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Sample records for alkaline water electrolysis

  1. Hydrogen production by alkaline water electrolysis

    Directory of Open Access Journals (Sweden)

    Diogo M. F. Santos

    2013-01-01

    Full Text Available Water electrolysis is one of the simplest methods used for hydrogen production. It has the advantage of being able to produce hydrogen using only renewable energy. To expand the use of water electrolysis, it is mandatory to reduce energy consumption, cost, and maintenance of current electrolyzers, and, on the other hand, to increase their efficiency, durability, and safety. In this study, modern technologies for hydrogen production by water electrolysis have been investigated. In this article, the electrochemical fundamentals of alkaline water electrolysis are explained and the main process constraints (e.g., electrical, reaction, and transport are analyzed. The historical background of water electrolysis is described, different technologies are compared, and main research needs for the development of water electrolysis technologies are discussed.

  2. Advanced alkaline water electrolysis

    International Nuclear Information System (INIS)

    Marini, Stefania; Salvi, Paolo; Nelli, Paolo; Pesenti, Rachele; Villa, Marco; Berrettoni, Mario; Zangari, Giovanni; Kiros, Yohannes

    2012-01-01

    A short review on the fundamental and technological issues relevant to water electrolysis in alkaline and proton exchange membrane (PEM) devices is given. Due to price and limited availability of the platinum group metal (PGM) catalysts they currently employ, PEM electrolyzers have scant possibilities of being employed in large-scale hydrogen production. The importance and recent advancements in the development of catalysts without PGMs are poised to benefit more the field of alkaline electrolysis rather than that of PEM devices. This paper presents our original data which demonstrate that an advanced alkaline electrolyzer with performances rivaling those of PEM electrolyzers can be made without PGM and with catalysts of high stability and durability. Studies on the advantages/limitations of electrolyzers with different architectures do show how a judicious application of pressure differentials in a recirculating electrolyte scheme helps reduce mass transport limitations, increasing efficiency and power density.

  3. Heavy water production by alkaline water electrolysis

    International Nuclear Information System (INIS)

    Kamath, Sachin; Sandeep, K.C.; Bhanja, Kalyan; Mohan, Sadhana; Sugilal, G.

    2014-01-01

    Several heavy water isotope production processes are reported in literature. Water electrolysis in combination with catalytic exchange CECE process is considered as a futuristic process to increase the throughput and reduce the cryogenic distillation load but the application is limited due to the high cost of electricity. Any improvement in the efficiency of electrolyzers would make this process more attractive. The efficiency of alkaline water electrolysis is governed by various phenomena such as activation polarization, ohmic polarization and concentration polarization in the cell. A systematic study on the effect of these factors can lead to methods for improving the efficiency of the electrolyzer. A bipolar and compact type arrangement of the alkaline water electrolyzer leads to increased efficiency and reduced inventory in comparison to uni-polar tank type electrolyzers. The bipolar type arrangement is formed when a number of single cells are stacked together. Although a few experimental studies have been reported in the open literature, CFD simulation of a bipolar compact alkaline water electrolyzer with porous electrodes is not readily available.The principal aim of this study is to simulate the characteristics of a single cell compact electrolyzer unit. The simulation can be used to predict the Voltage-Current Density (V-I) characteristics, which is a measure of the efficiency of the process.The model equations were solved using COMSOL multi-physics software. The simulated V-I characteristic is compared with the experimental data

  4. Endurance test and evaluation of alkaline water electrolysis cells

    Science.gov (United States)

    Burke, K. A.; Schubert, F. H.

    1981-01-01

    Utilization in the development of multi-kW low orbit power systems is discussed. The following technological developments of alkaline water electrolysis cells for space power application were demonstrated: (1) four 92.9 cm2 single water electrolysis cells, two using LST's advanced anodes and two using LST's super anodes; (2) four single cell endurance test stands for life testing of alkaline water electrolyte cells; (3) the solid performance of the advanced electrode and 355 K; (4) the breakthrough performance of the super electrode; (5) the four single cells for over 5,000 hours each significant cell deterioration or cell failure. It is concluded that the static feed water electrolysis concept is reliable and due to the inherent simplicity of the passive water feed mechanism coupled with the use of alkaline electrolyte has greater potential for regenerative fuel cell system applications than alternative electrolyzers. A rise in cell voltage occur after 2,000-3,000 hours which was attributed to deflection of the polysulfone end plates due to creepage of the thermoplastic. More end plate support was added, and the performance of the cells was restored to the initial performance level.

  5. Endurance Test and Evaluation of Alkaline Water Electrolysis Cells

    Science.gov (United States)

    Kovach, Andrew J.; Schubert, Franz H.; Chang, B. J.; Larkins, Jim T.

    1985-01-01

    The overall objective of this program is to assess the state of alkaline water electrolysis cell technology and its potential as part of a Regenerative Fuel Cell System (RFCS) of a multikilowatt orbiting powerplant. The program evaluates the endurance capabilities of alkaline electrolyte water electrolysis cells under various operating conditions, including constant condition testing, cyclic testing and high pressure testing. The RFCS demanded the scale-up of existing cell hardware from 0.1 sq ft active electrode area to 1.0 sq ft active electrode area. A single water electrolysis cell and two six-cell modules of 1.0 sq ft active electrode area were designed and fabricated. The two six-cell 1.0 sq ft modules incorporate 1.0 sq ft utilized cores, which allow for minimization of module assembly complexity and increased tolerance to pressure differential. A water electrolysis subsystem was designed and fabricated to allow testing of the six-cell modules. After completing checkout, shakedown, design verification and parametric testing, a module was incorporated into the Regenerative Fuel Cell System Breadboard (RFCSB) for testing at Life Systems, Inc., and at NASA JSC.

  6. Chemically durable polymer electrolytes for solid-state alkaline water electrolysis

    Science.gov (United States)

    Park, Eun Joo; Capuano, Christopher B.; Ayers, Katherine E.; Bae, Chulsung

    2018-01-01

    Generation of high purity hydrogen using electrochemical splitting of water is one of the most promising methods for sustainable fuel production. The materials to be used as solid-state electrolytes for alkaline water electrolyzer require high thermochemical stability against hydroxide ion attack in alkaline environment during the operation of electrolysis. In this study, two quaternary ammonium-tethered aromatic polymers were synthesized and investigated for anion exchange membrane (AEM)-based alkaline water electrolyzer. The membranes properties including ion exchange capacity (IEC), water uptake, swelling degree, and anion conductivity were studied. The membranes composed of all C-C bond polymer backbones and flexible side chain terminated by cation head groups exhibited remarkably good chemical stability by maintaining structural integrity in 1 M NaOH solution at 95 °C for 60 days. Initial electrochemical performance and steady-state operation performance were evaluated, and both membranes showed a good stabilization of the cell voltage during the steady-state operation at the constant current density at 200 mA/cm2. Although both membranes in current form require improvement in mechanical stability to afford better durability in electrolysis operation, the next generation AEMs based on this report could lead to potentially viable AEM candidates which can provide high electrolysis performance under alkaline operating condition.

  7. Behavior of oxygem bubbles during alkaline water electrolysis

    NARCIS (Netherlands)

    Wedershoven, H.M.S.; Jonge, de R.M.; Sillen, C.W.M.P.; Stralen, van S.J.D.

    1982-01-01

    Growth rate, departure radius and population of oxygen bubbles at the transparent anode during alkaline water electrolysis have been investigated experimentally. The supersaturation of dissolved oxygen in the electrolyte adjacent to the anode surface has been derived from bubble growth rates.

  8. Development of Hydrogen Electrodes for Alkaline Water Electrolysis

    DEFF Research Database (Denmark)

    Kjartansdóttir, Cecilía Kristín

    , production of electricity via fuel cells, fuel for internal combustion engines or gas turbines, or as a raw material for the production of synthetic fuels via Sabatier or Fischer - Tropsch process. In some situations it may be suitable to simply inject hydrogen into the existing natural gas based...... will be needed. Producing hydrogen via water electrolysis using surplus, low cost, power from renewables offers the possibility of increased production capacity and load management with no greenhouse emissions. Hydrogen is a valuable energy carrier, which is able to contribute to various forms of energy, such as...... infrastructure. Alkaline water electrolysis (AWE) is the current standard (stat of the art) for industrial large-scale water electrolysis systems. One of the main criteria for industrial AWE is efficient and durable electrodes. The aim of the present PhD study was to develop electrode materials for hydrogen...

  9. Towards a stable ion-solvating polymer electrolyte for advanced alkaline water electrolysis

    DEFF Research Database (Denmark)

    Aili, David; Wright, Andrew G.; Kraglund, Mikkel Rykær

    2017-01-01

    Advanced alkaline water electrolysis using ion-solvating polymer membranes as electrolytes represents a new direction in the field of electrochemical hydrogen production. Polybenzimidazole membranes equilibrated in aqueous KOH combine the mechanical robustness and gas-tightness of a polymer...... stability in alkaline environments. The novel electrolytes are extensively characterized with respect to physicochemical and electrochemical properties and the chemical stability is assessed in 0-50 wt% aqueous KOH for more than 6 months at 88 degrees C. In water electrolysis tests using porous 3...

  10. Stainless steel anodes for alkaline water electrolysis and methods of making

    Science.gov (United States)

    Soloveichik, Grigorii Lev

    2014-01-21

    The corrosion resistance of stainless steel anodes for use in alkaline water electrolysis was increased by immersion of the stainless steel anode into a caustic solution prior to electrolysis. Also disclosed herein are electrolyzers employing the so-treated stainless steel anodes. The pre-treatment process provides a stainless steel anode that has a higher corrosion resistance than an untreated stainless steel anode of the same composition.

  11. Alkaline water electrolysis technology for Space Station regenerative fuel cell energy storage

    Science.gov (United States)

    Schubert, F. H.; Hoberecht, M. A.; Le, M.

    1986-01-01

    The regenerative fuel cell system (RFCS), designed for application to the Space Station energy storage system, is based on state-of-the-art alkaline electrolyte technology and incorporates a dedicated fuel cell system (FCS) and water electrolysis subsystem (WES). In the present study, emphasis is placed on the WES portion of the RFCS. To ensure RFCS availability for the Space Station, the RFCS Space Station Prototype design was undertaken which included a 46-cell 0.93 cu m static feed water electrolysis module and three integrated mechanical components.

  12. Porous poly(perfluorosulfonic acid) membranes for alkaline water electrolysis

    DEFF Research Database (Denmark)

    Aili, David; Hansen, Martin Kalmar; Andreasen, Jens Wenzel

    2015-01-01

    Poly(perfluorosulfonic acid) (PFSA) is one of a few polymer types that combine excellent alkali resistance with extreme hydrophilicity. It is therefore of interest as a base material in separators for alkaline water electrolyzers. In the pristine form it, however, shows high cation selectivity. T...... for the unmodified membrane. The technological feasibility was demonstrated by testing the membranes in an alkaline water electrolysis cell with encouraging performance.......Poly(perfluorosulfonic acid) (PFSA) is one of a few polymer types that combine excellent alkali resistance with extreme hydrophilicity. It is therefore of interest as a base material in separators for alkaline water electrolyzers. In the pristine form it, however, shows high cation selectivity...... and washed out and the obtained porous materials allowed for swelling to reach water contents up to λ=85 [H2O] [−SO3K]−1. After equilibration in 22 wt% aqueous KOH, ion conductivity of 0.2 S cm−1 was recorded for this membrane type at room temperature, which is significantly higher than 0.01 S cm−1...

  13. Hydrogen production by alkaline water electrolysis

    OpenAIRE

    Santos, Diogo M. F.; Sequeira, César A. C.; Figueiredo, José L.

    2013-01-01

    Water electrolysis is one of the simplest methods used for hydrogen production. It has the advantage of being able to produce hydrogen using only renewable energy. To expand the use of water electrolysis, it is mandatory to reduce energy consumption, cost, and maintenance of current electrolyzers, and, on the other hand, to increase their efficiency, durability, and safety. In this study, modern technologies for hydrogen production by water electrolysis have been investigated. In this article...

  14. Separating hydrogen and oxygen evolution in alkaline water electrolysis using nickel hydroxide

    Science.gov (United States)

    Chen, Long; Dong, Xiaoli; Wang, Yonggang; Xia, Yongyao

    2016-01-01

    Low-cost alkaline water electrolysis has been considered a sustainable approach to producing hydrogen using renewable energy inputs, but preventing hydrogen/oxygen mixing and efficiently using the instable renewable energy are challenging. Here, using nickel hydroxide as a redox mediator, we decouple the hydrogen and oxygen production in alkaline water electrolysis, which overcomes the gas-mixing issue and may increase the use of renewable energy. In this architecture, the hydrogen production occurs at the cathode by water reduction, and the anodic Ni(OH)2 is simultaneously oxidized into NiOOH. The subsequent oxygen production involves a cathodic NiOOH reduction (NiOOH→Ni(OH)2) and an anodic OH− oxidization. Alternatively, the NiOOH formed during hydrogen production can be coupled with a zinc anode to form a NiOOH-Zn battery, and its discharge product (that is, Ni(OH)2) can be used to produce hydrogen again. This architecture brings a potential solution to facilitate renewables-to-hydrogen conversion. PMID:27199009

  15. Heterogeneous anion conducting membranes based on linear and crosslinked KOH doped polybenzimidazole for alkaline water electrolysis

    DEFF Research Database (Denmark)

    Aili, David; Hansen, Martin Kalmar; Renzaho, Richard Fulgence

    2013-01-01

    Polybenzimidazole is a highly hygroscopic polymer that can be doped with aqueous KOH to give a material with high ion conductivity in the 10−2Scm−1 range, which in combination with its low gas permeability makes it an interesting electrolyte material for alkaline water electrolysis. In this study...... on their linear counterpart. The technical feasibility of the membranes was evaluated by the preliminary water electrolysis tests showing performance comparable to that of commercially available cell separators with great potential of further improvement....

  16. Development of durable and efficient electrodes for large-scale alkaline water electrolysis

    DEFF Research Database (Denmark)

    Kjartansdóttir, Cecilia Kristin; Nielsen, Lars Pleth; Møller, Per

    2013-01-01

    A new type of electrodes for alkaline water electrolysis is produced by physical vapour depositing (PVD) of aluminium onto a nickel substrate. The PVD Al/Ni is heat-treated to facilitate alloy formation followed by a selective aluminium alkaline leaching. The obtained porous Ni surface is uniform...... and characterized by a unique interlayer adhesion, which is critical for industrial application. IR-compensated polarisation curves prepared in a half-cell setup with 1 M KOH electrolyte at room temperature reveals that at least 400 mV less potential is needed to decompose water into hydrogen and oxygen...... produced bipolar electrolyser stack. The developed electrodes showed stable behaviour under intermittent operation for over 9000 h indicating no serious deactivation in the density of active sites....

  17. Anion-selective materials with 1,4-diazabicyclo[2.2.2]octane functional groups for advanced alkaline water electrolysis

    Czech Academy of Sciences Publication Activity Database

    Hnát, J.; Plevová, M.; Žitka, Jan; Paidar, M.; Bouzek, K.

    2017-01-01

    Roč. 248, 10 September (2017), s. 547-555 ISSN 0013-4686 R&D Projects: GA ČR(CZ) GA16-20728S Institutional support: RVO:61389013 Keywords : water electrolysis * alkaline environment * anion-selective membrane Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 4.798, year: 2016

  18. Basic study of alkaline water electrolysis

    International Nuclear Information System (INIS)

    Manabe, A.; Kashiwase, M.; Hashimoto, T.; Hayashida, T.; Kato, A.; Hirao, K.; Shimomura, I.; Nagashima, I.

    2013-01-01

    In order to realize future hydrogen society, hydrogen production systems must meet the large demand of hydrogen usage. Alkaline water electrolysis (AWE) would be one of the candidate technologies to produce hydrogen on a large scale from renewable energy. We have conducted basic research into AWE, trying to reveal technical issues under zero gap system in new cell technology. The zero gap system contributes lower cell voltage without causing any major operating problems compared with conventional finite gap cell. However, it was observed that Ni base electrodes showed corrosion phenomena in a number of test trials including steady operating conditions and several shut-downs. Activated Raney Ni alloy coating for anode material had an advantage for oxygen overvoltage. It showed a saving of around 100 mV at 40 A/dm 2 (0.4 A/cm 2 ) against Ni bare anodes. In the Chlor–Alkali (C/A) industry, thermal decomposition coating of mixed noble metal on Ni substrate is commonly used for advanced activated cathodes. It showed very low hydrogen over-potential of around 100 mV in AWE. To achieve better cell performance, separator selection is very important. We evaluated several separators including ion exchange membrane (IEM) to understand the basic function in AWE. IEM for C/A electrolysis showed high cell voltage (over 2.2 V) but low O 2 impurity in H 2 gas. Hydrogen purity was over 99.95%. Porous separators made of polypropylene showed 1.76 V at 40 A/dm 2 (0.4 A/cm 2 ), 80 °C. But there was a weakness on the durability for continuous operation. Proper selection of separator is important in an actual plant for effective and safe cell operation. The concept of safety operation is referred to by diffusion coefficient of hydrogen

  19. Economic Analysis of Improved Alkaline Water Electrolysis

    International Nuclear Information System (INIS)

    Kuckshinrichs, Wilhelm; Ketelaer, Thomas; Koj, Jan Christian

    2017-01-01

    Alkaline water electrolysis (AWE) is a mature hydrogen production technology and there exists a range of economic assessments for available technologies. For advanced AWEs, which may be based on novel polymer-based membrane concepts, it is of prime importance that development comes along with new configurations and technical and economic key process parameters for AWE that might be of interest for further economic assessments. This paper presents an advanced AWE technology referring to three different sites in Europe (Germany, Austria, and Spain). The focus is on financial metrics, the projection of key performance parameters of advanced AWEs, and further financial and tax parameters. For financial analysis from an investor’s (business) perspective, a comprehensive assessment of a technology not only comprises cost analysis but also further financial analysis quantifying attractiveness and supply/market flexibility. Therefore, based on cash flow (CF) analysis, a comprehensible set of metrics may comprise levelised cost of energy or, respectively, levelized cost of hydrogen (LCH) for cost assessment, net present value (NPV) for attractiveness analysis, and variable cost (VC) for analysis of market flexibility. The German AWE site turns out to perform best in all three financial metrics (LCH, NPV, and VC). Though there are slight differences in investment cost and operation and maintenance cost projections for the three sites, the major cost impact is due to the electricity cost. Although investment cost is slightly lower and labor cost is significantly lower in Spain, the difference can not outweigh the higher electricity cost compared to Germany. Given the assumption that the electrolysis operators are customers directly and actively participating in power markets, and based on the regulatory framework in the three countries, in this special case electricity cost in Germany is lowest. However, as electricity cost is profoundly influenced by political decisions as

  20. Economic Analysis of Improved Alkaline Water Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kuckshinrichs, Wilhelm, E-mail: w.kuckshinrichs@fz-juelich.de; Ketelaer, Thomas; Koj, Jan Christian [Forschungszentrum Juelich, Institute for Energy and Climate Research – Systems Analysis and Technology Evaluation (IEK-STE), Juelich (Germany)

    2017-02-20

    Alkaline water electrolysis (AWE) is a mature hydrogen production technology and there exists a range of economic assessments for available technologies. For advanced AWEs, which may be based on novel polymer-based membrane concepts, it is of prime importance that development comes along with new configurations and technical and economic key process parameters for AWE that might be of interest for further economic assessments. This paper presents an advanced AWE technology referring to three different sites in Europe (Germany, Austria, and Spain). The focus is on financial metrics, the projection of key performance parameters of advanced AWEs, and further financial and tax parameters. For financial analysis from an investor’s (business) perspective, a comprehensive assessment of a technology not only comprises cost analysis but also further financial analysis quantifying attractiveness and supply/market flexibility. Therefore, based on cash flow (CF) analysis, a comprehensible set of metrics may comprise levelised cost of energy or, respectively, levelized cost of hydrogen (LCH) for cost assessment, net present value (NPV) for attractiveness analysis, and variable cost (VC) for analysis of market flexibility. The German AWE site turns out to perform best in all three financial metrics (LCH, NPV, and VC). Though there are slight differences in investment cost and operation and maintenance cost projections for the three sites, the major cost impact is due to the electricity cost. Although investment cost is slightly lower and labor cost is significantly lower in Spain, the difference can not outweigh the higher electricity cost compared to Germany. Given the assumption that the electrolysis operators are customers directly and actively participating in power markets, and based on the regulatory framework in the three countries, in this special case electricity cost in Germany is lowest. However, as electricity cost is profoundly influenced by political decisions as

  1. Preparation of anion exchange membrane using polyvinyl chloride (PVC) for alkaline water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Gab-Jin; Bong, Soo-Yeon; Ryu, Cheol-Hwi [Hoseo University, Asan (Korea, Republic of); Lim, Soo-Gon [Energy and Machinery Korea Co., Ltd., Changwon (Korea, Republic of); Choi, Ho-Sang [Kyungil University, Gyeongsan (Korea, Republic of)

    2015-09-15

    An anion exchange membrane was prepared by the chloromethylation and the amination of polyvinyl chloride (PVC), as the base polymer. The membrane properties of the prepared anion exchange membrane, including ionic conductivity, ion exchange capacity, and water content were measured. The ionic conductivity of the prepared anion exchange membrane was in the range of 0.098x10{sup -2} -7.0x10{sup -2}S cm{sup -1}. The ranges of ion exchange capacity and water content were 1.9-3.7meq./g-dry-membrane and 35.1-63.1%, respectively. The chemical stability of the prepared anion exchange membrane was tested by soaking in 30 wt% KOH solution to determine its availability as a separator in the alkaline water electrolysis. The ionic conductivity during the chemical stability test largely did not change.

  2. Synthesis and characterization of NiFe2O4 electrocatalyst for the hydrogen evolution reaction in alkaline water electrolysis using different polymer binders

    Czech Academy of Sciences Publication Activity Database

    Chanda, D.; Hnát, J.; Paidar, M.; Schauer, Jan; Bouzek, K.

    2015-01-01

    Roč. 285, 1 July (2015), s. 217-226 ISSN 0378-7753 Institutional support: RVO:61389013 Keywords : alkaline water electrolysis * spinel oxides * polymer binder Subject RIV: CG - Electrochemistry Impact factor: 6.333, year: 2015

  3. Polymer anion-selective membranes for electrolytic splitting of water. Part II: enhancement of ionic conductivity and performance under conditions of alkaline water electrolysis

    Czech Academy of Sciences Publication Activity Database

    Hnát, J.; Paidar, M.; Schauer, Jan; Žitka, Jan; Bouzek, K.

    2012-01-01

    Roč. 42, č. 8 (2012), s. 545-554 ISSN 0021-891X R&D Projects: GA MŠk(CZ) 7E08005 EU Projects: European Commission(XE) 212903 - WELTEMP Institutional research plan: CEZ:AV0Z40500505 Keywords : water electrolysis * alkaline environment * polymer electrolyte Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.836, year: 2012

  4. Improved electrodes and gas impurity investigations on alkaline electrolysers

    DEFF Research Database (Denmark)

    Reissner, R.; Schiller, G.; Knoeri, T.

    Alkaline water electrolysis for hydrogenproduction is a well-established techniquebut some technological issues regarding thecoupling of alkaline water electrolysis andRenewable Energy Sources (RES) remain tobe improved.......Alkaline water electrolysis for hydrogenproduction is a well-established techniquebut some technological issues regarding thecoupling of alkaline water electrolysis andRenewable Energy Sources (RES) remain tobe improved....

  5. High-pressure water electrolysis: Electrochemical mitigation of product gas crossover

    International Nuclear Information System (INIS)

    Schalenbach, Maximilian; Stolten, Detlef

    2015-01-01

    Highlights: • New technique to reduce gas crossover during water electrolysis • Increase of the efficiency of pressurized water electrolysis • Prevention of safety hazards due to explosive gas mixtures caused by crossover • Experimental realization for a polymer electrolyte membrane electrolyzer • Discussion of electrochemical crossover mitigation for alkaline water electrolysis - Abstract: Hydrogen produced by water electrolysis can be used as an energy carrier storing electricity generated from renewables. During water electrolysis hydrogen can be evolved under pressure at isothermal conditions, enabling highly efficient compression. However, the permeation of hydrogen through the electrolyte increases with operating pressure and leads to efficiency loss and safety hazards. In this study, we report on an innovative concept, where the hydrogen crossover is electrochemically mitigated by an additional electrode between the anode and the cathode of the electrolysis cell. Experimentally, the technique was applied to a proton exchange membrane water electrolyzer operated at a hydrogen pressure that was fifty times larger than the oxygen pressure. Therewith, the hydrogen crossover was reduced and the current efficiency during partial load operation was increased. The concept is also discussed for water electrolysis that is operated at balanced pressures, where the crossover of hydrogen and oxygen is mitigated using two additional electrodes

  6. Hydrogen generation through static-feed water electrolysis

    Science.gov (United States)

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

    1975-01-01

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

  7. Manufacturing of a LaNiO3 composite electrode for oxygen evolution in commercial alkaline water electrolysis

    DEFF Research Database (Denmark)

    Egelund, Sune; Caspersen, Michael; Nikiforov, Aleksey Valerievich

    2016-01-01

    results were compared to a non-catalysed Watts nickel reference sample and the electrochemical measurements confirmed that the coating decreased the OER overpotential by 70 mV. XRD furthermore revealed that a LaNiO3 + Ni composite structure was obtained. Conventional alkaline water electrolysis...... was carried out at a temperature of 120 °C and a current densities of 0.2 and 0.8 A cm-2. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD) were used for characterization of the morphology....

  8. Alkaline membrane water electrolysis with non-noble catalysts

    DEFF Research Database (Denmark)

    Kraglund, Mikkel Rykær

    at 1.7 V and 2800 mA cm-2 at 2.0 V. Electrochemical impedance spectroscopy data showed a 6-fold reduction in ohmic cell resistance compared to conventional materials. Albeit good performance, ex-situ characterization and durability tests showed that polymer backbone and membrane stability remained......As renewable energy sources reach higher grid penetration, large scale energy storage solutions are becoming increasingly important. Hydrogen produced with renewable energy by water electrolysis is currently the only option to solve this challenge on a global scale, and green hydrogen is essential...

  9. Site-Dependent Environmental Impacts of Industrial Hydrogen Production by Alkaline Water Electrolysis

    Directory of Open Access Journals (Sweden)

    Jan Christian Koj

    2017-06-01

    Full Text Available Industrial hydrogen production via alkaline water electrolysis (AEL is a mature hydrogen production method. One argument in favor of AEL when supplied with renewable energy is its environmental superiority against conventional fossil-based hydrogen production. However, today electricity from the national grid is widely utilized for industrial applications of AEL. Also, the ban on asbestos membranes led to a change in performance patterns, making a detailed assessment necessary. This study presents a comparative Life Cycle Assessment (LCA using the GaBi software (version 6.115, thinkstep, Leinfelden-Echterdingen, Germany, revealing inventory data and environmental impacts for industrial hydrogen production by latest AELs (6 MW, Zirfon membranes in three different countries (Austria, Germany and Spain with corresponding grid mixes. The results confirm the dependence of most environmental effects from the operation phase and specifically the site-dependent electricity mix. Construction of system components and the replacement of cell stacks make a minor contribution. At present, considering the three countries, AEL can be operated in the most environmentally friendly fashion in Austria. Concerning the construction of AEL plants the materials nickel and polytetrafluoroethylene in particular, used for cell manufacturing, revealed significant contributions to the environmental burden.

  10. Polymer Electrolyte Membranes for Water Photo-Electrolysis

    Science.gov (United States)

    Aricò, Antonino S.; Girolamo, Mariarita; Siracusano, Stefania; Sebastian, David; Baglio, Vincenzo; Schuster, Michael

    2017-01-01

    Water-fed photo-electrolysis cells equipped with perfluorosulfonic acid (Nafion® 115) and quaternary ammonium-based (Fumatech® FAA3) ion exchange membranes as separator for hydrogen and oxygen evolution reactions were investigated. Protonic or anionic ionomer dispersions were deposited on the electrodes to extend the interface with the electrolyte. The photo-anode consisted of a large band-gap Ti-oxide semiconductor. The effect of membrane characteristics on the photo-electrochemical conversion of solar energy was investigated for photo-voltage-driven electrolysis cells. Photo-electrolysis cells were also studied for operation under electrical bias-assisted mode. The pH of the membrane/ionomer had a paramount effect on the photo-electrolytic conversion. The anionic membrane showed enhanced performance compared to the Nafion®-based cell when just TiO2 anatase was used as photo-anode. This was associated with better oxygen evolution kinetics in alkaline conditions compared to acidic environment. However, oxygen evolution kinetics in acidic conditions were significantly enhanced by using a Ti sub-oxide as surface promoter in order to facilitate the adsorption of OH species as precursors of oxygen evolution. However, the same surface promoter appeared to inhibit oxygen evolution in an alkaline environment probably as a consequence of the strong adsorption of OH species on the surface under such conditions. These results show that a proper combination of photo-anode and polymer electrolyte membrane is essential to maximize photo-electrolytic conversion. PMID:28468242

  11. Development of Non-Platinum Catalysts for Intermediate Temperature Water Electrolysis

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey Valerievich; Petrushina, Irina Michailovna; Bjerrum, Niels J.

    2014-01-01

    Water electrolysis is recognized as an efficient energy storage (in the form of hydrogen) supplement in renewable energy production. However, industrial alkaline water electrolyzers are rather ineffective and space requiring for a commercial use in connection with energy storage. The most effective...... modern water electrolyzers are based on polymeric proton-conducting membrane electrolytes (PEM), e.g. Nafion®, a perfluorocarbon-sulfonic acid polymer. These electrolyzers work at temperatures up to around 80 °C, and, in extreme cases, up to 130-140 °C. The most developed PEM electrolyzers...... as electrolytes for the intermediate temperature applications, such as CsHSO4, KHSO45. The most successful systems have been developed with CsH2PO4 (solid acid fuel cells (SAFCs) and Sn0.9In0.1P2O7 electrolytes6,7. While developing materials for the promising medium temperature electrolysis systems...

  12. High Temperature Alkaline Electrolysis Cells with Metal Foam Based Gas Diffusion Electrodes

    DEFF Research Database (Denmark)

    Chatzichristodoulou, Christodoulos; Allebrod, Frank; Mogensen, Mogens Bjerg

    2016-01-01

    Alkaline electrolysis cells operating at 250°C and 40 bar are able to convert electrical energy into hydrogen at very high efficiencies and power densities. In the present work we demonstrate the application of a PTFE hydrophobic network and Ag nanowires as oxygen evolution electrocatalyst...

  13. PEM Water Electrolysis at Elevated Temperatures

    DEFF Research Database (Denmark)

    Hansen, Martin Kalmar

    . This is followed in chapter 4 by a description of the electrolysis setups and electrolysis cells used during the work. Two different setups were used, one operating at atmospheric pressure and another that could operate at elevated pressure so that liquid water electrolysis could be performed at temperature above...... such as porosity and resistance which were supported by images acquired using scanning electron microscopy (SEM). In chapters 6 and 7 the results of the steam electrolysis and pressurised water electrolysis, respectively, are presented and discussed. The steam electrolysis was tested at 130 °C and atmospheric...... needed and hence it has become acute to be able to store the energy. Hydrogen has been identified as a suitable energy carrier and water electrolysis is one way to produce it in a sustainable and environmentally friendly way. In this thesis an introduction to the subject (chapter 1) is given followed...

  14. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and an immobilized electrolyte allow for reversible operation as electrolysis cell or fuel...... cell. In the present work we demonstrate the application of hydrophobic, porous, and electro-catalytically active gas diffusion electrodes. PTFE particles and silver nanowires as electro-catalysts were used in the gas diffusion electrodes. Impedance spectroscopy and cyclic voltammetry were performed...... to determine the cell characteristics. The thickness of the electrolyte matrix was only 200 µm, thereby achieving a serial resistance and area specific resistance of 60 mΩ cm2 and 150 mΩ cm2, respectively, at 200 °C and 20 bar. A new production method was developed to increase the cell size from lab scale (1...

  15. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into chemical energy in the form of hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and a liquid immobilized electrolyte allow the operation...... of the newly designed electrolysis cell as a fuel cell, but condensation of steam may lead to blocked pores, thereby inhibiting gas diffusion and decreasing the performance of the cell. In the here presented work we present the application of a hydrophobic, porous, and electro-catalytically active layer...... the electrochemical characteristics of the cell. The thickness of the electrolyte matrix was reduced to 200 µm, thereby achieving a serial resistance and area specific resistance as low as 60 mΩ cm2 and 150 mΩ cm2, respectively, at a temperature of 200 °C and 20 bar pressure. A new production method was developed...

  16. Tritium separation from heavy water using electrolysis

    International Nuclear Information System (INIS)

    Ogata, Y.; Sakuma, Y.; Ohtani, N.; Kodaka, M.

    2001-01-01

    A tritium separation from heavy water by the electrolysis using a solid polymer electrode (SPE) was specified on investigation. The heavy water (∼10 Bq g -1 ) and the light water (∼70 Bq g -1 ) were electrolysed using an electrolysis device (Tripure XZ001, Permelec Electrode Ltd.) with the SPE layer. The cathode was made of stainless steel (SUS314). The electrolysis was carried out at 20 A x 60 min, with the electrolysis temperature at 10, 20, or 30degC, and 15 A x 80 min at 5degC. The produced hydrogen and oxygen gases were recombined using a palladium catalyst (ND-101, N.E. Chemcat Ltd.) with nitrogen gas as a carrier. The activities of the water in the cell and of the recombined water were analyzed using a liquid scintillation counter. The electrolysis potential to keep the current 20 A was 2-3 V. The yields of the recombined water were more than 90%. The apparent separation factors (SF) for the heavy water and the light water were ∼2 and ∼12, respectively. The SF value was in agreement with the results in other work. The factors were changed with the cell temperature. The electrolysis using the SPE is applicable for the tritium separation, and is able to perform the small-scale apparatus at the room temperature. (author)

  17. Static Feed Water Electrolysis Subsystem Testing and Component Development

    Science.gov (United States)

    Koszenski, E. P.; Schubert, F. H.; Burke, K. A.

    1983-01-01

    A program was carried out to develop and test advanced electrochemical cells/modules and critical electromechanical components for a static feed (alkaline electrolyte) water electrolysis oxygen generation subsystem. The accomplishments were refurbishment of a previously developed subsystem and successful demonstration for a total of 2980 hours of normal operation; achievement of sustained one-person level oxygen generation performance with state-of-the-art cell voltages averaging 1.61 V at 191 ASF for an operating temperature of 128F (equivalent to 1.51V when normalized to 180F); endurance testing and demonstration of reliable performance of the three-fluid pressure controller for 8650 hours; design and development of a fluid control assembly for this subsystem and demonstration of its performance; development and demonstration at the single cell and module levels of a unitized core composite cell that provides expanded differential pressure tolerance capability; fabrication and evaluation of a feed water electrolyte elimination five-cell module; and successful demonstration of an electrolysis module pressurization technique that can be used in place of nitrogen gas during the standby mode of operation to maintain system pressure and differential pressures.

  18. Factors in electrode fabrication for performance enhancement of anion exchange membrane water electrolysis

    Science.gov (United States)

    Cho, Min Kyung; Park, Hee-Young; Choe, Seunghoe; Yoo, Sung Jong; Kim, Jin Young; Kim, Hyoung-Juhn; Henkensmeier, Dirk; Lee, So Young; Sung, Yung-Eun; Park, Hyun S.; Jang, Jong Hyun

    2017-04-01

    To improve the cell performance for alkaline anion exchange membrane water electrolysis (AEMWE), the effects of the amount of polytetrafluoroethylene (PTFE) non-ionomeric binder in the anode and the hot-pressing conditions during the fabrication of the membrane electrode assemblies (MEAs) on cell performances are studied. The electrochemical impedance data indicates that hot-pressing at 50 °C for 1 min during MEA construction can reduce the polarization resistance of AEMWE by ∼12%, and increase the initial water electrolysis current density at 1.8 V (from 195 to 243 mA cm-2). The electrochemical polarization and impedance results also suggest that the AEMWE performance is significantly affected by the content of PTFE binder in the anode electrode, and the optimal content is found to be 9 wt% between 5 and 20 wt%. The AEMWE device fabricated with the optimized parameters exhibits good water splitting performance (299 mA cm-2 at 1.8 V) without noticeable degradation in voltage cycling operations.

  19. Phase transformation of the brownmillerite SrCoO{sub 2.5} thin film through alkaline water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Tambunan, Octolia Togibasa; Lee, Min Young; Kim, Deok Hyeon; Parwanta, Kadek Juliana; Jung, Chang Uk [Hankuk University of Foreign Studies, Yongin (Korea, Republic of)

    2014-06-15

    A phase transformation from insulating brownmillerite SrCoO{sub 2.5} to conducting perovskite SrCoO{sub 3} through electrochemical oxidation has been demonstrated for thin films of SrCoO{sub x} on a SrTiO{sub 3} (001) substrate. The cobalt-oxide film strongly favors the brownmillerite phase of SrCoO{sub 2.5} instead of the perovskite phase of SrCoO{sub 3} on a SrTiO{sub 3} (001) substrate due to its low lattice mismatch. Therefore, the phase transformation has its own retention. The alkaline water electrolysis occurs between the copper cathode and the SrCoO{sub 2.5} film anode. The H{sup +} ions are attracted to the cathode and generate H{sub 2} gas. The OH{sup -} ions are attracted to the film's surface and generate a rich amount of oxygen to fill the oxygen vacancy channel of brownmillerite SrCoO{sub 2.5}. The phase transformation was verified from the change in the out-of-plane lattice constant and the change in the resistivity of the electrolyzed film.

  20. Analysis of Trends and Emerging Technologies in Water Electrolysis Research Based on a Computational Method: A Comparison with Fuel Cell Research

    Directory of Open Access Journals (Sweden)

    Takaya Ogawa

    2018-02-01

    Full Text Available Water electrolysis for hydrogen production has received increasing attention, especially for accumulating renewable energy. Here, we comprehensively reviewed all water electrolysis research areas through computational analysis, using a citation network to objectively detect emerging technologies and provide interdisciplinary data for forecasting trends. The results show that all research areas increase their publication counts per year, and the following two areas are particularly increasing in terms of number of publications: “microbial electrolysis” and “catalysts in an alkaline water electrolyzer (AWE and in a polymer electrolyte membrane water electrolyzer (PEME.”. Other research areas, such as AWE and PEME systems, solid oxide electrolysis, and the whole renewable energy system, have recently received several review papers, although papers that focus on specific technologies and are cited frequently have not been published within the citation network. This indicates that these areas receive attention, but there are no novel technologies that are the center of the citation network. Emerging technologies detected within these research areas are presented in this review. Furthermore, a comparison with fuel cell research is conducted because water electrolysis is the reverse reaction to fuel cells, and similar technologies are employed in both areas. Technologies that are not transferred between fuel cells and water electrolysis are introduced, and future water electrolysis trends are discussed.

  1. Alkaline anion exchange membrane water electrolysis: Effects of electrolyte feed method and electrode binder content

    Science.gov (United States)

    Cho, Min Kyung; Park, Hee-Young; Lee, Hye Jin; Kim, Hyoung-Juhn; Lim, Ahyoun; Henkensmeier, Dirk; Yoo, Sung Jong; Kim, Jin Young; Lee, So Young; Park, Hyun S.; Jang, Jong Hyun

    2018-04-01

    Herein, we investigate the effects of catholyte feed method and anode binder content on the characteristics of anion exchange membrane water electrolysis (AEMWE) to construct a high-performance electrolyzer, revealing that the initial AEMWE performance is significantly improved by pre-feeding 0.5 M aqueous KOH to the cathode. The highest long-term activity during repeated voltage cycling is observed for AEMWE operation in the dry cathode mode, for which the best long-term performance among membrane electrode assemblies (MEAs) featuring polytetrafluoroethylene (PTFE) binder-impregnated (5-20 wt%) anodes is detected for a PTFE content of 20 wt%. MEAs with low PTFE content (5 and 9 wt%) demonstrate high initial performance, rapid performance decay, and significant catalyst loss from the electrode during long-term operation, whereas the MEA with 20 wt% PTFE allows stable water electrolysis for over 1600 voltage cycles. Optimization of cell operating conditions (i.e., operation in dry cathode mode at an optimum anode binder content following an initial solution feed) achieves an enhanced water splitting current density (1.07 A cm-2 at 1.8 V) and stable long-term AEMWE performance (0.01% current density reduction per voltage cycle).

  2. Bipolar performance of the electroplated iron-nickel deposits for water electrolysis

    International Nuclear Information System (INIS)

    Hu, C.-C.; Wu, Y.-R.

    2003-01-01

    The activities of oxygen and hydrogen evolution on Fe-Ni deposits with controllable compositions were systematically compared in the alkaline media. The redox behavior of Fe-Ni deposits prior to oxygen evolution could be generally related to their electrochemical activity for the oxygen evolution reaction meanwhile the activity of hydrogen evolution was found to be generally proportional to the mean roughness factor of deposits. Fe 24 Ni 76 , Fe 76 Ni 24 and Fe 90 Ni 10 deposits simultaneously exhibiting good activities of oxygen and hydrogen evolution were employed as electrode materials for water electrolysis in a bipolar hydrogen-oxygen electrolyzer in the stability test, examined at 50 and 200 mA cm -2 in 5 M KOH for 2 weeks. The morphological, compositional and crystalline information of these three materials before and after the bipolar studies were measured by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD) analysis, respectively. These studies demonstrated the potential applicability of these three deposits in the bipolar electrolyzer for water electrolysis

  3. Hydrogen Production by Water Electrolysis Via Photovoltaic Panel

    Directory of Open Access Journals (Sweden)

    Hydrogen Production by Water Electrolysis Via Photovoltaic Panel

    2016-07-01

    Full Text Available Hydrogen fuel is a good alternative to fossil fuels. It can be produced using a clean energy without contaminated emissions. This work is concerned with experimental study on hydrogen production via solar energy. Photovoltaic module is used to convert solar radiation to electrical energy. The electrical energy is used for electrolysis of water into hydrogen and oxygen by using alkaline water electrolyzer with stainless steel electrodes. A MATLAB computer program is developed to solve a four-parameter-model and predict the characteristics of PV module under Baghdad climate conditions. The hydrogen production system is tested at different NaOH mass concentration of (50,100, 200, 300 gram. The maximum hydrogen production rate is 153.3 ml/min, the efficiency of the system is 20.88% and the total amount of hydrogen produced in one day is 220.752 liter.

  4. Development of a pressurized bipolar alkaline water electrolyzer

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

    This paper reports the actual development status of a bipolar alkaline water electrolyzer with maximum production capacity of 1 m3/h of hydrogen and controlled by a PLC (Programmable Logic Controller), which also interfaces the electrolytic system with operators and other equipment, such as gas storage tanks, fuel cells and photovoltaic panels. The project also includes the construction of an electrolysis test bench to record electrical parameters (cathode, anode, separator and electrolyte potentials), the amount of produced gases and gas quality determined by gas chromatography. (author)

  5. Water Electrolysis at Different Current - Voltage Regimes

    International Nuclear Information System (INIS)

    Kleperis, J.; Blums, J.; Vanags, M.

    2007-01-01

    Full text: Electrochemical impedance and volt-amperic methods were used to compare an efficiency of water electrolysis for different materials and different electrode configurations. Two and three electrode measurements were made, using standard calomel reference electrode. Non-standard capacitative electrolysis was analyzed in special cell made from cylindrical steel electrodes. Volt-amperic measurements from - 15V to +15V DC didn't indicated the presence of oxidation - reduction reactions when distilled water was used as electrolyte. Impedance measurements showed unusual frequency behavior when the AC voltage increased till 0.5V. Different nickel and carbon electrodes (plate, porous and textile - type) were used to learn classical Faraday electrolysis in strong alkali solutions. Flying increase of current was indicator of the presence of electrolysis, and characteristic potential was used differ between materials accordingly they effectiveness for usage in an electrolyser device. (Aithors)

  6. Optimization of synthesis of the nickel-cobalt oxide based anode electrocatalyst and of the related membrane-electrode assembly for alkaline water electrolysis

    Science.gov (United States)

    Chanda, Debabrata; Hnát, Jaromir; Bystron, Tomas; Paidar, Martin; Bouzek, Karel

    2017-04-01

    In this work, the Ni-Co spinel oxides are synthesized via different methods and using different calcination temperatures. Properties of the prepared materials are compared. The best route is selected and used to prepare a Ni1+xCo2-xO4 (-1 ≤ x ≤ 1) series of materials in order to investigate their catalytic activity towards the oxygen evolution reaction (OER). The results show that hydroxide preparation yields NiCo2O4 oxide with the highest activity. 325 °C is identified as the optimum calcination temperature. Subsequently, the catalysts are tested in an electrolysis cell. To prepare an anode catalyst layer based on NiCo2O4 catalyst on top of a nickel foam substrate for membrane electrode assembly (MEA) construction, following polymer binders are used: anion-selective quaternized polyphenylene oxide (qPPO), inert polytetrafluoroethylene (PTFE®), and cation-selective Nafion®. qPPO ionomer containing MEA exhibited highest OER activity. The current density obtained using a MEA containing qPPO binder attains a value of 135 mA cm-2 at a cell voltage of 1.85 V. After 7 h chronopotentiometric experiment at a constant current density of 225 mA cm-2, the MEA employing PTFE® binder shows higher stability than the other binders in alkaline water electrolysis at 50 °C. Under similar conditions, stability of the PTFE®-binding MEA is examined for 135 h.

  7. Hydrogen by water electrolysis

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Hydrogen production by water electrolysis (aqueous solution of potassium hydroxide) is shortly presented with theoretical aspects (thermodynamics and kinetics), and components of the electrolytic cell (structural materials, cathodes, anodes, diaphragms), and examples of industrial processes. (A.B.). 4 figs

  8. Technology advancement of the static feed water electrolysis process

    Science.gov (United States)

    Schubert, F. H.; Wynveen, R. A.

    1977-01-01

    A program to advance the technology of oxygen- and hydrogen-generating subsystems based on water electrolysis was studied. Major emphasis was placed on static feed water electrolysis, a concept characterized by low power consumption and high intrinsic reliability. The static feed based oxygen generation subsystem consists basically of three subassemblies: (1) a combined water electrolysis and product gas dehumidifier module; (2) a product gas pressure controller and; (3) a cyclically filled water feed tank. Development activities were completed at the subsystem as well as at the component level. An extensive test program including single cell, subsystem and integrated system testing was completed with the required test support accessories designed, fabricated, and assembled. Mini-product assurance activities were included throughout all phases of program activities. An extensive number of supporting technology studies were conducted to advance the technology base of the static feed water electrolysis process and to resolve problems.

  9. The micro-electrolysis technique in waste water treatment

    International Nuclear Information System (INIS)

    Jiti Zhou; Weihen Yang; Fenglin Yang; Xuemin Xiang; Yulu Wang

    1997-01-01

    The micro-electrolysis is one of the efficient methods to treat some kinds of waste water. The experiments have shown its high efficiency in sewage treatment and some kinds of industrial waste water. It is suitable for pre-treatment of high concentrated waste water and deep treatment of waste water for reuse purpose. The disadvantage of micro-electrolysis is its high energy consumption in case of high electrolyte concentration. (author) 2 figs., 11 tabs., 2 refs

  10. The micro-electrolysis technique in waste water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Jiti Zhou; Weihen Yang; Fenglin Yang; Xuemin Xiang; Yulu Wang [Dalian Univ. of Technology, Dalian (China)

    1997-12-31

    The micro-electrolysis is one of the efficient methods to treat some kinds of waste water. The experiments have shown its high efficiency in sewage treatment and some kinds of industrial waste water. It is suitable for pre-treatment of high concentrated waste water and deep treatment of waste water for reuse purpose. The disadvantage of micro-electrolysis is its high energy consumption in case of high electrolyte concentration. (author) 2 figs., 11 tabs., 2 refs.

  11. Mediated water electrolysis in biphasic systems.

    Science.gov (United States)

    Scanlon, Micheál D; Peljo, Pekka; Rivier, Lucie; Vrubel, Heron; Girault, Hubert H

    2017-08-30

    The concept of efficient electrolysis by linking photoelectrochemical biphasic H 2 evolution and water oxidation processes in the cathodic and anodic compartments of an H-cell, respectively, is introduced. Overpotentials at the cathode and anode are minimised by incorporating light-driven elements into both biphasic reactions. The concepts viability is demonstrated by electrochemical H 2 production from water splitting utilising a polarised water-organic interface in the cathodic compartment of a prototype H-cell. At the cathode the reduction of decamethylferrocenium cations ([Cp 2 *Fe (III) ] + ) to neutral decamethylferrocene (Cp 2 *Fe (II) ) in 1,2-dichloroethane (DCE) solvent takes place at the solid electrode/oil interface. This electron transfer process induces the ion transfer of a proton across the immiscible water/oil interface to maintain electroneutrality in the oil phase. The oil-solubilised proton immediately reacts with Cp 2 *Fe (II) to form the corresponding hydride species, [Cp 2 *Fe (IV) (H)] + . Subsequently, [Cp 2 *Fe (IV) (H)] + spontaneously undergoes a chemical reaction in the oil phase to evolve hydrogen gas (H 2 ) and regenerate [Cp 2 *Fe (III) ] + , whereupon this catalytic Electrochemical, Chemical, Chemical (ECC') cycle is repeated. During biphasic electrolysis, the stability and recyclability of the [Cp 2 *Fe (III) ] + /Cp 2 *Fe (II) redox couple were confirmed by chronoamperometric measurements and, furthermore, the steady-state concentration of [Cp 2 *Fe (III) ] + monitored in situ by UV/vis spectroscopy. Post-biphasic electrolysis, the presence of H 2 in the headspace of the cathodic compartment was established by sampling with gas chromatography. The rate of the biphasic hydrogen evolution reaction (HER) was enhanced by redox electrocatalysis in the presence of floating catalytic molybdenum carbide (Mo 2 C) microparticles at the immiscible water/oil interface. The use of a superhydrophobic organic electrolyte salt was critical to

  12. Water electrolysis system refurbishment and testing

    Science.gov (United States)

    Greenough, B. M.

    1972-01-01

    The electrolytic oxygen generator for the back-up water electrolysis system in a 90-day manned test was refurbished, improved and subjected to a 182-day bench test. The performance of the system during the test demonstrated the soundness of the basic electrolysis concept, the high development status of the automatic controls which allowed completely hands-off operation, and the capability for orbital operation. Some design improvements are indicated.

  13. Hydrogen production by high-temperature electrolysis of water vapor steam. Test results obtained with an electrolysis tube

    International Nuclear Information System (INIS)

    Hino, Ryutaro; Miyamoto, Yoshiaki

    1995-01-01

    High-temperature electrolysis of water vapor steam is an advanced hydrogen production process decomposing high temperature steam up to 1,000degC, which applies an electro-chemical reaction reverse to the solid oxide fuel cell. At Japan Atomic Energy Research Institute, laboratory-scale experiments have been conducted using a practical electrolysis tube with 12 electrolysis cells in order to develop heat utilization systems for high-temperature gas-cooled reactors. The electrolysis cells of which electrolyte was yttria-stabilized zirconia were formed on a porous ceramic tube in series by plasma spraying. In the experiments, water steam mixed with argon carrier gas was supplied into the electrolysis tube heated at a constant temperature regulated in the range from 850degC to 950degC, and electrolysis power was supplied by a DC power source. Hydrogen production rate increased with applied voltage and electrolysis temperature; the maximum production rate was 6.9Nl/h at 950degC. Hydrogen production rate was correlated with applied current densities on the basis of experimental data. High energy efficiency was achieved under the applied current density ranging from 80 to 100 mA/cm 2 . (author)

  14. Electromagnetic radiation during electrolysis of heavy water

    International Nuclear Information System (INIS)

    Koval'chuk, E.P.; Yanchuk, O.M.; Reshetnyak, O.V.

    1994-01-01

    The radiation in the visible and ultraviolet spectral regions during electrolysis of heavy water on nickel and palladium cathodes was determined for the first time. A sharp jump of the intensity photon flow was observed at a current density of higher than 125 mA/cm 2 . A hypothesis about the relation of the electrochemiluminescence phenomenon during electrolysis of heavy water with the formation of fresh surfaces in consequence of the hydrogenous corrosion of the cathode material is formulated. ((orig.))

  15. Time efficiency of tritium measurement in the environmental water by electrolysis enrichment (2)

    International Nuclear Information System (INIS)

    Ogata, Y.; Koganezawa, T.; Iida, T.

    2003-01-01

    Now the electrolysis enrichment is necessary for tritium measurement of the environmental water in Japan. Generally, the electrolysis needs distilling the sample water before and after the electrolysis. To save the time to measure, it was investigated that a possibility of the omission of the distillation after the electrolysis and of the substitution the filtration for the distillation before the electrolysis. The electrolysis was carried out with a device using solid polymer electrolyte layer, which was recently developed in Japan. Initially, impurities eluted from the device were measured by enrichment of ultra pure water. Although some impurities eluted from the layer, the concentrations were so low that the enriched water brought ineffectual quenching for the liquid scintillation counting. Secondly, two filtration methods, i.e.; micro filtration with the pore size of 0.1 μm and reverse osmosis, were applied to eliminate the impurities in the environmental waters before the electrolysis. Although the impurity concentrations in the samples by the filtrations were higher than those by the distillation, the filtered water brought only slight quenching. However, the frequent electrolysis of the water treated with the micro filtration caused degradation of the electrolysis cell. Consequently, the distillation after the electrolysis may omit, and the reverse osmosis treatment may alternate the distillation before the electrolysis. Improving the treatment will not only save the time and labor but also reduce the error with the treatment. The measurement technique proposed here will take 25 hours to measure one sample using the electrolysis device produced commercially. A hypothetic electrolysis device of which final sample volume were 20 cm 3 could allow the measuring time of 10 hours. (author)

  16. Efficiency of tritium measurement in the environmental water by electrolysis enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Koganezawa, T.; Iida, T. [Nagoya Univ., Graduate School of Engineering, Nagoya, Aichi (Japan); Sakuma, Y.; Yamanishi, H. [National Inst. for Fusion Science, Toki, Gifu (Japan); Ogata, Y. [Nagoya Univ., School of Health Sciences, Nagoya, Aichi (Japan); Tsuji, N. [Japan Air-conditioning Service Co. and Ltd., Nagoya, Aichi (Japan); Kakiuchi, M. [Gakushuin Univ., Faculty of Science, Tokyo (Japan); Satake, H. [Toyama Univ., Faculty of Science, Toyama (Japan)

    2002-06-01

    Now tritium concentration in the environmental water is 0.5-2 Bq{center_dot}L{sup -1} in Japan. Tritium concentration cannot be measured accurately by liquid scintillation method, because the minimum detectable limits of liquid scintillation method is 0.5 Bq{center_dot}L{sup -1}. Therefore, one needs to enrich tritium concentration in the environmental water. Although the most popular method for tritium enrichment is electrolysis, the electrolysis takes much time and labor for distilling sample water at before and after the electrolysis. The purpose of this study is to investigate the possibility of more convenient method for tritium measurement. The method substitutes filtration for distillation at before electrolysis and omits distillation at after electrolysis. The method enables by using the electrolysis with solid polymer electrode. We performed two kinds of experiment to confirm the possibility of the method. First, impurities eluted from electrolysis installation with ultra pure water as sample was measured. Some impurities were eluted into the sample, but they brought noneffective quenching. Secondly, we applied new method to the environmental waters. Substituting for distillation, two filtration, 0.1 {mu}m filtration and reverse osmosis method, were investigated. Impurities in the samples by the filtrations were somewhat higher than that by the distillation, they brought noneffective quenching. We, however, observed distemper of the electrolysis happened by electrolysing filtered sample. Distillation is substituted filtration at before enrichment and omitted at after enrichment, leaving the influence of quenching out of consideration. (author)

  17. Efficiency of tritium measurement in the environmental water by electrolysis enrichment

    International Nuclear Information System (INIS)

    Koganezawa, T.; Iida, T.; Sakuma, Y.; Yamanishi, H.; Ogata, Y.; Tsuji, N.; Kakiuchi, M.; Satake, H.

    2002-01-01

    Now tritium concentration in the environmental water is 0.5-2 Bq·L -1 in Japan. Tritium concentration cannot be measured accurately by liquid scintillation method, because the minimum detectable limits of liquid scintillation method is 0.5 Bq·L -1 . Therefore, one needs to enrich tritium concentration in the environmental water. Although the most popular method for tritium enrichment is electrolysis, the electrolysis takes much time and labor for distilling sample water at before and after the electrolysis. The purpose of this study is to investigate the possibility of more convenient method for tritium measurement. The method substitutes filtration for distillation at before electrolysis and omits distillation at after electrolysis. The method enables by using the electrolysis with solid polymer electrode. We performed two kinds of experiment to confirm the possibility of the method. First, impurities eluted from electrolysis installation with ultra pure water as sample was measured. Some impurities were eluted into the sample, but they brought noneffective quenching. Secondly, we applied new method to the environmental waters. Substituting for distillation, two filtration, 0.1 μm filtration and reverse osmosis method, were investigated. Impurities in the samples by the filtrations were somewhat higher than that by the distillation, they brought noneffective quenching. We, however, observed distemper of the electrolysis happened by electrolysing filtered sample. Distillation is substituted filtration at before enrichment and omitted at after enrichment, leaving the influence of quenching out of consideration. (author)

  18. Water Electrolysis for In-Situ Resource Utilization (ISRU)

    Science.gov (United States)

    Lee, Kristopher A.

    2016-01-01

    Sending humans to Mars for any significant amount of time will require capabilities and technologies that enable Earth independence. To move towards this independence, the resources found on Mars must be utilized to produce the items needed to sustain humans away from Earth. To accomplish this task, NASA is studying In Situ Resource Utilization (ISRU) systems and techniques to make use of the atmospheric carbon dioxide and the water found on Mars. Among other things, these substances can be harvested and processed to make oxygen and methane. Oxygen is essential, not only for sustaining the lives of the crew on Mars, but also as the oxidizer for an oxygen-methane propulsion system that could be utilized on a Mars ascent vehicle. Given the presence of water on Mars, the electrolysis of water is a common technique to produce the desired oxygen. Towards this goal, NASA designed and developed a Proton Exchange Membrane (PEM) water electrolysis system, which was originally slated to produce oxygen for propulsion and fuel cell use in the Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project. As part of the Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA) project, this same electrolysis system, originally targeted at enabling in situ propulsion and power, operated in a life-support scenario. During HESTIA testing at Johnson Space Center, the electrolysis system supplied oxygen to a chamber simulating a habitat housing four crewmembers. Inside the chamber, oxygen was removed from the atmosphere to simulate consumption by the crew, and the electrolysis system's oxygen was added to replenish it. The electrolysis system operated nominally throughout the duration of the HESTIA test campaign, and the oxygen levels in the life support chamber were maintained at the desired levels.

  19. Thermodynamic evaluation of geothermal energy powered hydrogen production by PEM water electrolysis

    International Nuclear Information System (INIS)

    Yilmaz, Ceyhun; Kanoglu, Mehmet

    2014-01-01

    Thermodynamic energy and exergy analysis of a PEM water electrolyzer driven by geothermal power for hydrogen production is performed. For this purpose, work is produced from a geothermal resource by means of the organic Rankine cycle; the resulting work is used as a work input for an electrolysis process; and electrolysis water is preheated by the waste geothermal water. The first and second-law based performance parameters are identified for the considered system and the system performance is evaluated. The effects of geothermal water and electrolysis temperatures on the amount of hydrogen production are studied and these parameters are found to be proportional to each other. We consider a geothermal resource at 160 °C available at a rate of 100 kg/s. Under realistic operating conditions, 3810 kW power can be produced in a binary geothermal power plant. The produced power is used for the electrolysis process. The electrolysis water can be preheated to 80 °C by the geothermal water leaving the power plant and hydrogen can be produced at a rate of 0.0340 kg/s. The energy and exergy efficiencies of the binary geothermal power plant are 11.4% and 45.1%, respectively. The corresponding efficiencies for the electrolysis system are 64.0% and 61.6%, respectively, and those for the overall system are 6.7% and 23.8%, respectively. - Highlights: • Thermodynamic analysis of hydrogen production by PEM electrolysis powered by geothermal energy. • Power is used for electrolyser; used geothermal water is for preheating electrolysis water. • Effect of geothermal water and electrolysis temperatures on the amount of hydrogen production. • Hydrogen can be produced at a rate of 0.0340 kg/s for a resource at 160 °C available at 100 kg/s. • Energy and exergy efficiencies of the overall system are 6.7% and 23.8%, respectively

  20. Cobalt and molybdenum activated electrodes in foam based alkaline electrolysis cells at 150-250 °C and 40 bar

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    A new type of alkaline electrolysis cells with nickel foam based gas diffusion electrodes and KOH (aq) immobilized in mesoporous SrTiO3 has been developed and tested at temperatures of 150 C, 200 C and 250 C at a pressure of 40 bar. Two cells have been characterized during the 270 h long test...

  1. Advancements in oxygen generation and humidity control by water vapor electrolysis

    Science.gov (United States)

    Heppner, D. B.; Sudar, M.; Lee, M. C.

    1988-01-01

    Regenerative processes for the revitalization of manned spacecraft atmospheres or other manned habitats are essential for realization of long-term space missions. These processes include oxygen generation through water electrolysis. One promising technique of water electrolysis is the direct conversion of the water vapor contained in the cabin air to oxygen. This technique is the subject of the present program on water vapor electrolysis development. The objectives were to incorporate technology improvements developed under other similar electrochemical programs and add new ones; design and fabricate a mutli-cell electrochemical module and a testing facility; and demonstrate through testing the improvements. Each aspect of the water vapor electrolysis cell was reviewed. The materials of construction and sizing of each element were investigated analytically and sometime experimentally. In addition, operational considerations such as temperature control in response to inlet conditions were investigated. Three specific quantitative goals were established.

  2. Solid oxide electrolysis cell for decomposition of tritiated water

    International Nuclear Information System (INIS)

    Konishi, S.; Katsuta, H.; Naruse, Y.; Ohno, H.; Yoshida, H.

    1984-01-01

    The decomposition of tritiated water vapor with solid oxide electrolysis cell was proposed for the application to the D-T fusion reactor system. This method is essentially free from problems such as large tritium inventory, radiation damage, and generation of solid waste, so it is expected to be a promising one. Electrolysis of water vapor in argon carrier was performed using tube-type stabilized zirconia cell with porous platinum electrodes in the temperature range of 500 0 C to 950 0 C. High conversion ratio from water to hydrogen up to 99.9% was achieved. The characteristics of the cell is deduced from the Nernst's equation and conversion ratio is described as the function of the open circuit voltage. Experimental results agreed with the equation. Isotope effect in electrolysis is also discussed and experiments with heavy water were carried out. Obtained separation factor was slightly higher than the theoretical value

  3. Solid oxide electrolysis cell for decomposition of tritiated water

    International Nuclear Information System (INIS)

    Konishi, S.; Ohno, H.; Yoshida, H.; Katsuta, H.; Naruse, Y.

    1986-01-01

    The decomposition of tritiated water vapor by means of solid oxide electrolysis cells has been proposed for the application to the D-T fusion reactor system. This method is essentially free from problems such as large tritium inventory, radiation damage, and generation of solid waste, so it is expected to be a promising one. Electrolysis of water vapor in an argon carrier was performed using a tube-type stabilized zirconia cell with porous platinum electrodes over the temperature range 500-950 0 C. High conversion ratios from water to hydrogen, of up to 99.9%, were achieved. The characteristics of the cell were deduced from the Nernst equation and the conversion ratios expressed as a function of the IR-free voltage. Experimental results agreed with the equation. The isotope effect in electrolysis is also discussed and experiments with heavy water were carried out. The obtained separation factor was slightly higher than the theoretical value. (author)

  4. A Small-Scale and Low-Cost Apparatus for the Electrolysis of Water

    Science.gov (United States)

    Eggeen, Per-Odd; Kvittingen, Lise

    2004-01-01

    The construction of two simple, inexpensive apparatuses that clearly show the electrolysis of water are described. Traditionally the electrolysis of water is conducted in a Hofmann apparatus which is expensive and fragile.

