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Sample records for advanced water electrolysis

  1. Advanced alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Wakabayashi, N.; Torikai, E.; Kawami, Y.; Takenaka, H.

    Results are presented of experimental studies of possible separators and electrodes for use in advanced, high-temperature, high-pressure alkaline water electrolyzers. Material evaluations in alkaline water electrolyzers at temperatures from 100 to 120 C have shown a new type polytetrafluoroethylene membrane impregnated with potassium titanate to be the most promising when the separator is prepared by the hydrothermal treatment of a porous PFTE membrane impregnated with hydrated titanium oxide. Measurements of cell voltages in 30% KOH at current densities from 5 to 100 A/sq dm at temperatures up to 120 C with nickel electrodes of various structures have shown the foamed nickel electrode, with an average pore size of 1-1.5 mm, to have the best performance. When the foamed nickel is coated by fine powdered nickel, carbonyl nickel or Raney nickel to increase electrode surface areas, even lower cell voltages were found, indicating better performance.

  2. Technology advancement of the static feed water electrolysis process

    NASA Technical Reports Server (NTRS)

    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.

  3. Summary status of advanced water electrolysis and hydrogen storage/transport R and D

    SciTech Connect

    Mezzina, A.

    1984-04-01

    Major projects within the framework of the U.S. DOE Chemical/Hydrogen Energy Systems Program are described. Goals, accomplishments and status of investigations into advanced water electrolysis and hydrogen storage/transport are summarized. Electrolytic hydrogen production systems include: SPE electrolyzers; static feed water electrolysis; high temperature electrolysis; and other advanced concepts. Hydrogen transport studies have emphasized the characterization of hydrogen embrittlement effects on conventional natural gas pipeline steels.

  4. Advanced alkaline water electrolysis. Task 2 summary report. Model for alkaline water electrolysis systems

    SciTech Connect

    Yaffe, M.R.; Murray, J.N.

    1980-04-01

    Task 2 involved the establishment of an engineering and economic model for the evaluation of various options in water electrolysis. The mode, verification of the specific coding and four case studies are described. The model was tested by evaluation of a nearly commercial technology, i.e., an 80-kW alkaline electrolyte system, operating at 60/sup 0/C, which delivers approximately 255 SLM, hydrogen for applications such as electrical generation cooling or semiconductor manufacturing. The calculated cost of hydrogen from this installed non-optimized case system with an initial cost to the customer of $87,000 was $6.99/Kg H/sub 2/ ($1.67/100 SCF) on a 20-yr levelized basis using 2.5 cents/kWh power costs. This compares favorably to a levelized average merchant hydrogen cost value of $9.11/Kg H/sub 2/ ($2.17/100 SCF) calculated using the same program.

  5. Technology advancement of the static feed water electrolysis process

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    Some results are presented of a research and development program to continue the development of a method to generate oxygen for crew metabolic consumption during extended manned space flights. The concept being pursued is that of static feed water electrolysis. Specific major results of the work included: (1) completion of a 30-day electrode test using a Life Systems, Inc.-developed high performance catalyst. During startup the cell voltages were as low as 1.38 V at current densities of 108 mA/sq cm (100 ASF) and temperatures of 355 K (180 F). At the end of 30 days of testing the cell voltages were still only 1.42 V at 108 mA/sq cm, (2) determination that the Static Feed Water Electrolysis Module does not release an aerosol of the cell electrolyte into the product gas streams after a break-in period of 24 hours following a new electrolyte charge, and (3) completion of a detailed design analysis of an electrochemical Oxygen Generation Subsystem at a three-man level (4.19 kg/day (9.24 lb/day) of oxygen).

  6. Water electrolysis

    NASA Technical Reports Server (NTRS)

    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. Space water electrolysis: Space Station through advance missions

    NASA Technical Reports Server (NTRS)

    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.

  8. Space water electrolysis: Space Station through advance missions

    NASA Astrophysics Data System (ADS)

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

    1991-09-01

    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.

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

    PubMed

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  11. Water electrolysis module

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.

    1971-01-01

    Module utilizes static water-feed electrolysis system and air-cooled fins to remove heat generated by cell inefficiencies. Module generates 0.15 pounds of oxygen and 0.0188 pounds of hydrogen at current density of 100 amps per square foot. Generator operates in aircraft, spacecraft, or submarine cabins.

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

    NASA Technical Reports Server (NTRS)

    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.

  13. Static feed water electrolysis module

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  15. Water electrolysis and its applications

    SciTech Connect

    Shimamune, T.; Nakajima, Y.; Nishiki, Y.; Tanaka, M.

    1995-12-31

    Permelec Electrode has commercialized various electrodes for industrial uses since 1969. Recently, we are focusing on developing several electrolytic systems which are composed of such electrodes and an ion exchange membrane. The membrane has abilities of separating ions and proceeding electrolysis even in the solution of low conductivity. It is clarified that various applications can be realized by this type of the electrolysis cell, so called the zero gap electrolysis system. The profitable and potential applications are introduced here, such as ozone production and diluted salt electrolytic systems for disinfection and water treatments.

  16. Development and operation of a hybrid acid-alkaline advanced water electrolysis cell

    NASA Astrophysics Data System (ADS)

    Teschke, O.; Zwanziger, M.

    A hybrid acid-alkaline water electrolysis cell has been developed for hydrogen production. The cell is based on the use of an acidic solution at the cathode and a basic solution at the anode to reduce the minimum theoretical voltage for water decomposition from the thermoneutral potential of 1.47 V to close to 1.4 V at 25 C and 1 atm. The pH differential is maintained by the removal of OH ions from the cathode section and water removal from the anode section, which can be driven by heat energy. A practical cell has been built using a solid polymer electrolyte in which, however, the cathodic compartment is not acidic but neutral. Tests with a platinum black cathode catalyst and a platinum-iridium anode catalyst have resulted in steady-state water hydrolysis at an applied voltage of 0.9 V, and a V-I diagram with a considerably lower slope than that of a conventional cell has been obtained at 90 C.

  17. Materials for Hydrogen Generation via Water Electrolysis

    SciTech Connect

    Paul A. Lessing

    2007-05-01

    A review is presented of materials that could be utilized as electrolytes (and their associated electrodes and interconnect materials) in solid-state electrolysis cells to convert water (or steam) into hydrogen and oxygen. Electrolytes that function as oxygen ion conductors or proton conductors are considered for various operating temperatures from approximately 80 °C to 1000 °C. The fundamental electrochemical reactions are reviewed with some discussion of special sources of steam and DC electricity (advanced nuclear) to drive the reactions at the higher temperatures.

  18. Desulfurization from Bauxite Water Slurry (BWS) Electrolysis

    NASA Astrophysics Data System (ADS)

    Gong, Xuzhong; Ge, Lan; Wang, Zhi; Zhuang, Siyuan; Wang, Yuhua; Ren, Lihui; Wang, Mingyong

    2016-02-01

    Feasibility of high-sulfur bauxite electrolysis desulfurization was examined using the electrochemical characterization, XRD, DTA, and FTIR. The cyclic voltammetry curves indicated that bauxite water slurry (BWS) electrolysis in NaOH system was controlled by diffusion. Additionally, the desulfurization effect of NaCl as the electrolyte was significantly better than that of NaOH as an electrolyte. As the stirring rate increased, the desulfurization ratio in NaCl system was not increased obviously, while the desulfurization ratio in NaOH system increased significantly, indicating further that electrolysis desulfurization in NaOH solution was controlled by diffusion. According to XRD, DTA, and FTIR analysis, the characteristic peaks of sulfur-containing phase in bauxite after electrolysis weakened or disappeared, indicating that the pyrite in bauxite was removed from electrolysis. Finally, the electrolytic desulfurization technology of bauxite was proposed based on the characteristics of BWS electrolysis.

  19. Nanotechnology makes biomass electrolysis more energy efficient than water electrolysis

    NASA Astrophysics Data System (ADS)

    Chen, Y. X.; Lavacchi, A.; Miller, H. A.; Bevilacqua, M.; Filippi, J.; Innocenti, M.; Marchionni, A.; Oberhauser, W.; Wang, L.; Vizza, F.

    2014-06-01

    The energetic convenience of electrolytic water splitting is limited by thermodynamics. Consequently, significant levels of hydrogen production can only be obtained with an electrical energy consumption exceeding 45 kWh kg-1H2. Electrochemical reforming allows the overcoming of such thermodynamic limitations by replacing oxygen evolution with the oxidation of biomass-derived alcohols. Here we show that the use of an original anode material consisting of palladium nanoparticles deposited on to a three-dimensional architecture of titania nanotubes allows electrical energy savings up to 26.5 kWh kg-1H2 as compared with proton electrolyte membrane water electrolysis. A net energy analysis shows that for bio-ethanol with energy return of the invested energy larger than 5.1 (for example, cellulose), the electrochemical reforming energy balance is advantageous over proton electrolyte membrane water electrolysis.

  20. Water electrolysis system refurbishment and testing

    NASA Technical Reports Server (NTRS)

    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.

  1. Development status of a preprototype water electrolysis subsystem

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  3. Hydrogen production through solar energy water electrolysis

    NASA Astrophysics Data System (ADS)

    Dini, D.

    Water electrolysis systems are seen as the principal means of producing a large amount of hydrogen in the future. Hydrogen energy production from direct solar energy conversion facilities located on the shores of oceans and lakes is discussed. The electrolysis interface is shown to be conveniently adapted to direct solar energy conversion; this, however, will depend on technical and economic feasibility aspects as they emerge from the research phases. The basic requirements for relatively immense solar collection areas for large-scale central conversion facilities, with widely variable electricity charges, are outlined. The operation of electrolysis and photovoltaic array combination is verified at various insolation levels. It is pointed out that solar cell arrays and electrolyzers are producing the expected results with solar energy inputs that are continuously varying.

  4. Advanced water alkaline electrolysis - A two years running of a test plant: 120 C - 160 C, 20 bars /about 300 p.s.i./

    NASA Astrophysics Data System (ADS)

    Bailleux, C.

    Results acquired in the two-year operation of an advanced pressurized forced-flow alkaline water electrolysis test plant are reported. The test loop consists of eight monopolar cells, circulator, filter units and heat exchangers designed to operate with a 40 wt percent KOH electrolyte at a temperature between 120 and 160 C, a pressure of 20 bars, a current density of 10 kA/sq M and input electric power of 1.75 W. Each cell is made up of two shells of 290 mm external diameter and thickness 40 mm on either side of an FEP-coated diaphragm with a working area of 120 x 120 mm. During the two years of operation, the duty factor for temperature operation has increased from 44 percent to more than 80 percent and that for electrolysis operation has increased from 27 percent to 60 percent, with continuous steady state operation for as long as 35 days. Tests have confirmed the stability of a chrysotile asbestos diaphragm when the electrolyte is doped with silica ions, and revealed deteriorations in materials stability due to gasket creep and metal corrosion. The behavior of the nickel electrodes was observed to be influenced by operating temperatures, cathodic deposits, electrode structure and thermal treatment. In spite of the careful design of the gravity separating tanks, purity of the produced O2 was found unsatifactory, although no trouble arose on the hydrogen side. Results of the operation of the test loop have been scaled up in order to predict the performance of a large-scale pilot plant.

  5. Endurance test and evaluation of alkaline water electrolysis cells

    NASA Technical Reports Server (NTRS)

    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.

  6. Endurance test and evaluation of alkaline water electrolysis cells

    NASA Astrophysics Data System (ADS)

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

    1981-11-01

    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.

  7. Economics of liquid hydrogen from water electrolysis

    NASA Technical Reports Server (NTRS)

    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. Solid-State Water Electrolysis with an Alkaline Membrane

    SciTech Connect

    Leng, YJ; Chen, G; Mendoza, AJ; Tighe, TB; Hickner, MA; Wang, CY

    2012-06-06

    We report high-performance, durable alkaline membrane water electrolysis in a solid-state cell. An anion exchange membrane (AEM) and catalyst layer ionomer for hydroxide ion conduction were used without the addition of liquid electrolyte. At 50 degrees C, an AEM electrolysis cell using iridium oxide as the anode catalyst and Pt black as the cathode catalyst exhibited a current density of 399 mA/cm(2) at 1.80 V. We found that the durability of the AEM-based electrolysis cell could be improved by incorporating a highly durable ionomer in the catalyst layer and optimizing the water feed configuration. We demonstrated an AEM-based electrolysis cell with a lifetime of > 535 h. These first-time results of water electrolysis in a solid-state membrane cell are promising for low-cost, scalable hydrogen production.

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

    NASA Technical Reports Server (NTRS)

    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.

  10. Static Feed Water Electrolysis Subsystem Testing and Component Development

    NASA Technical Reports Server (NTRS)

    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.

  11. Highly energetic phenomena in water electrolysis.

    PubMed

    Postnikov, A V; Uvarov, I V; Lokhanin, M V; Svetovoy, V B

    2016-12-16

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine.

  12. Highly energetic phenomena in water electrolysis

    PubMed Central

    Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; Svetovoy, V. B.

    2016-01-01

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine. PMID:27982103

  13. Highly energetic phenomena in water electrolysis

    NASA Astrophysics Data System (ADS)

    Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; Svetovoy, V. B.

    2016-12-01

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine.

  14. Design of a water electrolysis flight experiment

    NASA Technical Reports Server (NTRS)

    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.

  15. A study of water electrolysis with photovoltaic solar energy conversion

    NASA Astrophysics Data System (ADS)

    Carpetis, C.

    The performance of the hydrogen production system consisting of the photovoltaic array and the water electrolysis unit is studied. The results of the calculation are compared with available experimental data and the performance of a hydrogen production plant by means of photovoltaic solar energy conversion is determined for two typical locations. A method for the estimation of the power matching conditions of the system solar array electrolysis unit is formulated to allow conclusions of general validity.

  16. THERMODYNAMIC CONSIDERATIONS FOR THERMAL WATER SPLITTING PROCESSES AND HIGH TEMPERATURE ELECTROLYSIS

    SciTech Connect

    J. E. O'Brien

    2008-11-01

    A general thermodynamic analysis of hydrogen production based on thermal water splitting processes is presented. Results of the analysis show that the overall efficiency of any thermal water splitting process operating between two temperature limits is proportional to the Carnot efficiency. Implications of thermodynamic efficiency limits and the impacts of loss mechanisms and operating conditions are discussed as they pertain specifically to hydrogen production based on high-temperature electrolysis. Overall system performance predictions are also presented for high-temperature electrolysis plants powered by three different advanced nuclear reactor types, over their respective operating temperature ranges.

  17. Impact of low gravity on water electrolysis operation

    NASA Technical Reports Server (NTRS)

    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.

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

    ERIC Educational Resources Information Center

    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.

  19. Computer simulation of the NASA water vapor electrolysis reactor

    NASA Technical Reports Server (NTRS)

    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.

  20. Electrolysis cell functions as water vapor dehumidifier and oxygen generator

    NASA Technical Reports Server (NTRS)

    Clifford, J. E.

    1971-01-01

    Water vapor is absorbed in hygroscopic electrolyte, and oxygen generated by absorbed water electrolysis at anode is added simultaneously to air stream. Cell applications include on-board aircraft oxygen systems, portable oxygen generators, oxygen concentration requirements, and commercial air conditioning and dehumidifying systems.

  1. Endurance Test and Evaluation of Alkaline Water Electrolysis Cells

    NASA Technical Reports Server (NTRS)

    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.

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

    ERIC Educational Resources Information Center

    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)

  3. Static feed water electrolysis subsystem development

    NASA Technical Reports Server (NTRS)

    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.

  4. Hydrogen generation through static-feed water electrolysis

    NASA Technical Reports Server (NTRS)

    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.

  5. Development of a static feed water electrolysis system

    NASA Technical Reports Server (NTRS)

    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.

  6. Cell for electrolysis of water vapor

    NASA Technical Reports Server (NTRS)

    Celino, V. A.; Roebelen, G.

    1972-01-01

    Electrolytic cells regenerate oxygen from the water vapor in the air of closed-loop life-support system and remove water vapor from air circulated through them. Water is converted into oxygen and hydrogen; the oxygen is returned to the air, the hydrogen is vented or used elsewhere.

  7. Generating Hydrogen through Water Electrolysis using Concentrator Photovoltaics

    SciTech Connect

    McConnell, R.; Thompson, J.

    2005-01-01

    Hydrogen can be an important element in reducing global climate change if the feedstock and process to produce the hydrogen are carbon free. Using nuclear energy to power a high temperature water electrolysis process meets these constraints while another uses heat and electricity from solar electric concentrators. Nuclear researchers have estimated the cost of hydrogen generated in this fashion and we will compare their estimates with those we have made for generating hydrogen using electricity and waste heat from a dish concentrator photovoltaic system. The conclusion is that the costs are comparable and low enough to compete with gasoline costs in the not too distant future.

  8. Recent developments on IME-alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Vandenborre, H.; Baetsle, L. H.; Hebel, W.; Leysen, R.; Nackaerts, H.; Spaepen, G.

    Demonstration on a laboratory scale is reported for the substitution of the conventional asbestos diaphragm in alkaline water electrolysis processes by thin sheets of polyantimonic acid and polysulfone. The membranes investigated withstand concentrated KOH solutions at up to 120 C, and have the necessary ion-conducting and gas-separating properties. It was also found that, by increasing the amount of polyantimonic acid in the membrane, electrolyte concentration can be lowered from 30 percent to 5 percent (by weight) without major effect on the cell voltage.

  9. Development of a solid polymer electrolyte electrolysis cell module and ancillary components for a breadboard water electrolysis system

    NASA Technical Reports Server (NTRS)

    Porter, F. J., Jr.

    1972-01-01

    Solid polymer electrolyte technology in a water electrolysis system along with ancillary components to generate oxygen and hydrogen for a manned space station application are considered. Standard commercial components are utilized wherever possible. Presented are the results of investigations, surveys, tests, conclusions and recommendations for future development efforts.

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

    ERIC Educational Resources Information Center

    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)…

  11. RECENT ADVANCES IN HIGH TEMPERATURE ELECTROLYSIS AT IDAHO NATIONAL LABORATORY: STACK TESTS

    SciTech Connect

    X, Zhang; J. E. O'Brien; R. C. O'Brien; J. J. Hartvigsen; G. Tao; N. Petigny

    2012-07-01

    High temperature steam electrolysis is a promising technology for efficient sustainable large-scale hydrogen production. Solid oxide electrolysis cells (SOECs) are able to utilize high temperature heat and electric power from advanced high-temperature nuclear reactors or renewable sources to generate carbon-free hydrogen at large scale. However, long term durability of SOECs needs to be improved significantly before commercialization of this technology. A degradation rate of 1%/khr or lower is proposed as a threshold value for commercialization of this technology. Solid oxide electrolysis stack tests have been conducted at Idaho National Laboratory to demonstrate recent improvements in long-term durability of SOECs. Electrolytesupported and electrode-supported SOEC stacks were provided by Ceramatec Inc., Materials and Systems Research Inc. (MSRI), and Saint Gobain Advanced Materials (St. Gobain), respectively for these tests. Long-term durability tests were generally operated for a duration of 1000 hours or more. Stack tests based on technology developed at Ceramatec and MSRI have shown significant improvement in durability in the electrolysis mode. Long-term degradation rates of 3.2%/khr and 4.6%/khr were observed for MSRI and Ceramatec stacks, respectively. One recent Ceramatec stack even showed negative degradation (performance improvement) over 1900 hours of operation. A three-cell short stack provided by St. Gobain, however, showed rapid degradation in the electrolysis mode. Improvements on electrode materials, interconnect coatings, and electrolyteelectrode interface microstructures contribute to better durability of SOEC stacks.

  12. Sensitivity Studies of Advanced Reactors Coupled to High Temperature Electrolysis (HTE) Hydrogen Production Processes

    SciTech Connect

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

    2007-04-01

    High Temperature Electrolysis (HTE), when coupled to an advanced nuclear reactor capable of operating at reactor outlet temperatures of 800 °C to 950 °C, has the potential to efficiently produce the large quantities of hydrogen needed to meet future energy and transportation needs. To evaluate the potential benefits of nuclear-driven hydrogen production, the UniSim process analysis software was used to evaluate different reactor concepts coupled to a reference HTE process design concept. The reference HTE concept included an Intermediate Heat Exchanger and intermediate helium loop to separate the reactor primary system from the HTE process loops and additional heat exchangers to transfer reactor heat from the intermediate loop to the HTE process loops. The two process loops consisted of the water/steam loop feeding the cathode side of a HTE electrolysis stack, and the steam or air sweep loop used to remove oxygen from the anode side. The UniSim model of the process loops included pumps to circulate the working fluids and heat exchangers to recover heat from the oxygen and hydrogen product streams to improve the overall hydrogen production efficiencies. The reference HTE process loop model was coupled to separate UniSim models developed for three different advanced reactor concepts (a high-temperature helium cooled reactor concept and two different supercritical CO2 reactor concepts). Sensitivity studies were then performed to evaluate the affect of reactor outlet temperature on the power cycle efficiency and overall hydrogen production efficiency for each of the reactor power cycles. The results of these sensitivity studies showed that overall power cycle and hydrogen production efficiencies increased with reactor outlet temperature, but the power cycle producing the highest efficiencies varied depending on the temperature range considered.

  13. Evaluation of disinfective potential of reactivated free chlorine in pooled tap water by electrolysis.

    PubMed

    Nakajima, Norihito; Nakano, Takashi; Harada, Fumiue; Taniguchi, Hiromasa; Yokoyama, Isao; Hirose, Jun; Daikoku, Eriko; Sano, Kouichi

    2004-05-01

    Tap water is one of the causative factors of hospital infections. We examined the disinfective potential of electrolysis and mechanism of disinfection, and clarified the disinfective effect of electrolysis on tap water contaminated with bacteria, and discussed its clinical applications. Tap waters artificially contaminated with Pseudomonas aeruginosa, Escherichia coli, Legionella pneumophila, and Staphylococcus aureus could be sterilized by electrolysis at 20-30 mA for 5 min. A high-density suspension (10(6) CFU/ml) of a spore forming bacterium, Bacillus subtilis was not completely sterilized by electrolysis at 50 mA up to 30 min, but a low-density suspension (10(5) CFU/ml) was totally sterilized by electrolysis at 50 mA for 5 min. Electrolyzed P. aeruginosa changed morphologically, that is, there was bleb formation on the cell wall and irregular aggregation of cytoplasmic small granules. Moreover, cytoplasmic enzyme, nitrate reductase, was inactivated by the electrolysis. On the other hand, genomic DNA of the electrolyzed bacteria was not degenerated, therefore, their DNA polymerase activity was not completely inactivated. Consequently, the major agent in electrolysis for bactericidal action was considered to be free chlorine, and the possible bactericidal mechanism was by destruction of bacterial membranes, followed by the aggregation of peripheral cytoplasmic proteins. Electrolysis of tap water for both disinfecting contaminating bacteria and increasing the disinfectant capacity was considered effective with some limitations, particularly against high-density contamination by spore-forming bacteria. In clinical settings, electrolysis of tap water is considered effective to disinfect water for hand washing in operation theatres, and bathing water for immunocompromised hosts.

  14. RECENT ADVANCES IN HIGH TEMPERATURE ELECTROLYSIS AT IDAHO NATIONAL LABORATORY: SINGLE CELL TESTS

    SciTech Connect

    X. Zhang; J. E. O'Brien; R. C. O'Brien

    2012-07-01

    An experimental investigation on the performance and durability of single solid oxide electrolysis cells (SOECs) is under way at the Idaho National Laboratory. In order to understand and mitigate the degradation issues in high temperature electrolysis, single SOECs with different configurations from several manufacturers have been evaluated for initial performance and long-term durability. A new test apparatus has been developed for single cell and small stack tests from different vendors. Single cells from Ceramatec Inc. show improved durability compared to our previous stack tests. Single cells from Materials and Systems Research Inc. (MSRI) demonstrate low degradation both in fuel cell and electrolysis modes. Single cells from Saint Gobain Advanced Materials (St. Gobain) show stable performance in fuel cell mode, but rapid degradation in the electrolysis mode. Electrolyte-electrode delamination is found to have significant impact on degradation in some cases. Enhanced bonding between electrolyte and electrode and modification of the microstructure help to mitigate degradation. Polarization scans and AC impedance measurements are performed during the tests to characterize the cell performance and degradation.

  15. Electrode kinetics of a water vapor electrolysis cell

    NASA Technical Reports Server (NTRS)

    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.

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    Yi, Xuenong; Wang, Yulin

    2016-08-01

    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.

  18. A theoretical study of the modelling and control of a solar water electrolysis plant

    NASA Astrophysics Data System (ADS)

    Vandergeest, P.; Fahidy, T. Z.

    1980-01-01

    A control-oriented model is presented for a hydrogen producing plant consisting of a conventional water electrolysis process and a photo-assisted water electrolytic installation which utilizes solar energy via a suitable semiconductor/electrolyte assembly. A control strategy for daily hydrogen production is illustrated by a numerical example. The proposed simulation of solar water electrolysis plants is of potential usefulness for automatic control of the photoelectrolytic process when combined with statistical data-logging and model updating carried out in a practical installation.

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

    PubMed

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  2. Sulfur removal from bauxite water slurry (BWS) electrolysis intensified by ultrasonic.

    PubMed

    Ge, Lan; Gong, Xuzhong; Wang, Zhi; Zhao, Lixin; Wang, Yuhua; Wang, Mingyong

    2015-09-01

    Effects of ultrasonic on desulfurization ratio from bauxite water slurry (BWS) electrolysis in NaOH solution were examined under constant current. The results indicated that ultrasonic improved the desulfurization ratio at high temperatures because of the diffusion and transfer of oxygen gas in electrolyte. However, due to the increase in oxygen gas emission, ultrasonic could not improve the desulfurization ratio obviously at low temperatures. Additionally, the particle size of bauxite became fine in the presence of ultrasonic, indicating that the mass transfer of FeS2 phase was improved. According to the polarization curves, the current density increased in the presence of ultrasonic, indicating that the mass transfer of liquid phase was improved. The apparent activation energy (AAE) of electrode reaction revealed that ultrasonic did not change the pathway of water electrolysis. However, ultrasonic changed the pathway of BWS electrolysis, converting indirect oxidation into direct oxidation. The AAE of BWS electrolysis in the presence of ultrasonic was higher than that in the absence of ultrasonic. And the low AAEs (less than 20 kJ/mol) clearly indicated the diffusion control during BWS electrolysis reaction.

  3. Incorporating Sulfur Inside the Pores of Carbons for Advanced Lithium-Sulfur Batteries: An Electrolysis Approach.

    PubMed

    He, Bin; Li, Wen-Cui; Yang, Chao; Wang, Si-Qiong; Lu, An-Hui

    2016-01-26

    We have developed an electrolysis approach that allows effective and uniform incorporation of sulfur inside the micropores of carbon nanosheets for advanced lithium-sulfur batteries. The sulfur-carbon hybrid can be prepared with a 70 wt % sulfur loading, in which no nonconductive sulfur agglomerations are formed. Because the incorporated sulfur is electrically connected to the carbon matrix in nature, the hybrid cathode shows excellent electrochemical performance, including a high reversible capacity, good rate capability, and good cycling stability, as compared to one prepared using the popular melt-diffusion method.

  4. Water rocket - Electrolysis propulsion and fuel cell power

    SciTech Connect

    Carter, P H; Dittman, M D; Kare, J T; Militsky, F; Myers, B; Weisberg, A H

    1999-07-24

    Water Rocket is the collective name for an integrated set of technologies that offer new options for spacecraft propulsion, power, energy storage, and structure. Low pressure water stored on the spacecraft is electrolyzed to generate, separate, and pressurize gaseous hydrogen and oxygen. These gases, stored in lightweight pressure tanks, can be burned to generate thrust or recombined to produce electric power. As a rocket propulsion system, Water Rocket provides the highest feasible chemical specific impulse (-400 seconds). Even higher specific impulse propulsion can be achieved by combining Water Rocket with other advanced propulsion technologies, such as arcjet or electric thrusters. With innovative pressure tank technology, Water Rocket's specific energy [Wh/kg] can exceed that of the best foreseeable batteries by an order of magnitude, and the tanks can often serve as vehicle structural elements. For pulsed power applications, Water Rocket propellants can be used to drive very high power density generators, such as MHD devices or detonation-driven pulse generators. A space vehicle using Water Rocket propulsion can be totally inert and non-hazardous during assembly and launch. These features are particularly important for the timely development and flight qualification of new classes of spacecraft, such as microsats, nanosats, and refuelable spacecraft.

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

    NASA Technical Reports Server (NTRS)

    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.

  6. Water electrolysis on La1-xSrxCoO3-δ perovskite electrocatalysts

    NASA Astrophysics Data System (ADS)

    Mefford, J. Tyler; Rong, Xi; Abakumov, Artem M.; Hardin, William G.; Dai, Sheng; Kolpak, Alexie M.; Johnston, Keith P.; Stevenson, Keith J.

    2016-03-01

    Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B-O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co-O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1-xSrxCoO3-δ. We attempt to rationalize the high activities of La1-xSrxCoO3-δ through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis.

  7. Water electrolysis on La(1-x)Sr(x)CoO(3-δ) perovskite electrocatalysts.

    PubMed

    Mefford, J Tyler; Rong, Xi; Abakumov, Artem M; Hardin, William G; Dai, Sheng; Kolpak, Alexie M; Johnston, Keith P; Stevenson, Keith J

    2016-03-23

    Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B-O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co-O bond and the concentration of oxygen vacancies are controlled through Sr(2+) substitution into La(1-x)Sr(x)CoO(3-δ) . We attempt to rationalize the high activities of La(1-x)Sr(x)CoO(3-δ) through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis.

  8. Water electrolysis on La1-xSrxCoO3-δ perovskite electrocatalysts

    DOE PAGES

    Mefford, J. Tyler; Rong, Xi; Abakumov, Artem M.; ...

    2016-03-23

    Here, perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B–O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co–O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1–xSrxCoO3–δ. We attempt to rationalize the highmore » activities of La1–xSrxCoO3–δ through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis.« less

  9. Solar generator performance with load matching to water electrolysis

    NASA Astrophysics Data System (ADS)

    Freudenberg, K.

    1982-08-01

    A 7 W generator, based on monocrystalline silicon solar cells, was directly wired to an electronic load, simulating the current-voltage characteristic of an advanced water electrolyzer. System performance was monitored from January 15 to July 7, 1980. Measurements included current and voltage at the load and at the point of maximum power output, global irradiance and ambient temperature. Solar generator efficiency ranged from 7.5% to 11.5%. A large spread of + or - 1% in instantaneous generator efficiency was observed at identical values of global irradiance and ambient temperature. The dependence of the average generator efficiency on global irradiance and ambient temperature is given by a simple relation to an accuracy of + or - 0.2%. Load matching was optimized for high global irradiance at high ambient temperature. Averaged over the half year, period losses by nonideal load matching amounted to only 8.9%. Assuming an ideal current efficiency of the simulated water electrolyzer, the overall efficiency of hydrogen production was 8.0%.

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

    PubMed

    Zhang, Yifeng; Angelidaki, Irini

    2014-06-01

    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 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 unfavorable biological/chemical reactions. This unique advantage of MECs has led to several alternative applications such as chemicals synthesis, recalcitrant pollutants removal, resources recovery, bioelectrochemical research platform and biosensors, which have greatly broaden the application scopes of MECs. MECs are becoming a versatile platform technology and offer a new solution for emerging environmental issues related to waste streams treatment and energy and resource recovery. Different from previous reviews that mainly focus on hydrogen production, this paper provides an up-to-date review of all the new applications of MECs and their resulting performance, current challenges and prospects of future.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    ERIC Educational Resources Information Center

    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)

  13. Electrolysis Propulsion for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    deGroot, Wim A.; Arrington, Lynn A.; McElroy, James F.; Mitlitsky, Fred; Weisberg, Andrew H.; Carter, Preston H., II; Myers, Blake; Reed, Brian D.

    1997-01-01

    Electrolysis propulsion has been recognized over the last several decades as a viable option to meet many satellite and spacecraft propulsion requirements. This technology, however, was never used for in-space missions. In the same time frame, water based fuel cells have flown in a number of missions. These systems have many components similar to electrolysis propulsion systems. Recent advances in component technology include: lightweight tankage, water vapor feed electrolysis, fuel cell technology, and thrust chamber materials for propulsion. Taken together, these developments make propulsion and/or power using electrolysis/fuel cell technology very attractive as separate or integrated systems. A water electrolysis propulsion testbed was constructed and tested in a joint NASA/Hamilton Standard/Lawrence Livermore National Laboratories program to demonstrate these technology developments for propulsion. The results from these testbed experiments using a I-N thruster are presented. A concept to integrate a propulsion system and a fuel cell system into a unitized spacecraft propulsion and power system is outlined.

