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Sample records for hydrogen production coupling

  1. Hydrogen production

    NASA Technical Reports Server (NTRS)

    England, C.; Chirivella, J. E.; Fujita, T.; Jeffe, R. E.; Lawson, D.; Manvi, R.

    1975-01-01

    The state of hydrogen production technology is evaluated. Specific areas discussed include: hydrogen production fossil fuels; coal gasification processes; electrolysis of water; thermochemical production of hydrogen; production of hydrogen by solar energy; and biological production of hydrogen. Supply options are considered along with costs of hydrogen production.

  2. Electrochemical production of hydrogen coupled with the oxidation of arsenite.

    PubMed

    Kim, Jungwon; Kwon, Daejung; Kim, Kitae; Hoffmann, Michael R

    2014-01-01

    The production of hydrogen accompanied by the simultaneous oxidation of arsenite (As(III)) was achieved using an electrochemical system that employed a BiOx-TiO2 semiconductor anode and a stainless steel (SS) cathode in the presence of sodium chloride (NaCl) electrolyte. The production of H2 was enhanced by the addition of As(III) during the course of water electrolysis. The synergistic effect of As(III) on H2 production can be explained in terms of (1) the scavenging of reactive chlorine species (RCS), which inhibit the production of H2 by competing with water molecules (or protons) for the electrons on the cathode, by As(III) and (2) the generation of protons, which are more favorably reduced on the cathode than water molecules, through the oxidation of As(III). The addition of 1.0 mM As(III) to the electrolyte at a constant cell voltage (E cell) of 3.0 V enhanced the production of H2 by 12% even though the cell current (I cell) was reduced by 5%. The net effect results in an increase in the energy efficiency (EE) for H2 production (ΔEE) by 17.5%. Furthermore, the value ΔEE, which depended on As(III) concentration, also depended on the applied E cell. For example, the ΔEE increased with increasing As(III) concentration in the micromolar range but decreased as a function of E cell. This is attributed to the fact that the reactions between RCS and As(III) are influenced by both RCS concentration depending on E cell and As(III) concentration in the solution. On the other hand, the ΔEE decreased with increasing As(III) concentration in the millimolar range due to the adsorption of As(V) generated from the oxidation of As(III) on the semiconductor anode. In comparison to the electrochemical oxidation of certain organic compounds (e.g., phenol, 4-chlorophenol, 2-chlorophenol, salicylic acid, catechol, maleic acid, oxalate, and urea), the ΔEE obtained during As(III) oxidation (17.5%) was higher than that observed during the oxidation of the above organic compounds

  3. Assessement of Codes and Standards Applicable to a Hydrogen Production Plant Coupled to a Nuclear Reactor

    SciTech Connect

    M. J. Russell

    2006-06-01

    This is an assessment of codes and standards applicable to a hydrogen production plant to be coupled to a nuclear reactor. The result of the assessment is a list of codes and standards that are expected to be applicable to the plant during its design and construction.

  4. Optimal control strategies for hydrogen production when coupling solid oxide electrolysers with intermittent renewable energies

    NASA Astrophysics Data System (ADS)

    Cai, Qiong; Adjiman, Claire S.; Brandon, Nigel P.

    2014-12-01

    The penetration of intermittent renewable energies requires the development of energy storage technologies. High temperature electrolysis using solid oxide electrolyser cells (SOECs) as a potential energy storage technology, provides the prospect of a cost-effective and energy efficient route to clean hydrogen production. The development of optimal control strategies when SOEC systems are coupled with intermittent renewable energies is discussed. Hydrogen production is examined in relation to energy consumption. Control strategies considered include maximizing hydrogen production, minimizing SOEC energy consumption and minimizing compressor energy consumption. Optimal control trajectories of the operating variables over a given period of time show feasible control for the chosen situations. Temperature control of the SOEC stack is ensured via constraints on the overall temperature difference across the cell and the local temperature gradient within the SOEC stack, to link materials properties with system performance; these constraints are successfully managed. The relative merits of the optimal control strategies are analyzed.

  5. Hydrogen Production

    SciTech Connect

    2014-09-01

    This 2-page fact sheet provides a brief introduction to hydrogen production technologies. Intended for a non-technical audience, it explains how different resources and processes can be used to produce hydrogen. It includes an overview of research goals as well as “quick facts” about hydrogen energy resources and production technologies.

  6. Pyruvate:Ferredoxin Oxidoreductase Is Coupled to Light-independent Hydrogen Production in Chlamydomonas reinhardtii*

    PubMed Central

    Noth, Jens; Krawietz, Danuta; Hemschemeier, Anja; Happe, Thomas

    2013-01-01

    In anaerobiosis, the green alga Chlamydomonas reinhardtii evolves molecular hydrogen (H2) as one of several fermentation products. H2 is generated mostly by the [Fe-Fe]-hydrogenase HYDA1, which uses plant type ferredoxin PETF/FDX1 (PETF) as an electron donor. Dark fermentation of the alga is mainly of the mixed acid type, because formate, ethanol, and acetate are generated by a pyruvate:formate lyase pathway similar to Escherichia coli. However, C. reinhardtii also possesses the pyruvate:ferredoxin oxidoreductase PFR1, which, like pyruvate:formate lyase and HYDA1, is localized in the chloroplast. PFR1 has long been suggested to be responsible for the low but significant H2 accumulation in the dark because the catalytic mechanism of pyruvate:ferredoxin oxidoreductase involves the reduction of ferredoxin. With the aim of proving the biochemical feasibility of the postulated reaction, we have heterologously expressed the PFR1 gene in E. coli. Purified recombinant PFR1 is able to transfer electrons from pyruvate to HYDA1, using the ferredoxins PETF and FDX2 as electron carriers. The high reactivity of PFR1 toward oxaloacetate indicates that in vivo, fermentation might also be coupled to an anaerobically active glyoxylate cycle. Our results suggest that C. reinhardtii employs a clostridial type H2 production pathway in the dark, especially because C. reinhardtii PFR1 was also able to allow H2 evolution in reaction mixtures containing Clostridium acetobutylicum 2[4Fe-4S]-ferredoxin and [Fe-Fe]-hydrogenase HYDA. PMID:23258532

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

    SciTech Connect

    Giraldi, M. R.; Francois, J. L.; Castro-Uriegas, D.

    2012-07-01

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

  8. Coupling of Solar Energy to Hydrogen Peroxide Production in the Cyanobacterium Anacystis nidulans

    PubMed Central

    Roncel, Mercedes; Navarro, José A.; De la Rosa, Miguel A.

    1989-01-01

    Hydrogen peroxide production by blue-green algae (cyanobacteria) under photoautotrophic conditions is of great interest as a model system for the bioconversion of solar energy. Our experimental system was based on the photosynthetic reduction of molecular oxygen with electrons from water by Anacystis nidulans 1402-1 as the biophotocatalyst and methyl viologen as a redox intermediate. It has been demonstrated that the metabolic conditions of the algae in their different growth stages strongly influence the capacity for hydrogen peroxide photoproduction, and so the initial formation rate and net peroxide yield became maximum in the mid-log phase of growth. The overall process can be optimized in the presence of certain metabolic inhibitors such as iodoacetamide and p-hydroxymercuribenzoate, as well as by permeabilization of the cellular membrane after drastic temperature changes and by immobilization of the cells in inert supports such as agar and alginate. PMID:16347855

  9. Solar-powered electrochemical oxidation of organic compounds coupled with the cathodic production of molecular hydrogen.

    PubMed

    Park, Hyunwoong; Vecitis, Chad D; Hoffmann, Michael R

    2008-08-21

    A Bi-doped TiO2 anode, which is prepared from a mixed metal oxide coating deposited on Ti metal, is shown to be efficient for conventional water splitting. In this hybrid photovoltaic-electrochemical system, a photovoltaic (PV) cell is used to convert solar light to electricity, which is then used to oxidize a series of phenolic compounds at the semiconductor anode to carbon dioxide with the simultaneous production of molecular hydrogen from water/proton reduction at the stainless steel cathode. Degradation of phenol in the presence of a background NaCl electrolyte produces chlorinated phenols as reaction intermediates, which are subsequently oxidized completely to carbon dioxide and low-molecular weight carboxylic acids. The anodic current efficiency for the complete oxidation of phenolic compounds ranges from 3% to 17%, while the cathodic current efficiency and the energy efficiency for hydrogen gas generation range from 68% to 95% and 30% to 70%, respectively. PMID:18656909

  10. Development of Efficient Flowsheet and Transient Modeling for Nuclear Heat Coupled Sulfur Iodine Cyclefor Hydrogen Production

    SciTech Connect

    Shripad T. Revankar; Nicholas R. Brown; Cheikhou Kane; Seungmin Oh

    2010-05-01

    The realization of the hydrogen as an energy carrier for future power sources relies on a practical method of producing hydrogen in large scale with no emission of green house gases. Hydrogen is an energy carrier which can be produced by a thermochemical water splitting process. The Sulfur-Iodine (SI) process is an example of a water splitting method using iodine and sulfur as recycling agents.

  11. Hydrogen production by Cyanobacteria

    PubMed Central

    Dutta, Debajyoti; De, Debojyoti; Chaudhuri, Surabhi; Bhattacharya, Sanjoy K

    2005-01-01

    The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to the traditional ways of hydrogen production (chemical, photoelectrical), Cyanobacterial hydrogen production is commercially viable. This review highlights the basic biology of cynobacterial hydrogen production, strains involved, large-scale hydrogen production and its future prospects. While integrating the existing knowledge and technology, much future improvement and progress is to be done before hydrogen is accepted as a commercial primary energy source. PMID:16371161

  12. Sustainable hydrogen production

    SciTech Connect

    Block, D.L.; Linkous, C.; Muradov, N.

    1996-01-01

    This report describes the Sustainable Hydrogen Production research conducted at the Florida Solar Energy Center (FSEC) for the past year. The report presents the work done on the following four tasks: Task 1--production of hydrogen by photovoltaic-powered electrolysis; Task 2--solar photocatalytic hydrogen production from water using a dual-bed photosystem; Task 3--development of solid electrolytes for water electrolysis at intermediate temperatures; and Task 4--production of hydrogen by thermocatalytic cracking of natural gas. For each task, this report presents a summary, introduction/description of project, and results.

  13. Compression effects in inductively coupled, high-power radio-frequency discharges for negative hydrogen ion production

    NASA Astrophysics Data System (ADS)

    Wilhelm, Rolf

    2003-02-01

    In the paper we present a simplified model description of inductively coupled plasma discharges operating at a rather high radio-frequency (rf) power. In this case the induced high plasma currents can cause periodic compressions over a substantial radial distance. Such conditions are obviously given in rf driven 1 MHz/150 kW plasma sources developed at the Institute for Plasma Physics Garching for negative (hydrogen) ion production in future neutral beam injection (NBI) systems for nuclear fusion research, such as the 1 MeV/50 MW NBI system for the International Thermonuclear Experimental Reactor [T. Inoue, R. Hemsworth, V. Kulygin, and Y. Okumura, Fusion Eng. Design 55, 291 (2001)]. The given model describes quite well the compression and other features of the discharge. The results include the Ohmic power input (i.e., electron heating), the resulting density build-up, and—as a new feature—periodical plasma compressions, leading to a direct energy input also into the plasma ions. The model also explains the strange effect of small argon admixtures, which improve the negative ion yield in rf sources by a factor of up to 2-3 (but which have no effect in conventional dc arc sources). With the calculated dependencies from external parameters (e.g., rf-power and frequency, gas pressure, ion mass or the specific geometry), the modeling may help for the further optimization of the rf source.

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

    PubMed

    Luo, Xi; Nam, Joo-Youn; Zhang, Fang; Zhang, Xiaoyuan; Liang, Peng; Huang, Xia; Logan, Bruce E

    2013-07-01

    Waste heat can be captured as electrical energy to drive hydrogen evolution in microbial reverse-electrodialysis electrolysis cells (MRECs) by using thermolytic solutions such as ammonium bicarbonate. To determine the optimal membrane stack configuration for efficient hydrogen production in MRECs using ammonium bicarbonate solutions, different numbers of cell pairs and stack arrangements were tested. The optimum number of cell pairs was determined to be five based on MREC performance and a desire to minimize capital costs. The stack arrangement was altered by placing an extra low concentration chamber adjacent to anode chamber to reduce ammonia crossover. This additional chamber decreased ammonia nitrogen losses into anolyte by 60%, increased the coulombic efficiency to 83%, and improved the hydrogen yield to a maximum of 3.5 mol H2/mol acetate, with an overall energy efficiency of 27%. These results improve the MREC process, making it a more efficient method for renewable hydrogen gas production. PMID:23711946

  15. Biomimetic Production of Hydrogen

    NASA Astrophysics Data System (ADS)

    Gust, Devens

    2004-03-01

    . Subsequent electron transfer reactions further separate the electron and hole spatially, reducing the electronic coupling, slowing charge recombination, and lengthening the useful lifetime of the charge separation.(3) Still following the example of natural bacterial photosynthesis, these artificial reaction centers may be inserted into the lipid bilayer membranes of liposomes. There, they are used to power transmembrane proton pumps based on a redox loop that employs a lipid-soluble quinone molecule to shuttle hydrogen ions across the membrane, acidifying the interior of the liposome.(4) Finally, ATP synthase isolated from spinach can be inserted into the liposomal bilayer. Protons flow out of the liposome through the enzyme, driven by the gradient produced by the proton pump. The energy released is used to convert adenosine diphosphate into adenosine triphosphate, which is a major biological energy currency.(5) The chromophores used in these artificial photosynthetic reaction centers may also be attached to wide band gap nanoparticulate semiconductor electrodes, where their excited states inject electrons into the semiconductor, generating the radical cation of the chromophore. Such electrodes have been incorporated into a photoelectrochemical biofuel cell.(6) In the cell, NADH reduces the radical cation, regenerating the chromophore and ultimately producing NAD+. The NAD+ is recycled by converting it back to NADH via dehydrogenase enzymes that oxidize carbohydrates and similar reduced carbon compounds, including glucose, ethanol and methanol. Addition of a suitable cathode produces a cell that generates electric current through the combined action of light and enzymatic oxidation. The two examples of artificial photosynthesis discussed above are potential sources of the reducing power necessary for hydrogen production. A biomimetic approach to this goal is to couple an artificial photosynthetic system to an enzymatic system for hydrogen production isolated from a suitable

  16. Development of Tritium Permeation Analysis Code and Tritium Transport in a High Temperature Gas-Cooled Reactor Coupled with Hydrogen Production System

    SciTech Connect

    Chang H. Oh; Eung S. Kim; Mike Patterson

    2010-06-01

    Abstract – A tritium permeation analyses code (TPAC) was developed by Idaho National Laboratory for the purpose of analyzing tritium distributions in very high temperature reactor (VHTR) systems, including integrated hydrogen production systems. A MATLAB SIMULINK software package was used in developing the code. The TPAC is based on the mass balance equations of tritium-containing species and various forms of hydrogen coupled with a variety of tritium sources, sinks, and permeation models. In the TPAC, ternary fission and neutron reactions with 6Li, 7Li 10B, and 3He were taken into considerations as tritium sources. Purification and leakage models were implemented as main tritium sinks. Permeation of tritium and H2 through pipes, vessels, and heat exchangers were considered as main tritium transport paths. In addition, electroyzer and isotope exchange models were developed for analyzing hydrogen production systems, including high temperature electrolysis and sulfur-iodine processes.

  17. Biological hydrogen production

    SciTech Connect

    Benemann, J.R.

    1995-11-01

    Biological hydrogen production can be accomplished by either thermochemical (gasification) conversion of woody biomass and agricultural residues or by microbiological processes that yield hydrogen gas from organic wastes or water. Biomass gasification is a well established technology; however, the synthesis gas produced, a mixture of CO and H{sub 2}, requires a shift reaction to convert the CO to H{sub 2}. Microbiological processes can carry out this reaction more efficiently than conventional catalysts, and may be more appropriate for the relatively small-scale of biomass gasification processes. Development of a microbial shift reaction may be a near-term practical application of microbial hydrogen production.

  18. Photoelectrochemical hydrogen production

    SciTech Connect

    Rocheleau, R.; Misra, A.; Miller, E.

    1998-08-01

    A significant component of the US DOE Hydrogen Program is the development of a practical technology for the direct production of hydrogen using a renewable source of energy. High efficiency photoelectrochemical systems to produce hydrogen directly from water using sunlight as the energy source represent one of the technologies identified by DOE to meet this mission. Reactor modeling and experiments conducted at UH provide strong evidence that direct solar-to-hydrogen conversion efficiency greater than 10% can be expected using photoelectrodes fabricated from low-cost, multijunction (MJ) amorphous silicon solar cells. Solar-to-hydrogen conversion efficiencies as high as 7.8% have been achieved using a 10.3% efficient MJ amorphous silicon solar cell. Higher efficiency can be expected with the use of higher efficiency solar cells, further improvement of the thin film oxidation and reduction catalysts, and optimization of the solar cell for hydrogen production rather than electricity production. Hydrogen and oxygen catalysts developed under this project are very stable, exhibiting no measurable degradation in KOH after over 13,000 hours of operation. Additional research is needed to fully optimize the transparent, conducting coatings which will be needed for large area integrated arrays. To date, the best protection has been afforded by wide bandgap amorphous silicon carbide films.

  19. Solar-Driven Water Oxidation and Decoupled Hydrogen Production Mediated by an Electron-Coupled-Proton Buffer.

    PubMed

    Bloor, Leanne G; Solarska, Renata; Bienkowski, Krzysztof; Kulesza, Pawel J; Augustynski, Jan; Symes, Mark D; Cronin, Leroy

    2016-06-01

    Solar-to-hydrogen photoelectrochemical cells (PECs) have been proposed as a means of converting sunlight into H2 fuel. However, in traditional PECs, the oxygen evolution reaction and the hydrogen evolution reaction are coupled, and so the rate of both of these is limited by the photocurrents that can be generated from the solar flux. This in turn leads to slow rates of gas evolution that favor crossover of H2 into the O2 stream and vice versa, even through ostensibly impermeable membranes such as Nafion. Herein, we show that the use of the electron-coupled-proton buffer (ECPB) H3PMo12O40 allows solar-driven O2 evolution from water to proceed at rates of over 1 mA cm(-2) on WO3 photoanodes without the need for any additional electrochemical bias. No H2 is produced in the PEC, and instead H3PMo12O40 is reduced to H5PMo12O40. If the reduced ECPB is subjected to a separate electrochemical reoxidation, then H2 is produced with full overall Faradaic efficiency. PMID:27159121

  20. Thermal-Hydraulic Analyses of Heat Transfer Fluid Requirements and Characteristics for Coupling A Hydrogen Production Plant to a High-Temperature Nuclear Reactor

    SciTech Connect

    C. B. Davis; C. H. Oh; R. B. Barner; D. F. Wilson

    2005-06-01

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

  1. Photoelectrochemical hydrogen production

    SciTech Connect

    Rocheleau, R.E.; Miller, E.; Misra, A.

    1996-10-01

    The large-scale production of hydrogen utilizing energy provided by a renewable source to split water is one of the most ambitious long-term goals of the U.S. Department of Energy`s Hydrogen Program. One promising option to meet this goal is direct photoelectrolysis in which light absorbed by semiconductor-based photoelectrodes produces electrical power internally to split water into hydrogen and oxygen. Under this program, direct solar-to-chemical conversion efficiencies as high as 7.8 % have been demonstrated using low-cost, amorphous-silicon-based photoelectrodes. Detailed loss analysis models indicate that solar-to-chemical conversion greater than 10% can be achieved with amorphous-silicon-based structures optimized for hydrogen production. In this report, the authors describe the continuing progress in the development of thin-film catalytic/protective coatings, results of outdoor testing, and efforts to develop high efficiency, stable prototype systems.

  2. Hydrogen production from coal

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The gasification reactions necessary for the production of hydrogen from montana subbituminous coal are presented. The coal composition is given. The gasifier types mentioned include: suspension (entrained) combustion; fluidized bed; and moving bed. Each gasification process is described. The steam-iron process, raw and product gas compositions, gasifier feed quantities, and process efficiency evaluations are also included.

  3. Dedicated nuclear facilities for electrolytic hydrogen production

    NASA Technical Reports Server (NTRS)

    Foh, S. E.; Escher, W. J. D.; Donakowski, T. D.

    1979-01-01

    An advanced technology, fully dedicated nuclear-electrolytic hydrogen production facility is presented. This plant will produce hydrogen and oxygen only and no electrical power will be generated for off-plant use. The conceptual design was based on hydrogen production to fill a pipeline at 1000 psi and a 3000 MW nuclear base, and the base-line facility nuclear-to-shaftpower and shaftpower-to-electricity subsystems, the water treatment subsystem, electricity-to-hydrogen subsystem, hydrogen compression, efficiency, and hydrogen production cost are discussed. The final conceptual design integrates a 3000 MWth high-temperature gas-cooled reactor operating at 980 C helium reactor-out temperature, direct dc electricity generation via acyclic generators, and high-current density, high-pressure electrolyzers based on the solid polymer electrolyte approach. All subsystems are close-coupled and optimally interfaced and pipeline hydrogen is produced at 1000 psi. Hydrogen costs were about half of the conventional nuclear electrolysis process.

  4. Photovoltaic hydrogen production

    SciTech Connect

    Hiser, H.W.; Memory, S.B.; Veziroglu, T.N.; Padin, J.

    1996-10-01

    This is a new project, which started in June 1995, and involves photovoltaic hydrogen production as a fuel production method for the future. In order to increase the hydrogen yield, it was decided to use hybrid solar collectors to generate D.C. electricity, as well as high temperature steam for input to the electrolyzer. In this way, some of the energy needed to dissociate the water is supplied in the form of heat (or low grade energy), to generate steam, which results in a reduction of electrical energy (or high grade energy) needed. As a result, solar to hydrogen conversion efficiency is increased. In the above stated system, the collector location, the collector tracking sub-system (i.e., orientation/rotation), and the steam temperature have been taken as variables. Five locations selected - in order to consider a variety of latitudes, altitudes, cloud coverage and atmospheric conditions - are Atlanta, Denver, Miami, Phoenix and Salt Lake City. Plain PV and hybrid solar collectors for a stationary south facing system and five different collector rotation systems have been analyzed. Steam temperatures have been varied between 200{degrees}C and 1200{degrees}C. During the first year, solar to hydrogen conversion efficiencies have been considered. The results show that higher steam temperatures, 2 dimensional tracking system, higher elevations and dryer climates causes higher conversion efficiencies. Cost effectiveness of the sub-systems and of the overall system will be analyzed during the second year. Also, initial studies will be made of an advanced high efficiency hybrid solar hydrogen production system.

  5. Hydrogen production from carbonaceous material

    DOEpatents

    Lackner, Klaus S.; Ziock, Hans J.; Harrison, Douglas P.

    2004-09-14

    Hydrogen is produced from solid or liquid carbon-containing fuels in a two-step process. The fuel is gasified with hydrogen in a hydrogenation reaction to produce a methane-rich gaseous reaction product, which is then reacted with water and calcium oxide in a hydrogen production and carbonation reaction to produce hydrogen and calcium carbonate. The calcium carbonate may be continuously removed from the hydrogen production and carbonation reaction zone and calcined to regenerate calcium oxide, which may be reintroduced into the hydrogen production and carbonation reaction zone. Hydrogen produced in the hydrogen production and carbonation reaction is more than sufficient both to provide the energy necessary for the calcination reaction and also to sustain the hydrogenation of the coal in the gasification reaction. The excess hydrogen is available for energy production or other purposes. Substantially all of the carbon introduced as fuel ultimately emerges from the invention process in a stream of substantially pure carbon dioxide. The water necessary for the hydrogen production and carbonation reaction may be introduced into both the gasification and hydrogen production and carbonation reactions, and allocated so as transfer the exothermic heat of reaction of the gasification reaction to the endothermic hydrogen production and carbonation reaction.

  6. The role of electronic coupling between substrate and 2D MoS2 nanosheets in electrocatalytic production of hydrogen.

    PubMed

    Voiry, Damien; Fullon, Raymond; Yang, Jieun; de Carvalho Castro E Silva, Cecilia; Kappera, Rajesh; Bozkurt, Ibrahim; Kaplan, Daniel; Lagos, Maureen J; Batson, Philip E; Gupta, Gautam; Mohite, Aditya D; Dong, Liang; Er, Dequan; Shenoy, Vivek B; Asefa, Tewodros; Chhowalla, Manish

    2016-09-01

    The excellent catalytic activity of metallic MoS2 edges for the hydrogen evolution reaction (HER) has led to substantial efforts towards increasing the edge concentration. The 2H basal plane is less active for the HER because it is less conducting and therefore possesses less efficient charge transfer kinetics. Here we show that the activity of the 2H basal planes of monolayer MoS2 nanosheets can be made comparable to state-of-the-art catalytic properties of metallic edges and the 1T phase by improving the electrical coupling between the substrate and the catalyst so that electron injection from the electrode and transport to the catalyst active site is facilitated. Phase-engineered low-resistance contacts on monolayer 2H-phase MoS2 basal plane lead to higher efficiency of charge injection in the nanosheets so that its intrinsic activity towards the HER can be measured. We demonstrate that onset potentials and Tafel slopes of ∼-0.1 V and ∼50 mV per decade can be achieved from 2H-phase catalysts where only the basal plane is exposed. We show that efficient charge injection and the presence of naturally occurring sulfur vacancies are responsible for the observed increase in catalytic activity of the 2H basal plane. Our results provide new insights into the role of contact resistance and charge transport on the performance of two-dimensional MoS2 nanosheet catalysts for the HER. PMID:27295098

  7. Photoelectrochemical hydrogen production

    SciTech Connect

    Rocheleau, R.E.; Miller, E.; Zhang, Z.

    1995-09-01

    The large-scale production of hydrogen utilizing energy provided by a renewable source to split water is one of the most ambitious long-term goals of the U.S. Department of Energy`s Hydrogen Program. Photoelectrochemical devices-direct photoconversion systems utilizing a photovoltaic-type structure coated with water-splitting catalysts-represent a promising option to meet this goal. Direct solar-to-chemical conversion efficiencies greater than 7% and photoelectrode lifetimes of up to 30 hours in 1 molar KOH have been demonstrated in our laboratory using low-cost, amorphous-silicon-based photoelectrodes. Loss analysis models indicate that the DOE`s goal of 10% solar-to-chemical conversion can be met with amorphous-silicon-based structures optimized for hydrogen production. In this report, we describe recent progress in the development of thin-film catalytic/protective coatings, improvements in photoelectrode efficiency and stability, and designs for higher efficiency and greater stability.

  8. Economics of hydrogen production

    SciTech Connect

    Gaines, L.L.; Wolsky, A.M.

    1984-01-01

    Much of the current interest in hydrogen (H/sub 2/) centers around its potential to displace oil and gas as a fuel. The results of this study should be useful to research and development managers making funding decisions, and they should also be of interest to energy analysts, economists, and proponents of a hydrogen economy. We examined the current costs of H/sub 2/ produced by commercially available technologies (from fossil fuels and by electrolysis) and projected these costs to 2010, to set cost goals for H/sub 2/ produced via new technologies. We also examined the sensitivity of H/sub 2/ costs to varying energy price forecasts, capital costs and the required rate of return on investment, and by-product credits. We find that conventionally produced H/sub 2/ will not break into the fuel market before 2010. 23 references, 19 figures, 12 tables.

  9. Surfactant-induced hydrogen production in cyanobacteria

    SciTech Connect

    Famiglietti, M.; Luisi, P.L. ); Hochkoeppler, A. . Dept. di Biologia)

    1993-10-01

    Addition of Tween 85 to aqueous suspensions of Anabaena variabilis induced photosynthetic evolution of hydrogen over a time span of several weeks: as much as 148 nmol H[sub 2]/h [center dot] mg dry weight was produced in the first week by a suspension containing 4.2 mg dry weight of cells and 77 mM Tween 85. The chemical structure of Tween 85 was a necessary prerequisite for inducing hydrogen production, as compounds such as Tween 20, 60, and 80 had a quite different effect. There was a coupling between photosynthetic oxygen evolution and hydrogen evolution: Hydrogen evolution started to be effective only when oxygen evolution subdued. The presence of heterocysts in A. variabilis was also required for the Tween-induced hydrogen production. Based on these observations, possible mechanisms for the photosynthetic effect of Tween 85 are advanced and discussed.

  10. Hydrogen production costs -- A survey

    SciTech Connect

    Basye, L.; Swaminathan, S.

    1997-12-04

    Hydrogen, produced using renewable resources, is an environmentally benign energy carrier that will play a vital role in sustainable energy systems. The US Department of Energy (DOE) supports the development of cost-effective technologies for hydrogen production, storage, and utilization to facilitate the introduction of hydrogen in the energy infrastructure. International interest in hydrogen as an energy carrier is high. Research, development, and demonstration (RD and D) of hydrogen energy systems are in progress in many countries. Annex 11 of the International Energy Agency (IEA) facilitates member countries to collaborate on hydrogen RD and D projects. The United States is a member of Annex 11, and the US representative is the Program Manager of the DOE Hydrogen R and D Program. The Executive Committee of the Hydrogen Implementing Agreement in its June 1997 meeting decided to review the production costs of hydrogen via the currently commercially available processes. This report compiles that data. The methods of production are steam reforming, partial oxidation, gasification, pyrolysis, electrolysis, photochemical, photobiological, and photoelectrochemical reactions.

  11. Multifunctional Pd/Ni-Co catalyst for hydrogen production by chemical looping coupled with steam reforming of acetic acid.