  5. 2nd Generation alkaline electrolysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Yde, L. [Aarhus Univ. Business and Social Science - Centre for Energy Technologies (CET), Aarhus (Denmark); Kjartansdottir, C.K. [Technical Univ. of Denmark. DTU Mechanical Engineering, Kgs. Lyngby (Denmark); Allebrod, F. [Technical Univ. of Denmark. DTU Energy Conversion, DTU Risoe Campus, Roskilde (Denmark)] [and others

    2013-03-15

    conditions and the degradation mechanism was examined. One of the strong visions for the 2{sup nd} generation electrolyser concept has been to develop a modular system with several standardized components. The following modules have been designed: 1) Electrolyser module; 2) Deoxer Module; 3) Dryer Module; 4) Water Treatment Module; 5) Power supply and Control unit; 6) Rack mount. The developed 2{sup nd} generation rack-mounted alkaline electrolyser system has been installed and demonstrated for 18 month in a college (H2College) with 66 apartments. A number of measurements were performed on the system installed in H2College. No measurements on the overall system efficiency were conducted. However measurement on the stack showed a stack efficiency of 86.5% at a current density of 177mA/cm{sup 2} and a temperature of 74.4 deg. C at the hydrogen outlet. The system is estimated to have run roughly 2000h during the demonstration period. The demonstration of the 2{sup nd} generation alkaline electrolyser is considered a success for several reasons. While not all technical goals were reached, the research and development in the project have resulted in some very good solutions for most of the challenges in high pressure alkaline electrolysis. The concept of a rack mounted electrolyser was proven viable, and all critical aspects of the modularisation have been covered. (LN)

  6. Alkaline electrolysis cell at high temperature and pressure of 250 °C and 42 bar

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2013-01-01

    A new type of alkaline electrolysis cells with nickel foam based gas diffusion electrodes and KOH (aq) immobilized in mesoporous SrTiO3 has been developed and tested at temperatures and pressures up to 250 °C and 42 bar, respectively. Current densities of 1.0 A cm−2 have been measured at a cell v...... voltage of 1.5 V without the use of expensive noble metal catalysts. High electrical efficiency and current density combined with relatively small production costs may lead to both reduced investment and operating costs for hydrogen and oxygen production....

  7. Water electrolysis system

    International Nuclear Information System (INIS)

    Mizoguchi, Tadao; Ikehara, Masahisa; Kataoka, Noboru; Ueno, Syuichi; Ishikawa, Nobuhide.

    1996-01-01

    Nissho Iwai Co. and Ebara Co. received an order for hydrogen and oxygen generating system (water electrolysis system) to be installed at Tokai-2 power station of The Japan Atomic Power Company, following the previous order at Tsuruga-1 where the gas injection from FY1996 is planned. Hydrogen gas generated by the system will be injected to coolant of boiling water reactors to improve corrosive environment. The system is being offered by a tripartite party, Nissho Iwai, Ebara, and Norsk Hydro Electrolysers of Norway (NHEL). NHEL provides a electrolyser unit, as a core of the system. Ebara provides procurement, installation, and inspection as well as total engineering work, under the basic design by NHEL which has over 60 years-experience in this field. (author)

  8. Analysis of cavitation effect for water purifier using electrolysis

    Science.gov (United States)

    Shin, Dong Ho; Ko, Han Seo; Lee, Seung Ho

    2015-11-01

    Water is a limited and vital resource, so it should not be wasted by pollution. A development of new water purification technology is urgent nowadays since the original and biological treatments are not sufficient. The microbubble-aided method was investigated for removal of algal in this study since it overcomes demerits of the existing purification technologies. Thus, the cavitation effect in a venturi-type tube using the electrolysis was analyzed. Ruthenium-coated titanium plates were used as electrodes. Optimum electrode interval and applied power were determined for the electrolysis. Then, the optimized electrodes were installed in the venturi-type tube for generating cavitation. The cavitation effect could be enhanced without any byproduct by the bubbly flow induced by the electrolysis. The optimum mass flow rate and current were determined for the cavitation with the electrolysis. Finally, the visualization techniques were used to count the cell number of algal and microbubbles for the confirmation of the performance. As a result, the energy saving and high efficient water purifier was fabricated in this study. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Korean government (MEST) (No. 2013R1A2A2A01068653).

  9. Production of hydrogen using composite membrane in PEM water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Santhi priya, E.L.; Mahender, C.; Mahesh, Naga; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad-500 085, A.P (India); Anjaneyulu, Y. [Director, TLGVRC, JSU Box 18739, JSU, Jackson, MS 32917-0939 (United States)

    2012-07-01

    Electrolysis of water is the best known technology till today to produce hydrogen. The only practical way to produce hydrogen using renewable energy sources is by proton exchange membrane (PEM) water electrolysis. The most commonly used PEM membrane is Nafion. Composite membrane of TiO2 is synthesized by casting method using Nafion 5wt% solution. RuO2 is used as anode and 10 wt% Pd on activated carbon is used as cathode in the water electrolyser system. The performance of this Composite membrane is studied by varying voltage range 1.8 to 2.6V with respect to hydrogen yield and at current density 0.1, 0.2, 0.3, 0.4, and 0.5(A cm-2). This Composite membrane has been tested using in-house fabricated single cell PEM water electrolysis cell with 10cm2 active area at temperatures ranging from 30,45,65 850c and at 1 atmosphere pressure.

  10. Static feed water electrolysis module

    Science.gov (United States)

    Powell, J. D.; Schubert, F. H.; Jensen, F. C.

    1974-01-01

    An advanced static feed water electrolysis module (SFWEM) and associated instrumentation for generating breathable O2 was developed. The system also generates a H2 byproduct for use in an air revitalization system for O2 recovery from metabolic CO2. Special attention was given to: (1) eliminating water feed compartment degassing, (2) eliminating need for zero gravity condenser/separators, (3) increasing current density capability, and (4) providing a self contained module so that operation is independent of laboratory instrumentation and complicated startup/shutdown procedures.

  11. Electrolysis of Water in the Secondary School Science Laboratory with Inexpensive Microfluidics

    Science.gov (United States)

    Davis, T. A.; Athey, S. L.; Vandevender, M. L.; Crihfield, C. L.; Kolanko, C. C. E.; Shao, S.; Ellington, M. C. G.; Dicks, J. K.; Carver, J. S.; Holland, L. A.

    2015-01-01

    This activity allows students to visualize the electrolysis of water in a microfluidic device in under 1 min. Instructional materials are provided to demonstrate how the activity meets West Virginia content standards and objectives. Electrolysis of water is a standard chemistry experiment, but the typical laboratory apparatus (e.g., Hoffman cell)…

  12. Proton-conductive nano zeolite-PVA composite film as a new water-absorbing electrolyte for water electrolysis

    Directory of Open Access Journals (Sweden)

    M. Nishihara

    2018-03-01

    Full Text Available In this study, organic-inorganic composite electrolyte membranes are developed for a novel water-absorbing porous electrolyte water electrolysis cell. As the materials of the composite electrolyte membrane, 80 wt% of a proton-conducting nano zeolite (H-MFI as an electrolyte and 20 wt% of poly(vinyl alcohol (PVA as a cross-linkable matrix are used. The nano zeolite is prepared by a milling process. The nano zeolite-PVA composite membrane precursors are prepared by spraying onto a substrate, followed by cross-linking. The resulting nano zeolite-cross-linked PVA composite films are then evaluated for their properties such as proton conductivity as electrolyte membranes for the water-absorbing porous electrolyte water electrolysis cell. It is confirmed that conventional materials such as zeolites and PVA can be used for the water electrolysis as an electrolyte.

  13. Carbon dioxide and water vapor high temperature electrolysis

    Science.gov (United States)

    Isenberg, Arnold O.; Verostko, Charles E.

    1989-01-01

    The design, fabrication, breadboard testing, and the data base obtained for solid oxide electrolysis systems that have applications for planetary manned missions and habitats are reviewed. The breadboard tested contains sixteen tubular cells in a closely packed bundle for the electrolysis of carbon dioxide and water vapor. The discussion covers energy requirements, volume, weight, and operational characteristics related to the measurement of the reactant and product gas compositions, temperature distribution along the electrolyzer tubular cells and through the bundle, and thermal energy losses. The reliability of individual cell performance in the bundle configuration is assessed.

  14. Development status of a preprototype water electrolysis subsystem

    Science.gov (United States)

    Martin, R. B.; Erickson, A. C.

    1981-01-01

    A preprototype water electrolysis subsystem was designed and fabricated for NASA's advanced regenerative life support program. A solid polymer is used for the cell electrolyte. The electrolysis module has 12 cells that can generate 5.5 kg/day of oxygen for the metabolic requirements of three crewmembers, for cabin leakage, and for the oxygen and hydrogen required for carbon dioxide collection and reduction processes. The subsystem can be operated at a pressure between 276 and 2760 kN/sq m and in a continuous constant-current, cyclic, or standby mode. A microprocessor is used to aid in operating the subsystem. Sensors and controls provide fault detection and automatic shutdown. The results of development, demonstration, and parametric testing are presented. Modifications to enhance operation in an integrated and manned test are described. Prospective improvements for the electrolysis subsystem are discussed.

  15. Analysis of Economic Efficiency of Production of Low-Concentrated Sodium Hypochlorite by Direct Electrolysis of Natural Waters

    Science.gov (United States)

    Fesenko, L. N.; Pchelnikov, I. V.; Fedotov, R. V.

    2017-11-01

    The study presents the economic efficiency of direct electrolysis of natural waters in comparison with the waters artificially prepared by electrolysis of the 3% sodium salt solution. The study used sea water (Black sea water); mineral water (underground water of the Melikhovskaya station, “Ognennaya” hole); brackish water (underground water from the Grushevskaya station of the Aksai district); 3% solution of sodium salt. As a result, the dependences characterizing the direct electrolysis of natural waters with different mineralization, economic, and energy parties are shown. The rational area of the electrolysis for each of the investigated solution is determined. The cost of a kilogram of active chlorine obtained by the direct water electrolysis: Black sea from 17.2 to 18.3 RUB/kg; the Melikhovskaya station “Ognennaya” hole - 14.3 to 15.0 Rubles/kg; 3% solution of NaCl - 30 Rubles./kg; Grushevskogo St. - 63,0-73,0 Rubles/kg.

  16. Electrocatalysis in Water Electrolysis with Solid Polymer Electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Rasten, Egil

    2001-10-01

    Development and optimization of the electrodes in a water electrolysis system using a polymer membrane as electrolyte have been carried out in this work. A cell voltage of 1.59 V (energy consumption of about 3.8 kWh/Nm{sub 3} H{sub 2}) has been obtained at practical operation conditions of the electrolysis cell (10 kA . m2, 90{sup o}C) using a total noble metal loading of less than 2.4 mg.cm{sub 2} and a Nafion -115 membrane. It is further shown that a cell voltage of less than 1.5 V is possible at the same conditions by combination of the best electrodes obtained in this work. The most important limitation of the electrolysis system using polymer membrane as electrolyte has proven to be the electrical conductivity of the catalysts due to the porous backing/current collector system, which increases the length of the current path and decreases the cross section compared to the apparent one. A careful compromise must therefore be obtained between electrical conductivity and active surface area, which can be tailored by preparation and annealing conditions of the metal oxide catalysts. Anode catalysts of different properties have been developed. The mixed oxide of Ir-Ta (85 mole% Ir) was found to exhibit highest voltage efficiency at a current density of 10 kA.m{sub 2} or below, whereas the mixed oxide of Ir and Ru (60-80 mole% Ir) was found to give the highest voltage efficiency for current densities of above 10 kA.m{sub 2}. Pt on carbon particles, was found to be less suitable as cathode catalyst in water electrolysis. The large carbon particles introduced an unnecessary porosity into the catalytic layer, which resulted in a high ohmic drop. Much better voltage efficiency was obtained by using Pt-black as cathode catalyst, which showed a far better electrical conductivity. Ru-oxide as cathode catalyst in water electrolysis systems using a polymer electrolyte was not found to be of particular interest due to insufficient electrochemical activity and too low

  17. Separation factor dependence upon cathode material for tritium separation from heavy water by electrolysis

    International Nuclear Information System (INIS)

    Ogata, Y.; Sakuma, Y.; Ohtani, N.; Kotaka, M.

    2002-01-01

    Using three cathode materials, i.e. carbon (C), stainless steel (SUS), and nickel (Ni), tritium was separated from heavy water by electrolysis, and the separation factors were compared. To separate hydrogen isotopes, heavy water was electrolyzed by an electrolysis device with a solid polymer electrode (SPE), which needed no electrolyte additives for electrolysis. The anode was made of 3 mm thickness of a sintered porous titanium plate covered with iridium oxide. The cathode was made of the same thickness of a sintered porous carbon, stainless steel, or nickel plate. Heavy water or light water spiked with tritiated water was electrolyzed 20 A x 60 min with the electrolysis cell temperature at 10, 20 or 30degC, and 15 A x 80 min at 5degC. The produced hydrogen and oxygen gases were recombined using a palladium catalyst with nitrogen gas as a carrier. The activities of the water in the electrolysis cell and of the recombined water were analyzed using a liquid scintillation counter. The apparent D-T separation factor (SF D/T ) and H-T separation factor (SF H/T ) were calculated as quotient the specific activity of the water in the cell divided by that of the recombined water. The electrolysis potential to keep the current 20 A was 2-3 V. The average yields of the recombined water were 95%. At the cell temperature of 20degC, SF D/T (C), SF D/T (SUS), and SF D/T (Ni) were 2.42, 2.17, and 2.05, respectively. At the same temperature, SF H/T (C), SF H/T (SUS), and SF H/T (Ni) were 12.5, 10.8, and 11.8, respectively. The SFs were in agreement with the results in other works. The SFs were changed with the cell temperature. (author)

  18. Sequential Washing with Electrolyzed Alkaline and Acidic Water Effectively Removes Pathogens from Metal Surfaces.

    Directory of Open Access Journals (Sweden)

    Yuichiro Nakano

    Full Text Available Removal of pathogenic organisms from reprocessed surgical instruments is essential to prevent iatrogenic infections. Some bacteria can make persistent biofilms on medical devices. Contamination of non-disposable equipment with prions also represents a serious risk to surgical patients. Efficient disinfection of prions from endoscopes and other instruments such as high-resolution cameras remains problematic because these instruments do not tolerate aggressive chemical or heat treatments. Herein, we develop a new washing system that uses both the alkaline and acidic water produced by electrolysis. Electrolyzed acidic water, containing HCl and HOCl as active substances, has been reported to be an effective disinfectant. A 0.15% NaCl solution was electrolyzed and used immediately to wash bio-contaminated stainless steel model systems with alkaline water (pH 11.9 with sonication, and then with acidic water (pH 2.7 without sonication. Two bacterial species (Staphylococcus aureus and Pseudomonas aeruginosa and a fungus (Candida albicans were effectively removed or inactivated by the washing process. In addition, this process effectively removed or inactivated prions from the stainless steel surfaces. This washing system will be potentially useful for the disinfection of clinical devices such as neuroendoscopes because electrolyzed water is gentle to both patients and equipment and is environmentally sound.

  19. An efficient route for catalytic activity promotion via hybrid electro-depositional modification on commercial nickel foam for hydrogen evolution reaction in alkaline water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Guanshui; He, Yongwei; Wang, Mei; Zhu, Fuchun; Tang, Bin [Research Institute of Surface Engineering, Taiyuan University of Technology, Yingze West Road 79, Taiyuan 030024 (China); Wang, Xiaoguang, E-mail: wangxiaog1982@163.com [Research Institute of Surface Engineering, Taiyuan University of Technology, Yingze West Road 79, Taiyuan 030024 (China); International Iberian Nanotechnology Laboratory (INL), 4715-330 Braga (Portugal)

    2014-09-15

    Highlights: • Mono-Cu surface modification depress the HER activity of Ni-foam. • Hybrid Ni-foam/Cu0.01/Co0.05 exhibits superior HER performance. • Layer-by-layer structure may contribute to a synergistic promoting effect. - Abstract: In this paper, the single- and hybrid-layered Cu, Ni and Co thin films were electrochemically deposited onto the three-dimensional nickel foam as composite cathode catalyst for hydrogen evolution reaction in alkaline water electrolysis. The morphology, structure and chemical composition of the electrodeposited composite catalysts were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). Electrochemical measurement depicted that, for the case of the monometallic layered samples, the general activity for hydrogen evolution reaction followed the sequence: Ni-foam/Ni > Ni-foam/Co > bare Ni-foam > Ni-foam/Cu. It is noteworthy that, the hybrid-layered Ni-foam/Cu0.01/Co0.05 exhibited the highest catalytic activity towards hydrogen evolution reaction with the current density as high as 2.82 times that of the bare Ni-foam. Moreover, both excellent electrochemical and physical stabilities can also be acquired on the Ni-foam/Cu0.01/Co0.05, making this hybrid-layered composite structure as a promising HER electro-catalyst.

  20. Treatment of high salt oxidized modified starch waste water using micro-electrolysis, two-phase anaerobic aerobic and electrolysis for reuse

    Science.gov (United States)

    Yi, Xuenong; Wang, Yulin

    2017-06-01

    A combined process of micro-electrolysis, two-phase anaerobic, aerobic and electrolysis was investigated for the treatment of oxidized modified starch wastewater (OMSW). Optimum ranges for important operating variables were experimentally determined and the treated water was tested for reuse in the production process of corn starch. The optimum hydraulic retention time (HRT) of micro-electrolysis, methanation reactor, aerobic process and electrolysis process were 5, 24, 12 and 3 h, respectively. The addition of iron-carbon fillers to the acidification reactor was 200 mg/L while the best current density of electrolysis was 300 A/m2. The biodegradability was improved from 0.12 to 0.34 by micro-electrolysis. The whole treatment was found to be effective with removal of 96 % of the chemical oxygen demand (COD), 0.71 L/day of methane energy recovery. In addition, active chlorine production (15,720 mg/L) was obtained by electrolysis. The advantage of this hybrid process is that, through appropriate control of reaction conditions, effect from high concentration of salt on the treatment was avoided. Moreover, the process also produced the material needed in the production of oxidized starch while remaining emission-free and solved the problem of high process cost.

  1. Hydrogen production by high temperature electrolysis of water vapour and nuclear reactors

    International Nuclear Information System (INIS)

    Jean-Pierre Py; Alain Capitaine

    2006-01-01

    This paper presents hydrogen production by a nuclear reactor (High Temperature Reactor, HTR or Pressurized Water Reactor, PWR) coupled to a High Temperature Electrolyser (HTE) plant. With respect to the coupling of a HTR with a HTE plant, EDF and AREVA NP had previously selected a combined cycle HTR scheme to convert the reactor heat into electricity. In that case, the steam required for the electrolyser plant is provided either directly from the steam turbine cycle or from a heat exchanger connected with such cycle. Hydrogen efficiency production is valued using high temperature electrolysis. Electrolysis production of hydrogen can be performed with significantly higher thermal efficiencies by operating in the steam phase than in the water phase. The electrolysis performance is assessed with solid oxide and solid proton electrolysis cells. The efficiency from the three operating conditions (endo-thermal, auto-thermal and thermo-neutral) of a high temperature electrolysis process is evaluated. The technical difficulties to use the gases enthalpy to heat the water are analyzed, taking into account efficiency and technological challenges. EDF and AREVA NP have performed an analysis to select an optimized process giving consideration to plant efficiency, plant operation, investment and production costs. The paper provides pathways and identifies R and D actions to reach hydrogen production costs competitive with those of other hydrogen production processes. (authors)

  2. Water electrolysis with a conducting carbon cloth: subthreshold hydrogen generation and superthreshold carbon quantum dot formation.

    Science.gov (United States)

    Biswal, Mandakini; Deshpande, Aparna; Kelkar, Sarika; Ogale, Satishchandra

    2014-03-01

    A conducting carbon cloth, which has an interesting turbostratic microstructure and functional groups that are distinctly different from other ordered forms of carbon, such as graphite, graphene, and carbon nanotubes, was synthesized by a simple one-step pyrolysis of cellulose fabric. This turbostratic disorder and surface chemical functionalities had interesting consequences for water splitting and hydrogen generation when such a cloth was used as an electrode in the alkaline electrolysis process. Importantly, this work also gives a new twist to carbon-assisted electrolysis. During electrolysis, the active sites in the carbon cloth allow slow oxidation of its surface to transform the surface groups from COH to COOH and so forth at a voltage as low as 0.2 V in a two-electrode system, along with platinum as the cathode, instead of 1.23 V (plus overpotential), which is required for platinum, steel, or even graphite anodes. The quantity of subthreshold hydrogen evolved was 24 mL cm(-2)  h(-1) at 1 V. Interestingly, at a superthreshold potential (>1.23 V+overpotential), another remarkable phenomenon was found. At such voltages, along with the high rate and quantity of hydrogen evolution, rapid exfoliation of the tiny nanoscale (5-7 nm) units of carbon quantum dots (CQDs) are found in copious amounts due to an enhanced oxidation rate. These CQDs show bright-blue fluorescence under UV light. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. The development and application of solid polymer electrolysis enrichment device of tritium in water

    International Nuclear Information System (INIS)

    Wen Xuelian; Yang Hailan Wu Bin; Yang Huaiyuan

    2003-01-01

    This paper briefly describes the working principle of solid polymer electrolysis enrichment device of tritium in water, presents experiments and works in development of SPE tritium automatic electrolysis enrichment device by CIRP, with which the water samples had been processed for TRIC2000, and the measurement results are satisfied

  4. Tritium separation from heavy water by electrolysis with solid polymer electrolyte

    International Nuclear Information System (INIS)

    Ogata, Y.; Ohtani, N.; Kotaka, M.

    2003-01-01

    A tritium separation from heavy water by electrolysis using a solid polymer electrode layer was specified. The cathode was made of stainless steel or nickel. The electrolysis was performed for 1 hour at 5, 10, 20, and 30 deg C. Using a palladium catalyst, generated hydrogen and oxygen gases were recombined, which was collected with a cold trap. The activities of the samples were measured by a liquid scintillation counter. The apparent tritium separation factors of the heavy and light water at 20 deg C were ∼2 and ∼12, respectively. (author)

  5. Water vapor pressure over molten KH2PO4 and demonstration of water electrolysis at ∼300ºC

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Nikiforov, Aleksey Valerievich; Petrushina, Irina

    2016-01-01

    A new potentially high-efficiency electrolyte for water electrolysis: molten monobasic potassium phosphate, KH2PO4 or KDP has been investigated at temperatures ∼275–325 °C. At these temperatures, KH2PO4 was found to dissociate into H2O gas in equilibrium with a melt mixture of KH2PO4—K2H2P2O7—KPO3...... of water and methane or hydrogen to be 0.40 ± 0.02 or 1.2 ± 0.03. At equilibrium the vapor pressure was much lower than the vapor pressure above liquid water at the same temperature. Electrolysis was realized by passing current through closed ampoules (vacuum sealed quartz glass electrolysis cells...... with platinum electrodes and the electrolyte melt). The formation of mixtures of hydrogen and oxygen gases as well as the water vapor was detected by Raman spectroscopy. In this way it was demonstrated that water is present in the new electrolyte: molten KH2PO4 can be split by electrolysis via the reaction 2H2O...

  6. Conceptual study of on orbit production of cryogenic propellants by water electrolysis

    Science.gov (United States)

    Moran, Matthew E.

    1991-01-01

    The feasibility is assessed of producing cryogenic propellants on orbit by water electrolysis in support of NASA's proposed Space Exploration Initiative (SEI) missions. Using this method, water launched into low earth orbit (LEO) would be split into gaseous hydrogen and oxygen by electrolysis in an orbiting propellant processor spacecraft. The resulting gases would then be liquified and stored in cryogenic tanks. Supplying liquid hydrogen and oxygen fuel to space vehicles by this technique has some possible advantages over conventional methods. The potential benefits are derived from the characteristics of water as a payload, and include reduced ground handling and launch risk, denser packaging, and reduced tankage and piping requirements. A conceptual design of a water processor was generated based on related previous studies, and contemporary or near term technologies required. Extensive development efforts would be required to adapt the various subsystems needed for the propellant processor for use in space. Based on the cumulative results, propellant production by on orbit water electrolysis for support of SEI missions is not recommended.

  7. Development of a static feed water electrolysis system

    Science.gov (United States)

    Schubert, F. H.; Lantz, J. B.; Hallick, T. M.

    1982-01-01

    A one person level oxygen generation subsystem was developed and production of the one person oxygen metabolic requirements, 0.82 kg, per day was demonstrated without the need for condenser/separators or electrolyte pumps. During 650 hours of shakedown, design verification, and endurance testing, cell voltages averaged 1.62 V at 206 mA/sq cm and at average operating temperature as low as 326 K, virtually corresponding to the state of the art performance previously established for single cells. This high efficiency and low waste heat generation prevented maintenance of the 339 K design temperature without supplemental heating. Improved water electrolysis cell frames were designed, new injection molds were fabricated, and a series of frames was molded. A modified three fluid pressure controller was developed and a static feed water electrolysis that requires no electrolyte in the static feed compartment was developed and successfully evaluated.

  8. High Temperature and Pressure Alkaline Electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank

    against conventional technologies for hydrogen production, such as natural gas reforming, the production and investment costs have to be reduced. A reduction of the investment costs may be achieved by increasing the operational pressure and temperature of the electrolyzer, as this will result in: 1.......3 A cm-2 combined with relatively small production costs may lead to both reduced investment and operating costs for hydrogen and oxygen production. One of the produced electrolysis cells was operated for 350 h. Based on the successful results a patent application covering this novel cell was filed...

  9. Advances in the electrolysis of tritiated water

    International Nuclear Information System (INIS)

    Pierini, G.; Spelta, B.; Maffei, S.; Modica, G.; Perez, G.; Possagno, E.

    1988-01-01

    The exhaust plasma processing plant, proposed a few years ago as an alternative to the Tritium Systems Test Assembly plant in operation at Los Alamos National Laboratory, required further research in such areas as low liquid inventory electrolytic cell and the types of separator or membrane resistant to beta radiation. Moreover, it was suggested that the value of the separation factors among H/sub 2/, D/sub 2/, and T/sub 2/ should be checked during electrolysis at high D/sub 2/O concentration in a alkaline medium by using different materials for the cathode. The results of experimental work carried out in these directions have shown the feasibility of the process, although some improvements can still be made in the optimization of the separators and in the design of the cell. The research carried out at the Joint Research Centre, Ispra, Italy, with support from other institutes, is described

  10. Vehicle Integrated Photovoltaics for Compression Ignition Vehicles: An Experimental Investigation of Solar Alkaline Water Electrolysis for Improving Diesel Combustion and a Solar Charging System for Reducing Auxiliary Engine Loads

    Science.gov (United States)

    Negroni, Garry Inocentes

    Vehicle-integrated photovoltaic electricity can be applied towards aspiration of hydrogen-oxygen-steam gas produced through alkaline electrolysis and reductions in auxiliary alternator load for reducing hydrocarbon emissions in low nitrogen oxide indirect-injection compression-ignition engines. Aspiration of 0.516 ± 0.007 liters-per-minute of gas produced through alkaline electrolysis of potassium-hydroxide 2wt.% improves full-load performance; however, part-load performance decreases due to auto-ignition of aspirated gas prior to top-dead center. Alternator load reductions offer improved part-load and full-load performance with practical limitations resulting from accessory electrical loads. In an additive approach, solar electrolysis can electrochemically convert solar photovoltaic electricity into a gas comprised of stoichiometric hydrogen and oxygen gas. Aspiration of this hydrogen-oxygen gas enhances combustion properties decreasing emissions and increased combustion efficiency in light-duty diesel vehicles. The 316L stainless steel (SS) electrolyser plates are arranged with two anodes and three cathodes space with four bipolar plates delineating four stacks in parallel with five cells per stack. The electrolyser was tested using potassium hydroxide 2 wt.% and hydronium 3wt.% at measured voltage and current inputs. The flow rate output from the reservoir cell was measured in parallel with the V and I inputs producing a regression model correlating current input to flow rate. KOH 2 wt.% produced 0.005 LPM/W, while H9O44 3 wt.% produced less at 0.00126 LPM/W. In a subtractive approach, solar energy can be used to charge a larger energy storage device, as is with plug-in electric vehicles, in order to alleviate the engine of the mechanical load placed upon it by the vehicles electrical accessories through the alternator. Solar electrolysis can improve part-load emissions and full-load performance. The average solar-to-battery efficiency based on the OEM rated

  11. Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water

    Directory of Open Access Journals (Sweden)

    Guoo-Shyng Wang Hsu

    2017-10-01

    Full Text Available Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW. DOW was electrolyzed in a glass electrolyzing cell equipped with platinum–plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be.

  12. Electrolysis

    DEFF Research Database (Denmark)

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

    Electrolysis is a well-established technology with many different applications. In particular, it can be used to produce hydrogen by using electricity to split water. As an increasing part of the energy system consists of fluctuating power sources such as wind and solar it becomes increasingly...... necessary to be able to store large amounts of electrical energy. One option is to do it in the form of hydrogen or hydrogen-rich synthetic compounds. This has led to increased interest in electrolysis with new cell types being developed. This entry provides an overview of the status and technological...... challenges of electrolysis systems and discusses their role in the future energy system....

  13. Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water.

    Science.gov (United States)

    Hsu, Guoo-Shyng Wang; Lu, Yi-Fa; Hsu, Shun-Yao

    2017-10-01

    Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW). DOW was electrolyzed in a glass electrolyzing cell equipped with platinum-plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be. Copyright © 2016. Published by Elsevier B.V.

  14. Water vapor pressure over molten KH_2PO_4 and demonstration of water electrolysis at ∼300 °C

    International Nuclear Information System (INIS)

    Berg, R.W.; Nikiforov, A.V.; Petrushina, I.M.; Bjerrum, N.J.

    2016-01-01

    Highlights: • The vapor pressure over molten KH_2PO_4 was measured by Raman spectroscopy to be about 8 bars at ∼300 °C. • Raman spectroscopy shows that molten KH_2PO_4 under its own vapor pressure contains much dissolved water. • It is demonstrated spectroscopically that water electrolysis is possible in KH_2PO_4 electrolyte forming H_2 and O_2 at 300 °C. • Molten KH_2PO_4 is a possible electrolyte for water electrolysis. - Abstract: A new potentially high-efficiency electrolyte for water electrolysis: molten monobasic potassium phosphate, KH_2PO_4 or KDP has been investigated at temperatures ∼275–325 °C. At these temperatures, KH_2PO_4 was found to dissociate into H_2O gas in equilibrium with a melt mixture of KH_2PO_4−K_2H_2P_2O_7−KPO_3−H_2O. The water vapor pressure above the melt, when contained in a closed ampoule, was determined quantitatively vs. temperature by use of Raman spectroscopy with methane or hydrogen gas as an internal calibration standard, using newly established relative ratios of Raman scattering cross sections of water and methane or hydrogen to be 0.40 ± 0.02 or 1.2 ± 0.03. At equilibrium the vapor pressure was much lower than the vapor pressure above liquid water at the same temperature. Electrolysis was realized by passing current through closed ampoules (vacuum sealed quartz glass electrolysis cells with platinum electrodes and the electrolyte melt). The formation of mixtures of hydrogen and oxygen gases as well as the water vapor was detected by Raman spectroscopy. In this way it was demonstrated that water is present in the new electrolyte: molten KH_2PO_4 can be split by electrolysis via the reaction 2H_2O → 2H_2 + O_2 at temperatures ∼275–325 °C. At these temperatures, before the start of the electrolysis, the KH_2PO_4 melt gives off H_2O gas that pressurizes the cell according to the following dissociations: 2KH_2PO_4 ↔ K_2H_2P_2O_7 + H_2O ↔ 2KPO_3 + 2H_2O. The spectra show however that the water by

  15. High temperature and pressure alkaline electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2013-01-01

    Alkaline electrolyzers have proven to operate reliable for decades on a large scale, but in order to become commercially attractive and compete against conventional technologies for hydrogen production, the production and investment costs have to be reduced. This may occur by increasing the opera......Alkaline electrolyzers have proven to operate reliable for decades on a large scale, but in order to become commercially attractive and compete against conventional technologies for hydrogen production, the production and investment costs have to be reduced. This may occur by increasing...

  16. Computer simulation of the NASA water vapor electrolysis reactor

    Science.gov (United States)

    Bloom, A. M.

    1974-01-01

    The water vapor electrolysis (WVE) reactor is a spacecraft waste reclamation system for extended-mission manned spacecraft. The WVE reactor's raw material is water, its product oxygen. A computer simulation of the WVE operational processes provided the data required for an optimal design of the WVE unit. The simulation process was implemented with the aid of a FORTRAN IV routine.

  17. Highly efficient high temperature electrolysis

    DEFF Research Database (Denmark)

    Hauch, Anne; Ebbesen, Sune; Jensen, Søren Højgaard

    2008-01-01

    High temperature electrolysis of water and steam may provide an efficient, cost effective and environmentally friendly production of H-2 Using electricity produced from sustainable, non-fossil energy sources. To achieve cost competitive electrolysis cells that are both high performing i.e. minimum...... internal resistance of the cell, and long-term stable, it is critical to develop electrode materials that are optimal for steam electrolysis. In this article electrolysis cells for electrolysis of water or steam at temperatures above 200 degrees C for production of H-2 are reviewed. High temperature...... electrolysis is favourable from a thermodynamic point of view, because a part of the required energy can be supplied as thermal heat, and the activation barrier is lowered increasing the H-2 production rate. Only two types of cells operating at high temperature (above 200 degrees C) have been described...

  18. Alkalinity in oil field waters - what alkalinity is and how it is measured

    International Nuclear Information System (INIS)

    Kaasa, B.; Oestvold, T.

    1996-01-01

    The alkalinity is an important parameter in the description of pH-behaviour, buffer capacity and scaling potentials in oil field waters. Although the alkalinity is widely used, it seems to be considerable confusion in connection with the concept. It is often used incorrectly and different authors define the concept in different ways. Several different methods for the determination of alkalinity can be found in the literature. This paper discusses the definition of alkalinity and how to use alkalinity in oil field waters to obtain data of importance for scale and pH predictions. There is also shown how a simple titration of oil field waters can give both the alkalinity and the content of organic acids in these waters. It is obvious from these findings that most of the methods used to day may give considerable errors when applied to oil field waters with high contents of organic acids. 8 refs., 8 figs., 5 tabs

  19. Polybenzimidazole membranes for zero gap alkaline electrolysis cells

    DEFF Research Database (Denmark)

    Kraglund, Mikkel Rykær; Aili, David; Christensen, Erik

    Membranes of m-PBI doped in KOH (aq), 15-35 wt%, show high ionic conductivity in the temperature range 20-80 ºC. In electrolysis cells with nickel foam electrodes m-PBI membranesprovide low internal resistance. With a 60 µm membraneat 80ºC in 20 wt% KOH,1000 mA/cm2 is achieved at 2.25....

  20. Electrochemical investigation of surface area effects on PVD Al-Ni as electrocatalyst for alkaline water electrolysis

    DEFF Research Database (Denmark)

    Kjartansdóttir, Cecilía Kristín; Caspersen, Michael; Egelund, Sune Daaskov

    2014-01-01

    , additional 40mV are gained. For the OER, smaller roughness values were observed with the same activity trend as for the HER. The electrocatalyst are however found not to be stable in the anodic environment during electrolysis. The corrosion mechanism of a skeletal nickel electrocatalyst during the OER...

  1. Solid polymer electrolyte water electrolysis system development. [to generate oxygen for manned space station applications

    Science.gov (United States)

    1975-01-01

    Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary instrumentation and controls was fabricated and tested. A six man rated, high pressure, high temperature, advanced preprototype WES was developed. This configuration included the design and development of an advanced water electrolysis module, capable of operation at 400 psig and 200 F, and a dynamic phase separator/pump in place of a passive phase separator design. Evaluation of this system demonstrated the goal of safe, unattended automated operation at high pressure and high temperature with an accumulated gas generation time of over 1000 hours.

  2. Space Station propulsion - Advanced development testing of the water electrolysis concept at MSFC

    Science.gov (United States)

    Jones, Lee W.; Bagdigian, Deborah R.

    1989-01-01

    The successful demonstration at Marshall Space Flight Center (MSFC) that the water electrolysis concept is sufficiently mature to warrant adopting it as the baseline propulsion design for Space Station Freedom is described. In particular, the test results demonstrated that oxygen/hydrogen thruster, using gaseous propellants, can deliver more than two million lbf-seconds of total impulse at mixture ratios of 3:1 to 8:1 without significant degradation. The results alao demonstrated succcessful end-to-end operation of an integrated water electrolysis propulsion system.

  3. Numerical modeling of hypolimnetic oxygenation by electrolysis of water

    Directory of Open Access Journals (Sweden)

    Jaćimović Nenad M.

    2017-01-01

    Full Text Available The paper presents a novel method for hypolimnetic oxygenation by electrolysis of water. The performance of the method is investigated by the laboratory and the field experiment. The laboratory experiment is conducted in a 90 L vessel, while the field experiment is conducted at the lake Biwa in Japan. In order to provide a better insight into involved processes, a numerical model for simulation of bubble flow is developed with consideration of gas compressibility and oxygen dissolution. The model simultaneously solves 3-D volume averaged two-fluid governing equations. Developed model is firstly verified by simulation of bubble flow experiments, reported in the literature, where good qualitative agreement between measured and simulated results is observed. In the second part, the model is applied for simulation of conducted water electrolysis experiments. The model reproduced the observed oxygen concentration dynamics reasonably well. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 37009

  4. Design Criteria, Operating Conditions, and Nickel-Iron Hydroxide Catalyst Materials for Selective Seawater Electrolysis.

    Science.gov (United States)

    Dionigi, Fabio; Reier, Tobias; Pawolek, Zarina; Gliech, Manuel; Strasser, Peter

    2016-05-10

    Seawater is an abundant water resource on our planet and its direct electrolysis has the advantage that it would not compete with activities demanding fresh water. Oxygen selectivity is challenging when performing seawater electrolysis owing to competing chloride oxidation reactions. In this work we propose a design criterion based on thermodynamic and kinetic considerations that identifies alkaline conditions as preferable to obtain high selectivity for the oxygen evolution reaction. The criterion states that catalysts sustaining the desired operating current with an overpotential seawater-mimicking electrolyte. The catalyst was synthesized by a solvothermal method and the activity, surface redox chemistry, and stability were tested electrochemically in alkaline and near-neutral conditions (borate buffer at pH 9.2) and under both fresh seawater conditions. The Tafel slope at low current densities is not influenced by pH or presence of chloride. On the other hand, the addition of chloride ions has an influence in the temporal evolution of the nickel reduction peak and on both the activity and stability at high current densities at pH 9.2. Faradaic efficiency close to 100 % under the operating conditions predicted by our design criteria was proven using in situ electrochemical mass spectrometry. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Determination of the Electronics Charge--Electrolysis of Water Method.

    Science.gov (United States)

    Venkatachar, Arun C.

    1985-01-01

    Presents an alternative method for measuring the electronic charge using data from the electrolysis of acidified distilled water. The process (carried out in a commercially available electrolytic cell) has the advantage of short completion time so that students can determine electron charge and mass in one laboratory period. (DH)

  6. Effects of low voltage electrolysis and freezing on coliform content of contaminated water

    International Nuclear Information System (INIS)

    Qazi, J.I.; Saleem, F.

    2003-01-01

    A sewage sample was mixed with drinking water and subjected to low voltage (15V) electrolysis in the presence of 1% NaCl. The prepared sample was also kept in freezer with and without the presence of sodium chloride for 4-hours. Among these treatments the electrolysis proved to kill the coliforms, while the freezing reduced the bacterial content. Antibiotics sensitivity patterns revealed that certain of the coliform strains survived the freezing and thawing shocks. Nature of such surviving bacteria and need to study chemical parameters of electrolyzed water are discussed. (author)

  7. Economics of liquid hydrogen from water electrolysis

    Science.gov (United States)

    Lin, F. N.; Moore, W. I.; Walker, S. W.

    1985-01-01

    An economical model for preliminary analysis of LH2 cost from water electrolysis is presented. The model is based on data from vendors and open literature, and is suitable for computer analysis of different scenarios for 'directional' purposes. Cost data associated with a production rate of 10,886 kg/day are presented. With minimum modification, the model can also be used to predict LH2 cost from any electrolyzer once the electrolyzer's cost data are available.

  8. Performance of supported catalysts for water electrolysis

    OpenAIRE

    Gurrik, Stian

    2012-01-01

    The most active catalyst for oxygen evolution in PEM water electrolysis is ruthenium oxide. Its major drawback as a commercial catalyst is its poor stability. In a mixed oxide with iridium, ruthenium becomes more stable. However, it would be favorable to find a less expensive substitute to iridium. In this work, the dissolution potential and lifetime of mixed oxides containing ruthenium and tantalum are investigated. In order to effectively determine what effects tantalum and particle size ha...

  9. Fabrication of cathode supported tubular solid oxide electrolysis cell for high temperature steam electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Le; Wang, Shaorong; Qian, Jiqin; Xue, Yanjie; Liu, Renzhu

    2011-01-15

    In recent years, hydrogen has been identified as a potential alternative fuel and energy carrier for the future energy supply. Water electrolysis is one of the important hydrogen production technologies which do not emit carbon dioxide. High temperature steam electrolysis (HTSE) consumes even less electrical energy than low temperature water electrolysis. Theoretically, HTSE using solid oxide electrolysis cells (SOEC) can efficiently utilize renewable energy to produce hydrogen, and it is also possible to operate the SOEC in reverse mode as the solid oxide fuel cell (SOFC) to produce electricity. Tubular SOFC have been widely investigated. In this study, tubular solid oxide cells were fabricated by dip-coating and cosintering techniques. In SOEC mode, results suggested that steam ratio had a strong impact on the performance of the tubular cell; the tubular SOEC preferred to be operated at high steam ratio in order to avoid concentration polarization. The microstructure of the tubular SOEC should therefore be optimized for high temperature steam electrolysis.

  10. Inactivation characteristics of ozone and electrolysis process for ballast water treatment using B. subtilis spores as a probe.

    Science.gov (United States)

    Jung, Youmi; Yoon, Yeojoon; Hong, Eunkyung; Kwon, Minhwan; Kang, Joon-Wun

    2013-07-15

    Since ballast water affects the ocean ecosystem, the International Maritime Organization (IMO) sets a standard for ballast water management and might impose much tighter regulations in the future. The aim of this study is to evaluate the inactivation efficiency of ozonation, electrolysis, and an ozonation-electrolysis combined process, using B. subtilis spores. In seawater ozonation, HOBr is the key active substance for inactivation, because of rapid reactivity of ozone with Br(-) in seawater. In seawater electrolysis, it is also HOBr, but not HOCl, because of the rapid reaction of HOCl with Br(-), which has not been recognized carefully, even though many electrolysis technologies have been approved by the IMO. Inactivation pattern was different in ozonation and electrolysis, which has some limitations with the tailing or lag-phase, respectively. However, each deficiency can be overcome with a combined process, which is most effective as a sequential application of ozonation followed by electrolysis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Effect of Strongly Alkaline Electrolyzed Water on Silk Degumming and the Physical Properties of the Fibroin Fiber.

    Directory of Open Access Journals (Sweden)

    Ting-Ting Cao

    Full Text Available Strongly alkaline electrolyzed water (SAEW was prepared by electrolysis of tap water in a laboratory-made water electrolyzer. The pH of stored SAEW was stable for more than one month. The hardness of the electrolyzed water was 30% lower and the Na(+ concentration was 18% higher than those of the tap water. Silkworm cocoon shells were boiled in pH 11.50 SAEW at a ratio of 1∶40∼80 (W/V for 20 min and the sericin layers around the silk fibroin fibers were removed completely. The tensile properties and thermal decomposition temperature of a single filament of silk fibroin obtained by the SAEW method were almost the same as those for the fiber obtained by the neutral soap, and much higher than those for the fiber obtained by Na2CO3 degumming. The results demonstrate that SAEW is an environmentally friendly and pollution-free silk degumming agent that allows highly efficient, low cost recovery of sericin.

  12. Physico-Chemical, Biological and Therapeutic Characteristics of Electrolyzed Reduced Alkaline Water (ERAW

    Directory of Open Access Journals (Sweden)

    Marc Henry

    2013-12-01

    Full Text Available The consumption of alkaline reduced water produced by domestic electrolysis devices was approved in Japan in 1965 by the Ministry of Health, Labour and Welfare for the cure of gastro-intestinal disorders. Today, these devices are freely available in several countries and can be easily purchased without reserve. The commercial information included with the device recommends the consumption of 1–1.5 L of water per day, not only for gastro-intestinal disorders but also for numerous other illnesses such as diabetes, cancer, inflammation, etc. Academic research in Japan on this subject has been undergoing since 1990 only but has established that the active ingredient is dissolved dihydrogen that eliminates the free radical HO• in vivo. In addition, it was demonstrated that degradation of the electrodes during functioning of the device releases very reactive nanoparticles of platinum, the toxicity of which has not yet been clearly proven. This report recommends alerting health authorities of the uncontrolled availability of these devices used as health products, but which generate drug substances and should therefore be sold according to regulatory requirements.

  13. Tritium separation from light and heavy water by bipolar electrolysis

    International Nuclear Information System (INIS)

    Ramey, D.W.; Petek, M.; Taylor, R.D.; Kobisk, E.H.; Ramey, J.; Sampson, C.A.

    1979-10-01

    Use of bipolar electrolysis with countercurrent electrolyte flow to separate hydrogen isotopes was investigated for the removal of tritium from light water effluents or from heavy water moderator. Deuterium-tritium and protium-tritium separation factors occurring on a Pd-25% Ag bipolar electrode were measured to be 2.05 to 2.16 and 11.6 to 12.4 respectively, at current densities between 0.21 and 0.50 A cm -2 , and at 35 to 90 0 C. Current densities up to 0.3 A cm -2 have been achieved in continuous operation, at 80 to 90 0 C, without significant gas formation on the bipolar electrodes. From the measured overvoltage at the bipolar electrodes and the electrolyte conductivity the power consumption per stage was calculated to be 3.0 kwh/kg H 2 O at 0.2 A cm -2 and 5.0 kwh/kg H 2 O at 0.5 A cm -2 current density, compared to 6.4 and 8.0 kwh/kg H 2 O for normal electrolysis. A mathematical model derived for hydrogen isotope separation by bipolar electrolysis, i.e., for a square cascade, accurately describes the results for protium-tritium separation in two laboratory scale, multistage experiments with countercurrent electrolyte flow; the measured tiritum concentration gradient through the cascade agreed with the calculated values

  14. A Demonstration of Carbon-Assisted Water Electrolysis

    Directory of Open Access Journals (Sweden)

    Olalekan D. Adeniyi

    2013-03-01

    Full Text Available It is shown that carbon fuel cell technology can be combined with that of high temperature steam electrolysis by the incorporation of carbon fuel at the cell anode, with the resulting reduction of the required electrolysis voltage by around 1 V. The behaviour of the cell current density and applied voltage are shown to be connected with the threshold of electrolysis and the main features are compared with theoretical results from the literature. The advantage arises from the avoidance of efficiency losses associated with electricity generation using thermal cycles, as well as the natural separation of the carbon dioxide product stream for subsequent processing.

  15. Experimental and Numerical Study of the Effect of Gas-Shrouded Plasma Spraying on Cathode Coating of Alkaline Electrolysis Cells

    Science.gov (United States)

    Liu, T.; Reißner, R.; Schiller, G.; Ansar, A.

    2018-01-01

    The aim of this work is to improve the performance of electrodes prepared via atmospheric plasma spray by means of gas shrouding which is expected to apparently reduce the oxygen content of the plasma plume and subsequently improve the coating quality. Electrodes with dual-layer coating for alkaline water electrolysis were deposited on Ni-coated perforated substrates. Microstructure and morphology were studied by SEM. Element content was measured by EDS. Enthalpy probe was employed for measuring plasma temperature and velocity as well as the gas composition. For verifying and better understanding the shrouding effect numerical calculation was carried out according to the experimental settings. Electrochemical test was carried out to validate the shrouding effect. The results showed slight protecting effect of gas shrouding on plasma plume and the final coating. Over the dual-layer section, the measured oxygen fraction was 3.46 and 3.15% for the case without gas shrouding and with gas shrouding, respectively. With gas shrouding the coating exhibited similar element contents as the coating sprayed by VPS, while no obvious improvement was observed in the microstructure or the morphology. Evident electrochemical improvement was nevertheless achieved that with gas shrouding the electrode exhibited similar performance as that of the VPS-sprayed electrode.

  16. Can high temperature steam electrolysis function with geothermal heat?

    International Nuclear Information System (INIS)

    Sigurvinsson, J.; Mansilla, C.; Werkoff, F.; Lovera, P.

    2007-01-01

    It is possible to improve the performance of electrolysis processes by operating at a high temperature. This leads to a reduction in electricity consumption but requires a part of the energy necessary for the dissociation of water to be in the form of thermal energy. Iceland produces low cost electricity and very low cost geothermal heat. However, the temperature of geothermal heat is considerably lower than the temperature required at the electrolyser's inlet, making heat exchangers necessary to recuperate part of the heat contained in the gases at the electrolyser's outlet. A techno-economic optimisation model devoted to a high-temperature electrolysis (HTE) process which includes electrolysers as well as a high temperature heat exchanger network was created. Concerning the heat exchangers, the unit costs used in the model are based on industrial data. For the electrolyser cells, the unit cost scaling law and the physical sub-model we used were formulated using analogies with solid oxide fuel cells. The method was implemented in a software tool, which performs the optimisation using genetic algorithms. The first application of the method is done by taking into account the prices of electricity and geothermal heat in the Icelandic context. It appears that even with a geothermal temperature as low as 230 degrees C, the HTE could compete with alkaline electrolysis. (authors)

  17. Thermodynamic analysis of the efficiency of high-temperature steam electrolysis system for hydrogen production

    Science.gov (United States)

    Mingyi, Liu; Bo, Yu; Jingming, Xu; Jing, Chen

    High-temperature steam electrolysis (HTSE), a reversible process of solid oxide fuel cell (SOFC) in principle, is a promising method for highly efficient large-scale hydrogen production. In our study, the overall efficiency of the HTSE system was calculated through electrochemical and thermodynamic analysis. A thermodynamic model in regards to the efficiency of the HTSE system was established and the quantitative effects of three key parameters, electrical efficiency (η el), electrolysis efficiency (η es), and thermal efficiency (η th) on the overall efficiency (η overall) of the HTSE system were investigated. Results showed that the contribution of η el, η es, η th to the overall efficiency were about 70%, 22%, and 8%, respectively. As temperatures increased from 500 °C to 1000 °C, the effect of η el on η overall decreased gradually and the η es effect remained almost constant, while the η th effect increased gradually. The overall efficiency of the high-temperature gas-cooled reactor (HTGR) coupled with the HTSE system under different conditions was also calculated. With the increase of electrical, electrolysis, and thermal efficiency, the overall efficiencies were anticipated to increase from 33% to a maximum of 59% at 1000 °C, which is over two times higher than that of the conventional alkaline water electrolysis.

  18. Electrochemical disinfection of coliform and Escherichia coli for drinking water treatment by electrolysis method using carbon as an electrode

    Science.gov (United States)

    Riyanto; Agustiningsih, W. A.

    2018-04-01

    Disinfection of coliform and E. Coli in water has been performed by electrolysis using carbon electrodes. Carbon electrodes were used as an anode and cathode with a purity of 98.31% based on SEM-EDS analysis. This study was conducted using electrolysis powered by electric field using carbon electrode as the anode and cathode. Electrolysis method was carried out using variations of time (30, 60, 90, 120 minutes at a voltage of 5 V) and voltage (5, 10, 15, 20 V for 30 minutes) to determine the effect of the disinfection of the bacteria. The results showed the number of coliform and E. coli in water before and after electrolysis was 190 and 22 MPN/100 mL, respectively. The standards quality of drinking water No. 492/Menkes/Per/IV/2010 requires the zero content of coliform and E. Coli. Electrolysis with the variation of time and potential can reduce the number of coliforms and E. Coli but was not in accordance with the standards. The effect of hydrogen peroxide (H2O2) to the electrochemical disinfection was determined using UV-Vis spectrophotometer. The levels of H2O2 formed increased as soon after the duration of electrolysis voltage but was not a significant influence to the mortality of coliform and E.coli.

  19. Interfacial behavior of alkaline protease at the air-water and oil-water interfaces

    Science.gov (United States)

    Zhang, Jian; Li, Yanyan; Wang, Jing; Zhang, Yue

    2018-03-01

    The interfacial behavior of alkaline protease at the air-water and n-hexane-water interfaces was investigated using interfacial tension, dilatational rheology and dynamic light scattering. Additionally, different adsorption models which are Langmuir, Frumkin, Reorientation-A and Reorientation-R were used to fitting the data of equilibrium interfacial tension for further understanding the interfacial behavior of alkaline protease. Data fitting of the equilibrium interfacial tension was achieved by IsoFit software. The results show that the molecules arrangement of the alkaline protease at the n-hexane-water interface is more tightly than at the air-water interface. The data were further analyzed to indicate that the hydrophobic chains of alkaline protease penetrate into oil phase deeper than the air phase. Also data indicate that the electrostatic interactions and hydrophobic interactions at the n-hexane-water interface are stronger than at the air-water interface within molecules of the alkaline protease. Based on comprehensive analysis of the adsorption kinetics and interfacial rheological properties, interfacial structures mechanism of alkaline protease at n-hexane-water and air-water interfaces was proposed.

  20. Technoeconomic analysis of a methanol plant based on gasification of biomass and electrolysis of water

    DEFF Research Database (Denmark)

    Clausen, Lasse Røngaard; Houbak, N.; Elmegaard, Brian

    2010-01-01

    , and the low-temperature waste heat is used for district heat production. This results in high total energy efficiencies (similar to 90%) for the plants. The specific methanol costs for the six plants are in the range 11.8-25.3 (sic)/GJ(exergy). The lowest cost is obtained by a plant using electrolysis......Methanol production process configurations based on renewable energy sources have been designed. The processes were analyzed in the thermodynamic process simulation tool DNA. The syngas used for the catalytic methanol production was produced by gasification of biomass, electrolysis of water, CO2...... with a different syngas production method, were compared. The plants achieve methanol exergy efficiencies of 59-72%, the best from a configuration incorporating autothermal reforming of biogas and electrolysis of water for syngas production. The different processes in the plants are highly heat integrated...

  1. Development of an advanced static feed water electrolysis module. [for spacecraft

    Science.gov (United States)

    Schubert, F. H.; Wynveen, R. A.; Jensen, F. C.; Quattrone, P. D.

    1975-01-01

    A Static Feed Water Electrolysis Module (SFWEM) was developed to produce 0.92 kg/day (2.0 lb/day) of oxygen (O2). Specific objectives of the program's scope were to (1) eliminate the need for feed water cavity degassing, (2) eliminate the need for subsystem condenser/separators, (3) increase current density capability while decreasing electrolysis cell power (i.e., cell voltage) requirements, and (4) eliminate subsystem rotating parts and incorporate control and monitor instrumentation. A six-cell, one-man capacity module having an active area of 0.00929 sq m (0.10 sq ft) per cell was designed, fabricated, assembled, and subjected to 111 days (2664 hr) of parametric and endurance testing. The SFWEM was successfully operated over a current density range of 0 to 1076 mA/sq cm (0 to 1000 ASF), pressures of ambient to 2067 kN/sq m (300 psia), and temperatures of ambient to 366 K (200 F). During a 94-day endurance test, the SFWEM successfully demonstrated operation without the need for feed water compartment degassing.

  2. Hydrogen from renewable energy - Photovoltaic/water electrolysis as an exemplary approach

    Science.gov (United States)

    Sprafka, R. J.; Tison, R. R.; Escher, W. J. D.

    1984-01-01

    A feasibility study has been conducted for a NASA Kennedy Space Center liquid hydrogen/liquid oxygen production facility using solar cell arrays as the power source for electrolysis. The 100 MW output of the facility would be split into 67.6 and 32 MW portions for electrolysis and liquefaction, respectively. The solar cell array would cover 1.65 sq miles, and would be made up of 249 modular 400-kW arrays. Hydrogen and oxygen are generated at either dispersed or centralized water electrolyzers. The yearly hydrogen output is projected to be 5.76 million lbs, with 8 times that much oxygen; these fuel volumes can support approximately 18 Space Shuttle launches/year.

  3. The analysis of energy efficiency in water electrolysis under high temperature and high pressure

    Science.gov (United States)

    Hourng, L. W.; Tsai, T. T.; Lin, M. Y.

    2017-11-01

    This paper aims to analyze the energy efficiency of water electrolysis under high pressure and high temperature conditions. The effects of temperature and pressure on four different kinds of reaction mechanisms, namely, reversible voltage, activation polarization, ohmic polarization, and concentration polarization, are investigated in details. Results show that the ohmic and concentration over-potentials are increased as temperature is increased, however, the reversible and activation over-potentials are decreased as temperature is increased. Therefore, the net efficiency is enhanced as temperature is increased. The efficiency of water electrolysis at 350°C/100 bars is increased about 17%, compared with that at 80°C/1bar.

  4. Studies of water electrolysis in polymeric membrane cells; Estudos de eletrolise aquosa em celulas de membrana polimerica

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira-Silva, M.A.; Linardi, M.; Saliba-Silva, A.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Celulas a Combustivel e Hidrogenio

    2010-07-01

    Hydrogen represents great opportunity to be a substitute for fossil fuels in the future. Water as a renewable source of hydrogen is of great interest, since it is abundant and can decompose, producing only pure H{sub 2} and O{sub 2}. This decomposition of water can be accomplished by processes such as electrolysis, thermal decomposition and thermochemical cycles. The membrane electrolysis has been proposed as a viable process for hydrogen production using thermal and electrical energy derived from nuclear energy or any renewable source like solar energy. In this work, within the context of optimization of the electrolysis process, it is intended to develop a mathematical model that can simulate and assist in parameterization of the electrolysis performed by polymer membrane electrolytic cell. The experimental process to produce hydrogen via the cell membrane, aims to optimize the amount of gas produced using renewable energy with non-carbogenic causing no harm by producing gases deleterious to the environment. (author)

  5. Solid polymer electrolyte water electrolysis preprototype subsystem. [oxygen production for life support systems on space stations

    Science.gov (United States)

    1979-01-01

    Hardware and controls developed for an electrolysis demonstration unit for use with the life sciences payload program and in NASA's regenerative life support evaluation program are described. Components discussed include: the electrolysis module; power conditioner; phase separator-pump and hydrogen differential regulator; pressure regulation of O2, He, and N2; air-cooled heat exchanger; water accumulator; fluid flow sight gage assembly; catalytic O2/H2 sensor; gas flow sensors; low voltage power supply; 100 Amp DC contactor assembly; and the water purifier design.

  6. Water electrolysis

    Science.gov (United States)

    Schubert, Franz H. (Inventor); Grigger, David J. (Inventor)

    1992-01-01

    This disclosure is directed to an electrolysis cell forming hydrogen and oxygen at space terminals. The anode terminal is porous and able to form oxygen within the cell and permit escape of the gaseous oxygen through the anode and out through a flow line in the presence of backpressure. Hydrogen is liberated in the cell at the opposing solid metal cathode which is permeable to hydrogen but not oxygen so that the migratory hydrogen formed in the cell is able to escape from the cell. The cell is maintained at an elevated pressure so that the oxygen liberated by the cell is delivered at elevated pressure without pumping to raise the pressure of the oxygen.

  7. Production of aluminum metal by electrolysis of aluminum sulfide

    Science.gov (United States)

    Minh, Nguyen Q.; Loutfy, Raouf O.; Yao, Neng-Ping

    1984-01-01

    Production of metallic aluminum by the electrolysis of Al.sub.2 S.sub.3 at 700.degree.-800.degree. C. in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

  8. Zero-Gap Alkaline Water Electrolysis Using Ion-Solvating Polymer Electrolyte Membranes at Reduced KOH Concentrations

    DEFF Research Database (Denmark)

    Kraglund, Mikkel Rykær; Aili, David; Jankova Atanasova, Katja

    2016-01-01

    Membranes based on poly(2,2'-(m-phenylene)-5,5-bibenzimidazole) (m-PBI) can dissolve large amounts of aqueous KOH to give electrolyte systems with ion conductivity in a practically useful range. The conductivity of the membrane strongly depends on the concentration of the aqueous KOH phase......, reaching about 10-1 S cm-1 or higher in 15-25 wt% KOH. Herein, m-PBI membranes are systematically characterized with respect to performance and short-term stability as electrolyte in a zero-gap alkaline water electrolyzer at different KOH concentrations. Using plain uncatalyzed nickel foam electrodes......, the cell based on m-PBI outperforms the cell based on the commercially available state-of-the-art diaphragm and reaches a current density of 1500 mA cm-2 at 2.4 V in 20 wt% KOH at 80°C. The cell performance remained stable during two days of operation, though post analysis of the membrane using size...

  9. TiO2-NT electrodes modified with Ag and diamond like carbon (DLC) for hydrogen production by alkaline water electrolysis

    Science.gov (United States)

    Baran, Evrim; Baz, Zeynep; Esen, Ramazan; Yazici Devrim, Birgül

    2017-10-01

    In present work, the two-step anodization technique was applied for synthesis of TiO2 nanotube (NT). Silver and diamond like carbon (DLC) were coated on the surface of as prepared TiO2-NT using chemical reduction method and MW ECR plasma system. The morphology, composition and structure of the electrodes were examined by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results showed that Ag nanoparticles, having size in the range of 48-115 nm, are evenly distributed on the top, inside and outside surface of TiO2-NT and when DLC was coated on the surface of TiO2-NT and TiO2-NT-Ag, the top of nanotubes were partially open and the pore diameter of hexagonal structure decreased from 165 nm to of 38-80 nm. On the other hand, the microhardness test and contact angle measurements revealed that additions of Ag and diamond like carbon have a positive effect on the mechanical properties of TiO2-NT film. The electrocatalytic properties of the electrodes towards the hydrogen evolution reaction (HER) were investigated by the electrochemical measurements recorded in 1 M KOH solution. In addition, long-term durability of electrodes towards HER and the energy consumption of alkaline electrolysis were investigated. The energy requirement showed that while the deposition of silver provides approximately 14.95% savings of the energy consumption, the DLC coating causes increase in energy consumption.

  10. Techno-economic study of hydrogen production by high temperature electrolysis coupled with an EPR-water steam production and coupling possibilities

    International Nuclear Information System (INIS)

    Tinoco, R. R.; Bouallou, C.; Mansilla, C.; Werkoff, F.

    2007-01-01

    Nuclear reactors present a wide range of coupling possibilities with several industrial processes, hydrogen production being one of them. Among the Pressurised Water nuclear Reactors (PWR), the new European Pressurised Reactor (EPR) offers the water steam production at low-medium temperatures, from 230 degree Celsius to 330 degree Celsius for the primary and secondary exchange circuits. The use of this water steam for hydrogen production by High Temperature Electrolysis is the subject of this study, under a French context. The study of this coupling, has considered two hypotheses. First, water steam drawing off in secondary circuit has been evaluated in terms of possible impact in electricity production and reactor availability. After the drawing off at 78 bar (EPR secondary circuit pressure), pressure has to be dropped in order to protect the high temperature electrolyser from damage, so an isenthalpic drop has been considered. Liquid-vapour equilibrium happens with pressure drops, so separation of gas phase and recycling of liquid phase are proposed. Second, only water steam production with an EPR has been evaluated. The feed water enters the secondary circuit and passes from liquid phase to vapour in the steam generators, and then all steam is canalized to the high temperature electrolyser. The potentiality of water steam production in the EPR has been evaluated from 15 to 40 bar. Small reactors could be the best choice if only water steam production is considered. After steam production, it steam enters into the High Temperature Electrolysis process, like a cold stream for two parallel series of three heat exchangers reaching temperatures up to 950 degree Celsius. Then the steam is heated by an electric device and finally it enters the electrolyser. The electrolysis product streams (hydrogen-steam mixture and oxygen) are used in the heat exchangers like hot streams. For both hypotheses, information about water composition has been studied in order to minimise

  11. Water electrolysis system - H2 and O2 generation. [for spacecraft atmosphere revitalization

    Science.gov (United States)

    Schubert, F. H.; Lee, M. K.; Davenport, R. J.; Quattrone, P. D.