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

    SciTech Connect

    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.

  15. Characteristics of the oxygen evolution reaction on synthetic copper - cobalt - oxide electrodes for water electrolysis

    NASA Astrophysics Data System (ADS)

    Park, Yoo Sei; Park, Chan Su; Kim, Chi Ho; Kim, Yang Do; Park, Sungkyun; Lee, Jae Ho

    2016-10-01

    A nano-sized Cu0.7Co2.3O4 powder was prepared using a thermal decomposition method to achieve an efficient anode catalyst for an economical water electrolysis system for high-purity hydrogen-gas production without using a noble-metal catalyst. This study showed that the calcination temperature should be maintained under 400 °C to obtain a spinel copper - cobalt oxide structure without secondary oxide phases. The powder calcined at 250 °C showed the highest current density at the oxygen evolution reaction. This was due mainly to the increased number of available active sites and the active surface area of the powders. Further systematic analyses of the electrochemical characteristics of Cu x Co3- x O4 synthesized by using the fusion method were performed to assess it as potential anode material for use in alkaline-anion-exchange-membrane water electrolysis.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Technical Reports Server (NTRS)

    Schmidt, George R.

    1988-01-01

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

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

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Astrophysics Data System (ADS)

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

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  2. HYDROGEN ISOTOPE RECOVERY USING PROTON EXCHANGE MEMBRANE ELECTROLYSIS OF WATER

    SciTech Connect

    Fox, E; Scott Greenway, S; Amy Ekechukwu, A

    2007-08-27

    A critical component of tritium glovebox operations is the recovery of high value tritium from the water vapor in the glove box atmosphere. One proposed method to improve existing tritium recovery systems is to replace the disposable hot magnesium beds used to separate the hydrogen and oxygen in water with continuous use Proton Exchange Membrane Electrolyzers (PEMEs). This study examines radiation exposure to the membrane of a PEME and examines the sizing difference that would be needed if the electrolyzer were operated with a cathode water vapor feed instead of an anode liquid water feed.

  3. A review of high temperature co-electrolysis of H2O and CO2 to produce sustainable fuels using solid oxide electrolysis cells (SOECs): advanced materials and technology.

    PubMed

    Zheng, Yun; Wang, Jianchen; Yu, Bo; Zhang, Wenqiang; Chen, Jing; Qiao, Jinli; Zhang, Jiujun

    2017-03-06

    High-temperature solid oxide electrolysis cells (SOECs) are advanced electrochemical energy storage and conversion devices with high conversion/energy efficiencies. They offer attractive high-temperature co-electrolysis routes that reduce extra CO2 emissions, enable large-scale energy storage/conversion and facilitate the integration of renewable energies into the electric grid. Exciting new research has focused on CO2 electrochemical activation/conversion through a co-electrolysis process based on the assumption that difficult C[double bond, length as m-dash]O double bonds can be activated effectively through this electrochemical method. Based on existing investigations, this paper puts forth a comprehensive overview of recent and past developments in co-electrolysis with SOECs for CO2 conversion and utilization. Here, we discuss in detail the approaches of CO2 conversion, the developmental history, the basic principles, the economic feasibility of CO2/H2O co-electrolysis, and the diverse range of fuel electrodes as well as oxygen electrode materials. SOEC performance measurements, characterization and simulations are classified and presented in this paper. SOEC cell and stack designs, fabrications and scale-ups are also summarized and described. In particular, insights into CO2 electrochemical conversions, solid oxide cell material behaviors and degradation mechanisms are highlighted to obtain a better understanding of the high temperature electrolysis process in SOECs. Proposed research directions are also outlined to provide guidelines for future research.

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

    PubMed

    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.

  5. Development of electrolysis-cell separator for 125/sup 0/C operation. Advanced alkaline electrolysis cell development. Final report

    SciTech Connect

    Murray, J N

    1983-03-01

    This report contains the findings of a seven-month contracted effort. The major technical task involved a 125/sup 0/C operating temperature test of the 20 v/o polybenzimidazole (PBI) - 80 v/o potassium titanate (K/sub 2/TiO/sub 3/) separator in combination with the nickel-molybdenum cathode electrocatalyst system dubbed the C-AN cathode using the ARIES test system which was developed previously. The test of the PBI-K/sub 2/TiO/sub 3/ separator was only partially successful. The anticipated 1.85 (75/sup 0/C) and 1.75 volt per cell (100/sup 0/C) input requirement at 550 ma/cm/sup 2/ were surpassed slightly. The test module operated stably for about 550 hr. Although there were some mechanical difficulties with the ARIES test unit, testing at 125/sup 0/C proceeded from 745 hr on test until the test was terminated at 2318 operating hours to allow diagnostic disassembly. The input voltage degraded to a value of 1.82 volt per cell at 125/sup 0/C which is unacceptable. Diagnostic disassembly showed the PBI portion of the separator was no longer present. PBI had been shown to be stable in 123/sup 0/C, 45 w/o KOH solutions in a 1000-hr test. The attack is suggested to be attributable to a peroxide or perchlorate type oxidizer which would be unique to the electrolysis mode and probably not present in alkaline fuel cell applications. Recommendations for further testing include an evaluation of the chemical compatibility of PBI with alkaline/oxidizer solutions and endurance testing the C-AN cathode with new improved anode structures at 125/sup 0/C using asbestos separators in combination with a silicate saturated KOH electrolyte. Demonstration of the stability of this 1.65 volt per cell (90% voltage efficiency) technology at 500 ma/cm/sup 2/ will document an inexpensive and intelligent hydrogen production process which will satisfy the needs of the United States in the 1990s.

  6. Cell and method for electrolysis of water and anode

    NASA Technical Reports Server (NTRS)

    Aylward, J. R. (Inventor)

    1981-01-01

    An electrolytic cell for converting water vapor to oxygen and hydrogen include an anode comprising a foraminous conductive metal substrate with a 65-85 weight percent iridium oxide coating and 15-35 weight percent of a high temperature resin binder. A matrix member contains an electrolyte to which a cathode substantially inert. The foraminous metal member is most desirably expanded tantalum mesh, and the cell desirably includes reservoir elements of porous sintered metal in contact with the anode to receive and discharge electrolyte to the matrix member as required. Upon entry of a water vapor containing airstream into contact with the outer surface of the anode and thence into contact with iridium oxide coating, the water vapor is electrolytically converted to hydrogen ions and oxygen with the hydrogen ions migrating through the matrix to the cathode and the oxygen gas produced at the anode to enrich the air stream passing by the anode.

  7. Development of solid electrolytes for water electrolysis at intermediate temperatures

    SciTech Connect

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

    1995-09-01

    If an electrolyzer could operate at higher temperatures, several benefits would accrue. The first is that the thermodynamic electrical energy requirement to drive the reaction would be reduced. Supplying the total enthalpy of reaction at any temperature involves a combination of electrical and thermal energy inputs. Because of the positive entropy associated with water decomposition, the thermal contribution increases as temperature rises, allowing the free energy requirement to decrease. Thus the open circuit voltage, V{sub oc}, for water splitting drops as temperature rises. At room temperature, V{sub oc} for water decomposition is 1.229 V. At 400{degrees}C, voltage requirement has dropped to 1.1 V; at 1000{degrees}C, it is only 0.92 V. Since electricity is a more expensive form of energy on a btu basis, the more energy taken from the thermal surroundings the better. Moreover, this thermal energy content could be solar-derived. While the cost of solar thermal energy varies in the range of $360-900/peak kilowatt, the installed cost of photovoltaic electricity is in the range of $4,000-5,000/peak kilowatt. Thus if one is compelled to erect an array of photovoltaic panels to generate the e.m.f. necessary to split water, substituting as much area with thermal collectors as possible represents a substantial cost savings.

  8. Photovoltaic electrolysis - Hydrogen and electricity from water and light

    NASA Astrophysics Data System (ADS)

    Murphy, O. J.; Bockris, J. Om.

    Two photovoltaic couples, consisting of n on p and p on n gallium arsenide, respectively, have been converted into a water splitting device. Light is allowed to fall on the p part of one couple, which is in contact with air, and on the n side platinum is plated, which contacts the solution. On the other couple, the n side is in contact with air, while on the p side ruthenium dioxide is plated, which is in contact with the solution. Such a device gives a performance (8 percent conversion efficiency of solar light to hydrogen) better than that of known photoelectrolysis devices operating without battery assistance. Comparison with a coupled photovoltaic-distant water electrolyzer shows, under certain circumstances, some advantages for the present device.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:26848031

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

    PubMed

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

    2016-02-05

    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.

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

    PubMed

    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.

  13. Development of solid electrolytes for water electrolysis at higher temperature

    SciTech Connect

    Linkous, C.A.

    1996-10-01

    This report describes efforts in developing new solid polymer electrolytes that will enable operation of proton exchange membrane electrolyzers at higher temperatures than are currently possible. Several ionomers have been prepared from polyetheretherketone (PEEK), polyethersulfone (PES), and polyphenylquinoxaline (PPQ) by employing various sulfonation procedures. By controlling the extent of sulfonation, a range of proton conductivities could be achieved, whose upper limit actually exceeded that of commercially available perfluoralkyl sulfonates. Thermoconductimetric analysis of samples at various degrees of sulfonation showed an inverse relationship between conductivity and maximum operating temperature. This was attributed to the dual effect of adding sulfonate groups to the polymer: more acid groups produce more protons for increased conductivity, but they also increase water uptake, which mechanically weakens the membrane. This situation was exacerbated by the limited acidity of the aromatic sulfonic acids (pK{sub A} {approx} 2-3). The possibility of using partial fluorination to raise the acid dissociation constant is discussed.

  14. Apparatus and method for the electrolysis of water

    DOEpatents

    Greenbaum, Elias

    2015-04-21

    An apparatus for the electrolytic splitting of water into hydrogen and/or oxygen, the apparatus comprising: (i) at least one lithographically-patternable substrate having a surface; (ii) a plurality of microscaled catalytic electrodes embedded in said surface; (iii) at least one counter electrode in proximity to but not on said surface; (iv) means for collecting evolved hydrogen and/or oxygen gas; (v) electrical powering means for applying a voltage across said plurality of microscaled catalytic electrodes and said at least one counter electrode; and (vi) a container for holding an aqueous electrolyte and housing said plurality of microscaled catalytic electrodes and said at least one counter electrode. Electrolytic processes using the above electrolytic apparatus or functional mimics thereof are also described.

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

    PubMed

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

    2016-10-31

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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.

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

    PubMed Central

    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

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

    PubMed Central

    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

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

    PubMed

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

    2016-05-20

    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.

  1. Investigations on degradation of the long-term proton exchange membrane water electrolysis stack

    NASA Astrophysics Data System (ADS)

    Sun, Shucheng; Shao, Zhigang; Yu, Hongmei; Li, Guangfu; Yi, Baolian

    2014-12-01

    A 9-cell proton exchange membrane (PEM) water electrolysis stack is developed and tested for 7800 h. The average degradation rate of 35.5 μV h-1 per cell is measured. The 4th MEA of the stack is offline investigated and characterized. The electrochemical impedance spectroscopy (EIS) shows that the charge transfer resistance and ionic resistance of the cell both increase. The linear sweep scan (LSV) shows the hydrogen crossover rate of the membrane has slight increase. The electron probe X-ray microanalyze (EPMA) illustrates further that Ca, Cu and Fe elements distribute in the membrane and catalyst layers of the catalyst-coated membranes (CCMs). The cations occupy the ion exchange sites of the Nafion polymer electrolyte in the catalyst layers and membrane, which results in the increase in the anode and the cathode overpotentials. The metallic impurities originate mainly from the feed water and the components of the electrolysis unit. Fortunately, the degradation was reversible and can be almost recovered to the initial performance by using 0.5 M H2SO4. This indicates the performance degradation of the stack running 7800 h is mainly caused by a recoverable contamination.

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

    PubMed

    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⁺).

  3. Alkali doped poly (2,5-benzimidazole) membrane for alkaline water electrolysis: Characterization and performance

    NASA Astrophysics Data System (ADS)

    Diaz, Liliana A.; Hnát, Jaromír; Heredia, Nayra; Bruno, Mariano M.; Viva, Federico A.; Paidar, Martin; Corti, Horacio R.; Bouzek, Karel; Abuin, Graciela C.

    2016-04-01

    The properties and performance of linear and cross-linked KOH doped ABPBI membranes as electrolyte/separator for zero gap alkaline water electrolysis cells are evaluated and compared with a commercial Zirfon® diaphragm. Stability in alkaline environment, swelling, thermal properties, water sorption, KOH uptake and conductivity of linear (L-ABPBI) and cross-linked (C-ABPBI) membranes doped with different concentrations of KOH are analyzed. Linear membranes show stability up to 3.0 mol·dm-3 KOH doping, while cross-linked membranes are stable up to 4.2 mol·dm-3 KOH doping. Both kinds of membranes exhibit good thermal stability and reasonable specific ionic conductivity at 22 °C in the range between 7 and 25 mS·cm-1, being slightly higher the conductivity of C-ABPBI membranes than that of L-ABPBI ones. In short-term electrolysis tests both L-ABPBI and C-ABPBI membranes show better performance than Zirfon diaphragm in the range from 50 to 70 °C. A current density of 335 mA·cm-2 at a cell voltage of 2.0 V is attained with C-ABPBI membranes doped in 3 mol·dm-3 KOH at 70 °C, a performance comparable with that of commercial units operating at temperatures ca. 80 °C and 30 wt% KOH (6.7 mol·dm-3) as electrolyte.

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

    NASA Astrophysics Data System (ADS)

    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).

  5. Drinking Water Disinfection by In-line Electrolysis: Product and Inorganic By-Product Formation

    NASA Astrophysics Data System (ADS)

    Bergmann, M. E. Henry

    This section covers peculiarities of so-called in-line electrolysis when drinking water is electrolysed to produce disinfection species killing microorganisms. Mainly mixed oxide electrodes (MIO) based on IrO2 and/or RuO2 coatings and boron-doped diamond electrodes were used in the studies. Artificial and real drinking water systems were electrolysed in continuous and discontinuous operating mode, varying water composition, current density and electrode materials. Results show, besides the ability of producing active chlorine, risks of inorganic disinfection by-products (DBPs) such as chlorate, perchlorate, nitrite, ammonium, chloramines, hydrogen peroxide and others. DBPs are responsible for analysis errors using DPD method for active chlorine measurements. Geometry may influence by-product yield. As a conclusion, the necessity of developing test routines for practical cell applications must be underlined.

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

    NASA Astrophysics Data System (ADS)

    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

  7. Pressurized Testing of Solid Oxide Electrolysis Stacks with Advanced Electrode-Supported Cells

    SciTech Connect

    J. E. O'Brien; X. Zhang; G. K. Housley; K. DeWall; L. Moore-McAteer; G. Tao

    2012-06-01

    A new facility has been developed at the Idaho National Laboratory for pressurized testing of solid oxide electrolysis stacks. Pressurized operation is envisioned for large-scale hydrogen production plants, yielding higher overall efficiencies when the hydrogen product is to be delivered at elevated pressure for tank storage or pipelines. Pressurized operation also supports higher mass flow rates of the process gases with smaller components. The test stand can accommodate cell dimensions up to 8.5 cm x 8.5 cm and stacks of up to 25 cells. The pressure boundary for these tests is a water-cooled spool-piece pressure vessel designed for operation up to 5 MPa. The stack is internally manifolded and operates in cross-flow with an inverted-U flow pattern. Feed-throughs for gas inlets/outlets, power, and instrumentation are all located in the bottom flange. The entire spool piece, with the exception of the bottom flange, can be lifted to allow access to the internal furnace and test fixture. Lifting is accomplished with a motorized threaded drive mechanism attached to a rigid structural frame. Stack mechanical compression is accomplished using springs that are located inside of the pressure boundary, but outside of the hot zone. Initial stack heatup and performance characterization occurs at ambient pressure followed by lowering and sealing of the pressure vessel and subsequent pressurization. Pressure equalization between the anode and cathode sides of the cells and the stack surroundings is ensured by combining all of the process gases downstream of the stack. Steady pressure is maintained by means of a backpressure regulator and a digital pressure controller. A full description of the pressurized test apparatus is provided in this paper.

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

    PubMed

    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.

  9. Water electrolysis on La1−xSrxCoO3−δ perovskite electrocatalysts

    PubMed Central

    Mefford, J. Tyler; Rong, Xi; Abakumov, Artem M.; Hardin, William G.; Dai, Sheng; Kolpak, Alexie M.; Johnston, Keith P.; Stevenson, Keith J.

    2016-01-01

    Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B–O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co–O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1−xSrxCoO3−δ. We attempt to rationalize the high activities of La1−xSrxCoO3−δ through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis. PMID:27006166

  10. Design of a system for solar energy storage via water electrolysis

    NASA Astrophysics Data System (ADS)

    Koukouvinos, A.; Lygerou, V.; Koumoutsos, N.

    The design and economic evaluation of a system that provides electricity for an average one-family dwelling by utilizing solar energy are detailed. Solar energy is converted by photovoltaic arrays to electricity which is then used for the electrolysis of water. The hydrogen produced is stored in the form of hydride and can be used either for direct burning, to meet the thermal energy requirements, or in a fuel cell to supply the electric energy needed. Particular emphasis was given to designing a control system that could guarantee a smooth intermittent operation of the electrolytic unit and the utilization of the maximum output of the photovoltaic cells. The system selected can operate with minimum attendance and very little maintenance. The cost of the electricity produced is as high as $3.30/kWh.

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

    NASA Technical Reports Server (NTRS)

    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.

  12. Commercial-Scale Performance Predictions for High-Temperature Electrolysis Plants Coupled to Three Advanced Reactor Types

    SciTech Connect

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

    2007-09-01

    This report presents results of system analyses that have been developed to assess the hydrogen production performance of commercial-scale high-temperature electrolysis (HTE) plants driven by three different advanced reactor – power-cycle combinations: a high-temperature helium cooled reactor coupled to a direct Brayton power cycle, a supercritical CO2-cooled reactor coupled to a direct recompression cycle, and a sodium-cooled fast reactor coupled to a Rankine cycle. The system analyses were performed using UniSim software. The work described in this report represents a refinement of previous analyses in that the process flow diagrams include realistic representations of the three advanced reactors directly coupled to the power cycles and integrated with the high-temperature electrolysis process loops. In addition, this report includes parametric studies in which the performance of each HTE concept is determined over a wide range of operating conditions. Results of the study indicate that overall thermal-to- hydrogen production efficiencies (based on the low heating value of the produced hydrogen) in the 45 - 50% range can be achieved at reasonable production rates with the high-temperature helium cooled reactor concept, 42 - 44% with the supercritical CO2-cooled reactor and about 33 - 34% with the sodium-cooled reactor.

  13. The dynamic-state effects of sodium ion contamination on the solid polymer electrolyte water electrolysis

    NASA Astrophysics Data System (ADS)

    Zhang, Linsong; Jie, Xiao; Shao, Zhi-Gang; Wang, Xunying; Yi, Baolian

    2013-11-01

    Na+ is a likely intrinsic impurity in water and is a potential cation impurity in the solid polymer electrolyte water electrolysis. In this paper, the dynamic-state effect of low concentration of Na+ is studied by adding Na+ into the deionized water fed in the SPE water electrolyser. The dynamic variation of cell voltage results show that the cell performance degraded more severely in the presence of Na+ impurity by anode poisoning than by cathode poisoning. The severity and poisoning rate of the cell depend on the Na+ concentration, water flow rate and cell temperature. However, the current density does not impact the extent of the cell voltage increase. In the meantime, an external reference electrode is used to measure the anode and cathode potentials. The performance degradation is mainly ascribed to the increase in cathode overpotential by anode poisoning. EIS measurements show that the performance difference primarily comes from the kinetics loss rather than the ohmic loss. The decrease of available protons in the three phase boundaries may lead to the increase in charge transfer resistance. The electron probe microanalysis tests show that Na+ remains in CCM even recovered with deionized water, which results in only partially recovered cell performance.

  14. Advances in Molten Oxide Electrolysis for the Production of Oxygen and Metals from Lunar Regolith

    NASA Technical Reports Server (NTRS)

    Sadoway, Donald R.; Sirk, Aislinn; Sibille, Laurent; Melendez, Orlando; Lueck, Dale; Curreri, Peter; Dominquez, Jesus; Whitlow, Jonathan

    2008-01-01

    As part of an In-Situ Resource Utilization infrastructure to sustain long term-human presence on the lunar surface, the production of oxygen and metals by electrolysis of lunar regolith has been the subject of major scrutiny. There is a reasonably large body of literature characterizing the candidate solvent electrolytes, including ionic liquids, molten salts, fluxed oxides, and pure molten regolith itself. In the light of this information and in consideration of available electrolytic technologies, the authors have determined that direct molten oxide electrolysis at temperatures of approx 1600 C is the most promising avenue for further development. Results from ongoing studies as well as those of previous workers will be presented. Topics include materials selection and testing, electrode stability, gas capture and analysis, and cell operation during feeding and tapping.

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

    PubMed

    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.

  16. Review of hydrogen production with photovoltaic electrolysis systems

    NASA Astrophysics Data System (ADS)

    Fischer, M.

    Characteristics and performance of H2 production by means of photovoltaic solar energy conversion and water electrolysis are studied and discussed. Experimental results of a small system consisting of a polycrystalline solar cell generator, water electrolysis and power conditioning are compared with calculated results of a system simulation model. The stationary and dynamic behavior of the system and components, and the efficiency and performance of power conditioning are investigated. For an optimized and reliable operation of photovoltaic electrolyzer systems, the behavior of electrolysis at part-load and overload, the start-up and shut-down behavior, and the corrosion and degradation effects are important aspects. The status and further improvements of advanced electrolysis are discussed, as well as results of system analysis studies for future large-scale solar H2 production.

  17. High performance robust F-doped tin oxide based oxygen evolution electro-catalysts for PEM based water electrolysis

    SciTech Connect

    Datta, Moni Kanchan; Kadakia, Karan; Velikokhatnyi, Oleg I; Jampani, Prashanth H; Chung, Sung Jae; Poston, James A; Manivannan, Ayyakkannu; Kumta, Prashant N

    2013-01-01

    Identification and development of non-noble metal based electro-catalysts or electro-catalysts comprising compositions with significantly reduced amounts of expensive noble metal contents (e.g. IrO{sub 2}, Pt) with comparable electrochemical performance to the standard noble metal/metal oxide for proton exchange membrane (PEM) based water electrolysis would signify a major breakthrough in hydrogen generation via water electrolysis. Development of such systems would lead to two primary outcomes: first, a reduction in the overall capital costs of PEM based water electrolyzers, and second, attainment of the targeted hydrogen production costs (<$3.00/gge delivered by 2015) comparable to conventional liquid fuels. In line with these goals, by exploiting a two-pronged theoretical first principles and experimental approach herein, we demonstrate for the very first time a solid solution of SnO{sub 2}:10 wt% F containing only 20 at.% IrO{sub 2} [e.g. (Sn{sub 0.80}Ir{sub 0.20})O{sub 2}:10F] displaying remarkably similar electrochemical activity and comparable or even much improved electrochemical durability compared to pure IrO{sub 2}, the accepted gold standard in oxygen evolution electro-catalysts for PEM based water electrolysis. We present the results of these studies.

  18. Oxygen evolution reaction characteristics of synthetic nickel-cobalt-oxide electrodes for alkaline anion-exchange membrane water electrolysis

    NASA Astrophysics Data System (ADS)

    Koo, Tae Woo; Park, ChanSu; Kim, Yang Do; Lee, Dooyong; Park, Sungkyun; Lee, Jae Ho; Choi, Sung Mook; Choi, Chul Young

    2015-11-01

    A polymer electrolyte membrane water electrolysis system can produce high-purity hydrogen gases in a highly efficient manner. However, the level of hydrogen gas production is still small. In addition, noble-metal catalysts for the reaction in acidic environments, as well as an additional drying step to remove water contained in the hydrogen, are required. Therefore, water electrolysis system with high efficiency and lower cost, an alkaline anion-exchange membrane system that can produce high-purity hydrogen without a noble-metal catalyst, is needed. Nano-size NiCo2O4 powders were prepared by using a sol-gel method to achieve an efficient and economical water electrolysis system. When the powder was calcined at 450 °C, the crystallinity and the cyclic voltammogram measurement showed the best values. In addition, the 15-wt.% polytetrafluoroethylene mixed NiCo2O4 powders exhibited the largest cyclic voltammetry active area and the highest oxygen evolution reaction activity with the appropriate stability.

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

    PubMed

    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.

  20. Radiation-Grafted Polymer Electrolyte Membranes for Water Electrolysis Cells: Evaluation of Key Membrane Properties.

    PubMed

    Albert, Albert; Barnett, Alejandro O; Thomassen, Magnus S; Schmidt, Thomas J; Gubler, Lorenz

    2015-10-14

    Radiation-grafted membranes can be considered an alternative to perfluorosulfonic acid (PFSA) membranes, such as Nafion, in a solid polymer electrolyte electrolyzer. Styrene, acrylonitrile, and 1,3-diisopropenylbenzene monomers are cografted into preirradiated 50 μm ethylene tetrafluoroethylene (ETFE) base film, followed by sulfonation to introduce proton exchange sites to the obtained grafted films. The incorporation of grafts throughout the thickness is demonstrated by scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) analysis of the membrane cross-sections. The membranes are analyzed in terms of grafting kinetics, ion-exchange capacity (IEC), and water uptake. The key properties of radiation-grafted membranes and Nafion, such as gas crossover, area resistance, and mechanical properties, are evaluated and compared. The plot of hydrogen crossover versus area resistance of the membranes results in a property map that indicates the target areas for membrane development for electrolyzer applications. Tensile tests are performed to assess the mechanical properties of the membranes. Finally, these three properties are combined to establish a figure of merit, which indicates that radiation-grafted membranes obtained in the present study are promising candidates with properties superior to those of Nafion membranes. A water electrolysis cell test is performed as proof of principle, including a comparison to a commercial membrane electrode assembly (MEA).

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

    SciTech Connect

    Kumta, Prashant

    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

  2. Conversion of sunlight into electrical power and photoassisted electrolysis of water in photoelectrochemical cells

    SciTech Connect

    Heller, A.

    1981-05-01

    The development of photoelectrochemical solar cells based on semiconductor liquid junctions is discussed. Over the past 6 years, the efficiency of solar energy conversion has increased from < 1% to 12%, and the operational life of these cells has increased from hours to months. Understanding the chemistry of surfaces and grain boundaries has made it possible to manipulate the position of the surface and grain boundary states and thus reduce losses due to electron-hole recombination. Cells exhibiting approx. 12% efficiency of conversion are: (1) chemisorbed Ru/sup 3 +/ ions on n-GaAs photoanodes; (2) diffused Ru/sup 3 +/ and Pb/sup 2 +/ into grain boundaries of polycrystalline n-GaAs films on graphite; (3) p-InP/VCl/sub 3/-VCl/sub 2/-HCl/C cell; and (4) p-InP(Ru)/HCl-KCl/Pt cell. Photoassisted electrolysis of water for conversion of solar energy to hydrogen using the last mentioned photoelectrochemical cell represents the most efficient system for solar energy conversion. 61 references are cited. (BLM)tic stainless steel is required to prevent stress corrosion cracking byd stuffs contamination in the USSR takes place in the framework of variations observed in separate countries of northern hemisphere.

  3. An analysis of degradation phenomena in polymer electrolyte membrane water electrolysis

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    The durability of a polymer electrolyte membrane (PEM) water electrolysis single cell, assembled with regular porous transport layers (PTLs) is investigated for just over 1000 h. We observe a significant degradation rate of 194 μV h-1 and conclude that 78% of the detectable degradation can be explained by an increase in ohmic resistance, arising from the anodic Ti-PTL. Analysis of the polarization curves also indicates a decrease in the anodic exchange current density, j0, that results from the over-time contamination of the anode with Ti species. Furthermore, the average Pt-cathode particle size increases during the test, but we do not believe this phenomenon makes a significant contribution to increased cell voltages. To validate the anode Ti-PTL as a crucial source of increasing resistance, a second cell is assembled using Pt-coated Ti-PTLs. This yields a substantially reduced degradation rate of only 12 μV h-1, indicating that a non-corroding anode PTL is vital for PEM electrolyzers. It is our hope that forthcoming tailored PTLs will not only contribute to fast progress on cost-efficient stacks, but also to its long-term application of PEM electrolyzers involved in industrial processes.

  4. Rapid biological synthesis of platinum nanoparticles using Ocimum sanctum for water electrolysis applications.

    PubMed

    Soundarrajan, C; Sankari, A; Dhandapani, P; Maruthamuthu, S; Ravichandran, S; Sozhan, G; Palaniswamy, N

    2012-06-01

    The leaf extract of Ocimum sanctum was used as a reducing agent for the synthesis of platinum nanoparticles from an aqueous chloroplatinic acid (H(2)PtCl(6)·6H(2)O). A greater conversion of platinum ions to nanoparticles was achieved by employing a tulsi leaf broth with a reaction temperature of 100 °C. Energy-dispersive absorption X-ray spectroscopy confirmed the platinum particles as major constituent in the reduction process. It is evident from scanning electron microscopy that the reduced platinum particles were found as aggregates with irregular shape. Fourier-transform infrared spectroscopy revealed that the compounds such as ascorbic acid, gallic acid, terpenoids, certain proteins and amino acids act as reducing agents for platinum ions reduction. X-ray diffraction spectroscopy suggested the associated forms of platinum with other molecules and the average particle size of platinum nanoparticle was 23 nm, calculated using Scherer equation. The reduced platinum showed similar hydrogen evolution potential and catalytic activity like pure platinum using linear scan voltammetry. This environmentally friendly method of biological platinum nanoparticles production increases the rates of synthesis faster which can potentially be used in water electrolysis applications.

  5. Technology Status: Fuel Cells and Electrolysis Cells

    NASA Technical Reports Server (NTRS)

    Mcbryar, H.

    1978-01-01

    The status of the baselined shuttle fuel cell as well as the acid membrane fuel cell and space-oriented water electrolysis technologies are presented. The more recent advances in the alkaline fuel cell technology area are the subject of a companion paper. A preliminary plan for the focusing of these technologies towards regenerative energy storage applications in the multi-hundred kilowatt range is also discussed.

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

    PubMed

    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.

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

    PubMed Central

    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 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. PMID:28345583

  8. Wind Electrolysis: Hydrogen Cost Optimization

    SciTech Connect

    Saur, G.; Ramsden, T.

    2011-05-01

    This report describes a hydrogen production cost analysis of a collection of optimized central wind based water electrolysis production facilities. The basic modeled wind electrolysis facility includes a number of low temperature electrolyzers and a co-located wind farm encompassing a number of 3MW wind turbines that provide electricity for the electrolyzer units.

  9. Electrolysis Performance Improvement and Validation Experiment

    NASA Technical Reports Server (NTRS)

    Schubert, Franz H.

    1992-01-01

    Viewgraphs on electrolysis performance improvement and validation experiment are presented. Topics covered include: water electrolysis: an ever increasing need/role for space missions; static feed electrolysis (SFE) technology: a concept developed for space applications; experiment objectives: why test in microgravity environment; and experiment description: approach, hardware description, test sequence and schedule.

  10. Hydrogen Generation From Electrolysis

    SciTech Connect

    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

  11. Express Electrolysis.

    ERIC Educational Resources Information Center

    Smithenry, Dennis; Gassman, Christopher; Goodridge, Brandon; Petersen, Tom

    1998-01-01

    Explains the process of student and teacher collaboration on a project to develop a faster electrolysis mechanism. Provides a good example of the problem-based approach to science instruction and curriculum. (DDR)

  12. 4 kW Test of Solid Oxide Electrolysis Stacks with Advanced Electrode-Supported Cells

    SciTech Connect

    J. E. O'Brien; X. Zhang; G. K. Housley; L. Moore-McAteer; G. Tao

    2012-06-01

    A new test stand has been developed at the Idaho National Laboratory for multi-kW testing of solid oxide electrolysis stacks. This test stand will initially be operated at the 4 KW scale. The 4 kW tests will include two 60-cell stacks operating in parallel in a single hot zone. The stacks are internally manifolded with an inverted-U flow pattern and an active area of 100 cm2 per cell. Process gases to and from the two stacks are distributed from common inlet/outlet tubing using a custom base manifold unit that also serves as the bottom current collector plate. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. Treated metallic interconnects with integral flow channels separate the cells and electrode gases. Sealing is accomplished with compliant mica-glass seals. A spring-loaded test fixture is used for mechanical stack compression. Due to the power level and the large number of cells in the hot zone, process gas flow rates are high and heat recuperation is required to preheat the cold inlet gases upstream of the furnace. Heat recuperation is achieved by means of two inconel tube-in-tube counter-flow heat exchangers. A current density of 0.3 A/cm2 will be used for these tests, resulting in a hydrogen production rate of 25 NL/min. Inlet steam flow rates will be set to achieve a steam utilization value of 50%. The 4 kW test will be performed for a minimum duration of 1000 hours in order to document the long-term durability of the stacks. Details of the test apparatus and initial results will be provided.