    PubMed

    Fermoso, Javier; Gil, María V; Rubiera, Fernando; Chen, De

    2014-11-01

    High yield of high-purity H2 from acetic acid, a model compound of bio-oil obtained from the fast pyrolysis of biomass, was produced by sorption-enhanced steam reforming (SESR). An oxygen carrier was introduced into a chemical loop (CL) coupled to the cyclical SESR process to supply heat in situ for the endothermic sorbent regeneration to increase the energy efficiency of the process. A new multifunctional 1 %Pd/20 %Ni-20 %Co catalyst was developed for use both as oxygen carrier in the CL and as reforming catalyst in the SESR whereas a CaO-based material was used as CO2 sorbent. In the sorbent-air regeneration step, the Ni-Co atoms in the catalyst undergo strong exothermic oxidation reactions that provide heat for the CaO decarbonation. The addition of Pd to the Ni-Co catalyst makes the catalyst active throughout the whole SESR-CL cycle. Pd significantly promotes the reduction of Ni-Co oxides to metallic Ni-Co during the reforming stage, which avoids the need for a reduction step after regeneration. H2 yield above 90 % and H2 purity above 99.2 vol % were obtained. PMID:25209388

  12. Photoelectrochemical Hydrogen Production

    SciTech Connect

    Hu, Jian

    2013-12-23

    The objectives of this project, covering two phases and an additional extension phase, were the development of thin film-based hybrid photovoltaic (PV)/photoelectrochemical (PEC) devices for solar-powered water splitting. The hybrid device, comprising a low-cost photoactive material integrated with amorphous silicon (a-Si:H or a-Si in short)-based solar cells as a driver, should be able to produce hydrogen with a 5% solar-to-hydrogen conversion efficiency (STH) and be durable for at least 500 hours. Three thin film material classes were studied and developed under this program: silicon-based compounds, copper chalcopyrite-based compounds, and metal oxides. With the silicon-based compounds, more specifically the amorphous silicon carbide (a-SiC), we achieved a STH efficiency of 3.7% when the photoelectrode was coupled to an a-Si tandem solar cell, and a STH efficiency of 6.1% when using a crystalline Si PV driver. The hybrid PV/a-SiC device tested under a current bias of -3~4 mA/cm{sup 2}, exhibited a durability of up to ~800 hours in 0.25 M H{sub 2}SO{sub 4} electrolyte. Other than the PV driver, the most critical element affecting the photocurrent (and hence the STH efficiency) of the hybrid PV/a-SiC device was the surface energetics at the a-SiC/electrolyte interface. Without surface modification, the photocurrent of the hybrid PEC device was ~1 mA/cm{sup 2} or lower due to a surface barrier that limits the extraction of photogenerated carriers. We conducted an extensive search for suitable surface modification techniques/materials, of which the deposition of low work function metal nanoparticles was the most successful. Metal nanoparticles of ruthenium (Ru), tungsten (W) or titanium (Ti) led to an anodic shift in the onset potential. We have also been able to develop hybrid devices of various configurations in a monolithic fashion and optimized the current matching via altering the energy bandgap and thickness of each constituent cell. As a result, the short

  13. Electrolytic hydrogen production

    NASA Astrophysics Data System (ADS)

    Ramani, M. P. S.

    In the role of a secondary energy carrier complementary to electricity in a postfossil-fuel era, hydrogen produced by the elecrolytic splitting of water may be obtained by a variety of methods whose technology development status is presently assessed. Nuclear heat can be converted into hydrogen either directly, via thermal splitting of water, or by means of water electrolysis, which can be of the unipolar tank type or the bipolar filter-press type. An evaluation is made of advanced electrolytic techniques involving exotic materials, as well as solid polymer electrolyte electrolysis and high-temperature water-vapor electrolysis.

  14. Using plants for hydrogen production

    SciTech Connect

    Greenbaum, E.

    1981-01-01

    The objective of this program is to make a quantitative assessment of the potential for using marine algae for producing hydrogen and oxygen from sea water. The approach is to screen selected species of green algae for simultaneous photoproduction of hydrogen and oxygen. Six marine green algae have been identified as having this property. The limiting step of algal hydrogen production is turnover time. This report contains data on the first simultaneous measurement of the turnover times of steady-state photosynthetic hydrogen and oxygen production. An instrument for measuring the absolute yield of hydrogen or oxygen per saturating single-turnover flash of light has been designed and built as part of this research program.

  15. Hydrogen Production Technical Team Roadmap

    SciTech Connect

    2013-06-01

    The Hydrogen Production Technical Team Roadmap identifies research pathways leading to hydrogen production technologies that produce near-zero net greenhouse gas (GHG) emissions from highly efficient and diverse renewable energy sources. This roadmap focuses on initial development of the technologies, identifies their gaps and barriers, and describes activities by various U.S. Department of Energy (DOE) offices to address the key issues and challenges.

  16. Technical Analysis of Hydrogen Production

    SciTech Connect

    Ali T-Raissi

    2005-01-14

    The aim of this work was to assess issues of cost, and performance associated with the production and storage of hydrogen via following three feedstocks: sub-quality natural gas (SQNG), ammonia (NH{sub 3}), and water. Three technology areas were considered: (1) Hydrogen production utilizing SQNG resources, (2) Hydrogen storage in ammonia and amine-borane complexes for fuel cell applications, and (3) Hydrogen from solar thermochemical cycles for splitting water. This report summarizes our findings with the following objectives: Technoeconomic analysis of the feasibility of the technology areas 1-3; Evaluation of the hydrogen production cost by technology areas 1; and Feasibility of ammonia and/or amine-borane complexes (technology areas 2) as a means of hydrogen storage on-board fuel cell powered vehicles. For each technology area, we reviewed the open literature with respect to the following criteria: process efficiency, cost, safety, and ease of implementation and impact of the latest materials innovations, if any. We employed various process analysis platforms including FactSage chemical equilibrium software and Aspen Technologies AspenPlus and HYSYS chemical process simulation programs for determining the performance of the prospective hydrogen production processes.

  17. Coupling hydrogen fuel and carbonless utilities

    SciTech Connect

    Berry, G.D.

    1998-08-01

    A number of previous analyses have focused on comparisons of single hydrogen vehicles to petroleum and alternative fuel vehicles or of stationary hydrogen storage for utility or local power applications. LLNL`s approach is to compare combined transportation/utility storage systems using hydrogen and fossil fuels. Computer models have been constructed to test the hypothesis that combining carbonless electricity sources and vehicles fueled by electrolytic hydrogen can reduce carbon emissions more cost effectively than either approach alone. Three scenarios have been developed and compared using computer simulations, hourly utility demand data, representative data for solar and wind energy sites, and the latest available EIA projections for transportation and energy demand in the US in 2020. Cost projections were based on estimates from GRI, EIA, and a recent DOE/EPRI report on renewable energy technologies. The key question guiding this analysis was: what can be gained by combining hydrogen fuel production and renewable electricity? Bounding scenarios were chosen to analyze three carbon conscious options for the US transportation fuel and electricity supply system beyond 2020: Reference Case -- petroleum transportation and natural gas electric sector; Benchmark Case -- petroleum transportation and carbonless electric sector; and Target Case -- hydrogen transportation and carbonless electric sector.

  18. Thermochemical production of hydrogen

    DOEpatents

    Dreyfuss, Robert M.

    1976-07-13

    A thermochemical reaction cycle for the generation of hydrogen from water comprising the following sequence of reactions wherein M represents a metal and Z represents a metalloid selected from the arsenic-antimony-bismuth and selenium-tellurium subgroups of the periodic system: 2MO + Z + SO.sub.2 .fwdarw. MZ + MSO.sub.4 (1) mz + h.sub.2 so.sub.4 .fwdarw. mso.sub.4 + h.sub.2 z (2) 2mso.sub.4 .fwdarw. 2mo + so.sub.2 + so.sub.3 + 1/20.sub.2 (3) h.sub.2 z .fwdarw. z + h.sub.2 (4) h.sub.2 o + so.sub.3 .fwdarw. h.sub.2 so.sub.4 (5) the net reaction is the decomposition of water into hydrogen and oxygen.

  19. Hydrogen production from solar energy

    NASA Technical Reports Server (NTRS)

    Eisenstadt, M. M.; Cox, K. E.

    1975-01-01

    Three alternatives for hydrogen production from solar energy have been analyzed on both efficiency and economic grounds. The analysis shows that the alternative using solar energy followed by thermochemical decomposition of water to produce hydrogen is the optimum one. The other schemes considered were the direct conversion of solar energy to electricity by silicon cells and water electrolysis, and the use of solar energy to power a vapor cycle followed by electrical generation and electrolysis. The capital cost of hydrogen via the thermochemical alternative was estimated at $575/kW of hydrogen output or $3.15/million Btu. Although this cost appears high when compared with hydrogen from other primary energy sources or from fossil fuel, environmental and social costs which favor solar energy may prove this scheme feasible in the future.

  20. Hydrogen Production by Water Biophotolysis

    SciTech Connect

    Ghirardi, Maria L.; King, Paul W.; Mulder, David W.; Eckert, Carrie; Dubini, Alexandra; Maness, Pin-Ching; Yu, Jianping

    2014-01-22

    The use of microalgae for production of hydrogen gas from water photolysis has been studied for many years, but its commercialization is still limited by multiple challenges. Most of the barriers to commercialization are attributed to the existence of biological regulatory mechanisms that, under anaerobic conditions, quench the absorbed light energy, down-regulate linear electron transfer, inactivate the H2-producing enzyme, and compete for electrons with the hydrogenase. Consequently, the conversion efficiency of absorbed photons into H2 is significantly lower than its estimated potential of 12–13 %. However, extensive research continues towards addressing these barriers by either trying to understand and circumvent intracellular regulatory mechanisms at the enzyme and metabolic level or by developing biological systems that achieve prolonged H2 production albeit under lower than 12–13 % solar conversion efficiency. This chapter describes the metabolic pathways involved in biological H2 photoproduction from water photolysis, the attributes of the two hydrogenases, [FeFe] and [NiFe], that catalyze biological H2 production, and highlights research related to addressing the barriers described above. These highlights include: (a) recent advances in improving our understanding of the O2 inactivation mechanism in different classes of hydrogenases; (b) progress made in preventing competitive pathways from diverting electrons from H2 photoproduction; and (c) new developments in bypassing the non-dissipated proton gradient from down-regulating photosynthetic electron transfer. As an example of a major success story, we mention the generation of truncated-antenna mutants in Chlamydomonas and Synechocystis that address the inherent low-light saturation of photosynthesis. In addition, we highlight the rationale and progress towards coupling biological hydrogenases to non-biological, photochemical charge-separation as a means to bypass the barriers of photobiological

  1. Negative hydrogen ion production mechanisms

    SciTech Connect

    Bacal, M.; Wada, M.

    2015-06-15

    Negative hydrogen/deuterium ions can be formed by processes occurring in the plasma volume and on surfaces facing the plasma. The principal mechanisms leading to the formation of these negative ions are dissociative electron attachment to ro-vibrationally excited hydrogen/deuterium molecules when the reaction takes place in the plasma volume, and the direct electron transfer from the low work function metal surface to the hydrogen/deuterium atoms when formation occurs on the surface. The existing theoretical models and reported experimental results on these two mechanisms are summarized. Performance of the negative hydrogen/deuterium ion sources that emerged from studies of these mechanisms is reviewed. Contemporary negative ion sources do not have negative ion production electrodes of original surface type sources but are operated with caesium with their structures nearly identical to volume production type sources. Reasons for enhanced negative ion current due to caesium addition to these sources are discussed.

  2. Solar Hydrogen Production

    SciTech Connect

    Koval, C.; Sutin, N.; Turner, J.

    1996-09-01

    This panel addressed different methods for the photoassisted dissociation of water into its component parts, hydrogen and oxygen. Systems considered include PV-electrolysis, photoelectrochemical cells, and transition-metal based microheterogeneous and homogeneous systems. While none of the systems for water splitting appear economically viable at the present time, the panel identified areas of basic research that could increase the overall efficiency and decrease the costs. Common to all the areas considered was the underlying belief that the water-to-hydrogen half reaction is reasonably well characterized, while the four-electron oxidation of water-to-oxygen is less well understood and represents a significant energy loss. For electrolysis, research in electrocatalysis to reduce overvoltage losses was identified as a key area for increased efficiency. Non-noble metal catalysts and less expensive components would reduce capital costs. While potentially offering higher efficiencies and lower costs, photoelectrochemical-based direct conversion systems undergo corrosion reactions and often have poor energetics for the water reaction. Research is needed to understand the factors that control the interfacial energetics and the photoinduced corrosion. Multi-photon devices were identified as promising systems for high efficiency conversion.

  3. Hydrogen production by photosynthetic microorganisms

    SciTech Connect

    Akano, T.; Fukatsu, K.; Miyasaka, H. |

    1996-12-31

    Hydrogen is a clean energy alternative to the fossil fuels, the main source of greenhouse gas emissions. We developed a stable system for the conversion of solar energy into hydrogen using photosynthetic microorganisms. Our system consists of the following three stages: (1) Photosynthetic starch accumulation in green microalgae (400 L x2); (2) Dark anaerobic fermentation of the algal starch biomass to produce hydrogen and organic compounds (155 L x2); and (3) Further conversion of the organic compounds to produce hydrogen using photosynthetic bacteria (three types of reactors, parallel plate, raceway, and tubular). We constructed a test plant of this process at Nankoh power plant of Kansai Electric Power Company in Osaka, Japan, and carried out a series of tests using CO{sub 2} obtained from a chemical absorption pilot-plant. The photobiological hydrogen production process used a combination of a marine alga, Chlamydomonas sp. MGA 161 and marine photosynthetic bacterium, Rhodopseudomonas sp. W-1S. The dark anaerobic fermentation of algal starch biomass was also investigated. Sustained and stable starch accumulation, starch degradation in the algal cell, and hydrogen production from algal fermentation and photosynthetic bacteria in the light were demonstrated during several experiments. 3 refs., 12 figs., 1 tab.

  4. Benefits of hydrogen production research

    NASA Technical Reports Server (NTRS)

    Manvi, R.; Fujita, T.; Rossen, W.; Jacobs, C.

    1976-01-01

    An economic analysis of total monetary benefits arising from increased volume and efficiency of hydrogen production from various primary energy sources is carried out. The analysis is based on NASA's projections of future hydrogen demand in terms of both established industrial-chemical uses and new energy system applications, along with the mix of primary energy sources needed to meet this demand. A cost methodology model is worked out with the basic cost elements being plant construction costs, feedstock and energy costs, and operating and labor-related costs. A computer simulation technique was developed and a set of model calculations was performed. Some representative outputs of the computer analysis are displayed and conclusions are drawn on major factors determining the overall savings possible in hydrogen production and on its technological and economic impact.

  5. Hydrogen production: Catalysing artificial photosynthesis

    NASA Astrophysics Data System (ADS)

    Mao, Samuel S.; Shen, Shaohua

    2013-12-01

    Efficient photocatalytic splitting of water to realize carbon-free production of hydrogen from sunlight remains a challenge. New precious-metal-free molecular catalysts in semiconductor-based, visible-light-driven water-splitting systems are promising for realizing practical artificial photosynthesis.

  6. Microbial hydrogen production

    SciTech Connect

    Weaver, P.F.; Maness, P.C.; Martin, S.

    1995-09-01

    Photosynthetic bacteria inhabit an anaerobic or microaerophilic world where H{sub 2} is produced and consumed as a shared intermediary metabolite. Within a given bacterial isolate there are as many as 4 to 6 distinct enzymes that function to evolve or consume H{sub 2}. Three of the H{sub 2}-evolving physiologies involving three different enzymes from photosynthetic bacteria have been examined in detail for commercial viability. Nitrogenase-mediated H{sub 2} production completely dissimilates many soluble organic compounds to H{sub 2} and CO{sub 2} at rates up to 131 {mu}mol H{sub 2}{sm_bullet}min{sup -1}{sm_bullet}g cdw{sup -1} and can remain active for up to 20 days. This metabolism is very energy intensive, however, which limits solar conversion efficiencies. Fermentative hydrogenase can produce H{sub 2} at rates of 440 {mu}mol{sm_bullet}min{sup -1}{sm_bullet}g cdw{sup -1} at low levels of irradiation over indefinite periods. The equilibrium for this activity is low (<0.15 atmospheres), thereby requiring gas sparging, vacuuming, or microbial scavenging to retain prolonged activity. Microbial H{sub 2} production from the CO component of synthesis or producer gases maximally reaches activities of 1.5 mmol{sm_bullet}min{sup -1}{sm_bullet}g cdw{sup -1}. Mass transport of gaseous CO into an aqueous bacterial suspension is the rate-limiting step. Increased gas pressure strongly accelerates these rates. Immobilized bacteria on solid supports at ambient pressures also show enhanced shift activity when the bulk water is drained away. Scaled-up bioreactors with 100-200 cc bed volume have been constructed and tested. The near-term goal of this portion of the project is to engineer and economically evaluate a prototype system for the biological production of H{sub 2} from biomass. The CO shift enables a positive selection technique for O{sub 2}-resistant, H{sub 2}-evolving bacterial enzymes from nature.

  7. Methods and systems for the production of hydrogen

    DOEpatents

    Oh, Chang H.; Kim, Eung S.; Sherman, Steven R.

    2012-03-13

    Methods and systems are disclosed for the production of hydrogen and the use of high-temperature heat sources in energy conversion. In one embodiment, a primary loop may include a nuclear reactor utilizing a molten salt or helium as a coolant. The nuclear reactor may provide heat energy to a power generation loop for production of electrical energy. For example, a supercritical carbon dioxide fluid may be heated by the nuclear reactor via the molten salt and then expanded in a turbine to drive a generator. An intermediate heat exchange loop may also be thermally coupled with the primary loop and provide heat energy to one or more hydrogen production facilities. A portion of the hydrogen produced by the hydrogen production facility may be diverted to a combustor to elevate the temperature of water being split into hydrogen and oxygen by the hydrogen production facility.

  8. Hydrogen Storage and Production Project

    SciTech Connect

    Bhattacharyya, Abhijit; Biris, A. S.; Mazumder, M. K.; Karabacak, T.; Kannarpady, Ganesh; Sharma, R.

    2011-07-31

    This is the final technical report. This report is a summary of the project. The goal of our project is to improve solar-to-hydrogen generation efficiency of the PhotoElectroChemical (PEC) conversion process by developing photoanodes with high absorption efficiency in the visible region of the solar radiation spectrum and to increase photo-corrosion resistance of the electrode for generating hydrogen from water. To meet this goal, we synthesized nanostructured heterogeneous semiconducting photoanodes with a higher light absorption efficiency compared to that of TiO2 and used a corrosion protective layer of TiO2. While the advantages of photoelectrochemical (PEC) production of hydrogen have not yet been realized, the recent developments show emergence of new nanostructural designs of photoanodes and choices of materials with significant gains in photoconversion efficiency.

  9. Low Cost Hydrogen Production Platform

    SciTech Connect

    Timothy M. Aaron, Jerome T. Jankowiak

    2009-10-16

    A technology and design evaluation was carried out for the development of a turnkey hydrogen production system in the range of 2.4 - 12 kg/h of hydrogen. The design is based on existing SMR technology and existing chemical processes and technologies to meet the design objectives. Consequently, the system design consists of a steam methane reformer, PSA system for hydrogen purification, natural gas compression, steam generation and all components and heat exchangers required for the production of hydrogen. The focus of the program is on packaging, system integration and an overall step change in the cost of capital required for the production of hydrogen at small scale. To assist in this effort, subcontractors were brought in to evaluate the design concepts and to assist in meeting the overall goals of the program. Praxair supplied the overall system and process design and the subcontractors were used to evaluate the components and system from a manufacturing and overall design optimization viewpoint. Design for manufacturing and assembly (DFMA) techniques, computer models and laboratory/full-scale testing of components were utilized to optimize the design during all phases of the design development. Early in the program evaluation, a review of existing Praxair hydrogen facilities showed that over 50% of the installed cost of a SMR based hydrogen plant is associated with the high temperature components (reformer, shift, steam generation, and various high temperature heat exchange). The main effort of the initial phase of the program was to develop an integrated high temperature component for these related functions. Initially, six independent concepts were developed and the processes were modeled to determine overall feasibility. The six concepts were eventually narrowed down to the highest potential concept. A US patent was awarded in February 2009 for the Praxair integrated high temperature component design. A risk analysis of the high temperature component was

  10. Coupling hydrogen separation with butanone hydrogenation in an electrochemical hydrogen pump with sulfonated poly (phthalazinone ether sulfone ketone) membrane

    NASA Astrophysics Data System (ADS)

    Huang, Shiqi; Wang, Tao; Wu, Xuemei; Xiao, Wu; Yu, Miao; Chen, Wei; Zhang, Fengxiang; He, Gaohong

    2016-09-01

    This work reports the novel work of coupling H2/CO2 separation with biomass-derived butanone hydrogenation in non-fluorinated sulfonated poly (phthalazinone ether sulfone ketone) (SPPESK) electrochemical hydrogen pump (EHP) reactor. Due to higher resistance to swelling, SPPESK-based EHP reactor exhibits more excellent reaction rate in elevated temperature (60 °C) and higher butanone concentration (2 M) as 270, 260 nmol cm-2 s-1, respectively, higher than 240, 200 nmol cm-2 s-1of Nafion-based EHP reactors. Also, the SPPESK-based EHP reactor remains 90% of initial hydrogenation rate after 4 batches, better than that of Nafion-based EHP reactors, which is only 62%. The energy efficiency of EHP separator reaches 40% under H2/CO2 mixture feed mode, and electricity of about 0.3 kWh is consumed per Nm3 H2 product, being superior to energy consumption compared with alternative processes like PSA and electrolysis of water. In addition, SPPESK-based EHP exhibits better hydrogenation stability due to lower CO2 permeation than Nafion. With increasing CO2 content in H2 feed, hydrogenation rate almost keeps constant at around 210 nmol cm-2 s-1 in SPPESK-based EHP reactor while decreases fast to 50 nmol cm-2 s-1 in Nafion/PTFE-based EHP reactor. These results show integration of gas separation with hydrogenation reactor is feasible in SPPESK-based EHP reactor.

  11. System for thermochemical hydrogen production

    DOEpatents

    Werner, R.W.; Galloway, T.R.; Krikorian, O.H.

    1981-05-22

    Method and apparatus are described for joule boosting a SO/sub 3/ decomposer using electrical instead of thermal energy to heat the reactants of the high temperature SO/sub 3/ decomposition step of a thermochemical hydrogen production process driven by a tandem mirror reactor. Joule boosting the decomposer to a sufficiently high temperature from a lower temperature heat source eliminates the need for expensive catalysts and reduces the temperature and consequent materials requirements for the reactor blanket. A particular decomposer design utilizes electrically heated silicon carbide rods, at a temperature of 1250/sup 0/K, to decompose a cross flow of SO/sub 3/ gas.

  12. Utilization of solar energy for the production of hydrogen

    NASA Astrophysics Data System (ADS)

    Steeb, H.; Kleinkauf, W.; Mehrmann, A.

    1983-09-01

    The combination of photovoltaic solar generators and electrolyzers for hydrogen production was investigated. Two different small solar-hydrogen systems are described. The coupling of photovoltaics and electrolysis; the mode of operation of a unit for power processing; and practical operation experiences are discussed. The proposed active electronic adaptation unit can improve photovoltaic electrolyse systems. Solar energy can be converted into the energy carrier hydrogen with a total yearly average efficiency of 16%. This corresponds to 23 Ncum hydrogen per sqm active solar cell surface for a yearly radiation of 1000 kWh/sqm.

  13. Fluid-Plasma Coupling in Hydrogen Flames

    NASA Astrophysics Data System (ADS)

    Massa, Luca; Retter, Jonathan; Glumac, Nick; Elliot, Gregg; Freund, Jonathan

    2015-11-01

    Recent experiments show that hydrogen diffusion flames at low Reynolds number can be markedly affected by a dielectric barrier discharge (DBD) plasma. The flame surface deforms and flattens, and light emissions increase. We develop a simulation model to analyze the mechanisms that causes these changes, and apply it to numerical calculations of axisymmetric flames with co-annular DBD, matching the corresponding experiments. Body forces due to charge sheaths are found to be the main mechanism, with radicals produced by plasma excitation playing a secondary role for the present conditions. The non-actuated flame flickers at approximately 10 Hz, in good agreement with the experiments. As the DBD voltage is increased, the flame flattens and oscillations decrease, eventually ceasing above a threshold value. The fully flattened case has a stoichiometric surface lying flat across the fuel orifice, with flame temperature exceeding significantly the adiabatic flame value. A force based on a linearized plasma sheath model, calibrated against air experiments, reproduces the main features of the experiments and provides a good estimate for the threshold flattening potential. In faster flowing regimes, radical production by the plasma becomes more important.

  14. Hydrogen production from microbial strains

    DOEpatents

    Harwood, Caroline S; Rey, Federico E

    2012-09-18

    The present invention is directed to a method of screening microbe strains capable of generating hydrogen. This method involves inoculating one or more microbes in a sample containing cell culture medium to form an inoculated culture medium. The inoculated culture medium is then incubated under hydrogen producing conditions. Once incubating causes the inoculated culture medium to produce hydrogen, microbes in the culture medium are identified as candidate microbe strains capable of generating hydrogen. Methods of producing hydrogen using one or more of the microbial strains identified as well as the hydrogen producing strains themselves are also disclosed.

  15. Patent landscape for biological hydrogen production.

    PubMed

    Levin, David B; Lubieniechi, Simona

    2013-12-01

    Research and development of biological hydrogen production have expanded significantly in the past decade. Production of renewable hydrogen from agricultural, forestry, or other organic waste streams offers the possibility to contribute to hydrogen production capacity with no net, or at least with lower, greenhouse gas emissions. Significant improvements in the volumetric or molar yields of hydrogen production have been accomplished through genetic engineering of hydrogen synthesizing microorganisms. Although no commercial scale renewable biohydrogen production facilities are currently in operation, a few pilot scale systems have been demonstrated successfully, and while industrial scale production of biohydrogen still faces a number of technical and economic barriers, understanding the patent landscape is an important step in developing a viable commercialization strategy. In this paper, we review patents filed on biological hydrogen production. Patents on biohydrogen production from both the Canadian and American Patents databases were classified into three main groups: (1) patents for biological hydrogen by direct photolysis; (2) patents for biological hydrogen by dark fermentation; and (3) patents for process engineering for biological hydrogen production. PMID:23521705

  16. Concepts for solar production of hydrogen

    NASA Technical Reports Server (NTRS)

    Hanson, J. A.

    1979-01-01

    Some basic technical approaches to producing hydrogen from solar energy are surveyed. Solar energy forms are divided into: (1) direct solar radiation and (2) indirect forms such as wind and ocean thermal gradient. Technical approaches are separated into: (1) direct hydrogen production from the action of sunlight on some substrate, (2) hydrogen production from sunlight via an intermediate form of energy such as heat and electricity, and (3) hydrogen production from indirect solar energy via an intermediate energy form. It is concluded that while hydrogen from solar energy will be expensive by present standards, the depletion of fossil fuels will cause solar hydrogen to emerge as one of the few alternatives to a nuclear-electric or nuclear-electric-hydrogen energy system.

  17. Coupling renewables via hydrogen into utilities: Temporal and spatial issues, and technology opportunities

    SciTech Connect

    Iannucci, J.J.; Horgan, S.A.; Eyer, J.M.

    1996-10-01

    This paper discusses the technical potential for hydrogen used as an energy storage medium to couple time-dependent renewable energy into time-dependent electric utility loads. This analysis will provide estimates of regional and national opportunities for hydrogen production, storage and conversion, based on current and near-term leading renewable energy and hydrogen production and storage technologies. Appropriate renewable technologies, wind, photovoltaics and solar thermal, are matched to their most viable regional resources. The renewables are assumed to produce electricity which will be instantaneously used by the local utility to meet its loads; any excess electricity will be used to produce hydrogen electrolytically and stored for later use. Results are derived based on a range of assumptions of renewable power plant capacity and fraction of regional electric load to be met (e.g., the amount of hydrogen storage required to meet the Northwest region`s top 10% of electric load). For each renewable technology national and regional totals will be developed for maximum hydrogen production per year and ranges of hydrogen storage capacity needed in each year (hydroelectric case excluded). The sensitivity of the answers to the fraction of peak load to be served and the land area dedicated for renewable resources are investigated. These analyses can serve as a starting point for projecting the market opportunity for hydrogen storage and distribution technologies. Sensitivities will be performed for hydrogen production, conversion. and storage efficiencies representing current and near-term hydrogen technologies.

  18. Hydrogen energy for tomorrow: Advanced hydrogen production technologies

    SciTech Connect

    1995-08-01

    The future vision for hydrogen is that it will be cost-effectively produced from renewable energy sources and made available for widespread use as an energy carrier and a fuel. Hydrogen can be produced from water and when burned as a fuel, or converted to electricity, joins with oxygen to again form water. It is a clean, sustainable resource with many potential applications, including generating electricity, heating homes and offices, and fueling surface and air transportation. To achieve this vision, researchers must develop advanced technologies to produce hydrogen at costs competitive with fossil fuels, using sustainable sources. Hydrogen is now produced primarily by steam reforming of natural gas. For applications requiring extremely pure hydrogen, production is done by electrolysis. This is a relatively expensive process that uses electric current to dissociate, or split, water into its hydrogen and oxygen components. Technologies with the best potential for producing hydrogen to meet future demand fall into three general process categories: photobiological, photoelectrochemical, and thermochemical. Photobiological and photoelectrochemical processes generally use sunlight to split water into hydrogen and oxygen. Thermochemical processes, including gasification and pyrolysis systems, use heat to produce hydrogen from sources such as biomass and solid waste.

  19. Hydrogen production by recombinant Escherichia coli strains

    PubMed Central

    Maeda, Toshinari; Sanchez‐Torres, Viviana; Wood, Thomas K.

    2012-01-01

    Summary The production of hydrogen via microbial biotechnology is an active field of research. Given its ease of manipulation, the best‐studied bacterium Escherichia coli has become a workhorse for enhanced hydrogen production through metabolic engineering, heterologous gene expression, adaptive evolution, and protein engineering. Herein, the utility of E. coli strains to produce hydrogen, via native hydrogenases or heterologous ones, is reviewed. In addition, potential strategies for increasing hydrogen production are outlined and whole‐cell systems and cell‐free systems are compared. PMID:21895995

  20. Redirection of metabolism for hydrogen production

    SciTech Connect

    Harwood, Caroline S.