    1978-01-01

    An oxygen generation system design based on the static feed water electrolysis concept is described. The system is designed to generate 4.20 kg/d of oxygen to satisfy the metabolic needs of a three-person crew, to compensate for spacecraft leakage, and to provide the oxygen required by the electrochemical depolarized CO2 concentrator. The system has a fixed hardware weight of 75 kg, occupies a volume of 0.11 cu m, and requires only 1.1 kw of electrical power. The static feed electrolysis concept is discussed, and experimental data on the high-performance electrode are presented.

  12. Development of a simplified treatment for measuring tritium concentration in the environmental water. Removal of dissolved ions by reverse osmosis membrane for electrolysis enrichment

    International Nuclear Information System (INIS)

    Koganezawa, Takayuki; Iida, Takao; Ogata, Yoshimune; Tsuji, Naruhito; Kakiuchi, Masahisa; Satake, Hiroshi; Yamanishi, Hirokuni; Sakuma, Yoichi

    2004-01-01

    An apparatus for tritium enrichment by electrolysis using solid polymer electrolyte was recently developed. The apparatus has the advantage that is to be electrolyzed without adding electrolyte to the sample water. The new treatment both being replaced the distillation process with filtration before electrolysis and being omitted the distillation process after electrolysis, was proposed. Impurities eluted by the electrolysis of ultra pure water with the device introduced no influence on tritium measurement. As alternative treatment to distillation before enrichment, micro filtration and reverse osmosis was carried out. When the sample water treated by micro filtration was electrolyzed, ions adhered both to the electrodes and the solid polymer electrolyte of the device since micro filtration cannot remove ions in the sample water. Therefore, the sample water treated by micro filtration caused some troubles in the electrolysis device. On the other hand, the sample water treated by reverse osmosis did not cause any troubles because it could remove ions. Applying the new treatment to measure some environmental waters, such as river water, resulted in an effective measurement without any influence to liquid scintillation counting. The results proved that a period of the pretreatment process of the water sample could be decreased from about 2 days to about 1.5 hours by applying the proposed treatment. A simplified treatment on the procedure of electrolysis enrichment was established for tritium measurements in the environmental water samples via liquid scintillation counting. (author)

  13. Water electrolysis from the sources of aeolian and photovoltaic energies; Eletrolise da agua a partir de fontes de energia eolica e fotovoltaica

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ennio Peres da [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Lab. de Hidrogenio

    2006-07-01

    This paper presents an overview on the water electrolysis from aeolic and photovoltaic energies sources, considering the following aspects: hydrogen technology; water electrolysis; water dissociators; 3000 A unipolar dissociators; 4000 A unipolar dissociators; bipolar dissociators; generation systems connected to the network; generation systems disconnected from the network; costs of the hydrogen.

  14. Phosphonate removal from discharged circulating cooling water using iron-carbon micro-electrolysis.

    Science.gov (United States)

    Zhou, Zhen; Qiao, Weimin; Lin, Yangbo; Shen, Xuelian; Hu, Dalong; Zhang, Jianqiao; Jiang, Lu-Man; Wang, Luochun

    2014-01-01

    Phosphonate is a commonly used corrosion and scale inhibitor for a circulating cooling water (CCW) system. Its discharge could cause eutrophication of receiving waters. The iron-carbon (Fe/C) micro-electrolysis technology was used to degrade and remove phosphonate from discharged CCW. The influences of initial pH, Fe/C ratio (FCR) and temperature on phosphonate removal were investigated in a series of batch tests and optimized by response surface methodology. The quadratic model of phosphonate removal was obtained with satisfactory degrees of fitness. The optimum conditions with total phosphorus removal efficiency of 95% were obtained at pH 7.0, FCR of 1.25, and temperature of 45 °C. The phosphonate removal mechanisms were also studied. Phosphonate removal occurred predominantly via two consecutive reactive phases: the degradation of phosphonate complexes (Ca-phosphonate) and the precipitation of Fe/C micro-electrolysis products (PO₄(3-), Ca²⁺ and Fe³⁺).

  15. Development of a separate tank with an electrolysis-dependent bacteria controlling system for the long term storage of potable water.

    Science.gov (United States)

    Ishizuka, Akinori; Tanji, Masataka; Hayashi, Nobuatsu; Wakabayashi, Akihiro; Tatsumoto, Hideki; Hotta, Kunimoto

    2006-12-01

    For the long term storage of tap water, we developed a separate type of tank (5 m3) equipped with an electrolysis system to control bacterial growth. The electrolysis conditions using 20A direct current and a water flow rate of 10 L/min were capable of producing available chlorine (AC) at the rate of 5-8mg/min and raising the AC level of the stored tap water by about 0.2 mg/kg within 20-30 min The electrolyzed tap water with 0.2 mg/kg AC showed a capability per ml of killing 10(5)-10(6) cfu of bacteria such as Escherichia coli and Pseudomonas aeruginosa within 15 sec. A 6-month trial operation of the storage system with an automatic electrolysis control to keep AC level ranging 0.2-0.4 mg/kg demonstrated that the system worked well for the stored tap water in suppressing bacterial growth as well as in keeping good potable quality with reference to the 46 parameters specified for Japanese tap water. Actually, the electrolysis treatment was administered intermittently with an interval of about two weeks. Thus we believe the developed system has good potential to secure a potable water supply not only in the occasion of emergencies but also in countries having problems in the supply of safe drinking water.

  16. Direct anodic hydrochloric acid and cathodic caustic production during water electrolysis

    Science.gov (United States)

    Lin, Hui-Wen; Cejudo-Marín, Rocío; Jeremiasse, Adriaan W.; Rabaey, Korneel; Yuan, Zhiguo; Pikaar, Ilje

    2016-02-01

    Hydrochloric acid (HCl) and caustic (NaOH) are among the most widely used chemicals by the water industry. Direct anodic electrochemical HCl production by water electrolysis has not been successful as current commercially available electrodes are prone to chlorine formation. This study presents an innovative technology simultaneously generating HCl and NaOH from NaCl using a Mn0.84Mo0.16O2.23 oxygen evolution electrode during water electrolysis. The results showed that protons could be anodically generated at a high Coulombic efficiency (i.e. ≥ 95%) with chlorine formation accounting for 3 ~ 5% of the charge supplied. HCl was anodically produced at moderate strengths at a CE of 65 ± 4% together with a CE of 89 ± 1% for cathodic caustic production. The reduction in CE for HCl generation was caused by proton cross-over from the anode to the middle compartment. Overall, this study showed the potential of simultaneous HCl and NaOH generation from NaCl and represents a major step forward for the water industry towards on-site production of HCl and NaOH. In this study, artificial brine was used as a source of sodium and chloride ions. In theory, artificial brine could be replaced by saline waste streams such as Reverse Osmosis Concentrate (ROC), turning ROC into a valuable resource.

  17. Decoupling Hydrogen and Oxygen Production in Acidic Water Electrolysis Using a Polytriphenylamine-Based Battery Electrode.

    Science.gov (United States)

    Ma, Yuanyuan; Dong, Xiaoli; Wang, Yonggang; Xia, Yongyao

    2018-03-05

    Hydrogen production through water splitting is considered a promising approach for solar energy harvesting. However, the variable and intermittent nature of solar energy and the co-production of H 2 and O 2 significantly reduce the flexibility of this approach, increasing the costs of its use in practical applications. Herein, using the reversible n-type doping/de-doping reaction of the solid-state polytriphenylamine-based battery electrode, we decouple the H 2 and O 2 production in acid water electrolysis. In this architecture, the H 2 and O 2 production occur at different times, which eliminates the issue of gas mixing and adapts to the variable and intermittent nature of solar energy, facilitating the conversion of solar energy to hydrogen (STH). Furthermore, for the first time, we demonstrate a membrane-free solar water splitting through commercial photovoltaics and the decoupled acid water electrolysis, which potentially paves the way for a new approach for solar water splitting. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Development and Study of Tantalum and Niobium Carbides as Electrocatalyst Supports for the Oxygen Electrode for PEM Water Electrolysis at Elevated Temperatures

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Prag, Carsten Brorson

    2013-01-01

    Polymer electrolyte membrane (PEM) water electrolysis is a prospective method of producing hydrogen. We focused on one of its issues – the lack of a suitable support material for the anode electrocatalyst. TaC and NbC were studied as possible electrocatalyst supports for the PEM water electrolysis...

  19. Fast electrochemical deposition of Ni(OH)2 precursor involving water electrolysis for fabrication of NiO thin films

    Science.gov (United States)

    Koyama, Miki; Ichimura, Masaya

    2018-05-01

    Ni(OH)2 precursor films were deposited by galvanostatic electrochemical deposition (ECD), and NiO thin films were fabricated by annealing in air. The effects of the deposition current densities were studied in a range that included current densities high enough to electrolyze water and generate hydrogen bubbles. The films fabricated by ECD involving water electrolysis had higher transparency and smoother surface morphology than those deposited with lower current densities. In addition, the annealed NiO films clearly had preferred (111) orientation when the deposition was accompanied by water electrolysis. p-type conduction was confirmed for the annealed films.

  20. Solar water splitting by photovoltaic-electrolysis with a solar-to-hydrogen efficiency over 30%

    Science.gov (United States)

    Jia, Jieyang; Seitz, Linsey C.; Benck, Jesse D.; Huo, Yijie; Chen, Yusi; Ng, Jia Wei Desmond; Bilir, Taner; Harris, James S.; Jaramillo, Thomas F.

    2016-01-01

    Hydrogen production via electrochemical water splitting is a promising approach for storing solar energy. For this technology to be economically competitive, it is critical to develop water splitting systems with high solar-to-hydrogen (STH) efficiencies. Here we report a photovoltaic-electrolysis system with the highest STH efficiency for any water splitting technology to date, to the best of our knowledge. Our system consists of two polymer electrolyte membrane electrolysers in series with one InGaP/GaAs/GaInNAsSb triple-junction solar cell, which produces a large-enough voltage to drive both electrolysers with no additional energy input. The solar concentration is adjusted such that the maximum power point of the photovoltaic is well matched to the operating capacity of the electrolysers to optimize the system efficiency. The system achieves a 48-h average STH efficiency of 30%. These results demonstrate the potential of photovoltaic-electrolysis systems for cost-effective solar energy storage. PMID:27796309

  1. The electrolysis of water: An actuation principle for MEMS with a big opportunity

    NARCIS (Netherlands)

    Rusu, C.R.; Neagu, Cristina; Jansen, Henricus V.; Gardeniers, Johannes G.E.; Elwenspoek, Michael Curt

    In this paper the theory of water electrolysis in a closed electrochemical cell, that contains two electrodes, an electrolyte and a pressure sensor is described. From the leakage and electrochemical experiments done with this macrocell it is possible to obtain information about the applicability of

  2. Development of solid electrolytes for water electrolysis at intermediate temperatures. Task 3 report; Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Linkous, C.A.; Anderson, R.; Kopitzke, R.W.

    1995-12-01

    This project is an attempt to synthesize and fabricate proton exchange membranes for hydrogen production via water electrolysis that can take advantage of the better kinetic and thermodynamic conditions that exist at higher temperatures. Current PEM technology is limited to the 125--150 C range. Based on previous work evaluating thermohydrolytic stability, some 5 families of polymers were chosen as viable candidates: polyether ketones, polyether sulfones, fluorinated polyimides, polybenzimidazoles, and polyphenyl quinoxalines. Several of these have been converted into ionomers via sulfonation and fashioned into membranes for evaluation. In particular, the sulfonated polyetheretherketone, or SPEEK, was tested for water uptake, thermo-conductimetric analysis, and performance as the solid electrolyte material in an electrolysis cell. Results comparable to commercial perfluorocarbon sulfonates were obtained.

  3. Test results of six-month test of two water electrolysis systems

    Science.gov (United States)

    Mills, E. S.; Wells, G. W.

    1972-01-01

    The two water electrolysis systems used in the NASA space station simulation 90-day manned test of a regenerative life support system were refurbished as required and subjected to 26-weeks of testing. The two electrolysis units are both promising systems for oxygen and hydrogen generation and both needed extensive long-term testing to evaluate the performance of the respective cell design and provide guidance for further development. Testing was conducted to evaluate performance in terms of current, pressure, variable oxygen demands, and orbital simulation. An automatic monitoring system was used to record, monitor and printout performance data at one minute, ten minute or one-hour intervals. Performance data is presented for each day of system operation for each module used during the day. Failures are analyzed, remedial action taken to eliminate problems is discussed and recommendations for redesign for future space applications are stated.

  4. [Water disinfection by the combined exposure to super-high frequency energy and available chlorine produced during water electrolysis].

    Science.gov (United States)

    Klimarev, S I; Siniak, Iu E

    2014-01-01

    The article reports the results of studying the effects on polluted water of SHF-energy together with the residual free (active) chlorine as a by-product of electrolysis action on dissolved chlorine-containing salts. Purpose of the studies was to evaluate input of these elements to the water disinfection effect. The synergy was found to kill microorganisms without impacts on the physicochemical properties of processed water or nutrient medium; therefore, it can be used for water treatment, and cultivation of microorganisms in microbiology.

  5. Voltammogram of stainless steel/Fe-Co-Ni electrode on water electrolysis in base condition with dahlia pinnata tuber starch media

    Science.gov (United States)

    Isana S. Y., L.; Yuanita, Dewi; Sulistyani, Al, Heru Pratomo

    2017-08-01

    Hydrogen production in a safe, enviromentally friendly, and inexpensive is an attempt to realize energy needs commercially, one of them is electrolysis. Many attempts which relate with water electrolysis had been conducted to produce hydrogen, for example by using wastewater as water substitution. The research is to study the effect of dahlia pinnata tuber starch to stainless steel/Fe-Co-Ni electrode activity on water electrolysis in base condition. Stainless steel/Fe-Co-Ni electrode activity for breaking the water molecules eventually is better than stainless steel electrode, either there is existance of dahlia pinnata tuber starch or not. The presence of dahlia pinnata tuber starch apparently makes the covering on surface of the electrode so the catalytic activity of the electrode is reduced. Covering is mostly affected by dahlia pinnata tuber starch concentration. Wastewater which contains starch, especially dahlia pinnata tuber starch, obviously is not good enough because hydrogen production rate becomes obstructed.

  6. Two-stage electrolysis to enrich tritium in environmental water

    International Nuclear Information System (INIS)

    Shima, Nagayoshi; Muranaka, Takeshi

    2007-01-01

    We present a two-stage electrolyzing procedure to enrich tritium in environmental waters. Tritium is first enriched rapidly through a commercially-available electrolyser with a large 50A current, and then through a newly-designed electrolyser that avoids the memory effect, with a 6A current. Tritium recovery factor obtained by such a two-stage electrolysis was greater than that obtained when using the commercially-available device solely. Water samples collected in 2006 in lakes and along the Pacific coast of Aomori prefecture, Japan, were electrolyzed using the two-stage method. Tritium concentrations in these samples ranged from 0.2 to 0.9 Bq/L and were half or less, that in samples collected at the same sites in 1992. (author)

  7. Microbial Challenge Testing of Single Liquid Cathode Feed Water Electrolysis Cells for the International Space Station (ISS) Oxygen Generator Assembly (OGA)

    Science.gov (United States)

    Roy, Robert J.; Wilson, Mark E.; Diderich, Greg S.; Steele, John W.

    2011-01-01

    The International Space Station (ISS) Oxygen Generator Assembly (OGA) operational performance may be adversely impacted by microbiological growth and biofilm formation over the electrolysis cell membranes. Biofilms could hinder the transport of water from the bulk fluid stream to the membranes and increase the cell concentration overpotential resulting in higher cell voltages and a shorter cell life. A microbial challenge test was performed on duplicate single liquid-cathode feed water electrolysis cells to evaluate operational performance with increasing levels of a mixture of five bacteria isolated from ISS and Space Shuttle potable water systems. Baseline performance of the single water electrolysis cells was determined for approximately one month with deionized water. Monthly performance was also determined following each inoculation of the feed tank with 100, 1000, 10,000 and 100,000 cells/ml of the mixed suspension of test bacteria. Water samples from the feed tank and recirculating water loops for each cell were periodically analyzed for enumeration and speciation of bacteria and total organic carbon. While initially a concern, this test program has demonstrated that the performance of the electrolysis cell is not adversely impacted by feed water containing the five species of bacteria tested at a concentration measured as high as 1,000,000 colony forming units (CFU)/ml. This paper presents the methodologies used in the conduct of this test program along with the performance test results at each level of bacteria concentration.

  8. Modeling Bubble Flow and Current Density Distribution in an Alkaline Electrolysis Cell

    Directory of Open Access Journals (Sweden)

    Ravichandra S. Jupudi

    2009-12-01

    Full Text Available The effect of bubbles on the current density distribution over the electrodes of an alkaline electrolyzer cell is studied using a two-dimensional computational fluid dynamics model. Model includes Eulerian-Eulerian two-phase flow methodology to model the multiphase flow of Hydrogen and Oxygen with water and the behavior of each phase is accounted for using first principle. Hydrogen/Oxygen evolution, flow field and current density distribution are incorporated in the model to account for the complicated physics involved in the process. Fluent 6.2 is used to solve two-phase flow and electrochemistry is incorporated using UDF (User Defined Function feature of Fluent. Model is validated with mesh refinement study and by comparison with experimental measurements. Model is found to replicate the effect of cell voltage and inter-electrode gap (distance between the electrodes on current density accurately. Further, model is found to capture the existence of optimum cell height. The validated model is expected to be a very useful tool in the design and optimization of alkaline electrolyzer cells.

  9. Search for neutron emission during the electrolysis of heavy water

    International Nuclear Information System (INIS)

    Coelho, P.R.P.; Saxena, R.N.; Morato, S.P.; Goldman, I.D.; Pinho, A.G. de; Nascimento, I.C.

    1990-03-01

    A liquid scintillator detector NE 213 with pulse shape discrimination technique was used to observe neutrons during the electrolysis of heavy water with a palladium cathode. From the measured fore and background couting rates, a neutron emission rate of (8.2 ± 2.9) x 10 -3 n/(sec.g.) Pd was determined implying (2.9 ± 1.0) x 10 -24 fusions / [(dd pair).sec.] as compared to ≅ 10 -23 fusion/ [(dd pair).sec.] reported by Jones et al. using titanium electrode. (author) [pt

  10. Hydrogen Through Water Electrolysis and Biomass Gasification for Application in Fuel Cells

    Directory of Open Access Journals (Sweden)

    Y. Kirosa

    2017-03-01

    Full Text Available Hydrogen is considered to be one of the most promising green energy carrier in the energy storage and conversion scenario. Although it is abundant on Earth in the form of compounds, its occurrence in free form is extremely low. Thus, it has to be produced by reforming processes, steam reforming (SR, partial oxidation (POX and auto-thermal reforming (ATR mainly from fossil fuels for high throughput with high energy requirements, pyrolysis of biomass and electrolysis. Electrolysis is brought about by passing electric current though two electrodes to evolve water into its constituent parts, viz. hydrogen and oxygen, respectively. Hydrogen produced by non-noble metal catalysts for both anode and cathode is therefore cost-effective and can be integrated into fuel cells for direct chemical energy conversion into electrical energy electricity, thus meeting the sustainable and renewable use with low carbon footprint.

  11. Microbial electrolysis cells as innovative technology for hydrogen production

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  12. Feasibility of Using an Electrolysis Cell for Quantification of the Electrolytic Products of Water from Gravimetric Measurement.

    Science.gov (United States)

    Melaku, Samuel; Gebeyehu, Zewdu; Dabke, Rajeev B

    2018-01-01

    A gravimetric method for the quantitative assessment of the products of electrolysis of water is presented. In this approach, the electrolysis cell was directly powered by 9 V batteries. Prior to electrolysis, a known amount of potassium hydrogen phthalate (KHP) was added to the cathode compartment, and an excess amount of KHCO 3 was added to the anode compartment electrolyte. During electrolysis, cathode and anode compartments produced OH - (aq) and H + (aq) ions, respectively. Electrolytically produced OH - (aq) neutralized the KHP, and the completion of this neutralization was detected by a visual indicator color change. Electrolytically produced H + (aq) reacted with HCO 3 - (aq) liberating CO 2 (g) from the anode compartment. Concurrent liberation of H 2 (g) and O 2 (g) at the cathode and anode, respectively, resulted in a decrease in the mass of the cell. Mass of the electrolysis cell was monitored. Liberation of CO 2 (g) resulted in a pronounced effect of a decrease in mass. Experimentally determined decrease in mass (53.7 g/Faraday) agreed with that predicted from Faraday's laws of electrolysis (53.0 g/Faraday). The efficacy of the cell was tested to quantify the acid content in household vinegar samples. Accurate results were obtained for vinegar analysis with a precision better than 5% in most cases. The cell offers the advantages of coulometric method and additionally simplifies the circuitry by eliminating the use of a constant current power source or a coulometer.

  13. Studies on membrane acid electrolysis for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marco Antonio Oliveira da; Linardi, Marcelo; Saliba-Silva, Adonis Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Celulas a Combustivel e Hidrogenio], Email: saliba@ipen.br

    2010-07-01

    Hydrogen represents great opportunity to be a substitute for fossil fuels in the future. Water as a renewable source of hydrogen is of great interest, since it is abundant and can decompose, producing only pure H{sub 2} and O{sub 2}. This decomposition of water can be accomplished by processes such as electrolysis, thermal decomposition and thermochemical cycles. The electrolysis by membrane has been proposed as a viable process for hydrogen production using thermal and electrical energy derived from nuclear energy or any renewable source like solar energy. In this work, within the context of optimization of the electrolysis process, it is intended to develop a mathematical model that can simulate and assist in parameterization of the electrolysis performed by polymer membrane electrolytic cell. The experimental process to produce hydrogen via the cell membrane, aims to optimize the amount of gas produced using renewable energy with noncarbogenic causing no harm by producing gases deleterious to the environment. (author)

  14. Electrodes for the hydrogen through water electrolysis using BMI.BF{sub 4} as electrolyte; Eletrodos para a producao de hidrogenio via eletrolise da agua utilizando BMI.BF{sub 4} como eletrolito

    Energy Technology Data Exchange (ETDEWEB)

    Botton, Janine Padilha; Martini, Emilse M.A.; Souza, Michele Oberson de; Souza, Roberto Fernando de [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica. Lab. de Eletroquimica e Catalise]. E-mail: janine@iq.ufrgs.br; Loget, Gabriel [Universite de Rennes 1, Rennes (France). Lab. de Eletroquimica Molecular e Macromolecular. UMR CNRS 6510

    2008-07-01

    The hydrogen production by water electrolysis was tested with different electrocatalysts (nickel, iron alloys containing nickel, chromium and manganese, and molybdenum) in the ionic liquid electrolyte, 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF{sub 4}), 10 vol.% in water. The hydrogen evolution reaction (HER) worked at room temperature with a platinum quasi-reference electrode (PtQRE) applying a -1.7 V potential. The experimental conditions used were determined in previous work and such parameters of operation were confirmed with the electrocatalysts employed in this work. A Hoffman cell apparatus was used to perform the water electrolysis. The current density values, j, obtained were between 3.0 mA cm{sup -2} and 77.5 mA cm{sup -2}. The system efficiency was very high for all electrocatalysts tested, between 97.0% and 99.2%. The molybdenum (Mo) electrode was better than others showing the highest current density value in HER. This behavior has been explained by the lower value of activation energy for the electrolysis reaction when Mo is employed comparing with Pt electrode. The energy activation of the HER using platinum (Pt) as electrocatalyst in an aqueous solution of BMI.BF{sub 4} 10 vol.% was 23.40 kJ mol{sup -1}, whereas with electrode of Mo in the same conditions , was 9.22 kJ mol{sup -1}. In an alkaline aqueous electrolyte (usual medium for such reaction), Mo is less efficient than Pt explaining the lack of published citation using pure Mo as cathode for the HER. The excellent results obtained with a Mo electrode employing ionic liquid as electrolyte show that the hydrogen production can be carried out with cheap electrode material at room temperature, which makes this method economically attractive. (author)

  15. Characterization of Ni:Zn:S materials for use in alkaline electrolysis

    International Nuclear Information System (INIS)

    Martinez, W.M.; Fernandez, A.M.; Cano, U.

    2004-01-01

    'Full-text:' This work describes the synthesis of the Ni:Zn:S materials, which are prepared on a substratum of stainless steel, to use them as electrodes in an alkaline electrolyzer. The synthesis of the electrodes was carried out making a nickel electrodeposit on a substratum of stainless steel and then a ZnS film was deposited using the technique of chemical bath. After of it these electrodes were annealed at 3 different temperatures (200, 250, 300 o C) in an inert atmosphere. The studies of microscopy of electronic sweeping (SEM) and diffraction of rays X (XRD) shows that the obtained electrodes are polycrystallines, being obtained in the case of the nickel electrodes, grain sizes of approximately 1 ·m. In the electrodes in which we used chemical bath we found traces of zinc sulfide (phase wurtzita). The analyses of cyclic voltametry obtained at ambient temperature showed good potentials for water splitting of the electrodes annealed at 200 and 300 o C. These overpotentials are in 1300 mV, inferior in 25 mV to the nickel electrode. The cronoamperometry curves obtained at ambient temperature showed that both electrodes show an appropriate stability. It is important to also mention that all the Ni:Zn:S electrodes have a good anodic sobrepotential to be used as anodes in an alkaline electrolyzer. (author)

  16. SISGR-Fundamental Experimental and Theoretical Studies on a Novel Family of Oxide Catalyst Supports for Water Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kumta, Prashant [University of Pittsburgh

    2014-10-03

    Identification and development of non-noble metal based electro-catalysts or electro-catalysts with significant reduction of expensive noble metal contents (E.g. IrO2, Pt) with comparable electrochemical performance as the standard noble metal/metal oxide for proton exchange membrane (PEM) based water electrolysis would constitute a major breakthrough in the generation of hydrogen by water electrolysis. Accomplishing such a system would not only result reduction of the overall capital costs of PEM based water electrolyzers, but also help attain the targeted hydrogen production cost [< $ 3.0 / gallon gasoline equivalent (gge)] comparable to conventional liquid fuels. In line with these goals, it was demonstrated that fluorine doped IrO2 thin films and nanostructured high surface area powders display remarkably higher electrochemical activity, and comparable durability as pure IrO2 electro-catalyst for the oxygen evolution reaction (OER) in PEM based water electrolysis. Furthermore, corrosion resistant SnO2 and NbO2 support has been doped with F and coupled with IrO2 or RuO2 for use as an OER electro-catalyst. A solid solution of SnO2:F or NbO2:F with only 20 - 30 mol.% IrO2 or RuO2 yielding a rutile structure in the form of thin films and bulk nanoparticles displays similar electrochemical activity and stability as pure IrO2/RuO2. This would lead to more than 70 mol.% reduction in the noble metal oxide content. Novel nanostructured ternary (Ir,Sn,Nb)O2 thin films of different compositions FUNDAMENTAL STUDY OF NANOSTRUCTURED ELECTRO-CATALYSTS WITH REDUCED NOBLE METAL CONTENT FOR PEM BASED WATER ELECTROLYSIS 4 have also been studied. It has been shown that (Ir0.40Sn0.30Nb0.30)O2 shows similar electrochemical activity and enhanced chemical robustness as compared to pure IrO2. F doping of the ternary (Ir,Sn,Nb)O2 catalyst helps in further decreasing the noble metal oxide content of the catalyst. As a result, these reduced noble metal oxide catalyst systems would

  17. Achievement report for fiscal 1974 on Sunshine Program. Research and development of hydrogen production technology using high-temperature and high-pressure water electrolysis; 1974 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-05-30

    The goals at present are to clarify conditions for the realization of the water electrolysis process relative to various primary energy sources and to experimentally construct a small practical electrobath to operate at high temperature and high pressure for the attainment of high economic efficiency. Efforts in this fiscal year are mentioned below. Surveys and studies are conducted about hydrogen production by water electrolysis and about achievements in the past and problems at present concerning hydrogen production by water electrolysis in Japan and overseas. The expected role of water electrolysis in various primary energy sources is also studied and evaluated. For a high-temperature high-pressure water electrolysis bath conceptual design (small test plant, bathing temperature 120 degrees C, pressure 20atm, hydrogen production rate 2Nm{sup 3}/h), studies are conducted about a constant-load type high-temperature high-pressure (bipolar) diaphragm-assisted water electrolysis bath and a variable-load type high-temperature high-pressure diaphragm-assisted water electrolysis bath. Surveys and studies are also conducted about the expected role of water electrolysis in various primary energy sources, and the role is evaluated. (NEDO)

  18. A cost-effective nanoporous ultrathin film electrode based on nanoporous gold/IrO2 composite for proton exchange membrane water electrolysis

    Science.gov (United States)

    Zeng, Yachao; Guo, Xiaoqian; Shao, Zhigang; Yu, Hongmei; Song, Wei; Wang, Zhiqiang; Zhang, Hongjie; Yi, Baolian

    2017-02-01

    A cost-effective nanoporous ultrathin film (NPUF) electrode based on nanoporous gold (NPG)/IrO2 composite has been constructed for proton exchange membrane (PEM) water electrolysis. The electrode was fabricated by integrating IrO2 nanoparticles into NPG through a facile dealloying and thermal decomposition method. The NPUF electrode is featured in its 3D interconnected nanoporosity and ultrathin thickness. The nanoporous ultrathin architecture is binder-free and beneficial for improving electrochemical active surface area, enhancing mass transport and facilitating releasing of oxygen produced during water electrolysis. Serving as anode, a single cell performance of 1.728 V (@ 2 A cm-2) has been achieved by NPUF electrode with a loading of IrO2 and Au at 86.43 and 100.0 μg cm-2 respectively, the electrolysis voltage is 58 mV lower than that of conventional electrode with an Ir loading an order of magnitude higher. The electrolysis voltage kept relatively constant up to 300 h (@250 mA cm-2) during the course of durability test, manifesting that NPUF electrode is promising for gas evolution.

  19. Model-supported characterization of a PEM water electrolysis cell for the effect of compression

    DEFF Research Database (Denmark)

    Frensch, Steffen Henrik; Olesen, Anders Christian; Simon Araya, Samuel

    2018-01-01

    This paper investigates the influence of the cell compression of a PEM water electrolysis cell. A small single cell is therefore electrochemically analyzed by means of polarization behavior and impedance spectroscopy throughout a range of currents (0.01 A cm−2 to 2.0 A cm−2) at two temperatures (60...

  20. The use of electrolysis for accurate delta O-17 and delta O-18 isotope measurements in water

    NARCIS (Netherlands)

    Meijer, HAJ; Li, WJ

    1998-01-01

    We present a new system to measure the relative isotopic abundances of both rare isotopes of oxygen in water. Using electrolysis with CuSO4 as electrolyte, water is transformed into oxygen gas. This gas is subsequently analyzed with a standard Isotope Ratio Mass Spectrometer. We investigated the

  1. Preliminary study of synthesis gas production from water electrolysis, using the ELECTROFUEL® concept

    International Nuclear Information System (INIS)

    Guerra, L.; Gomes, J.; Puna, J.; Rodrigues, J.

    2015-01-01

    This paper describes preliminary work on the generation of synthesis gas from water electrolysis using graphite electrodes without the separation of the generated gases. This is an innovative process, that has no similar work been done earlier. Preliminary tests allowed to establish correlations between the applied current to the electrolyser and flow rate and composition of the generated syngas, as well as a characterisation of generated carbon nanoparticles. The obtained syngas can further be used to produce synthetic liquid fuels, for example, methane, methanol or DME (dimethyl ether) in a catalytic reactor, in further stages of a present ongoing project, using the ELECTROFUEL ® concept. The main competitive advantage of this project lies in the built-in of an innovative technology product, from RE (renewable energy) power in remote locations, for example, islands, villages in mountains as an alternative for energy storage for mobility constraints. - Highlights: • Generation of synthesis gas from water electrolysis without separation of gases. • Obtained syngas: 7.7% CO; 10.3% O 2 and 2.0% CO 2 . • Syngas can further be used to produce synthetic liquid fuels

  2. The advanced EctoSys electrolysis as an integral part of a ballast water treatment system.

    Science.gov (United States)

    Echardt, J; Kornmueller, A

    2009-01-01

    A full-scale 500 m(3)/h ballast water treatment system was tested according to the landbased type approval procedure of the International Maritime Organization (IMO). The system consists of disc filters followed by the advanced EctoSys electrolysis as an integral part for disinfection. The test water quality exceeded by far the minimum requirements for type approval testing. Due to the properties of the special electrodes used together with the striking disinfection effect, the disinfectants assumed to be produced inline by the EctoSys cell in river water were hydroxyl radicals, while in brackish water additionally chlorine and consequently the more stable bromine were formed. In river water, no residual oxidants could be detected in accordance with the assumed production of not responding, highly-reactive and short-living hydroxyl radicals. Accordingly, disinfection byproduct (DBP) formation was very low and close to the limit of quantification in river water. While in brackish water, initial residual oxidant concentrations were maximum 2 mg/L as chlorine and mostly brominated DBP (especially bromoform and bromate) were found. Overall considering this worst case test approach, the DBP concentrations of the treated effluents were below or in the range of the WHO Drinking Water Guideline values and therefore evaluated as acceptable for discharge to the environment. The stringent discharge standard by IMO concerning viable organisms was fully met in river and brackish water, proving the disinfection efficiency of the EctoSys electrolysis against smaller plankton and bacteria.

  3. Impact of low gravity on water electrolysis operation

    Science.gov (United States)

    Powell, F. T.; Schubert, F. H.; Lee, M. G.

    1989-01-01

    Advanced space missions will require oxygen and hydrogen utilities for several important operations including the following: (1) propulsion; (2) electrical power generation and storage; (3) environmental control and life support; (4) extravehicular activity; (5) in-space manufacturing and (6) in-space science activities. An experiment suited to a Space Shuttle standard middeck payload has been designed for the Static Feed Water Electrolysis technology which has been viewed as being capable of efficient, reliable oxygen and hydrogen generation with few subsystem components. The program included: end use design requirements, phenomena to be studied, Space Shuttle Orbiter experiment constraints, experiment design and data requirements, and test hardware requirements. The objectives are to obtain scientific and engineering data for future research and development and to focus on demonstrating and monitoring for safety of a standard middeck payload.

  4. Feasibility Analysis of Liquefying Oxygen Generated from Water Electrolysis Units on Lunar Surface

    Science.gov (United States)

    Jeng, Frank F.

    2009-01-01

    Concepts for liquefying oxygen (O2) generated from water electrolysis subsystems on the Lunar surface were explored. Concepts for O2 liquefaction units capable of generating 1.38 lb/hr (0.63 kg/hr) liquid oxygen (LOX) were developed. Heat and mass balance calculations for the liquefaction concepts were conducted. Stream properties, duties of radiators, heat exchangers and compressors for the selected concepts were calculated and compared.

  5. Systematic review of the association between dietary acid load, alkaline water and cancer.

    Science.gov (United States)

    Fenton, Tanis R; Huang, Tian

    2016-06-13

    To evaluate the evidence for a causal relationship between dietary acid/alkaline and alkaline water for the aetiology and treatment of cancer. A systematic review was conducted on published and grey literature separately for randomised intervention and observational studies with either varying acid-base dietary intakes and/or alkaline water with any cancer outcome or for cancer treatment. Incidence of cancer and outcomes of cancer treatment. 8278 citations were identified, and 252 abstracts were reviewed; 1 study met the inclusion criteria and was included in this systematic review. No randomised trials were located. No studies were located that examined dietary acid or alkaline or alkaline water for cancer treatment. The included study was a cohort study with a low risk of bias. This study revealed no association between the diet acid load with bladder cancer (OR=1.15: 95% CI 0.86 to 1.55, p=0.36). No association was found even among long-term smokers (OR=1.72: 95% CI 0.96 to 3.10, p=0.08). Despite the promotion of the alkaline diet and alkaline water by the media and salespeople, there is almost no actual research to either support or disprove these ideas. This systematic review of the literature revealed a lack of evidence for or against diet acid load and/or alkaline water for the initiation or treatment of cancer. Promotion of alkaline diet and alkaline water to the public for cancer prevention or treatment is not justified. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. Design considerations for a 10-kW integrated hydrogen-oxygen regenerative fuel cell system

    Science.gov (United States)

    Hoberecht, M. A.; Miller, T. B.; Rieker, L. L.; Gonzalez-Sanabria, O. D.

    1984-01-01

    Integration of an alkaline fuel cell subsystem with an alkaline electrolysis subsystem to form a regenerative fuel cell (RFC) system for low earth orbit (LEO) applications characterized by relatively high overall round trip electrical efficiency, long life, and high reliability is possible with present state of the art technology. A hypothetical 10 kW system computer modeled and studied based on data from ongoing contractual efforts in both the alkaline fuel cell and alkaline water electrolysis areas. The alkaline fuel cell technology is under development utilizing advanced cell components and standard Shuttle Orbiter system hardware. The alkaline electrolysis technology uses a static water vapor feed technique and scaled up cell hardware is developed. The computer aided study of the performance, operating, and design parameters of the hypothetical system is addressed.

  7. Influence from sea water constituents on the efficiency of water electrolysis by PEM-cells

    DEFF Research Database (Denmark)

    Agersted, Karsten; Bentzen, Janet Jonna; Yde-Andersen, S.

    Among the sea-water specific impurities tested, magnesium has the most profound effect on PEM-cell degradation. Significant amounts of the cation was retrieved in the NAFION®-membrane structure after testing. Degradation was seen from a magnesium concentration as low as 3 10-7 mol/l, and increasing...... with concentration it led to a 86% increase of the area specific resistance at a concentration of 3 10-5 mol/l; equivalent to a conductivity of ~5 μS/cm. Other species (Cl-, Na+, SO4 2- ) seems to affect, though slowly, the performance negatively. If PEM will be used for electrolysis it seems therefore necessary...... to purify the feed water to ~1 μS/cm or even further while particularly focusing on the concentrations of polyvalent cations. e.g. magnesium....

  8. The Interconversion of Electrical and Chemical Energy: The Electrolysis of Water and the Hydrogen-Oxygen Fuel Cell.

    Science.gov (United States)

    Roffia, Sergio; And Others

    1988-01-01

    Discusses some of the drawbacks of using a demonstration of the electrolysis of water to illustrate the interconversion between electrical and chemical energy. Illustrates a simple apparatus allowing demonstration of this concept while overcoming these drawbacks. (CW)

  9. Recovery of fission products from waste solutions utilizing controlled cathodic potential electrolysis

    International Nuclear Information System (INIS)

    Carlin, W.W.; Darlington, W.B.

    1975-01-01

    Fission products, e.g., palladium, rhodium and technetium, are recovered from aqueous waste solutions thereof, e.g., aged Purex alkaline waste solutions. The metal values from the waste solutions are extracted by ion exchange techniques. The metals adsorbed by the ion exchange resin are eluted and selectively recovered by controlled cathodic potential electrolysis. The metal values deposited on the cathode are recovered and, if desired, further purified

  10. Debromination and decomposition of bromoform by contact glow discharge electrolysis in an aqueous solution

    International Nuclear Information System (INIS)

    Wang, Lei; Liu, Panliang; Zhang, Songlin

    2015-01-01

    Bromoform (BF) is a stable and carcinogenic contaminant in water. In this study, efficient debromination and decomposition of BF induced by contact glow discharge electrolysis (CGDE) in a sodium sulfate solution were investigated. Intermediate byproducts were determined by ionic chromatography and gas chromatography, respectively. Experimental results showed that alkaline conditions and additions of organic additives to the solution were favorable for both the removal and the debromination of BF. Oxalic acid, formic acid, dibromomethane and bromate ion were determined as the major intermediate byproducts. Final products were inorganic carbon and bromide ion. Hydrated electrons may be the most likely active species responsible for the initiation of the debromination, and hydroxyl radicals may be the ones for the oxidation of the intermediate byproducts

  11. Conversion of laser energy to chemical energy by the photoassisted electrolysis of water

    Science.gov (United States)

    Wrighton, M. S.

    1976-01-01

    Ultraviolet irradiation of the n-type semiconductor TiO2 crystal electrode of an aqueous electrochemical cell evolves O2 at the TiO2 electrode and H2 at the Pt electrode. The gases are typically evolved in a 2:1 (H2:O2) volume ratio. The photoassisted reaction seems to require applied voltages, but values as low as 0.25 V do allow the photoassisted electrolysis to proceed. Prolonged irradiation in either acid or base evolves the gaseous products in amounts which clearly demonstrate that the reaction is catalytic with respect to the TiO2. The wavelength response of the TiO2 and the correlation of product yield and current are reported. The results support the claim that TiO2 is a true photoassistance agent for the electrolysis of water. Minimum optical storage efficiencies of the order of 1 percent can be achieved by the production of H2.

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

    Science.gov (United States)

    Schmidt, George R.

    1988-01-01

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

  13. Polymer electrolyte membrane water electrolysis: Restraining degradation in the presence of fluctuating power

    Science.gov (United States)

    Rakousky, Christoph; Reimer, Uwe; Wippermann, Klaus; Kuhri, Susanne; Carmo, Marcelo; Lueke, Wiebke; Stolten, Detlef

    2017-02-01

    Polymer electrolyte membrane (PEM) water electrolysis generates 'green' hydrogen when conducted with electricity from renewable - but fluctuating - sources like wind or solar photovoltaic. Unfortunately, the long-term stability of the electrolyzer performance is still not fully understood under these input power profiles. In this study, we contrast the degradation behavior of our PEM water electrolysis single cells that occurs under operation with constant and intermittent power and derive preferable operating states. For this purpose, five different current density profiles are used, of which two were constant and three dynamic. Cells operated at 1 A cm-2 show no degradation. However, degradation was observed for the remaining four profiles, all of which underwent periods of high current density (2 A cm-2). Hereby, constant operation at 2 A cm-2 led to the highest degradation rate (194 μV h-1). Degradation can be greatly reduced when the cells are operated with an intermittent profile. Current density switching has a positive effect on durability, as it causes reversible parts of degradation to recover and results in a substantially reduced degradation per mole of hydrogen produced. Two general degradation phenomena were identified, a decreased anode exchange current density and an increased contact resistance at the titanium porous transport layer (Ti-PTL).

  14. Polymer anion-selective membrane for electrolytic water splitting: the impact of a liquid electrolyte composition on the process parameters and long-term stability

    Czech Academy of Sciences Publication Activity Database

    Hnát, J.; Paidar, M.; Schauer, Jan; Bouzek, K.

    2014-01-01

    Roč. 39, č. 10 (2014), s. 4779-4787 ISSN 0360-3199 Institutional support: RVO:61389013 Keywords : water electrolysis * alkaline environment * polymer electrolyte Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.313, year: 2014

  15. Microscale Electrolysis Using Coin-Type Lithium Batteries and Filter

    Science.gov (United States)

    Kamata, Masahiro; Yajima, Seiko

    2013-01-01

    An educational experiment illustrates the electrolysis of water and copper chloride to middle school science students. The electrolysis cell is composed of filter paper soaked with Na[subscript 2]SO[subscript 4] or CuCl[subscript 2] aqueous solution sandwiched, along with a sheet of platinum foil, between two coin-type lithium batteries. When the…

  16. VOF modelling of gas–liquid flow in PEM water electrolysis cell micro-channels

    DEFF Research Database (Denmark)

    Lafmejani, Saeed Sadeghi; Olesen, Anders Christian; Kær, Søren Knudsen

    2017-01-01

    In this study, the gaseliquid flow through an interdigitated anode flow field of a PEM water electrolysis cell (PEMEC) is analysed using a three-dimensional, transient, computational fluid dynamics (CFD) model. To account for two-phase flow, the volume of fluid (VOF) method in ANSYS Fluent 17...... of the channel. The model is capable of revealing effect of different bubble shapes/lengths in the outgoing channel. Shape and the sequence of the bubbles affect the water flow distribution in the ATL. The model presented in this work is the first step in the development of a comprehensive CFD model...

  17. Water electrolysis for hydrogen production in Brazilian perspective

    Energy Technology Data Exchange (ETDEWEB)

    Saliba-Silva, Adonis Marcelo; Carvalho, Fatima M.S.; Bergamaschi, Vanderlei Sergio; Linardi, Marcelo [Instituto de Pesquisas Energeticas e Nucleares (CCCH/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Fuel Cell and Hydrogen Center], Email: saliba@ipen.br

    2009-07-01

    Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation and distributed energy sector of Brazilian economy. Fossil fuels are polluting by carbogenic emissions from their combustion, being so co-responsible for present global warming. However, no large scale, cost-effective, environmentally non-carbogenic hydrogen production process is currently available for commercialization. There are feasible possibilities to use electrolysis as one of the main sources of hydrogen, especially thinking on combination with renewable sources of energy, mainly eolic and solar. In this work some perspectives for Brazilian energy context is presented, where electrolysis combined with renewable power source and fuel cell power generation would be a good basis to improve the distributed energy supply for remote areas, where the electricity grid is not present or is deficient. (author)

  18. High Temperature Electrolysis

    DEFF Research Database (Denmark)

    Elder, Rachael; Cumming, Denis; Mogensen, Mogens Bjerg

    2015-01-01

    High temperature electrolysis of carbon dioxide, or co-electrolysis of carbon dioxide and steam, has a great potential for carbon dioxide utilisation. A solid oxide electrolysis cell (SOEC), operating between 500 and 900. °C, is used to reduce carbon dioxide to carbon monoxide. If steam is also i...

  19. A study of water electrolysis using ionic polymer-metal composite for solar energy storage

    Science.gov (United States)

    Keow, Alicia; Chen, Zheng

    2017-04-01

    Hydrogen gas can be harvested via the electrolysis of water. The gas is then fed into a proton exchange membrane fuel cell (PEMFC) to produce electricity with clean emission. Ionic polymer-metal composite (IPMC), which is made from electroplating a proton-conductive polymer film called Nafion encourages ion migration and dissociation of water under application of external voltage. This property has been proven to be able to act as catalyst for the electrolysis of pure water. This renewable energy system is inspired by photosynthesis. By using solar panels to gather sunlight as the source of energy, the generation of electricity required to activate the IPMC electrolyser is acquired. The hydrogen gas is collected as storable fuel and can be converted back into energy using a commercial fuel cell. The goal of this research is to create a round-trip energy efficient system which can harvest solar energy, store them in the form of hydrogen gas and convert the stored hydrogen back to electricity through the use of fuel cell with minimal overall losses. The effect of increasing the surface area of contact is explored through etching of the polymer electrolyte membrane (PEM) with argon plasma or manually sanding the surface and how it affects the increase of energy conversion efficiency of the electrolyser. In addition, the relationship between temperature and the IPMC is studied. Experimental results demonstrated that increases in temperature of water and changes in surface area contact correlate with gas generation.

  20. Systemic and local effects of long-term exposure to alkaline drinking water in rats.

    Science.gov (United States)

    Merne, M E; Syrjänen, K J; Syrjänen, S M

    2001-08-01

    Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water or bicarbonate toothpaste. The effects of alkaline pH on oral mucosa have not been systematically studied. To assess the systemic (organ) and local (oral mucosal) effects of alkalinity, drinking water supplemented with Ca(OH)2 or NaOH, with pH 11.2 or 12 was administered to rats (n = 36) for 52 weeks. Tissues were subjected to histopathological examination; oral mucosal biopsy samples were also subjected to immunohistochemical (IHC) analyses for pankeratin, CK19, CK5, CK4, PCNA, ICAM-1, CD44, CD68, S-100, HSP 60, HSP70, and HSP90. At completion of the study, animals in the study groups had lower body weights (up to 29% less) than controls despite equal food and water intake, suggesting a systemic response to the alkaline treatment. The lowest body weight was found in rats exposed to water with the highest pH value and starting the experiment when young (6 weeks). No histological changes attributable to alkaline exposure occurred in the oral mucosa or other tissues studied. Alkaline exposure did not affect cell proliferation in the oral epithelium, as shown by the equal expression of PCNA in groups. The up-regulation of HSP70 protein expression in the oral mucosa of rats exposed to alkaline water, especially Ca(OH)2 treated rats, may indicate a protective response. Intercellular adhesion molecule-1 (ICAM-1) positivity was lost in 6/12 rats treated with Ca(OH)2 with pH 11.2, and loss of CD44 expression was seen in 3/6 rats in both study groups exposed to alkaline water with pH 12. The results suggest that the oral mucosa in rats is resistant to the effects of highly alkaline drinking water. However, high alkalinity may have some unknown systemic effects leading to growth retardation, the cause of which remains to be determined.

  1. Advancements in water vapor electrolysis technology. [for Space Station ECLSS

    Science.gov (United States)

    Chullen, Cinda; Heppner, Dennis B.; Sudar, Martin

    1988-01-01

    The paper describes a technology development program whose goal is to develop water vapor electrolysis (WVE) hardware that can be used selectively as localized topping capability in areas of high metabolic activity without oversizing the central air revitalization system on long-duration manned space missions. The WVE will be used primarily to generate O2 for the crew cabin but also to provide partial humidity control by removing water vapor from the cabin atmosphere. The electrochemically based WVE interfaces with cabin air which is controlled in the following ranges: dry bulb temperature of 292 to 300 K; dew point temperature of 278 to 289 K; relative humidity of 25 to 75 percent; and pressure of 101 + or - 1.4 kPa. Design requirements, construction details, and results for both single-cell and multicell module testing are presented, and the preliminary sizing of a multiperson subsystem is discussed.

  2. Enhanced shock wave generation via pre-breakdown acceleration using water electrolysis in negative streamer pulsed spark discharges

    Science.gov (United States)

    Lee, Kern; Chung, Kyoung-Jae; Hwang, Y. S.

    2018-03-01

    This paper presents a method for enhancement of shock waves generated from underwater pulsed spark discharges with negative (anode-directed) subsonic streamers, for which the pre-breakdown process is accelerated by preconditioning a gap with water electrolysis. Hydrogen microbubbles are produced at the cathode by the electrolysis and move towards the anode during the preconditioning phase. The numbers and spatial distributions of the microbubbles vary with the amplitude and duration of each preconditioning pulse. Under our experimental conditions, the optimum pulse duration is determined to be ˜250 ms at a pulse voltage of 400 V, where the buoyancy force overwhelms the electric force and causes the microbubbles to be swept out from the water gap. When a high-voltage pulse is applied to the gap just after the preconditioning pulse, the pre-breakdown process is significantly accelerated in the presence of the microbubbles. At the optimum preconditioning pulse duration, the average breakdown delay is reduced by 87% and, more importantly, the energy consumed during the pre-breakdown period decreases by 83%. This reduced energy consumption during the pre-breakdown period, when combined with the morphological advantages of negative streamers, such as thicker and longer stalks, leads to a significant improvement in the measured peak pressure (˜40%) generated by the underwater pulsed spark discharge. This acceleration of pre-breakdown using electrolysis overcomes the biggest drawback of negative subsonic discharges, which is slow vapor bubble formation due to screening effects, and thus enhances the efficiency of the shock wave generation process using pulsed spark discharges in water.

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

    Science.gov (United States)

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

    2016-10-29

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

  4. Water containing deuterium electrolysis to obtain gaseous hydrogen isotope in a high state of purity

    International Nuclear Information System (INIS)

    Bellanger, Gilbert

    1992-01-01

    In this paper, the basic concept is to prepare hydrogen in a high state of purity by electrolysing water using a palladium cathode. During electrolysis, hydrogen is at first adsorbed at the palladium surface, and next it diffuses through it till opposite face of its entry where it is desorbed; thus permitting to regain it in a very pure state for storage. The method can be used from water containing deuterium. To improve hydrogen adsorption, surface effect of palladium must be studied. It was found that heat treatment of palladium improved the hydrogen permeation flux. The diffusivity of hydrogen is controlled by Fick and Sieverts equations in which temperature has a significant influence on permeation rates. Anyway, hydrogen desorption does not cause any difficulty. In a second part, we have studied the isotopic separation factor using water containing deuterium. We remarked in fact that it depends on current density, overpotential, diffusivity of hydrogen and deuterium and isotopic composition of electrolyte as expected. In the last part, we realized an original electrolysis model in a glove-box in which are taken into account the results given before and also the technology components employed in processes involving the use of tritium. (author) [fr

  5. Temperature Dependence of Mineral Solubility in Water. Part 2. Alkaline and Alkaline Earth Bromides

    Science.gov (United States)

    Krumgalz, B. S.

    2018-03-01

    Databases of alkaline and alkaline earth bromide solubilities in water at various temperatures were created using experimental data from publications over about the last two centuries. Statistical critical evaluation of the created databases was produced since there were enough independent data sources to justify such evaluation. The reliable experimental data were adequately described by polynomial expressions over various temperature ranges. Using the Pitzer approach for ionic activity and osmotic coefficients, the thermodynamic solubility products for the discussed bromide minerals have been calculated at various temperature intervals and also represented by polynomial expressions.

  6. High performance of nitrogen and phosphorus removal in an electrolysis-integrated biofilter.

    Science.gov (United States)

    Gao, Y; Xie, Y W; Zhang, Q; Yu, Y X; Yang, L Y

    A novel electrolysis-integrated biofilter system was developed in this study to evaluate the intensified removal of nitrogen and phosphorus from contaminated water. Two laboratory-scale biofilter systems were established, one with electrolysis (E-BF) and one without electrolysis (BF) as control. The dynamics of intensified nitrogen and phosphorus removal and the changes of inflow and outflow water qualities were also evaluated. The total nitrogen (TN) removal rate was 94.4% in our newly developed E-BF, but only 74.7% in the control BF. Ammonium removal rate was up to 95% in biofilters with or without electrolysis integration with an influent ammonium concentration of 40 mg/L, and the accumulation of nitrate and nitrite was much lower in the effluent of E-BF than that of BF. Thus electrolysis plays an important role in TN removal especially the nitrate and nitrite removal. Phosphorus removal was significantly enhanced, exceeding 90% in E-BF by chemical precipitation, physical adsorption, and flocculation of phosphorus because of the in situ formation of ferric ions by the anodizing of sacrificial iron anodes. Results from this study indicate that the electrolysis integrated biofilter is a promising solution for intensified nitrogen and phosphorus removal.

  7. Achievement report for fiscal 1976 on Sunshine Program. Research and development of hydrogen production technology using high-temperature high-pressure water electrolysis; 1976 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-03-01

    Basic data are collected for the construction of a high-temperature high-pressure membrane-assisted water electrolysis test plant of the constant load type and another of the variable load type. To collect the data, basic experiments are conducted on a small water electrolysis unit, diaphragms are fabricated and tested for performance, design calculation is performed using a computer, a test unit for testing electrolysis bath constituting materials is built for the construction of a gas/liquid separation unit. The ultimate goal of this project is to develop a high-temperature high-pressure water electrolysis test apparatus. The first part of this report is titled 'Outline' and states the objectives of this research, summarizes the achievements of fiscal 1974, 1975, and 1976, and mentions the names of officers responsible for the execution of the research and development, etc. The second part is titled 'Contents of research' and reports the details of the research conducted in fiscal 1976. The subjects taken up in the second part are 'Research on constant-load type high-temperature high-pressure (bipolar) diaphragm-assisted water electrolysis bath,' 'Research on Teflon-based diaphragms for high-temperature high-pressure water electrolysis baths,' 'Research on variable-load type high-temperature high-pressure diaphragm-assisted water electrolysis bath,' 'Research on small test plant electrolysis bath design,' etc., which are being undertaken by Showa Denko K.K. and four other corporations. (NEDO)

  8. Production of Synthetic Fuels by Co-Electrolysis of Steam and Carbon Dioxide

    DEFF Research Database (Denmark)

    Ebbesen, Sune; Graves, Christopher R.; Mogensen, Mogens Bjerg

    2009-01-01

    reactions, the equilibrium of the water-gas shift reaction is reached, and moreover, CO is produced via the water-gas shift reaction. The degradation observed when performing co-electrolysis in these SOCs occurs mainly at the Ni/YSZ cathode and may be a consequence of impurities in the gas stream, adsorbing......Co-electrolysis of H2O and CO2 was studied in solid oxide cells (SOCs) supported by nickel-/yittria-stabilized zirconia (Ni/YSZ) electrode. Polarization characterization indicates that electrochemical reduction of both CO2 and H2O occurs during co-electrolysis. In parallel with the electrochemical...

  9. Urbanization accelerates long-term salinization and alkalinization of fresh water

    Science.gov (United States)

    Kaushal, S.; Duan, S.; Doody, T.; Haq, S.; Smith, R. M.; Newcomer Johnson, T. A.; Delaney Newcomb, K.; Gorman, J. K.; Bowman, N.; Mayer, P. M.; Wood, K. L.; Belt, K.; Stack, W.

    2017-12-01

    Human dominated land-use increases transport a major ions in streams due to anthropogenic salts and accelerated weathering. We show long-term trends in calcium, magnesium, sodium, alkalinity, and hardness over 50 years in the Baltimore metropolitan region and elsewhere. We also examine how major ion concentrations have increased significantly with impervious surface cover in watersheds across land use. Base cations show strong relationships with acid anions, which illustrates the coupling of major biogeochemical cycles in urban watersheds over time. Longitudinal patterns in major ions can also show increasing trends from headwaters to coastal waters, which suggests coupled biogeochemical cycles over space. We present new results from manipulative experiments and long-term monitoring across different urban regions regarding patterns and processes of salinization and alkalinization. Overall, our work demonstrates that urbanization dramatically increases major ions, ionic strength, and pH over decades from headwaters to coastal waters, which impacts the integrity of aquatic life, infrastructure, drinking water, and coastal ocean alkalinization.

  10. Treatment of process water containing heavy metals with a two-stage electrolysis procedure in a membrane electrolysis cell

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, R.; Krebs, P. [Technische Universitaet Dresden, Institut fuer Siedlungs- und Industriewasserwirtschaft, Mommsenstrasse 13, 01062 Dresden (Germany); Seidel, H. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Bioremediation, Permoserstrasse 15, D-04318 Leipzig (Germany); Morgenstern, P. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Analytik, Permoserstrasse 15, D-04318 Leipzig (Germany); Foerster, H.J.; Thiele, W. [Eilenburger Elektrolyse- und Umwelttechnik GmbH, Ziegelstrasse 2, D-04838 Eilenburg (Germany)

    2005-04-01

    The capability of a two-stage electrochemical treatment for the regeneration of acidic heavy-metal containing process water was examined. The process water came from sediment bioleaching and was characterized by a wide spectrum of dissolved metals, a high sulfate content, and a pH of about 3. In the modular laboratory model cell used, the anode chamber and the cathode chamber were separated by a central chamber fitted with an ion exchanger membrane on either side. The experiments were carried out applying a platinum anode and a graphite cathode at a current density of 0.1 A/cm{sup 2}. The circulation flow of the process water in the batch process amounted to 35 L/h, the electrolysis duration was 5.5 h at maximum and the total electrolysis current was about 1 A. In the first stage, the acidic process water containing metals passed through the cathode chamber. In the second stage, the cathodically pretreated process water was electrolyzed anodically. In the cathode chamber the main load of dissolved Cu, Zn, Cr and Pb was eliminated. The sulfuric acid surplus of 3-4 g/L decreased to about 1 g/L, the pH rose from initially 3.0 to 4-5, but the desired pH of 9-10 was not achieved. Precipitation in the proximity to the cathode evidently takes place at a higher pH than farther away. The dominant process in the anode chamber was the precipitation of amorphous MnO{sub 2} owing to the oxidation of dissolved Mn(II). The further depletion of the remaining heavy metals in the cathodically pretreated process water by subsequent anodic treatment was nearly exhaustive, more than 99 % of Cd, Cr, Cu, Mn, Ni, Pb, and Zn were removed from the leachate. The high depletion of heavy metals might be due to both the sorption on MnO{sub 2} precipitates and/or basic ferrous sulfate formed anodically, and the migration of metal ions through the cation exchanger membrane via the middle chamber into the cathode chamber. In the anode chamber, the sulfuric acid content increased to 6-7 g/L and the

  11. Electrode kinetics of a water vapor electrolysis cell

    Science.gov (United States)

    Jacobs, G.

    1974-01-01

    The anodic electrochemical behavior of the water vapor electrolysis cell was investigated. A theoretical review of various aspects of cell overvoltage is presented with special emphasis on concentration overvoltage and activation overvoltage. Other sources of overvoltage are described. The experimental apparatus controlled and measured anode potential and cell current. Potentials between 1.10 and 2.60 V (vs NHE) and currents between 0.1 and 3000 mA were investigated. Different behavior was observed between the standard cell and the free electrolyte cell. The free electrolyte cell followed typical Tafel behavior (i.e. activation overvoltage) with Tafel slopes of about 0.15, and the exchange current densities of 10 to the minus 9th power A/sq cm, both in good agreement with literature values. The standard cell exhibitied this same Tafel behavior at lower current densities but deviated toward lower than expected current densities at higher potentials. This behavior and other results were examined to determine their origin.

  12. Long-term evolution of highly alkaline steel slag drainage waters.

    Science.gov (United States)

    Riley, Alex L; Mayes, William M

    2015-07-01

    The disposal of slag generated by the steel industry can have negative consequences upon the surrounding aquatic environment by the generation of high pH waters, leaching of potentially problematic trace metals, and rapid rates of calcite precipitation which smother benthic habitats. A 36-year dataset was collated from the long-term ambient monitoring of physicochemical parameters and elemental concentrations of samples from two steel slag leachate-affected watercourses in northern England. Waters were typified by elevated pH (>10), high alkalinity, and were rich in dissolved metals (e.g. calcium (Ca), aluminium (Al), and zinc (Zn)). Long-term trend analysis was performed upon pH, alkalinity, and Ca concentration which, in addition to Ca flux calculations, were used to highlight the longevity of pollution arising as a result of the dumping and subsequent leaching of steel slags. Declines in calcium and alkalinity have been modest over the monitoring period and not accompanied by significant declines in water pH. If the monotonic trends of decline in alkalinity and calcium continue in the largest of the receiving streams, it will be in the region of 50-80 years before calcite precipitation would be expected to be close to baseline levels, where ecological impacts would be negligible.

  13. On the Effect of Clamping Pressure and Method on the Current Mapping of Proton Exchange Membrane Water Electrolysis

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Zhou, Fan; Kær, Søren Knudsen

    The degradation of the electrochemical reaction of the proton exchange membrane water electrolysis (PEMWE) can be characterized using in-situ current mapping measurements (CMM). CMM is significantly affected by the amount of clamping pressure and method. In this work the current is mapped...

  14. Design considerations for a 10-KW integrated hydrogen-oxygen regenerative fuel cell system

    International Nuclear Information System (INIS)

    Hoberecht, M.A.; Gonzalez-Sanabria, O.D.; Miller, T.B.; Rieker, L.L.

    1984-01-01

    Integration of an alkaline fuel cell subsystem with an alkaline electrolysis subsystem to form a regenerative fuel cell (RFC) system for low-earth-orbit (LEO) applications characterized by relatively high overall round-trip electrical efficiency, long life, and high reliability is possible with present state-of-the-art technology. A hypothetical 10-kW system is being computer modeled and studied based on data from ongoing contractual efforts in both the alkaline fuel cell and alkaline water electrolysis areas. The alkaline fuel cell technology is being developed under an NASA-LeRC program with United Technologies Corporation (UTC), utilizing advanced cell components and standard Shuttle-Orbiter system hardware. The alkaline electrolysis technology is that of Life Systems, Inc. (LSI), which uses a static water vapor feed technique and scaled-up cell hardware being developed under an NASA-LeRC program. This paper addresses the computeraided study of the performance, operating, and design parameters of the hypothetical system

  15. Mathematical Analysis of High-Temperature Co-electrolysis of CO2 and O2 Production in a Closed-Loop Atmosphere Revitalization System

    Energy Technology Data Exchange (ETDEWEB)

    Michael G. McKellar; Manohar S. Sohal; Lila Mulloth; Bernadette Luna; Morgan B. Abney

    2010-03-01

    NASA has been evaluating two closed-loop atmosphere revitalization architectures based on Sabatier and Bosch carbon dioxide, CO2, reduction technologies. The CO2 and steam, H2O, co-electrolysis process is another option that NASA has investigated. Utilizing recent advances in the fuel cell technology sector, the Idaho National Laboratory, INL, has developed a CO2 and H2O co-electrolysis process to produce oxygen and syngas (carbon monoxide, CO and hydrogen, H2 mixture) for terrestrial (energy production) application. The technology is a combined process that involves steam electrolysis, CO2 electrolysis, and the reverse water gas shift (RWGS) reaction. A number of process models have been developed and analyzed to determine the theoretical power required to recover oxygen, O2, in each case. These models include the current Sabatier and Bosch technologies and combinations of those processes with high-temperature co-electrolysis. The cases of constant CO2 supply and constant O2 production were evaluated. In addition, a process model of the hydrogenation process with co-electrolysis was developed and compared. Sabatier processes require the least amount of energy input per kg of oxygen produced. If co-electrolysis replaces solid polymer electrolyte (SPE) electrolysis within the Sabatier architecture, the power requirement is reduced by over 10%, but only if heat recuperation is used. Sabatier processes, however, require external water to achieve the lower power results. Under conditions of constant incoming carbon dioxide flow, the Sabatier architectures require more power than the other architectures. The Bosch, Boudouard with co-electrolysis, and the hydrogenation with co-electrolysis processes require little or no external water. The Bosch and hydrogenation processes produce water within their reactors, which aids in reducing the power requirement for electrolysis. The Boudouard with co-electrolysis process has a higher electrolysis power requirement because carbon

  16. The initiation of excess power and possible products of nuclear interactions during the electrolysis of heavy water

    International Nuclear Information System (INIS)

    Scott, C.D.; Mrochek, J.E.; Scott, T.C.; Michaels, G.E.; Newman, E.; Petek, M.

