flavor and functionality of dried ingredients. Currently, the precise mechanisms of off-flavor development and functionality changes are not entirely understood. Iron reactions in a bleached liquid whey system may play a key role. Reactions between iron and hydrogen peroxide have been widely studied since the reaction between these 2 relatively stable species can cause great destruction in biological and chemical systems. The actual mechanism of the reaction of iron with hydrogen peroxide has been a controversy in the chemistry and biological community. The precise mechanism for a given reaction can vary greatly based upon the concentration of reactants, temperature, pH, and addition of biological material. In this review, some hypotheses for the mechanisms of iron reactions that may occur in fluid whey that may impact bleaching efficacy, off-flavor development, and changes in functionality are presented. Cheese whey is bleached to remove residual carotenoid cheese colorant. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have

  17. Effect of Hydrogenated, Liquid and Ghee Oils on Serum Lipids Profile

    OpenAIRE

    Mohammadifard, Noushin; Nazem, Masoud; Naderi, Gholam-Ali; Saghafian, Faezeh; Sajjadi, Firoozeh; Maghroon, Maryam; Bahonar, Ahmad; Alikhasi, Hasan; Nouri, Fatemeh

    2010-01-01

    BACKGROUND Trans fatty acids are known as the most harmful type of dietary fats, so this study was done to compare the effects of hydrogenated, liquid and ghee oils on serum lipids profile of healthy adults. METHODS This study was a randomized clinical trial conducted on 129 healthy participants aged from 20 to 60 years old who were beneficiaries of Imam-e-Zaman charitable organization. Subjects were randomly divided into 3 groups and each group was treated with a diet containing cooking and ...

  18. Analysis of the Quasi-Elastic Scattering of Neutrons in Hydrogenous Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Porohit, S.N. [Nuclear Science and Engineering Dept., Rensselaer Polytechnique Inst., Troy, NY (United States)

    1966-11-15

    A critical discussion of the quasi-elastic scattering of neutrons by incoherent (hydrogenous) liquids is presented. Using the line shape expression a comparative discussion of several phenomenological models has been carried out. Extension of the Singwi-Sjoelander zero phonon expression, for the jump-diffusion model, so as to include the one phonon expression has also been given. For a delayed diffusion model a complete treatment of S(K, {omega}) is presented. Along the lines of the macroscopic diffusion cooling, a microscopic diffusion cooling effect in fluids is speculated.

  19. Method and apparatus for electrokinetic co-generation of hydrogen and electric power from liquid water microjets

    Science.gov (United States)

    Saykally, Richard J; Duffin, Andrew M; Wilson, Kevin R; Rude, Bruce S

    2013-02-12

    A method and apparatus for producing both a gas and electrical power from a flowing liquid, the method comprising: a) providing a source liquid containing ions that when neutralized form a gas; b) providing a velocity to the source liquid relative to a solid material to form a charged liquid microjet, which subsequently breaks up into a droplet spay, the solid material forming a liquid-solid interface; and c) supplying electrons to the charged liquid by contacting a spray stream of the charged liquid with an electron source. In one embodiment, where the liquid is water, hydrogen gas is formed and a streaming current is generated. The apparatus comprises a source of pressurized liquid, a microjet nozzle, a conduit for delivering said liquid to said microjet nozzle, and a conductive metal target sufficiently spaced from said nozzle such that the jet stream produced by said microjet is discontinuous at said target. In one arrangement, with the metal nozzle and target electrically connected to ground, both hydrogen gas and a streaming current are generated at the target as it is impinged by the streaming, liquid spray microjet.

  20. Interplay between Hydrogen Bonding and Vibrational Coupling in Liquid N-Methylacetamide.

    Science.gov (United States)

    Cunha, Ana V; Salamatova, Evgeniia; Bloem, Robbert; Roeters, Steven J; Woutersen, Sander; Pshenichnikov, Maxim S; Jansen, Thomas L C

    2017-06-01

    Intrinsically disordered proteins play an important role in biology, and unraveling their labile structure presents a vital challenge. However, the dynamical structure of such proteins thwarts their study by standard techniques such as X-ray diffraction and NMR spectroscopy. Here, we use a neat liquid composed of N-methylacetamide molecules as a model system to elucidate dynamical and structural properties similar to those one can expect to see in intrinsically disordered proteins. To examine the structural dynamics in the neat liquid, we combine molecular dynamics, response-function-based spectral simulations, and two-dimensional polarization-resolved infrared spectroscopy in the amide I (CO stretch) region. The two-dimensional spectra reveal a delicate interplay between hydrogen bonding and intermolecular vibrational coupling effects, observed through a fast anisotropy decay. The present study constitutes a general platform for understanding the structure and dynamics of highly disordered proteins.

  1. Towards a unified description of the hydrogen bond network of liquid water: a dynamics based approach.

    Science.gov (United States)

    Ozkanlar, Abdullah; Zhou, Tiecheng; Clark, Aurora E

    2014-12-07

    The definition of a hydrogen bond (H-bond) is intimately related to the topological and dynamic properties of the hydrogen bond network within liquid water. The development of a universal H-bond definition for water is an active area of research as it would remove many ambiguities in the network properties that derive from the fixed definition employed to assign whether a water dimer is hydrogen bonded. This work investigates the impact that an electronic-structure based definition, an energetic, and a geometric definition of the H-bond has upon both topological and dynamic network behavior of simulated water. In each definition, the use of a cutoff (either geometric or energetic) to assign the presence of a H-bond leads to the formation of transiently bonded or broken dimers, which have been quantified within the simulation data. The relative concentration of transient species, and their duration, results in two of the three definitions sharing similarities in either topological or dynamic features (H-bond distribution, H-bond lifetime, etc.), however no two definitions exhibit similar behavior for both classes of network properties. In fact, two networks with similar local network topology (as indicated by similar average H-bonds) can have dramatically different global network topology (as indicated by the defect state distributions) and altered H-bond lifetimes. A dynamics based correction scheme is then used to remove artificially transient H-bonds and to repair artificially broken bonds within the network such that the corrected network exhibits the same structural and dynamic properties for two H-bond definitions (the properties of the third definition being significantly improved). The algorithm described represents a significant step forward in the development of a unified hydrogen bond network whose properties are independent of the original hydrogen bond definition that is employed.

  2. Bavarian liquid hydrogen bus demonstration project - safety, licensing and acceptability aspects

    Energy Technology Data Exchange (ETDEWEB)

    Wurster, R.; Knorr, H.; Pruemm, W.

    1999-07-01

    A regular 12 m city bus of the MAN SL 202 type with an internal combustion engine adapted to hydrogen operation and auxiliary gasoline operation was demonstrated in the Bavarian cities of Erlangen and Munich between April 1996 and August 1998. Three bus operators, Erlanger Stadtwerke, Stadtwerke Muenchen and Autobus Oberbayern were testing the bus in three different operating schemes. In order to be able to perform this worldwide first public demonstration of a liquid hydrogen (LH{sub 2}) city bus in regular service, several requirements with respect to safety, licensing, training and acceptability had to be fulfilled. These activities were focusing mainly on the hydrogen specific issues such as (a) integration of onboard LH{sub 2} storage vessels, piping and instrumentation, (b) implementation of storage and refueling infrastructure in the operators' yards, (c) adaptation of the maintenance garages, (d) training of operating and maintenance personnel. During phase II of the demonstration activity a poll was performed on passengers traveling onboard the hydrogen-powered city bus in order to determined the level of acceptance among the users of the bus. The bus was designed and manufactured by MAN Nutzfahrzeuge Aktiengesellschaft. The cryogenic fuel storage and the refueling equipment were designed and manufactured by Linde AG. The realization of the hardware was financially supported by the European Commission (EC) within the Euro-Quebec Hydro-Hydrogen Pilot Project. The demonstration phase was financially supported by EC and the Bavarian State Government. Ludwig-Boelkow-Systemtechnik performed project monitoring for both funding organizations. The presentation will summarize the most important results of this demonstration phase and will address the measures undertaken in order to get the bus, the refueling infrastructure and the maintenance and operating procedures approved by the relevant authorities.

  3. Recycling the liquid fraction of alkaline hydrogen peroxide in the pretreatment of corn stover.

    Science.gov (United States)

    Alencar, Bárbara Ribeiro Alves; Reis, Alexandre Libanio Silva; de Souza, Raquel de Fatima Rodrigues; Morais, Marcos Antônio; Menezes, Rômulo Simões Cezar; Dutra, Emmanuel Damilano

    2017-10-01

    The aim of this study was to evaluate the influence of recycling the liquid fraction of pretreatment with alkaline hydrogen peroxide (AHP) on the hydrolysis of corn stover. Corn stover was pretreated in the traditional condition with 7.5% v/v H 2 O 2 . After pretreatment, the solids were separated from the liquid fraction and five successive reuse cycles of the liquid fraction were tested. The solid fraction from pretreatment in each recycle was submitted to enzymatic hydrolysis. The number of recycles had a linear negative effect (R 2 =0.98) on biomass delignification efficiency and also affected negatively the enzymatic conversion efficiency. Despite the decrease in efficiency after each recycling step, reuse of the liquid fraction leads to reduction in water, H 2 O 2 and NaOH consumption of up to 57.6%, 59.6% and 57.6%, respectively. These findings point to an efficient recycling technology, which may reduce costs and save water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Automatic regulation of liquid- and vapor-phase chambers in hydrogenation at the Leuna Plant

    Energy Technology Data Exchange (ETDEWEB)

    1944-01-23

    A chronological survey is given of the development and implementation of automatic regulation at Leuna. The first such apparatus introduced was a regulator for liquid level in a vessel used for allowing gases to escape from the sludge coming from the product separator of liquid-phase hydrogenation of brown coal. Next was developed a compressed-air-operated regulator for liquid level in the product separator itself. Next came a time-and-temperature regulated automatic valve for removing sand from oven I of the liquid-phase chambers. In order to measure and regulate the flow of liquid product under high pressure, there was developed a meter combining electric-pneumatic and photoelectric elements together with a specially-developed membrane-regulated valve structure, which seemed to be a great improvement in accuracy and dependability over previous valve structures. The electric-pneumatic valve apparatus mentioned above was also used in regulating reaction-oven temperature by regulating the rate of injection of cold gas into the oven to reduce the temperature built up by the exothermic reaction; temperature measurement was done by resistance thermometers. Another use for the electric-pneumatic valve apparatus was in the regulation of liquid level in intermediate seprator vessels; an improved design for cartridge valves was involved in such regulators. The arrangement of certain similar components of these regulators in a central location together with simple compressed-air connections to other operating components of the separate regulators is described. The compressed-air system using several different pressures used to operatethe regulators, is also considered. 10 diagrams, 1 table.

  5. Critical Current Test of Liquid Hydrogen Cooled HTC Superconductors under External Magnetic Field

    Science.gov (United States)

    Shirai, Yasuyuki; Shiotsu, Masahiro; Tatsumoto, Hideki; Kobayashi, Hiroaki; Naruo, Yoshihiro; Nonaka, Satoshi; Inatani, Yoshifumi

    High-Tc (HTC) superconductors including MgB2 will show excellent properties under temperature of Liquid Hydrogen (LH2:20K), which has large latent heat and low viscosity coefficient. In order to design and fabricate the LH2 cooled superconducting energy devices, we must clear the cooling property of LH2 for superconductors, the cooling system and safety design of LH2 cooled superconducting devices and electro-magnetic property evaluation of superconductors (BSCCO, REBCO and MgB2) and their magnets cooled by LH2. As the first step of the study, an experimental setup which can be used for investigating heat transfer characteristics of LH2 in a pool and also in forced flow (circulation loop with a pump), and also for evaluation of electro-magnetic properties of LH2 cooled superconductors under external magnetic field (up to 7 T). In this paper, we will show a short sketch of the experimental set-up, practical experiences in safety operation of liquid hydrogen cooling system and example test results of critical current evaluation of HTC superconductors cooled by LH2.

  6. On the dissociative electron attachment as a potential source of molecular hydrogen in irradiated liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Cobut, V.; Jay-Gerin, J.-P.; Frongillo, Y. [Sherbrooke Univ., PQ (Canada). Faculte de Medecine; Patau, J.P. [Toulouse-3 Univ., 31 (France)

    1996-02-01

    In the radiolysis of liquid water, different mechanisms for the formation of molecular hydrogen (H{sub 2}) are involved at different times after the initial energy disposition. It has been suggested that the contributions of the e{sub aq}{sup -} + e{sub aq}{sup -}, H + e{sub aq}{sup -} and H + H reactions between hydrated electrons (e{sub aq}{sup -}) and hydrogen atoms in the spurs are not sufficient to account for all of the observed H{sub 2} yield (0.45 molecules/100 eV) on the microsecond time scale. Addressing the question of the origin of an unscavengeable H{sub 2} yield of 0.15 molecules/100 eV produced before spur expansion, we suggest that the dissociative capture of the so-called vibrationally-relaxing electrons by H{sub 2}O molecules is a possible pathway for the formation of part of the initial H{sub 2} yield. Comparison of recent dissociative-electron-attachment H{sup -}-anion yield-distribution measurements from amorphous H{sub 2}O films with the energy spectrum of vibrationally-relaxing electrons in irradiated liquid water, calculated by Monte Carlo simulations, plays in favor of this hypothesis. (author).

  7. Design of a reconfigurable liquid hydrogen fuel tank for use in the Genii unmanned aerial vehicle

    Science.gov (United States)

    Adam, Patrick; Leachman, Jacob

    2014-01-01

    Long endurance flight, on the order of days, is a leading flight performance characteristic for Unmanned Aerial Vehicles (UAVs). Liquid hydrogen (LH2) is well suited to providing multi-day flight times with a specific energy 2.8 times that of conventional kerosene based fuels. However, no such system of LH2 storage, delivery, and use is currently available for commercial UAVs. In this paper, we develop a light weight LH2 dewar for integration and testing in the proton exchange membrane (PEM) fuel cell powered, student designed and constructed, Genii UAV. The fuel tank design is general for scaling to suit various UAV platforms. A cylindrical vacuum-jacketed design with removable end caps was chosen to incorporate various fuel level gauging, pressurizing, and slosh mitigation systems. Heat and mechanical loadings were modeled to compare with experimental results. Mass performance of the fuel tank is characterized by the fraction of liquid hydrogen to full tank mass, and the insulation performance was characterized by effective thermal conductivity and boil-off rate.

  8. Application of Liquid Hydrogen with SMES for Efficient Use of Renewable Energy in the Energy Internet

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2017-02-01

    Full Text Available Considering that generally frequency instability problems occur due to abrupt variations in load demand growth and power variations generated by different renewable energy sources (RESs, the application of superconducting magnetic energy storage (SMES may become crucial due to its rapid response features. In this paper, liquid hydrogen with SMES (LIQHYSMES is proposed to play a role in the future energy internet in terms of its combination of the SMES and the liquid hydrogen storage unit, which can help to overcome the capacity limit and high investment cost disadvantages of SMES. The generalized predictive control (GPC algorithm is presented to be appreciatively used to eliminate the frequency deviations of the isolated micro energy grid including the LIQHYSMES and RESs. A benchmark micro energy grid with distributed generators (DGs, electrical vehicle (EV stations, smart loads and a LIQHYSMES unit is modeled in the Matlab/Simulink environment. The simulation results show that the proposed GPC strategy can reschedule the active power output of each component to maintain the stability of the grid. In addition, in order to improve the performance of the SMES, a detailed optimization design of the superconducting coil is conducted, and the optimized SMES unit can offer better technical advantages in damping the frequency fluctuations.

  9. Liquid-phase Hydrogenation of Phenol to Cyclohexanone over Supported Palladium Catalysts

    Directory of Open Access Journals (Sweden)

    Lihui Fan

    2016-10-01

    Full Text Available The ZSM-5, g-Al2O3, SiO2 and MgO supported Pd-catalysts were prepared for the phenol hydrogenation to cyclohexanone in liquid-phase. The natures of these catalysts were characterized by XRD, N2 adsorption-desorption analysis, H2-TPR, CO2-TPD and NH3-TPD. The catalytic performance of the supported Pd-catalyst for phenol hydrogenation to cyclohexanone is closely related to nature of the support and the size of Pd nanoparticles. The Pd/MgO catalyst which possesses higher basicity shows higher cyclohexanone selectivity, but lower phenol conversion owing to the lower specific surface area. The Pd/SiO2 catalyst prepared by precipitation gives higher cyclohexanone selectivity and phenol conversion, due to the moderate amount of Lewis acidic sites, and the smaller size and higher dispersion of Pd nanoparticles on the surface. Under the reaction temperature of 135 oC and H2 pressure of 1 MPa, after reacting for 3.5 h, the phenol conversion of 71.62% and the cyclohexanone selectivity of 90.77% can be obtained over 0.5 wt% Pd/SiO2 catalyst. Copyright © 2016 BCREC GROUP. All rights reserved Received: 7th March 2016; Revised: 13rd May 2016; Accepted: 7th June 2016 How to Cite: Fan, L., Zhang, L., Shen, Y., Liu, D., Wahab, N., Hasan, M.M. (2016. Liquid-phase Hydrogenation of Phenol to Cyclohexanone over Supported Palladium Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (3: 354-362 (doi: 10.9767/bcrec.11.3.575.354-362 Permalink/DOI: http://doi.org/10.9767/bcrec.11.3.575.354-362

  10. Development of a Practical Hydrogen Storage System Based on Liquid Organic Hydrogen Carriers and a Homogeneous Catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Craig [Hawaii Hydrogen Carriers, LLC, Honolulu, HI (United States); Brayton, Daniel [Hawaii Hydrogen Carriers, LLC, Honolulu, HI (United States); Jorgensen, Scott W. [General Motors, LLC, Warren, MI (United States). Research and Development Center. Chemical and Material Systems Lab.; Hou, Peter [General Motors, LLC, Warren, MI (United States). Research and Development Center. Chemical and Material Systems Lab.

    2017-03-24

    The objectives of this project were: 1) optimize a hydrogen storage media based on LOC/homogeneous pincer catalyst (carried out at Hawaii Hydrogen Carriers, LLC) and 2) develop space, mass and energy efficient tank and reactor system to house and release hydrogen from the media (carried out at General Motor Research Center).

  11. Characterization of electrochemically deposited films from aqueous and ionic liquid cobalt precursors toward hydrogen evolution reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dushatinski, Thomas; Huff, Clay; Abdel-Fattah, Tarek M., E-mail: fattah@cnu.edu

    2016-11-01

    Highlights: • Co films deposition via aqueous and ionic liquid Precursors. • Hydrogen evolution produced from reactive surfaces. • Co deposited films characterized by SEM, AFM, EDX and XRD techniques. - Abstract: Electrodepositions of cobalt films were achieved using an aqueous or an ethylene glycol based non-aqueous solution containing choline chloride (vitamin B4) with cobalt chloride hexahydrate precursor toward hydrogen evolution reactions from sodium borohydride (NaBH{sub 4}) as solid hydrogen feedstock (SHF). The resulting cobalt films had reflectivity at 550 nm of 2.2% for aqueously deposited films (ACoF) and 1.3% for non-aqueously deposited films (NCoF). Surface morphology studied by scanning electron microscopy showed a positive correlation between particle size and thickness. The film thicknesses were tunable between >100 μm and <300 μm for each film. The roughness (Ra) value measurements by Dektak surface profiling showed that the NCoF (Ra = 165 nm) was smoother than the ACoF (Ra = 418 nm). The NCoFs and ACoFs contained only α phase (FCC) crystallites. The NCoFs were crystalline while the ACoFs were largely amorphous from X-ray diffraction analysis. The NCoF had an average Vickers hardness value of 84 MPa as compared to 176 MPa for ACoF. The aqueous precursor has a single absorption maximum at 510 nm and the non-aqueous precursor had three absorption maxima at 630, 670, and 695 nm. The hydrogen evolution reactions over a 1 cm{sup 2} catalytic surface with aqueous NaBH{sub 4} solutions generated rate constants (K) = equal to 4.9 × 10{sup −3} min{sup −1}, 4.6 × 10{sup −3} min{sup −1}, and 3.3 × 10{sup −3} min{sup −1} for ACoF, NCoF, and copper substrate respectively.

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

    Science.gov (United States)

    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.

  13. Molecular Dynamics Simulations of Small Clusters and Liquid Hydrogen Sulfide at Different Thermodynamic Conditions.

    Science.gov (United States)

    Albertí, M; Amat, A; Aguilar, A; Pirani, F

    2016-07-14

    A new force field for the intermolecular H2S-H2S interaction has been used to study the most relevant properties of the hydrogen sulfide system from gaseous to liquid phases by means of molecular dynamics (MD) simulations. In order to check the validity of the interaction formulation, ab initio CCSD(T)/aug-cc-pVTZ calculations, including the counterpoise correction on the H2S, (H2S)2, and (H2S)3 structures optimized at the MP2/aug-cc-pVDZ level, have been performed. The (H2S)2,3 systems have been characterized by performing NVE MD simulations at decreasing values of the temperature, while the liquid sulfide behavior has been investigated considering a NpT ensemble of 512 molecules at several thermodynamic states, defined by different pressure and temperature values. Additional calculations using an ensemble of 2197 molecules at two different temperatures have been performed to investigate the liquid/vapor interface of the system. The S-S, S-H, and H-H radial distribution functions and the coordination number, calculated at the same conditions used in X-ray and neutron diffraction experiments, and the evaluated thermodynamic and structural properties have been compared successfully with experimental data, thus confirming the reliability of the force field formulation and of the MD predictions.

  14. Intensity enhancement of cold neutrons from a coupled liquid-hydrogen moderator for pulsed cold neutron sources

    CERN Document Server

    Ogawa, Y; Kosugi, N; Iwasa, H; Furusaka, M; Watanabe, N

    1999-01-01

    In order to obtain higher cold neutron intensity from a coupled liquid-hydrogen moderator with a premoderator for pulsed cold neutron sources, we examined a partial enhancement method, namely, narrow beam extraction for both a flat liquid-hydrogen moderator and a single-groove one. Combined with the narrow beam extraction, which is especially suitable for small-angle scattering and neutron reflectometry experiments, a single-groove moderator provides higher intensity, by about 30%, than a flat-surface moderator at the region of interest on a viewed surface. The effect of double-side beam extraction from such moderators on the intensity gain factor is also discussed. (author)

  15. Liquid Hydrogen Propellant Tank Sub-Surface Pressurization with Gaseous Helium

    Science.gov (United States)

    Stephens, J. R.; Cartagena, W.

    2015-01-01

    A series of tests were conducted to evaluate the performance of a propellant tank pressurization system with the pressurant diffuser intentionally submerged beneath the surface of the liquid. Propellant tanks and pressurization systems are typically designed with the diffuser positioned to apply pressurant gas directly into the tank ullage space when the liquid propellant is settled. Space vehicles, and potentially propellant depots, may need to conduct tank pressurization operations in micro-gravity environments where the exact location of the liquid relative to the diffuser is not well understood. If the diffuser is positioned to supply pressurant gas directly to the tank ullage space when the propellant is settled, then it may become partially or completely submerged when the liquid becomes unsettled in a microgravity environment. In such case, the pressurization system performance will be adversely affected requiring additional pressurant mass and longer pressurization times. This series of tests compares and evaluates pressurization system performance using the conventional method of supplying pressurant gas directly to the propellant tank ullage, and then supplying pressurant gas beneath the liquid surface. The pressurization tests were conducted on the Engineering Development Unit (EDU) located at Test Stand 300 at NASA Marshall Space Flight Center (MSFC). EDU is a ground based Cryogenic Fluid Management (CFM) test article supported by Glenn Research Center (GRC) and MSFC. A 150 ft3 propellant tank was filled with liquid hydrogen (LH2). The pressurization system used regulated ambient helium (GHe) as a pressurant, a variable position valve to maintain flow rate, and two identical independent pressurant diffusers. The ullage diffuser was located in the forward end of the tank and was completely exposed to the tank ullage. The submerged diffuser was located in the aft end of the tank and was completely submerged when the tank liquid level was 10% or greater

  16. Decreasing the Viscosity in CO2 Capture by Amino-Functionalized Ionic Liquids through the Formation of Intramolecular Hydrogen Bond.

    Science.gov (United States)

    Luo, Xiao Y; Fan, Xi; Shi, Gui L; Li, Hao R; Wang, Cong M

    2016-03-17

    A strategy for decreasing the viscosity variation in the process of CO2 capture by amino-functionalized ionic liquids (ILs) through the formation of intramolecular hydrogen bond was reported. Different with the dramatic increase in viscosity during CO2 uptake by traditional amino-functionalized ILs, slight increase or even decrease in viscosity was achieved through introducing a N or O atom as hydrogen acceptor into amino-functionalized anion, which could stabilize the active hydrogen of produced carbamic acid. Quantum chemical calculations and spectroscopic investigations demonstrated that the formation of intramolecular hydrogen bond between introduced hydrogen acceptor and carbamic acid was the key to avoid the dramatic increase in viscosity during the capture of CO2 by these amino-functionalized ILs.

  17. Changing Hydrogen-Bond Structure during an Aqueous Liquid-Liquid Transition Investigated with Time-Resolved and Two-Dimensional Vibrational Spectroscopy.

    Science.gov (United States)

    Bruijn, Jeroen R; van der Loop, Tibert H; Woutersen, Sander

    2016-03-03

    We investigate the putative liquid-liquid phase transition in aqueous glycerol solution, using the OD-stretch mode in dilute OD/OH isotopic mixtures to probe the hydrogen-bond structure. The conversion exhibits Avrami kinetics with an exponent of n = 2.9 ± 0.1 (as opposed to n = 1.7 observed upon inducing ice nucleation and growth in the same sample), which indicates a transition from one liquid phase to another. Two-dimensional infrared (2D-IR) spectroscopy shows that the initial and final phases have different hydrogen-bond structures: the former has a single Gaussian distribution of hydrogen-bond lengths, whereas the latter has a bimodal distribution consisting of a broad distribution and a narrower, ice-like distribution. The 2D-IR spectrum of the final phase is identical to that of ice/glycerol at the same temperature. Combined with the kinetic data this suggests that the liquid-liquid transformation is immediately followed by a rapid formation of small (probably nanometer-sized) ice crystals.

  18. Hazards Induced by Breach of Liquid Rocket Fuel Tanks: Conditions and Risks of Cryogenic Liquid Hydrogen-Oxygen Mixture Explosions

    CERN Document Server

    Osipov, Viatcheslav; Hafiychuk, Halyna; Ponizovskaya-Devine, Ekaterina; Smelyanskiy, Vadim; Mathias, Donovan; Lawrence, Scott; Werkheiser, Mary

    2010-01-01

    We analyze the data of purposeful rupture experiments with LOx and LH2 tanks, the Hydrogen-Oxygen Vertical Impact (HOVI) tests that were performed to clarify the ignition mechanisms, the explosive power of cryogenic H2/Ox mixtures under different conditions, and to elucidate the puzzling source of the initial formation of flames near the intertank section during the Challenger disaster. We carry out a physics-based analysis of general explosions scenarios for cryogenic gaseous H2/Ox mixtures and determine their realizability conditions, using the well-established simplified models from the detonation and deflagration theory. We study the features of aerosol H2/Ox mixture combustion and show, in particular, that aerosols intensify the deflagration flames and can induce detonation for any ignition mechanism. We propose a cavitation-induced mechanism of self-ignition of cryogenic H2/Ox mixtures that may be realized when gaseous H2 and Ox flows are mixed with a liquid Ox turbulent stream, as occurred in all HOVI ...

  19. Sodium-ion electrolytes based on ionic liquids: a role of cation-anion hydrogen bonding.

    Science.gov (United States)

    Chaban, Vitaly V; Andreeva, Nadezhda A

    2016-08-01

    Recent success of the sodium-ion batteries fosters an academic interest for their investigation. Room-temperature ionic liquids (RTILs) constitute universal solvents providing non-volatility and non-flammability to electrolytes. In the present work, we consider four families of RTILs as prospective solvents for NaBF4 and NaNO3 with an inorganic salt concentration of 25 and 50 mol%. We propose a methodology to rate RTILs according to their solvation capability using parameters of the computed radial distribution functions. Hydrogen bonds between the cations and the anions of RTILs were found to indirectly favor sodium solvation, irrespective of the particular RTIL and its concentration. The best performance was recorded in the case of cholinium nitrate. The reported observations and correlations of ionic structures and properties offer important assistance to an emerging field of sodium-ion batteries. Graphical Abstract Sodium-ion electrolytes.

  20. Fail-safe system for activity cooled supersonic and hypersonic aircraft. [using liquid hydrogen fuel

    Science.gov (United States)

    Jones, R. A.; Braswell, D. O.; Richie, C. B.

    1975-01-01

    A fail-safe-system concept was studied as an alternative to a redundant active cooling system for supersonic and hypersonic aircraft which use the heat sink of liquid-hydrogen fuel for cooling the aircraft structure. This concept consists of an abort maneuver by the aircraft and a passive thermal protection system (TPS) for the aircraft skin. The abort manuever provides a low-heat-load descent from normal cruise speed to a lower speed at which cooling is unnecessary, and the passive TPS allows the aircraft skin to absorb the abort heat load without exceeding critical skin temperature. On the basis of results obtained, it appears that this fail-safe-system concept warrants further consideration, inasmuch as a fail-safe system could possibly replace a redundant active cooling system with no increase in weight and would offer other potential advantages.

  1. Study of Thermodynamic Vent and Screen Baffle Integration for Orbital Storage and Transfer of Liquid Hydrogen

    Science.gov (United States)

    Cady, E. C.

    1973-01-01

    A comprehensive analytical and experimental program was performed to determine the feasibility of integrating an internal thermodynamic vent system and a full wall-screen liner for the orbital storage and transfer of liquid hydrogen (LH2). Ten screens were selected from a comprehensive screen survey. The experimental study determined the screen bubble point, flow-through pressure loss, and pressure loss along rectangular channels lined with screen on one side, for the 10 screens using LH2 saturated at 34.5 N/cm2 (50 psia). The correlated experimental data were used in an analysis to determine the optimum system characteristics in terms of minimum weight for 6 tanks ranging from 141.6 m3 (5,000 ft3) to 1.416 m3 (50 ft3) for orbital storage times of 30 and 300 days.

  2. Solar Thermal Upper Stage Liquid Hydrogen Pressure Control Testing and Analytical Modeling

    Science.gov (United States)

    Olsen, A. D.; Cady, E. C.; Jenkins, D. S.; Chandler, F. O.; Grayson, G. D.; Lopez, A.; Hastings, L. J.; Flachbart, R. H.; Pedersen, K. W.

    2012-01-01

    The demonstration of a unique liquid hydrogen (LH2) storage and feed system concept for solar thermal upper stage was cooperatively accomplished by a Boeing/NASA Marshall Space Flight Center team. The strategy was to balance thermodynamic venting with the engine thrusting timeline during a representative 30-day mission, thereby, assuring no vent losses. Using a 2 cubic m (71 cubic ft) LH2 tank, proof-of-concept testing consisted of an engineering checkout followed by a 30-day mission simulation. The data were used to anchor a combination of standard analyses and computational fluid dynamics (CFD) modeling. Dependence on orbital testing has been incrementally reduced as CFD codes, combined with standard modeling, continue to be challenged with test data such as this.

  3. Low-Temperature Carrier Transport in Ionic-Liquid-Gated Hydrogen-Terminated Silicon

    Science.gov (United States)

    Sasama, Yosuke; Yamaguchi, Takahide; Tanaka, Masashi; Takeya, Hiroyuki; Takano, Yoshihiko

    2017-11-01

    We fabricated ionic-liquid-gated field-effect transistors on the hydrogen-terminated (111)-oriented surface of undoped silicon. Ion implantation underneath electrodes leads to good ohmic contacts, which persist at low temperatures down to 1.4 K. The sheet resistance of the channel decreases by more than five orders of magnitude as the gate voltage is changed from 0 to -1.6 V at 220 K. This is caused by the accumulation of hole carriers. The sheet resistance shows thermally activated behavior at temperatures below 10 K, which is attributed to hopping transport of the carriers. The activation energy decreases towards zero with increasing carrier density, suggesting the approach to an insulator-metal transition. We also report the variation of device characteristics induced by repeated sweeps of the gate voltage.

  4. Evaluation of mechanical property data on the 2219 aluminum alloy and application of the data to the design of liquid hydrogen tankage

    Science.gov (United States)

    Witzell, W. E.

    1977-01-01

    The potential use of thin guage 2219 aluminum alloy for airborne liquid hydrogen tankage was examined. Existing data were processed using the Newman two parameter equation, a prediction was made for the life expectancy of a hypothetical liquid hydrogen tank, and additional experimental data were generated in an attempt to correct the deficiencies in the existing data.

  5. Large-Scale Liquid Hydrogen Testing of Variable Density Multilayer Insulation with a Foam Substrate

    Science.gov (United States)

    Martin, J. J.; Hastings, L.

    2001-01-01

    The multipurpose hydrogen test bed (MHTB), with an 18-cu m liquid hydrogen tank, was used to evaluate a combination foam/multilayer combination insulation (MLI) concept. The foam element (Isofoam SS-1171) insulates during ground hold/ascent flight, and allowed a dry nitrogen purge as opposed to the more complex/heavy helium purge subsystem normally required. The 45-layer MLI was designed for an on-orbit storage period of 45 days. Unique WI features include a variable layer density, larger but fewer double-aluminized Mylar perforations for ascent to orbit venting, and a commercially established roll-wrap installation process that reduced assembly man-hours and resulted in a roust, virtually seamless MLI. Insulation performance was measured during three test series. The spray-on foam insulation (SOFI) successfully prevented purge gas liquefaction within the MLI and resulted in the expected ground hold heat leak of 63 W/sq m. The orbit hold tests resulted in heat leaks of 0.085 and 0.22 W/sq m with warm boundary temperatures of 164 and 305 K, respectively. Compared to the best previously measured performance with a traditional MLI system, a 41-percent heat leak reduction with 25 fewer MLI layers was achieved. The MHTB MLI heat leak is half that calculated for a constant layer density MLI.

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

    Science.gov (United States)

    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.

  7. Observation of the slow, Debye-like relaxation in hydrogen-bonded liquids by dynamic light scattering.

    Science.gov (United States)

    Wang, Yangyang; Griffin, Philip J; Holt, Adam; Fan, Fei; Sokolov, Alexei P

    2014-03-14

    The slow, Debye-like relaxation in hydrogen-bonded liquids has largely remained a dielectric phenomenon and has thus far eluded observation by other experimental techniques. Here we report the first observation of a slow, Debye-like relaxation by both depolarized dynamic light scattering (DLS) and dielectric spectroscopy in a model hydrogen-bonded liquid, 2-ethyl-4-methylimidazole (2E4MIm). The relaxation times obtained by these two techniques are in good agreement and can be well explained by the Debye model of rotational diffusion. On the one hand, 2E4MIm is analogous to the widely studied monohydroxy alcohols in which transient chain-like supramolecular structure can be formed by hydrogen bonding. On the other hand, the hydrogen-bonded backbone of 2E4MIm is much more optically polarizable, making it possible to apply light scattering to study the dynamics of the supramolecular structure. These findings provide the missing evidence of the slow, Debye-like relaxation in DLS and open the venue for the application of dynamic light scattering to the study of supramolecular structures in hydrogen-bonded liquids.

  8. Hydrogen utilization international clean energy system technology (WE-NET). Subtask 5. Development of technology of hydrogen transportation/storage (3rd edition, development of liquid hydrogen storage equipment, report on results of Air Liquide); Suiso riyo kokusai clean energy system gijutsu (WE-NET). Subtask 5. Suiso yuso chozo gijutsu no kaihatsu (daisanpen ekitai suiso chozo setsubi no kaihatsu Air Liquide sha seika hokoku)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    In the fiscal 1995 study, items were searched which are keys to the design of a liquid hydrogen tanker of a capacity of 200,000m{sup 3}. Among those, the basic concepts were summarized which are necessary for the design of a liquid hydrogen tanker in terms of safety, and the extraporation of the existing low temperature technology into the large liquid hydrogen tank was studied. When adopting safety conditions of IGC Code applied to LNG to the liquid hydrogen tanker, it is necessary to limit the discharge amount of hydrogen to 3 kg/s. When considering safety at fire, for keeping safety of the same level as that of the LNG tanker, it is not appropriate to adopt the conventional vacuum insulation liquid hydrogen tank. In the fiscal 1995 study, 7 kinds of concept of the insulation structure were assumed, and it was concluded that BOR of 0.04-0.23/d was obtained. Also in fiscal 1996, the large liquid hydrogen tank was studied. For insulation of the large liquid hydrogen tank, the structure is most promising where AEROSIL bag or homogeneous AEROSIL is substituted for a forming heat insulating material of 4 design, but further study is needed for selection of the optimum heat insulating structure. 9 figs., 6 tabs.

  9. The effect of a micro bubble dispersed gas phase on hydrogen isotope transport in liquid metals under nuclear irradiation

    CERN Document Server

    Fradera, Jorge

    2013-01-01

    The present work intend to be a first step towards the understanding and quantification of the hydrogen isotope complex phenomena in liquid metals for nuclear technology. Liquid metals under nuclear irradiation in,e.g., breeding blankets of a nuclear fusion reactor would generate tritium which is to be extracted and recirculated as fuel. At the same time that tritium is bred, helium is also generated and may precipitate in the form of nano bubbles. Other liquid metal systems of a nuclear reactor involve hydrogen isotope absorption processes, e.g., tritium extraction system. Hence, hydrogen isotope absorption into gas bubbles modelling and control may have a capital importance regarding design, operation and safety. Here general models for hydrogen isotopes transport in liquid metal and absorption into gas phase, that do not depend on the mass transfer limiting regime, are exposed and implemented in OpenFOAMR CFD tool for 0D to 3D simulations. Results for a 0D case show the impact of a He dispersed phase of na...

  10. Modeling the vapor-liquid equilibria of polymer-solvent mixtures: Systems with complex hydrogen bonding behavior

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Kontogeorgis, Georgios

    2009-01-01

    The vapor–liquid equilibria of binary polymer–solvent systems was modeled using the Non-Random Hydrogen Bonding (NRHB) model. Mixtures of poly(ethylene glycol), poly(propylene glycol), poly(vinyl alcohol) and poly(vinyl acetate) with various solvents were investigated, while emphasis was put on h...

  11. Design and prototyping of an ionic liquid piston compressor as a new generation of compressors for hydrogen refueling stations

    DEFF Research Database (Denmark)

    Arjomand Kermani, Nasrin

    to investigate the heat transfer phenomena inside the compression chamber; the system performance is evaluated, followed by the design process. The model is developed based on the mass and energy balance of the hydrogen, and liquid bounded by the wall of the compression chamber. Therefore, at each time step...... that depending on the heat transfer correlation, the hydrogen temperature reduces slightly between 0.2 and 0.4% compared to the adiabatic case, at 500 bar. The main reasons for the small temperature reduction are the large wall resistance and the small contact area at the interface. Moreover, the results......) or at the wall (200 times), leads to 22 % or 33% reduction of the hydrogen temperature, compared to the adiabatic case, at 500 bar, during 3.5 seconds compression, respectively. A suitable ionic liquid is selected as the most reliable replacement for the solid piston in the conventional reciprocating compressors...

  12. C1 CHEMISTRY FOR THE PRODUCTION OF ULTRA-CLEAN LIQUID TRANSPORTATION FUELS AND HYDROGEN

    Energy Technology Data Exchange (ETDEWEB)

    Gerald P. Huffman

    2003-09-30

    The Consortium for Fossil Fuel Science (CFFS) is a research consortium with participants from the University of Kentucky, University of Pittsburgh, University of Utah, West Virginia University, and Auburn University. The CFFS is conducting a research program to develop C1 chemistry technology for the production of clean transportation fuel from resources such as coal and natural gas, which are more plentiful domestically than petroleum. The processes under development will convert feedstocks containing one carbon atom per molecular unit into ultra clean liquid transportation fuels (gasoline, diesel, and jet fuel) and hydrogen, which many believe will be the transportation fuel of the future. These feedstocks include synthesis gas, a mixture of carbon monoxide and hydrogen produced by coal gasification or reforming of natural gas, methane, methanol, carbon dioxide, and carbon monoxide. Some highlights of the results obtained during the first year of the current research contract are summarized as: (1) Terminal alkynes are an effective chain initiator for Fischer-Tropsch (FT) reactions, producing normal paraffins with C numbers {ge} to that of the added alkyne. (2) Significant improvement in the product distribution towards heavier hydrocarbons (C{sub 5} to C{sub 19}) was achieved in supercritical fluid (SCF) FT reactions compared to that of gas-phase reactions. (3) Xerogel and aerogel silica supported cobalt catalysts were successfully employed for FT synthesis. Selectivity for diesel range products increased with increasing Co content. (4) Silicoaluminophosphate (SAPO) molecular sieve catalysts have been developed for methanol to olefin conversion, producing value-added products such as ethylene and propylene. (5) Hybrid Pt-promoted tungstated and sulfated zirconia catalysts are very effective in cracking n-C{sub 36} to jet and diesel fuel; these catalysts will be tested for cracking of FT wax. (6) Methane, ethane, and propane are readily decomposed to pure

  13. An overview of dehydration, aldol-condensation and hydrogenation processes for production of liquid alkanes from biomass-derived carbohydrates

    Energy Technology Data Exchange (ETDEWEB)

    Chheda, Juben N.; Dumesic, James A. [University of Wisconsin-Madison, Department of Chemical and Biological Engineering, Madison, WI 53706 (United States)

    2007-05-30

    We present results for the conversion of carbohydrate feedstocks to liquid alkanes by the combination of dehydration, aldol-condensation/hydrogenation, and dehydration/hydrogenation processing. With respect to the first dehydration step, we demonstrate that HMF can be produced in good selectivity from abundantly available polysaccharides (such as inulin, sucrose) containing fructose monomer units using a biphasic batch reactor system. The reaction system can be optimized to achieve good yields to 5-hydroxymethylfurfural (HMF) from fructose by varying the contents of aqueous-phase modifiers such as dimethylsulfoxide (DMSO) and 1-methyl-2-pyrrolidinone (NMP). Regarding the aldol-condensation/hydrogenation step, we present the development of stable, solid base catalysts in aqueous environments. We address the effects of various reaction parameters such as the molar ratio of reactants and temperature on overall product yield for sequential aldol-condensation and hydrogenation steps. Overall, our results show that it is technically possible to convert carbohydrate feedstocks to produce liquid alkanes by the combination of dehydration, aldol-condensation/hydrogenation, and dehydration/hydrogenation processing; however, further optimization of these processes is required to decrease the overall number of separate steps (and reactors) required in this conversion. (author)

  14. Hydrogen bonding interactions in nicotinamide Ionic Liquids: A comparative spectroscopic and DFT studies

    Science.gov (United States)

    Shukla, Madhulata

    2017-03-01

    Being biodegradable in nature nicotinamide based Ionic Liquids (ILs) are gaining much attention now a day. Nicotinamide iodide (i.e 1-methyl-3ethoxy carbonyl pyridinium iodide (mNicI)) and 1-methyl-3ethoxy carbonyl pyridinium trifilimide (mNicNTf2) new ILs has been synthesized and has been characterized using different spectroscopic techniques like NMR, UV visible and infrared spectroscopy. Theoretical studies have been performed on several nicotinamide ILs. Geometry and spectral features were further characterized by Density Functional Theory (DFT) calculation. NBO charge distribution and electrostatic potential diagram presents in depth knowledge about interactions between cation and anion. A comparative theoretical study between mNicI and its other analogues i. e 1-methyl-3 ethoxy carbonyl pyridinium chloride and bromide i. e mNicCl and mNicBr has also been performed. Csbnd H⋯X hydrogen bonding along with C⋯X interaction has been reported for the first time for the nicotinamide based ILs. C2sbnd H stretching frequency shifts to higher wavenumber with change to a lesser electronegative anion. mNicCl and mNicBr are expected to be solid in nature with the evidence from the red shift in stretching frequency as compared to mNicI. TD-DFT calculation of mNicI proved that pale yellow color of liquid is due to inherent transition from anion to cation.

  15. Modification of a liquid hydrogen tank for integrated refrigeration and storage

    Science.gov (United States)

    Swanger, A. M.; Jumper, K. M.; Fesmire, J. E.; Notardonato, W. U.

    2015-12-01

    The modification and outfitting of a 125,000-liter liquid hydrogen tank was performed to provide integrated refrigeration and storage capability. These functions include zero boil-off, liquefaction, and densification and therefore require provisions for sub-atmospheric tank pressures within the vacuum-jacketed, multilayer insulated tank. The primary structural modification was to add stiffening rings inside the inner vessel. The internal stiffening rings were designed, built, and installed per the ASME Boiler and Pressure Vessel Code, Section VIII, to prevent collapse in the case of vacuum jacket failure in combination with sub-atmospheric pressure within the tank. For the integrated refrigeration loop, a modular, skeleton-type heat exchanger, with refrigerant temperature instrumentation, was constructed using the stiffening rings as supports. To support the system thermal performance testing, three custom temperature rakes were designed and installed along the 21-meter length of the tank, once again using rings as supports. The temperature rakes included a total of 20 silicon diode temperature sensors mounted both vertically and radially to map the bulk liquid temperature within the tank. The tank modifications were successful and the system is now operational for the research and development of integrated refrigeration technology.