    2011-11-28

    This project is to develop and apply techniques in metabolic engineering to improve the biocatalytic potential of the bacterium Rhodopseudomonas palustris for nitrogenase-catalyzed hydrogen gas production. R. palustris, is an ideal platform to develop as a biocatalyst for hydrogen gas production because it is an extremely versatile microbe that produces copious amounts of hydrogen by drawing on abundant natural resources of sunlight and biomass. Anoxygenic photosynthetic bacteria, such as R. palustris, generate hydrogen and ammonia during a process known as biological nitrogen fixation. This reaction is catalyzed by the enzyme nitrogenase and normally consumes nitrogen gas, ATP and electrons. The applied use of nitrogenase for hydrogen production is attractive because hydrogen is an obligatory product of this enzyme and is formed as the only product when nitrogen gas is not supplied. Our challenge is to understand the systems biology of R. palustris sufficiently well to be able to engineer cells to produce hydrogen continuously, as fast as possible and with as high a conversion efficiency as possible of light and electron donating substrates. For many experiments we started with a strain of R. palustris that produces hydrogen constitutively under all growth conditions. We then identified metabolic pathways and enzymes important for removal of electrons from electron-donating organic compounds and for their delivery to nitrogenase in whole R. palustris cells. For this we developed and applied improved techniques in 13C metabolic flux analysis. We identified reactions that are important for generating electrons for nitrogenase and that are yield-limiting for hydrogen production. We then increased hydrogen production by blocking alternative electron-utilizing metabolic pathways by mutagenesis. In addition we found that use of non-growing cells as biocatalysts for hydrogen gas production is an attractive option, because cells divert all resources away from growth and

  1. Continuous hydrogen production from organic waste.

    PubMed

    Noike, T; Ko, I B; Yokoyama, S; Kohno, Y; Li, Y Y

    2005-01-01

    The antibiotic effects of lactic acid bacteria, Lactobacillus paracasei, on hydrogen production were investigated using glucose as the substrate for the batch experiments. The effects of lactic acid bacteria on hydrogen fermentation depended on pH and the inhibition of hydrogen-producing bacteria was prevented by keeping the pH over 5.0. Then, a continuous hydrogen production experiment was conducted by using bean curd manufacturing waste as an actual organic waste at pH 5.5 at 35 degrees C. The increase of the substrate concentration and the addition of nitrogen gave precedence to acetic and butyric acids production in the metabolic pathway and suppressed propionic acid production. As the result, continuous hydrogen production from municipal organic waste was enabled. PMID:16180421

  2. Hydrogen Production and Delivery Research

    SciTech Connect

    Iouri Balachov, PhD

    2007-10-15

    In response to DOE's Solicitation for Grant Applications DE-PS36-03GO93007, 'Hydrogen Production and Delivery Research', SRI International (SRI) proposed to conduct work under Technical Topic Area 5, Advanced Electrolysis Systems; Sub-Topic 5B, High-Temperature Steam Electrolysis. We proposed to develop a prototype of a modular industrial system for low-cost generation of H{sub 2} (<$2/kg) by steam electrolysis with anodic depolarization by CO. Water will be decomposed electrochemically into H{sub 2} and O{sub 2} on the cathode side of a high-temperature electrolyzer. Oxygen ions will migrate through an oxygen-ion-conductive solid oxide electrolyte. Gas mixtures on the cathode side (H{sub 2} + H{sub 2}O) and on the anode side (CO + CO{sub 2}) will be reliably separated by the solid electrolyte. Depolarization of the anodic process will decrease the electrolysis voltage, and thus the electricity required for H{sub 2} generation and the cost of produced H{sub 2}. The process is expected to be at least 10 times more energy-efficient than low-temperature electrolysis and will generate H{sub 2} at a cost of approximately $1-$1.5/kg. The operating economics of the system can be made even more attractive by deploying it at locations where waste heat is available; using waste heat would reduce the electricity required for heating the system. Two critical targets must be achieved: an H{sub 2} production cost below $2/kg, and scalable design of the pilot H{sub 2} generation system. The project deliverables would be (1) a pilot electrolysis system for H{sub 2} generation, (2) an economic analysis, (3) a market analysis, and (4) recommendations and technical documentation for field deployment. DOE was able to provide only 200K out of 1.8M (or about 10% of awarded budget), so project was stopped abruptly.

  3. Bioreactor design for photofermentative hydrogen production.

    PubMed

    Uyar, Basar

    2016-09-01

    Hydrogen will become a significant fuel in the near future. Photofermentative production of hydrogen is a promising and sustainable process. The design, construction and successful operation of the photobioreactors are of critical importance for photofermentative hydrogen production and became a major field of research where novel technologies are developed and adapted frequently. This paper gives an overview of the design aspects related to photobioreactors giving particular attention to design limitations, construction material, type, operating mode and scale-up. Sub-components of the overall system setup such as mixing, temperature control and hydrogen collection are also discussed. Recent achievements in the photobioreactor technologies are described. PMID:27142376

  4. Production of hydrogen from alcohols

    DOEpatents

    Deluga, Gregg A.; Schmidt, Lanny D.

    2007-08-14

    A process for producing hydrogen from ethanol or other alcohols. The alcohol, optionally in combination with water, is contacted with a catalyst comprising rhodium. The overall process is preferably carried out under autothermal conditions.

  5. Production of Hydrogen from Underground Coal Gasification

    DOEpatents

    Upadhye, Ravindra S.

    2008-10-07

    A system of obtaining hydrogen from a coal seam by providing a production well that extends into the coal seam; positioning a conduit in the production well leaving an annulus between the conduit and the coal gasification production well, the conduit having a wall; closing the annulus at the lower end to seal it from the coal gasification cavity and the syngas; providing at least a portion of the wall with a bifunctional membrane that serves the dual purpose of providing a catalyzing reaction and selectively allowing hydrogen to pass through the wall and into the annulus; and producing the hydrogen through the annulus.

  6. Photobiological production of hydrogen using cyanobacteria

    SciTech Connect

    Borthakur, D.; McKinley, K.R.; Bylina, E.J.

    1995-09-01

    Cyanobacteria are capable of generating hydrogen using sunlight and water. In both Spirulina and Anabaena, there is a soluble reversible hydrogenase that is involved in hydrogen evolution under anaerobic conditions in the dark. In addition, the nitrogen-fixing cyanobacterium Anabaena produces hydrogen as a by-product of nitrogen fixation. Most of this hydrogen is recaptured by a membrane-bound uptake hydrogenase present in Anabaena cells. Experiments have continued to develop a gene transfer system in Spirulina in preparation for improved hydrogen production via genetic manipulation of the reversible hydrogenase. We have identified and characterized four restriction enzymes in Spirulina and cloned the genes for two methylases that protect their own DNA from cleavage by restriction enzymes. We have also cloned and sequenced parts of hupB and hupM genes involved in the synthesis of uptake hydrogenase in Anabaena. Successful cloning of these hup genes represents an important and necessary step in our project because this will enable us to construct Anabaena strains with enhanced hydrogen production ability by disrupting the hup genes involved in hydrogen uptake. We are also setting up a bio-reactor to determine the amount of hydrogen released by different Spirulina and Anabaena strains under different physiological conditions.

  7. Coupling of exothermic and endothermic hydrogen storage materials

    NASA Astrophysics Data System (ADS)

    Brooks, Kriston P.; Bowden, Mark E.; Karkamkar, Abhijeet J.; Houghton, Adrian Y.; Autrey, S. Thomas

    2016-08-01

    Chemical hydrogen storage (CHS) materials are a high-storage-density alternative to the gaseous compressed hydrogen currently used to provide hydrogen for fuel cell vehicles. One of the challenges of CHS materials is addressing the energy barriers required to break the chemical bonds and release the hydrogen. Coupling CHS reactions that are endothermic and exothermic during dehydrogenation can improve onboard energy efficiency and thermal control for the system, making such materials viable. Acceptable coupling between reactions requires both thermodynamic and kinetic considerations. In this work, models were developed to predict the reaction enthalpy and rate required to achieve high conversions for both reactions based on experimental measurements. Modeling results show that the coupling efficiency of exothermic and endothermic reactions is more sensitive to the ratio of the exothermic and endothermic enthalpies than to the ratio of the rates of the two steps. Modeling results also show that a slower endothermic step rate is desirable to permit sufficient heating of the reactor by the exothermic step. We look at two examples of a sequential and parallel reaction scheme and provide some of the first published insight into the required temperature range to maximize the hydrogen release from 1,2-BN cyclohexane and indoline.

  8. Hydrogen production using ammonia borane

    SciTech Connect

    Hamilton, Charles W; Baker, R. Thomas; Semelsberger, Troy A; Shrestha, Roshan P

    2013-12-24

    Hydrogen ("H.sub.2") is produced when ammonia borane reacts with a catalyst complex of the formula L.sub.nM-X wherein M is a base metal such as iron, X is an anionic nitrogen- or phosphorus-based ligand or hydride, and L is a neutral ancillary ligand that is a neutral monodentate or polydentate ligand.

  9. Swine manure fermentation for hydrogen production.

    PubMed

    Zhu, Jun; Li, Yecong; Wu, Xiao; Miller, Curtis; Chen, Paul; Ruan, Roger

    2009-11-01

    Biohydrogen fermentation using liquid swine manure as substrate supplemented with glucose was investigated in this project. Experiments were conducted using a semi-continuously-fed fermenter (8L in total volume and 4 L in working volume) with varying pHs from 4.7 through 5.9 under controlled temperature (35+/-1 degrees C). The hydraulic retention time (HRT) tested include 16, 20, and 24h; however, in two pH conditions (5.0 and 5.3), an additional HRT of 12h was also tried. The experimental design combining HRT and pH provided insight on the fermenter performance in terms of hydrogen generation. The results indicated that both HRT and pH had profound influences on fermentative hydrogen productivity. A rising HRT would lead to greater variation in hydrogen concentration in the offgas and the best HRT was found to be 16 h for the fermenter in this study. The best pH value in correspondence to the highest hydrogen generation was revealed to be 5.0 among all the pHs studied. There was no obvious inhibition on hydrogen production by methanogenesis when methane content in the offgas was lower than 2%. Otherwise, an inverse linear relationship between hydrogen and methane content was observed with a correlation coefficient of 0.9699. Therefore, to increase hydrogen content in the offgas, methane production has to be limited to below 2%. PMID:19157863

  10. Hydrolysis reactor for hydrogen production

    SciTech Connect

    Davis, Thomas A.; Matthews, Michael A.

    2012-12-04

    In accordance with certain embodiments of the present disclosure, a method for hydrolysis of a chemical hydride is provided. The method includes adding a chemical hydride to a reaction chamber and exposing the chemical hydride in the reaction chamber to a temperature of at least about 100.degree. C. in the presence of water and in the absence of an acid or a heterogeneous catalyst, wherein the chemical hydride undergoes hydrolysis to form hydrogen gas and a byproduct material.

  11. Running coupling corrections to inclusive gluon production

    NASA Astrophysics Data System (ADS)

    Horowitz, W. A.; Kovchegov, Y. V.

    2011-12-01

    We calculate running coupling corrections for the lowest-order gluon production cross section in high energy hadronic and nuclear scattering using the BLM scale-setting prescription. At leading order, there are three powers of fixed coupling; in our final answer, these three couplings are replaced by seven factors of running coupling: five in the numerator and two in the denominator, forming a 'septumvirate' of running couplings, analogous to the 'triumvirate' of running couplings found earlier for the small-x BFKL/BK/JIMWLK evolution equations. It is interesting to note that the two running couplings in the denominator of the 'septumvirate' run with complex-valued momentum scales, which are complex conjugates of each other, such that the production cross section is indeed real. We use our lowest-order result to conjecture how running coupling corrections may enter the full fixed-coupling kT-factorization formula for gluon production which includes nonlinear small-x evolution.

  12. ON-SITE APPLICABILITY OF HYDROGEN PEROXIDE PRODUCING MICROBIAL ELECTROCHEMICAL CELLS COUPLED WITH UV IN WASTEWATER DISINFECTION STUDY

    EPA Science Inventory

    There is an increased interest in the application of microbial electrochemical cell (MEC) for the recovery of value-added products such as hydrogen gas and hydrogen peroxide (H2O2) from wastewater. H2O2 has strong oxidation capability and produces hydroxyl radicals when coupled w...

  13. Low-cost process for hydrogen production

    DOEpatents

    Cha, Chang Y.; Bauer, Hans F.; Grimes, Robert W.

    1993-01-01

    A method is provided for producing hydrogen and carbon black from hydrocarbon gases comprising mixing the hydrocarbon gases with a source of carbon and applying radiofrequency energy to the mixture. The hydrocarbon gases and the carbon can both be the products of gasification of coal, particularly the mild gasification of coal. A method is also provided for producing hydrogen an carbon monoxide by treating a mixture of hydrocarbon gases and steam with radio-frequency energy.

  14. Low-cost process for hydrogen production

    DOEpatents

    Cha, C.H.; Bauer, H.F.; Grimes, R.W.

    1993-03-30

    A method is provided for producing hydrogen and carbon black from hydrocarbon gases comprising mixing the hydrocarbon gases with a source of carbon and applying radiofrequency energy to the mixture. The hydrocarbon gases and the carbon can both be the products of gasification of coal, particularly the mild gasification of coal. A method is also provided for producing hydrogen and carbon monoxide by treating a mixture of hydrocarbon gases and steam with radio-frequency energy.

  15. Photoelectrochemical Hydrogen Production - Final Report

    SciTech Connect

    Miller, E.L.; Marsen, B.; Paluselli, D.; Rocheleau, R.

    2004-11-17

    The scope of this photoelectrochemical hydrogen research project is defined by multijunction photoelectrode concepts for solar-powered water splitting, with the goal of efficient, stable, and economic operation. From an initial selection of several planar photoelectrode designs, the Hybrid Photoelectrode (HPE) has been identified as the most promising candidate technology. This photoelectrode consists of a photoelectrochemical (PEC) junction and a solid-state photovoltaic (PV) junction. Immersed in aqueous electrolyte and exposed to sunlight, these two junctions provide the necessary voltage to split water into hydrogen and oxygen gas. The efficiency of the conversion process is determined by the performance of the PEC- and the PV-junctions and on their spectral match. Based on their stability and cost effectiveness, iron oxide (Fe2O3) and tungsten oxide (WO3) films have been studied and developed as candidate semiconductor materials for the PEC junction (photoanode). High-temperature synthesis methods, as reported for some high-performance metal oxides, have been found incompatible with multijunction device fabrication. A low-temperature reactive sputtering process has been developed instead. In the parameter space investigated so far, the optoelectronic properties of WO3 films were superior to those of Fe2O3 films, which showed high recombination of photo-generated carriers. For the PV-junction, amorphous-silicon-based multijunction devices have been studied. Tandem junctions were preferred over triple junctions for better stability and spectral matching with the PEC junction. Based on a tandem a-SiGe/a-SiGe device and a tungsten trioxide film, a prototype hybrid photoelectrode has been demonstrated at 0.7% solar-to-hydrogen (STH) conversion efficiency. The PEC junction performance has been identified as the most critical element for higher-efficiency devices. Research into sputter-deposited tungsten trioxide films has yielded samples with higher photocurrents of

  16. Systematic Discrimination of Advanced Hydrogen Production Technologies

    SciTech Connect

    Charles V. Park; Michael W. Patterson

    2010-07-01

    The U.S. Department of Energy, in concert with industry, is developing a high-temperature gas-cooled reactor at the Idaho National Laboratory (INL) to demonstrate high temperature heat applications to produce hydrogen and electricity or to support other industrial applications. A key part of this program is the production of hydrogen from water that would significantly reduce carbon emissions compared to current production using natural gas. In 2009 the INL led the methodical evaluation of promising advanced hydrogen production technologies in order to focus future resources on the most viable processes. This paper describes how the evaluation process was systematically planned and executed. As a result, High-Temperature Steam Electrolysis was selected as the most viable near-term technology to deploy as a part of the Next Generation Nuclear Plant Project.

  17. Analytical approaches to photobiological hydrogen production in unicellular green algae.

    PubMed

    Hemschemeier, Anja; Melis, Anastasios; Happe, Thomas

    2009-01-01

    Several species of unicellular green algae, such as the model green microalga Chlamydomonas reinhardtii, can operate under either aerobic photosynthesis or anaerobic metabolism conditions. A particularly interesting metabolic condition is that of "anaerobic oxygenic photosynthesis", whereby photosynthetically generated oxygen is consumed by the cell's own respiration, causing anaerobiosis in the culture in the light, and induction of the cellular "hydrogen metabolism" process. The latter entails an alternative photosynthetic electron transport pathway, through the oxygen-sensitive FeFe-hydrogenase, leading to the light-dependent generation of molecular hydrogen in the chloroplast. The FeFe-hydrogenase is coupled to the reducing site of photosystem-I via ferredoxin and is employed as an electron-pressure valve, through which electrons are dissipated, thus permitting a sustained electron transport in the thylakoid membrane of photosynthesis. This hydrogen gas generating process in the cells offers testimony to the unique photosynthetic metabolism that can be found in many species of green microalgae. Moreover, it has attracted interest by the biotechnology and bioenergy sectors, as it promises utilization of green microalgae and the process of photosynthesis in renewable energy production. This article provides an overview of the principles of photobiological hydrogen production in microalgae and addresses in detail the process of induction and analysis of the hydrogen metabolism in the cells. Furthermore, methods are discussed by which the interaction of photosynthesis, respiration, cellular metabolism, and H(2) production in Chlamydomonas can be monitored and regulated. PMID:19291418

  18. Method for the enzymatic production of hydrogen

    DOEpatents

    Woodward, Jonathan; Mattingly, Susan M.

    1999-01-01

    The present invention is an enzymatic method for producing hydrogen comprising the steps of: a) forming a reaction mixture within a reaction vessel comprising a substrate capable of undergoing oxidation within a catabolic reaction, such as glucose, galactose, xylose, mannose, sucrose, lactose, cellulose, xylan and starch. The reaction mixture further comprises an amount of glucose dehydrogenase in an amount sufficient to catalyze the oxidation of the substrate, an amount of hydrogenase sufficient to catalyze an electron-requiring reaction wherein a stoichiometric yield of hydrogen is produced, an amount of pH buffer in an amount sufficient to provide an environment that allows the hydrogenase and the glucose dehydrogenase to retain sufficient activity for the production of hydrogen to occur and also comprising an amount of nicotinamide adenine dinucleotide phosphate sufficient to transfer electrons from the catabolic reaction to the electron-requiring reaction; b) heating the reaction mixture at a temperature sufficient for glucose dehydrogenase and the hydrogenase to retain sufficient activity and sufficient for the production of hydrogen to occur, and heating for a period of time that continues until the hydrogen is no longer produced by the reaction mixture, wherein the catabolic reaction and the electron-requiring reactions have rates of reaction dependent upon the temperature; and c) detecting the hydrogen produced from the reaction mixture.

  19. Method for the enzymatic production of hydrogen

    DOEpatents

    Woodward, J.; Mattingly, S.M.

    1999-08-24

    The present invention is an enzymatic method for producing hydrogen comprising the steps of: (a) forming a reaction mixture within a reaction vessel comprising a substrate capable of undergoing oxidation within a catabolic reaction, such as glucose, galactose, xylose, mannose, sucrose, lactose, cellulose, xylan and starch; the reaction mixture also comprising an amount of glucose dehydrogenase in an amount sufficient to catalyze the oxidation of the substrate, an amount of hydrogenase sufficient to catalyze an electron-requiring reaction wherein a stoichiometric yield of hydrogen is produced, an amount of pH buffer in an amount sufficient to provide an environment that allows the hydrogenase and the glucose dehydrogenase to retain sufficient activity for the production of hydrogen to occur and also comprising an amount of nicotinamide adenine dinucleotide phosphate sufficient to transfer electrons from the catabolic reaction to the electron-requiring reaction; (b) heating the reaction mixture at a temperature sufficient for glucose dehydrogenase and the hydrogenase to retain sufficient activity and sufficient for the production of hydrogen to occur, and heating for a period of time that continues until the hydrogen is no longer produced by the reaction mixture, wherein the catabolic reaction and the electron-requiring reactions have rates of reaction dependent upon the temperature; and (c) detecting the hydrogen produced from the reaction mixture. 8 figs.

  20. Enzymatic production of hydrogen from glucose

    SciTech Connect

    Woodward, J.; Mattingly, S.M.

    1995-06-01

    The objective of this research is to optimize conditions for the enzymatic production of hydrogen gas from biomass-derived glucose. This new project is funded at 0.5 PY level of effort for FY 1995. The rationale for the work is that cellulose is, potentially, a vast source of hydrogen and that enzymes offer a specific and efficient method for its extraction with minimal environmental impact. This work is related to the overall hydrogen program goal of technology development and validation. The approach is based on knowledge that glucose is oxidized by the NADP{sup +} requiring enzyme glucose dehydrogenase (GDH) and that the resulting NADPH can donate its electrons to hydrogenase (H{sub 2}ase) which catalyzes the evolution of H{sub 2}. Thus hydrogen production from glucose was achieved using calf liver GDH and Pyrococcus furiosus H{sub 2}ase yielding 17% of theoretical maximum expected. The cofactor NADP{sup +} for this reaction was regenerated and recycled. Current and future work includes understanding the rate limiting steps of this process and the stabilization/immobilization of the enzymes for long term hydrogen production. Cooperative interactions with the Universities of Georgia and Bath for obtaining thermally stable enzymes are underway.

  1. Enzymatic production of hydrogen from glucose

    NASA Astrophysics Data System (ADS)

    Woodward, J.; Mattingly, S. M.

    The objective of this research is to optimize conditions for the enzymatic production of hydrogen gas from biomass-derived glucose. This new project is funded at 0.5 PY level of effort for FY 1995. The rationale for the work is that cellulose is, potentially, a vast source of hydrogen and that enzymes offer a specific and efficient method for its extraction with minimal environmental impact. This work is related to the overall hydrogen program goal of technology development and validation. The approach is based on knowledge that glucose is oxidized by the NADP(sup +) requiring enzyme glucose dehydrogenase (GDH) and that the resulting NADPH can donate its electrons to hydrogenase (H2ase) which catalyzes the evolution of H2. Thus hydrogen production from glucose was achieved using calf liver GDH and Pyrococcus furiosus H2ase yielding 17% of theoretical maximum expected. The cofactor NADP(sup +) for this reaction was regenerated and recycled. Current and future work includes understanding the rate limiting steps of this process and the stabilization/immobilization of the enzymes for long term hydrogen production. Cooperative interactions with the Universities of Georgia and Bath for obtaining thermally sta

  2. Catalytic carbon membranes for hydrogen production

    SciTech Connect

    Damle, A.S.; Gangwal, S.K.

    1992-01-01

    Commercial carbon composite microfiltration membranes may be modified for gas separation applications by providing a gas separation layer with pores in the 1- to 10-nm range. Several organic polymeric precursors and techniques for depositing a suitable layer were investigated in this project. The in situ polymerization technique was found to be the most promising, and pure component permeation tests with membrane samples prepared with this technique indicated Knudsen diffusion behavior. The gas separation factors obtained by mixed-gas permeation tests were found to depend strongly on gas temperature and pressure indicating significant viscous flow at high-pressure conditions. The modified membranes were used to carry out simultaneous water gas shift reaction and product hydrogen separation. These tests indicated increasing CO conversions with increasing hydrogen separation. A simple process model was developed to simulate a catalytic membrane reactor. A number of simulations were carried out to identify operating conditions leading to product hydrogen concentrations over 90 percent. (VC)

  3. Methanol Conversion for the Production of Hydrogen

    SciTech Connect

    Taylor, C.E.; Howard, B.H.; Myers, C.R.

    2007-12-19

    The production of methanol from a variety of biomass sources is gaining favor. Several facilities exist or are under construction throughout the world to convert biogenerated methane from the decomposition of biomass into methanol using conventional steam reforming. Methanol is an excellent liquid-hydrogen-transport medium. When powered by hydrogen, fuel cells have the potential to be the cleanest and most efficient source of electricity for use by the automotive industry. On-board reforming of liquid hydrocarbon fuels is a viable alternative to the storage of compressed hydrogen. A problem in current reforming processes is the quantity of carbon monoxide (CO) produced. Our research is geared toward circumventing the production of carbon monoxide in methanol reforming through the development of novel reforming catalysts. By modifying a copper-based catalyst, we have produced several catalysts that retain their activity and high surface area after extended methanol reforming runs both with and without the addition of steam.

  4. Method for the continuous production of hydrogen

    DOEpatents

    Getty, John Paul; Orr, Mark T.; Woodward, Jonathan

    2002-01-01

    The present invention is a method for the continuous production of hydrogen. The present method comprises reacting a metal catalyst with a degassed aqueous organic acid solution within a reaction vessel under anaerobic conditions at a constant temperature of .ltoreq.80.degree. C. and at a pH ranging from about 4 to about 9. The reaction forms a metal oxide when the metal catalyst reacts with the water component of the organic acid solution while generating hydrogen, then the organic acid solution reduces the metal oxide thereby regenerating the metal catalyst and producing water, thus permitting the oxidation and reduction to reoccur in a continual reaction cycle. The present method also allows the continuous production of hydrogen to be sustained by feeding the reaction with a continuous supply of degassed aqueous organic acid solution.

  5. Reactors Save Energy, Costs for Hydrogen Production

    NASA Technical Reports Server (NTRS)

    2014-01-01

    While examining fuel-reforming technology for fuel cells onboard aircraft, Glenn Research Center partnered with Garrettsville, Ohio-based Catacel Corporation through the Glenn Alliance Technology Exchange program and a Space Act Agreement. Catacel developed a stackable structural reactor that is now employed for commercial hydrogen production and results in energy savings of about 20 percent.

  6. Enzymatic Hydrogen Production from Starch and Water

    SciTech Connect

    Zhang, Y.-H. Percival; Evans, Barbara R; Mielenz, Jonathan R; Hopkins, Robert C.; Adams, Michael W. W.

    2007-01-01

    A novel enzymatic reaction was conducted for producing hydrogen from starch and water at 30oC. The overall reaction comprised of 13 enzymes, 1 cofactor (NADP+), and phosphate was driven by energy stored in carbohydrate starch according to the overall stoichiometry stoichiometric reaction of C6H10O5 (l) + 7 H2O (l) --> 12 H2 (g) + 6 CO2 (g). It is spontaneous and unidirectional because of negative Gibbs free energy and the removal of gaseous products from the aqueous reaction solution. With technology improvement and integration with fuel cells, this technology would be suitable for mobile applications and also solve the challenges associated with hydrogen storage, distribution, and infrastructure in a hydrogen economy.

  7. Photosynthetic hydrogen and oxygen production - Kinetic studies

    NASA Astrophysics Data System (ADS)

    Greenbaum, E.

    1982-01-01

    The simultaneous photoproduction of hydrogen and oxygen was measured in a study of the steady-state turnover times of two biological systems, by driving them into the steady state with repetitive, single-turnover flash illumination. The systems were: (1) in vitro, isolated chloroplasts, ferredoxin and hydrogenase; and (2) the anaerobically-adapted green alga Chlamydomonas reinhardtii. It is found that the turnover times for production of both oxygen and hydrogen in photosynthetic water splitting are in milliseconds, and either equal to, or less than, the turnover time for carbon dioxide reduction in intact algal cells. There is therefore mutual compatibility between hydrogen and oxygen turnover times, and partial compatibility with the excitation rate of the photosynthetic reaction centers under solar irradiation conditions.

  8. Catalytic glycerol steam reforming for hydrogen production

    SciTech Connect

    Dan, Monica Mihet, Maria Lazar, Mihaela D.

    2015-12-23

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H{sub 2}. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al{sub 2}O{sub 3}. The catalyst was prepared by wet impregnation method and characterized through different methods: N{sub 2} adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H{sub 2}, CH{sub 4}, CO, CO{sub 2}. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H{sub 2}O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  9. Catalytic glycerol steam reforming for hydrogen production

    NASA Astrophysics Data System (ADS)

    Dan, Monica; Mihet, Maria; Lazar, Mihaela D.

    2015-12-01

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H2. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al2O3. The catalyst was prepared by wet impregnation method and characterized through different methods: N2 adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H2, CH4, CO, CO2. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H2O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  10. Self-assembling hydrogel scaffolds for photocatalytic hydrogen production

    NASA Astrophysics Data System (ADS)

    Weingarten, Adam S.; Kazantsev, Roman V.; Palmer, Liam C.; McClendon, Mark; Koltonow, Andrew R.; Samuel, Amanda P. S.; Kiebala, Derek J.; Wasielewski, Michael R.; Stupp, Samuel I.

    2014-11-01

    Integration into a soft material of all the molecular components necessary to generate storable fuels is an interesting target in supramolecular chemistry. The concept is inspired by the internal structure of photosynthetic organelles, such as plant chloroplasts, which colocalize molecules involved in light absorption, charge transport and catalysis to create chemical bonds using light energy. We report here on the light-driven production of hydrogen inside a hydrogel scaffold built by the supramolecular self-assembly of a perylene monoimide amphiphile. The charged ribbons formed can electrostatically attract a nickel-based catalyst, and electrolyte screening promotes gelation. We found the emergent phenomenon that screening by the catalyst or the electrolytes led to two-dimensional crystallization of the chromophore assemblies and enhanced the electronic coupling among the molecules. Photocatalytic production of hydrogen is observed in the three-dimensional environment of the hydrogel scaffold and the material is easily placed on surfaces or in the pores of solid supports.

  11. Renewable hydrogen production by photosynthetic water splitting

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1998-06-01

    This mission-oriented research project is focused on the production of renewable hydrogen. The authors have demonstrated that certain unicellular green algae are capable of sustained simultaneous photoproduction of hydrogen and oxygen by light-activated photosynthetic water splitting. It is the goal of this project to develop a practical chemical engineering system for the development of an economic process that can be used to produce renewable hydrogen. There are several fundamental problems that need to be solved before the application of this scientific knowledge can be applied to the development a practical process: (I) maximizing net thermodynamic conversion efficiency of light energy into hydrogen energy, (2) development of oxygen-sensitive hydrogenase-containing mutants, and (3) development of bioreactors that can be used in a real-world chemical engineering process. The authors are addressing each of these problems here at ORNL and in collaboration with their research colleagues at the National Renewable Energy Laboratory, the University of California, Berkeley, and the University of Hawaii. This year the authors have focused on item 1 above. In particular, they have focused on the question of how many light reactions are required to split water to molecular hydrogen and oxygen.

  12. Assessment of biological Hydrogen production processes: A review

    NASA Astrophysics Data System (ADS)

    Najafpour, G. D.; Shahavi, M. H.; Neshat, S. A.

    2016-06-01

    Energy crisis created a special attention on renewable energy sources. Among these sources; hydrogen through biological processes is well-known as the most suitable and renewable energy sources. In terms of process yield, hydrogen production from various sources was evaluated. A summary of microorganisms as potential hydrogen producers discussed along with advantages and disadvantages of several bioprocesses. The pathway of photo-synthetic and dark fermentative organisms was discussed. In fact, the active enzymes involved in performance of biological processes for hydrogen generation were identified and their special functionalities were discussed. The influential factors affecting on hydrogen production were known as enzymes assisting liberation specific enzymes such as nitrogenase, hydrogenase and uptake hydrogenase. These enzymes were quite effective in reduction of proton and form active molecular hydrogen. Several types of photosynthetic systems were evaluated with intension of maximum hydrogen productivities. In addition dark fermentative and light intensities on hydrogen productions were evaluated. The hydrogen productivities of efficient hydrogen producing strains were evaluated.