    1990-01-01

    The electrolysis of heavy water is being investigated with an insulated flow calorimetric system. The electrolyte was 0.1 to 1.0 N LiOD in D 2 O and cylindrical palladium cathodes surrounded by wire-wound platinum anodes have been used at cathode current densities of 100 to 800 mA/cm 2 . The most recent test has been made with a ''closed system'' without off-gal in which the electrolysis gases were internally recombined. Fast neutrons and gamma rays were measured continuously during the tests. It was shown that certain system perturbations could initiate and extend generation of excess power. In one test, there was an apparent increase in the neutron count rate that was also coincident with system perturbations. 4 refs., 6 figs

  17. Combined electrolysis and catalytic exchange (CECE) technology - an economical alternative for heavy water upgraders using water distillation

    International Nuclear Information System (INIS)

    Ryland, D.K.; Sadhankar, R.R.

    2003-01-01

    Heavy water upgrading is a unique and crucial part of a CANDU power station. Water distillation (DW) systems are used for heavy water upgrading in all CANDU stations. The DW upgrader is designed to take advantage of the difference in relative volatility (a measure of separation of isotopes) between H 2 O and D 2 O. However, the low relative volatility of the H 2 O/D 2 O system requires large number of stages (long columns) and large reflux ratios (large reboiler loads) - thus resulting in significant capital and operating costs. Atomic Energy of Canada Limited (AECL) developed the Combined Electrolysis and Catalytic Exchange (CECE) technology as an economical alternative to the DW system. CECE-based upgraders have been demonstrated in pilot scale facilities at AECL Chalk River Laboratories and in Hamilton, Ontario. This design is based on catalytic hydrogen isotope exchange between water and hydrogen gas. (author)

  18. Electrolysis apparatus and method

    International Nuclear Information System (INIS)

    1975-01-01

    A procedure in which electrolysis is combined with radiolysis to improve the reaction yield is proposed for the production of hydrogen and oxygen from water. An apparatus for this procedure is disclosed. High-energy electric pulses are applied between the anode and kathode of an electrolytical cell in such a way that short-wave electromagnetic radiation is generated at the same time

  19. Fiscal 1975 Sunshine Project research report. R and D on hydrogen production technology by high-temperature high- pressure water electrolysis; 1975 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-05-29

    This report details the research result in fiscal 1975. Part 1 'Outlines' includes the research target, the summary of fiscal 1974 research results, the summary of fiscal 1975 research results, and responsible researchers. Part 2 'Details of the research' includes the fiscal 1975 research results. Chapter 1 reports 'Study on constant-load high- temperature high-pressure (multi-electrode type) diaphragm water electrolysis tank' promoted by Mitsubishi Kakoki Kaisha. Chapter 2 reports 'Study on Teflon system diaphragm for high-temperature high-pressure water electrolysis tanks' promoted by Yuasa Battery Co. through Mitsubishi Kakoki Kaisha. Chapter 3 reports 'Study on variable-load high- temperature high-pressure diaphragm water electrolysis tank' promoted by Showa Denko K.K. Chapter 4 reports 'The first detailed design of the electrolysis tank for a small test plant' promoted by Hitachi Zosen Corp. through Showa Denko K.K. Chapter 5 reports 'Research on the applicability of water electrolysis systems to various fields' promoted by Mitsubishi Research Institute, Inc. through Showa Denko K.K. (NEDO)

  20. Design of a water electrolysis flight experiment

    Science.gov (United States)

    Lee, M. Gene; Grigger, David J.; Thompson, C. Dean; Cusick, Robert J.

    1993-01-01

    Supply of oxygen (O2) and hydrogen (H2) by electolyzing water in space will play an important role in meeting the National Aeronautics and Space Administration's (NASA's) needs and goals for future space missios. Both O2 and H2 are envisioned to be used in a variety of processes including crew life support, spacecraft propulsion, extravehicular activity, electrical power generation/storage as well as in scientific experiment and manufacturing processes. The Electrolysis Performance Improvement Concept Study (EPICS) flight experiment described herein is sponsored by NASA Headquarters as a part of the In-Space Technology Experiment Program (IN-STEP). The objective of the EPICS is to further contribute to the improvement of the SEF technology, specifially by demonstrating and validating the SFE electromechanical process in microgravity as well as investigating perrformance improvements projected possible in a microgravity environment. This paper defines the experiment objective and presents the results of the preliminary design of the EPICS. The experiment will include testing three subscale self-contained SFE units: one containing baseline components, and two units having variations in key component materials. Tests will be conducted at varying current and thermal condition.

  1. RES Hydrogen: efficient pressurised alkaline electrolysers

    DEFF Research Database (Denmark)

    Bowen, Jacob R.; Bentzen, Janet Jonna; Jørgensen, Peter Stanley

    The RESelyser project addresses issues associated with coupling alkaline electrolysis to renewable energy sources such as electrode stability and gas purity by implementing improved electrodes and a new separator membrane concept. The project aims to improve performance, operation pressure...... and reduce system cost. The project supports DTU Energy's activities on electrodes within the larger FCH-JU project. The overall project demonstrated: improved electrode efficiency also during cyclic operation, safe gas purity at a system pressure of 30 bar, 10 kW stack operation and estimated system costs...

  2. Hydrogen Production from Nuclear Energy via High Temperature Electrolysis

    International Nuclear Information System (INIS)

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

    2006-01-01

    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

  3. Suitable alkaline for graphene peeling grown on metallic catalysts using chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Karamat, S., E-mail: shumailakaramat@gmail.com [Department of Physics, Middle East Technical University, Ankara 06800 (Turkey); COMSATS Institute of Information Technology, Islamabad 54000 (Pakistan); Sonuşen, S. [Sabancı Üniversitesi (SUNUM), İstanbul 34956 (Turkey); Çelik, Ü. [Nanomagnetics Instruments, Ankara (Turkey); Uysallı, Y. [Department of Physics, Middle East Technical University, Ankara 06800 (Turkey); Oral, A., E-mail: orahmet@metu.edu.tr [Department of Physics, Middle East Technical University, Ankara 06800 (Turkey)

    2016-04-15

    Graphical abstract: - Highlights: • Graphene layers were grown on Pt and Cu foil via ambient pressure chemical vapor deposition method and for the delicate removal of graphene from metal catalysts, electrolysis method was used by using different alkaline (sodium hydroxide, potassium hydroxide, lithium hydroxide and barium hydroxide). • The delamination speed of PMMA/graphene stack was higher during the KOH and LiOH electrolysis as compare to NaOH and Ba(OH){sub 2}. Ba(OH){sub 2} is not advisable because of the residues left on the graphene surface which would further trapped in between graphene and SiO{sub 2}/Si surface after transfer. The average peeling time in case of Pt electrode is ∼6 min for KOH and LiOH and ∼15 min for NaOH and Ba(OH){sub 2}. • Electrolysis method also works for the Cu catalyst. The peeling of graphene was faster in the case of Cu foil due to small size of bubbles which moves faster between the stack and the electrode surface. The average peeling time was ∼3–5 min. • XPS analysis clearly showed that the Pt substrates can be re-used again. Graphene layer was transferred to SiO{sub 2}/Si substrates and to the flexible substrate by using the same peeling method. - Abstract: In chemical vapor deposition, the higher growth temperature roughens the surface of the metal catalyst and a delicate method is necessary for the transfer of graphene from metal catalyst to the desired substrates. In this work, we grow graphene on Pt and Cu foil via ambient pressure chemical vapor deposition (AP-CVD) method and further alkaline water electrolysis was used to peel off graphene from the metallic catalyst. We used different electrolytes i.e., sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH) and barium hydroxide Ba(OH){sub 2} for electrolysis, hydrogen bubbles evolved at the Pt cathode (graphene/Pt/PMMA stack) and as a result graphene layer peeled off from the substrate without damage. The peeling time for KOH and Li

  4. Suitable alkaline for graphene peeling grown on metallic catalysts using chemical vapor deposition

    International Nuclear Information System (INIS)

    Karamat, S.; Sonuşen, S.; Çelik, Ü.; Uysallı, Y.; Oral, A.

    2016-01-01

    Graphical abstract: - Highlights: • Graphene layers were grown on Pt and Cu foil via ambient pressure chemical vapor deposition method and for the delicate removal of graphene from metal catalysts, electrolysis method was used by using different alkaline (sodium hydroxide, potassium hydroxide, lithium hydroxide and barium hydroxide). • The delamination speed of PMMA/graphene stack was higher during the KOH and LiOH electrolysis as compare to NaOH and Ba(OH)_2. Ba(OH)_2 is not advisable because of the residues left on the graphene surface which would further trapped in between graphene and SiO_2/Si surface after transfer. The average peeling time in case of Pt electrode is ∼6 min for KOH and LiOH and ∼15 min for NaOH and Ba(OH)_2. • Electrolysis method also works for the Cu catalyst. The peeling of graphene was faster in the case of Cu foil due to small size of bubbles which moves faster between the stack and the electrode surface. The average peeling time was ∼3–5 min. • XPS analysis clearly showed that the Pt substrates can be re-used again. Graphene layer was transferred to SiO_2/Si substrates and to the flexible substrate by using the same peeling method. - Abstract: In chemical vapor deposition, the higher growth temperature roughens the surface of the metal catalyst and a delicate method is necessary for the transfer of graphene from metal catalyst to the desired substrates. In this work, we grow graphene on Pt and Cu foil via ambient pressure chemical vapor deposition (AP-CVD) method and further alkaline water electrolysis was used to peel off graphene from the metallic catalyst. We used different electrolytes i.e., sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH) and barium hydroxide Ba(OH)_2 for electrolysis, hydrogen bubbles evolved at the Pt cathode (graphene/Pt/PMMA stack) and as a result graphene layer peeled off from the substrate without damage. The peeling time for KOH and LiOH was ∼6 min and for NaOH and

  5. Experimental and thermodynamic study on the performance of water electrolysis by solid oxide electrolyzer cells with Nb-doped Co-based perovskite anode

    International Nuclear Information System (INIS)

    Pan, Zehua; Liu, Qinglin; Zhang, Lan; Zhou, Juan; Zhang, Caizhi; Chan, Siew Hwa

    2017-01-01

    Highlights: • BCFN was applied on traditional YSZ electrolyte with GDC interlayer. • Dense YSZ-GDC bilayer electrolyte was obtained by co-sintering at 1300 °C. • Area specific resistance of full cell is 0.195 Ω cm"2 at 800 °C with 60% water vapor. • Cell voltage is 1.13 V at 1 A cm"−"2 at 800 °C with feedstock of 60% H_2O-40% H_2. • The electricity to hydrogen efficiency is 73% with generation rate of 4180 L h"−"1 m"−"2. - Abstract: In this work, Solid Oxide Electrolyzer Cell (SOEC) based on Ba_0_._9Co_0_._7Fe_0_._2Nb_0_._1O_3_-_δ (BCFN) air electrode and YSZ-GDC bilayer electrolyte was systematically investigated and the efficiency of high-temperature water electrolysis by such a cell was analyzed. Firstly, chemical compatibility test between BCFN and YSZ showed that BaZrO_3 formed after heat treatment at 1000 °C for 5 h, which adversely influenced the performance of BCFN dramatically. A fully dense GDC interlayer was thus developed by co-sintering GDC layer, with addition of 0.5 at.% Fe_2O_3, with YSZ electrolyte at only 1300 °C. The as-prepared fuel electrode-supported eletrolyzer cell consisting of Ni-YSZ fuel electrode, YSZ-GDC bilayer electrolyte and BCFN air electrode was evaluated for water electrolysis. Specifically, at 800 °C using a feedstock of 60% H_2O-40% H_2, the cell showed total area specific resistance of 0.195 Ω cm"2 and the cell voltage was 1.13 V with an electrolysis current of 1 A cm"−"2. After short-term stability test for 120 h with 1 A cm"−"2 electrolysis current at 800 °C, the cell showed no microstructural changes as observed by scanning electron microscopy. At last, a high-temperature water electrolysis system based on the cell studied was proposed and the system analysis shows that the overall electricity to hydrogen efficiency can reach 73% based on lower heating value of hydrogen, with a hydrogen generation rate of 4180 L h"−"1 m"−"2.

  6. Space water electrolysis: Space Station through advance missions

    Science.gov (United States)

    Davenport, Ronald J.; Schubert, Franz H.; Grigger, David J.

    1991-01-01

    Static Feed Electrolyzer (SFE) technology can satisfy the need for oxygen (O2) and Hydrogen (H2) in the Space Station Freedom and future advanced missions. The efficiency with which the SFE technology can be used to generate O2 and H2 is one of its major advantages. In fact, the SFE is baselined for the Oxygen Generation Assembly within the Space Station Freedom's Environmental Control and Life Support System (ECLSS). In the conventional SFE process an alkaline electrolyte is contained within the matrix and is sandwiched between two porous electrodes. The electrodes and matrix make up a unitized cell core. The electrolyte provides the necessary path for the transport of water and ions between the electrodes, and forms a barrier to the diffusion of O2 and H2. A hydrophobic, microporous membrane permits water vapor to diffuse from the feed water to the cell core. This membrane separates the liquid feed water from the product H2, and, therefore, avoids direct contact of the electrodes by the feed water. The feed water is also circulated through an external heat exchanger to control the temperature of the cell.

  7. Treatment of tanneries waste water by ultrasound assisted electrolysis process

    International Nuclear Information System (INIS)

    Farooq, R.; Ahmed, Z.; Gilani, M. A.; Durrani, M.; Mahmood, Q.; Shaukat, S. F.; Choima, N.

    2013-01-01

    The leather industry is a major producer of wastewater and solid waste containing potential water and soil contaminants. Considering the large amount and variety of chemical agents used in skin processing, the wastewaters generated by tanneries are very complex. Therefore, the development of treatment methods for these effluents is extremely necessary. In this work the electrochemical treatment of a tannery wastewater by ultrasound assisted electrochemical process, using stainless steel and lead cathode and titanium anodes was studied. Effect of ultrasound irradiation at various ultrasonic intensities 0, 40, 60 and 80% on electrochemical removal of chromium was investigated. Experiments were conducted at two pH conditions of pH 3 and 9. Significant removal of chromium was found at pH 3 and it was also noticed that by increasing ultrasonic intensities, percentage removal of chromium and sulfate also increases. The optimum removal of chromium and sulfate ions was observed at 80% ultrasonic intensity. The technique of electrolysis assisted with ultrasonic waves can be further improved and can be the future waste water treatment process for industries. (author)

  8. Fiscal 1975 Sunshine Project research report. R and D on hydrogen production technology by high-temperature high- pressure water electrolysis; 1975 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-05-29

    This report details the research result in fiscal 1975. Part 1 'Outlines' includes the research target, the summary of fiscal 1974 research results, the summary of fiscal 1975 research results, and responsible researchers. Part 2 'Details of the research' includes the fiscal 1975 research results. Chapter 1 reports 'Study on constant-load high- temperature high-pressure (multi-electrode type) diaphragm water electrolysis tank' promoted by Mitsubishi Kakoki Kaisha. Chapter 2 reports 'Study on Teflon system diaphragm for high-temperature high-pressure water electrolysis tanks' promoted by Yuasa Battery Co. through Mitsubishi Kakoki Kaisha. Chapter 3 reports 'Study on variable-load high- temperature high-pressure diaphragm water electrolysis tank' promoted by Showa Denko K.K. Chapter 4 reports 'The first detailed design of the electrolysis tank for a small test plant' promoted by Hitachi Zosen Corp. through Showa Denko K.K. Chapter 5 reports 'Research on the applicability of water electrolysis systems to various fields' promoted by Mitsubishi Research Institute, Inc. through Showa Denko K.K. (NEDO)

  9. High temperature electrolysis for hydrogen production using nuclear energy

    International Nuclear Information System (INIS)

    Herring, J. Stephen; O'brien, James E.; Stoots, Carl M.; Hawkes, Grant L.; Hartvigsen, Joseph J.

    2005-01-01

    High-temperature nuclear reactors have the potential for substantially increasing the efficiency of hydrogen production from water splitting, which can be accomplished via high-temperature electrolysis (HTE) or thermochemical processes. In order to achieve competitive efficiencies, both processes require high-temperature operation (∼850degC). High-temperature electrolytic water splitting supported by nuclear process heat and electricity has the potential to produce hydrogen with overall system efficiencies of 45 to 55%. At the Idaho National Laboratory, we are developing solid-oxide cells to operate in the steam electrolysis mode. The research program includes both experimental and modeling activities. Experimental results were obtained from ten-cell and 22-cell planar electrolysis stacks, fabricated by Ceramatec, Inc. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (∼200 μm thick, 64 cm 2 active area), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions, gas glow rates, and current densities. Hydrogen production rates greater than 100 normal liters per hour for 196 hours have been demonstrated. In order to evaluate the performance of large-scale HTE operations, we have developed single-cell models, based on FLUENT, and a process model, using the systems-analysis code HYSYS. (author)

  10. Overcoming the Instability of Nanoparticle-Based Catalyst Films in Alkaline Electrolyzers by using Self-Assembling and Self-Healing Films.

    Science.gov (United States)

    Barwe, Stefan; Masa, Justus; Andronescu, Corina; Mei, Bastian; Schuhmann, Wolfgang; Ventosa, Edgar

    2017-07-10

    Engineering stable electrodes using highly active catalyst nanopowders for electrochemical water splitting remains a challenge. We report an innovative and general approach for attaining highly stable catalyst films with self-healing capability based on the in situ self-assembly of catalyst particles during electrolysis. The catalyst particles are added to the electrolyte forming a suspension that is pumped through the electrolyzer. Particles with negatively charged surfaces stick onto the anode, while particles with positively charged surfaces stick to the cathode. The self-assembled catalyst films have self-healing properties as long as sufficient catalyst particles are present in the electrolyte. The proof-of-concept was demonstrated in a non-zero gap alkaline electrolyzer using NiFe-LDH and Ni x B catalyst nanopowders for anode and cathode, respectively. Steady cell voltages were maintained for at least three weeks during continuous electrolysis at 50-100 mA cm -2 . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Electrochemically reduced water exerts superior reactive oxygen species scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water.

    Directory of Open Access Journals (Sweden)

    Takeki Hamasaki

    Full Text Available Electrochemically reduced water (ERW is produced near a cathode during electrolysis and exhibits an alkaline pH, contains richly dissolved hydrogen, and contains a small amount of platinum nanoparticles. ERW has reactive oxygen species (ROS-scavenging activity and recent studies demonstrated that hydrogen-dissolved water exhibits ROS-scavenging activity. Thus, the antioxidative capacity of ERW is postulated to be dependent on the presence of hydrogen levels; however, there is no report verifying the role of dissolved hydrogen in ERW. In this report, we clarify whether the responsive factor for antioxidative activity in ERW is dissolved hydrogen. The intracellular ROS scavenging activity of ERW and hydrogen-dissolved water was tested by both fluorescent stain method and immuno spin trapping assay. We confirm that ERW possessed electrolysis intensity-dependent intracellular ROS-scavenging activity, and ERW exerts significantly superior ROS-scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water. ERW retained its ROS-scavenging activity after removal of dissolved hydrogen, but lost its activity when autoclaved. An oxygen radical absorbance capacity assay, the 2,2-diphenyl-1-picrylhydrazyl assay and chemiluminescence assay could not detect radical-scavenging activity in both ERW and hydrogen-dissolved water. These results indicate that ERW contains electrolysis-dependent hydrogen and an additional antioxidative factor predicted to be platinum nanoparticles.

  12. A comparative economic assessment of hydrogen production from coke oven gas, water electrolysis and steam reforming of natural gas

    International Nuclear Information System (INIS)

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

    2003-01-01

    This paper presents the comparative economics of producing hydrogen for the hydrogen economy by recovering it from waste gases from the steel industry, by water electrolysis and by conventional steam reforming of natural gas. Steel makers produce coke for their blast furnace operation by baking coal at high temperature in a reduced environment in their coke ovens. These ovens produce a coke oven gas from the volatiles in the coal. The gas, containing up to 60% hydrogen, is commonly used for its heating value with some of it being flared. The feasibility of recovering this hydrogen from the gas will be presented. A comparison of this opportunity with that of hydrogen from water electrolysis using low cost off-peak electricity from nuclear energy will be made. The impact of higher daily average electricity rate in Ontario will be discussed. The benefits of these opportunities compared with those from conventional steam reforming of natural gas will be highlighted. (author)

  13. Hydrogen production through small capacity water electrolysis systems; Production d'hydrogene par electrolyse de l'eau. Application a des systemes de petite capacite

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Ph. [TotalFinaElf, la Defense 6, 92 - Courbevoie (France)

    2002-01-01

    Less than 1 % of the world's hydrogen is produced by electrolysis of water, in large plants mainly in connection with hydropower. For users requiring extremely pure hydrogen, electrolysis can be a convenient mean of obtaining the required hydrogen quality, where cheap electricity is available. This paper aims at presenting the latest technical developments of small capacity electrolyzers, that could fuel hydrogen cells or internal combustion engines. (author)

  14. FY 1974 report on the results of the Sunshine Project. R and D of hydrogen production technology by the high-temperature/high-pressure water electrolysis method (outline); 1974 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho. Gaiyo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1985-05-30

    As the R and D of hydrogen production technology by the high-temperature/high pressure water electrolysis method, this paper outlined (1) the concept design and the investigational research on the constant load type high-temperature/high-pressure (multi-pole type) diaphragm water electrolysis tank (in charge of Mitsubishi Kakoki Kaisha, Ltd.); (2) the concept design and the investigational research on the load variation type high-temperature/high-pressure diaphragm water electrolysis equipment (in charge of Showa Denko K.K. and Hitachi Zosen Corp.); (3) the investigational research on the role of water electrolysis in various primary energy sources and the evaluation (in charge of Mitsubishi Research Institute Inc.). In (1), the concept design of a small test plant was made, and the detailed design and test plan on the material test equipment were drew up. In (2), Showa Denko K.K. is running the water electrolysis plant. As a result of studying the electric power unit and operational conditions of hydrogen production, it was concluded that high-temperature/high-pressure operation should be tried for making the water electrolysis tank highly efficient. Hitachi Zosen Corp. made the study of the multi-pole type pressurized filter system high-pressure water electrolysis equipment which was developed for submarine and the design of the bubble behavior observing tank and material test tank for the concept design of load variation type test plant. (NEDO)

  15. Transient nanobubbles in short-time electrolysis

    NARCIS (Netherlands)

    Svetovoy, Vitaly; Sanders, Remco G.P.; Elwenspoek, Michael Curt

    2013-01-01

    Water electrolysis in a microsystem is observed and analyzed on a short-time scale of ∼10 μs. The very unusual properties of the process are stressed. An extremely high current density is observed because the process is not limited by the diffusion of electroactive species. The high current is

  16. Using algae and submerged calcifying water flora for treating neutral to alkaline uranium-contaminated water

    International Nuclear Information System (INIS)

    Dienemann, C.; Dienemann, H.; Stolz, L.; Dudel, E.G.

    2005-01-01

    Elimination of uranium from neutral to alkaline water is a complex technical process involving decarbonation, usually with HCl, followed by uranium removal by adding alkaline substances. In passive water treatment systems, uranium species - which often consist of a combination of oxidation and reduction stages - are not sufficiently considered. Algae and submerged water plants provide a natural alternative. They remove carbon dioxides or hydrogen carbonate, depending on the species, thus reducting the concentrations of the carbonate species. As the uranium species in alkaline water are coupled on the one hand to the carbonate species and on the other hand on the earth alkali metals, algae and submerged calcifying water plants are an excellent preliminary stage as a supplement to conventional passive water treatment systems. For a quantification of this effect, laboratory experiments were made with Cladophara spec. and with uranium concentrations of 100, 250 and 1000 μg U.L -1 at pH 8.3. The pH was adjusted with NaOH resp. Na2CO3 resulting in different uranium species. After 20 minutes, there was a difference in self-absorption between the different species (higher uranium concentration for NaOH than for Na2CO3), which was no longer observeable after 24 h. On the basis of data on the biomass development of macrophytic algae (Cladophora and Microspora) in a flowing river section near Neuensalz/Vogtland district, the final dimensions of a purification stage of this type are assessed. (orig.)

  17. Transportation cost of nuclear off-peak power for hydrogen production based on water electrolysis

    International Nuclear Information System (INIS)

    Shimizu, Saburo; Ueno, Shuichi

    2004-01-01

    The paper describes transportation cost of the nuclear off-peak power for a hydrogen production based on water electrolysis in Japan. The power could be obtainable by substituting hydropower and/or fossil fueled power supplying peak and middle demands with nuclear power. The transportation cost of the off-peak power was evaluated to be 1.42 yen/kWh when an electrolyser receives the off-peak power from a 6kV distribution wire. Marked reduction of the cost was caused by the increase of the capacity factor. (author)

  18. The development of a non-cryogenic nitrogen/oxygen supply system. [using hydrazine/water electrolysis

    Science.gov (United States)

    Greenough, B. M.; Mahan, R. E.

    1974-01-01

    A hydrazine/water electrolysis process system module design was fabricated and tested to demonstrate component and module performance. This module is capable of providing both the metabolic oxygen for crew needs and the oxygen and nitrogen for spacecraft leak makeup. The component designs evolved through previous R and D efforts, and were fabricated and tested individually and then were assembled into a complete module which was successfully tested for 1000 hours to demonstrate integration of the individual components. A survey was made of hydrazine sensor technology and a cell math model was derived.

  19. Comparative thermoeconomic analysis of hydrogen production by water electrolysis and by ethanol steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Riveros-Godoy, Gustavo; Chavez-Rodriguez, Mauro; Cavaliero, Carla [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Mechanical Engineering School], Email: garg@fem.unicamp.br

    2010-07-01

    Hydrogen is the focus of this work that evaluates in comparative form through thermo economic analysis two hydrogen production processes: water electrolysis and ethanol steam reforming. Even though technical-economical barriers still exist for the development of an economy based on hydrogen, these difficulties are opportunities for the appearance of new business of goods and services, diversification of the energy mix, focus of research activities, development and support to provide sustainability to the new economy. Exergy and rational efficiency concept are used to make a comparison between both processes. (author)

  20. Combined electrolysis catalytic exchange (CECE) process for hydrogen isotope separation

    International Nuclear Information System (INIS)

    Hammerli, M.; Stevens, W.H.; Butler, J.P.

    1978-01-01

    Hydrogen isotopes can be separated efficiently by a process which combines an electrolysis cell with a trickle bed column packed with a hydrophobic platinum catalyst. The column effects isotopic exchange between countercurrent streams of electrolytic hydrogen and liquid water while the electrolysis cell contributes to isotope separation by virtue of the kinetic isotope effect inherent in the hydrogen evolution reaction. The main features of the CECE process for heavy water production are presented as well as a discussion of the inherent positive synergistic effects, and other advantages and disadvantages of the process. Several potential applications of the process in the nuclear power industry are discussed. 3 figures, 2 tables

  1. Steam electrolysis by solid oxide electrolysis cells (SOECs) with proton-conducting oxides

    KAUST Repository

    Bi, Lei; Boulfrad, Samir; Traversa, Enrico

    2014-01-01

    Energy crisis and environmental problems caused by the conventional combustion of fossil fuels boost the development of renewable and sustainable energies. H2 is regarded as a clean fuel for many applications and it also serves as an energy carrier for many renewable energy sources, such as solar and wind power. Among all the technologies for H2 production, steam electrolysis by solid oxide electrolysis cells (SOECs) has attracted much attention due to its high efficiency and low environmental impact, provided that the needed electrical power is generated from renewable sources. However, the deployment of SOECs based on conventional oxygen-ion conductors is limited by several issues, such as high operating temperature, hydrogen purification from water, and electrode stability. To avoid these problems, proton-conducting oxides are proposed as electrolyte materials for SOECs. This review paper provides a broad overview of the research progresses made for proton-conducting SOECs, summarizing the past work and finding the problems for the development of proton-conducting SOECs, as well as pointing out potential development directions.

  2. Steam electrolysis by solid oxide electrolysis cells (SOECs) with proton-conducting oxides.

    Science.gov (United States)

    Bi, Lei; Boulfrad, Samir; Traversa, Enrico

    2014-12-21

    Energy crisis and environmental problems caused by the conventional combustion of fossil fuels boost the development of renewable and sustainable energies. H2 is regarded as a clean fuel for many applications and it also serves as an energy carrier for many renewable energy sources, such as solar and wind power. Among all the technologies for H2 production, steam electrolysis by solid oxide electrolysis cells (SOECs) has attracted much attention due to its high efficiency and low environmental impact, provided that the needed electrical power is generated from renewable sources. However, the deployment of SOECs based on conventional oxygen-ion conductors is limited by several issues, such as high operating temperature, hydrogen purification from water, and electrode stability. To avoid these problems, proton-conducting oxides are proposed as electrolyte materials for SOECs. This review paper provides a broad overview of the research progresses made for proton-conducting SOECs, summarizing the past work and finding the problems for the development of proton-conducting SOECs, as well as pointing out potential development directions.

  3. The occurrence of perchlorate during drinking water electrolysis using BDD anodes

    International Nuclear Information System (INIS)

    Bergmann, M.E. Henry; Rollin, Johanna; Iourtchouk, Tatiana

    2009-01-01

    Electrochemical studies were carried out to estimate the risks of perchlorate formation in drinking water disinfected by direct electrolysis. Boron Doped Diamond (BDD) anodes were used in laboratory and commercially available cells at 20 deg. C. The current density was changed between 50 and 500 A m -2 . For comparison, other anode materials such as platinum and mixed oxide were also tested. It was found that BDD anodes have a thousandfold higher perchlorate formation potential compared with the other electrode materials that were tested. In long-term discontinuous experiments all the chloride finally reacted to form perchlorate. The same result was obtained when probable oxychlorine intermediates (OCl - , ClO 2 - , ClO 3 - ) were electrolysed in synthetic waters in the ppm range of concentrations. The tendency to form perchlorate was confirmed when the flow rate of drinking water was varied between 100 and 300 L h -1 and the temperature increased to 30 deg. C. In a continuous flow mode of operation a higher chloride concentration in the water resulted in a lower perchlorate formation. This can be explained by reaction competition of species near and on the anode surface for experiments both with synthetic and local drinking waters. It is concluded that the use of electrodes producing highly reactive species must be more carefully controlled in hygienically and environmentally oriented applications

  4. New Electrolytes for CO2 Electrolysis Cells

    DEFF Research Database (Denmark)

    Mollerup, Pia Lolk

    The aim of this thesis has been to explore the potential of aqueous immobilized K2CO3 as a possible electrolyte for co-electrolysis of CO2 and water at approx. 200 °C. This has been done by exploring the properties of pure K2CO3 (aq) and immobilized K2CO3 (aq) as well as the properties...... was observed for 10 wt% K2CO3 immobilized in TiO2 when changing the atmosphere from N2 to CO2. K2CO3 (aq) immobilized in TiO2 shows good promise as a potential electrolyte for co-electrolysis of CO2 and water at 200 °C....... in a 10 wt% K2CO3 (aq) solution are K+ and HCO3-. The water partial pressure as well as the amount of water vapour at different temperatures, pressures and K2CO3 (aq) concentrations was also calculated using FactSage. K2CO3 (aq) was immobilized in both SrTiO3 and TiO2. It was found that a loss...

  5. Treatment of oilfield produced water by anaerobic process coupled with micro-electrolysis.

    Science.gov (United States)

    Li, Gang; Guo, Shuhai; Li, Fengmei

    2010-01-01

    Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis (ME), focusing on changes in chemical oxygen demand (COD) and biodegradability. Results showed that COD exhibited an abnormal change in the single anaerobic system in which it increased within the first 168 hr, but then decreased to 222 mg/L after 360 hr. The biological oxygen demand (five-day) (BODs)/COD ratio of the water increased from 0.05 to 0.15. Hydrocarbons in the wastewater, such as pectin, degraded to small molecules during the hydrolytic acidification process. Comparatively, the effect of ME was also investigated. The COD underwent a slight decrease and the BOD5/COD ratio of the water improved from 0.05 to 0.17 after ME. Removal of COD was 38.3% under the idealized ME conditions (pH 6.0), using iron and active carbon (80 and 40 g/L, respectively). Coupling the anaerobic process with ME accelerated the COD removal ratio (average removal was 53.3%). Gas chromatography/mass spectrometry was used to analyze organic species conversion. This integrated system appeared to be a useful option for the treatment of water produced in oilfields.

  6. Proton hopping mechanism in solid polymer electrolysis demonstrated by tritium enrichment and electro-osmotic drag measurement

    International Nuclear Information System (INIS)

    Saito, Masaaki; Imaizumi, Hiroshi; Kato, Norio; Ishii, Yoshiyuki; Saito, Keiichi

    2010-01-01

    Anomalies in tritium enrichment cannot be explained only by isotopic effects in water electrolysis. The temperature dependence of the enrichment factor had been reported as increasing with 1/T. However, the increase was difficult to explain on the basis of kinetics. In this study, electro-osmotic drag (EOD, number of water molecule accompanied by a proton) and tritium enrichment ratio were investigated using light water (H 2 O) and heavy water (D 2 O) by solid polymer electrolysis. The EOD decreased and tritium enrichment ratio increased at low temperature for H 2 O. Electrolysis showed no temperature dependence for D 2 O. It was revealed that proton hopping by a hydrogen bond network of water molecules (the Grotthuss mechanism) affects the temperature dependence of EOD and tritium enrichment in the case of H 2 O. (author)

  7. Static feed water electrolysis subsystem development

    Science.gov (United States)

    Schubert, Franz H. (Inventor); Grigger, David J. (Inventor)

    1991-01-01

    This disclosure is directed to an electrolysis cell forming hydrogen and oxygen at spaced terminals. The anode terminal is porous and able to form oxygen within the cell and permit escape of the gaseous oxygen through the anode and out through a flow line in the presence of backpressure. Hydrogen is liberated in the cell at the opposing solid metal cathode which is permeable to hydrogen but not oxygen so that the migratory hydrogen formed in the cell is able to escape from the cell. The cell is maintained at an elevated pressure so that oxygen liberated by the cell is delivered at elevated pressure without pumping to raise the pressure of the oxygen.

  8. Redistribution of wastewater alkalinity with a microbial fuel cell to support nitrification of reject water.

    Science.gov (United States)

    Modin, Oskar; Fukushi, Kensuke; Rabaey, Korneel; Rozendal, René A; Yamamoto, Kazuo

    2011-04-01

    In wastewater treatment plants, the reject water from the sludge treatment processes typically contains high ammonium concentrations, which constitute a significant internal nitrogen load in the plant. Often, a separate nitrification reactor is used to treat the reject water before it is fed back into the plant. The nitrification reaction consumes alkalinity, which has to be replenished by dosing e.g. NaOH or Ca(OH)(2). In this study, we investigated the use of a two-compartment microbial fuel cell (MFC) to redistribute alkalinity from influent wastewater to support nitrification of reject water. In an MFC, alkalinity is consumed in the anode compartment and produced in the cathode compartment. We use this phenomenon and the fact that the influent wastewater flow is many times larger than the reject water flow to transfer alkalinity from the influent wastewater to the reject water. In a laboratory-scale system, ammonium oxidation of synthetic reject water passed through the cathode chamber of an MFC, increased from 73.8 ± 8.9 mgN/L under open-circuit conditions to 160.1 ± 4.8 mgN/L when a current of 1.96 ± 0.37 mA (15.1 mA/L total MFC liquid volume) was flowing through the MFC. These results demonstrated the positive effect of an MFC on ammonium oxidation of alkalinity-limited reject water. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Impact of low-concentrated acidic electrolysed water obtained by membrane electrolysis on the decontamination of meat microbiota

    Directory of Open Access Journals (Sweden)

    Brychcy Ewa

    2015-09-01

    Full Text Available The influence of acidic electrolysed water (AEW treatment on inactivation of pure bacterial cultures inoculated onto the surface of agarised media and surface microbiota of pork meat were examined. Low-concentrated AEW (low concentration of sodium chloride and low current electrolysis was generated by electrolysis (5 or 10 min of 0.001% or 0.01% NaCl solution. The number of viable microorganisms was determined using a plate count method. The effect of AEW on bacterial cell morphology were investigated using scanning electron microscopy (SEM. After treatment with AEW, a significant, about 3.00 log reduction of Pseudomonas fluorescens, Yersinia enterocolitica, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes, and Micrococcus luteus populations was observed. In the AEW treatment of pork, the highest reduction of total number of microorganisms (2.1 log reduction, yeast and moulds (2.5-2.6 log reduction, and psychrotrophs (more than 1 log reduction was observed after spraying with 0.001% NaCl subjected to 10 min electrolysis. SEM revealed disruption and lysis of E. coli and S. aureus cells treated with AEW, suggesting a bactericidal effect. Higher available chlorine concentration (0.37-8.45 mg/L, redox potential (863.1-1049.8 mV, and lower pH (2.73-3.70 had an influence on the shape of bacteria and the number of breaks in the bacterial membrane.

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

    International Nuclear Information System (INIS)

    Ueno, Syuichi; Sato, Takao; Ishikawa, Nobuhide

    1997-01-01

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

  11. Perovskites As Electrocatalysts for Alkaline Water Electrolysis

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey Valerievich; De La Osa Puebla, Ana Raquel; Jensen, Jens Oluf

    2014-01-01

    such as X-ray diffraction, electrical conductivity, scanning electron microscopy (SEM), energy dispersive microscopy (EDX) and rotating disk electrode. The perovskites tested in this work were both produced by a ball-milling technique and by an auto-combustion synthesis, which appeared to be a fast...... and robust method for synthesis of perovskites with various chemical compositions1. The electrochemical performance of the materials was tested through pellet pressing of the perovskite powders. This involved in some case a time consuming preparation process. Furthermore the technique should show...... the adequate reproducibility.2 In this work we show the development of the method, which was further used to compare the activity of various electrocatalysts (Figures 1,2). The electrocatalytic activity of all prepared perovskites was tested in 1M KOH at 80 °C, using an ink consisting of potassium exchanged...

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

    International Nuclear Information System (INIS)

    Ferrero, Domenico; Santarelli, Massimo

    2017-01-01

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

  13. Rapid changes in water hardness and alkalinity: Calcite formation is lethal to Daphnia magna.

    Science.gov (United States)

    Bogart, Sarah J; Woodman, Samuel; Steinkey, Dylan; Meays, Cindy; Pyle, Greg G

    2016-07-15

    There is growing concern that freshwater ecosystems may be negatively affected by ever-increasing anthropogenic inputs of extremely hard, highly alkaline effluent containing large quantities of Ca(2+), Mg(2+), CO3(2-), and HCO3(-) ions. In this study, the toxicity of rapid and extreme shifts in water hardness (38-600mg/L as CaCO3) and alkalinity (30-420mg/L as CaCO3) to Daphnia magna was tested, both independently and in combination. Within these ranges, where no precipitation event occurred, shifts in water hardness and/or alkalinity were not toxic to D. magna. In contrast, 98-100% of D. magna died within 96h after exposure to 600mg/L as CaCO3 water hardness and 420mg/L as CaCO3 alkalinity (LT50 of 60h with a 95% CI of 54.2-66.0h). In this treatment, a CaCO3 (calcite) precipitate formed in the water column which was ingested by and thoroughly coated the D. magna. Calcite collected from a mining impacted stream contained embedded organisms, suggesting field streams may also experience similar conditions and possibly increased mortality as observed in the lab tests. Although further investigation is required to determine the exact fate of aquatic organisms exposed to rapid calcite precipitation in the field, we caution that negative effects may occur more quickly or at lower concentrations of water hardness and alkalinity in which we observed effects in D. magna, because some species, such as aquatic insects, are more sensitive than cladocerans to changes in ionic strength. Our results provide evidence that both calcite precipitation and the major ion balance of waters should be managed in industrially affected ecosystems and we support the development of a hardness+alkalinity guideline for the protection of aquatic life. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  14. Suitable alkaline for graphene peeling grown on metallic catalysts using chemical vapor deposition

    Science.gov (United States)

    Karamat, S.; Sonuşen, S.; Çelik, Ü.; Uysallı, Y.; Oral, A.

    2016-04-01

    In chemical vapor deposition, the higher growth temperature roughens the surface of the metal catalyst and a delicate method is necessary for the transfer of graphene from metal catalyst to the desired substrates. In this work, we grow graphene on Pt and Cu foil via ambient pressure chemical vapor deposition (AP-CVD) method and further alkaline water electrolysis was used to peel off graphene from the metallic catalyst. We used different electrolytes i.e., sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH) and barium hydroxide Ba(OH)2 for electrolysis, hydrogen bubbles evolved at the Pt cathode (graphene/Pt/PMMA stack) and as a result graphene layer peeled off from the substrate without damage. The peeling time for KOH and LiOH was ∼6 min and for NaOH and Ba(OH)2 it was ∼15 min. KOH and LiOH peeled off graphene very efficiently as compared to NaOH and Ba(OH)2 from the Pt electrode. In case of copper, the peeling time is ∼3-5 min. Different characterizations like optical microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were done to analyze the as grown and transferred graphene samples.

  15. Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System

    Science.gov (United States)

    Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

    2017-03-01

    A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system was stocked by 42 GIFT tilapia (Oreochromis niloticus) fish with the rearing density of 13 kg/m3. During the experiments, the TAN concentration remained below 1.0 mg/L. The nitrite concentration was lower than 0.2 mg/L and the nitrate concentration had increased continuously to 12.79 mg/L at the end. Furthermore, the concentration of residual chlorine in culture ponds remained below 0.3 mg/L, ORP maintained slight fluctuations in the range of 190~240 mV, and pH of the water showed the downtrend. Tilapia weight increased constantly to 339.3 ± 10 g. For disinfection, the active chlorine generated by electrochemical treatment caused Escherichia coli inactivation. Enzyme activity assay indicated that the activity of glutamate dehydrogenase, carbonic anhydrase and glutamic pyruvic transaminase increased within the normal range. The preliminary feasibility was verified by using this physico-chemical technology in the RAS.

  16. Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System.

    Science.gov (United States)

    Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

    2017-03-27

    A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system was stocked by 42 GIFT tilapia (Oreochromis niloticus) fish with the rearing density of 13 kg/m 3 . During the experiments, the TAN concentration remained below 1.0 mg/L. The nitrite concentration was lower than 0.2 mg/L and the nitrate concentration had increased continuously to 12.79 mg/L at the end. Furthermore, the concentration of residual chlorine in culture ponds remained below 0.3 mg/L, ORP maintained slight fluctuations in the range of 190~240 mV, and pH of the water showed the downtrend. Tilapia weight increased constantly to 339.3 ± 10 g. For disinfection, the active chlorine generated by electrochemical treatment caused Escherichia coli inactivation. Enzyme activity assay indicated that the activity of glutamate dehydrogenase, carbonic anhydrase and glutamic pyruvic transaminase increased within the normal range. The preliminary feasibility was verified by using this physico-chemical technology in the RAS.

  17. Degradation of Remazol Red in batik dye waste water by contact glow discharge electrolysis method using NaOH and NaCl electrolytes

    Science.gov (United States)

    Saksono, Nelson; Putri, Dita Amelia; Suminar, Dian Ratna

    2017-03-01

    Contact Glow Discharge Electrolysis (CGDE) method is one of Plasma Electrolysis technology which has been approved to degrade organic waste water because it is very productive in producing hydroxyl radical. This study aims to degrade Remazol Red by CGDE method and evaluate important parameters that have influent in degradation process of Remazol Red in Batik dye waste water in batch system. The kind of electrolyte (acid and base) and the addition of metal ion such as Fe2+ have affected Remazol Red degradation percentage. Ultraviolet-Visible (UV-Vis) absorption spectra were used to monitor the degradation process. The result of study showed that percentage degradation was 99.97% which obtained by using NaCl 0.02 M with addition Fe2+ 20 ppm, applied voltage 700 volt, anode depth 0.5 cm, initial concentration of Remazol Red 250 ppm and the temperature of solutions was maintained 50-60 ˚C.

  18. Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System

    OpenAIRE

    Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

    2017-01-01

    A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system wa...

  19. Assessing the Feasibility of Using Co-electrolysis to Concurrently Convert Carbon Dioxide and Water into Methane and Oxygen for Propellant and Life Support on Mars

    Data.gov (United States)

    National Aeronautics and Space Administration — By using co-electrolysis with task-specific ionic liquids (TSILs), water from Martian regolith and carbon dioxide from the Martian atmosphere may be simultaneously...

  20. Recycling Carbon Dioxide into Sustainable Hydrocarbon Fuels: Electrolysis of Carbon Dioxide and Water

    Science.gov (United States)

    Graves, Christopher Ronald

    Great quantities of hydrocarbon fuels will be needed for the foreseeable future, even if electricity based energy carriers begin to partially replace liquid hydrocarbons in the transportation sector. Fossil fuels and biomass are the most common feedstocks for production of hydrocarbon fuels. However, using renewable or nuclear energy, carbon dioxide and water can be recycled into sustainable hydrocarbon fuels in non-biological processes which remove oxygen from CO2 and H2O (the reverse of fuel combustion). Capture of CO2 from the atmosphere would enable a closed-loop carbon-neutral fuel cycle. The purpose of this work was to develop critical components of a system that recycles CO2 into liquid hydrocarbon fuels. The concept is examined at several scales, beginning with a broad scope analysis of large-scale sustainable energy systems and ultimately studying electrolysis of CO 2 and H2O in high temperature solid oxide cells as the heart of the energy conversion, in the form of three experimental studies. The contributions of these studies include discoveries about electrochemistry and materials that could significantly improve the overall energy use and economics of the CO2-to-fuels system. The broad scale study begins by assessing the sustainability and practicality of the various energy carriers that could replace petroleum-derived hydrocarbon fuels, including other hydrocarbons, hydrogen, and storage of electricity on-board vehicles in batteries, ultracapacitors, and flywheels. Any energy carrier can store the energy of any energy source. This sets the context for CO2 recycling -- sustainable energy sources like solar and wind power can be used to provide the most energy-dense, convenient fuels which can be readily used in the existing infrastructure. The many ways to recycle CO2 into hydrocarbons, based on thermolysis, thermochemical loops, electrolysis, and photoelectrolysis of CO2 and/or H 2O, are critically reviewed. A process based on high temperature co-electrolysis

  1. HYFIRE: a tokamak/high-temperature electrolysis system

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.P.; Benenati, R.; Varljen, T.C.; Chi, J.W.H.; Karbowski, J.S.

    1981-01-01

    The HYFIRE studies to date have investigated a number of technical approaches for using the thermal energy produced in a high-temperature Tokamak blanket to provide the electrical and thermal energy required to drive a high-temperature (> 1000 0 C) water electrolysis process. Current emphasis is on two design points, one consistent with electrolyzer peak inlet temperatures of 1400 0 C, which is an extrapolation of present experience, and one consistent with a peak electrolyzer temperature of 1100 0 C. This latter condition is based on current laboratory experience with high-temperature solid electrolyte fuel cells. Our major conclusion to date is that the technical integration of fusion and high-temperature electrolysis appears to be feasible and that overall hydrogen production efficiencies of 50 to 55% seem possible

  2. Electrolysis byproduct D2O provides a third way to mitigate CO2

    International Nuclear Information System (INIS)

    Schenewerk, William Ernest

    2009-01-01

    Rapid atomic power deployment may be possible without using fast breeder reactors or making undue demands on uranium resource. Using by-product D2O and thorium-U233 in CANDU and RBMK piles may circumvent need for either fast breeder reactors or seawater uranium. Atmospheric CO2 is presently increasing 2.25%/year in proportion to 2.25%/year exponential fossil fuel consumption increase. Roughly 1/3 anthropologic CO2 is removed by various CO2 sinks. CO2 removal is modelled as being proportional to 45-year-earlier CO2 amount above 280 ppm-C Water electrolysis produces roughly 0.1 kg-D20/kWe-y. Material balance assumes each electrolysis stage increases D2O bottoms concentration times 3. Except for first two electrolysis stages, all water from hydrogen consumption is returned to electrolysis. The unique characteristic of this process is the ability to economically burn all deuterium-enriched H2 in vehicles. Condensate from vehicles returns to appropriate electrolysis stage. Fuel cell condensate originally from reformed natural gas may augment second-sage feed. Atomic power expansion is 5%/year, giving 55000 GWe by 2100. World primary energy increases 2.25%/y, exceeding 4000 EJ/y by 2100. CO2 maximum is roughly 600 ppm-C around year 2085. CO2 declines back below 300 ppm-C by 2145 if the 45-year-delay seawater sink remains effective

  3. Hydrophilic cobalt sulfide nanosheets as a bifunctional catalyst for oxygen and hydrogen evolution in electrolysis of alkaline aqueous solution.

    Science.gov (United States)

    Zhu, Mingchao; Zhang, Zhongyi; Zhang, Hu; Zhang, Hui; Zhang, Xiaodong; Zhang, Lixue; Wang, Shicai

    2018-01-01

    Hydrophilic medium and precursors were used to synthesize a hydrophilic electro-catalyst for overall water splitting. The cobalt sulfide (Co 3 S 4 ) catalyst exhibits a layered nanosheet structure with a hydrophilic surface, which can facilitate the diffusion of aqueous substrates into the electrode pores and towards the active sites. The Co 3 S 4 catalyst shows excellent bifunctional catalytic activity for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solution. The assembled water electrolyzer based on Co 3 S 4 exhibits better performance and stability than that of Pt/C-RuO 2 catalyst. Thereforce the hydrophilic Co 3 S 4 is a highly promising bifunctional catalyst for the overall water splitting reaction. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The influence of Ferric ion contamination on the solid polymer electrolyte water electrolysis performance

    International Nuclear Information System (INIS)

    Wang, Xunying; Zhang, Linsong; Li, Guangfu; Zhang, Geng; Shao, Zhi-Gang; Yi, Baolian

    2015-01-01

    Highlights: • The cathode possesses higher tolerance for the Fe 3+ contamination than the anode. • Fe 3+ are mostly reduced to Fe 2+ rather than occur underpotential deposition. • Increased electrolysis voltage was mainly attributed to ohmic overpotential. • Voltage lags behind current for minutes in the multi-current-step test. • Poisoned electrolyser is mostly recovered by 0.5 M H 2 SO 4 solution treatment for 13 h. - Abstract: Fe 3+ is a sort of common metal ion contaminant for the solid polymer electrolyte (SPE) water electrolyser. In this paper, the effect of Fe 3+ on the performance of SPE water electrolyser has been investigated by both in-situ and ex-situ characterizations. The electron probe microanalysis and ultraviolet test results showed that Fe 3+ could migrate from the anode to the cathode and mostly be reduced to Fe 2+ in the cathode rather than occurred underpotential deposition as described in the previous report. The in-situ dynamic contamination test showed that the anode voltage increased sharply as soon as the Fe 3+ was fed into the anode, while the cathode voltage kept constant until the contamination time was over 30 minutes, indicating the higher tolerance of the cathode than the anode for the Fe 3+ contamination. The calculation results based on the electrochemistry impedance spectroscopy test results revealed that the striking increase of the electrolysis voltage was mainly attributed to the ohmic overpotential, which was due to the replacement of H + by Fe 3+ in the Nafion resin. Interestingly, the voltage lagged behind the current for several minutes in the multi-current-step test for the contaminated electrolyser, which phenomenon may be used for judging whether the SPE water electrolyser performance degradation is due to the metal ions contamination. Furthermore, recovery strategy has been developed, and it was found that the contaminated electrolyser could be mostly recovered by 0.5 M H 2 SO 4 solution treatment for 13 h

  5. Direct fabrication of gas diffusion cathode by pulse electrodeposition for proton exchange membrane water electrolysis

    Science.gov (United States)

    Park, Hyanjoo; Choe, Seunghoe; Kim, Hoyoung; Kim, Dong-Kwon; Cho, GeonHee; Park, YoonSu; Jang, Jong Hyun; Ha, Don-Hyung; Ahn, Sang Hyun; Kim, Soo-Kil

    2018-06-01

    Pt catalysts for water electrolysis were prepared on carbon paper by using both direct current and pulse electrodeposition. Controlling the mass transfer of Pt precursor in the electrolyte by varying the deposition potential enables the formation of various Pt particle shapes such as flower-like and polyhedral particles. Further control of the deposition parameters for pulse electrodeposition resulted in changes to the particle size and density. In particular, the upper potential of pulse was found to be the critical parameter controlling the morphology of the particles and their catalytic activity. In addition to the typical electrochemical measurements, Pt samples deposited on carbon paper were used as cathodes for a proton exchange membrane water electrolyser. This single cell test revealed that our Pt particle samples have exceptional mass activity while being cost effective.

  6. Electrolysis activities at FCH Test Center

    DEFF Research Database (Denmark)

    Ravn Nielsen, Eva; Nygaard, Frederik Berg

    FCH Test Center for fuel cell and hydrogen technologies was established in 2010 at Risø DTU in Denmark. Today, the test center is part of DTU Energy Conversion. The center gives industry access to advanced testing and demonstration of components and systems. A number of national projects and EU...... projects regarding water electrolysis involve FCH Test Center as a partner. This presentation gives an overview of the activities....

  7. Calculated solubility isotherm of a system of alkaline earth sulfates and hydroxides in water

    International Nuclear Information System (INIS)

    MOshinskii, A.S.; TIkomirova, K.A.

    1986-01-01

    Tis paper examines the calculation of the isothermal solubility diagram of a system of alkaline earth sulfates and hydroxides in water which makes it possible to substantiate, to a considerable extent, the natural physicochemical mineralization of natural waters, in particular water from geochemical sources. The present paper investigates the solubility of the equilibrium solid phases of a system of alkaline earth sulfates and hydroxides in water. A projection is shown of the composition prism of the quinary reciprocal system with demarcation of the crystallization areas of each sulfate and hydroxide of the component subsystems. The computational formulas for calculating solubility were derived from the solubility product principle, with allowance for ion activity coefficients in saturated hydroxide solutions

  8. Tritium isotope separation from light and heavy water by bipolar electrolysis

    International Nuclear Information System (INIS)

    Petek, M.; Ramey, D.W.; Taylor, R.D.; Kobisk, E.H.

    1980-01-01

    A process for separating tritium from light and heavy water is described. Hydrogen is transferred at and through bipolar electrodes at rates H > D > T. In a cell containing several bipolar electrodes placed in series between two terminal electrodes, a flow of hydrogen is established from the terminal anode compartment toward the terminal cathode. An electrolyte feed containing tritium is continuously added to the system and is subsequently transported countercurrent to the hydrogen mass transfer. A cascaded system is established, in which effluent streams enriched and depleted in tritium can be withdrawn. The voltage drop is smaller at any bipolar electrode as compared to the voltage for normal electrolysis. Cell design is compact because isotope separation occurs at bipolar electrodes without evolution of gas. Isotope separation was demonstrated in laboratory cells where a steady-state tritium concentration gradient was attained. This gradient was in agreement with concentrations calculated from a derived mathematical model

  9. GenHyPEM: an EC-supported STREP program on high pressure PEM water electrolysis

    International Nuclear Information System (INIS)

    Millet, P.

    2006-01-01

    GenHyPEM (generateur d'hydrogene PEM) is an international research project related to the electrolytic production of hydrogen from water, using proton exchange membrane (PEM) - based electrochemical generators. The specificity of this project is that all basic research efforts are devoted to the optimization of already existing electrolysers of industrial size, in order to facilitate the introduction of this technology in the industry and to propose technological solutions for the industrial and domestic production of electrolytic hydrogen. GenHyPEM is a three years long research program financially supported by the European Commission, gathering partners from academic institutions and from the industry, in order to reach three main technological objectives aimed at improving the performances of current 1000 Nliter/hour H 2 industrial PEM water electrolysers: (i) Development of alternative low-cost membrane electrode assemblies and stack components with electrochemical performances similar to those of state-of-the-art systems. The objectives are the development of nano-scaled electrocatalytic structures for reducing the amount of noble metals; the synthesis and characterization of non-noble metal catalytic compounds provided by molecular chemistry and bio-mimetic approaches; the preparation of new composite membrane materials for high current density, high pressure and high temperature operation; the development and optimization of low-cost porous titanium sheets acting as current collectors in the electrolysis stack; (ii) Development of an optimized stack structure for high current density (1 A.cm-2) and high pressure (50 bars) operation for direct pressurized storage; (iii) Development of an automated and integrated electrolysis unit allowing gas production from intermittent renewable sources of energy such as photovoltaic-solar and wind. Current status of the project as well as perspectives are described in this paper. This project, coordinated by University of

  10. Effect of administration of water enriched in O2 by injection or electrolysis on transcutaneous oxygen pressure in anesthetized pigs.

    Science.gov (United States)

    Charton, Antoine; Péronnet, François; Doutreleau, Stephane; Lonsdorfer, Evelyne; Klein, Alexis; Jimenez, Liliana; Geny, Bernard; Diemunsch, Pierre; Richard, Ruddy

    2014-01-01

    Oral administration of oxygenated water has been shown to improve blood oxygenation and could be an alternate way for oxygen (O2) supply. In this experiment, tissue oxygenation was compared in anesthetized pigs receiving a placebo or water enriched in O2 by injection or a new electrolytic process. Forty-two pigs randomized in three groups received either mineral water as placebo or water enriched in O2 by injection or the electrolytic process (10 mL/kg in the stomach). Hemodynamic parameters, partial pressure of oxygen in the arterial blood (PaO2), skin blood flow, and tissue oxygenation (transcutaneous oxygen pressure, or TcPO2) were monitored during 90 minutes of general anesthesia. Absorption and tissue distribution of the three waters administered were assessed using dilution of deuterium oxide. Mean arterial pressure, heart rate, PaO2, arteriovenous oxygen difference, and water absorption from the gut were not significantly different among the three groups. The deuterium to protium ratio was also similar in the plasma, skin, and muscle at the end of the protocol. Skin blood flow decreased in the three groups. TcPO2 slowly decreased over the last 60 minutes of the experiment in the three groups, but when compared to the control group, the values remained significantly higher in animals that received the water enriched in O2 by electrolysis. In this protocol, water enriched in O2 by electrolysis lessened the decline of peripheral tissue oxygenation. This observation is compatible with the claim that the electrolytic process generates water clathrates which trap O2 and facilitate O2 diffusion along pressure gradients. Potential applications of O2-enriched water include an alternate method of oxygen supply.

  11. The electrolysis time on electrosynthesis of hydroxyapatite with bipolar membrane

    Science.gov (United States)

    Nur, Adrian; Jumari, Arif; Budiman, Anatta Wahyu; Puspitaningtyas, Stella Febianti; Cahyaningrum, Suci; Nazriati, Nazriati; Fajaroh, Fauziatul

    2018-02-01

    The electrochemical method with bipolar membrane has been successfully used for the synthesis of hydroxyapatite. In this work, we have developed 2 chambers electrolysis system separated by a bipolar membrane. The membrane was used to separate cations (H+ ions produced by the oxidation of water at the anode) and anions (OH- ions produced by the reduction of water at the cathode). With this system, we have designed that OH- ions still stay in the anions chamber because OH- ions was very substantial in the hydroxyapatite particles formation. The aim of this paper was to compare the electrolysis time on electrosynthesis of hydroxyapatite with and without the bipolar membrane. The electrosynthesis was performed at 500 mA/cm2 for 0.5 to 2 hours at room temperature and under ultrasonic cleaner to void agglomeration with and without the bipolar membrane. The electrosynthesis of hydroxyapatite with the bipolar membrane more effective than without the bipolar membrane. The hydroxyapatite has been appeared at 0.5 h of the electrolysis time with the bipolar membrane (at the cathode chamber) while it hasn't been seen without the bipolar membrane. The bipolar membrane prevents OH- ions migrate to the cation chamber. The formation of HA becomes more effective because OH- ions just formed HA particle.

  12. Vapor pressure and specific electrical conductivity in the solid and molten H2O-CsH2PO4-CsPO3 system—a novel electrolyte for water electrolysis at ~ 225–400 °C

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey Valerievich; Berg, Rolf W.; Bjerrum, Niels J.

    2018-01-01

    Cesium dihydrogen phosphate, CsH2PO4 (CDP) was studied for water electrolysis at ~ 225–400 °C. In the presence of sufficient humidity, CDP is structurally disordered and super-protonic conducting with conductivities reaching 0.2–0.25 S cm−1, when determined in suitable H-shaped sealed conductivity...... on internal reference gases. Pressures up to ~ 49 bar were estimated, much higher than previously expected. Conductivities were given as polynomials and plotted in solid and liquid states. Water splitting electrolysis 2H2O → 2H2 + O2 was demonstrated by Raman at ~ 355 °C under a water pressure of ~ 23 bar...... in a quartz cell with platinum electrodes, showing molten CDP to have significant potential for water electrolysis....

  13. Alkalinity of the Mediterranean Sea

    OpenAIRE

    Schneider, Anke; Wallace, Douglas W.R.; Körtzinger, Arne

    2007-01-01

    Total alkalinity (AT) was measured during the Meteor 51/2 cruise, crossing the Mediterranean Sea from west to east. AT concentrations were high (∼2600 μmol kg−1) and alkalinity-salinity-correlations had negative intercepts. These results are explained by evaporation coupled with high freshwater AT inputs into coastal areas. Salinity adjustment of AT revealed excess alkalinity throughout the water column compared to mid-basin surface waters. Since Mediterranean waters are supersaturated with r...

  14. Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis.

    Science.gov (United States)

    Read, Tania L; Macpherson, Julie V

    2016-01-06

    Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp(2) carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail.

  15. Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

    Science.gov (United States)

    Read, Tania L.; Macpherson, Julie V.

    2016-01-01

    Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp2 carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail. PMID:26779959

  16. Microbial electrolysis cells turning to be versatile technology: recent advances and future challenges

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2014-01-01

    and achieve high-yield hydrogen production from wide range of organic matters at relatively mild conditions. This approach greatly reduces the electric energy cost for hydrogen production in contrast to direct water electrolysis. In addition to hydrogen production, MECs may also support several energetically......Microbial electrolysis cells (MECs) are an electricity-mediated microbial bioelectrochemical technology, which is originally developed for high-efficiency biological hydrogen production from waste streams. Compared to traditional biological technologies, MECs can overcome thermodynamic limitations...

  17. Procedure and technique critique for tritium enrichment by electrolysis at the IAEA Laboratory (effective November 1976)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-11-05

    This publication gives a detailed description of the experimental and calculation procedures for tritium enrichment. Most descriptive sections are divided into 2 parts: Section A describes the procedure in the IAEA laboratory; section B discusses the reasons behind the various procedures, and may indicate alternative acceptable, or in some cases even better, procedures. The description of the equipment focuses on electrolysis cells, cooling system and power supply. Routine procedures are discussed including handling and checking of samples after receipt, 'spike' and blank water, initial sample distillation, preparation of cells and samples for electrolysis, electrolysis and completion of electrolysis (weighing of cells, neutralisation and distillation) and precautions against contaminations (prevention, detection and cure). A list of equipment required for electrolytic enrichment of tritium is provided.