  16. A very light and thin liquid hydrogen/deuterium heat pipe target for COSY experiments

    Science.gov (United States)

    Abdel-Bary, M.; Abdel-Samad, S.; Kilian, K.

    2005-07-01

    A liquid hydrogen/deuterium heat pipe (HP) target is used at the COSY external experiments TOF, GEM and MOMO. The target liquid is produced at a cooled condenser and guided through a central tube assisted by gravitation into the target cell. An aluminum condenser is used instead of copper, which requires less material, improves conductivities and provides shorter cooling down time. Residual condenser temperature fluctuations in the order of ≈0.4 K are reduced by using thermal resistances between the cooling machine and the condenser of the heat pipe combined with a controlled heating power. A new design with only a 7-mm-diameter HP has been developed. The diameter of the condenser part remains at 16 mm to provide enough condensation area. The small amount of material ensures short cooling down times. A cold gas deuterium HP target has been designed and developed which allows protons with energy ⩽1 MeV to be measured. A 7-mm-diameter HP is used to fill a cooling jacket around the D 2 gas cell with LH 2. The D 2 gas is stabilized at 200 mbar to allow for thin windows. Its density is increased by factor 15 compared to room temperature.

  17. Structural and thermotropic peculiarities of hydrogen-bonded liquid crystals confined in mesoporous molecular sieves

    Science.gov (United States)

    Gnatyuk, I.; Gavrilko, T.; Yaroshchuk, O.; Holovina, N.; Shcherban, N.; Baran, J.; Drozd, M.

    2016-12-01

    The phase behaviour and structural organization of hydrogen-bonded liquid crystals were investigated under confinement to mesoporous molecular sieves. As such liquid crystalline compounds, 4-hexylbenzoic and 4-butylcyclohexanecarboxylic acids with different head group structure and alkyl chain length where selected and filled in the AlMCM-41 sieves. With FTIR spectroscopy it was found that some part of incorporated acid molecules, presumably located in the inner space of the AlMCM-41 pores, is in undissociated form of open dimers or chain associates and thus shows spectroscopic features characteristic to the bulk-like species. The other FTIR spectra components indicate strong interaction of the incorporated monomeric molecules with the pore surface. Two specific mechanisms are shown to be involved in molecular interactions at the interface: (1) deprotonation of monomeric acid molecules on the pore surface with formation of COO- carboxylate ions and (2) bonding of these ions to the pore surface by a coordinated bond R-COO-…Al+ with Lewis acid sites. Differential scanning calorimetry revealed that these near-surface processes lead to complete suppression of mesomorphic properties of the studied acids under confinement to nanopores.

  18. Using Aerogel-Based Insulation Material To Prevent Foam Loss on the Liquid-Hydrogen Intertank

    Science.gov (United States)

    2008-01-01

    Uninsulated areas on cryogenic propellant tanks and feedlines cause moisture in the air to condense or ice to form. Flange joints, bracket supports, expansion bellows, and other cavities are uninsulated by design. These areas cannot be sealed because conventional thermal insulation materials would restrict mechanical articulations. Aerogel-based thermal insulation systems are able to seal critical locations such as the liquid-oxygen (LO2) feedline bellows. A new thermal insulation system was also necessary between the intertank wall, flange, and the liquid-hydrogen (LH2) tank dome, where there is a cavity (or crevice) with an exposed 20-K surface. When nitrogen gas is used for purging within the intertank volume, it condenses on this cold surface. Some solid nitrogen may also form on the colder side of the crevice. Voids or discontinuities within the foam can pressurize and cause areas of foam to weaken and break off, reducing thermal efficiency and creating potentially dangerous debris. To prevent this foam loss, we developed a thermal insulation system using bulk-fill aerogel material and demonstrated it with a one-tenth-scale model of the LH2 intertank flange area

  19. Hydrogen in all its states: from solid to gas and liquid; L'hydrogene dans tous ses etats: du solide au gaz en passant par le liquide

    Energy Technology Data Exchange (ETDEWEB)

    Latroche, M.; Joubert, J.M.; Cuevas, F.; Paul-Boncour, V.; Percheron-Guegan, A. [Institut de Chimie et des Materiaux Paris-Est, Chimie Metallurgique des Terres Rares (CMTR-ICMPE-UMR 7182), CNRS, 94 - Thiais (France)

    2007-07-01

    Hydrogen is considered as one of the future energy vector. Several means of hydrogen storage are presented here: physical solutions (compression, liquefaction) and chemical solutions (adsorption in porous solids and absorption in chemical hydrides). Each of these means presents advantages and disadvantages according to economical, energetic, specific capacity, safety and sorption/desorption kinetics criteria. (O.M.)

  20. Conference on results in small (hydrogenation) apparatus with OHW (Blechhammer Hydrogenation Plant) in Ludwigshafen on October 25, 1943. A. Liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Leonhardt

    1943-10-25

    This conference covered experimental results in a 10-liter hydrogenation oven at Ludwigshafen on raw materials which might be used for hydrogenation at Blechhammer; the materials were two different kinds of coal (Myslowitz and Radzionkaugrube) and a mixture of heavy oil with pitch from carbonization tar. Each of the different raw materials was compared to a third type of coal (Beuthen-Heinitz, which possibly was what Blechhammer had been using), in terms of the results of hydrogenation using those raw materials. The Myslowitz coal gave somewhat better yield of gasoline and middle oil (0.31 kg/liter/hour vs. 0.26) and losses to gas formation (22% vs. 27%), but somewhat worse decomposition of coal (93% to 94% vs. 96% to 97%) than did Heinitz coal, and the heavy oil from Myslowitz coal distilled so easily that additional thinning oil had to be added to the sludge residue before processing it. The Radzionkaugrube coal was geologically very similar to the Heinitz coal and their behavior in hydrogenation was also similar. The hydrogenation of heavy oil, even with admixture of pitch, proved to be unfavorable in terms of results in the liquid phase, but might be better in the vapor phase processing.

  1. Liquid-liquid equilibrium constant for acetic acid in an olive oil-epoxidized olive oil-acetic acid-hydrogen peroxide-water system

    Directory of Open Access Journals (Sweden)

    Janković Milovan R.

    2016-01-01

    Full Text Available The liquid-liquid equilibrium constant for acetic acid in a quinary system olive oil-epoxidized olive oil-acetic acid-hydrogen peroxide-water was experimentally determined for temperatures and component ratios relevant for in situ epoxidation of plant oils. The values has the constant range from 1.52 to 2.73. To predict the equilibrium constant for acetic acid, the experimental data were correlated with UNIQUAC (universal quasi chemical and NRTL (non-random two liquid activity coefficient models. For simplified calculation of the phase equilibrium the insolubility of olive oil and epoxidized olive oil in the water, as well as insolubility of water and hydrogen peroxide in the olive oil and epoxidized olive oil, was assumed. The root mean square deviation (RMSD of the experimental and calculated values of the liquid-liquid equilibrium constant for acetic acid is 0.1910 for the UNIQUAC model and 0.1815 for the NRTL model. For rigorous flash calculation, when the partitioning of all components between the phases was assumed, the RMSD for the NRTL model is 0.1749. [Projekat Ministarstva nauke Republike Srbije, br. 45022

  2. Hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M.

    1943-02-19

    A transcript is presented of a speech on the history of the development of hydrogenation of coal and tar. Apparently the talk had been accompanied by the showing of photographic slides, but none of the pictures were included with the report. In giving the history, Dr. Pier mentioned the dependence of much of the development of hydrogenation upon previous development in the related areas of ammonia and methanol syntheses, but he also pointed out several ways in which equipment appropriate for hydrogenation differed considerably from that used for ammonia and methanol. Dr. Pier discussed the difficulties encountered with residue processing, design of the reaction ovens, manufacture of ovens and preheaters, heating of reaction mixtures, development of steels, and development of compressor pumps. He described in some detail his own involvement in the development of the process. In addition, he discussed the development of methods of testing gasolines and other fuels. Also he listed some important byproducts of hydrogenation, such as phenols and polycyclic aromatics, and he discussed the formation of iso-octane fuel from the butanes arising from hydrogenation. In connection with several kinds of equipment used in hydrogenation (whose pictures were being shown), Dr. Pier gave some of the design and operating data.

  3. Solvation of apolar compounds in protic ionic liquids: the non-synergistic effect of electrostatic interactions and hydrogen bonds.

    Science.gov (United States)

    Sedov, I A; Magsumov, T I; Salikov, T M; Solomonov, B N

    2017-09-27

    The solvation properties of protic ionic liquids such as alkylammonium salts are still virtually uncharacterized. Both electrostatic interactions between charged particles and hydrogen bond networks in a solvent are known to hinder the solubility of apolar species. Protic ionic liquids can be a priori expected to dissolve hydrocarbons worse than aprotic ionic liquids which do not form hydrogen bonds between the ions. We measured the limiting activity coefficients of several alkanes and alkylbenzenes in propylammonium and butylammonium nitrates at 298 K. Surprisingly, we observed the tendency of higher solubility than for the same compounds in aprotic ionic liquids with a similar molar volume. The calculations of the excess Gibbs free energies using test particle insertions into the snapshots of molecular dynamics trajectories reproduced lower values in protic rather than in aprotic ionic liquids for both methane molecules and hard sphere solutes. This can be explained by the favorable solvation of apolar species in the apolar domain of nanostructured PILs. For the first time, we point out at the essential difference between the solvation properties of two types of ionic liquids and prove that it arises from the cavity formation term.

  4. Production of hydrogen, liquid fuels, and chemicals from catalytic processing of bio-oils

    Science.gov (United States)

    Huber, George W; Vispute, Tushar P; Routray, Kamalakanta

    2014-06-03

    Disclosed herein is a method of generating hydrogen from a bio-oil, comprising hydrogenating a water-soluble fraction of the bio-oil with hydrogen in the presence of a hydrogenation catalyst, and reforming the water-soluble fraction by aqueous-phase reforming in the presence of a reforming catalyst, wherein hydrogen is generated by the reforming, and the amount of hydrogen generated is greater than that consumed by the hydrogenating. The method can further comprise hydrocracking or hydrotreating a lignin fraction of the bio-oil with hydrogen in the presence of a hydrocracking catalyst wherein the lignin fraction of bio-oil is obtained as a water-insoluble fraction from aqueous extraction of bio-oil. The hydrogen used in the hydrogenating and in the hydrocracking or hydrotreating can be generated by reforming the water-soluble fraction of bio-oil.

  5. Process for detecting and removing small amounts of hydrogen from circulating liquids. Verfahren zum Erkennen und Entfernen geringer Mengen von Wasserstoff aus Fluessigkeitskreislaeufen

    Energy Technology Data Exchange (ETDEWEB)

    Burghoff, H.G.; Gutjahr, M.A.

    1983-04-14

    A process is described for detecting and removing small quantities of hydrogen from circulating liquids, especially from such used for heat control in metal hydride storage tanks. The hydrogen is separated from the circulating liquid by means of a gas-liquid separator, and applied through a first porous wall to an oxyhydrogen recombination catalyst connected to the outside air by a second porous wall. The porous walls have a pore diameter of 0.0001 to 0.1 mm. At the catalyst, hydrogen and oxygen combine to form water. The resulting temperature rise serves the purpose of detecting the presence of hydrogen; at the same time, the escape of hydrogen into the atmosphere is prevented. Even gas bubbles containing as little as 5 cm/sup 3/ of hydrogen can be detected.

  6. On the yield of cold and ultracold neutrons for liquid hydrogen at low temperatures near the melting point

    CERN Document Server

    Morishima, N

    1999-01-01

    The neutron scattering cross sections for liquid hydrogen in the temperature range from the melting point to the boiling point are calculated. It is shown that lowering the temperature results in a significant increase in the yield of cold neutrons: for instance, a 44% increase for an incident neutron energy of 19.4 meV. The major cause of this increment is the para-to-ortho transition of a hydrogen molecule though accompanied by an appreciable increase in the density. The results of the cold- and ultracold-neutron yields are discussed in connection with the experimental results of Altarev et al. at the WWR-M reactor.

  7. Hydrogen production by reforming of liquid hydrocarbons in a membrane reactor for portable power generation-Experimental studies

    Science.gov (United States)

    Damle, Ashok S.

    One of the most promising technologies for lightweight, compact, portable power generation is proton exchange membrane (PEM) fuel cells. PEM fuel cells, however, require a source of pure hydrogen. Steam reforming of hydrocarbons in an integrated membrane reactor has potential to provide pure hydrogen in a compact system. Continuous separation of product hydrogen from the reforming gas mixture is expected to increase the yield of hydrogen significantly as predicted by model simulations. In the laboratory-scale experimental studies reported here steam reforming of liquid hydrocarbon fuels, butane, methanol and Clearlite ® was conducted to produce pure hydrogen in a single step membrane reformer using commercially available Pd-Ag foil membranes and reforming/WGS catalysts. All of the experimental results demonstrated increase in hydrocarbon conversion due to hydrogen separation when compared with the hydrocarbon conversion without any hydrogen separation. Increase in hydrogen recovery was also shown to result in corresponding increase in hydrocarbon conversion in these studies demonstrating the basic concept. The experiments also provided insight into the effect of individual variables such as pressure, temperature, gas space velocity, and steam to carbon ratio. Steam reforming of butane was found to be limited by reaction kinetics for the experimental conditions used: catalysts used, average gas space velocity, and the reactor characteristics of surface area to volume ratio. Steam reforming of methanol in the presence of only WGS catalyst on the other hand indicated that the membrane reactor performance was limited by membrane permeation, especially at lower temperatures and lower feed pressures due to slower reconstitution of CO and H 2 into methane thus maintaining high hydrogen partial pressures in the reacting gas mixture. The limited amount of data collected with steam reforming of Clearlite ® indicated very good match between theoretical predictions and

  8. The Use of Liquid Isopropyl Alcohol and Hydrogen Peroxide Gas Plasma to Biologically Decontaminate Spacecraft Electronics

    Science.gov (United States)

    Bonner, J. K.; Tudryn, Carissa D.; Choi, Sun J.; Eulogio, Sebastian E.; Roberts, Timothy J.; Tudryn, Carissa D.

    2006-01-01

    Legitimate concern exists regarding sending spacecraft and their associated hardware to solar system bodies where they could possibly contaminate the body's surface with terrestrial microorganisms. The NASA approved guidelines for sterilization as set forth in NPG 8020.12C, which is consistent with the biological contamination control objectives of the Committee on Space Research (COSPAR), recommends subjecting the spacecraft and its associated hardware to dry heat-a dry heat regimen that could potentially employ a temperature of 110(deg)C for up to 200 hours. Such a temperature exposure could prove detrimental to the spacecraft electronics. The stimulated growth of intermetallic compounds (IMCs) in metallic interconnects and/or thermal degradation of organic materials composing much of the hardware could take place over a prolonged temperature regimen. Such detrimental phenomena would almost certainly compromise the integrity and reliability of the electronics. Investigation of sterilization procedures in the medical field suggests that hydrogen peroxide (H202) gas plasma (HPGP) technology can effectively function as an alternative to heat sterilization, especially for heat-sensitive items. Treatment with isopropyl alcohol (IPA) in liquid form prior to exposure of the hardware to HPGP should also prove beneficial. Although IPA is not a sterilant, it is frequently used as a disinfectant because of its bactericidal properties. The use of IPA in electronics cleaning is widely recognized and has been utilized for many years with no adverse affects reported. In addition, IPA is the principal ingredient of the test fluid used in ionic contamination testers to assess the amount of ionic contamination found on the surfaces of printed wiring assemblies. This paper will set forth experimental data confirming the feasibility of the IPA/H202 approach to reach acceptable microbial reduction (MR) levels of spacecraft electronic hardware. In addition, a proposed process flow in

  9. Hydrogen.

    Science.gov (United States)

    Bockris, John O'M

    2011-11-30

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

  10. Neutron Scattering of Residual Hydrogen in 1,4-Dioxane-D8 Liquid. Understanding Measurements with Molecular Dynamics Simulations

    Energy Technology Data Exchange (ETDEWEB)

    de Almeida, Valmor F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Hongjun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Herwig, Kenneth W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kidder, Michelle [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-25

    That incoherent scattering from protiated molecular liquids adds a constant background to the measured scattering intensity is well known, but less appreciated is the fact that coherent scattering is also induced by the presence of hydrogen in a deuterated liquid. In fact, the scattering intensity can be very sensitive, in the small-q region, with respect to the amounts and distribution of residual H in the system. We used 1,4-dioxane liquid to demonstrate that the partial structure factors of the HD and DD atom pairs contribute significantly to inter-molecular scattering and that uncertainty in the extent of deuteration account for discrepancies between simulations and measurements. Both contributions to uncertainty have similar magnitudes: scattering interference of the hydrogen-deuterium pair, and complementary interference from the deuterium-deuterium pair by virtue of chemical inhomogeneity. This situation arises in practice since deuteration of liquids is often 99% or less. A combined experimental and extensive computational study of static thermal neutron scattering of 1,4-dioxane demonstrates the foregoing. We show, through simulations, that the reason for the differences is the content of protiated dioxane (vendors quote 1%). We estimate that up to 5% (at 298K and at 343K) protiated mole fraction may be involved in generating the scattering differences. Finally, we find that the particular distribution of hydrogen in the protiated molecules affects the results significantly; here we considered molecules to be either fully protiated or fully deuterated. This scenario best reconciles the computational and experimental results, and leads us to speculate that the deuteration synthesis process tends to leave a molecule either fully deuterated or fully protiated. Although we have used 1,4-dioxane as a model liquid, the effects described in this study extend to similar liquids and similar systematic experimental/computational studies can be performed to either

  11. Key study on the potential of hydrazine bisborane for solid- and liquid-state chemical hydrogen storage.

    Science.gov (United States)

    Pylypko, Sergii; Petit, Eddy; Yot, Pascal G; Salles, Fabrice; Cretin, Marc; Miele, Philippe; Demirci, Umit B

    2015-05-04

    Hydrazine bisborane N2H4(BH3)2 (HBB; 16.8 wt %) recently re-emerged as a potential hydrogen storage material. However, such potential is controversial: HBB was seen as a hazardous compound up to 2010, but now it would be suitable for hydrogen storage. In this context, we focused on fundamentals of HBB because they are missing in the literature and should help to shed light on its effective potential while taking into consideration any risk. Experimental/computational methods were used to get a complete characterization data sheet, including, e.g., XRD, NMR, FTIR, Raman, TGA, and DSC. From the reported results and discussion, it is concluded that HBB has potential in the field of chemical hydrogen storage given that both thermolytic and hydrolytic dehydrogenations were analyzed. In solid-state chemical hydrogen storage, it cannot be used in the pristine state (risk of explosion during dehydrogenation) but can be used for the synthesis of derivatives with improved dehydrogenation properties. In liquid-state chemical hydrogen storage, it can be studied for room-temperature dehydrogenation, but this requires the development of an active and selective metal-based catalyst. HBB is a thus a candidate for chemical hydrogen storage.

  12. Model Catalytic Studies of Novel Liquid Organic Hydrogen Carriers: Indole, Indoline and Octahydroindole on Pt(111).

    Science.gov (United States)

    Schwarz, Matthias; Bachmann, Philipp; Silva, Thais Nascimento; Mohr, Susanne; Scheuermeyer, Marlene; Späth, Florian; Bauer, Udo; Düll, Fabian; Steinhauer, Johann; Hohner, Chantal; Döpper, Tibor; Noei, Heshmat; Stierle, Andreas; Papp, Christian; Steinrück, H-P; Wasserscheid, Peter; Görling, Andreas; Libuda, Jörg

    2017-10-20

    Indole derivatives were recently proposed as potential liquid organic hydrogen carriers (LOHC) for storage of renewable energies. In this work, we have investigated the adsorption, dehydrogenation and degradation mechanisms in the indole/indoline/octahydroindole system on Pt(111). We have combined infrared reflection absorption spectroscopy (IRAS), X-ray photoelectron spectroscopy (XPS) and DFT calculations. Indole multilayers show a crystallization transition at 200 K, in which the molecules adopt a strongly tilted orientation, before the multilayer desorbs at 220 K. For indoline, a less pronounced restructuring transition occurs at 150 K and multilayer desorption is observed at 200 K. Octahydroindole multilayers desorb already at 185 K, without any indication for restructuring. Adsorbed monolayers of all three compounds are stable up to room temperature and undergo deprotonation at the NH bond above 300 K. For indoline, the reaction is followed by partial dehydrogenation at the 5-membered ring, leading to the formation of a flat-lying di-σ-indolide in the temperature range from 330-390 K. Noteworthy, the same surface intermediate is formed from indole. In contrast, the reaction of octahydroindole with Pt(111) leads to the formation of a different intermediate, which originates from partial dehydrogenation of the 6-membered ring. Above 390 K, all three compounds again form the same strongly dehydrogenated and partially decomposed surface species. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. WS{sub 2} nanosheets based on liquid exfoliation as effective electrocatalysts for hydrogen evolution reaction

    Energy Technology Data Exchange (ETDEWEB)

    Han, Guan-Qun [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Yan-Ru; Hu, Wen-Hui [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Dong, Bin, E-mail: dongbin@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Li, Xiao; Chai, Yong-Ming; Liu, Yun-Qi [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Chen-Guang, E-mail: cgliu@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China)

    2015-11-01

    WS{sub 2} nanosheets (WS{sub 2} NSs) as electrocatalysts for hydrogen evolution reaction (HER) have been prepared based on liquid exfoliation in dimethyl-formamide (DMF) via a direct dispersion and ultrasonication method. X-ray diffraction (XRD) shows the decreasing crystalline of the exfoliated WS{sub 2} (E-WS{sub 2}). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the as prepared E-WS{sub 2} consists of a few two-dimensional nanosheets, with large wrinkles on the surface. Electrochemical measurements show an excellent activity and stability of the E-WS{sub 2}, with a low overpotential of 80 mV and high current density (10 mA cm{sup −2}, at η = 205 mV), which indicates that through the process of exfoliation in DMF, both the dispersion and the amount of active sites have been improved greatly. Therefore, DMF is a promising alternative for exfoliating two-dimensional nanomaterials for highly efficient HER electrocatalysts. - Highlights: • A facile exfoliation process in DMF has been used to prepare E-WS{sub 2} for HER. • E-WS{sub 2} shows the better electrocatalytic activity than bulk WS{sub 2}. • DMF provides a promising alternative for enhancing exfoliation of 2D materials.

  14. Coupled Cluster in Condensed Phase. Part II: Liquid Hydrogen Fluoride from Quantum Cluster Equilibrium Theory.

    Science.gov (United States)

    Spickermann, Christian; Perlt, Eva; von Domaros, Michael; Roatsch, Martin; Friedrich, Joachim; Kirchner, Barbara

    2011-04-12

    Treating the bulk phase with high-level ab initio methods, such as coupled cluster, is a nontrivial task because of the computational costs of these electronic structure methods. In this part of our hydrogen fluoride study we make use of the quantum cluster equilibrium method, which employs electronic structure input of small clusters and combines it with simple statistical mechanics in order to describe condensed phase phenomena. If no parameter adjustment is applied, then the lower quantum chemical methods, such as density functional theory in conjunction with the generalized gradient approximation, provide wrong results in accordance with the description of the strength of the interaction in the clusters. While density functional theory describes the liquid phase too dense due to overbinding of the clusters, the coupled cluster method and the perturbation theory at the complete basis set limit agree well with experimental observations. If we allow the two parameters in the quantum cluster equilibrium method to vary, then these are able to compensate the overbinding, thereby leading to very good agreement with experiment. Correlated methods in combination with small basis sets giving rise to too weakly bound clusters cannot reach this accuracy even if the parameters are flexible. Only at the complete basis set limit, the performance of the correlated methods is again excellent.

  15. Metal nanoparticles/ionic liquid/cellulose: polymeric membrane for hydrogenation reactions

    Directory of Open Access Journals (Sweden)

    Marcos Alexandre Gelesky

    2014-01-01

    Full Text Available Rhodium and platinum nanoparticles were supported in polymeric membranes with 10, 20 and 40 µm thickness. The polymeric membranes were prepared combining cellulose acetate and the ionic liquid (IL 1-n-butyl-3-methylimidazolium bis(trifluoromethane sulfonylimide (BMI.(NTf2. The presence of metal nanoparticles induced an increase in the polymeric membrane surface areas. The increase of the IL content resulted in an improvement of elasticity and decrease in tenacity and toughness, whereas the stress at break was not affected. The presence of IL probably causes an increase in the separation between the cellulose molecules that result in a higher flexibility and processability of the polymeric membrane. The CA/IL/M(0 combinations exhibit an excellent synergistic effect that enhances the activity and durability of the catalyst for the hydrogenation of cyclohexene. The CA/IL/M(0 polymeric membrane displays higher catalytic activity (up to 7.353 h-1 for the 20 mm of CA/IL/Pt(0 and stability than the nanoparticles dispersed only in the IL.

  16. Binary mixtures of hydrogen-bonded ferroelectric liquid crystals. Thermal span enhancement in smectic X* phase

    Energy Technology Data Exchange (ETDEWEB)

    Sangameswari, Gopal; Prabu, Nataraj Pongali Sathya; Madhu Mohan, Mathukumalli Lakshmi Narayana [Bannari Amman Institute of Technology, Sathyamangalam (India). Liquid Crystal Research Laboratory (LCRL)

    2015-07-01

    Thermotropic hydrogen-bonded ferroelectric binary liquid crystal mixtures comprising of N-carbamyl-l-glutamic acid (CGA) and p-n-alkyloxy benzoic acids (BAO) are investigated. Variation in the molar proportion of X and Y (where X=CGA+5BAO and Y=CGA+9BAO, CGA+10BAO, CGA+11BAO, and CGA+12BAO) comprising of four series yielded 36 binary mixtures. Optical and thermal properties of these mixtures are meticulously studied in the present article. In addition to the traditional phases, a novel smectic ordering namely smectic X* is observed in all the four series. The aim of the investigation is to obtain abundance occurrence of smectic X* with a large thermal span, and hence, the proportions of the binary mixtures are so chosen that the prelude task is accomplished. Optical tilt angle in smectic X* and smectic C* phases is experimentally determined, and a theoretical fit is performed. Phase diagrams of the four series are constructed from the data obtained from the differential scanning calorimetry and correlated with the phases recorded by the polarising optical microscope studies. Thermal stability factor and thermal equilibrium are also premeditated.

  17. Self-pressurization of a flightweight liquid hydrogen storage tank subjected to low heat flux

    Science.gov (United States)

    Hasan, M. M.; Lin, C. S.; Vandresar, N. T.

    1991-01-01

    Results are presented for an experimental investigation of self-pressurization and thermal stratification of a 4.89 cu m liquid hydrogen (LH2) storage tank subjected to low heat flux (0.35, 2.0, and 3.5 W/sq m) under normal gravity conditions. Tests were performed at fill levels of 83 to 84 percent (by volume). The LH2 tank was representative of future spacecraft tankage, having a low mass-to-volume ratio and high performance multilayer thermal insulation. Results show that the pressure rise rate and thermal stratification increase with increasing heat flux. At the lowest heat flux, the pressure rise rate is comparable to the homogenous rate, while at the highest heat flux, the rate is more than three times the homogeneous rate. It was found that initial conditions have a significant impact on the initial pressure rise rate. The quasi-steady pressure rise rates are nearly independent of the initial condition after an initial transient period has passed.

  18. Optimization of a Brayton cryocooler for ZBO liquid hydrogen storage in space

    Science.gov (United States)

    Deserranno, D.; Zagarola, M.; Li, X.; Mustafi, S.

    2014-11-01

    NASA is evaluating and developing technology for long-term storage of cryogenic propellant in space. A key technology is a cryogenic refrigerator which intercepts heat loads to the storage tank, resulting in a reduced- or zero-boil-off condition. Turbo-Brayton cryocoolers are particularly well suited for cryogen storage applications because the technology scales well to high capacities and low temperatures. In addition, the continuous-flow nature of the cycle allows direct cooling of the cryogen storage tank without mass and power penalties associated with a cryogenic heat transport system. To quantify the benefits and mature the cryocooler technology, Creare Inc. performed a design study and technology demonstration effort for NASA on a 20 W, 20 K cryocooler for liquid hydrogen storage. During the design study, we optimized these key components: three centrifugal compressors, a modular high-capacity plate-fin recuperator, and a single-stage turboalternator. The optimization of the compressors and turboalternator were supported by component testing. The optimized cryocooler has an overall flight mass of 88 kg and a specific power of 61 W/W. The coefficient of performance of the cryocooler is 23% of the Carnot cycle. This is significantly better performance than any 20 K space cryocooler existing or under development.

  19. Thermal Analysis on Cryogenic Liquid Hydrogen Tank on an Unmanned Aerial Vehicle System

    Science.gov (United States)

    Wang, Xiao-Yen; Harpster, George; Hunter, James

    2007-01-01

    Thermal analyses are performed on the liquid hydrogen (LH2) tank designed for an unmanned aerial vehicle (UAV) powered by solar arrays and a regenerative proton-exchange membrane (PEM) fuel cell. A 14-day cruise mission at a 65,000 ft altitude is considered. Thermal analysis provides the thermal loads on the tank system and the boiling-off rates of LH2. Different approaches are being considered to minimize the boiling-off rates of the LH2. It includes an evacuated multilayer insulation (MLI) versus aerogel insulation on the LH2 tank and aluminum versus stainless steel spacer rings between the inner and outer tank. The resulting boil-off rates of LH2 provided by the one-dimensional model and three-dimensional finite element analysis (FEA) on the tank system are presented and compared to validate the results of the three-dimensional FEA. It concludes that heat flux through penetrations by conduction is as significant as that through insulation around the tank. The tank system with MLI insulation and stainless steel spacer rings result in the lowest boiling-off rate of LH2.

  20. Epoxidation of cottonseed oil by aqueous hydrogen peroxide catalysed by liquid inorganic acids.

    Science.gov (United States)

    Dinda, Srikanta; Patwardhan, Anand V; Goud, Vaibhav V; Pradhan, Narayan C

    2008-06-01

    The kinetics of epoxidation of cottonseed oil by peroxyacetic acid generated in situ from hydrogen peroxide and glacial acetic acid in the presence of liquid inorganic acid catalysts were studied. It was possible to obtain up to 78% relative conversion to oxirane with very less oxirane cleavage by in situ technique. The rate constants for sulphuric acid catalysed epoxidation of cottonseed oil were in the range 0.39-5.4 x 10(-6)L mol(-1)s(-1) and the activation energy was found to be 11.7 kcal mol(-1). Some thermodynamic parameters such as enthalpy, entropy, and free energy of activation were determined to be of 11.0 kcal mol(-1), -51.4 cal mol(-1)K(-1) and 28.1 kcal mol(-1), respectively. The order of effectiveness of catalysts was found to be sulphuric acid>phosphoric acid>nitric acid>hydrochloric acid. Acetic acid was found to be superior to formic acid for the in situ cottonseed oil epoxidation.

  1. ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-01-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through December 1999.

  2. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere VII. Further Insights into the Chromosphere and Corona

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available In the liquid metallic hydrogen model of the Sun, the chromosphere is responsible for the capture of atomic hydrogen in the solar atmosphere and its eventual re-entry onto the photospheric surface (P.M. Robitaille. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere IV. On the Nature of the Chromosphere. Prog. Phys., 2013, v. 3, L15–L21. As for the corona, it represents a diffuse region containing both gaseous plasma and condensed matter with elevated electron affinity (P.M. Robitaille. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere V. On the Nature of the Corona. Prog. Phys., 2013, v. 3, L22–L25. Metallic hydrogen in the corona is thought to enable the continual harvest of electrons from the outer reaches of the Sun, thereby preserving the neutrality of the solar body. The rigid rotation of the corona is offered as the thirty-third line of evidence that the Sun is comprised of condensed matter. Within the context of the gaseous models of the Sun, a 100 km thick transition zone has been hypothesized to exist wherein temperatures increase dramatically from 104–106 K. Such extreme transitional temperatures are not reasonable given the trivial physical scale of the proposed transition zone, a region adopted to account for the ultra-violet emission lines of ions such as C IV, O IV, and Si IV. In this work, it will be argued that the transition zone does not exist. Rather, the intermediate ionization states observed in the solar atmosphere should be viewed as the result of the simultaneous transfer of protons and electrons onto condensed hydrogen structures, CHS. Line emissions from ions such as C IV, O IV, and Si IV are likely to be the result of condensation reactions, manifesting the involvement of species such as CH4, SiH4, H3O+ in the synthesis of CHS in the chromosphere. In addition, given the presence of a true solar surface at the level of the photosphere in the liquid metallic hydrogen model

  3. Selective conversion of polyenes to monoenes by RuCl(3) -catalyzed transfer hydrogenation: the case of cashew nutshell liquid.

    Science.gov (United States)

    Perdriau, Sébastien; Harder, Sjoerd; Heeres, Hero J; de Vries, Johannes G

    2012-12-01

    Cardanol, a constituent of cashew nutshell liquid (CNSL), was subjected to transfer hydrogenation catalyzed by RuCl(3) using isopropanol as a reductant. The side chain of cardanol, which is a mixture of a triene, a diene, and a monoene, was selectively reduced to the monoene. Surprisingly, it is the C8-C9 double bond that is retained with high selectivity. A similar transfer hydrogenation of linoleic acid derivatives succeeded only if the substrate contained an aromatic ring, such as a benzyl ester. TEM and a negative mercury test showed that the catalyst was homogeneous. By using ESI-MS, ruthenium complexes were identified that contained one, two, or even three molecules of substrate, most likely as allyl complexes. The interaction between ruthenium and the aromatic ring determines selectivity in the hydrogenation reaction. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Hydrogen

    Directory of Open Access Journals (Sweden)

    John O’M. Bockris

    2011-11-01

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

  5. Calibrating the Helium Pressurization System for the Space Shuttle Liquid-Hydrogen Tank

    Science.gov (United States)

    2008-01-01

    Analysis of the results from the STS-114 tanking tests and subsequent launch called into question existing thermal and mass models of helium pressurization of the liquid hydrogen tank. This hydrogen tank, which makes up the bottom two-thirds of the External Tank, is pressurized prior to launch to avoid cavitation in the Shuttle Main Engine pumps. At about 2 minutes prior to launch, the main vent valve is closed, and pressurized helium flows into the tank ullage space to achieve set point pressure. As the helium gas cools, its pressure drops, calling for additional helium. Subsequent helium flows are provided in short, timed pulses. The number of pulses is taken as a rough leak indicator. An analysis of thermal models by Marshall Space Flight Center showed considerable uncertainty in the pressure-versus-time behavior of the helium ullage space and the ability to predict the number of pulses normally expected. Kennedy Space Center proposed to calibrate the dime-sized orifice, which together with valves, controls the helium flow quantity (Figure 1). Pressure and temperature sensors were installed to provide upstream and downstream measurements necessary to compute flow rate based on the orifice discharge coefficient. An assessment of flow testing with helium indicated an extremely costly use of this critical resource. In order to reduce costs, we proposed removing the orifices from each Mobile Launcher Platform (MLP) and asking Colorado Engineering Experiment Station Inc. (CEESI) to calibrate the flow. CEESI has a high-pressure air flow system with traceable flow meters capable of handling the large flow rates. However, literature research indicated that square-edged orifices of small diameters often exhibit significant hysteresis and nonrepeatability in the vicinity of choked or sonic flow. Fortunately, the MLP orifices behaved relatively well in testing (Figure 2). Using curve fitting of the air-flow data, in conjunction with ASME orifice modeling equations, a

  6. Hydrogen from catalytic reforming of biomass-derived hydrocarbons in liquid water.

    Science.gov (United States)

    Cortright, R D; Davda, R R; Dumesic, J A

    2002-08-29

    Concerns about the depletion of fossil fuel reserves and the pollution caused by continuously increasing energy demands make hydrogen an attractive alternative energy source. Hydrogen is currently derived from nonrenewable natural gas and petroleum, but could in principle be generated from renewable resources such as biomass or water. However, efficient hydrogen production from water remains difficult and technologies for generating hydrogen from biomass, such as enzymatic decomposition of sugars, steam-reforming of bio-oils and gasification, suffer from low hydrogen production rates and/or complex processing requirements. Here we demonstrate that hydrogen can be produced from sugars and alcohols at temperatures near 500 K in a single-reactor aqueous-phase reforming process using a platinum-based catalyst. We are able to convert glucose -- which makes up the major energy reserves in plants and animals -- to hydrogen and gaseous alkanes, with hydrogen constituting 50% of the products. We find that the selectivity for hydrogen production increases when we use molecules that are more reduced than sugars, with ethylene glycol and methanol being almost completely converted into hydrogen and carbon dioxide. These findings suggest that catalytic aqueous-phase reforming might prove useful for the generation of hydrogen-rich fuel gas from carbohydrates extracted from renewable biomass and biomass waste streams.

  7. Rapid Production of High-Purity Hydrogen Fuel through Microwave-Promoted Deep Catalytic Dehydrogenation of Liquid Alkanes with Abundant Metals.

    Science.gov (United States)

    Jie, Xiangyu; Gonzalez-Cortes, Sergio; Xiao, Tiancun; Wang, Jiale; Yao, Benzhen; Slocombe, Daniel R; Al-Megren, Hamid A; Dilworth, Jonathan R; Thomas, John M; Edwards, Peter P

    2017-08-14

    Hydrogen as an energy carrier promises a sustainable energy revolution. However, one of the greatest challenges for any future hydrogen economy is the necessity for large scale hydrogen production not involving concurrent CO2 production. The high intrinsic hydrogen content of liquid-range alkane hydrocarbons (including diesel) offers a potential route to CO2 -free hydrogen production through their catalytic deep dehydrogenation. We report here a means of rapidly liberating high-purity hydrogen by microwave-promoted catalytic dehydrogenation of liquid alkanes using Fe and Ni particles supported on silicon carbide. A H2 production selectivity from all evolved gases of some 98 %, is achieved with less than a fraction of a percent of adventitious CO and CO2 . The major co-product is solid, elemental carbon. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Dehydrogenation mechanism of liquid organic hydrogen carriers: dodecahydro-N-ethylcarbazole on Pd(111).

    Science.gov (United States)

    Amende, Max; Schernich, Stefan; Sobota, Marek; Nikiforidis, Ioannis; Hieringer, Wolfgang; Assenbaum, Daniel; Gleichweit, Christoph; Drescher, Hans-Jörg; Papp, Christian; Steinrück, Hans-Peter; Görling, Andreas; Wasserscheid, Peter; Laurin, Mathias; Libuda, Jörg

    2013-08-12

    Dodecahydro-N-ethylcarbazole (H12-NEC) has been proposed as a potential liquid organic hydrogen carrier (LOHC) for chemical energy storage, as it combines both favourable physicochemical and thermodynamic properties. The design of optimised dehydrogenation catalysts for LOHC technology requires a detailed understanding of the reaction pathways and the microkinetics. Here, we investigate the dehydrogenation mechanism of H12-NEC on Pd(111) by using a surface-science approach under ultrahigh vacuum conditions. By combining infrared reflection-absorption spectroscopy, density functional theory calculations and X-ray photoelectron spectroscopy, surface intermediates and their stability are identified. We show that H12-NEC adsorbs molecularly up to 173 K. Above this temperature (223 K), activation of C-H bonds is observed within the five-membered ring. Rapid dehydrogenation occurs to octahydro-N-ethylcarbazole (H8-NEC), which is identified as a stable surface intermediate at 223 K. Above 273 K, further dehydrogenation of H8-NEC proceeds within the six-membered rings. Starting from clean Pd(111), C-N bond scission, an undesired side reaction, is observed above 350 K. By complementing surface spectroscopy, we present a temperature-programmed molecular beam experiment, which permits direct observation of dehydrogenation products in the gas phase during continuous dosing of the LOHC. We identify H8-NEC as the main product desorbing from Pd(111). The onset temperature for H8-NEC desorption is 330 K, the maximum reaction rate is reached around 550 K. The fact that preferential desorption of H8-NEC is observed even above the temperature threshold for H8-NEC dehydrogenation on the clean surface is attributed to the presence of surface dehydrogenation and decomposition products during continuous reactant exposure. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Au/MO2N as a new catalyst formulation for the hydrogenation of p-chloronitrobenzene in both liquid and gas phases

    NARCIS (Netherlands)

    Cárdenas-Lizana, F.; Lamey, D.; Perret, N.; Gómez-Quero, S.; Kiwi-Minsker, L.; Keane, M.A.

    2012-01-01

    The batch liquid phase hydrogenation of p-chloronitrobenzene over MO2N resulted in the sole formation of p-chloroaniline. Incorporation of Au nanoparticles (mean size = 8 nm) enhanced hydrogen uptake with a fourfold increase in rate, retention of ultraselectivity with stability over repeated

  10. Catalytic Dehydrogenative Coupling of Hydrosilanes with Alcohols for the Production of Hydrogen On-demand: Application of a Silane/Alcohol Pair as a Liquid Organic Hydrogen Carrier.

    Science.gov (United States)

    Ventura-Espinosa, David; Carretero-Cerdán, Alba; Baya, Miguel; García, Hermenegildo; Mata, Jose A

    2017-08-10

    The compound [Ru(p-cym)(Cl)2 (NHC)] is an effective catalyst for the room-temperature coupling of silanes and alcohols with the concomitant formation of molecular hydrogen. High catalyst activity is observed for a variety of substrates affording quantitative yields in minutes at room temperature and with a catalyst loading as low as 0.1 mol %. The coupling reaction is thermodynamically and, in the presence of a Ru complex, kinetically favourable and allows rapid molecular hydrogen generation on-demand at room temperature, under air, and without any additive. The pair silane/alcohol is a potential liquid organic hydrogen carrier (LOHC) for energy storage over long periods in a safe and secure way. Silanes and alcohols are non-toxic compounds and do not require special handling precautions such as high pressure or an inert atmosphere. These properties enhance the practical applications of the pair silane/alcohol as a good LOHC in the automotive industry. The variety and availability of silanes and alcohols permits a pair combination that fulfils the requirements for developing an efficient LOHC. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Probing molecular interaction in ionic liquids by low frequency spectroscopy: Coulomb energy, hydrogen bonding and dispersion forces.

    Science.gov (United States)

    Fumino, Koichi; Reimann, Sebastian; Ludwig, Ralf

    2014-10-28

    Ionic liquids are defined as salts composed solely of ions with melting points below 100 °C. These remarkable liquids have unique and fascinating properties and offer new opportunities for science and technology. New combinations of ions provide changing physical properties and thus novel potential applications for this class of liquid materials. To a large extent, the structure and properties of ionic liquids are determined by the intermolecular interaction between anions and cations. In this perspective we show that far infrared and terahertz spectroscopy are suitable methods for studying the cation-anion interaction in these Coulomb fluids. The interpretation of the measured low frequency spectra is supported by density functional theory calculations and molecular dynamics simulations. We present results for selected aprotic and protic ionic liquids and their mixtures with molecular solvents. In particular, we focus on the strength and type of intermolecular interaction and how both parameters are influenced by the character of the ions and their combinations. We show that the total interaction between cations and anions is a result of a subtle balance between Coulomb forces, hydrogen bonds and dispersion forces. For protic ionic liquids we could measure distinct vibrational modes in the low frequency spectra indicating clearly the cation-anion interaction characterized by linear and medium to strong hydrogen bonds. Using isotopic substitution we have been able to dissect frequency shifts related to pure interaction strength between cations and anions and to different reduced masses only. In this context we also show how these different types of interaction may influence the physical properties of ionic liquids such as the melting point, viscosity or enthalpy of vaporization. Furthermore we demonstrate that low frequency spectroscopy can also be used for studying ion speciation. Low vibrational features can be assigned to contact ion pairs and solvent separated

  12. Leaching performance of imidazolium based ionic liquids in the presence of hydrogen peroxide for recovery of metals from brass waste

    Energy Technology Data Exchange (ETDEWEB)

    Kelicarslan, A.; Saridede, M. N.

    2016-05-01

    The application of ionic liquids (ILs), 1-methylimidazolium hydrogen sulfate (HmimHSO{sub 4}), 1-ethyl-3-methylimidazolium hydrogen sulfate (EmimHSO{sub 4}) and 1-butyl-3-methylimidazolium chloride (BmimCl) as leaching agents was investigated in the leaching of copper and zinc from brass waste in the presence of an oxidant, hydrogen peroxide (H{sub 2}O{sub 2}). Factors that affect copper and zinc dissolution rates such as ionic liquid concentration, time and temperature were investigated. The results indicated that zinc was dissolved in leach solutions with EmimHSO{sub 4} and HmimHSO{sub 4}, completely. Temperature had no considerable influence on copper dissolution rate whilst the rate increased with decreasing IL concentration. In the EmimHSO{sub 4} system, higher copper recoveries were achieved with 40% and 60% IL concentrations compared with IL concentrations of 20% and 80% at 40 degree centigrade leaching temperature. Copper dissolution rates decreased with EmimHSO{sub 4} concentration at 60 degree centigrade and 80 degree centigrade in the following order; 40%>20%>60%>80%. On the other hand the leaching system with BmimCl generally resulted in poor extractions of copper and zinc. (Author)

  13. Research on Liquid Management Technology in Water Tank and Reactor for Propulsion System with Hydrogen Production System Utilizing Aluminum and Water Reaction

    Science.gov (United States)

    Imai, Ryoji; Imamura, Takuya; Sugioka, Masatoshi; Higashino, Kazuyuki

    2017-12-01

    High pressure hydrogen produced by aluminum and water reaction is considered to be applied to space propulsion system. Water tank and hydrogen production reactor in this propulsion system require gas and liquid separation function under microgravity condition. We consider to install vane type liquid acquisition device (LAD) utilizing surface tension in the water tank, and install gas-liquid separation mechanism by centrifugal force which swirling flow creates in the hydrogen reactor. In water tank, hydrophilic coating was covered on both tank wall and vane surface to improve wettability. Function of LAD in water tank and gas-liquid separation in reaction vessel were evaluated by short duration microgravity experiments using drop tower facility. In the water tank, it was confirmed that liquid was driven and acquired on the outlet due to capillary force created by vanes. In addition of this, it was found that gas-liquid separation worked well by swirling flow in hydrogen production reactor. However, collection of hydrogen gas bubble was sometimes suppressed by aluminum alloy particles, which is open problem to be solved.