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

    SciTech Connect

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  15. Evidence for the electrolysis of water by atmospheric-pressure plasmas formed at the surface of aqueous solutions

    NASA Astrophysics Data System (ADS)

    Witzke, Megan; Rumbach, Paul; Go, David B.; Mohan Sankaran, R.

    2012-11-01

    The formation of atmospheric-pressure plasmas with liquid electrodes holds great importance for a number of emerging technologies and applications, yet fundamental questions remain about the nature of the interactions at the plasma/liquid interface. In particular, when the liquid serves as the anode, the plasma supplies gas-phase electrons to the liquid surface, and how these electrons interact with the liquid has not been fully explained. In this work, we present experimental evidence that in the case of water, plasma electrons are involved in electrolytic reactions leading to the conversion of protons (H+) to hydrogen gas. Reactions associated with water electrolysis are indirectly characterized by pH measurements that show qualitatively and quantitatively that the liquid at the plasma interface increases in basicity, consistent with the reduction of protons by plasma electrons. Mass spectrometry measurements confirm the evolution of hydrogen gas, directly providing evidence of water electrolysis. This work highlights the critical role that plasma electrons can play in plasma/liquid interactions with broad implications for any plasma system involving an aqueous electrode, including emerging applications in plasma medicine and plasma-liquid materials synthesis.

  16. Comparative studies on performance of radiation-induced and thermal cross-linked ion-exchange membrane for water electrolysis

    NASA Astrophysics Data System (ADS)

    Chakrabarty, Tina; Jasti, Amaranadh; Goel, N. K.; Shahi, Vinod K.; Sabharwal, Sunil

    2011-07-01

    Radiation-induced and thermal cross-linked sulfonated poly(ether sulfone) (SPS)-sulfonated poly(ether ether ketone) (SPK) composite ion-exchange membranes (SPS/SPK(γ) and SPS/SPK(T), respectively) were prepared. Their performances for water electrolysis were comparatively assessed. Thermal cross-linked membrane (SPS/SPK(T)) showed cross-linking of part functional groups (-SO 3H) and thus deterioration in membrane conductivity. While, radiation-induced cross-linked membrane (SPS/SPK(γ)) avoided any cross-linking between functional groups and thus conductivity. Electrolysis performances of these membranes were evaluated in comparison with Nafion117 membrane. Relatively low current efficiency (CE) for SPS/SPK and SPS/SPK(T) membranes was due to their high mass transfer (water) via electro-osmotic drag, which was negligible for SPS/SPK(γ) membrane. SPS/SPK(γ) membrane exhibited comparable stabilities and water splitting performance with Nafion117 membrane, which revealed its suitability as substitute for electrochemical applications.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed

    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.

  19. An Analysis of Methanol and Hydrogen Production via High-Temperature Electrolysis Using the Sodium Cooled Advanced Fast Reactor

    SciTech Connect

    Shannon M. Bragg-Sitton; Richard D. Boardman; Robert S. Cherry; Wesley R. Deason; Michael G. McKellar

    2014-03-01

    Integration of an advanced, sodium-cooled fast spectrum reactor into nuclear hybrid energy system (NHES) architectures is the focus of the present study. A techno-economic evaluation of several conceptual system designs was performed for the integration of a sodium-cooled Advanced Fast Reactor (AFR) with the electric grid in conjunction with wind-generated electricity. Cases in which excess thermal and electrical energy would be reapportioned within an integrated energy system to a chemical plant are presented. The process applications evaluated include hydrogen production via high temperature steam electrolysis and methanol production via steam methane reforming to produce carbon monoxide and hydrogen which feed a methanol synthesis reactor. Three power cycles were considered for integration with the AFR, including subcritical and supercritical Rankine cycles and a modified supercritical carbon dioxide modified Brayton cycle. The thermal efficiencies of all of the modeled power conversions units were greater than 40%. A thermal efficiency of 42% was adopted in economic studies because two of the cycles either performed at that level or could potentially do so (subcritical Rankine and S-CO2 Brayton). Each of the evaluated hybrid architectures would be technically feasible but would demonstrate a different internal rate of return (IRR) as a function of multiple parameters; all evaluated configurations showed a positive IRR. As expected, integration of an AFR with a chemical plant increases the IRR when “must-take” wind-generated electricity is added to the energy system. Additional dynamic system analyses are recommended to draw detailed conclusions on the feasibility and economic benefits associated with AFR-hybrid energy system operation.

  20. Vanadium nanobelts coated nickel foam 3D bifunctional electrode with excellent catalytic activity and stability for water electrolysis

    NASA Astrophysics Data System (ADS)

    Yu, Yu; Li, Pei; Wang, Xiaofang; Gao, Wenyu; Shen, Zongxu; Zhu, Yanan; Yang, Shuliang; Song, Weiguo; Ding, Kejian

    2016-05-01

    Pursuit of highly active, stable and low-cost electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key point for large-scale water splitting. A vanadium nanobelts coating on a nickel foam (V/NF) is proposed as an excellent 3D bifunctional electrode for water electrolysis here, which exhibits high activities with overpotentials of 292 and 176 mV at 10 mA cm-2 for OER and HER, respectively. When employed as a bifunctional electrocatalyst in an alkaline water electrolyzer, a cell voltage of 1.80 V was required to achieve 20 mA cm-2 with a slight increase during a 24 h durability test. The existence of the appropriate amount of nitrogen and oxygen elements in the surface region of vanadium nanobelts is regarded to be responsible for the electrocatalytic activity.Pursuit of highly active, stable and low-cost electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key point for large-scale water splitting. A vanadium nanobelts coating on a nickel foam (V/NF) is proposed as an excellent 3D bifunctional electrode for water electrolysis here, which exhibits high activities with overpotentials of 292 and 176 mV at 10 mA cm-2 for OER and HER, respectively. When employed as a bifunctional electrocatalyst in an alkaline water electrolyzer, a cell voltage of 1.80 V was required to achieve 20 mA cm-2 with a slight increase during a 24 h durability test. The existence of the appropriate amount of nitrogen and oxygen elements in the surface region of vanadium nanobelts is regarded to be responsible for the electrocatalytic activity. Electronic supplementary information (ESI) available: More SEM, TEM images, XRD patterns, LSV curves, XPS spectra. See DOI: 10.1039/c6nr02395a

  1. Advanced water recycling through electrochemical treatment of effluent from dissolved air flotation unit of food processing industry.

    PubMed

    Yoo, Sukjoon; Hsieh, Jeffery S

    2010-01-01

    This study elucidates the feasibility of electrochemical treatment as a water recycling process in the dissolved air flotation (DAF) unit in the food industry. Effects of operation parameters such as current density, electrolysis time, initial pH of effluent, and mixing process were investigated on the removal of COD, TSS, and TDS of the DAF pretreated effluent. An increase of current density enhances the removal rates and reduces the electrolysis time to reach the maximum performance. The initial pH less than 7 and the addition of mixing process were proven to increase the efficiency of EC treatment. About 80% of COD, 100% of TSS, and 60% of TDS were successfully removed at 500 mA current for 1 hour of electrolysis. The final treated effluent was found to meet the discharge standard from the US Environmental Protection Agency. It was concluded that EC process could be effective as an advanced water resourcing technology in the food industry.

  2. Advances in water resources technology

    NASA Astrophysics Data System (ADS)

    The presentation of technological advances in the field of water resources will be the focus of Advances in Water Resources Technology, a conference to be held in Athens, Greece, March 20-23, 1991. Organized by the European Committee for Water Resources Management, in cooperation with the National Technical University of Athens, the conference will feature state-of-the art papers, contributed original research papers, and poster papers. Session subjects will include surface water, groundwater, water resources conservation, water quality and reuse, computer modeling and simulation, real-time control of water resources systems, and institutions and methods for technology.The official language of the conference will be English. Special meetings and discussions will be held for investigating methods of effective technology transfer among European countries. For this purpose, a wide representation of research institutions, universities and companies involved in water resources technology will be attempted.

  3. Water electrolysis on La1-xSrxCoO3-δ perovskite electrocatalysts

    SciTech Connect

    Mefford, J. Tyler; Rong, Xi; Abakumov, Artem M.; Hardin, William G.; Dai, Sheng; Kolpak, Alexie; Johnston, Keith P.; Stevenson, Keith J.

    2016-03-23

    Here, perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B–O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co–O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1–xSrxCoO3–δ. We attempt to rationalize the high activities of La1–xSrxCoO3–δ through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis.

  4. Non-noble metal based electro-catalyst compositions for proton exchange membrane based water electrolysis and methods of making

    DOEpatents

    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.

  5. Electrocatalytic activities of cathode electrodes for water electrolysis using tetra-alkyl-ammonium-sulfonic acid ionic liquid as electrolyte

    NASA Astrophysics Data System (ADS)

    Fiegenbaum, Fernanda; de Souza, Michèle O.; Becker, Márcia R.; Martini, Emilse M. A.; de Souza, Roberto F.

    2015-04-01

    The hydrogen evolution reaction (HER) performed with platinum (Pt), nickel (Ni), stainless steel 304 (SS) or glassy carbon (GC) cathodes in 0.1 M 3-triethylammonium-propanesulfonic acid tetrafluoroborate (TEA-PS.BF4) solution is studied using quasi-potentiostatic and impedance spectroscopy techniques. The objective is to compare the catalytic effect on the cathode using different materials to obtain hydrogen by water electrolysis. Furthermore, the catalytic effect of the ionic liquid (IL) on the cathode compared with that of a hydrochloric acid (HCl) solution with same pH value (0.8) is reported. A low activation energy (Ea) of 8.7 kJ mol-1 is found for the glassy carbon cathode. Tafel plots obtained with TEA-PS.BF4 IL suggest the formation of an electroactive layer of IL on the cathode, which may be responsible for the catalytically enhanced performance observed.

  6. Solar generator performance with load matching to water electrolysis - Longterm averages and range of instantaneous efficiencies

    NASA Astrophysics Data System (ADS)

    Freudenberg, K.

    Performance results of a solar cell array coupled to a hydrogen producing electrolyzer are presented. The ultimate performance of the system is dependent on the cell efficiencies, the load matching, and the electrolyzer efficiency. An electronic simulation of an electrolyzer operation was connected to a solar cell array to determine the significant parameters over a six month operational period. Load matching losses, arising when the electrolysis does not draw power, were avoided by altering the system voltages. The array of 30 monocrystalline Si cells displayed a 10 pct efficiency with 800 W/sq m input at 293 K, average. The load matching was significantly influenced by the ambient temperature.Interposition of electrochemical cells in lesser amounts in low temperatures and greater amounts at high temperatures improved the overall system performance, which could be controlled to 8.9 pct losses over the lifetime of the experiment. The total system efficiency was calculated to be 8.0 pct.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Production of Oxygen from Lunar Regolith using Molten Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Sibille, Laurent; Sadoway, Donald R.; Sirk, Aislinn; Tripathy, Prabhat; Melendez, Orlando; Standish, Evan; Dominquez, Jesus A.; Stefanescu, Doru M.; Curreri, Peter A.; Poizeau, Sophie

    2009-01-01

    This slide presentation reviews the possible use of molten oxide electrolysis to extract oxygen from the Lunar Regolith. The presentation asserts that molten regolith electrolysis has advanced to be a useful method for production of oxygen and metals in situ on the Moon. The work has demonstrated an 8 hour batch of electrolysis at 5 amps using Iridium inert anodes.

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

    NASA Technical Reports Server (NTRS)

    Diderich, Greg S.; Roy, Robert J.; Steele, John W.; Van Keuren, Steven P.; Wilson, Mark E.

    2010-01-01

    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 resistance resulting in higher cell voltages and a shorter cell life. A microbial challenge test was performed on duplicate single liquid cathode feed electrolyzer 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.

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

    PubMed

    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, <200mg/L) by ED, at the optimal conditions of voltage 40 V and 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%.

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

    SciTech Connect

    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

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

    PubMed

    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.

  13. Complete degradation of Orange G by electrolysis in sub-critical water.

    PubMed

    Yuksel, Asli; Sasaki, Mitsuru; Goto, Motonobu

    2011-06-15

    Complete degradation of azo dye Orange G was studied using a 500 mL continuous flow reactor made of SUS 316 stainless steel. In this system, a titanium reactor wall acted as a cathode and a titanium plate-type electrode was used as an anode in a subcritical reaction medium. This hydrothermal electrolysis process provides an environmentally friendly route that does not use any organic solvents or catalysts to remove organic pollutants from wastewater. Reactions were carried out from 30 to 90 min residence times at a pressure of 7 MPa, and at different temperatures of 180-250°C by applying various direct currents ranging from 0.5 to 1A. Removal of dye from the product solution and conversion of TOC increased with increasing current value. Moreover, the effect of salt addition on degradation of Orange G and TOC conversion was investigated, because in real textile wastewater, many salts are also included together with dye. Addition of Na(2)CO(3) resulted in a massive degradation of the dye itself and complete mineralization of TOC, while NaCl and Na(2)SO(4) obstructed the removal of Orange G. Greater than 99% of Orange G was successfully removed from the product solution with a 98% TOC conversion.

  14. Hydrogen production from inexhaustible supplies of fresh and salt water using microbial reverse-electrodialysis electrolysis cells

    PubMed Central

    Kim, Younggy; Logan, Bruce E.

    2011-01-01

    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 H2 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 H2 production rate increased from 0.8 to 1.6 m3-H2/m3-anolyte/day for seawater and river water flow rates ranging from 0.1 to 0.8 mL/ min. H2 recovery, the ratio of electrons used for H2 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 (MoS2) demonstrated H2 production at a rate of 0.8 m3/m3/d and an energy efficiency of 51%. These results show that pure H2 gas can efficiently be produced from virtually limitless supplies of seawater and river water, and biodegradable organic matter. PMID:21930953

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Phase transformation of the brownmillerite SrCoO2.5 thin film through alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Tambunan, Octolia Togibasa; Lee, Min Young; Kim, Deok Hyeon; Parwanta, Kadek Juliana; Jung, Chang Uk

    2014-06-01

    A phase transformation from insulating brownmillerite SrCoO2.5 to conducting perovskite SrCoO3 through electrochemical oxidation has been demonstrated for thin films of SrCoOx on a SrTiO3 (001) substrate. The cobalt-oxide film strongly favors the brownmillerite phase of SrCoO2.5 instead of the perovskite phase of SrCoO3 on a SrTiO3 (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 SrCoO2.5 film anode. The H+ ions are attracted to the cathode and generate H2 gas. The OH- ions are attracted to the film's surface and generate a rich amount of oxygen to fill the oxygen vacancy channel of brownmillerite SrCoO2.5. 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.

  17. RESEARCH OF ELECTROLYSIS CELL-FUEL CELL METHOD OF RECOVERING POTABLE WATER FROM URINE (PROJECT ELF)

    DTIC Science & Technology

    fuel cell so that oxygen and hydrogen which are electrolyzed from human urine recombine in the fuel cell to yield potable water and power. The latter, in turn, will satisfy some of the power require ents of the electrolyll. The experimental laboratory systems were synthesized from latest ion-exchange membrane technology, and produced water that is both chemically and bacteriologically well within limits of the 1961 U.S. Public Health Standards for Drinking Water. The system has high yield (98% of available water content), long operating life (37 days

  18. Space Station propulsion electrolysis system - 'A technology challenge'

    NASA Technical Reports Server (NTRS)

    Le, Michael

    1989-01-01

    The Space Station propulsion system will utilize a water electrolysis system to produce the required eight-to-one ratio of gaseous hydrogen and oxygen propellants. This paper summarizes the state of the art in water electrolysis technologies and the supporting development programs at the NASA Lyndon B. Johnson Space Center. Preliminary proof of concept test data from a fully integrated propulsion testbed are discussed. The technical challenges facing the development of the high-pressure water electrolysis system are discussed.

  19. Development of an electrolysis system for tritium enrichment in superficial water samples.

    PubMed

    Garbarino, G; Magnoni, M; Bertino, S; Losana, M C

    2009-12-01

    Tritium present in the environment gradually decreased in the last decades and nowadays it has reached extremely low activity concentrations. The purpose of the present work is the implementation of a tritium enrichment system in water samples using electrolytic techniques and pure nickel and iron electrodes. In the present work a mean tritium enrichment factor of 13.0 +/- 3.2 was obtained. This result should allow to reach a minimum detectable activity of tritium in water samples of about 1 tritium unit (TU) or less. The present enrichment system necessitates further adjustments and improvements, such as a cooling system in order to reduce the tritium losses due to evaporation.

  20. Highlights from Faraday Discussion 182: Solid Oxide Electrolysis: Fuels and Feedstocks from Water and Air, York, UK, July 2015.

    PubMed

    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.

  1. Effect of Morphology of Co3O4 for Oxygen Evolution Reaction in Alkaline Water Electrolysis

    PubMed Central

    Xu, Qi-Zhi; Xu, Qi-Zhi; Su, Yu-Zhi; Wu, Hao; Cheng, Hui; Hui, Yun-Ping; Li, Nan; Liu, Zhao-Qing

    2014-01-01

    In this paper, three different morphological Co3O4 electrodes for oxygen evolution reaction (OER) have been synthesized. By comparing the three morphologies of Co3O4, the electrocatalytic properties show that the urchin-like spheres of Co3O4 electrode has relative low overpotential and good electrocatalysis stability, indicating that the structure of urchin-like Co3O4 spheres exhibit an easy OER for water splitting. PMID:25525423

  2. Stability and Degradation Mechanisms of Radiation-Grafted Polymer Electrolyte Membranes for Water Electrolysis.

    PubMed

    Albert, Albert; Lochner, Tim; Schmidt, Thomas J; Gubler, L

    2016-06-22

    Radiation-grafted membranes are a promising alternative to commercial membranes for water electrolyzers, since they exhibit lower hydrogen crossover and area resistance, better mechanical properties, and are of potentially lower cost than perfluoroalkylsulfonic acid membranes, such as Nafion. Stability is an important factor in view of the expected lifetime of 40 000 h or more of an electrolyzer. In this study, combinations of styrene (St), α-methylstyrene (AMS), acrylonitrile (AN), and 1,3-diisopropenylbenzene (DiPB) are cografted into 50 μm preirradiated poly(ethylene-co-tetrafluoroethylene) (ETFE) base film, followed by sulfonation to produce radiation-grafted membranes. The stability of the membranes with different monomer combinations is compared under an accelerated stress test (AST), and the degradation mechanisms are investigated. To mimic the conditions in an electrolyzer, in which the membrane is always in contact with liquid water at elevated temperature, the membranes are immersed in water for 5 days at 90 °C, so-called thermal stress test (TST). In addition to testing in air atmosphere tests are also carried out under argon to investigate the effect of the absence of oxygen. The water is analyzed with UV-vis spectroscopy and ion chromatography. The ion exchange capacity (IEC), swelling degree, and Fourier transform infrared (FTIR) spectra of the membranes are compared before and after the test. Furthermore, energy-dispersive X-ray (EDX) spectroscopic analysis of the membrane cross-section is performed. Finally, the influence of the TST to the membrane area resistance and hydrogen crossover is measured. The stability increases along the sequence St/AN, St/AN/DiPB, AMS/AN, and AMS/AN/DiPB grafted membrane. The degradation at the weak-link, oxygen-induced degradation, and hydrothermal degradation are proposed in addition to the "swelling-induced detachment" reported in the literature. By mitigating the possible paths of degradation, the AMS

  3. A preliminary investigation of cold fusion by electrolysis of heavy water

    NASA Astrophysics Data System (ADS)

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

    1989-11-01

    Several tests have been made with electrolytic cells utilizing 0.1 to 0.2 N LiOD in D2O as the electrolyte and a palladium cathode surrounded by a wire-wound platinum anode operating at cathode current densities of 100 to 600 mA/sq cm. The cathodes were swaged to diameters of 2.8 or 5.5 mm with 8.0 to 8.5 cm of active length and then annealed in some tests. The electrolyte temperature was controlled and heat was removed by flowing water in a cooling jacket, and the cell was insulated. Cooling water and electrolyte temperatures were determined by thermocouples; neutron and gamma-ray spectra were measured; and the electrolyte was periodically analyzed for tritium. In one test, an internal wire coil of platinum coated with palladium black was used in a closed system to recombine the electrolytically generated D2 and O2 without release of any off-gas. The electrolyte was periodically sampled and electrolyte of the nominal concentration was added to replace the volume withdrawn; makeup D2O was also added, when required, in those experiments which did not include a recombiner. Neutron and gamma-ray spectra were recorded on magnetic media; temperatures, coolant flow rate, and voltages were recorded and, in the last two experiments, acquired by a computer data acquisition system. Tests up to 1000 h in duration were made, and in some experiments excess power was detected for periods of many hours, usually in the range of 5 to 15 percent. However, during one 12-h period, excess power of up to 50 percent was observed. On three separate occasions, the neutron count rate exceeded the background by three standard deviations; in addition, an apparent transient increase of tritium in the electrolyte by at least a factor of 25 occurred during one test.

  4. A preliminary investigation of cold fusion by electrolysis of heavy water

    SciTech Connect

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

    1989-11-01

    Several tests have been made with electrolytic cells utilizing 0.1 to 0.2 N LiOD in D{sub 2}O as the electrolyte and a palladium cathode surrounded by a wire-wound platinum anode operating at cathode current densities of 100 to 600 mA/cm{sup 2}. The cathodes were swaged to diameters of 2.8 or 5.5 mm with 8.0 to 8.5 cm of active length and then annealed in some tests. The electrolyte temperature was controlled and heat was removed by flowing water in a cooling jacket, and the cell was insulated. Cooling water and electrolyte temperatures were determined by thermocouples; neutron and gamma-ray spectra were measured; and the electrolyte was periodically analyzed for tritium. In one test, an internal wire coil of platinum coated with palladium black was used in a closed system to recombine the electrolytically generated D{sub 2} and O{sub 2} without release of any off-gas. The electrolyte was periodically sampled and electrolyte of the nominal concentration was added to replace the volume withdrawn; makeup D{sub 2}O was also added, when required, in those experiments which did not include a recombiner. Neutron and gamma-ray spectra were recorded on magnetic media; temperatures, coolant flow rate, and voltages were recorded and, in the last two experiments, acquired by a computer data acquisition system. Tests up to 1000 h in duration were made, and in some experiments excess power was detected for periods of many hours, usually in the range of 5 to 15%. However, during one 12-h period, excess power of up to 50% was observed. On three separate occasions, the neutron count rate exceeded the background by three standard deviations; in addition, an apparent transient increase of tritium in the electrolyte by at least a factor of 25 occurred during one test. 8 refs., 14 figs., 3 tabs.

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

    NASA Astrophysics Data System (ADS)

    Chanda, Debabrata; Hnát, Jaromír; Paidar, Martin; Schauer, Jan; Bouzek, Karel

    2015-07-01

    NiFe2O4 electrocatalyst for the hydrogen evolution reaction (HER) has been synthesized using the co-precipitation method of the respective metal ions from water solution. After calcination of the precipitate, the resulting electrocatalyst was characterized by a broad range of techniques to obtain information on its crystallographic structure, specific surface area, morphology and chemical composition. The electrocatalytic activity towards HER in alkaline water electrolysis was investigated by means of linear sweep voltammetry. The catalyst showed promising electrocatalytic properties. Subsequently three types of binders were used to prepare a cathode catalytic layer based on a catalyst synthesized on top of a nickel foam support, namely an anion-selective quaternized poly(phenylene oxide) (qPPO) ionomer, an electroneutral polymer polytetrafluoroethylene and cation-selective Nafion®. The resulting membrane-electrode assemblies (MEAs), based on an anion-selective membrane, were tested in an alkaline water electrolyzer. In a single-cell test the MEA with a qPPO ionomer exhibited higher HER activity compared to the remaining binders tested. The current density obtained using a MEA containing qPPO binder attained a value of 125 mA cm-2 at a cell voltage of 1.85 V. The stability of the MEA containing qPPO binder was examined by continuous operation for 143 h, followed by 55 h intermittent electrolysis.

  6. Advanced Raman water vapor lidar

    NASA Technical Reports Server (NTRS)

    Whiteman, David N.; Melfi, S. Harvey; Ferrare, Richard A.; Evans, Keith A.; Ramos-Izquierdo, Luis; Staley, O. Glenn; Disilvestre, Raymond W.; Gorin, Inna; Kirks, Kenneth R.; Mamakos, William A.

    1992-01-01

    Water vapor and aerosols are important atmospheric constituents. Knowledge of the structure of water vapor is important in understanding convective development, atmospheric stability, the interaction of the atmosphere with the surface, and energy feedback mechanisms and how they relate to global warming calculations. The Raman Lidar group at the NASA Goddard Space Flight Center (GSFC) developed an advanced Raman Lidar for use in measuring water vapor and aerosols in the earth's atmosphere. Drawing on the experience gained through the development and use of our previous Nd:YAG based system, we have developed a completely new lidar system which uses a XeF excimer laser and a large scanning mirror. The additional power of the excimer and the considerably improved optical throughput of the system have resulted in approximately a factor of 25 improvement in system performance for nighttime measurements. Every component of the current system has new design concepts incorporated. The lidar system consists of two mobile trailers; the first (13m x 2.4m) houses the lidar instrument, the other (9.75m x 2.4m) is for system control, realtime data display, and analysis. The laser transmitter is a Lambda Physik LPX 240 iCC operating at 400 Hz with a XeF gas mixture (351 nm). The telescope is a .75m horizontally mounted Dall-Kirkham system which is bore sited with a .8m x 1.1m elliptical flat which has a full 180 degree scan capability - horizon to horizon within a plane perpendicular to the long axis of the trailer. The telescope and scan mirror assembly are mounted on a 3.65m x .9m optical table which deploys out the rear of the trailer through the use of a motor driven slide rail system. The Raman returns from water vapor (403 nm), nitrogen (383 nm) and oxygen (372 nm) are measured in addition to the direct Rayleigh/Mie backscatter (351). The signal from each of these is split at about a 5/95 ratio between two photomultiplier detectors. The 5 percent detector is used for

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

    NASA Astrophysics Data System (ADS)

    Sahu, Omprakash

    2016-06-01

    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.

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

    PubMed

    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.

  9. Time-Dependent Changes in Morphology and Composition of Solid Particles Collected From Heavy Water Electrolyte after Electrolysis with a Palladium Cathode

    NASA Astrophysics Data System (ADS)

    Dash, John; Wang, Q.

    2009-03-01

    Recently, we have observed particles floating on the surfaces of electrolytes after electrolysis, in four cells, each of which contained a heavy water electrolyte and a Pd cathode. Solid particles were unexpected from electrolysis, so it seemed important to characterize these particles. Cu grids were used to collect particles from the electrolyte surface. Then, a scanning electron microscope ( SEM ) and an energy dispersive spectrometer ( EDS ) were used to study the surfaces of these particles and to record time-dependent changes which were occurring. The morphology and composition of the particles were determined . After storage at ambient for 11 days, there were large changes in the morphology and composition of the particles. For example, one portion of the particles contained a large number of microspheres. A typical microsphere contained mostly carbon and palladium, whereas the matrix near the microsphere contained mostly palladium with less carbon and a significant amount of silver. One day later the same microsphere had increased carbon and reduced palladium, but there was no significant change in the composition of the matrix. Results for other particles from other cells will also be presented.

  10. 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.

    PubMed

    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.

  11. Anodes for alkaline electrolysis

    DOEpatents

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  12. Morphology-Controllable Synthesis of Zn-Co-Mixed Sulfide Nanostructures on Carbon Fiber Paper Toward Efficient Rechargeable Zinc-Air Batteries and Water Electrolysis.

    PubMed

    Wu, Xiaoyu; Han, Xiaopeng; Ma, Xiaoya; Zhang, Wei; Deng, Yida; Zhong, Cheng; Hu, Wenbin

    2017-04-12

    It remains an ongoing challenge to develop cheap, highly active, and stable electrocatalysts to promote the sluggish electrocatalytic oxygen evolution, oxygen reduction, and hydrogen evolution reactions for rechargeable metal-air batteries and water-splitting systems. In this work, we report the morphology-controllable synthesis of zinc cobalt mixed sulfide (Zn-Co-S) nanoarchitectures, including nanosheets, nanoplates, and nanoneedles, grown on conductive carbon fiber paper (CFP) and the micronanostructure dependent electrochemical efficacy for catalyzing hydrogen and oxygen in zinc-air batteries and water electrolysis. The formation of different Zn-Co-S morphologies was attributed to the synergistic effect of decomposed urea products and the corrosion of NH4F. Among synthesized Zn-Co-S nanostructures, the nanoneedle arrays supported on CFP exhibit superior trifunctional activity for oxygen reduction, oxygen evolution, and hydrogen evolution reactions than its nanosheet and nanoplate counterparts through half reaction testing. It also exhibited better catalytic durability than Pt/C and RuO2. Furthermore, the Zn-Co-S nanoneedle/CFP electrode enables rechargeable Zn-air batteries with low overpotential (0.85 V), high efficiency (58.1%), and long cycling lifetimes (200 cycles) at 10 mA cm(-2) as well as considerable performance for water splitting. The superior performance is contributed to the integrated nanoneedle/CFP nanostructure, which not only provides enhanced electrochemical active area, but also facilitates ion and gas transfer between the catalyst surface and electrolyte, thus maintaining an effective solid-liquid-gas interface necessary for electrocatalysis. These results indicate that the Zn-Co-S nanoneedle/CFP system is a low cost, highly active, and durable electrode for highly efficient rechargeable zinc-air batteries and water electrolysis in alkaline solution.

  13. Performance of photovoltaic electrolysis system

    NASA Astrophysics Data System (ADS)

    Esteve, D.; Ganibal, C.; Steinmetz, D.; Vialaron, A.

    A photovoltaic generator with concentrated light is combined with a water electrolysis cell in an effort to further the development of solar energy utilization. SOPHOCLE, a photovoltaic generator with limited concentration of energy, is a heliostat of the altazimuth type, consisting of an optical device to focus the sunlight on the photocells, a tracking device to follow the position of the sun, and a cooling device to allow dissipation of thermal energy. The combined cost and performance of SOPHOCLE gives an overall efficiency of 9 percent (for direct solar radiation). A power conditioning device matches the generator photocell characteristics with the electrolysis cell to give maximum hydrogen production. Hydrogen can be produced by this method with an overall efficiency of 7 percent.

  14. Solid oxide electrolysis: Concluding remarks.

    PubMed

    Jun, Areum; Ju, Young-Wan; Kim, Guntae

    2015-01-01

    Renewable energy resources such as solar energy, wind energy, hydropower or geothermal energy have attracted significant attention in recent years. Renewable energy sources have to match supply with demand, therefore it is essential that energy storage devices (e.g., secondary batteries) are developed. However, secondary batteries are accompanied with critical problems such as high cost for the limited energy storage capacity and loss of charge over time. Energy storage in the form of chemical species, such as H2 or CO2, have no constraints on energy storage capacity and will also be essential. When plentiful renewable energy exists, for example, it could be used to convert H2O into hydrogen via water electrolysis. Also, renewable energy resources could be used to reduce CO2 into CO and recycle CO2 and H2O into sustainable hydrocarbon fuels in solid oxide electrolysis (SOE).

  15. Some Aspects of PDC Electrolysis

    NASA Astrophysics Data System (ADS)

    Poláčik, Ján; Pospíšil, Jiří

    2016-10-01

    In this paper, aspects of pulsed direct current (PDC) water splitting are described. Electrolysis is a simple and well-known method to produce hydrogen. The efficiency is relatively low in normal conditions using conventional DC. PDC in electrolysis brings about many advantages. It increases efficiency of hydrogen production, and performance of the electrolyser may be smoothly controlled without compromising efficiency of the process. In our approach, ultra-short pulses are applied. This method enhances efficiency of electrical energy in the process of decomposition of water into hydrogen and oxygen. Efficiency depends on frequency, shape and width of the electrical pulses. Experiments proved that efficiency was increased by 2 to 8 per cent. One of the prospects of PDC electrolysis producing hydrogen is in increase of efficiency of energy storage efficiency in the hydrogen. There are strong efforts to make the electrical grid more efficient and balanced in terms of production by installing electricity storage units. Using hydrogen as a fuel decreases air pollution and amount of carbon dioxide emissions in the air. In addition to energy storage, hydrogen is also important in transportation and chemical industry.