  18. Procedure and technique critique for tritium enrichment by electrolysis at the IAEA Laboratory (effective November 1976)

    International Nuclear Information System (INIS)

    1976-01-01

    This publication gives a detailed description of the experimental and calculation procedures for tritium enrichment. Most descriptive sections are divided into 2 parts: Section A describes the procedure in the IAEA laboratory; section B discusses the reasons behind the various procedures, and may indicate alternative acceptable, or in some cases even better, procedures. The description of the equipment focuses on electrolysis cells, cooling system and power supply. Routine procedures are discussed including handling and checking of samples after receipt, 'spike' and blank water, initial sample distillation, preparation of cells and samples for electrolysis, electrolysis and completion of electrolysis (weighing of cells, neutralisation and distillation) and precautions against contaminations (prevention, detection and cure). A list of equipment required for electrolytic enrichment of tritium is provided

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

    International Nuclear Information System (INIS)

    O'Brien, James E.

    2010-01-01

    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.

  20. A review of proton exchange membrane water electrolysis on degradation mechanisms and mitigation strategies

    Science.gov (United States)

    Feng, Qi; Yuan, Xiao-Zi; Liu, Gaoyang; Wei, Bing; Zhang, Zhen; Li, Hui; Wang, Haijiang

    2017-10-01

    Proton exchange membrane water electrolysis (PEMWE) is an advanced and effective solution to the primary energy storage technologies. A better understanding of performance and durability of PEMWE is critical for the engineers and researchers to further advance this technology for its market penetration, and for the manufacturers of PEM water electrolyzers to implement quality control procedures for the production line or on-site process monitoring/diagnosis. This paper reviews the published works on performance degradations and mitigation strategies for PEMWE. Sources of degradation for individual components are introduced. With degradation causes discussed and degradation mechanisms examined, the review emphasizes on feasible strategies to mitigate the components degradation. To avoid lengthy real lifetime degradation tests and their high costs, the importance of accelerated stress tests and protocols is highlighted for various components. In the end, R&D directions are proposed to move the PEMWE technology forward to become a key element in future energy scenarios.

  1. Destruction of 4-phenolsulfonic acid in water by anodic contact glow discharge electrolysis.

    Science.gov (United States)

    Yang, Haiming; An, Baigang; Wang, Shaoyan; Li, Lixiang; Jin, Wenjie; Li, Lihua

    2013-06-01

    Destruction of 4-phenolsulfonic acid (4-PSA) in water was carried out using anodic contact glow discharge electrolysis. Accompanying the decay of 4-PSA, the amount of total organic carbon (TOC) in water correspondingly decreased, while the sulfonate group of 4-PSA was released as sulfate ion. Oxalate and formate were obtained as minor by-products. Additionally, phenol, 1,4-hydroquinone, hydroxyquinol and 1,4-benzoquinone were detected as primary intermediates in the initial stages of decomposition of 4-PSA. A reaction pathway involving successive attacks of hydroxyl and hydrogen radicals was assumed on the basis of the observed products and kinetics. It was revealed that the decay of both 4-PSA and TOC obeyed a first-order rate law. The effects of different Fe ions and initial concentrations of 4-PSA on the degradation rate were investigated. It was found that the presence of Fe ions could increase the degradation rate of 4-PSA, while initial concentrations lower than 80 mmol/L had no significant effect on kinetic behaviour. The disappearance rate of 4-PSA was significantly affected by pH.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

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

  3. Control of New Copper Corrosion in High-Alkalinity Drinking Water using Orthophosphate - article

    Science.gov (United States)

    Research and field experience have shown that high-alkalinity waters can be associated with elevated copper levels in drinking water. The objective of this study was to document the application of orthophosphate to the distribution system of a building with a copper problem asso...

  4. ANALYSIS OF A POSSIBLE REDUCTION IN ENERGY CONSUMPTION IN WATER ELECTROLYSIS REACTION

    Directory of Open Access Journals (Sweden)

    Aurel George POPESCU

    2013-05-01

    Full Text Available It was experimentally observed that the electrolysis reaction continues a short period of time - time torelax c - after the cell power supply is interrupted. This paper presents an analysis of transient phenomenaoccurring and pr opose technical solutions

  5. Investigation of the Alkaline Electrochemical Interface and Development of Composite Metal/Metal-Oxides for Hydrogen and Oxygen Electrodes

    Science.gov (United States)

    Bates, Michael

    Understanding the fundamentals of electrochemical interfaces will undoubtedly reveal a path forward towards a society based on clean and renewable energy. In particular, it has been proposed that hydrogen can play a major role as an energy carrier of the future. To fully utilize the clean energy potential of a hydrogen economy, it is vital to produce hydrogen via water electrolysis, thus avoiding co-production of CO2 inherent to reformate hydrogen. While significant research efforts elsewhere are focused on photo-chemical hydrogen production from water, the inherent low efficiency of this method would require a massive land-use footprint to achieve sufficient hydrogen production rates to integrate hydrogen into energy markets. Thus, this research has primarily focused on the water splitting reactions on base-metal catalysts in the alkaline environment. Development of high-performance base-metal catalysts will help move alkaline water electrolysis to the forefront of hydrogen production methods, and when paired with solar and wind energy production, represents a clean and renewable energy economy. In addition to the water electrolysis reactions, research was conducted to understand the de-activation of reversible hydrogen electrodes in the corrosive environment of the hydrogen-bromine redox flow battery. Redox flow batteries represent a promising energy storage option to overcome the intermittency challenge of wind and solar energy production methods. Optimization of modular and scalable energy storage technology will allow higher penetration of renewable wind and solar energy into the grid. In Chapter 1, an overview of renewable energy production methods and energy storage options is presented. In addition, the fundamentals of electrochemical analysis and physical characterization of the catalysts are discussed. Chapter 2 reports the development of a Ni-Cr/C electrocatalyst with unprecedented mass-activity for the hydrogen evolution reaction (HER) in alkaline

  6. Hydrogen Generation From Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Steven Cohen; Stephen Porter; Oscar Chow; David Henderson

    2009-03-06

    Small-scale (100-500 kg H2/day) electrolysis is an important step in increasing the use of hydrogen as fuel. Until there is a large population of hydrogen fueled vehicles, the smaller production systems will be the most cost-effective. Performing conceptual designs and analyses in this size range enables identification of issues and/or opportunities for improvement in approach on the path to 1500 kg H2/day and larger systems. The objectives of this program are to establish the possible pathways to cost effective larger Proton Exchange Membrane (PEM) water electrolysis systems and to identify areas where future research and development efforts have the opportunity for the greatest impact in terms of capital cost reduction and efficiency improvements. System design and analysis was conducted to determine the overall electrolysis system component architecture and develop a life cycle cost estimate. A design trade study identified subsystem components and configurations based on the trade-offs between system efficiency, cost and lifetime. Laboratory testing of components was conducted to optimize performance and decrease cost, and this data was used as input to modeling of system performance and cost. PEM electrolysis has historically been burdened by high capital costs and lower efficiency than required for large-scale hydrogen production. This was known going into the program and solutions to these issues were the focus of the work. The program provided insights to significant cost reduction and efficiency improvement opportunities for PEM electrolysis. The work performed revealed many improvement ideas that when utilized together can make significant progress towards the technical and cost targets of the DOE program. The cell stack capital cost requires reduction to approximately 25% of today’s technology. The pathway to achieve this is through part count reduction, use of thinner membranes, and catalyst loading reduction. Large-scale power supplies are available

  7. Processing Methods of Alkaline Hydrolysate from Rice Husk

    Directory of Open Access Journals (Sweden)

    Olga D. Arefieva

    2017-07-01

    Full Text Available This paper devoted to finding processing methods of alkaline hydrolysate produced from rice husk pre-extraction, and discusses alkaline hydrolysate processing schemed and disengagement of some products: amorphous silica of various quality, alkaline lignin, and water and alkaline extraction polysaccharides. Silica samples were characterized: crude (air-dried, burnt (no preliminary water treatment, washed in distilled water, and washed in distilled water and burnt. Waste water parameters upon the extraction of solids from alkaline hydrolysate dropped a few dozens or thousand times depending on the applied processing method. Color decreased a few thousand times, turbidity was virtually eliminated, chemical oxygen demanded about 20–136 times; polyphenols content might decrease 50% or be virtually eliminated. The most prospective scheme obtained the two following solid products from rice husk alkaline hydrolysate: amorphous silica and alkaline extraction polysaccharide. Chemical oxygen demand of the remaining waste water decreased about 140 times compared to the silica-free solution.

  8. Effect of water electrolysis temperature of hydrogen production system using direct coupling photovoltaic and water electrolyzer

    Directory of Open Access Journals (Sweden)

    Tetsuhiko Maeda

    2016-01-01

    Full Text Available We propose control methods of a photovoltaic (PV-water electrolyzer (ELY system that generates hydrogen by controlling the number of ELY cells. The advantage of this direct coupling between PV and ELY is that the power loss of DC/DC converter is avoided. In this study, a total of 15 ELY cells are used. In the previous researches, the electrolyzer temperature was constantly controlled with a thermostat. Actually, the electrolyzer temperature is decided by the balance of the electrolysis loss and the heat loss to the outside. Here, the method to control the number of ELY cells was investigated. Maximum Power Point Tracking efficiency of more than 96% was achieved without ELY temperature control. Furthermore we construct a numerical model taking into account of ELY temperature. Using this model, we performed a numerical simulation of 1-year. Experimental data and the simulation results shows the validity of the proposed control method.

  9. Development of conductometric biosensors based on alkaline phosphatases for the water quality control

    Science.gov (United States)

    Berezhetskyy, A.

    2008-09-01

    Researches are focused on the elaboration of enzymatic microconductometric device for heavy metal ions detection in water solutions. The manuscript includes a general introduction, the first chapter contains bibliographic review, the second chapter described the fundamentals of conductometric transducers, the third chapter examining the possibility to create and to optimize conductometric biosensor based on bovine alkaline phosphatase for heavy metals ions detection, the fourth chapter devoted to creation and optimization of conductometric biosensor based on alkaline phosphatase active microalgae and sol gel technology, the last chapter described application of the proposed algal biosensor for measurements of heavy metal ions toxicity of waste water, general conclusions stating the progresses achieved in the field of environmental monitoring

  10. Recovery of nitrogen and water from landfill leachate by a microbial electrolysis cell-forward osmosis system.

    Science.gov (United States)

    Qin, Mohan; Molitor, Hannah; Brazil, Brian; Novak, John T; He, Zhen

    2016-01-01

    A microbial electrolysis cell (MEC)-forward osmosis (FO) system was previously reported for recovering ammonium and water from synthetic solutions, and here it has been advanced with treating landfill leachate. In the MEC, 65.7±9.1% of ammonium could be recovered in the presence of cathode aeration. Without aeration, the MEC could remove 54.1±10.9% of ammonium from the leachate, but little ammonia was recovered. With 2M NH4HCO3 as the draw solution, the FO process achieved 51% water recovery from the MEC anode effluent in 3.5-h operation, higher than that from the raw leachate. The recovered ammonia was used as a draw solute in the FO for successful water recovery from the treated leachate. Despite the challenges with treating returning solution from the FO, this MEC-FO system has demonstrated the potential for resource recovery from wastes, and provide a new solution for sustainable leachate management. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Introducing TEX86 as a Water pH Proxy for Alkaline Lakes on the Tibetan Plateau

    Science.gov (United States)

    Wang, M.; Tian, Q.; Li, X.; Liang, J.; Yue, H.; Hou, J.

    2017-12-01

    Lake water pH represents one of the most important indicators for lake evolution and factors influencing the evolution of aquatic ecosystem, however, which is less studied on the Tibetan Plateau (TP). Applicability of diatom assemblages, an effective proxy of lake water pH variation in freshwater lakes, is highly limited on the TP because the widespread distribution of alkaline lakes is unfavorable for preservation of diatom shells. Glycerol dialkyl glycerol tetraethers (GDGTs) are a series of specific membrane lipids biosynthesized by archaea and bacteria, which appear to be a promising method to reflect lake water pH variation. Here we present the distribution of iGDGTs compounds in surface sediments across the TP to discuss the effect of various environmental factors on iGDGTs distribution. The results show that TEX86 is a promising proxy for lake water pH in high-elevation alkaline lakes, as water pH appears to be the most important factor to affect the cyclization of iGDGTs. We proposed the water pH calibration for lakes (salinitywater pH. The TEX86-derived pH at Bangong Co varied from 8.69 to 9.49 since the last 16 kyr BP, which is generally consistent with precipitation isotope variation that was reconstructed from leaf wax D/H ratios in the same sediment core, suggesting the lake water pH was mainly controlled by local hydrology. We believe that TEX86 will be able to infer past water pH of alkaline lakes over TP and could be a potentially useful tool for reconstructing pH in alkaline lakes worldwide after regional calibrated.

  12. Methanol and ethanol electrooxidation on Pt and Pd supported on carbon microspheres in alkaline media

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Changwei; Cheng, Liqiang; Liu, Yingliang [Department of Chemistry and Institute of Nanochemistry, Jinan University, Guangzhou 510632 (China); Shen, Peikang [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

    2007-05-15

    Noble metal (Pt, Pd) electrocatalysts supported on carbon microspheres (CMS) are used for methanol and ethanol oxidation in alkaline media. The results show that noble metal electrocatalysts supported on carbon microspheres give better performance than that supported on carbon black. It is well known that palladium is not a good electrocatalyst for methanol oxidation, but it shows excellently higher activity and better steady-state electrolysis than Pt for ethanol electrooxidation in alkaline media. The results show a synergistic effect by the interaction between Pd and carbon microspheres. The Pd supported on carbon microspheres in this paper possesses excellent electrocatalytic properties and may be of great potential in direct ethanol fuel cells. (author)

  13. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    KAUST Repository

    Logan, Bruce E.

    2008-12-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few years ago, rapid developments have led to hydrogen yields approaching 100%, energy yields based on electrical energy input many times greater than that possible by water electrolysis, and increased gas production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here the materials, architectures, performance, and energy efficiencies of these MEC systems that show promise as a method for renewable and sustainable energy production, and wastewater treatment. © 2008 American Chemical Society.

  14. Summary of the Mol electrolysis cell test program in the CRL tritium laboratory

    International Nuclear Information System (INIS)

    Miller, J.M.; Keyes, R.J.

    1996-01-01

    The development of electrolysis technology for highly tritiated water at the Studiecentrum voor Kernenergie/Centre d'Etude de l'Energie Nucleaire (SCK/CEN), Mol, Belgium, focused on A Low Inventory Capillary Electrolyser (ALICE). The key characteristic of ALICE is its low liquid inventory, a key feature for the radio-toxicity of tritiated water. A program to test this electrolytic cell design with highly tritiated water in the Chalk River Tritium Laboratory was initiated in 1988 and extended through to early 1995. The activities conducted at CRL and associated with the experimental program-design, installation, licensing and commissioning activities- are described in this report along with the results of the test program conducted on the experimental system with non-tritiated heavy water. The installation in the CRL Tritium Laboratory consisted of three main sections: the electrolysis section, the tritium storage and supply section, and the recombination section. 16 figs., 2 tabs., 10 refs

  15. Development status of solid polymer electrolyte water electrolysis for manned spacecraft life support systems

    Science.gov (United States)

    Nuttall, L. J.; Titterington, W. A.

    1974-01-01

    Details of the design and system verification test results are presented for a six-man-rated oxygen generation system. The system configuration incorporates components and instrumentation for computer-controlled operation with automatic start-up/shutdown sequencing, fault detection and isolation, and with self-contained sensors and controls for automatic safe emergency shutdown. All fluid and electrical components, sensors, and electronic controls are designed to be easily maintainable under zero-gravity conditions. On-board component spares are utilized in the system concept to sustain long-term operation (six months minimum) in a manned spacecraft application. The system is centered on a 27-cell solid polymer electrolyte water electrolysis module which, combined with the associated system components and controls, forms a total system envelope 40 in. high, 40 in. wide, and 30 in. deep.

  16. Poisoning of Solid Oxide Electrolysis Cells by Impurities

    DEFF Research Database (Denmark)

    Ebbesen, Sune; Graves, Christopher R.; Hauch, Anne

    2010-01-01

    Electrolysis of H2O, CO2, and co-electrolysis of H2O and CO2 was studied in Ni/yttria-stabilized zirconia (YSZ) electrode supported solid oxide electrolysis cells (SOECs) consisting of a Ni/YSZ support, a Ni/YSZ electrode layer, a YSZ electrolyte, and an lanthanum strontium manganite (LSM)/YSZ ox...

  17. Real-time measurement of dynamic structure for Pd-D system in heavy-water electrolysis cell

    International Nuclear Information System (INIS)

    Wang Jun; Zeng Xianxin; Yang Jilian; Zhang Baisheng; Ruan Jinghui

    1993-01-01

    The real-time dynamic structure of Pd-D system in D 2 O electrolysis cell is measured on neutron powder diffractometer in CIAE. Diffraction patterns in 2 θ range of 34 degree-95 degree are obtained under the conditions of electrolysing for 0, 3 and 48 A ·h respectively, and the gradual transition of Pd-D system from α-phase to β-phase is observed. The real-time measurements of β peak of (220) reflection show that intensity of β peak almost reaches the saturation point after electrolysing for 0.65 A · h and increases slowly with further electrolysis afterwards

  18. Hydrogen production from fusion reactors coupled with high temperature electrolysis

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.; Steinberg, M.

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and complement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Processes which may be considered for this purpose include electrolysis, thermochemical decomposition or thermochemical-electrochemical hybrid cycles. Preliminary studies at Brookhaven indicate that high temperature electrolysis has the highest potential efficiency for production of hydrogen from fusion. Depending on design electric generation efficiencies of approximately 40 to 60 percent and hydrogen production efficiencies of approximately 50 to 70 percent are projected for fusion reactors using high temperature blankets

  19. Measurement of pH, alkalinity and acidity in ultra-soft waters

    African Journals Online (AJOL)

    drinie

    2001-10-04

    Oct 4, 2001 ... A blend composed of the raw water, sodium chloride (to increase conductivity), and standard bicarbonate (to increase buffering capacity) was titrated with standard strong acid in two pH regions: 6.3 pH < 4.0. In both methods, total alkalinity was determined using the latter set of points, ...

  20. Elimination of heavy metals from leachates by membrane electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, R. [Technische Universitaet Dresden, Institut fuer Siedlungs- und Industriewasserwirtschaft, Mommsenstrasse 13, 01062 Dresden (Germany); Seidel, H. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Bioremediation, Permoserstrasse 15, D-04318 Leipzig (Germany); Rahner, D. [Technische Universitaet Dresden, Institut fuer Physikalische Chemie und Eektrochemie, Mommsenstrasse 13, D-01062 Dresden (Germany); Morgenstern, P. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Analytik, Permoserstrasse 15, D-04318 Leipzig (Germany); Loeser, C. [Technische Universitaet Dresden, Institut fuer Lebensmittel- und Bioverfahrenstechnik, Bergstrasse 120, D-01062 Dresden (Germany)

    2004-10-01

    The elimination of heavy metals from bioleaching process waters (leachates) by electrolysis was studied in the anode and cathode region of a membrane electrolysis cell at current densities of 5-20 mA/cm{sup 2} using various electrode materials. The leaching waters containing a wide range of dissolved heavy metals, were high in sulfate, and had pH values of approx. 3. In preliminary tests using a rotating disc electrode the current density-potential curve (CPK) was recorded at a rotation velocity of 0, 1000 and 2000 rpm and a scan rate of 10 mV/s in order to collect information on the influence of transport processes on the electrochemical processes taking place at the electrodes. The electrochemical deposition-dissolution processes at the cathode are strongly dependent on the hydrodynamics. Detailed examination of the anodic oxidation of dissolved Mn(II) indicated that the manganese dioxide which formed adhered well to the electrode surface but in the cathodic return run it was again reduced. Electrode pairs of high-grade steel, lead and coal as well as material combinations were used to investigate heavy metal elimination in a membrane electrolysis cell. Using high-grade steel, lead and carbon electrode pairs, the reduction and deposition of Cu, Zn, Cr, Ni and some Cd in metallic or hydroxide form were observed in an order of 10-40 % in the cathode chamber. The dominant process in the anode chamber was the precipitation of manganese dioxide owing to the oxidation of dissolved Mn(II). Large amounts of heavy metals were co-precipitated by adsorption onto the insoluble MnO{sub 2}. High-grade steel and to some extent lead anodes were dissolved and hence were proven unsuitable as an anode material. These findings were largely confirmed by experiments using combination electrodes of coal and platinized titanium as an anode material and steel as a cathode material.The results indicate that electrochemical metal separation in the membrane electrolysis cell can represent a

  1. Theoretical considerations and a simple method for measuring alkalinity and acidity in low-pH waters by gran titration

    Science.gov (United States)

    Barringer, J.L.; Johnsson, P.A.

    1996-01-01

    Titrations for alkalinity and acidity using the technique described by Gran (1952, Determination of the equivalence point in potentiometric titrations, Part II: The Analyst, v. 77, p. 661-671) have been employed in the analysis of low-pH natural waters. This report includes a synopsis of the theory and calculations associated with Gran's technique and presents a simple and inexpensive method for performing alkalinity and acidity determinations. However, potential sources of error introduced by the chemical character of some waters may limit the utility of Gran's technique. Therefore, the cost- and time-efficient method for performing alkalinity and acidity determinations described in this report is useful for exploring the suitability of Gran's technique in studies of water chemistry.

  2. Polymer anion selective membranes for electrolytic splitting of water. Part I: stability of ion-exchange groups and impact of the polymer binder

    Czech Academy of Sciences Publication Activity Database

    Hnát, J.; Paidar, M.; Schauer, Jan; Žitka, Jan; Bouzek, K.

    2011-01-01

    Roč. 41, č. 9 (2011), s. 1043-1052 ISSN 0021-891X. [International Congress of Chemical and Process Engineering CHISA 2010 /19./ and European Congress of Chemical Engineering ECCE-7 /7./. Praha, 28.08.2010-01.09.2010] R&D Projects: GA MŠk(CZ) 7E08005 Institutional research plan: CEZ:AV0Z40500505 Keywords : water electrolysis * alkaline environment * polymer electrolyte Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.745, year: 2011

  3. Hydrogen electrolysis using a NASICON solid protonic conductor

    Energy Technology Data Exchange (ETDEWEB)

    Gulens, J.; Longhurst, T.H.; Kuriakose, A.K.; Canaday, J.D.

    1988-09-01

    A protonic conductor based on a bonded NASICON disc has been used for hydrogen electrolysis at 300 K. Currents up to 200 mA can be passed through the disc, and the electrolysis proceeds with 100% current efficiency. The resistance of the ceramic is affected by its extent of hydration. Degradation and failure of the ceramic occurs at the cathode as a result of electrolysis.

  4. Isotope exchange between alkaline earth metal hydroxide and HTO water in the equilibrium state

    International Nuclear Information System (INIS)

    Imaizumi, H.; Gounome, J.; Kano, N.

    1997-01-01

    In order reveal to what extent tritium ( 3 H or T) can be incorporated into hydroxides, the isotope exchange reaction (OT-for-OH exchange reaction) between each alkaline earth metal hydroxide (M(OH) 2 ), where M means alkaline earth metal (M=Ca, Sr or Ba) and HTO water was observed homogeneously at 30 deg C under equilibrium after mixing. Consequently, the followings were obtained: a quantitative relation between the electronegativity of each M ion and the ability (of the M ion) incorporating OT - into the M hydroxide can be found and the ability is small when the temperature is high, the exchange rate for the OT-for-OH exchange reaction is small when the electronegativity of the M ion in the M hydroxide is great, as for the dissociation of HTO water, it seems that formula (HTO ↔ T + + OH - ) is more predominant than the formula (HTO ↔H + + OT - ) when the temperature is high and the method used in this work is useful to estimate the reactivity of a certain alkaline material. (author)

  5. Micro-electrolysis technology for industrial wastewater treatment.

    Science.gov (United States)

    Jin, Yi-Zhong; Zhang, Yue-Feng; Li, Wei

    2003-05-01

    Experiments were conducted to study the role of micro-electrolysis in removing chromaticity and COD and improving the biodegradability of wastewater from pharmaceutical, dye-printing and papermaking plants. Results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of pharmaceutical wastewater. Lower initial pH could be advantageous to the removal of chromaticity. A retention time of 30 minutes was recommended for the process design of micro-electrolysis. For the use of micro-electrolysis in treatment of dye-printing wastewater, the removal rates of both chromaticity and COD were increased from neutral condition to acid condition for disperse blue wastewater; more than 90% of chromaticity and more than 50% of COD could be removed in neutral condition for vital red wastewater.

  6. Study of deuterium charging in palladium by electrolysis of heavy water

    International Nuclear Information System (INIS)

    De Ninno, A.; Violante, V.

    1992-01-01

    A mathematical model supported by a numerical computer code with distributed parameters was developed in order to describe the evolution of the deuteron concentration profile inside a Pd cathode under pulsed electrolysis. A delocalized gas picture was used when the deuterons exceeded the ratio, x=0.8, in Pd-D compounds. Several boundary conditions were taken into account. A good agreement was found between the system evolution and experimental data

  7. Electrolysis Bubble Noise in Small-Scale Tests of a Seawater MHD thruster

    Science.gov (United States)

    1990-09-01

    SECURITY CLAS&ICATION AUTHORITY I DISTRIBUTION/ AVAILABILIT Y OF REPORT 2b. DECLSIFICATIONJDOWNGRADING SCHEDULE Approved for public release...to those which might occur in an undersea MI-D-powered vesseL The electrolysis of sea water at current densities up to 0.3 A/cn, ’produced broad-band...3 Test Equipm eni ...................................................... 5 Water Table Facility and Flow Channels

  8. Electrochemical extraction of oxygen using PEM electrolysis technology

    Directory of Open Access Journals (Sweden)

    BOULBABA ELADEB

    2012-11-01

    Full Text Available Electrochemical extraction of oxygen from air can be carried out by chemical reduction of oxygen at the cathode and simultaneous oxygen evolution by water anode oxidation. The present investigation deals with the use of an electrolysis cell of PEM technology for this purpose. A dedicated 25 cm2 cell provided with a commercial water electrolysis MEA and titanium grooved plates has been designed for continuous operation at pressures close to the ambient level. The MEA consisted of a Nafion 117 membrane sandwiched between a Pt/C cathode and a non-supported Pt-Ir anode. Oxygen partial consumption in long-term runs was evaluated by analysis of the outlet air by gas chromatography, depending on the cell voltage - or the current density - and the excess in air oxygen fed to the cathode. Runs over more 50 hours indicated the relative stability of the components used for current densities ranging from 0.1 to 0.2 A cm-2 with high efficiency of oxygen reduction. Higher current density could be envisaged with more efficient MEA’s, exhibiting lower overpotentials for oxygen evolution to avoid too significant degradation of the anode material and the membrane. Interpretation of the data has been carried out by calculation of the cathode current efficiency.

  9. Corrosion behaviour of construction materials for high temperature water electrolysers

    Energy Technology Data Exchange (ETDEWEB)

    Nikiforov, A.; Petruchina, I.; Christensen, E.; Bjerrum, N.J.; Tomas-Garcya, A.L. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemistry, Materials Science Group

    2010-07-01

    This presentation reported on a study in which the feasibility of using different corrosion resistant stainless steels as a possible metallic bipolar plate and construction material was evaluated in terms of corrosion resistance under conditions corresponding to the conditions in high temperature proton exchange membrane (PEM) water electrolysers (HTPEMWE). PEM water electrolysis technology has been touted as an effective alternative to more conventional alkaline water electrolysis. Although the energy efficiency of this technology can be increased considerably at temperatures above 100 degrees C, this increases the demands to all the used materials with respect to corrosion stability and thermal stability. In this study, Ni-based alloys as well as titanium and tantalum samples were exposed to anodic polarization in 85 per cent phosphoric acid electrolyte solution. Tests were performed at 80 and 120 degrees C to determine the dependence of corrosion speed and working temperature. Platinum and gold plates were also tested for a comparative evaluation. Steady-state voltammetry was used along with scanning electron microscopy and energy-dispersive X-ray spectroscopy. Titanium showed the poorest corrosion resistance, while Ni-based alloys showed the highest corrosion resistance, with Inconel R 625 being the most promising alloy for the bipolar plate of an HTPEMWE. 3 refs., 1 tab., 2 figs.

  10. Performance of polyethylene based radiation grafted anion exchange membrane with polystyrene-b-poly (ethylene/butylene)-b-polystyrene based ionomer using NiCo2O4 catalyst for water electrolysis

    Science.gov (United States)

    Gupta, Gaurav; Scott, Keith; Mamlouk, Mohamed

    2018-01-01

    A soluble anion exchange ionomer with high OH- ion conductivity comparable to that of H+ conductivity of Nafion is synthesised by chloromethylation of polystyrene-b-poly (ethylene/butylene)-b-polystyrene (SEBS) and used with NiCo2O4 electro-catalyst for water electrolysis. The ionomer has an ion exchange capacity of 1.9 mmol g-1 and ionic conductivity of 0.14 S cm-2 at 50 °C. The cell voltage at 20 °C at 100 mA cm-2 is 1.77 and 1.72 V in, 0.1 and 1.0 M NaOH, respectively, for an optimum loading of 10 mg cm-2 NiCo2O4. At 10 mg cm-2 NiCo2O4 electrolyser cell performance is at least equal to or superior to that of IrO2 at 2 mg cm-2 with excellent stability over 1 h. When the catalyst is sprayed on the GDL instead of CCM, the performance is further improved to 1.65 V at 100 mA cm-2 at 60 °C & 0.1 M KOH. The limited AEM electrolyser performance when operating with deionised water in comparison to PEM and alkaline electrolyser arises from the sluggish OER in the AEM environment equivalent to pH of 11.5 and the two orders of magnitude lower HER activity with respect to acid medium combined with the high Tafel slope of 120 mV dec-1.

  11. High Temperature and Pressure Alkaline Electrochemical Reactor for Conversion of Power to Chemicals

    DEFF Research Database (Denmark)

    Chatzichristodoulou, Christodoulos

    2016-01-01

    forces. Raising the operating temperature offers a means to boost performance, as both ionic transport and reaction kinetics are exponentially activated with temperature. Indeed, we have demonstrated alkaline electrolysis cells operating at 200-250 °C and 20-50 bar at very high efficiencies and power...... been established enabling experiments with gaseous or liquids reactants/products at cell sizes of up to 25 cm2. Efforts are currently directed towards the investigation of the intrinsic activity of mixed oxides for the oxygen evolution reaction at elevated temperatures and pressures...

  12. Electro-activity of cobalt and nickel complexes for the reduction of protons into di-hydrogen. Application to PEM water electrolysis

    International Nuclear Information System (INIS)

    Pantani, O.; Anxolabehere, E.; Aukauloo, A.; Millet, P.

    2006-01-01

    Proton exchange membrane (PEM) water electrolysis is a safe and efficient way to perform water splitting into di-hydrogen and di-oxygen. In a PEM water electrolyser, platinum is commonly used as electro-catalyst on the cathodic side of the cells, mostly because of its efficiency for hydrogen evolution. But for cost considerations, there is a need to find alternative low-cost electrocatalysts. Molecular chemistry offers the possibility of synthesizing new compounds for this purpose, such as transition metal complexes. Results obtained with nickel- and cobalt-oximes compounds are presented in this paper. They have been chemically (1H NMR, EPR) and electrochemically (voltametry, spectro-electrochemistry) characterized. Their ability to electrochemically reduce protons into di-hydrogen when they are either dissolved in solution or immobilized at the surface of a solid electrode is discussed. (authors)

  13. High Temperature Electrolysis using Electrode-Supported Cells

    International Nuclear Information System (INIS)

    O'Brien, J.E.; Stoots, C.M.

    2010-01-01

    An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production. The cells currently under study were developed primarily for the fuel cell mode of operation. Results presented in this paper were obtained from single cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes (∼10 (micro)m thick), nickel-YSZ steam/hydrogen electrodes (∼1400 (micro)m thick), and manganite (LSM) air-side electrodes (∼90 (micro)m thick). The purpose of the present study was to document and compare the performance and degradation rates of these cells in the fuel cell mode and in the electrolysis mode under various operating conditions. Initial performance was documented through a series of DC potential sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-duration testing, first in the fuel cell mode, then in the electrolysis mode over more than 500 hours of operation. Results indicate accelerated degradation rates in the electrolysis mode compared to the fuel cell mode, possibly due to electrode delamination. The paper also includes details of the single-cell test apparatus developed specifically for these experiments.

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

    KAUST Repository

    Nam, Joo-Youn; Cusick, Roland D.; Kim, Younggy; Logan, Bruce E.

    2012-01-01

    Hydrogen gas can be electrochemically produced in microbial reverse-electrodialysis electrolysis cells (MRECs) using current derived from organic matter and salinity-gradient energy such as river water and seawater solutions. Here, it is shown

  15. Nanoporous materials for reducing the over potential of creating hydrogen by water electrolysis

    Science.gov (United States)

    Anderson, Marc A.; Leonard, Kevin C.

    2016-06-14

    Disclosed is an electrolyzer including an electrode including a nanoporous oxide-coated conducting material. Also disclosed is a method of producing a gas through electrolysis by contacting an aqueous solution with an electrode connected to an electrical power source, wherein the electrode includes a nanoporous oxide-coated conducting material.

  16. Development of new electrode materials for hydrogen production by water electrolysis

    International Nuclear Information System (INIS)

    Rozain, Caroline

    2013-01-01

    It is expected that PEM water electrolysis will play a significant role in the hydrogen society as a key process for producing hydrogen from renewable energy sources but before this, substantial cost reductions are still required. Because of the high acidity of membrane materials used in PEM water electrolysers, expensive noble-metals or their oxides are required as electrocatalysts (platinum for hydrogen evolution and iridium for oxygen evolution). As the oxygen evolution reaction takes place with a large overpotential (anodic potential ≥ 1.6 V) only few materials can be used to avoid corrosion. In state-of-the-art, noble metal oxides are generally used alone in the active layer with typical loadings of 2-3 mg/cm 2 and act as both catalyst and electronic conductor.In order to reduce the noble metal loadings and keep a good electronic conductivity of the catalytic layer, iridium can be supported onto a conductive and electrochemical stable material support. To gain more insights, several MEAs with anodes made of pure iridium oxide or 50 wt % IrO 2 /Ti anodes have been prepared and characterized using cyclic voltammetry and impedance spectroscopy, and by measuring polarization curves at different operating temperatures. Without the catalyst support, anodic loadings can be reduced down to 0,5 mg/cm 2 without any degradation in the electrochemical performances. By using anodes made of iridium oxide and titanium particles, further reductions of anodic loading can be made down to 0.1 mg/cm 2 with performances similar to those obtained with conventional loadings of several mg cm 2 . (author) [fr

  17. Growth of brown trout in acid and alkaline waters

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R N

    1961-01-01

    Studies have been performed to determine the factors affecting the growth and maturity of brown trout in lochs in the Highlands of Scotland. Evidence has been found which supports the view that the growth rate depends more on the relation between the trout population and the food supply than on any direct influence of the chemical composition of the water. Details are given of the growth rate of trout in nine lochs with a wide range of alkalinities where spawning facilities are either very good or poor or non-existent.

  18. Mathematical model of water transport in Bacon and alkaline matrix-type hydrogen-oxygen fuel cells

    Science.gov (United States)

    Prokopius, P. R.; Easter, R. W.

    1972-01-01

    Based on general mass continuity and diffusive transport equations, a mathematical model was developed that simulates the transport of water in Bacon and alkaline-matrix fuel cells. The derived model was validated by using it to analytically reproduce various Bacon and matrix-cell experimental water transport transients.

  19. Surface topography of a palladium cathode after electrolysis in heavy water

    International Nuclear Information System (INIS)

    Silver, D.S.; Dash, J.; Keefe, P.S.

    1993-01-01

    Electrolysis was performed with a palladium cathode and an electrolyte containing both hydrogen and deuterium ions. The cathode bends toward the anode during this process. Examination of both the concave and the convex surfaces with the scanning electron microscope, scanning tunneling microscope, and atomic force microscope shows unusual surface characteristics. Rimmed craters with faceted crystals inside and multitextural surfaces were observed on an electrolyzed palladium cathode but not on palladium that has not been electrolyzed. 9 refs., 9 figs

  20. Process optimization of ultrasound-assisted alcoholic-alkaline treatment for granular cold water swelling starches.

    Science.gov (United States)

    Zhu, Bo; Liu, Jianli; Gao, Weidong

    2017-09-01

    This paper reports on the process optimization of ultrasonic assisted alcoholic-alkaline treatment to prepare granular cold water swelling (GCWS) starches. In this work, three statistical approaches such as Plackett-Burman, steepest ascent path analysis and Box-Behnken design were successfully combined to investigate the effects of major treatment process variables including starch concentration, ethanol volume fraction, sodium hydroxide dosage, ultrasonic power and treatment time, and drying operation, that is, vacuum degree and drying time on cold-water solubility. Results revealed that ethanol volume fraction, sodium hydroxide dosage, applied power and ultrasonic treatment time were significant factors that affected the cold-water solubility of GCWS starches. The maximum cold-water solubility was obtained when treated at 400W of applied power for 27.38min. Optimum volume fraction of ethanol and sodium hydroxide dosage were 66.85% and 53.76mL, respectively. The theoretical values (93.87%) and the observed values (93.87%) were in reasonably good agreement and the deviation was less than 1%. Verification and repeated trial results indicated that the ultrasound-assisted alcoholic-alkaline treatment could be successfully used for the preparation of granular cold water swelling starches at room temperatures and had excellent improvement on the cold-water solubility of GCWS starches. Copyright © 2016. Published by Elsevier B.V.

  1. Fusion reactors for hydrogen production via electrolysis

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.; Steinberg, M.

    1979-01-01

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of approx. 50 to 70% are projected for fusion reactors using high temperature blankets

  2. Apparent Km of mitochondria for oxygen computed from Vmax measured in permeabilized muscle fibers is lower in water enriched in oxygen by electrolysis than injection.

    Science.gov (United States)

    Zoll, Joffrey; Bouitbir, Jamal; Sirvent, Pascal; Klein, Alexis; Charton, Antoine; Jimenez, Liliana; Péronnet, François R; Geny, Bernard; Richard, Ruddy

    2015-01-01

    It has been suggested that oxygen (O2) diffusion could be favored in water enriched in O2 by a new electrolytic process because of O2 trapping in water superstructures (clathrates), which could reduce the local pressure/content relationships for O2 and facilitate O2 diffusion along PO2 gradients. Mitochondrial respiration was compared in situ in saponin-skinned fibers isolated from the soleus muscles of Wistar rats, in solution enriched in O2 by injection or the electrolytic process 1) at an O2 concentration decreasing from 240 µmol/L to 10 µmol/L (132 mmHg to 5 mmHg), with glutamate-malate or N, N, N', N'-tetramethyl-p-phenylenediamine dihydrochloride (TMPD)-ascorbate (with antimycin A) as substrates; and 2) at increasing adenosine diphosphate (ADP) concentration with glutamate-malate as substrate. As expected, maximal respiration decreased with O2 concentration and, when compared to glutamate-malate, the apparent Km O2 of mitochondria for O2 was significantly lower with TMPD-ascorbate with both waters. However, when compared to the water enriched in O2 by injection, the Km O2 was significantly lower with both electron donors in water enriched in O2 by electrolysis. This was not associated with any increase in the sensitivity of mitochondria to ADP; no significant difference was observed for the Km ADP between the two waters. In this experiment, a higher affinity of the mitochondria for O2 was observed in water enriched in O2 by electrolysis than by injection. This observation is consistent with the hypothesis that O2 diffusion can be facilitated in water enriched in O2 by the electrolytic process.

  3. The influence of lake water alkalinity and humic substances on particle dispersion and lanthanum desorption from a lanthanum modified bentonite

    DEFF Research Database (Denmark)

    Reitzel, Kasper; Balslev, Kristiane Astrid; Jensen, Henning S

    2017-01-01

    A 12 days laboratory study on potential desorption of Lanthanum (La) from a commercial La modified clay (Phoslock) was conducted using lake water from 17 Danish lakes with alkalinities between 0.02 and 3.7 meq L-1and varying concentrations of DOC and humic acids (HA's). A similar study...... was conducted in artificial lake water with alkalinities from 0 to 2.5 meq L-1in order to exclude interference from dissolved HA's. To test if La in solution (FLa) was associated with fine particles, the water samples were filtered sequentially through three filter sizes (1.2 μm, 0.45 μm and 0.2 μm...... at low alkalinities. In addition, this study showed that HA's seem to increase the FLa concentrations in soft water lakes, most likely through complexation of La retained in the Phoslock matrix. In summary, we conclude that elevated La concentrations in lake water after a Phoslock treatment should only...

  4. Treatment of oilfield wastewater by combined process of micro-electrolysis, Fenton oxidation and coagulation.

    Science.gov (United States)

    Zhang, Zhenchao

    2017-12-01

    In this study, a combined process was developed that included micro-electrolysis, Fenton oxidation and coagulation to treat oilfield fracturing wastewater. Micro-electrolysis and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance organic components gradability, respectively. Orthogonal experiment were employed to investigate the influence factors of micro-electrolysis and Fenton oxidation on COD removal efficiency. For micro-electrolysis, the optimum conditions were: pH, 3; iron-carbon dosage, 50 mg/L; mass ratio of iron-carbon, 2:3; reaction time, 60 min. For Fenton oxidation, a total reaction time of 90 min, a H 2 O 2 dosage of 12 mg/L, with a H 2 O 2 /Fe 2+ mole ratio of 30, pH of 3 were selected to achieve optimum oxidation. The optimum conditions in coagulation process: pH, cationic polyacrylamide dosage, mixing speed and time is 4.3, 2 mg/L, 150 rpm and 30 s, respectively. In the continuous treatment process under optimized conditions, the COD of oily wastewater fell 56.95%, 46.23%, 30.67%, respectively, from last stage and the total COD removal efficiency reached 83.94% (from 4,314 to 693 mg/L). In the overall treatment process under optimized conditions, the COD of oily wastewater was reduced from 4,314 to 637 mg/L, and the COD removal efficiency reached 85.23%. The contribution of each stage is 68.45% (micro-electrolysis), 24.07% (Fenton oxidation), 7.48% (coagulation), respectively. Micro-electrolysis is the uppermost influencing process on COD removal. Compared with the COD removal efficiency of three processes on raw wastewater under optimized conditions: the COD removal efficiency of single micro-electrolysis, single Fenton oxidation, single coagulation is 58.34%, 44.88% and 39.72%, respectively. Experiments proved the effect of combined process is marvelous and the overall water quality of the final effluent could meet the class III national wastewater discharge standard of petrochemical industry of China

  5. Degradation in Solid Oxide Cells During High Temperature Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Manohar Sohal

    2009-05-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells. One goal of that project is to address the technical and degradation issues associated with solid oxide electrolysis cells. This report covers a variety of these degradation issues, which were discussed during a workshop on “Degradation in Solid Oxide Electrolysis Cells and Strategies for its Mitigation,” held in Phoenix, AZ on October 27, 2008. Three major degradation issues related to solid oxide electrolysis cells discussed at the workshop are: • Delamination of O2-electrode and bond layer on steam/O2-electrode side • Contaminants (Ni, Cr, Si, etc.) on reaction sites (triple-phase boundary) • Loss of electrical/ionic conductivity of electrolyte. This list is not all inclusive, but the workshop summary can be useful in providing a direction for future research related to the degradation of solid oxide electrolysis cells.

  6. Recovery of copper and water from copper-electroplating wastewater by the combination process of electrolysis and electrodialysis.

    Science.gov (United States)

    Peng, Changsheng; Liu, Yanyan; Bi, Jingjing; Xu, Huizhen; Ahmed, Abou-Shady

    2011-05-30

    In this paper, a laboratory-scale process which combined electrolysis (EL) and electrodialysis (ED) was developed to treat copper-containing wastewater. The feasibility of such process for copper recovery as well as water reuse was determined. Effects of three operating parameters, voltage, initial Cu(2+) concentration and water flux on the recovery of copper and water were investigated and optimized. The results showed that about 82% of copper could be recovered from high concentration wastewater (HCW, >400mg/L) by EL, at the optimal conditions of voltage 2.5 V/cm and water flux 4 L/h; while 50% of diluted water could be recycled from low concentration wastewater (LCW, water flux 4 L/h. However, because of the limitation of energy consumption (EC), LCW for EL and HCW for ED could not be treated effectively, and the effluent water of EL and concentrated water of ED should be further treated before discharged. Therefore, the combination process of EL and ED was developed to realize the recovery of copper and water simultaneously from both HCW and LCW. The results of the EL-ED process showed that almost 99.5% of copper and 100% of water could be recovered, with the energy consumption of EL ≈ 3 kW h/kg and ED ≈ 2 kW h/m(3). According to SEM and EDX analysis, the purity of recovered copper was as high as 97.9%. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Bioelectrohydrogenesis and inhibition of methanogenic activity in microbial electrolysis cells - A review.

    Science.gov (United States)

    Karthikeyan, Rengasamy; Cheng, Ka Yu; Selvam, Ammaiyappan; Bose, Arpita; Wong, Jonathan W C

    2017-11-01

    Microbial electrolysis cells (MECs) are a promising technology for biological hydrogen production. Compared to abiotic water electrolysis, a much lower electrical voltage (~0.2V) is required for hydrogen production in MECs. It is also an attractive waste treatment technology as a variety of biodegradable substances can be used as the process feedstock. Underpinning this technology is a recently discovered bioelectrochemical pathway known as "bioelectrohydrogenesis". However, little is known about the mechanism of this pathway, and numerous hurdles are yet to be addressed to maximize hydrogen yield and purity. Here, we review various aspects including reactor configurations, microorganisms, substrates, electrode materials, and inhibitors of methanogenesis in order to improve hydrogen generation in MECs. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Contact glow discharge electrolysis: its origin, plasma diagnostics and non-faradaic chemical effects

    International Nuclear Information System (INIS)

    Sen Gupta, Susanta K

    2015-01-01

    Contact glow discharge electrolysis (CGDE) also termed plasma electrolysis is a novel electrolysis where a stable sheath of light emitting plasma develops around an electrode immersed well inside a relatively high-conductivity liquid electrolyte during normal electrolysis (NE) at several hundred volts. The phenomenon may develop in dc-, pulsed dc-, ac- as well as RF-driven electrolyses. The chemical effects of CGDE are remarkably non-faradaic in respect to the nature of the products as well as their yields. The article traces comprehensively the progress made in studies of CGDE in aqueous and non-aqueous solutions since 1844 and reviews the developments in the understanding of its origin, light emission, plasma state and non-faradaic effects leading to the elucidation of detailed mechanism of the origin of CGDE on the basis of the onset of hydrodynamic instabilities in local vaporization of the solvent near the working electrode during NE, and that of highly non-faradaic effects of CGDE based on a model of two reaction zones located within the electrode plasma and at the plasma–liquid interface producing solvent derived radicals at high local concentrations. Keeping in view the recent surge of interest in varied applications of CGDE, the article is appended with highlights of these applications across synthetic chemistry, waste water treatment, electrosurgical devices, nanoparticle fabrications, surface engineering and micro-machining. (topical review)

  9. Fused salt electrolysis

    International Nuclear Information System (INIS)

    Ares, Osvaldo; Botbol, Jose.

    1989-01-01

    Working conditions for zirconium preparation by fused salt electrolysis were studied. For such purpose, a cell was built for operation under argon atmosphere. A graphite crucible served as anode, with steel cathodes. Proper design allowed cathode rechange under the inert atmosphere. Cathodic deposits of zirconium powder occluded salts from the bath. After washing with both water and hydrochloric acid, the metallic powder was consolidated by fusion. Optimum operating conditions were found to arise from an electrolyte of 12% potassium hexafluorzirconate -88% sodium chloride, at 820 deg C and 5 A/cm 2 cathodic current density. Deposits contained 35% of metal and current efficiency reached 66%. The powder contained up to 600 ppm of chlorine and 1.700 ppm of fluorine; after fusion, those amounts decreased to 2 ppm and 3 ppm respectively, with low proportion of metallic impurities. Though oxygen proportion was 4.500 ppm, it should be lowered by improving working conditions, as well as working on an ampler scale. (Author)

  10. Experimental Study of Hydroxy Gas (HHO) Production with Variation in Current, Voltage and Electrolyte Concentration

    Science.gov (United States)

    Alam, Noor; Pandey, K. M.

    2017-08-01

    In this paper, work has been carried out experimentally for the investigation of the effects of variation incurrent, voltage, temperature, chemical concentration and reaction time on the amount of hydroxy gas produced. Further effects on the overall electrolysis efficiency of advance alkaline water is also studied. The hydroxy gas (HHO) has been produced experimentally by the electrolysis of alkaline water with parallel plate electrode of 316L-grade stainless steel. The electrode has been selected on the basis of corrosion resistance and inertness with respect to electrolyte (KOH). The process used for the production of HHO is conventional as compared to the other production processes because of reduced energy consumption, less maintenance and low setup cost. From the experimental results, it has been observed that with increase in voltage, temperature and electrolyte concentration of alkaline solution, the production of hydroxy gas has increased about 30 to 40% with reduction in electrical energy consumption.

  11. Increased river alkalinization in the Eastern U.S.

    Science.gov (United States)

    Kaushal, Sujay S; Likens, Gene E; Utz, Ryan M; Pace, Michael L; Grese, Melissa; Yepsen, Metthea

    2013-09-17

    The interaction between human activities and watershed geology is accelerating long-term changes in the carbon cycle of rivers. We evaluated changes in bicarbonate alkalinity, a product of chemical weathering, and tested for long-term trends at 97 sites in the eastern United States draining over 260,000 km(2). We observed statistically significant increasing trends in alkalinity at 62 of the 97 sites, while remaining sites exhibited no significant decreasing trends. Over 50% of study sites also had statistically significant increasing trends in concentrations of calcium (another product of chemical weathering) where data were available. River alkalinization rates were significantly related to watershed carbonate lithology, acid deposition, and topography. These three variables explained ~40% of variation in river alkalinization rates. The strongest predictor of river alkalinization rates was carbonate lithology. The most rapid rates of river alkalinization occurred at sites with highest inputs of acid deposition and highest elevation. The rise of alkalinity in many rivers throughout the Eastern U.S. suggests human-accelerated chemical weathering, in addition to previously documented impacts of mining and land use. Increased river alkalinization has major environmental implications including impacts on water hardness and salinization of drinking water, alterations of air-water exchange of CO2, coastal ocean acidification, and the influence of bicarbonate availability on primary production.

  12. Defluoridation of drinking water by combined electrocoagulation: effects of the molar ratio of alkalinity and fluoride to Al(III).

    Science.gov (United States)

    Zhao, Hua-Zhang; Yang, Wei; Zhu, Jun; Ni, Jin-Ren

    2009-03-01

    The defluoridation efficiency (epsilon(F)) of electrocoagulation (EC) is closely related to the pH level of the F(-)-containing solution. The pH level usually needs to be adjusted by adding acid in order to obtain the highest epsilon(F) for the F(-)-containing groundwater. The use of combined EC (CEC), which is the combination of chemical coagulation with EC, was proposed to remove fluoride from drinking water for the first time in this study. The optimal scheme for the design and operation of CEC were obtained through experiments on the treatment of F(-)-containing groundwater. It was found, with OH(-) being the only alkalinity of the raw water, that the highest efficiency would be obtained when the molar ratio of alkalinity and fluoride to Al(III) (gamma(Alkalinity+F)) was controlled at 3.0. However, when the raw water contained HCO(3)(-) alkalinity, a correction coefficient was needed to correct the concentration of HCO(3)(-) to obtain the optimal defluoridation condition of gamma(Alkalinity+F)=3.0 for CEC. The correction coefficient of HCO(3)(-) concentration was concluded as 0.60 from the experiment. For the practical F(-)-containing groundwater treatment, CEC can achieve similar epsilon(F) as an acid-adding EC process. The consumption of aluminum electrode was decreased in CEC. The energy consumption also declined greatly in CEC, which is less than one third of that in the acid-adding EC process.

  13. NASA fuel cell applications for space: Endurance test results on alkaline fuel cell electrolyzer components

    International Nuclear Information System (INIS)

    Sheibley, D.W.

    1984-01-01

    Fuel cells continue to play a major role in manned spacecraft power generation. The Gemini and Apollo programs used fuel cell power plants as the primary source of mission electrical power, with batteries as the backup. The current NASA use for fuel cells is in the Orbiter program. Here, low temperature alkaline fuel cells provide all of the on-board power with no backup power source. Three power plants per shipset are utilized; the original power plant contained 32-cell substacks connected in parallel. For extended life and better power performance, each power plant now contains three 32-cell substacks connected in parallel. One of the possible future applications for fuel cells will be for the proposed manned Space Station in low earth orbit (LEO)(1, 2, 3). By integrating a water electrolysis capability with a fuel cell (a regenerative fuel cell system), a multikilowatt energy storage capability ranging from 35 kW to 250 kW can be achieved. Previous development work on fuel cell and electrolysis systems would tend to minimize the development cost of this energy storage system. Trade studies supporting initial Space Station concept development clearly show regenerative fuel cell (RFC) storage to be superior to nickel-cadmium and nickel-hydrogen batteries with regard to subsystem weight, flexibility in design, and integration with other spacecraft systems when compared for an initial station power level ranging from 60 kW to 75 kW. The possibility of scavenging residual O 2 and H 2 from the Shuttle external tank for use in fuel cells for producing power also exists

  14. Microbial electrolysis desalination and chemical-production cell for CO2 sequestration

    KAUST Repository

    Zhu, Xiuping

    2014-05-01

    Mineral carbonation can be used for CO2 sequestration, but the reaction rate is slow. In order to accelerate mineral carbonation, acid generated in a microbial electrolysis desalination and chemical-production cell (MEDCC) was examined to dissolve natural minerals rich in magnesium/calcium silicates (serpentine), and the alkali generated by the same process was used to absorb CO2 and precipitate magnesium/calcium carbonates. The concentrations of Mg2+ and Ca2+ dissolved from serpentine increased 20 and 145 times by using the acid solution. Under optimal conditions, 24mg of CO2 was absorbed into the alkaline solution and 13mg of CO2 was precipitated as magnesium/calcium carbonates over a fed-batch cycle (24h). Additionally, the MEDCC removed 94% of the COD (initially 822mg/L) and achieved 22% desalination (initially 35g/L NaCl). These results demonstrate the viability of this process for effective CO2 sequestration using renewable organic matter and natural minerals. © 2014 Elsevier Ltd.

  15. Electrolysis with diamond anodes: Eventually, there are refractory species!

    Science.gov (United States)

    Mena, Ismael F; Cotillas, Salvador; Díaz, Elena; Sáez, Cristina; Rodríguez, Juan J; Cañizares, P; Mohedano, Ángel F; Rodrigo, Manuel A

    2018-03-01

    In this work, synthetic wastewater polluted with ionic liquid 1-butyl-3-methylimidazolium (Bmim) bis(trifluoromethanesulfonyl)imide (NTf 2 ) undergoes four electrolytic treatments with diamond anodes (bare electrolysis, electrolysis enhanced with peroxosulfate promoters, irradiated with UV light and with US) and results obtained were compared with those obtained with the application of Catalytic Wet Peroxide Oxidation (CWPO). Despite its complex heterocyclic structure, Bmim + cation is successfully depleted with the five technologies tested, being transformed into intermediates that eventually can be mineralized. Photoelectrolysis attained the lowest concentration of intermediates, while CWPO is the technology less efficient in their degradation. However, the most surprising result is that concentration of NTf 2 - anion does not change during the five advanced oxidation processes tested, pointing out its strong refractory character, being the first species that exhibits this character in wastewater undergoing electrolysis with diamond. This means that the hydroxyl and sulfate radicals mediated oxidation and the direct electrolysis are inefficient for breaking the C-S, C-F and S-N bounds of the NTf 2 - anion, which is a very interesting mechanistic information to understand the complex processes undergone in electrolysis with diamond. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Heavy water upgrading system in the Fugen heavy water reactor

    International Nuclear Information System (INIS)

    Matsushita, T.; Susaki, S.

    1980-01-01

    The heavy water upgrading system, which is installed in the Fugen heavy water reactor (HWR) was designed to reuse degraded heavy water generated from the deuteration-dedeuteration of resin in the ion exchange column of the moderator purification system. The electrolysis method has been applied in this system on the basis of the predicted generation rate and concentration of degraded heavy water. The structural feature of the electrolytic cell is that it consists of dual cylindrical electrodes, instead of a diaphragm as in the case of conventional water electrolysis. 2 refs

  17. A model-based understanding of solid-oxide electrolysis cells (SOECs) for syngas production by H2O/CO2 co-electrolysis

    Science.gov (United States)

    Menon, Vikram; Fu, Qingxi; Janardhanan, Vinod M.; Deutschmann, Olaf

    2015-01-01

    High temperature co-electrolysis of H2O and CO2 offers a promising route for syngas (H2, CO) production via efficient use of heat and electricity. The performance of a SOEC during co-electrolysis is investigated by focusing on the interactions between transport processes and electrochemical parameters. Electrochemistry at the three-phase boundary is modeled by a modified Butler-Volmer approach that considers H2O electrolysis and CO2 electrolysis, individually, as electrochemically active charge transfer pathways. The model is independent of the geometrical structure. A 42-step elementary heterogeneous reaction mechanism for the thermo-catalytic chemistry in the fuel electrode, the dusty gas model (DGM) to account for multi-component diffusion through porous media, and a plug flow model for flow through the channels are used in the model. Two sets of experimental data are reproduced by the simulations, in order to deduce parameters of the electrochemical model. The influence of micro-structural properties, inlet cathode gas velocity, and temperature are discussed. Reaction flow analysis is performed, at OCV, to study methane production characteristics and kinetics during co-electrolysis. Simulations are carried out for configurations ranging from simple one-dimensional electrochemical button cells to quasi-two-dimensional co-flow planar cells, to demonstrate the effectiveness of the computational tool for performance and design optimization.

  18. Researches on the electrolysis of metal oxides dissolved in boric anhydride or in melt borates. New methods of preparation of amorphous boron, borides and some metals; Recherches sur l'electrolyse des oxydes metalliques dissous dans l'anhydride borique ou dans les borates fondus. Nouvelles methodes de preparation du bore amorphe, des borures et de quelques metaux

    Energy Technology Data Exchange (ETDEWEB)

    Andrieux, Lucien

    1929-06-15

    This research thesis reports the investigation of the electrolysis of alkaline borates, alkaline earth borates and magnesium borate, and the investigation of mixtures containing a metal oxide dissolved in a bath formed by a tetraborate and a fluoride. The author more particularly studies the chemical products separated at the cathode level, i.e. boron (more or less pure), borates and other metals (zinc, tungsten, molybdenum)

  19. Carbon-encapsulated nickel-cobalt alloys nanoparticles fabricated via new post-treatment strategy for hydrogen evolution in alkaline media

    Science.gov (United States)

    Guo, Hailing; Youliwasi, Nuerguli; Zhao, Lei; Chai, Yongming; Liu, Chenguang

    2018-03-01

    This paper addresses a new post-treatment strategy for the formation of carbon-encapsulated nickel-cobalt alloys nanoparticles, which is easily controlled the performance of target products via changing precursor composition, calcination conditions (e.g., temperature and atmosphere) and post-treatment condition. Glassy carbon electrode (GCE) modified by the as-obtained carbon-encapsulated mono- and bi-transition metal nanoparticles exhibit excellent electro-catalytic activity for hydrogen production in alkaline water electrolysis. Especially, Ni0.4Co0.6@N-Cs800-b catalyst prepared at 800 °C under an argon flow exhibited the best electrocatalytic performance towards HER. The high HER activity of the Ni0.4Co0.6@N-Cs800-b modified electrode is related to the appropriate nickel-cobalt metal ratio with high crystallinity, complete and homogeneous carbon layers outside of the nickel-cobalt with high conductivity and the synergistic effect of nickel-cobalt alloys that also accelerate electron transfer process.

  20. Durable solid oxide electrolysis cells and stacks

    Energy Technology Data Exchange (ETDEWEB)

    Ming Chen

    2010-08-15

    The purpose of this project was to make a substantial contribution to development of a cost competitive electrolysis technology based on solid oxide cells. The strategy was to address what had been identified as the key issues in previous research projects. Accordingly five lines of work were carried out in the here reported project: 1) Cell and stack element testing and post test characterization to identify major degradation mechanisms under electrolysis operation. 2) Development of interconnects and coatings to allow stable electrolysis operation at approx850 deg. C or above. 3) Development of seals with reduced Si emission. 4) Development of durable SOEC cathodes. 5) Modeling. Good progress has been made on several of the planned activities. The outcome and most important achievements of the current project are listed for the five lines of the work. (LN)

  1. Ballast Water Treatment, U.S. Great Lakes Bulk Carrier Engineering and Cost Study. Volume 2: Analysis of On-Board Treatment Methods, Alternative Ballast Water Management Practices, and Implementation Costs

    Science.gov (United States)

    2013-11-01

    on discharge 3 CleanBallast Ballast Water Management System RWO Marine Water Technology 55 μm automatic back-flushing disc filter, electrolysis ...did not independently validate manufacturers’ claims. BWT technologies which apply electric current to ballast water ( electrolysis ) are affected by low...salinity prior to electrolysis , and the feed water must be preheated when the ballast water temperatures drop below 15 ºC. 1. Power Consumption

  2. Experimental and analytical analysis of polarization and water transport behaviors of hydrogen alkaline membrane fuel cell

    Science.gov (United States)

    Huo, Sen; Zhou, Jiaxun; Wang, Tianyou; Chen, Rui; Jiao, Kui

    2018-04-01

    Experimental test and analytical modeling are conducted to investigate the operating behavior of an alkaline electrolyte membrane (AEM) fuel cell fed by H2/air (or O2) and explore the effect of various operating pressures on the water transfer mechanism. According to the experimental test, the cell performance is greatly improved through increasing the operating pressure gradient from anode to cathode which leads to significant liquid water permeation through the membrane. The high frequency resistance of the A901 alkaline membrane is observed to be relatively stable as the operating pressure varies based on the electrochemical impedance spectroscopy (EIS) method. Correspondingly, based on the modeling prediction, the averaged water content in the membrane electrode assembly (MEA) does not change too much which leads to the weak variation of membrane ohmic resistance. This reveals that the performance enhancement should give the credit to better electro-chemical reaction kinetics for both the anode and cathode, also prone by the EIS results. The reversion of water back diffusion direction across the membrane is also observed through analytical solution.

  3. Performance of metal compound on thermolysis and electrolysis on sugar industries waste water treatment: COD and color removal with sludge analysis (batch-experiment)

    Science.gov (United States)

    Sahu, Omprakash

    2017-10-01

    The sugar cane industry is one of the most water demanding industries. Sugar industries consume and generate excess amount of water. The generated water contains organic compounds, which would cause pollution. The aim of this research work is to study the effectiveness of metal compound for treatment of sugar industry waste water by thermolysis and electrolysis process. The result shows ferrous metal catalyst shows 80 and 85 % chemical oxygen demand and color removal at pH 6, optimum mass loading 4 kg/m3, treatment temperature 85 °C and treatment time 9 h. When ferrous material was used as electrode, maximum 81 % chemical oxygen demand and 84 % color removal at pH 6, current density 156 Am-2, treatment time 120 min and anode consumption 0.7 g for 1.5 L wastewater were obtained.