  13. Thermochemical hydrogen production based on magnetic fusion

    SciTech Connect

    Krikorian, O.H.; Brown, L.C.

    1982-06-10

    Conceptual design studies have been carried out on an integrated fusion/chemical plant system using a Tandem Mirror Reactor fusion energy source to drive the General Atomic Sulfur-Iodine Water-Splitting Cycle and produce hydrogen as a future feedstock for synthetic fuels. Blanket design studies for the Tandem Mirror Reactor show that several design alternatives are available for providing heat at sufficiently high temperatures to drive the General Atomic Cycle. The concept of a Joule-boosted decomposer is introduced in one of the systems investigated to provide heat electrically for the highest temperature step in the cycle (the SO/sub 3/ decomposition step), and thus lower blanket design requirements and costs. Flowsheeting and conceptual process designs have been developed for a complete fusion-driven hydrogen plant, and the information has been used to develop a plot plan for the plant and to estimate hydrogen production costs. Both public and private utility financing approaches have been used to obtain hydrogen production costs of $12-14/GJ based on July 1980 dollars.

  14. Electrolysis Production of Hydrogen from Wind and Hydropower Workshop Proceedings

    SciTech Connect

    2003-09-01

    This document summarizes the opportunities and challenges for low-cost renewable hydrogen production from wind and hydropower. The Workshop on Electrolysis Production of Hydrogen from Wind and Hydropower was held September 9-10, 2003.

  15. Startech Hydrogen Production Final Technical Report

    SciTech Connect

    Startech Engineering Department

    2007-11-27

    The assigned work scope includes the modification and utilization of the Plasma Converter System, Integration of a StarCell{trademark} Multistage Ceramic Membrane System (StarCell), and testing of the integrated systems towards DOE targets for gasification and membrane separation. Testing and evaluation was performed at the Startech Engineering and Demonstration Test Center in Bristol, CT. The Objectives of the program are as follows: (1) Characterize the performance of the integrated Plasma Converter and StarCell{trademark} Systems for hydrogen production and purification from abundant and inexpensive feedstocks; (2) Compare integrated hydrogen production performance to conventional technologies and DOE benchmarks; (3) Run pressure and temperature testing to baseline StarCell's performance; and (4) Determine the effect of process contaminants on the StarCell{trademark} system.

  16. Space-based bacterial production of hydrogen

    NASA Technical Reports Server (NTRS)

    Tennakoon, C. L.; Bhardwaj, R. C.; Bockris, J. O.; Henninger, D. L. (Principal Investigator)

    1994-01-01

    This paper deals with the electrochemical production of hydrogen by depolarizing the oxygen evolution reaction using human feces and urine, which contains 30-40% bacteria and yeast. The electroactivity of graphite, tungsten carbide, perovskite and RuO2-coated Ebonex (Ti4O7) as anode materials are compared. The scale-up of the process in a laboratory-scale three-dimensional packed bed cell is discussed.

  17. Photoelectrolytic production of hydrogen using semiconductor electrodes

    NASA Technical Reports Server (NTRS)

    Byvik, C. E.; Walker, G. H.

    1976-01-01

    Experimental data for the photoelectrolytic production of hydrogen using GaAs photoanodes was presented. Four types of GaAs anodes were investigated: polished GaAs, GaAs coated with gold, GaAs coated with silver, and GaAs coated with tin. The maximum measured efficiency using a tungsten light source was 8.9 percent for polished GaAs electrodes and 6.3 percent for tin coated GaAs electrodes.

  18. Solar-driven hydrogen production in green algae.

    PubMed

    Burgess, Steven J; Tamburic, Bojan; Zemichael, Fessehaye; Hellgardt, Klaus; Nixon, Peter J

    2011-01-01

    The twin problems of energy security and global warming make hydrogen an attractive alternative to traditional fossil fuels with its combustion resulting only in the release of water vapor. Biological hydrogen production represents a renewable source of the gas and can be performed by a diverse range of microorganisms from strict anaerobic bacteria to eukaryotic green algae. Compared to conventional methods for generating H(2), biological systems can operate at ambient temperatures and pressures without the need for rare metals and could potentially be coupled to a variety of biotechnological processes ranging from desalination and waste water treatment to pharmaceutical production. Photobiological hydrogen production by microalgae is particularly attractive as the main inputs for the process (water and solar energy) are plentiful. This chapter focuses on recent developments in solar-driven H(2) production in green algae with emphasis on the model organism Chlamydomonas reinhardtii. We review the current methods used to achieve sustained H(2) evolution and discuss possible approaches to improve H(2) yields, including the optimization of culturing conditions, reducing light-harvesting antennae and targeting auxiliary electron transport and fermentative pathways that compete with the hydrogenase for reductant. Finally, industrial scale-up is discussed in the context of photobioreactor design and the future prospects of the field are considered within the broader context of a biorefinery concept. PMID:21807246

  19. Hydrogen Production from Nuclear Energy via High Temperature Electrolysis

    SciTech Connect

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

    2006-04-01

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

  20. Photobiological hydrogen production and carbon dioxide sequestration

    NASA Astrophysics Data System (ADS)

    Berberoglu, Halil

    Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of

  1. Analysis of Hydrogen Production from Renewable Electricity Sources: Preprint

    SciTech Connect

    Levene, J. I.; Mann, M. K.; Margolis, R.; Milbrandt, A.

    2005-09-01

    To determine the potential for hydrogen production via renewable electricity sources, three aspects of the system are analyzed: a renewable hydrogen resource assessment, a cost analysis of hydrogen production via electrolysis, and the annual energy requirements of producing hydrogen for refueling. The results indicate that ample resources exist to produce transportation fuel from wind and solar power. However, hydrogen prices are highly dependent on electricity prices.

  2. Increasing Efficiency in Photoelectrochemical Hydrogen Production

    SciTech Connect

    Warren, S.; Turner, J.

    2002-01-01

    Photoelectrochemical hydrogen production promises to be a renewable, clean, and efficient way of storing the sun's energy for use in hydrogen-powered fuel cells. We use p-type Ga.51In.49P semiconductor (henceforth as GaInP2) to absorb solar energy and produce a photocurrent. When the semiconductor is immersed in water, the photocurrent can break down water into hydrogen and oxygen. However, before the GaInP2 can produce hydrogen and oxygen, the conduction band and the Fermi level of the semiconductor must overlap the water redox potentials. In an unmodified system, the conduction band and Fermi level of GaInP2 do not overlap the water redox potentials. When light shines on the semiconductor, electrons build up on the surface, shifting the bandedges and Fermi level further away from overlap of the water redox potentials. We report on surface treatments with metallated porphyrins and transition metals that suppress bandedge migration and allow bandedge overlap to occur. Coating ruthenium octaethylporphyrin carbonyl (RuOEP CO) on the GaInP2 surface shifted bandedges in the positive direction by 270 mV on average, allowing the bandedges to frequently overlap the water redox potentials. Coating the GaInP2 surface with RuCl3 catalyzed charge transfer from the semiconductor to the water, lessening bandedge migration under light irradiation. Future work will focus on the long-term surface stability of these new treatments and quantitative applications of porphyrins.

  3. Hydrogen Plasmas for Negative Ion Production

    SciTech Connect

    Pagano, D.; Gorse, C.; Capitelli, M.

    2005-05-16

    We have improved a zero-dimensional model, built to simulate the operating conditions in the excitation ('driver') region of a multicusp ion source optimized for negative ion production of great interest in thermonuclear applications. The new approach to couple heavy particle and electron kinetics is discussed.

  4. Integrated Ceramic Membrane System for Hydrogen Production

    SciTech Connect

    Schwartz, Joseph; Lim, Hankwon; Drnevich, Raymond

    2010-08-05

    Phase I was a technoeconomic feasibility study that defined the process scheme for the integrated ceramic membrane system for hydrogen production and determined the plan for Phase II. The hydrogen production system is comprised of an oxygen transport membrane (OTM) and a hydrogen transport membrane (HTM). Two process options were evaluated: 1) Integrated OTM-HTM reactor – in this configuration, the HTM was a ceramic proton conductor operating at temperatures up to 900°C, and 2) Sequential OTM and HTM reactors – in this configuration, the HTM was assumed to be a Pd alloy operating at less than 600°C. The analysis suggested that there are no technical issues related to either system that cannot be managed. The process with the sequential reactors was found to be more efficient, less expensive, and more likely to be commercialized in a shorter time than the single reactor. Therefore, Phase II focused on the sequential reactor system, specifically, the second stage, or the HTM portion. Work on the OTM portion was conducted in a separate program. Phase IIA began in February 2003. Candidate substrate materials and alloys were identified and porous ceramic tubes were produced and coated with Pd. Much effort was made to develop porous substrates with reasonable pore sizes suitable for Pd alloy coating. The second generation of tubes showed some improvement in pore size control, but this was not enough to get a viable membrane. Further improvements were made to the porous ceramic tube manufacturing process. When a support tube was successfully coated, the membrane was tested to determine the hydrogen flux. The results from all these tests were used to update the technoeconomic analysis from Phase I to confirm that the sequential membrane reactor system can potentially be a low-cost hydrogen supply option when using an existing membrane on a larger scale. Phase IIB began in October 2004 and focused on demonstrating an integrated HTM/water gas shift (WGS) reactor to

  5. A Technical and Economic Review of Solar Hydrogen Production Technologies

    ERIC Educational Resources Information Center

    Wilhelm, Erik; Fowler, Michael

    2006-01-01

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

  6. Extremophile mediated hydrogen production for hydrogenation of substrates in aqueous media

    NASA Astrophysics Data System (ADS)

    Anjom, Mouzhgun

    Catalytic hydrogenation reactions are pervasive throughout our economy, from production of margarine as food, liquid fuels for transportation and chiral drugs such as L-DOPA. H2 production from non-fossil fuel feedstocks is highly desirable for transition to the "Hydrogen Economy". Also, the rates of hydrogenation reactions that involve a substrate, H 2 gas and a catalyst are often limited by the solubility of H2 in solvent. The present research thus envisioned designing water-soluble catalysts that could effectively utilize biologically produced H2 in a coupled system to hydrogenate substrates in homogeneous mode (two-phase system). Biological production of H2 as an end product or byproduct of the metabolism of organisms that operate under strict anaerobic conditions has been proposed. However, contrary to what was previously observed, Thermotoga neapolitana, belonging to the order of Thermotogales efficiently produces H2 gas under microaerobic conditions (Van Ooteghem et al. 2004). For H2 production by T. neapolitana in the bacterial growth medium (DSM 5068) at an optimum temperature of 70 C, our results in batch mode show that: (1) H2 was produced from glucose though with 16% efficiency, the rest goes to biomass production, (2) H2 gas was produced even when the cultures were inoculated under microaerobic conditions (up to 8% (v/v) O2) suggesting a protective mechanism for one or more [Fe-Fe] hydrogenases in T. neapolitana, (3) H2 production was pH dependent but addition of simple, non-toxic physiological buffering additives such as Methylene succinic acid increased H2 production and (4) H2 production rate varied linearly in the 100--6800 kPa pressure range. We then screened various water-soluble metal catalysts in batch mode and selected the RhCl3.3H2O/TPPTS (TPPTS is a water-soluble ligand) system that achieved 86% hydrogenation of Methylene succinic acid (an olefin) in an aqueous medium pressurized with preformed H2. When water was replaced with the DSM 5068

  7. Resource Assessment for Hydrogen Production: Hydrogen Production Potential from Fossil and Renewable Energy Resources

    SciTech Connect

    Melaina, M.; Penev, M.; Heimiller, D.

    2013-09-01

    This study examines the energy resources required to produce 4-10 million metric tonnes of domestic, low-carbon hydrogen in order to fuel approximately 20-50 million fuel cell electric vehicles. These projected energy resource requirements are compared to current consumption levels, projected 2040 business as usual consumptions levels, and projected 2040 consumption levels within a carbonconstrained future for the following energy resources: coal (assuming carbon capture and storage), natural gas, nuclear (uranium), biomass, wind (on- and offshore), and solar (photovoltaics and concentrating solar power). The analysis framework builds upon previous analysis results estimating hydrogen production potentials and drawing comparisons with economy-wide resource production projections

  8. Hydrogen Production via a Commercially Ready

    SciTech Connect

    Paul K. T. Liu

    2007-03-31

    The commercial stainless steel (SS) porous substrate (i.e., ZrO{sub 2}/SS from Pall Corp.) was evaluated comprehensively as substrate for the deposition of the CMS membrane for hydrogen separation. The CMS membrane synthesis protocol we developed originally for the ceramic substrate was adapted here for the stainless steel substrate. Unfortunately no successful hydrogen selective membranes had been prepared during Yr I of this project. The characterization results indicated two major sources of defect present in the stainless steel substrate, which may contribute to the poor CMS membrane quality. They include (i) leaking from the crimp boundary of the stainless steel substrate, and (ii) the delamination of the ZrO{sub 2} layer deposited on the stainless steel substrate during CMS membrane preparation. Recently a new batch of the stainless steel substrate (as the 2nd generation product) was received from the supplier. Our characterization results confirm that leaking of the crimp boundary no longer exists. The thermal stability of the ZrO{sub 2}/stainless steel substrate under the CMS membrane preparation condition will be evaluated during the remaining period of the project. Our goal here is to determine the suitability of the 2nd generation ZrO{sub 2}/SS as substrate for the preparation of the CMS membrane for hydrogen separation by the end of this project period.

  9. Hydrogen slush production with a large auger

    NASA Technical Reports Server (NTRS)

    Daney, D. E.; Arp, V. D.; Voth, R. O.

    1990-01-01

    The design and construction of a 178-mm-diameter auger-type hydrogen slush generator are described. A supercritical helium flow loop, which simulates the performance of a helium refrigerator, cools the generator. The coolant temperature varies down to 5 K and the flow varies about the 1.4 L/s (3 cfm) design point. The computer model of the auger-type generator shows that coolant temperature and auger speed have the greatest influence on slush production rate, although coolant flow rate and auger radial clearance are also important.

  10. Research of advanced electrolytic hydrogen production

    NASA Astrophysics Data System (ADS)

    Isaacs, H. S.; Yang, C. Y.; McBreen, J.

    1982-02-01

    Research on advanced electrolytic hydrogen production consisted of two areas. One was the development of an electrochemical method for investigation of the solid polymer electrolyte (SPE) electrocatalyst interface, the other was the development of stable photoanodes for photodecomposition of water by coating low barrier n type semiconductor with a thin film of n type TiO2. By using various types of contact electrodes on SPE membranes, it was possible to use modern electrochemical techniques to investigate the SPE electrocatalyst interface under conditions simulating electrolyzer operation. Low barrier heterojunctions of thin films of n type TiO2 on n type Fe2O3 were successfully demonstrated.

  11. Hydrogen Production in the U.S. and Worldwide - 2013

    SciTech Connect

    Brown, Daryl R.

    2015-04-01

    This article describes the different categories of hydrogen production (captive, by-product, and merchant) and presents production data for 2013 by industry within these categories. Merchant production data is provided for the top-four industrial gas companies.

  12. Production of hydrogen from municipal solid waste

    SciTech Connect

    Coleman, S.L.

    1995-11-01

    The Gasification of Municipal Solid Waste (MSW) includes gasification and the process for producing a gasificable slurry from raw MSW by using high pressures of steam. A potential energy source, MSW is a composite of organic materials such as: paper, wood, food waste, etc. There are different paper grades producing different results with low-quality paper forming better slurries than high-quality papers; making MSW a difficult feedstock for gasification. The objective of the bench-scale laboratory work has been to establish operating conditions for a hydrothermal pre-processing scheme for municipal solid waste (MSW) that produces a good slurry product that can be pumped and atomized to the gasifier for the production of hydrogen. Batch reactors are used to determine product yields as a function of hydrothermal treatment conditions. Various ratios of water-to-paper were used to find out solid product, gas product, and soluble product yields of MSW. Experimental conditions covered were temperature, time, and water to feed ratio. Temperature had the strongest effect on product yields.

  13. 40 CFR 415.410 - Applicability; description of the hydrogen production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrogen production subcategory. 415.410 Section 415.410 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Hydrogen Production Subcategory § 415.410 Applicability; description of the hydrogen production... hydrogen as a refinery by-product....

  14. 40 CFR 415.410 - Applicability; description of the hydrogen production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrogen production subcategory. 415.410 Section 415.410 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Hydrogen Production Subcategory § 415.410 Applicability; description of the hydrogen production... hydrogen as a refinery by-product....

  15. 40 CFR 415.410 - Applicability; description of the hydrogen production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrogen production subcategory. 415.410 Section 415.410 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Hydrogen Production Subcategory § 415.410 Applicability; description of the hydrogen production... hydrogen as a refinery by-product....

  16. 40 CFR 415.410 - Applicability; description of the hydrogen production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hydrogen production subcategory. 415.410 Section 415.410 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Hydrogen Production Subcategory § 415.410 Applicability; description of the hydrogen production... hydrogen as a refinery by-product....

  17. 40 CFR 415.410 - Applicability; description of the hydrogen production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrogen production subcategory. 415.410 Section 415.410 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Hydrogen Production Subcategory § 415.410 Applicability; description of the hydrogen production... hydrogen as a refinery by-product....

  18. Coupled molybdenum carbide and reduced graphene oxide electrocatalysts for efficient hydrogen evolution

    PubMed Central

    Li, Ji-Sen; Wang, Yu; Liu, Chun-Hui; Li, Shun-Li; Wang, Yu-Guang; Dong, Long-Zhang; Dai, Zhi-Hui; Li, Ya-Fei; Lan, Ya-Qian

    2016-01-01

    Electrochemical water splitting is one of the most economical and sustainable methods for large-scale hydrogen production. However, the development of low-cost and earth-abundant non-noble-metal catalysts for the hydrogen evolution reaction remains a challenge. Here we report a two-dimensional coupled hybrid of molybdenum carbide and reduced graphene oxide with a ternary polyoxometalate-polypyrrole/reduced graphene oxide nanocomposite as a precursor. The hybrid exhibits outstanding electrocatalytic activity for the hydrogen evolution reaction and excellent stability in acidic media, which is, to the best of our knowledge, the best among these reported non-noble-metal catalysts. Theoretical calculations on the basis of density functional theory reveal that the active sites for hydrogen evolution stem from the pyridinic nitrogens, as well as the carbon atoms, in the graphene. In a proof-of-concept trial, an electrocatalyst for hydrogen evolution is fabricated, which may open new avenues for the design of nanomaterials utilizing POMs/conducting polymer/reduced-graphene oxide nanocomposites. PMID:27032372

  19. Coupled molybdenum carbide and reduced graphene oxide electrocatalysts for efficient hydrogen evolution

    NASA Astrophysics Data System (ADS)

    Li, Ji-Sen; Wang, Yu; Liu, Chun-Hui; Li, Shun-Li; Wang, Yu-Guang; Dong, Long-Zhang; Dai, Zhi-Hui; Li, Ya-Fei; Lan, Ya-Qian

    2016-04-01

    Electrochemical water splitting is one of the most economical and sustainable methods for large-scale hydrogen production. However, the development of low-cost and earth-abundant non-noble-metal catalysts for the hydrogen evolution reaction remains a challenge. Here we report a two-dimensional coupled hybrid of molybdenum carbide and reduced graphene oxide with a ternary polyoxometalate-polypyrrole/reduced graphene oxide nanocomposite as a precursor. The hybrid exhibits outstanding electrocatalytic activity for the hydrogen evolution reaction and excellent stability in acidic media, which is, to the best of our knowledge, the best among these reported non-noble-metal catalysts. Theoretical calculations on the basis of density functional theory reveal that the active sites for hydrogen evolution stem from the pyridinic nitrogens, as well as the carbon atoms, in the graphene. In a proof-of-concept trial, an electrocatalyst for hydrogen evolution is fabricated, which may open new avenues for the design of nanomaterials utilizing POMs/conducting polymer/reduced-graphene oxide nanocomposites.

  20. Coupled molybdenum carbide and reduced graphene oxide electrocatalysts for efficient hydrogen evolution.

    PubMed

    Li, Ji-Sen; Wang, Yu; Liu, Chun-Hui; Li, Shun-Li; Wang, Yu-Guang; Dong, Long-Zhang; Dai, Zhi-Hui; Li, Ya-Fei; Lan, Ya-Qian

    2016-01-01

    Electrochemical water splitting is one of the most economical and sustainable methods for large-scale hydrogen production. However, the development of low-cost and earth-abundant non-noble-metal catalysts for the hydrogen evolution reaction remains a challenge. Here we report a two-dimensional coupled hybrid of molybdenum carbide and reduced graphene oxide with a ternary polyoxometalate-polypyrrole/reduced graphene oxide nanocomposite as a precursor. The hybrid exhibits outstanding electrocatalytic activity for the hydrogen evolution reaction and excellent stability in acidic media, which is, to the best of our knowledge, the best among these reported non-noble-metal catalysts. Theoretical calculations on the basis of density functional theory reveal that the active sites for hydrogen evolution stem from the pyridinic nitrogens, as well as the carbon atoms, in the graphene. In a proof-of-concept trial, an electrocatalyst for hydrogen evolution is fabricated, which may open new avenues for the design of nanomaterials utilizing POMs/conducting polymer/reduced-graphene oxide nanocomposites. PMID:27032372

  1. Plasma processing methods for hydrogen production

    NASA Astrophysics Data System (ADS)

    Mizeraczyk, Jerzy; Jasiński, Mariusz

    2016-08-01

    In the future a transfer from the fossil fuel-based economy to hydrogen-based economy is expected. Therefore the development of systems for efficient H2 production becomes important. The several conventional methods of mass-scale (or central) H2 production (methane, natural gas and higher hydrocarbons reforming, coal gasification reforming) are well developed and their costs of H2 production are acceptable. However, due to the H2 transport and storage problems the small-scale (distributed) technologies for H2 production are demanded. However, these new technologies have to meet the requirement of producing H2 at a production cost of (1-2)/kg(H2) (or 60 g(H2)/kWh) by 2020 (the U.S. Department of Energy's target). Recently several plasma methods have been proposed for the small-scale H2 production. The most promising plasmas for this purpose seems to be those generated by gliding, plasmatron and nozzle arcs, and microwave discharges. In this paper plasma methods proposed for H2 production are briefly described and critically evaluated from the view point of H2 production efficiency. The paper is aiming at answering a question if any plasma method for the small-scale H2 production approaches such challenges as the production energy yield of 60 g(H2)/kWh, high production rate, high reliability and low investment cost. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

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

    NASA Technical Reports Server (NTRS)

    Anderson, Tim; Balaban, Canan

    2008-01-01

    The activities presented are a broad based approach to advancing key hydrogen related technologies in areas such as fuel cells, hydrogen production, and distributed sensors for hydrogen-leak detection, laser instrumentation for hydrogen-leak detection, and cryogenic transport and storage. Presented are the results from research projects, education and outreach activities, system and trade studies. The work will aid in advancing the state-of-the-art for several critical technologies related to the implementation of a hydrogen infrastructure. Activities conducted are relevant to a number of propulsion and power systems for terrestrial, aeronautics and aerospace applications. Hydrogen storage and in-space hydrogen transport research focused on developing and verifying design concepts for efficient, safe, lightweight liquid hydrogen cryogenic storage systems. Research into hydrogen production had a specific goal of further advancing proton conducting membrane technology in the laboratory at a larger scale. System and process trade studies evaluated the proton conducting membrane technology, specifically, scale-up issues.

  3. Microwave plasma torches used for hydrogen production

    NASA Astrophysics Data System (ADS)

    Dias, F. M.; Bundaleska, N.; Henriques, J.; Tatarova, E.; Ferreira, C. M.

    2014-06-01

    A microwave plasma torch operating at 2.45 GHz and atmospheric pressure has been used as a medium and a tool for decomposition of alcohol in order to produce molecular hydrogen. Plasma in a gas mixture of argon and ethanol/methanol, with or without water, has been created using a waveguide surfatron launcher and a microwave generator delivering a power in the range 0.2-2.0 kW. Mass, Fourier Transform Infrared, and optical emission spectrometry have been applied as diagnostic tools. The decomposition yield of methanol was nearly 100 % with H2, CO, CO2, H2O, and solid carbon as the main reaction products. The influence of the fraction of Ar flow through the liquid ethanol/methanol on H2, CO, and CO2 partial pressures has been investigated, as well as the dependence of the produced H2 flow on the total flow and power. The optical emission spectrum in the range 250-700 nm has also been detected. There is a decrease of the OH(A-X) band intensity with the increase of methanol in the mixture. The emission of carbon atoms in the near UV range (240-300 nm) exhibits a significant increase as the amount of alcohol in the mixture grows. The obtained results clearly show that this microwave plasma torch at atmospheric pressure provides an efficient plasma environment for hydrogen production.

  4. Hydrogen in the Methanol Production Process

    ERIC Educational Resources Information Center

    Kralj, Anita Kovac; Glavic, Peter

    2006-01-01

    Hydrogen is a very important industrial gas in chemical processes. It is very volatile; therefore, it can escape from the process units and its mass balance is not always correct. In many industrial processes where hydrogen is reacted, kinetics are often related to hydrogen pressure. The right thermodynamic properties of hydrogen can be found for…

  5. A Novel Membrane Reactor for Direct Hydrogen Production From Coal

    SciTech Connect

    Shain Doong; Estela Ong; Mike Atrosphenko; Francis Lau; Mike Roberts

    2006-01-20

    Gas Technology Institute has developed a novel concept of a membrane reactor closely coupled with a coal gasifier for direct extraction of hydrogen from coal-derived syngas. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under the coal gasification conditions. The best performing membranes were selected for preliminary reactor design and cost estimate. The overall economics of hydrogen production from this new process was assessed and compared with conventional hydrogen production technologies from coal. Several proton-conducting perovskite membranes based on the formulations of BCN (BaCe{sub 0.8}Nd{sub 0.2}O{sub 3-x}), BCY (BaCe{sub 0.8}Y{sub 0.2}O{sub 3-x}), SCE (Eu-doped SrCeO{sub 3}) and SCTm (SrCe{sub 0.95}Tm{sub 0.05}O{sub 3}) were successfully tested in a new permeation unit at temperatures between 800 and 1040 C and pressures from 1 to 12 bars. The experimental data confirm that the hydrogen flux increases with increasing hydrogen partial pressure at the feed side. The highest hydrogen flux measured was 1.0 cc/min/cm{sup 2} (STP) for the SCTm membrane at 3 bars and 1040 C. The chemical stability of the perovskite membranes with respect to CO{sub 2} and H{sub 2}S can be improved by doping with Zr, as demonstrated from the TGA (Thermal Gravimetric Analysis) tests in this project. A conceptual design, using the measured hydrogen flux data and a modeling approach, for a 1000 tons-per-day (TPD) coal gasifier shows that a membrane module can be configured within a fluidized bed gasifier without a substantial increase of the gasifier dimensions. Flowsheet simulations show that the coal to hydrogen process employing the proposed membrane reactor concept can increase the hydrogen production efficiency by more than 50% compared to the conventional process. Preliminary economic analysis also shows a 30% cost reduction for the proposed membrane

  6. Thermodynamic prediction of hydrogen production from mixed-acid fermentations.

    PubMed

    Forrest, Andrea K; Wales, Melinda E; Holtzapple, Mark T

    2011-10-01

    The MixAlco™ process biologically converts biomass to carboxylate salts that may be chemically converted to a wide variety of chemicals and fuels. The process utilizes lignocellulosic biomass as feedstock (e.g., municipal solid waste, sewage sludge, and agricultural residues), creating an economic basis for sustainable biofuels. This study provides a thermodynamic analysis of hydrogen yield from mixed-acid fermentations from two feedstocks: paper and bagasse. During batch fermentations, hydrogen production, acid production, and sugar digestion were analyzed to determine the energy selectivity of each system. To predict hydrogen production during continuous operation, this energy selectivity was then applied to countercurrent fermentations of the same systems. The analysis successfully predicted hydrogen production from the paper fermentation to within 11% and the bagasse fermentation to within 21% of the actual production. The analysis was able to faithfully represent hydrogen production and represents a step forward in understanding and predicting hydrogen production from mixed-acid fermentations. PMID:21875794

  7. Hydrogen fuel production by transgenic microalgae.

    PubMed

    Melis, Anastasios; Seibert, Michael; Ghirardi, Maria L

    2007-01-01

    This chapter summarizes the state-of-art in the field of green algal H2-production and examines physiological and genetic engineering approaches by which to improve the hydrogen metabolism characteristics of these microalgae. Included in this chapter are emerging topics pertaining to the application of sulfur-nutrient deprivation to attenuate O2-evolution and to promote H2-production, as well as the genetic engineering of sulfate uptake through manipulation of a newly reported sulfate permease in the chloroplast of the model green alga Chlamydomonas reinhardtii. Application of the green algal hydrogenase assembly genes is examined in efforts to confer H2-production capacity to other commercially significant unicellular green algae. Engineering a solution to the O2 sensitivity of the green algal hydrogenase is discussed as an alternative approach to sulfur nutrient deprivation, along with starch accumulation in microalgae for enhanced H2-production. Lastly, current efforts aiming to optimize light utilization in transgenic microalgae for enhanced H2-production under mass culture conditions are presented. It is evident that application of genetic engineering technologies and the use of transgenic green algae will improve prospects for commercial exploitation of these photosynthetic micro-organisms in the generation of H2, a clean and renewable fuel. PMID:18161495

  8. Coupling of Algal Biofuel Production with Wastewater

    PubMed Central

    Panwar, Amit; Bisht, Tara Singh; Tamta, Sushma

    2014-01-01

    Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area. PMID:24982930

  9. Hydrogen Gas Production from Nuclear Power Plant in Relation to Hydrogen Fuel Cell Technologies Nowadays

    SciTech Connect

    Yusibani, Elin; Kamil, Insan; Suud, Zaki

    2010-06-22

    Recently, world has been confused by issues of energy resourcing, including fossil fuel use, global warming, and sustainable energy generation. Hydrogen may become the choice for future fuel of combustion engine. Hydrogen is an environmentally clean source of energy to end-users, particularly in transportation applications because without release of pollutants at the point of end use. Hydrogen may be produced from water using the process of electrolysis. One of the GEN-IV reactors nuclear projects (HTGRs, HTR, VHTR) is also can produce hydrogen from the process. In the present study, hydrogen gas production from nuclear power plant is reviewed in relation to commercialization of hydrogen fuel cell technologies nowadays.