  16. Advanced water iodinating system. [for potable water aboard manned spacecraft

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    Potable water stores aboard manned spacecraft must remain sterile. Suitable sterilization techniques are needed to prevent microbial growth. The development of an advanced water iodinating system for possible application to the shuttle orbiter and other advanced spacecraft, is considered. The AWIS provides a means of automatically dispensing iodine and controlling iodination levels in potable water stores. In a recirculation mode test, simulating application of the AWIS to a water management system of a long term six man capacity space mission, noniodinated feed water flowing at 32.2 cu cm min was iodinated to 5 + or - ppm concentrations after it was mixed with previously iodinated water recirculating through a potable water storage tank. Also, the AWIS was used to successfully demonstrate its capability to maintain potable water at a desired I2 concentration level while circulating through the water storage tank, but without the addition of noniodinated water.

  17. EPA Water Strategy: Advancing Technologies

    EPA Science Inventory

    National Risk Management Research Laboratory conducts innovative research to manage contaminants in water supplies that pose a threat to human health and the environment, and to develop approaches and tools to monitor, treat, characterize, protect, and restore impaired waterways,...

  18. Next Steps: Water Technology Advances (Research)

    EPA Science Inventory

    This project will focus on contaminants and their impact on health, adequate removal of contaminants from various water systems, and water and resource recovery within treatment systems. It will develop the next generation of technological advances to provide guidance in support ...

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

    SciTech Connect

    James E. O'Brien

    2010-08-01

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

  20. Advanced Water Purification System for In Situ Resource Utilization

    NASA Technical Reports Server (NTRS)

    Anthony, Stephen M.; Jolley, Scott T.; Captain, James G.

    2013-01-01

    A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extraterrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtration material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removal technique. Our studies have shown a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

  1. Advanced Water Purification System for In Situ Resource Utilization Project

    NASA Technical Reports Server (NTRS)

    Anthony, Stephen M.

    2014-01-01

    A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extratrrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtrtion material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removable technique. Our studies have show a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

  2. Advanced piggyback water power generator

    SciTech Connect

    Wiggs, B.R.

    1988-02-16

    A power generating system is described including: a central boat containing gearing and electric and/or power generation equipment, with a forward angled-back deflection screen and a rear non-angled deflection screen, with a smaller outrigger pontoon on each respective side of the central boat, with closed cell, waterproof, plastic foam filling in the central boat and pontoons, and with the bow of the respective outrigger pontoons angled so as to completely turn water away from, and to the outside of, the space and/or incoming water area between each such respective pontooon and the central boat. There are legs with cone shaped bottoms and with wheels attached, with the wheels extending slightly below the cone shaped bottoms; paddle wheels on each side of the central boat, between the central boat, and respective outrigger pontoons, with 90 degree spaced, flat, paddle blades, and with a solid, disk division vertically dividing each respective side paddle wheel in half and extending at right angles to, and from, the central axle, to the outside extreme end of the paddle blades, with each such half of the equally divided paddle wheel being constructed so that the 90 degree spaced paddle blades in one half are offset by 45 degrees from the 90 degree space paddle blades in the other half, and with the extreme ends of each such set of divided paddle wheels being enclosed via a similar solid.

  3. Bipolar Electrochemistry for Concurrently Evaluating the Stability of Anode and Cathode Electrocatalysts and the Overall Cell Performance during Long-Term Water Electrolysis.

    PubMed

    Eßmann, Vera; Barwe, Stefan; Masa, Justus; Schuhmann, Wolfgang

    2016-09-06

    Electrochemical efficiency and stability are among the most important characteristics of electrocatalysts. These parameters are usually evaluated separately for the anodic and cathodic half-cell reactions in a three-electrode system or by measuring the overall cell voltage between the anode and cathode as a function of current or time. Here, we demonstrate how bipolar electrochemistry can be exploited to evaluate the efficiency of electrocatalysts for full electrochemical water splitting while simultaneously and independently monitoring the individual performance and stability of the half-cell electrocatalysts. Using a closed bipolar electrochemistry setup, all important parameters such as overvoltage, half-cell potential, and catalyst stability can be derived from a single galvanostatic experiment. In the proposed experiment, none of the half-reactions is limiting on the other, making it possible to precisely monitor the contribution of the individual half-cell reactions on the durability of the cell performance. The proposed approach was successfully employed to investigate the long-term performance of a bifunctional water splitting catalyst, specifically amorphous cobalt boride (Co2B), and the durability of the electrocatalyst at the anode and cathode during water electrolysis. Additionally, by periodically alternating the polarization applied to the bipolar electrode (BE) modified with a bifunctional oxygen electrocatalyst, it was possible to explicitly follow the contributions of the oxygen reduction (ORR) and the oxygen evolution (OER) half-reactions on the overall long-term durability of the bifunctional OER/ORR electrocatalyst.

  4. Advanced Atmospheric Water Vapor DIAL Detection System

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Elsayed-Ali, Hani E.; DeYoung, Russell J. (Technical Monitor)

    2000-01-01

    Measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The remote sensing Differential Absorption Lidar (DIAL) technique is a powerful method to perform such measurement from aircraft and space. This thesis describes a new advanced detection system, which incorporates major improvements regarding sensitivity and size. These improvements include a low noise advanced avalanche photodiode detector, a custom analog circuit, a 14-bit digitizer, a microcontroller for on board averaging and finally a fast computer interface. This thesis describes the design and validation of this new water vapor DIAL detection system which was integrated onto a small Printed Circuit Board (PCB) with minimal weight and power consumption. Comparing its measurements to an existing DIAL system for aerosol and water vapor profiling validated the detection system.

  5. A study on the electrolysis of sulfur dioxide and water for the sulfur cycle hydrogen production process

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Experimental electrolysis cells using various platinum catalyzed carbon electrodes were tested. When operated at 200 mA/sq cm current density using 50 w/o acid at 50 C and 1 atm, a reference cell required 1.22 volts and degraded rapidly. After several improvements were incorporated into electrodes and the test cell configuration, a later cell required only 0.77 volts under identical operating conditions. At a lower current density, 100 mA/sq cm, the cell required only 0.63 volts. Kinetic studies on metal electrodes, measurements of temperature effects on electrode kinetics, investigations of electrocatalytic activities of metal electrodes over a wide range of acid concentrations, cyclic voltametric studies and evaluation of alternate catalysts were also conducted. From diffusivity experiments, a cation exchange membrane material, P-4010, exhibited an excellent diffusion coefficient, more than two orders of magnitude lower than that of rubber. Ionic resistivity measurements of eight materials showed that microporous rubber had the lowest resistivity.

  6. Advancing Water Science through Data Visualization

    NASA Astrophysics Data System (ADS)

    Li, X.; Troy, T.

    2014-12-01

    As water scientists, we are increasingly handling larger and larger datasets with many variables, making it easy to lose ourselves in the details. Advanced data visualization will play an increasingly significant role in propelling the development of water science in research, economy, policy and education. It can enable analysis within research and further data scientists' understanding of behavior and processes and can potentially affect how the public, whom we often want to inform, understands our work. Unfortunately for water scientists, data visualization is approached in an ad hoc manner when a more formal methodology or understanding could potentially significantly improve both research within the academy and outreach to the public. Firstly to broaden and deepen scientific understanding, data visualization can allow for more analyzed targets to be processed simultaneously and can represent the variables effectively, finding patterns, trends and relationships; thus it can even explores the new research direction or branch of water science. Depending on visualization, we can detect and separate the pivotal and trivial influential factors more clearly to assume and abstract the original complex target system. Providing direct visual perception of the differences between observation data and prediction results of models, data visualization allows researchers to quickly examine the quality of models in water science. Secondly data visualization can also improve public awareness and perhaps influence behavior. Offering decision makers clearer perspectives of potential profits of water, data visualization can amplify the economic value of water science and also increase relevant employment rates. Providing policymakers compelling visuals of the role of water for social and natural systems, data visualization can advance the water management and legislation of water conservation. By building the publics' own data visualization through apps and games about water

  7. Advance prototype silver ion water bactericide system

    NASA Technical Reports Server (NTRS)

    Jasionowski, W. J.; Allen, E. T.

    1974-01-01

    An advance prototype unit was designed and fabricated to treat anticipated fuel cell water. The unit is a single canister that contains a membrane-type prefilter and a silver bromide contacting bed. A seven day baseline simulated mission test was performed; the performance was satisfactory and the effluent water was within all specifications for potability. After random vibrations another seven day simulated mission test was performed, and results indicate that simulated launch vibrations have no effects on the design and performance of the advanced prototype. Bench tests and accelerated breadboard tests were conducted to define the characteristics of an upgraded model of the advance prototype unit which would have 30 days of operating capability. A preliminary design of a silver ion generator for the shuttle orbiter was also prepared.

  8. NTTC Course 315: Advanced Water Examination.

    ERIC Educational Resources Information Center

    Department of the Navy, Washington, DC.

    This publication is the examination booklet used for a home study course in water treatment. This course is the advanced part of a series produced by the Department of the Navy. This publication is designed to be used in conjunction with a course textbook. Each of the four examinations contained in this document are referenced to a specific…

  9. Thermodynamics and Transport Phenomena in High Temperature Steam Electrolysis Cells

    SciTech Connect

    James E. O'Brien

    2012-03-01

    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. 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. An overview of high temperature electrolysis technology will be presented, including basic thermodynamics, experimental methods, heat and mass transfer phenomena, and computational fluid dynamics modeling.

  10. X-ray Photoelectron Spectroscopy ofGaP_{1-x}N_x Photocorroded as a Result of Hydrogen Productionthrough Water Electrolysis

    SciTech Connect

    Mayer, Marie A.; /Illinois U., Urbana /SLAC

    2006-09-27

    Photoelectrochemical (PEC) cells produce hydrogen gas through the sunlight driven electrolysis of water. By extracting hydrogen and oxygen from water and storing solar energy in the H-H bond, they offer a promising renewable energy technology. Addition of dilute amounts of nitrogen to III-V semiconductors has been shown to dramatically increase the stability of these materials for hydrogen production. In an effort to learn more about the origin of semiconductor photocorrosion in PEC cells, three samples of p-type GaP with varying levels of nitrogen content (0%, 0.2%, 2%) were photocorroded and examined by X-ray Photoelectron Spectroscopy (XPS). GaPN samples were observed to be more efficient during the hydrogen production process than the pure GaP samples. Sample surfaces contained gallium oxides in the form of Ga{sub 2}O{sub 3} and Ga(OH){sub 3} and phosphorus oxide (P{sub 2}O{sub 5}), as well as surface oxides from exposure to air. A significant shift in intensity from bulk to surface peaks dramatic nitrogen segregation to the surface during photoelectrochemical hydrogen production. Further investigations, including using a scanning electron microscope to investigate sample topography and inductively coupled plasma mass spectroscopy (ICP-MS) analysis for solution analyses, are under way to determine the mechanism for these changes.

  11. Advancing Water Science through Improved Cyberinfrastructure

    NASA Astrophysics Data System (ADS)

    Koch, B. J.; Miles, B.; Rai, A.; Ahalt, S.; Band, L. E.; Minsker, B.; Palmer, M.; Williams, M. R.; Idaszak, R.; Whitton, M. C.

    2012-12-01

    Major scientific advances are needed to help address impacts of climate change and increasing human-mediated environmental modification on the water cycle at global and local scales. However, such advances within the water sciences are limited in part by inadequate information infrastructures. For example, cyberinfrastructure (CI) includes the integrated computer hardware, software, networks, sensors, data, and human capital that enable scientific workflows to be carried out within and among individual research efforts and across varied disciplines. A coordinated transformation of existing CI and development of new CI could accelerate the productivity of water science by enabling greater discovery, access, and interoperability of data and models, and by freeing scientists to do science rather than create and manage technological tools. To elucidate specific ways in which improved CI could advance water science, three challenges confronting the water science community were evaluated: 1) How does ecohydrologic patch structure affect nitrogen transport and fate in watersheds?, 2) How can human-modified environments emulate natural water and nutrient cycling to enhance both human and ecosystem well-being?, 3) How do changes in climate affect water availability to support biodiversity and human needs? We assessed the approaches used by researchers to address components of these challenges, identified barriers imposed by limitations of current CI, and interviewed leaders in various water science subdisciplines to determine the most recent CI tools employed. Our preliminary findings revealed four areas where CI improvements are likely to stimulate scientific advances: 1) sensor networks, 2) data quality assurance/quality control, 3) data and modeling standards, 4) high performance computing. In addition, the full potential of a re-envisioned water science CI cannot be realized without a substantial training component. In light of these findings, we suggest that CI

  12. Electrolysis-based diaphragm actuators

    NASA Astrophysics Data System (ADS)

    Pang, C.; Tai, Y.-C.; Burdick, J. W.; Andersen, R. A.

    2006-02-01

    This work presents a new electrolysis-based microelectromechanical systems (MEMS) diaphragm actuator. Electrolysis is a technique for converting electrical energy to pneumatic energy. Theoretically electrolysis can achieve a strain of 136 000% and is capable of generating a pressure above 200 MPa. Electrolysis actuators require modest electrical power and produce minimal heat. Due to the large volume expansion obtained via electrolysis, small actuators can create a large force. Up to 100 µm of movement was achieved by a 3 mm diaphragm. The actuator operates at room temperature and has a latching and reversing capability.

  13. Treatment of oilfield produced water using Fe/C micro-electrolysis assisted by zero-valent copper and zero-valent aluminium.

    PubMed

    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.

  14. How Water Advances on Superhydrophobic Surfaces

    NASA Astrophysics Data System (ADS)

    Schellenberger, Frank; Encinas, Noemí; Vollmer, Doris; Butt, Hans-Jürgen

    2016-03-01

    Superliquid repellency can be achieved by nano- and microstructuring surfaces in such a way that protrusions entrap air underneath the liquid. It is still not known how the three-phase contact line advances on such structured surfaces. In contrast to a smooth surface, where the contact line can advance continuously, on a superliquid-repellent surface, the contact line has to overcome an air gap between protrusions. Here, we apply laser scanning confocal microscopy to get the first microscopic videos of water drops advancing on a superhydrophobic array of micropillars. In contrast to common belief, the liquid surface gradually bends down until it touches the top face of the next micropillars. The apparent advancing contact angle is 180°. On the receding side, pinning to the top faces of the micropillars determines the apparent receding contact angle. Based on these observations, we propose that the apparent receding contact angle should be used for characterizing superliquid-repellent surfaces rather than the apparent advancing contact angle and hysteresis.

  15. Advanced Water Purification System for In Situ Resource Utilization

    NASA Technical Reports Server (NTRS)

    Anthony, Stephen M.; Jolley, Scott T.; Captain, James G.

    2013-01-01

    One of NASA's goals is to enable longterm human presence in space, without the need for continuous replenishment of consumables from Earth. In situ resource utilization (ISRU) is the use of extraterrestrial resources to support activities such as human life-support, material fabrication and repair, and radiation shielding. Potential sources of ISRU resources include lunar and Martian regolith, and Martian atmosphere. Water and byproducts (including hydrochloric and hydrofluoric acids) can be produced from lunar regolith via a high-temperature hydrogen reduction reaction and passing the produced gas through a condenser. center dot Due to the high solubility of HCI and HF in water, these byproducts are expected to be present in the product stream (up to 20,000 ppm) and must be removed (less than 10 ppm) prior to water consumption or electrolysis.

  16. Hydrogen Production from Nuclear Energy via High Temperature Electrolysis

    SciTech Connect

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

    2006-04-01

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

  17. A new class of electrocatalysts for hydrogen production from water electrolysis: metal monolayers supported on low-cost transition metal carbides.

    PubMed

    Esposito, Daniel V; Hunt, Sean T; Kimmel, Yannick C; Chen, Jingguang G

    2012-02-15

    This work explores the opportunity to substantially reduce the cost of hydrogen evolution reaction (HER) catalysts by supporting monolayer (ML) amounts of precious metals on transition metal carbide substrates. The metal component includes platinum (Pt), palladium (Pd), and gold (Au); the low-cost carbide substrate includes tungsten carbides (WC and W(2)C) and molybdenum carbide (Mo(2)C). As a platform for these studies, single-phase carbide thin films with well-characterized surfaces have been synthesized, allowing for a direct comparison of the intrinsic HER activity of bare and Pt-modified carbide surfaces. It is found that WC and W(2)C are both excellent cathode support materials for ML Pt, exhibiting HER activities that are comparable to bulk Pt while displaying stable HER activity during chronopotentiometric HER measurements. The findings of excellent stability and HER activity of the ML Pt-WC and Pt-W(2)C surfaces may be explained by the similar bulk electronic properties of tungsten carbides to Pt, as is supported by density functional theory calculations. These results are further extended to other metal overlayers (Pd and Au) and supports (Mo(2)C), which demonstrate that the metal ML-supported transition metal carbide surfaces exhibit HER activity that is consistent with the well-known volcano relationship between activity and hydrogen binding energy. This work highlights the potential of using carbide materials to reduce the costs of hydrogen production from water electrolysis by serving as stable, low-cost supports for ML amounts of precious metals.

  18. Application of electrolysis to inactivation of antibacterials in clinical use.

    PubMed

    Nakano, Takashi; Hirose, Jun; Kobayashi, Toyohide; Hiro, Naoki; Kondo, Fumitake; Tamai, Hiroshi; Tanaka, Kazuhiko; Sano, Kouichi

    2013-04-01

    Contamination of surface water by antibacterial pharmaceuticals (antibacterials) from clinical settings may affect aquatic organisms, plants growth, and environmental floral bacteria. One of the methods to decrease the contamination is inactivation of antibacterials before being discharged to the sewage system. Recently, we reported the novel method based on electrolysis for detoxifying wastewater containing antineoplastics. In the present study, to clarify whether the electrolysis method is applicable to the inactivation of antibacterials, we electrolyzed solutions of 10 groups of individual antibacterials including amikacin sulfate (AMK) and a mixture (MIX) of some commercial antibacterials commonly prescribed at hospitals, and measured their antibacterial activities. AMK was inactivated in its antibacterial activities and its concentration decreased by electrolysis in a time-dependent manner. Eighty to ninety-nine percent of almost all antibacterials and MIX were inactivated within 6h of electrolysis. Additionally, cytotoxicity was not detected in any of the electrolyzed solutions of antibacterials and MIX by the Molt-4-based cytotoxicity test.

  19. High temperature electrolysis for syngas production

    DOEpatents

    Stoots, Carl M.; O'Brien, James E.; Herring, James Stephen; Lessing, Paul A.; Hawkes, Grant L.; Hartvigsen, Joseph J.

    2011-05-31

    Syngas components hydrogen and carbon monoxide may be formed by the decomposition of carbon dioxide and water or steam by a solid-oxide electrolysis cell to form carbon monoxide and hydrogen, a portion of which may be reacted with carbon dioxide to form carbon monoxide. One or more of the components for the process, such as steam, energy, or electricity, may be provided using a nuclear power source.

  20. Hydrogen production by plasma electrolysis reactor of KOH-ethanol solution

    NASA Astrophysics Data System (ADS)

    Saksono, N.; Batubara, T.; Bismo, S.

    2016-11-01

    Plasma electrolysis has great potential in industrial hydrogen production, chlor-alkali production, and waste water treatment. Plasma electrolysis produces more hydrogen with less energy consumption than hydrocarbon or Faraday electrolysis. This paper investigated the hydrogen production by plasma electrolysis of KOH-ethanol solution at 80 °C and 1 atm. The effects of voltage, KOH solution, ethanol addition, and cathode deep on plasma electrolysis performance were studied. The hydrogen production was analyzed using bubble flow meter and hydrogen analyzer. The electrical energy consumption was measured by a digital multimeter. The effectiveness of plasma electrolysis in terms of hydrogen production was evaluated by comparing it with Faraday Electrolysis. The results showed that hydrogen produced by plasma electrolysis is 149 times higher than the hydrogen produced by Faraday electrolysis. The optimum hydrogen production was 50.71 mmol/min, obtained at 700 V with 0.03 M KOH, 10% vol ethanol and 6.6 cm cathode deep, with energy consumption 1.49 kJ/mmol. The result demonstrates a promising path for hydrogen production by utilizing plasma electrolysis reactor.

  1. Advanced ceramic cladding for water reactor fuel

    SciTech Connect

    Feinroth, H.

    2000-07-01

    Under the US Department of Energy's Nuclear Energy Research Initiatives (NERI) program, continuous fiber ceramic composites (CFCCs) are being developed as cladding for water reactor fuel elements. The purpose is to substantially increase the passive safety of water reactors. A development effort was initiated in 1991 to fabricate CFCC-clad tubes using commercially available fibers and a sol-gel process developed by McDermott Technologies. Two small-diameter CFCC tubes were fabricated using pure alumina and alumina-zirconia fibers in an alumina matrix. Densities of {approximately}60% of theoretical were achieved. Higher densities are required to guarantee fission gas containment. This NERI work has just begun, and only preliminary results are presented herein. Should the work prove successful, further development is required to evaluate CFCC cladding and performance, including in-pile tests containing fuel and exploring a marriage of CFCC cladding materials with suitable advanced fuel and core designs. The possibility of much higher temperature core designs, possibly cooled with supercritical water, and achievement of plant efficiencies {ge}50% would be examined.

  2. Risk assessment of human health from exposure to the discharged ballast water after full-scale electrolysis treatment.

    PubMed

    Zhang, Nahui; Wang, Yidan; Xue, Junzeng; Yuan, Lin; Wang, Qiong; Liu, Liang; Wu, Huixian; Hu, Kefeng

    2016-06-01

    The presence of disinfection by-products (DBPs) releasing from ballast water management systems (BWMS) can cause a possible adverse effects on humans. The objectives of this study were to compute the Derived No Effect Levels (DNELs) for different exposure scenarios and to compare these levels with the exposure levels from the measured DBPs in treated ballast water. The risk assessment showed that when using animal toxicity data, all the DNELs values were approximately 10(3)-10(12) times higher than the exposure levels of occupational and general public exposure scenarios, indicating the level of risk was low (risk characterization ratios (RCRs) < 1). However, when using human data, the RCRs were higher than 1 for dichlorobromomethane and trichloromethane, indicating that the risk of adverse effects on human were significant. This implies that there are apparent discrepancies between risk characterization from animal and human data, which may affect the overall results. We therefore recommend that when appropriate, human data should be used in risk assessment as much as possible, although human data are very limited. Moreover, more appropriate assessment factors can be considered to be employed in estimating the DNELs for human when the animal data is selected as the dose descriptors.

  3. Biogenic metals in advanced water treatment.

    PubMed

    Hennebel, Tom; De Gusseme, Bart; Boon, Nico; Verstraete, Willy

    2009-02-01

    Microorganisms can change the oxidation state of metals and concomitantly deposit metal oxides and zerovalent metals on or into their cells. The microbial mechanisms involved in these processes have been extensively studied in natural environments, and researchers have recently gained interest in the applications of microbe-metal interactions in biotechnology. Because of their specific characteristics, such as high specific surface areas and high catalytic reactivity, biogenic metals offer promising perspectives for the sorption and (bio)degradation of contaminants. In this review, the precipitation of biogenic manganese and iron species and the microbial reduction of precious metals, such as palladium, platinum, silver and gold, are discussed with specific attention to the application of these biogenic metals in innovative remediation technologies in advanced water treatment.

  4. Enhanced photoassisted water electrolysis using vertically oriented anodically fabricated Ti-Nb-Zr-O mixed oxide nanotube arrays.

    PubMed

    Allam, Nageh K; Alamgir, Faisal; El-Sayed, Mostafa A

    2010-10-26

    Self-ordered, highly oriented arrays of titanium-niobium-zirconium mixed oxide nanotube films were fabricated by the anodization of Ti(35)Nb(5)Zr alloy in aqueous and formamide electrolytes containing NH(4)F at room temperature. The nanostructure topology was found to depend on the nature of the electrolyte and the applied voltage. Our results demonstrate the possibility to grow mixed oxide nanotube array films possessing several-micrometer-thick layers by a simple and straightforward electrochemical route. The fabricated Ti-Nb-Zr-O nanotubes showed a ∼17.5% increase in the photoelectrochemical water oxidation efficiency as compared to that measured for pure TiO(2) nanotubes under UV illumination (100 mW/cm(2), 320-400 nm, 1 M KOH). This enhancement could be related to a combination of the effect of the thin wall of the fabricated Ti-Nb-Zr-O nanotubes (10 ± 2 nm) and the formation of Zr oxide and Nb oxide layers on the nanotube surface, which seems to slow down the electron-hole recombination in a way similar to that reported for Grätzel solar cells.

  5. Electrolysis and isoelectric focusing

    NASA Astrophysics Data System (ADS)

    Choi, Y. S.; Lui, Roger; Yu, Xun

    1994-01-01

    This paper consists of two parts. In the first part, the authors prove the existence of steady-state solutions for a three-species electrolyte. The species are subject to both dissociation-association reactions inside the electrolyte and electrochemical reactions at the boundary electrodes. This is a common occurrence in electrolysis. In the second part, the authors investigate how to use this model to describe isoelectric focusing, which is a common technique used to separate large protein molecules. In particular, the isoelectric focusing point for a particular type of protein molecule is calculated using formal perturbation analysis.

  6. Chemical oxygen demand removal efficiency and limited factors study of aminosilicone polymers in a water emulsion by iron-carbon micro-electrolysis.

    PubMed

    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.

  7. High Temperature Electrolysis 4 kW Experiment Design, Operation, and Results

    SciTech Connect

    J.E. O'Brien; X. Zhang; K. DeWall; L. Moore-McAteer; G. Tao

    2012-09-01

    This report provides results of long-term stack testing completed in the new high-temperature steam electrolysis multi-kW test facility recently developed at INL. The report includes detailed descriptions of the piping layout, steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. This facility has provided a demonstration of high-temperature steam electrolysis operation at the 4 kW scale with advanced cell and stack technology. This successful large-scale demonstration of high-temperature steam electrolysis will help to advance the technology toward near-term commercialization.

  8. Magnetic Resonance Imaging of Electrolysis.

    NASA Astrophysics Data System (ADS)

    Meir, Arie; Hjouj, Mohammad; Rubinsky, Liel; Rubinsky, Boris

    2015-02-01

    This study explores the hypothesis that Magnetic Resonance Imaging (MRI) can image the process of electrolysis by detecting pH fronts. The study has relevance to real time control of cell ablation with electrolysis. To investigate the hypothesis we compare the following MR imaging sequences: T1 weighted, T2 weighted and Proton Density (PD), with optical images acquired using pH-sensitive dyes embedded in a physiological saline agar solution phantom treated with electrolysis and discrete measurements with a pH microprobe. 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 MRI to image electrolysis produced pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E. Coli model grown on the phantom. The results are promising and invite further experimental research.

  9. Membrane Cells for Brine Electrolysis.

    ERIC Educational Resources Information Center

    Tingle, M.

    1982-01-01

    Membrane cells were developed as alternatives to mercury and diaphragm cells for the electrolysis of brine. Compares the three types of cells, focusing on the advantages and disadvantages of membrane cells. (JN)

  10. Electrolysis Performance Improvement Concept Study (EPICS) flight experiment phase C/D

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    The overall purpose of the Electrolysis Performance Improvement Concept Study flight experiment is to demonstrate and validate in a microgravity environment the Static Feed Electrolyzer concept as well as investigate the effect of microgravity on water electrolysis performance. The scope of the experiment includes variations in microstructural characteristics of electrodes and current densities in a static feed electrolysis cell configuration. The results of the flight experiment will be used to improve efficiency of the static feed electrolysis process and other electrochemical regenerative life support processes by reducing power and expanding the operational range. Specific technologies that will benefit include water electrolysis for propulsion, energy storage, life support, extravehicular activity, in-space manufacturing and in-space science in addition to other electrochemical regenerative life support technologies such as electrochemical carbon dioxide and oxygen separation, electrochemical oxygen compression and water vapor electrolysis. The Electrolysis Performance Improvement Concept Study flight experiment design incorporates two primary hardware assemblies: the Mechanical/Electrochemical Assembly and the Control/Monitor Instrumentation. The Mechanical/Electrochemical Assembly contains three separate integrated electrolysis cells along with supporting pressure and temperature control components. The Control/Monitor Instrumentation controls the operation of the experiment via the Mechanical/Electrochemical Assembly components and provides for monitoring and control of critical parameters and storage of experimental data.

  11. 3D CFD Model of High Temperature H2O/CO2 Co-electrolysis

    SciTech Connect

    Grant Hawkes; James O'Brien; Carl Stoots; Stephen Herring; Joe Hartvigsen

    2007-06-01

    War II. High-temperature nuclear reactors have the potential for substantially increasing the efficiency of syn-gas production from CO2 and water, with no consumption of fossil fuels, and no production of greenhouse gases. Thermal CO2-splitting and water splitting for syn-gas production can be accomplished via high-temperature electrolysis, using high-temperature nuclear process heat and electricity. A high-temperature advanced nuclear reactor coupled with a high-efficiency high-temperature electrolyzer could achieve a competitive thermal-to-syn-gas conversion efficiency of 45 to 55%.

  12. ADVANCES IN GROUND WATER SAMPLING PROCEDURES

    EPA Science Inventory

    Obtaining representative ground water samples is important for site assessment and remedial performance monitoring objectives. Issues which must be considered prior to initiating a ground-water monitoring program include defining monitoring goals and objectives, sampling point...

  13. Evaluation of an electrolysis apparatus for inactivating antineoplastics in clinical wastewater.

    PubMed

    Kobayashi, Toyohide; Hirose, Jun; Sano, Kouichi; Hiro, Naoki; Ijiri, Yoshio; Takiuchi, Hiroya; Tamai, Hiroshi; Takenaka, Hiroshi; Tanaka, Kazuhiko; Nakano, Takashi

    2008-06-01

    We recently reported a system for inactivating antineoplastics in which sodium hypochlorite is supplied by the electrolysis of sodium chloride solution. In this study, we designed an electrolysis apparatus for inactivating the cytotoxicity of antineoplastics in clinical wastewater using the system. The apparatus consists of an electrolysis cell with platinum-iridium electrodes, a pool tank, a circulating system for wastewater, a safety system for explosive gas and overflow, and an exhaust duct. The free chlorine concentration increased linearly up to 6500 mg l(-1), and pH also increased to 9.0-10.0 within 2h, when 0.9% sodium chloride solution was electrolyzed. We examined its efficacy with model and clinical wastewaters. The reciprocal of dilution factor for disappearance of cytotoxicity using Molt-4 cells was compared before and after electrolysis. In the model wastewater, that was 9.10 x 10(4) before electrolysis, and 3.56 x 10(2) after 2h of electrolysis. In the clinical wastewater (n=26), that was 6.90 x 10(3)-1.02 x 10(6) before electrolysis, and 1.08 x 10(2)-1.45 x 10(4) after 2h of electrolysis. Poisonous and explosive gases released by the electrolysis were measured; however, they were found to be negligible in terms of safety. The environmental load was evaluated by carbon dioxide generation as an index and it was found that the carbon dioxide generated by the electrolysis method was 1/70 lower than that by the dilution method with tap water. Moreover, the cost of the electrolysis method was 1/170 lower than that of the dilution method. This method was found to be both effective and economically valuable.

  14. Fusion reactors for hydrogen production via electrolysis

    NASA Astrophysics Data System (ADS)

    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 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 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of 50 to 70% are projected for fusion reactors using high temperature blankets.

  15. Application of electrolysis for detoxification of an antineoplastic in urine.

    PubMed

    Kobayashi, Toyohide; Hirose, Jun; Sano, Kouichi; Kato, Ryuji; Ijiri, Yoshio; Takiuchi, Hiroya; Tanaka, Kazuhiko; Goto, Emi; Tamai, Hiroshi; Nakano, Takashi

    2012-04-01

    Antineoplastics in excreta from patients have been considered to be one of the origins of cytotoxic, carcinogenic, teratogenic, and mutagenic contaminants in surface water. Recent studies have demonstrated that antineoplastics in clinical wastewater can be detoxified by electrolysis. In this study, to develop a method for the detoxification of antineoplastics in excreta, methotrexate solution in the presence of human urine was electrolyzed and evaluated. We found that urine inhibits detoxification by electrolysis; however, this inhibition decreased by diluting urine. In urine samples, the concentrations of active chlorine generated by anodic oxidation from 0.9% NaCl solution for inactivation of antineoplastics increased in dilution-dependent and time-dependent manner. These results indicate that electrolysis with platinum-based iridium oxide composite electrode is a possible method for the detoxification of a certain antineoplastic in urine.