  14. Research on Liquid Management Technology in Water Tank and Reactor for Propulsion System with Hydrogen Production System Utilizing Aluminum and Water Reaction

    Science.gov (United States)

    Imai, Ryoji; Imamura, Takuya; Sugioka, Masatoshi; Higashino, Kazuyuki

    2017-11-01

    High pressure hydrogen produced by aluminum and water reaction is considered to be applied to space propulsion system. Water tank and hydrogen production reactor in this propulsion system require gas and liquid separation function under microgravity condition. We consider to install vane type liquid acquisition device (LAD) utilizing surface tension in the water tank, and install gas-liquid separation mechanism by centrifugal force which swirling flow creates in the hydrogen reactor. In water tank, hydrophilic coating was covered on both tank wall and vane surface to improve wettability. Function of LAD in water tank and gas-liquid separation in reaction vessel were evaluated by short duration microgravity experiments using drop tower facility. In the water tank, it was confirmed that liquid was driven and acquired on the outlet due to capillary force created by vanes. In addition of this, it was found that gas-liquid separation worked well by swirling flow in hydrogen production reactor. However, collection of hydrogen gas bubble was sometimes suppressed by aluminum alloy particles, which is open problem to be solved.

  15. Experimental Evaluation of the Applicability of Capacitive and Optical Measurement Methods for the Determination of Liquid Hydrogen Volume Flow

    Directory of Open Access Journals (Sweden)

    Gert HOLLER

    2009-08-01

    Full Text Available This paper presents a capacitive and a vision-based method for measuring the velocity of cryogenic hydrogen flows. The capacitive sensing principle exploits the spatial frequency signature of perturbations moving through a multi-electrode structure. This setup increases the sensitivity to dielectric permittivity variations compared to a simple two-electrode structure while preserving the ability to detect small perturbations. The vision-based method relies on a high-speed camera system that monitors the liquid hydrogen flow through an optical window yielding the flow velocity by cross-correlating subsequent images of the flow. Although a comprehensive analysis of the obtainable measurement uncertainty was not performed yet, current measurement results show the applicability of both principles for the non-invasive measurement of the volume flow of cryogenic fuels inside conveyor pipes.

  16. Simulations of the THz spectrum of liquid water incorporating the effects of intermolecular charge fluxes through hydrogen bonds

    Energy Technology Data Exchange (ETDEWEB)

    Torii, Hajime, E-mail: torii.hajime@shizuoka.ac.jp [Department of Chemistry, Faculty of Education, and Department of Optoelectronics and Nanostructure Science, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Shizuoka 422-8529 (Japan)

    2015-12-31

    The intensity of the band at ∼200 cm{sup −1} (∼6 THz) in the Terahertz spectrum of liquid water mainly arises from the modulations of the extent of intermolecular charge transfer through hydrogen bonds, called intermolecular charge fluxes, occurring upon molecular translations along the O…H hydrogen bonds. To obtain reasonable spectral profiles from simulations, it is necessary to effectively incorporate the effects of those intermolecular charge fluxes, but apparently it is not possible by simple classical molecular dynamics simulations with fixed atomic partial charges even if they are amended by molecular induced dipoles due to intermolecular electrostatic interactions. The present paper shows how we can do reasonably correct spectral simulations, without resorting to fully ab initio molecular dynamics.

  17. On the physical origin of the cation-anion intermediate bond in ionic liquids Part I. Placing a (weak) hydrogen bond between two charges.

    Science.gov (United States)

    Lehmann, Sebastian B C; Roatsch, Martin; Schöppke, Matthias; Kirchner, Barbara

    2010-07-21

    The intermediate bond forces in ionic liquids are investigated from static quantum chemical calculations at various methods and two basis sets. The experimentally observed red-shift of the donor-proton bond stretching frequency due to a bond elongation is confirmed by all methods. Comparing Hartree-Fock to second-order Møller-Plesset perturbation theory, the Hartree-Fock method gives in many cases an erroneous description of the geometries. Furthermore, the Hartree-Fock interaction energies can deviate up to 60 kJ mol(-1) from Møller-Plesset perturbation theory indicating the importance of dispersion interaction. While the usual trends of decreasing stability or interaction energies with increasing ion sizes are found, the geometries involving hydrogen atoms do not change this order of total interaction energies. Therefore, the hydrogen bond is not the most important interaction for ion pairs with regard to the total interaction energy. On the other hand, the different established analysis methods give rise to hydrogen bonding in several ion pairs. Charge analysis reveals the hydrogen-bonding character of the ion pair and shows, depending on the type of ions combined and further on the type of conformers considered, that a hydrogen bond can be present. The possibility of hydrogen bonding is also shown by an analysis of the frontier orbitals. Calculating potential energy surfaces and observing from this the change in the donor proton bond indicates that regular hydrogen bonds are possible in ion pairs of ionic liquids. Thereby, the maximum of bond elongation exceeds the one of a usual hydrogen bond by far. The more salt-like hydrogen-bonded ion pair [NH(4)][BF(4)] exhibits a steeper maximum than the more ionic liquid like ion pair [EtNH(3)][BF(4)]. The fact that imidazolium-based ionic liquids as [Emim][Cl] can display two faces, hydrogen bonding and purely ionic bonding, points to a disturbing rather than stabilizing role of hydrogen bonding on the interaction of

  18. Liquid Hydrogen Regulated Low Pressure High Flow Pneumatic Panel AFT Arrow Analysis

    Science.gov (United States)

    Jones, Kelley, M.

    2013-01-01

    Project Definition: Design a high flow pneumatic regulation panel to be used with helium and hydrogen. The panel will have two circuits, one for gaseous helium (GHe) supplied from the GHe Movable Storage Units (MSUs) and one for gaseous hydrogen (GH2) supplied from an existing GH2 Fill Panel. The helium will supply three legs; to existing panels and on the higher pressure leg and Simulated Flight Tanks (SFTs) for the lower pressure legs. The hydrogen line will pressurize a 33,000 gallon vacuum jacketed vessel.

  19. MINOS: A vertex tracker coupled to a thick liquid-hydrogen target for in-beam spectroscopy of exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Obertelli, A.; Delbart, A.; Anvar, S.; Audirac, L.; Authelet, G.; Bruyneel, B.; Calvet, D.; Chateau, F.; Corsi, A.; Gheller, J.M.; Giganon, A.; Lahonde-Hamdoun, C.; Leboeuf, D.; Loiseau, D.; Mohamed, A.; Mols, J.P.; Peron, C.; Peyaud, A.; Pollacco, E.C.; Prono, G.; Rousse, J.Y.; Santamaria, C. [CEA, Centre de Saclay, IRFU, Gif-sur-Yvette (France); Baba, H.; Doornenbal, P.; Otsu, H.; Uesaka, T. [RIKEN Nishina Center, Wako, Saitama (Japan)

    2014-01-15

    MINOS is a new apparatus dedicated to in-beam nuclear structure experiments with low-intensity exotic beams in inverse kinematics at intermediate energies above 150 MeV/nucleon. The device is composed of a thick liquid-hydrogen target coupled to a compact time projection chamber (TPC) serving as a vertex tracker. Either used for in-beam gamma spectroscopy of bound excited states or invariant-mass spectroscopy of unbound states, MINOS aims at improving the luminosity by a very significant factor compared to standard solid-target material experiments while improving experimental resolutions. (orig.)

  20. Modeling the Solid-Liquid Equilibrium in Pharmaceutical-Solvent Mixtures: Systems with Complex Hydrogen Bonding Behvaior

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Economou, Ioannis; Kontogeorgis, Georgios

    2009-01-01

    simpler molecules of similar chemical structure and/or are fitted to Hansen's partial solubility parameters. The methodology is applied to modeling the solubility of three pharmaceuticals, namely acetanilide, phenacetin, and paracetamol, using the nonrandom hydrogen bonding (NRHB) EoS. In all cases......, accurate correlations were obtained. The prediction ability of the approach was evaluated against predictions from the COSMO-RS model. A thorough discussion is made for the appropriate modeling of solid solubility considering the effect of the difference of the heat capacities of the solute in liquid...

  1. Catalytic Hydrogen Production by Ruthenium Complexes from the Conversion of Primary Amines to Nitriles: Potential Application as a Liquid Organic Hydrogen Carrier.

    Science.gov (United States)

    Ventura-Espinosa, David; Marzá-Beltrán, Aida; Mata, Jose A

    2016-12-05

    The potential application of the primary amine/nitrile pair as a liquid organic hydrogen carrier (LOHC) has been evaluated. Ruthenium complexes of formula [(p-cym)Ru(NHC)Cl2 ] (NHC=N-heterocyclic carbene) catalyze the acceptorless dehydrogenation of primary amines to nitriles with the formation of molecular hydrogen. Notably, the reaction proceeds without any external additive, under air, and under mild reaction conditions. The catalytic properties of a ruthenium complex supported on the surface of graphene have been explored for reutilization purposes. The ruthenium-supported catalyst is active for at least 10 runs without any apparent loss of activity. The results obtained in terms of catalytic activity, stability, and recyclability are encouraging for the potential application of the amine/nitrile pair as a LOHC. The main challenge in the dehydrogenation of benzylamines is the selectivity control, such as avoiding the formation of imine byproducts due to transamination reactions. Herein, selectivity has been achieved by using long-chain primary amines such as dodecylamine. Mechanistic studies have been performed to rationalize the key factors involved in the activity and selectivity of the catalysts in the dehydrogenation of amines. The experimental results suggest that the catalyst resting state contains a coordinated amine. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Accelerating ab initio Molecular Dynamics and Probing the Weak Dispersive Forces in Dense Liquid Hydrogen.

    Science.gov (United States)

    Mazzola, Guglielmo; Sorella, Sandro

    2017-01-06

    We propose an ab initio molecular dynamics method, capable of dramatically reducing the autocorrelation time required for the simulation of classical and quantum particles at finite temperatures. The method is based on an efficient implementation of a first order Langevin dynamics modified by means of a suitable, position dependent acceleration matrix S. Here, we apply this technique to both Lennard-Jones models, to demonstrate the accuracy and speeding-up of the sampling, and within a quantum Monte Carlo based wave function approach, for determining the phase diagram of high-pressure hydrogen with simulations much longer than the autocorrelation time. With the proposed method, we are able to equilibrate in a few hundred steps even close to the liquid-liquid phase transition (LLT). Within our approach, we find that the LLT transition is consistent with recent density functionals predicting a much larger transition pressure when the long range dispersive forces are taken into account.

  3. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere VI. Helium in the Chromosphere

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available Molecular hydrogen and hydrides have recently been advanced as vital agents in the generation of emission spectra in the chromosphere. This is a result of the role they play in the formation of condensed hydrogen structures (CHS within the chromosphere (P.M. Robitaille. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere IV. On the Nature of the Chromosphere. Progr. Phys., 2013, v. 3, 15–21. Next to hydrogen, helium is perhaps the most intriguing component in this region of the Sun. Much like other elements, which combine with hydrogen to produce hydrides, helium can form the well-known helium hydride molecular ion, HeH+, and the excited neutral helium hydride molecule, HeH∗. While HeH+ is hypothesized to be a key cosmologicalmolecule, its possible presence in the Sun, and that of its excited neutral counterpart, has not been considered. Still, these hydrides are likely to play a role in the synthesis of CHS, as the He I and He II emission lines strongly suggest. In this regard, the study of helium emission spectra can provide insight into the condensed nature of the Sun, especially when considering the 10830 Å line associated with the 23P→2 3S triplet state transition. This line is strong in solar prominences and can be seen clearly on the disk. The excessive population of helium triplet states cannot be adequately explained using the gaseous models, since these states should be depopulated by collisional processes. Conversely, when He-based molecules are used to build CHS in a liquid metallic hydrogen model, an ever increasing population of the 23S and 23P states might be expected. The overpopulation of these triplet states leads to the conclusion that these emission lines are unlikely to be produced through random collisional or photon excitation, as required by the gaseous models. This provides a significant hurdle for these models. Thus, the strong 23P→2 3S lines and the overpopulation of the helium triplet

  4. Liquid Metallic Hydrogen III. Intercalation and Lattice Exclusion Versus Gravitational Settling and Their Consequences Relative to Internal Structure, Surface Activity, and Solar Winds in the Sun

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-04-01

    Full Text Available Invocation of a liquid metallic hydrogen model (Robitaille P.M. Liquid Metallic Hydro- gen: A Building Block for the Liquid Sun. Progr. Phys ., 2011, v. 3, 60–74; Robitaille P.M. Liquid Metallic Hydrogen II: A Critical Assessment of Current and Primordial He- lium Levels in Sun. Progr. Phys ., 2013, v. 2, 35–47 brings with it a set of advantages for understanding solar physics which will always remain unavailable to the gaseous models. Liquids characteristically act as solvents and incorporate solutes within their often fleeting structural matrix. They possess widely varying solubility products and often reject the solute altogether. In that case, the solute becomes immiscible. “Lattice exclusion” can be invoked for atoms which attempt to incorporate themselves into liquid metallic hydrogen. In order to conserve the integrity of its conduction bands, it is antic- ipated that a graphite-like metallic hydrogen lattice should not permit incorporation of other elements into its in-plane hexagonal hydrogen framework. Based on the physics observed in the intercalation compounds of graphite, non-hydrogen atoms within liq- uid metallic hydrogen could reside between adjacent hexagonal proton planes. Conse- quently, the forces associated with solubility products and associated lattice exclusion envisioned in liquid metallic hydrogen for solutes would restrict gravitational settling. The hexagonal metallic hydrogen layered lattice could provide a powerful driving force for excluding heavier elements from the solar body. Herein lies a new exfoliative force to drive both surface activity (flares, coronal mass ejections, prominences and solar winds with serious consequences relative to the p–p reaction and CNO cycle in the Sun. At the same time, the idea that non-hydrogen atomic nuclei can exist between layers of metallic hydrogen leads to a fascinating array of possibilities with respect to nucleosyn- thesis. Powerful parallels can be drawn to the

  5. Study of Liquid Alkanes Production from Biomass-Derived Carbohydrates by Aldol-Condensation and Hydrogenation Processes

    Directory of Open Access Journals (Sweden)

    Navadol Laosiripojana

    2010-10-01

    Full Text Available This research aims to synthesis liquid alkanes from biomass-derived hydroxyl methyl furfural (HMF and furfural by aldol-condensation and hydrogenation processes over several catalysts i.e. TiO2, TiO2-ZrO2, Pd/Al2O3 and Pd/CeO2. It was found that the catalysts make significant impact on the selectivity and yield of alkanes product. It is noted that Pd/Al2O3 provided the highest alkane yield and selectivity. The aldol-condensation and hydrogenation of HMF over Pd/Al2O3 provide high C12 selectivity whereas the aldol-condensation and hydrogenation of furfural over Pd/Al2O3 provide high C8 selectivity. The effects of reaction temperature, reaction pressure and reaction time were then studied. The effect of inlet furfural to acetone molar ratio was also determined. It was also found that the optimized conditions to maximize the yield of alkane production from the aldol-condensation/hydrogenation of HMF and furfural are (i at 53oC and 24 hr for aldol-condenstation of HMF, (ii 80oC and 24 hr for aldol-condenstation of furfural, and (iii 120oC for 6 hr with HMF to acetone molar ratio of 3:1 and furfural to acetone molar ratio of 4:1 in the presence of Pd/Al2O3 (calcined at 500oC for hydrogenation reaction.

  6. Bond Strength of White Mineral Trioxide Aggregate with and without Disodium Hydrogen Phosphate with Different Liquid-to-Powder Ratios.

    Science.gov (United States)

    Mokhtari, Hadi; Jafarizadeh, Sara; Mokhtari Zonouzi, Hamid Reza; Lotfi, Mehrdad; Forough Reyhani, Mohammad; Sohrabi, Aydin

    2017-01-01

    Mineral trioxide aggregate (MTA) can be used in the treatment of irritated vital pulp and repair of root perforations. However, the initial reaction of inflammatory cells to this material and also its setting time are not ideal. Studies have shown that disodium hydrogen phosphate (DHP), decreases the setting time of MTA, with no effect on its pH. This study was undertaken to evaluate the effect of DHP on push-out bond strength of MTA at different liquid-to-powder ratios. A total of 120 samples were prepared from the middle third of the roots of single-rooted teeth for evaluation of push-out bond strength. The push-out bond strength was measured in both groups after 72 h at different liquid-to-powder ratios, including 0.33:1, 0.5:1 and 0.6:1. Factorial ANOVA and Tukey's HSD post-hoc tests were used to compare the differences between the independent groups. Statistical significant was set at PMTA and MTA+DHP groups were 10.96±5.78 and 13.32±5.03, respectively. Tukey's HSD post-hoc test revealed significant differences between the two groups. Furthermore, there were no interactive effect between material and the liquid: powder ratio. Incorporation of DHP into MTA resulted in an increase in push-out bond strength of MTA, and an increase in liquid-to-powder ratio resulted in a decrease in push-out bond strength.

  7. Chemistry and catalysis of coal liquefaction: catalytic and thermal upgrading of coal liquid and hydrogenation of CO to produce fuels. Quarterly progress report, January-March 1980

    Energy Technology Data Exchange (ETDEWEB)

    Wiser, W.H.

    1980-08-01

    Analysis of a group of coal liquids produced by catalytic hydrogenation of Utah coals with ZnCl/sub 2/ catalyst was begun. Carbon-13 nuclear magnetic resonance and liquid chromatography techniques will be used to correlate chemical properties with hydrogenation reactivity. Equipment previously used for downflow measurements of heat and momentum transfer in a gas-coal suspension was modified for upflow measurements. The catalytic hydrodeoxygenation of methyl benzoate has been studied to elucidate the reactions of ester during upgrading of coal-derived liquids. The kinetics of hydrogenation of phenanthrene have also been determined. The catalytic cracking mechanism of octahydroanthracene is reported in detail. Studies of the hydrodesulfurization of thiophene indicate that some thiophene is strongly adsorbed as a hydrogen-deficient polymer on cobalt-molybdate catalyst. Part of the polymer can be desorbed as thiophene by hydrogenation. Poisoning of the catalyst inhibits the hydrosulfurization activity to a greater degree than the hydrogenation activity. Iron-manganese catalysts for carbon monoxide hydrogenation is studied to determine the role of iron carbide formation on selectivity. Pure iron catalyst forms a Hagg iron carbide phase under reaction conditions.

  8. Analytical and experimental investigation of rubbing interaction in labyrinth seals for a liquid hydrogen fuel pump. [space shuttle main engine

    Science.gov (United States)

    Dolan, F. X.; Kennedy, F. E.; Schulson, E. M.

    1984-01-01

    Cracking of the titanium knife edges on the labyrinth seals of the liquid hydrogen fuel pump in the Space Shuttle main engine is considered. Finite element analysis of the thermal response of the knife edge in sliding contact with the wear ring surface shows that interfacial temperatures can be quite high and they are significantly influenced by the thermal conductivity of the surfaces in rubbing contact. Thermal shock experiments on a test specimen similar to the knife edge geometry demonstrate that cracking of the titanium alloy is possible in a situation involving repeated thermal cycles over a wide temperature range, as might be realized during a rub in the liquid hydrogen fuel pump. High-speed rub interaction tests were conducted using a representative knife edge and seal geometry over a broad range of interaction rates and alternate materials were experimentally evaluated. Plasma-sprayed aluminum-graphite was found to be significantly better than presently used aluminum alloy seals from the standpoint of rub performance. Ion nitriding the titanium alloy knife-edges also improved rub performance compared to the untreated baseline.

  9. The PRESPEC liquid-hydrogen target for in-beam gamma spectroscopy of exotic nuclei at GSI

    Energy Technology Data Exchange (ETDEWEB)

    Louchart, C., E-mail: C.Louchart-Henning@gsi.de [CEA, Centre de Saclay, IRFU, F-91191 Gif-sur-Yvette (France); Gheller, J.M.; Chesny, Ph.; Authelet, G.; Rousse, J.Y.; Obertelli, A. [CEA, Centre de Saclay, IRFU, F-91191 Gif-sur-Yvette (France); Boutachkov, P. [GSI, D-64291 Darmstadt (Germany); IKP, TU Darmstadt, D-64289 Darmstadt (Germany); Pietri, S.; Ameil, F. [GSI, D-64291 Darmstadt (Germany); Audirac, L.; Corsi, A. [CEA, Centre de Saclay, IRFU, F-91191 Gif-sur-Yvette (France); Dombradi, Z. [ATOMKI, P.O. Box 51, H-4001 Debrecen (Hungary); Gerl, J. [GSI, D-64291 Darmstadt (Germany); Gillibert, A.; Korten, W.; Mailleret, C. [CEA, Centre de Saclay, IRFU, F-91191 Gif-sur-Yvette (France); Merchan, E. [GSI, D-64291 Darmstadt (Germany); IKP, TU Darmstadt, D-64289 Darmstadt (Germany); Nociforo, C. [GSI, D-64291 Darmstadt (Germany); Pietralla, N.; Ralet, D. [IKP, TU Darmstadt, D-64289 Darmstadt (Germany); and others

    2014-02-01

    We report on a new liquid hydrogen and deuterium target dedicated to in-beam γ spectroscopy experiments in inverse kinematics at relativistic incident energies at GSI/FAIR. Target thicknesses from 10 to 80 mm can be achieved for an effective diameter of 60 mm. The target-cell and entrance window are maded of 200μm thick Mylar. The design has the advantage of being free of absorbing material at forward angles and 90°, allowing the detection of photons in a wide angular range. A commissioning experiment with a {sup 54}Cr beam at 130 MeV/nucleon has been performed at GSI, using the Rare Isotopes INvestigation at GSI (RISING) detectors. The target has been shown to behave as expected and is ready for experiments at fragmentation Radioactive-Ion Beam Facilities. -- Highlights: • We report on a new liquid hydrogen target for gamma spectroscopy experiments at FAIR. • A commissioning experiment has been performed at GSI, using the RISING detectors. • The target behaves as expected and is ready for experiments.

  10. Model Catalytic Studies of Liquid Organic Hydrogen Carriers: Dehydrogenation and Decomposition Mechanisms of Dodecahydro-N-ethylcarbazole on Pt(111).

    Science.gov (United States)

    Amende, Max; Gleichweit, Christoph; Werner, Kristin; Schernich, Stefan; Zhao, Wei; Lorenz, Michael P A; Höfert, Oliver; Papp, Christian; Koch, Marcus; Wasserscheid, Peter; Laurin, Mathias; Steinrück, Hans-Peter; Libuda, Jörg

    2014-02-07

    Liquid organic hydrogen carriers (LOHC) are compounds that enable chemical energy storage through reversible hydrogenation. They are considered a promising technology to decouple energy production and consumption by combining high-energy densities with easy handling. A prominent LOHC is N-ethylcarbazole (NEC), which is reversibly hydrogenated to dodecahydro-N-ethylcarbazole (H12-NEC). We studied the reaction of H12-NEC on Pt(111) under ultrahigh vacuum (UHV) conditions by applying infrared reflection-absorption spectroscopy, synchrotron radiation-based high resolution X-ray photoelectron spectroscopy, and temperature-programmed molecular beam methods. We show that molecular adsorption of H12-NEC on Pt(111) occurs at temperatures between 173 and 223 K, followed by initial C-H bond activation in direct proximity to the N atom. As the first stable dehydrogenation product, we identify octahydro-N-ethylcarbazole (H8-NEC). Dehydrogenation to H8-NEC occurs slowly between 223 and 273 K and much faster above 273 K. Stepwise dehydrogenation to NEC proceeds while heating to 380 K. An undesired side reaction, C-N bond scission, was observed above 390 K. H8-NEC and H8-carbazole are the dominant products desorbing from the surface. Desorption occurs at higher temperatures than H8-NEC formation. We show that desorption and dehydrogenation activity are directly linked to the number of adsorption sites being blocked by reaction intermediates.

  11. Final design, fluid dynamic and structural mechanical analysis of a liquid hydrogen Moderator for the European Spallation Source

    Science.gov (United States)

    Bessler, Y.; Henkes, C.; Hanusch, F.; Schumacher, P.; Natour, G.; Butzek, M.; Klaus, M.; Lyngh, D.; Kickulies, M.

    2017-02-01

    The European Spallation Source (ESS) is currently in the construction phase and should have first beam on Target in 2019. ESS, located in Sweden, will be the most powerful spallation neutron source worldwide, with the goal to produce neutrons for research. As an in-kind partner the Forschungszentrum Juelich will among others, design and manufacture the four liquid hydrogen Moderators, which are located above and below the Target. Those vessels are confining the cold hydrogen used to reduce the energy level of the fast neutrons, produced by spallation in the Target, in order to make the neutrons usable for neutron scattering instruments. Due to the requirements [1], a fluid dynamic analysis with pressure and temperature depended hydrogen data, taking into account the pseudo critical phenomena and the pulsed neutronic heating (pressure waves) is necessary. With the fluid dynamic results, a structure mechanical analysis including radiation damage investigation (RCC-MRx code [5]), low temperature properties as well as strength reduction by welding can be realized. Finally, the manufacturing and welding completes the design process.

  12. Quantitative evaluation on activated property-tunable bulk liquid water with reduced hydrogen bonds using deconvoluted Raman spectroscopy.

    Science.gov (United States)

    Chen, Hsiao-Chien; Mai, Fu-Der; Yang, Kuang-Hsuan; Chen, Liang-Yih; Yang, Chih-Ping; Liu, Yu-Chuan

    2015-01-06

    Interesting properties of water with distinguishable hydrogen-bonding structure on interfacial phase or in confined environment have drawn wide attentions. However, these unique properties of water are only found within the interfacial phase and confined environment, thus, their applications are limited. In addition, quantitative evaluation on these unique properties associating with the enhancement of water's physical and chemical activities represents a notable challenge. Here we report a practicable production of free-standing liquid water at room temperature with weak hydrogen-bonded structure naming Au nanoparticles (NPs)-treated (AuNT) water via treating by plasmon-induced hot electron transfer occurred on resonantly illuminated gold NPs (AuNPs). Compared to well-known untreated bulk water (deionized water), the prepared AuNT water exhibits many distinct activities in generally physical and chemical reactions, such as high solubilities to NaCl and O2. Also, reducing interaction energy within water molecules provides lower overpotential and higher efficiency in electrolytic hydrogen production. In addition, these enhanced catalytic activities of AuNT water are tunable by mixing with deionized water. Also, most of these tunable activities are linearly proportional to its degree of nonhydrogen-bonded structure (DNHBS), which is derived from the O-H stretching in deconvoluted Raman spectrum.

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

    Science.gov (United States)

    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.

  14. Evidence for cooperative vibrational relaxation of the NH-, OH-, and OD-stretching modes in hydrogen-bonded liquids using infrared pump-probe spectroscopy.

    Science.gov (United States)

    Shaw, D J; Panman, M R; Woutersen, S

    2009-11-27

    Vibrational energy relaxation of the NH-, OH-, and OD-stretching modes in hydrogen-bonded liquids has been investigated by means of infrared pump-probe spectroscopy. The relaxation rates have been determined both in neat liquids and in isotopic mixtures with systematically varied isotope fractions. In all liquids, the vibrational relaxation rate increases as the isotope fraction is increased and reaches a maximum in the neat liquid. The dependence of the relaxation rate on the isotope fraction suggests a relaxation channel in which the vibrational energy is partitioned between accepting modes of two neighboring molecules.

  15. Hydrogen-Free Liquid-Helium Recovery Plants: The Solution for Low-Temperature Flow Impedance Blocking

    Science.gov (United States)

    Gabal, M.; Arauzo, A.; Camón, A.; Castrillo, M.; Guerrero, E.; Lozano, M. P.; Pina, M. P.; Sesé, J.; Spagna, S.; Diederichs, J.; Rayner, G.; Sloan, J.; Galli, F.; van der Geest, W.; Haberstroh, C.; Dittmar, N.; Oca, A.; Grau, F.; Fernandes, A.; Rillo, C.

    2016-08-01

    The blocking of fine-capillary tubes used as flow impedances in 4H3 evaporation cryostats to achieve temperatures below 4.2 K is generally attributed to nitrogen or air impurities entering these tubes from the main bath. The failure of even the most rigorous low-temperature laboratory best practices aimed at eliminating the problem by maintaining the cleanliness of the helium bath and preventing impurities from entering the capillary tubes suggests that a different cause is responsible for the inexplicable reduction of impedance flow. Many low-temperature research laboratories around the world have suffered this nuisance at a considerable financial cost due to the fact that the affected systems have to be warmed to room temperature in order to recover their normal low-temperature operation performance. Here, we propose an underlying physical mechanism responsible for the blockages based upon the freezing of molecular H2 traces present in the liquid-helium bath. Solid H2 accumulates at the impedance low-pressure side, and, after some time, it produces a total impedance blockage. The presence of H2 traces is unavoidable due its occurrence in the natural gas wells where helium is harvested, forcing gas suppliers to specify a lower bound for impurity levels at about 100 ppb even in high-grade helium. In this paper, we present a simple apparatus to detect hydrogen traces present in liquid helium and easily check the quality of the liquid. Finally, we propose a solution to eliminate the hydrogen impurities in small- and large-scale helium recovery plants. The solution has been implemented in several laboratories that previously experienced a chronic occurrence of blocking, eliminating similar occurrences for more than one year.

  16. Gas-Liquid Precipitation of water dissolved heavy metal ions using hydrogen sulfide gas

    NARCIS (Netherlands)

    Al Tarazi, M.Y.M.

    2004-01-01

    Precipitation of solids promoted by gas-liquid reactions is applied in many industrial processes such as the production of ammonium phosphate, ammonium sulphate, barium carbonate, calcium carbonate, calcium fluoride, ypsum (calcium sulphate), goethite, sodium bicarbonate, strontium carbonate and

  17. Isotopic exchange between molecular hydrogen and liquid ammonia catalysed by alkali amides; Echange isotopique entre l'hydrogene moleculaire et l'ammoniac liquide catalyse par les amidures alcalins

    Energy Technology Data Exchange (ETDEWEB)

    Delmas, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-06-15

    The catalytic action of alkali amides on the isotopic exchange between hydrogen and liquid ammonia has been reinvestigated. It was clear before this work that the reaction is homogeneous and first order with respect to the concentration of dissolved hydrogen, but the nature of the catalytic species was still subject to discussion. On one hand new precise kinetic measurements have been made with sodium, potassium, rubidium and cesium amide. On the other hand, the dissociation of these salts has been calculated with the help of the FUOSS-ONSAGER equation. If the rate of exchange is plotted as a function of the concentration of the free amide ion, a linear relationship is obtained. In our experimental conditions, primary salt effects are negligible and the concentration has to be used in the rate equations. This shows that only the free amide ion is acting as a catalytic species. Experiments on common ion effects and secondary salt effects support this conclusion. The results are in agreement with an associative mechanism. (author) [French] Une nouvelle etude de l'echange isotopique entre l'hydrogene et l'ammoniac liquide catalyse par les amidures alcalins a ete effectuee. II etait bien etabli avant le present travail que la reaction etait homogene et que sa vitesse etait du premier ordre par rapport a la concentration d'hydrogene dissous, mais la nature de l'espece catalytique etait encore controversee. De nouvelles mesures cinetiques precises ont ete faites avec les amidures de sodium, de potassium, de rubidium et de cesium. D'autre part, la dissociation de ces sels a ete calculee a l'aide de l'equation de FUOSS-ONSAGER. On constate que la vitesse d'echange est proportionnelle a la concentration de l'ion amidure libre. Dans nos conditions experimentales, les effets de sel primaires sont negligeables, l'equation de vitesse doit s'exprimer simplement en fonction des concentrations. Ceci indique que l

  18. Thermodynamics of hydrogen bonding and van der Waals interactions of organic solutes in solutions of imidazolium based ionic liquids: “Structure-property” relationships

    Energy Technology Data Exchange (ETDEWEB)

    Varfolomeev, Mikhail A., E-mail: vma.ksu@gmail.com; Khachatrian, Artashes A.; Akhmadeev, Bulat S.; Solomonov, Boris N.

    2016-06-10

    Highlights: • Solution enthalpies of organic solutes in imidazolium based ionic liquids were measured. • van der Waals interactions scale of imidazolium based ionic liquids was proposed. • Enthalpies of solvation of organic solutes in ionic liquids were determined. • Hydrogen bond enthalpies of organic solutes with ionic liquids were calculated. • Relationships between structure of ionic liquids and thermochemical data were obtained. - Abstract: In the present work thermochemistry of intermolecular interactions of organic compounds in solutions of imidazolium based ionic liquids (ILs) has been studied using solution calorimetry method. Enthalpies of solution at infinite dilution of non-polar (alkanes, aromatic hydrocarbons) and polar (alcohols, amides, and etc.) organic solutes in two ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium trifluoromethanesulfonate were measured at 298.15 K. The scale of van der Waals interactions of imidazolium based ILs has been proposed on the basis of solution enthalpies of n-alkanes in their media. The effect of the cation and anion structure of ILs on the enthalpies of solvation was analyzed. Enthalpies of hydrogen bonding of organic solutes with imidazolium based ILs were determined. It has been shown that these values are close to zero for proton acceptor solutes. At the same time, enthalpies of hydrogen bonding of proton donor solutes with ionic liquids are increased depending the anion: tetrafluoroborate ≈ bis(trifluoromethylsulfonyl)imide < 2-(2-methoxyethoxy)ethyl sulfate < trifluoromethanesulfonate. Enthalpies of van der Waals interactions and hydrogen bonding in the solutions of imidazolium based ionic liquids were compared with the same data for molecular solvents.

  19. Molecular dynamics study of nanoscale organization and hydrogen bonding in binary mixtures of butylammonium nitrate ionic liquid and primary alcohols

    Science.gov (United States)

    Shrivastav, Gourav; Gupta, Aditya; Rastogi, Aman; Dhabal, Debdas; Kashyap, Hemant K.

    2017-02-01

    Molecular dynamics simulations are utilized here to explore the nanoscale morphology and the nature of hydrogen bonding in the equimolar mixtures of butylammonium nitrate protic ionic liquid with ethanol, propanol, and butanol. The X-ray scattering experimental study of Greaves et al. [Phys. Chem. Chem. Phys. 13, 13 501 (2011)] has evidenced that alkylammonium nitrate plus alcohol mixtures possess nanoscale structural order which becomes more pronounced as the chain length of the alcohol increases. Our analysis carried out using simulated total and partial X-ray scattering structure functions quantifies the basis of these observations. The partial structure functions highlight the off-phase density correlations of alcohol with both cation and anion in the low-q region. We demonstrate that the chain lengthening of alcohols offers significant variation in the structuring of the polar and apolar moieties in the mixtures. The inspection based on radial distribution functions manifests the non-linear hydrogen bonds of cations with nitrate anions as well as alcohol molecules. The alcohol's hydroxyl group prefers to form linear hydrogen bonds with anions and with other alcohol molecules. Incremented chain length of alcohol improves the extent of hydrogen bonding but does not alter their geometry. Spatial distribution functions delineate similar preferences. It shows stronger directional preferences of the hydroxyl group of alcohols than cation in the vicinity of an anion. Enhanced pair correlations associated with the terminal methyl carbons suggest aggregation of butanol chains in apolar domains. Triplet correlation functions (TCFs) are also used to evaluate the orientational preferences of the present polar moieties in the mixtures. Information based on TCFs for distribution of polar head group of cations and anions unveils the dominance of equilateral configurations over the less frequent isosceles configurations in all the three mixtures.

  20. DNB heat flux in forced convection of liquid hydrogen for a wire set in central axis of vertically mounted flow channel

    Science.gov (United States)

    Matsumoto, T.; Shirai, Y.; Shiotsu, M.; Fujita, K.; Kainuma, T.; Tatsumoto, H.; Naruo, Y.; Kobayashi, H.; Nonaka, S.; Inatani, Y.

    2017-12-01

    Liquid hydrogen has excellent physical properties, high latent heat and low viscosity of liquid, as a coolant for superconductors like MgB2. The knowledge of Departure from Nucleate Boiling (DNB) heat flux of liquid hydrogen is necessary for designing and cooling analysis of high critical temperature superconducting devices. In this paper, DNB heat fluxes of liquid hydrogen were measured under saturated and subcooled conditions at absolute pressures of 400, 700 and 1100 kPa for various flow velocities. Two wire test heaters made by Pt-Co alloy with the length of 200 mm and the diameter of 0.7 mm were used. And these round heaters were set in central axis of a flow channel made of Fiber Reinforced Plastic (FRP) with inner diameters of 8 mm and 12 mm. These test bodies were vertically mounted and liquid hydrogen flowed upward through the channel. From these experimental values, the correlations of DNB heat flux under saturated and subcooled conditions are presented in this paper.

  1. Study of Systems and Technology for Liquid Hydrogen Production Independent of Fossil Fuels

    Science.gov (United States)

    Sprafka, R. J.; Escher, W. J. D.; Foster, R. W.; Tison, R. R.; Shingleton, J.; Moore, J. S.; Baker, C. R.

    1983-01-01

    Based on Kennedy Space Center siting and logistics requirements and the nonfossil energy resources at the Center, a number of applicable technologies and system candidates for hydrogen production were identified and characterized. A two stage screening of these technologies in the light of specific criteria identified two leading candidates as nonfossil system approaches. Conceptual design and costing of two solar-operated, stand alone systems, one photovoltaic based on and the other involving the power tower approach reveals their technical feasibility as sited as KSC, and the potential for product cost competitiveness with conventional supply approaches in the 1990 to 1210 time period. Conventional water hydrolysis and hydrogen liquefaction subsystems are integrated with the solar subsystems.

  2. Biological conversion of carbon dioxide and hydrogen into liquid fuels and industrial chemicals.

    Science.gov (United States)

    Hawkins, Aaron S; McTernan, Patrick M; Lian, Hong; Kelly, Robert M; Adams, Michael W W

    2013-06-01

    Non-photosynthetic routes for biological fixation of carbon dioxide into valuable industrial chemical precursors and fuels are moving from concept to reality. The development of 'electrofuel'-producing microorganisms leverages techniques in synthetic biology, genetic and metabolic engineering, as well as systems-level multi-omic analysis, directed evolution, and in silico modeling. Electrofuel processes are being developed for a range of microorganisms and energy sources (e.g. hydrogen, formate, electricity) to produce a variety of target molecules (e.g. alcohols, terpenes, alkenes). This review examines the current landscape of electrofuel projects with a focus on hydrogen-utilizing organisms covering the biochemistry of hydrogenases and carbonic anhydrases, kinetic and energetic analyses of the known carbon fixation pathways, and the state of genetic systems for current and prospective electrofuel-producing microorganisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Test results from a simple, low-cost, pressure-fed liquid hydrogen/liquid oxygen rocket combustor

    Science.gov (United States)

    Dressler, G. A.; Stoddard, F. J.; Gavitt, K. R.; Klem, M. D.

    1993-01-01

    A simple, low-cost rocket engine was designed, fabricated, and successfully hot fire tested over a wide range of interface conditions and operating parameters. The engine used low enthalpy hydrogen (45 to 70 R, 200 to 390 psia) and oxygen (139 to 163 R, 210 to 480 psia) propellants pressure-fed directly from facility cryogenic tanks. The engine demonstrated excellent performance, with 97% average combustion efficiency, and absence of combustion instabilities. Engine design chamber pressure was 300 psia, yielding about 16,500 pounds thrust at sea level with a 3:1 expansion ration test nozzle. The engine used a fixed-element injector based on TRW's unique coaxial pintle design, but was operated at 60%, 80%, and 100% thrust levels by throttling facility propellant valves. The engine was tested at propellant mixture ratios (O/F) from 5.8 to 8.4; design O/F was 6.6. To document combustion stability, in five tests RDX explosive pulse guns were detonated in radial and tangential directions across the combustion chamber during steady-state operation. The largest disturbance consisted of simultaneous detonation of a 20-grain radial gun and a 40-grain tangential gun. In no case was an instability, either feed system mode or chamber acoustic mode, excited. High-frequency piezoelectric pressure transducers documented stable recovery from disturbance overpressures within 40 milliseconds of peak pressure. A total of 67 firing tests, accumulating 149 seconds of firing time above 10% P(sub c), were performed. Since parametric testing required run durations of only 2 to 3 seconds, a heat sink combustion chamber was employed for most runs. To evaluate the feasibility of a low-cost ablative system for a flight engine design, one 20-second continuous firing was conducted with a silicone rubber chamber/throat/nozzle liner cast in one piece directly into the engine. The ablative engine operated at the equivalent of 309 seconds sea level specific impulse, when adjusted to a 98% efficient

  4. Test results from a simple, low-cost, pressure-fed liquid hydrogen/liquid oxygen rocket combustor

    Science.gov (United States)

    Dressler, G. A.; Stoddard, F. J.; Gavitt, K. R.; Klem, M. D.

    1993-11-01

    A simple, low-cost rocket engine was designed, fabricated, and successfully hot fire tested over a wide range of interface conditions and operating parameters. The engine used low enthalpy hydrogen (45 to 70 R, 200 to 390 psia) and oxygen (139 to 163 R, 210 to 480 psia) propellants pressure-fed directly from facility cryogenic tanks. The engine demonstrated excellent performance, with 97% average combustion efficiency, and absence of combustion instabilities. Engine design chamber pressure was 300 psia, yielding about 16,500 pounds thrust at sea level with a 3:1 expansion ration test nozzle. The engine used a fixed-element injector based on TRW's unique coaxial pintle design, but was operated at 60%, 80%, and 100% thrust levels by throttling facility propellant valves. The engine was tested at propellant mixture ratios (O/F) from 5.8 to 8.4; design O/F was 6.6. To document combustion stability, in five tests RDX explosive pulse guns were detonated in radial and tangential directions across the combustion chamber during steady-state operation. The largest disturbance consisted of simultaneous detonation of a 20-grain radial gun and a 40-grain tangential gun. In no case was an instability, either feed system mode or chamber acoustic mode, excited. High-frequency piezoelectric pressure transducers documented stable recovery from disturbance overpressures within 40 milliseconds of peak pressure. A total of 67 firing tests, accumulating 149 seconds of firing time above 10% P(sub c), were performed. Since parametric testing required run durations of only 2 to 3 seconds, a heat sink combustion chamber was employed for most runs. To evaluate the feasibility of a low-cost ablative system for a flight engine design, one 20-second continuous firing was conducted with a silicone rubber chamber/throat/nozzle liner cast in one piece directly into the engine. The ablative engine operated at the equivalent of 309 seconds sea level specific impulse, when adjusted to a 98% efficient

  5. Hydrogen-Bonded Liquids: Effects of Correlations of Orientational Degrees of Freedom

    OpenAIRE

    Franzese, G.; Yamada, M.; Stanley, H. E.

    2000-01-01

    We improve a lattice model of water introduced by Sastry, Debenedetti, Sciortino, and Stanley to give insight on experimental thermodynamic anomalies in supercooled phase, taking into account the correlations between intra-molecular orientational degrees of freedom. The original Sastry et al. model including energetic, entropic and volumic effect of the orientation-dependent hydrogen bonds (HBs), captures qualitatively the experimental water behavior, but it ignores the geometrical correlatio...

  6. Helium Refrigeration and Liquefaction Using a Liquid Hydrogen Refrigerator for Precooling

    Science.gov (United States)

    1960-01-27

    presented by Mann and Stewart 3 , Keesom4 and Zelmanov 5. The hydrogen calculations are based on the properties given by Woolley, Scott and Brickwedde 6...Communication, Supplement No. 108c. 5. J. Zelmanov , "The Entropy Diagram for Helium at Low Temperatures", Journal of Physics (USSR), Volume 8, Number 3...Ortho-Para Modifications", Journal of Research, National Bureau of Standards, 41, 379 (1948) RP 1932. 7. I. L. Zelmanov , Comptes rendus (Doklady) Acad. Sci. URSS, 2Z, 25 (1939).

  7. Getter materials for the vacuum insulation of liquid hydrogen storage vessels or transport lines

    Energy Technology Data Exchange (ETDEWEB)

    Boffito, C.; Doni, F.; Ferrario, B.