  4. Electrolytic materials for hydrogen production by water electrolysis; Materiais eletroliticos para a producao de hidrogenio por eletrolise da agua

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E R; Avaca, L A; Motheo, A J [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica e Quimica; Carvalho, J de [Alagoas Univ., Maceio, AL (Brazil)

    1985-12-31

    The hydrogen and oxygen evolution reactions in the electrolysis of water were studied on Ni-Fe and Ni-Co co deposits, respectively, in 28% KOH solution at 60 deg C. The studies were carried out on micro and macro electrodes and the results compared to those obtained with conventional materials. In the HER is observed a significant improvement in the electrocatalytic activity which points out the Ni-Fe co deposits as good substitutes for the conventional mild steel electrodes. In contrast, the Ni-Co co deposits don`t present enhanced activity when compared to Ni electro deposits. However the higher mechanic resistance observed make its utilization attractive. (author). 3 tabs., 2 figs., 11 refs

  5. Health Effects of Alkaline Diet and Water, Reduction of Digestive-tract Bacterial Load, and Earthing.

    Science.gov (United States)

    Mousa, Haider Abdul-Lateef

    2016-04-01

    In the article, the author discusses the issue of chronic, low-grade acidosis that is thought to be brought about primarily by 2 factors: (1) advancing age, with a consequent decline in renal function; and (2) diet. An acid-forming diet can induce low-grade metabolic acidosis, which causes very small decreases in blood pH and plasma bicarbonate (HCO3-) that remain within the range considered to be normal. However, if the duration of the acidosis is prolonged or chronically present, even a low degree of acidosis can become significant. This article reviews supporting evidence in the literature that has shown that consumption of abundant alkaline-forming foods can result in improvement in bone mineral density (BMD) and muscle mass, protection from chronic illnesses, reduced tumor-cell invasion and metastasis, and effective excretion of toxins from the body. In addition, a large number of studies showing the benefits of alkaline water (mineral water) have revealed that people consuming water with a high level of total dissolved solids (TDS) (ie, with a high mineral content) have shown a lower incidence of coronary heart disease (CHD), cardiovascular disease (CVD), and cancer and lower total mortality rates. Consumption of alkaline water also may prevent osteoporosis and protect pancreatic beta cells with its antioxidant effects. In addition, this article discusses the literature that shows that reducing digestive-tract bacterial load can play an important role in increasing blood alkalinity toward the normal upper limit. That change occurs through good oral hygiene, flossing of teeth, perfect chewing of food, and bowel evacuation as soon as possible. Finally, the author reviews the literature that shows that earthing (ie, the direct contact of the human body with the earth) can supply a current of plentiful electrons. Earthing has been shown to reduce acute and chronic inflammation, blood glucose in patients with diabetes, red blood cell (RBC) aggregation, and blood

  6. Novel bio-electro-Fenton technology for azo dye wastewater treatment using microbial reverse-electrodialysis electrolysis cell

    DEFF Research Database (Denmark)

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan

    2017-01-01

    Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater. In such ......Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater....... In such MREC-Fenton integrated process, the production of H2O2 which is the key reactant of fenton-reaction was driven by the electrons harvested from the exoelectrogens and salinity-gradient between sea water and fresh water in MREC. Complete decolorization and mineralization of 400 mg L-1 Orange G...

  7. FY 1985 report on research and development project commissioned by the Sunshine Project. Research and development of electrolysis of water by combined thermochemical, photochemical and electrochemical cycles; 1985 nendo netsu kagaku, hikari kagaku, denki kagaku konsei cycle ni yoru mizu bunkai no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-03-01

    Reported herein are the FY 1985 research results on the combined water electrolysis cycles by effective utilization of sunlight. The tests for determining activity coefficient of an iron/iodine system is continued from the previous year, and the results are used to find the optimum conditions under which the photochemical and electrolysis reactions are effected simultaneously in a light-irradiated electrolysis tank. It is found that a photochemical reaction efficiency of approximately 0.3% is obtained at 5 W/cm{sup 2} as light intensity and 25 degrees C. For electrolysis of water by the multi-stage hybrid cycles, it is necessary for the reaction in each stage to proceed to almost the same extent so that it gives a just enough quantity of product for the subsequent stage. The data obtained are analyzed comprehensively, while taking the system matching conditions into consideration. The system for simultaneously measure two or more parameters, developed in the previous year, is equipped with a high-level language compiler of high effective speed, to simultaneously measure these parameters at shorter intervals. (NEDO)

  8. Solução oxidante gerada a partir da eletrólise de rejeitos de dessalinizadores de água Oxidant solution generated by electrolysis from residue of water desalinators

    Directory of Open Access Journals (Sweden)

    Jeruza Feitosa de Matos

    2006-06-01

    Full Text Available Neste trabalho foram realizados estudos para a produção de solução oxidante a partir de rejeito de dessalinizadores de água pelo processo de eletrólise, visando a sua utilização como desinfetante. O experimento foi realizado em escala de laboratório. Três soluções oxidantes foram geradas eletroliticamente, a partir de rejeitos de dessalinizadores de água com concentrações de 1,7 x 10³ mg; 5,5 x 10³ mg e 10,2 x 10³ mg de Cl-/L. O processo de eletrólise tinha duração de oito horas e, a cada hora da reação, o pH, a condutividade elétrica, a temperatura e o cloro total eram monitorados. Foi observado que a produção de cloro está diretamente relacionada com a concentração de cloreto; o teor médio de cloro das soluções oxidantes geradas foi de 0,10%; 0,24 % e 0,27 % m/m.This work carried out studies about the use of the electrolysis process to produce oxidant solutions from water desalinators wastes for water disinfection. The experiment was conducted in laboratory scale. Three oxidant solutions were generated by electrolysis from wastes of water desalinators that presented concentrations of 1.7 x 10³ mg, 5.5 x 10³ mg and 10.2 x 10³ mg of Cl-/L.The electrolysis process lasted eight hours and the following parameters were monitored every hour: pH, electrical conductivity, temperature, total chlorine. It was observed that the production of chlorine is directly related to chloride concentration; the average content of chlorine of the oxidant solutions generated from the desalinators wastes was 0.10%, 0.24% and 0.27% m/m.

  9. Progress in Aluminum Electrolysis Control and Future Direction for Smart Aluminum Electrolysis Plant

    Science.gov (United States)

    Zhang, Hongliang; Li, Tianshuang; Li, Jie; Yang, Shuai; Zou, Zhong

    2017-02-01

    The industrial aluminum reduction cell is an electrochemistry reactor that operates under high temperatures and highly corrosive conditions. However, these conditions have restricted the measurement of key control parameters, making the control of aluminum reduction cells a difficult problem in the industry. Because aluminum electrolysis control systems have a significant economic influence, substantial research has been conducted on control algorithms, control systems and information systems for aluminum reduction cells. This article first summarizes the development of control systems and then focuses on the progress made since 2000, including alumina concentration control, temperature control and electrolyte molecular ratio control, fault diagnosis, cell condition prediction and control system expansion. Based on these studies, the concept of a smart aluminum electrolysis plant is proposed. The frame construction, key problems and current progress are introduced. Finally, several future directions are discussed.

  10. 'Radiation-induced electrolysis'. A potential root cause of hydrogen explosions in the Fukushima Daiichi accident

    International Nuclear Information System (INIS)

    Saji, Genn

    2014-01-01

    Although water radiolysis, decomposition of water by radiation, is a well-known phenomenon the exact mechanism is not well characterized especially for potential hydrogen generation during severe accidents. The author first reviewed the water radiolysis phenomena in LWRs during normal operation to severe accidents (e.g., TMI- and Chernobyl accidents) and performed a scoping estimation of H_2 generation modeled for the Fukushima Daiichi accident. The estimation incorporates the decay heat curve combined with G-values. When a set of radiological chain reactions are incorporated the resultant reverse reactions were found to reduce the hydrogen generation substantially. In view of the observation that the water radiolysis is not likely induced appreciable effects in H_2 generation during the accident, this author investigated his basic theory named 'radiation-induced electrolysis' in the estimation of amounts of H_2 generation during the active phase of the Fukushima accident. The author's theory was originally developed by including Faraday's Law of Electrolysis into the basic time-dependent material balance equation of radiation-chemical species for his study on accelerated corrosion phenomena which is widely observed in aged plants. With this mechanism as much as 5,300 m"3-STP of accumulated hydrogen gas is estimated to be inside the PCV just prior to the hydrogen explosion which occurred a day after the reactor trip in Unit 1. For Units 2 and 3, the estimated volumes are 5,900 m"3-STP. Within just several hours after the initiation of SBO, as much as a few thousand cubic meters in STP of hydrogen gas is generated due to a high decay heat. With these large volumes of hydrogen gas the hydrogen explosion was a viable possibility upon the 'venting' operation. For the 1F4 Spent Fuel Pool where the entire core loading had been evacuated, SBO was found to have induced a rapid on-set of electrolysis when the pool water temperature reached as high as 50°C with a range of

  11. Water stress index for alkaline fen habitat based on UAV and continuous tower measurements of canopy infrared temperature

    Science.gov (United States)

    Ciężkowski, Wojciech; Jóźwiak, Jacek; Chormański, Jarosław; Szporak-Wasilewska, Sylwia; Kleniewska, Małgorzata

    2017-04-01

    This study is focused on developing water stress index for alkaline fen, to evaluate water stress impact on habitat protected within Natura 2000 network: alkaline fens (habitat code:7230). It is calculated based on continuous measurements of air temperature, relative humidity and canopy temperature from meteorological tower and several UAV flights for canopy temperature registration. Measurements were taken during the growing season in 2016 in the Upper Biebrza Basin in north-east Poland. Firstly methodology of the crop water stress index (CWSI) determination was used to obtained non-water stress base line based on continuous measurements (NWSBtower). Parameters of NWSBtower were directly used to calculate spatial variability of CWSI for UAV thermal infrared (TIR) images. Then for each UAV flight day at least 3 acquisition were performed to define NWSBUAV. NWSBUAV was used to calculate canopy waters stress for whole image relative to the less stressed areas. The spatial distribution of developed index was verified using remotely sensed indices of vegetation health. Results showed that in analysed area covered by sedge-moss vegetation NWSB cannot be used directly. The proposed modification of CWSI allows identifying water stress in alkaline fen habitats and was called as Sedge-Moss Water Stress Index (SMWSI). The study shows possibility of usage remotely sensed canopy temperature data to detect areas exposed to the water stress on wetlands. This research has been carried out under the Biostrateg Programme of the Polish National Centre for Research and Development (NCBiR), project No.: DZP/BIOSTRATEG-II/390/2015: The innovative approach supporting monitoring of non-forest Natura 2000 habitats, using remote sensing methods (HabitARS).

  12. Technical status study of heavy water enrichment

    International Nuclear Information System (INIS)

    Sukarsono; Imam Dahroni; Didik Herhady

    2007-01-01

    Technical status study of heavy water enrichment in Indonesia and also in the world has been done. Heavy water enrichment processes have been investigated were water distillation, hydrogen distillation, laser enrichment, electrolysis and isotop exchange. For the isotop exchange, the chemical pair can be used were water-hydrogen sulphite, ammonium-hydrogen, aminomethane-hydrogen, and water-hydrogen. For the isotope exchange, there was carried out by mono thermal or bi thermal. The highest producer of heavy water is Canada, and the other producer is USA, Norwegian and India. The processes be used in the world are isotope exchange Girdler Sulphide (GS), distillation and electrolysis. Research of heavy water carried out in Batan Yogyakarta, has a purpose to know the characteristic of heavy water purification. Several apparatus which has erected were 3 distillation column: Pyrex glass of 2 m tall, stainless steel column of 3 m tall and steel of 6 m tall. Electrolysis apparatus is 50 cell electrolysis and an isotope exchange unit which has catalyst: Ni- Cr 2 O 3 and Pt-Carbon. These apparatus were not ready to operate. (author)

  13. Titanium metal obtention by fused salts electrolysis

    International Nuclear Information System (INIS)

    Perillo, P.M.; Ares, Osvaldo; Botbol, Jose.

    1989-01-01

    Potassium fluorotitanate dissolved in fused sodium chloride or potassium chloride may be electrolyzed under an inert gas atmosphere. Solid electrolysis products are formed on the cathode which contains titanium metal, sodium chloride, lower fluorotitanates and small quantities of alkali metal fluorotitanate. The extraction of titanium from the electrolysis products may be carried out by aqueous leaching (removal of chloride salts of alkali metals and a certain amount of fluorotitanates). Titanium metal obtained is relatively pure. (Author)

  14. Diaphragms obtained by radiochemical grafting in PTFE

    International Nuclear Information System (INIS)

    Nenner, T.; Fahrasmane, A.

    1984-01-01

    Diaphragms for alkaline water electrolysis are prepared by radiochemical grafting of PTFE fabric with styrene, which is later on sulfonated, or with acrylic acid. The diaphragms obtained are mechanically resistant to potash at temperatures up to 200 0 C, but show some degrafting, which limits the lifetime. The sulfonated styrene group has been found to be more stable in electrolysis than the acrylic acid. In both cases, the incorporation of a cross-linking agent like divinyl benzene improves the lifetime of the diaphragms. Electrolysis during 500 hours at 120 0 C and 10 kAm 2 could be performed. (author)

  15. Durability of solid oxide electrolysis cells for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-05-15

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

  16. Model-based analysis of water management in alkaline direct methanol fuel cells

    Science.gov (United States)

    Weinzierl, C.; Krewer, U.

    2014-12-01

    Mathematical modelling is used to analyse water management in Alkaline Direct Methanol Fuel Cells (ADMFCs) with an anion exchange membrane as electrolyte. Cathodic water supply is identified as one of the main challenges and investigated at different operation conditions. Two extreme case scenarios are modelled to study the feasible conditions for sufficient water supply. Scenario 1 reveals that water supply by cathodic inlet is insufficient and, thus, water transport through membrane is essential for ADMFC operation. The second scenario is used to analyse requirements on water transport through the membrane for different operation conditions. These requirements are influenced by current density, evaporation rate, methanol cross-over and electro-osmotic drag of water. Simulations indicate that water supply is mainly challenging for high current densities and demands on high water diffusion are intensified by water drag. Thus, current density might be limited by water transport through membrane. The presented results help to identify important effects and processes in ADMFCs with a polymer electrolyte membrane and to understand these processes. Furthermore, the requirements identified by modelling show the importance of considering water transport through membrane besides conductivity and methanol cross-over especially for designing new membrane materials.

  17. Geochemical study of water-rock interaction processes on geothermal systems of alkaline water in granitic massif

    International Nuclear Information System (INIS)

    Buil gutierrez, B.; Garcia Sanz, S.; Lago San Jose, M.; Arranz Yague, E.; Auque Sanz, L.

    2002-01-01

    The study of geothermal systems developed within granitic massifs (with alkaline waters and reducing ORP values) is a topic of increasing scientific interest. These systems are a perfect natural laboratory for studying the water-rock interaction processes as they are defined by three main features: 1) long residence time of water within the system, 2) temperature in the reservoir high enough to favour reaction kinetics and finally, 3) the comparison of the chemistry of the incoming and outgoing waters of the system allows for the evaluation of the processes that have modified the water chemistry and its signature, The four geothermal systems considered in this paper are developed within granitic massifs of the Spanish Central Pyrenes; these systems were studied from a geochemical point of view, defining the major, trace and REE chemistry of both waters and host rocks and then characterizing the composition and geochemical evolution of the different waters. Bicarbonate-chloride-sodic and bicarbonate-sodic compositions are the most representative of the water chemistry in the deep geothermal system, as they are not affected by secondary processes (mixing, conductive cooling, etc). (Author)

  18. Formation of Sulfonyl Aromatic Alcohols by Electrolysis of a Bisazo Reactive Dye

    Directory of Open Access Journals (Sweden)

    María P. Elizalde-González

    2012-12-01

    Full Text Available Five sulfonyl aromatic alcohols, namely 4-((2-hydroxyethylsulfonylphenol, 4-((2-(2-((4-hydroxyphenylsulfonylethoxyvinylsulfonylphenol, 4-(ethylsulfonylphenol, 4-(vinylsulfonylphenol and 5-((4-aminophenylsulfonyl-2-penten-1-ol were identified by LC-ESI-Qq-TOF-MS as products formed by electrolysis of the bisazo reactive dye Reactive Black 5 (RB5. Since electrolyses were performed in an undivided cell equipped with Ni electrodes in alkaline medium, amines like 4-(2-methoxyethylsulfonylbenzene-amine (MEBA with m/z 216 were also suspected to be formed due to the plausible chemical reaction in the bulk or the cathodic reduction of RB5 and its oxidation by-products. Aiming to check this hypothesis, a method was used for the preparation of MEBA with 98% purity, via chemical reduction also of the dye RB5. The logP of the synthesized sulfonyl aromatic compounds was calculated and their logkw values were determined chromatographically. These data were discussed in regard to the relationship between hydrophobicity/lipophilicity and toxicity.

  19. River Liffey survey. II. The food consumed by the brown trout (Salmo trutta. L. ) in acid and alkaline waters

    Energy Technology Data Exchange (ETDEWEB)

    Frost, W E

    1939-01-01

    The brown trout (Salmo trutta) of the fresh waters of Ireland may be divided roughly into two categories, small slow-growing fish found in acid waters derived from non-lime-bearing rocks and larger quick-growing fish found in alkaline waters derived from lime-bearing rocks. The food of the trout from two contrasting stations, one where the water is acid and the other where it is alkaline, has been investigated. The stations are on the R. Liffey; the acid water one, Ballysmuttan (pH 4.4 to 6.8, usually 5.6), and the alkaline station (pH 7.4 to 8.4, usually 7.8 to 8.0) at Straffan. The trout were caught by rod and line, 349 specimens from Ballysmuttan, 228 from Straffan. The food eaten at Ballysmuttan during the months of January to December and at Straffan during February to October is compared and contrasted. The stomach contents of the trout have been weighed and the ratio of the weight of food to the total body weight has been determined. The food organisms have been classified as surface, mid-water, and bottom food. On the whole a higher percentage of surface organisms and of surface feeding fish is found at Straffan than at Ballysmuttan, but at both stations the proportion of bottom food organisms and fish feeding on them is higher than that for surface organisms and feeders. The size of the trout in relation to the kind of food eaten is described for both stations. An account of the food eaten during the winter months (November, December, and January) by the Ballysmuttan trout is given. The question of food and its effect on the size and growth of trout from acid and alkaline waters is discussed in the light of the data obtained from Ballysmuttan and Straffan. The evidence from these two places suggests that probably some factor other than that of the amount of food conditions affects the difference of size and growth rate of the trout from the two stations.

  20. The influence of lake water alkalinity and humic substances on particle dispersion and lanthanum desorption from a lanthanum modified bentonite.

    Science.gov (United States)

    Reitzel, Kasper; Balslev, Kristiane Astrid; Jensen, Henning S

    2017-11-15

    A 12 days laboratory study on potential desorption of Lanthanum (La) from a commercial La modified clay (Phoslock) was conducted using lake water from 17 Danish lakes with alkalinities between 0.02 and 3.7 meq L -1 and varying concentrations of DOC and humic acids (HA's). A similar study was conducted in artificial lake water with alkalinities from 0 to 2.5 meq L -1 in order to exclude interference from dissolved HA's. To test if La in solution (FLa) was associated with fine particles, the water samples were filtered sequentially through three filter sizes (1.2 μm, 0.45 μm and 0.2 μm), and finally, ultracentrifugation was used in an attempt to separate colloidal La from dissolved La. The study showed that higher FLa (up to 2.5 mg L -1 or 14% of the total La in the Phoslock) concentrations were found in soft water lakes compared to hard water lakes, probably due to dispersion of the clay at low alkalinities. In addition, this study showed that HA's seem to increase the FLa concentrations in soft water lakes, most likely through complexation of La retained in the Phoslock matrix. In summary, we conclude that elevated La concentrations in lake water after a Phoslock treatment should only be expected in soft water lakes rich in DOC and HA's. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Microbial electrosynthesis of hydrogen peroxide in microbial reverse-electrodialysis electrolysis cell

    DEFF Research Database (Denmark)

    Li, Xiaohu; Angelidaki, Irini; Zhang, Yifeng

    2016-01-01

    Microbial reverse-electrodialysis electrolysis cell (MREC) as a novel type of microbial electrochemical technologies has been proposed to produce H2 and CH4. In this study, we developed MREC to produce the strong oxidant H2O2. In the MREC, electrical potential generated by the exoelectrogens...... and the salinity-gradient between sea water and river water were utilized to drive the high-rate H2O2 production without external power supply. Operational parameters such as air flow rate, pH, cathodic potential, flow rate of high and low concentration solution were investigated. The optimal H2O2 production were...

  2. Thermal dynamic analysis of sulfur removal from coal by electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Gao, J.; Meng, F. [Qinghua University, Beijing (China). Dept. of Thermal Engineering

    2002-06-01

    The electrolytic reactions about sulfur removal from coal were studied by using chemical thermal dynamic analysis. According to the thermodynamical data, the Gibbs free energy value of the electrolytic reactions of pyritic and organic sulfur removal from coal is higher than zero. So, these electrolytic reactions are not spontaneous chemical reactions. In order to carry out desulfurisation by electrolysis, a certain voltage is necessary and important. Because theoretic decomposition voltage of pyrite and some parts of organic sulfur model compound is not very high, electrolysis reactions are easily to be carried out by using electrolysis technology. Mn ion and Fe ion are added into electrolysis solutions to accelerate the desulfurisation reaction. The electrolytic decomposition of coal is discussed. Because the theoretical decomposition voltage of some organic model compound is not high, the coal decomposition might happen. 17 refs., 4 tabs.

  3. Carbon-encapsulated nickel-iron nanoparticles supported on nickel foam as a catalyst electrode for urea electrolysis

    International Nuclear Information System (INIS)

    Wu, Mao-Sung; Jao, Chi-Yu; Chuang, Farn-Yih; Chen, Fang-Yi

    2017-01-01

    Highlights: • Electrochemical process can purify the urea-rich wastewater, producing hydrogen gas. • Carbon-encapsulated nickel iron nanoparticles (CE-NiFe) are prepared by pyrolysis. • An ultra-thin layer of CE-NiFe nanoparticles is attached to the 3D Ni foam. • CE-NiFe nanoparticles escalate both the urea electrolysis and hydrogen evolution. - Abstract: A cyanide-bridged bimetallic coordination polymer, nickel hexacyanoferrate, could be pyrolyzed to form carbon-encapsulated nickel-iron (CE-NiFe) nanoparticles. The formation of nitrogen-doped spherical carbon shell with ordered mesoporous structure prevented the structural damage of catalyst cores and allowed the migration and diffusion of electrolyte into the hollow carbon spheres. An ultra-thin layer of CE-NiFe nanoparticles could be tightly attached to the three-dimensional macroporous nickel foam (NF) by electrophoretic deposition. The CE-NiFe nanoparticles could lower the onset potential and increase the current density in anodic urea electrolysis and cathodic hydrogen production as compared with bare NF. Macroporous NF substrate was very useful for the urea electrolysis and hydrogen production, which allowed for fast transport of electron, electrolyte, and gas products. The superior electrocatalytic ability of CE-NiFe/NF electrode in urea oxidation and water reduction made it favorable for versatile applications such as water treatment, hydrogen generation, and fuel cells.

  4. Electrical impedance tomography of electrolysis.

    Directory of Open Access Journals (Sweden)

    Arie Meir

    Full Text Available The primary goal of this study is to explore the hypothesis that changes in pH during electrolysis can be detected with Electrical Impedance Tomography (EIT. The study has relevance to real time control of minimally invasive surgery with electrolytic ablation. To investigate the hypothesis, we compare EIT reconstructed images to optical images acquired using pH-sensitive dyes embedded in a physiological saline agar gel phantom treated with electrolysis. We further demonstrate the biological relevance of our work using a bacterial E.Coli model, grown on the phantom. The results demonstrate the ability of EIT to image pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E.coli model. The results are promising, and invite further experimental explorations.

  5. Finishing and upgrading of heavy water

    International Nuclear Information System (INIS)

    Butler, J.P.; Hammerli, M.

    1981-01-01

    This invention provides a process and apparatus for deuterium enrichment as a final stage in a heavy water plant, for continuous on-line enrichment of the heavy water in moderator and heat transfer systems in heavy water nuclear reactors, and for enrichment of hevy water that has been downgraded with natural water during the course of operating a heavy water nuclear reactor. The method comprises contacting partially-enriched heavy water feed in a catalyst column with hydrogen gas (essentially D 2 ) orginating in an electrolysis cell so as to enrich the feed water with deuterium extracted from the electrolytic hydrogen gas and passing the deuterium-enriched water to the electrolysis cell. The apparatus comprises a catalyst isotope exchange column with hydrogen gas and liquid water passing through in countercurrent isotope exchange, an electrolysis cell, a dehumidifer-scrubber; and means for passing the liquid water enriched in deuterium from the catalyst column through the dehumidifer-scrubber to the electrolysis cell, for passing the hydrogen gas evolved in the cathode side of the cell through the dehumidifier-scrubber to the catalyst column, for passing the hydrogen gas from the catalyst column to an output, for introducing an input water feed to the upper portion of the catalyst column, and for taking a product enriched in deuterium from the system. (LL)

  6. Device and method to enrich and process heavy water

    International Nuclear Information System (INIS)

    Hammerli, M.M.; Butler, J.P.

    1979-01-01

    A device to process and enrich heavy water is proposed which is based on a combined electrolysis catalyst exchange system in which a D 2 O enrichment of more than 99.8% is achieved in the end stage. Water partly enriched with D 2 -containing hydrogen gas from an electrolysis cell is brought into contact in a catalyst column. The water is further enriched here with deuterium. It is then fed to the electrolysis cell. Details of the apparatus are closely described. (UWI) [de

  7. Reconsidering Water Electrolysis

    DEFF Research Database (Denmark)

    Xue, Song; Watzele, Sebastian; Čolić, Viktor

    2017-01-01

    Electrocatalysis for the oxygen evolution reaction (OER) is of great interest for improving the effectiveness of water splitting devices. Decreasing the anodic overpotential and simultaneously changing the anodic reaction selectively to produce valuable chemicals instead of O2 would be a major...

  8. Treatment of chitin-producing wastewater by micro-electrolysis-contact oxidization.

    Science.gov (United States)

    Yang, Yue-ping; Xu, Xin-hua; Chen, Hai-feng

    2004-04-01

    The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater. Results showed that Fe-C micro-electrolysis can remove about 30% COD(cr), raise pH from 0.7 to 5.5. The COD(cr) removal efficiency by biochemical process can be more than 80%. During a half year's operation, the whole system worked very stably and had good results, as proved by the fact that every quality indicator of effluent met the expected discharge standards; which means that chitin wastewater can be treated by the technique of micro-electrolysis, contact oxidization.

  9. Achievement report for fiscal 1983 on Sunshine Program-entrusted research and development. Research on hydrogen production technology using electrolysis (Research on electrolysis of water using alkali type solid polymer electrolyte); 1983 nendo denki bunkaiho ni yoru suiso seizo gijutsu no kenkyu seika hokokusho. Arukarigata kotai kobunshi denkaishitsu suidenkai no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1984-03-01

    The report covers the outcome of the research conducted for the establishment of basic techniques for the electrolysis of water using the alkali type solid polymer electrolyte. This fiscal year, following the previous fiscal year, anode materials fit for the electrolysis of water by the AZEC method are investigated, and a medium-size cell, high-temperature cell, and test unit are built. As the result, it becomes clear that the Raney Nickel electrode is relatively active as anode as well as cathode and that it is excellent in durability. The Raney Nickel electrode, with its activity further improved by modification using rhodium and rhenium, is durable, and exhibits the lowest overvoltage. As for the medium-size cell, a cell structure excellent in outgassing while maintaining electrode flatness is sought for, and it is found that it is capable of electrolytic performance similar to that of a small-size cell. As for the high-temperature cell, studies are conducted about the impact of temperature and pressure on the bath voltage. The pressure control system experimentally built in this research is found to be excellent in transient response too. (NEDO)

  10. Hydrogen production from inexhaustible supplies of fresh and salt water using microbial reverse-electrodialysis electrolysis cells

    KAUST Repository

    Kim, Y.

    2011-09-19

    There is a tremendous source of entropic energy available from the salinity difference between river water and seawater, but this energy has yet to be efficiently captured and stored. Here we demonstrate that H(2) can be produced in a single process by capturing the salinity driven energy along with organic matter degradation using exoelectrogenic bacteria. Only five pairs of seawater and river water cells were sandwiched between an anode, containing exoelectrogenic bacteria, and a cathode, forming a microbial reverse-electrodialysis electrolysis cell. Exoelectrogens added an electrical potential from acetate oxidation and reduced the anode overpotential, while the reverse electrodialysis stack contributed 0.5-0.6 V at a salinity ratio (seawater:river water) of 50. The H(2) production rate increased from 0.8 to 1.6 m(3)-H(2)/m(3)-anolyte/day for seawater and river water flow rates ranging from 0.1 to 0.8 mL/ min. H(2) recovery, the ratio of electrons used for H(2) evolution to electrons released by substrate oxidation, ranged from 72% to 86%. Energy efficiencies, calculated from changes in salinities and the loss of organic matter, were 58% to 64%. By using a relatively small reverse electrodialysis stack (11 membranes), only ~1% of the produced energy was needed for pumping water. Although Pt was used on the cathode in these tests, additional tests with a nonprecious metal catalyst (MoS(2)) demonstrated H(2) production at a rate of 0.8 m(3)/m(3)/d and an energy efficiency of 51%. These results show that pure H(2) gas can efficiently be produced from virtually limitless supplies of seawater and river water, and biodegradable organic matter.

  11. Microwave alkaline roasting-water dissolving process for germanium extraction from zinc oxide dust and its analysis by response surface methodology (RSM)

    Science.gov (United States)

    Wang, Wankun; Wang, Fuchun; Lu, Fanghai

    2017-12-01

    Microwave alkaline roasting-water dissolving process was proposed to improve the germanium (Ge) extraction from zinc oxide (ZnO) dust. The effects of important parameters were investigated and the process conditions were optimized using response surface methodology (RSM). The Ge extraction is consistent with the linear polynomial model type. Alkali-material ratio, microwave heating temperature and leaching temperature are the significant factors for this process. The optimized conditions are obtained as follows, alkali-material ratio of 0.9 kg/kg, aging time of 1.12 day, microwave heating at 658 K for 10 min, liquid-solid ratio of 4.31 L/kg, leaching temperature at 330 K, leaching time of 47 min with the Ge extraction about 99.38%. It is in consistence with the predictive value of 99.31%. Compared to the existed alkaline roasting process heated by electric furnace in literature, the alkaline roasting temperature and holding time. It shows a good prospect on leaching Ge from ZnO dust with microwave alkaline roasting-water dissolving process.

  12. Stability of a Cu0.7Co2.3O4 electrode during the oxygen evolution reaction for alkaline anion-exchange membrane water electrolysis

    Science.gov (United States)

    Kang, Kyoung Eun; Kim, Chi Ho; Lee, Myung Sup; Jung, Chang Wook; Kim, Yang Do; Lee, Jae Ho

    2018-01-01

    The electrode materials for oxygen evolution, especially non-platinum group metal oxides, have attracted increasing attention. Among the spinel-type transition metal oxides, Cu0.7Co2.3O4 powders were evaluated as a potential replacement for expensive dimensionally stabilized anode materials. Cu0.7Co2.3O4 powder for use as an electrode material for oxygen evolution in an alkaline anion-exchange membrane water electrolyzer was prepared using a thermal decomposition method. The Cu0.7Co2.3O4 powders heat-treated at 250 °C exhibited the same X-ray diffraction patterns without any secondary phases as the Co3O4 spinel structure did. The Cu0.7Co2.3O4 powders heat-treated at 250 °C for 30 minutes showed the smallest mean particle size of approximately 376 nm with the powders having a homogeneous shape and size distribution. The fine powders with a relatively homogeneous size distribution showed a higher current density during the oxygen evolution reaction. The lifetime of the Cu0.7Co2.3O4 electrode was relatively long at a low current density, but was quickly shortened due to physical detachment of the Cu0.7Co2.3O4 powders as the current density was increased. This study showed that the efficiency and the stability of Cu0.7Co2.3O4 powders during the oxygen evolution reaction were related directly to the active electrode area.

  13. Anodic oxidation of ammonia in alkaline solutions at Pt/Pt electrodes. Hakkin denkyokujo ni okeru enkisei ammonia yoeki no anodo sanka

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Ryoichiro; Katsuta, Masahiro; Matsumoto, Tamotsu; Kobayashi, Yoshikazu; Asami, Yusaku; Hirano, Katsuhiko (Shibaura Inst. of Tech., Tokyo (Japan))

    1989-01-05

    Anodic oxidation of ammonia in alkaline solutions on Pt/Pt electrode, in which NH {sub 3} is oxidized producing N {sub 2}, is a promising reaction in application to a fuel cell and water treatment. In this study, the relations between electrode potential and adsorbed intermediates, reaction process were elucidated by potentiodynamic method and potential step method. In measurement, a transient memory device and a microprocessor were connected to an electrolysis device as a new method, then measurement of electric potential and current and integral calculation were perfromed at high speed. Active sites of electrode were covered by Pt NH {sub x}. Faradic current corresponds to the N {sub 2} evolution was shown markedly by anodic scanning. The relation between electrode potential and reaction process was revealed by potential step method. It is found that Pt-NH {sub 2} is the active intermediate for the N {sub 2} evolution, and when current shows maximum, its coverage is nearly 0.5. 15 refs., 7 figs.

  14. Research Progress of Hydrogen Production fromOrganic Wastes in Microbial Electrolysis Cell(MEC

    Directory of Open Access Journals (Sweden)

    YU Yin-sheng

    2015-08-01

    Full Text Available Microbial electrolysis cell(MECtechnology as an emerging technology, has achieved the target of hydrogen production from different substrates such as waste water, forestry wastes, activated sludge by simultaneous enzymolysis and fermentation, which can effectively improve the efficiency of resource utilization. This paper described the working principle of MEC and analyzed these factors influencing the process of hydrogen production from organic waste in MEC.

  15. Biological denitrification process based on the Fe(0)-carbon micro-electrolysis for simultaneous ammonia and nitrate removal from low organic carbon water under a microaerobic condition.

    Science.gov (United States)

    Deng, Shihai; Li, Desheng; Yang, Xue; Xing, Wei; Li, Jinlong; Zhang, Qi

    2016-11-01

    A combined process between micro-electrolysis and biological denitrification (MEBD) using iron scraps and an activated carbon-based micro-electrolysis carrier was developed for nitrogen removal under a microaerobic condition. The process provided NH4(+)-N and total nitrogen (TN) removal efficiencies of 92.6% and 95.3%, respectively, and TN removal rate of 0.373±0.11kgN/(m(3)d) at corresponding DO of 1.0±0.1mg/L and HRT of 3h, and the optimal pH of 7.6-8.4. High-throughput sequencing analysis verified that dominant classes belonged to β-, α-, and γ-Proteobacteria, and Nitrospira. The dominant genera Hydrogenophaga and Sphaerotilus significantly increased during the operation, covering 13.2% and 6.1% in biofilms attached to the carrier in the middle of the reactor, respectively. Autotrophic denitrification contributed to >80% of the TN removal. The developed MEBD achieved efficient simultaneous nitrification and autotrophic denitrification, presenting significant potential for application in practical low organic carbon water treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Experimentale Study of Alkaline Precipitation on Thermal Process SeaWater Desalination Condition

    International Nuclear Information System (INIS)

    Sumijanto

    2000-01-01

    The experiment of alkaline precipitation by separated method has beencarry out. Experiment took please by heating sea water simulation with eachother consist of a).142 ppm bicarbonate and 400 ppm calcium ion b). 142 ppmbicarbonate and magnesium ion at temperature 40,50,60,70,80,90,100,110 and120 o C respectively by using autoclave. Sampling has been done periodicalfor 30 minute in interval 300 minute for each temperature. The calculation ofalkaline precipitation on each step calculated through the decreasing ofcalcium and magnesium concentration with analysis by AAS. From experimentdata have the information that alkaline precipitation have been formed since40 o C. From time variable have been the information that the precipitationformed at 30 th minute rapidly. Whether at further time the increasing ofprecipitation are not significant. This phenomena can explained that at eachheating step from 40 o C bicarbonate ion be come decomposition with theresult carbonate and hydroxide ion and react with calcium and magnesium formcalcium carbonate and magnesium hydroxide. From this information could beimplemented as base for avoiding using chemical material in desalinationthermal process. (author)

  17. HIGH-TEMPERATURE ELECTROLYSIS FOR HYDROGEN PRODUCTION FROM NUCLEAR ENERGY

    Energy Technology Data Exchange (ETDEWEB)

    James E. O& #39; Brien; Carl M. Stoots; J. Stephen Herring; Joseph J. Hartvigsen

    2005-10-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (~140 µm thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1 - 0.6), gas flow rates (1000 - 4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 90 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate.

  18. Enhancing the efficiency of zero valent iron by electrolysis: Performance and reaction mechanism.

    Science.gov (United States)

    Xiong, Zhaokun; Lai, Bo; Yang, Ping

    2018-03-01

    Electrolysis was applied to enhance the efficiency of micron-size zero valent iron (mFe 0 ) and thereby promote p-nitrophenol (PNP) removal. The rate of PNP removal by mFe 0 with electrolysis was determined in cylindrical electrolysis reactor that employed annular aluminum plate cathode as a function of experimental factors, including initial pH, mFe 0 dosage and current density. The rate constants of PNP removal by Ele-mFe 0 were 1.72-144.50-fold greater than those by pristine mFe 0 under various tested conditions. The electrolysis-induced improvement could be primarily ascribed to stimulated mFe 0 corrosion, as evidenced by Fe 2+ release. The application of electrolysis could extend the working pH range of mFe 0 from 3.0 to 6.0 to 3.0-10.0 for PNP removal. Additionally, intermediates analysis and scavengers experiments unraveled the reduction capacity of mFe 0 was accelerated in the presence of electrolysis instead of oxidation. Moreover, the electrolysis effect could also delay passivation of mFe 0 under acidic condition, as evidenced by SEM-EDS, XRD, and XPS analysis after long-term operation. This is mainly due to increased electromigration meaning that iron corrosion products (iron hydroxides and oxides) are not primarily formed in the vicinity of the mFe 0 or at its surface. In the presence of electrolysis, the effect of electric field significantly promoted the efficiency of electromigration, thereby enhanced mFe 0 corrosion and eventually accelerated the PNP removal rates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Solid oxide electrolysis cells - Performance and durability

    Energy Technology Data Exchange (ETDEWEB)

    Hauch, A.

    2007-10-15

    In this work H2 electrode supported solid oxide cells (SOC) produced at Risoe National Laboratory, DTU, have been used for steam electrolysis. Electrolysis tests have been performed at temperatures from 650AeC to 950AeC, p(H2O)/p(H2) from 0.99/0.01 to 0.30/0.70 and current densities from -0.25 A/cm2 to -2 A/cm2. The solid oxide electrolysis cells (SOEC) have been characterised by iV curves and electrochemical impedance spectroscopy (EIS) at start and end of tests and by EIS under current load during electrolysis testing. The tested SOCs have shown the best initial electrolysis performance reported in literature to date. Area specific resistances of 0.26 Oecm2 at 850AeC and 0.17 Oecm2 at 950AeC were obtained from electrolysis iV curves. The general trend for the SOEC tests was: 1) a short-term passivation in first few hundred hours, 2) then an activation and 3) a subsequent and underlying long-term degradation. The transient phenomenon (passivation/activation) was shown to be a set-up dependent artefact caused by the albite glass sealing with a p(Si(OH)4) of 1.10-7 atm, leading to silica contamination of the triple-phase boundaries (TPBs) of the electrode. The long-term degradation for the SOECs was more pronounced than for fuel cell testing of similar cells. Long-term degradation of 2%/1000 h was obtained at 850AeC, p(H2O)/p(H2) = 0.5/0.5 and -0.5 A/cm2, whereas the degradation rate increased to 6%/1000h at 950AeC, p(H2O)/p(H2) = 0.9/0.1 and -1.0 A/cm2. Both the short-term passivation and the long-term degradation appear mainly to be related to processes in the H2 electrode. Scanning electron microscopy micrographs show that only limited changes occur in the Ni particle size distribution and these are not the main degradation mechanism for the SOECs. Micro and nano analysis using energy dispersive spectroscopy in combination with transmission electron microscopy (TEM) and scanning TEM reveals that glassy phase impurities have accumulated at the TPBs as a result of

  20. High performance reversible electrochemical cell for H2O electrolysis or conversion of CO2 and H2O to fuel

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to a reversible electrochemical cell, such as an electrolysis cell for water splitting or for conversion of carbon dioxide and water into fuel. The present invention relates also to an electrochemical cell that when operated in reverse performs as a fuel cell...

  1. Study on in-situ electrochemical impedance spectroscopy measurement of anodic reaction in SO_2 depolarized electrolysis process

    International Nuclear Information System (INIS)

    Xue Lulu; Zhang Ping; Chen Songzhe; Wang Laijun

    2014-01-01

    SO_2 depolarized electrolysis (SDE) is the pivotal reaction in hybrid sulfur process, one of the most promising approaches for mass hydrogen production without CO_2 emission. The net result of hybrid sulfur process is to split water into hydrogen and oxygen at a relatively low voltage, which will dramatically decrease the energy consumption for the production of hydrogen. The potential loss of SDE process could be separated into four components, i.e. reversible cell potential, anode overpotential, cathode overpotential and ohmic loss. So far, it has been identified that the total cell potential for the SO_2 depolarized electrolyzer is dominantly controlled by sulfuric acid concentration of the anolyte and electrolysis temperature of the electrolysis process. In this work, an in-situ Electrochemical Impedance Spectroscopy (EIS) measurement of the anodic SDE reaction was conducted. Results show that anodic overpotential is mainly resulted from the SO_2 oxidation reaction other than ohmic resistance or mass transfer limitation. This study extends the understanding to SDE process and gives suggestions for the further improvement of the SDE performance. (author)

  2. Changes in contaminant composition at landfill sites. (9). ; Application of soil covering to treatment of alkaline seepage water. Umetate ni okeru odaku seibun no doko. (9). ; Alkali sei shinsutsueki no gaido shori

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Y; Sugai, T; Masuda, T; Watanabe, Y; Kobayashi, S [Saitama Institute of Environmental Pollution, Saitama (Japan)

    1990-10-29

    Recently, alkaline seepage water has been found in many landfill sites. Strong alkaline seepage water results from the use of alkaline agents, such as quicklime and slaked lime, for water removal from waste. In the present report, the neutralizing ability of different types of soil is studied to provide a method to neutralize seepage water by using soil covering at landfill sites. Results show that clay contained in soil is playing a major role in neutralizing alkaline seepage penetrating the soil. Clay generally has negative electric charges, suggesting that positive ions in alkaline water is neutralized after being replaced by hydrogen ions. Another major factor is the carbonate ion and carbon dioxide existing in soil, which precipitate and solidify calcium hydroxide as calcium carbonate to achieve neutralization. Investigations indicate that top soil comprising volcanic ash is useful as material for soil covering. 2 figs., 5 tabs.

  3. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water

    Science.gov (United States)

    Patton, Charles J.; Kryskalla, Jennifer R.

    2003-01-01

    Alkaline persulfate digestion was evaluated and validated as a more sensitive, accurate, and less toxic alternative to Kjeldahl digestion for routine determination of nitrogen and phosphorus in surface- and ground-water samples in a large-scale and geographically diverse study conducted by U.S. Geological Survey (USGS) between October 1, 2001, and September 30, 2002. Data for this study were obtained from about 2,100 surface- and ground-water samples that were analyzed for Kjeldahl nitrogen and Kjeldahl phosphorus in the course of routine operations at the USGS National Water Quality Laboratory (NWQL). These samples were analyzed independently for total nitrogen and total phosphorus using an alkaline persulfate digestion method developed by the NWQL Methods Research and Development Program. About half of these samples were collected during nominally high-flow (April-June) conditions and the other half were collected during nominally low-flow (August-September) conditions. The number of filtered and whole-water samples analyzed from each flow regime was about equal.By operational definition, Kjeldahl nitrogen (ammonium + organic nitrogen) and alkaline persulfate digestion total nitrogen (ammonium + nitrite + nitrate + organic nitrogen) are not equivalent. It was necessary, therefore, to reconcile this operational difference by subtracting nitrate + nitrite concentra-tions from alkaline persulfate dissolved and total nitrogen concentrations prior to graphical and statistical comparisons with dissolved and total Kjeldahl nitrogen concentrations. On the basis of two-population paired t-test statistics, the means of all nitrate-corrected alkaline persulfate nitrogen and Kjeldahl nitrogen concentrations (2,066 paired results) were significantly different from zero at the p = 0.05 level. Statistically, the means of Kjeldahl nitrogen concentrations were greater than those of nitrate-corrected alkaline persulfate nitrogen concentrations. Experimental evidence strongly

  4. Ni-Zn electrodes for hydrogen production by acid electrolysis; Eletrodos de Ni-Zn para producao de hidrogenio por eletrolise acida

    Energy Technology Data Exchange (ETDEWEB)

    Torres, C.S.; Malfatti, C.F., E-mail: camilator@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre (Brazil). Departamento de Metalurgia. Lab. de Pesquisa em Corrosao

    2014-07-01

    Hydrogen production by electrolysis of water, have an important role in countries that have great renewable potential for electricity production. The electrolysis of water has been proposed to use the excess capacity of hydroelectric plants. However, to improve process efficiency, research has been undertaken to improve the catalytic reduction reaction of hydrogen from the development of electrodes with better performance. Thus, the selection of low cost electrode materials with good electrocatalytic activity is required. In this work, the hydrogen evolution reaction (HER) employing electrodes of Ni-Zn and Ni was investigated. Morphological characterization of the electrodes was performed using SEM/ EDX and profilometry and electrochemical behavior was evaluated by cathodic polarization curves. The results showed that the addition of Zn promotes the increase the electrocatalytic activity of HER compared to nickel electrode. (author)

  5. Study on hydrogen production by high temperature electrolysis of steam

    International Nuclear Information System (INIS)

    Hino, Ryutaro; Aita, Hideki; Sekita, Kenji; Haga, Katsuhiro; Iwata, Tomo-o.

    1997-09-01

    In JAERI, design and R and D works on hydrogen production process have been conducted for connecting to the HTTR under construction at the Oarai Research Establishment of JAERI as a nuclear heat utilization system. As for a hydrogen production process by high-temperature electrolysis of steam, laboratory-scale experiments were carried out with a practical electrolysis tube with 12 cells connected in series. Hydrogen was produced at a maximum density of 44 Nml/cm 2 h at 950degC, and know-how of operational procedures and operational experience were also accumulated. Thereafter, a planar electrolysis cell supported by a metallic plate was fabricated in order to improve hydrogen production performance and durability against thermal cycles. In the preliminary test with the planar cell, hydrogen has been produced continuously at a maximum density of 33.6 Nml/cm 2 h at an electrolysis temperature of 950degC. This report presents typical test results mentioned above, a review of previous studies conducted in the world and R and D items required for connecting to the HTTR. (author)

  6. Hydrogen Production System with High Temperature Electrolysis for Nuclear Power Plant

    International Nuclear Information System (INIS)

    Kentaro, Matsunaga; Eiji, Hoashi; Seiji, Fujiwara; Masato, Yoshino; Taka, Ogawa; Shigeo, Kasai

    2006-01-01

    Steam electrolysis with solid oxide cells is one of the most promising methods for hydrogen production, which has the potential to be high efficiency. Its most parts consist of environmentally sound and common materials. Recent development of ceramics with high ionic conductivity suggests the possibility of widening the range of operating temperature with maintaining the high efficiency. Toshiba is constructing a hydrogen production system with solid oxide electrolysis cells for nuclear power plants. Tubular-type cells using YSZ (Yttria-Stabilized- Zirconia) as electrolyte showed good performance of steam electrolysis at 800 to 900 deg C. Larger electrolysis cells with present configuration are to be combined with High Temperature Reactors. The hydrogen production efficiency on the present designed system is expected around 50% at 800 to 900 deg C of operating temperature. For the Fast Reactors, 'advanced cell' with higher efficiency at lower temperature are to be introduced. (authors)

  7. Application of alkaline waterflooding to a high acidity crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Sayyouh, M.H. (King Sand Univ., Riyadh (SA). Petroleum Engineering Dept.); Abdel-Waly, A.; Osman, A. (Cairo Univ. (EG). Petroleum Engineering Dept.); Awara, A.Z. (Geisum Oil Company, Cairo (EG))

    The enhanced recovery of a high acidity crude oil (South Geisum crude) by alkaline solutions is studied. Acidity, interfacial tension, and contact angle, were investigated. Displacement tests were carried out to study the effect of alkaline slug concentration, slug size, oil alkali type, temperature and viscosity on recovery. The interfacial tension between crude oil and formation water decreases with increasing alkaline concentration until a minimum, after which it increases again. Contact angle measurements indicated oil-wetting conditions that increase by the addition of alkaline solutions. At the early stages of displacement, oil recovery increases with increasing alkaline concentration until a maximum at 4% by weight NaOH concentration. Also, at such early stages, an excessive increase in alkaline concentration results in lower oil recovery. On the other hand, after the injection of many pore volumes of water, oil recovery is almost the same regardless of the alkaline concentration. Oil recovery increases with increasing alkaline slug size until a maximum at 15% PV. Sodium hydroxide slugs produce more oil recovery than sodium carbonate slugs. Oil recovery increases with increasing temperature (from 25 to 55{sup 0}C) and decreasing oil viscosity.

  8. Biological Apatite Formed from Polyphosphate and Alkaline Phosphatase May Exchange Oxygen Isotopes from Water through Carbonate

    Science.gov (United States)

    Omelon, S. J.; Stanley, S. Y.; Gorelikov, I.; Matsuura, N.

    2011-12-01

    The oxygen isotopic composition in bone mineral phosphate is known to reflect the local water composition, environmental humidity, and diet1. Once ingested, biochemical processes presumably equilibrate PO43- with "body water" by the many biochemical reactions involving PO43- 2. Blake et al. demonstrated that enzymatic release of PO43- from organophosphorus compounds, and microbial metabolism of dissolved orthophosphate, significantly exchange the oxygen in precipitated apatite within environmental water3,4, which otherwise does not exchange with water at low temperatures. One of the enzymes that can cleave phosphates from organic substrates is alkaline phosphastase5, the enzyme also associated with bone mineralization. The literature often states that the mineral in bone in hydroxylapatite, however the mineral in bone is carbonated apatite that also contains some fluoride6. Deprotonation of HPO32- occurs at pH 12, which is impossibly high for biological system, and the predominate carbonate species in solution at neutral pH is HCO3-. To produce an apatite mineral without a significant hydroxyl content, it is possible that apatite biomineralization occurs through a polyphosphate pathway, where the oxygen atom required to transform polyphosphate into individual phosphate ions is from carbonate: [PO3-]n + CO32- -> [PO3-]n-1 + PO43- + CO2. Alkaline phosphatase can depolymerise polyphosphate into orthophosphate5. If alkaline phosphatase cleaves an oxygen atom from a calcium-carbonate complex, then there is no requirement for removing a hydrogen atom from the HCO3- or HPO43- ions of body water to form bioapatite. A mix of 1 mL of 1 M calcium polyphosphate hydogel, or nano-particles of calcium polyphosphate, and amorphous calcium carbonate were reacted with alkaline phosphatase, and maintained at neutral to basic pH. After two weeks, carbonated apatite and other calcium phosphate minerals were identified by powder x-ray diffraction. Orthophosphate and unreacted

  9. Use of sodium salt electrolysis in the process of continuous ...

    Indian Academy of Sciences (India)

    This paper presents test results concerning the selection of sodium salt for the technology of continuous modification of the EN AC-AlSi12 alloy, which is based on electrolysis of sodium salts, occurring directly in a crucible with liquid alloy. Sodium ions formed as a result of the sodium salt dissociation and the electrolysis are ...

  10. Generation of Hydrogen, Lignin and Sodium Hydroxide from Pulping Black Liquor by Electrolysis

    Directory of Open Access Journals (Sweden)

    Guangzai Nong

    2015-12-01

    Full Text Available Black liquor is generated in Kraft pulping of wood or non-wood raw material in pulp mills, and regarded as a renewable resource. The objective of this paper was to develop an effective means to remove the water pollutants by recovery of both lignin and sodium hydroxide from black liquor, based on electrolysis. The treatment of a 1000 mL of black liquor (122 g/L solid contents consumed 345.6 kJ of electric energy, and led to the generation of 30.7 g of sodium hydroxide, 0.82 g of hydrogen gas and 52.1 g of biomass solids. Therefore, the recovery ratios of elemental sodium and biomass solids are 80.4% and 76%, respectively. Treating black liquor by electrolysis is an environmentally friendly technology that can, in particular, be an alternative process in addressing the environmental issues of pulping waste liquor to the small-scale mills without black liquor recovery.

  11. A novel bioactive haemodialysis system using dissolved dihydrogen (H2) produced by water electrolysis: a clinical trial.

    Science.gov (United States)

    Nakayama, Masaaki; Nakano, Hirofumi; Hamada, Hiromi; Itami, Noritomo; Nakazawa, Ryoichi; Ito, Sadayoshi

    2010-09-01

    Chronic inflammation in haemodialysis (HD) patients indicates a poor prognosis. However, therapeutic approaches are limited. Hydrogen gas (H(2)) ameliorates oxidative and inflammatory injuries to organs in animal models. We developed an HD system using a dialysis solution with high levels of dissolved H(2) and examined the clinical effects. Dialysis solution with H(2) (average of 48 ppb) was produced by mixing dialysate concentrates and reverse osmosis water containing dissolved H(2) generated by a water electrolysis technique. Subjects comprised 21 stable patients on standard HD who were switched to the test HD for 6 months at three sessions a week. During the study period, no adverse clinical signs or symptoms were observed. A significant decrease in systolic blood pressure (SBP) before and after dialysis was observed during the study, and a significant number of patients achieved SBP <140 mmHg after HD (baseline, 21%; 6 months, 62%; P < 0.05). Changes in dialysis parameters were minimal, while significant decreases in levels of plasma monocyte chemoattractant protein 1 (P < 0.01) and myeloperoxidase (P < 0.05) were identified. Adding H(2) to haemodialysis solutions ameliorated inflammatory reactions and improved BP control. This system could offer a novel therapeutic option for control of uraemia.

  12. Preliminary estimations on the heat recovery method for hydrogen production by the high temperature steam electrolysis

    International Nuclear Information System (INIS)

    Koh, Jae Hwa; Yoon, Duck Joo

    2009-01-01

    As a part of the project 'development of hydrogen production technologies by high temperature electrolysis using very high temperature reactor', we have developed an electrolyzer model for high temperature steam electrolysis (HTSE) system and carried out some preliminary estimations on the effects of heat recovery on the HTSE hydrogen production system. To produce massive hydrogen by using nuclear energy, the HTSE process is one of the promising technologies with sulfur-iodine and hybrid sulfur process. The HTSE produces hydrogen through electrochemical reaction within the solid oxide electrolysis cell (SOEC), which is a reverse reaction of solid oxide fuel cell (SOFC). The HTSE system generally operates in the temperature range of 700∼900 .deg. C. Advantages of HTSE hydrogen production are (a) clean hydrogen production from water without carbon oxide emission, (b) synergy effect due to using the current SOFC technology and (c) higher thermal efficiency of system when it is coupled nuclear reactor. Since the HTSE system operates over 700 .deg. C, the use of heat recovery is an important consideration for higher efficiency. In this paper, four different heat recovery configurations for the HTSE system have been investigated and estimated

  13. Review on heavy water separation at pilot scale

    International Nuclear Information System (INIS)

    Wuryanto; Soeroto Ronodirdjo.

    1976-01-01

    The isotope exchange system ammonia-water and hydrogen sulfide water dual temperature are studied. Comparison of the two methods with water electrolysis, water distillation, hydrogen distillation and catalytic water hydrogen exchange are discussed. Water distillation is a simple method. Electrolysis of water has the highest separation factor. The isotope exchange hydrogen sulfide water dual temperature will be done in accord with the report on the operation of a dual temperature single stage for deuterium concentration written by M.L.Eidinoff and C.F. Hiskey. (authors)

  14. Method and apparatus for enrichment or upgrading heavy water

    International Nuclear Information System (INIS)

    Butler, J.P.; Hammerli, M.

    1979-01-01

    A method and apparatus for upgrading and final enrichment of heavy water are described, comprising means for contacting partially enriched heavy water feed in a catalyst column with hydrogen gas (essentially D 2 ) originating in an electrolysis cell so as to enrich the feed water with deuterium extracted from the electrolytic hydrogen gas and means for passing the deuterium enriched water to the electrolysis cell. (author)

  15. Using algae and submerged calcifying water flora for treating neutral to alkaline uranium-contaminated water; Verwendung von Algen und submersen kalzifizierenden Wasserpflanzen zur Aufbereitung neutraler bis basischer uranhaltiger Waesser

    Energy Technology Data Exchange (ETDEWEB)

    Dienemann, C.; Dienemann, H.; Stolz, L.; Dudel, E.G. [TU Dresden (DE). Inst. fuer Allgemeine Oekologie und Umweltschutz, Tharandt (Germany)

    2005-07-01

    Elimination of uranium from neutral to alkaline water is a complex technical process involving decarbonation, usually with HCl, followed by uranium removal by adding alkaline substances. In passive water treatment systems, uranium species - which often consist of a combination of oxidation and reduction stages - are not sufficiently considered. Algae and submerged water plants provide a natural alternative. They remove carbon dioxides or hydrogen carbonate, depending on the species, thus reducting the concentrations of the carbonate species. As the uranium species in alkaline water are coupled on the one hand to the carbonate species and on the other hand on the earth alkali metals, algae and submerged calcifying water plants are an excellent preliminary stage as a supplement to conventional passive water treatment systems. For a quantification of this effect, laboratory experiments were made with Cladophara spec. and with uranium concentrations of 100, 250 and 1000 {mu}g U.L{sup -1} at pH 8.3. The pH was adjusted with NaOH resp. Na2CO3 resulting in different uranium species. After 20 minutes, there was a difference in self-absorption between the different species (higher uranium concentration for NaOH than for Na2CO3), which was no longer observeable after 24 h. On the basis of data on the biomass development of macrophytic algae (Cladophora and Microspora) in a flowing river section near Neuensalz/Vogtland district, the final dimensions of a purification stage of this type are assessed. (orig.)

  16. Water-quality data for two surface coal mines reclaimed with alkaline waste or urban sewage sludge, Clarion County, Pennsylvania, May 1983 through November 1989

    Science.gov (United States)

    Dugas, D.L.; Cravotta, C.A.; Saad, D.A.

    1993-01-01

    Water-quality and other hydrologic data for two surface coal mines in Clarion County, Pa., were collected during 1983-89 as part of studies conducted by the U.S. Geological Survey in cooperation with the Pennsylvania Department of Environmental Resources. Water samples were collected from streams, seeps, monitor wells, and lysimeters on a monthly basis to evaluate changes in water quality resulting from the addition of alkaline waste or urban sewage sludge to the reclaimed mine-spoil surface. The mines are about 3.5 miles apart and were mined for bituminous coal of the upper and lower Clarion seams of the Allegheny Group of Pennsylvanian age. The coal had high sulfur (greater than 2 weight percent) concentrations. Acidic mine drainage is present at both mines. At one mine, about 8 years after mining was completed, large quantities (greater than 400 tons per acre) of alkaline waste consisting of limestone and lime-kiln flue dust were applied on two 2.5-acre plots within the 65-acre mine area. Water-quality data for the alkaline-addition plots and surrounding area were collected for 1 year before and 3 years after application of the alkaline additives (May 1983-July 1987). Data collected for the alkaline-addition study include ground-water level, surface-water discharge rate, temperature, specific conductance, pH, and concentrations of alkalinity, acidity, sulfate, iron (total and ferrous), manganese, aluminum, calcium, and magnesium. At the other mine, about 3.5 years after mining was completed, urban sewage sludge was applied over 60 acres within the 150-acre mine area. Waterquality data for the sludge-addition study were collected for 3.5 years after the application of the sludge (June 1986-December 1989). Data collected for the sludge-addition study include the above constituents plus dissolved oxygen, redox potential (Eh), and concentrations of dissolved solids, phosphorus, nitrogen species, sulfide, chloride, silica, sodium, potassium, cyanide, arsenic, barium

  17. A numerical study of the gas-liquid, two-phase flow maldistribution in the anode of a high pressure PEM water electrolysis cell

    DEFF Research Database (Denmark)

    Olesen, Anders Christian; Rømer, Carsten; Kær, Søren Knudsen

    2016-01-01

    In this work, the use of a circular-planar, interdigitated flow field for the anode of a high pressure proton exchange membrane (PEM) water electrolysis cell is investigated in a numerical study. While PEM fuel cells have separated flow fields for reactant transport and coolant, it is possible...... causes maldistribution, if land areas of equal width are applied. Moreover, below a water stoichiometry of 350, and at a current density of 1 A/cm2, flow and temperature maldistribution is adversely affected by the presence of the gas phase; particularly gas hold-up near outlet channels can cause......-phase flow model for establishing the effect of geometry and a two-phase flow model for studying the effect of dispersed gas bubbles. Both models account for turbulence and heat transport. By means of the developed models, it is elucidated that the circular-planar shape of the interdigitated flow field...

  18. Predicting Gran alkalinity and calcium concentrations in river waters over a national scale using a novel modification to the G-BASH model

    International Nuclear Information System (INIS)

    Cresser, Malcolm S.; Ahmed, Nayan; Smart, Richard P.; Arowolo, Toyin; Calver, Louise J.; Chapman, Pippa J.

    2006-01-01

    Monthly stream water calcium and Gran alkalinity concentration data from 11 sub-catchments of the Nether Beck in the English Lake District have been used to appraise the transferability of the Scottish, River Dee-based G-BASH model. Readily available riparian zone geochemistry and flow paths were used initially to predict minimum and mean stream water concentrations at the Nether Beck, based on calibration equations from the River Dee catchment data. Predicted values significantly exceeded observed values. Differences in runoff between the two areas, leading to a dilution effect in the Nether Beck, explained most of the difference between observed and predicted values. Greater acid deposition in the Lake District also reduced stream water Gran alkalinity concentrations in that area. If regional differences in precipitation, evapotranspiration and pollutant deposition are incorporated into the model, it may then be used reliably to predict catchment susceptibility to acidification over a wide regional (national) scale. - A modified G-BASH model predicts calcium and Gran alkalinity in streams at a national scale, taking account of regional deposition and climatic variations

  19. Removal of pigments from molasses wastewater by combining micro-electrolysis with biological treatment method.

    Science.gov (United States)

    Chen, Ben; Tian, Xiaofei; Yu, Lian; Wu, Zhenqiang

    2016-12-01

    Pigments in molasses wastewater (MWW) effluent, such as melanoidins, were considered as kinds of the most recalcitrant and hazardous colorant contaminants to the environment. In this study, de-coloring the MWW by a synergistic combination of micro-electrolysis with bio-treatment was performed. Aiming to a high de-colorization yield, levels of nutrition source supplies, MWW dilution ratio, and micro-electrolysis reaction time were optimized accordingly. For a diluted (50 %, v/v) MWW, an maximum overall de-colorization yield (97.1 ± 0.5 %, for absorbance at 475 nm) was achieved through the bio-electrolysis treatment. In electrolysis bio-treatment, the positive effect of micro-electrolysis was also revealed by a promoted growth of fungal biomass as well as activities of ligninolytic enzymes. Activities of lignin peroxidase, manganese peroxidase, and laccase were promoted by 111.2, 103.9, and 7.7 %, respectively. This study also implied that the bio-treatment and the micro-electrolysis had different efficiencies on removal of pigments with distinct polarities.

  20. Perspectives de développement de la production industrielle d'hydrogène par électrolyse alcaline avancée Development Outlook for Industrial Hydrogen Production by Advanced Alkaline Electrolysis

    Directory of Open Access Journals (Sweden)

    Derive C.

    2006-11-01

    -prototypes sont prolongés et deux programmes complémentaires d'essais sur les composants principaux sont actuellement menés avant l'engagement de la phase de qualification de l'électrolyseur industriel sur un pilote de 2 MWe. Under the development conditions of the French nuclear program, which has succeeded in producing electricity at an interesting cost in off-peak hours, hydrogen production by water electrolysis can be considered in the mediumterm to be in competition with other hydrogen production processes such as natural-gas reforming. Since 1976 Electricité de France (EDF and Gaz de France (GDF have been cooperating on an R & D project on hydrogen production by alkaline water electrolysis with the aim of reducing the investment cost and maintaining the efficiency level compared to present-day installations. Prior research has shown that these objectives can be attained by advanced electrolysis with increased current density and temperature. These technical constraints have led EDF and GDF to undertake research on the chemical and mechanical resistance of materials, on the selection of suitable cell components, and on improving the overall design of installations. The two French industrial groups, headed by Alsthom-Atlantique and Creusot-Loire, have been associated to this research since 1979 and have set the following operating conditions:(a potash-base electrolyte (40% mass;(b temperatures of 120 and 160°C;(c pressures of 30 and 70 bar. In an initial phase, these groups made a technico-economic survey of the massive production of hydrogen by plants having a power of about 300 MWe. Detailed plans were drawn up for a 2-MWe pilot plant, and technological choices were made on 25-30 kWe prototype loops. To give further certainty to the choices made and to go further into problems of scaling up to large-size electrolyzers, tests on prototype loops were extended, and additional tests are now being made of the principal components before undertaking the qualification phase

  1. Development of an operation strategy for hydrogen production using solar PV energy based on fluid dynamic aspects

    Directory of Open Access Journals (Sweden)

    Amores Ernesto

    2017-06-01

    Full Text Available Alkaline water electrolysis powered by renewable energy sources is one of the most promising strategies for environmentally friendly hydrogen production. However, wind and solar energy sources are highly dependent on weather conditions. As a result, power fluctuations affect the electrolyzer and cause several negative effects. Considering these limiting effects which reduce the water electrolysis efficiency, a novel operation strategy is proposed in this study. It is based on pumping the electrolyte according to the current density supplied by a solar PV module, in order to achieve the suitable fluid dynamics conditions in an electrolysis cell. To this aim, a mathematical model including the influence of electrode-membrane distance, temperature and electrolyte flow rate has been developed and used as optimization tool. The obtained results confirm the convenience of the selected strategy, especially when the electrolyzer is powered by renewable energies.