  16. Partial oxidation of methane (POM) assisted solid oxide co-electrolysis

    DOEpatents

    Chen, Fanglin; Wang, Yao

    2017-02-21

    Methods for simultaneous syngas generation by opposite sides of a solid oxide co-electrolysis cell are provided. The method can comprise exposing a cathode side of the solid oxide co-electrolysis cell to a cathode-side feed stream; supplying electricity to the solid oxide co-electrolysis cell such that the cathode side produces a product stream comprising hydrogen gas and carbon monoxide gas while supplying oxygen ions to an anode side of the solid oxide co-electrolysis cell; and exposing the anode side of the solid oxide co-electrolysis cell to an anode-side feed stream. The cathode-side feed stream comprises water and carbon dioxide, and the anode-side feed stream comprises methane gas such that the methane gas reacts with the oxygen ions to produce hydrogen and carbon monoxide. The cathode-side feed stream can further comprise nitrogen, hydrogen, or a mixture thereof.

  17. Hydrogen Evolution by Plasma Electrolysis in Aqueous Solution

    NASA Astrophysics Data System (ADS)

    Mizuno, Tadahiko; Akimoto, Tadashi; Azumi, Kazuhisa; Ohmori, Tadayoshi; Aoki, Yoshiaki; Takahashi, Akito

    2005-01-01

    Hydrogen has recently attracted attention as a possible solution to environmental and energy problems. If hydrogen should be considered an energy storage medium rather than a natural resource. However, free hydrogen does not exist on earth. Many techniques for obtaining hydrogen have been proposed. It can be reformulated from conventional hydrocarbon fuels, or obtained directly from water by electrolysis or high-temperature pyrolysis with a heat source such as a nuclear reactor. However, the efficiencies of these methods are low. The direct heating of water to sufficiently high temperatures for sustaining pyrolysis is very difficult. Pyrolysis occurs when the temperature exceeds 4000°C. Thus plasma electrolysis may be a better alternative, it is not only easier to achieve than direct heating, but also appears to produce more hydrogen than ordinary electrolysis, as predicted by Faraday’s laws, which is indirect evidence that it produces very high temperatures. We also observed large amounts of free oxygen generated at the cathode, which is further evidence of direct decomposition, rather than electrolytic decomposition. To achieve the continuous generation of hydrogen with efficiencies exceeding Faraday efficiency, it is necessary to control the surface conditions of the electrode, plasma electrolysis temperature, current density and input voltage. The minimum input voltage required induce the plasma state depends on the density and temperature of the solution, it was estimated as 120 V in this study. The lowest electrolyte temperature at which plasma forms is ˜75°C. We have observed as much as 80 times more hydrogen generated by plasma electrolysis than by conventional electrolysis at 300 V.

  18. Improving electrochemical methods of producing hydrogen in alkaline media via ammonia and urea electrolysis

    NASA Astrophysics Data System (ADS)

    Boggs, Bryan Kenneth

    Theoretically, ammonia electrolysis consumes 95% less energy than its major competitor water electrolysis and offers an economical, environmental, and efficient means for reducing nitrate contaminations in ground and drinking water. Thermodynamically at standard conditions, ammonia electrolysis consumes 1.55 Wh to produce one gram of hydrogen. This same gram of hydrogen generates 33 Wh utilizing a proton exchange membrane fuel cell (PEMFC). There is a potential of 31.45 Wh of net energy when coupling an ammonia electrolytic cell (AEC) and a PEMFC. Considering that PEMFCs are 60% efficient, the actual energy output ranges between 18 and 20 Wh. Prior to the research shown here, ammonia electrolysis in alkaline media was requiring more than 20 Wh of energy input due to slow anode kinetics and poor electrochemical cell design thus making any chances of a self-sustaining energy generator unfeasible. This research focused on improving and optimizing anode electrocatalyst materials, electrode configurations, and cell designs, as well as demonstrating stationary and mobile applications of ammonia electrolysis. In addition to ammonia electrolysis, a novel electrochemical technique, urea electrolysis in alkaline media, was created and investigated. Similar to ammonia electrolysis, the anodic reaction, which is the oxidation of urea, was found to be the most rate-limiting half-cell reaction and required improvement. This research focused on fundamentally understanding the mechanism of urea electrolysis as well as investigating common electrocatalysts for small organic molecules. As a result, urea electrolysis in alkaline media proved to be a direct, economical, and environmental approach to producing hydrogen electrochemically with an inexpensive transition metal.

  19. Advances in water resources monitoring from space

    NASA Technical Reports Server (NTRS)

    Salomonson, V. V.

    1974-01-01

    Nimbus-5 observations indicate that over the oceans the total precipitable water in a column of atmosphere can be estimated to within + or - 10%, the liquid water content of clouds can be estimated to within + or - 25%, areas of precipitation can be delineated, and broad estimates of the precipitation rate obtained. ERTS-1 observations permit the measurement of snow covered area to within a few percent of drainage basin area and snowline altitudes can be estimated to within 60 meters. Surface water areas as small as 1 hectare can be inventoried over large regions such as playa lakes region of West Texas and Eastern New Mexico. In addition, changes in land use on water-sheds occurring as a result of forest fires, urban development, clear cutting, or strip mining can be rapidly obtained.

  20. Case history advanced coatings for water treatment plant components

    SciTech Connect

    Stephenson, L.D.; Kumar, A.

    2008-12-15

    Components of water treatment plants (WTPs) are susceptible to corrosion from constant immersion in water. A case history of corrosion and proximity to chlorine problems and their treatment at an Army WTP is presented. Solutions included using high micro-silica restoration mortar and advanced coal tar epoxy coatings.

  1. Advanced Water Removal via Membrane Solvent Extraction

    SciTech Connect

    2009-02-01

    This factsheet describes a research project that will focus on further concept and technology development and verification at the pilot scale of an MSE technology developed by 3M. The technology shows great promise to substantially decrease energy and water consumption in bioethanol production.

  2. Advances in nitrogen management for water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The creation of this book was inspired by collaborative discussions with some of the individuals who presented at the 7th annual symposium that was jointly held by the Soil and Water Conservation Society (SWCS) and Soil Science Society of America (SSSA) in 2006. These individuals were asked to work ...

  3. Atomic Structure and Valence: Level II, Unit 10, Lesson 1; Chemical Bonding: Lesson 2; The Table of Elements: Lesson 3; Electrolysis: Lesson 4. Advanced General Education Program. A High School Self-Study Program.

    ERIC Educational Resources Information Center

    Manpower Administration (DOL), Washington, DC. Job Corps.

    This self-study program for high-school level contains lessons on: Atomic Structure and Valence, Chemical Bonding, The Table of Elements, and Electrolysis. Each of the lessons concludes with a Mastery Test to be completed by the student. (DB)

  4. Improved Durability of SOEC Stacks for High Temperature Electrolysis

    SciTech Connect

    James E. O'Brien; Robert C. O'Brien; Xiaoyu Zhang; Joseph J. Hartvigsen; Greg Tao

    2013-01-01

    High temperature steam electrolysis is a promising technology for efficient and sustainable large-scale hydrogen production. Solid oxide electrolysis cells (SOECs) are able to utilize high temperature heat and electric power from advanced high-temperature nuclear reactors or renewable sources to generate carbon-free hydrogen at large scale. However, long term durability of SOECs needs to be improved significantly before commercialization of this technology can be realized. A degradation rate of 1%/khr or lower is proposed as a threshold value for commercialization of this technology. Solid oxide electrolysis stack tests have been conducted at Idaho National Laboratory to demonstrate recent improvements in long-term durability of SOECs. Electrolyte-supported and electrode-supported SOEC stacks were provided by Ceramatec Inc. and Materials and Systems Research Inc. (MSRI), respectively, for these tests. Long-term durability tests were generally operated for a duration of 1000 hours or more. Stack tests based on technologies developed at Ceramatec and MSRI have shown significant improvement in durability in the electrolysis mode. Long-term degradation rates of 3.2%/khr and 4.6%/khr were observed for MSRI and Ceramatec stacks, espectively. One recent Ceramatec stack even showed negative degradation (performance improvement) over 1900 hours of operation. Optimization of electrode materials, interconnect coatings, and electrolyte-electrode interface microstructures contribute to better durability of SOEC stacks.

  5. Editorial changes - Advances in Water Resources

    NASA Astrophysics Data System (ADS)

    Barry, D. A.; D'Odorico, P.; Rinaldo, A.

    2015-10-01

    Prof. Miller's longevity of service as Editor is remarkable - he started this role in August 1997. During his nearly 18 years as Editor, he provided unstinting energy, attention to detail, and commitment to the water resources community. A hallmark of his stewardship of the journal is that he "led from the front". He undertook not only to sustain a suitable venue for high quality research, but also to foster special issues, especially in emerging research topics. Prof. Miller ensured that at all times the journal's core focus of fundamental water resources science was not diluted. Indeed, a major legacy of Prof. Miller's vision is that the journal is a destination of choice for such contributions.

  6. Basic trends and chief products in the electrolysis of methanolic solutions of monomethyl adipate and its alkali salts

    SciTech Connect

    Shul'zhenko, G.I.; Freidlin, G.N.; Kovsman, E.P.; Vasil'ev, Yu. B.

    1986-08-01

    Preparative electrolysis under galvanostatic conditions was used to study the effect of the principal adjustable process parameters, such as temperature, the water content of the original electrolyte, current density, electrolysis time, and the concentration of monoester salt, on the formation of methyl valerate and methyl allylacetate. The character of the influence of these parameters was established.

  7. Electrolysis-reducing electrodes for electrokinetic devices.

    PubMed

    Erlandsson, Per G; Robinson, Nathaniel D

    2011-03-01

    Direct current electrokinetic systems generally require Faradaic reactions to occur at a pair of electrodes to maintain an electric field in an electrolyte connecting them. The vast majority of such systems, e.g. electrophoretic separations (capillary electrophoresis) or electroosmotic pumps (EOPs), employ electrolysis of the solvent in these reactions. In many cases, the electrolytic products, such as H+ and OH⁻ in the case of water, can negatively influence the chemical or biological species being transported or separated, and gaseous products such as O₂ and H₂ can break the electrochemical circuit in microfluidic devices. This article presents an EOP that employs the oxidation/reduction of the conjugated polymer poly(3,4-ethylenedioxythiophene), rather than electrolysis of a solvent, to drive flow in a capillary. Devices made with poly(3,4-ethylenedioxythiophene) electrodes are compared with devices made with Pt electrodes in terms of flow and local pH change at the electrodes. Furthermore, we demonstrate that flow is driven for applied potentials under 2 V, and the electrodes are stable for potentials of at least 100 V. Electrochemically active electrodes like those presented here minimize the disadvantage of integrated EOP in, e.g. lab-on-a-chip applications, and may open new possibilities, especially for battery-powered disposable point-of-care devices.

  8. Advanced Water Vapor Lidar Detection System

    NASA Technical Reports Server (NTRS)

    Elsayed-Ali, Hani

    1998-01-01

    In the present water vapor lidar system, the detected signal is sent over long cables to a waveform digitizer in a CAMAC crate. This has the disadvantage of transmitting analog signals for a relatively long distance, which is subjected to pickup noise, leading to a decrease in the signal to noise ratio. Generally, errors in the measurement of water vapor with the DIAL method arise from both random and systematic sources. Systematic errors in DIAL measurements are caused by both atmospheric and instrumentation effects. The selection of the on-line alexandrite laser with a narrow linewidth, suitable intensity and high spectral purity, and its operation at the center of the water vapor lines, ensures minimum influence in the DIAL measurement that are caused by the laser spectral distribution and avoid system overloads. Random errors are caused by noise in the detected signal. Variability of the photon statistics in the lidar return signal, noise resulting from detector dark current, and noise in the background signal are the main sources of random error. This type of error can be minimized by maximizing the signal to noise ratio. The increase in the signal to noise ratio can be achieved by several ways. One way is to increase the laser pulse energy, by increasing its amplitude or the pulse repetition rate. Another way, is to use a detector system with higher quantum efficiency and lower noise, on the other hand, the selection of a narrow band optical filter that rejects most of the day background light and retains high optical efficiency is an important issue. Following acquisition of the lidar data, we minimize random errors in the DIAL measurement by averaging the data, but this will result in the reduction of the vertical and horizontal resolutions. Thus, a trade off is necessary to achieve a balance between the spatial resolution and the measurement precision. Therefore, the main goal of this research effort is to increase the signal to noise ratio by a factor of

  9. THE HIGH-TEMPERATURE ELECTROLYSIS PROGRAM AT THE IDAHO NATIONAL LABORATORY: OBSERVATIONS ON PERFORMANCE DEGRADATION

    SciTech Connect

    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.

  10. Hydrogen Production System with High Temperature Electrolysis for Nuclear Power Plant

    SciTech Connect

    Kentaro, Matsunaga; Eiji, Hoashi; Seiji, Fujiwara; Masato, Yoshino; Taka, Ogawa; Shigeo, Kasai

    2006-07-01

    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)

  11. Hydrogen Production from Nuclear Energy via High-Temperature Electrolysis

    SciTech Connect

    Herring, J.S.; O'Brien, J.E.; Stoots, C.M.; Lessing, P.A.

    2004-07-01

    High-temperature electrolytic water-splitting supported by nuclear process heat and electricity has the potential to produce H{sub 2} with an overall system efficiency near those of the hydrocarbon and thermochemical processes, but without the corrosive conditions of thermochemical processes and without the fossil fuel consumption and greenhouse gas emissions associated with hydrocarbon processes. Specifically, a high-temperature advanced nuclear reactor coupled with a high-efficiency high-temperature electrolyzer could achieve a competitive thermal-to-hydrogen conversion efficiency of 45 to 55%. A research program is under way at INEEL to develop a conceptual design for large-scale nuclear production of hydrogen via planar solid oxide electrolysis technology. The design effort is addressing solid oxide cell materials and configuration, performance, durability, operating conditions, economics, and safety. Single and multiple cell experimental studies are being conducted. Interim results indicate that this technology performs close to theoretical predictions and remains a viable means for hydrogen production using nuclear energy. (authors)

  12. Advanced Water-Gas Shift Membrane Reactor

    SciTech Connect

    Sean Emerson; Thomas Vanderspurt; Susanne Opalka; Rakesh Radhakrishnan; Rhonda Willigan

    2009-01-07

    The overall objectives for this project were: (1) to identify a suitable PdCu tri-metallic alloy membrane with high stability and commercially relevant hydrogen permeation in the presence of trace amounts of carbon monoxide and sulfur; and (2) to identify and synthesize a water gas shift catalyst with a high operating life that is sulfur and chlorine tolerant at low concentrations of these impurities. This work successfully achieved the first project objective to identify a suitable PdCu tri-metallic alloy membrane composition, Pd{sub 0.47}Cu{sub 0.52}G5{sub 0.01}, that was selected based on atomistic and thermodynamic modeling alone. The second objective was partially successful in that catalysts were identified and evaluated that can withstand sulfur in high concentrations and at high pressures, but a long operating life was not achieved at the end of the project. From the limited durability testing it appears that the best catalyst, Pt-Re/Ce{sub 0.333}Zr{sub 0.333}E4{sub 0.333}O{sub 2}, is unable to maintain a long operating life at space velocities of 200,000 h{sup -1}. The reasons for the low durability do not appear to be related to the high concentrations of H{sub 2}S, but rather due to the high operating pressure and the influence the pressure has on the WGS reaction at this space velocity.

  13. Electrical impedance tomography of electrolysis.

    PubMed

    Meir, Arie; Rubinsky, Boris

    2015-01-01

    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.

  14. Electrolysis of a molten semiconductor

    NASA Astrophysics Data System (ADS)

    Yin, Huayi; Chung, Brice; Sadoway, Donald R.

    2016-08-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

  15. Transient nanobubbles in short-time electrolysis.

    PubMed

    Svetovoy, Vitaly B; Sanders, Remco G P; Elwenspoek, Miko C

    2013-05-08

    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 accompanied by a high relative supersaturation, S > 1000, that results in homogeneous nucleation of bubbles. On the short-time scale only nanobubbles can be formed. These nanobubbles densely cover the electrodes and aggregate at a later time to microbubbles. The effect is significantly intensified with a small increase of temperature. Application of alternating polarity voltage pulses produces bubbles containing a mixture of hydrogen and oxygen. Spontaneous reaction between gases is observed for stoichiometric bubbles with sizes smaller than ∼150 nm. Such bubbles disintegrate violently affecting the surfaces of the electrodes.

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

    PubMed

    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.

  17. Advanced Exploration Systems Water Architecture Study Interim Results

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam J.

    2013-01-01

    The mission of the Advanced Exploration System (AES) Water Recovery Project (WRP) is to develop advanced water recovery systems that enable NASA human exploration missions beyond low Earth orbit (LEO). The primary objective of the AES WRP is to develop water recovery technologies critical to near-term missions beyond LEO. The secondary objective is to continue to advance mid-readiness-level technologies to support future NASA missions. An effort is being undertaken to establish the architecture for the AES Water Recovery System (WRS) that meets both near- and long-term objectives. The resultant architecture will be used to guide future technical planning, establish a baseline development roadmap for technology infusion, and establish baseline assumptions for integrated ground and on-orbit Environmental Control and Life Support Systems definition. This study is being performed in three phases. Phase I established the scope of the study through definition of the mission requirements and constraints, as well as identifying all possible WRS configurations that meet the mission requirements. Phase II focused on the near-term space exploration objectives by establishing an International Space Station-derived reference schematic for long-duration (>180 day) in-space habitation. Phase III will focus on the long-term space exploration objectives, trading the viable WRS configurations identified in Phase I to identify the ideal exploration WRS. The results of Phases I and II are discussed in this paper.

  18. On photovoltaic electrolysis

    SciTech Connect

    Murphy, O.J.; Bockris, J.O.M.

    1983-12-01

    Photoelectrochemical conversion of light to stored energy in a convenient medium--hydrogen--has been researched extensively. There are no cases where, without the use of external power sources, efficiencies of energy conversion of better than 1-2% have been achieved. For this reason, the present research concerns itself with photovoltaic couples and the use of the resultant electrical power to electrolyze water. The novelty is in the arrangement. An arrangement, consisting of the two GaAs couples, separated by aqueous solution, was irradiated, using solar-simulated light. Hydrogen, oxygen and electricity were produced. The current was varied by using the cell as a light-driven fuel cell passing electric current through an external load which could be varied. The maximum efficiency of conversion of solar light to H2 occurred with the external load at zero ohms.

  19. Uranium dioxide electrolysis

    DOEpatents

    Willit, James L.; Ackerman, John P.; Williamson, Mark A.

    2009-12-29

    This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

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

    PubMed

    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.

  1. Advanced Nuclear Technology: Advanced Light Water Reactors Utility Requirements Document Small Modular Reactors Inclusion Summary

    SciTech Connect

    Loflin, Leonard; McRimmon, Beth

    2014-12-18

    This report summarizes a project by EPRI to include requirements for small modular light water reactors (smLWR) into the EPRI Utility Requirements Document (URD) for Advanced Light Water Reactors. The project was jointly funded by EPRI and the U.S. Department of Energy (DOE). The report covers the scope and content of the URD, the process used to revise the URD to include smLWR requirements, a summary of the major changes to the URD to include smLWR, and how to use the URD as revised to achieve value on new plant projects.

  2. HYFIRE: A Tokamak/high-temperature electrolysis system

    NASA Astrophysics Data System (ADS)

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

    1982-06-01

    The HYFIRE studies to date have investigated a number of technical approaches for using the thermal energy produced in a high-temperature Tokamak blankets to provide the electrical and thermal energy required to drive a high-temperature ( 1000 C) water electrolysis process. Current emphasis is on two design points, one consistent with electrolyzer peak inlet temperatures of approximately 1300 C, which is an extrapolation of present experience, and one consistent with a peak electrolyzer temperature of 1100 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.

  3. HYFIRE: A Tokamak/high-temperature electrolysis system

    NASA Astrophysics Data System (ADS)

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

    The development of a system 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 water electrolysis process is described. Emphasis is on two design points, one consistent with electrolyzer peak inlet temperatures of 1400 C, which is an extrapolation of present experience, and one consistent with a peak electrolyzer temperature of 1100 C. This latter condition is based on laboratory experience with high temperature solid electrolyte fuel cells. A major conclusion 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.

  4. Electrolysis of Titanium Oxide to Titanium in Molten Cryolite Salt

    NASA Astrophysics Data System (ADS)

    Yan, Bennett Chek Kin

    Cost-effective production of titanium is becoming a challenge being tackled in the metallurgical and sustainability sector and technological advancements are required to effectively separate the metal from its oxide. The existing methods of Ti production are extremely energy intensive and slow. This proof-of-concept study investigated the feasibility of separating and capturing Ti from TiO2 through electrolysis after it has been dissolved in a cryolite bath at 1050°C. XRD and SEM/EDS results verified that TiO 2 is only partially reduced. However, addition of Al assisted in the precipitation of Ti in the form of TiAl and TiAl3. Parameters such as electrolysis time, concentration of TiO2, and electrolysis potential were explored. The experiments that were run for 4h, with TiO2 <15wt% of the total bath gave promising results as there was intermetallic formation without the excessive evaporation of cryolite.

  5. Low-Energy Catalytic Electrolysis for Simultaneous Hydrogen Evolution and Lignin Depolymerization.

    PubMed

    Du, Xu; Liu, Wei; Zhang, Zhe; Mulyadi, Arie; Brittain, Alex; Gong, Jian; Deng, Yulin

    2017-03-09

    Here, a new proton-exchange-membrane electrolysis is presented, in which lignin was used as the hydrogen source at the anode for hydrogen production. Either polyoxometalate (POM) or FeCl3 was used as the catalyst and charge-transfer agent at the anode. Over 90 % Faraday efficiency was achieved. In a thermal-insulation reactor, the heat energy could be maintained at a very low level for continuous operation. Compared to the best alkaline-water electrolysis reported in literature, the electrical-energy consumption could be 40 % lower with lignin electrolysis. At the anode, the Kraft lignin (KL) was oxidized to aromatic chemicals by POM or FeCl3 , and reduced POM or Fe ions were regenerated during the electrolysis. Structure analysis of the residual KL indicated a reduction of the amount of hydroxyl groups and the cleavage of ether bonds. The results suggest that POM- or FeCl3 -mediated electrolysis can significantly reduce the electrolysis energy consumption in hydrogen production and, simultaneously, depolymerize lignin to low-molecular-weight value-added aromatic chemicals.

  6. 76 FR 61118 - Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water Reactor...

  7. Characterization of Advanced Avalanche Photodiodes for Water Vapor Lidar Receivers

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Halama, Gary E.; DeYoung, Russell J.

    2000-01-01

    Development of advanced differential absorption lidar (DIAL) receivers is very important to increase the accuracy of atmospheric water vapor measurements. A major component of such receivers is the optical detector. In the near-infrared wavelength range avalanche photodiodes (APD's) are the best choice for higher signal-to-noise ratio, where there are many water vapor absorption lines. In this study, characterization experiments were performed to evaluate a group of silicon-based APD's. The APD's have different structures representative of different manufacturers. The experiments include setups to calibrate these devices, as well as characterization of the effects of voltage bias and temperature on the responsivity, surface scans, noise measurements, and frequency response measurements. For each experiment, the setup, procedure, data analysis, and results are given and discussed. This research was done to choose a suitable APD detector for the development of an advanced atmospheric water vapor differential absorption lidar detection system operating either at 720, 820, or 940 nm. The results point out the benefits of using the super low ionization ratio (SLIK) structure APD for its lower noise-equivalent power, which was found to be on the order of 2 to 4 fW/Hz(sup (1/2)), with an appropriate optical system and electronics. The water vapor detection systems signal-to-noise ratio will increase by a factor of 10.

  8. Electrolysis of a molten semiconductor

    PubMed Central

    Yin, Huayi; Chung, Brice; Sadoway, Donald R.

    2016-01-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides. PMID:27553525

  9. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a recirculating control loop which had no water quality maintenance. Results show that periodic water maintenance can improve performance of the SWME. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage of this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing sublimator technology. The driver for the evaluation of water recirculation maintenance components was to enhance the robustness of the SWME through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A patented bed design that was developed for a United Technologies Aerospace System military application provided a low pressure drop means for water maintenance in the SWME recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for the ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  10. The Consortium for Advanced Simulation of Light Water Reactors

    SciTech Connect

    Ronaldo Szilard; Hongbin Zhang; Doug Kothe; Paul Turinsky

    2011-10-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) is a DOE Energy Innovation Hub for modeling and simulation of nuclear reactors. It brings together an exceptionally capable team from national labs, industry and academia that will apply existing modeling and simulation capabilities and develop advanced capabilities to create a usable environment for predictive simulation of light water reactors (LWRs). This environment, designated as the Virtual Environment for Reactor Applications (VERA), will incorporate science-based models, state-of-the-art numerical methods, modern computational science and engineering practices, and uncertainty quantification (UQ) and validation against data from operating pressurized water reactors (PWRs). It will couple state-of-the-art fuel performance, neutronics, thermal-hydraulics (T-H), and structural models with existing tools for systems and safety analysis and will be designed for implementation on both today's leadership-class computers and the advanced architecture platforms now under development by the DOE. CASL focuses on a set of challenge problems such as CRUD induced power shift and localized corrosion, grid-to-rod fretting fuel failures, pellet clad interaction, fuel assembly distortion, etc. that encompass the key phenomena limiting the performance of PWRs. It is expected that much of the capability developed will be applicable to other types of reactors. CASL's mission is to develop and apply modeling and simulation capabilities to address three critical areas of performance for nuclear power plants: (1) reduce capital and operating costs per unit energy by enabling power uprates and plant lifetime extension, (2) reduce nuclear waste volume generated by enabling higher fuel burnup, and (3) enhance nuclear safety by enabling high-fidelity predictive capability for component performance.

  11. Advanced fuels for plutonium management in pressurized water reactors

    NASA Astrophysics Data System (ADS)

    Vasile, A.; Dufour, Ph; Golfier, H.; Grouiller, J. P.; Guillet, J. L.; Poinot, Ch; Youinou, G.; Zaetta, A.

    2003-06-01

    Several fuel concepts are under investigation at CEA with the aim of manage plutonium inventories in pressurized water reactors. This options range from the use of mature technologies like MOX adapted in the case of MOX-EUS (enriched uranium support) and COmbustible Recyclage A ILot (CORAIL) assemblies to more innovative technologies using IMF like DUPLEX and advanced plutonium assembly (APA). The plutonium burning performances reported to the electrical production go from 7 to 60 kg (TW h) -1. More detailed analysis covering economic, sustainability, reliability and safety aspects and their integration in the whole fuel cycle would allow identifying the best candidate.

  12. A Hydrological Perspective to Advance Understanding of the Water Cycle

    NASA Astrophysics Data System (ADS)

    Berghuijs, W.

    2014-12-01

    In principle hydrologists are scientists that study relationships within the water cycle. Yet, current technology makes it tempting for hydrology students to lose their "hydrological perspective" and become instead full-time computer programmers or statisticians. I assert that students should ensure their hydrological perspective thrives, notwithstanding the importance and possibilities of current technology. This perspective is necessary to advance the science of hydrology. As other hydrologists have pondered similar views before, I make no claims of originality here. I just hope that in presenting my perspective on this issue I may spark the interest of other early career hydrologists.

  13. Electrolysis: Information and Opportunities for Electric Power Utilities

    SciTech Connect

    Kroposki, B.; Levene, J.; Harrison, K.; Sen, P.K.; Novachek, F.

    2006-09-01

    Recent advancements in hydrogen technologies and renewable energy applications show promise for economical near- to mid-term conversion to a hydrogen-based economy. As the use of hydrogen for the electric utility and transportation sectors of the U.S. economy unfolds, electric power utilities need to understand the potential benefits and impacts. This report provides a historical perspective of hydrogen, discusses the process of electrolysis for hydrogen production (especially from solar and wind technologies), and describes the opportunities for electric power utilities.

  14. Proton transfer in microbial electrolysis cells

    DOE PAGES

    Borole, Abhijeet P.; Lewis, Alex J.

    2017-02-15

    Proton transfer and electron transfer are of prime importance in the development of microbial electrochemical cells. While electron transfer is primarily controlled by biology, proton transfer is controlled by process engineering and cell design. To develop commercially feasible technologies around the concept of a bioelectrochemical cell, real feedstocks have to be explored and associated limitations have to be identified. Here in this study, the proton transfer rate was quantified for a microbial electrolysis cell (MEC) and its dependence on process parameters was investigated using a proton balance model. The reaction system consisted of a biomass-derived pyrolytic aqueous stream as amore » substrate producing hydrogen in a flow-through MEC. The proton transfer rate increased with anode flow rate and organic loading rate up to a maximum of 0.36 ± 0.01 moles per m2 per h, equivalent to a hydrogen production rate of 9.08 L per L per day. Higher rates of hydrogen production, reaching 11.7 ± 0.2 L per L per day were achieved, when additional protons were provided via the cathode buffer. Electrochemical impedance spectroscopy shows that proton transfer was the dominant resistance in the production of hydrogen. The quantification of proton transfer rates for MECs with potential for biorefinery application and the demonstration of high hydrogen production rates approaching those required for commercial consideration indicate the strong potential of this technology for renewable hydrogen production. Understanding the transport phenomenon in bioelectrochemical cells is of great significance since these systems have potential for wide-ranging applications including energy production, bioremediation, chemical and nanomaterial synthesis, electro-fermentation, energy storage, desalination, and produced water treatment. Electron transfer in anode biofilms has been investigated extensively, but proton transfer studies are also important, since many cathodic half reactions

  15. ELECTROLYSIS OF THORIUM AND URANIUM

    DOEpatents

    Hansen, W.N.

    1960-09-01

    An electrolytic method is given for obtaining pure thorium, uranium, and thorium-uranium alloys. The electrolytic cell comprises a cathode composed of a metal selected from the class consisting of zinc, cadmium, tin, lead, antimony, and bismuth, an anode composed of at least one of the metals selected from the group consisting of thorium and uranium in an impure state, and an electrolyte composed of a fused salt containing at least one of the salts of the metals selected from the class consisting of thorium, uranium. zinc, cadmium, tin, lead, antimony, and bismuth. Electrolysis of the fused salt while the cathode is maintained in the molten condition deposits thorium, uranium, or thorium-uranium alloys in pure form in the molten cathode which thereafter may be separated from the molten cathode product by distillation.

  16. Fractional capacity electrolyzer development for CO2 and H2O electrolysis

    NASA Technical Reports Server (NTRS)

    Wynveen, R. A.

    1980-01-01

    The electrolyzer module was designed to produce 0.24 kg/d (0.53 lb/d) of breathable oxygen from the electrolysis of metabolic carbon dioxide and water vapor. The fractional capacity electrolyzer module is constructed from three electrochemical tube cells and contains only three critical seals. The module design illustrated an 84 percent reduction in the total number of seals for a one person capacity oxygen generating system based on the solid electrolyte carbon dioxide and water vapor electrolysis concept. The electrolyzer module was successfully endurance tested for 71 days.

  17. Electrolysis-induced bubbling in soft solids for elastic-wave generation

    NASA Astrophysics Data System (ADS)

    Montalescot, S.; Roger, B.; Zorgani, A.; Souchon, R.; Grasland-Mongrain, P.; Ben Haj Slama, R.; Bera, J.-C.; Catheline, S.

    2016-02-01

    Water electrolysis was discovered in 1800, with the famous experiment investigated here within soft tissue from an elastic-wave point of view. Indeed, we report that the rapid formation of hydrogen bubbles after transient (10 ms) electrolysis in water-based gels produces elastic waves. These bubbles are observed using an ultrafast optical camera. As the bubbles are trapped between the rigid electrode and the soft matter, they act as a source of elastic waves that are measured in the bulk using an ultrafast ultrasound scanner. The elastic-wave amplitude is shown to be in good agreement with a simple bubble model.

  18. Design of an Integrated Laboratory Scale Test for Hydrogen Production via High Temperature Electrolysis

    SciTech Connect

    G.K. Housley; K.G. Condie; J.E. O'Brien; C. M. Stoots

    2007-06-01

    The Idaho National Laboratory (INL) is researching the feasibility of high-temperature steam electrolysis for high-efficiency carbon-free hydrogen production using nuclear energy. Typical temperatures for high-temperature electrolysis (HTE) are between 800º-900ºC, consistent with anticipated coolant outlet temperatures of advanced high-temperature nuclear reactors. An Integrated Laboratory Scale (ILS) test is underway to study issues such as thermal management, multiple-stack electrical configuration, pre-heating of process gases, and heat recuperation that will be crucial in any large-scale implementation of HTE. The current ILS design includes three electrolysis modules in a single hot zone. Of special design significance is preheating of the inlet streams by superheaters to 830°C before entering the hot zone. The ILS system is assembled on a 10’ x 16’ skid that includes electronics, power supplies, air compressor, pumps, superheaters, , hot zone, condensers, and dew-point sensor vessels. The ILS support system consists of three independent, parallel supplies of electrical power, sweep gas streams, and feedstock gas mixtures of hydrogen and steam to the electrolysis modules. Each electrolysis module has its own support and instrumentation system, allowing for independent testing under different operating conditions. The hot zone is an insulated enclosure utilizing electrical heating panels to maintain operating conditions. The target hydrogen production rate for the ILS is 5000 Nl/hr.