    1990-09-04

    A getter material is provided which efficiently sorbs gases at low pressure but, when a system failure causes high pressures of hydrogen and oxygen to be present, does not increase its temperature to that which would cause explosive ignition of the hydrogen-oxygen mixture. The material of the invention comprises an alloy of the general formula Zr{sub 1{minus}a}Ti{sub a}V{sub 2{minus}x}Fe{sub x{minus}y}Ni{sub y}. In this formula, a is from 0 to 0.3, x is from 0.5 to 1.5, and y is from 0 to x. Preferably, a=0, x=1, y=0 to 0.5 and even more preferably y=0. Experiments are described to illustrate the performance of materials of the invention in comparison with previously known getter materials. It is shown that preferred traditional Zr-V-Fe getter devices show an extremely high temperature increase up to 720{degree}C when exposed to a high pressure of hydrogen, while the getter devices of the invention reach a temperature of only 230{degree}C. 2 figs., 1 tab.

  8. Influence of hydrogen bond accepting ability of anions on the adsorption performance of ionic liquid surface molecularly imprinted polymers.

    Science.gov (United States)

    Zhu, Guifen; Gao, Xia; Wang, Xiaolong; Wang, Jianji; Fan, Jing

    2018-01-12

    To illuminate the influence mechanism of anionic structure of ionic liquids (ILs) on the adsorption performance of surface molecularly imprinted polymers (MIPs), in this work, six newly designed MIPs were prepared on the surface of amino-poly(styrene-divinylbenzene) particles by using imidazolium ILs with the same cation [C 4 mim] + but different anions (Cl, CH 3 SO 3 , PF 6 , BF 4 , C 4 F 7 O 2 , C 4 F 9 SO 3 ) as template molecules, methacrylic acid as functional monomer, and ethylene dimethacrylate as cross-linker. The resulting MIP materials were characterized by IR and SEM, and the influence of hydrogen bond accepting ability of anions on the adsorption performance of the MIPs for the ILs was investigated in acetonitrile. It was found that adsorption capacity of the MIPs towards the ILs decreased in the order MIP [C4mim][Cl]  > MIP [C4mim][C4F7O2]  ≥ MIP [C4mim][BF4] and MIP [C4mim][CH3SO3]  > MIP [C4mim][C4F9SO3]  > MIP [C4mim][PF6] , which is in good agreement with the ability of anions of the ILs to form hydrogen bonds. Ultraviolet, 1 H-NMR and 35 Cl-NMR spectroscopy was then used to study the interactions of anions of the ILs with the functional monomer. It was found that the hydrogen bond interaction between anions of the ILs and acidic proton of the functional monomer was the main driving force for the high adsorption selectivity of the imprinted polymers, and the stronger hydrogen bond interaction indicates higher binding capacity and higher selectivity of the polymers towards the ILs. It was also verified that the ILs with stronger hydrogen bond accepting ability of anions could be selectively extracted by the corresponding IL-MIPs. These results may provide new insight into the recognition mechanism of MIPs for ILs, and are also useful for the rational design of this new class of imprinting materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere IV. On the Nature of the Chromosphere

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available The chromosphere is the site of weak emission lines characterizing the flash spectrum observed for a few seconds during a total eclipse. This layer of the solar atmosphere is known to possess an opaque Hα emission and a great number of spicules, which can extend well above the photosphere. A stunning variety of hydrogen emission lines have been observed in this region. The production of these lines has provided the seventeenth line of evidence that the Sun is comprised of condensed matter (Robitaille P.M. Liquid Metallic Hydrogen II: A critical assessment of current and primordial helium levels in Sun. Progr. Phys., 2013, v. 2, 35–47. Contrary to the gaseous solar models, the simplest mechanism for the production of emission lines is the evaporation of excited atoms from condensed surfaces existing within the chromosphere, as found in spicules. This is reminiscent of the chemiluminescence which occurs during the condensation of silver clusters (Konig L., Rabin I., Schultze W., and Ertl G. Chemiluminescence in the Agglomeration of Metal Clusters. Science, v. 274, no. 5291, 1353–1355. The process associated with spicule formation is an exothermic one, requiring the transport of energy away from the site of condensation. As atoms leave localized surfaces, their electrons can occupy any energy level and, hence, a wide variety of emission lines are produced. In this regard, it is hypothesized that the presence of hydrides on the Sun can also facilitate hydrogen condensation in the chromosphere. The associated line emission from main group and transition elements constitutes the thirtieth line of evidence that the Sun is condensed matter. Condensation processes also help to explain why spicules manifest an apparently constant temperature over their entire length. Since the corona supports magnetic field lines, the random orientations associated with spicule formation suggests that the hydrogen condensates in the chromosphere are not metallic in

  10. Magnetic resonance studies of atomic hydrogen at zero field and low temperature. Recombination and binding on liquid helium

    Energy Technology Data Exchange (ETDEWEB)

    Jochemsen, R.; Morrow, M.; Berlinsky, A.J.; Hardy, W.N. (British Columbia Univ., Vancouver (Canada). Dept. of Physics)

    1982-07-01

    Magnetic resonance studies at zero field are reported for atomic hydrogen gas confined in a closed glass bulb with helium-coated walls for T<1 K in a dilution refrigerator. Low-energy r.f. discharge pulses have been used to produce H atoms at temperatures as low as T=0.06 K. The atom density nsub(H) (10/sup 9/..H/sub 2/+wall. From the temperature dependence of the rate constant K we have determined the binding energy of H on liquid /sup 4/He and /sup 3/He, and also the cross section for recombination on the surface.

  11. Balancing low cost with reliable operation in the rotordynamic design of the ALS Liquid Hydrogen Fuel Turbopump

    Science.gov (United States)

    Greenhill, L. M.

    1990-01-01

    The Air Force/NASA Advanced Launch System (ALS) Liquid Hydrogen Fuel Turbopump (FTP) has primary design goals of low cost and high reliability, with performance and weight having less importance. This approach is atypical compared with other rocket engine turbopump design efforts, such as on the Space Shuttle Main Engine (SSME), which emphasized high performance and low weight. Similar to the SSME turbopumps, the ALS FTP operates supercritically, which implies that stability and bearing loads strongly influence the design. In addition, the use of low cost/high reliability features in the ALS FTP such as hydrostatic bearings, relaxed seal clearances, and unshrouded turbine blades also have a negative influence on rotordynamics. This paper discusses the analysis conducted to achieve a balance between low cost and acceptable rotordynamic behavior, to ensure that the ALS FTP will operate reliably without subsynchronous instabilities or excessive bearing loads.

  12. The PRESPEC liquid-hydrogen target for in-beam gamma spectroscopy of exotic nuclei at GSI

    Science.gov (United States)

    Louchart, C.; Gheller, J. M.; Chesny, Ph.; Authelet, G.; Rousse, J. Y.; Obertelli, A.; Boutachkov, P.; Pietri, S.; Ameil, F.; Audirac, L.; Corsi, A.; Dombradi, Z.; Gerl, J.; Gillibert, A.; Korten, W.; Mailleret, C.; Merchan, E.; Nociforo, C.; Pietralla, N.; Ralet, D.; Reese, M.; Stepanov, V.

    2014-02-01

    We report on a new liquid hydrogen and deuterium target dedicated to in-beam γ spectroscopy experiments in inverse kinematics at relativistic incident energies at GSI/FAIR. Target thicknesses from 10 to 80 mm can be achieved for an effective diameter of 60 mm. The target-cell and entrance window are maded of 200 μm thick Mylar. The design has the advantage of being free of absorbing material at forward angles and 90°, allowing the detection of photons in a wide angular range. A commissioning experiment with a 54Cr beam at 130 MeV/nucleon has been performed at GSI, using the Rare Isotopes INvestigation at GSI (RISING) detectors. The target has been shown to behave as expected and is ready for experiments at fragmentation Radioactive-Ion Beam Facilities.

  13. Adaptive resolution simulation of liquid para-hydrogen: testing the robustness of the quantum-classical adaptive coupling.

    Science.gov (United States)

    Poma, A B; Delle Site, L

    2011-06-14

    Adaptive resolution simulations for classical systems are currently made within a reasonably consistent theoretical framework. Recently we have extended this approach to the quantum-classical coupling by mapping the quantum nature of an atom onto a classical polymer ring representation within the path integral approach [Poma & Delle Site, Phys. Rev. Lett., 2010, 104, 250201]. In this way the process of interfacing adaptively a quantum representation to a classical one corresponds to the problem of interfacing two regions with a different number of effective "classical" degrees of freedom; thus the classical formulation of the adaptive algorithm applies straightforwardly to the quantum-classical problem. In this work we show the robustness of such an approach for a liquid of para-hydrogen at low temperature. This system represents a highly challenging conceptual and technical test for the adaptive approach due to the extreme thermodynamical conditions where quantum effects play a central role. This journal is © the Owner Societies 2011

  14. Reduced Order Modeling of SLS Liquid Hydrogen Pre-Valve Flow Guide to Enable Rapid Transient Analysis

    Science.gov (United States)

    Brown, Andrew M.; Mulder, Andrew

    2017-01-01

    NASA is developing a new launch vehicle, called the Space Launch System (SLS), which is intended on taking humans out of low earth orbit to destinations including the moon, asteroids, and Mars. The propulsion system for the core stage of this vehicle includes four RS-25 Liquid Hydrogen/Oxygen rocket engines. These engines are upgraded versions of the Space Shuttle Main Engines (SSME); the upgrades include higher power levels and affordability enhancements. As with any new vehicle, the Main Propulsion System (MPS), which include the feedlines and ancillary hardware connecting the engines to the fuel and oxidizer tanks, had to be redesigned (figure 1 - export clearance in progress), as the previous MPS for the SSME's was inherently part of the Space Shuttle System, which had a completely different overall configuration.

  15. Tuning the Chemoselective Hydrogenation of Nitrostyrenes Catalyzed by Ionic Liquid-Supported Platinum Nanoparticles

    DEFF Research Database (Denmark)

    Beier, Matthias Josef; Andanson, Jean-Michel; Baiker, Alfons

    2012-01-01

    Pt nanoparticles (NPs) in the range of 1.7–3.4 nm were synthesized in an ionic liquid (IL). Subsequent immobilization on various solid supports (silica, alumina, titania, carbon nanotubes (CNTs)) in some cases proved to be beneficial. These catalysts exhibited excellent performance...

  16. Semiquantal molecular dynamics simulations of hydrogen-bond dynamics in liquid water using multi-dimensional Gaussian wave packets.

    Science.gov (United States)

    Ono, Junichi; Ando, Koji

    2012-11-07

    A semiquantal (SQ) molecular dynamics (MD) simulation method based on an extended Hamiltonian formulation has been developed using multi-dimensional thawed gaussian wave packets (WPs), and applied to an analysis of hydrogen-bond (H-bond) dynamics in liquid water. A set of Hamilton's equations of motion in an extended phase space, which includes variance-covariance matrix elements as auxiliary coordinates representing anisotropic delocalization of the WPs, is derived from the time-dependent variational principle. The present theory allows us to perform real-time and real-space SQMD simulations and analyze nuclear quantum effects on dynamics in large molecular systems in terms of anisotropic fluctuations of the WPs. Introducing the Liouville operator formalism in the extended phase space, we have also developed an explicit symplectic algorithm for the numerical integration, which can provide greater stability in the long-time SQMD simulations. The application of the present theory to H-bond dynamics in liquid water is carried out under a single-particle approximation in which the variance-covariance matrix and the corresponding canonically conjugate matrix are reduced to block-diagonal structures by neglecting the interparticle correlations. As a result, it is found that the anisotropy of the WPs is indispensable for reproducing the disordered H-bond network compared to the classical counterpart with the use of the potential model providing competing quantum effects between intra- and intermolecular zero-point fluctuations. In addition, the significant WP delocalization along the out-of-plane direction of the jumping hydrogen atom associated with the concerted breaking and forming of H-bonds has been detected in the H-bond exchange mechanism. The relevance of the dynamical WP broadening to the relaxation of H-bond number fluctuations has also been discussed. The present SQ method provides the novel framework for investigating nuclear quantum dynamics in the many

  17. Hydrogen Bonding in Ion-pair Molecules in Vapors over ionic liquids, studied by Raman Spectroscopy and ab initio Calculations

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    The hydrogen bonding interactions in selected archetypal vapor molecules formed in the gas phase over protic ionic liquids are discussed, based on Raman spectroscopy assisted with ab initio molecular orbital DFT-type quantum mechanical calculations (B3LYP with 6-311+G(d,p) basis sets) on assumed......-O distances in the N-H…O bond were found as 1.730 and 1.005 Å. The comparable H-O distance in solid ethanoic acid is ~1.011 Å (neutron diffraction). [1] R. W. Berg, A. Riisager & R. Fehrmann, Formation of an ion pair molecule with a single NH+…Cl- hydrogen bond: Raman spectra of 1,1,3,3-Tetramethylguanidin...... of 1,1,3,3-tetramethylguanidinium chloride. The optimized N-H distance in the N-H…Cl bond was 1.099 Å. The H-Cl distance was 1.832 Å to compare with the ~1.27 Å in HCl gas. The bromide behaved similarly [ref 2]. Fig. 2. Not so likely 1-methylimidazolium ethanoate gas molecule. The optimized N-H and H...

  18. Development and validation of purged thermal protection systems for liquid hydrogen fuel tanks of hypersonic vehicles

    Science.gov (United States)

    Helenbrook, R. D.; Colt, J. Z.

    1977-01-01

    An economical, lightweight, safe, efficient, reliable, and reusable insulation system was developed for hypersonic cruise vehicle hydrogen fuel tanks. Results indicate that, a nitrogen purged, layered insulation system with nonpermeable closed-cell insulation next to the cryogenic tank and a high service temperature fibrous insulation surrounding it, is potentially an attractive solution to the insulation problem. For the postulated hypersonic flight the average unit weight of the purged insulation system (including insulation, condensate and fuel boil off) is 6.31 kg/sq m (1.29 psf). Limited cyclic tests of large specimens of closed cell polymethacrylimide foam indicate it will withstand the expected thermal cycle.

  19. Large-Scale Demonstration of Liquid Hydrogen Storage with Zero Boiloff for In-Space Applications

    Science.gov (United States)

    Hastings, L. J.; Bryant, C. B.; Flachbart, R. H.; Holt, K. A.; Johnson, E.; Hedayat, A.; Hipp, B.; Plachta, D. W.

    2010-01-01

    Cryocooler and passive insulation technology advances have substantially improved prospects for zero-boiloff cryogenic storage. Therefore, a cooperative effort by NASA s Ames Research Center, Glenn Research Center, and Marshall Space Flight Center (MSFC) was implemented to develop zero-boiloff concepts for in-space cryogenic storage. Described herein is one program element - a large-scale, zero-boiloff demonstration using the MSFC multipurpose hydrogen test bed (MHTB). A commercial cryocooler was interfaced with an existing MHTB spray bar mixer and insulation system in a manner that enabled a balance between incoming and extracted thermal energy.

  20. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere VIII. "Futile" Processes in the Chromosphere (Letters to Progress in Physics

    Directory of Open Access Journals (Sweden)

    Robitaille L.

    2014-01-01

    Full Text Available In the liquid metallic hydrogen solar model (LMHSM, the chr omosphere is the site of hydrogen condensation (P.M. Robitaille. The Liquid Metall ic Hydrogen Model of the Sun and the Solar Atmosphere IV. On the Nature of the Chromosp here. Progr. Phys. , 2013, v. 3, L15–L21. Line emission is associated with the di ssipation of energy from condensed hydrogen structures, CHS. Previously considere d reactions resulted in hy- drogen atom or cluster addition to the site of condensation. In this work, an additional mechanism is presented, wherein atomic or molecular specie s interact with CHS, but do not deposit hydrogen. These reactions channel heat away f rom CHS, enabling them to cool even more rapidly. As a result, this new class of proce sses could complement true hydrogen condensation reactions by providing an auxil iary mechanism for the re- moval of heat. Such ‘futile’ reactions lead to the formation of activated atoms, ions, or molecules and might contribute to line emission from such sp ecies. Evidence that com- plimentary ‘futile’ reactions might be important in the chr omosphere can be extracted from lineshape analysis.

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

    Science.gov (United States)

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

    2017-01-01

    The formation of aqueous biphasic systems (ABS) when mixing aqueous solutions of polyethylene glycol (PEG) and an ionic liquid (IL) can be controlled by modification of the hydrogen bond ability of the polymer’s end groups. It is shown that the miscibility/immiscibility on 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 salt anion. The reduction of even one hydrogen bond in PEG can noticeably affect the phase behavior, especially in those regions of the phase diagram where 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, i.e., in a higher ability to form ABS, as a result of the much weaker interactions between the IL anion and the PEG end groups. PMID:25943332

  2. Investigation of thermal and optical properties of some quartet mixed hydrogen-bonded liquid crystals

    Science.gov (United States)

    Okumuş, Mustafa

    2017-11-01

    In this study, the thermal and optical properties of quartet mixtures formed at different weight ratios (1:1:1:1 and 1.5:1:1:1) from liquid crystals 4-octyloxy-4‧-cyanobiphenyl (8OCB), 4-hexylbenzoic acid, 4-(octyloxy)benzoic acid and 4-(decyloxy)benzoic acid were investigated by differential scanning calorimeter (DSC) and polarized optic microscopy (POM). The phase transition temperatures of the novel quartet mixtures measured in the DSC experiments are in line with the POM experiments. The experimental results clearly show that the novel liquid crystal mixtures have displayed pure liquid crystalline properties. According to the phase diagram drawn from DSC results, the nematic range of the novel mixture at the eutectic point is larger than the nematic ranges of the components. The mesomorphic structures of produced homolog complex mixtures are found to be smectic and nematic phases. But the smectic phase cannot be observed in the novel complex 1.5:1:1:1 mixture during continuous cooling. The nematic range of the novel complex 1.5:1:1:1 mixture is bigger than the nematic range of the novel complex 1:1:1:1 mixture with increasing 8OCB. Also, the nematic-to-isotropic phase transition temperature decreases with increasing the weight ratio of 8OCB in the complex quartet mixture. Another interesting result is that the produced mixtures are to be like a medical cream at room temperatures. Furthermore, order parameter and thermal stability factor of the transitions are also calculated.

  3. Path integral centroid molecular dynamics simulations of semiinfinite slab and bulk liquid of para-hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kinugawa, Kenichi [Nara Women`s Univ., Nara (Japan). Dept. of Chemistry

    1998-10-01

    It has been unsuccessful to solve a set of time-dependent Schroedinger equations numerically for many-body quantum systems which involve, e.g., a number of hydrogen molecules, protons, and excess electrons at a low temperature, where quantum effect evidently appears. This undesirable situation is fatal for the investigation of real low-temperature chemical systems because they are essentially composed of many quantum degrees of freedom. However, if we use a new technique called `path integral centroid molecular dynamics (CMD) simulation` proposed by Cao and Voth in 1994, the real-time semi-classical dynamics of many degrees of freedom can be computed by utilizing the techniques already developed in the traditional classical molecular dynamics (MD) simulations. Therefore, the CMD simulation is expected to be very powerful tool for the quantum dynamics studies or real substances. (J.P.N.)

  4. Liquid hydrogen bubble chamber (diam. 30 cm), seen here being inserted into its vacuum tank

    CERN Multimedia

    CERN PhotoLab

    1959-01-01

    In the 1950s and 1960s, bubble and spark chambers were the dominant experimental tools in high-energy physics. While spark chambers were usually built and fitted to specific experiments, bubble chambers were constructed as general purpose devices that could be used for a variety of experiments. At CERN, the bubble chamber programme started under Charles Peyrou in the late 1950s. The first of CERN's bubble chambers, a 30 cm hydrogen chamber, is seen here being inserted into its vacuum tank. The HBC30, as it was called, took its first beam from the SC in 1959. One of the first pictures taken, of a positive pion-proton interaction, began a long series of pretty images for which bubble chambers would become famous. When it stopped operating in spring 1962, the HBC30 had consumed 150 km of film in its 3 years of operation.

  5. Influence of the fineness of grinding coal on the results in liquid-phase hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Rank, V.

    1944-02-08

    This short note reported older results of experiments on brown coal from Boehlen, of which two different samples were hydrogenated at 250 atm, with each sample ground to a different degree of fineness. In sieving with a sieve of 16,900 mesh, 76.8% of one sample went through, whereas only 63.4% of the other sample went through. The more finely ground sample gave better values of coal decomposition (98.8% vs. 97.7%), yield of gasoline and middle oil (0.30 kg/liter/hr vs. 0.26), and losses to gas formation (19.3% vs. 20.7%). The experiments were carried out in a 10-liter oven.

  6. Selective hydrogenation of 1,3-butadiene from crude C{sub 4} cracker stream with a solid catalyst with ionic liquid layer (SCILL). DSC and solubility study

    Energy Technology Data Exchange (ETDEWEB)

    Mangartz, T.; Korth, W.; Kern, C.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

    2013-11-01

    In petroleum as well as in fine chemical industry, selective catalytic hydrogenation is an important reaction. The selective hydrogenation of 1,3-butadiene (BD) to butene (trans-,1- and cis-butene) from the crude C4 steam cracker fraction represents one example, but under today's technical conditions undesired butane forms inevitably in relevant amounts. To increase the butene yield, the concept of Solid Catalyst with Ionic Liquid Layer (SCILL) was employed. The SCILL catalyst, in contrast to the uncoated catalyst, yielded a remarkably high selectivity to butenes (S{sub butenes} > 99 %) even at high residence times or at high hydrogen partial pressure. Nearly no butane (S{sub butane} {approx} 0 %) was analytically detected. We expected that due to different solubility, the poorer soluble compounds discharged from the ionic liquid and, thus, caused the shift in selectivity to a great extent. Temperature dependent solubility measurements in the used ionic liquid ([DMIM][DMP]) revealed that the order of increasing solubility is 1,3-butadiene > butenes > butane which matches the assumption. However, since differences in solubility cannot explain this SCILL effect satisfyingly, ionic liquids are expected to affect the surface of the catalyst (side-specific ligand-type effect). Investigations using spectroscopic methods (e.g. FTIR) confirmed this suggestion. (orig.)

  7. Ultrasound promoted catalytic liquid-phase dehydrogenation of isopropanol for Isopropanol-Acetone-Hydrogen chemical heat pump.

    Science.gov (United States)

    Xu, Min; Xin, Fang; Li, Xunfeng; Huai, Xiulan; Liu, Hui

    2015-03-01

    The apparent kinetic of the ultrasound assisted liquid-phase dehydrogenation of isopropanol over Raney nickel catalyst was determined in the temperature range of 346-353 K. Comparison of the effects of ultrasound and mechanical agitation on the isopropanol dehydrogenation was investigated. The ultrasound assisted dehydrogenation rate was significantly improved when relatively high power density was used. Moreover, the Isopropanol-Acetone-Hydrogen chemical heat pump (IAH-CHP) with ultrasound irradiation, in which the endothermic reaction is exposure to ultrasound, was proposed. A mathematical model was established to evaluate its energy performance in term of the coefficient of performance (COP) and the exergy efficiency, into which the apparent kinetic obtained in this work was incorporated. The operating performances between IAH-CHP with ultrasound and mechanical agitation were compared. The results indicated that the superiority of the IAH-CHP system with ultrasound was present even if more than 50% of the power of the ultrasound equipment was lost. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Characterization of Pump-Induced Acoustics in Space Launch System Main Propulsion System Liquid Hydrogen Feedline Using Airflow Test Data

    Science.gov (United States)

    Eberhart, C. J.; Snellgrove, L. M.; Zoladz, T. F.

    2015-01-01

    High intensity acoustic edgetones located upstream of the RS-25 Low Pressure Fuel Turbo Pump (LPFTP) were previously observed during Space Launch System (STS) airflow testing of a model Main Propulsion System (MPS) liquid hydrogen (LH2) feedline mated to a modified LPFTP. MPS hardware has been adapted to mitigate the problematic edgetones as part of the Space Launch System (SLS) program. A follow-on airflow test campaign has subjected the adapted hardware to tests mimicking STS-era airflow conditions, and this manuscript describes acoustic environment identification and characterization born from the latest test results. Fluid dynamics responsible for driving discrete excitations were well reproduced using legacy hardware. The modified design was found insensitive to high intensity edgetone-like discretes over the bandwidth of interest to SLS MPS unsteady environments. Rather, the natural acoustics of the test article were observed to respond in a narrowband-random/mixed discrete manner to broadband noise thought generated by the flow field. The intensity of these responses were several orders of magnitude reduced from those driven by edgetones.

  9. Leaching performance of imidazolium based ionic liquids in the presence of hydrogen peroxide for recovery of metals from brass waste

    Directory of Open Access Journals (Sweden)

    Kilicarslan, Ayfer

    2016-03-01

    Full Text Available The application of ionic liquids (ILs, 1-methylimidazolium hydrogen sulfate (HmimHSO4, 1-ethyl-3-methylimidazolium hydrogen sulfate (HmimHSO4 and 1-butyl-3-methylimidazolium chloride (BmimCl as leaching agents was investigated in the leaching of copper and zinc from brass waste in the presence of an oxidant, hydrogen peroxide (H2O2. Factors that affect copper and zinc dissolution rates such as ionic liquid concentration, time and temperature were investigated. The results indicated that zinc was dissolved in leach solutions with EmimHSO4 and HmimHSO4, completely. Temperature had no considerable influence on copper dissolution rate whilst the rate increased with decreasing IL concentration. In the EmimHSO4 system, higher copper recoveries were achieved with 40% and 60% IL concentrations compared with IL concentrations of 20% and 80% at 40 °C leaching temperature. Copper dissolution rates decreased with EmimHSO4 concentration at 60 °C and 80 °C in the following order; 40% > 20% > 60% > 80%. On the other hand the leaching system with BmimCl generally resulted in poor extractions of copper and zinc.Este trabajo investiga el uso de líquidos iónicos (LIs, hidrogenosulfato de 1-metillimidazolio (HmimHSO4, hidrogenosulfato de 1-etil-3- metilimidazolio (EmimHSO4 y cloruro de 1-butil-1-metilimidazolio (BmimCl, como agentes de lixiviación de cobre y zinc a partir de residuos de latón en presencia de un oxidante, peróxido de hidrógeno (H2O2. Se estudiaron distintos factores que afectan a la velocidad de disolución del cobre y el zinc, como la concentración del líquido iónico, el tiempo y la temperatura. Los resultados indican que el zinc se disuelve completamente en las disoluciones que contienen EmimHSO4 y HmimHSO4. La temperatura no tiene un efecto significativo en la velocidad de disolución del cobre, mientras que dicha velocidad aumenta al disminuir la concentración del líquido iónico. En los sistemas que contienen EmimHSO4, los mejores

  10. Evaluation of the nonrandom hydrogen bonding (NRHB) theory and the simplified perturbed-chain-statistical associating fluid theory (sPC-SAFT). 1. Vapor-liquid equilibria

    DEFF Research Database (Denmark)

    Grenner, Andreas; Tsivintzelis, Ioannis; Economou, Ioannis

    2008-01-01

    A standard database for the validation of vapor-liquid equilibrium (VLE) models was used to evaluate prediction and correlation accuracy of the nonrandom hydrogen bonding (NRHB) theory and the simplified perturbed-chain-statistical associating fluid theory (PC-SAFT). Pure-component parameters...... for the models were taken from literature or estimated in this work. Generalized pure-component parameters were fitted to pure-component vapor-pressure and liquid-density data. For the majority of the mixtures examined, satisfactory results were obtained. For a number of mixtures, different modeling approaches...

  11. Intermolecular structure and hydrogen-bonding in liquid 1,2-propylene carbonate and 1,2-glycerol carbonate determined from neutron scattering

    OpenAIRE

    Delavoux, Yoan; Gilmore, Mark; Atkins, Martin P.; Swadzba-Kwasny, Malgorzata; Holbrey, John D.

    2017-01-01

    Neutron diffraction with isotopic substitution has been used to investigate the liquid structures of propylene carbonate and glycerol carbonate. C-H···O=C hydrogen-bonding motifs dominate the local structure of propylene carbonate, giving rise to the formation of head-to-tail correlated chains of molecules. In contrast, glycerol carbonate exhibits a more disordered structure with no overall dominant interactions in which the pendant hydroxyl function disrupts structure-making correlations pre...

  12. Identification of reaction products of methamphetamine and hydrogen peroxide in hair dye and decolorant treatments by high-performance liquid chromatography/mass spectrometry.

    Science.gov (United States)

    Tanaka, S; Iio, R; Chinaka, S; Takayama, N; Hayakawa, K

    2001-02-01

    The effect of hydrogen peroxide, a main component of hair dye and decolorant treatments, on methamphetamine (MA) was studied. Two analytical methods, thin-layer chromatography (TLC) and high-performance liquid chromatography/mass spectrometry (LC/MS), were used for the separation and identification of MA derivatives. Mixtures of MA solutions and hydrogen peroxide that had been incubated at 39 degrees C for 24 h were shown to contain para-hydroxy MA by TLC and para-, meta- and ortho-hydroxy MAs by LC/MS. In addition, MA N-oxide and N-hydroxy MA were found in MA/hydrogen peroxide mixtures immediately after mixing. Therefore, we concluded that MA changed to MA N-oxide and N-hydroxy MA before changing to para-, meta- and ortho-hydroxy MAs.

  13. Induced Smectic X Phase Through Intermolecular Hydrogen-Bonded Liquid Crystals Formed Between Citric Acid and p- n-(Octyloxy)Benzoic Acid

    Science.gov (United States)

    Sundaram, S.; Subhasri, P.; Rajasekaran, T. R.; Jayaprakasam, R.; Senthil, T. S.; Vijayakumar, V. N.

    2017-08-01

    Hydrogen-bonded liquid crystal (HBLC) is synthesized from citric acid (CA) and 4-(octyloxy)benzoic acid (8OBA) with different mole ratios. Fourier transform infrared spectroscopy (FT-IR) confirms the presence of hydrogen bond between CA and 8OBA. Nuclear magnetic resonance (NMR) spectroscopic studies validate the intermolecular complementary, cyclic type of hydrogen bond, and molecular environment in the designed HBLC complex. Powder X-ray diffraction analysis reveals the monoclinic nature of liquid crystal complex in solid phase. Liquid crystal parameters such as phase transition temperature and enthalpy values for the corresponding mesogenic phases are investigated using a polarizing optical microscope (POM) and differential scanning calorimetry (DSC). It is observed that the change in chain length and steric hindrance while increasing the mole ratio in HBLC complex induces a new smectic X (Sm X) along with higher-order smectic G (Sm G) phases by quenching of smectic C (Sm C). From the experimental observations, induced Sm X phase has been identified as a finger print texture. Also, Sm G is a multi-colored mosaic texture in 1:1, 1:2, and 1:3 mol ratios. The optical tilt angle, thermal stability factor, and enhanced thermal span width of CA + 8OBA complex are discussed.

  14. Study of high gain spherical shell ICF targets containing uniform layers of liquid deuterium tritium fuel. A numericial model for analyzing thermal layering of liquid mixtures of hydrogen isotopes inside a spherical inertial confinement fusion target: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, E.M.; Kim, Kyekyoon [Lawrence Livermore National Lab., CA (United States)

    1994-05-01

    A numerical model has been developed to describe the thermally induced behavior of a liquid layer of hydrogen isotopes inside a spherical Inertial Confinement Fusion (ICF) target and to calculate the far-field temperature gradient which will sustain a uniform liquid layer. This method is much faster than the trial-and-error method previously employed. The governing equations are the equations of continuity, momentum, energy, mass diffusion-convection, and conservation of the individual isotopic species. Ordinary and thermal diffusion equations for the diffusion of fluxes of the species are included. These coupled equations are solved by a finite-difference method using upwind schemes, variable mesh, and rigorous boundary conditions. The solution methodology unique to the present problem is discussed in detail. in particular, the significance of the surface tension gradient driven flows (also called Marangoni flows) in forming uniform liquid layers inside ICF targets is demonstrated. Using the theoretical model, the values of the externally applied thermal gradients that give rise to uniform liquid layers of hydrogen inside a cryogenic spherical-shell ICF target are calculated, and the results compared with the existing experimental data.

  15. Analysis of the effects of explosion of a hydrogen cylinder on the transfer of radioactive liquid wastes at nuclear power stations

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Karina B., E-mail: karina@inb.gov.b [Industrias Nucleares do Brasil (INB), Rio de Janeiro, RJ (Brazil); Melo, Paulo Fernando F.F. e, E-mail: frutoso@nuclear.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear

    2011-07-01

    This work presents a study of explosion effects of a stored hydrogen cylinder on the transfer of radioactive liquid wastes at nuclear power plants. The peak overpressure is calculated, as well as the strength of resulting fragments, thus confirming the main harmful effect of an explosion of flammable vapor cloud, based on the TNT equivalent method. The scenarios identified are calculated and compared with the overpressure ranges of 1%, 50% and 99% of structural damages, which were determined by the Eisenberg's vulnerability model. The results show that the overpressure and the resulting fragments from the explosion of a hydrogen gas cylinder are not able to cause the overturning of the tanker under study, and also show that a minimum distance of 30 meters between the hydrogen cylinder and the tanker can be considered a safe distance to the passage of this tanker during the transfer of radioactive liquid waste, in which the likelihood of occurrence of structural damages is less than 1%. (author)

  16. Liquid Hydrogen Pump

    Science.gov (United States)

    1964-11-01

    S V 15 8 Inlet Nozzle Profile for Inducer Impeller 17 9 LH2 Pump Inl- Characteristics vs TSH 18 10 LH2 Test Pump Inlet Edge Loading, 2-Degree Turning...boundary condition. The inlet nozzle profile is shown in Figure 8. Inducer Diameter A parametric investigation was made to determine the optimum inlet

  17. Hydrogen bonded structure, polarity, molecular motion and frequency fluctuations at liquid-vapor interface of a water-methanol mixture: an ab initio molecular dynamics study.

    Science.gov (United States)

    Choudhuri, Jyoti Roy; Chandra, Amalendu

    2014-10-07

    We have performed ab initio molecular dynamics simulations of a liquid-vapor interfacial system consisting of a mixture of water and methanol molecules. Detailed results are obtained for the structural and dynamical properties of the bulk and interfacial regions of the mixture. Among structural properties, we have looked at the inhomogeneous density profiles of water and methanol molecules, hydrogen bond distributions and also the orientational profiles of bulk and interfacial molecules. The methanol molecules are found to have a higher propensity to be at the interface than water molecules. It is found that the interfacial molecules show preference for specific orientations so as to form water-methanol hydrogen bonds at the interface with the hydrophobic methyl group pointing towards the vapor side. It is also found that for both types of molecules, the dipole moment decreases at the interface. It is also found that the local electric field of water influences the dipole moment of methanol molecules. Among the dynamical properties, we have calculated the diffusion, orientational relaxation, hydrogen bond dynamics, and vibrational frequency fluctuations in bulk and interfacial regions. It is found that the diffusion and orientation relaxation of the interfacial molecules are faster than those of the bulk. However, the hydrogen bond lifetimes are longer at the interface which can be correlated with the time scales found from the decay of frequency time correlations. The slower hydrogen bond dynamics for the interfacial molecules with respect to bulk can be attributed to diminished cooperative effects at the interface due to reduced density and number of hydrogen bonds.

  18. Liquid mixtures involving hydrogenated and fluorinated chains: (p, ρ, T, x) surface of (ethanol + 2,2,2-trifluoroethanol), experimental and simulation.

    Science.gov (United States)

    Duarte, Pedro; Silva, Marcelo; Rodrigues, Djêide; Morgado, Pedro; Martins, Luís F G; Filipe, Eduardo J M

    2013-08-22

    The effect of mixing hydrogenated and fluorinated molecules that simultaneously interact through strong hydrogen bonding was investigated: (ethanol + 2,2,2-trifluoroethanol) binary mixtures were studied both experimentally and by computer simulation. This mixture displays a very complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The excess volumes are large and positive (unlike those of mixtures of hydrogenated alchools), while the excess enthalpies are large and negative (contrasting with those of mixtures of alkanes and perfluoroalkanes). In this work, the liquid density of the mixtures was measured as a function of composition, at several temperatures from 278.15 to 353.15 K and from atmospheric pressure up to 70 MPa. The corresponding excess molar volumes, compressibilities, and expansivities were calculated over the whole (p, ρ, T, x) surface. In order to obtain molecular level insight, the behavior of the mixture was also studied by molecular dynamics simulation, using the OPLS-AA force field. The combined analysis of the experimental and simulation results indicates that the peculiar phase behavior of this system stems from a balance between the weak dispersion forces between the hydrogenated and fluorinated groups and a preferential hydrogen bond between ethanol and 2,2,2-trifluoroethanol. Additionally, it was observed that a 25% reduction of the F-H dispersive interaction in the simulations brings agreement between the experimental and simulated excess enthalpy but produces no effect in the excess volumes. This reveals that the main reason causing the volume increase in these systems is not entirely related to the weak dispersive interactions, as it is usually assumed, and should thus be connected to the repulsive part of the intermolecular potential.

  19. Liquid phase hydrogenation of acethydrazone to N'-methyl acethydrazide over Pd/γ-Al2O3 catalyst

    Directory of Open Access Journals (Sweden)

    S. G. Pakdehi

    2010-03-01

    Full Text Available Catalytic hydrogenation of acethydrazide (AH is the main step in the production of N'-methyl acethydrazide (MAH. In this step, AH reacts with formaldehyde to produce acetylhydrazone (AOH. AOH is hydrogenated in the presence of 5% Pd/γ-Al2O3 catalyst to MAH. In this paper, the effects of hydrogen pressure, catalyst loading and initial concentration of AOH on the initial rate of hydrogenation were studied in a batch slurry reactor within a temperature range of 303-333K. The hydrogenation rate was first order with respect to hydrogen concentration at lower hydrogen pressures. However, at higher pressures, the rate became independent of both hydrogen and initial AOH concentrations. A single site Langmuir-Hinshelwood type formulation was found to describe adequately the kinetic data. A good correlation was observed between the predicted concentration vs. time profiles and those determined experimentally. The apparent activation energy was calculated from the initial rates as 40.6 kJ/mol.

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

    Science.gov (United States)

    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.

  1. The hydrogen state: from the solid to the gas taking into account the liquid; L'hydrogene dans tous ses etats: du solide au gaz en passant par le liquide

    Energy Technology Data Exchange (ETDEWEB)

    Latroche, M.; Joubert, J.M.; Cuevas, F.; Paul-Boncour, V.; Percheron-Guegan, A. [Centre National de la Recherche Scientifique (CNRS), Institut de Chimie et des Materiaux Paris-Est (CMTR-ICMPE-UMR7182), 94 - Thiais (France)

    2007-07-01

    Hydrogen is considered as a future energy vector. To become a viable solution, the hydrogen storage processes must be safe, economic and adapted to the use possibilities. Today many storage modes offer interesting possibilities but need also more researches before realization of prototypes. These modes are described taking into account the physical (compression, liquefaction) and chemical (adsorption in porous solids and absorption in chemical hydrides) solutions. (A.L.B.)

  2. Review of Current State of the Art and Key Design Issues With Potential Solutions for Liquid Hydrogen Cryogenic Storage Tank Structures for Aircraft Applications

    Science.gov (United States)

    Mital, Subodh K.; Gyekenyesi, John Z.; Arnold, Steven M.; Sullivan, Roy M.; Manderscheid, Jane M.; Murthy, Pappu L. N.

    2006-01-01

    Due to its high specific energy content, liquid hydrogen (LH2) is emerging as an alternative fuel for future aircraft. As a result, there is a need for hydrogen tank storage systems, for these aircraft applications, that are expected to provide sufficient capacity for flight durations ranging from a few minutes to several days. It is understood that the development of a large, lightweight, reusable cryogenic liquid storage tank is crucial to meet the goals of and supply power to hydrogen-fueled aircraft, especially for long flight durations. This report provides an annotated review (including the results of an extensive literature review) of the current state of the art of cryogenic tank materials, structural designs, and insulation systems along with the identification of key challenges with the intent of developing a lightweight and long-term storage system for LH2. The broad classes of insulation systems reviewed include foams (including advanced aerogels) and multilayer insulation (MLI) systems with vacuum. The MLI systems show promise for long-term applications. Structural configurations evaluated include single- and double-wall constructions, including sandwich construction. Potential wall material candidates are monolithic metals as well as polymer matrix composites and discontinuously reinforced metal matrix composites. For short-duration flight applications, simple tank designs may suffice. Alternatively, for longer duration flight applications, a double-wall construction with a vacuum-based insulation system appears to be the most optimum design. The current trends in liner material development are reviewed in the case that a liner is required to minimize or eliminate the loss of hydrogen fuel through permeation.

  3. Eddy Current Loss Induced in Aluminum Thermal Conduction Strips for ASPCS Coils Indirectly Cooled by Liquid Hydrogen through Thermo-siphon System

    Science.gov (United States)

    Ota, Narumi; Katsura, Masashi; Ando, Kennosuke; Takao, Tomoaki; Shintomi, Takakazu; Makida, Yasuhiro; Hamajima, Takataro; Tsuda, Makoto; Miyagi, Daisuke; Tsujigami, Hiroshi; Fujikawa, Shizuichi; Semba, Toshiaki; Iwaki, Katsuya

    To promote renewable energy sources, we proposed a new system called the Advanced Superconducting Power Conditioning System (ASPCS), which consists of Superconducting Magnetic Energy Storage-system (SMES), Electrolyzer, and Fuel Cell, and is also combined with a liquid hydrogen station for vehicles. The SMES plays a role to compensate the fast fluctuations generated by the renewable energies. In case of the ASPCS with a capacity of 5 MW, we designed the 50 MJ-class SMES composed of 4 solenoid coils. The winding of the solenoid coils is double pancake and a basic coil is 2 m in diameter and 0.5 m in height. Each SMES coil is wound with MgB2 conductor and indirectly cooled at 20 K by liquid hydrogen flowing through a thermo-siphon cooling system. Pure aluminum strips are inserted between the double-pancake coils and the pure aluminum plates gathering the strips lead to liquid hydrogen pipes. This scheme enables the strips and the plates to transfer the heat load in the coils to the cooling pipes and keep the coils at low temperature. On the other hand, we must consider that the strips generate eddy current loss which is strongly affected by a width of the strips. At the same time as the primary study of the SMES coils, we experimented on the thermo-siphon cooling system and investigated the relationship between the heat load and the heat extraction ability of the cooling system. The experiments showed that the cooling system could proficiently function. The estimation of eddy current loss from the particular cooling aluminum strips for the SMES in the ASPCS is reported with the results of the thermo-siphon driving experiment.

  4. Solvent effects on the Raman spectra of the isolated carbon-hydrogen stretches of cyclohexane-d11: A molecular dynamics simulation study of liquid and supercritical solvation

    Science.gov (United States)

    Frankland, Sarah-Jane Victoria

    Molecular dynamics simulations of solvent effects on the Raman spectra of isotopically isolated C-H stretches of cyclohexane-d11 were performed in liquids and supercritical CO2. The red spectral shifts from the gas phase origin were derived three different ways: (1) from the Lennard-Jones force on the normal coordinate of the vibration; (2) from this force with an additional term to account for the polarizabilily change on excitation, and (3) as an empirical difference potential between the v = 0 and v = 1 state of the hydrogen atom involved in the vibration. Model 3 was successfully parametrized to reproduce the experimental spectral shifts and linewidths. The simulated lineshapes from these models were homogeneously broadened from gas to liquid densities primarily by collisions of nearby solvent molecules with the solute. Both the simulations and isolated binary collision theory showed the density dependence of the linewidth to be related to that of the collision rate. Two additional projects were done which use Monte-Carlo algorithms involving two molecules. In the first project 1:1 complexes of solute and solvent were formed at the potential surface minima such that the geometries of conformers, energies of formation, and electronic spectral shifts could be studied. Complexes between 7- azaindole, indole, carbazole, and 1-azacarbazole and hydrogen-bonding solvents were most stable when the solvent was hydrogen-bonded at the solute N-H site. The energies of formation compared well with values obtained from ab initio calculations. Complexes of coumarins 102 and 153 and fluorinated alcohols showed the more stable conformers to have the alcohols bound at the coumarin carbonyl group. In the second project, one solvent molecule was randomly placed around the solute molecule in order to simplify bulk liquid simulation to only two molecules. This approximation was rised to show that the dynamic Stokes shift of coumarin 153 in over 30 solvents correlates with the

  5. Hydrogen production by reforming of liquid hydrocarbons in a membrane reactor for portable power generation-Model simulations

    Science.gov (United States)

    Damle, Ashok S.