  2. Nitrate removal and microbial analysis by combined micro-electrolysis and autotrophic denitrification.

    Science.gov (United States)

    Xing, Wei; Li, Desheng; Li, Jinlong; Hu, Qianyi; Deng, Shihai

    2016-07-01

    A process combining micro-electrolysis and autotrophic denitrification (CEAD) with iron-carbon micro-electrolysis carriers was developed for nitrate removal. The process was performed using organic-free influent with a NO3(-)-N concentration of 40.0±3.0mg/L and provided an average nitrate removal efficiency of 95% in stable stages. The total nitrogen removal efficiency reached 75%, with 21% of NO3(-)-N converted into NH4(+)-N. The corresponding hydraulic retention time was 8-10h, and the optimal pH ranged from 8.5 to 9.5. Microbial analysis with high-throughput sequencing revealed that dominant microorganisms in the reactor belonged to the classes of β-, γ-, and α-Proteobacteria. The abundance of the genera Thermomonas significantly increased during the operation, comprising 21.4% and 24.1% in sludge attached to the carriers in the middle and at the bottom of the reactor, respectively. The developed CEAD achieved efficient nitrate removal from water without organics, which is suitable for practical application. Copyright © 2016. Published by Elsevier Ltd.

  3. Estimating Hydrogen Production Potential in Biorefineries Using Microbial Electrolysis Cell Technology

    Energy Technology Data Exchange (ETDEWEB)

    Borole, Abhijeet P [ORNL; Mielenz, Jonathan R [ORNL

    2011-01-01

    Microbial electrolysis cells (MECs) are devices that use a hybrid biocatalysis-electrolysis process for production of hydrogen from organic matter. Future biofuel and bioproducts industries are expected to generate significant volumes of waste streams containing easily degradable organic matter. The emerging MEC technology has potential to derive added- value from these waste streams via production of hydrogen. Biorefinery process streams, particularly the stillage or distillation bottoms contain underutilized sugars as well as fermentation and pretreatment byproducts. In a lignocellulosic biorefinery designed for producing 70 million gallons of ethanol per year, up to 7200 m3/hr of hydrogen can be generated. The hydrogen can either be used as an energy source or a chemical reagent for upgrading and other reactions. The energy content of the hydrogen generated is sufficient to meet 57% of the distillation energy needs. We also report on the potential for hydrogen production in existing corn mills and sugar-based biorefineries. Removal of the organics from stillage has potential to facilitate water recycle. Pretreatment and fermentation byproducts generated in lignocellulosic biorefinery processes can accumulate to highly inhibitory levels in the process streams, if water is recycled. The byproducts of concern including sugar- and lignin- degradation products such as furans and phenolics can also be converted to hydrogen in MECs. We evaluate hydrogen production from various inhibitory byproducts generated during pretreatment of various types of biomass. Finally, the research needs for development of the MEC technology and aspects particularly relevant to the biorefineries are discussed.

  4. Removal of six pesticide residues in cowpea with alkaline electrolysed water.

    Science.gov (United States)

    Han, Yongtao; Song, Le; An, Quanshun; Pan, Canping

    2017-06-01

    Reduction of six pesticide residues (isoprocarb, chlorpyrifos, bifenthrin, beta-cypermethrin, difenoconazole and azoxystrobin) in cowpea by alkaline electrolysed water (AlEW) solutions with different pH was investigated. The commonly used washing treatments in household processing were used for comparison. The residue magnitudes were determined by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). Results showed that the removal effect of AlEW solution on the six pesticides was superior to tap water, 5% sodium chloride, 5% sodium carbonate and 5% acetic acid solution. AlEW with pH 12.2 had more potential to eliminate the six pesticides in cowpeas. Moreover, the reduction of pesticide residues gradually increased with the increase of washing time. This study demonstrated that AlEW solution with pH of 12.2 could be used to reduce pesticide residues on fresh cowpea samples. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  5. An investigation of energy balances in palladium cathode electrolysis experiments

    Science.gov (United States)

    Longhurst, G. R.; Dolan, T. J.; Henriksen, G. L.

    1990-09-01

    A series of experiments was performed at the Idaho National Engineering Laboratory (INEL) to investigate mechanisms that may contribute to energy flows in electrolysis cells like those of Fleischmann and Pons. Ordinary water (H2O), heavy water (D2O), and a mixture of the two were used in the INEL experiments. Cathodes used include a 51-μm Pd foil and 1-mm diameter extruded wire Pd rods in straight and coiled configurations. Energy balances in these experiments revealed no significant net gain or net loss of energy. Cell overpotential curves were fit well with a Tafel equation, with parameters dependent on electrode configuration, electrolyte composition, and temperature. Water evaporation and interactions of hydrogen isotopes with the Pd cathode were evaluated and found not to be significant to energy balances. No ionizing radiation, tritium production, or other evidence of fusion reactions was observed in the INEL experiments.

  6. Stability of CoP x Electrocatalysts in Continuous and Interrupted Acidic Electrolysis of Water.

    Science.gov (United States)

    Goryachev, Andrey; Gao, Lu; Zhang, Yue; Rohling, Roderigh Y; Vervuurt, René H J; Bol, Ageeth A; Hofmann, Jan P; Hensen, Emiel J M

    2018-04-11

    Cobalt phosphides are an emerging earth-abundant alternative to platinum-group-metal-based electrocatalysts for the hydrogen evolution reaction (HER). Yet, their stability is inferior to platinum and compromises the large-scale applicability of CoP x in water electrolyzers. In the present study, we employed flat, thin CoP x electrodes prepared through the thermal phosphidation (PH 3 ) of Co 3 O 4 films made by plasma-enhanced atomic layer deposition to evaluate their stability in acidic water electrolysis by using a multi-technique approach. The films were found to be composed of two phases: CoP in the bulk and a P-rich surface CoP x (P/Co>1). Their performance was evaluated in the HER and the exchange current density was determined to be j 0 =-8.9 ⋅ 10 -5  A/cm 2 . The apparent activation energy of HER on CoP x ( E a =81±15 kJ/mol) was determined for the first time. Dissolution of the material in 0.5 M H 2 SO 4 was observed, regardless of the constantly applied cathodic potential, pointing towards a chemical instead of an electrochemical origin of the observed cathodic instability. The current density and HER faradaic efficiency (FE) were found to be stable during chronoamperometric treatment, as the chemical composition of the HER-active phase remained unchanged. On the contrary, a dynamic potential change performed in a repeated way facilitated dissolution of the film, yielding its complete degradation within 5 h. There, the FE was also found to be changing. An oxidative route of CoP x dissolution has also been proposed.

  7. Proton exchange membrane water electrolysers

    International Nuclear Information System (INIS)

    Millet, P.

    2007-01-01

    This work deals with the PEM water electrolysis process. Are successively described: the thermodynamical, kinetic and energetic aspects, the different possible used electrolysis cells, the preparation of the membrane-electrode assembling, the used electrolysers, the annex production equipment, the uses fields and the limits of the process. (O.M.)

  8. Alkaline Peptone Water-Based Enrichment Method for mcr-3 From Acute Diarrheic Outpatient Gut Samples

    Directory of Open Access Journals (Sweden)

    Qiaoling Sun

    2018-05-01

    Full Text Available A third plasmid-mediated colistin resistance gene, mcr-3, is increasingly being reported in Enterobacteriaceae and Aeromonas spp. from animals and humans. To investigate the molecular epidemiology of mcr in the gut flora of Chinese outpatients, 152 stool specimens were randomly collected from outpatients in our hospital from May to June, 2017. Stool specimens enriched in alkaline peptone water or Luria-Bertani (LB broth were screened for mcr-1, mcr-2, and mcr-3 using polymerase chain reaction (PCR-based assays. Overall, 19.1% (29/152 and 5.3% (8/152 of the stool samples enriched in alkaline peptone water were PCR-positive for mcr-1 and mcr-3, respectively, while 2.7% (4/152 of samples were positive for both mcr-1 and mcr-3. Strains isolated from the samples that were both mcr-1- and mcr-3-positive were subjected to antimicrobial susceptibility testing by broth microdilution. They were also screened for the presence of other resistance genes by PCR, while multilocus sequence typing and whole-genome sequencing were used to investigate the molecular epidemiology and genetic environment, respectively, of the resistance genes. mcr-3-positive Aeromonas veronii strain 126-14, containing a mcr-3.8-mcr-3-like2 segment, and mcr-1-positive Escherichia coli strain 126-1, belonging to sequence type 1485, were isolated from the sample from a diarrheic butcher with no history of colistin treatment. A. veronii 126-14 had a colistin minimum inhibitory concentration (MIC of 2 µg/mL and was susceptible to antibiotics in common use, while E. coli 126-1 produced TEM-1, CTX-M-55, and CTX-M-14 β-lactamases and was resistant to colistin, ceftazidime, and cefotaxime. Overall, there was a higher detection rate of mcr-3-carrying strains with low colistin MICs from the samples enriched in alkaline peptone water than from samples grown in LB broth.

  9. Non-noble metal based electro-catalyst compositions for proton exchange membrane based water electrolysis and methods of making

    Science.gov (United States)

    Kumta, Prashant N.; Kadakia, Karan Sandeep; Datta, Moni Kanchan; Velikokhatnyi, Oleg

    2017-02-07

    The invention provides electro-catalyst compositions for an anode electrode of a proton exchange membrane-based water electrolysis system. The compositions include a noble metal component selected from the group consisting of iridium oxide, ruthenium oxide, rhenium oxide and mixtures thereof, and a non-noble metal component selected from the group consisting of tantalum oxide, tin oxide, niobium oxide, titanium oxide, tungsten oxide, molybdenum oxide, yttrium oxide, scandium oxide, cooper oxide, zirconium oxide, nickel oxide and mixtures thereof. Further, the non-noble metal component can include a dopant. The dopant can be at least one element selected from Groups III, V, VI and VII of the Periodic Table. The compositions can be prepared using a surfactant approach or a sol gel approach. Further, the compositions are prepared using noble metal and non-noble metal precursors. Furthermore, a thin film containing the compositions can be deposited onto a substrate to form the anode electrode.

  10. Transmutation in the electrolysis of light water - excess energy and iron production in a gold electrode

    International Nuclear Information System (INIS)

    Ohmori, Tadayoshi; Mizuno, Tadahiko; Nodasaka, Yoshinobu; Enyo, Michio; Minagawa, Hideki

    1997-01-01

    The identification of some reaction products possibly produced during the generation of excess energy is attempted. Electrolysis is performed for 7 days with a constant current intensity of 1 A. The electrolytes used are Na 2 SO 4 , K 2 SO 4 , K 2 CO 3 , and KOH. After the electrolysis, the elements in the electrode near the surface are analyzed by Auger electron spectroscopy and electron probe microanalysis. In every case, a notable amount of iron atoms in the range of 1.0 x 10 16 to 1.8 x 10 17 atom/cm 2 (true area) are detected together with the generation of a certain amount of excess energy evolution. The isotopic abundance of iron atoms, which are 6.5, 77.5, and 14.5% for 54 Fe, 56 Fe, and 57 Fe, respectively, and are obviously different from the natural isotopic abundance, are measured at the top surface of a gold electrode by secondary ion mass spectrometry. The content of 57 Fe tends to increase up to 25% in the more inner layers of the electrode. 8 refs., 11 figs., 3 tabs

  11. Comparison of two modified coal ash ferric-carbon micro-electrolysis ceramic media for pretreatment of tetracycline wastewater.

    Science.gov (United States)

    Yang, Kunlun; Jin, Yang; Yue, Qinyan; Zhao, Pin; Gao, Yuan; Wu, Suqing; Gao, Baoyu

    2017-05-01

    Application of modified sintering ferric-carbon ceramics (SFC) and sintering-free ferric-carbon ceramics (SFFC) based on coal ash and scrap iron for pretreatment of tetracycline (TET) wastewater was investigated in this article. Physical property, morphological character, toxic metal leaching content, and crystal component were studied to explore the application possibility of novel ceramics in micro-electrolysis reactors. The influences of operating conditions including influent pH, hydraulic retention time (HRT), and air-water ratio (A/W) on the removal of tetracycline were studied. The results showed that SFC and SFFC were suitable for application in micro-electrolysis reactors. The optimum conditions of SFC reactor were pH of 3, HRT of 7 h, and A/W of 10. For SFFC reactor, the optimum conditions were pH of 2, HRT of 7 h, and A/W of 15. In general, the TET removal efficiency of SFC reactor was better than that of SFFC reactor. However, the harden resistance of SFFC was better than that of SFC. Furthermore, the biodegradability of TET wastewater was improved greatly after micro-electrolysis pretreatment for both SFC and SFFC reactors.

  12. Sulfur-oxidizing autotrophic and mixotrophic denitrification processes for drinking water treatment: elimination of excess sulfate production and alkalinity requirement.

    Science.gov (United States)

    Sahinkaya, Erkan; Dursun, Nesrin

    2012-09-01

    This study evaluated the elimination of alkalinity need and excess sulfate generation of sulfur-based autotrophic denitrification process by stimulating simultaneous autotrophic and heterotrophic (mixotrophic) denitrification process in a column bioreactor by methanol supplementation. Also, denitrification performances of sulfur-based autotrophic and mixotrophic processes were compared. In autotrophic process, acidity produced by denitrifying sulfur-oxidizing bacteria was neutralized by the external NaHCO(3) supplementation. After stimulating mixotrophic denitrification process, the alkalinity need of the autotrophic process was satisfied by the alkalinity produced by heterotrophic denitrifiers. Decreasing and lastly eliminating the external alkalinity supplementation did not adversely affect the process performance. Complete denitrification of 75 mg L(-1) NO(3)-N under mixotrophic conditions at 4 h hydraulic retention time was achieved without external alkalinity supplementation and with effluent sulfate concentration lower than the drinking water guideline value of 250 mg L(-1). The denitrification rate of mixotrophic process (0.45 g NO(3)-N L(-1) d(-1)) was higher than that of autotrophic one (0.3 g NO(3)-N L(-1) d(-1)). Batch studies showed that the sulfur-based autotrophic nitrate reduction rate increased with increasing initial nitrate concentration and transient accumulation of nitrite was observed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Solid State Sensor for Simultaneous Measurement of Total Alkalinity and pH of Seawater.

    Science.gov (United States)

    Briggs, Ellen M; Sandoval, Sergio; Erten, Ahmet; Takeshita, Yuichiro; Kummel, Andrew C; Martz, Todd R

    2017-09-22

    A novel design is demonstrated for a solid state, reagent-less sensor capable of rapid and simultaneous measurement of pH and Total Alkalinity (A T ) using ion sensitive field effect transistor (ISFET) technology to provide a simplified means of characterization of the aqueous carbon dioxide system through measurement of two "master variables": pH and A T . ISFET-based pH sensors that achieve 0.001 precision are widely used in various oceanographic applications. A modified ISFET is demonstrated to perform a nanoliter-scale acid-base titration of A T in under 40 s. This method of measuring A T , a Coulometric Diffusion Titration, involves electrolytic generation of titrant, H + , through the electrolysis of water on the surface of the chip via a microfabricated electrode eliminating the requirement of external reagents. Characterization has been performed in seawater as well as titrating individual components (i.e., OH - , HCO 3 - , CO 3 2- , B(OH) 4 - , PO 4 3- ) of seawater A T . The seawater measurements are consistent with the design in reaching the benchmark goal of 0.5% precision in A T over the range of seawater A T of ∼2200-2500 μmol kg -1 which demonstrates great potential for autonomous sensing.

  14. A Feasibility Study of Steelmaking by Molten Oxide Electrolysis (TRP9956)

    Energy Technology Data Exchange (ETDEWEB)

    Donald R. Sadoway; Gerbrand Ceder

    2009-12-31

    Molten oxide electrolysis (MOE) is an extreme form of molten salt electrolysis, a technology that has been used to produce tonnage metals for over 100 years - aluminum, magnesium, lithium, sodium and the rare earth metals specifically. The use of carbon-free anodes is the distinguishing factor in MOE compared to other molten salt electrolysis techniques. MOE is totally carbon-free and produces no CO or CO2 - only O2 gas at the anode. This project is directed at assessing the technical feasibility of MOE at the bench scale while determining optimum values of MOE operating parameters. An inert anode will be identified and its ability to sustain oxygen evalution will be demonstrated.

  15. Evaluation of hydraulic conductivities of bentonite and rock under hyper alkaline and nitrate conditions. 2

    International Nuclear Information System (INIS)

    Iriya, Keishiro; Fujii, Kensuke; Kubo, Hiroshi

    2003-02-01

    Circumstance of TRU waste repository shows alkaline condition due to leaching of cementitious materials. The waste containing significant soluble nitrate may changes ground water chemistry to high ion strength. Several experimental studies have been carried out in this study in order to assess quantitatively water conductivity of bentonite which is altered by hyper alkaline and nitrate. Modeling for previous results is carried out and several requirements to be defined are proposed. The conclusion of this study is summarized as below. Secondary minerals of bentonite alteration due to hyper alkaline with nitrate: 1) CSH and CAH were observed corresponding to solving montmorillonite in AWN solution. 2) Na 2 O Al 2 O 3 1.68SiO 2 generated from 90 days in batch experiment and it was observed in 360 days. Assessment of swelling and water conductivity changing by hyper alkaline with nitrate: 1) Little changing of water conductivity of bentonite was observed by saturated Ca(OH) 2 solution and hyper alkaline solution. The conductivity significantly increased by penetrating sodium nitrate solution. 2) Water conductivity of ion exchanged bentonite by hyper alkaline solution significantly increased. It increased more by penetrating AWN solution. Modeling of tuff alteration by hyper alkaline solution: 1) Flow through test is proposed since soluble velocity to hyper alkaline solution should be defined. (author)

  16. The Detoxification and Degradation of Benzothiazole from the Wastewater in Microbial Electrolysis Cells

    Directory of Open Access Journals (Sweden)

    Xianshu Liu

    2016-12-01

    Full Text Available In this study, the high-production-volume chemical benzothiazole (BTH from synthetic water was fully degraded into less toxic intermediates of simple organic acids using an up-flow internal circulation microbial electrolysis reactor (UICMER under the hydraulic retention time (HRT of 24 h. The bioelectrochemical system was operated at 25 ± 2 °C and continuous-flow mode. The BTH loading rate varied during experiments from 20 g·m−3·day−1 to 110 g·m−3·day−1. BTH and soluble COD (Chemical Oxygen Demand removal efficiency reached 80% to 90% under all BTH loading rates. Bioluminescence based Shewanella oneidensis strain MR-1 ecotoxicity testing demonstrated that toxicity was largely decreased compared to the BTH wastewater influent and effluent of two control experiments. The results indicated that MEC (Microbial Electrolysis Cell was useful and reliable for improving BTH wastewater treatment efficiency, enabling the microbiological reactor to more easily respond to the requirements of higher loading rate, which is meaningful for economic and efficient operation in future scale-up.

  17. The application of alkaline and acidic electrolyzed water in the sterilization of chicken breasts and beef liver

    OpenAIRE

    Shimamura, Yuko; Shinke, Momoka; Hiraishi, Miki; Tsuchiya, Yusuke; Masuda, Shuichi

    2015-01-01

    Abstract The sterilization effect of a combination treatment with alkaline electrolyzed water (AlEW) and strong acidic electrolyzed water (StAEW) on fresh chicken breasts and beef liver was evaluated. Samples (1, 5, and 10?g) were inoculated with Salmonella Enteritidis NBRC3313, Escherichia coli ATCC 10798, Staphylococcus aureus FDA209P, and S.?aureus C?29 [staphylococcal enterotoxin A (SEA) productive strain] and subjected to a dipping combination treatment (4?C and 25?C for 3?min) with AlEW...

  18. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    NARCIS (Netherlands)

    Logan, B.E.; Call, D.; Cheng, S.; Hamelers, H.V.M.; Sleutels, T.H.J.A.; Jeremiasse, A.W.; Rozendal, R.A.

    2008-01-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few

  19. Flow maldistribution in the anode of a polymer electrolyte membrane electrolysis cell employing interdigitated channels

    DEFF Research Database (Denmark)

    Olesen, Anders Christian; Kær, Søren Knudsen

    2014-01-01

    of liquid water towards the catalytic layer of the electrode. As opposed to the more common serpentine and parallel channels, interdigitated channels force liquid water through the porous gas diffusion layer (GDL) of the electrode. This improves the supply of water, however it increases pressure losses......-circular cell design on the distribution of water in the anode. In the electrolysis of water using PEMEC the anode is fed by demineralized water. Throughout the anode, oxygen is produced and a two-phase flow develops. Interdigitated channels assist in avoiding that gaseous oxygen obstructs the transport......: water stoichiometry, temperature, GDL permeability and thickness. In conclusion, it is found that the interdigitated flow field results in an uneven distribution across the cell and that the extent depends strongly on the permeability and weaker on the remaining parameters....

  20. Electrolysis test of different composite membranes at elevated temperatures

    DEFF Research Database (Denmark)

    Hansen, Martin Kalmar

    temperatures, phosphoric acid (H3PO4)[1] and zirconium phosphate (ZrP)[2] were introduced. These composite membranes were tested in an electrolysis setup. A typical electrolysis test was performed at 130°C with a galvanostatic load. Polarization curves were recorded under stationary conditions. Testing...... night at 150°C in a zirconium phosphate saturated 85wt% phosphoric acid solution. Different thicknesses of membranes were tested and as expected, the performance increased when the thickness of the membranes decreased. Furthermore composite membranes only treated with phosphoric acid or only treated...

  1. Economical hydrogen production by electrolysis using nano pulsed DC

    Energy Technology Data Exchange (ETDEWEB)

    Dharmaraj, C.H. [Tangedco, Tirunelveli, ME Environmental Engineering (India); Adshkumar, S. [Department of Civil Engineering, Anna University of Technology Tirunelveli, Tirunelveli - 627007 (India)

    2012-07-01

    Hydrogen is an alternate renewable eco fuel. The environmental friendly hydrogen production method is electrolysis. The cost of electrical energy input is major role while fixing hydrogen cost in the conventional direct current Electrolysis. Using nano pulse DC input makes the input power less and economical hydrogen production can be established. In this investigation, a lab scale electrolytic cell developed and 0.58 mL/sec hydrogen/oxygen output is obtained using conventional and nano pulsed DC. The result shows that the nano pulsed DC gives 96.8 % energy saving.

  2. Cation exchange properties of zeolites in hyper alkaline aqueous media.

    Science.gov (United States)

    Van Tendeloo, Leen; de Blochouse, Benny; Dom, Dirk; Vancluysen, Jacqueline; Snellings, Ruben; Martens, Johan A; Kirschhock, Christine E A; Maes, André; Breynaert, Eric

    2015-02-03

    Construction of multibarrier concrete based waste disposal sites and management of alkaline mine drainage water requires cation exchangers combining excellent sorption properties with a high stability and predictable performance in hyper alkaline media. Though highly selective organic cation exchange resins have been developed for most pollutants, they can serve as a growth medium for bacterial proliferation, impairing their long-term stability and introducing unpredictable parameters into the evolution of the system. Zeolites represent a family of inorganic cation exchangers, which naturally occur in hyper alkaline conditions and cannot serve as an electron donor or carbon source for microbial proliferation. Despite their successful application as industrial cation exchangers under near neutral conditions, their performance in hyper alkaline, saline water remains highly undocumented. Using Cs(+) as a benchmark element, this study aims to assess the long-term cation exchange performance of zeolites in concrete derived aqueous solutions. Comparison of their exchange properties in alkaline media with data obtained in near neutral solutions demonstrated that the cation exchange selectivity remains unaffected by the increased hydroxyl concentration; the cation exchange capacity did however show an unexpected increase in hyper alkaline media.

  3. [Complex technology for water and wastewater disinfection and its industrial realization in prototype unit].

    Science.gov (United States)

    Arakcheev, E N; Brunman, V E; Brunman, M V; Konyashin, A V; Dyachenko, V A; Petkova, A P

    Usage of complex automated electrolysis unit for drinking water disinfection and wastewater oxidation and coagulation is scoped, its ecological and energy efficiency is shown. Properties of technological process of anolyte production using membrane electrolysis of brine for water disinfection in municipal pipelines and potassium ferrate production using electrochemical dissolution of iron anode in NaOH solution for usage in purification plants are listed. Construction of modules of industrial prototype for anolyte and ferrate production and applied aspects of automation of complex electrolysis unit are proved. Results of approbation of electrolytic potassium ferrate for drinking water disinfection and wastewater, rain water and environmental water oxidation and coagulation are shown.

  4. PREPARATION OF NICKEL - COBALT SPINEL OXIDES NixCO3 ...

    African Journals Online (AJOL)

    During the last decade, the improvement of the alkaline water electrolysis cells has drained a lot of interest, especially due to an increase in consummation and prices of natural energetic resources. Oxides constitute a wide class of materials with good electrocatalytic activity for many electrode reactions from O2 evolution to ...

  5. Irrigation water acidification to neutralize alkalinity for nursery crop production: Substrate pH, electrical conductivity, nutrient concentrations, and plant nutrition and growth

    Science.gov (United States)

    Liming agents in irrigation water, typically associated with carbonates and bicarbonates of calcium and magnesium, contribute to water alkalinity. Repeated application of LA to container crops can cause media-solution pH to rise overtime, that uncorrected, can lead to a nutrient availability imbalan...

  6. Ni nanotube array-based electrodes by electrochemical alloying and de-alloying for efficient water splitting.

    Science.gov (United States)

    Teng, Xue; Wang, Jianying; Ji, Lvlv; Lv, Yaokang; Chen, Zuofeng

    2018-05-17

    The design of cost-efficient earth-abundant catalysts with superior performance for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is extremely important for future renewable energy production. Herein, we report a facile strategy for constructing Ni nanotube arrays (NTAs) on a Ni foam (NF) substrate through cathodic deposition of NiCu alloy followed by anodic stripping of metallic Cu. Based on Ni NTAs, the as-prepared NiSe2 NTA electrode by NiSe2 electrodeposition and the NiFeOx NTA electrode by dipping in Fe3+ solution exhibit excellent HER and OER performance in alkaline conditions. In these systems, Ni NTAs act as a binder-free multifunctional inner layer to support the electrocatalysts, offer a large specific surface area and serve as a fast electron transport pathway. Moreover, an alkaline electrolyzer has been constructed using NiFeOx NTAs as the anode and NiSe2 NTAs as the cathode, which only demands a cell voltage of 1.78 V to deliver a water-splitting current density of 500 mA cm-2, and demonstrates remarkable stability during long-term electrolysis. This work provides an attractive method for the design and fabrication of nanotube array-based catalyst electrodes for highly efficient water-splitting.

  7. Mineral textures in Serpentine-hosted Alkaline Springs from the Oman ophiolite

    Science.gov (United States)

    Giampouras, Manolis; Garcia-Ruiz, Juan Manuel; Bach, Wolfgang; Garrido, Carlos J.; Los, Karin; Fussmann, Dario; Monien, Monien

    2017-04-01

    Meteoric water infiltration in ultramafic rocks leads to serpentinization and the formation of subaerial, low temperature, hydrothermal alkaline springs. Here, we present a detailed investigation of the mineral precipitation mechanisms and textural features of mineral precipitates, along as the geochemical and hydrological characterization, of two alkaline spring systems in the Semail ophiolite (Nasif and Khafifah sites, Wadi Tayin massif). The main aim of the study is to provide new insights into mineral and textural variations in active, on-land, alkaline vents of the Oman ophiolite. Discharge of circulating fluids forms small-scale, localized hydrological catchments consisting in unevenly interconnected ponds. Three different types of waters can be distinguished within the pond systems: i) Mg-type; alkaline (7.9 11.6), Ca-OH-rich waters; and iii) Mix-type waters arising from the mixing of Mg-type and Ca-type waters (9.6 ponds were carried out by X-ray diffraction (XRD), Raman spectroscopy and field-emission scanning electron microscopy coupled to dispersive energy spectroscopy (FE-SEM-EDS). Aragonite and calcite are the dominant minerals (95 vol.%) of the total mineralogical index in all sites. Mg-type waters host hydrated magnesium carbonates (nesquehonite) and magnesium hydroxycarbonate hydrates (artinite) due to evaporation. Brucite, hydromagnesite and dypingite presence in Mix-type waters is spatially controlled by the hydrology of the system and is localized around mixing zones between Ca-type with Mg-type waters. Residence time of discharging waters in the ponds before mixing has an impact on fluid chemistry as it influences the equilibration time with the atmosphere. Acicular aragonite is the main textural type in hyper-alkaline Ca-type waters, acting as a substratum for the growth of calcite and brucite crystals. Low crystallinity, dumbbell shaped and double pyramid aragonite dominates in Mix-type water precipitates. Rate of supersaturation is essential

  8. Electrochemical manipulation of localized electrolysis of water: application to determination of gallium by stripping voltammetry

    International Nuclear Information System (INIS)

    Gopinath, N.; Kamat, J.V.; Aggarwal, S.K.

    2003-01-01

    A large enhancement in the stripping peak current of gallium disproportionate to the preconcentration deposition potential, more negative than -1.4 V, was observed in 0.005 M HCl electrolyte. It was attributed to the fact that water was electrolysed and an alkaline environment (OH ions) in the vicinity of the Hg drop electrode was generated. As a result, the Ga +3 ions were hydrolysed and gallate ions were in situ produced. The easy-to-reduce gallate ions were involved in the preconcentration step instead of the difficult-to-reduce Ga + 3 ions. Hence there was an increase in the quantity of gallium deposited / dissolved in the Hg drop electrode. Experimental conditions were optimized for the determination of gallium in 0.005 M HCl electrolyte. (author)

  9. NOx generation method from recovered nitric acid by electrolysis

    International Nuclear Information System (INIS)

    Suzuki, Y.; Shimizu, H.; Inoue, M.; Fujiso, M.; Shibuya, M.; Iwamoto, F.; Outou, Y.; Ochi, E.; Tsuyuki, T.

    1998-01-01

    An R and D has been conducted on an electrolytic NO x generation process utilizing recovered nitric acid from a PUREX reprocessing plant. The purpose of the study is to drastically reduce the amount of low-level-liquid waste(LLW). The research program phase-1, constituting mainly of electrochemical reaction mechanism study, material balance evaluation and process design study, finished in 1995. The results were presented in the previous papers). The research program phase-2 has started in 1995. The schedule is as follows: FY 1991-1994: Research program phase-1 Basic study using electrolysis equipment with 100-700 cm 2 electrodes FY 1995-1999: Research program phase-2 Process performance test by larger scale electrolysis equipment with 3.6 m 2 electrodes - pilot plant design (FY 1995) - pilot plant construction (FY 1996) - engineering data acquisition (FY 1997-1999). The process consists of many unit operations such as electrolysis, oxidation, nitric acid concentration, NO x compression and storage, NO x recovery, off-gas treatment and acid supplier. This paper outlines the pilot test plant. (author)

  10. Preliminary study of the electrolysis of aluminum sulfide in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

    1983-02-01

    A preliminary laboratory-scale study of the electrolysis of aluminum sulfide in molten salts investigated the (1) solubility of Al/sub 2/S/sub 3/ in molten salts, (2) electrochemical behavior of Al/sub 2/S/sub 3/, and (3) electrolysis of Al/sub 2/S/sub 3/ with the determination of current efficiency as a function of current density. The solubility measurements show that MgCl/sub 2/-NaCl-KCl eutectic electrolyte at 1023 K can dissolve up to 3.3 mol % sulfide. The molar ratio of sulfur to aluminum in the eutectic is about one, which suggests that some sulfur remains undissolved, probably in the form of MgS. The experimental data and thermodynamic calculations suggest that Al/sub 2/S/sub 3/ dissolves in the eutectic to form AlS/sup +/ species in solution. Addition of AlCl/sub 3/ to the eutectic enhances the solubility of Al/sub 2/S/sub 3/; the solubility increases with increasing AlCl/sub 3/ concentration. The electrode reaction mechanism for the electrolysis of Al/sub 2/S/sub 3/ was elucidated by using linear sweep voltammetry. The cathodic reduction of aluminum-ion-containing species to aluminum proceeds by a reversible, diffusion-controlled, three-electron reaction. The anodic reaction involves the two-electron discharge of sulfide-ion-containing species, followed by the fast dimerization of sulfur atoms to S/sub 2/. Electrolysis experiments show that Al/sub 2/S/sub 3/ dissolved in molten MgCl/sub 2/-NaCl-KCl eutectic or in eutectic containing AlCl/sub 3/ can be electrolyzed to produce aluminum and sulfur. In the eutectic at 1023 K, the electrolysis can be conducted up to about 300 mA/cm/sup 2/ for the saturation solubility of Al/sub 2/S/sub 3/. Although these preliminary results are promising, additional studies are needed to elucidate many critical operating parameters before the technical potential of the electrolysis can be accurately assessed. 20 figures, 18 tables.

  11. Performance of single chamber biocatalyzed electrolysis with different types of ion exchange membranes

    NARCIS (Netherlands)

    Rozendal, R.A.; Hamelers, H.V.M.; Molenkamp, R.J.; Buisman, C.J.N.

    2007-01-01

    In this paper hydrogen production through biocatalyzed electrolysis was studied for the first time in a single chamber configuration. Single chamber biocatalyzed electrolysis was tested in two configurations: (i) with a cation exchange membrane (CEM) and (ii) with an anion exchange membrane (AEM).

  12. Properties of whey protein isolates extruded under acidic and alkaline conditions.

    Science.gov (United States)

    Onwulata, C I; Isobe, S; Tomasula, P M; Cooke, P H

    2006-01-01

    Whey proteins have wide acceptance and use in many products due to their beneficial nutritional properties. To further increase the amount of whey protein isolates (WPI) that may be added to products such as extruded snacks and meats, texturization of WPI is necessary. Texturization changes the folding of globular proteins to improve interaction with other ingredients and create new functional ingredients. In this study, WPI pastes (60% solids) were extruded in a twin-screw extruder at 100 degrees C with 4 pH-adjusted water streams: acidic (pH 2.0 +/- 0.2) and alkaline (pH 12.4 +/- 0.4) streams from 2 N HCl and 2 N NaOH, respectively, and acidic (pH 2.5 +/- 0.2) and alkaline (pH 11.5 +/- 0.4) electrolyzed water streams; these were compared with WPI extruded with deionized water. The effects of water acidity on WPI solubility at pH 7, color, microstructure, Rapid Visco Analyzer pasting properties, and physical structure were determined. Alkaline conditions increased insolubility caused yellowing and increased pasting properties significantly. Acidic conditions increased solubility and decreased WPI pasting properties. Subtle structural changes occurred under acidic conditions, but were more pronounced under alkaline conditions. Overall, alkaline conditions increased denaturation in the extruded WPI resulting in stringy texturized WPI products, which could be used in meat applications.

  13. Effect of electrolysis condition of zinc powder production on zinc-silver oxide battery operation

    International Nuclear Information System (INIS)

    Mojtahedi, M.; Goodarzi, M.; Sharifi, B.; Vahdati Khaki, J.

    2011-01-01

    A research conducted to produce zinc powder through electrolysis of alkaline solutions by using various concentrations of KOH and zincate in the bath. Different current densities were applied for each concentration and then, morphological changes of Zn powder batches were examined by scanning electron microscopy. Afterward, an anode electrode was produced from each pack of powder. Thirty-six Zn-AgO battery cells were prepared totally. Discharge parameters of the cells were examined and time-voltage curves were analyzed. Discharge times were investigated for various conditions of Zn deposition and the proper terms were suggested. It has been seen that increase of KOH concentration and decrease of zincate ion in the bath solution will change the zinc morphology and increase the resultant battery discharge time. The longest time of discharge, before reduction of cell voltage to 1.25 V, was 7.91 min. This result was obtained for Zn powder produced in zincate concentration of 0.5 M, KOH concentration of 11 M and current density of 2500 A/m 2 .

  14. Integrated Microbial Electrolysis Cell (MEC) with an anaerobic Membrane Bioreactor (MBR) for low strength wastewater treatment, energy harvesting and water reclamation

    KAUST Repository

    Jimenez Sandoval, Rodrigo J.

    2013-11-01

    Shortage of potable water is a problem that affects many nations in the world and it will aggravate in a near future if pertinent actions are not carried out. Decrease in consumption, improvements in water distribution systems to avoid losses and more efficient water treatment processes are some actions that can be implemented to attack this problem. Membrane technology and biological processes are used in wastewater treatment to achieve high water quality standards. Some other technologies, besides water treatment, attempt to obtain energy from organic wastes present in water. In this study, a proof-of-concept was accomplished demonstrating that a Microbial Electrolysis Cell can be fully integrated with a Membrane Bioreactor to achieve wastewater treatment and harvest energy. Conductive hollow fiber membranes made of nickel functioned as both filter material for treated water reclamation and as a cathode to catalyze hydrogen production reaction. The produced hydrogen was subsequently converted into methane by hydrogenotrophic methanogens. Organic removal was 98.9% irrespective of operation mode. Maximum volumetric hydrogen production rate was 0.2 m3/m3d, while maximum current density achieved was 6.1 A/m2 (based on cathode surface area). Biofouling, an unavoidable phenomenon in traditional MBRs, can be minimized in this system through self-cleaning approach of hybrid membranes by hydrogen production. The increased rate of hydrogen evolution at high applied voltage (0.9 V) reduces the membrane fouling. Improvements can be done in the system to make it as a promising net energy positive technology for the low strength wastewater treatment.

  15. A Comparison of Alkaline Water and Mediterranean Diet vs Proton Pump Inhibition for Treatment of Laryngopharyngeal Reflux.

    Science.gov (United States)

    Zalvan, Craig H; Hu, Shirley; Greenberg, Barbara; Geliebter, Jan

    2017-10-01

    Laryngopharyngeal reflux (LPR) is a common disorder with protean manifestations in the head and neck. In this retrospective study, we report the efficacy of a wholly dietary approach using alkaline water, a plant-based, Mediterranean-style diet, and standard reflux precautions compared with that of the traditional treatment approach of proton pump inhibition (PPI) and standard reflux precautions. To determine whether treatment with a diet-based approach with standard reflux precautions alone can improve symptoms of LPR compared with treatment with PPI and standard reflux precautions. This was a retrospective medical chart review of 2 treatment cohorts. From 2010 to 2012, 85 patients with LPR that were treated with PPI and standard reflux precautions (PS) were identified. From 2013 to 2015, 99 patients treated with alkaline water (pH >8.0), 90% plant-based, Mediterranean-style diet, and standard reflux precautions (AMS) were identified. The outcome was based on change in Reflux Symptom Index (RSI). Recorded change in the RSI after 6 weeks of treatment. Of the 184 patients identified in the PS and AMS cohorts, the median age of participants in each cohort was 60 years (95% CI, 18-82) and 57 years (95% CI, 18-93), respectively (47 [56.3%] and 61 [61.7%] were women, respectively). The percentage of patients achieving a clinically meaningful (≥6 points) reduction in RSI was 54.1% in PS-treated patients and 62.6% in AMS-treated patients (difference between the groups, 8.05; 95% CI, -5.74 to 22.76). The mean reduction in RSI was 27.2% for the PS group and 39.8% in the AMS group (difference, 12.10; 95% CI, 1.53 to 22.68). Our data suggest that the effect of PPI on the RSI based on proportion reaching a 6-point reduction in RSI is not significantly better than that of alkaline water, a plant-based, Mediterranean-style diet, and standard reflux precautions, although the difference in the 2 treatments could be clinically meaningful in favor of the dietary approach. The

  16. Highlights from Faraday Discussion 182: Solid Oxide Electrolysis: Fuels and Feedstocks from Water and Air, York, UK, July 2015.

    Science.gov (United States)

    Stefan, Elena; Norby, Truls

    2016-01-31

    The rising importance of converting high peak electricity from renewables to fuels has urged field specialists to organize this Faraday Discussion on Solid Oxide Electrolysis. The topic is of essential interest in order to achieve a greater utilization of renewable energy and storage at higher densities.

  17. Photovoltaic hydrogen production with commercial alkaline electrolysers

    Energy Technology Data Exchange (ETDEWEB)

    Ursua, A.; Lopez, J.; Gubia, E.; Marroyo, L.; Sanchis, P. [Public Univ. of Navarra, Pamplona (Spain). Dept. of Electric and Electronic Engineering

    2010-07-01

    Renewable energy sources and Electrolysis generate the so-called green Hydrogen, a zero-emission and potentially fossil fuel independent energy source. However, the inherent variability of the renewable energy sources implies a mode of operation for which most current electrolysers have not been designed. This paper analyses the operation of a water electrolyser fed with photovoltaic (PV) generator electric profile. The system, Integrated by a 1 Nm{sup 3}/h Hydrogenics alkaline electrolyser and a 5100 W PV generator with 60 BP585 modules, is installed at the Public University of Navarra (Spain). The PV generator profile fed to the electrolyser is emulated by a custom-made apparatus designed and built by the authors of this paper. The profile is designed according to real irradiance data measured by a calibration cell. The irradiance data are converted to the electric power profile that the PV generator would have delivered in case of having been connected to the electrolyser by means of a DC/DC converter with maximum power point tracking (MPPT). Finally, from previously measured power-current electrolyser characteristic curves, the current profile to be delivered to the electrolyser is obtained and programmed to the electronic device. The electrolyser was tested for two types of days. During the first day, the irradiance was very stable, whereas during the second day, the irradiance was very variable. The experimental results show an average power consumption rate and an efficiency of 4908 Wh/Nm{sup 3} and 72.1%, on the first day, and 4842 Wh/Nm{sup 3} and 73.3% on the second day. The electrolyser performance was particularly good in spite of the high variability of the electric supply of the second day. (orig.)

  18. Advanced Additive Manufacturing Feedstock from Molten Regolith Electrolysis

    Data.gov (United States)

    National Aeronautics and Space Administration — Demonstrate the feasibility of Molten Regolith Electrolysis (MRE) Reactor start by initiating resistive-heating of the regolith past its melting point using...

  19. Zeolite A synthesized from alkaline assisted pre-activated halloysite for efficient heavy metal removal in polluted river water and industrial wastewater.

    Science.gov (United States)

    Meng, Qingpeng; Chen, Hong; Lin, Junzhong; Lin, Zhang; Sun, Junliang

    2017-06-01

    High quality zeolite A was synthesized through a hydrothermal process using alkaline-assisted pre-activated halloysite mineral as the alumina and silica source. The synthesis conditions employed in this study were finely tuned by varying the activating temperature, sodium hydroxide content, water content and Si/Al ratio. The obtained zeolite A showed excellent adsorption properties for both single metal cation solutions and mixed cation solutions when the concentrations of the mixed cations were comparable with those in polluted natural river water and industrial wastewater. High adsorptive capacities for Ag + (123.05mg/g) and Pb 2+ (227.70mg/g) were achieved using the synthesized zeolite A. This observation indicates that the zeolite A synthesized from alkaline-assisted pre-activated halloysite can be used as a low-cost and relatively effective adsorbent to purify heavy metal cation polluted natural river water and industrial wastewater. Copyright © 2016. Published by Elsevier B.V.

  20. Study of the effect of pressure on electrolysis of H2O and co-electrolysis of H2O and CO2 at high temperature

    International Nuclear Information System (INIS)

    Bernadet, Lucile

    2016-01-01

    This thesis work investigates the behavior of a solid oxide cell operating under pressure in high temperature steam electrolysis and co-electrolysis mode (H 2 O and CO 2 ). The experimental study of single cell associated with the development of multi-physical models have been set up. The experiments, carried out using an original test bench developed by the CEA-Grenoble on two types of cells between 1 and 10 bar and 700 to 800 C, allowed to identify in both operating modes that the pressure has a positive or negative effect on performance depending on the cell operating point (current, voltage). In addition, gas analyzes performed in co-electrolysis led to detect in situ CH 4 production under pressure. These pressure effects were simulated by models calibrated at atmospheric pressure. Simulations analysis helped identify the pressure dependent mechanisms and propose operating conditions thanks to the establishment of operating maps. (author) [fr

  1. Electrolysis of a nitrosyl hexafluoro-molybdate in anhydrous hydrogen fluoride

    International Nuclear Information System (INIS)

    Mougin, Jacques

    1972-01-01

    This thesis addresses the field of irradiated fuel reprocessing, and more particularly the study of the formation of molybdenum hexafluoride (MoF_6) by electrolysis of nitrosyl hexafluoro-molybdate (NOMoF_6) in solution in HF. The author presents the conditions of preparation of an electrolysis in anhydrous HF: solvent purification and control, production of a reference electrode, potential-kinetic study of the behaviour of materials selected for the electrode. The author then addresses the actual hydrolysis of the solution of nitrosyl hexafluoro-molybdate [fr

  2. Apparent Km of mitochondria for oxygen computed from Vmax measured in permeabilized muscle fibers is lower in water enriched in oxygen by electrolysis than injection

    Directory of Open Access Journals (Sweden)

    Zoll J

    2015-07-01

    significantly lower with both electron donors in water enriched in O2 by electrolysis. This was not associated with any increase in the sensitivity of mitochondria to ADP; no significant difference was observed for the Km ADP between the two waters.Conclusion: In this experiment, a higher affinity of the mitochondria for O2 was observed in water enriched in O2 by electrolysis than by injection. This observation is consistent with the hypothesis that O2 diffusion can be facilitated in water enriched in O2 by the electrolytic process.Keywords: saponin-skinned fibers, mitochondrial respiration, glutamate–malate, TMPD–ascorbate, Km O2

  3. Alkalinity production in intertidal sands intensified by lugworm bioirrigation.

    Science.gov (United States)

    Rao, Alexandra M F; Malkin, Sairah Y; Montserrat, Francesc; Meysman, Filip J R

    2014-07-05

    Porewater profiles and sediment-water fluxes of oxygen, nutrients, pH, calcium, alkalinity, and sulfide were measured in intertidal sandflat sediments from the Oosterschelde mesotidal lagoon (The Netherlands). The influence of bioturbation and bioirrigation by the deep-burrowing polychaete Arenicola marina on the rates and sources of benthic alkalinity generation was examined by comparing measurements in intact and defaunated sediment cores before and after the addition of A. marina in summer and fall 2011. Higher organic matter remineralization rates, shallower O 2 penetration, and greater sediment-water solute fluxes were observed in summer, consistent with higher sediment community metabolic rates at a higher temperature. Lugworm activity stimulated porewater exchange (5.1 × in summer, 1.9 × in fall), organic matter remineralization (6.2 × in summer, 1.9 × in fall), aerobic respiration (2.4 × in summer, 2.1 × in fall), alkalinity release (4.7 × in summer, 4.0 × in fall), nutrient regeneration, and iron cycling. The effects of lugworm activity on net sediment-water fluxes were similar but more pronounced in summer than in fall. Alkalinity release in fall was entirely driven by metabolic carbonate dissolution, while this process explained between 22 and 69% of total alkalinity production in summer, indicating the importance of other processes in this season. By enhancing organic matter remineralization and the reoxidation of reduced metabolites by the sediment microbial community, lugworm activity stimulated the production of dissolved inorganic carbon and metabolic acidity, which in turn enhanced metabolic CaCO 3 dissolution efficiency. In summer, evidence of microbial long distance electron transport (LDET) was observed in defaunated sediment. Thus, alkalinity production by net carbonate dissolution was likely supplemented by anaerobic respiration and LDET in summer.

  4. THE HIGH-TEMPERATURE ELECTROLYSIS PROGRAM AT THE IDAHO NATIONAL LABORATORY: OBSERVATIONS ON PERFORMANCE DEGRADATION

    Energy Technology Data Exchange (ETDEWEB)

    J. E. O' Brien; C. M. Stoots; J. S. Herring; K. G. Condie; G. K. Housley

    2009-06-01

    This paper presents an overview of the high-temperature electrolysis research and development program at the Idaho National Laboratory, with selected observations of electrolysis cell degradation at the single-cell, small stack and large facility scales. The objective of the INL program is to address the technical and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for hydrogen production from steam. In the envisioned application, high-temperature electrolysis would be coupled to an advanced nuclear reactor for efficient large-scale non-fossil non-greenhouse-gas hydrogen production. The program supports a broad range of activities including small bench-scale experiments, larger scale technology demonstrations, detailed computational fluid dynamic modeling, and system modeling. A summary of the current status of these activities and future plans will be provided, with a focus on the problem of cell and stack degradation.

  5. Degradation of 3,3'-iminobis-propanenitrile in aqueous solution by Fe(0)/GAC micro-electrolysis system.

    Science.gov (United States)

    Lai, Bo; Zhou, Yuexi; Yang, Ping; Yang, Jinghui; Wang, Juling

    2013-01-01

    The degradation of 3,3'-iminobis-propanenitrile was investigated using the Fe(0)/GAC micro-electrolysis system. Effects of influent pH value, Fe(0)/GAC ratio and granular activated carbon (GAC) adsorption on the removal efficiency of the pollutant were studied in the Fe(0)/GAC micro-electrolysis system. The degradation of 3,3'-iminobis-propanenitrile was affected by influent pH, and a decrease of the influent pH values from 8.0 to 4.0 led to the increase of degradation efficiency. Granular activated carbon was added as cathode to form macroscopic galvanic cells between Fe(0) and GAC and enhance the current efficiency of the Fe(0)/GAC micro-electrolysis system. The GAC could only adsorb the pollutant and provide buffer capacity for the Fe(0)/GAC micro-electrolysis system, and the macroscopic galvanic cells of the Fe(0)/GAC micro-electrolysis system played a leading role in degradation of 3,3'-iminobis-propanenitrile. With the analysis of the degradation products with GC-MS, possible reaction pathway for the degradation of 3,3'-iminobis-propanenitrile by the Fe(0)/GAC micro-electrolysis system was suggested. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Batch and column adsorption of herbicide fluroxypyr on different types of activated carbons from water with varied degrees of hardness and alkalinity.

    Science.gov (United States)

    Pastrana-Martínez, L M; López-Ramón, M V; Fontecha-Cámara, M A; Moreno-Castilla, C

    2010-02-01

    There has been little research into the effects of the water hardness and alkalinity of surface waters on the adsorption of herbicides on activated carbons. The aim of this study was to determine the influence of these water characteristics on fluroxypyr adsorption on different activated carbons. At low fluroxypyr surface concentrations, the amount adsorbed from distilled water was related to the surface hydrophobicity. Surface area of carbons covered by fluroxypyr molecules ranged from 60 to 65%. Variations in fluroxypyr solubility with water hardness and alkalinity showed a salting-in effect. Calcium, magnesium and bicarbonate ions were adsorbed to a varied extent on the activated carbons. The presence of fluroxypyr in solution decreased their adsorption due to a competition effect. K(F) from the Freundlich equation linearly increased with water hardness due to salt-screened electrostatic repulsions between charged fluroxypyr molecules. The amount adsorbed from distilled water was largest at high fluroxypyr solution concentrations, because there was no competition between inorganic ions and fluroxypyr molecules. The column breakthrough volume and the amount adsorbed at breakthrough were smaller in tap versus distilled water. Carbon consumption was lower with activated carbon cloth than with the use of granular activated carbon. (c) 2009 Elsevier Ltd. All rights reserved.

  7. Chemical oxygen demand removal efficiency and limited factors study of aminosilicone polymers in a water emulsion by iron-carbon micro-electrolysis.

    Science.gov (United States)

    Yang, Shangyuan; Liang, Zhiwei; Yu, Huadong; Wang, Yunlong; Chen, Yingxu

    2014-02-01

    Micro-electrolysis was applied in the present study to investigate the effect of pH, iron-carbon mass ratio, contact time, and treatment batch on the removal efficiency of chemical oxygen demand (COD) within an aminosilicone emulsion. The results exhibited that the removal efficiency of COD decreased linearly with the batch increase, and this tendency was consistent under the various conditions. The adsorption of activated carbons contributes a large portion to the elimination of COD within the aminosilicone emulsion. The oxidation action of iron-carbon micro-electrolysis was proven and the aminosilicone emulsion's COD removal contribution was approximately 16%. Aminosilicone polymers were adsorbed on the surface of activated carbons and iron chips, which contributes to the decline of COD removal efficiency and limits the contribution of oxidation action.

  8. Thermal Measurement during Electrolysis of Pd-Ni Thin-film -Cathodes in Li2SO4/H2O Solution

    Science.gov (United States)

    Castano, C. H.; Lipson, A. G.; S-O, Kim; Miley, G. H.

    2002-03-01

    Using LENR - open type calorimeters, measurements of excess heat production were carried out during electrolysis in Li_2SO_4/H_2O solution with a Pt-anode and Pd-Ni thin film cathodes (2000-8000 Åthick) sputtered on the different dielectric substrates. In order to accurately evaluate actual performance during electrolysis runs in the open-type calorimeter used, considering effects of heat convection, bubbling and possible H_2+O2 recombination, smooth Pt sheets were used as cathodes. Pt provides a reference since it does not produce excess heat in the light water electrolyte. To increase the accuracy of measurements the water dissociation potential was determined for each cathode taking into account its individual over-voltage value. It is found that this design for the Pd-Ni cathodes resulted in the excess heat production of ~ 20-25 % of input power, equivalent to ~300 mW. In cases of the Pd/Ni- film fracture (or detachment from substrate) no excess heat was detected, providing an added reference point. These experiments plus use of optimized films will be presented.

  9. Irrigation water acidification to neutralize alkalinity for nursery crop production: Substrate pH, electrical conductivity, and nutrient concentrations; and plant nutrition and growth

    Science.gov (United States)

    Liming agents (LA) in irrigation water, typically associated with carbonates and bicarbonates of calcium (Ca) and magnesium (Mg), contribute to water alkalinity. Repeated application of LA to container crops can cause media-solution pH to rise overtime, that uncorrected, can lead to a nutrient avail...

  10. Cementitious porous pavement in stormwater quality control: pH and alkalinity elevation.

    Science.gov (United States)

    Kuang, Xuheng; Sansalone, John

    2011-01-01

    A certain level of alkalinity acts as a buffer and maintains the pH value in a stable range in water bodies. With rapid urban development, more and more acidic pollutants flow to watersheds with runoff and drop alkalinity to a very low level and ultimately degrade the water environment. Cementitious porous pavement is an effective tool for stormwater acidic neutralization. When stormwater infiltrates cement porous pavement (CPP) materials, alkalinity and pH will be elevated due to the basic characteristics of cement concrete. The elevated alkalinity will neutralize acids in water bodies and maintain the pH in a stable level as a buffer. It is expected that CPP materials still have a certain capability of alkalinity elevation after years of service, which is important for CPP as an effective tool for stormwater management. However, few previous studies have reported on how CPP structures would elevate runoff alkalinity and pH after being exposed to rainfall-runoff for years. In this study, three groups of CPP specimens, all exposed to rainfall-runoff for 3 years, were used to test the pH and alkalinity elevation properties. It was found that runoff pH values were elevated from 7.4 to the range of 7.8-8.6 after infiltrating through the uncoated specimens, and from 7.4 to 8.5-10.7 after infiltrating through aluminum-coated specimens. Runoff alkalinity elevation efficiencies are 11.5-14.5% for uncoated specimens and 42.2% for coated specimens. The study shows that CPP is an effective passive unit operation for stormwater acid neutralization in our built environment.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  13. Hydrology and Alkalinity Regulation of Soft Florida Waters: An Integrated Assessment

    Science.gov (United States)

    Stauffer, Robert E.; Canfield, Daniel E., Jr.

    1992-06-01

    Natural waters in ridge provinces of Florida and southeast Georgia were classified geographically, by degrees of cultural disturbance, and according to the dominant hydrologic and biogeochemical processes controlling chemistry. The ionic composition of lakes, upland streams, and surficial aquifer (water table) springs in relatively undeveloped catchments reflects the geographic variations in bulk deposition corrected for evapotranspiration (Na, Cl), plus a slight gain (net watershed mobilization) of Mg, and partial to nearly complete losses (net retention) of nitrate, sulfate, Ca, and K. Recharge to the Floridan aquifer in infertile, forested, sandy ridge provinces of northern Florida contains 360-580 μmol CO2. On the basis of indirect geochemical evidence, sulfate retention appears less important in lake sediments than in the region's highly weathered, ferruginous, kaolinitic, sand soils. Silica concentrations in upland streams and water table springs closely reflect the predicted equilibrium between kaolinite and gibbsite. Along with other evidence, the Si concentrations in ridge lakes indicate that seepage inflow is much more important than assumed in Baker et al.'s (1988) regional model. Lakes and streams are acidified either by humic acids or nonmarine sulfate but rarely by both, as reflected by the significant inverse correlation between these two components. Contrary to previous reports, there is no significant difference in alkalinity for culturally undisturbed lakes in the northern Trail versus southern Highlands Ridge areas.

  14. Boosting water oxidation layer-by-layer.

    Science.gov (United States)

    Hidalgo-Acosta, Jonnathan C; Scanlon, Micheál D; Méndez, Manuel A; Amstutz, Véronique; Vrubel, Heron; Opallo, Marcin; Girault, Hubert H

    2016-04-07

    Electrocatalysis of water oxidation was achieved using fluorinated tin oxide (FTO) electrodes modified with layer-by-layer deposited films consisting of bilayers of negatively charged citrate-stabilized IrO2 NPs and positively charged poly(diallyldimethylammonium chloride) (PDDA) polymer. The IrO2 NP surface coverage can be fine-tuned by controlling the number of bilayers. The IrO2 NP films were amorphous, with the NPs therein being well-dispersed and retaining their as-synthesized shape and sizes. UV/vis spectroscopic and spectro-electrochemical studies confirmed that the total surface coverage and electrochemically addressable surface coverage of IrO2 NPs increased linearly with the number of bilayers up to 10 bilayers. The voltammetry of the modified electrode was that of hydrous iridium oxide films (HIROFs) with an observed super-Nernstian pH response of the Ir(III)/Ir(IV) and Ir(IV)-Ir(IV)/Ir(IV)-Ir(V) redox transitions and Nernstian shift of the oxygen evolution onset potential. The overpotential of the oxygen evolution reaction (OER) was essentially pH independent, varying only from 0.22 V to 0.28 V (at a current density of 0.1 mA cm(-2)), moving from acidic to alkaline conditions. Bulk electrolysis experiments revealed that the IrO2/PDDA films were stable and adherent under acidic and neutral conditions but degraded in alkaline solutions. Oxygen was evolved with Faradaic efficiencies approaching 100% under acidic (pH 1) and neutral (pH 7) conditions, and 88% in alkaline solutions (pH 13). This layer-by-layer approach forms the basis of future large-scale OER electrode development using ink-jet printing technology.

  15. Simulation of future stream alkalinity under changing deposition and climate scenarios

    International Nuclear Information System (INIS)

    Welsch, Daniel L.; Jack Cosby, B.; Hornberger, George M.

    2006-01-01

    Models of soil and stream water acidification have typically been applied under scenarios of changing acidic deposition, however, climate change is usually ignored. Soil air CO 2 concentrations have potential to increase as climate warms and becomes wetter, thus affecting soil and stream water chemistry by initially increasing stream alkalinity at the expense of reducing base saturation levels on soil exchange sites. We simulate this change by applying a series of physically based coupled models capable of predicting soil air CO 2 and stream water chemistry. We predict daily stream water alkalinity for a small catchment in the Virginia Blue Ridge for 60 years into the future given stochastically generated daily climate values. This is done for nine different combinations of climate and deposition. The scenarios for both climate and deposition include a static scenario, a scenario of gradual change, and a scenario of abrupt change. We find that stream water alkalinity continues to decline for all scenarios (average decrease of 14.4 μeq L - 1 ) except where climate is gradually warming and becoming more moist (average increase of 13 μeq L - 1 ). In all other scenarios, base cation removal from catchment soils is responsible for limited alkalinity increase resulting from climate change. This has implications given the extent that acidification models are used to establish policy and legislation concerning deposition and emissions

  16. HYFIRE: fusion-high temperature electrolysis system

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Dang, V.D.; Horn, F.; Isaacs, H.; Lazareth, O.; Makowitz, H.; Usher, J.

    1980-01-01

    The Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constitutents, H 2 and O 2 , electrical input is required. Power cycle efficiencies of approx. 40% require He cooling for steam superheat. Fourteen hundred degree steam coupled with 40% power cycle efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

  17. Measurement of pH, alkalinity and acidity in ultra-soft waters | Lahav ...

    African Journals Online (AJOL)

    In the "blend" method, equilibrium chemistry data were used to calculate total acidity for each point based on the known total alkalinity, pH reading, temperature and ionic strength. The two methods gave excellent results (in terms of both repetition and accuracy) as compared to characterisation based on total alkalinity and ...

  18. Design and Modelling of a Microfluidic Electro-Lysis Device with Controlling Plates

    Science.gov (United States)

    Jenkins, A.; Chen, C. P.; Spearing, S.; Monaco, L. A.; Steele, A.; Flores, G.

    2006-04-01

    Many Lab-on-Chip applications require sample pre-treatment systems. Using electric fields to perform cell lysis in bio-MEMS systems has provided a powerful tool which can be integrated into Lab-on-a- Chip platforms. The major design considerations for electro-lysis devices include optimal geometry and placement of micro-electrodes, cell concentration, flow rates, optimal electric field (e.g. pulsed DC vs. AC), etc. To avoid electrolysis of the flowing solution at the exposed electrode surfaces, magnitudes and the applied voltages and duration of the DC pulse, or the AC frequency of the AC, have to be optimized for a given configuration. Using simulation tools for calculation of electric fields has proved very useful, for exploring alternative configurations and operating conditions for achieving electro cell-lysis. To alleviate the problem associated with low electric fields within the microfluidics channel and the high voltage demand on the contact electrode strips, two ''control plates'' are added to the microfluidics configuration. The principle of placing the two controlling plate-electrodes is based on the electric fields generated by a combined insulator/dielectric (glass/water) media. Surface charges are established at the insulator/dielectric interface. This paper discusses the effects of this interface charge on the modification of the electric field of the flowing liquid/cell solution.

  19. Carbon dioxide electrolysis using a ceramic electrolyte. [for space processing

    Science.gov (United States)

    Erstfeld, T. E.; Mullins, O., Jr.; Williams, R. J.

    1979-01-01

    This paper discusses the results of an experimental study of the electrical aspects of carbon dioxide electrolysis using a ceramic electrolyte. The electrolyte compositions used in this study are 8% Y2O3 stabilized ZrO2, 7.5% CaO stabilized ZrO2, and 5% Y2O3 stabilized ThO2. Results indicate that the 8% Y2O3 stabilized ZrO2 is the best material to use for electrolysis, in terms of current as a function of voltage and temperature, and in terms of efficiency of oxide ion flow through it. The poorest results were obtained with the 5% Y2O3 stabilized ThO2 composition. An electrolysis system which might be employed to reclaim oxygen and carbon from effluents of space manufacturing, assuming that an industry would have to electrolyze 258,000 tonnes of CO2 per year, is predicted to require a total cell area of 110,000 sq m of 1 mm thickness and electrical capacity of 441 MW.