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

    SciTech Connect

    Schenewerk, William Ernest

    2009-09-01

    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.

  20. Advanced treatment of sodium acetate in water by ozone oxidation.

    PubMed

    Yang, De-Min; Yuan, Jian-Mei

    2014-02-01

    Ozone oxidation is an advanced oxidation process for treatment of organic and inorganic wastewater. In this paper, sodium acetate (according to chemical oxygen demand [COD]) was selected as the model pollutant in water, and the degradation efficiencies and mechanism of sodium acetate in water by ozone oxidation were investigated. The results showed that the ozone oxidation was an effective treatment technology for advanced treatment of sodium acetate in water; the COD removal rate obtained the maximum value of 45.89% from sodium acetate solution when the pH value was 10.82, ozone concentration was 100 mg/L, reaction time was 30 minutes, and reaction temperature was 25 degrees C. The COD removal rate increased first and decreased subsequently with the bicarbonate (HCO3-) concentration from 0 to 200 mg/L, the largest decline being 20.35%. The COD removal rate declined by 25.38% with the carbonate (CO3(2-)) concentration from 0 to 200 mg/L; CO3(2-) has a more obvious scavenging effect to inhibit the formation of hydroxyl free radicals than HCO3-. Calcium chloride (CaCl2) and calcium hydroxide (Ca(OH)2) could enhance the COD removal rate greatly; they could reach 77.35 and 96.53%, respectively, after a reaction time of 30 minutes, which was increased by 31.46 and 50.64%, respectively, compared with only ozone oxidation. It was proved that the main ozone oxidation product of sodium acetate was carbon dioxide (CO2), and the degradation of sodium acetate in the ozone oxidation process followed the mechanism of hydroxyl free radicals.

  1. Performance of Water Recirculation Loop Maintentance Components for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Peyton, Barbara; Steele, John W.; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessonslearned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  2. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  3. Competitively priced hydrogen via high-efficiency nuclear electrolysis

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    A fully dedicated nuclear-electrolytic hydrogen-production facility, based on advanced (1985) technology, has been synthesized and assessed at the conceptual level. The facility integrates an HTGR operating a binary shaftpower-extraction cycle at 980 C top temperature, direct dc electricity generation via acyclic generators, and high-current density high-pressure electrolyzers based on the solid polymer electrolyte approach. All subsystems are close-coupled and optimally interfaced. Pipeline-pressure hydrogen and coproduct oxygen are produced at 6900 kPa. On consistent costing bases, the advanced facility concept was found to provide hydrogen costs that were approximately half those associated with conventional, contemporary-technology nuclear electrolysis. The nuclear heat-to-hydrogen energy conversion efficiency for the advanced system was estimated as 43%, against 25% for the baseline present-day approach.

  4. Non-covalent interactions in water electrolysis: influence on the activity of Pt(111) and iridium oxide catalysts in acidic media.

    PubMed

    Ganassin, Alberto; Colic, Viktor; Tymoczko, Jakub; Bandarenka, Aliaksandr S; Schuhmann, Wolfgang

    2015-04-07

    Electrolyte components, which are typically not considered to be directly involved in catalytic processes at solid-liquid electrified interfaces, often demonstrate a significant or even drastic influence on the activity, stability and selectivity of electrocatalysts. While there has been certain progress in the understanding of these electrolyte effects, lack of experimental data for various important systems frequently complicates the rational design of new active materials. Modern proton-exchange membrane (PEM) electrolyzers utilize Pt- and Ir-based electrocatalysts, which are among the very few materials that are both active and stable under the extreme conditions of water splitting. We use model Pt(111) and Ir-oxide films grown on Ir(111) electrodes and explore the effect of alkali metal cations and sulfate-anions on the hydrogen evolution and the oxygen evolution reactions in acidic media. We demonstrate that sulfate anions decrease the activity of Ir-oxide towards the oxygen evolution reaction while Rb(+) drastically promotes hydrogen evolution reaction at the Pt(111) electrodes as compared to the reference HClO4 electrolytes. Issues related to the activity benchmarking for these catalysts are discussed.

  5. Electrolysis-enhanced anaerobic digestion of wastewater.

    PubMed

    Tartakovsky, B; Mehta, P; Bourque, J-S; Guiot, S R

    2011-05-01

    This study demonstrates enhanced methane production from wastewater in laboratory-scale anaerobic reactors equipped with electrodes for water electrolysis. The electrodes were installed in the reactor sludge bed and a voltage of 2.8-3.5 V was applied resulting in a continuous supply of oxygen and hydrogen. The oxygen created micro-aerobic conditions, which facilitated hydrolysis of synthetic wastewater and reduced the release of hydrogen sulfide to the biogas. A portion of the hydrogen produced electrolytically escaped to the biogas improving its combustion properties, while another part was converted to methane by hydrogenotrophic methanogens, increasing the net methane production. The presence of oxygen in the biogas was minimized by limiting the applied voltage. At a volumetric energy consumption of 0.2-0.3 Wh/L(R), successful treatment of both low and high strength synthetic wastewaters was demonstrated. Methane production was increased by 10-25% and reactor stability was improved in comparison to a conventional anaerobic reactor.

  6. Advanced Water Recovery Technologies for Long Duration Space Exploration Missions

    NASA Technical Reports Server (NTRS)

    Liu, Scan X.

    2005-01-01

    Extended-duration space travel and habitation require recovering water from wastewater generated in spacecrafts and extraterrestrial outposts since the largest consumable for human life support is water. Many wastewater treatment technologies used for terrestrial applications are adoptable to extraterrestrial situations but challenges remain as constraints of space flights and habitation impose severe limitations of these technologies. Membrane-based technologies, particularly membrane filtration, have been widely studied by NASA and NASA-funded research groups for possible applications in space wastewater treatment. The advantages of membrane filtration are apparent: it is energy-efficient and compact, needs little consumable other than replacement membranes and cleaning agents, and doesn't involve multiphase flow, which is big plus for operations under microgravity environment. However, membrane lifespan and performance are affected by the phenomena of concentration polarization and membrane fouling. This article attempts to survey current status of membrane technologies related to wastewater treatment and desalination in the context of space exploration and quantify them in terms of readiness level for space exploration. This paper also makes specific recommendations and predictions on how scientist and engineers involving designing, testing, and developing space-certified membrane-based advanced water recovery technologies can improve the likelihood of successful development of an effective regenerative human life support system for long-duration space missions.

  7. Wash water reclamation technology for advanced manned spacecraft

    NASA Technical Reports Server (NTRS)

    Putnam, D. F.

    1977-01-01

    The results of an analytical study and assessment of state-of-the-art wash water reclamation technology for advanced manned spacecraft is presented. All non-phase-change unit operations, unit processes, and subsystems currently under development by NASA are considered. Included among these are: filtration, ultrafiltration, carbon adsorption, ion exchange, chemical pretreatment, reverse osmosis, hyperfiltration, and certain urea removal techniques. Performance data are given together with the projected weights and sizes of key components and subsystems. In the final assessment, a simple multifiltration approach consisting of surface-type cartridge filters, carbon adsorption and ion exchange resins receives the highest rating for six-man orbital missions of up to 10 years in duration.

  8. Advancing Water and Water-Energy-Food Cluster Activities within Future Earth

    NASA Astrophysics Data System (ADS)

    Lawford, R. G.; Bhaduri, A.; Pahl-Wostl, C.

    2014-12-01

    In building its emerging program, Future Earth has encouraged former Earth System Science Partnership (ESSP) projects to redefine their objectives, priorities and problem approaches so they are aligned with those of Future Earth. These new projects will be characterized by more integrated applications of natural and social sciences as well as dialogue and science integrated across disciplinary boundaries to address a wide range of environmental and social issues. The Global Water System Project (GWSP) has had a heritage of integrating natural and social sciences, and recently started to also look at issues within the Water-Energy-Food (WEF) cluster using similar integrated approaches. As part of the growth of the scientific elements of this cluster, GWSP has approached Future Earth opportunities by addressing the sustainability for Water, Energy, and Food through integrated water information and improved governance.In this presentation the approaches being considered for promoting integration in both water and the WEF cluster will be discussed. In particular, potential contributions of Future Earth to research related to the use and management of water and to issues and science underpinning the W-E-F nexus deliberations will be identified. In both cases the increasing ability to utilize Earth observations and big data will advance this research agenda. In addition, the better understanding of the implications of governance structures in addressing these issues and the options for harmonizing the use of scientific knowledge and technological advances will be explored. For example, insights gained from water management studies undertaken within the GWSP are helping to focus plans for a "sustainable water futures" project and a WEF cluster within Future Earth. The potential role of the Sustainable Development Goals in bringing together the monitoring and science capabilities, and understanding of governance approaches, will be discussed as a framework for facilitating

  9. Recent Experimental Advances to Determine (noble) Gases in Waters

    NASA Astrophysics Data System (ADS)

    Kipfer, R.; Brennwald, M. S.; Huxol, S.; Mächler, L.; Maden, C.; Vogel, N.; Tomonaga, Y.

    2013-12-01

    In aquatic systems noble gases, radon, and bio-geochemically conservative transient trace gases (SF6, CFCs) are frequently applied to determine water residence times and to reconstruct past environmental and climatic conditions. Recent experimental breakthroughs now enable ● to apply the well-established concepts of terrestrial noble gas geochemistry in waters to the minute water amounts stored in sediment pore space and in fluid inclusions (A), ● to determine gas exchange processes on the bio-geochemical relevant time scales of minutes - hours (B), and ● to separate diffusive and advective gas transport in soil air (C). A. Noble-gas analysis in water samples (< 1 g) facilitates determining the solute transport in the pore space and identifying the origin of bio- and geogenic fluids in (un) consolidated sediments [1]. Advanced techniques that combine crushing and sieving speleothem samples in ultra-high-vacuum to a specific grain size allow to separate air and water-bearing fluid inclusions and thus enables noble-gas-based reconstruction of environmental conditions from water masses as small as 1mg [2]. B. The coupling of noble gas analysis with approaches of gas chromatography permits combined analysis of noble gases and other gases species (e.g., SF6, CFCs, O2, N2) from a single water sample. The new method substantially improves ground water dating by SF6 and CFCs as excess air is quantified from the same sample and hence can adequately be corrected for [3]. Portable membrane-inlet mass spectrometers enable the quasi-continuous and real-time analysis of noble gases and other dissolved gases directly in the field, allowing, for instance, quantification of O2 turnover rates on small time scales [4]. C. New technical developments perfect 222Rn analysis in water by the synchronous the determination of the short-lived 220Rn. The combined 220,222Rn analysis sheds light on the emanation behaviour of radon by identifying soil water content to be the crucial

  10. Anticipatory Water Management in Phoenix using Advanced Scenario Planning and Analyses: WaterSim 5

    NASA Astrophysics Data System (ADS)

    Sampson, D. A.; Quay, R.; White, D. D.; Gober, P.; Kirkwood, C.

    2013-12-01

    Complexity, uncertainty, and variability are inherent properties of linked social and natural processes; sustainable resource management must somehow consider all three. Typically, a decision support tool (using scenario analyses) is used to examine management alternatives under suspected trajectories in driver variables (i.e., climate forcing's, growth or economic projections, etc.). This traditional planning focuses on a small set of envisioned scenarios whose outputs are compared against one-another in order to evaluate their differing impacts on desired metrics. Human cognition typically limits this to three to five scenarios. However, complex and highly uncertain issues may require more, often much more, than five scenarios. In this case advanced scenario analysis provides quantitative or qualitative methods that can reveal patterns and associations among scenario metrics for a large ensemble of scenarios. From this analysis, then, a smaller set of heuristics that describe the complexity and uncertainty revealed provides a basis to guide planning in an anticipatory fashion. Our water policy and management model, termed WaterSim, permits advanced scenario planning and analysis for the Phoenix Metropolitan Area. In this contribution we examine the concepts of advanced scenario analysis on a large scale ensemble of scenarios using our work with WaterSim as a case study. For this case study we created a range of possible water futures by creating scenarios that encompasses differences in water supplies (our surrogates for climate change, drought, and inherent variability in riverine flows), population growth, and per capital water consumption. We used IPCC estimates of plausible, future, alterations in riverine runoff, locally produced and vetted estimates of population growth projections, and empirical trends in per capita water consumption for metropolitan cities. This ensemble consisted of ~ 30, 700 scenarios (~575 k observations). We compared and contrasted

  11. Improved enzymatic hydrolysis of lignocellulosic biomass through pretreatment with plasma electrolysis.

    PubMed

    Gao, Jing; Chen, Li; Zhang, Jian; Yan, Zongcheng

    2014-11-01

    A comprehensive research on plasma electrolysis as pretreatment method for water hyacinth (WH) was performed based on lignin content, crystalline structure, surface property, and enzymatic hydrolysis. A large number of active particles, such as HO and H2O2, generated by plasma electrolysis could decompose the lignin of the biomass samples and reduce the crystalline index. An efficient pretreatment process made use of WH pretreated at a load of 48 wt% (0.15-0.18 mm) in FeCl3 solution for 30 min at 450 V. After the pretreatment, the sugar yield of WH was increased by 126.5% as compared with unpretreated samples.

  12. Contact Electrification of Regolith Particles and Chloride Electrolysis: Synthesis of Perchlorates on Mars

    NASA Astrophysics Data System (ADS)

    Tennakone, K.

    2016-10-01

    Contact electrification of chloride-impregnated martian regolith particles due to eolian agitation and moisture condensation on coalesced oppositely charged grains may lead to spontaneous electrolysis that generates hypochlorite, chlorite, chlorate, and perchlorate with a concomitant reduction of water to hydrogen. This process is not curtailed even if moisture condenses as ice because chloride ionizes on the surface of ice. Limitations dictated by potentials needed for electrolysis and breakdown electric fields enable estimation of the required regolith grain size. The estimated dimension turns out to be of the same order of magnitude as the expected median size of martian regolith, and a simple calculation yields the optimum rate of perchlorate production.

  13. Water cooled metal optics for the Advanced Light Source

    SciTech Connect

    McKinney, W.R.; Irick, S.C.; Lunt, D.L.J.

    1991-10-28

    The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.

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

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1997-12-31

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

  15. Microbial electrolysis cells for high yield hydrogen gas production from organic matter.

    PubMed

    Logan, Bruce E; Call, Douglas; Cheng, Shaoan; Hamelers, Hubertus V M; Sleutels, Tom H J A; Jeremiasse, Adriaan W; Rozendal, René A

    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.

  16. Study of Pu consumption in Advanced Light Water Reactors. Evaluation of GE Advanced Boiling Water Reactor plants

    SciTech Connect

    Not Available

    1993-05-13

    Timely disposal of the weapons plutonium is of paramount importance to permanently safeguarding this material. GE`s 1300 MWe Advanced Boiling Water Reactor (ABWR) has been designed to utilize fill] core loading of mixed uranium-plutonium oxide fuel. Because of its large core size, a single ABWR reactor is capable of disposing 100 metric tons of plutonium within 15 years of project inception in the spiking mode. The same amount of material could be disposed of in 25 years after the start of the project as spent fuel, again using a single reactor, while operating at 75 percent capacity factor. In either case, the design permits reuse of the stored spent fuel assemblies for electrical energy generation for the remaining life of the plant for another 40 years. Up to 40 percent of the initial plutonium can also be completely destroyed using ABWRS, without reprocessing, either by utilizing six ABWRs over 25 years or by expanding the disposition time to 60 years, the design life of the plants and using two ABWRS. More complete destruction would require the development and testing of a plutonium-base fuel with a non-fertile matrix for an ABWR or use of an Advanced Liquid Metal Reactor (ALMR). The ABWR, in addition, is fully capable of meeting the tritium target production goals with already developed target technology.

  17. 21 CFR 886.4250 - Ophthalmic electrolysis unit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to...

  18. 21 CFR 886.4250 - Ophthalmic electrolysis unit.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to...

  19. 21 CFR 886.4250 - Ophthalmic electrolysis unit.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to...

  20. 21 CFR 886.4250 - Ophthalmic electrolysis unit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to...

  1. 21 CFR 886.4250 - Ophthalmic electrolysis unit.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to...

  2. The ISS Water Processor Catalytic Reactor as a Post Processor for Advanced Water Reclamation Systems

    NASA Technical Reports Server (NTRS)

    Nalette, Tim; Snowdon, Doug; Pickering, Karen D.; Callahan, Michael

    2007-01-01

    Advanced water processors being developed for NASA s Exploration Initiative rely on phase change technologies and/or biological processes as the primary means of water reclamation. As a result of the phase change, volatile compounds will also be transported into the distillate product stream. The catalytic reactor assembly used in the International Space Station (ISS) water processor assembly, referred to as Volatile Removal Assembly (VRA), has demonstrated high efficiency oxidation of many of these volatile contaminants, such as low molecular weight alcohols and acetic acid, and is considered a viable post treatment system for all advanced water processors. To support this investigation, two ersatz solutions were defined to be used for further evaluation of the VRA. The first solution was developed as part of an internal research and development project at Hamilton Sundstrand (HS) and is based primarily on ISS experience related to the development of the VRA. The second ersatz solution was defined by NASA in support of a study contract to Hamilton Sundstrand to evaluate the VRA as a potential post processor for the Cascade Distillation system being developed by Honeywell. This second ersatz solution contains several low molecular weight alcohols, organic acids, and several inorganic species. A range of residence times, oxygen concentrations and operating temperatures have been studied with both ersatz solutions to provide addition performance capability of the VRA catalyst.

  3. EPA Science Matters Newsletter: Advancing Ways to Clean Up Drinking Water Systems (Published November 2013)

    EPA Pesticide Factsheets

    To advance the science and engineering of decontaminating pipe systems and safely disposing of high-volumes of contaminated water, Agency homeland security researchers are developing a Water Security Test Bed (WSTB).

  4. Production of Oxygen from Lunar Regolith by Molten Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Curreri, Peter A.

    2009-01-01

    This paper describes the use of the molten oxide electrolysis (MOE) process for the extraction of oxygen for life support and propellant, and silicon and metallic elements for use in fabrication on the Moon. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis is ideal for extraction, since the electron is the only practical reducing agent. MOE has several advantages over other extraction methods. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. Alternatively, MOE requires no import of consumable reagents (e.g. fluorine and carbon) as other processes do, and does not rely on interfacing multiple processes to obtain refined products. Electrolytic processing has the advantage of selectivity of reaction in the presence of a multi-component feed. Products from lunar regolith can be extracted in sequence according to the stabilities of their oxides as expressed by the values of the free energy of oxide formation (e.g. chromium, manganese, Fe, Si, Ti, Al, magnesium, and calcium). Previous work has demonstrated the viability of producing Fe and oxygen from oxide mixtures similar in composition to lunar regolith by molten oxide electrolysis (electrowinning), also called magma electrolysis having shown electrolytic extraction of Si from regolith simulant. This paper describes recent advances in demonstrating the MOE process by a joint project with participation by NASA KSC and

  5. Technology Evaluation for an Advanced Individual Protection System (AIPS)

    DTIC Science & Technology

    1992-12-01

    from CO2 Using Electrolysis........................ 21 3.1.4.3 OG from Water Vapor Electrolysis (WVE).................. 22 3.1.4.4 OG from Plant/ Algae ...Dioxide Water (vapor) Electrolysis Plant/ Algae Bioregenerative Support System Respirat$ Hyperthermal Atomic Oxygen Generation Oxygen$ Surrogate Lungs...bioregernerative support -’ from Plant/ Algae system to generate oxygen, supply fresh food, Growth and remove CO2. - Impractical Artificial Gills Water flowing

  6. Lunar production of oxygen by electrolysis

    NASA Technical Reports Server (NTRS)

    Keller, Rudolf

    1991-01-01

    Two approaches to prepare oxygen from lunar resources by direct electrolysis are discussed. Silicates can be melted or dissolved in a fused salt and electrolyzed with oxygen evolved at the anode. Direct melting and electrolysis is potentially a very simple process, but high temperatures of 1400-1500 C are required, which aggravates materials problems. Operating temperatures can be lowered to about 1000 C by employing a molten salt flux. In this case, however, losses of electrolyte components must be avoided. Experimentation on both approaches is progressing.

  7. Water Vapor Permeability of the Advanced Crew Escape Suit

    NASA Technical Reports Server (NTRS)

    Bue, Grant; Kuzneth, Larry; Gillis, David; Jones, Jeffery; Daniel, Brian; Gernhardt, Michael; Hamilton, Douglas

    2009-01-01

    Crew Exploration Vehicle (CEV) crewmembers are expected to return to earth wearing a suit similar to the current Advanced Crew Escape Suit (ACES). To ensure optimum cognitive performance, suited crewmembers must maintain their core body temperature within acceptable limits. There are currently several options for thermal maintenance in the post-landing phase. These include the current baseline, which uses an ammonia boiler, purge flow using oxygen in the suit, accessing sea water for liquid cooling garment (LCG) cooling and/or relying on the evaporative cooling capacity of the suit. These options vary significantly in mass, power, engineering and safety factors, with relying on the evaporative cooling capacity of the suit being the least difficult to implement. Data from previous studies indicates that the evaporative cooling capacity of the ACES was much higher than previously expected, but subsequent tests were performed for longer duration and higher metabolic rates to better define the water vapor permeability of the ACES. In these tests five subjects completed a series of tests performing low to moderate level exercise in order to control for a target metabolic rate while wearing the ACES in an environmentally controlled thermal chamber. Four different metabolic profiles at a constant temperature of 95 F and relative humidity of 50% were evaluated. These tests showed subjects were able to reject about twice as much heat in the permeable ACES as they were in an impermeable suit that had less thermal insulation. All of the heat rejection differential is attributed to the increased evaporation capability through the Gortex bladder of the suit.

  8. 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

    NASA Astrophysics Data System (ADS)

    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

  9. Electrolysis Propulsion Provides High-Performance, Inexpensive, Clean Spacecraft Propulsion

    NASA Technical Reports Server (NTRS)

    deGroot, Wim A.

    1999-01-01

    An electrolysis propulsion system consumes electrical energy to decompose water into hydrogen and oxygen. These gases are stored in separate tanks and used when needed in gaseous bipropellant thrusters for spacecraft propulsion. The propellant and combustion products are clean and nontoxic. As a result, costs associated with testing, handling, and launching can be an order of magnitude lower than for conventional propulsion systems, making electrolysis a cost-effective alternative to state-of-the-art systems. The electrical conversion efficiency is high (>85 percent), and maximum thrust-to-power ratios of 0.2 newtons per kilowatt (N/kW), a 370-sec specific impulse, can be obtained. A further advantage of the water rocket is its dual-mode potential. For relatively high thrust applications, the system can be used as a bipropellant engine. For low thrust levels and/or small impulse bit requirements, cold gas oxygen can be used alone. An added innovation is that the same hardware, with modest modifications, can be converted into an energy-storage and power-generation fuel cell, reducing the spacecraft power and propulsion system weight by an order of magnitude.

  10. 77 FR 3009 - Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Advanced Boiling Water Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ... COMMISSION Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Advanced Boiling Water Reactors..., ``Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Advanced Boiling Water Reactors.'' DATES... developed using this Catalog along with the Operator Licensing Examination Standards for Power...

  11. Technology advancement of an oxygen generation subsystem

    NASA Technical Reports Server (NTRS)

    Lee, M. K.; Burke, K. A.; Schubert, F. H.; Wynveen, R. A.

    1979-01-01

    An oxygen generation subsystem based on water electrolysis was developed and tested to further advance the concept and technology of the spacecraft air revitalization system. Emphasis was placed on demonstrating the subsystem integration concept and hardware maturity at a subsystem level. The integration concept of the air revitalization system was found to be feasible. Hardware and technology of the oxygen generation subsystem was demonstrated to be close to the preprototype level. Continued development of the oxygen generation technology is recommended to further reduce the total weight penalties of the oxygen generation subsystem through optimization.

  12. Combining Electrolysis and Electroporation for Tissue Ablation.

    PubMed

    Phillips, Mary; Rubinsky, Liel; Meir, Arie; Raju, Narayan; Rubinsky, Boris

    2015-08-01

    Electrolytic ablation is a method that operates by delivering low magnitude direct current to the target region over long periods of time, generating electrolytic products that destroy cells. This study was designed to explore the hypothesis stating that electrolytic ablation can be made more effective when the electrolysis-producing electric charges are delivered using electric pulses with field strength typical in reversible electroporation protocols. (For brevity we will refer to tissue ablation protocols that combine electroporation and electrolysis as E(2).) The mechanistic explanation of this hypothesis is related to the idea that products of electrolysis generated by E(2) protocols can gain access to the interior of the cell through the electroporation permeabilized cell membrane and therefore cause more effective cell death than from the exterior of an intact cell. The goal of this study is to provide a first-order examination of this hypothesis by comparing the charge dosage required to cause a comparable level of damage to a rat liver, in vivo, when using either conventional electrolysis or E(2) approaches. Our results show that E(2) protocols produce tissue damage that is consistent with electrolytic ablation. Furthermore, E(2) protocols cause damage comparable to that produced by conventional electrolytic protocols while delivering orders of magnitude less charge to the target tissue over much shorter periods of time.

  13. The Production and Characterization of Ceramic Carbon Electrode Materials for CuCl-HCl Electrolysis

    NASA Astrophysics Data System (ADS)

    Edge, Patrick

    Current H2 gas supplies are primarily produced through steam methane reforming and other fossil fuel based processes. This lack of viable large scale and environmentally friendly H2 gas production has hindered the wide spread adoption of H2 fuel cells. A potential solution to this problem is the Cu-Cl hybrid thermochemical cycle. The cycle captures waste heat to drive two thermochemical steps creating CuCl as well as O2 gas and HCl from CuCl2 and water. The CuCl is oxidized in HCl to produce H2 gas and regenerate CuCl2, this process occurs at potentials well below those required for water electrolysis. The electrolysis process occurs in a traditional PEM fuel-cell. In the aqueous anolyte media Cu(I) will form anionic complexes such as CuCl 2 - or CuCl32-. The slow transport of these species to the anode surface limits the overall electrolysis process. To improve this transport process we have produced ceramic carbon electrode (CCE) materials through a sol-gel method incorporating a selection of amine containing silanes with increasing numbers of primary and secondary amines. When protonated these amines allow for improved transport of anionic copper complexes. The electrochemical and physical characterization of these CCE materials in a half and full-cell electrolysis environment will be presented. Electrochemical analysis was performed using cell polarization, cyclic voltammetry, and electrochemical impedance spectroscopy.

  14. Toxicity of irradiated advanced heavy water reactor fuels.

    PubMed

    Priest, N D; Richardson, R B; Edwards, G W R

    2013-02-01

    The good neutron economy and online refueling capability of the CANDU® heavy water moderated reactor (HWR) enable it to use many different fuels such as low enriched uranium (LEU), plutonium, or thorium, in addition to its traditional natural uranium (NU) fuel. The toxicity and radiological protection methods for these proposed fuels, unlike those for NU, are not well established. This study uses software to compare the fuel composition and toxicity of irradiated NU fuel against those of two irradiated advanced HWR fuel bundles as a function of post-irradiation time. The first bundle investigated is a CANFLEX® low void reactor fuel (LVRF), of which only the dysprosium-poisoned central element, and not the outer 42 LEU elements, is specifically analyzed. The second bundle investigated is a heterogeneous high-burnup (LEU,Th)O(2) fuelled bundle, whose two components (LEU in the outer 35 elements and thorium in the central eight elements) are analyzed separately. The LVRF central element was estimated to have a much lower toxicity than that of NU at all times after shutdown. Both the high burnup LEU and the thorium fuel had similar toxicity to NU at shutdown, but due to the creation of such inhalation hazards as (238)Pu, (240)Pu, (242)Am, (242)Cm, and (244)Cm (in high burnup LEU), and (232)U and (228)Th (in irradiated thorium), the toxicity of these fuels was almost double that of irradiated NU after 2,700 d of cooling. New urine bioassay methods for higher actinoids and the analysis of thorium in fecal samples are recommended to assess the internal dose from these two fuels.

  15. Microbial fuel cells and microbial electrolysis cells for the production of bioelectricity and biomaterials.

    PubMed

    Zhou, Minghua; Yang, Jie; Wang, Hongyu; Jin, Tao; Xu, Dake; Gu, Tingyue

    2013-01-01

    Today's global energy crisis requires a multifaceted solution. Bioenergy is an important part of the solution. The microbial fuel cell (MFC) technology stands out as an attractive potential technology in bioenergy. MFCs can convert energy stored in organic matter directly into bioelectricity. MFCs can also be operated in the electrolysis mode as microbial electrolysis cells to produce bioproducts such as hydrogen and ethanol. Various wastewaters containing low-grade organic carbons that are otherwise unutilized can be used as feed streams for MFCs. Despite major advances in the past decade, further improvements in MFC power output and cost reduction are needed for MFCs to be practical. This paper analysed MFC operating principles using bioenergetics and bioelectrochemistry. Several major issues were explored to improve the MFC performance. An emphasis was placed on the use of catalytic materials for MFC electrodes. Recent advances in the production of various biomaterials using MFCs were also investigated.

  16. Efficient removal of insecticide "imidacloprid" from water by electrochemical advanced oxidation processes.

    PubMed

    Turabik, Meral; Oturan, Nihal; Gözmen, Belgin; Oturan, Mehmet A

    2014-01-01

    The oxidative degradation of imidacloprid (ICP) has been carried out by electrochemical advanced oxidation processes (EAOPs), anodic oxidation, and electro-Fenton, in which hydroxyl radicals are generated electrocatalytically. Carbon-felt cathode and platinum or boron-doped diamond (BDD) anodes were used in electrolysis cell. To determine optimum operating conditions, the effects of applied current and catalyst concentration were investigated. The decay of ICP during the oxidative degradation was well fitted to pseudo-first-order reaction kinetics and absolute rate constant of the oxidation of ICP by hydroxyl radicals was found to be k abs(ICP) = 1.23 × 10(9) L mol(-1) s(-1). The results showed that both anodic oxidation and electro-Fenton process with BDD anode exhibited high mineralization efficiency reaching 91 and 94% total organic carbon (TOC) removal at 2 h, respectively. For Pt-EF process, mineralization efficiency was also obtained as 71%. The degradation products of ICP were identified and a plausible general oxidation mechanism was proposed. Some of the main reaction intermediates such as 6-chloronicotinic acid, 6-chloronicotinaldehyde, and 6-hydroxynicotinic acid were determined by GC-MS analysis. Before complete mineralization, formic, acetic, oxalic, and glyoxylic acids were identified as end-products. The initial chlorine and organic nitrogen present in ICP were found to be converted to inorganic anions Cl(-), NO₃(-), and NH₄(+).

  17. SSWR Water Systems Project 2: Next Steps – Technology Advances

    EPA Science Inventory

    EPA is responsible for protecting America’s water resources under the Clean Water Act (CWA) and for ensuring that the Nation’s drinking water is safe under the Safe Drinking Water Act (SDWA). Further, it is the responsibility of EPA to conduct research and analyses t...

  18. Advanced Materials for RSOFC Dual Operation with Low Degradation

    SciTech Connect

    Eric, Tang; Tony, Wood; Sofiane, Benhaddad; Casey, Brown; Hongpeng, He; Jeff, Nelson; Oliver, Grande; Ben, Nuttall; Mark, Richards; Randy, Petri

    2012-12-27

    Reversible solid oxide fuel cells (RSOFCs) are energy conversion devices. They are capable of operating in both power generation mode (SOFC) and electrolysis modes (SOEC). RSOFC can integrate renewable production of electricity and hydrogen when power generation and steam electrolysis are coupled in a system, which can turn intermittent solar and wind energy into "firm power." In this DOE EERE project, VPS continuously advanced RSOFC cell stack technology in the areas of endurance and performance. Over 20 types of RSOFC cells were developed in the project. Many of those exceeded performance (area specific resistance less than 300 mohmcm2) and endurance (degradation rate less than 4% per 1000 hours) targets in both fuel cell and electrolysis modes at 750C. One of those cells, RSOFC-7, further demonstrated the following: Steady-state electrolysis with a degradation rate of 1.5% per 1000 hours. Ultra high current electrolysis over 3 A/cm2 at 75% water electrolysis efficiency voltage of 1.67 V. Daily SOFC/SOEC cyclic test of over 600 days with a degradation rate of 1.5% per 1000 hours. Over 6000 SOFC/SOEC cycles in an accelerated 20-minute cycling with degradation less than 3% per 1000 cycles. In RSOFC stack development, a number of kW-class RSOFC stacks were developed and demonstrated the following: Steady-state electrolysis operation of over 5000 hours. Daily SOFC/SOEC cyclic test of 100 cycles. Scale up capability of using large area cells with 550 cm2 active area showing the potential for large-scale RSOFC stack development in the future. Although this project is an open-ended development project, this effort, leveraging Versa Power Systems' years of development experience, has the potential to bring renewable energy RSOFC storage systems significantly closer to commercial viability through improvements in RSOFC durability, performance, and cost. When unitized and deployed in renewable solar and wind installations, an RSOFC system can enable higher availability for

  19. [Research advances in simulating land water-carbon coupling].