    One of the most promising technologies for lightweight, compact, portable power generation is proton exchange membrane (PEM) fuel cells. PEM fuel cells, however, require a source of pure hydrogen. Steam reforming of hydrocarbons in an integrated membrane reactor has potential to provide pure hydrogen in a compact system. In a membrane reactor process, the thermal energy needed for the endothermic hydrocarbon reforming may be provided by combustion of the membrane reject gas. The energy efficiency of the overall hydrogen generation is maximized by controlling the hydrogen product yield such that the heat value of the membrane reject gas is sufficient to provide all of the heat necessary for the integrated process. Optimization of the system temperature, pressure and operating parameters such as net hydrogen recovery is necessary to realize an efficient integrated membrane reformer suitable for compact portable hydrogen generation. This paper presents results of theoretical model simulations of the integrated membrane reformer concept elucidating the effect of operating parameters on the extent of fuel conversion to hydrogen and hydrogen product yield. Model simulations indicate that the net possible hydrogen product yield is strongly influenced by the efficiency of heat recovery from the combustion of membrane reject gas and from the hot exhaust gases. When butane is used as a fuel, a net hydrogen recovery of 68% of that stoichiometrically possible may be achieved with membrane reformer operation at 600 °C (873 K) temperature and 100 psig (0.791 MPa) pressure provided 90% of available combustion and exhaust gas heat is recovered. Operation at a greater pressure or temperature provides a marginal improvement in the performance whereas operation at a significantly lower temperature or pressure will not be able to achieve the optimal hydrogen yield. Slightly higher, up to 76%, net hydrogen recovery is possible when methanol is used as a fuel due to the lower heat

  6. Direct experimental evidence for a negative heat capacity in the liquid-to-gas like phase transition in hydrogen cluster ions backbending of the caloric curve

    CERN Document Server

    Gobet, F; Carré, M; Farizon, B; Farizon, M; Gaillard, M J; Maerk, T D; Scheier, P

    2002-01-01

    By (i) selecting specific decay reactions in high energy collisions (60 keV/amu) of hydrogen cluster ions with a helium target (utilizing event-by-event data of a recently developed multi-coincidence experiment) and by (ii) deriving corresponding temperatures for these microcanonical cluster ensembles (analyzing the respective fragment distributions) we are able to construct caloric curves for ii sub 3 sup + (ii sub 2) sub m cluster ions (6 <= m <= 14). All individual curves and the mean of these curves show a backbending in the plateau region thus constituting direct evidence for a negative microcanonical heat capacity in the liquid-to-gas like transition of these finite systems.

  7. Variable-temperature Fourier transform near-infrared imaging spectroscopy of the deuterium/hydrogen exchange in liquid D₂O.

    Science.gov (United States)

    Unger, Miriam; Ozaki, Yukihiro; Siesler, Heinz W

    2014-01-01

    In the present publication, the deuterium/hydrogen (D/H) exchange of liquid D2O exposed to water vapor of the surrounding atmosphere has been studied by variable-temperature Fourier transform near-infrared (FT-NIR) imaging spectroscopy. Apart from the visualization of the exchange process in the time-resolved FT-NIR images, kinetic parameters and the activation energy for this D/H exchange reaction have been derived from the Arrhenius plot of the variable-temperature spectroscopic data.

  8. Hydrogen sulphate-based ionic liquid-assisted electro-polymerization of PEDOT catalyst material for high-efficiency photoelectrochemical solar cells

    OpenAIRE

    Carbas, Buket Bezgin; Gulen, Mahir; Tolu, Merve Celik; Sonmezoglu, Savas

    2017-01-01

    This work reports the facile, one-step electro-polymerization synthesis of poly (3,4-ethylenedioxythiophene) (PEDOT) using a 1-ethyl-3-methylimidazolium hydrogen sulphate (EMIMHSO4) ionic liquid (IL) and, for the first time its utilization as a counter electrode (CE) in dye-sensitized solar cells (DSSCs). Using the IL doped PEDOT as CE, we effectively improve the solar cell efficiency to as high as 8.52%, the highest efficiency reported in 150 mC/cm2 charge capacity, an improvement of ~52% ov...

  9. Characterization of Doubly Ionic Hydrogen Bonds in Protic Ionic Liquids by NMR Deuteron Quadrupole Coupling Constants: Differences to H-bonds in Amides, Peptides, and Proteins.

    Science.gov (United States)

    Khudozhitkov, Alexander E; Stange, Peter; Golub, Benjamin; Paschek, Dietmar; Stepanov, Alexander G; Kolokolov, Daniil I; Ludwig, Ralf

    2017-11-06

    We present the first deuteron quadrupole coupling constants (DQCCs) for selected protic ionic liquids (PILs) measured by solid-state NMR spectroscopy. The experimental data are supported by dispersion-corrected density functional theory (DFT-D3) calculations and molecular dynamics (MD) simulations. The DQCCs of the N-D bond in the triethylammonium cations are the lowest reported for deuterons in PILs, indicating strong hydrogen bonds between ions. The NMR coupling parameters are compared to those in amides, peptides, and proteins. The DQCCs show characteristic behavior with increasing interaction strength of the counterion and variation of the H-bond motifs. We report the similar presence of the quadrupolar splitting pattern and the narrow liquid line in the NMR spectra over large temperature ranges, indicating the heterogeneous nature of PILs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Direct Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol at Room Temperature Using Imidazolium Hydrogen Carbonate Ionic Liquid as a Recyclable Catalyst and Dehydrant.

    Science.gov (United States)

    Zhao, Tianxiang; Hu, Xingbang; Wu, Dongsheng; Li, Rui; Yang, Guoqiang; Wu, Youting

    2017-05-09

    The direct synthesis of dimethyl carbonate (DMC) from CO2 and CH3 OH was achieved at room temperature with 74 % CH3 OH conversion in the presence of an imidazolium hydrogen carbonate ionic liquid ([Cn Cm Im][HCO3 ]). Experimental and theoretical results reveal that [Cn Cm Im][HCO3 ] can transform quickly into a CO2 adduct, which serves as an effective catalyst and dehydrant. Its dehydration ability is reversible. The energy barrier of the rate-determining step for the DMC synthesis is only 21.7 kcal mol(-1) . The ionic liquid can be reused easily without a significant loss of its catalytic and dehydrating ability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Low-cost industrially available molybdenum boride and carbide as "platinum-like" catalysts for the hydrogen evolution reaction in biphasic liquid systems.

    Science.gov (United States)

    Scanlon, Micheál D; Bian, Xiaojun; Vrubel, Heron; Amstutz, Véronique; Schenk, Kurt; Hu, Xile; Liu, BaoHong; Girault, Hubert H

    2013-02-28

    Rarely reported low-cost molybdenum boride and carbide microparticles, both of which are available in abundant quantities due to their widespread use in industry, adsorb at aqueous acid-1,2-dichloroethane interfaces and efficiently catalyse the hydrogen evolution reaction in the presence of the organic electron donor - decamethylferrocene. Kinetic studies monitoring biphasic reactions by UV/vis spectroscopy, and further evidence provided by gas chromatography, highlight (a) their superior rates of catalysis relative to other industrially significant transition metal carbides and silicides, as well as a main group refractory compound, and (b) their highly comparable rates of catalysis to Pt microparticles of similar dimensions. Insight into the catalytic processes occurring for each adsorbed microparticle was obtained by voltammetry at the liquid-liquid interface.

  12. Forty Lines of Evidence for Condensed Matter — The Sun on Trial: Liquid Metallic Hydrogen as a Solar Building Block

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-10-01

    . Collectively, these lines of evidence provide a systematic challenge to the gaseous models of the Sun and expose the many hurdles faced by modern approaches. Observational astronomynand laboratory physics have remained unable to properly justify claims that the solar body must be gaseous. At the same time, clear signs of condensed matter interspersed with gaseous plasma in the chromosphere and corona have been regrettably dismissed. As such, it is hoped that this exposition will serve as an invitation to consider condensed matter, especially metallic hydrogen, when pondering the phase of the Sun. The Sun is a world so different from our own . . . However [relative to understanding its structure], one must not lose heart; over the past few years science has made a lot of progress, and those who come after us will not fail to make even more. Father Angelo Secchi, S.J., 1875 [1, p. 300, V. I]∗ 1 Introduction A long time ago, men like Gustav Kirchhoff, Johann Z¨ollner, William Thomson (Lord Kelvin, and James Jeans viewed the photosphere (or the solar body as existing in the liquid state [2, 3]. Despite their stature, scientists, since the days of Herbert Spencer and Angelo Secchi, slowly drifted towards ∗Translations from French were executed by the author. the concept that the Sun was a ball

  13. Development of simulation approach for two-dimensional chiral molecular self-assembly driven by hydrogen bond at the liquid/solid interface

    Science.gov (United States)

    Qin, Yuan; Yao, Man; Hao, Ce; Wan, Lijun; Wang, Yunhe; Chen, Ting; Wang, Dong; Wang, Xudong; Chen, Yonggang

    2017-09-01

    Two-dimensional (2D) chiral self-assembly system of 5-(benzyloxy)-isophthalic acid derivative/(S)-(+)-2-octanol/highly oriented pyrolytic graphite was studied. A combined density functional theory/molecular mechanics/molecular dynamics (DFT/MM/MD) approach for system of 2D chiral molecular self-assembly driven by hydrogen bond at the liquid/solid interface was thus proposed. Structural models of the chiral assembly were built on the basis of scanning tunneling microscopy (STM) images and simplified for DFT geometry optimization. Merck Molecular Force Field (MMFF) was singled out as the suitable force field by comparing the optimized configurations of MM and DFT. MM and MD simulations for hexagonal unit model which better represented the 2D assemble network were then preformed with MMFF. The adhesion energy, evolution of self-assembly process and characteristic parameters of hydrogen bond were obtained and analyzed. According to the above simulation, the stabilities of the clockwise and counterclockwise enantiomorphous networks were evaluated. The calculational results were supported by STM observations and the feasibility of the simulation method was confirmed by two other systems in the presence of chiral co-absorbers (R)-(-)-2-octanol and achiral co-absorbers 1-octanol. This theoretical simulation method assesses the stability trend of 2D enantiomorphous assemblies with atomic scale and can be applied to the similar hydrogen bond driven 2D chirality of molecular self-assembly system.

  14. Size and Structure Effects Controlling the Stability of the Liquid Organic Hydrogen Carrier Dodecahydro-N-ethylcarbazole during Dehydrogenation over Pt Model Catalysts.

    Science.gov (United States)

    Amende, Max; Gleichweit, Christoph; Schernich, Stefan; Höfert, Oliver; Lorenz, Michael P A; Zhao, Wei; Koch, Marcus; Obesser, Katharina; Papp, Christian; Wasserscheid, Peter; Steinrück, Hans-Peter; Libuda, Jörg

    2014-04-17

    Hydrogen can be stored conveniently using so-called liquid organic hydrogen carriers (LOHCs), for example, N-ethylcarbazole (NEC), which can be reversibly hydrogenated to dodecahydro-N-ethylcarbazole (H12-NEC). In this study, we focus on the dealkylation of H12-NEC, an undesired side reaction, which competes with dehydrogenation. The structural sensivity of dealkylation was studied by high-resolution X-ray photoelectron spectroscopy (HR-XPS) on Al2O3-supported Pt model catalysts and Pt(111) single crystals. We show that the morphology of the Pt deposit strongly influences LOHC degradation via C-N bond breakage. On smaller, defect-rich Pt particles, the onset of dealkylation is shifted by 90 K to lower temperatures as compared to large, well-shaped particles and well-ordered Pt(111). We attribute these effects to a reduced activation barrier for C-N bond breakage at low-coordinated Pt sites, which are abundant on small Pt aggregates but are rare on large particles and single crystal surfaces.

  15. Fiscal 1997 survey report. Subtask 5 (hydrogen utilization worldwide clean energy system technology) (WE-NET) (development of hydrogen transportation/storage technology. 2. development of the liquid hydrogen transportation tanker); 1997 nendo seika hokokusho. Suiso riyo kokusai clean energy system gijutsu (WE-NET) subtask 5 suiso yuso chozo gijutsu no kaihatsu dai 2 hen ekitai suiso yuso tanker no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Technology development is being conducted for construction of the long distance transportation tanker of large quantity liquid hydrogen. In fiscal 1997, test pieces of thermal insulating materials to be planned for fiscal 1998 were designed and studied. The purpose of the test is to confirm thermal insulating performance and behaviors of each material under the temperature of liquid hydrogen. The inside of the outer tank of the experimental equipment was held at vacuum of 10{sup -6} to 10{sup -7} Torr to exclude thermal convection effects and evaluate only heat coming from heater through the test piece. The heat from the heater at the lower part of the test piece is through the test piece and makes the liquid hydrogen of the upper tank evaporate. Thermal conductivity of the test piece is calculated from the evaporation quantity. As to PUF (polyurethane foam) panels, studied were reformation preventive measures, influential evaluation of the side transfer heat quantity, and the time required for vacuuming. In the vacuum panel, study subjects were extracted on the selection of core materials, reformation preventive measures, deterioration with age, the practical manufacturing method of experimental panels, etc. As to the super insulation, subjects were studied on the performance measuring method/accuracy, measures against heat transfer from the inside of the experimental equipment, control of the vacuum degree, etc. 10 refs., 45 figs., 6 tabs.

  16. Hydrogen bonding versus van der Waals interactions: competitive influence of noncovalent interactions on 2D self-assembly at the liquid-solid interface.

    Science.gov (United States)

    Mali, Kunal S; Lava, Kathleen; Binnemans, Koen; De Feyter, Steven

    2010-12-27

    The structures of the self-assembled monolayers of various 4-alkoxybenzoic acids physisorbed at the liquid-solid interface were established by employing scanning tunnelling microscopy (STM). This study has been essentially undertaken to explore the competitive influence of van der Waals and hydrogen-bonding interactions on the process of two-dimensional self-assembly. These acid derivatives form hydrogen-bonded dimers as expected; however, the dimers organise themselves in the form of relatively complex lamellae. The characteristic feature of these lamellae is the presence of regular discommensurations or kinks along the lamella propagation direction. The formation of kinked lamellae is discussed in light of the registry mechanism of the alkyl chains with the underlying graphite substrate. The location of the kinks along a lamella depends on the number (odd or even) of carbon atoms in the alkyl chain. This result indicates that concerted van der Waals interactions of the alkyl chain units introduce the odd/even chain-length effect on the surface-assembled supramolecular patterns. The odd/even effects are retained even upon complexation with a hydrogen-bond acceptor. However, as the solvent is changed from 1-phenyloctane to 1-octanoic acid, the kinked lamellae as well as the odd/even effects disappear. This solvent-induced convergence of supramolecular patterns is attained by means of co-crystallisation of octanoic acid molecules in the 2D crystal lattice, which is evident from high-resolution STM images. The solvent co-adsorption phenomenon is discussed in terms of competing van der Waals and hydrogen-bonding interactions.

  17. Thermal and hydrodynamic study of a whirling liquid hydrogen layer under high heat flux; Etude thermique et hydrodynamique d'une couche tourbillonnaire d'hydrogenen liquide sous flux de chaleur eleve

    Energy Technology Data Exchange (ETDEWEB)

    Ewald, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1968-03-01

    In order to achieve a cold neutrons source ({lambda} {>=} 4.10{sup -10} m) in a high flux reactor ({approx} 10{sup 15} neutrons/cm{sup 2}.s), a whirling liquid hydrogen layer (145 mm OD, effective thickness 15 mm, height about 180 mm) was formed, out-of-pile, in a cylindrical transparent glass vessel. The whirling motion was obtained by tangential injection of the liquid, near the wall. Thermal and hydrodynamical conditions of formation and laws of similarity of such a layer were studied. The characteristics of this whirling flow were observed as a function of mass flow rate (5 to 27 g/s; 4.3 to 23 l/mn), and of spillway width (18 and 25 mm). Six different nozzles were used : 1.0; 1.5; 1.9; 2.25; 2.65 and 3.0 mm ID. The total heat influx was found between 8.6 and 10.4 kW. The heat flux density was about 9.4 W/cm{sup 2} and the mean layer density around 80 per cent of that of the liquid hydrogen at 20.4 Kelvin. High speed movies were used to analyze the boiling regime. (author) [French] En vue de realiser une source de neutrons froids ({lambda} {>=} 4.10{sup -10} m) dans un reacteur a haut flux ({approx} 10{sup 15} neutrons thermiques/cm{sup 2}.s), on a forme dans un vase cylindrique transparent en verre, hors-pile, une couche tourbillonnaire ('vortex') d'hydrogene liquide (diametre exterieur 145 mm, epaisseur effective 15 mm, hauteur 180 mm environ). Le mouvement giratoire est obtenu par injection tangentielle du liquide pres de la paroi. L'etude porte sur la determination des conditions thermiques et hydrodynamiques de la formation d'une telle couche et sur les regles de similitude de ce phenomene. On a observe les caracteristiques de l'ecoulement giratoire en fonction du debit (de 5 a 27 g/s, soit de 4.3 a 23 1/mn), de la vitesse d'injection (entre 10 et 110 m/s) et de la largeur du deversoir (18 et 25 mm), ceci pour six diametres differents d'injecteur (1.0 ; 1.5; 1.9; 2.25; 2.65 et 3.0 mm). Le flux de chaleur total mesure

  18. Abstract of report on the automatic regulation of the liquid and vapor phase hydrogenation stalls at Leuna

    Energy Technology Data Exchange (ETDEWEB)

    1944-01-23

    The first topic discussed in this report was liquid level regulations in the HOLD vessels. The hot oil letdown from the hot catchpot passed through a so-called letdown vessel for the purpose of degassing, from which it was pumped for further processing. Figure 1 showed the regulation of the liquid level in the hot oil letdown vessel. The next topic was liquid level regulation in the hot catchpot. The level regulator for the hot catchpot was an electro-pneumatic regulator working on the open-shut principle. This was shown in Figure 2. Holding the gas bubble constant in the liquid level measurements, automatic desanding of converter 1, liquid level regulation in the cold catchpot, cold gas regulators for holding a constant converter temperature, a liquid level regulator for the intermediate catchpot, and other considerations were all topics discussed in this report. Figure 3 was a diagram of the filter orifice or throttle. Figure 10 was a diagram summary of the whole process, and Figure 6 showed a diagram of the cold gas regulation apparatus including positions of temperature regulators, resistance thermometers, the control panel, and the registering thermograph. 3 diagrams; some mentioned are missing.

  19. On the Development of Hydrogen Isotope Extraction Technologies for a Full LiMIT-Style PFC Liquid Lithium Loop

    Science.gov (United States)

    Christenson, Michael; Szott, Matthew; Stemmley, Steven; Mettler, Jeremy; Wendeborn, John; Moynihan, Cody; Ahn, Chisung; Andruczyk, Daniel; Ruzic, David

    2017-10-01

    Lithium has proven over numerous studies to improve core confinement, allowing access to operational regimes previously unattainable when using solid, high-Z divertor and limiter modules in magnetic confinement devices. Lithium readily absorbs fuel species, and while this is advantageous, it is also detrimental with regards to tritium inventory and safety concerns. As such, extraction technologies for the recovery of hydrogenic isotopes captured by lithium require development and testing in the context of a larger lithium loop recycling system. Proposed reclamation technologies at the University of Illinois at Urbana-Champaign (UIUC) will take advantage of the thermophysical properties of the lithium-hydrogen-lithium hydride system as the driving force for recovery. Previous work done at UIUC indicates that hydrogen release from pure lithium hydride reaches a maximum of 7 x 1018 s-1 at 665 °C. While this recovery rate is appreciable, reactor-scale scenarios will require isotope recycling to happen on an even faster timescale. The ratio of isotope dissolution to hydride precipitate formation must therefore be determined, along with the energy needed to recoup trapped hydrogen isotopes. Extraction technologies for use with a LiMIT-style loop system will be discussed and results will be presented. DOE/ALPS DE-FG02-99ER54515.

  20. Hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Donath, E.

    1942-10-16

    This report mentioned that not very severe demands for purity were made on the hydrogen used in hydrogenation of coal or similar raw materials, because the catalysts were not very sensitive to poisoning. However, the hydrogenation plants tried to remove most impurities anyway by means of oil washes. The report included a table giving the amount of wash oil used up and the amount of hydrogen lost by dissolving into the wash oil used up and the amount of hydrogen lost by dissolving into the wash oil in order to remove 1% of various impurities from 1000 m/sup 3/ of the circulating gas. The amounts of wash oil used up were 1.1 m/sup 3/ for removing 1% nitrogen, 0.3 m/sup 3/ for 1% carbon monoxide, 0.03 m/sup 3/ for 1% methane. The amount of hydrogen lost was 28 m/sup 3/ for 1% nitrogen, 9 m/sup 3/ for 1% methane and ranged from 9 m/sup 3/ to 39 m/sup 3/ for 1% carbon monoxide and 1 m/sup 3/ to 41 m/sup 3/ for carbon dioxide depending on whether the removal was done in liquid phase or vapor phase and with or without reduction of the oxide to methane. Next the report listed and described the major processes used in German hydrogenation plants to produce hydrogen. Most of them produced water gas, which then had its carbon monoxide changed to carbon dioxide, and the carbon oxides washed out with water under pressure and copper hydroxide solution. The methods included the Winkler, Pintsch-Hillebrand, and Schmalfeldt-Wintershall processes, as well as roasting of coke in a rotating generator, splitting of gases formed during hydrogenation, and separation of cokery gas into its components by the Linde process.

  1. Polymer membrane based electrolytic cell and process for the direct generation of hydrogen peroxide in liquid streams

    Science.gov (United States)

    White, James H. (Inventor); Schwartz, Michael (Inventor); Sammells, Anthony F. (Inventor)

    1997-01-01

    An electrolytic cell for generating hydrogen peroxide is provided including a cathode containing a catalyst for the reduction of oxygen, and an anode containing a catalyst for the oxidation of water. A polymer membrane, semipermeable to either protons or hydroxide ions is also included and has a first face interfacing to the cathode and a second face interfacing to the anode so that when a stream of water containing dissolved oxygen or oxygen bubbles is passed over the cathode and a stream of water is passed over the anode, and an electric current is passed between the anode and the cathode, hydrogen peroxide is generated at the cathode and oxygen is generated at the anode.

  2. Phase transition behavior of hydrogen bonded liquid crystal (6BA){sub 2}-(BPy){sub x} as studied by {sup 2}H NMR

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, M., E-mail: mizuno@se.kanazawa-u.ac.jp; Tabota, K.; Oigawa, T.; Miyatou, T.; Kumagai, Y.; Ohashi, R.; Ida, T. [Kanazawa University, Department of Chemistry, Graduate School of Natural Science & Technology (Japan)

    2016-12-15

    The thermal properties and the orientational order of hydrogen-bonded liquid crystals (6BA){sub 2}-(BPy){sub 0.4} and (6BA){sub 2}-(BPy){sub 0.3} (6BA: 4-n-hexylbenzoicacid, BPy: 4,4’-bipyridine) were investigated by DSC and {sup 2}H NMR. On cooling, isotropic liquid - liquid crystal phase transition temperatures were T{sub C}= 409 and 405 K for (6BA){sub 2}-(BPy){sub 0.4} and (6BA){sub 2}-(BPy){sub 0.3}, respectively. Thermal anomalies in the liquid crystal phase were observed at T{sub LC1}= 402 and T{sub LC2}= 375 K for (6BA){sub 2}-(BPy){sub 0.4} and at T{sub LC1}= 398 and T{sub LC2}= 375 K for (6BA){sub 2}-(BPy){sub 0.3}. For (6BA){sub 2}-(BPy){sub 0.4}, only the smectic component was created above T{sub LC1}. In addition, the nematic component was created below T{sub LC1}. The nematic component gradually changed to the smectic component with decreasing temperature and only the smectic component was observed below T{sub LC2}. For (6BA){sub 2}-(BPy){sub 0.3}, only the nematic component was created above T{sub LC2}. The phase transition from the nematic phase to the smectic phase took place at around T{sub LC2}.

  3. The study of correlations between hydrogen bonding characteristics in liquid, sub- and supercritical methanol. Molecular dynamics simulations and Raman spectroscopy analysis.

    Science.gov (United States)

    idrissi, Abdenacer; Oparin, Roman D; Krishtal, Sergey P; Krupin, Sergey V; Vorobiev, Evgeny A; Frolov, Andrey I; Dubois, Leo; Kiselev, Mikhail G

    2013-01-01

    Molecular dynamics (MD) studies of hydrogen bonding (H-bonding) in liquid, sub- and supercritical methanol have been performed in a wide range of thermodynamic parameters of state, using various potential models and two H-bond criteria. It was shown that there is the universal correlation between the average number of H-bonds per molecule (n(HB)) and the mole fraction of H-bonded molecules (X(HB)) for the studied thermodynamic parameters of state. The same feature was observed for the correlations between fractions of molecules forming one (f1), two (f2), three (f3) H-bonds and X(HB). These correlations served to fit experimental Raman spectra of methanol recorded under sub- and supercritical conditions. The advantage of the approach used here is that f1, f2, f3 values have a clear physical meaning and are dependent on the values of state parameters.

  4. Determination of hydrogen-bond-accepting and -donating abilities of ionic liquids with halogeno complex anions by means of 1H NMR spectroscopy.

    Science.gov (United States)

    Lungwitz, Ralf; Spange, Stefan

    2012-05-14

    Hydrogen-bond-accepting (HBA) and -donating (HBD) parameters of ionic liquids (ILs) with halogeno complex anions are determined by means of (1)H NMR spectroscopy. Thereby, the imidazolium cation serves both as part of the IL and as (1)H NMR probe. The HBA and HBD strength are calculated in terms of the empirical polarity parameters β and α according to the Kamlet-Taft equation. The study includes 1-butyl-3-methylimidazolium ILs with chloroaluminates of various mole fractions from 0 to 0.67 of AlCl(3), anions of the general chemical formula MtX(n)(-) (Mt=metal, X=halide) as well as tri- and pentaiodide. The (1)H NMR chemical shift of the hydrogen atom in the two position of the imidazolium cation is a function of the HBA ability of the corresponding anion. For the chloroaluminates the HBA ability decreases and the HBD ability increases with increasing mole fraction of the Lewis acid. In general, the HBA strength of the studied ILs increases in the following order: MoCl(6)(-) < Al(2)Cl(7)(-) < AlCl(4)(-) < WCl(7)(-) < I(5)(-) < SnCl(5)(-) < I(3)(-) < SbCl(6)(-) < TiCl(5)(-) < BBr(4)(-) < SnCl(3)(-). The corresponding HBD ability shows a reverse trend. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. A strategy of utilizing Zn(II) as metallic pivot in room temperature ionic liquid to prepare molecularly imprinted polymers for compound with intramolecular hydrogen bonds.

    Science.gov (United States)

    Sun, Ya Kun; Jia, Man; Yang, Jian; Huang, Yan-Ping; Liu, Zhao-Sheng; Aisa, Haji Akber

    2018-01-01

    A method of preparing molecularly imprinted polymers (MIPs) with Zn(II) as a metallic pivot was adopted to solve the problem of imprinting compound with intramolecular hydrogen bonds by forming stronger coordination binding interaction among the template-functional monomer-Zn2+ complex. A ternary porogenic system including dimethyl sulfoxide, dimethylformamide, and room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate was employed to fabricate imprinted monolith with high porosity and good flow-through properties, in which chicoric acid (CA), zinc acetate, 4-vinylpyridine (4-VP), and ethylene glycol dimethacrylate (EDMA) was the template, metallic ion, functional monomer, as well as crosslinker, respectively. The influence of polymerization factors including the 4-VP-CA ratio, monomer-crosslinker ratio, template-Zn2+ ratio on imprinting factors was systematically investigated. When the ratio of 4-VP to CA was 24:1, the greatest IF value (24.81) was achieved on the CA-MIP prepared with zinc acetate. In addition, off-line SPE with the optimal MIPs monolith led to high purity of CA (98.0% ± 0.5%) from extraction of Cichorium intybus L. roots with the recovery of 77.5% ± 2.5% (n = 6). As a conclusion, the strategy of introducing metal ions as metal pivot to prepare MIPs was a powerful method for the MIPs synthesis to the template molecules with intramolecular hydrogen bonds.

  6. Comparative analysis of the electroactive area of Pt/C PEMFC electrodes in liquid and solid polymer contact by underpotential hydrogen adsorption/desorption

    Energy Technology Data Exchange (ETDEWEB)

    Chaparro, A.M.; Martin, A.J.; Folgado, M.A.; Gallardo, B. [Dep. de Energia, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Daza, L. [Dep. de Energia, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Instituto de Catalisis y Petroleoquimica (CSIC), Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain)

    2009-06-15

    Because of the different experimental conditions found in literature for the measurement of the electroactive area of Pt/C electrodes of proton exchange membrane fuel cells (PEMFC) by means of underpotential hydrogen adsorption (H{sub UPD}) voltammetry, specially concerning sweep rate and temperature, it was found necessary to perform an analysis of these parameters. With this aim, the electroactive area of PEMFC electrodes has been measured by means of H{sub UPD} voltammetry at different sweep rates and temperatures, in liquid electrolyte and solid polymer contact. Both configurations show that H{sub UPD} adsorption and desorption charges are strongly dependent on sweep rate voltage and temperature. The most common behaviour observed is a maximum in H{sub UPD} desorption charge, typically in the 100-10 mV s{sup -1} sweep rate range, whereas H{sub UPD} adsorption charge shows continuous increase with decreasing sweep rate. The decrease of desorption charge at low sweep rates is attributed to adsorbing species related with carbon support reactivity. These processes are also responsible for the increase in desorption H{sub UPD} charge at low sweep rate. At high sweep rate, both adsorption and desorption H{sub UPD} charges decrease due to limiting diffusion of protons through the microporous electrode. As a consequence, it is found that the closest approximation to the real electroactive area (i.e. the area accessible to protons) corresponds to the maximum in the H{sub UPD} desorption charge in the range of 10-100 mV s{sup -1} sweep rate. The influence of measuring temperature is also tested in the range 25 C-80 C. A dependence of the adsorption and desorption hydrogen charges is found, due to thermodynamic and kinetics factors. We observe that the processes competing with hydrogen adsorption, i.e. generation and adsorption of carbon species are enhanced with temperature, so a low measuring temperature is found as most appropriate. (author)

  7. Achievement report for fiscal 2000 on the phase II research and development for hydrogen utilizing international clean energy system technology (WE-NET). Task 9. Development of liquid hydrogen transportation and storage technologies - 1; 2000 nendo suiso riyo kokusai clean energy system gijutsu (WE-NET) dai 2 ki kenkyu kaihatsu. Task 9. Ekitai suiso yuso chozo gijutsu no kaihatsu - 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    This paper describes the achievements in fiscal 2000 from the development of liquid hydrogen transportation and storage technologies. Discussions were given on the following three types of specimens as the heat insulation performance test structures: the vacuum panel type (polyurethane foam coated with SUS sheet, while the inside is kept in the vacuum state); the solid vacuum type (combination of polyurethane foam with vacuum heat insulation); and the powder under normal pressure type (a structure in which the ambient of powder pearlite heat insulating material becomes the atmospheric pressure, whereas a SUS case is set up to separate vacuum layer of the test apparatus from atmosphere layer of the specimen, with the SUS case filled with pearlite). Adding the two types of specimens used in the previous fiscal year, five test specimens in total were discussed on the result of the performance tests to advance the database management. As a low temperature strength test for the insulating materials, the compression test was performed on a microsphere being a kind of solid vacuum (normal pressure) heat insulating materials at room temperature, the liquid nitrogen temperature and in liquid hydrogen atmosphere. The compression strength under liquid hydrogen is 1,044 MPa, which is two times greater than the normal temperature strength of 496 MPa, representing the compression strength rising in proportion with temperature drop. Problems were extracted in developing a small capacity liquid hydrogen transportation and storage system. (NEDO)

  8. Uranium hexafluoride liquid thermal expansion, elusive eutectic with hydrogen fluoride, and very first production using chlorine trifluoride

    Energy Technology Data Exchange (ETDEWEB)

    Rutledge, G.P. [Central Environmental, Inc., Anchorage, AK (United States)

    1991-12-31

    Three unusual incidents and case histories involving uranium hexafluoride in the enrichment facilities of the USA in the late 1940`s and early 1950`s are presented. The history of the measurements of the thermal expansion of liquids containing fluorine atoms within the molecule is reviewed with special emphasis upon uranium hexafluoride. A comparison is made between fluorinated esters, fluorocarbons, and uranium hexafluoride. The quantitative relationship between the thermal expansion coefficient, a, of liquids and the critical temperature, T{sub c} is presented. Uranium hexafluoride has an a that is very high in a temperature range that is used by laboratory and production workers - much higher than any other liquid measured. This physical property of UF{sub 6} has resulted in accidents involving filling the UF{sub 6} containers too full and then heating with a resulting rupture of the container. Such an incident at a uranium gaseous diffusion plant is presented. Production workers seldom {open_quotes}see{close_quotes} uranium hexafluoride. The movement of UF{sub 6} from one container to another is usually trailed by weight, not sight. Even laboratory scientists seldom {open_quotes}see{close_quotes} solid or liquid UF{sub 6} and this can be a problem at times. This inability to {open_quotes}see{close_quotes} the UF{sub 6}-HF mixtures in the 61.2{degrees}C to 101{degrees}C temperature range caused a delay in the understanding of the phase diagram of UF{sub 6}-HF which has a liquid - liquid immiscible region that made the eutectic composition somewhat elusive. Transparent fluorothene tubes solved the problem both for the UF{sub 6}-HF phase diagram as well as the UF{sub 6}-HF-CIF{sub 3} phase diagram with a miscibility gap starting at 53{degrees}C. The historical background leading to the first use of CIF{sub 3} to produce UF{sub 6} in both the laboratory and plant at K-25 is presented.

  9. ASRDI oxygen technology survey. Volume 5: Density and liquid level measurement instrumentation for the cryogenic fluids oxygen, hydrogen, and nitrogen

    Science.gov (United States)

    Roder, H. M.

    1974-01-01

    Information is presented on instrumentation for density measurement, liquid level measurement, quantity gauging, and phase measurement. Coverage of existing information directly concerned with oxygen was given primary emphasis. A description of the physical principle of measurement for each instrumentation type is included. The basic materials of construction are listed if available from the source document for each instrument discussed. Cleaning requirements, procedures, and verification techniques are included.

  10. Insights into the Chemistry of Metal Nanoparticles in Ionic Liquids and their Application for Hydrogen Generation from Biogenic Feedstocks

    OpenAIRE

    Berger, Markus E. M.

    2014-01-01

    Nano-sized catalysts strongly depend on their surrounding media. The stability of the nanoparticles and in most cases also their formation is predetermined by the used solvent and its interactions with the metal ions and particles. The solvent or, if necessary, the added stabilizers must be capable of the electrostatic or -steric stabilization of the nano sized catalysts during a catalytic reaction. A characteristic property of some ionic liquids is their inherent ability to promote the forma...

  11. Magnetic resonance lineshape of atomic hydrogen on liquid helium surfaces. The sticking probability of H on /sup 4/He and /sup 3/He

    Energy Technology Data Exchange (ETDEWEB)

    Berlinsky, A.J.; Morrow, M.; Jochemsen, R.; Hardy, W.N. (British Columbia Univ., Vancouver (Canada). Dept. of Physics)

    1982-07-01

    High resolution magnetic resonance studies of the 1420 MHz transition in atomic hydrogen confined in a liquid helium coated container have been performed at temperatures 0.06liquid helium surface, by the exchange rate between atoms in the gas and atoms on the surface, and by the hyperfine frequency shift of an H atom in the bound surface state. Using a model with a Poisson distribution for the residency times, it is possible to interpret both the hyperfine frequency shift and the width of the resonance line as a function of temperature for H on /sup 4/He. The analysis gives the binding energy, the frequency in the surface state, and the sticking probability ..cap alpha.. for H on /sup 4/He. We obtain ..cap alpha..=0.035+-0.004. The results for H on /sup 3/He are more complicated, and possible explanations are discussed.

  12. Forced convection of liquid hydrogen - part 2 - case of large temperature differences between the fluid and the wall - final report (cylindrical channel); Convection forcee de l'hydrogene liquide - 2. partie - cas de grands ecarts de temperatures entre fluide et paroi - rapport final (canal cylindrique)

    Energy Technology Data Exchange (ETDEWEB)

    Perroud, P.; Rebiere, J. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    Measurements have been performed in a smooth Inconel tube of 2 mm ID and 2.5 mm OD, electrically heated on 300 mm by Joule effect (AC) The liquid enters the test section subcooled at the constant temperature of 25 deg. K of average; then it is heated till, most-often, complete vaporization. The conditions are: inlet pressure (subcritical) 8 atm (a number of experiences have been made under supercritical pressure of 16 atm), mass velocity 11 to 115 g/cm{sup 2}.s, heat flux density 9 to 385 W/cm{sup 2}, wall temperature reaching 800 deg. K. The liquid hydrogen used was composed of about 60 per cent of para-hydrogen (the transformation para-ortho does not happen in the process). A flow model, connected with the wall temperatures observed, is established. In the region of two-phase flow, the wall temperature highly decreases and passes through a minimum just when the steam quality reaches unity. A correlation for the heat transfer coefficients is given, in the two-phase flow region (steam quality from 0 to 1) and in the region of homogeneous gaseous phase (Reynolds varying from 15 000 to 420 000). Comparison with former correlations is also given. In the mixed-phase region, head losses due to friction are negligible with the respect to the pressure drop due to the variation of momentum. This latter can be calculated with good approximation using one-dimensional model. The head losses in gaseous phase follows the classical laws. Physical properties of liquid hydrogen extracted from the most recent literature, are given in supplement. (authors) [French] Les mesures ont ete effectuees a l'aide d'un tube cylindrique lisse en inconel de 2 x 2,5 mm de diametre, chauffe electriquement sur une longueur de 300 mm par effet Joule (courant alternatif). Le liquide entre sous-refroidi a la temperature de 25 deg. K en moyenne; il est ensuite chauffe jusqu'a vaporisation complete le plus souvent. Le domaine explore est le suivant: pression d'entree (subcritique) 8

  13. Significant enhanced uranyl ions extraction efficiency with phosphoramidate-functionalized ionic liquids via synergistic effect of coordination and hydrogen bond.

    Science.gov (United States)

    Xie, Xiang; Qin, Zhen; He, Yao; Xiong, Penghui; Huang, Zeng; Mao, Yiwu; Wei, Hongyuan; Zhuo, Liangang

    2017-11-16

    The influence of the linking group between the phosphoryl and bridging moieties in phosphoryl-containing task-specific ionic liquids (TSILs) on the extraction of uranyl ions was experimentally and theoretically investigated. A novel phosphoramidate-based TSIL with an amine group as the linking moiety resulted in a higher uranyl ion extraction efficiency compared with that of other phosphoryl-based TSILs. A distribution ratio of 4999 ± 51 can be achieved for uranyl ions. The uranyl ions (76.7 ± 1.5%) were stripped from the loaded ionic liquid phase in a single stage using 0.05 M diethylenetriamine pentaacetic acid in a 1.0 M guanidine carbonate solution. The extraction stoichiometry of the uranyl ions was determined by a slope analysis of the extraction data. Furthermore, the fundamental nature of the interaction between the phosphoramidate-based TSIL and uranyl ions was theoretically studied for the first time. The theoretical calculations demonstrated that the synergistic effect of the complexation interaction and H-bond formation between the phosphoramidate-functional ionic liquid and uranyl nitrate led to the higher extraction efficiency. These results provide a basis for rational design, synthesis and potential applications of novel TSILs for uranyl extraction.

  14. Valorization of Waste Lipids through Hydrothermal Catalytic Conversion to Liquid Hydrocarbon Fuels with in Situ Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongwook; Vardon, Derek R.; Murali, Dheeptha; Sharma, Brajendra K.; Strathmann, Timothy J.

    2016-03-07

    We demonstrate hydrothermal (300 degrees C, 10 MPa) catalytic conversion of real waste lipids (e.g., waste vegetable oil, sewer trap grease) to liquid hydrocarbon fuels without net need for external chemical inputs (e.g., H2 gas, methanol). A supported bimetallic catalyst (Pt-Re/C; 5 wt % of each metal) previously shown to catalyze both aqueous phase reforming of glycerol (a triacylglyceride lipid hydrolysis coproduct) to H2 gas and conversion of oleic and stearic acid, model unsaturated and saturated fatty acids, to linear alkanes was applied to process real waste lipid feedstocks in water. For reactions conducted with an initially inert headspace gas (N2), waste vegetable oil (WVO) was fully converted into linear hydrocarbons (C15-C17) and other hydrolyzed byproducts within 4.5 h, and H2 gas production was observed. Addition of H2 to the initial reactor headspace accelerated conversion, but net H2 production was still observed, in agreement with results obtained for aqueous mixtures containing model fatty acids and glycerol. Conversion to liquid hydrocarbons with net H2 production was also observed for a range of other waste lipid feedstocks (animal fat residuals, sewer trap grease, dry distiller's grain oil, coffee oil residual). These findings demonstrate potential for valorization of waste lipids through conversion to hydrocarbons that are more compatible with current petroleum-based liquid fuels than the biodiesel and biogas products of conventional waste lipid processing technologies.

  15. Study of the vapor-liquid equilibria used in the fabrication process of hydrogen by thermochemistry: Final report. Etude des equilibres liquide-vapeur utiles dans les procedes de fabrication d'hydrogene par thermochimie: Rapport final

    Energy Technology Data Exchange (ETDEWEB)

    Berthelot, P.; Houzelle, C.; Laugier, S.; Legret, D.; Muehbauer, R.; Renon, H.; Richon, D.

    1986-01-01

    Two new flow apparatuses have been designed and constructed to determine vapor-liquid equilibria of very corrosive components. Main differences between the two apparatuses are their temperature and pressure ranges of operation. When using each of the two equipments, a monophasic mixture is introduced continuously at constant pressure into a thermostated equilibrium coil. The vapor and liquid leave the coil at equilibrium and enter a separator from which each phase is withdrawn continuously to maintain a constant level of the interface in the separator. Samples taken from the outcoming flows are analyzed. The first apparatus (medium temperature-low pressure) was developed to test the new dynamic method. The experimental results obtained for the system water-acetic acid are in good agreement with those of Othmer et al. (1952). The second apparatus for measurements up to 50 bar and 823/sup 0/K was used to obtain SO/sub 3/-H/sub 2/O equilibrium data. The results obtained are presented; at low pressures they are in good agreement with tabulated data of Gmitro and Vermeulen (1963, 1964).

  16. LiquidPower-1. Development and proof-of-concept of core methanol reformer for stationary and motive fuel cell systems and hydrogen refuelling stations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Krogsgaard, J.; Mortensen, Henrik [H2 Logic A/S, Herning (Denmark); Skipper, T. [Dantherm Power A/S, Hobro (Denmark)

    2013-03-15

    LiquidPower-1 has developed laboratory test systems for methanol reforming and tested reformers from four different suppliers. This has contributed to determining the state-of-the-art level for methanol reforming and enabled an update of the LiquidPower R and D Roadmap onwards a commercialisation of the technology. The project has achieved the following results: 1) A detailed technical specification of methanol reformers for the fuel cell back-up power and hydrogen refueling station markets has been conducted; 2) Laboratory test systems for methanol reformers has been developed and established at Dantherm Power and H2 Logic; 3) Initial test of reformers from four suppliers has been conducted - with two suppliers being selected for continued tests; 4) Extensive laboratory tests conducted of reformers from two suppliers, with the aim to determine state-of-the-art for price, efficiency, capacity and lifetime. Several errors and break-downs were experienced during the test period, which revealed a need for further R and D to improve lifetime and stability; 5) The LiquidPower F and U Roadmap has been updated. Reformer TCO targets (Total Cost of Operation) for each of the markets have been calculated including updated targets for efficiency and cost. These targets also serve as the main ones to be pursued as part of the continued R and D roadmap execution. Compared to the previous edition of the Roadmap, the project has confirmed the viability of methanol reforming, but also revealed that stability and lifetime needs to be addressed and solved before commencing commercialization of the technology. If the Roadmap is successful a commercialization can commence beyond 2015. (Author)

  17. In vivo metabolic investigation of moxifloxacin using liquid chromatography/electrospray ionization tandem mass spectrometry in combination with online hydrogen/deuterium exchange experiments.

    Science.gov (United States)

    Raju, B; Ramesh, M; Borkar, Roshan M; Srinivas, R; Padiya, Raju; Banerjee, Sanjay K

    2012-08-30

    Tuberculosis is a leading cause of death from an infectious disease and moxifloxacin is an effective drug as compared to other fluoroquinolones. To date only two metabolites of the drug are known. Therefore, the present study on characterization of hitherto unknown in vivo metabolites of moxifloxacin using liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) is undertaken. In vivo metabolites of moxifloxacin have been identified and characterized by using LC/ESI-MS/MS in combination with an online hydrogen/deuterium (H/D) exchange technique. To identify in vivo metabolites, blood, urine and faeces samples were collected after oral administration of moxifloxacin to Sprague-Dawley rats. The samples were prepared using an optimized sample preparation approach involving protein precipitation, liquid-liquid extraction followed by solid-phase extraction and LC/MS/MS analysis. A total of nine phase I and ten phase II metabolites of moxifloxacin have been identified in urine samples including N-sulphated, glucuronide and hydroxylated metabolites which are also observed in plasma samples. In faeces samples, only the N-sulphated metabolite is observed. The structures of metabolites have been elucidated based on fragmentation patterns, accurate mass measurements and online H/D exchange LC/MS/MS experiments. Online H/D exchange experiments are used to support the identification and structural characterization of drug metabolites. A total of 19 in vivo metabolites of moxifloxacin have been characterized using LC/ESI-MS/MS in combination with accurate mass measurements and online H/D exchange experiments. The main phase I metabolites of moxifloxacin are hydroxylated, decarbonylated, desmethylated and desmethylhydroxylated metabolites which undergo subsequent phase II glucuronidation pathways. Copyright © 2012 John Wiley & Sons, Ltd.

  18. Initial dissolution of D2O at the gas-liquid interface of the ionic liquid [C4min][NTf2] associated with hydrogen-bond network formation.