  20. Probing absorption of deuterium into palladium cathodes during D2O electrolysis with an in situ electrochemical microbalance technique

    International Nuclear Information System (INIS)

    Oyama, Noboru; Yamamoto, Nobushige; Hatozaki, Osamu; Ohsaka, Takeo

    1990-01-01

    The in situ observation of the absorption of deuterium (or hydrogen) into the Pd cathode during D 2 O (or H 2 O) electrolysis was made by an electrochemical microbalance technique which is based on the quartz-crystal electrode. The resonant frequency of the Pd-coated quartz-crystal electrode decreased with increasing amount of charge passed during electrolysis, and the frequency change for the D 2 O electrolysis was about twice that for the H 2 O electrolysis. The atom ratios of H/Pd and D/Pd of the H-Pd and D-Pd compounds resulting from the electrolysis were estimated to be 0.59 and 0.57, respectively. (author)

  1. Influence of Oil Viscosity on Alkaline Flooding for Enhanced Heavy Oil Recovery

    Directory of Open Access Journals (Sweden)

    Yong Du

    2013-01-01

    Full Text Available Oil viscosity was studied as an important factor for alkaline flooding based on the mechanism of “water drops” flow. Alkaline flooding for two oil samples with different viscosities but similar acid numbers was compared. Besides, series flooding tests for the same oil sample were conducted at different temperatures and permeabilities. The results of flooding tests indicated that a high tertiary oil recovery could be achieved only in the low-permeability (approximately 500 mD sandpacks for the low-viscosity heavy oil (Zhuangxi, 390 mPa·s; however, the high-viscosity heavy oil (Chenzhuang, 3450 mPa·s performed well in both the low- and medium-permeability (approximately 1000 mD sandpacks. In addition, the results of flooding tests for the same oil at different temperatures also indicated that the oil viscosity put a similar effect on alkaline flooding. Therefore, oil with a high-viscosity is favorable for alkaline flooding. The microscopic flooding test indicated that the water drops produced during alkaline flooding for oils with different viscosities differed significantly in their sizes, which might influence the flow behaviors and therefore the sweep efficiencies of alkaline fluids. This study provides an evidence for the feasibility of the development of high-viscosity heavy oil using alkaline flooding.

  2. Renewable and high efficient syngas production from carbon dioxide and water through solar energy assisted electrolysis in eutectic molten salts

    KAUST Repository

    Wu, Hongjun; Liu, Yue; Ji, Deqiang; Li, Zhida; Yi, Guanlin; Yuan, Dandan; Wang, Baohui; Zhang, Zhonghai; Wang, Peng

    2017-01-01

    sustainable energy sources: concentrated solar light heats molten salt and solar cell supplies electricity for electrolysis. The eutectic Li0.85Na0.61K0.54CO3/nLiOH molten electrolyte is rationally designed with low melting point (<450 °C). The synthesized

  3. The Estimation Formation Alkaline In The Proses Desalination MSF

    International Nuclear Information System (INIS)

    Latiffah, Siti Nurul

    2000-01-01

    Already to go on estimation phenomena formation alkaline scale of a seawater. In desalination system seawater on MSF to go on scale by a thermal decomposition HCO sub.3- ion and hydrolysis carbonate ion with water on the temperature operation. The varieties alkaline scale in attached on tube surface, while reduced efficiency heat transfer and to raise corrosion attack to structure material is caused all this high cost. Estimation to take please which a sum step by step decomposition ion bicarbonate from then information scale which carbonate and hydroxyl ion. The various scale maximal is alkaline form is a calcium carbonate = 116,5 gram per meter cubic the various sedimentation is alkaline and magnesium hydroxide = 67,57 gram per meter cubic

  4. Treatment of oilfield produced water using Fe/C micro-electrolysis assisted by zero-valent copper and zero-valent aluminium.

    Science.gov (United States)

    Zhang, Qi

    2015-01-01

    In this study, the Fe/Cu/C and Fe/Al/C inner micro-electrolysis systems were used to treat actual oilfield produced water to evaluate the feasibility of the technology. Effects of reaction time, pH value, the dosage of metals and activated carbon, and Fe:C mass ratio on the treatment efficiency of wastewater were studied. The results showed that the optimum conditions were reaction time 120 min, initial solution pH 4.0, Fe dosage 13.3 g/L, activated carbon dosage 6.7 g/L, Cu dosage 2.0 g/L or Al dosage 1.0 g/L. Under the optimum conditions, the removal efficiencies of chemical oxygen demand (COD) were 39.3%, 49.7% and 52.6% in the Fe/C, Fe/Cu/C and Fe/Al/C processes, respectively. Meanwhile, the ratio of five-day biochemical oxygen demand to COD was raised from 0.18 to above 0.35, which created favourable conditions for the subsequent biological treatment. All these led to an easy maintenance and low operational cost.

  5. Towards solid oxide electrolysis plants in 2020

    DEFF Research Database (Denmark)

    Chen, Ming; Blennow, Peter; Mathiesen, Brian Vad

    The goal of the project is to further improve performance and durability of solid oxide electrolysis cells (SOECs) and stacks targeting applications specifically for regulating the future Danish power system with a high amount of fluctuating renewable energies, and at the same time enhance the co...

  6. Intensified nitrogen and phosphorus removal in a novel electrolysis-integrated tidal flow constructed wetland system.

    Science.gov (United States)

    Ju, Xinxin; Wu, Shubiao; Zhang, Yansheng; Dong, Renjie

    2014-08-01

    A novel electrolysis-integrated tidal flow constructed wetland (CW) system was developed in this study. The dynamics of intensified nitrogen and phosphorus removal and that of hydrogen sulphide control were evaluated. Ammonium removal of up to 80% was achieved with an inflow concentration of 60 mg/L in wetland systems with and without electrolysis integration. Effluent nitrate concentration decreased from 2 mg/L to less than 0.5 mg/L with the decrease in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2) in the electrolysis-integrated wetland system, thus indicating that the current intensity of electrolysis plays an important role in nitrogen transformations. Phosphorus removal was significantly enhanced, exceeding 95% in the electrolysis-integrated CW system because of the in-situ formation of a ferric iron coagulant through the electro-dissolution of a sacrificial iron anode. Moreover, the electrolyzed wetland system effectively inhibits sulphide accumulation as a result of a sulphide precipitation coupled with ferrous-iron electro-dissolution and/or an inhibition of bacterial sulphate reduction under increased aerobic conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Net alkalinity and net acidity 2: Practical considerations

    Science.gov (United States)

    Kirby, C.S.; Cravotta, C.A.

    2005-01-01

    The pH, alkalinity, and acidity of mine drainage and associated waters can be misinterpreted because of the chemical instability of samples and possible misunderstandings of standard analytical method results. Synthetic and field samples of mine drainage having various initial pH values and concentrations of dissolved metals and alkalinity were titrated by several methods, and the results were compared to alkalinity and acidity calculated based on dissolved solutes. The pH, alkalinity, and acidity were compared between fresh, unoxidized and aged, oxidized samples. Data for Pennsylvania coal mine drainage indicates that the pH of fresh samples was predominantly acidic (pH 2.5-4) or near neutral (pH 6-7); ??? 25% of the samples had pH values between 5 and 6. Following oxidation, no samples had pH values between 5 and 6. The Standard Method Alkalinity titration is constrained to yield values >0. Most calculated and measured alkalinities for samples with positive alkalinities were in close agreement. However, for low-pH samples, the calculated alkalinity can be negative due to negative contributions by dissolved metals that may oxidize and hydrolyze. The Standard Method hot peroxide treatment titration for acidity determination (Hot Acidity) accurately indicates the potential for pH to decrease to acidic values after complete degassing of CO2 and oxidation of Fe and Mn, and it indicates either the excess alkalinity or that required for neutralization of the sample. The Hot Acidity directly measures net acidity (= -net alkalinity). Samples that had near-neutral pH after oxidation had negative Hot Acidity; samples that had pH mine drainage treatment can lead to systems with insufficient Alkalinity to neutralize metal and H+ acidity and is not recommended. The use of net alkalinity = -Hot Acidity titration is recommended for the planning of mine drainage treatment. The use of net alkalinity = (Alkalinitymeasured - Aciditycalculated) is recommended with some cautions

  8. HYFIRE: a tokamak-high-temperature electrolysis system

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Horn, F.; Isaacs, H.; Lazareth, O.W.; Makowitz, H.; Usher, J.

    1980-01-01

    Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 0 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constituents, H 2 and O 2 , electrical input is required. Fourteen hundred degree steam coupled with 40% power efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

  9. HYFIRE: a tokamak-high-temperature electrolysis system

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Horn, F.; Isaacs, H.; Lazareth, O.W.; Makowitz, H.; Usher, J.

    1980-01-01

    Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 0 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constituents, H 2 and O 2 , electrical input is required. Fourteen hundred degree steam coupled with 40% power cycle efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

  10. Zinc electrodeposition from flowing alkaline zincate solutions: Role of hydrogen evolution reaction

    Science.gov (United States)

    Dundálek, Jan; Šnajdr, Ivo; Libánský, Ondřej; Vrána, Jiří; Pocedič, Jaromír; Mazúr, Petr; Kosek, Juraj

    2017-12-01

    The hydrogen evolution reaction is known as a parasitic reaction during the zinc electrodeposition from alkaline zincate solutions and is thus responsible for current efficiency losses during the electrolysis. Besides that, the rising hydrogen bubbles may cause an extra convection within a diffusion layer, which leads to an enhanced mass transport of zincate ions to an electrode surface. In this work, the mentioned phenomena were studied experimentally in a flow through electrolyzer and the obtained data were subsequently evaluated by mathematical models. The results prove the indisputable influence of the rising hydrogen bubbles on the additional mixing of the diffusion layer, which partially compensates the drop of the current efficiency of the zinc deposition at higher current flows. Moreover, the results show that the current density ratio (i.e., the ratio of an overall current density to a zinc limiting current density) is not suitable for the description of the zinc deposition, because the hydrogen evolution current density is always involved in the overall current density.

  11. La0.8Sr0.2Co0.8Ni0.2O3-δ impregnated oxygen electrode for H2O/CO2 co-electrolysis in solid oxide electrolysis cells

    Science.gov (United States)

    Zheng, Haoyu; Tian, Yunfeng; Zhang, Lingling; Chi, Bo; Pu, Jian; Jian, Li

    2018-04-01

    High-temperature H2O/CO2 co-electrolysis through reversible solid oxide electrolysis cell (SOEC) provides potentially a feasible and eco-friendly way to convert electrical energy into chemicals stored in syngas. In this work, La0.8Sr0.2Co0.8Ni0.2O3-δ (LSCN) impregnated Gd0.1Ce0.9O1.95 (GDC)-(La0.8Sr0.2)0.95MnO3-δ (LSM) composite oxygen electrode is studied as high-performance electrode for H2O/CO2 co-electrolysis. The LSCN impregnated cell exhibits competitive performance with the peak power density of 1057 mW cm-2 at 800 °C in solid oxide fuel cell (SOFC) mode; in co-electrolysis mode, the current density can reach 1.60 A cm-2 at 1.5 V at 800 °C with H2O/CO2 ratio of 2/1. With LSCN nanoparticles dispersed on the surface of GDC-LSM to maximize the reaction active sites, the LSCN impregnated cell shows significant enhanced electrochemical performance at both SOEC and SOFC modes. The influence of feed gas composition (H2O-H2-CO2) and operating voltages on the performance of co-electrolysis are discussed in detail. The cell shows a very stable performance without obvious degradation for more than 100 h. Post-test characterization is analyzed in detail by multiple measurements.

  12. Ammonia synthesis. Ammonia synthesis by N₂ and steam electrolysis in molten hydroxide suspensions of nanoscale Fe₂O₃.

    Science.gov (United States)

    Licht, Stuart; Cui, Baochen; Wang, Baohui; Li, Fang-Fang; Lau, Jason; Liu, Shuzhi

    2014-08-08

    The Haber-Bosch process to produce ammonia for fertilizer currently relies on carbon-intensive steam reforming of methane as a hydrogen source. We present an electrochemical pathway in which ammonia is produced by electrolysis of air and steam in a molten hydroxide suspension of nano-Fe2O3. At 200°C in an electrolyte with a molar ratio of 0.5 NaOH/0.5 KOH, ammonia is produced at 1.2 volts (V) under 2 milliamperes per centimeter squared (mA cm(-2)) of applied current at coulombic efficiency of 35% (35% of the applied current results in the six-electron conversion of N2 and water to ammonia, and excess H2 is cogenerated with the ammonia). At 250°C and 25 bar of steam pressure, the electrolysis voltage necessary for 2 mA cm(-2) current density decreased to 1.0 V. Copyright © 2014, American Association for the Advancement of Science.

  13. The Use of Multi-Reactor Cascade Plasma Electrolysis for Linear Alkylbenzene Sulfonate Degradation

    Science.gov (United States)

    Saksono, Nelson; Ibrahim; Zainah; Budikania, Trisutanti

    2018-03-01

    Plasma electrolysis is a method that can produce large amounts of hydroxyl radicals to degrade organic waste. The purpose of this study is to improve the effectiveness of Linear alkylbenzene sulfonate (LAS) degradation by using multi-reactor cascade plasma electrolysis. The reactor which operated in circulation system, using 3 reactors series flow and 6 L of LAS with initial concentration of 100 ppm. The results show that the LAS degradation can be improved multi-reactor cascade plasma electrolysis. The greatest LAS degradation is achieved up to 81.91% with energy consumption of 2227.34 kJ/mmol that is obtained during 120 minutes by using 600 Volt, 0.03 M of KOH, and 0.5 cm of the anode depth.

  14. Water nanoelectrolysis: A simple model

    Science.gov (United States)

    Olives, Juan; Hammadi, Zoubida; Morin, Roger; Lapena, Laurent

    2017-12-01

    A simple model of water nanoelectrolysis—defined as the nanolocalization at a single point of any electrolysis phenomenon—is presented. It is based on the electron tunneling assisted by the electric field through the thin film of water molecules (˜0.3 nm thick) at the surface of a tip-shaped nanoelectrode (micrometric to nanometric curvature radius at the apex). By applying, e.g., an electric potential V1 during a finite time t1, and then the potential -V1 during the same time t1, we show that there are three distinct regions in the plane (t1, V1): one for the nanolocalization (at the apex of the nanoelectrode) of the electrolysis oxidation reaction, the second one for the nanolocalization of the reduction reaction, and the third one for the nanolocalization of the production of bubbles. These parameters t1 and V1 completely control the time at which the electrolysis reaction (of oxidation or reduction) begins, the duration of this reaction, the electrolysis current intensity (i.e., the tunneling current), the number of produced O2 or H2 molecules, and the radius of the nanolocalized bubbles. The model is in good agreement with our experiments.

  15. Mass and charge transfer within a floating water bridge

    Science.gov (United States)

    Fuchs, Elmar C.; Agostinho, Luewton L. F.; Eisenhut, Mathias; Woisetschläger, Jakob

    2010-11-01

    When high voltage is applied to pure water filled into two beakers close to each other, a connection forms spontaneously, giving the impression of a floating water bridge 1-8. This phenomenon is of special interest, since it comprises a number of phenomena currently tackled in modern water science. In this work, the charge and mass transfer through the water bridge are investigated with schlieren visualization and laser interferometry. It can be shown that the addition of a pH dye increases the H+ and OH- production with subsequent electrolysis, whereas schlieren and interferometric methods reveal another mechanism where charge and mass transfer appear to be coupled. Whereas this mechanism seems to be responsible for the electrolysis-less charge and mass transfer in the water bridge, it is increasingly superseded by the electrochemical mechanism with rising conductivity. Thus it can be shown that a pH dye does only indirectly visualize the charge transfer in the water bridge since it is dragged along with the water flow like any other dye, and additionally promotes conventional electrochemical conduction mechanisms, thereby enhancing electrolysis and reducing the masscoupled charge transport and thus destabilizing the bridge.

  16. A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

    Science.gov (United States)

    Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

    2015-12-01

    The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Natural gas anodes for aluminium electrolysis in molten fluorides.

    Science.gov (United States)

    Haarberg, Geir Martin; Khalaghi, Babak; Mokkelbost, Tommy

    2016-08-15

    Industrial primary production of aluminium has been developed and improved over more than 100 years. The molten salt electrolysis process is still suffering from low energy efficiency and considerable emissions of greenhouse gases (CO2 and PFC). A new concept has been suggested where methane is supplied through the anode so that the CO2 emissions may be reduced significantly, the PFC emissions may be eliminated and the energy consumption may decrease significantly. Porous carbon anodes made from different graphite grades were studied in controlled laboratory experiments. The anode potential, the anode carbon consumption and the level of HF gas above the electrolyte were measured during electrolysis. In some cases it was found that the methane oxidation was effectively participating in the anode process.

  18. Energy-Efficient and Environmentally Friendly Solid Oxide Membrane Electrolysis Process for Magnesium Oxide Reduction: Experiment and Modeling

    Science.gov (United States)

    Guan, Xiaofei; Pal, Uday B.; Powell, Adam C.

    2014-06-01

    This paper reports a solid oxide membrane (SOM) electrolysis experiment using an LSM(La0.8Sr0.2MnO3-δ)-Inconel inert anode current collector for production of magnesium and oxygen directly from magnesium oxide at 1423 K (1150 °C). The electrochemical performance of the SOM cell was evaluated by means of various electrochemical techniques including electrochemical impedance spectroscopy, potentiodynamic scan, and electrolysis. Electronic transference numbers of the flux were measured to assess the magnesium dissolution in the flux during SOM electrolysis. The effects of magnesium solubility in the flux on the current efficiency and the SOM stability during electrolysis are discussed. An inverse correlation between the electronic transference number of the flux and the current efficiency of the SOM electrolysis was observed. Based on the experimental results, a new equivalent circuit of the SOM electrolysis process is presented. A general electrochemical polarization model of SOM process for magnesium and oxygen gas production is developed, and the maximum allowable applied potential to avoid zirconia dissociation is calculated as well. The modeling results suggest that a high electronic resistance of the flux and a relatively low electronic resistance of SOM are required to achieve membrane stability, high current efficiency, and high production rates of magnesium and oxygen.

  19. Study of the bipolar electrolysis of the tritiated water applied to the hydrogen isotopes separation by electrochemical permeation threw Pd-Ag alloy membranes

    International Nuclear Information System (INIS)

    Heinze, S.

    2000-01-01

    The objective of the study is to enrich waters of poor tritium concentration, by electrolysis in the same time of an hydrogen emission of low activity. In this framework the hydrogen electrochemical permeation threw Pd-Ag alloy membranes has been used. The first part of the study concerns the hydrogen and the deuterium diffusion threw these membranes. The activation and the thermal treatments influence have been studied. A relation between the membrane microstructure and the diffusion mechanism has been proposed. The second part of the study is devoted to the hydrogen gate mechanism determination in the membrane by impedance spectroscopy. The last part concerns the determination of the isotopic separation factor hydrogen-deuterium. Experimental results agree the calculated theoretical data. The operation of an operational membrane cell has been simulated and the process feasibility has been proved. (A.L.B.)

  20. Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    José L. Arias-Buría

    2015-01-01

    Full Text Available Objective. To compare effects of ultrasound- (US- guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n=17 group or exercise (n=19 group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions. Shoulder pain (NPRS and disability (DASH were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P<0.01: individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention.

  1. The Effect of PFSA Membrane Compression on the Predicted Performance of a High Pressure PEM Electrolysis Cell

    DEFF Research Database (Denmark)

    Olesen, Anders Christian; Kær, Søren Knudsen

    2015-01-01

    In this work, a non-equilibrium formulation of a compression dependent water uptake model has been implemented in a two-dimensional, two-phase, multi-component and non-isothermal high pressure PEM electrolysis model. The non-equilibrium formulation of the water uptake model was chosen in order...... to account for interfacial transport kinetics between each fluid phase and the perfluorinated sulfonic acid membrane. Besides modeling water uptake, the devised membrane model accounts for water transport through diffusion and electro-osmotic drag in the electrolyte phase, and hydraulic permeation...... in the liquid phase. Charge transport and electrochemistry are likewise included. The obtained model is validated against experimental measurements. In order to investigate the effect of membrane compression, a parametric study is carried. Results underline that the predicted water uptake and cell voltage...

  2. Metal bioavailability and toxicity to fish in low-alkalinity lakes: A critical review

    Science.gov (United States)

    Spry, D.J.; Wiener, James G.

    1991-01-01

    Fish in low-alkalinity lakes having pH of 6·0–6·5 or less often have higher body or tissue burdens of mercury, cadmium, and lead than do fish in nearby lakes with higher pH. The greater bioaccumulation of these metals in such waters seems to result partly from the greater aqueous abundances of biologically available forms (CH3 Hg+, Cd2+, and Pb2+) at low pH. In addition, the low concentrations of aqueous calcium in low-alkalinity lakes increase the permeability of biological membranes to these metals, which in fish may cause greater uptake from both water and food. Fish exposed to aqueous inorganic aluminum in the laboratory and field accumulate the metal in and on the epithelial cells of the gills; however, there is little accumulation of aluminum in the blood or internal organs. In low-pH water, both sublethal and lethal toxicity of aluminum has been clearly demonstrated in both laboratory and field studies at environmental concentrations. In contrast, recently measured aqueous concentrations of total mercury, methylmercury, cadmium, and lead in low-alkalinity lakes are much lower than the aqueous concentrations known to cause acute or chronic toxicity in fish, although the vast majority of toxicological research has involved waters with much higher ionic strength than that in low-alkalinity lakes. Additional work with fish is needed to better assess (1) the toxicity of aqueous metals in low-alkalinity waters, and (2) the toxicological significance of dietary methylmercury and cadmium.

  3. Window of cold nuclear fusion and biased-pulse electrolysis experiment

    International Nuclear Information System (INIS)

    Takahashi, Akito; Jida, Toshiyuki; Maekawa, Fujio; Sugimoto, Hisashi; Yoshida, Shigeo

    1989-01-01

    Based on the electron screening effect and the excitation of deuteron harmonic oscillators in palladium lattice, theoretical aspects are given to explain the cold fusion phenomena and the possibility of nuclear heating. A narrow window is proposed to meet ≅ 10 watts per cubic centimeter for the nuclear heating, by the hypothetical excitation-screening model. A relatively wide window is feasible to meet a few fusion events per second per cc under the non-stationary conditions of deuteron-charging and discharging. For stationary lattice conditions, the probability of cold fusion is not feasible at all. To confirm the cold fusion phenomena, a heavy water electrolysis experiment was carried out using biased-pulse-electrolytic currents, expecting the enhancement of cold fusion events under charging and discharging of deuterons. For the neutron detection, a cross-checking system between a recoil-proton scintillation detector and a 3 He thermal neutron detector was employed to see coincident time-patterns of neutron emission from an electrolysis cell. To check the energy of emitted neutrons, pulse height spectrum of the recoil-proton detector was monitored. Up to the D-charging time of 300 hr, neutron yields of 1-2 n/s/cc were obtained for time-intervals of 60-200 hr. From the recoil-proton spectra, it was confirmed that 2.45 MeV neutrons by the D(d, n) 3 He fusion branch were emitted. The observed time-patterns of neutron emission suggest the existence of cold fusion under the charging and discharging conditions. (orig.)

  4. Electrolyte engineering toward efficient water splitting at mild pH

    KAUST Repository

    Shinagawa, Tatsuya; Ng, Marcus Tze-Kiat; Takanabe, Kazuhiro

    2017-01-01

    The development of processes for the conversion of H2O/CO2 driven by electricity generated in renewable manners is essential to achieve sustainable energy and chemical cycles, in which the electrocatalytic oxygen evolution reaction (OER) is one of the bottlenecks. In this contribution, the influences of the electrolyte molarity and identity on OER at alkaline to neutral pH were investigated at an appreciable current density of ~10 mA cm-2, revealing (1) the clear boundary of reactant switching between H2O/OH- due to the diffusion limitation of OH- and (2) the substantial contribution of the mass transport of the buffered species in buffered mild pH conditions. These findings propose a strategy of electrolyte engineering: tuning the electrolyte properties to maximize the mass-transport flux. The concept was successfully demonstrated for OER as well as overall water electrolysis in buffered mild pH conditions, shedding light on the development of practical solar fuel production systems.

  5. Electrolyte engineering toward efficient water splitting at mild pH

    KAUST Repository

    Shinagawa, Tatsuya

    2017-08-28

    The development of processes for the conversion of H2O/CO2 driven by electricity generated in renewable manners is essential to achieve sustainable energy and chemical cycles, in which the electrocatalytic oxygen evolution reaction (OER) is one of the bottlenecks. In this contribution, the influences of the electrolyte molarity and identity on OER at alkaline to neutral pH were investigated at an appreciable current density of ~10 mA cm-2, revealing (1) the clear boundary of reactant switching between H2O/OH- due to the diffusion limitation of OH- and (2) the substantial contribution of the mass transport of the buffered species in buffered mild pH conditions. These findings propose a strategy of electrolyte engineering: tuning the electrolyte properties to maximize the mass-transport flux. The concept was successfully demonstrated for OER as well as overall water electrolysis in buffered mild pH conditions, shedding light on the development of practical solar fuel production systems.

  6. First report of vertically aligned (Sn,Ir)O2:F solid solution nanotubes: Highly efficient and robust oxygen evolution electrocatalysts for proton exchange membrane based water electrolysis

    Science.gov (United States)

    Ghadge, Shrinath Dattatray; Patel, Prasad P.; Datta, Moni K.; Velikokhatnyi, Oleg I.; Shanthi, Pavithra M.; Kumta, Prashant N.

    2018-07-01

    One dimensional (1D) vertically aligned nanotubes (VANTs) of (Sn0.8Ir0.2)O2:10F are synthesized for the first time by a sacrificial template assisted approach. The aim is to enhance the electrocatalytic activity of F doped (Sn,Ir)O2 solid solution electrocatalyst for oxygen evolution reaction (OER) in proton exchange membrane (PEM) based water electrolysis by generating (Sn0.8Ir0.2)O2:10F nanotubes (NTs). The 1D vertical channels and the high electrochemically active surface area (ECSA ∼38.46 m2g-1) provide for facile electron transport. This results in low surface charge transfer resistance (4.2 Ω cm2), low Tafel slope (58.8 mV dec-1) and excellent electrochemical OER performance with ∼2.3 and ∼2.6 fold higher electrocatalytic activity than 2D thin films of (Sn0.8Ir0.2)O2:10F and benchmark IrO2 electrocatalysts, respectively. Furthermore, (Sn0.8Ir0.2)O2:10F NTs exhibit excellent mass activity (21.67 A g-1), specific activity (0.0056 mAcm-2) and TOF (0.016 s-1), which is ∼2-2.6 fold higher than thin film electrocatalysts at an overpotential of 270 mV, with a total mass loading of 0.3 mg cm-2. In addition, (Sn0.8Ir0.2)O2:10F NTs demonstrate remarkable electrochemical durability - comparable to thin films of (Sn0.8Ir0.2)O2:10F and pure IrO2, operated under identical testing conditions in PEM water electrolysis. These results therefore indicate promise of (Sn0.8Ir0.2)O2:10F NTs as OER electrocatalysts for efficient and sustainable hydrogen production.

  7. Life Time Performance Characterization of Solid Oxide Electrolysis Cells for Hydrogen Production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

    2015-01-01

    Solid oxide electrolysis cells (SOECs) offer a promising technological solution for efficient energy conversion and production of hydrogen or syngas. The commercialization of the SOEC technology can be promoted if SOECs can be operated at high current density with stable performance over ~5 years...... - 3 years (continuous operation, setting 1.5 V as the upper voltage defining “end of life”). The results provide technological input to future design of electrolysis plants for hydrogen production. © 2015 ECS - The Electrochemical Society...

  8. A Vivens Ex Vivo Study on the Synergistic Effect of Electrolysis and Freezing on the Cell Nucleus.

    Science.gov (United States)

    Lugnani, Franco; Zanconati, Fabrizio; Marcuzzo, Thomas; Bottin, Cristina; Mikus, Paul; Guenther, Enric; Klein, Nina; Rubinsky, Liel; Stehling, Michael K; Rubinsky, Boris

    2015-01-01

    Freezing-cryosurgery, and electrolysis-electrochemical therapy (EChT), are two important minimally invasive surgery tissue ablation technologies. Despite major advantages they also have some disadvantages. Cryosurgery cannot induce cell death at high subzero freezing temperatures and requires multiple freeze thaw cycles, while EChT requires high concentrations of electrolytic products-which makes it a lengthy procedure. Based on the observation that freezing increases the concentration of solutes (including products of electrolysis) in the frozen region and permeabilizes the cell membrane to these products, this study examines the hypothesis that there could be a synergistic effect between freezing and electrolysis in their use together for tissue ablation. Using an animal model we refer to as vivens ex vivo, which may be of value in reducing the use of animals for experiments, combined with a Hematoxylin stain of the nucleus, we show that there are clinically relevant protocols in which the cell nucleus appears intact when electrolysis and freezing are used separately but is affected by certain combinations of electrolysis and freezing.

  9. Efficient uranous nitrate production using membrane electrolysis

    International Nuclear Information System (INIS)

    Zhongwei Yuan; Taihong Yan; Weifang Zheng; Hongying Shuang; Liang Xian; Xiaoyan Bian; Chen Zuo; Chuanbo Li; Zhi Cao

    2013-01-01

    Electrochemical reduction of uranyl nitrate is a green, simple way to make uranous ion. In order to improve the ratio of uranous ion to the total uranium and maintain high current efficiency, an electrolyser with very thin cathodic and anodic compartment, which were separated by a cation exchange membrane, was setup, and its performance was tested. The effects of various parameters on the reduction were also evaluated. The results show that the apparatus is quite positive. It runs well with 120 mA/cm 2 current density (72 cm 2 cathode, constant current batch operation). U(IV) yield can achieve 93.1 % (500 mL feed, total uranium 199 g/L) after 180 min electrolysis. It was also shown that when U(IV) yield was below 80 %, very high current efficiency was maintained, and there was almost a linear relationship between uranous ion yield and electrolysis time; under the range of experimental conditions, the concentration of uranyl nitrate, hydrazine, and nitric acid had little effect on the reduction. (author)

  10. Investigation of the synergistic effects for p-nitrophenol mineralization by a combined process of ozonation and electrolysis using a boron-doped diamond anode

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Cuicui [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Yuan, Shi [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Li, Xiang; Wang, Huijiao; Bakheet, Belal [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Komarneni, Sridhar [Department of Ecosystem Science and Management and Material Research Institute, 205 MRL Building, The Pennsylvania State University, University Park, PA 16802 (United States); Wang, Yujue, E-mail: wangyujue@tsinghua.edu.cn [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China)

    2014-09-15

    Graphical abstract: - Highlights: • Combining electrolysis with ozonation greatly enhances nitrophenol mineralization. • O{sub 3} can rapidly degrade nitrophenol to carboxylic acids in the bulk solution. • Carboxylic acids can be mineralized by ·OH generated from multiple sources in the electrolysis-O{sub 3} process. • Electrolysis and ozonation can compensate for each other's weakness on pollutant degradation. - Abstract: Electrolysis and ozonation are two commonly used technologies for treating wastewaters contaminated with nitrophenol pollutants. However, they are often handicapped by their slow kinetics and low yields of total organic carbon (TOC) mineralization. To improve TOC mineralization efficiency, we combined electrolysis using a boron-doped diamond (BDD) anode with ozonation (electrolysis-O{sub 3}) to treat a p-nitrophenol (PNP) aqueous solution. Up to 91% TOC was removed after 60 min of the electrolysis-O{sub 3} process. In comparison, only 20 and 44% TOC was respectively removed by individual electrolysis and ozonation treatment conducted under similar reaction conditions. The result indicates that when electrolysis and ozonation are applied simultaneously, they have a significant synergy for PNP mineralization. This synergy can be mainly attributed to (i) the rapid degradation of PNP to carboxylic acids (e.g., oxalic acid and acetic acid) by O{sub 3}, which would otherwise take a much longer time by electrolysis alone, and (ii) the effective mineralization of the ozone-refractory carboxylic acids to CO{sub 2} by ·OH generated from multiple sources in the electrolysis-O{sub 3} system. The result suggests that combining electrolysis with ozonation can provide a simple and effective way to mutually compensate the limitations of the two processes for degradation of phenolic pollutants.

  11. High-resolution Imaging of pH in Alkaline Sediments and Water Based on a New Rapid Response Fluorescent Planar Optode

    Science.gov (United States)

    Han, Chao; Yao, Lei; Xu, Di; Xie, Xianchuan; Zhang, Chaosheng

    2016-05-01

    A new dual-lumophore optical sensor combined with a robust RGB referencing method was developed for two-dimensional (2D) pH imaging in alkaline sediments and water. The pH sensor film consisted of a proton-permeable polymer (PVC) in which two dyes with different pH sensitivities and emission colors: (1) chloro phenyl imino propenyl aniline (CPIPA) and (2) the coumarin dye Macrolex® fluorescence yellow 10 GN (MFY-10 GN) were entrapped. Calibration experiments revealed the typical sigmoid function and temperature dependencies. This sensor featured high sensitivity and fast response over the alkaline working ranges from pH 7.5 to pH 10.5. Cross-sensitivity towards ionic strength (IS) was found to be negligible for freshwater when IS applications.

  12. Direct LiT Electrolysis in a Metallic Fusion Blanket

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Luke [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-30

    A process that simplifies the extraction of tritium from molten lithium-based breeding blankets was developed. The process is based on the direct electrolysis of lithium tritide using a ceramic Li ion conductor that replaces the molten salt extraction step. Extraction of tritium in the form of lithium tritide in the blankets/targets of fusion/fission reactors is critical in order to maintain low concentrations. This is needed to decrease the potential tritium permeation to the surroundings and large releases from unforeseen accident scenarios. Extraction is complicated due to required low tritium concentration limits and because of the high affinity of tritium for the blanket. This work identified, developed and tested the use of ceramic lithium ion conductors capable of recovering hydrogen and deuterium through an electrolysis step at high temperatures.

  13. Direct LiT Electrolysis in a Metallic Fusion Blanket

    International Nuclear Information System (INIS)

    Olson, Luke

    2016-01-01

    A process that simplifies the extraction of tritium from molten lithium-based breeding blankets was developed. The process is based on the direct electrolysis of lithium tritide using a ceramic Li ion conductor that replaces the molten salt extraction step. Extraction of tritium in the form of lithium tritide in the blankets/targets of fusion/fission reactors is critical in order to maintain low concentrations. This is needed to decrease the potential tritium permeation to the surroundings and large releases from unforeseen accident scenarios. Extraction is complicated due to required low tritium concentration limits and because of the high affinity of tritium for the blanket. This work identified, developed and tested the use of ceramic lithium ion conductors capable of recovering hydrogen and deuterium through an electrolysis step at high temperatures.

  14. Oxidation of organic pollutants on BDD anodes using modulated current electrolysis

    International Nuclear Information System (INIS)

    Panizza, M.; Kapalka, Agnieszka; Comninellis, Ch.

    2008-01-01

    In this paper, a theoretical model is presented for organic pollutants mineralization at high current efficiency (close to 100%) and low energy consumption on boron-doped diamond electrodes. The model is formulated for a perfect mixed electrochemical reactor operated as a batch recirculation system under multiple current steps, in which the applied current is adjusted during the electrolysis to be close to the limiting value. An experimental validation with the anodic oxidation of 3,4,5-trihydroxybenzoic acid is also provided. The results have shown that multiple current steps electrolysis and continuous current control allowed obtaining high oxidation rate and current efficiency

  15. Oxidation of organic pollutants on BDD anodes using modulated current electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Panizza, M. [Department of Chemical and Process Engineering, University of Genoa, P.le J.F. Kennedy 1, 16129 Genova (Italy)], E-mail: marco.panizza@unige.it; Kapalka, Agnieszka [Institute of Chemical Sciences and Engineering, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Comninellis, Ch. [Institute of Chemical Sciences and Engineering, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)], E-mail: christos.comninellis@epfl.ch

    2008-01-01

    In this paper, a theoretical model is presented for organic pollutants mineralization at high current efficiency (close to 100%) and low energy consumption on boron-doped diamond electrodes. The model is formulated for a perfect mixed electrochemical reactor operated as a batch recirculation system under multiple current steps, in which the applied current is adjusted during the electrolysis to be close to the limiting value. An experimental validation with the anodic oxidation of 3,4,5-trihydroxybenzoic acid is also provided. The results have shown that multiple current steps electrolysis and continuous current control allowed obtaining high oxidation rate and current efficiency.

  16. Radium, uranium and metals in acidic or alkaline uranium mill

    International Nuclear Information System (INIS)

    Somot, St.

    1997-01-01

    Uranium mill study sites have been chosen in function of their different characteristics: deposits age, treatment nature (alkaline or acid), mill origin. The realization of specific drilling allowed the simultaneous study of the interstitial water and the solid fraction of samples, cut at determined deep. A radiation imbalance between 230 Th and 226 Ra is observed in the acid treatment residues. The trace elements concentration spectrum is directly bound to the nature of the ore. Diamagnetic evolutions are observed in residues. The uranium concentrations are higher in carbonated waters than in calcic sulfated waters. The selective sequential lixiviation showed that the 226 Ra activity of the interstitial water is controlled by the Gypsum in acid treatment residues. In other hand in the alkaline treatment waters, the carbonates occur. The Ra retention is largely bound to the Fe and Mn oxy-hydroxides. (A.L.B.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-15

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

  18. The influence of iridium chemical oxidation state on the performance and durability of oxygen evolution catalysts in PEM electrolysis

    Science.gov (United States)

    Siracusano, S.; Baglio, V.; Grigoriev, S. A.; Merlo, L.; Fateev, V. N.; Aricò, A. S.

    2017-10-01

    Nanosized Ir-black (3 nm) and Ir-oxide (5 nm) oxygen evolution electrocatalysts showing high performance in polymer electrolyte membrane (PEM) water electrolysis based on Aquivion® short-side chain ionomer membrane are investigated to understand the role of the Ir oxidation state on the electrocatalytic activity and stability. Despite the smaller mean crystallite size, the Ir-black electrocatalyst shows significantly lower initial performance than the Ir-oxide. During operation at high current density, the Ir-black shows a decrease of cell potential with time whereas the Ir-oxide catalyst shows increasing cell potential resulting in a degradation rate of about 10 μV/h, approaching 1000 h. The unusual behaviour of the Ir-black results from the oxidation of metallic Ir to IrOx. The Ir-oxide catalyst shows instead a hydrated structure on the surface and a negative shift of about 0.5 eV for the Ir 4f binding energy after 1000 h electrolysis operation. This corresponds to the formation of a sub-stoichiometric Ir-oxide on the surface. These results indicate that a hydrated IrO2 with high oxidation state on the surface is favourable in decreasing the oxygen evolution overpotential. Modifications of the Ir chemical oxidation state during operation can affect significantly the catalytic activity and durability of the electrolysis system.

  19. A post Gurney quantum mechanical perspective on the electrolysis of water: ion neutralization in solution

    Science.gov (United States)

    Guo, Enyi; McKenzie, David R.

    2017-11-01

    Electron fluxes crossing the interface between a metallic conductor and an aqueous environment are important in many fields; hydrogen production, environmental scanning tunnelling microscopy, scanning electrochemical microscopy being some of them. Gurney (Gurney 1931 Proc. R. Soc. Lond. 134, 137 (doi:10.1098/rspa.1931.0187)) provided in 1931 a scheme for tunnelling during electrolysis and outlined conditions for it to occur. We measure the low-voltage current flows between gold electrodes in pure water and use the time-dependent behaviour at voltage switch-on and switch-off to evaluate the relative contribution to the steady current arising from tunnelling of electrons between the electrodes and ions in solution and from the neutralization of ions adsorbed onto the electrode surface. We ascribe the larger current contribution to quantum tunnelling of electrons to and from ions in solution near the electrodes. We refine Gurney's barrier scheme to include solvated electron states and quantify energy differences using updated information. We show that Gurney's conditions would prevent the current flow at low voltages we observe but outline how the ideas of Marcus (Marcus 1956 J. Chem. Phys. 24, 966-978 (doi:10.1063/1.1742723)) concerning solvation fluctuations enable the condition to be relaxed. We derive an average barrier tunnelling model and a multiple pathways tunnelling model and compare predictions with measurements of the steady-state current-voltage relation. The tunnelling barrier was found to be wide and low in agreement with other experimental studies. Applications as a biosensing mechanism are discussed that exploit the fast tunnelling pathways along molecules in solution.

  20. Enhanced dewaterability of textile dyeing sludge using micro-electrolysis pretreatment.

    Science.gov (United States)

    Ning, Xun-An; Wen, Weibin; Zhang, Yaping; Li, Ruijing; Sun, Jian; Wang, Yujie; Yang, Zuoyi; Liu, Jingyong

    2015-09-15

    The effects of micro-electrolysis treatment on textile dyeing sludge dewatering and its mechanisms were investigated in this study. Capillary suction time (CST) and settling velocity (SV) were used to evaluate sludge dewaterability. Extracellular polymeric substances (EPS) concentration and sludge disintegration degree (DDSCOD) were determined to explain the observed changes in sludge dewaterability. The results demonstrated that the micro-electrolysis could significantly improve sludge dewaterability by disrupting the sludge floc structure. The optimal conditions of sludge dewatering were the reaction time of 20 min, initial pH of 2.5, Fe/C mass ratio of 1/1, and the iron powder dosage of 2.50 g/L, which achieved good CST (from 34.1 to 27.8 s) and SV (from 75 to 60%) reduction efficiency. In addition, the scanning electron microscope (SEM) images revealed that the treated sludge floc clusters are broken up and that the dispersion degree is better than that of a raw sludge sample. The optimal EPS concentration and DDSCOD to obtain maximum sludge dewaterability was 43-46 mg/L and 4.2-4.9%, respectively. The destruction of EPS was one of the primary reasons for the improvement of sludge dewaterability during micro-electrolysis treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Alkaline hydrogen peroxide treatment for TiO_2 nanoparticles with superior water-dispersibility and visible-light photocatalytic activity

    International Nuclear Information System (INIS)

    Wu, Chung-Yi; Tu, Kuan-Ju; Lo, Yu-Shiu; Pang, Yean Ling; Wu, Chien-Hou

    2016-01-01

    Alkaline hydrogen peroxide treatment was proposed as a simple and green way to improve the performance of commercial TiO_2 powder for water-dispersibility and visible-light photocatalytic activity on the degradation of dye pollutants. The performance of treated TiO_2 was evaluated as a function of NaOH concentration, H_2O_2 concentration, and treatment time. The optimal conditions were determined to be 24 h in 100 mM H_2O_2 and 8 M NaOH. The treated samples were characterized by Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible spectrophotometry. The analysis revealed that the crystal structure, morphology, and absorption band gap were retained, but the surface of the treated TiO_2 was dramatically changed. The treated TiO_2 was highly dispersible with a uniform hydrodynamic size of 41 ± 12 nm and stable over months in water at pH 3 without any stabilizing ligand and could significantly enhance the visible-light photodegradation of dye pollutants. The superior performance might be attributed to the formation of abundant surface hydroxyl groups. This treatment paves the way for developing water-dispersible TiO_2 with superior visible-light induced photocatalytic degradation of dye pollutants without any complicated and expensive surface modification. - Highlights: • Alkaline hydrogen peroxide is proposed to treat commercial TiO_2 powder. • The treated TiO_2 powder exhibits superior water-dispersibility with a uniform size distribution. • The treated TiO_2 powder can significantly enhance the visible-light photodegradation of dyes.

  2. Rare earths and rare earth alloys electrolytic preparation process and device for this process

    International Nuclear Information System (INIS)

    Seon, F.; Barthole, G.

    1986-01-01

    Electrolysis of a molten salt of rare earth or rare earth alloy for preparation of the metal or alloy is described. The molten salt bath comprises at least a rare earth chloride, at least an alkaline or alkaline earth chloride and at least an alkaline or alkaline earth fluoride [fr

  3. Analysis and Countermeasures of Wind Power Accommodation by Aluminum Electrolysis Pot-Lines in China

    Science.gov (United States)

    Zhang, Hongliang; Ran, Ling; He, Guixiong; Wang, Zhenyu; Li, Jie

    2017-10-01

    The unit energy consumption and its price have become the main obstacles for the future development of the aluminum electrolysis industry in China. Meanwhile, wind power is widely being abandoned because of its instability. In this study, a novel idea for wind power accommodation is proposed to achieve a win-win situation: the idea is for nearby aluminum electrolysis plants to absorb the wind power. The features of the wind power distribution and aluminum electrolysis industry are first summarized, and the concept of wind power accommodation by the aluminum industry is introduced. Then, based on the characteristics of aluminum reduction cells, the key problems, including the bus-bar status, thermal balance, and magnetohydrodynamics instabilities, are analyzed. In addition, a whole accommodation implementation plan for wind power by aluminum reduction is introduced to explain the theoretical value of accommodation, evaluation of the reduction cells, and the industrial experiment scheme. A numerical simulation of a typical scenario proves that there is large accommodation potential for the aluminum reduction cells. Aluminum electrolysis can accommodate wind power and remain stable under the proper technique and accommodation scheme, which will provide promising benefits for the aluminum plant and the wind energy plant.

  4. Hydrogen by electrolysis of water

    Science.gov (United States)

    1975-01-01

    Hydrogen production by electrolytic decomposition of water is explained. Power efficiency, efficient energy utilization, and costs were emphasized. Four systems were considered: two were based on current electrolyzer technology using present efficiency values for electrical generation by fossil fired and nuclear thermal stations, and two using projected electrolyzer technology with advanced fossil and nuclear plants.

  5. Present status of r and d on hydrogen production by high temperature electrolysis of steam

    International Nuclear Information System (INIS)

    Hino, Ryutaro; Aita, Hideki; Sekita, Kenji; Haga, Katsuhiro; Miyamoto, Yoshiaki; Iwata, Tomo-o.

    1995-08-01

    In JAERI, design and R and D works on hydrogen production process have been conducted for connecting to the HTTR under construction at the Oarai Establishment of the JAERI as the nuclear heat utilization system. As for a hydrogen production process by high-temperature electrolysis of steam, laboratory-scale experiments have been conducted using a practical electrolysis tube with 12 cells connected in series. Hydrogen was produced at a maximum density of 44 Nml/cm 2 h at 950degC, and know-how of operational procedures and operational experience have been also accumulated. Then, a self-supporting planar electrolysis cell was fabricated in order to improve hydrogen production performance. In the preliminary test with the planar cell, hydrogen has been produced continuously at a maximum density of 36 Nml/cm 2 h at lower electrolysis temperature of 850degC. This report presents typical test results mentioned above, a review of previous studies conducted in the world and R and D items required for connecting to the HTTR. (author)

  6. Physicochemical Properties of Edible Chitosan/Hydroxypropyl Methylcellulose/Lysozyme Films Incorporated with Acidic Electrolyzed Water

    Directory of Open Access Journals (Sweden)

    Ewa Brychcy

    2015-01-01

    Full Text Available The treatment with acidic electrolyzed water (AEW is a promising disinfection method due to its effectiveness in reducing microbial population. The aim of the study was to evaluate physicochemical properties of chitosan/HPMC films incorporated with lysozyme and acidic electrolyzed water. In the composite films, decreasing film solubility and increasing concentration of sodium chloride solution and prolongation of electrolysis time were observed. Electrolysis process with sodium chloride induces spongy network of film structure. The use of AEW has not changed chemical composition of films which was proved by 1H NMR, MALDI-TOF, and FT-IR spectroscopy. The research confirmed that electrolysis significantly improved thermomechanical properties of the examined films. The contact angle values of the films were quite similar and ranged between 56° and 73°. The increase of salt concentration used in the electrolysis process had an impact on increasing flexibility of samples. Application of electrolyzed water in commonly used food processing systems is possible. Fusion of AEW and biopolymers may provide better integration with coated food product and multidirectional protecting effect.

  7. ENHANCED OIL RECOVERY USING LOCAL ALKALINE

    African Journals Online (AJOL)

    user

    the discovery of new oil producing fields and the ever increasing ... followed by water flooding is between 35 to 50% of the ... involved and lack of scale up and is considered among ... carbonate alkaline chemical reacts with certain types of ... reservoirs because of the profusion of calcium and the ... damage the formation.

  8. Manufacturing of a micro-tungsten carbide electrode using a supersonic-aided electrolysis process

    International Nuclear Information System (INIS)

    Weng, Feng-Tsai; Ho, Chi-Ting

    2008-01-01

    In this study, a novel micromachining technology for fabricating micro parts was described. The original diameter of a tungsten carbide rod was 3 mm, and it was first processed to a rod with a diameter of 50 µm by a precision-grinding process. It could then be machined to the desired diameter by a supersonic-aided electrolysis process. A high-aspect ratio of the micro-tungsten carbide rod was easily obtained by this process. The surface roughness of the sample that was processed by electrolysis with supersonic-aided agitation was compared with that of the sample obtained without agitation. The machined surface of the sample was smooth, and the reason may be that ionized particles in the anode could be removed by supersonic-aided agitation during the electrolysis process. A microelectrode with a tip of approximately 1 µm could be obtained by this process. (technical note)

  9. Carbon Deposition in Solid Oxide Cells during Co-Electrolysis of H2O and CO2

    DEFF Research Database (Denmark)

    Tao, Youkun; Ebbesen, Sune Dalgaard; Mogensen, Mogens Bjerg

    2014-01-01

    current densities from 1.5 to 2.25 A/cm2 and reactant (H2O + CO2) conversion of up to 67%. Delamination and carbon nano-fibers were observed at the Ni-YSZ|YSZ interface for two cells with a dense microstructure operated at electrolysis current densities of 2.0 and 2.25 A/cm2 and a conversion of 59% and 67...... and the active Ni-YSZ electrode. Carbon nano-fibers were only observed close to the YSZ electrolyte, indicating a very reducing atmosphere and a large over-potential gradient in the active electrode, being highest at the interface to the bulk electrolyte and decreasing toward the Ni-YSZ support.......Carbon formation during co-electrolysis of H2O and CO2 in Ni-YSZ supported Solid Oxide Electrolysis Cells (SOECs) may occur, especially at high current density and high conversion. In order to evaluate the carbon formation limits, five galvanostatic tests were performed in this work at electrolysis...

  10. Effect of clay content in rock on oil extraction under alkaline seam conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vezirov, D Sh; Gorbunov, A T; Kasimov, Sh A; Kashchavtsev, V E; Tairov, N D

    1978-01-01

    When oil beds are flooded with alkaline solutions, the alkaline concentration in the solution can be significantly reduced as a result of the interaction between clay and alkali. Large losses of alkali in the bed can render the flooding method ineffective. Experimental studies were conducted on porous media containing up to 25% clay at a constant permeability of 1 D in order to determine the oil extraction indices for clay-containing rock. Constant permeability is maintained by using clays, marshalite, and quartz sand in various proportions. Oil having a viscosity of 99.17 sP, and containing a large amount of surfactants, including 1.1% naphthenic acid, was extracted by fresh water and a 0.25% solution of NaOH. The extraction of oil by fresh water and NaOH solution from quartz sand indicated the advantage of using alkaline solutions. The extraction coefficient increased by 11% with the use of this method. As clay is added to the sand, the extraction coefficient decreases, and is reduced to 12.7% when the clay content reaches 25%. Nevertheless, a comparison of data obtained for quartz sand with fresh water on a porous medium containing 25% clay with an alkaline solution, indicates that the extraction coefficient is just 1.5% lower even in the presence of such a large amount of clay. Consequently, alkaline flooding should still be given preference over the usual methods under specific conditions and where the rock has a comparatively large amount of clay, in view of all the basic factors that influence the extraction process. The results obtained can be used for selecting alkaline concentration in evaluating the efficiency of flooding oil beds with alkaline solutions. 2 figures, 2 tables.

  11. Hydrogen-rich water affected blood alkalinity in physically active men.

    Science.gov (United States)

    Ostojic, Sergej M; Stojanovic, Marko D

    2014-01-01

    Possible appliance of effective and safe alkalizing agent in the treatment of metabolic acidosis could be of particular interest to humans experiencing an increase in plasma acidity, such as exercise-induced acidosis. In the present study we tested the hypothesis that the daily oral intake of 2L of hydrogen-rich water (HRW) for 14 days would increase arterial blood alkalinity at baseline and post-exercise as compared with the placebo. This study was a randomized, double blind, placebo-controlled trial involving 52 presumably healthy physically active male volunteers. Twenty-six participants received HRW and 26 a placebo (tap water) for 14 days. Arterial blood pH, partial pressure for carbon dioxide (pCO2), and bicarbonates were measured at baseline and postexercise at the start (day 0) and at the end of the intervention period (day 14). Intake of HRW significantly increased fasting arterial blood pH by 0.04 (95% confidence interval; 0.01 - 0.08; p < 0.001), and postexercise pH by 0.07 (95% confidence interval; 0.01 - 0.10; p = 0.03) after 14 days of intervention. Fasting bicarbonates were significantly higher in the HRW trial after the administration regimen as compared with the preadministration (30.5 ± 1.9 mEq/L vs. 28.3 ± 2.3 mEq/L; p < 0.0001). No volunteers withdrew before the end of the study, and no participant reported any vexatious side effects of supplementation. These results support the hypothesis that HRW administration is safe and may have an alkalizing effect in young physically active men.

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

    Science.gov (United States)

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

    2018-03-01

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

  13. Kinetic modelling of methane production during bio-electrolysis from anaerobic co-digestion of sewage sludge and food waste.

    Science.gov (United States)

    Prajapati, Kalp Bhusan; Singh, Rajesh

    2018-05-10

    In present study batch tests were performed to investigate the enhancement in methane production under bio-electrolysis anaerobic co-digestion of sewage sludge and food waste. The bio-electrolysis reactor system (B-EL) yield more methane 148.5 ml/g COD in comparison to reactor system without bio-electrolysis (B-CONT) 125.1 ml/g COD. Whereas bio-electrolysis reactor system (C-EL) Iron Scraps amended yield lesser methane (51.2 ml/g COD) in comparison to control bio-electrolysis reactor system without Iron scraps (C-CONT - 114.4 ml/g COD). Richard and Exponential model were best fitted for cumulative methane production and biogas production rates respectively as revealed modelling study. The best model fit for the different reactors was compared by Akaike's Information Criterion (AIC) and Bayesian Information Criterion (BIC). The bioelectrolysis process seems to be an emerging technology with lesser the loss in cellulase specific activity with increasing temperature from 50 to 80 °C. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Technetium electrodeposition from aqueous formate solutions: electrolysis kinetics and material balance study

    International Nuclear Information System (INIS)

    Maslennikov, A.; Peretroukhine, V.

    1998-01-01

    The kinetics of the Tc electrodeposition and the material balance of potentiostatic electrolysis of formate buffer solutions (pH = 1.79-8.5) containing 5*10 -4 - 1*10 -2 M Tc(VII) at graphite cathode has been studied. The deposition of Tc from the solution was found to become possible at E x *y H 2 O (x ≤ 2, 1.5 cath. ) towards more negative values and the augmentation of the electrolyte surface/volume ratio (S/V) were found to increase the yield of the electrolysis and the rate of the electrodeposition process. A maximum technetium recovery of 92-95% has been observed in the electrolysis of neutral HCOONa solutions (pH = 6.0-7.5, μ = 1.0) containing up to 5*10 -1 M Tc(VII) at potentials of the graphite cathode E 2 . A starting Tc concentration in the solution of [Tc(VII)] > 5 *10 -1 M and the presence of more than 0.05 M NO 3 - in the electrolyte were found to suppress the recovery of technetium from the solution. (orig.)

  15. Corrosion of copper in alkaline chloride environments

    International Nuclear Information System (INIS)

    King, F.

    2002-08-01

    The available literature information on the corrosion and electrochemical behaviour of copper in alkaline environments has been reviewed. The purpose of the review was to assess the impact of an alkaline plume from cementitious material on the corrosion behaviour of a copper canister in an SKB-3 type repository. The effect of the evolution of the environmental conditions within the repository have been considered, including the effects of temperature, redox conditions, pore-water salinity and pH. If the pore-water pH increases prior to the establishment of anoxic conditions, the canister surface will passivate as the pore-water pH exceeds a value of ∼ pH 9. Passivation will result from the formation of a duplex Cu 2 O/Cu(OH) 2 film. The corrosion potential will be determined by the equilibrium potential for the Cu 2 O/Cu(OH) 2 couple under oxic conditions, or by the Cu/Cu 2 O redox couple under anoxic conditions (in the absence of sulphide). Pitting corrosion is only likely to occur early in the evolution of the repository environment, whilst the canister is still relatively cool ( 2 available to support localised corrosion, and prior to the increase in pore-water pH and salinity. The subsequent increase in canister surface temperature, pore-water pH and salinity, and decrease in O 2 will make pit initiation less likely, although the canister will remain passive provided the pore-water pH is maintained above pH 9. The higher the pore-water pH, the more strongly the canister is passivated and the less likely the surface is to undergo localised attack. If the pore-water salinity increases prior to the increase in pH, there could be a period of active canister corrosion before passivation occurs.Under these circumstances, the corrosion potential will be a true mixed potential, determine by the relative kinetics of Cu dissolution as CuCl 2 - and of the reduction of O 2 . The development of anoxic conditions and an increase in pore-water sulphide concentration will

  16. Alkaline approach to treating cooling towers for control of Legionella pneumophila

    Energy Technology Data Exchange (ETDEWEB)

    States, S.J.; Conley, L.F.; Towner, S.G.; Wolford, R.S.; Stephenson, T.E.; McNamara, M.; Wadowsky, R.M.; Yee, R.B.

    1987-08-01

    Earlier field and laboratory studies have shown that Legionella species survive and multiply in the pH range 5.5 to 9.2. Additionally, the technical feasibility of operating cooling towers at elevated alkalinities and pH has previously been documented by published guidelines. The guidelines indicate that these conditions facilitate corrosion control and favor chlorine persistence which enhances the effectiveness of continuous chlorination in biofouling control. This information suggest that control of Legionella species in cooling towers can be accomplished by operating the towers under alkaline conditions. To test this possibility, we collected water samples over a period of months from a hospital cooling tower. The samples were analyzed for a variety of chemical parameters. Subsamples were pasteurized and inoculated with non-agar-passaged Legionella pneumophila which had been maintained in tap water. Correlation of subsequent Legionella growth with corresponding pH and alkalinity values revealed statistically significant inverse associations. These data support the hypothesis that operating cooling towers outside of the optimal conditions for Legionella growth (e.g., at elevated alkalinities and a pH greater than 9) may be a useful approach to controlling growth in this habitat.

  17. Comparative costs of hydrogen produced from photovoltaic electrolysis and from photoelectrochemical processes

    International Nuclear Information System (INIS)

    Block, D.L.

    1998-01-01

    The need for hydrogen produced from renewable energy sources is the key element to the world's large-scale usage of hydrogen and to the hydrogen economy envisioned by the World Hydrogen Energy Association. Renewables-produced hydrogen is also the most technically difficult problem to be solved. Hydrogen will never achieve large-scale usage until it can be competitively produced from renewable energy. One of the important questions that has to be addressed is: What are the economics of present and expected future technologies that will be used to produce hydrogen from renewables? The objective of this study is to give an answer to this question by determining the cost of hydrogen (in U.S.$/MBtu) from competing renewable production technologies. It should be noted that the costs and efficiencies assumed in this paper are assumptions of the author, and that the values are expected to be achieved after additional research on photoelectrochemical process technologies. The cost analysis performed is for three types of hydrogen (H 2 ) produced from five different types of renewable processes: photovoltaic (PV) electrolysis, three photoelectrochemical (PEC) processes and higher temperature electrolysis (HTE). The costs and efficiencies for PV, PEC and HTE processes are established for present day, and for expected costs and efficiencies 10 years into the future. A second objective of this analysis is to set base case costs of PV electrolysis. For any other renewable process, the costs for PV electrolysis, which is existing technology, sets the numbers which the other processes must better. (author)

  18. Investigation on the electrochemical properties and crack growth rates of stainless steels in BWR alkaline environments

    International Nuclear Information System (INIS)

    Wang, L.H.; Hsu, T.Y.; Huang, C.S.

    2000-01-01

    Increasing pH of reactor water to mildly alkaline is considered as one of the mitigating water chemistry strategies to reduce the activity release of radioactive oxides and suppress the growth rate of stress corrosion cracking. However, only limited experimental data are currently available in the published literature, it is imperative to perform additional tests to verify the effectiveness of slightly alkaline reactor water. Because the electrochemical behavior and SCC are intricately related, this study will attempt to investigates the electrochemical properties and measures the crack growth rates (CGRs) of type 304 stainless steel (SS) in both normal water chemistry (200 ppb O 2 , neutral pH 25 ) and alkaline chemistry (200 ppb O 2 , pH 25 = 8.0). The additive for pH control is potassium hydroxide (KOH). The crack growth rate was monitored by reversing DC potential drop technique. The electrochemical measurements include AC impedance measurement and potential pulsing test to measure the repassivation behavior. The characteristics of electrochemical properties and its effect on stress corrosion crocking in BWR alkaline environments have been further examined. (author)

  19. Alteration behavior of bentonite barrier of radioactive waste disposal by alkaline solutions. Part 1. Permeability change of compacted bentonite immersed in alkaline solutions

    International Nuclear Information System (INIS)

    Yokoyama, Shingo; Nakamura, Kunihiko

    2010-01-01

    Permeability tests using the compacted bentonites and alkaline solutions were carried out to estimate of alteration behavior and the change of permeability during the alteration reaction. The permeability tests of the compacted bentonites were carried out at 23degC for one week after they were immersed in alkaline solution at 60degC for four weeks (immersing test). After permeability tests, the compacted bentonites were repeatedly tested as the same procedure (i.e. repetition of permeability test and immersing test) at 11 cycles. The compacted bentonites with initial dry density of 1.6 Mg/m 3 were reacted with the different type of the alkaline solutions (deionized water, NaOH (pH=12 and 14), KOH (pH=12 and 14) and Ca(OH) 2 (pH=12)) in each experiments. In the case of deionized water and alkaline solutions of pH12, the mineral compositions of altered bentonite were similar to original bentonite while the exchangeable cations of altered bentonites were changed. No changes of the mineralogical features of montmorillonite in altered bentonites (i.e. illitization, baideritization and increasing of layer charge) were observed in the case of deionized water, pH12-NaOH and pH12-Ca(OH) 2 . The montmorillonite was changed to the illite/smectite interstratified mineral containing about 40% illite like component during the reaction with pH12-KOH. In the case of alkaline solutions with pH14, the component minerals of bentonite (e.g. montmorillonite, quartz and clinoptilolite) were dissolved, consequently secondly minerals (e.g. analcime and phillipsite) were crystallized during experiments. Furthermore, the mineralogical features of montmorillonite were changed as illitization (pH14-KOH), beidellitization (pH14-NaOH and pH14-KOH) and increasing of layer charge (pH14-NaOH and pH14-KOH). No increasing of permeability were observed during the experiment using pH12-NaOH and pH12-Ca(OH) 2 as well as the case of deionized water. In the case of pH12-KOH, the permeability continually

  20. Paleochemistry of Plio-Pleistocene Lake Turkana, Kenya. [Alkalinity

    Energy Technology Data Exchange (ETDEWEB)

    Cerling, T.

    1979-01-01

    The paleochemisry of Plio-Pleistocene Lake Turkana can be estimated by using the chemistry of lakes from the Eastern Rift of Africa as an analogue. Most modern East Africa lakes occupy closed basins; their chemistries follow an evaporation trend defined by the precipitation of certain mineral phases with increasing alkalinity. Estimates of paleoalkalinity can be used to closely estimate the chemical composition of ancient lakes. Three methods are used to estimate paleoalkalinity. Diatoms, molluscs, and fish have certain metabolic requirements that are dependent on pH, alkalinity, or calcium levels; thus fauna and flora can be used as paleoalkalinity indicators. Exchangeable cations on clay minerals can also be used because the relative concentrations of sodium and calcium in lake waters are related to alkalinity. Absence or presence of certain minerals also can serve as a paleoalkalinity indicator. Although the latter two techniques give estimates of paleoalkalinity that are averaged over several hundred or thousand years, their estimates agree with the instantaneous estimates based on biologic considerations. This study shows that the earliest lake phase was very fresh and contained until the end of the Kubi Algi Formation. The Lower Member of the Koobi Fora Formation is shown to have been a fresh- to brackish-water lake. From the beginning of Upper Member time (about 1.8 MY ago) to the present, the lake occupying the Turkana Depression has varied from a brackish lake that overflowed to a closed basin lake that fell below overflow level and whose alkalinity rose to about 200 meq/l.