    PubMed

    Liu, Ning; Sun, Peng-Sen; Liu, Shi-Rong

    2012-11-01

    The increasing demand of adaptive management of land, forest, and water resources under the background of global change and water resources crisis has promoted the comprehensive study of coupling ecosystem water and carbon cycles and their restrictive relations. To construct the water-carbon coupling model and to approach the ecosystem water-carbon balance and its interactive response mechanisms under climate change at multiple spatiotemporal scales is nowadays a major concern. After reviewing the coupling relationships of water and carbon at various scales, this paper explored the implications and estimation methods of the key processes and related parameters of water-carbon coupling, the construction of evapotranspiration model at large scale based on RS, and the importance of this model in water-carbon coupling researches. The applications of assimilative multivariate data in water-carbon coupling researches under future climate change scenarios were also prospected.

  20. 3D CFD Model of a Tubular Porous-Metal Supported Solid Oxide Electrolysis Cell

    SciTech Connect

    G.L. Hawkes; B.D. Hawkes; M.S. Sohal; P.T. Torgerson; T. Armstrong; M.C. Williams

    2007-10-01

    Currently there is strong interest in the large-scale production of hydrogen as an energy carrier for the non-electrical market [1, 2, and 3]. High-temperature nuclear reactors have the potential for substantially increasing the efficiency of hydrogen production from water splitting, with no consumption of fossil fuels, no production of greenhouse gases, and no other forms of air pollution. A high-temperature advanced nuclear reactor coupled with a high-efficiency high-temperature electrolyzer could achieve a competitive thermal-to-hydrogen conversion efficiency of 45 to 55%. A research program is under way at the INL to simultaneously address the research and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for hydrogen production from steam. The future SOEC market includes the 1200MW GEN4 reactor which has projected 40-50% efficiency, 400 tones H2 production per day (at 5kg H2/car/300 mile day this corresponds to 80,000 cars/day). DOE is planning for 26GW of nuclear hydrogen production by 2025.

  1. Soil Water: Advanced Crop and Soil Science. A Course of Study.

    ERIC Educational Resources Information Center

    Miller, Larry E.

    The course of study represents the fourth of six modules in advanced crop and soil science and introduces the agriculture student to the topic of soil water. Upon completing the three day module, the student will be able to classify water as to its presence in the soil, outline the hydrological cycle, list the ways water is lost from the soil,…

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    Gupta, Susanta K. Sen

    2015-12-01

    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.

  4. Advanced Decentralized Water/Energy Network Design for Sustainable Infrastructure

    EPA Science Inventory

    In order to provide a water infrastructure that is more sustainable into and beyond the 21st century, drinking water distribution systems and wastewater collection systems must account for our diminishing water supply, increasing demands, climate change, energy cost and availabil...

  5. ADVANCES IN DRINKING WATER TREATMENT IN THE UNITED STATES

    EPA Science Inventory

    The United States drinking water public health protection goal is to provide water that meets all health-based standards to ninety-five percent of the population served by public drinking water supplies by 2005. In 2002, the level of compliance with some eighty-five health-based ...

  6. Recent Advances in Water Analysis with Gas Chromatograph Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    MacAskill, John A.; Tsikata, Edem

    2014-01-01

    We report on progress made in developing a water sampling system for detection and analysis of volatile organic compounds in water with a gas chromatograph mass spectrometer (GCMS). Two approaches are described herein. The first approach uses a custom water pre-concentrator for performing trap and purge of VOCs from water. The second approach uses a custom micro-volume, split-splitless injector that is compatible with air and water. These water sampling systems will enable a single GC-based instrument to analyze air and water samples for VOC content. As reduced mass, volume, and power is crucial for long-duration, manned space-exploration, these water sampling systems will demonstrate the ability of a GCMS to monitor both air and water quality of the astronaut environment, thereby reducing the amount of required instrumentation for long duration habitation. Laboratory prototypes of these water sampling systems have been constructed and tested with a quadrupole ion trap mass spectrometer as well as a thermal conductivity detector. Presented herein are details of these water sampling system with preliminary test results.

  7. [Oxidative efficiency of the system of electrolysis coupled ozonation].

    PubMed

    Zhou, Qi; Zhang, Rong; Wang, Xun-Hua; Tong, Shao-Ping; Ma, Chun-An

    2010-09-01

    The oxidation system of electrolysis coupled ozonation (electrolysis-ozonation) was used to degrade 4-chlorophenol (4-CP), and its mechanism was discussed on the basis of kinetic analysis. The experimental results indicated the electrolysis-ozonation system had a significant synergistic effect during degradation of 4-CP. For example, the electrolysis-ozonation had the 4-CP removal rate of 92.7% and the COD removal rate of 64.9% in 900 s, respectively; while electrolysis alone plus ozonation alone only had the 4-CP removal rate of 69.7% and the COD removal rate of 30.1% under the same conditions. The results of H2O2 concentration analysis and photocurrent test showed that the synergistic mechanism of electrolysis-ozonation included two factors: (1) production of *03- at the cathode; (2) H2O2 generation resulting from reduction of dissolved oxygen. The above two factors led to generation of *OH in system effectively.

  8. Recent Advances in Point-of-Access Water Quality Monitoring

    NASA Astrophysics Data System (ADS)

    Korostynska, O.; Arshak, K.; Velusamy, V.; Arshak, A.; Vaseashta, Ashok

    Clean water is one of our most valuable natural resources. In addition to providing safe drinking water it assures functional ecosystems that support fisheries and recreation. Human population growth and its associated increased demands on water pose risks to maintaining acceptable water quality. It is vital to assess source waters and the aquatic systems that receive inputs from industrial waste and sewage treatment plants, storm water systems, and runoff from urban and agricultural lands. Rapid and confident assessments of aquatic resources form the basis for sound environmental management. Current methods engaged in tracing the presence of various bacteria in water employ bulky laboratory equipment and are time consuming. Thus, real-time water quality monitoring is essential for National and International Health and Safety. Environmental water monitoring includes measurements of physical characteristics (e.g. pH, temperature, conductivity), chemical parameters (e.g. oxygen, alkalinity, nitrogen and phosphorus compounds), and abundance of certain biological taxa. Monitoring could also include assays of biological activity such as alkaline phosphatase, tests for toxins such as microcystins and direct measurements of pollutants such as heavy metals or hydrocarbons. Real time detection can significantly reduce the level of damage and also the cost to remedy the problem. This paper presents overview of state-of-the-art methods and devices used for point-of-access water quality monitoring and suggest further developments in this area.

  9. 77 FR 62270 - Proposed Revision Treatment of Non-Safety Systems for Passive Advanced Light Water Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-12

    ... Non-Safety Systems for Passive Advanced Light Water Reactors AGENCY: Nuclear Regulatory Commission... Systems (RTNSS) for Passive Advanced Light Water Reactors.'' The current SRP does not contain guidance on the proposed RTNSS for Passive Advance Light Water Reactors. DATES: Submit comments by November...

  10. 78 FR 41436 - Proposed Revision to Treatment of Non-Safety Systems for Passive Advanced Light Water Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-10

    ... COMMISSION Proposed Revision to Treatment of Non-Safety Systems for Passive Advanced Light Water Reactors... Treatment of Non-Safety Systems (RTNSS) for Passive Advanced Light Water Reactors.'' The NRC seeks public...- Safety Systems (RTNSS) for Passive Advanced Light Water Reactors.'' This area includes a revised...

  11. ADVANCED TOOLS FOR ASSESSING SELECTED PRESCRIPTION AND ILLICIT DRUGS IN TREATED SEWAGE EFFLUENTS AND SOURCE WATERS

    EPA Science Inventory

    The purpose of this poster is to present the application and assessment of advanced technologies in a real-world environment - wastewater effluent and source waters - for detecting six drugs (azithromycin, fluoxetine, omeprazole, levothyroxine, methamphetamine, and methylenedioxy...

  12. Overview of advances in water management in agricultural production:Sensor based irrigation management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technological advances in irrigated agriculture are crucial to meeting the challenge of increasing demand for agricultural products given limited quality and quantity of water resources for irrigation, impacts of climate variability, and the need to reduce environmental impacts. Multidisciplinary ap...

  13. Advanced Technology Used to Monitor Ground Water in a Restricted Access Area of Fort Riley, Kansas

    USGS Publications Warehouse

    Breedlove, J.D.; Finnegan, P.J.; Myers, N.C.

    1998-01-01

    The purpose of this fact sheet is to describe how advanced communication technology is being used to overcome difficulties in collecting reliable ground-water data in areas with restricted access, such as at Fort Riley in northeast Kansas.

  14. Advances in water resources assessment with SWAT - an overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper introduces a Special Issue containing 12 research articles which present current applications of the Soil and Water Assessment Tool (SWAT) for water resources assessment. Firstly, an overview of selected recently published articles with application of SWAT is given. The articles address ...

  15. Study of Pu consumption in advanced light water reactors: Evaluation of GE advanced boiling water reactor plants - compilation of Phase 1B task reports

    SciTech Connect

    1993-09-15

    This report contains an extensive evaluation of GE advanced boiling water reactor plants prepared for United State Department of Energy. The general areas covered in this report are: core and system performance; fuel cycle; infrastructure and deployment; and safety and environmental approval.

  16. Simple Electrolyzer Model Development for High-Temperature Electrolysis System Analysis Using Solid Oxide Electrolysis Cell

    SciTech Connect

    JaeHwa Koh; DuckJoo Yoon; Chang H. Oh

    2010-07-01

    An electrolyzer model for the analysis of a hydrogen-production system using a solid oxide electrolysis cell (SOEC) has been developed, and the effects for principal parameters have been estimated by sensitivity studies based on the developed model. The main parameters considered are current density, area specific resistance, temperature, pressure, and molar fraction and flow rates in the inlet and outlet. Finally, a simple model for a high-temperature hydrogen-production system using the solid oxide electrolysis cell integrated with very high temperature reactors is estimated.

  17. Recent advances in drinking water disinfection: successes and challenges.

    PubMed

    Ngwenya, Nonhlanhla; Ncube, Esper J; Parsons, James

    2013-01-01

    Drinking water is the most important single source of human exposure to gastroenteric diseases, mainly as a result of the ingestion of microbial contaminated water. Waterborne microbial agents that pose a health risk to humans include enteropathogenic bacteria, viruses, and protozoa. Therefore, properly assessing whether these hazardous agents enter drinking water supplies, and if they do, whether they are disinfected adequately, are undoubtedly aspects critical to protecting public health. As new pathogens emerge, monitoring for relevant indicator microorganisms (e.g., process microbial indicators, fecal indicators, and index and model organisms) is crucial to ensuring drinking water safety. Another crucially important step to maintaining public health is implementing Water Safety Plans (WSPs), as is recommended by the current WHO Guidelines for Drinking Water Quality. Good WSPs include creating health-based targets that aim to reduce microbial risks and adverse health effects to which a population is exposed through drinking water. The use of disinfectants to inactivate microbial pathogens in drinking water has played a central role in reducing the incidence of waterborne diseases and is considered to be among the most successful interventions for preserving and promoting public health. Chlorine-based disinfectants are the most commonly used disinfectants and are cheap and easy to use. Free chlorine is an effective disinfectant for bacteria and viruses; however, it is not always effective against C. parvum and G. lamblia. Another limitation of using chlorination is that it produces disinfection by-products (DBPs), which pose potential health risks of their own. Currently, most drinking water regulations aggressively address DBP problems in public water distribution systems. The DBPs of most concern include the trihalomethanes (THMs), the haloacetic acids (HAAs), bromate, and chlorite. However, in the latest edition of the WHO Guidelines for Drinking Water Quality

  18. The function of advanced treatment process in a drinking water treatment plant with organic matter-polluted source water.

    PubMed

    Lin, Huirong; Zhang, Shuting; Zhang, Shenghua; Lin, Wenfang; Yu, Xin

    2015-08-07

    To understand the relationship between chemical and microbial treatment at each treatment step, as well as the relationship between microbial community structure in biofilms in biofilters and their ecological functions, a drinking water plant with severe organic matter-polluted source water was investigated. The bacterial community dynamics of two drinking water supply systems (traditional and advanced treatment processes) in this plant were studied from the source to the product water. Analysis by 454 pyrosequencing was conducted to characterize the bacterial diversity in each step of the treatment processes. The bacterial communities in these two treatment processes were highly diverse. Proteobacteria, which mainly consisted of beta-proteobacteria, was the dominant phylum. The two treatment processes used in the plant could effectively remove organic pollutants and microbial polution, especially the advanced treatment process. Significant differences in the detection of the major groups were observed in the product water samples in the treatment processes. The treatment processes, particularly the biological pretreatment and O3-biological activated carbon in the advanced treatment process, highly influenced the microbial community composition and the water quality. Some opportunistic pathogens were found in the water. Nitrogen-relative microorganisms found in the biofilm of filters may perform an important function on the microbial community composition and water quality improvement.

  19. Biological efficacy and toxic effect of emergency water disinfection process based on advanced oxidation technology.

    PubMed

    Tian, Yiping; Yuan, Xiaoli; Xu, Shujing; Li, Rihong; Zhou, Xinying; Zhang, Zhitao

    2015-12-01

    An innovative and removable water treatment system consisted of strong electric field discharge and hydrodynamic cavitation based on advanced oxidation technologies was developed for reactive free radicals producing and waterborne pathogens eliminating in the present study. The biological efficacy and toxic effects of this advanced oxidation system were evaluated during water disinfection treatments. Bench tests were carried out with synthetic microbial-contaminated water, as well as source water in rainy season from a reservoir of Dalian city (Liaoning Province, China). Results showed that high inactivation efficiency of Escherichia coli (>5 log) could be obtained for synthetic contaminated water at a low concentration (0.5-0.7 mg L(-1)) of total oxidants in 3-10 s. The numbers of wild total bacteria (108 × 10(3) CFU mL(-1)) and total coliforms (260 × 10(2) MPN 100 mL(-1)) in source water greatly reduced to 50 and 0 CFU mL(-1) respectively after treated by the advanced oxidation system, which meet the microbiological standards of drinking water, and especially that the inactivation efficiency of total coliforms could reach 100%. Meanwhile, source water qualities were greatly improved during the disinfection processes. The values of UV254 in particular were significantly reduced (60-80%) by reactive free radicals. Moreover, the concentrations of possible disinfection by-products (formaldehyde and bromide) in treated water were lower than detection limits, indicating that there was no harmful effect on water after the treatments. These investigations are helpful for the ecotoxicological studies of advanced oxidation system in the treatments of chemical polluted water or waste water. The findings of this work suggest that the developed water treatment system is ideal in the acute phases of emergencies, which also could offer additional advantages over a wide range of applications in water pollution control.

  20. Organic coal-water fuel: Problems and advances (Review)

    NASA Astrophysics Data System (ADS)

    Glushkov, D. O.; Strizhak, P. A.; Chernetskii, M. Yu.

    2016-10-01

    The study results of ignition of organic coal-water fuel (OCWF) compositions were considered. The main problems associated with investigation of these processes were identified. Historical perspectives of the development of coal-water composite fuel technologies in Russia and worldwide are presented. The advantages of the OCWF use as a power-plant fuel in comparison with the common coal-water fuels (CWF) were emphasized. The factors (component ratio, grinding degree of solid (coal) component, limiting temperature of oxidizer, properties of liquid and solid components, procedure and time of suspension preparation, etc.) affecting inertia and stability of the ignition processes of suspensions based on the products of coaland oil processing (coals of various types and metamorphism degree, filter cakes, waste motor, transformer, and turbine oils, water-oil emulsions, fuel-oil, etc.) were analyzed. The promising directions for the development of modern notions on the OCWF ignition processes were determined. The main reasons limiting active application of the OCWF in power generation were identified. Characteristics of ignition and combustion of coal-water and organic coal-water slurry fuels were compared. The effect of water in the composite coal fuels on the energy characteristics of their ignition and combustion, as well as ecological features of these processes, were elucidated. The current problems associated with pulverization of composite coal fuels in power plants, as well as the effect of characteristics of the pulverization process on the combustion parameters of fuel, were considered. The problems hindering the development of models of ignition and combustion of OCWF were analyzed. It was established that the main one was the lack of reliable experimental data on the processes of heating, evaporation, ignition, and combustion of OCWF droplets. It was concluded that the use of high-speed video recording systems and low-inertia sensors of temperature and gas

  1. Towards Versatile and Sustainable Hydrogen Production through Electrocatalytic Water Splitting: Electrolyte Engineering.

    PubMed

    Shinagawa, Tatsuya; Takanabe, Kazuhiro

    2016-12-16

    Recent advances in power generation from renewable resources necessitate conversion of electricity to chemicals and fuels in an efficient manner. Electrocatalytic water splitting is one of the most powerful and widespread technologies. The development of highly efficient, inexpensive, flexible, and versatile water electrolysis devices is desired. This review discusses the significance and impact of the electrolyte on electrocatalytic performance. Depending on the circumstances under which the water splitting reaction is conducted, the required solution conditions, such as the identity and molarity of ions, may significantly differ. Quantitative understanding of such electrolyte properties on electrolysis performance is effective to facilitate the development of efficient electrocatalytic systems. The electrolyte can directly participate in reaction schemes (kinetics), affect electrode stability, and/or indirectly impact the performance by influencing the concentration overpotential (mass transport). This review aims to guide fine-tuning of the electrolyte properties, or electrolyte engineering, for (photo)electrochemical water splitting reactions.

  2. Advances in the hydrogeochemistry and microbiology of acid mine waters

    USGS Publications Warehouse

    Nordstrom, D. Kirk

    2000-01-01

    The last decade has witnessed a plethora of research related to the hydrogeochemistry and microbiology of acid mine waters and associated tailings and waste-rock waters. Numerous books, reviews, technical papers, and proceedings have been published that examine the complex bio-geochemical process of sulfide mineral oxidation, develop and apply geochemical models to site characterization, and characterize the microbial ecology of these environments. This review summarizes many of these recent works, and provides references for those investigating this field. Comparisons of measured versus calculated Eh and measured versus calculated pH for water samples from several field sites demonstrate the reliability of some current geochemical models for aqueous speciation and mass balances. Geochemical models are not, however, used to predict accurately time-dependent processes but to improve our understanding of these systems and to constrain possible processes that contribute to actual or potential water quality issues. Microbiological studies are demonstrating that there is much we have yet to learn about the types of different microorganisms and their function and ecology in mine-waste environments. A broad diversity of green algae, bacteria, archaea, yeasts, and fungi are encountered in acid mine waters, and a better understanding of their ecology and function may potentially enhance remediation possibilities as well as our understanding of the evolution of life.

  3. Advanced Detector and Waveform Digitizer for Water Vapor DIAL Systems

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Luck, William S., Jr.; DeYoung, Russell J.

    1998-01-01

    Measurement of atmospheric water vapor has become a major requirement for understanding moist-air processes. Differential absorption lidar (DIAL) is a technique best suited for the measurement of atmospheric water vapor. NASA Langley Research Center is continually developing improved DIAL systems. One aspect of current development is focused on the enhancement of a DIAL receiver by applying state-of-the-art technology in building a new compact detection system that will be placed directly on the DIAL receiver telescope. The newly developed detection system has the capability of being digitally interfaced with a simple personal computer, using a discrete input/output interface. This has the potential of transmitting digital data over relatively long distances instead of analog signals, which greatly reduces measurement noise. In this paper, we discuss some results from the new compact water vapor DIAL detection system which includes a silicon based avalanche photodiode (APD) detector, a 14-bit, 10-MHz waveform digitizer, a microcontroller and other auxiliary electronics. All of which are contained on a small printed-circuit-board. This will significantly reduce the weight and volume over the current CAMAC system and eventually will be used in a water vapor DIAL system on an unpiloted atmospheric vehicle (UAV) aircraft, or alternatively on an orbiting spacecraft.

  4. Degradation in Solid Oxide Cells During High Temperature Electrolysis

    SciTech Connect

    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.

  5. Liquid Fuel Production from Biomass via High Temperature Steam Electrolysis

    SciTech Connect

    Grant L. Hawkes; Michael G. McKellar

    2009-11-01

    A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Hydrogen from electrolysis allows a high utilization of the biomass carbon for syngas production. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-fed biomass gasifier. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon monoxide and hydrogen). Assuming the thermal efficiency of the power cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K. Parametric studies of system pressure, biomass moisture content and low temperature alkaline electrolysis are also presented.

  6. Watts nickel and rinse water recovery via an advanced reverse osmosis system

    SciTech Connect

    Schmidt, C.; White, I.E.; Ludwig, R.

    1993-08-01

    The report summarizes the results of an eight month test program conducted at the Hewlett Packard Printed Circuit Board Production Plant, Sunnyvale, CA (H.P.) to assess the effectiveness of an advanced reverse osmosis system (AROS). The AROS unit, manufactured by Water Technologies, Inc. (WTI) of Minneapolis, MN, incorporates membrane materials and system components designed to treat metal plating rinse water and produce two product streams; (1) a concentrated metal solution suitable for the plating bath, and (2) rinse water suitable for reuse as final rinse. Waste water discharge can be virtually eliminated and significant reductions realized in the need for new plating bath solution and rinse water.

  7. Evolutionary/advanced light water reactor data report

    SciTech Connect

    1996-02-09

    The US DOE Office of Fissile Material Disposition is examining options for placing fissile materials that were produced for fabrication of weapons, and now are deemed to be surplus, into a condition that is substantially irreversible and makes its use in weapons inherently more difficult. The principal fissile materials subject to this disposition activity are plutonium and uranium containing substantial fractions of plutonium-239 uranium-235. The data in this report, prepared as technical input to the fissile material disposition Programmatic Environmental Impact Statement (PEIS) deal only with the disposition of plutonium that contains well over 80% plutonium-239. In fact, the data were developed on the basis of weapon-grade plutonium which contains, typically, 93.6% plutonium-239 and 5.9% plutonium-240 as the principal isotopes. One of the options for disposition of weapon-grade plutonium being considered is the power reactor alternative. Plutonium would be fabricated into mixed oxide (MOX) fuel and fissioned (``burned``) in a reactor to produce electric power. The MOX fuel will contain dioxides of uranium and plutonium with less than 7% weapon-grade plutonium and uranium that has about 0.2% uranium-235. The disposition mission could, for example, be carried out in existing power reactors, of which there are over 100 in the United States. Alternatively, new LWRs could be constructed especially for disposition of plutonium. These would be of the latest US design(s) incorporating numerous design simplifications and safety enhancements. These ``evolutionary`` or ``advanced`` designs would offer not only technological advances, but also flexibility in siting and the option of either government or private (e.g., utility) ownership. The new reactor designs can accommodate somewhat higher plutonium throughputs. This data report deals solely with the ``evolutionary`` LWR alternative.

  8. Unitized electrolysis propulsion and fuel cell power for selected satellite missions

    SciTech Connect

    McElroy, J.F.; Humble, R.; Groot, W.A. de; Oleson, S.R.; Mitlitsky, R.; Weisberg, A.H.; Myers, B.; Carter, P.H. II

    1998-07-01

    An integrated modular propulsion and regenerative electro-energy storage system for propulsion and power functions on board spacecraft is described. The system is based on electrolysis and fuel cell principles integrated in a single unit. With water as the working fluid for both the power and propulsion systems, a clean, safe, low cost and low weight solution for many spacecraft missions is assured. The system can be designed for stand-alone propulsion, or integrated with the power system. Representative missions for two different size spacecraft are given. Both missions show a significant weight savings when electrolysis propulsion systems are used. The weight savings are augmented when the power system is unified with the propulsion system.

  9. Summary Report on Solid-oxide Electrolysis Cell Testing and Development

    SciTech Connect

    J.E. O'Brien; X. Zhang; R.C. O'Brien; G.L. Hawkes

    2012-01-01

    Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cells (SOECs) for large-scale hydrogen production from steam over a temperature range of 800 to 900 C. From 2003 to 2009, this work was sponsored by the United States Department of Energy Nuclear Hydrogen Initiative, under the Office of Nuclear Energy. Starting in 2010, the high-temperature electrolysis (HTE) research program has been sponsored by the INL Next Generation Nuclear Plant Project. This report provides a summaryof program activities performed in Fiscal Year (FY) 2011 and the first quarter of FY-12, with a focus on small-scale testing and cell development activities. HTE research priorities during this period have included the development and testing of SOEC and stack designs that exhibit high-efficiency initial performance and low, long-term degradation rates. This report includes contributions from INL and five industry partners: Materials and Systems Research, Incorporated (MSRI); Versa Power Systems, Incorporated (VPS); Ceramatec, Incorporated; National Aeronautics and Space Administration - Glenn Research Center (NASA - GRC); and the St. Gobain Advanced Materials Division. These industry partners have developed SOEC cells and stacks for in-house testing in the electrolysis mode and independent testing at INL. Additional fundamental research and post-test physical examinations have been performed at two university partners: Massachusetts Institute of Technology (MIT) and the University of Connecticut. Summaries of these activities and test results are also presented in this report.

  10. Status of the INL high-temperature electrolysis research program –experimental and modeling

    SciTech Connect

    J. E. O'Brien; C. M. Stoots; M. G. McKellar; E. A. Harvego; K. G. Condie; G. K. Housley; J. S. Herring; J. J. Hartvigsen

    2009-04-01

    This paper provides a status update on the high-temperature electrolysis (HTE) research and development program at the Idaho National Laboratory (INL), with an overview of recent large-scale system modeling results and the status of the experimental program. System analysis results have been obtained using the commercial code UniSim, augmented with a custom high-temperature electrolyzer module. The process flow diagrams for the system simulations include an advanced nuclear reactor as a source of high-temperature process heat, a power cycle and a coupled steam electrolysis loop. Several reactor types and power cycles have been considered, over a range of reactor coolant outlet temperatures. In terms of experimental research, the INL has recently completed an Integrated Laboratory Scale (ILS) HTE test at the 15 kW level. The initial hydrogen production rate for the ILS test was in excess of 5000 liters per hour. Details of the ILS design and operation will be presented. Current small-scale experimental research is focused on improving the degradation characteristics of the electrolysis cells and stacks. Small-scale testing ranges from single cells to multiple-cell stacks. The INL is currently in the process of testing several state-of-the-art anode-supported cells and is working to broaden its relationship with industry in order to improve the long-term performance of the cells.

  11. Meeting Summary Advanced Light Water Reactor Fuels Industry Meeting Washington DC October 27 - 28, 2011

    SciTech Connect

    Not Listed

    2011-11-01

    The Advanced LWR Fuel Working Group first met in November of 2010 with the objective of looking 20 years ahead to the role that advanced fuels could play in improving light water reactor technology, such as waste reduction and economics. When the group met again in March 2011, the Fukushima incident was still unfolding. After the March meeting, the focus of the program changed to determining what we could do in the near term to improve fuel accident tolerance. Any discussion of fuels with enhanced accident tolerance will likely need to consider an advanced light water reactor with enhanced accident tolerance, along with the fuel. The Advanced LWR Fuel Working Group met in Washington D.C. on October 72-18, 2011 to continue discussions on this important topic.

  12. Performance of a Water Recirculation Loop Maintenance Device and Process for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Steele, John W.; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2012-01-01

    A water loop maintenance device and process to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been undergoing a performance evaluation. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the water recirculation maintenance device and process is to further enhance this advantage through the leveraging of fluid loop management lessons-learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance process further leverages a sorbent developed for ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware. This

  13. Electrochemical Advanced Oxidation Process for Shipboard Final Purification of Filtered Black Water, Gray Water, and Bilge Water, Vol. 1

    DTIC Science & Technology

    2001-08-01

    Shipboard Final Purification of Filtered Black Water , Gray Water , and Bilge Water O. Weres, PhD and H.E. O’Donnell Sonoma Research Company Napa...Process for Shipboard Final Purification of Filtered Black Water , Gray Water , and Bilge Water 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...Shipboard Final Purification of Filtered Black Water , Gray Water , and Bilge Water Final Report Submitted to: SERDP Office 901 North Stuart Street, Suite

  14. OTEC Advanced Composite Cold Water Pipe: Final Technical Report

    SciTech Connect

    Dr. Alan Miller; Matthew Ascari

    2011-09-12

    Ocean Thermal Energy Conversion can exploit natural temperature gradients in the oceans to generate usable forms of energy (for example, cost-competitive baseload electricity in tropical regions such as Hawaii) free from fossil fuel consumption and global warming emissions.The No.1 acknowledged challenge of constructing an OTEC plant is the Cold Water Pipe (CWP), which draws cold water from 1000m depths up to the surface, to serve as the coolant for the OTEC Rankine cycle. For a commercial-scale plant, the CWP is on the order of 10m in diameter.This report describes work done by LMSSC developing the CWP for LM MS2 New Ventures emerging OTEC business. The work started in early 2008 deciding on the minimum-cost CWP architecture, materials, and fabrication process. In order to eliminate what in previous OTEC work had been a very large assembly/deployment risk, we took the innovative approach of building an integral CWP directly from theOTEC platform and down into the water. During the latter half of 2008, we proceeded to a successful small-scale Proof-of-Principles validation of the new fabrication process, at the Engineering Development Lab in Sunnyvale. During 2009-10, under the Cooperative Agreement with the US Dept. of Energy, we have now successfully validated key elements of the process and apparatus at a 4m diameter scale suitable for a future OTEC Pilot Plant. The validations include: (1) Assembly of sandwich core rings from pre-pultruded hollow 'planks,' holding final dimensions accurately; (2) Machine-based dispensing of overlapping strips of thick fiberglass fabric to form the lengthwise-continuous face sheets, holding accurate overlap dimensions; (3) Initial testing of the fabric architecture, showing that the overlap splices develop adequate mechanical strength (work done under a parallel US Naval Facilities Command program); and (4) Successful resin infusion/cure of 4m diameter workpieces, obtaining full wet-out and a non-discernable knitline between

  15. [Study advance on haloacetic acids in drinking water].

    PubMed

    Ye, Bi-Xiong; Wang, Wu-Yi; Yang, Lin-Sheng; Wang, Yong-Hua

    2006-05-01

    Haloacetic acids (HAAs) in drinking water have attracted more and more attention of researchers due to their higher potential combination of chlorine, their carcinogenic and mutagenic effects and higher carcinogenic. The formation mechanism, analytical methods, the effects of many factors on HAAs formation such as precursor types, chlorine doses, pH, temperature, bromide, reaction time and seasonal change, toxicological character and the minimizing technology of HAAs in resent studies about HAAs are discussed in details in this paper. Further researches are still needed to clarify the formation mechanism of HAAs and find a feasible minimizing technology. New concerns including toxicological characters that correlate with human and other HAAs exposure routes besides oral ingestion (i.e., inhalation and dermal adsorption) should be put forward.

  16. Design and Evaluation of a Water Recirculation Loop Maintenance Device for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Steele, John W.; Rector, Tony; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2011-01-01

    A dual-bed device to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been designed and is undergoing testing. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the development of a water recirculation maintenance device is to further enhance this advantage through the leveraging of fluid loop management lessons-learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The bed design further leverages a sorbent developed for ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a clear demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  17. Design and Evaluation of a Water Recirculation Loop Maintenance Device for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Steele, John W.; Rector, Tony; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2012-01-01

    A dual-bed device to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been designed and is undergoing testing. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing sublimator technology. The driver for the development of a water recirculation maintenance device is to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high-capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit Transport Water Loop. The bed design further leverages a sorbent developed for the ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System. The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of crewed spaceflight Environmental Control and Life Support System hardware.

  18. Performance of a Water Recirculation Loop Maintenance Device and Process for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Steele, John W.; Rector, Tony; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2013-01-01

    A dual-bed device to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been designed and is undergoing testing. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the development of a water recirculation maintenance device is to further enhance this advantage through the leveraging of fluid loop management lessons-learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The bed design further leverages a sorbent developed for ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  19. Light Water Reactor Sustainability Program Advanced Seismic Soil Structure Modeling

    SciTech Connect

    Bolisetti, Chandrakanth; Coleman, Justin Leigh

    2015-06-01

    of interest. The specific nonlinear soil behavior included in the NLSSI calculation presented in this report is gapping and sliding. Other NLSSI effects are not included in the calculation. The results presented in this report document initial model runs in the linear and nonlinear analysis process. Final comparisons between traditional and advanced SPRA will be presented in the September 30th deliverable.