    Science.gov (United States)

    Ohoyama, H; Teramoto, T

    2016-10-12

    We have studied the initial dissolution of D2O at the interfacial surface of the flowing jet sheet beam of the ionic liquid (IL) [C4min][NTf2] using the King and Wells method as a function of both the temperature and collision energy of the IL. The initial dissolution probability of D2O into the IL [C4min][NTf2] was found to follow the general propensity that the solubility of gases into a liquid decreases with temperature. However, a large partial molar enthalpy and entropy for the initial dissolution of D2O in the IL [C4min][NTf2] were observed from the temperature dependence of the initial dissolution probability: ΔHl = -53 ± 8 kJ mol-1, ΔSl = -210 ± 30 J mol-1 K-1. In addition, it was found that the collision energy significantly reduced the initial dissolution probability. We propose that the associated D2O molecules at the interface of the IL [C4min][NTf2] make a hydrogen-bond network around the [NTf2]- anion before dissolution into the deeper portion of the interface layer.

  19. Polarized Light from the Sun: Unification of the Corona and Analysis of the Second Solar Spectrum — Further Implications of a Liquid Metallic Hydrogen Solar Model

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2015-07-01

    Full Text Available In order to account for the slight polarization of the continuum towards the limb, propo- nents of the Standard Solar Model (SSM must have recourse to electron or hydrogen- based scattering of light, as no other mechanism is possible in a gaseous Sun. Con- versely, acceptance that the solar body is comprised of condensed matter opens up new avenues in the analysis of this problem, even if the photospheric surface itself is viewed as incapable of emitting polarized light. Thus, the increased disk polarization, from the center to the limb, can be explained by invoking the scattering of light by the at- mosphere above the photosphere. The former is reminiscent of mechanisms which are known to account for the polarization of sunlight in the atmosphere of the Earth. Within the context of the Liquid Metallic Hydrogen Solar Model (LMHSM, molecules and small particles, not electrons or hydrogen atoms as required by the SSM, would primarily act as scattering agents in regions also partially comprised of condensed hy- drogen structures (CHS. In addition, the well-known polarization which characterizes the K-corona would become a sign of emission polarization from an anisotropic source, without the need for scattering. In the LMHSM, the K, F, and T- coronas can be viewed as emissive and reflective manifestations of a single corona l entity adopting a radially anisotropic structure, while slowly cooling with altitude above the photosphere. The presence of “dust particles”, advanced by proponents of the SSM, would no longer be required to explain the F and T-corona, as a single cooling structure would account for the properties of the K, F, and T coronas. At the same time, the polarized “Second Solar Spectrum”, characterized by the dominance of certain elemental or ionic spectral lines and an abundance of molecular lines, could be explained in the LMHSM, by first invoking interface polarization and coordination of these species with condensed matter

  20. Hydrogen Recovery System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Liquid hydrogen is used extensively by NASA to support cryogenic rocket testing. In addition, there are many commercial applications in which delivery and use of...

  1. Water's Hydrogen Bond Strength

    CERN Document Server

    Chaplin, Martin

    2007-01-01

    Water is necessary both for the evolution of life and its continuance. It possesses particular properties that cannot be found in other materials and that are required for life-giving processes. These properties are brought about by the hydrogen bonded environment particularly evident in liquid water. Each liquid water molecule is involved in about four hydrogen bonds with strengths considerably less than covalent bonds but considerably greater than the natural thermal energy. These hydrogen bonds are roughly tetrahedrally arranged such that when strongly formed the local clustering expands, decreasing the density. Such low density structuring naturally occurs at low and supercooled temperatures and gives rise to many physical and chemical properties that evidence the particular uniqueness of liquid water. If aqueous hydrogen bonds were actually somewhat stronger then water would behave similar to a glass, whereas if they were weaker then water would be a gas and only exist as a liquid at sub-zero temperature...

  2. Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Air Products and Chemicals

    2008-09-30

    An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology to prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.

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

    Science.gov (United States)

    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.

  4. Lattice Boltzmann simulation on liquid flow and mass transport in a bioreactor with cylinder bundle for hydrogen production

    Science.gov (United States)

    Liao, Qiang; Yang, Yan-Xia; Zhu, Xun; Wang, Hong; Ding, Yu-Dong

    2015-06-01

    The lattice Boltzmann method is adopted to simulate hydrodynamics and mass transfer accompanying with biochemical reaction in a channel with cylinder bundle, which is the scenario of biohydrogen production by photosynthetic bacteria in the biofilm attached on the surface of cylinder bundle in photobioreactor. The effects of cylinder spacing, Reynolds number and cylinder arrangement are investigated. The numerical results reveal that highest glucose concentration and the lowest hydrogen concentration are obtained at the front of the first row cylinders for all cases. The staggered arrangement leads to an increment in average drag coefficient, Sherwood number and consumption efficiency of substrate under a given condition, and the increment in Sherwood number reaches up to 30 %, while that in drag coefficient is around 1 %, moreover, the increment in consumption efficiency reaches the maximum value of 12 %. The results indicate that the staggered arrangement is beneficial to the mass transfer and biochemical reaction.

  5. Cryogenic hydrogen release research.

    Energy Technology Data Exchange (ETDEWEB)

    LaFleur, Angela Christine [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    The objective of this project was to devolop a plan for modifying the Turbulent Combustion Laboratory (TCL) with the necessary infrastructure to produce a cold (near liquid temperature) hydrogen jet. The necessary infrastructure has been specified and laboratory modifications are currently underway. Once complete, experiments from this platform will be used to develop and validate models that inform codes and standards which specify protection criteria for unintended releases from liquid hydrogen storage, transport, and delivery infrastructure.

  6. Hydrogen Storage Tank

    CERN Multimedia

    1983-01-01

    This huge stainless steel reservoir,placed near an end of the East Hall, was part of the safety equipment connected to the 2 Metre liquid hydrogen Bubble Chamber. It could store all the hydrogen in case of an emergency. The picture shows the start of its demolition.

  7. Hydrogen rich gas generator

    Science.gov (United States)

    Houseman, J. (Inventor)

    1976-01-01

    A process and apparatus is described for producing a hydrogen rich gas by introducing a liquid hydrocarbon fuel in the form of a spray into a partial oxidation region and mixing with a mixture of steam and air that is preheated by indirect heat exchange with the formed hydrogen rich gas, igniting the hydrocarbon fuel spray mixed with the preheated mixture of steam and air within the partial oxidation region to form a hydrogen rich gas.

  8. Hydrogen energy systems studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, J.M.; Kreutz, T.G.; Steinbugler, M. [Princeton Univ., NJ (United States)] [and others

    1996-10-01

    In this report the authors describe results from technical and economic assessments carried out during the past year with support from the USDOE Hydrogen R&D Program. (1) Assessment of technologies for small scale production of hydrogen from natural gas. Because of the cost and logistics of transporting and storing hydrogen, it may be preferable to produce hydrogen at the point of use from more readily available energy carriers such as natural gas or electricity. In this task the authors assess near term technologies for producing hydrogen from natural gas at small scale including steam reforming, partial oxidation and autothermal reforming. (2) Case study of developing a hydrogen vehicle refueling infrastructure in Southern California. Many analysts suggest that the first widespread use of hydrogen energy is likely to be in zero emission vehicles in Southern California. Several hundred thousand zero emission automobiles are projected for the Los Angeles Basin alone by 2010, if mandated levels are implemented. Assuming that hydrogen vehicles capture a significant fraction of this market, a large demand for hydrogen fuel could evolve over the next few decades. Refueling a large number of hydrogen vehicles poses significant challenges. In this task the authors assess near term options for producing and delivering gaseous hydrogen transportation fuel to users in Southern California including: (1) hydrogen produced from natural gas in a large, centralized steam reforming plant, and delivered to refueling stations via liquid hydrogen truck or small scale hydrogen gas pipeline, (2) hydrogen produced at the refueling station via small scale steam reforming of natural gas, (3) hydrogen produced via small scale electrolysis at the refueling station, and (4) hydrogen from low cost chemical industry sources (e.g. excess capacity in refineries which have recently upgraded their hydrogen production capacity, etc.).

  9. Hydrogen storage methods

    Science.gov (United States)

    Züttel, Andreas

    Hydrogen exhibits the highest heating value per mass of all chemical fuels. Furthermore, hydrogen is regenerative and environmentally friendly. There are two reasons why hydrogen is not the major fuel of today's energy consumption. First of all, hydrogen is just an energy carrier. And, although it is the most abundant element in the universe, it has to be produced, since on earth it only occurs in the form of water and hydrocarbons. This implies that we have to pay for the energy, which results in a difficult economic dilemma because ever since the industrial revolution we have become used to consuming energy for free. The second difficulty with hydrogen as an energy carrier is its low critical temperature of 33 K (i.e. hydrogen is a gas at ambient temperature). For mobile and in many cases also for stationary applications the volumetric and gravimetric density of hydrogen in a storage material is crucial. Hydrogen can be stored using six different methods and phenomena: (1) high-pressure gas cylinders (up to 800 bar), (2) liquid hydrogen in cryogenic tanks (at 21 K), (3) adsorbed hydrogen on materials with a large specific surface area (at Tchemically bonded in covalent and ionic compounds (at ambient pressure), or (6) through oxidation of reactive metals, e.g. Li, Na, Mg, Al, Zn with water. The most common storage systems are high-pressure gas cylinders with a maximum pressure of 20 MPa (200 bar). New lightweight composite cylinders have been developed which are able to withstand pressures up to 80 MPa (800 bar) and therefore the hydrogen gas can reach a volumetric density of 36 kg.m-3, approximately half as much as in its liquid state. Liquid hydrogen is stored in cryogenic tanks at 21.2 K and ambient pressure. Due to the low critical temperature of hydrogen (33 K), liquid hydrogen can only be stored in open systems. The volumetric density of liquid hydrogen is 70.8 kg.m-3, and large volumes, where the thermal losses are small, can cause hydrogen to reach a

  10. Magnetic levitation of condensed hydrogen

    Science.gov (United States)

    Paine, C. G.; Seidel, G. M.

    1991-01-01

    Liquid and solid molecular hydrogen has been levitated using a pair of small superconducting solenoids. The hydrogen samples, up to 3 mm in dimension, were trapped in a magnetic potential having either a discrete minimum or a minimum in the form of a ring 1 cm in diameter. The hydrogen could be moved about in the magnetic trap by applying an electric field.

  11. Understanding the role of hydrogen bonding in Brønsted acidic ionic liquid-catalyzed transesterification: a combined theoretical and experimental investigation.

    Science.gov (United States)

    Li, Kaixin; Yan, Yibo; Zhao, Jun; Lei, Junxi; Jia, Xinli; Mushrif, Samir H; Yang, Yanhui

    2016-12-07

    Brønsted acidic ionic liquids (BAILs) can play a dual role, as a solvent and as a catalyst, in many reactions. However, molecular details of the catalytic mechanism are poorly understood. We present here a density functional theory (DFT) study for the catalytic mechanism of the transesterification of methyl ester (ME) with trimethylolpropane (TMP), in the presence of three representative BAILs, namely, N-methylimidazole-IL, pyridinium-IL, and triethylamine-IL. The deprotonation of the BAIL cation and the transesterification step are investigated. Key inter- and intra-molecular hydrogen bonds (HBs) that govern the catalytic performance of BAILs were identified and analyzed using natural bond orbital (NBO) and atoms in molecule (AIM) methods. For the deprotonation of BAILs, it was found that the intermolecular O-HO HB between the hydroxyl group of TMP and the oxygen of the sulfonic group of BAIL was indispensable for proton transfer. DFT computed free energy barriers for the transesterification step are in excellent agreement with the experimental results only after taking into account the BAIL cation-anion interaction in terms of HBs in which the O-HO between the hydroxyl group of the anion and the oxygen of the sulfonic group of the cation was the strongest HB, suggesting the role of the anion in governing the catalytic activity of BAILs. The existence of the HBs suggested by DFT calculations was further validated using in situ FTIR experiments/ATR-FTIR.

  12. Quantum Cluster Equilibrium Theory Applied in Hydrogen Bond Number Studies of Water. 1. Assessment of the Quantum Cluster Equilibrium Model for Liquid Water.

    Science.gov (United States)

    Lehmann, S B C; Spickermann, C; Kirchner, B

    2009-06-09

    Different cluster sets containing only 2-fold coordinated water, 2- and 3-fold coordinated water, and 2-fold, 3-fold, and tetrahedrally coordinated water molecules were investigated by applying second-order Møller-Plesset perturbation theory and density functional theory based on generalized gradient approximation functionals in the framework of the quantum cluster equilibrium theory. We found an improvement of the calculated isobars at low temperatures if tetrahedrally coordinated water molecules were included in the set of 2-fold hydrogen-bonded clusters. This was also reflected in a reduced parameter for the intercluster interaction. If all parameters were kept constant and only the electronic structure methods were varied, large basis set dependencies in the liquid state for the density functional theory results were found. The behavior of the intercluster parameter was also examined for the case that cooperative effects were neglected. The values were 3 times as large as in the calculations including the total electronic structure. Furthermore, these effects are more severe in the tetrahedrally coordinated clusters. Different populations were considered, one weighted by the total number of clusters and one depending on the monomers.

  13. Test of the consistency of various linearized semiclassical initial value time correlation functions in application to inelastic neutron scattering from liquid para-hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William; Liu, Jian; Miller, William H.

    2008-03-15

    The linearized approximation to the semiclassical initial value representation (LSC-IVR) is used to calculate time correlation functions relevant to the incoherent dynamic structure factor for inelastic neutron scattering from liquid para-hydrogen at 14 K. Various time correlations functions were used which, if evaluated exactly, would give identical results, but they do not because the LSC-IVR is approximate. Some of the correlation functions involve only linear operators, and others involve non-linear operators. The consistency of the results obtained with the various time correlation functions thus provides a useful test of the accuracy of the LSC-IVR approximation and its ability to treat correlation functions involving both linear and nonlinear operators in realistic anharmonic systems. The good agreement of the results obtained from different correlation functions, their excellent behavior in the spectral moment tests based on the exact moment constraints, and their semi-quantitative agreement with the inelastic neutron scattering experimental data all suggest that the LSC-IVR is indeed a good short-time approximation for quantum mechanical correlation functions.

  14. Sensors for Highly Toxic Gases: Methylamine and Hydrogen Chloride Detection at Low Concentrations in an Ionic Liquid on Pt Screen Printed Electrodes

    Directory of Open Access Journals (Sweden)

    Krishnan Murugappan

    2015-10-01

    Full Text Available Commercially available Pt screen printed electrodes (SPEs have been employed as possible electrode materials for methylamine (MA and hydrogen chloride (HCl gas detection. The room temperature ionic liquid (RTIL 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonylimide ([C2mim][NTf2] was used as a solvent and the electrochemical behaviour of both gases was first examined using cyclic voltammetry. The reaction mechanism appears to be the same on Pt SPEs as on Pt microelectrodes. Furthermore, the analytical utility was studied to understand the behaviour of these highly toxic gases at low concentrations on SPEs, with calibration graphs obtained from 10 to 80 ppm. Three different electrochemical techniques were employed: linear sweep voltammetry (LSV, differential pulse voltammetry (DPV and square wave voltammetry (SWV, with no significant differences in the limits of detection (LODs between the techniques (LODs were between 1.4 to 3.6 ppm for all three techniques for both gases. The LODs achieved on Pt SPEs were lower than the current Occupational Safety and Health Administration Permissible Exposure Limit (OSHA PEL limits of the two gases (5 ppm for HCl and 10 ppm for MA, suggesting that Pt SPEs can successfully be combined with RTILs to be used as cheap alternatives for amperometric gas sensing in applications where these toxic gases may be released.

  15. Fabrication of gallium hexacyanoferrate modified carbon ionic liquid paste electrode for sensitive determination of hydrogen peroxide and glucose.

    Science.gov (United States)

    Haghighi, Behzad; Khosravi, Mehdi; Barati, Ali

    2014-07-01

    Gallium hexacyanoferrate (GaHCFe) and graphite powder were homogeneously dispersed into n-dodecylpyridinium hexafluorophosphate and paraffin to fabricate GaHCFe modified carbon ionic liquid paste electrode (CILPE). Mixture experimental design was employed to optimize the fabrication of GaHCFe modified CILPE (GaHCFe-CILPE). A pair of well-defined redox peaks due to the redox reaction of GaHCFe through one-electron process was observed for the fabricated electrode. The fabricated GaHCFe-CILPE exhibited good electrocatalytic activity towards reduction and oxidation of H2O2. The observed sensitivities for the electrocatalytic oxidation and reduction of H2O2 at the operating potentials of +0.8 and -0.2V were about 13.8 and 18.3 mA M(-1), respectively. The detection limit (S/N=3) for H2O2 was about 1 μM. Additionally, glucose oxidase (GOx) was immobilized on GaHCFe-CILPE using two methodology, entrapment into Nafion matrix and cross-linking with glutaraldehyde and bovine serum albumin, in order to fabricate glucose biosensor. Linear dynamic rage, sensitivity and detection limit for glucose obtained by the biosensor fabricated using cross-linking methodology were 0.1-6mM, 0.87 mA M(-1) and 30 μM, respectively and better than those obtained (0.2-6mM, 0.12 mA M(-1) and 50 μM) for the biosensor fabricated using entrapment methodology. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Carbon: Hydrogen Carrier or Disappearing Skeleton?

    NARCIS (Netherlands)

    Jong, K.P. de; Wechem, H.M.H. van

    1994-01-01

    The use of liquid hydrocarbons as energy carriers implies the use of carbon as a carrier for hydrogen to facilitate hydrogen transport and storage. The current trend for liquid energy carriers used in the transport sector is to maximize the load of hydrogen on the carbon carrier. The recently

  17. Process for desulphurisation of liquid commercial fuels for applications in fuel cell systems by partial evaporation followed by hydrogenating desulphurisation; Verfahren zur Entschwefelung von fluessigen handelsueblichen Brennstoffen fuer die Anwendung in Brennstoffzellensystemen durch partielle Verdampfung und anschliessende hydrierende Entschwefelung

    Energy Technology Data Exchange (ETDEWEB)

    Brune, Markus

    2010-07-01

    Desulphurisation of commercial liquid fuels by partial evaporation followed by hydrogenating desulphurisation is a promising process for decentral fuel cell systems. This is a newly developed process in which only the fraction to be used in the fuel cell is evaporated and is then desulphurized in the gaseous phase using recycled hydrogen from combustion gas production. The residue of the partial evaporation can be recirculated either directly into a reformer burner of an allothermal steam reforming process, into a heating burner, into an engine, or into a storage tank depending on the intended application. The publication also takes a short look at other desulphurisation processes and attempts a comparison. The results of hydrogenating desulphurisation of partially evaporated kerosene and heating oil using a CoMo catalyst illustrate the feasibility of the process. Most of the sulphur compounds are converted, and the end product has sufficient purity for application in a fuel cell process, i.e. less than ppm. (orig./MM)

  18. Determination of hydrogen sulfide and volatile thiols in air samples by mercury probe derivatization coupled with liquid chromatography-atomic fluorescence spectrometry.

    Science.gov (United States)

    Bramanti, Emilia; D'Ulivo, Lucia; Lomonte, Cristina; Onor, Massimo; Zamboni, Roberto; Raspi, Giorgio; D'Ulivo, Alessandro

    2006-10-02

    A new procedure is proposed for the sampling and storage of hydrogen sulphide (H2S) and volatile thiols (methanethiol or methyl mercaptan, ethanethiol and propanethiol) for their determination by liquid chromatography. The sampling procedure is based on the trapping/pre-concentration of the analytes in alkaline aqueous solution containing an organic mercurial probe p-hydroxymercurybenzoate, HO-Hg-C6H4-COO- (PHMB), where they are derivatized to stable PHMB complexes based on mercury-sulfur covalent bonds. PHMB complexes are separated on a C18 reverse phase column, allowing their determination by liquid chromatography coupled with sequential non-selective UV-vis (DAD) and mercury specific (chemical vapor generation atomic fluorescence spectrometry, CVGAFS) on-line detectors. PHMB complexes, S(PHMB)2CH3S-PHMB, C2H5S-PHMB and C3H7S-PHMB, are stable alt least for 12 h at room temperature and for 3 months if stored frozen (-20 degrees C). The best analytical figures of merits in the optimized conditions were obtained by CVGAFS detection, with detection limits (LODc) of 9.7 microg L(-1) for H2S, 13.7 microg L(-1) for CH(3)SH, 17.7 microg L(-1) for C2H5SH and 21.7 microg L(-1) for C3H7SH in the trapping solution in form of RS-PHMB complexes, the relative standard deviation (R.S.D.) ranging between 1.0 and 1.5%, and a linear dynamic range (LDR) between 10 and 9700 microg L(-1). Conventional UV absorbance detectors tuned at 254 nm can be employed as well with comparable R.S.D. and LDR, but with LODc one order of magnitude higher than AFS detector and lower specificity. The sampling procedure followed by LC-DAD-CVGAFS analysis has been validated, as example, for H2S determination by a certified gas permeation tube as a source of 3.071+/-0.154 microg min(-1) of H2S, giving a recovery of 99.8+/-7% and it has been applied to the determination of sulfur compounds in real gas samples (biogas and the air of a plant for fractional distillation of crude oil).

  19. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere II. Continuous Emission and Condensed Matter Within the Corona

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available The K-corona, a significant portion of the solar atmosphere, displays a continuous spectrum which closely parallels photospheric emission, though without the presence of overlying Fraunhofer lines. The E-corona exists in the same region and is characterized by weak emission lines from highly ionized atoms. For instance, the famous green emission line from coronium (FeXIV is part of the E-corona. The F-corona exists beyond the K/E-corona and, like the photospheric spectrum, is characterized by Fraunhofer lines. The F-corona represents photospheric light scattered by dust particles in the interplanetary medium. Within the gaseous models of the Sun, the K-corona is viewed as photospheric radiation which has been scattered by relativistic electrons. This scattering is thought to broaden the Fraunhofer lines of the solar spectrum such that they can no longer be detected in the K-corona. Thus, the gaseous models of the Sun account for the appearance of the K-corona by distorting photospheric light, since they are unable to have recourse to condensed matter to directly produce such radiation. Conversely, it is now advanced that the continuous emission of the K-corona and associated emission lines from the E-corona must be interpreted as manifestations of the same phenomenon: condensed matter exists in the corona. It is well-known that the Sun expels large amounts of material from its surface in the form of flares and coronal mass ejections. Given a liquid metallic hydrogen model of the Sun, it is logical to assume that such matter, which exists in the condensed state on the solar surface, continues to manifest its nature once expelled into the corona. Therefore, the continuous spectrum of the K-corona provides the twenty-seventh line of evidence that the Sun is composed of condensed matter.

  20. Hydrogen vehicle fueling station

    Energy Technology Data Exchange (ETDEWEB)

    Daney, D.E.; Edeskuty, F.J.; Daugherty, M.A. [Los Alamos National Lab., NM (United States)] [and others

    1995-09-01

    Hydrogen fueling stations are an essential element in the practical application of hydrogen as a vehicle fuel, and a number of issues such as safety, efficiency, design, and operating procedures can only be accurately addressed by a practical demonstration. Regardless of whether the vehicle is powered by an internal combustion engine or fuel cell, or whether the vehicle has a liquid or gaseous fuel tank, the fueling station is a critical technology which is the link between the local storage facility and the vehicle. Because most merchant hydrogen delivered in the US today (and in the near future) is in liquid form due to the overall economics of production and delivery, we believe a practical refueling station should be designed to receive liquid. Systems studies confirm this assumption for stations fueling up to about 300 vehicles. Our fueling station, aimed at refueling fleet vehicles, will receive hydrogen as a liquid and dispense it as either liquid, high pressure gas, or low pressure gas. Thus, it can refuel any of the three types of tanks proposed for hydrogen-powered vehicles -- liquid, gaseous, or hydride. The paper discusses the fueling station design. Results of a numerical model of liquid hydrogen vehicle tank filling, with emphasis on no vent filling, are presented to illustrate the usefulness of the model as a design tool. Results of our vehicle performance model illustrate our thesis that it is too early to judge what the preferred method of on-board vehicle fuel storage will be in practice -- thus our decision to accommodate all three methods.

  1. Hydrogen bond dynamics in bulk alcohols

    NARCIS (Netherlands)

    Shinokita, Keisuke; Cunha, Ana V.; Jansen, Thomas L. C.; Pshenichnikov, Maxim S.

    2015-01-01

    Hydrogen-bonded liquids play a significant role in numerous chemical and biological phenomena. In the past decade, impressive developments in multidimensional vibrational spectroscopy and combined molecular dynamics-quantum mechanical simulation have established many intriguing features of hydrogen

  2. An ab initio molecular dynamics study of the liquid-vapor interface of an aqueous NaCl solution: inhomogeneous density, polarity, hydrogen bonds, and frequency fluctuations of interfacial molecules.

    Science.gov (United States)

    Choudhuri, Jyoti Roy; Chandra, Amalendu

    2014-11-21

    We have presented a first principles simulation study of the structural and dynamical properties of a liquid-vapor interfacial system of a concentrated (5.3 M) aqueous NaCl solution. We have used ab initio molecular dynamics to examine the structural and dynamical properties of the bulk and interfacial regions. The structural aspects of the system that have been considered here include the inhomogeneous density profiles of ions and water molecules, hydrogen bond distributions, orientational profiles, and also vibrational frequency distributions in the bulk and interfacial regions. It is found that the sodium ions are mostly located in the interior, while the chloride anions occupy a significant portion of the interface of the slab. The water dipoles at the interface prefer to orient parallel to the surface. The dynamical aspects of the interfaces are investigated in terms of diffusion, orientational relaxation, hydrogen bond dynamics, and vibrational spectral diffusion. The results of the interfacial dynamics are compared with those of the corresponding bulk region. It is observed that the interfacial molecules exhibit faster diffusion and orientational relaxation with respect to the bulk. However, the interfacial molecules are found to have longer hydrogen bond lifetimes than those of the bulk. We have also investigated the correlations of hydrogen bond relaxation with the vibrational frequency fluctuations of interfacial water molecules.

  3. An investigation of the accuracy of empirical aircraft design for the development of an unmanned aerial vehicle intended for liquid hydrogen fuel

    Science.gov (United States)

    Chaney, Christopher Scott

    A study was conducted to assess the accuracy of empirical techniques used for the calculation of flight performance for unmanned aerial vehicles. This was achieved by quantifying the error between a mathematical model developed with these techniques and experimental test data taken using an unmanned aircraft. The vehicle utilized for this study was developed at Washington State University for the purpose of flying using power derived from hydrogen stored as a cryogenic liquid. The vehicle has a mass of 32.8 kg loaded and performed a total of 14 flights under battery power for 3.58 total flight hours. Over these flights, the design proved it is capable of sustaining level flight from the power available from a PEM fuel cell propulsion system. The empirical techniques used by the model are explicitly outlined within. These yield several performance metrics that are compared to measurements taken during flight testing. Calculations of required thrust for steady flight over all airspeeds and rates of climb modeled are found to have a mean percent error of 3.2%+/-7.0% and a mean absolute percent error of 34.6%+/-5.1%. Comparison of the calculated and measured takeoff distance are made and the calculated thrust required to perform a level turn at a given rate is compared to flight test data. A section of a test flight is analyzed, over which the vehicle proves it can sustain level flight under 875 watts of electrical power. The aircraft's design is presented including the wing and tail, propulsion system, and build technique. The software and equipment used for the collection and analysis of flight data are given. Documentation and validation is provided of a unique test rig for the characterization of propeller performance using a car. The aircraft remains operational to assist with research of alternative energy propulsion systems and novel fuel storage techniques. The results from the comparison of the mathematical model and flight test data can be utilized to assist

  4. Hydrogen, lithium, and lithium hydride production

    Science.gov (United States)

    Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.; Powell, G. Louis; Campbell, Peggy J.

    2017-06-20

    A method is provided for extracting hydrogen from lithium hydride. The method includes (a) heating lithium hydride to form liquid-phase lithium hydride; (b) extracting hydrogen from the liquid-phase lithium hydride, leaving residual liquid-phase lithium metal; (c) hydriding the residual liquid-phase lithium metal to form refined lithium hydride; and repeating steps (a) and (b) on the refined lithium hydride.

  5. Onboard hydrogen generation for automobiles

    Science.gov (United States)

    Houseman, J.; Cerini, D. J.

    1976-01-01

    Problems concerning the use of hydrogen as a fuel for motor vehicles are related to the storage of the hydrogen onboard a vehicle. The feasibility is investigated to use an approach based on onboard hydrogen generation as a means to avoid these storage difficulties. Two major chemical processes can be used to produce hydrogen from liquid hydrocarbons and methanol. In steam reforming, the fuel reacts with water on a catalytic surface to produce a mixture of hydrogen and carbon monoxide. In partial oxidation, the fuel reacts with air, either on a catalytic surface or in a flame front, to yield a mixture of hydrogen and carbon monoxide. There are many trade-offs in onboard hydrogen generation, both in the choice of fuels as well as in the choice of a chemical process. Attention is given to these alternatives, the results of some experimental work in this area, and the combustion of various hydrogen-rich gases in an internal combustion engine.

  6. Liquid fuel cells

    National Research Council Canada - National Science Library

    Soloveichik, Grigorii L

    2014-01-01

    The advantages of liquid fuel cells (LFCs) over conventional hydrogen-oxygen fuel cells include a higher theoretical energy density and efficiency, a more convenient handling of the streams, and enhanced safety...

  7. Hydrogen and helium recycling from a JxB-force convected liquid metal Ga{sub 67}In{sub 20.5}Sn{sub 12.5} under steady state plasma bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Hirooka, Yoshi, E-mail: hirooka.yoshihiko@nifs.ac.jp [National institute for Fusion Science, Oroshi, Toki, Gifu 509-5292 (Japan); Graduate University for Advanced Studies, Oroshi, Toki, Gifu 509-5292 (Japan); Bi, Hailin [Graduate University for Advanced Studies, Oroshi, Toki, Gifu 509-5292 (Japan); Shimada, Michiya [Japan Atomic Energy Agency, Rokkasho, Kamikita, Aomori 039-3212 (Japan); Ono, Masa [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States)

    2017-04-15

    A series of first-of-a-kind laboratory-scale experiments on the JxB-force convected liquid metal divertor concept have been carried out in the temperature range from room temperature to ∼200 °C, employing a eutectic alloy: Ga{sub 67}In{sub 20.5}Sn{sub 12.5}, the melting point of which is 10.5 °C. The electrical current conducted through the alloy is set at about 70A and the magnetic field is set at about 700 G. It has reproducibly been observed that hydrogen as well as helium particle recycling is noticeably reduced under steady state plasma bombardment when the liquid is convected by the JxB force.

  8. Rate-controlling steps in a three-phase (solid-liquid-gas) photoreactor: a phenomenological approach applied to hydrogen photoproduction using Pt-TiO/sub 2/ aqueous suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Escudero, J.C.; Simarro, R.; Cervera-March, S.; Gimenez, J.

    1989-01-01

    Water photolysis has been studied using a three-phase solid-liquid-gas photoreactor, continuous with respect to the gas phase. The Pt-TiO/sub 2/ catalytic powders were kept suspended in water by means of gas bubbling through the liquid. In this case the hydrogen production rate can be controlled by luminic and dark (chemical or mass-transfer) processes. The relative importance of each of these processes depends on the lamp-photoreactor system used, the nature and physical characteristics of the photocatalysts, and the operating (fluidodynamic) conditions. A description of the steps involved in the overall photocatalytic process is given. The importance of mass transfer in limiting the process yield is demonstrated, showing that this step has to be considered in the development of photocatalysts even at early stages.

  9. Handheld hydrogen - a new concept for hydrogen storage

    DEFF Research Database (Denmark)

    Johannessen, Tue; Sørensen, Rasmus Zink

    2005-01-01

    A method of hydrogen storage using metal ammine complexes in combination with an ammonia decomposition catalyst is presented. This dense hydrogen storage material has high degree of safety compared to all the other available alternatives. This technology reduces the safety hazards of using liquid...... ammonia and benefits from the properties of ammonia as a fuel. The system can be used as a safe, reversible, low-cost hydrogen carrier....

  10. Hydrogen application dynamics and networks

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, E. [Air Liquide Large Industries, Champigny-sur-Marne (France)

    2010-12-30

    The Chemical Industry consumes large volumes of hydrogen as raw material for the manufacture of numerous products (e.g. polyamides and polyurethanes account for 60% of hydrogen demand). The hydrogen demand was in the recent past and will continue to be driven by the polyurethane family. China will host about 60% of new hydrogen needs over the period 2010-2015 becoming the first hydrogen market next year and reaching 25% of market share by 2015 (vs. only 4% in 2001). Air Liquide supplies large volumes of Hydrogen (and other Industrial Gases) to customers by on-site plants and through pipeline networks which offer significant benefits such as higher safety, reliability and flexibility of supply. Thanks to its long term strategy and heavy investment in large units and pipeline networks, Air Liquide is the Industrial Gas leader in most of the world class Petrochemical basins (Rotterdam, Antwerp, US Gulf Coast, Yosu, Caojing,..) (orig.)

  11. High-performance liquid chromatography method for the determination of hydrogen peroxide present or released in teeth bleaching kits and hair cosmetic products.

    Science.gov (United States)

    Gimeno, Pascal; Bousquet, Claudine; Lassu, Nelly; Maggio, Annie-Françoise; Civade, Corinne; Brenier, Charlotte; Lempereur, Laurent

    2015-03-25

    This manuscript presents an HPLC/UV method for the determination of hydrogen peroxide present or released in teeth bleaching products and hair products. The method is based on an oxidation of triphenylphosphine into triphenylphosphine oxide by hydrogen peroxide. Triphenylphosphine oxide formed is quantified by HPLC/UV. Validation data were obtained using the ISO 12787 standard approach, particularly adapted when it is not possible to make reconstituted sample matrices. For comparative purpose, hydrogen peroxide was also determined using ceric sulfate titrimetry for both types of products. For hair products, a cross validation of both ceric titrimetric method and HPLC/UV method using the cosmetic 82/434/EEC directive (official iodometric titration method) was performed. Results obtained for 6 commercialized teeth whitening products and 5 hair products point out similar hydrogen peroxide contain using either the HPLC/UV method or ceric sulfate titrimetric method. For hair products, results were similar to the hydrogen peroxide content using the cosmetic 82/434/EEC directive method and for the HPLC/UV method, mean recoveries obtained on spiked samples, using the ISO 12787 standard, ranges from 100% to 110% with a RSD<3.0%. To assess the analytical method proposed, the HPLC method was used to control 35 teeth bleaching products during a market survey and highlight for 5 products, hydrogen peroxide contents higher than the regulated limit. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Autothermal hydrogen storage and delivery systems

    Science.gov (United States)

    Pez, Guido Peter [Allentown, PA; Cooper, Alan Charles [Macungie, PA; Scott, Aaron Raymond [Allentown, PA

    2011-08-23

    Processes are provided for the storage and release of hydrogen by means of dehydrogenation of hydrogen carrier compositions where at least part of the heat of dehydrogenation is provided by a hydrogen-reversible selective oxidation of the carrier. Autothermal generation of hydrogen is achieved wherein sufficient heat is provided to sustain the at least partial endothermic dehydrogenation of the carrier at reaction temperature. The at least partially dehydrogenated and at least partially selectively oxidized liquid carrier is regenerated in a catalytic hydrogenation process where apart from an incidental employment of process heat, gaseous hydrogen is the primary source of reversibly contained hydrogen and the necessary reaction energy.

  13. Hydrogen sensor

    Science.gov (United States)

    Duan, Yixiang; Jia, Quanxi; Cao, Wenqing

    2010-11-23

    A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.

  14. Storing Renewable Energy in the Hydrogen Cycle.

    Science.gov (United States)

    Züttel, Andreas; Callini, Elsa; Kato, Shunsuke; Atakli, Züleyha Özlem Kocabas

    2015-01-01

    An energy economy based on renewable energy requires massive energy storage, approx. half of the annual energy consumption. Therefore, the production of a synthetic energy carrier, e.g. hydrogen, is necessary. The hydrogen cycle, i.e. production of hydrogen from water by renewable energy, storage and use of hydrogen in fuel cells, combustion engines or turbines is a closed cycle. Electrolysis splits water into hydrogen and oxygen and represents a mature technology in the power range up to 100 kW. However, the major technological challenge is to build electrolyzers in the power range of several MW producing high purity hydrogen with a high efficiency. After the production of hydrogen, large scale and safe hydrogen storage is required. Hydrogen is stored either as a molecule or as an atom in the case of hydrides. The maximum volumetric hydrogen density of a molecular hydrogen storage is limited to the density of liquid hydrogen. In a complex hydride the hydrogen density is limited to 20 mass% and 150 kg/m(3) which corresponds to twice the density of liquid hydrogen. Current research focuses on the investigation of new storage materials based on combinations of complex hydrides with amides and the understanding of the hydrogen sorption mechanism in order to better control the reaction for the hydrogen storage applications.

  15. Precipitation hardening and hydrogen embrittlement of aluminum ...

    Indian Academy of Sciences (India)

    AA7020 Al–Mg–Zn, a medium strength aluminium alloy, is used in welded structures in military and aerospace applications. As it may be subjected to extremes of environmental exposures, including high pressure liquid hydrogen, it could suffer hydrogen embrittlement. Hydrogen susceptibility of alloy AA7020 was ...

  16. Storage, generation, and use of hydrogen

    Science.gov (United States)

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

    2006-05-30

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

  17. Influence of Sulfuric Acid on the Performance of Ruthenium-based Catalysts in the Liquid-Phase Hydrogenation of Levulinic Acid to γ-Valerolactone

    NARCIS (Netherlands)

    Ftouni, Jamal; Genuino, Homer C.|info:eu-repo/dai/nl/371571685; Muñoz-murillo, Ara; Bruijnincx, Pieter C. A.|info:eu-repo/dai/nl/33799529X; Weckhuysen, Bert M.|info:eu-repo/dai/nl/285484397

    2017-01-01

    The presence of biogenic or process-derived impurities poses a major problem on the efficient catalytic hydrogenation of biomass-derived levulinic acid to γ-valerolactone; hence, studies on their influence on catalyst stability are now required. Herein, the influence of sulfuric acid as feed

  18. On the ground state of metallic hydrogen

    Science.gov (United States)

    Chakravarty, S.; Ashcroft, N. W.

    1978-01-01

    A proposed liquid ground state of metallic hydrogen at zero temperature is explored and a variational upper bound to the ground state energy is calculated. The possibility that the metallic hydrogen is a liquid around the metastable point (rs = 1.64) cannot be ruled out. This conclusion crucially hinges on the contribution to the energy arising from the third order in the electron-proton interaction which is shown here to be more significant in the liquid phase than in crystals.

  19. Low-cost industrially available molybdenum boride and carbide as “platinum-like” catalysts for the hydrogen evolution reaction in biphasic liquid systems

    OpenAIRE

    Scanlon, Micheal Diarmaid; Bian, Xiaojun; Vrubel, Heron; Amstutz, Véronique; Schenk, Kurt; Hu, Xile; Liu, Baohong; Girault, Hubert

    2013-01-01

    Rarely reported low cost molybdenum boride and carbide microparticles both of which are available in abundant quantities due to their widespread use in industry adsorb at aqueous acid 12 dichloroethane interfaces and efficiently catalyse the hydrogen evolution reaction in the presence of the organic electron donor decamethylferrocene. Kinetic studies monitoring biphasic reactions by UV/vis spectroscopy and further evidence provided by gas chromatography highlight (a) their superior rates of c...

  20. Hydrogen bonded supramolecular materials

    CERN Document Server

    Li, Zhan-Ting

    2015-01-01

    This book is an up-to-date text covering topics in utilizing hydrogen bonding for constructing functional architectures and supramolecular materials. The first chapter addresses the control of photo-induced electron and energy transfer. The second chapter summarizes the formation of nano-porous materials. The following two chapters introduce self-assembled gels, many of which exhibit unique functions. Other chapters cover the advances in supramolecular liquid crystals and the versatility of hydrogen bonding in tuning/improving the properties and performance of materials. This book is designed

  1. Polymerization of liquid propylene with a 4th generation Ziegler-Natta catalyst-influence of temperature, hydrogen and monomer concentration and prepolymerization method on polymerization kinetics

    NARCIS (Netherlands)

    Pater, J.T.M.; Weickert, G.; van Swaaij, Willibrordus Petrus Maria

    2002-01-01

    In a batch-wise operated autoclave reactor, liquid propylene was polymerized using a 4th generation, TiCl4/MgCl2/phthalate ester-AlEt3-R2Si(OMe)2, Ziegler-Natta catalyst system. By using a calorimetric principle it was possible to measure full reaction rate versus time curves for obtaining data on

  2. Hydrogen Generator

    Science.gov (United States)

    1983-01-01

    A unit for producing hydrogen on site is used by a New Jersey Electric Company. The hydrogen is used as a coolant for the station's large generator; on-site production eliminates the need for weekly hydrogen deliveries. High purity hydrogen is generated by water electrolysis. The electrolyte is solid plastic and the control system is electronic. The technology was originally developed for the Gemini spacecraft.

  3. Color Changing Hydrogen Sensors

    Science.gov (United States)

    Roberson, Luke B.; Williams, Martha; Captain, Janine E.; Mohajeri, Nahid; Raissi, Ali

    2015-01-01

    During the Space Shuttle Program, one of the most hazardous operation that occurred was the loading of liquid hydrogen (LH2) during fueling operations of the spacecraft. Due to hydrogen's low explosive limit, any amount leaked could lead to catastrophic event. Hydrogen's chemical properties make it ideal as a rocket fuel; however, the fuel is deemed unsafe for most commercial use because of the inability to easily detect the gas leaking. The increased use of hydrogen over traditional fossil fuels would reduce greenhouse gases and America's dependency on foreign oil. Therefore a technology that would improve safety at NASA and in the commercial sector while creating a new economic sector would have a huge impact to NASA's mission. The Chemochromic Detector for sensing hydrogen gas leakage is a color-changing detector that is useful in any application where it is important to know not only the presence but also the location of the hydrogen gas leak. This technology utilizes a chemochromicpigment and polymer matrix that can be molded or spun into rigid or pliable shapes useable in variable temperature environments including atmospheres of inert gas, hydrogen gas, or mixtures of gases. A change in color of the detector material indicates where gaseous hydrogen leaks are occurring. The irreversible sensor has a dramatic color change from beige to dark grey and remains dark grey after exposure. A reversible pigment changes from white to blue in the presence of hydrogen and reverts back to white in the presence of oxygen. Both versions of the sensor's pigments were comprised of a mixture of a metal oxide substrate and a hydro-chromic compound (i.e., the compound that changed color in the presence of hydrogen) and immediately notified the operator of the presence of low levels of hydrogen. The detector can be used in a variety of formats including paint, tape, caulking, injection molded parts, textiles and fabrics, composites, and films. This technology brings numerous

  4. Hydrogen gas detector card

    Directory of Open Access Journals (Sweden)

    Francisco Sánchez Niño

    2016-04-01

    Full Text Available A small card used for detecting hydrogen gas in a crystal growth system by the liquid phase epitaxy technique was designed and built. The small size of the card enables its portability to other laboratories where leakage detection of hydrogen or other flammable gas is required. Card dimensions are approximately 10 cm long and 5 cm wide enabling easy transportation. The design is based on a microcontroller which reads the signal from the hydrogen sensor and internally compares the read value with preset values. Depending on the signal voltage a red, yellow or green LED will light to indicate the levels of concentration of the flammable gas. The card is powered by a 9 V battery.

  5. Preparation of Ag@mSiO{sub 2} and Pt@mSiO{sub 2}nano composites using trioctylmethyl ammonium hydrogen phthalate (TOMAHP) ionic liquid as reaction medium

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Sujoy, E-mail: sujoyb@barc.gov.in [Chemical Engineering Group, Bhabha Atomic Research Centre, Mumbai 400085 (India); Dasgupta, Kinshuk [Materials Group, Bhabha Atomic Research Centre, Mumbai 400085 (India); Bahadur, Jitendra [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tewari, Raghavendra [Materials Group, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mazumder, Subhasish [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2016-09-15

    A novel one step green chemistry approach utilizing trioctylmethyl ammonium hydrogen phthalate (TOMAHP), task specific ionic liquid has been attempted for synthesis of Ag and Pt nanoparticles supported on silica (Ag@mSiO{sub 2} and Pt@mSiO{sub 2}). Structure, size distribution and morphology of these nano-composite particles were evaluated using X-ray diffraction (XRD), transmission electron microscopy (TEM), small angle neutron scattering (SANS) as well as small angle X-ray scattering (SAXS) techniques. The XRD results show that Ag/Pt metal nanoparticles deposited on to SiO{sub 2} surface are face center cubic (fcc) in nature. The TEM and SAXS/SANS results show the morphology and size distributions of Ag and Pt nanoparticles loaded on to the surface of SiO{sub 2}. It has been found that Ag nanoparticles are well dispersed on to the SiO{sub 2} surface and are quite monodisperse in size, whereas Pt nanoparticles are quite polydisperse in size and forms aggregate or chain like structure on SiO{sub 2} surface containing primary nanoparticles of typical size range 3–7 nm. The stability of nanoparticles, which controls its dispersion on SiO{sub 2} substrate, has been discussed. - Graphical abstract: Mechanism for Ag@mSiO{sub 2} and Pt@mSiO{sub 2} nano composites in TOMAHP ionic liquid medium. - Highlights: • Novel methods for preparation of Pt@SiO{sub 2} and Ag@SiO{sub 2} nano composite in functionalized ionic liquid. • Pt@SiO{sub 2} and Ag@SiO{sub 2} nano composite are characterized using XRD, TEM as well as small angle x-ray scattering techniques. • The sizes of nano composite is <10 nm in size. • The method is simple one step, green chemical reduction method to prepare SiO{sub 2} support nano catalyst.