  10. Hydrogen Gas Production from Nuclear Power Plant in Relation to Hydrogen Fuel Cell Technologies Nowadays

    NASA Astrophysics Data System (ADS)

    Yusibani, Elin; Kamil, Insan; Suud, Zaki

    2010-06-01

    Recently, world has been confused by issues of energy resourcing, including fossil fuel use, global warming, and sustainable energy generation. Hydrogen may become the choice for future fuel of combustion engine. Hydrogen is an environmentally clean source of energy to end-users, particularly in transportation applications because without release of pollutants at the point of end use. Hydrogen may be produced from water using the process of electrolysis. One of the GEN-IV reactors nuclear projects (HTGRs, HTR, VHTR) is also can produce hydrogen from the process. In the present study, hydrogen gas production from nuclear power plant is reviewed in relation to commercialization of hydrogen fuel cell technologies nowadays.

  11. Nuclear Hydrogen for Peak Electricity Production and Spinning Reserve

    SciTech Connect

    Forsberg, C.W.

    2005-01-20

    Nuclear energy can be used to produce hydrogen. The key strategic question is this: ''What are the early markets for nuclear hydrogen?'' The answer determines (1) whether there are incentives to implement nuclear hydrogen technology today or whether the development of such a technology could be delayed by decades until a hydrogen economy has evolved, (2) the industrial partners required to develop such a technology, and (3) the technological requirements for the hydrogen production system (rate of production, steady-state or variable production, hydrogen purity, etc.). Understanding ''early'' markets for any new product is difficult because the customer may not even recognize that the product could exist. This study is an initial examination of how nuclear hydrogen could be used in two interconnected early markets: the production of electricity for peak and intermediate electrical loads and spinning reserve for the electrical grid. The study is intended to provide an initial description that can then be used to consult with potential customers (utilities, the Electric Power Research Institute, etc.) to better determine the potential real-world viability of this early market for nuclear hydrogen and provide the starting point for a more definitive assessment of the concept. If this set of applications is economically viable, it offers several unique advantages: (1) the market is approximately equivalent in size to the existing nuclear electric enterprise in the United States, (2) the entire market is within the utility industry and does not require development of an external market for hydrogen or a significant hydrogen infrastructure beyond the utility site, (3) the technology and scale match those of nuclear hydrogen production, (4) the market exists today, and (5) the market is sufficient in size to justify development of nuclear hydrogen production techniques independent of the development of any other market for hydrogen. These characteristics make it an ideal

  12. Fermentation and Electrohydrogenic Approaches to Hydrogen Production (Presentation)

    SciTech Connect

    Maness, P. C.; Thammannagowda, S.; Magnusson, L.; Logan, B.

    2010-06-01

    This work describes the development of a waste biomass fermentation process using cellulose-degrading bacteria for hydrogen production. This process is then integrated with an electrohydrogenesis process via the development of a microbial electrolysis cell reactor, during which fermentation waste effluent is further converted to hydrogen to increase the total output of hydrogen from biomass.

  13. U-GAS process for production of hydrogen from coal

    SciTech Connect

    Dihu, R.J.; Patel, J.G.

    1982-01-01

    Today, hydrogen is produced mainly from natural gas and petroleum fractions. Tomorrow, because reserves of natural gas and oil are declining while demand continues to increase, they cannot be considered available for long-term, large-scale production of hydrogen. Hydrogen obtained from coal is expected to be the lowest cost, large-scale source of hydrogen in the future. The U-GAS coal gasification process and its potential application to the manufacture of hydrogen is discussed. Pilot plant results, the current status of the process, and economic projections for the cost of hydrogen manufactured are presented.

  14. Method for low temperature catalytic production of hydrogen

    DOEpatents

    Mahajan, Devinder

    2003-07-22

    The invention provides a process for the catalytic production of a hydrogen feed by exposing a hydrogen feed to a catalyst which promotes a base-catalyzed water-gas-shift reaction in a liquid phase. The hydrogen feed can be provided by any process known in the art of making hydrogen gas. It is preferably provided by a process that can produce a hydrogen feed for use in proton exchange membrane fuel cells. The step of exposing the hydrogen feed takes place preferably from about 80.degree. C. to about 150.degree. C.

  15. A review on hydrogen production: methods, materials and nanotechnology.

    PubMed

    Lang, Yizhao; Arnepalli, Ranga Rao; Tiwari, Ashutosh

    2011-05-01

    In recent years hydrogen production and storage has attracted a lot of attention in both academia and industry due to its variety of applications in energy sector. Hydrogen is recognized as one of the most important components of the next generation clean energy technology. Within the whole cycle of the use of hydrogen energy, hydrogen production is considered as the key element of the upcoming hydrogen economy. Since the first production method invented for hydrogen on a smaller scale by dissolving iron in the acid vitriol in the 15th century, many improvements have been made to make the production viable and more cost effective. It is known that "nano" is playing its role in many technologies from medicine to material science and it has its say even in the production of hydrogen energy with continuous improvements in materials and methodologies. In this review we attempt to list various methods of producing hydrogen from different sources of materials followed by the description of most recent developments in the materials prospective. We explain the role of nanotechnology in making the hydrogen production technology a viable and cost effective process. The chemical reaction cycle, mechanism and configurations of various methods of hydrogen production are elaborated. PMID:21780363

  16. Solar Thermochemical Hydrogen Production Research (STCH)

    SciTech Connect

    Perret, Robert

    2011-05-01

    Eight cycles in a coordinated set of projects for Solar Thermochemical Cycles for Hydrogen production (STCH) were self-evaluated for the DOE-EERE Fuel Cell Technologies Program at a Working Group Meeting on October 8 and 9, 2008. This document reports the initial selection process for development investment in STCH projects, the evaluation process meant to reduce the number of projects as a means to focus resources on development of a few most-likely-to-succeed efforts, the obstacles encountered in project inventory reduction and the outcomes of the evaluation process. Summary technical status of the projects under evaluation is reported and recommendations identified to improve future project planning and selection activities.

  17. Hydrogen Production from Hydrogen Sulfide in IGCC Power Plants

    SciTech Connect

    Elias Stefanakos; Burton Krakow; Jonathan Mbah

    2007-07-31

    IGCC power plants are the cleanest coal-based power generation facilities in the world. Technical improvements are needed to help make them cost competitive. Sulfur recovery is one procedure in which improvement is possible. This project has developed and demonstrated an electrochemical process that could provide such an improvement. IGCC power plants now in operation extract the sulfur from the synthesis gas as hydrogen sulfide. In this project H{sub 2}S has been electrolyzed to yield sulfur and hydrogen (instead of sulfur and water as is the present practice). The value of the byproduct hydrogen makes this process more cost effective. The electrolysis has exploited some recent developments in solid state electrolytes. The proof of principal for the project concept has been accomplished.

  18. A New Hydrogen-Producing Strain and Its Characterization of Hydrogen Production.

    PubMed

    Sun, Mingxing; Lv, Yongkang; Liu, Yuxiang

    2015-12-01

    A newly isolated photo non-sulfur (PNS) bacterium was identified as Rhodopseudomonas palustris PB-Z by sequencing of 16S ribosomal DNA (rDNA) genes and phylogenetic analysis. Under vigorous stirring (240 rpm), the hydrogen production performances were greatly improved: The maximum hydrogen production rate and cumulative hydrogen production increased by 188.9 ± 0.07 % and 83.0 ± 0.06 %, respectively, due to the hydrogen bubbles were immediately removed from the culture medium. The effects of different wavelength of light on hydrogen production with stirring were much different from that without stirring. The ranking on the photo-hydrogen production performance was white > yellow > green > blue > red without stirring and white > yellow > blue > red > green under stirring. The best light source for hydrogen production was tungsten filament lamp. The optimum temperature was 35 °C. The maximal hydrogen production rate and cumulative hydrogen production reached 78.7 ± 2.3 ml/l/h and 1728.1 ± 92.7 mol H2/l culture, respectively, under 35 °C, 240 rpm, and illumination of 4000 lux. Pyruvate was one of the main sources of CO2 and has a great impact on the gas composition. PMID:26369783

  19. Recent work in advanced hydrogen production concepts

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.

    1981-01-01

    The hydrogen photoelectrolytic conversion activity investigated the practicability of semiconductor electrolytic devises that use solar energy to decompose water into hydrogen and oxygen in an apparent single step process. The photocatalytic decomposition of inorganic hydrogen compounds; i.e., hydrobromic and hydriodic acids using rhodium organic bridge complexes were also studied. The feasibility of direct high temperature thermal decompositions of water with diffusion processes for separation of the equilibrium mixture of hydrogen and oxygen into usable energy sources was examined.

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

    SciTech Connect

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

    2008-08-01

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

  1. Applications of light-induced electron-transfer and hydrogen-abstraction processes: photoelectrochemical production of hydrogen from reducing radicals

    SciTech Connect

    Chandrasekaran, K.; Whitten, D.G.

    1980-07-16

    A study of several photoprocesses which generate reducing radicals in similar photoelectrochemical cells was reported. Coupling of a light-induced reaction to produce a photocurrent concurrent with hydrogen generation in a second compartment can occur for a number of electron transfers and hydrogen abstractions in what appears to be a fairly general process. Irradiation of the RuL/sub 3//sup +2//Et/sub 3/N: photoanode compartment leads to production of a photocurrent together with generation of hydrogen at the cathode. A rather different type of reaction that also results in formation of two reducing radicals as primary photoproducts if the photoreduction of ketones and H-heteroaromatics by alcohols and other hydrogen atom donors. Irradiation of benzophenone/2-propanol/MV/sup +2/ solutions in the photoanode compartment (intensity 1.4 x 10/sup -8/ einstein/s) leads to a buildup of moderate levels of MV/sup +/ and to a steady photocurrent of 320 ..mu..A. The MV/sup +/ is oxidized at the anode of the photolyzed compartment with concomitant reduction of H/sup +/ in the cathode compartment. There was no decrease in benzophenone concentration over moderate periods of irradiation, and a steady production of hydrogen in the cathode compartment was observed. The photocurrent produced was linear with the square of absorbed light intensity. The quantum efficiency at the above-indicated intensity is 22%; quantitative analysis of the hydrogen produced gives good agreement with this value. 1 figure, 1 table. (DP)

  2. Hydrogen sulfide production from subgingival plaque samples.

    PubMed

    Basic, A; Dahlén, G

    2015-10-01

    Periodontitis is a polymicrobial anaerobe infection. Little is known about the dysbiotic microbiota and the role of bacterial metabolites in the disease process. It is suggested that the production of certain waste products in the proteolytic metabolism may work as markers for disease severity. Hydrogen sulfide (H2S) is a gas produced by degradation of proteins in the subgingival pocket. It is highly toxic and believed to have pro-inflammatory properties. We aimed to study H2S production from subgingival plaque samples in relation to disease severity in subjects with natural development of the disease, using a colorimetric method based on bismuth precipitation. In remote areas of northern Thailand, adults with poor oral hygiene habits and a natural development of periodontal disease were examined for their oral health status. H2S production was measured with the bismuth method and subgingival plaque samples were analyzed for the presence of 20 bacterial species with the checkerboard DNA-DNA hybridization technique. In total, 43 subjects were examined (age 40-60 years, mean PI 95 ± 6.6%). Fifty-six percent had moderate periodontal breakdown (CAL > 3 < 7 mm) and 35% had severe periodontal breakdown (CAL > 7 mm) on at least one site. Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis and Fusobacterium nucleatum were frequently detected. H2S production could not be correlated to periodontal disease severity (PPD or CAL at sampled sites) or to a specific bacterial composition. Site 21 had statistically lower production of H2S (p = 0.02) compared to 16 and 46. Betel nut chewers had statistically significant lower H2S production (p = 0.01) than non-chewers. Rapid detection and estimation of subgingival H2S production capacity was easily and reliably tested by the colorimetric bismuth sulfide precipitation method. H2S may be a valuable clinical marker for degradation of proteins in the subgingival pocket. PMID:25280920

  3. A microBio reactor for hydrogen production.

    SciTech Connect

    Volponi, Joanne V.; Walker, Andrew William

    2003-12-01

    The purpose of this work was to explore the potential of developing a microfluidic reactor capable of enzymatically converting glucose and other carbohydrates to hydrogen. This aggressive project was motivated by work in enzymatic hydrogen production done by Woodward et al. at OWL. The work reported here demonstrated that hydrogen could be produced from the enzymatic oxidation of glucose. Attempts at immobilizing the enzymes resulted in reduced hydrogen production rates, probably due to buffer compatibility issues. A novel in-line sensor was also developed to monitor hydrogen production in real time at levels below 1 ppm. Finally, a theoretical design for the microfluidic reactor was developed but never produced due to the low production rates of hydrogen from the immobilized enzymes. However, this work demonstrated the potential of mimicking biological systems to create energy on the microscale.

  4. Hydrogen production from municipal solid waste

    SciTech Connect

    Wallman, P.H.; Richardson, J.H.; Thorsness, C.B.

    1996-06-28

    We have modified a Municipal Solid Waste (MSW) hydrothermal pretreatment pilot plant for batch operation and blowdown of the treated batch to low pressure. We have also assembled a slurry shearing pilot plant for particle size reduction. Waste paper and a mixture of waste paper/polyethylene plastic have been run in the pilot plant with a treatment temperature of 275{degrees}C. The pilot-plant products have been used for laboratory studies at LLNL. The hydrothermal/shearing pilot plants have produced acceptable slurries for gasification tests from a waste paper feedstock. Work is currently underway with combined paper/plastic feedstocks. When the assembly of the Research Gasification Unit at Texaco (feed capacity approximately 3/4-ton/day) is complete (4th quarter of FY96), gasification test runs will commence. Laboratory work on slurry samples during FY96 has provided correlations between slurry viscosity and hydrothermal treatment temperature, degree of shearing, and the presence of surfactants and admixed plastics. To date, pumpable slurries obtained from an MSW surrogate mixture of treated paper and plastic have shown heating values in the range 13-15 MJ/kg. Our process modeling has quantified the relationship between slurry heating value and hydrogen yield. LLNL has also performed a preliminary cost analysis of the process with the slurry heating value and the MSW tipping fee as parameters. This analysis has shown that the overall process with a 15 MJ/kg slurry gasifier feed can compete with coal-derived hydrogen with the assumption that the tipping fee is of the order $50/ton.

  5. Production of negative hydrogen ions on metal grids

    SciTech Connect

    Oohara, W.; Maetani, Y.; Takeda, Takashi; Takeda, Toshiaki; Yokoyama, H.; Kawata, K.

    2015-03-15

    Negative hydrogen ions are produced on a nickel grid with positive-ion irradiation. In order to investigate the production mechanism, a copper grid without the chemisorption of hydrogen atoms and positive helium ions without negative ionization are used for comparison. Positive hydrogen ions reflected on the metal surface obtain two electrons from the surface and become negatively ionized. It is found that the production yield of negative ions by desorption ionization of chemisorbed hydrogen atoms seems to be small, and the production is a minor mechanism.

  6. Interfacing primary heat sources and cycles for thermochemical hydrogen production

    SciTech Connect

    Bowman, M.G.

    1980-01-01

    Advantages cited for hydrogen production from water by coupling thermochemical cycles with primary heat include the possibility of high efficiencies. These can be realized only if the cycle approximates the criteria required to match the characteristics of the heat source. Different types of cycles may be necessary for fission reactors, for fusion reactors or for solar furnaces. Very high temperature processes based on decomposition of gaseous H/sub 2/O or CO/sub 2/ appear impractical even for projected solar technology. Cycles based on CdO decomposition are potentially quite efficient and require isothermal heat at temperatures that may be available from solar furnaces of fusion reactors. Sulfuric acid and solid sulfate cycles are potentially useful at temperatures available from each heat source. Solid sulfate cycles offer advantages for isothermal heat sources. All cycles under development include concentration and drying steps. Novel methods for improving such operations would be beneficial.

  7. Two-dimensional B- B NMR spectroscopy: coupling through bridging hydrogen atoms

    SciTech Connect

    Gaines, D.F.; Edvenson, G.M.; Hill, T.G.; Adams, B.R.

    1987-06-03

    Application of B- B two-dimensional correlated spectroscopy (COSY) to a variety of boranes and substituted boranes has shown coupling between B nuclei linked by bridging hydrogen atoms to be more common than previously observed. Coupling between the hydrogen-bridged boron nuclei in decaborane(14), 2-(CH3)B5H8, B4H10, (Me2N)2B4H8, ( -Me2NCH2)B5H8, and ( -Me3CCH=N)B5H8 are reported. The factors that contribute to the detection of coupling between hydrogen-bridged boron atoms are discussed.

  8. Hydrogen production from water: Recent advances in photosynthesis research

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1997-12-31

    The great potential of hydrogen production by microalgal water splitting is predicated on quantitative measurement of the algae`s hydrogen-producing capability, which is based on the following: (1) the photosynthetic unit size of hydrogen production; (2) the turnover time of photosynthetic hydrogen production; (3) thermodynamic efficiencies of conversion of light energy into the Gibbs free energy of molecular hydrogen; (4) photosynthetic hydrogen production from sea water using marine algae; (5) the potential for research advances using modern methods of molecular biology and genetic engineering to maximize hydrogen production. ORNL has shown that sustained simultaneous photoevolution of molecular hydrogen and oxygen can be performed with mutants of the green alga Chlamydomonas reinhardtii that lack a detectable level of the Photosystem I light reaction. This result is surprising in view of the standard two-light reaction model of photosynthesis and has interesting scientific and technological implications. This ORNL discovery also has potentially important implications for maximum thermodynamic conversion efficiency of light energy into chemical energy by green plant photosynthesis. Hydrogen production performed by a single light reaction, as opposed to two, implies a doubling of the theoretically maximum thermodynamic conversion efficiency from {approx}10% to {approx}20%.

  9. Solar and Wind Technologies for Hydrogen Production Report to Congress

    SciTech Connect

    None, None

    2005-12-01

    DOE's Solar and Wind Technologies for Hydrogen Production Report to Congress summarizes the technology roadmaps for solar- and wind-based hydrogen production. Published in December 2005, it fulfills the requirement under section 812 of the Energy Policy Act of 2005.

  10. Maximizing Light Utilization Efficiency and Hydrogen Production in Microalgal Cultures

    SciTech Connect

    Melis, Anastasios

    2014-12-31

    The project addressed the following technical barrier from the Biological Hydrogen Production section of the Fuel Cell Technologies Program Multi-Year Research, Development and Demonstration Plan: Low Sunlight Utilization Efficiency in Photobiological Hydrogen Production is due to a Large Photosystem Chlorophyll Antenna Size in Photosynthetic Microorganisms (Barrier AN: Light Utilization Efficiency).

  11. Process for the thermochemical production of hydrogen

    DOEpatents

    Norman, John H.; Russell, Jr., John L.; Porter, II, John T.; McCorkle, Kenneth H.; Roemer, Thomas S.; Sharp, Robert

    1978-01-01

    Hydrogen is thermochemically produced from water in a cycle wherein a first reaction produces hydrogen iodide and H.sub.2 SO.sub.4 by the reaction of iodine, sulfur dioxide and water under conditions which cause two distinct aqueous phases to be formed, i.e., a lighter sulfuric acid-bearing phase and a heavier hydrogen iodide-bearing phase. After separation of the two phases, the heavier phase containing most of the hydrogen iodide is treated, e.g., at a high temperature, to decompose the hydrogen iodide and recover hydrogen and iodine. The H.sub.2 SO.sub.4 is pyrolyzed to recover sulfur dioxide and produce oxygen.

  12. Fermentative hydrogen production from agroindustrial lignocellulosic substrates

    PubMed Central

    Reginatto, Valeria; Antônio, Regina Vasconcellos

    2015-01-01

    To achieve economically competitive biological hydrogen production, it is crucial to consider inexpensive materials such as lignocellulosic substrate residues derived from agroindustrial activities. It is possible to use (1) lignocellulosic materials without any type of pretreatment, (2) lignocellulosic materials after a pretreatment step, and (3) lignocellulosic materials hydrolysates originating from a pretreatment step followed by enzymatic hydrolysis. According to the current literature data on fermentative H2 production presented in this review, thermophilic conditions produce H2 in yields approximately 75% higher than those obtained in mesophilic conditions using untreated lignocellulosic substrates. The average H2 production from pretreated material is 3.17 ± 1.79 mmol of H2/g of substrate, which is approximately 50% higher compared with the average yield achieved using untreated materials (2.17 ± 1.84 mmol of H2/g of substrate). Biological pretreatment affords the highest average yield 4.54 ± 1.78 mmol of H2/g of substrate compared with the acid and basic pretreatment - average yields of 2.94 ± 1.85 and 2.41 ± 1.52 mmol of H2/g of substrate, respectively. The average H2 yield from hydrolysates, obtained from a pretreatment step and enzymatic hydrolysis (3.78 ± 1.92 mmol of H2/g), was lower compared with the yield of substrates pretreated by biological methods only, demonstrating that it is important to avoid the formation of inhibitors generated by chemical pretreatments. Based on this review, exploring other microorganisms and optimizing the pretreatment and hydrolysis conditions can make the use of lignocellulosic substrates a sustainable way to produce H2. PMID:26273246

  13. Anti-reflective nanoporous silicon for efficient hydrogen production

    DOEpatents

    Oh, Jihun; Branz, Howard M

    2014-05-20

    Exemplary embodiments are disclosed of anti-reflective nanoporous silicon for efficient hydrogen production by photoelectrolysis of water. A nanoporous black Si is disclosed as an efficient photocathode for H.sub.2 production from water splitting half-reaction.

  14. Effect of process variables on photosynthetic algal hydrogen production.

    PubMed

    Hahn, John J; Ghirardi, Maria L; Jacoby, William A

    2004-01-01

    Chlamydomonas reinhardtii is a green alga that can use the sun's energy to split water into O(2) and H(2). This is accomplished by means of a two-phase cycle, an aerobic growth phase followed by an anaerobic hydrogen production phase. The effects of process variables on hydrogen production are examined here. These variables include cell concentration, light intensity, and reactor design parameters that affect light transport and mixing. An optimum cell concentration and light intensity are identified, and two reactor designs are compared. The maximum hydrogen production observed in this study was 0.29 mL of hydrogen per milliliter of suspension. This was measured at atmospheric pressure during a 96 h production cycle. This corresponds to an average hydrogen production rate of 0.12 mmol/mL.h. PMID:15176910

  15. A continuous flow strategy for the coupled transfer hydrogenation and etherification of 5-(hydroxymethyl)furfural using Lewis acid zeolites.

    PubMed

    Lewis, Jennifer D; Van de Vyver, Stijn; Crisci, Anthony J; Gunther, William R; Michaelis, Vladimir K; Griffin, Robert G; Román-Leshkov, Yuriy

    2014-08-01

    Hf-, Zr- and Sn-Beta zeolites effectively catalyze the coupled transfer hydrogenation and etherification of 5-(hydroxymethyl)furfural with primary and secondary alcohols into 2,5-bis(alkoxymethyl)furans, thus making it possible to generate renewable fuel additives without the use of external hydrogen sources or precious metals. Continuous flow experiments reveal nonuniform changes in the relative deactivation rates of the transfer hydrogenation and etherification reactions, which impact the observed product distribution over time. We found that the catalysts undergo a drastic deactivation for the etherification step while maintaining catalytic activity for the transfer hydrogenation step. (119) Sn and (29) Si magic angle spinning (MAS) NMR studies show that this deactivation can be attributed to changes in the local environment of the metal sites. Additional insights were gained by studying effects of various alcohols and water concentration on the catalytic reactivity. PMID:25045144

  16. Production and Physiological Effects of Hydrogen Sulfide

    PubMed Central

    2014-01-01

    Abstract Significance: Hydrogen sulfide (H2S) has been recognized as a physiological mediator with a variety of functions. It regulates synaptic transmission, vascular tone, inflammation, transcription, and angiogenesis; protects cells from oxidative stress and ischemia-reperfusion injury; and promotes healing of ulcers. Recent Advances: In addition to cystathionine β-synthase and cystathionine γ-lyase, 3-mercaptopyruvate sulfurtransferase along with cysteine aminotransferase was recently demonstrated to produce H2S. Even in bacteria, H2S produced by these enzymes functions as a defense against antibiotics, suggesting that the cytoprotective effect of H2S is a universal defense mechanism in organisms from bacteria to mammals. Critical Issues: The functional form of H2S—undissociated H2S gas, dissociated HS ion, or some other form of sulfur—has not been identified. Future Directions: The regulation of H2S production by three enzymes may lead to the identification of the physiological signals that are required to release H2S. The identification of the physiological functions of other forms of sulfur may also help understand the biological significance of H2S. Antioxid. Redox Signal. 20, 783–793. PMID:23581969

  17. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, R.; Randhava, S.S.; Tsai, S.P.

    1997-09-02

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H{sub 2}O{sub 2} laden permeate. 1 fig.

  18. Fluidic hydrogen detector production prototype development

    NASA Technical Reports Server (NTRS)

    Roe, G. W.; Wright, R. E.

    1976-01-01

    A hydrogen gas sensor that can replace catalytic combustion sensors used to detect leaks in the liquid hydrogen transfer systems at Kennedy Space Center was developed. A fluidic sensor concept, based on the principle that the frequency of a fluidic oscillator is proportional to the square root of the molecular weight of its operating fluid, was utilized. To minimize sensitivity to pressure and temperature fluctuations, and to make the sensor specific for hydrogen, two oscillators are used. One oscillator operates on sample gas containing hydrogen, while the other operates on sample gas with the hydrogen converted to steam. The conversion is accomplished with a small catalytic converter. The frequency difference is taken, and the hydrogen concentration computed with a simple digital processing circuit. The output from the sensor is an analog signal proportional to hydrogen content. The sensor is shown to be accurate and insensitive to severe environmental disturbances. It is also specific for hydrogen, even with large helium concentrations in the sample gas.

  19. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, Rathin; Randhava, Sarabjit S.; Tsai, Shih-Perng

    1997-01-01

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H.sub.2 O.sub.2 laden permeate.

  20. Hydrogen production by the decomposition of water

    DOEpatents

    Hollabaugh, C.M.; Bowman, M.G.

    A process is described for the production of hydrogen from water by a sulfuric acid process employing electrolysis and thermo-chemical decomposition. The water containing SO/sub 2/ is electrolyzed to produce H/sub 2/ at the cathode and to oxidize the SO/sub 2/ to form H/sub 2/SO/sub 4/ at the anode. After the H/sub 2/ has been separated, a compound of the type M/sub r/X/sub s/ is added to produce a water insoluble sulfate of M and a water insoluble oxide of the metal in the radical X. In the compound M/sub r/X/sub s/, M is at least one metal selected from the group consisting of Ba/sup 2 +/, Ca/sup 2 +/, Sr/sup 2 +/, La/sup 2 +/, and Pb/sup 2 +/; X is at least one radical selected from the group consisting of molybdate (MoO/sub 4//sup 2 -/), tungstate (WO/sub 4//sup 2 -/), and metaborate (BO/sub 2//sup 1 -/); and r and s are either 1, 2, or 3 depending upon the valence of M and X. The precipitated mixture is filtered and heated to a temperature sufficiently high to form SO/sub 3/ gas and to reform M/sub r/X/sub s/. The SO/sub 3/ is dissolved in a small amount of H/sub 2/O to produce concentrated H/sub 2/SO/sub 4/, and the M/sub r/X/sub s/ is recycled to the process. Alternatively, the SO/sub 3/ gas can be recycled to the beginning of the process to provide a continuous process for the production of H/sub 2/ in which only water need be added in a substantial amount. (BLM)

  1. Hydrogen Production Cost Estimate Using Biomass Gasification: Independent Review

    SciTech Connect

    Ruth, M.

    2011-10-01

    This independent review is the conclusion arrived at from data collection, document reviews, interviews and deliberation from December 2010 through April 2011 and the technical potential of Hydrogen Production Cost Estimate Using Biomass Gasification. The Panel reviewed the current H2A case (Version 2.12, Case 01D) for hydrogen production via biomass gasification and identified four principal components of hydrogen levelized cost: CapEx; feedstock costs; project financing structure; efficiency/hydrogen yield. The panel reexamined the assumptions around these components and arrived at new estimates and approaches that better reflect the current technology and business environments.

  2. Analysis of Improved Reference Design for a Nuclear-Driven High Temperature Electrolysis Hydrogen Production Plant

    SciTech Connect

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

    2010-06-01

    The use of High Temperature Electrolysis (HTE) for the efficient production of hydrogen without the greenhouse gas emissions associated with conventional fossil-fuel hydrogen production techniques has been under investigation at the Idaho National Engineering Laboratory (INL) for the last several years. The activities at the INL have included the development, testing and analysis of large numbers of solid oxide electrolysis cells, and the analyses of potential plant designs for large scale production of hydrogen using an advanced Very-High Temperature Reactor (VHTR) to provide the process heat and electricity to drive the electrolysis process. The results of these system analyses, using the UniSim process analysis software, have shown that the HTE process, when coupled to a VHTR capable of operating at reactor outlet temperatures of 800 °C to 950 °C, has the potential to produce the large quantities of hydrogen needed to meet future energy and transportation needs with hydrogen production efficiencies in excess of 50%. In addition, economic analyses performed on the INL reference plant design, optimized to maximize the hydrogen production rate for a 600 MWt VHTR, have shown that a large nuclear-driven HTE hydrogen production plant can to be economically competitive with conventional hydrogen production processes, particularly when the penalties associated with greenhouse gas emissions are considered. The results of this research led to the selection in 2009 of HTE as the preferred concept in the U.S. Department of Energy (DOE) hydrogen technology down-selection process. However, the down-selection process, along with continued technical assessments at the INL, has resulted in a number of proposed modifications and refinements to improve the original INL reference HTE design. These modifications include changes in plant configuration, operating conditions and individual component designs. This paper describes the resulting new INL reference design and presents

  3. Effect of green laser irradiation on hydrogen production

    NASA Astrophysics Data System (ADS)

    Bidin, Noriah; Razak, Siti Noraiza A.; Radiana Azni, Siti; Nguroho, Waskito; Mohsin, Ali Kamel; Abdullah, Mundzir; Krishnan, Ganesan; Bakhtiar, Hazri

    2014-06-01

    The effect of green laser irradiation on hydrogen production via water electrolysis was investigated. Diode pumped solid-state laser operating in second harmonic generation was employed as a source of irradiation. The hydrogen production system was also irradiated by a conventional light, a halogen source, for comparison. The best catalyst was identified by mixing distilled water with two types of salt: NaCl and Na2SO4. Optimization of hydrogen production from water electrolysis was realized by using NaCl and green laser irradiation. The power of green laser irradiation and the concentration of NaCl in water contribute to hydrogen production. The hydrogen yield also depends on the distance and direction of the green beam to the electrode.