  6. Solvation Thermodynamic Properties of Hydrogen Sulfide in [C4mim][PF6], [C4mim][BF4], and [C4mim][Cl] Ionic Liquids, Determined by Molecular Simulations.

    Science.gov (United States)

    Sánchez-Badillo, Joel; Gallo, Marco; Alvarado, Sandra; Glossman-Mitnik, Daniel

    2015-08-20

    Removal of hydrogen sulfide (H2S) and acid gases from natural gas is accomplished by absorption processes using a solvent. The gas solubility in a liquid can be used to measure the degree of removal of the gas and is quantified by the Henry's constant, the free energy of solvation at infinite dilution, or the excess chemical potential. In this work, Henry's constants and thermodynamic properties of solvation of H2S were calculated in three ionic liquids: [C4mim][PF6], [C4mim][BF4], and [C4mim][Cl] ([C4mim], 1-butyl-3-methyl imidazolium). The first step in this work was the evaluation of the force fields for the gas and condensed phases in order to obtain accurate values for the excess chemical potential for H2S on each ionic liquid using free energy perturbation techniques. In the H2S-[C4mim][PF6] and H2S-[C4mim][BF4] systems, the results obtained by molecular simulation agree with the experimental values reported in the literature. However, the solvation free energy calculated for the H2S-[C4mim][Cl] system can be considered predictive because of the lack of experimental data at the simulated conditions. Based on these results, the best solvent for removing H2S is [C4mim][Cl] because it has the highest affinity for this species (lowest value of the Henry's constant). Also, solvation thermodynamic properties such as enthalpy and entropy were calculated in order to evaluate their contribution to the free energy of solvation.

  7. Hydrogen-rich gas generator

    Science.gov (United States)

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

    1976-01-01

    A process and apparatus are described for producing hydrogen-rich product gases. A spray of liquid hydrocarbon is mixed with a stream of air in a startup procedure and the mixture is ignited for partial oxidation. The stream of air is then heated by the resulting combustion to reach a temperature such that a signal is produced. The signal triggers a two way valve which directs liquid hydrocarbon from a spraying mechanism to a vaporizing mechanism with which a vaporized hydrocarbon is formed. The vaporized hydrocarbon is subsequently mixed with the heated air in the combustion chamber where partial oxidation takes place and hydrogen-rich product gases are produced.

  8. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  9. Hydrogen Embrittlement

    Science.gov (United States)

    Woods, Stephen; Lee, Jonathan A.

    2016-01-01

    Hydrogen embrittlement (HE) is a process resulting in a decrease in the fracture toughness or ductility of a metal due to the presence of atomic hydrogen. In addition to pure hydrogen gas as a direct source for the absorption of atomic hydrogen, the damaging effect can manifest itself from other hydrogen-containing gas species such as hydrogen sulfide (H2S), hydrogen chloride (HCl), and hydrogen bromide (HBr) environments. It has been known that H2S environment may result in a much more severe condition of embrittlement than pure hydrogen gas (H2) for certain types of alloys at similar conditions of stress and gas pressure. The reduction of fracture loads can occur at levels well below the yield strength of the material. Hydrogen embrittlement is usually manifest in terms of singular sharp cracks, in contrast to the extensive branching observed for stress corrosion cracking. The initial crack openings and the local deformation associated with crack propagation may be so small that they are difficult to detect except in special nondestructive examinations. Cracks due to HE can grow rapidly with little macroscopic evidence of mechanical deformation in materials that are normally quite ductile. This Technical Memorandum presents a comprehensive review of experimental data for the effects of gaseous Hydrogen Environment Embrittlement (HEE) for several types of metallic materials. Common material screening methods are used to rate the hydrogen degradation of mechanical properties that occur while the material is under an applied stress and exposed to gaseous hydrogen as compared to air or helium, under slow strain rates (SSR) testing. Due to the simplicity and accelerated nature of these tests, the results expressed in terms of HEE index are not intended to necessarily represent true hydrogen service environment for long-term exposure, but rather to provide a practical approach for material screening, which is a useful concept to qualitatively evaluate the severity of

  10. Fusion Energy for Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Fillo, J. A.; Powell, J. R.; Steinberg, M.; Salzano, F.; Benenati, R.; Dang, V.; Fogelson, S.; Isaacs, H.; Kouts, H.; Kushner, M.; Lazareth, O.; Majeski, S.; Makowitz, H.; Sheehan, T. V.

    1978-09-01

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approximately 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of approximately 50 to 70% are projected for fusion reactors using high temperature blankets.

  11. Magnetic refrigerator for hydrogen liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, K; Kondo, T [Department of Physics, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Yoshioka, S; Kamiya, K; Numazawa, T [Tsukuba Magnet Laboratory, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003 (Japan)], E-mail: kmatsu@kenroku.kanazawa-u.ac.jp

    2009-02-01

    Magnetic refrigeration which is based on the magnetocaloric effect of solids has the potential to achieve high thermal efficiency for hydrogen liquefaction. We have been developing a magnetic refrigerator for hydrogen liquefaction which cools down hydrogen gas from liquid natural gas temperature and liquefies at 20 K. The magnetic liquefaction system consists of two magnetic refrigerators: Carnot magnetic refrigerator (CMR) and active magnetic regenerator (AMR) device. CMR with Carnot cycle succeeded in liquefying hydrogen at 20K. Above liquefaction temperature, a regenerative refrigeration cycle should be necessary to precool hydrogen gas, because adiabatic temperature change of magnetic material is reduced due to a large lattice specific heat of magnetic materials. We have tested an AMR device as the precooling stage. It was confirmed for the first time that AMR cycle worked around 20 K.

  12. Design of the cryogenic hydrogen release laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Hecht, Ethan S. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Zimmerman, Mark D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); LaFleur, Angela Christine [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ciotti, Michael [H< sub> 2< /sub> Fueling Engineering Linde, LLC, Murray Hill, NJ (United States)

    2015-09-01

    A cooperative research and development agreement was made between Linde, LLC and Sandia to develop a plan for modifying the Turbulent Combustion Laboratory (TCL) with the necessary infrastructure to produce a cold (near liquid temperature) hydrogen jet. A three-stage heat exchanger will be used to cool gaseous hydrogen using liquid nitrogen, gaseous helium, and liquid helium. A cryogenic line from the heat exchanger into the lab will allow high-fidelity diagnostics already in place in the lab to be applied to cold hydrogen jets. Data from these experiments will be used to develop and validate models that inform codes and standards which specify protection criteria for unintended releases from liquid hydrogen storage, transport, and delivery infrastructure.

  13. The new competitive mechanism of hydrogen bonding interactions and transition process for the hydroxyphenyl imidazo [1, 2-a] pyridine in mixed liquid solution.

    Science.gov (United States)

    Li, Yongqing; Yang, Yunfan; Ding, Yong

    2017-05-08

    The new competitive mechanism of intermolecular and intramolecular hydrogen bond can be proposed with an improved mixed model. Upon the photoinduced process, the twisting intramolecular charge transfer (TICT) structure of the hydroxyphenyl imidazo [1, 2-a] pyridine (HPIP) can be obtained. TICT character prompts the fluorescent inactivation via non-radiative decay process. For exploring the photochemical and photophysical properties, the electronic spectra and the infrared (IR) vibrational spectra of titled compounds have been detailedly investigated. In addition, the frontier molecular orbitals (MOs) analysis visually reveals that the unbalanced electron population can give rise to the torsion of molecular structure. To further give an attractive insight into the non-radiative decay process, the potential energy curves have been depicted on the ground state (S0), the first excited state (S1) and the triple excited state (T1). Minimum energy crossing point (MECP) has been found in the S1 and T1 state. On the MECP, the intersystem crossing (ISC) might be dominant channel. The density functional theory (DFT) and the time-dependent density functional theory (TDDFT) methods have been throughout employed in the S0 state, T1 state and S1 state, respectively. The theoretical results are consistent with experiment in mixed and PCM model.

  14. Influence of the pH on molecular hydrogen primary yields in He{sup 2+} ion tracks in liquid water. A Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Cobut, Vincent [Departement de Chimie, Universite de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville/Oise, 95031 Cergy-Pontoise Cedex (France)]. E-mail: vincent.cobut@chim.u-cergy.fr; Corbel, Catherine [CEA-Saclay, DSM/DRECAM/SCM/Laboratoire de Radiolyse, Bat. 546, Piece 5, 91191 Gif-sur-Yvette Cedex (France); Patau, Jean Paul [Faculte de Pharmacie, Universite Paul-Sabatier, 35 chemin des Maraichers, 31062 Toulouse Cedex 4 (France)

    2005-02-01

    Monte Carlo calculations are performed to investigate how the acidity of aqueous solutions at room temperature affects the molecular hydrogen (H{sub 2}) yield as a function of time in 20 MeV-He{sup 2+} ion track segments. For pH values varying from 1 to 13, the time dependence of the calculated yields is nearly independent of pH in the time range 10{sup -12}-10{sup -8} s and only weakly dependent in the time range 10{sup -8}-10{sup -6} s. To understand this behaviour, the kinetic mechanisms governing H{sub 2} formation are examined as a function of time. It is found that the main reactions responsible for the H{sub 2} yield as a function of time are strongly pH-dependent at low and high pH values. The pH-dependences of the reaction yields are however such that the variations in the yields compensate each other. This is why the time dependence of the H{sub 2} yield is only weakly pH-dependent.

  15. California Hydrogen Infrastructure Project

    Energy Technology Data Exchange (ETDEWEB)

    Heydorn, Edward C

    2013-03-12

    stations with a focus on safe, convenient, fast-fills. These potential areas were then compared to and overlaid with suitable sites from various energy companies and other potential station operators. Work continues to match vehicle needs with suitable fueling station locations. Once a specific site was identified, the necessary agreements could be completed with the station operator and expected station users. Detailed work could then begin on the site drawings, permits, safety procedures and training needs. Permanent stations were successfully installed in Irvine (delivered liquid hydrogen), Torrance (delivered pipeline hydrogen) and Fountain Valley (renewable hydrogen from anaerobic digester gas). Mobile fueling stations were also deployed to meet short-term fueling needs in Long Beach and Placerville. Once these stations were brought online, infrastructure data was collected and reported to DOE using Air Products Enterprise Remote Access Monitoring system. Feedback from station operators was incorporated to improve the station user's fueling experience.

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

    Science.gov (United States)

    Anderson, Tim; Balaban, Canan

    2008-01-01

    The activities presented are a broad based approach to advancing key hydrogen related technologies in areas such as fuel cells, hydrogen production, and distributed sensors for hydrogen-leak detection, laser instrumentation for hydrogen-leak detection, and cryogenic transport and storage. Presented are the results from research projects, education and outreach activities, system and trade studies. The work will aid in advancing the state-of-the-art for several critical technologies related to the implementation of a hydrogen infrastructure. Activities conducted are relevant to a number of propulsion and power systems for terrestrial, aeronautics and aerospace applications. 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.

  17. Report of National Research Institute for Pollution and Resources for fiscal 1979. Research on conversion of coal to petroleum, research on coal liquefaction, high pressure liquid phase hydrogenation of coal by continuous test equipment, and manufacture of coal chemicals; 1979 nendo sekitan no yuka no kenkyu / sekitan no ekika no kenkyu / renzoku shiken sochi ni yoru sekitan no koatsu ekiso suisoka bunkai / coal chemicals no seizo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-07-01

    Research was conducted on conversion of coal to petroleum for the purpose of securing substitute liquid fuel. Recovery of hydrogen from the waste gas from the conversion process was explained, as were the conversion results from various coals produced in Japan. In coal liquefaction researches with the aim of manufacturing artificial petroleum, a report was made on each of the researches, i.e., the experiment results of coal liquefaction using various catalysts, manufacture of hydrogen by water gas reaction, catalytic action against coal paste, action of mixed oil and pressure against coal paste, result of hydrogen adding test for coal paste using an intermediate scale device, test result of secondary hydrogen addition for coal liquefied oil, and the test result of continuous secondary hydrogen addition for the liquefied oil. In the manufacture of fuel oil by hydro-cracking of coal or tar, a report was made on high pressure liquid phase hydrogenation of coal using a continuous testing device. Aromatic chemicals useful as chemical materials are supposed to be obtained by cutting inter-polymerized-unit bonding to make low molecules from the chemical structure of coal, removing surrounding radicals and simplifying it. A report was also made on the experiment of manufacturing coal chemicals by combination of high pressure liquid phase hydrogenation and hydro-dealkylation. (NEDO)

  18. Hydrogen Bibliography

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-01

    The Hydrogen Bibliography is a compilation of research reports that are the result of research funded over the last fifteen years. In addition, other documents have been added. All cited reports are contained in the National Renewable Energy Laboratory (NREL) Hydrogen Program Library.

  19. Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC/ESI-MS/MS Study for the Identification and Characterization of In Vivo Metabolites of Cisplatin in Rat Kidney Cancer Tissues: Online Hydrogen/Deuterium (H/D Exchange Study.

    Directory of Open Access Journals (Sweden)

    Raju Bandu

    Full Text Available In vivo rat kidney tissue metabolites of an anticancer drug, cisplatin (cis-diamminedichloroplatinum [II] (CP which is used for the treatment of testicular, ovarian, bladder, cervical, esophageal, small cell lung, head and neck cancers, have been identified and characterized by using liquid chromatography positive ion electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS in combination with on line hydrogen/deuterium exchange (HDX experiments. To identify in vivo metabolites, kidney tissues were collected after intravenous administration of CP to adult male Sprague-Dawley rats (n = 3 per group. The tissue samples were homogenized and extracted using newly optimized metabolite extraction procedure which involves liquid extraction with phosphate buffer containing ethyl acetate and protein precipitation with mixed solvents of methanol-water-chloroform followed by solid-phase clean-up procedure on Oasis HLB 3cc cartridges and then subjected to LC/ESI-HRMS analysis. A total of thirty one unknown in vivo metabolites have been identified and the structures of metabolites were elucidated using LC-MS/MS experiments combined with accurate mass measurements. Online HDX experiments have been used to further support the structural characterization of metabolites. The results showed that CP undergoes a series of ligand exchange biotransformation reactions with water and other nucleophiles like thio groups of methionine, cysteine, acetylcysteine, glutathione and thioether. This is the first research approach focused on the structure elucidation of biotransformation products of CP in rats, and the identification of metabolites provides essential information for further pharmacological and clinical studies of CP, and may also be useful to develop various effective new anticancer agents.

  20. Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC/ESI-MS/MS) Study for the Identification and Characterization of In Vivo Metabolites of Cisplatin in Rat Kidney Cancer Tissues: Online Hydrogen/Deuterium (H/D) Exchange Study.

    Science.gov (United States)

    Bandu, Raju; Ahn, Hyun Soo; Lee, Joon Won; Kim, Yong Woo; Choi, Seon Hee; Kim, Hak Jin; Kim, Kwang Pyo

    2015-01-01

    In vivo rat kidney tissue metabolites of an anticancer drug, cisplatin (cis-diamminedichloroplatinum [II]) (CP) which is used for the treatment of testicular, ovarian, bladder, cervical, esophageal, small cell lung, head and neck cancers, have been identified and characterized by using liquid chromatography positive ion electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) in combination with on line hydrogen/deuterium exchange (HDX) experiments. To identify in vivo metabolites, kidney tissues were collected after intravenous administration of CP to adult male Sprague-Dawley rats (n = 3 per group). The tissue samples were homogenized and extracted using newly optimized metabolite extraction procedure which involves liquid extraction with phosphate buffer containing ethyl acetate and protein precipitation with mixed solvents of methanol-water-chloroform followed by solid-phase clean-up procedure on Oasis HLB 3cc cartridges and then subjected to LC/ESI-HRMS analysis. A total of thirty one unknown in vivo metabolites have been identified and the structures of metabolites were elucidated using LC-MS/MS experiments combined with accurate mass measurements. Online HDX experiments have been used to further support the structural characterization of metabolites. The results showed that CP undergoes a series of ligand exchange biotransformation reactions with water and other nucleophiles like thio groups of methionine, cysteine, acetylcysteine, glutathione and thioether. This is the first research approach focused on the structure elucidation of biotransformation products of CP in rats, and the identification of metabolites provides essential information for further pharmacological and clinical studies of CP, and may also be useful to develop various effective new anticancer agents.

  1. Hydrogen exchange

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Rand, Kasper Dyrberg

    2016-01-01

    Hydrogen exchange (HX) monitored by mass spectrometry (MS) is a powerful analytical method for investigation of protein conformation and dynamics. HX-MS monitors isotopic exchange of hydrogen in protein backbone amides and thus serves as a sensitive method for probing protein conformation...... and dynamics along the entire protein backbone. This chapter describes the exchange of backbone amide hydrogen which is highly quenchable as it is strongly dependent on the pH and temperature. The HX rates of backbone amide hydrogen are sensitive and very useful probes of protein conformation......, as they are distributed along the polypeptide backbone and form the fundamental hydrogen-bonding networks of basic secondary structure. The effect of pressure on HX in unstructured polypeptides (poly-dl-lysine and oxidatively unfolded ribonuclease A) and native folded proteins (lysozyme and ribonuclease A) was evaluated...

  2. Hydrogen and Hydrocarbon Gases, Polycyclic Aromatic Hydrocarbons, and Amorphous Carbon Produced by Multiple Shock Compression of Liquid Benzene up to 27.4 GPa.

    Science.gov (United States)

    Mimura, Koichi; Nishida, Tamihito

    2017-08-31

    Phase diagrams of benzene have been reported on the basis of data mainly obtained from static compression at various pressure-temperature, P-T, conditions. However, there are few data in the high-pressure and high temperature-region of the phase diagram. To understand the physical and chemical behavior of benzene in that region, multiple shock compression of benzene was evaluated by a recovery experimental system that directly analyzed the shocked samples. The shocked samples were composed of the remaining benzene, gases (H2, CH4, C2H4, C2H6, C3H6, and C3H8), polycyclic aromatic hydrocarbons with molecular weights from 128 (naphthalene) to 300 (coronene), and amorphous carbon. The abundances of these chemical species varied according to the P-T conditions induced by shock compression. Samples in the lower-pressure and lower-temperature region of the a-C:H phase in the phase diagram contained a significant amount of benzene as well as amorphous carbon. In the higher-pressure and higher-temperature region of the a-C:H phase, benzene was mostly converted into amorphous carbon (H/C = 0.2), H2, and CH4. Therefore, the amorphous carbon in the present study was produced by a different pathway than that in previous studies that have detected hydrogenated amorphous carbon (H/C = 1). For earth sciences, the present study can provide basic information on the delivery to the early earth of extraterrestrial organic materials related to the origin of life.

  3. Decentralized hydrogen production from diesel and biodiesel

    OpenAIRE

    Martin, S.; Kraaij, G.; Wörner, A.

    2014-01-01

    Assuming that from 2015 onwards an increasing amount of fuel cell powered vehicles will enter the market, hydrogen production from liquid fuels offers a promising option to meet short- and midterm hydrogen fuelling requirements. Besides, on-board hydrogen generation from logistic fuels for auxiliary power applications has attracted increasing attention. The German Aerospace Center acts as coordinator of the 3-year project NEMESIS2+ (www.nemesis-project.eu), a collaborative project funded ...

  4. Atomic hydrogen storage method and apparatus

    Science.gov (United States)

    Woollam, J. A. (Inventor)

    1980-01-01

    Atomic hydrogen, for use as a fuel or as an explosive, is stored in the presence of a strong magnetic field in exfoliated layered compounds such as molybdenum disulfide or an elemental layer material such as graphite. The compounds maintained at liquid helium temperatures and the atomic hydrogen is collected on the surfaces of the layered compound which are exposed during delamination (exfoliation). The strong magnetic field and the low temperature combine to prevent the atoms of hydrogen from recombining to form molecules.

  5. Fiscal 1998 research report on International Clean Energy Network using Hydrogen Conversion (WE-NET). Subtask 2. Research on promotion of international cooperation (research on standardization of hydrogen energy technologies); 1998 nendo suiso riyo kokusai clean energy system gijutsu (WE-NET) sub task. 2. Kokusai kyoryoku suishin no tame no chosa kento (suiso energy gijutsu hyojunka ni kansuru chosa kento)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This report summarizes the fiscal 1998 research result on the basic research on standardization of hydrogen energy technologies, and ISO/TC197. As for the standardization, in relation to the hydrogen station in the WE-NET second phase research, the laws related to handling of gaseous hydrogen, and the basic issues on facility and safe handling were studied. As for ISO/TC197, the following draft standards were examined: Fuel supply system interface for liquid hydrogen vehicles, fuel tank for liquid hydrogen vehicles, container for liquid hydrogen transport, specification of hydrogen fuel, hydrogen fuel supply facility for air ports, gaseous hydrogen and hydrogen mixture fuel system for vehicles, gaseous hydrogen fuel connector for vehicles, gaseous hydrogen fuel tank for vehicles, and basic items for hydrogen system safety. Final examination of the fuel supply system interface for liquid hydrogen vehicles, and the specification of hydrogen fuel was finished, and these are scheduled to be registered for ISO. (NEDO)

  6. Two tools for applying chromatographic retention data to the mass-based identification of peptides during hydrogen/deuterium exchange experiments by nano-liquid chromatography/matrix-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Gershon, P D

    2010-12-15

    Two tools are described for integrating LC elution position with mass-based data in hydrogen-deuterium exchange (HDX) experiments by nano-liquid chromatography/matrix-assisted laser desorption/ionization mass spectrometry (nanoLC/MALDI-MS, a novel approach to HDX-MS). The first of these, 'TOF2H-Z Comparator', highlights peptides in HDX experiments that are potentially misidentified on the basis of mass alone. The program first calculates normalized values for the organic solvent concentration responsible for the elution of ions in nanoLC/MALDI HDX experiments. It then allows the solvent gradients for the multiple experiments contributing to an MS/MS-confirmed peptic peptide library to be brought into mutual alignment by iteratively re-modeling variables among LC parameters such as gradient shape, solvent species, fraction duration and LC dead time. Finally, using the program, high-probability chromatographic outliers can be flagged within HDX experimental data. The role of the second tool, 'TOF2H-XIC Comparator', is to normalize the LC chromatograms corresponding to all deuteration timepoints of all HDX experiments of a project, to a common reference. Accurate normalization facilitates the verification of chromatographic consistency between all ions whose spectral segments contribute to particular deuterium uptake plots. Gradient normalization in this manner revealed chromatographic inconsistencies between ions whose masses were either indistinguishable or separated by precise isotopic increments. Copyright © 2010 John Wiley & Sons, Ltd.

  7. High-performance liquid chromatographic method to evaluate the hydrogen atom transfer during reaction between 1,1-diphenyl-2-picryl-hydrazyl radical and antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Boudier, Ariane; Tournebize, Juliana [CITHEFOR - EA 3452, Faculte de Pharmacie, Nancy-Universite, 5 Rue Albert Lebrun, BP 80403, 54001 Nancy Cedex (France); Bartosz, Grzegorz [Department of Molecular Biophysics, University of Lodz, Lodz (Poland); El Hani, Safae; Bengueddour, Rachid [Laboratoire de Nutrition et Sante, Biology Department, Faculty of Sciences, Ibn Tofail University, Kenitra (Morocco); Sapin-Minet, Anne [CITHEFOR - EA 3452, Faculte de Pharmacie, Nancy-Universite, 5 Rue Albert Lebrun, BP 80403, 54001 Nancy Cedex (France); Leroy, Pierre, E-mail: pierre.leroy@pharma.uhp-nancy.fr [CITHEFOR - EA 3452, Faculte de Pharmacie, Nancy-Universite, 5 Rue Albert Lebrun, BP 80403, 54001 Nancy Cedex (France)

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer Both 1,1-diphenyl-2-picrylhydrazyl radical and its product measurement by HPLC. Black-Right-Pointing-Pointer Lowest limit of detection by monitoring 1,1-diphenyl-2-picryl-hydrazine. Black-Right-Pointing-Pointer Adsorption problem of the radical on HPLC parts have been pointed out. - Abstract: 1,1-Diphenyl-2-picrylhydrazyl (DPPH{center_dot}) is a stable nitrogen centred radical widely used to evaluate direct radical scavenging properties of various synthetic or natural antioxidants (AOs). The bleaching rate of DPPH{center_dot} absorbance at 515 nm is usually monitored for this purpose. In order to avoid the interference of complex coloured natural products used as antioxidant supplements or cosmetics, HPLC systems have been reported as alternative techniques to spectrophotometry. They also rely upon measurement of DPPH{center_dot} quenching rate and none of them permits to identify and measure 1,1-diphenyl-2-picryl-hydrazine (DPPH-H), the reduced product of DPPH{center_dot} resulting from hydrogen atom transfer (HAT), which is the main mechanism of the reaction between DPPH{center_dot} and AOs. We presently report an HPLC method devoted to the simultaneous measurement of DPPH{center_dot} and DPPH-H. Both were fully separated on a C18 column eluted with acetonitrile-10 mM ammonium citrate buffer pH 6.8 (70:30, v/v) and detected at 330 nm. Adsorption process of DPPH{center_dot} onto materials of the HPLC system was pointed out. Consequently, the linearity range observed for DPPH{center_dot} was restricted, thus a much lower limit of detection was obtained for DPPH-H than for DPPH{center_dot} using standards (0.02 and 14 {mu}M, respectively). The method was applied to three commonly used AOs, i.e. Trolox{sup Registered-Sign }, ascorbic acid and GSH, and compared with spectrophotometry. Further application to complex matrices (cell culture media, vegetal extracts) and nanomaterials demonstrated (i) its usefulness because of

  8. Shock compression of liquid helium and helium-hydrogen mixtures : development of a cryogenic capability for shock compression of liquid helium on Z, final report for LDRD Project 141536.

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Andrew J.; Knudson, Marcus D.; Shelton, Keegan P.; Hanson, David Lester

    2010-10-01

    This final report on SNL/NM LDRD Project 141536 summarizes progress made toward the development of a cryogenic capability to generate liquid helium (LHe) samples for high accuracy equation-of-state (EOS) measurements on the Z current drive. Accurate data on He properties at Mbar pressures are critical to understanding giant planetary interiors and for validating first principles density functional simulations, but it is difficult to condense LHe samples at very low temperatures (<3.5 K) for experimental studies on gas guns, magnetic and explosive compression devices, and lasers. We have developed a conceptual design for a cryogenic LHe sample system to generate quiescent superfluid LHe samples at 1.5-1.8 K. This cryogenic system adapts the basic elements of a continuously operating, self-regulating {sup 4}He evaporation refrigerator to the constraints of shock compression experiments on Z. To minimize heat load, the sample holder is surrounded by a double layer of thermal radiation shields cooled with LHe to 5 K. Delivery of LHe to the pumped-He evaporator bath is controlled by a flow impedance. The LHe sample holder assembly features modular components and simplified fabrication techniques to reduce cost and complexity to levels required of an expendable device. Prototypes have been fabricated, assembled, and instrumented for initial testing.

  9. Magnetic refrigerator for hydrogen liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Numazawa, T [National Institute for Materials Science, Tsukuba (Japan); Kamlya, K. [Japan Atomic Energy Agency, Naka (Japan); Utaki, T. [Osaka University, Osaka (Japan); Matsumoto, K. [Kanazawa University, Kanazawa (Japan)

    2013-06-15

    This paper reviews the development status of magnetic refrigeration system for hydrogen liquefaction. There is no doubt that hydrogen is one of most important energy sources in the near future. In particular, liquid hydrogen can be utilized for infrastructure construction consisting of storage and transportation. Liquid hydrogen is in cryogenic temperatures and therefore high efficient liquefaction method must be studied. Magnetic refrigeration which uses the magneto-caloric effect has potential to realize not only the higher liquefaction efficiency > 50 %, but also to be environmentally friendly and cost effective. Our hydrogen magnetic refrigeration system consists of Carnot cycle for liquefaction stage and AMR (active magnetic regenerator) cycle for precooling stages. For the Carnot cycle, we develop the high efficient system > 80 % liquefaction efficiency by using the heat pipe. For the AMR cycle, we studied two kinds of displacer systems, which transferred the working fluid. We confirmed the AMR effect with the cooling temperature span of 12 K for 1.8 T of the magnetic field and 6 second of the cycle. By using the simulation, we estimate the total efficiency of the hydrogen liquefaction plant for 10 kg/day. A FOM of 0.47 is obtained in the magnetic refrigeration system operation temperature between 20 K and 77 K including LN2 work input.

  10. The dynamic bulk modulus of three glass-forming liquids

    DEFF Research Database (Denmark)

    Niss, Kristine; Christensen, Tage Emil; Dyre, J. C.

    2014-01-01

    We present dynamic adiabatic bulk modulus data for three organic glass-forming liquids: two van der Waal's liquids, trimethyl-pentaphenyl-trisiloxane (DC705) and dibuthyl phtalate (DBP), and one hydrogen-bonded liquid, 1,2-propanediol (PD). All three liquids are found to obey time-temperature sup......We present dynamic adiabatic bulk modulus data for three organic glass-forming liquids: two van der Waal's liquids, trimethyl-pentaphenyl-trisiloxane (DC705) and dibuthyl phtalate (DBP), and one hydrogen-bonded liquid, 1,2-propanediol (PD). All three liquids are found to obey time...

  11. Economic data on hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    1943-07-22

    General information is recorded about hydrogenation plants and their operation up to July 1943. For 12 German plants, there is a table indicating date of beginning construction, start of operation, and production capacity, including gas. Another chart gives the same data for foreign plants, in the United States, England, Italy, Iran and Holland. Domestic and foreign partners and agreements are also listed, as well as license returns from hydrogenation. Extent of I.G. Farben patent ownership is given in a short list. Development of production costs for liquid products is indicated for the years 1927-1941. Data on test costs are also given. Production figures for hydrogenation are shown, as well as the share of Farben synthetics in total German fuel production. The report gives a breakdown for requirements of raw materials, manpower, capital, and construction steels for production of four million metric tons of fuels from hydrogenation. Finally, the report lists the special areas in which Farben was carrying on work related to synthetic fuels. The data are given mostly in tabular form.

  12. Diffusion of hydrogen (1); eicosane (2)

    Science.gov (United States)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) hydrogen; (2) eicosane

  13. Hydrogen. A small molecule with large impact

    Energy Technology Data Exchange (ETDEWEB)

    Gehrke, H.; Ruthardt, K.; Mathiak, J.; Roosen, C. [Uhde GmbH, Dortmund (Germany)

    2010-12-30

    The first section of the presentation will provide general information about hydrogen including physical data, natural abundance, production and consumption figures. This will be followed by detailed information about current industrial production routes for hydrogen. Main on-purpose production for hydrogen is by classical steam reforming (SR) of natural gas. A brief overview of most important steps in stream reforming is given including reforming section, CO conversion and gas purification. Also the use of heavier than methane feedstocks and refinery off-gases is discussed. Alternative routes for hydrogen production or production of synthesis gas are autothermal reforming (ATR) or partial oxidation (POX). Pros and Cons for each specific technology are given and discussed. Gasification, especially gasification of renewable feedstocks, is a further possibility to produce hydrogen or synthesis gas. New developments and current commercial processes are presented. Hydrogen from electrolysis plants has only a small share on the hydrogen production slate, but in some cases this hydrogen is a suitable feedstock for niche applications with future potential. Finally, production of hydrogen by solar power as a new route is discussed. The final section focuses on the use of hydrogen. Classical applications are hydrogenation reactions in refineries, like HDS, HDN, hydrocracking and hydrofinishing. But, with an increased demand for liquid fuels for transportation or power supply, hydrogen becomes a key player in future as an energy source. Use of hydrogen in synthesis gas for the production of liquid fuels via Fischer-Tropsch synthesis or coal liquefaction is discussed as well as use of pure hydrogen in fuel cells. Additional, new application for biomass-derived feedstocks are discussed. (orig.)

  14. Recirculating cryogenic hydrogen maser

    Energy Technology Data Exchange (ETDEWEB)

    Huerlimann, M.D.; Hardy, W.N.; Berlinsky, A.J.; Cline, R.W.

    1986-08-01

    We report on the design and initial testing of a new type of hydrogen maser, operated at dilution refrigerator temperatures, in which H atoms circulate back and forth between a microwave-pumped state selector and the maser cavity. Other novel design features include liquid-/sup 4/He-coated walls, He-cooled electronics, and the use of microscopic magnetic particles to relax the two lowest hyperfine levels in the state selector. Stabilities at least as good as that of a Rb clock and a high-stability quartz oscillator are observed for measuring times between 1 and 300 s.

  15. Ionic liquids in chemical engineering.

    Science.gov (United States)

    Werner, Sebastian; Haumann, Marco; Wasserscheid, Peter

    2010-01-01

    The development of engineering applications with ionic liquids stretches back to the mid-1990s when the first examples of continuous catalytic processes using ionic liquids and the first studies of ionic liquid-based extractions were published. Ever since, the use of ionic liquids has seen tremendous progress in many fields of chemistry and engineering, and the first commercial applications have been reported. The main driver for ionic liquid engineering applications is to make practical use of their unique property profiles, which are the result of a complex interplay of coulombic, hydrogen bonding and van der Waals interactions. Remarkably, many ionic liquid properties can be tuned in a wide range by structural modifications at their cation and anion. This review highlights specific examples of ionic liquid applications in catalysis and in separation technologies. Additionally, the application of ionic liquids as working fluids in process machines is introduced.

  16. Metallization of fluid hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Nellis, W.J.; Louis, A.A.; Ashcroft, N.W.

    1997-05-14

    The electrical activity of liquid hydrogen has been measured at the high dynamic pressures, and temperatures that can be achieved with a reverberating shock wave. The resulting data are most naturally interpreted in terms of a continuous transition from a semiconducting to a metallic, largely diatomic fluid, the latter at 140 CPa, (ninefold compression) and 3000 K. While the fluid at these conditions resembles common liquid metals by the scale of its resistivity of 500 micro-ohm-cm, it differs by retaining a strong pairing character, and the precise mechanism by which a metallic state might be attained is still a matter of debate. Some evident possibilities include (i) physics of a largely one-body character, such as a band-overlap transition, (ii) physics of a strong-coupling or many-body character,such as a Mott-Hubbard transition, and (iii) process in which structural changes are paramount.

  17. Impact of hydrogen onboard storage technologies on the performance of hydrogen fuelled vehicles: A techno-economic well-to-wheel assessment

    NARCIS (Netherlands)

    de Wit, M.P.|info:eu-repo/dai/nl/310873754; Faaij, A.P.C.|info:eu-repo/dai/nl/10685903X

    2007-01-01

    Hydrogen onboard storage technologies form an important factor in the overall performance of hydrogen fuelled transportation, both energetically and economically. Particularly, advanced storage options such as metal hydrides and carbon nanotubes are often hinted favourable to conventional, liquid

  18. Hydrogen in an oscillating porous vycor glass

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Y.; Schindler, M.; Pobell, F. [Universitaet Bayreuth (Germany)

    1995-10-01

    The authors investigate hydrogen in porous Vycor glass with a torsional oscillator technique. Although our primary purpose is searching for a superfluid transition of hydrogen supercooled in Vycor, we find that hydrogen molecules which are adsorbed and liquefied in Vycor at T > T{sub 3} (triple point of bulk H{sub 2}) leave the Vycor when decreasing the temperature to below a characteristic value T{sub c} < T{sub 3}. We discuss this phenomenon in terms of a free enregy balance between solid/liquid hydrogen inside and outside the Vycor.

  19. Hydrogenation balances for bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Hoelscher

    1944-02-11

    This report was intended to set up predictive curves concerning how certain variables involved in coal hydrogenation output would change in response to changes in certain operational or input variables, for hydrogenation of Gelsenberg coal. The particular dependences investigated in the article were the following: (1) for liquid phase, the dependence of oil output, amount of product to be distilled, and hydrogen use upon the ash content of the coal, the carbon content of the coal, and the percentage of formation of gases, and (2) for vapor phase, the dependence of gasoline yield, hydrogen use, and excess hydrocarbon gas products on the percentage of gasification in the 6434 step. Within certain limits of validity, these dependences seemed mostly to be linear and were illustrated in graphs in the report (most of which were very hard to read on the microfilm image). The limits of validity were 2 to 8% ash content, 80 to 86.2% carbon content, 20 to 25% gasification in liquid phase, and 17 to 25% gasification in the 6434 vapor phase. As an example of the data and calculations, it was observed that at 2% ash content, there was 628 kg of oil output in the liquid phase, at 4% ash content, there was 621 kg oil output, and at 8% ash content, there was 607 kg oil output, so it was calculated that oil output would decrease by 0.56% for each percent increase in ash content between 2% and 8%. 7 tables, 2 graphs.

  20. Ionic Liquid-Assisted Synthesis of Nanoscale (MoS2)x(SnO2)1-x on Reduced Graphene Oxide for the Electrocatalytic Hydrogen Evolution Reaction.

    Science.gov (United States)

    Ravula, Sudhir; Zhang, Chi; Essner, Jeremy B; Robertson, J David; Lin, Jian; Baker, Gary A

    2017-03-08

    Layered transition metal dichalcogenides (TMDs) have attracted increased attention due to their enhanced hydrogen evolution reaction (HER) performance. More specifically, ternary TMD nanohybrids, such as MoS2(1-x)Se2x or bimetallic sulfides, have arisen as promising electrocatalysts compared to MoS2 and MoSe2 due to their electronic, morphologic, and size tunabilities. Herein, we report the successful synthesis of few-layered MoS2/rGO, SnS2/rGO, and (MoS2)x(SnO2)1-x/rGO nanohybrids anchored on reduced graphene oxide (rGO) through a facile hydrothermal reaction in the presence of ionic liquids as stabilizing, delayering agents. Spectroscopic and microscopic techniques (electron microscopy, X-ray diffraction, Raman spectroscopy, neutron activation analysis, and UV-vis spectrophotometry) are used to validate the hierarchical properties, phase identity, and the smooth compositional tunability of the (MoS2)x(SnO2)1-x/rGO nanohybrids. Linear sweep voltammetry measurements reveal that incorporation of Sn into the ternary nanohybrids (as a discrete SnO2 phase) greatly reduces the overpotential by 90-130 mV relative to the MoS2 electrocatalyst. Significantly, the (MoS2)0.6(SnO2)0.4/rGO nanohybrid displays superior catalytic performance over MoS2 alone, exhibiting a low overpotential (η10) of 263 ± 5 mV and a small Tafel slope of 50.8 mV dec(-1). The hybrid catalyst shows high stability for the HER in acidic solutions, with negligible activity loss after 1000 cycles. The hierarchical structures and large surface areas possessing exposed, active edge sites make few-layered (MoS2)x(SnO2)1-x/rGO nanohybrids promising nonprecious metal electrocatalysts for the HER.

  1. Hydrogen program overview

    Energy Technology Data Exchange (ETDEWEB)

    Gronich, S. [Dept. of Energy, Washington, DC (United States). Office of Utility Technologies

    1997-12-31

    This paper consists of viewgraphs which summarize the following: Hydrogen program structure; Goals for hydrogen production research; Goals for hydrogen storage and utilization research; Technology validation; DOE technology validation activities supporting hydrogen pathways; Near-term opportunities for hydrogen; Market for hydrogen; and List of solicitation awards. It is concluded that a full transition toward a hydrogen economy can begin in the next decade.

  2. Hydrogen storage using a hot pressure swing reactor

    OpenAIRE

    Preuster, P.; Dürr, S.; Seidel, A.; Müller, K.; Bösmann, A.; Jorschick, Holger; Wasserscheid, Peter

    2017-01-01

    Our contribution demonstrates that hydrogen storage in stationary Liquid Organic Hydrogen Carrier (LOHC) systems becomes much simpler and significantly more efficient if both, the LOHC hydrogenation and the LOHC dehydrogenation reaction are carried out in the same reactor using the same catalyst. The finding that the typical dehydrogenation catalyst for hydrogen release from perhydro dibenzyltoluene (H18-DBT), Pt on alumina, turns into a highly active and very selective dibenzyltoluene hydrog...

  3. Thermomorphic phase separation in ionic liquid-organic liquid systems - conductivity and spectroscopic characterization

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Berg, Rolf W.

    2005-01-01

    Electrical conductivity, FT-Raman and NMR measurements are demonstrated as useful tools to probe and determine phase behavior of thermomorphic ionic liquid-organic liquid systems. To illustrate the methods, consecutive conductivity measurements of a thermomorphic methoxyethoxyethyl-imidazolium io...... of the components in the system, the liquid-liquid equilibrium phase diagram of the binary mixture, and signify the importance of hydrogen bonding between the ionic liquid and the hydroxyl group of the alcohol....

  4. Hydrogen usage

    Energy Technology Data Exchange (ETDEWEB)

    1942-10-22

    This short tabular report listed the number of m/sup 3/ of hydrogen required for a (metric) ton of product for various combinations of raw material and product in a hydrogenation procedure. In producing auto gasoline, bituminous coal required 2800 m/sup 3/, brown coal required 2400 m/sup 3/, high-temperature-carbonization tar required 2100 m/sup 3/, bituminous coal distillation tar required 1300 m/sup 3/, brown-coal low-temperature-carbonization tar required 850 m/sup 3/, petroleum residues required 900 m/sup 3/, and gas oil required 500 m/sup 3/. In producing diesel oil, brown coal required 1900 m/sup 3/, whereas petroleum residues required 500 m/sup 3/. In producing diesel oil, lubricants, and paraffin by the TTH (low-temperature-hydrogenation) process, brown-coal low-temperature-carbonization tar required 550 m/sup 3/. 1 table.

  5. Electrochemical Hydrogen Peroxide Generator

    Science.gov (United States)

    Tennakoon, Charles L. K.; Singh, Waheguru; Anderson, Kelvin C.

    2010-01-01

    Two-electron reduction of oxygen to produce hydrogen peroxide is a much researched topic. Most of the work has been done in the production of hydrogen peroxide in basic media, in order to address the needs of the pulp and paper industry. However, peroxides under alkaline conditions show poor stabilities and are not useful in disinfection applications. There is a need to design electrocatalysts that are stable and provide good current and energy efficiencies to produce hydrogen peroxide under acidic conditions. The innovation focuses on the in situ generation of hydrogen peroxide using an electrochemical cell having a gas diffusion electrode as the cathode (electrode connected to the negative pole of the power supply) and a platinized titanium anode. The cathode and anode compartments are separated by a readily available cation-exchange membrane (Nafion 117). The anode compartment is fed with deionized water. Generation of oxygen is the anode reaction. Protons from the anode compartment are transferred across the cation-exchange membrane to the cathode compartment by electrostatic attraction towards the negatively charged electrode. The cathode compartment is fed with oxygen. Here, hydrogen peroxide is generated by the reduction of oxygen. Water may also be generated in the cathode. A small amount of water is also transported across the membrane along with hydrated protons transported across the membrane. Generally, each proton is hydrated with 3-5 molecules. The process is unique because hydrogen peroxide is formed as a high-purity aqueous solution. Since there are no hazardous chemicals or liquids used in the process, the disinfection product can be applied directly to water, before entering a water filtration unit to disinfect the incoming water and to prevent the build up of heterotrophic bacteria, for example, in carbon based filters. The competitive advantages of this process are: 1. No consumable chemicals are needed in the process. The only raw materials

  6. Metallic Hydrogen - Potentially a High Energy Rocket Propellant

    Science.gov (United States)

    Cole, John; Silvera, Ike

    2007-01-01

    Pure metallic hydrogen is predicted to have a specific impulse (Isp) of 1700 seconds, but the reaction temperature is too high for current engine materials. Diluting metallic hydrogen with liquid hydrogen can reduce the reaction temperature to levels compatible with current material limits and still provide an Isp greater than 900 s. Metallic hydrogen has not yet been produced on earth, but experimental techniques exist that may change this situation. This paper will provide a brief description of metallic hydrogen and the status of experiments that may soon produce detectable quantities of this material in the lab. Also provided are some characteristics for diluted metallic hydrogen engines and launch vehicles.

  7. Real Time, Non-intrusive Detection of Liquid Nitrogen in Liquid Oxygen (LOX) at High Pressure and High Flow Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Technical Abstract The Stennis Space Center (SSC) needs the sensors that are capable and can be operated in liquid oxygen (LOX) and or liquid hydrogen (LH2)...

  8. Real time, Non-intrusive Detection of Liquid Nitrogen in Liquid Oxygen (LOX) at High Pressure and High Flow Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SSC needs the sensors that are capable and can be operated in liquid oxygen (LOX) and or liquid hydrogen (LH2) cryogenic environment to improve SSC cryogenic...

  9. Hydrogen-methane fuel control systems for turbojet engines

    Science.gov (United States)

    Goldsmith, J. S.; Bennett, G. W.