  4. FEASIBILITY OF HYDROGEN PRODUCTION USING LASER INERTIAL FUSION AS THE PRIMARY ENERGY SOURCE

    SciTech Connect

    Gorensek, M

    2006-11-03

    The High Average Power Laser (HAPL) program is developing technology for Laser IFE with the goal of producing electricity from the heat generated by the implosion of deuterium-tritium (DT) targets. Alternatively, the Laser IFE device could be coupled to a hydrogen generation system where the heat would be used as input to a water-splitting process to produce hydrogen and oxygen. The production of hydrogen in addition to electricity would allow fusion energy plants to address a much wider segment of energy needs, including transportation. Water-splitting processes involving direct and hybrid thermochemical cycles and high temperature electrolysis are currently being developed as means to produce hydrogen from high temperature nuclear fission reactors and solar central receivers. This paper explores the feasibility of this concept for integration with a Laser IFE plant, and it looks at potential modifications to make this approach more attractive. Of particular interest are: (1) the determination of the advantages of Laser IFE hydrogen production compared to other hydrogen production concepts, and (2) whether a facility of the size of FTF would be suitable for hydrogen production.

  5. Rechargeable Hydrogen Storage System Based on the Dehydrogenative Coupling of Ethylenediamine with Ethanol.

    PubMed

    Hu, Peng; Ben-David, Yehoshoa; Milstein, David

    2016-01-18

    A novel and simple hydrogen storage system was developed, based on the dehydrogenative coupling of inexpensive ethylenediamine with ethanol to form diacetylethylenediamine. The system is rechargeable and utilizes the same ruthenium pincer catalyst for both hydrogen loading and unloading procedures. It is efficient and uses a low catalyst loading. Repetitive reversal reactions without addition of new catalyst result in excellent conversions in both the dehydrogenation and hydrogenation procedures in three cycles. PMID:26211515

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

    SciTech Connect

    James E. O'Brien

    2010-08-01

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

  7. A definition of the coupled-product for multivariate coupled-exponentials

    NASA Astrophysics Data System (ADS)

    Nelson, Kenric P.

    2015-03-01

    The coupled-product and coupled-exponential of the generalized calculus of nonextensive statistical mechanics are defined for multivariate functions. The nonlinear statistical coupling is indexed such that κd = κ / 1 + dκ, where d is the dimension of the argument of the multivariate coupled-exponential. The coupled-Gaussian distribution is defined such that the argument of the coupled-exponential depends on the coupled-moments but not the coupling parameter. The multivariate version of the coupled-product is defined such that the output dimensions are the sum of the input dimensions. This enables construction of the multivariate coupled-Gaussian from univariate coupled-Gaussians. The resulting construction forms a model of coupling between distributions, generalizing the product of independent Gaussians.

  8. Cost Analysis of a Concentrator Photovoltaic Hydrogen Production System

    SciTech Connect

    Thompson, J. R.; McConnell, R. D.; Mosleh, M.

    2005-08-01

    The development of efficient, renewable methods of producing hydrogen are essential for the success of the hydrogen economy. Since the feedstock for electrolysis is water, there are no harmful pollutants emitted during the use of the fuel. Furthermore, it has become evident that concentrator photovoltaic (CPV) systems have a number of unique attributes that could shortcut the development process, and increase the efficiency of hydrogen production to a point where economics will then drive the commercial development to mass scale.

  9. Process for the production of hydrogen from water

    DOEpatents

    Miller, William E.; Maroni, Victor A.; Willit, James L.

    2010-05-25

    A method and device for the production of hydrogen from water and electricity using an active metal alloy. The active metal alloy reacts with water producing hydrogen and a metal hydroxide. The metal hydroxide is consumed, restoring the active metal alloy, by applying a voltage between the active metal alloy and the metal hydroxide. As the process is sustainable, only water and electricity is required to sustain the reaction generating hydrogen.

  10. Hydrogen production with coal using a pulverization device

    DOEpatents

    Paulson, Leland E.

    1989-01-01

    A method for producing hydrogen from coal is described wherein high temperature steam is brought into contact with coal in a pulverizer or fluid energy mill for effecting a steam-carbon reaction to provide for the generation of gaseous hydrogen. The high temperature steam is utilized to drive the coal particles into violent particle-to-particle contact for comminuting the particulates and thereby increasing the surface area of the coal particles for enhancing the productivity of the hydrogen.

  11. Thermochemical Production of Hydrogen from Water.

    ERIC Educational Resources Information Center

    Bamberger, C. E.; And Others

    1978-01-01

    Discusses the possible advantages of decomposing water by means of thermochemical cycles. Explains that, if energy consumption can be minimized, this method is capable of producing hydrogen more efficiently than electrolysis. (GA)

  12. Compact hydrogen production systems for solid polymer fuel cells

    NASA Astrophysics Data System (ADS)

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

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

  13. Electrolytic production and dispensing of hydrogen

    SciTech Connect

    Thomas, C.E.; Kuhn, I.F. Jr.

    1995-09-01

    The fuel cell electric vehicle (FCEV) is undoubtedly the only option that can meet both the California zero emission vehicle (ZEV) standard and the President`s goal of tripling automobile efficiency without sacrificing performance in a standard 5-passenger vehicle. The three major automobile companies are designing and developing FCEVs powered directly by hydrogen under cost-shared contracts with the Department of Energy. Once developed, these vehicles will need a reliable and inexpensive source of hydrogen. Steam reforming of natural gas would produce the least expensive hydrogen, but funding may not be sufficient initially to build both large steam reforming plants and the transportation infrastructure necessary to deliver that hydrogen to geographically scattered FCEV fleets or individual drivers. This analysis evaluates the economic feasibility of using small scale water electrolysis to provide widely dispersed but cost-effective hydrogen for early FCEV demonstrations. We estimate the cost of manufacturing a complete electrolysis system in large quantities, including compression and storage, and show that electrolytic hydrogen could be cost competitive with fully taxed gasoline, using existing residential off-peak electricity rates.

  14. Estimation of bacterial hydrogen sulfide production in vitro

    PubMed Central

    Basic, Amina; Blomqvist, Susanne; Carlén, Anette; Dahlén, Gunnar

    2015-01-01

    Oral bacterial hydrogen sulfide (H2S) production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways. PMID:26130377

  15. Estimation of bacterial hydrogen sulfide production in vitro.

    PubMed

    Basic, Amina; Blomqvist, Susanne; Carlén, Anette; Dahlén, Gunnar

    2015-01-01

    Oral bacterial hydrogen sulfide (H2S) production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways. PMID:26130377

  16. Potential Application of Anaerobic Extremophiles for Hydrogen Production

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.

    2004-01-01

    During substrate fermentation many anaerobes produce the hydrogen as a waste product, which often regulates the growth of the cultures as an inhibitor. In nature the hydrogen is usually removed from the ecosystem due to its physical properties or by consumption of hydrogen by secondary anaerobes, which sometimes behave as competitors for electron donors as is seen in the classical example in anaerobic microbial communities via the interaction between methanogens and sulfate- or sulfur- reducers. It was demonstrated previously on mixed cultures of anaerobes at neutral pH that bacterial hydrogen production could provide an alternative energy source. But at neutral pH the original cultures can easily be contaminated by methanogens, a most unpleasant side effect of these conditions is the development of pathogenic bacteria. In both cases the rate of hydrogen production was dramatically decreased since some part of the hydrogen was transformed to methane, and the cultivation of human pathogens on a global scale is very dangerous. In our laboratory, experiments with obligately alkaliphilic bacteria that excrete hydrogen as the end metabolic product were performed at different temperature regimes. Mesophilic and moderately thermophilic bacterial cultures have been studied and compared for the most effective hydrogen production. For high-mineralized media with pH 9.5-10.0 not many methanogens are known to exist. Furthermore, the development of pathogenic contaminant microorganisms is virtually impossible: carbonate-saturated solutions are used as antiseptics in medicine. Therefore the cultivation of alkaliphilic hydrogen producing bacteria could be considered as most safe process for global Scale industry in future. Here we present experimental data on the rates of hydrogen productivity for mesophilic, alkaliphilic, obligately anaerobic bacterium Spirocheta americana ASpG1 and moderately thermophilic, alkaliphilic, facultative anaerobe Anoxybacillus pushchinoensis K1 and

  17. On-Board Hydrogen Gas Production System For Stirling Engines

    DOEpatents

    Johansson, Lennart N.

    2004-06-29

    A hydrogen production system for use in connection with Stirling engines. The production system generates hydrogen working gas and periodically supplies it to the Stirling engine as its working fluid in instances where loss of such working fluid occurs through usage through operation of the associated Stirling engine. The hydrogen gas may be generated by various techniques including electrolysis and stored by various means including the use of a metal hydride absorbing material. By controlling the temperature of the absorbing material, the stored hydrogen gas may be provided to the Stirling engine as needed. A hydrogen production system for use in connection with Stirling engines. The production system generates hydrogen working gas and periodically supplies it to the Stirling engine as its working fluid in instances where loss of such working fluid occurs through usage through operation of the associated Stirling engine. The hydrogen gas may be generated by various techniques including electrolysis and stored by various means including the use of a metal hydride absorbing material. By controlling the temperature of the absorbing material, the stored hydrogen gas may be provided to the Stirling engine as needed.

  18. Carbonate thermochemical cycle for the production of hydrogen

    DOEpatents

    Collins, Jack L [Knoxville, TN; Dole, Leslie R [Knoxville, TN; Ferrada, Juan J [Knoxville, TN; Forsberg, Charles W [Oak Ridge, TN; Haire, Marvin J [Oak Ridge, TN; Hunt, Rodney D [Oak Ridge, TN; Lewis, Jr, Benjamin E [Knoxville, TN; Wymer, Raymond G [Oak Ridge, TN

    2010-02-23

    The present invention is directed to a thermochemical method for the production of hydrogen from water. The method includes reacting a multi-valent metal oxide, water and a carbonate to produce an alkali metal-multi-valent metal oxide compound, carbon dioxide, and hydrogen.

  19. Carbonate Thermochemical Cycle for the Production of Hydrogen

    SciTech Connect

    Ferrada, Juan J; Collins, Jack Lee; Dole, Leslie Robert; Forsberg, Charles W; Haire, Marvin Jonathan; Hunt, Rodney Dale; Lewis Jr, Benjamin E; Wymer, Raymond; Ladd-Lively, Jennifer L

    2009-01-01

    The present invention is directed to a thermochemical method for the production of hydrogen from water. The method includes reacting a multi-valent metal oxide, water and a carbonate to produce an alkali metal-multi-valent metal oxide compound, carbon dioxide, and hydrogen.

  20. Hydrogen production econometric studies. [hydrogen and fossil fuels

    NASA Technical Reports Server (NTRS)

    Howell, J. R.; Bannerot, R. B.

    1975-01-01

    The current assessments of fossil fuel resources in the United States were examined, and predictions of the maximum and minimum lifetimes of recoverable resources according to these assessments are presented. In addition, current rates of production in quads/year for the fossil fuels were determined from the literature. Where possible, costs of energy, location of reserves, and remaining time before these reserves are exhausted are given. Limitations that appear to hinder complete development of each energy source are outlined.

  1. Renewable hydrogen production for fossil fuel processing

    SciTech Connect

    Greenbaum, E.; Lee, J.W.; Tevault, C.V.

    1995-06-01

    In the fundamental biological process of photosynthesis, atmospheric carbon dioxide is reduced to carbohydrate using water as the source of electrons with simultaneous evolution of molecular oxygen: H{sub 2}O + CO{sub 2} + light {yields} O{sub 2} + (CH{sub 2}O). It is well established that two light reactions, Photosystems I and II (PSI and PSII) working in series, are required to perform oxygenic photosynthesis. Experimental data supporting the two-light reaction model are based on the quantum requirement for complete photosynthesis, spectroscopy, and direct biochemical analysis. Some algae also have the capability to evolve molecular hydrogen in a reaction energized by the light reactions of photosynthesis. This process, now known as biophotolysis, can use water as the electron donor and lead to simultaneous evolution of molecular hydrogen and oxygen. In green algae, hydrogen evolution requires prior incubation under anaerobic conditions. Atmospheric oxygen inhibits hydrogen evolution and also represses the synthesis of hydrogenase enzyme. CO{sub 2} fixation competes with proton reduction for electrons relased from the photosystems. Interest in biophotolysis arises from both the questions that it raises concerning photosynthesis and its potential practical application as a process for converting solar energy to a non-carbon-based fuel. Prior data supported the requirement for both Photosystem I and Photosystem II in spanning the energy gap necessary for biophotolysis of water to oxygen and hydrogen. In this paper we report the at PSII alone is capable of driving sustained simultaneous photoevolution of molecular hydrogen and oxygen in an anaerobically adapted PSI-deficient strain of Chlamydomonas reinhardtii, mutant B4, and that CO{sub 2} competes as an electron acceptor.

  2. Metal dichalcogenides monolayers: novel catalysts for electrochemical hydrogen production.

    PubMed

    Pan, Hui

    2014-01-01

    Catalyst-driven electrolysis of water is considered as a "cleanest" way for hydrogen production. Finding cheap and abundant catalysts is critical to the large-scale implementation of the technology. Two-dimensional metal dichalcogenides nanostructures have attracted increasing attention because of their catalytic performances in water electrolysis. In this work, we systematically investigate the hydrogen evolution reduction of metal dichalcogenides monolayers based on density-functional-theory calculations. We find that metal disulfide monolayers show better catalytic performance on hydrogen production than other metal dichalcogenides. We show that their hydrogen evolution reduction strongly depends on the hydrogen coverage and the catalytic performance reduces with the increment of coverage because of hydrogenation-induced lower conductivity. We further show that the catalytic performance of vanadium disulfide monolayer is comparable to that of Pt at lower hydrogen coverage and the performance at higher coverage can be improved by hybridizing with conducting nanomaterials to enhance conductivity. These metal disulfide monolayers with lower overpotentials may apply to water electrolysis for hydrogen production. PMID:24967679

  3. Metal Dichalcogenides Monolayers: Novel Catalysts for Electrochemical Hydrogen Production

    PubMed Central

    Pan, Hui

    2014-01-01

    Catalyst-driven electrolysis of water is considered as a “cleanest” way for hydrogen production. Finding cheap and abundant catalysts is critical to the large-scale implementation of the technology. Two-dimensional metal dichalcogenides nanostructures have attracted increasing attention because of their catalytic performances in water electrolysis. In this work, we systematically investigate the hydrogen evolution reduction of metal dichalcogenides monolayers based on density-functional-theory calculations. We find that metal disulfide monolayers show better catalytic performance on hydrogen production than other metal dichalcogenides. We show that their hydrogen evolution reduction strongly depends on the hydrogen coverage and the catalytic performance reduces with the increment of coverage because of hydrogenation-induced lower conductivity. We further show that the catalytic performance of vanadium disulfide monolayer is comparable to that of Pt at lower hydrogen coverage and the performance at higher coverage can be improved by hybridizing with conducting nanomaterials to enhance conductivity. These metal disulfide monolayers with lower overpotentials may apply to water electrolysis for hydrogen production. PMID:24967679

  4. Exergetic life cycle assessment of hydrogen production from renewables

    NASA Astrophysics Data System (ADS)

    Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.

    Life cycle assessment is extended to exergetic life cycle assessment and used to evaluate the exergy efficiency, economic effectiveness and environmental impact of producing hydrogen using wind and solar energy in place of fossil fuels. The product hydrogen is considered a fuel for fuel cell vehicles and a substitute for gasoline. Fossil fuel technologies for producing hydrogen from natural gas and gasoline from crude oil are contrasted with options using renewable energy. Exergy efficiencies and greenhouse gas and air pollution emissions are evaluated for all process steps, including crude oil and natural gas pipeline transportation, crude oil distillation and natural gas reforming, wind and solar electricity generation, hydrogen production through water electrolysis, and gasoline and hydrogen distribution and utilization. The use of wind power to produce hydrogen via electrolysis, and its application in a fuel cell vehicle, exhibits the lowest fossil and mineral resource consumption rate. However, the economic attractiveness, as measured by a "capital investment effectiveness factor," of renewable technologies depends significantly on the ratio of costs for hydrogen and natural gas. At the present cost ratio of about 2 (per unit of lower heating value or exergy), capital investments are about five times lower to produce hydrogen via natural gas rather than wind energy. As a consequence, the cost of wind- and solar-based electricity and hydrogen is substantially higher than that of natural gas. The implementation of a hydrogen fuel cell instead of an internal combustion engine permits, theoretically, an increase in a vehicle's engine efficiency of about of two times. Depending on the ratio in engine efficiencies, the substitution of gasoline with "renewable" hydrogen leads to (a) greenhouse gas (GHG) emissions reductions of 12-23 times for hydrogen from wind and 5-8 times for hydrogen from solar energy, and (b) air pollution (AP) emissions reductions of 38

  5. Mechanistic modeling of sulfur-deprived photosynthesis and hydrogen production in suspensions of Chlamydomonas reinhardtii.

    PubMed

    Williams, C R; Bees, M A

    2014-02-01

    The ability of unicellular green algal species such as Chlamydomonas reinhardtii to produce hydrogen gas via iron-hydrogenase is well known. However, the oxygen-sensitive hydrogenase is closely linked to the photosynthetic chain in such a way that hydrogen and oxygen production need to be separated temporally for sustained photo-production. Under illumination, sulfur-deprivation has been shown to accommodate the production of hydrogen gas by partially-deactivating O2 evolution activity, leading to anaerobiosis in a sealed culture. As these facets are coupled, and the system complex, mathematical approaches potentially are of significant value since they may reveal improved or even optimal schemes for maximizing hydrogen production. Here, a mechanistic model of the system is constructed from consideration of the essential pathways and processes. The role of sulfur in photosynthesis (via PSII) and the storage and catabolism of endogenous substrate, and thus growth and decay of culture density, are explicitly modeled in order to describe and explore the complex interactions that lead to H2 production during sulfur-deprivation. As far as possible, functional forms and parameter values are determined or estimated from experimental data. The model is compared with published experimental studies and, encouragingly, qualitative agreement for trends in hydrogen yield and initiation time are found. It is then employed to probe optimal external sulfur and illumination conditions for hydrogen production, which are found to differ depending on whether a maximum yield of gas or initial production rate is required. The model constitutes a powerful theoretical tool for investigating novel sulfur cycling regimes that may ultimately be used to improve the commercial viability of hydrogen gas production from microorganisms. PMID:24026984

  6. Mechanistic modeling of sulfur-deprived photosynthesis and hydrogen production in suspensions of Chlamydomonas reinhardtii

    PubMed Central

    Williams, C R; Bees, MA

    2014-01-01

    The ability of unicellular green algal species such as Chlamydomonas reinhardtii to produce hydrogen gas via iron-hydrogenase is well known. However, the oxygen-sensitive hydrogenase is closely linked to the photosynthetic chain in such a way that hydrogen and oxygen production need to be separated temporally for sustained photo-production. Under illumination, sulfur-deprivation has been shown to accommodate the production of hydrogen gas by partially-deactivating O2 evolution activity, leading to anaerobiosis in a sealed culture. As these facets are coupled, and the system complex, mathematical approaches potentially are of significant value since they may reveal improved or even optimal schemes for maximizing hydrogen production. Here, a mechanistic model of the system is constructed from consideration of the essential pathways and processes. The role of sulfur in photosynthesis (via PSII) and the storage and catabolism of endogenous substrate, and thus growth and decay of culture density, are explicitly modeled in order to describe and explore the complex interactions that lead to H2 production during sulfur-deprivation. As far as possible, functional forms and parameter values are determined or estimated from experimental data. The model is compared with published experimental studies and, encouragingly, qualitative agreement for trends in hydrogen yield and initiation time are found. It is then employed to probe optimal external sulfur and illumination conditions for hydrogen production, which are found to differ depending on whether a maximum yield of gas or initial production rate is required. The model constitutes a powerful theoretical tool for investigating novel sulfur cycling regimes that may ultimately be used to improve the commercial viability of hydrogen gas production from microorganisms. Biotechnol. Bioeng. 2014;111: 320–335. © 2013 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. PMID:24026984

  7. NGNP Process Heat Applications: Hydrogen Production Accomplishments for FY2010

    SciTech Connect

    Charles V Park

    2011-01-01

    This report summarizes FY10 accomplishments of the Next Generation Nuclear Plant (NGNP) Engineering Process Heat Applications group in support of hydrogen production technology development. This organization is responsible for systems needed to transfer high temperature heat from a high temperature gas-cooled reactor (HTGR) reactor (being developed by the INL NGNP Project) to electric power generation and to potential industrial applications including the production of hydrogen.

  8. Solar photoproduction of hydrogen. IEA technical report of the IEA Agreement of the Production and Utilization of Hydrogen

    SciTech Connect

    Bolton, J.R.

    1996-09-30

    The report was prepared for the International Energy Agency (IEA) Hydrogen Program and represents the result of subtask C, Annex 10 - Photoproduction of Hydrogen. The concept of using solar energy to drive the conversion of water into hydrogen and oxygen has been examined, from the standpoints of potential and ideal efficiencies, measurement of (and how to calculate) solar hydrogen production efficiencies, a survey of the state-of-the-art, and a technological assessment of various solar hydrogen options. The analysis demonstrates that the ideal limit of the conversion efficiency for 1 sun irradiance is {approximately}31% for a single photosystem scheme and {approximately}42% for a dual photosystem scheme. However, practical considerations indicate that real efficiencies will not likely exceed {approximately}10% and {approximately}16% for single and dual photosystem schemes, respectively. Four types of solar photochemical hydrogen systems have been identified: photochemical systems, semiconductor systems, photobiological systems, and hybrid and other systems. A survey of the state-of-the-art of these four types is presented. The four types (and their subtypes) have also been examined in a technological assessment, where each has been examined as to efficiency, potential for improvement, and long-term functionality. Four solar hydrogen systems have been selected as showing sufficient promise for further research and development: (1) Photovoltaic cells plus an electrolyzer; (2) Photoelectrochemical cells with one or more semiconductor electrodes; (3) Photobiological systems; and (4) Photodegradation systems. The following recommendations were presented for consideration of the IEA: (1) Define and measure solar hydrogen conversion efficiencies as the ratio of the rate of generation of Gibbs energy of dry hydrogen gas (with appropriate corrections for any bias power) to the incident solar power (solar irradiance times the irradiated area); (2) Expand support for pilot

  9. In vitro hydrogen production by glucose dehydrogenase and hydrogenase

    SciTech Connect

    Woodward, J.

    1996-10-01

    A new in vitro enzymatic pathway for the generation of molecular hydrogen from glucose has been demonstrated. The reaction is based upon the oxidation of glucose by Thermoplasma acidophilum glucose dehydrogenase with the concomitant oxidation of NADPH by Pyrococcus furiosus hydrogenase. Stoichiometric yields of hydrogen were produced from glucose with continuous cofactor recycle. This simple system may provide a method for the biological production of hydrogen from renewable sources. In addition, the other product of this reaction, gluconic acid, is a high-value commodity chemical.

  10. PHOTOBIOREACTOR FOR HYDROGEN PRODUCTION FROM CATTLE MANURE

    EPA Science Inventory

    Hydrogen has been identified as an energy-efficient and pollution-free energy carrier that has the potential to replace the existing nonrenewable fossil fuels. The student team at the New Mexico State University will design a prototype of an anaerobic reactor for biohydrogen ...

  11. Light irradiance and spectral distribution effects on cyanobacterial hydrogen production

    NASA Astrophysics Data System (ADS)

    Fatihah Salleh, Siti; Kamaruddin, Azlina; Hekarl Uzir, Mohamad; Rahman Mohamed, Abdul; Halim Shamsuddin, Abdul

    2016-03-01

    Light is an essential energy source for photosynthetic cyanobacteria. Changes in both light irradiance and spectral distribution will affect their photosynthetic productivity. Compared to the light irradiance, little investigations have been carried out on the effect of light spectra towards cyanobacterial hydrogen production. Hence, this work aims to investigate the effects of both light quantity and quality on biohydrogen productivity of heterocystous cyanobacterium, A.variabilis. Under white light condition, the highest hydrogen production rate of 31 µmol H2 mg chl a -1 h-1 was achieved at 70 µE m-2 s-1. When the experiment was repeated at the same light irradiance but different light spectra of blue, red and green, the accumulations of hydrogen were significantly lower than the white light except for blue light. As the light irradiance was increased to 350 µE m-2 s-1, the accumulated hydrogen under the blue light doubled that of the white light. Besides that, an unusual prolongation of the hydrogen production up to 120 h was observed. The results obtained suggest that blue light could be the most desirable light spectrum for cyanobacterial hydrogen production.

  12. Production of hydrogen by thermocatalytic cracking of natural gas

    SciTech Connect

    Muradov, N.Z.

    1995-09-01

    It is universally accepted that in the next few decades hydrogen production will continue to rely on fossil fuels (primarily, natural gas). On the other hand, the conventional methods of hydrogen production from natural gas (for example, steam reforming) are complex multi-step processes. These processes also result in the emission of large quantities of CO{sub 2} into the atmosphere that produce adverse ecological effects. One alternative is the one-step thermocatalytic cracking (TCC) (or decomposition) of natural gas into hydrogen and carbon. Preliminary analysis indicates that the cost of hydrogen produced by thermal decomposition of natural gas is somewhat lower than the conventional processes after by-product carbon credit is taken. In the short term, this process can be used for on-site production of hydrogen-methane mixtures in gas-filling stations and for CO{sub x}-free production of hydrogen for fuel cell driven prime movers. The experimental data on the thermocatalytic cracking of methane over various catalysts and supports in a wide range of temperatures (500-900{degrees}C) are presented in this paper. Two types of reactors were designed and built at FSEC: continuous flow and pulse fix bed catalytic reactors. The temperature dependence of the hydrogen production yield using oxide type catalysts was studied. Alumina-supported Ni- and Fe-catalysts demonstrated relatively high efficiency in the methane cracking reaction at moderate temperatures (600-800{degrees}C). Kinetic curves of hydrogen production over metal and metal oxide catalysts at different temperatures are presented in the paper. Fe-catalyst demonstrated good stability (for several hours), whereas alumina-supported Pt-catalyst rapidly lost its catalytic activity.

  13. Oxidant-free dehydrogenative coupling reactions via hydrogen evolution.

    PubMed

    He, Ke-Han; Li, Yang

    2014-10-01

    Oxidant-free dehydrogenative coupling reactions: Recently, coupling reactions have followed a novel strategy for the construction of C==C, C==N, C==P, and S==S bonds by dehydrogenation without using any extra oxidant, via H2 evolution. These breakthroughs inspire a new direction in the construction of chemical bonds, towards more sustainable, highly atom-economical, and environmentally benign synthetic methods. PMID:25139249

  14. Hydrogen production from coal using a nuclear heat source

    NASA Technical Reports Server (NTRS)

    Quade, R. N.

    1976-01-01

    A strong candidate for hydrogen production in the intermediate time frame of 1985 to 1995 is a coal-based process using a high-temperature gas-cooled reactor (HTGR) as a heat source. Expected process efficiencies in the range of 60 to 70% are considerably higher than all other hydrogen production processes except steam reforming of a natural gas. The process involves the preparation of a coal liquid, hydrogasification of that liquid, and steam reforming of the resulting gaseous or light liquid product. A study showing process efficiency and cost of hydrogen vs nuclear reactor core outlet temperature has been completed, and shows diminishing returns at process temperatures above about 1500 F. A possible scenario combining the relatively abundant and low-cost Western coal deposits with the Gulf Coast hydrogen users is presented which provides high-energy density transportation utilizing coal liquids and uranium.

  15. Self-Assembling Hydrogel Scaffolds for Photocatalytic Hydrogen Production

    PubMed Central

    Weingarten, Adam S.; Kazantsev, Roman V.; Palmer, Liam C.; McClendon, Mark; Koltonow, Andrew R.; Samuel, Amanda P. S.; Kiebala, Derek J.; Wasielewski, Michael R.; Stupp, Samuel I.

    2015-01-01

    Integration in a soft material of all molecular components necessary to generate storable fuels is an interesting target in supramolecular chemistry. The concept is inspired by the internal structure of photosynthetic organelles such as plant chloroplasts which co-localize molecules involved in light absorption, charge transport, and catalysis to create chemical bonds with light energy. We report here on the light-driven production of hydrogen inside a hydrogel scaffold built by the supramolecular self-assembly of a perylene monoimide amphiphile. The charged ribbons formed can electrostatically attract a nickel-based catalyst, and electrolyte screening promotes gelation. We found the emergent phenomenon that screening by the catalyst or the electrolytes led to two-dimensional crystallization of the chromophore assemblies and enhanced the electronic coupling among the molecules. Photocatalytic production of hydrogen is observed in the three-dimensional environment of the hydrogel scaffold and the material is easily placed on surfaces or in the pores of solid supports. The development of soft materials that integrate all necessary molecular components to generate storable fuels in the presence of sunlight is an unexplored area of chemistry with potential impact in renewable energy. Such systems could have advantages over the use of large volumes of liquids, dispersions of expensive or toxic inorganic particles, or complex devices. The use of such soft materials with integrated functions and high water content is bioinspired by the internal structure of chloroplasts in plants. These photosynthetic organelles have evolved to co-localize within stacked lipid bilayers in their stroma the protein machinery which integrates light-absorption, charge transport, and the catalytic functions necessary to convert light energy into chemical bonds1,2. Efforts to emulate natural photosynthetic systems over the past several decades have concentrated on the development of efficient

  16. Synergistic Hydrogen Production in a Biorefinery via Bioelectrochemical Systems

    SciTech Connect

    Borole, A. P.; Hamilton, C. Y.; Schell, D. J.

    2012-01-01

    Microbial electrolysis cells are devices that use biocatalysis and electrolysis for production of hydrogen from organic matter. Biorefinery process streams contain fermentation by products and inhibitors which accumulate in the process stream if the water is recycled. These molecules also affect biomass to biofuel yields if not removed from the recycle water. The presence of sugar- and lignin- degradation products such as furfural, vanillic acid and 4-hydroxybenzaldehyde has been shown to reduce fermentation yields. In this work, we calculate the potential for hydrogen production using microbial electrolysis cells from these molecules as substrates. Conversion of these substrates to electricity is demonstrated in microbial fuel cells and will also be presented.

  17. Hydrogen production by nitrogen-starved cultures of Anabaena cylindrica.

    PubMed Central

    Weissman, J C; Benemann, J R

    1977-01-01

    Nitrogen-starved cultures of the alga Anabaena cylindrica 629 produced hydrogen and oxygen continuously for 7 to 19 days. Hydrogen production attained a maximum level after 1 to 2 days of starvation and was followed by a slow decline. The maximum rates were 30 ml of H2 evolved per liter of culture per h or 32 mul of H2 per mg of dry weight per h. In 5 to 7 days the rate of H2 evolution by the more productive cultures fell to one-half its maximum value. The addition of 10(-4) to 5 X 10(-4) M ammonium increased the rate of oxygen evolution and the total hydrogen production of the cultures. H2-O2 ratios were 4:1 under conditions of complete nitrogen starvation and about 1.7:1 after the addition of ammonium. Thus, oxygen evolution was affected by the extent of the nitrogen starvation. Thermodynamic efficiencies of converting incident light energy to free energy of hydrogen via algal photosynthesis were 0.4%. Possible factors limiting hydrogen production were decline of reductant supply and filament breakage. Hydrogen production by filamentous, heterocystous blue-green algae could be used for development of a biophotolysis system. PMID:402109

  18. Aerobic Hydrogen Production via Nitrogenase in Azotobacter vinelandii CA6

    PubMed Central

    Noar, Jesse; Loveless, Telisa; Navarro-Herrero, José Luis; Olson, Jonathan W.

    2015-01-01

    The diazotroph Azotobacter vinelandii possesses three distinct nitrogenase isoenzymes, all of which produce molecular hydrogen as a by-product. In batch cultures, A. vinelandii strain CA6, a mutant of strain CA, displays multiple phenotypes distinct from its parent: tolerance to tungstate, impaired growth and molybdate transport, and increased hydrogen evolution. Determining and comparing the genomic sequences of strains CA and CA6 revealed a large deletion in CA6's genome, encompassing genes related to molybdate and iron transport and hydrogen reoxidation. A series of iron uptake analyses and chemostat culture experiments confirmed iron transport impairment and showed that the addition of fixed nitrogen (ammonia) resulted in cessation of hydrogen production. Additional chemostat experiments compared the hydrogen-producing parameters of different strains: in iron-sufficient, tungstate-free conditions, strain CA6's yields were identical to those of a strain lacking only a single hydrogenase gene. However, in the presence of tungstate, CA6 produced several times more hydrogen. A. vinelandii may hold promise for developing a novel strategy for production of hydrogen as an energy compound. PMID:25911479

  19. USE OF THE MODULAR HELIUM REACTOR FOR HYDROGEN PRODUCTION

    SciTech Connect

    SCHULTZ,KR

    2003-09-01

    OAK-B135 A significant ''Hydrogen Economy'' is predicted that will reduce our dependence on petroleum imports and reduce pollution and greenhouse gas emissions. Hydrogen is an environmentally attractive fuel that has the potential to displace fossil fuels, but contemporary hydrogen production is primarily based on fossil fuels. The author has recently completed a three-year project for the US Department of Energy (DOE) whose objective was to ''define an economically feasible concept for production of hydrogen, using an advanced high-temperature nuclear reactor as the energy source''. Thermochemical water-slitting, a chemical process that accomplishes the decomposition of water into hydrogen and oxygen, met this objective. The goal of the first phase of this study was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen, and to select one for further detailed consideration. They selected the Sulfur-Iodine cycle. In the second phase, they reviewed all the basic reactor types for suitability to provide the high temperature heat needed by the selected thermochemical water splitting cycle and chose the helium gas-cooled reactor. In the third phase they designed the chemical flowsheet for the thermochemical process and estimated the efficiency and cost of the process and the projected cost of producing hydrogen. These results are summarized in this report.

  20. Hydrogen production by the decomposition of water

    DOEpatents

    Hollabaugh, Charles M.; Bowman, Melvin G.

    1981-01-01

    How to produce hydrogen from water was a problem addressed by this invention. The solution employs a combined electrolytical-thermochemical sulfuric acid process. Additionally, high purity sulfuric acid can be produced in the process. Water and SO.sub.2 react in electrolyzer (12) so that hydrogen is produced at the cathode and sulfuric acid is produced at the anode. Then the sulfuric acid is reacted with a particular compound M.sub.r X.sub.s so as to form at least one water insoluble sulfate and at least one water insoluble oxide of molybdenum, tungsten, or boron. Water is removed by filtration; and the sulfate is decomposed in the presence of the oxide in sulfate decomposition zone (21), thus forming SO.sub.3 and reforming M.sub.r X.sub.s. The M.sub.r X.sub.s is recycled to sulfate formation zone (16). If desired, the SO.sub.3 can be decomposed to SO.sub.2 and O.sub.2 ; and the SO.sub.2 can be recycled to electrolyzer (12) to provide a cycle for producing hydrogen.

  1. Solar Hydrogen Production by Amorphous Silicon Photocathodes Coated with a Magnetron Sputter Deposited Mo2C Catalyst.

    PubMed

    Morales-Guio, Carlos G; Thorwarth, Kerstin; Niesen, Bjoern; Liardet, Laurent; Patscheider, Jörg; Ballif, Christophe; Hu, Xile

    2015-06-10

    Coupling of Earth-abundant hydrogen evolution catalysts to photoabsorbers is crucial for the production of hydrogen fuel using sunlight. In this work, we demonstrate the use of magnetron sputtering to deposit Mo2C as an efficient hydrogen evolution reaction catalyst onto surface-protected amorphous silicon (a-Si) photoabsorbers. The a-Si/Mo2C photocathode evolves hydrogen under simulated solar illumination in strongly acidic and alkaline electrolytes. Onsets of photocurrents are observed at potentials as positive as 0.85 V vs RHE. Under AM 1.5G (1 sun) illumination, the photocathodes reach current densities of -11.2 mA cm(-2) at the reversible hydrogen potential in 0.1 M H2SO4 and 1.0 M KOH. The high photovoltage and low-cost of the Mo2C/a-Si assembly make it a promising photocathode for solar hydrogen production. PMID:26005904

  2. Onboard Plasmatron Hydrogen Production for Improved Vehicles

    SciTech Connect

    Daniel R. Cohn; Leslie Bromberg; Kamal Hadidi

    2005-12-31

    A plasmatron fuel reformer has been developed for onboard hydrogen generation for vehicular applications. These applications include hydrogen addition to spark-ignition internal combustion engines, NOx trap and diesel particulate filter (DPF) regeneration, and emissions reduction from spark ignition internal combustion engines First, a thermal plasmatron fuel reformer was developed. This plasmatron used an electric arc with relatively high power to reform fuels such as gasoline, diesel and biofuels at an oxygen to carbon ratio close to 1. The draw back of this device was that it has a high electric consumption and limited electrode lifetime due to the high temperature electric arc. A second generation plasmatron fuel reformer was developed. It used a low-current high-voltage electric discharge with a completely new electrode continuation. This design uses two cylindrical electrodes with a rotating discharge that produced low temperature volumetric cold plasma., The lifetime of the electrodes was no longer an issue and the device was tested on several fuels such as gasoline, diesel, and biofuels at different flow rates and different oxygen to carbon ratios. Hydrogen concentration and yields were measured for both the thermal and non-thermal plasmatron reformers for homogeneous (non-catalytic) and catalytic reforming of several fuels. The technology was licensed to an industrial auto part supplier (ArvinMeritor) and is being implemented for some of the applications listed above. The Plasmatron reformer has been successfully tested on a bus for NOx trap regeneration. The successful development of the plasmatron reformer and its implementation in commercial applications including transportation will bring several benefits to the nation. These benefits include the reduction of NOx emissions, improving engine efficiency and reducing the nation's oil consumption. The objective of this program has been to develop attractive applications of plasmatron fuel reformer

  3. Biological hydrogen production using chloroform-treated methanogenic granules.

    PubMed

    Hu, Bo; Chen, Shulin

    2008-03-01

    In fermentative hydrogen production, the low-hydrogen-producing bacteria retention rate limits the suspended growth reactor productivity because of the long hydraulic retention time (HRT) required to maintain adequate bacteria population. Traditional bacteria immobilization methods such as calcium alginate entrapment have many application limitations in hydrogen fermentation, including limited duration time, bacteria leakage, cost, and so on. The use of chloroform-treated anaerobic granular sludge as immobilized hydrogen-producing bacteria in an immobilized hydrogen culture may be able to overcome the limitations of traditional immobilization methods. This paper reports the findings on the performance of fed-batch cultures and continuous cultures inoculated with chloroform-treated granules. The chloroform-treated granules were able to be reused over four fed-batch cultures, with pH adjustment. The upflow reactor packed with chloroform-treated granules was studied, and the HRT of the upflow reactor was found to be as low as 4 h without any decrease in hydrogen production yield. Initial pH and glucose concentration of the culture medium significantly influenced the performance of the reactor. The optimum initial pH of the culture medium was neutral, and the optimum glucose concentration of the culture medium was below 20 g chemical oxygen demand/L at HRT 4 h. This study also investigated the possibility of integrating immobilized hydrogen fermentation using chloroform-treated granules with immobilized methane production using untreated granular sludge. The results showed that the integrated batch cultures produced 1.01 mol hydrogen and 2 mol methane per mol glucose. Treating the methanogenic granules with chloroform and then using the treated granules as immobilized hydrogen-producing sludge demonstrated advantages over other immobilization methods because the treated granules provide hydrogen-producing bacteria with a protective niche, a long duration of an active

  4. Biological Hydrogen Production Using Chloroform-treated Methanogenic Granules

    NASA Astrophysics Data System (ADS)

    Hu, Bo; Chen, Shulin

    In fermentative hydrogen production, the low-hydrogen-producing bacteria retention rate limits the suspended growth reactor productivity because of the long hydraulic retention time (HRT) required to maintain adequate bacteria population. Traditional bacteria immobilization methods such as calcium alginate entrapment have many application limitations in hydrogen fermentation, including limited duration time, bacteria leakage, cost, and so on. The use of chloroform-treated anaerobic granular sludge as immobilized hydrogen-producing bacteria in an immobilized hydrogen culture may be able to overcome the limitations of traditional immobilization methods. This paper reports the findings on the performance of fed-batch cultures and continuous cultures inoculated with chloroform-treated granules. The chloroform-treated granules were able to be reused over four fed-batch cultures, with pH adjustment. The upflow reactor packed with chloroform-treated granules was studied, and the HRT of the upflow reactor was found to be as low as 4 h without any decrease in hydrogen production yield. Initial pH and glucose concentration of the culture medium significantly influenced the performance of the reactor. The optimum initial pH of the culture medium was neutral, and the optimum glucose concentration of the culture medium was below 20 g chemical oxygen demand/L at HRT 4 h. This study also investigated the possibility of integrating immobilized hydrogen fermentation using chloroform-treated granules with immobilized methane production using untreated granular sludge. The results showed that the integrated batch cultures produced 1.01 mol hydrogen and 2 mol methane per mol glucose. Treating the methanogenic granules with chloroform and then using the treated granules as immobilized hydrogen-producing sludge demonstrated advantages over other immobilization methods because the treated granules provide hydrogen-producing bacteria with a protective niche, a long duration of an active

  5. Technoeconomic analysis of renewable hydrogen production, storage, and detection systems

    SciTech Connect

    Mann, M.K.; Spath, P.L.; Kadam, K.

    1996-10-01

    Technical and economic feasibility studies of different degrees of completeness and detail have been performed on several projects being funded by the Department of Energy`s Hydrogen Program. Work this year focused on projects at the National Renewable Energy Laboratory, although analyses of projects at other institutions are underway or planned. Highly detailed analyses were completed on a fiber optic hydrogen leak detector and a process to produce hydrogen from biomass via pyrolysis followed by steam reforming of the pyrolysis oil. Less detailed economic assessments of solar and biologically-based hydrogen production processes have been performed and focused on the steps that need to be taken to improve the competitive position of these technologies. Sensitivity analyses were conducted on all analyses to reveal the degree to which the cost results are affected by market changes and technological advances. For hydrogen storage by carbon nanotubes, a survey of the competing storage technologies was made in order to set a baseline for cost goals. A determination of the likelihood of commercialization was made for nearly all systems examined. Hydrogen from biomass via pyrolysis and steam reforming was found to have significant economic potential if a coproduct option could be co-commercialized. Photoelectrochemical hydrogen production may have economic potential, but only if low-cost cells can be modified to split water and to avoid surface oxidation. The use of bacteria to convert the carbon monoxide in biomass syngas to hydrogen was found to be slightly more expensive than the high end of currently commercial hydrogen, although there are significant opportunities to reduce costs. Finally, the cost of installing a fiber-optic chemochromic hydrogen detection system in passenger vehicles was found to be very low and competitive with alternative sensor systems.

  6. Evidence For The Production Of Slow Antiprotonic Hydrogen In Vacuum

    SciTech Connect

    Zurlo, N.; Rizzini, E. Lodi; Venturelli, L.; Amoretti, M.; Macri, M.; Testera, G.; Variola, A.; Amsler, C.; Pruys, H.; Regenfus, C.; Bonomi, G.; Carraro, C.; Lagomarsino, V.; Manuzio, G.; Cesar, C. L.; Charlton, M.; Joergensen, L. V.; Madsen, N.; Mitchard, D.; Werf, D. P. van der

    2006-10-13

    We present evidence showing how antiprotonic hydrogen, the quasistable antiproton (p)-proton bound system, has been synthesized following the interaction of antiprotons with the molecular ion H{sub 2}{sup +} in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events, evidence is presented for antiprotonic hydrogen production with sub-eV kinetic energies in states around n=70, and with low angular momenta. The slow antiprotonic hydrogen may be studied using laser spectroscopic techniques.

  7. Evidence for the production of slow antiprotonic hydrogen in vacuum.

    PubMed

    Zurlo, N; Amoretti, M; Amsler, C; Bonomi, G; Carraro, C; Cesar, C L; Charlton, M; Doser, M; Fontana, A; Funakoshi, R; Genova, P; Hayano, R S; Jørgensen, L V; Kellerbauer, A; Lagomarsino, V; Landua, R; Rizzini, E Lodi; Macrì, M; Madsen, N; Manuzio, G; Mitchard, D; Montagna, P; Posada, L G; Pruys, H; Regenfus, C; Rotondi, A; Testera, G; Van der Werf, D P; Variola, A; Venturelli, L; Yamazaki, Y

    2006-10-13

    We present evidence showing how antiprotonic hydrogen, the quasistable antiproton (p)-proton bound system, has been synthesized following the interaction of antiprotons with the molecular ion H2+ in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events, evidence is presented for antiprotonic hydrogen production with sub-eV kinetic energies in states around n=70, and with low angular momenta. The slow antiprotonic hydrogen may be studied using laser spectroscopic techniques. PMID:17155325

  8. Hydrogen production using hydrogenase-containing oxygenic photosynthetic organisms

    DOEpatents

    Melis, Anastasios; Zhang, Liping; Benemann, John R.; Forestier, Marc; Ghirardi, Maria; Seibert, Michael

    2006-01-24

    A reversible physiological process provides for the temporal separation of oxygen evolution and hydrogen production in a microorganism, which includes the steps of growing a culture of the microorganism in medium under illuminated conditions to accumulate an endogenous substrate, depleting from the medium a nutrient selected from the group consisting of sulfur, iron, and/or manganese, sealing the culture from atmospheric oxygen, incubating the culture in light whereby a rate of light-induced oxygen production is equal to or less than a rate of respiration, and collecting an evolved gas. The process is particularly useful to accomplish a sustained photobiological hydrogen gas production in cultures of microorganisms, such as Chlamydomonas reinhardtii.

  9. Hydrogen Production Using Hydrogenase-Containing Oxygenic Photosynthetic Organisms

    DOEpatents

    Melis, A.; Zhang, L.; Benemann, J. R.; Forestier, M.; Ghirardi, M.; Seibert, M.

    2006-01-24

    A reversible physiological process provides for the temporal separation of oxygen evolution and hydrogen production in a microorganism, which includes the steps of growing a culture of the microorganism in medium under illuminated conditions to accumulate an endogenous substrate, depleting from the medium a nutrient selected from the group consisting of sulfur, iron, and/or manganese, sealing the culture from atmospheric oxygen, incubating the culture in light whereby a rate of light-induced oxygen production is equal to or less than a rate of respiration, and collecting an evolved gas. The process is particularly useful to accomplish a sustained photobiological hydrogen gas production in cultures of microorganisms, such as Chlamydomonas reinhardtii.

  10. Thermal coupling of protons and neutral hydrogen with anisotropic temperatures in the fast solar wind

    NASA Astrophysics Data System (ADS)

    Allen, Lorraine A.; Habbal, Shadia R.; Li, Xing

    2000-10-01

    The thermal coupling between the neutral hydrogen and protons in the inner corona is explored by extending the study of Allenet al. [1998] to include anisotropic proton temperature to determine what the neutral hydrogen Ly α spectral line measurements reveal about the proton temperature, temperature anisotropy, and outflow velocity in the fast solar wind. The anisotropic proton temperature is produced by ion cyclotron resonant interaction of protons with high-frequency waves, produced by a nonlinear cascade at the Kolmogorov dissipation rate from dominant lower-frequency Alfvén waves. As a result of the coupling between the respective parallel and perpendicular components of the neutral hydrogen and proton temperatures, a greater temperature anisotropy in the neutral hydrogen develops as compared to the case when the proton temperature is isotropic. The neutral hydrogen and proton effective temperatures (Teff), incorporating both random and wave motions of the particles, and outflow velocities, are comparable below ~3Rs. Neutral hydrogen anisotropy ratios, TH(eff)/T∥, ~4 below 3Rs are readily attained, in agreement with observations. Below ~3Rs, these reflect the proton anisotropy ratio. For plasma conditions typical of the fast solar wind, these results imply that the measured Ly α spectral line profiles, from which the neutral hydrogen temperature, anisotropy ratio, and outflow velocity are inferred, are equivalent to measurements of protons below ~3Rs. Beyond this distance the width of the measured Ly α spectral lines provides a lower limit to the proton effective temperature and temperature anisotropy in the inner corona.

  11. Production of hydrogen by thermocatalytic cracking of natural gas

    SciTech Connect

    Muradov, N.

    1996-10-01

    The conventional methods of hydrogen production from natural gas (for example, steam reforming and partial oxidation) are complex, multi-step processes that produce large quantities of CO{sub 2}. The main goal of this project is to develop a technologically simple process for hydrogen production from natural gas (NG) and other hydrocarbon fuels via single-step decomposition of hydrocarbons. This approach eliminates or significantly reduces CO{sub 2} emission. Carbon is a valuable by-product of this process, whereas conventional methods of hydrogen production from NG produce no useful by-products. This approach is based on the use of special catalysts that reduce the maximum temperature of the process from 1400-1500{degrees}C (thermal non-catalytic decomposition of methane) to 500-900{degrees}C. Transition metal based catalysts and various forms of carbon are among the candidate catalysts for the process. This approach can advantageously be used for the development of compact NG reformers for on-site production of hydrogen-methane blends at refueling stations and, also, for the production of hydrogen-rich gas for fuel cell applications. The author extended the search for active methane decomposition catalysts to various modifications of Ni-, Fe-, Mo- and Co-based catalysts. Variation in the operational parameters makes it possible to produce H{sub 2}-CH{sub 4} blends with a wide range of hydrogen concentrations that vary from 15 to 98% by volume. The author found that Ni-based catalysts are more effective at temperatures below 750{degrees}C, whereas Fe-based catalysts are effective at temperatures above 800{degrees}C for the production of hydrogen with purity of 95% v. or higher. The catalytic pyrolysis of liquid hydrocarbons (pentane, gasoline) over Fe-based catalyst was conducted. The author observed the production of a hydrogen-rich gas (hydrogen concentration up to 97% by volume) at a rate of approximately 1L/min.mL of hydrocarbon fuel.

  12. Discovery of Photocatalysts for Hydrogen Production

    SciTech Connect

    D. Brent MacQueen

    2006-10-01

    This project for DOE was designed to address these materials-related issues through a combination of high-throughput screening of semiconductor candidates and theoretical modeling of nanostructures. High-throughput screening is an effective and economical way to examine a large number of candidates and identify those worthy of further study. Unfortunately, in the course of this project, we discovered no semiconductor candidates that can meet the DOE’s stringent requirements for an economically feasible photoelectrochemical process. However, some of our results indicated that several systems may have potential if further optimized. In particular, the published theoretical modeling work indicates that core-shell nanorod structures, if properly engineered, have the potential to overcome the shortfalls of current semiconductors. Although the synthesis of the designed core-shell nanorod structures proved to be beyond the current capabilities of our laboratories, recent advances in the synthesis of core-shell nanorod structures imply that the designed structures can be synthesized. SRI is confident that once these materials are made they will validate our models and lead to economical and environmentally friendly hydrogen from sunlight and water. The high-throughput photolysis analysis module developed at SRI will also have utility in applications such as identifying catalysts for photo-assisted chemical detoxification, as well as non-photolytic applications such as hydrogen storage, which can take advantage of the ability of the analysis module to monitor pressure over time.

  13. A Nonmitochondrial Hydrogen Production in Naegleria gruberi

    PubMed Central

    Tsaousis, Anastasios D.; Nývltová, Eva; Šuták, Robert; Hrdý, Ivan; Tachezy, Jan

    2014-01-01

    Naegleria gruberi is a free-living heterotrophic aerobic amoeba well known for its ability to transform from an amoeba to a flagellate form. The genome of N. gruberi has been recently published, and in silico predictions demonstrated that Naegleria has the capacity for both aerobic respiration and anaerobic biochemistry to produce molecular hydrogen in its mitochondria. This finding was considered to have fundamental implications on the evolution of mitochondrial metabolism and of the last eukaryotic common ancestor. However, no actual experimental data have been shown to support this hypothesis. For this reason, we have decided to investigate the anaerobic metabolism of the mitochondrion of N. gruberi. Using in vivo biochemical assays, we have demonstrated that N. gruberi has indeed a functional [FeFe]-hydrogenase, an enzyme that is attributed to anaerobic organisms. Surprisingly, in contrast to the published predictions, we have demonstrated that hydrogenase is localized exclusively in the cytosol, while no hydrogenase activity was associated with mitochondria of the organism. In addition, cytosolic localization displayed for HydE, a marker component of hydrogenase maturases. Naegleria gruberi, an obligate aerobic organism and one of the earliest eukaryotes, is producing hydrogen, a function that raises questions on the purpose of this pathway for the lifestyle of the organism and potentially on the evolution of eukaryotes. PMID:24682152

  14. 40 CFR 415.330 - Applicability; description of the carbon monoxide and by-product hydrogen production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... carbon monoxide and by-product hydrogen production subcategory. 415.330 Section 415.330 Protection of... MANUFACTURING POINT SOURCE CATEGORY Carbon Monoxide and By-Product Hydrogen Production Subcategory § 415.330 Applicability; description of the carbon monoxide and by-product hydrogen production subcategory. The...

  15. 40 CFR 415.330 - Applicability; description of the carbon monoxide and by-product hydrogen production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... carbon monoxide and by-product hydrogen production subcategory. 415.330 Section 415.330 Protection of... MANUFACTURING POINT SOURCE CATEGORY Carbon Monoxide and By-Product Hydrogen Production Subcategory § 415.330 Applicability; description of the carbon monoxide and by-product hydrogen production subcategory. The...

  16. 40 CFR 415.330 - Applicability; description of the carbon monoxide and by-product hydrogen production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... carbon monoxide and by-product hydrogen production subcategory. 415.330 Section 415.330 Protection of... MANUFACTURING POINT SOURCE CATEGORY Carbon Monoxide and By-Product Hydrogen Production Subcategory § 415.330 Applicability; description of the carbon monoxide and by-product hydrogen production subcategory. The...

  17. 40 CFR 415.330 - Applicability; description of the carbon monoxide and by-product hydrogen production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... carbon monoxide and by-product hydrogen production subcategory. 415.330 Section 415.330 Protection of... MANUFACTURING POINT SOURCE CATEGORY Carbon Monoxide and By-Product Hydrogen Production Subcategory § 415.330 Applicability; description of the carbon monoxide and by-product hydrogen production subcategory. The...

  18. 40 CFR 415.330 - Applicability; description of the carbon monoxide and by-product hydrogen production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... carbon monoxide and by-product hydrogen production subcategory. 415.330 Section 415.330 Protection of... MANUFACTURING POINT SOURCE CATEGORY Carbon Monoxide and By-Product Hydrogen Production Subcategory § 415.330 Applicability; description of the carbon monoxide and by-product hydrogen production subcategory. The...

  19. Photosynthetic hydrogen and oxygen production by green algae

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1997-12-31

    An overview of photosynthetic hydrogen and oxygen production by green algae in the context of its potential as a renewable chemical feed stock and energy carrier is presented. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of photosynthesis throughout the entire range of terrestrial solar irradiance--including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transport and (3) the minimum number of light reactions that are required to split water to elemental hydrogen and oxygen. Each of these research topics is being actively addressed by the photobiological hydrogen research community.

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

    NASA Astrophysics Data System (ADS)

    Wu, Xiao

    2009-12-01

    The idea of coupling renewable energy production and agricultural waste management inspired this thesis. The production of an important future fuel---hydrogen gas---from high strength waste stream-liquid swine manure---using anaerobic treatment processes makes the most sustainable sense for both wastewater utilization and energy generation. The objectives of this thesis were to develop a fermentation process for converting liquid swine manure to hydrogen and to maximize hydrogen productivity. Anaerobic sequencing batch reactor (ASBR) systems were constructed to carry out this fermentation process, and seed sludge obtained from a dairy manure anaerobic digester and pretreated by nutrient acclimation, heat and pH treatment was used as inoculum. High system stability was indicated by a short startup period of 12 days followed by stable hydrogen production, and successful sludge granulation occurred within 23 days of startup at a hydraulic retention time (HRT) of 24 hours. Operation at a progressively decreasing HRT from 24 to 8h gave rise to an increasing biogas production rate from 15.2-34.4L/d, while good linear relationships were observed between both total biogas and hydrogen production rates correlated to HRT, with R2 values of 0.993 and 0.997, respectively. The maximum hydrogen yield of 1.63 mol-H 2/mol-hexose-feed occurred at HRT of 16h, while the HRT of 12h was highly suggested to achieve both high production rate and efficient yield. Hexose utilization efficiencies over 98%, considerable hydrogen production rate up to 14.3 L/d and hydrogen percentage of off-gas up to 43% (i.e., a CO 2/H2 ratio of 1.2) with the absence of CH4 production throughout the whole course of experiment at a pH of 5.0 strongly validated the feasibility of the fermentative H2 production from liquid swine manure using an ASBR system. Ethanol as well as acetic, butyric and valeric acids were produced in the system accompanying the hydrogen production, with acetic acid being the dominant

  1. EVermont Renewable Hydrogen Production and Transportation Fueling System

    SciTech Connect

    Garabedian, Harold T. Wight, Gregory Dreier, Ken Borland, Nicholas

    2008-03-30

    A great deal of research funding is being devoted to the use of hydrogen for transportation fuel, particularly in the development of fuel cell vehicles. When this research bears fruit in the form of consumer-ready vehicles, will the fueling infrastructure be ready? Will the required fueling systems work in cold climates as well as they do in warm areas? Will we be sure that production of hydrogen as the energy carrier of choice for our transit system is the most energy efficient and environmentally friendly option? Will consumers understand this fuel and how to handle it? Those are questions addressed by the EVermont Wind to Wheels Hydrogen Project: Sustainable Transportation. The hydrogen fueling infrastructure consists of three primary subcomponents: a hydrogen generator (electrolyzer), a compression and storage system, and a dispenser. The generated fuel is then used to provide transportation as a motor fuel. EVermont Inc., started in 1993 by then governor Howard Dean, is a public-private partnership of entities interested in documenting and advancing the performance of advanced technology vehicles that are sustainable and less burdensome on the environment, especially in areas of cold climates, hilly terrain and with rural settlement patterns. EVermont has developed a demonstration wind powered hydrogen fuel producing filling system that uses electrolysis, compression to 5000 psi and a hydrogen burning vehicle that functions reliably in cold climates. And that fuel is then used to meet transportation needs in a hybrid electric vehicle whose internal combustion engine has been converted to operate on hydrogen Sponsored by the DOE EERE Hydrogen, Fuel Cells & Infrastructure Technologies (HFC&IT) Program, the purpose of the project is to test the viability of sustainably produced hydrogen for use as a transportation fuel in a cold climate with hilly terrain and rural settlement patterns. Specifically, the project addresses the challenge of building a renewable

  2. Iron-Catalyzed Regioselective Transfer Hydrogenative Couplings of Unactivated Aldehydes with Simple Alkenes.

    PubMed

    Zheng, Yan-Long; Liu, Yan-Yao; Wu, Yi-Mei; Wang, Yin-Xia; Lin, Yu-Tong; Ye, Mengchun

    2016-05-17

    An FeBr3 -catalyzed reductive coupling of various aldehydes with alkenes that proceeds through a direct hydride transfer pathway has been developed. With (i) PrOH as the hydrogen donor under mild conditions, previously challenging coupling reactions of unactivated alkyl and aryl aldehydes with simple alkenes, such as styrene derivatives and α-olefins, proceeded smoothly to furnish a diverse range of functionalized alcohols with complete linear regioselectivity. PMID:27072872

  3. Production of hydrogen by photovoltaic-powered electrolysis. Task 1 report

    SciTech Connect

    Block, D.L.

    1995-12-01

    The report presents results of a cooperative effort among the Florida Energy Office, NASA/Kennedy Space Center, the US Department of Energy and the Florida Solar Energy Center (FSEC). It reports on a task to evaluate hydrogen production from photovoltaic (PV)-powered electrolysis. The resulting activities covered five years of effort funded at a total of $216,809. The results represent a successful, coordinated effort among two state agencies and two federal agencies. Results are reported on two separate investigations. The first investigation looked at the use of line focus concentrating photovoltaics coupled with single-cell electrolyzers to produce gaseous hydrogen. The concept, and its design, construction and operation, are presented. The objectives of the line focusing PV system are to reduce overall system cost under the assumptions that lenses and mirrors are cheaper to deploy than are PV cells, and that low-voltage, high-current dc electricity can efficiently power a single-cell elctrolyzer to produce hydrogen. The second investigation evaluated a base case cost of PV electrolysis hydrogen production based on present-day PV and electrolyzer costs and efficiencies. A second step analyzed the hydrogen costs based on a best prediction of where PV costs and efficiencies will be in 10 years. These results set the minimum cost standards that other renewable production technologies must meet or better.