    1973-01-01

    Design, development, and test of a fuel conditioning and control system utilizing liquid methane (natural gas) and liquid hydrogen fuels for operation of a J85 jet engine were performed. The experimental program evaluated the stability and response of an engine fuel control employing liquid pumping of cryogenic fuels, gasification of the fuels at supercritical pressure, and gaseous metering and control. Acceptably stable and responsive control of the engine was demonstrated throughout the sea level power range for liquid gas fuel and up to 88 percent engine speed using liquid hydrogen fuel.

  10. Liquid Acquisition Device Testing with Sub-Cooled Liquid Oxygen

    Science.gov (United States)

    Jurns, John M.; McQuillen, John B.

    2008-01-01

    When transferring propellant in space, it is most efficient to transfer single phase liquid from a propellant tank to an engine. In earth s gravity field or under acceleration, propellant transfer is fairly simple. However, in low gravity, withdrawing single-phase fluid becomes a challenge. A variety of propellant management devices (PMD) are used to ensure single-phase flow. One type of PMD, a liquid acquisition device (LAD) takes advantage of capillary flow and surface tension to acquire liquid. Previous experimental test programs conducted at NASA have collected LAD data for a number of cryogenic fluids, including: liquid nitrogen (LN2), liquid oxygen (LOX), liquid hydrogen (LH2), and liquid methane (LCH4). The present work reports on additional testing with sub-cooled LOX as part of NASA s continuing cryogenic LAD development program. Test results extend the range of LOX fluid conditions examined, and provide insight into factors affecting predicting LAD bubble point pressures.

  11. Modeling liquid-vapor equilibria with an equation of state taking into account dipolar interactions and association by hydrogen bonding; Modelisation des proprietes PVTX des fluides du systeme H{sub 2}O-gaz prenant en compte l'association par liaisons hydrogenes et les interactions dipolaires

    Energy Technology Data Exchange (ETDEWEB)

    Perfetti, E

    2006-11-15

    Modelling fluid-rock interactions as well as mixing and unmixing phenomena in geological processes requires robust equations of state (EOS) which must be applicable to systems containing water, gases over a broad range of temperatures and pressures. Cubic equations of state based on the Van der Waals theory (e. g. Soave-Redlich-Kwong or Peng-Robinson) allow simple modelling from the critical parameters of the studied fluid components. However, the accuracy of such equations becomes poor when water is a major component of the fluid since neither association trough hydrogen bonding nor dipolar interactions are accounted for. The Helmholtz energy of a fluid may be written as the sum of different energetic contributions by factorization of partition function. The model developed in this thesis for the pure H{sub 2}O and H{sub 2}S considers three contributions. The first contribution represents the reference Van der Waals fluid which is modelled by the SRK cubic EOS. The second contribution accounts for association through hydrogen bonding and is modelled by a term derived from Cubic Plus Association (CPA) theory. The third contribution corresponds to the dipolar interactions and is modelled by the Mean Spherical Approximation (MSA) theory. The resulting CPAMSA equation has six adjustable parameters, which three represent physical terms whose values are close to their experimental counterpart. This equation results in a better reproduction of the thermodynamic properties of pure water than obtained using the classical CPA equation along the vapour-liquid equilibrium. In addition, extrapolation to higher temperatures and pressure is satisfactory. Similarly, taking into account dipolar interactions together with the SRK cubic equation of state for calculating molar volume of H{sub 2}S as a function of pressure and temperature results in a significant improvement compared to the SRK equation alone. Simple mixing rules between dipolar molecules are proposed to model the H

  12. Use of triphenyl phosphate as risk mitigant for metal amide hydrogen storage materials

    Science.gov (United States)

    Cortes-Concepcion, Jose A.; Anton, Donald L.

    2016-04-26

    A process in a resulting product of the process in which a hydrogen storage metal amide is modified by a ball milling process using an additive of TPP. The resulting product provides for a hydrogen storage metal amide having a coating that renders the hydrogen storage metal amide resistant to air, ambient moisture, and liquid water while improving useful hydrogen storage and release kinetics.

  13. Hydrogen on the rise. Wasserstoff im Aufwind

    Energy Technology Data Exchange (ETDEWEB)

    Bracha, M.; Patzelt, A. (Linde AG, Hoellriegelskreuth (Germany))

    1992-11-01

    With the growing environmental problems caused by the use of fossil fuels, hydrogen as clean secondary energy-carrier becomes part of the public interest, especially when the 'solar hydrogen economy' is concerned. Presently the biggest part of the worldwide hydrogen production is based on fossil sources, but regenerative energies combined with electrolyzer-plants will contribute to the future hydrogen production on a wider scale. Apart from typical areas such as the chemical or the semiconductor industry a new market for hydrogen is seen in civil-aviation and the overland traffic. Due to its high density and purity liquid-hydrogen (LH[sub 2]) is gaining special attention. (orig.).

  14. Ammonia for hydrogen storage: challenges and opportunities

    DEFF Research Database (Denmark)

    Klerke, Asbjørn; Christensen, Claus H.; Nørskov, Jens Kehlet

    2008-01-01

    and alcohols, it has the advantage that there is no CO2 emission at the end user. The drawbacks are mainly the toxicity of liquid ammonia and the problems related to trace amounts of ammonia in the hydrogen after decomposition. Storage of ammonia in metal ammine salts is discussed, and it is shown......The possibility of using ammonia as a hydrogen carrier is discussed. Compared to other hydrogen storage materials, ammonia has the advantages of a high hydrogen density, a well-developed technology for synthesis and distribution, and easy catalytic decomposition. Compared to hydrocarbons...... that this maintains the high volumetric hydrogen density while alleviating the problems of handling the ammonia. Some of the remaining challenges for research in ammonia as a hydrogen carrier are outlined....

  15. Versatile Hydrogen

    Indian Academy of Sciences (India)

    Hydrogen is probably the most intriguing ele- ment in the periodic table. Although it is only the seventh most abundant element on earth, it is the most abundant element in the uni- verse. It combines with almost all the ele- ments of the periodic table, except for a few transition elements, to form binary compounds of the type E.

  16. Hydrogen for road transport: implementations and developments; L'hydrogene pour le transport sur route: realisations et developpements

    Energy Technology Data Exchange (ETDEWEB)

    Junker, M.; Bocquet, L.; Bendif, M.; Karboviac, D. [Alphea, 57 - Forbach (France)

    2000-07-01

    The different technologies for the use of hydrogen in the road transport are overviewed: type of propulsion (fuel cell and electric motor or internal combustion motor), hydrogen production, on-board storage, infrastructure. The aspects of safety, standardization and regulation are approached too. At the present time, main of the hydrogen buses are equipped with polymer membrane cells (PEMFC), directly supplied in hydrogen and stored in tanks under pressure (300 bars). On the other hand, the automobile manufacturers are developing different types of prototypes: internal combustion engines with liquid hydrogen storage, PEM cell cars with hydrogen storage (liquid, gas or hydrides) or with methanol storage. The infrastructure type will depend on the primary fuel chosen by the automobile manufacturers and on the requirements of the petroleum firms. Several hydrogen service stations have been constructed. They deliver hydrogen, on a gaseous or liquid state; the hydrogen being produced by natural gas reforming or by electrolysis. The setting of a 'Hydrogen system' require indeed the development of specific means of production, transport, distribution and storage. The public acceptance will be won by safeguards of safety, reliability, performance and competitiveness. The research and development studies are nowadays particularly centred on: 1)the on-board hydrogen storage 2)the on-board systems of hydrogen production from methanol and gasoline 3)the standardization and regulation. (O.M.)

  17. Catalytic partial oxidation of methanol and ethanol for hydrogen generation.

    Science.gov (United States)

    Hohn, Keith L; Lin, Yu-Chuan

    2009-01-01

    Hydrogen-powered fuel cell vehicles feature high energy efficiency and minor environmental impact. Liquid fuels are ideal hydrogen carriers, which can catalytically be converted into syngas or hydrogen to power vehicles. Among the potential liquid fuels, alcohols have several advantages. The hydrogen/carbon ratio is higher than that of other liquid hydrocarbons or oxygenates, especially in the case of methanol. In addition, alcohols can be derived from renewable biomass resources. Catalytic partial oxidation of methanol or ethanol offers immense potential for onboard hydrogen generation due to its rapid reaction rate and exothermic nature. These benefits stimulate a burgeoning research community in catalyst design, reaction engineering, and mechanistic investigation. The purpose of this Minireview is to provide insight into syngas and hydrogen production from methanol and ethanol partial oxidation, particularly highlighting catalytic chemistry.

  18. Regenerators for Liquid Hydrogen Cryocoolers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA exloration, planetary and astrophysics missions will require various enhancements in multi-stage cryocoolers. These include increased efficiency, reduced...

  19. Hydrogen in metals

    CSIR Research Space (South Africa)

    Carter, TJ

    2001-04-01

    Full Text Available The effects of hydrogen on various metals and the use of metal hydrides for hydrogen storage are discussed. The mechanisms of, and differences between, hydrogen embrittlement and hydrogen attack of ferritic steels are compared, common sources...

  20. Hydrogen bond dynamics in bulk alcohols.

    Science.gov (United States)

    Shinokita, Keisuke; Cunha, Ana V; Jansen, Thomas L C; Pshenichnikov, Maxim S

    2015-06-07

    Hydrogen-bonded liquids play a significant role in numerous chemical and biological phenomena. In the past decade, impressive developments in multidimensional vibrational spectroscopy and combined molecular dynamics-quantum mechanical simulation have established many intriguing features of hydrogen bond dynamics in one of the fundamental solvents in nature, water. The next class of a hydrogen-bonded liquid--alcohols--has attracted much less attention. This is surprising given such important differences between water and alcohols as the imbalance between the number of hydrogen bonds, each molecule can accept (two) and donate (one) and the very presence of the hydrophobic group in alcohols. Here, we use polarization-resolved pump-probe and 2D infrared spectroscopy supported by extensive theoretical modeling to investigate hydrogen bond dynamics in methanol, ethanol, and isopropanol employing the OH stretching mode as a reporter. The sub-ps dynamics in alcohols are similar to those in water as they are determined by similar librational and hydrogen-bond stretch motions. However, lower density of hydrogen bond acceptors and donors in alcohols leads to the appearance of slow diffusion-controlled hydrogen bond exchange dynamics, which are essentially absent in water. We anticipate that the findings herein would have a potential impact on fundamental chemistry and biology as many processes in nature involve the interplay of hydrophobic and hydrophilic groups.

  1. Water, Hydrogen Bonding and the Microwave Background

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2009-04-01

    Full Text Available n this work, the properties of the water are briefly revisited. Though liquid water has a fleeting structure, it displays an astonishingly stable network of hydrogen bonds. Thus, even as a liquid, water possesses a local lattice with short range order. The presence of hydroxyl (O-H and hydrogen (H....OH2 bonds within water, indicate that it can simultaneously maintain two separate energy systems. These can be viewed as two very different temperatures. The analysis presented uses results from vibrational spec- troscopy, extracting the force constant for the hydrogen bonded dimer. By idealizing this species as a simple diatomic structure, it is shown that hydrogen bonds within wa- ter should be able to produce thermal spectra in the far infrared and microwave regions of the electromagnetic spectrum. This simple analysis reveals that the oceans have a physical mechanism at their disposal, which is capable of generating the microwave background.

  2. Hydrogen storage in insulated pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Aceves, S.M.; Garcia-Villazana, O. [Lawrence Livermore National Lab., CA (United States)

    1998-08-01

    Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LH{sub 2}) or ambient-temperature compressed hydrogen (CH{sub 2}). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (lower energy requirement for hydrogen liquefaction and reduced evaporative losses). This paper shows an evaluation of the applicability of the insulated pressure vessels for light-duty vehicles. The paper shows an evaluation of evaporative losses and insulation requirements and a description of the current analysis and experimental plans for testing insulated pressure vessels. The results show significant advantages to the use of insulated pressure vessels for light-duty vehicles.

  3. Design and Development of New Carbon-Based Sorbent Systems for an Effective Containment of Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Alan C. Cooper

    2012-05-03

    This is a summary for work performed under cooperative agreement DE FC36 04GO14006 (Design and Development of New Carbon-based Sorbent Systems for an Effective Containment of Hydrogen). The project was directed to discover new solid and liquid materials that use reversible catalytic hydrogenation as the mechanism for hydrogen capture and storage. After a short period of investigation of solid materials, the inherent advantages of storing and transporting hydrogen using liquid-phase materials focused our attention exclusively on organic liquid hydrogen carriers (liquid carriers). While liquid carriers such as decalin and methylcyclohexane were known in the literature, these carriers suffer from practical disadvantages such as the need for very high temperatures to release hydrogen from the carriers and difficult separation of the carriers from the hydrogen. In this project, we were successful in using the prediction of reaction thermodynamics to discover liquid carriers that operate at temperatures up to 150 C lower than the previously known carriers. The means for modifying the thermodynamics of liquid carriers involved the use of certain molecular structures and incorporation of elements other than carbon into the carrier structure. The temperature decrease due to the more favorable reaction thermodynamics results in less energy input to release hydrogen from the carriers. For the first time, the catalytic reaction required to release hydrogen from the carriers could be conducted with the carrier remaining in the liquid phase. This has the beneficial effect of providing a simple means to separate the hydrogen from the carrier.

  4. Liquid fuel cells.

    Science.gov (United States)

    Soloveichik, Grigorii L

    2014-01-01

    The advantages of liquid fuel cells (LFCs) over conventional hydrogen-oxygen fuel cells include a higher theoretical energy density and efficiency, a more convenient handling of the streams, and enhanced safety. This review focuses on the use of different types of organic fuels as an anode material for LFCs. An overview of the current state of the art and recent trends in the development of LFC and the challenges of their practical implementation are presented.

  5. Recent development of ionic liquid stationary phases for liquid chromatography.

    Science.gov (United States)

    Shi, Xianzhe; Qiao, Lizhen; Xu, Guowang

    2015-11-13

    Based on their particular physicochemical characteristics, ionic liquids have been widely applied in many fields of analytical chemistry. Many types of ionic liquids were immobilized on a support like silica or monolith as stationary phases for liquid chromatography. Moreover, different approaches were developed to bond covalently ionic liquids onto the supporting materials. The obtained ionic liquid stationary phases show multi-mode mechanism including hydrophobic, hydrophilic, hydrogen bond, anion exchange, π-π, and dipole-dipole interactions. Therefore, they could be used in different chromatographic modes including ion-exchange, RPLC, NPLC and HILIC to separate various classes of compounds. This review mainly summarizes the immobilized patterns and types of ionic liquid stationary phases, their retention mechanisms and applications in the recent five years. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Carbon Dioxide-Free Hydrogen Production with Integrated Hydrogen Separation and Storage.

    Science.gov (United States)

    Dürr, Stefan; Müller, Michael; Jorschick, Holger; Helmin, Marta; Bösmann, Andreas; Palkovits, Regina; Wasserscheid, Peter

    2017-01-10

    An integration of CO2 -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 CH4 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.

  7. The hydrogen; L'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

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

  8. Changes in Hydrogen Content During Steelmaking

    Directory of Open Access Journals (Sweden)

    Vrbek K.

    2015-04-01

    Full Text Available Štore Steel produces steel grades for spring, forging and engineering industry applications. Steelmaking technology consists of scrap melting in Electric Arc Furnace (EAF, secondary metallurgy in Ladle Furnace (LF and continuous casting of billets (CC. Hydrogen content during steelmaking of various steel grades and steelmaking technologies was measured. Samples of steel melt from EAF, LF and CC were collected and investigated. Sampling from Electric Arc Furnace and Ladle Furnace was carried out using vacuum pin tubes. Regular measurements of hydrogen content in steel melt were made using Hydris device. Hydrogen content results measured in tundish by Hydris device were compared with results from pin tube samples. Based on the measurement results it was established that hydrogen content during steelmaking increases. The highest values were determined in tundish during casting. Factors that influence the hydrogen content in liquid steel the most were steelmaking technology and alloying elements.

  9. Technology issues associated with using densified hydrogen for space vehicles

    Science.gov (United States)

    Hardy, Terry L.; Whalen, Margaret V.

    1992-01-01

    Slush hydrogen and triple-point hydrogen offer the potential for reducing the size and weight of future space vehicles because these fluids have greater densities than normal-boiling-point liquid hydrogen. In addition, these fluids have greater heat capacities, which make them attractive fuels for such applications as the National Aerospace Plane and cryogenic depots. Some of the benefits of using slush hydrogen and triple-point hydrogen for space missions are quantified. Some of the major issues associated with using these densified cryogenic fuels for space applications are examined, and the technology efforts that have been made to address many of these issues are summarized.

  10. A mixed quantum-classical molecular dynamics study of anti-tetrol and syn-tetrol dissolved in liquid chloroform II: infrared emission spectra, vibrational excited-state lifetimes, and nonequilibrium hydrogen-bond dynamics.

    Science.gov (United States)

    Kwac, Kijeong; Geva, Eitan

    2013-11-21

    The effect of vibrational excitation and relaxation of the hydroxyl stretch on the hydrogen-bond structure and dynamics of stereoselectively synthesized syn-tetrol and anti-tetrol dissolved in deuterated chloroform are investigated via a mixed quantum-classical molecular dynamics simulation. Emphasis is placed on the changes in hydrogen-bond structure upon photoexcitation and the nonequilibrium hydrogen-bond dynamics that follows the subsequent relaxation from the excited to the ground vibrational state. The propensity to form hydrogen bonds is shown to increase upon photoexcitation of the hydroxyl stretch, thereby leading to a sizable red-shift of the infrared emission spectra relative to the corresponding absorption spectra. The vibrational excited state lifetimes are calculated within the framework of Fermi's golden rule and the harmonic-Schofield quantum correction factor, and found to be sensitive reporters of the underlying hydrogen-bond structure. The energy released during the relaxation from the excited to the ground state is shown to break hydrogen bonds involving the relaxing hydroxyl. The spectral signature of this nonequilibrium relaxation process is analyzed in detail.

  11. A study of the efficiency of hydrogen liquefaction

    Science.gov (United States)

    Baker, C. R.; Shaner, R. L.

    1976-01-01

    The use of liquid hydrogen as a jet aircraft fuel has a number of environmental and technological advantages over conventional fuels. The liquefaction of hydrogen requires a large expenditure of energy. There are many inefficiencies that are a part of any practical liquefaction process. Current technology was investigated for the best available system. Parametric studies were made to identify where inefficiencies occur and to optimize and integrate the component parts. Flowsheets are presented for a module that produces 250 tons per day of liquid hydrogen. Approximately ten of these modules is needed for a major airport in the 1990's. The advantages of producing a product with a minimum amount of ortho to para hydrogen conversion are pointed out. The optimum degree of conversion was determined for a liquid hydrogen product that will be used within a given time. An assessment was made regarding the potentials for improvement of the processing schemes and equipment over the next 10 to 25 years.

  12. Solid Hydrogen Particles Analyzed for Atomic Fuels

    Science.gov (United States)

    Palaszewski, Bryan A.

    2001-01-01

    Solid hydrogen particles have been selected as a means of storing atomic propellants in future launch vehicles (refs. 1 to 2). In preparation for this, hydrogen particle formation in liquid helium was tested experimentally. These experiments were conducted to visually characterize the particles and to observe their formation and molecular transformations (aging) while in liquid helium. The particle sizes, molecular transformations, and agglomeration times were estimated from video image analyses. The experiments were conducted at the NASA Glenn Research Center in the Supplemental Multilayer Insulation Research Facility (SMIRF, ref. 3). The facility has a vacuum tank, into which the experimental setup was placed. The vacuum tank prevented heat leaks and subsequent boiloff of the liquid helium, and the supporting systems maintained the temperature and pressure of the liquid helium bath where the solid particles were created. As the operation of the apparatus was developed, the hydrogen particles were easily visualized. The figures (ref. 1) show images from the experimental runs. The first image shows the initial particle freezing, and the second image shows the particles after the small particles have agglomerated. The particles finally all clump, but stick together loosely. The solid particles tended to agglomerate within a maximum of 11 min, and the agglomerate was very weak. Because the hydrogen particles are buoyant in the helium, the agglomerate tends to compact itself into a flat pancake on the surface of the helium. This pancake agglomerate is easily broken apart by reducing the pressure above the liquid. The weak agglomerate implies that the particles can be used as a gelling agent for the liquid helium, as well as a storage medium for atomic boron, carbon, or hydrogen. The smallest particle sizes that resulted from the initial freezing experiments were about 1.8 mm. About 50 percent of the particles formed were between 1.8 to 4.6 mm in diameter. These very

  13. Renewable hydrogen utilisation for the production of methanol.

    OpenAIRE

    Galindo, Cifre P; Badr, Ossama

    2007-01-01

    Electrolytic hydrogen production is an efficient way of storing renewable energy generated electricity and securing the contribution of renewables in the future electricity supply. The use of this hydrogen for the production of methanol results in a liquid fuel that can be utilised directly with minor changes in the existing infrastructure. To utilise the renewable generated hydrogen for production of renewable methanol, a sustainable carbon source is needed. This carbon can...

  14. High Temperature Equation of State of Metallic Hydrogen

    OpenAIRE

    V.T.Shvets

    2016-01-01

    The equation of state of liquid metallic hydrogen is solved numerically. Investigations are carried out at temperatures, which correspond both to the experimental conditions under which metallic hydrogen is produced on earth and the conditions in the cores of giant planets of the solar system such as Jupiter and Saturn. It is assumed that hydrogen is in an atomic state and all its electrons are collectivized. Perturbation theory in the electron and proton interaction is applied to determine t...

  15. Atomic hydrogen storage. [cryotrapping and magnetic field strength

    Science.gov (United States)

    Woollam, J. A. (Inventor)

    1980-01-01

    Atomic hydrogen, for use as a fuel or as an explosive, is stored in the presence of a strong magnetic field in exfoliated layered compounds such as molybdenum disulfide or an elemental layer material such as graphite. The compound is maintained at liquid temperatures and the atomic hydrogen is collected on the surfaces of the layered compound which are exposed during delamination (exfoliation). The strong magnetic field and the low temperature combine to prevent the atoms of hydrogen from recombining to form molecules.

  16. Fermi liquids and Luttinger liquids

    OpenAIRE

    Schulz, H. J.; Cuniberti, G.; Pieri, P.

    1998-01-01

    In these lecture notes, the basic physics of Fermi liquids and Luttinger liquids is presented. Fermi liquids are discussed both from a phenomenological viewpoint, in relation to microscopic approaches, and as renormalization group fixed points. Luttinger liquids are introduced using the bosonization formalism, and their essential differences with Fermi liquids are pointed out. Applications to transport effects, the effect of disorder, quantum spin chains, and spin ladders, both insulating and...

  17. Microwave-assisted chemoselective hydrogenation reactions incorporating hydrogen as reducing agent

    Energy Technology Data Exchange (ETDEWEB)

    Schmoeger, C.; Gallert, T.; Stolle, A.; Ondruschka, B. [Institute for Technical Chemistry and Environmental Chemistry, Friedrich-Schiller University Jena, Jena (Germany); Bonrath, W. [R and D Chemical Process Technology, DSM Nutritional Products, Basel (Switzerland)

    2011-03-15

    The use of modern microwave equipment affords an easy and safe handling in the laboratory routine. The described quartz reactor system was tested in different reaction types to show its versatile applications. Various liquid-phase hydrogenations were carried out successfully. The construction of the reactor allows the direct introduction of gases into the reaction mixture so that the reduction can be performed with gaseous hydrogen. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Modeling the Hydrogen Bond within Molecular Dynamics

    Science.gov (United States)

    Lykos, Peter

    2004-01-01

    The structure of a hydrogen bond is elucidated within the framework of molecular dynamics based on the model of Rahman and Stillinger (R-S) liquid water treatment. Thus, undergraduates are exposed to the powerful but simple use of classical mechanics to solid objects from a molecular viewpoint.

  19. Hydrogen bond dynamics in bulk alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Shinokita, Keisuke; Cunha, Ana V.; Jansen, Thomas L. C.; Pshenichnikov, Maxim S., E-mail: Maxim.Pchenitchnikov@RuG.nl [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

    2015-06-07

    Hydrogen-bonded liquids play a significant role in numerous chemical and biological phenomena. In the past decade, impressive developments in multidimensional vibrational spectroscopy and combined molecular dynamics–quantum mechanical simulation have established many intriguing features of hydrogen bond dynamics in one of the fundamental solvents in nature, water. The next class of a hydrogen-bonded liquid—alcohols—has attracted much less attention. This is surprising given such important differences between water and alcohols as the imbalance between the number of hydrogen bonds, each molecule can accept (two) and donate (one) and the very presence of the hydrophobic group in alcohols. Here, we use polarization-resolved pump-probe and 2D infrared spectroscopy supported by extensive theoretical modeling to investigate hydrogen bond dynamics in methanol, ethanol, and isopropanol employing the OH stretching mode as a reporter. The sub-ps dynamics in alcohols are similar to those in water as they are determined by similar librational and hydrogen-bond stretch motions. However, lower density of hydrogen bond acceptors and donors in alcohols leads to the appearance of slow diffusion-controlled hydrogen bond exchange dynamics, which are essentially absent in water. We anticipate that the findings herein would have a potential impact on fundamental chemistry and biology as many processes in nature involve the interplay of hydrophobic and hydrophilic groups.

  20. Hydrogen bond dynamics in bulk alcohols

    Science.gov (United States)

    Shinokita, Keisuke; Cunha, Ana V.; Jansen, Thomas L. C.; Pshenichnikov, Maxim S.

    2015-06-01

    Hydrogen-bonded liquids play a significant role in numerous chemical and biological phenomena. In the past decade, impressive developments in multidimensional vibrational spectroscopy and combined molecular dynamics-quantum mechanical simulation have established many intriguing features of hydrogen bond dynamics in one of the fundamental solvents in nature, water. The next class of a hydrogen-bonded liquid—alcohols—has attracted much less attention. This is surprising given such important differences between water and alcohols as the imbalance between the number of hydrogen bonds, each molecule can accept (two) and donate (one) and the very presence of the hydrophobic group in alcohols. Here, we use polarization-resolved pump-probe and 2D infrared spectroscopy supported by extensive theoretical modeling to investigate hydrogen bond dynamics in methanol, ethanol, and isopropanol employing the OH stretching mode as a reporter. The sub-ps dynamics in alcohols are similar to those in water as they are determined by similar librational and hydrogen-bond stretch motions. However, lower density of hydrogen bond acceptors and donors in alcohols leads to the appearance of slow diffusion-controlled hydrogen bond exchange dynamics, which are essentially absent in water. We anticipate that the findings herein would have a potential impact on fundamental chemistry and biology as many processes in nature involve the interplay of hydrophobic and hydrophilic groups.

  1. Removing hydrogen sulphide from a gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Baar, J.F. Van; Lith, W.J. Van.

    1990-05-08

    A process is provided for selectively removing hydrogen sulfide from a gas mixture containing hydrogen sulfide and carbon dioxide, such as natural gas or a reduced off-gas from the Claus process. The process comprises contacting the gas mixture with a liquid absorbent composition including an aminopyridine, such as 4-dimethylaminopyridine. The absorbent composition suitably contains between 1 and 2 moles of aminopyridine per liter of physical solvent (such as sulfolane). Contacting is carried out at 20-80{degree}C and at approximately atmospheric pressure, usually in countercurrent fashion in a gas/liquid contacting column. The rich absorbent composition laden with hydrogen sulfide is regenerated by heating the solution and/or stripping the composition with an inert gas such as steam. Experiments are described to illustrate the process of the invention. 2 tabs.

  2. Solid Hydrogen Particles and Flow Rates Analyzed for Atomic Fuels

    Science.gov (United States)

    Palaszewski, Bryan A.

    2003-01-01

    The experiments were conducted at Glenn's Small Multipurpose Research Facility (SMIRF, ref. 5). The experimental setup was placed in the facility's vacuum tank to prevent heat leaks and subsequent boiloff of the liquid helium. Supporting systems maintained the temperature and pressure of the liquid helium bath where the solid particles were created. Solid hydrogen particle formation was tested from February 23 to April 2, 2001. Millimeter-sized solid-hydrogen particles were formed in a Dewar of liquid helium as a prelude to creating atomic fuels and propellants for aerospace vehicles. Atomic fuels or propellants are created when atomic boron, carbon, or hydrogen is stored in solid hydrogen particles. The current testing characterized the solid hydrogen particles without the atomic species, as a first step to creating a feed system for the atomic fuels and propellants. This testing did not create atomic species, but only sought to understand the solid hydrogen particle formation and behavior in the liquid helium. In these tests, video images of the solid particle formation were recorded, and the total mass flow rate of the hydrogen was measured. The mass of hydrogen that went into the gaseous phase was also recorded using a commercially available residual gas analyzer. The temperatures, pressures, and flow rates of the liquids and gases in the test apparatus were recorded as well. Testing conducted in 1999 recorded particles as small as 2 to 5 mm in diameter. The current testing extended the testing conditions to a very cold Dewar ullage gas of about 20 to 90 K above the 4 K liquid helium. With the very cold Dewar gas, the hydrogen freezing process took on new dimensions, in some cases creating particles so small that they seemed to be microscopic, appearing as infinitesimally small scintillations on the videotaped images.

  3. Ab initio molecular dynamics simulation of hydrogen fluoride at several thermodynamic states

    DEFF Research Database (Denmark)

    Kreitmeir, M.; Bertagnolli, H.; Mortensen, Jens Jørgen

    2003-01-01

    Liquid hydrogen fluoride is a simple but interesting system for studies of the influence of hydrogen bonds on physical properties. We have performed ab initio molecular dynamics simulations of HF at several thermodynamic states, where we examine the microscopic structure of the liquid as well...

  4. Specialist gelator for ionic liquids.

    Science.gov (United States)

    Hanabusa, Kenji; Fukui, Hiroaki; Suzuki, Masahiro; Shirai, Hirofusa

    2005-11-08

    Cyclo(l-beta-3,7-dimethyloctylasparaginyl-L-phenylalanyl) (1) and cyclo(L-beta-2-ethylhexylasparaginyl-L-phenylalanyl) (2), prepared from L-asparaginyl-L-phenylalanine methyl ester, have been found to be specialist gelators for ionic liquids. They can gel a wide variety of ionic liquids, including imizazolium, pyridinium, pyrazolidinium, piperidinium, morpholinium, and ammonium salts. The mean minimum gel concentrations (MGCs) necessary to make gels at 25 degrees C were determined for ionic liquids. The gel strength increased at a rate nearly proportional to the concentration of added gelator. The strength of the transparent gel of 1-butylpyridinium tetrafluoroborate ([C(4)py]BF(4)), prepared at a concentration of 60 g L(-1) (gelator 1/[C(4)py]BF(4)), was ca. 1500 g cm(-2). FT-IR spectroscopy indicated that a driving force for gelation was intermolecular hydrogen bonding between amides and that the phase transition from gel to liquid upon heating was brought about by the collapse of hydrogen bonding. The gels formed from ionic liquids were very thermally stable; no melting occurs up to 140 degrees C when the gels were prepared at a concentration of 70 g L(-1) (gelator/ionic liquid). The ionic conductivities of the gels were nearly the same as those of pure ionic liquids. The gelator had electrochemical stability and a wide electrochemical window. When the gels were prepared from ionic liquids containing propylene carbonate, the ionic conductivities of the resulting gels increased to levels rather higher than those of pure ionic liquids. The gelators also gelled ionic liquids containing supporting electrolytes.

  5. Strong pressure-energy correlations in van der Waals liquids

    DEFF Research Database (Denmark)

    Pedersen, Ulf Rørbæk; Bailey, Nicholas; Schrøder, Thomas

    2008-01-01

    Strong correlations between equilibrium fluctuations of the configurational parts of pressure and energy are found in computer simulations of the Lennard-Jones liquid and other simple liquids, but not for hydrogen-bonding liquids such as methanol and water. The correlations that are present also ...

  6. Experimental Results of Hydrogen Slosh in a 62 Cubic Foot (1750 Liter) Tank

    Science.gov (United States)

    Moran, Matthew E.; Mcnelis, Nancy B.; Kudlac, Maureen T.; Haberbusch, Mark S.; Satornino, George A.

    1994-01-01

    Extensive slosh testing with liquid and slush hydrogen was conducted in a 62 cubic foot spherical tank to characterize the thermodynamic response of the system under normal gravity conditions. Slosh frequency and amplitude, pressurant type, ramp pressure, and ullage volume were parametrically varied to assess the effect of each of these parameters on the tank pressure and fluid/wall temperatures. A total of 91 liquid hydrogen and 62 slush hydrogen slosh tests were completed. Both closed tank tests and expulsions during sloshing were performed. This report presents and discusses highlights of the liquid hydrogen closed tank results in detail and introduces some general trends for the slush hydrogen tests. Summary comparisons between liquid and slush hydrogen slosh results are also presented.

  7. An overview of hydrogen storage materials: Making a case for metal organic frameworks

    CSIR Research Space (South Africa)

    Langmi, Henrietta W

    2013-04-01

    Full Text Available One of the major challenges facing the transition to a Hydrogen Economy is the development of a suitable storage medium for hydrogen. Conventionally, hydrogen is stored as compressed gas or cryogenically as a liquid. In order to meet future targets...

  8. Development Of A Centrifugal Hydrogen Pipeline Gas Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Di Bella, Francis A. [Concepts NREC, White River Junction, VY (United States)

    2015-04-16

    Concepts NREC (CN) has completed a Department of Energy (DOE) sponsored project to analyze, design, and fabricate a pipeline capacity hydrogen compressor. The pipeline compressor is a critical component in the DOE strategy to provide sufficient quantities of hydrogen to support the expected shift in transportation fuels from liquid and natural gas to hydrogen. The hydrogen would be generated by renewable energy (solar, wind, and perhaps even tidal or ocean), and would be electrolyzed from water. The hydrogen would then be transported to the population centers in the U.S., where fuel-cell vehicles are expected to become popular and necessary to relieve dependency on fossil fuels. The specifications for the required pipeline hydrogen compressor indicates a need for a small package that is efficient, less costly, and more reliable than what is available in the form of a multi-cylinder, reciprocating (positive displacement) compressor for compressing hydrogen in the gas industry.

  9. Safety Issues with Hydrogen as a Vehicle Fuel

    Energy Technology Data Exchange (ETDEWEB)

    L. C. Cadwallader; J. S. Herring

    1999-09-01

    This report is an initial effort to identify and evaluate safety issues associated with the use of hydrogen as a vehicle fuel in automobiles. Several forms of hydrogen have been considered: gas, liquid, slush, and hydrides. The safety issues have been discussed, beginning with properties of hydrogen and the phenomenology of hydrogen combustion. Safety-related operating experiences with hydrogen vehicles have been summarized to identify concerns that must be addressed in future design activities and to support probabilistic risk assessment. Also, applicable codes, standards, and regulations pertaining to hydrogen usage and refueling have been identified and are briefly discussed. This report serves as a safety foundation for any future hydrogen safety work, such as a safety analysis or a probabilistic risk assessment.

  10. Safety Issues with Hydrogen as a Vehicle Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Cadwallader, Lee Charles; Herring, James Stephen

    1999-10-01

    This report is an initial effort to identify and evaluate safety issues associated with the use of hydrogen as a vehicle fuel in automobiles. Several forms of hydrogen have been considered: gas, liquid, slush, and hydrides. The safety issues have been discussed, beginning with properties of hydrogen and the phenomenology of hydrogen combustion. Safety-related operating experiences with hydrogen vehicles have been summarized to identify concerns that must be addressed in future design activities and to support probabilistic risk assessment. Also, applicable codes, standards, and regulations pertaining to hydrogen usage and refueling have been identified and are briefly discussed. This report serves as a safety foundation for any future hydrogen safety work, such as a safety analysis or a probabilistic risk assessment.

  11. Metallic hydrogen: The most powerful rocket fuel yet to exist

    Energy Technology Data Exchange (ETDEWEB)

    Silvera, Isaac F [Lyman Laboratory of Physics, Harvard University, Cambridge MA 02138 (United States); Cole, John W, E-mail: silvera@physics.harvard.ed [NASA MSFC, Huntsville, AL 35801 (United States)

    2010-03-01

    Wigner and Huntington first predicted that pressures of order 25 GPa were required for the transition of solid molecular hydrogen to the atomic metallic phase. Later it was predicted that metallic hydrogen might be a metastable material so that it remains metallic when pressure is released. Experimental pressures achieved on hydrogen have been more than an order of magnitude higher than the predicted transition pressure and yet it remains an insulator. We discuss the applications of metastable metallic hydrogen to rocketry. Metastable metallic hydrogen would be a very light-weight, low volume, powerful rocket propellant. One of the characteristics of a propellant is its specific impulse, I{sub sp}. Liquid (molecular) hydrogen-oxygen used in modern rockets has an Isp of {approx}460s; metallic hydrogen has a theoretical I{sub sp} of 1700s. Detailed analysis shows that such a fuel would allow single-stage rockets to enter into orbit or carry economical payloads to the moon. If pure metallic hydrogen is used as a propellant, the reaction chamber temperature is calculated to be greater than 6000 K, too high for currently known rocket engine materials. By diluting metallic hydrogen with liquid hydrogen or water, the reaction temperature can be reduced, yet there is still a significant performance improvement for the diluted mixture.

  12. A hydrogen ice cube

    NARCIS (Netherlands)

    Peters, C.J.; Schoonman, J.; Schrauwers, A.

    2004-01-01

    Hydrogen is considered to be a highly promising energy carrier. Nonetheless, before hydrogen can become the fuel of choice for the future a number of slight problems will have to be overcome. For example, how can hydrogen be safely stored? Motor vehicles running on hydrogen may be clean in concept

  13. Overview of interstate hydrogen pipeline systems.

    Energy Technology Data Exchange (ETDEWEB)

    Gillette, J .L.; Kolpa, R. L

    2008-02-01

    . The following discussion will focus on the similarities and differences between the two pipeline networks. Hydrogen production is currently concentrated in refining centers along the Gulf Coast and in the Farm Belt. These locations have ready access to natural gas, which is used in the steam methane reduction process to make bulk hydrogen in this country. Production centers could possibly change to lie along coastlines, rivers, lakes, or rail lines, should nuclear power or coal become a significant energy source for hydrogen production processes. Should electrolysis become a dominant process for hydrogen production, water availability would be an additional factor in the location of production facilities. Once produced, hydrogen must be transported to markets. A key obstacle to making hydrogen fuel widely available is the scale of expansion needed to serve additional markets. Developing a hydrogen transmission and distribution infrastructure would be one of the challenges to be faced if the United States is to move toward a hydrogen economy. Initial uses of hydrogen are likely to involve a variety of transmission and distribution methods. Smaller users would probably use truck transport, with the hydrogen being in either the liquid or gaseous form. Larger users, however, would likely consider using pipelines. This option would require specially constructed pipelines and the associated infrastructure. Pipeline transmission of hydrogen dates back to late 1930s. These pipelines have generally operated at less than 1,000 pounds per square inch (psi), with a good safety record. Estimates of the existing hydrogen transmission system in the United States range from about 450 to 800 miles. Estimates for Europe range from about 700 to 1,100 miles (Mohipour et al. 2004; Amos 1998). These seemingly large ranges result from using differing criteria in determining pipeline distances. For example, some analysts consider only pipelines above a certain diameter as transmission lines

  14. Hydrogen synthesis from ethanol; La synthese de l'hydrogene a partir d'ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Lepetit, V.

    2006-03-15

    The US HyRadix company and the French Institute of Petroleum (IFP) are joining their efforts to develop an hydrogen generation unit from liquid hydrocarbons (ethanol, gas oil, kerosene). The system will be based on an adaptation of the auto-thermal reforming system (ATR), developed by HyRadix, to liquid fuels. Short paper. (J.S.)

  15. Highly hydrogenated graphene via active hydrogen reduction of graphene oxide in the aqueous phase at room temperature.

    Science.gov (United States)

    Sofer, Zdeněk; Jankovský, Ondřej; Šimek, Petr; Soferová, Lýdie; Sedmidubský, David; Pumera, Martin

    2014-02-21

    Hydrogenated graphene and graphane are in the forefront of graphene research. Hydrogenated graphene is expected to exhibit ferromagnetism, tunable band gap, fluorescence, and high thermal and low electrical conductivity. Currently available techniques for fabrication of highly hydrogenated graphene use either a liquid ammonia (-33 °C) reduction pathway using alkali metals or plasma low pressure or ultra high pressure hydrogenation. These methods are either technically challenging or pose inherent risks. Here we wish to demonstrate that highly hydrogenated graphene can be prepared at room temperature in the aqueous phase by reduction of graphene oxide by nascent hydrogen generated by dissolution of metal in acid. Nascent hydrogen is known to be a strong reducing agent. We studied the influence of metal involved in nascent hydrogen generation and characterized the samples in detail. The resulting reduced graphenes and hydrogenated graphenes were characterized in detail. The resulting hydrogenated graphene had the chemical formula C1.16H1O0.66. Such simple hydrogenation of graphene is of high importance for large scale safe synthesis of hydrogenated graphene.

  16. The hydrogen refuelling plant in Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Giron, Enrique [Repsol YPF, Carretera de Extremadura, A-5 km 18, 28931 Mostoles (Madrid) (Spain)

    2007-07-15

    In 2003, the first hydrogen filling station with hydrogen on-site production was built in Madrid. The companies Air Liquide Spain (AL), Gas Natural and Repsol YPF joined forces and established a consortium, esH{sub 2}, to design and build such a station to supply hydrogen to Madrid's local bus operator (EMT) for the exploitation of a small fleet of electric buses propelled by fuel cells. Natural gas steam reforming was chosen as the most adequate technology for the hydrogen supply, since it is a well-known process in large-scale plants. The challenge was to reach a compact, trustworthy and fully automated system. To allow for an operation free of starts and stops, the production plant was designed with a smaller capacity than the maximum hydrogen required by the four buses. The system was designed such that AL would truck in from an external source the supplementary hydrogen needed. The filling station also allows to truck out hydrogen in case of over production. This paper tries to show the results of two years of operation, the problems encountered and the solutions found. (author)

  17. Why hydrogen; Pourquoi l'hydrogene?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-02-01

    The energy consumption increase and the associated environmental risks, led to develop new energy sources. The authors present the potentialities of the hydrogen in this context of energy supply safety. They detail the today market and the perspectives, the energy sources for the hydrogen production (fossils, nuclear and renewable), the hydrogen transport, storage, distribution and conversion, the application domains, the associated risks. (A.L.B.)

  18. Hydrogen nanobubble at normal hydrogen electrode

    Science.gov (United States)

    Nakabayashi, S.; Shinozaki, R.; Senda, Y.; Yoshikawa, H. Y.

    2013-05-01

    Electrochemically formed hydrogen nanobubbles at a platinum rotating disk electrode (RDE) were detected by re-oxidation charge. The dissolution time course of the hydrogen nanobubbles was measured by AFM tapping topography under open-circuit conditions at stationary platinum and gold single-crystal electrodes. The bubble dissolution at platinum was much faster than that at gold because two types of diffusion, bulk and surface diffusion, proceeded at the platinum surface, whereas surface diffusion was prohibited at the gold electrode. These findings indicated that the electrochemical reaction of normal hydrogen electrode partly proceeded heterogeneously on the three-phase boundary around the hydrogen nanobubble.

  19. Electrokinetic Power Generation from Liquid Water Microjets

    Energy Technology Data Exchange (ETDEWEB)

    Duffin, Andrew M.; Saykally, Richard J.

    2008-02-15

    Although electrokinetic effects are not new, only recently have they been investigated for possible use in energy conversion devices. We have recently reported the electrokinetic generation of molecular hydrogen from rapidly flowing liquid water microjets [Duffin et al. JPCC 2007, 111, 12031]. Here, we describe the use of liquid water microjets for direct conversion of electrokinetic energy to electrical power. Previous studies of electrokinetic power production have reported low efficiencies ({approx}3%), limited by back conduction of ions at the surface and in the bulk liquid. Liquid microjets eliminate energy dissipation due to back conduction and, measuring only at the jet target, yield conversion efficiencies exceeding 10%.

  20. Hydrogen bond dynamics at the water/hydrocarbon interface.

    Science.gov (United States)

    Chowdhary, Janamejaya; Ladanyi, Branka M

    2009-04-02

    The dynamics of hydrogen bond formation and breakage for water in the vicinity of water/hydrocarbon liquid interfaces is studied using molecular dynamics simulations. Several liquid alkanes are considered as the hydrocarbon phase in order to determine the effects of their chain length and extent of branching on the properties of the adjacent water phase. In addition to defining the interface location in terms of the laboratory-frame density profiles, the effects of interfacial fluctuations are considered by locating the interface in terms of the proximity of the molecules of the other phase. We find that the hydrogen bond dynamics of interfacial water is weakly influenced by the identity of the hydrocarbon phase and by capillary waves. In addition to calculating hydrogen bond time correlations, we examine how the hydrogen bond dynamics depend on local coordination and determine the extent of cooperativity in the population relaxation of the hydrogen bonds that a given molecule participates in. The contributions of translational diffusion and reorientation of molecular O-H bonds to the mechanism of hydrogen bond breakage and reformation are investigated. In previous work, we have shown that rotation of the principal axes of water is anisotropic at the interface and depends on the initial orientation of the molecule relative to the interface. Here, we extend this analysis to the reorientation of the O-H vector and to hydrogen bond time correlation. We find that hydrogen bond dynamics are also sensitive to the initial orientation of the molecules participating in the hydrogen bond.