  4. Efficiency and cost advantages of an advanced-technology nuclear electrolytic hydrogen-energy production facility

    NASA Technical Reports Server (NTRS)

    Donakowski, T. D.; Escher, W. J. D.; Gregory, D. P.

    1977-01-01

    The concept of an advanced-technology (viz., 1985 technology) nuclear-electrolytic water electrolysis facility was assessed for hydrogen production cost and efficiency expectations. The facility integrates (1) a high-temperature gas-cooled nuclear reactor (HTGR) operating a binary work cycle, (2) direct-current (d-c) electricity generation via acyclic generators, and (3) high-current-density, high-pressure electrolyzers using a solid polymer electrolyte (SPE). All subsystems are close-coupled and optimally interfaced for hydrogen production alone (i.e., without separate production of electrical power). Pipeline-pressure hydrogen and oxygen are produced at 6900 kPa (1000 psi). We found that this advanced facility would produce hydrogen at costs that were approximately half those associated with contemporary-technology nuclear electrolysis: $5.36 versus $10.86/million Btu, respectively. The nuclear-heat-to-hydrogen-energy conversion efficiency for the advanced system was estimated as 43%, versus 25% for the contemporary system.

  5. Carbon sequestration in soybean crop soils: the role of hydrogen-coupled CO2 fixation

    NASA Astrophysics Data System (ADS)

    Graham, A.; Layzell, D. B.; Scott, N. A.; Cen, Y.; Kyser, T. K.

    2011-12-01

    Conversion of native vegetation to agricultural land in order to support the world's growing population is a key factor contributing to global climate change. However, the extent to which agricultural activities contribute to greenhouse gas emissions compared to carbon storage is difficult to ascertain, especially for legume crops, such as soybeans. Soybean establishment often leads to an increase in N2O emissions because N-fixation leads to increased soil available N during decomposition of the low C:N legume biomass. However, soybean establishment may also reduce net greenhouse gas emissions by increasing soil fertility, plant growth, and soil carbon storage. The mechanism behind increased carbon storage, however, remains unclear. One explanation points to hydrogen coupled CO2 fixation; the process by which nitrogen fixation releases H2 into the soil system, thereby promoting chemoautotrophic carbon fixation by soil microbes. We used 13CO2 as a tracer to track the amount and fate of carbon fixed by hydrogen coupled CO2 fixation during one-year field and laboratory incubations. The objectives of the research are to 1) quantify rates of 13CO2 fixation in soil collected from a field used for long-term soybean production 2) examine the impact of H2 gas concentration on rates of 13CO2 fixation, and 3) measure changes in δ13C signature over time in 3 soil fractions: microbial biomass, light fraction, and acid stable fraction. If this newly-fixed carbon is incorporated into the acid-stable soil C fraction, it has a good chance of contributing to long-term soil C sequestration under soybean production. Soil was collected in the field both adjacent to root nodules (nodule soil) and >3cm away (root soil) and labelled with 13CO2 (1% v/v) in the presence and absence of H2 gas. After a two week labelling period, δ13C signatures already revealed differences in the four treatments of bulk soil: -17.1 for root, -17.6 for nodule, -14.2 for root + H2, and -6.1 for nodule + H2

  6. In vitro hydrogen production--using energy from the sun.

    PubMed

    Krassen, Henning; Ott, Sascha; Heberle, Joachim

    2011-01-01

    Using solar energy to produce molecular hydrogen is a promising way to supply the civilization with clean energy. Nature provides the key components to collect solar energy as well as to reduce protons, scientists have developed mimics of these enzymatic centers and also found new ways to catalyze the same reactions. This perspective article surveys the different components and in particular the various coupling possibilities of a light sensitizer and catalyst. Pros and cons are discussed. PMID:21103567

  7. Electrochemical production of ozone and hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor)

    1999-01-01

    Methods of using ozone have been developed which sterilize instruments and medical wastes, oxidize organics found in wastewater, clean laundry, break down contaminants in soil into a form more readily digested by microbes, kill microorganisms present in food products, and destroy toxins present in food products. The preferred methods for killing microorganisms and destroying toxins use pressurized, humidified, and concentrated ozone produced by an electrochemical cell.

  8. CERAMIC MEMBRANES FOR HYDROGEN PRODUCTION FROM COAL

    SciTech Connect

    George R. Gavalas

    2001-11-27

    The present project is devoted to developing hydrogen permselective silica membranes supported on composite supports to achieve high flux and selectivity. The supports consist of a thin zeolite silicalite layer coated on {alpha}-Al{sub 2}O{sub 3} tubes of mean pore size 1 {micro}m. The zeolite layer is grown by reaction in a suitable silicate solution at 95 C. After two or three reaction periods a layer of silicalite crystals about 20 {micro}m thick grows inside the pores of alumina. In addition to the zeolitic pores, this layer contains voids of a few nanometer diameter that remain between the crystals or between the crystals and the pore walls. The quality of the silicalite/alumina composites was evaluated by gas permeation measurements and by nitrogen adsorption and it was found that the residual voids were below 5 nm in diameter. Three techniques were investigated for chemical vapor deposition (CVD) of the silica layer on the silicalite/alumina composite support. The first was TEOS pyrolysis at approximately one millibar partial pressure and 650 C. After 8 h reaction the fluxes of hydrogen and nitrogen at ambient temperature had declined by a factor of approximately 100 indicating sealing of defects and zeolitic pores alike. The second CVD technique investigated was SiCl{sub 4} hydrolysis at 90 C. Deposition in this case was conducted in a series of cycles, each cycle comprising two half reactions, i.e. exposure to SiCl{sub 4} followed by exposure to water vapor. The deposition was interrupted every five cycles to measure the permeation properties of the nascent membrane at 120 C. After a few cycles the membrane pores were sealed, but the silica layer was not thermally stable when the temperature was raised to 400 C. In the third technique investigated, silica deposition was carried out by SiCl{sub 4} hydrolysis at 400 C, again in a sequence of half reaction cycles. After 15 cycles the membrane pores were well sealed by a layer stable to at least 400 C.

  9. [Activity of hydrogen sulfide production enzymes in kidneys of rats].

    PubMed

    Mel'nyk, A V; Pentiuk, O O

    2009-01-01

    An experimental research of activity and kinetic descriptions of enzymes participating in formation of hydrogen sulfide in the kidney of rats has been carried out. It was established that cystein, homocystein and thiosulphate are the basic substrates for hydrogen sulfide synthesis. The higest activity for hydrogen sulfide production belongs to thiosulfate-dithiolsulfurtransferase and cysteine aminotransferase, less activity is characteristic of cystathionine beta-synthase and cystathio-nine gamma-lyase. The highest affinity to substrate is registered for thiosulfate-dithiolsulfurtransferase and cystathionine gamma-lyase. It is discovered that the substrate inhibition is typical of all hydrogen sulfide formation enzymes, although this characteristic is the most expressed thiosulfat-dithiolsulfurtransferase. PMID:20387629

  10. Hydrogen Production from the Next Generation Nuclear Plant

    SciTech Connect

    M. Patterson; C. Park

    2008-03-01

    The Next Generation Nuclear Plant (NGNP) is a high temperature gas-cooled reactor that will be capable of producing hydrogen, electricity and/or high temperature process heat for industrial use. The project has initiated the conceptual design phase and when completed will demonstrate the viability of hydrogen generation using nuclear produced process heat. This paper explains how industry and the U.S. Government are cooperating to advance nuclear hydrogen technology. It also describes the issues being explored and the results of recent R&D including materials development and testing, thermal-fluids research, and systems analysis. The paper also describes the hydrogen production technologies being considered (including various thermochemical processes and high-temperature electrolysis).

  11. Engineering aspects of hydrogen production from photosynthetic bacteria

    SciTech Connect

    Herlevich, A.; Karpuk, M.

    1982-02-01

    Certain photosynthetic bacteria (PSB), for example, Rhodopseudomonas capsulata, evolve hydrogen when placed in an anaerobic environment with light and a suitable organic substrate. An engineering effort to use such bacteria for large-scale hydrogen production from sunlight is described. A system to produce 28,000 m/sup 3//day (1 x 10/sup 6/ ft/sup 3//day) of hydrogen has been designed on a conceptual level and includes hydrogen cleanup, substrate storage, and waste disposal. The most critical component in the design is the solar bacterial reactor. Several designs were developed and analyzed. A large covered pond concept appears most attractive. Cost estimates for the designs show favorable economics.

  12. Surface Production of Hydride Ions by Backscattering Hyperthermal Hydrogen Atoms

    NASA Astrophysics Data System (ADS)

    Lee, Brian Seungwhan

    The thesis experimentally demonstrates the surface production of H^- ions by backscattering hyperthermal hydrogen atoms of energy 1-10 eV from clean molybdenum and cesiated molybdenum surfaces. Hyperthermal hydrogen atoms are produced by electron impact dissociation through Frank-Condon excitation process in a hydrogen plasma. Theoretical calculations of the hyperthermal hydrogen atom flux density in various plasmas are made by using particle balance equations. A Lisitano-Coil interdigital slow wave structure is used for plasma production. The efficient production of hyperthermal hydrogen atoms by electron impact dissociation makes the discharge source an excellent source of hyperthermal hydrogen atom beams. The total H^- ion yield, which is the ratio of the H^- ion flux density to the atom flux density, is estimated taking a Maxwellian beam distribution and a cosine angular scattering distribution of H atoms on the basis of theoretical calculation of surface charge transfer probability. More than 20% of total H^- ion yield is expected for atomic hydrogen beams of a few eV temperature from cesiated metal surfaces with an extraction electric field of thousands Volts/cm. The abundant presence of hyperthermal hydrogen atoms and the high H^- ion yield suggest that major parts of H^ - ions in most H^- ion sources are produced by the surface process by backscattering hyperthermal hydrogen atoms from cesiated walls. H^ - ions produced on external converter surfaces, located outside the plasma, are analyzed by magnetic spectroscopy developed for this purpose. The measured parallel energy distribution of H^- ions follows a Maxwellian with temperature of a few eV. Several experimental results of parallel energy distributions are obtained for different operating conditions. Experimental data on production of H^ - ions from clean molybdenum and cesiated molybdenum converter surfaces as functions of discharge power and H_2 gas flow rate for several operating modes are presented

  13. Capacitively Coupled Radio Frequency Discharge Plasmas In Hydrogen: Particle Modeling and Negative Ion Kinetics

    SciTech Connect

    Diomede, P.; Longo, S.; Capitelli, M.

    2005-05-16

    We present a 1D(r)2D(v) particle code for capacitively coupled radio frequency discharge plasmas in hydrogen, which includes a rigorous kinetic modeling of ion transport and several solutions to speed up the convergence. In a test case the effect of surface atom recombination and molecule vibrational deactivation on H- concentration is investigated.

  14. Thermochemical cycles for the production of hydrogen

    DOEpatents

    Steinberg, M.; Dang, V.D.

    Two-step processes for the preparation of hydrogen are described: CrCl/sub 3/(g) ..-->.. CrCl/sub 2/(g) + 1/2Cl/sub 2/(g) and CrCl/sub 2/(s) + HCl(g) reversible CrCl/sub 3/(s) + 1/2H/sub 2/(g); UCl/sub 4/(g) ..-->.. UCl/sub 3/(g) + 1/2Cl/sub 2/(g) and UCl/sub 3/(s) + HCl(g) ..-->.. UCl/sub 4/(s) + 1/2H/sub 2/(g); and CaSO/sub 4/(s) ..-->.. CaO(s) + SO/sub 2/(g) + 1/2O/sub 2/(g) and CaO(s) + SO/sub 2/(g) + H/sub 2/O(l) ..-->.. CaSO/sub 4/(s) + H/sub 2/(g). The high temperature available from solar collectors, high temperature gas reactors or fusion reactors is utilized in the first step in which the reaction is endothermic. The efficiency is at least 60% and with process heat recovery, the efficiency may be increased up to 74.4%. An apparatus fr carrying out the process in conjunction with a fusion reactor, is described.

  15. Continuous fermentative hydrogen production from a wheat starch co-product by mixed microflora.

    PubMed

    Hussy, I; Hawkes, F R; Dinsdale, R; Hawkes, D L

    2003-12-20

    For the transition to the hydrogen economy, hydrogen must be produced sustainably, e.g., by the fermentation of agricultural material. Continuous fermentative production of hydrogen from an insoluble substrate in nonsterile conditions is yet to be reported. In this study hydrogen production using mixed microflora from heat-treated digested sewage sludge in nonsterile conditions from a particulate co-product of the wheat flour industry (7.5 g L(-1) total hexose) at 18- and 12-hour hydraulic retention times, pH 4.5 and 5.2, 30 degrees C and 35 degrees C was examined. In continuous operation, hydrogen yields of approximately 1.3 moles hydrogen/mole hexose consumed were obtained, but decreased if acetate or propionate levels rose, indicating metabolism shifted towards hydrogen consumption by homoacetogenesis or propionate producers. These shifts occurred both at pH 4.5 and 5.2. Sparging the reactor with nitrogen to reduce hydrogen in the off-gas from 50% to 7% gave stable operation with a hydrogen yield of 1.9 moles hydrogen /mole hexose consumed over an 18-day period. PMID:14595774

  16. Photosynthetic Hydrogen and Oxygen Production by Green Algae

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1999-08-22

    Photosynthesis research at Oak Ridge National Laboratory is focused on hydrogen and oxygen production by green algae in the context of its potential as a renewable fuel and chemical feed stock. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are: (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of hotosynthesis throughout the entire range of terrestrial solar irradiance-including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transpor;t and (3) constructing real-world bioreactors, including the generation of hydrogen and oxygen against workable back pressures of the photoproduced gases.

  17. Designer proton-channel transgenic algae for photobiological hydrogen production

    DOEpatents

    Lee, James Weifu

    2011-04-26

    A designer proton-channel transgenic alga for photobiological hydrogen production that is specifically designed for production of molecular hydrogen (H.sub.2) through photosynthetic water splitting. The designer transgenic alga includes proton-conductive channels that are expressed to produce such uncoupler proteins in an amount sufficient to increase the algal H.sub.2 productivity. In one embodiment the designer proton-channel transgene is a nucleic acid construct (300) including a PCR forward primer (302), an externally inducible promoter (304), a transit targeting sequence (306), a designer proton-channel encoding sequence (308), a transcription and translation terminator (310), and a PCR reverse primer (312). In various embodiments, the designer proton-channel transgenic algae are used with a gas-separation system (500) and a gas-products-separation and utilization system (600) for photobiological H.sub.2 production.

  18. Hydrogen and Formate Oxidation Coupled to Dissimilatory Reduction of Iron or Manganese by Alteromonas putrefaciens

    PubMed Central

    Lovley, Derek R.; Phillips, Elizabeth J. P.; Lonergan, Debra J.

    1989-01-01

    The ability of Alteromonas putrefaciens to obtain energy for growth by coupling the oxidation of various electron donors to dissimilatory Fe(III) or Mn(IV) reduction was investigated. A. putrefaciens grew with hydrogen, formate, lactate, or pyruvate as the sole electron donor and Fe(III) as the sole electron acceptor. Lactate and pyruvate were oxidized to acetate, which was not metabolized further. With Fe(III) as the electron acceptor, A. putrefaciens had a high affinity for hydrogen and formate and metabolized hydrogen at partial pressures that were 25-fold lower than those of hydrogen that can be metabolized by pure cultures of sulfate reducers or methanogens. The electron donors for Fe(III) reduction also supported Mn(IV) reduction. The electron donors for Fe(III) and Mn(IV) reduction and the inability of A. putrefaciens to completely oxidize multicarbon substrates to carbon dioxide distinguish A. putrefaciens from GS-15, the only other organism that is known to obtain energy for growth by coupling the oxidation of organic compounds to the reduction of Fe(III) or Mn(IV). The ability of A. putrefaciens to reduce large quantities of Fe(III) and to grow in a defined medium distinguishes it from a Pseudomonas sp., which is the only other known hydrogen-oxidizing, Fe(III)-reducing microorganism. Furthermore, A. putrefaciens is the first organism that is known to grow with hydrogen as the electron donor and Mn(IV) as the electron acceptor and is the first organism that is known to couple the oxidation of formate to the reduction of Fe(III) or Mn(IV). Thus, A. putrefaciens provides a much needed microbial model for key reactions in the oxidation of sediment organic matter coupled to Fe(III) and Mn(IV) reduction. PMID:16347876

  19. Hydrogen and formate oxidation coupled to dissimilatory reduction of iron or manganese by Alteromonas putrefaciens

    USGS Publications Warehouse

    Lovley, D.R.; Phillips, E.J.P.; Lonergan, D.J.

    1989-01-01

    The ability of Alteromonas putrefaciens to obtain energy for growth by coupling the oxidation of various electron donors to dissimilatory Fe(III) or Mn(IV) reduction was investigated. A. putrefaciens grew with hydrogen, formate, lactate, or pyruvate as the sole electron donor and Fe(III) as the sole electron acceptor. Lactate and pyruvate were oxidized to acetate, which was not metabolized further. With Fe(III) as the electron acceptor, A. putrefaciens had a high affinity for hydrogen and formate and metabolized hydrogen at partial pressures that were 25-fold lower than those of hydrogen that can be metabolized by pure cultures of sulfate reducers or methanogens. The electron donors for Fe(III) reduction also supported Mn(IV) reduction. The electron donors for Fe(III) and Mn(IV) reduction and the inability of A. putrefaciens to completely oxidize multicarbon substrates to carbon dioxide distinguish A. putrefaciens from GS-15, the only other organism that is known to obtain energy for growth by coupling the oxidation of organic compounds to the reduction of Fe(III) or Mn(IV). The ability of A. putrefaciens to reduce large quantities of Fe(III) and to grow in a defined medium distinguishes it from a Pseudomonas sp., which is the only other known hydrogen-oxidizing, Fe(III)-reducing microorganism. Furthermore, A. putrefaciens is the first organism that is known to grow with hydrogen as the electron donor and Mn(IV) as the electron acceptor and is the first organism that is known to couple the oxidation of formate to the reduction of Fe(III) or Mn(IV). Thus, A. putrefaciens provides a much needed microbial model for key reactions in the oxidation of sediment organic matter coupled to Fe(III) and Mn(IV) reduction.

  20. Comparison of hydrogen production and electrical power generation for energy capture in closed-loop ammonium bicarbonate reverse electrodialysis systems.

    PubMed

    Hatzell, Marta C; Ivanov, Ivan; Cusick, Roland D; Zhu, Xiuping; Logan, Bruce E

    2014-01-28

    Currently, there is an enormous amount of energy available from salinity gradients, which could be used for clean hydrogen production. Through the use of a favorable oxygen reduction reaction (ORR) cathode, the projected electrical energy generated by a single pass ammonium bicarbonate reverse electrodialysis (RED) system approached 78 W h m(-3). However, if RED is operated with the less favorable (higher overpotential) hydrogen evolution electrode and hydrogen gas is harvested, the energy recovered increases by as much ~1.5× to 118 W h m(-3). Indirect hydrogen production through coupling an RED stack with an external electrolysis system was only projected to achieve 35 W h m(-3) or ~1/3 of that produced through direct hydrogen generation. PMID:24322796

  1. Nonadiabatic coupling in cold collisions of spin-polarized metastable hydrogen atoms

    SciTech Connect

    Forrey, Robert C.; Dalgarno, Alex; Vanne, Yulian V.; Saenz, Alejandro; Froelich, Piotr

    2007-11-15

    Previous calculations of low-temperature cross sections for collisions between spin-polarized metastable hydrogen atoms are improved to include nonadiabatic radial and angular coupling at large interatomic separations. The electrostatic dipole-quadrupole interaction produces nonadiabatic radial coupling between (2s,2p) and (2p,2p) states, while the Coriolis interaction produces nonadiabatic angular coupling. Both of these long-range contributions are handled in a space-fixed atomic gauge that is particularly convenient for a spin-polarized system. The improved theoretical results are compared with an existing experiment.

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

    SciTech Connect

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

    2010-06-01

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

  3. A Process Model for the Production of Hydrogen Using High Temperature Electrolysis

    SciTech Connect

    M. G. Mc Kellar; E. A. Harvego; M. Richards; A. Shenoy

    2006-07-01

    High temperature electrolysis (HTE) involves the splitting of stream into hydrogen and oxygen at high temperatures. The primary advantage of HTE over conventional low temperature electrolysis is that considerably higher hydrogen production efficiencies can be achieved. Performing the electrolysis process at high temperatures results in more favorable thermodynamics for electrolysis, more efficient production of electricity, and allows direct use of process heat to generate steam. This paper presents the results of process analyses performed to evaluate the hydrogen production efficiencies of an HTE plant coupled to a 600 MWt Modular Helium Reactor (MHR) that supplies both the electricity and process heat needed to drive the process. The MHR operates with a coolant outlet temperature of 950 C. Approximately 87% of the high-temperature heat is used to generate electricity at high efficiency using a direct, Brayton-cycle power conversion system. The remaining high-temperature heat is used to generate a superheated steam / hydrogen mixture that is supplied to the electrolyzers. The analyses were performed using the HYSYS process modeling software. The model used to perform the analyses consisted of three loops; a primary high temperature helium loop, a secondary helium loop and the HTE process loop. The detailed model included realistic representations of all major components in the system, including pumps, compressors, heat exchange equipment, and the electrolysis stack. The design of the hydrogen production process loop also included a steam-sweep gas system to remove oxygen from the electrolysis stack so that it can be recovered and used for other applications. Results of the process analyses showed that hydrogen production efficiencies in the range of 45% to 50% are achievable with this system.

  4. CERAMIC MEMBRANES FOR HYDROGEN PRODUCTION FROM COAL

    SciTech Connect

    George R. Gavalas

    2004-04-01

    The preparation and performance of membranes for application to hydrogen separation from coal-derived gas is described. The membrane material investigated was dense amorphous silica deposited on a suitable support by chemical vapor deposition (CVD). Two types of support materials were pursued. One type consisted of a two-layer composite, zeolite silicalite/{alpha}-Al{sub 2}O{sub 3}, in the form of tubes approximately 0.7 cm in diameter. The other type was porous glass tubes of diameter below 0.2 cm. The first type of support was prepared starting from {alpha}-Al{sub 2}O{sub 3} tubes of 1{micro}m mean pore diameter and growing by hydrothermal reaction a zeolite silicalite layer inside the pores of the alumina at the OD side. After calcination to remove the organic template used in the hydrothermal reaction, CVD was carried out to deposit the final silica layer. CVD was carried out by alternating exposure of the surface with silicon tetrachloride and water vapor. SEM and N2 adsorption measurements were employed to characterize the membranes at several stages during their preparation. Permeation measurements of several gases yielded H{sub 2}:N{sub 2} ideal selectivity of 150-200 at room temperature declining to 110 at 250 C. The second type of support pursued was porous glass tubes prepared by a novel extrusion technique. A thick suspension of borosilicate glass powder in a polyethersulfone solution was extruded through a spinneret and after gelation the glass-polymer tube was heat treated to obtain a gas-tight glass tube. Leaching of the glass tube in hot water yielded connected pores with diameter on the order of 100 nm. CVD of the final silica layer was not carried out on these tubes on account of their large pore size.

  5. Methanol Steam Reforming for Hydrogen Production

    SciTech Connect

    Palo, Daniel R.; Dagle, Robert A.; Holladay, Jamie D.

    2007-09-11

    Review article covering developments in methanol steam reforming in the context of PEM fuel cell power systems. Subjects covered include methanol background, use, and production, comparison to other fuels, power system considerations, militrary requirements, competing technologies, catalyst development, and reactor and system development and demonstration.

  6. Nanowire-nanoparticle conjugate photolytic devices for renewable hydrogen production

    NASA Astrophysics Data System (ADS)

    Maclaskey, Sean Kelly

    A clean energy driven economy requires renewable production of zero--emission fuels, such as hydrogen (H2). Photocatalytic generation of H2 is one such method to fulfill this demand. Photocatalytic water splitting is an electrochemical process driven by solar energy to produce H2. Although there have been many investigations on photocatalytic water splitting, the number of concepts utilizing visible light is limited. In the present study, H2 evolution from water splitting is demonstrated using the novel concept of nanowire--nanoparticle (NW--NP) conjugate devices irradiated by visible light. Photolytic nanodevice suspensions are fabricated via sol--gel synthesis of vanadium oxyhydrate (V3O 7·H2O) NWs, followed by solution chemistry with HAuCl 4 for reduction of gold (Au) NPs on the NW surfaces. Characterization of nanodevices was performed via TEM, SEM, and optical spectroscopy. Products of photolysis were quantified and analyzed by Gas Chromatography (GC). The performance of the nanowire--nanoparticle conjugate devices was compared with previous photolytic device designs by the use of quantum and internal conversion efficiencies (QE and ICE, respectively). The present thesis demonstrates photocatalytic production of H2 using V3O7·H 2O NW -- Au NP conjugate devices under 470 nm excitation. The "photolytic nanodevice suspension in water" concept poses the potential for scalable H2 production, in addition to the provision for a low--cost technique due to fabrication by sol--gel synthesis and solution chemistry. The V3O7·H2O aerogel, a recently discovered semiconductor material, is found to be a suitable photoanode due to its narrow band gap energy of 2.18 eV, and its stability during photolysis. The diameters of the V3O7·H2O NWs are found to be 12 nm (+/- 2.4 nm) from SEM images. The decoration of NWs with Au NPs is verified by TEM imaging and Au NPs are estimated to be 7.5 nm (+/- 2.2 nm) in size. After decoration of NWs by Au NPs, a near--field enhancement

  7. Methods and apparatus for the on-site production of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Buschmann, Wayne E. (Inventor); James, Patrick I. (Inventor)

    2010-01-01

    Methods, apparatus, and applications for the on-site production of hydrogen peroxide are described. An embodiment of the apparatus comprises at least one anolyte chamber coupled to at least one anode, at least one catholyte chamber, wherein the at least one catholyte chamber is coupled to at least one cathode, at least one anode membrane and at least one cathode membrane, wherein the anode membrane is adjacent to the at least one anode, wherein the cathode membrane is adjacent to the at least one cathode, at least one central chamber disposed between the at least one anolyte chamber and the at least one catholyte chamber. Hydrogen peroxide is produced by reduction of an oxygen-containing gas at the cathode.

  8. DOE Hydrogen, Fuel Cells and Infrastructure Technologies Program Integrated Hydrogen Production, Purification and Compression System

    SciTech Connect

    Tamhankar, Satish; Gulamhusein, Ali; Boyd, Tony; DaCosta, David; Golben, Mark

    2011-06-30

    The project was started in April 2005 with the objective to meet the DOE target of delivered hydrogen of <$1.50/gge, which was later revised by DOE to $2-$3/gge range for hydrogen to be competitive with gasoline as a fuel for vehicles. For small, on-site hydrogen plants being evaluated at the time for refueling stations (the 'forecourt'), it was determined that capital cost is the main contributor to the high cost of delivered hydrogen. The concept of this project was to reduce the cost by combining unit operations for the entire generation, purification, and compression system (refer to Figure 1). To accomplish this, the Fluid Bed Membrane Reactor (FBMR) developed by MRT was used. The FBMR has hydrogen selective, palladium-alloy membrane modules immersed in the reformer vessel, thereby directly producing high purity hydrogen in a single step. The continuous removal of pure hydrogen from the reformer pushes the equilibrium 'forward', thereby maximizing the productivity with an associated reduction in the cost of product hydrogen. Additional gains were envisaged by the integration of the novel Metal Hydride Hydrogen Compressor (MHC) developed by Ergenics, which compresses hydrogen from 0.5 bar (7 psia) to 350 bar (5,076 psia) or higher in a single unit using thermal energy. Excess energy from the reformer provides up to 25% of the power used for driving the hydride compressor so that system integration improved efficiency. Hydrogen from the membrane reformer is of very high, fuel cell vehicle (FCV) quality (purity over 99.99%), eliminating the need for a separate purification step. The hydride compressor maintains hydrogen purity because it does not have dynamic seals or lubricating oil. The project team set out to integrate the membrane reformer developed by MRT and the hydride compression system developed by Ergenics in a single package. This was expected to result in lower cost and higher efficiency compared to conventional hydrogen production technologies. The

  9. Catalytic carbon membranes for hydrogen production. Final report

    SciTech Connect

    Damle, A.S.; Gangwal, S.K.

    1992-01-01

    Commercial carbon composite microfiltration membranes may be modified for gas separation applications by providing a gas separation layer with pores in the 1- to 10-nm range. Several organic polymeric precursors and techniques for depositing a suitable layer were investigated in this project. The in situ polymerization technique was found to be the most promising, and pure component permeation tests with membrane samples prepared with this technique indicated Knudsen diffusion behavior. The gas separation factors obtained by mixed-gas permeation tests were found to depend strongly on gas temperature and pressure indicating significant viscous flow at high-pressure conditions. The modified membranes were used to carry out simultaneous water gas shift reaction and product hydrogen separation. These tests indicated increasing CO conversions with increasing hydrogen separation. A simple process model was developed to simulate a catalytic membrane reactor. A number of simulations were carried out to identify operating conditions leading to product hydrogen concentrations over 90 percent. (VC)

  10. Experimental study of hydrogen production by direct decomposition of water

    NASA Astrophysics Data System (ADS)

    Bilgen, E.; Galindo, J.; Baykara, S. Z.

    The hydrogen production by direct decomposition of water in a solar furnace is studied. The set-up is a horizontal axis system consisting of two 1.0 kW parabolic concentrators, both powered by a single heliostat. A temperature of 3000 K is possible. The water is fed to the reactor installed at the focal space of the concentrator, and the steam is decomposed at about 2500 K. The reactor consisted of a cylindrical cavity type refractory receiver covered with a silica cupola. The steam was introduced at a known rate into the cavity and the product gases were quenched. After the condensation of steam, hydrogen and oxygen were collected in a reservoir. Results indicate that with an optimized system, it is possible to produce hydrogen at about 70 percent rate of the theoretical value at the temperature level studied.