  20. HIGH-TEMPERATURE ELECTROLYSIS FOR LARGE-SCALE HYDROGEN AND SYNGAS PRODUCTION FROM NUCLEAR ENERGY – SYSTEM SIMULATION AND ECONOMICS

    SciTech Connect

    J. E. O'Brien; M. G. McKellar; E. A. Harvego; C. M. Stoots

    2009-05-01

    A research and development program is under way at the Idaho National Laboratory (INL) to assess the technological and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for efficient high-temperature hydrogen production from steam. This work is supported by the US Department of Energy, Office of Nuclear Energy, under the Nuclear Hydrogen Initiative. This paper will provide an overview of large-scale system modeling results and economic analyses that have been completed to date. System analysis results have been obtained using the commercial code UniSim, augmented with a custom high-temperature electrolyzer module. Economic analysis results were based on the DOE H2A analysis methodology. The process flow diagrams for the system simulations include an advanced nuclear reactor as a source of high-temperature process heat, a power cycle and a coupled steam electrolysis loop. Several reactor types and power cycles have been considered, over a range of reactor outlet temperatures. Pure steam electrolysis for hydrogen production as well as coelectrolysis for syngas production from steam/carbon dioxide mixtures have both been considered. In addition, the feasibility of coupling the high-temperature electrolysis process to biomass and coal-based synthetic fuels production has been considered. These simulations demonstrate that the addition of supplementary nuclear hydrogen to synthetic fuels production from any carbon source minimizes emissions of carbon dioxide during the production process.

  1. Antimicrobial Materials for Advanced Microbial Control in Spacecraft Water Systems

    NASA Technical Reports Server (NTRS)

    Birmele, Michele; Caro, Janicce; Newsham, Gerard; Roberts, Michael; Morford, Megan; Wheeler, Ray

    2012-01-01

    Microbial detection, identification, and control are essential for the maintenance and preservation of spacecraft water systems. Requirements set by NASA put limitations on the energy, mass, materials, noise, cost, and crew time that can be devoted to microbial control. Efforts are being made to attain real-time detection and identification of microbial contamination in microgravity environments. Research for evaluating technologies for capability enhancement on-orbit is currently focused on the use of adenosine triphosphate (ATP) analysis for detection purposes and polymerase chain reaction (peR) for microbial identification. Additional research is being conducted on how to control for microbial contamination on a continual basis. Existing microbial control methods in spacecraft utilize iodine or ionic silver biocides, physical disinfection, and point-of-use sterilization filters. Although these methods are effective, they require re-dosing due to loss of efficacy, have low human toxicity thresholds, produce poor taste, and consume valuable mass and crew time. Thus, alternative methods for microbial control are needed. This project also explores ultraviolet light-emitting diodes (UV-LEDs), surface passivation methods for maintaining residual biocide levels, and several antimicrobial materials aimed at improving current microbial control techniques, as well as addressing other materials presently under analysis and future directions to be pursued.

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Hydrogen production by hybrid electrolysis combined with assistance of solar energy

    NASA Astrophysics Data System (ADS)

    Takehara, Z.; Yoshizawa, S.

    As a means of reducing the electrical energy needed to produce hydrogen from water, a process is presented, whereby an aqueous sulfuric acid solution containing Fe(2+) ions is electrolyzed, hydrogen being an energy storage material which levels load variation of electrical utilities. In an electrolytic cell, Fe(2+) ions are oxidized on a packed bed carbon anode to form Fe(3+) ions. H(+) ions diffuse through a cation exchange membrane, and are then reduced to hydrogen gas on the cathode. The Fe(3+) ions, produced in the cell, are decomposed in a photodecomposition cell. Oxygen evolves on the TiO2 anode, illuminated by solar light; the produced H(+) ions are diffused through a cation exchange membrane and electrons move through the metal inserted in the membrane to the cathode. The solution containing Fe(+) ions, introduced in the cathode chamber, is reduced cathodically on the platinized platinum. Cell voltage is determined for the process and it is found to be only about 1.0 V for electrolysis of 50mA/sq cm at room temperature. For the case of direct electrolysis of 2N NaOH aqueous solution, the cell voltage is 2.2V electrolysis of 30mA/sq cm. Results indicate a large reduction of electrical energy needed for the production of hydrogen in the process presented.

  5. TiO2-Based Advanced Oxidation Nanotechnologies For Water Purification And Reuse

    EPA Science Inventory

    TiO2 photocatalysis, one of the UV-based advanced oxidation technologies (AOTs) and nanotechnologies (AONs), has attracted great attention for the development of efficient water treatment and purification systems due to the effectiveness of TiO2 to generate ...

  6. Design of GA thermochemical water-splitting process for the Mirror Advanced Reactor System

    SciTech Connect

    Brown, L.C.

    1983-04-01

    GA interfaced the sulfur-iodine thermochemical water-splitting cycle to the Mirror Advanced Reactor System (MARS). The results of this effort follow as one section and part of a second section to be included in the MARS final report. This section describes the process and its interface to the reactor. The capital and operating costs for the hydrogen plant are described.

  7. ADVANCED TOOLS FOR ASSESSING SELECTED PRESCRIPTION AND ILLICIT DRUGS IN TREATED SEWAGE EFFLUENTS AND SOURCE WATERS

    EPA Science Inventory

    The purpose of this poster is to present the application and assessment of advanced state-of-the-art technologies in a real-world environment - wastewater effluent and source waters - for detecting six drugs [azithromycin, fluoxetine, omeprazole, levothyroxine, methamphetamine, m...

  8. Advanced precoat filtration and competitive processes for water purification. Technical report

    SciTech Connect

    Wang, L.K.; Wang, M.H.S.

    1989-01-28

    An advanced precoat filtration process system is introduced. Also presented and discussed are major competitive processes for water purification, such as conventional precoat filtration, conventional physical-chemical process, lime softening, carbon adsorption, ion exchange, activated alumina, reverse osmosis, ultrafiltration, microfiltration, electrodialysis, and packed aeration column.

  9. Electrode Coatings for High Temperature Hydrogen Electrolysis

    SciTech Connect

    W. E. Windes; D. Wendt; C. Smith; A. Erickson; J. Walraven; P. A. Lessing

    2007-04-01

    A discussion of fabrication techniques and performance testing of solid oxide components for use in hydrogen steam electrolysis is presented. Novel plasma spray techniques are utilized to deposit the thin ceramic oxide electrode, electrolyte, and interconnect layers on a planar intermetallic bipolar plate. Optimal porosity is achieved within the electrode microstructure through mixed feed techniques that are a combination of dry powder feed and liquid solution injection. The perovskite anode coatings formed from liquid precursor feedstock require post-deposition annealing in an oxygen-rich atmosphere to form the desired perovskite structures. Electrical conductivity measurements were measured for all electrodes and interconnect materials as a function of temperature to 1000 ºC.

  10. [Research advances in water quality monitoring technology based on UV-Vis spectrum analysis].

    PubMed

    Wei, Kang-Lin; Wen, Zhi-yu; Wu, Xin; Zhang, Zhong-Wei; Zeng, Tian-Ling

    2011-04-01

    The application of spectral analysis to water quality monitoring is an important developing trend in the field of modern environment monitoring technology. The principle and characteristic of water quality monitoring technology based on UV-Vis spectrum analysis are briefly reviewed. And the research status and advances are introduced from two aspects, on-line monitoring and in-situ monitoring. Moreover, the existent key technical problems are put forward. Finally, the technology trends of multi-parameter water quality monitoring microsystem and microsystem networks based on microspectrometer are prospected, which has certain reference value for the research and development of environmental monitoring technology and modern scientific instrument in the authors' country.

  11. Advances in Diode-Laser-Based Water Vapor Differential Absorption Lidar

    NASA Astrophysics Data System (ADS)

    Spuler, Scott; Repasky, Kevin; Morley, Bruce; Moen, Drew; Weckwerth, Tammy; Hayman, Matt; Nehrir, Amin

    2016-06-01

    An advanced diode-laser-based water vapor differential absorption lidar (WV-DIAL) has been developed. The next generation design was built on the success of previous diode-laser-based prototypes and enables accurate measurement of water vapor closer to the ground surface, in rapidly changing atmospheric conditions, and in daytime cloudy conditions up to cloud base. The lidar provides up to 1 min resolution, 150 m range resolved measurements of water vapor in a broad range of atmospheric conditions. A description of the instrument and results from its initial field test in 2014 are discussed.

  12. Materials Degradation Studies for High Temperature Steam Electrolysis Systems

    SciTech Connect

    Paul Demkowicz; Pavel Medvedev; Kevin DeWall; Paul Lessing

    2007-06-01

    Experiments are currently in progress to assess the high temperature degradation behavior of materials in solid oxide electrolysis systems. This research includes the investigation of various electrolysis cell components and balance of plant materials under both anodic and cathodic gas atmospheres at temperatures up to 850°C. Current results include corrosion data for a high temperature nickel alloy used for the air-side flow field in electrolysis cells and a commercial ferritic stainless steel used as the metallic interconnect. Three different corrosion inhibiting coatings were also tested on the steel material. The samples were tested at 850ºC for 500 h in both air and H2O/H2 atmospheres. The results of this research will be used to identify degradation mechanisms and demonstrate the suitability of candidate materials for long-term operation in electrolysis cells.

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

    SciTech Connect

    2003-09-01

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

  14. Thermophysical properties of saturated light and heavy water for Advanced Neutron Source applications

    SciTech Connect

    Crabtree, A.; Siman-Tov, M.

    1993-05-01

    The Advanced Neutron Source is an experimental facility being developed by Oak Ridge National Laboratory. As a new nuclear fission research reactor of unprecedented flux, the Advanced Neutron Source Reactor will provide the most intense steady-state beams of neutrons in the world. The high heat fluxes generated in the reactor [303 MW(t) with an average power density of 4.5 MW/L] will be accommodated by a flow of heavy water through the core at high velocities. In support of this experimental and analytical effort, a reliable, highly accurate, and uniform source of thermodynamic and transport property correlations for saturated light and heavy water were developed. In order to attain high accuracy in the correlations, the range of these correlations was limited to the proposed Advanced Neutron Source Reactor`s nominal operating conditions. The temperature and corresponding saturation pressure ranges used for light water were 20--300{degrees}C and 0.0025--8.5 MPa, respectively, while those for heavy water were 50--250{degrees}C and 0.012--3.9 MPa. Deviations between the correlation predictions and data from the various sources did not exceed 1.0%. Light water vapor density was the only exception, with an error of 1.76%. The physical property package consists of analytical correlations, SAS codes, and FORTRAN subroutines incorporating these correlations, as well as an interactive, easy-to-use program entitled QuikProp.

  15. Thermophysical properties of saturated light and heavy water for advanced neutron source applications

    SciTech Connect

    Crabtree, A.; Siman-Tov, M.

    1993-05-01

    The Advanced Neutron Source is an experimental facility being developed by Oak Ridge National Laboratory. As a new nuclear fission research reactor of unprecedented flux, the Advanced Neutron Source Reactor will provide the most intense steady-state beams of neutrons in the world. The high heat fluxes generated in the reactor [303 MW(t) with an average power density of 4.5 MW/L] will be accommodated by a flow of heavy water through the core at high velocities. In support of this experimental and analytical effort, a reliable, highly accurate, and uniform source of thermodynamic and transport property correlations for saturated light and heavy water were developed. In order to attain high accuracy in the correlations, the range of these correlations was limited to the proposed Advanced Neutron Source Reactor's nominal operating conditions. The temperature and corresponding saturation pressure ranges used for light water were 20--300[degrees]C and 0.0025--8.5 MPa, respectively, while those for heavy water were 50--250[degrees]C and 0.012--3.9 MPa. Deviations between the correlation predictions and data from the various sources did not exceed 1.0%. Light water vapor density was the only exception, with an error of 1.76%. The physical property package consists of analytical correlations, SAS codes, and FORTRAN subroutines incorporating these correlations, as well as an interactive, easy-to-use program entitled QuikProp.

  16. Development of Electrolysis System Powered by Solar-Cell Array to Supply Hydrogen Gas for Fuel-Cell Energy Resource Systems

    NASA Astrophysics Data System (ADS)

    Priambodo, Purnomo Sidi; Yusivar, Feri; Subiantoro, Aries; Gunawan, Ridwan

    2009-09-01

    The huge demand of energy worldwide and the depletion of fossil based energy, is a strong reason to rapidly develop any kind of renewable energy resources, which has economical advantages and zero pollution effect. One of the renewable energy technologies aimed in this paper is the generation of electric-energy based on fuel-cell technology, where the input hydrogen (H2) gas is supplied by electrolysis system powered by renewable energy system based on solar cell. In this paper, the authors explain the development of electrolysis system which is powered by solar cell array to supply hydrogen for fuel-cell system. The authors explain in detail how to design an efficient electrolysis system to obtain high ratio conversion of electric energy to hydrogen gas volume. It includes the explanation of the usage of multiple anodes with a single cathode for many solar cell inputs in a single electrolysis system. Hereinafter this is referred as multiple anode electrolysis system. This multiple anode electrolysis system makes the management of hydrogen gas becomes more efficient and effective by using only a single hydrogen gas storage system. This paper also explain the careful design of the resistance value of the electrolysis system to protect or avoid the solar cell panel to deliver excessive current to the electrolysis system which can cause damage on the solar cell panel. Moreover, the electrolyte volume detector is applied on the system as a tool to measure the electrolyte concentration to assure the system resistance is still in the allowed range. Further, the hydrogen gas produced by electrolysis system is stored into the gas storage which consists of silica-gel purifier, first stage low pressure gas bottle, vacuum pump, and second stage high pressure gas bottle. In the first step, the pump will vacuum the first bottle. The first bottle will collect the hydrogen from the electrolysis system through the silica gel to get rid of water vapor. When the first bottle

  17. "Spontaneous electrolysis" and simultaneously assembly hierarchy nanostructures of copper tetracyanoquinodimethane.

    PubMed

    Ji, Zhuoyu; Li, Hongxiang; Liu, Yaling; Hu, Wenping; Liu, Ming

    2010-02-01

    A simple method was developed to generate nanolamellas of CuTCNQ based on the principle of "spontaneous electrolysis". The nanolamellas were identified to belong to phase I of CuTCNQ. Intermediate products before nanolamellas were monitored with this method and beautiful artificial flowers were assembled based on the "spontaneous electrolysis." Moreover, CuTCNQ nanocrystal arrays could be grown on TCNQ single crystal surface homogeneously, which suggested a new method to assembly nanomaterials on crystal surface.

  18. Chemical drinking water quality in Ghana: water costs and scope for advanced treatment.

    PubMed

    Rossiter, Helfrid M A; Owusu, Peter A; Awuah, Esi; Macdonald, Alan M; Schäfer, Andrea I

    2010-05-01

    To reduce child mortality and improve health in Ghana boreholes and wells are being installed across the country by the private sector, NGO's and the Ghanaian government. Water quality is not generally monitored once a water source has been improved. Water supplies were sampled across Ghana from mostly boreholes, wells and rivers as well as some piped water from the different regions and analysed for the chemical quality. Chemical water quality was found to exceed the WHO guidelines in 38% of samples, while pH varied from 3.7 to 8.9. Excess levels of nitrate (NO(3)(-)) were found in 21% of the samples, manganese (Mn) and fluoride (F(-)) in 11% and 6.7%, respectively. Heavy metals such as lead (Pb), arsenic (As) and uranium (U) were localised to mining areas. Elements without health based guideline values such as aluminium (Al, 95%) and chloride (Cl, 5.7%) were found above the provisional guideline value. Economic information was gathered to identify water costs and ability to pay. Capital costs of wells and boreholes are about pound1200 and pound3800 respectively. The majority of installation costs are generally paid by the government or NGO's, while the maintenance is expected to be covered by the community. At least 58% of the communities had a water payment system in place, either an annual fee/one-off fee or "pay-as-you-fetch". The annual fee was between pound0.3-21, while the boreholes had a water collection fee of pound0.07-0.7/m(3), many wells were free. Interestingly, the most expensive water ( pound2.9-3.5/m(3)) was brought by truck. Many groundwater sources were not used due to poor chemical water quality. Considering the cost of unsuccessful borehole development, the potential for integrating suitable water treatment into the capital and maintenance costs of water sources is discussed. Additionally, many sources were not in use due to lack of water capacity, equipment malfunction or lack of economic resources to repair and maintain equipment. Those

  19. The development and evaluation of electrolysis in conjunction with power ultrasound for the disinfection of bacterial suspensions.

    PubMed

    Joyce, E; Mason, T J; Phull, S S; Lorimer, J P

    2003-07-01

    There is an increasing incidence in health problems related to environmental issues that originate from inadequate treatment of potable waters. This has compelled scientists and engineers to engage in innovative technologies to achieve a maximum disinfection at affordable costs. Some species of bacteria produce colonies and spores that can agglomerate in spherical clusters and thus protect organisms on the inside of the cluster against biocidal attack. Flocs of fine particles (e.g., clay) can entrap bacteria and this can also protect them against the biocides. Other bacteria have the ability to mutate, thus building up resistance to conventional biocides (e.g., chlorine). Ultrasound has been shown to be effective in improving the effectiveness of biocides such as chlorine. The aim of this present study was to investigate the effect of electrolysis and power ultrasound as a disinfection treatment and to provide a greater knowledge of the fundamentals of disinfection through the production of hypochlorite in situ from saline solution via electrolysis. The electrode materials investigated were, carbon (felt and graphite), copper and stainless steel rods. The results show that sonication appears to amplify the effect of electrolysis. A combination of both treatments is significantly better than sonication or electrolysis alone.

  20. Development of an advanced combined iodine dispenser/detector. [for spacecraft water supplies

    NASA Technical Reports Server (NTRS)

    Lantz, J. B.; Jensen, F. C.; Winkler, H. E.; Schubert, F. A.

    1977-01-01

    Injection of iodine into water is widely used to control microbial growth. An entirely automated device for I2 injection has been developed for spacecraft application. Transfer of I2 into the water from a concentrated form is controlled electrochemically via feedback from an integrated photometric I2 level detector. All components are contained within a package weighing only 1.23 kg (2.7 lb) dry, which occupies only 1213 cu cm (74 cu in) of space, and which has the capacity to iodinate 10,900 kg (24,000 lb) of water of 5 ppm. These features exceed design specifications. The device performed satisfactorily during extended testing at variable water flow rates and temperatures. Designed to meet specifications of the Shuttle Orbiter, the device will find application in the regenerative water systems of advanced spacecraft.

  1. Microalgae-based advanced municipal wastewater treatment for reuse in water bodies.

    PubMed

    Wang, Jing-Han; Zhang, Tian-Yuan; Dao, Guo-Hua; Xu, Xue-Qiao; Wang, Xiao-Xiong; Hu, Hong -Ying

    2017-04-01

    Reuse of secondary municipal effluent from wastewater treatment plants in water bodies could effectively alleviate freshwater resource shortage. However, excessive nutrients must be efficiently removed to prevent eutrophication. Compared with other means of advanced wastewater treatment, microalgae-based processes display overwhelming advantages including efficient and simultaneous N and P removal, no requirement of additional chemicals, O2 generation, CO2 mitigation, and potential value-added products from harvested biomass. One particular challenge of microalgae-based advanced municipal wastewater treatment compared to treatment of other types of wastewater is that concentrations of nutrients and N:P ratios in secondary municipal effluent are much lower and imbalanced. Therefore, there should be comprehensive considerations on nutrient removal from this specific type of effluent. Removal of nutrients and organic substances, and other environmental benefits of microalgae-based advanced municipal wastewater treatment systems were summarized. Among the existing studies on microalgal advanced nutrient removal, much information on major parameters is absent, rendering performances between studies not really comparable. Mechanisms of microalgae-based nitrogen and phosphorus removal were respectively analyzed to better understand advanced nutrient removal from municipal secondary effluent. Factors influencing microalgae-based nutrient removal were divided into intrinsic, environmental, and operational categories; several factors were identified in each category, and their influences on microalgal nutrient removal were discussed. A multiplicative kinetic model was integrated to estimate microalgal growth-related nutrient removal based majorly on environmental and intrinsic factors. Limitations and prospects of future full-scale microalgae-based advanced municipal wastewater treatment were also suggested. The manuscript could offer much valuable information for future

  2. Regeneration of oxygen from carbon dioxide and water.

    NASA Technical Reports Server (NTRS)

    Weissbart, J.; Smart, W. H.; Wydeven, T.

    1972-01-01

    In a closed ecological system it is necessary to reclaim most of the oxygen required for breathing from respired carbon dioxide and the remainder from waste water. One of the advanced physicochemical systems being developed for generating oxygen in manned spacecraft is the solid electrolyte-electrolysis system. The solid electrolyte system consists of two basic units, an electrolyzer and a carbon monoxide disproportionator. The electrolyzer can reclaim oxygen from both carbon dioxide and water. Electrolyzer preparation and assembly are discussed together with questions of reactor design and electrolyzer performance data.

  3. Piping benchmark problems for the General Electric Advanced Boiling Water Reactor

    SciTech Connect

    Bezler, P.; DeGrassi, G.; Braverman, J.; Wang, Y.K.

    1993-08-01

    To satisfy the need for verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for an advanced boiling water reactor standard design, three benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the advanced reactor standard design. It will be required that the combined license holders demonstrate that their solutions to these problems are in agreement with the benchmark problem set.

  4. Development of Advanced High Uranium Density Fuels for Light Water Reactors

    SciTech Connect

    Blanchard, James; Butt, Darryl; Meyer, Mitchell; Xu, Peng

    2016-02-15

    This work conducts basic materials research (fabrication, radiation resistance, thermal conductivity, and corrosion response) on U3Si2 and UN, two high uranium density fuel forms that have a high potential for success as advanced light water reactor (LWR) fuels. The outcome of this proposed work will serve as the basis for the development of advance LWR fuels, and utilization of such fuel forms can lead to the optimization of the fuel performance related plant operating limits such as power density, power ramp rate and cycle length.

  5. High Temperature Electrolysis Pressurized Experiment Design, Operation, and Results

    SciTech Connect

    J.E. O'Brien; X. Zhang; G.K. Housley; K. DeWall; L. Moore-McAteer

    2012-09-01

    A new facility has been developed at the Idaho National Laboratory for pressurized testing of solid oxide electrolysis stacks. Pressurized operation is envisioned for large-scale hydrogen production plants, yielding higher overall efficiencies when the hydrogen product is to be delivered at elevated pressure for tank storage or pipelines. Pressurized operation also supports higher mass flow rates of the process gases with smaller components. The test stand can accommodate planar cells with dimensions up to 8.5 cm x 8.5 cm and stacks of up to 25 cells. It is also suitable for testing other cell and stack geometries including tubular cells. The pressure boundary for these tests is a water-cooled spool-piece pressure vessel designed for operation up to 5 MPa. Pressurized operation of a ten-cell internally manifolded solid oxide electrolysis stack has been successfully demonstrated up 1.5 MPa. The stack is internally manifolded and operates in cross-flow with an inverted-U flow pattern. Feed-throughs for gas inlets/outlets, power, and instrumentation are all located in the bottom flange. The entire spool piece, with the exception of the bottom flange, can be lifted to allow access to the internal furnace and test fixture. Lifting is accomplished with a motorized threaded drive mechanism attached to a rigid structural frame. Stack mechanical compression is accomplished using springs that are located inside of the pressure boundary, but outside of the hot zone. Initial stack heatup and performance characterization occurs at ambient pressure followed by lowering and sealing of the pressure vessel and subsequent pressurization. Pressure equalization between the anode and cathode sides of the cells and the stack surroundings is ensured by combining all of the process gases downstream of the stack. Steady pressure is maintained by means of a backpressure regulator and a digital pressure controller. A full description of the pressurized test apparatus is provided in this

  6. ECLSS evolution: Advanced instrumentation interface requirements. Volume 3: Appendix C

    NASA Technical Reports Server (NTRS)

    1991-01-01

    An Advanced ECLSS (Environmental Control and Life Support System) Technology Interfaces Database was developed primarily to provide ECLSS analysts with a centralized and portable source of ECLSS technologies interface requirements data. The database contains 20 technologies which were previously identified in the MDSSC ECLSS Technologies database. The primary interfaces of interest in this database are fluid, electrical, data/control interfaces, and resupply requirements. Each record contains fields describing the function and operation of the technology. Fields include: an interface diagram, description applicable design points and operating ranges, and an explaination of data, as required. A complete set of data was entered for six of the twenty components including Solid Amine Water Desorbed (SAWD), Thermoelectric Integrated Membrane Evaporation System (TIMES), Electrochemical Carbon Dioxide Concentrator (EDC), Solid Polymer Electrolysis (SPE), Static Feed Electrolysis (SFE), and BOSCH. Additional data was collected for Reverse Osmosis Water Reclaimation-Potable (ROWRP), Reverse Osmosis Water Reclaimation-Hygiene (ROWRH), Static Feed Solid Polymer Electrolyte (SFSPE), Trace Contaminant Control System (TCCS), and Multifiltration Water Reclamation - Hygiene (MFWRH). A summary of the database contents is presented in this report.

  7. Systems Engineering Provides Successful High Temperature Steam Electrolysis Project

    SciTech Connect

    Charles V. Park; Emmanuel Ohene Opare, Jr.

    2011-06-01

    This paper describes two Systems Engineering Studies completed at the Idaho National Laboratory (INL) to support development of the High Temperature Stream Electrolysis (HTSE) process. HTSE produces hydrogen from water using nuclear power and was selected by the Department of Energy (DOE) for integration with the Next Generation Nuclear Plant (NGNP). The first study was a reliability, availability and maintainability (RAM) analysis to identify critical areas for technology development based on available information regarding expected component performance. An HTSE process baseline flowsheet at commercial scale was used as a basis. The NGNP project also established a process and capability to perform future RAM analyses. The analysis identified which components had the greatest impact on HTSE process availability and indicated that the HTSE process could achieve over 90% availability. The second study developed a series of life-cycle cost estimates for the various scale-ups required to demonstrate the HTSE process. Both studies were useful in identifying near- and long-term efforts necessary for successful HTSE process deployment. The size of demonstrations to support scale-up was refined, which is essential to estimate near- and long-term cost and schedule. The life-cycle funding profile, with high-level allocations, was identified as the program transitions from experiment scale R&D to engineering scale demonstration.

  8. Guidance for Developing Principal Design Criteria for Advanced (Non-Light Water) Reactors

    SciTech Connect

    Holbrook, Mark; Kinsey, Jim

    2015-03-01

    In July 2013, the US Department of Energy (DOE) and US Nuclear Regulatory Commission (NRC) established a joint initiative to address a key portion of the licensing framework essential to advanced (non-light water) reactor technologies. The initiative addressed the “General Design Criteria for Nuclear Power Plants,” Appendix A to10 Code of Federal Regulations (CFR) 50, which were developed primarily for light water reactors (LWRs), specific to the needs of advanced reactor design and licensing. The need for General Design Criteria (GDC) clarifications in non-LWR applications has been consistently identified as a concern by the industry and varied stakeholders and was acknowledged by the NRC staff in their 2012 Report to Congress1 as an area for enhancement. The initiative to adapt GDC requirements for non-light water advanced reactor applications is being accomplished in two phases. Phase 1, managed by DOE, consisted of reviews, analyses and evaluations resulting in recommendations and deliverables to NRC as input for NRC staff development of regulatory guidance. Idaho National Laboratory (INL) developed this technical report using technical and reactor technology stakeholder inputs coupled with analysis and evaluations provided by a team of knowledgeable DOE national laboratory personnel with input from individual industry licensing consultants. The DOE national laboratory team reviewed six different classes of emerging commercial reactor technologies against 10 CFR 50 Appendix A GDC requirements and proposed guidance for their adapted use in non-LWR applications. The results of the Phase 1 analysis are contained in this report. A set of draft Advanced Reactor Design Criteria (ARDC) has been proposed for consideration by the NRC in the establishment of guidance for use by non-LWR designers and NRC staff. The proposed criteria were developed to preserve the underlying safety bases expressed by the original GDC, and recognizing that advanced reactors may take

  9. Post-treatment of reclaimed waste water based on an electrochemical advanced oxidation process

    NASA Technical Reports Server (NTRS)

    Verostko, Charles E.; Murphy, Oliver J.; Hitchens, G. D.; Salinas, Carlos E.; Rogers, Tom D.

    1992-01-01

    The purification of reclaimed water is essential to water reclamation technology life-support systems in lunar/Mars habitats. An electrochemical UV reactor is being developed which generates oxidants, operates at low temperatures, and requires no chemical expendables. The reactor is the basis for an advanced oxidation process in which electrochemically generated ozone and hydrogen peroxide are used in combination with ultraviolet light irradiation to produce hydroxyl radicals. Results from this process are presented which demonstrate concept feasibility for removal of organic impurities and disinfection of water for potable and hygiene reuse. Power, size requirements, Faradaic efficiency, and process reaction kinetics are discussed. At the completion of this development effort the reactor system will be installed in JSC's regenerative water recovery test facility for evaluation to compare this technique with other candidate processes.

  10. Seawater injection barrier recharge with advanced reclaimed water at Llobregat delta aquifer (Spain).

    PubMed

    Ortuño, F; Molinero, J; Garrido, T; Custodio, E

    2012-01-01

    The main aquifer of the Llobregat delta (Barcelona, Spain) has been affected by seawater intrusion since the 1960s. The Catalan Water Agency (ACA) has sponsored the construction of a positive hydraulic barrier in order to stop the progress of seawater intrusion advance due to the intensive aquifer development. The hydraulic barrier consists of 15 wells into which highly treated reclaimed water from the waste water treatment plant of the Baix Llobregat is injected. Water is subjected, prior to the distribution to the injection wells, to secondary and tertiary treatments, and later to ultrafiltration, UV disinfection without chlorination, and salinity reduction through reverse osmosis. A preliminary pilot phase of the project was started in late 2007, with highly positive results, and the second phase started in mid 2010. Hydrogeological and hydrochemical monitoring data indicate an efficient performance and aquifer improvement. The evaluation of such efficiency and operational costs has been analyzed and discussed.

  11. Design of Advanced Atmospheric Water Vapor Differential Absorption Lidar (DIAL) Detection System

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Luck, William S., Jr.; DeYoung, Russell J.

    1999-01-01

    The measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The lidar atmospheric sensing experiment (LASE) is an instrument designed and operated by the Langley Research Center for high precision water vapor measurements. The design details of a new water vapor lidar detection system that improves the measurement sensitivity of the LASE instrument by a factor of 10 are discussed. The new system consists of an advanced, very low noise, avalanche photodiode (APD) and a state-of-the-art signal processing circuit. The new low-power system is also compact and lightweight so that it would be suitable for space flight and unpiloted atmospheric vehicles (UAV) applications. The whole system is contained on one small printed circuit board (9 x 15 sq cm). The detection system is mounted at the focal plane of a lidar receiver telescope, and the digital output is read by a personal computer with a digital data acquisition card.

  12. Using CONFIG for Simulation of Operation of Water Recovery Subsystems for Advanced Control Software Evaluation

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Flores, Luis; Fleming, Land; Throop, Daiv

    2002-01-01

    A hybrid discrete/continuous simulation tool, CONFIG, has been developed to support evaluation of the operability life support systems. CON FIG simulates operations scenarios in which flows and pressures change continuously while system reconfigurations occur as discrete events. In simulations, intelligent control software can interact dynamically with hardware system models. CONFIG simulations have been used to evaluate control software and intelligent agents for automating life support systems operations. A CON FIG model of an advanced biological water recovery system has been developed to interact with intelligent control software that is being used in a water system test at NASA Johnson Space Center

  13. Local Institutional Development and Organizational Change for Advancing Sustainable Urban Water Futures

    NASA Astrophysics Data System (ADS)

    Brown, Rebekah R.

    2008-02-01

    This paper presents the local institutional and organizational development insights from a five-year ongoing interdisciplinary research project focused on advancing the implementation of sustainable urban water management. While it is broadly acknowledged that the inertia associated with administrative systems is possibly the most significant obstacle to advancing sustainable urban water management, contemporary research still largely prioritizes investigations at the technological level. This research is explicitly concerned with critically informing the design of methodologies for mobilizing and overcoming the administrative inertia of traditional urban water management practice. The results of fourteen in-depth case studies of local government organizations across Metropolitan Sydney primarily reveal that (i) the political institutionalization of environmental concern and (ii) the commitment to local leadership and organizational learning are key corporate attributes for enabling sustainable management. A typology of five organizational development phases has been proposed as both a heuristic and capacity benchmarking tool for urban water strategists, policy makers, and decision makers that are focused on improving the level of local implementation of sustainable urban water management activity. While this investigation has focused on local government, these findings do provide guideposts for assessing the development needs of future capacity building programs across a range of different institutional contexts.

  14. Local institutional development and organizational change for advancing sustainable urban water futures.

    PubMed

    Brown, Rebekah R

    2008-02-01

    This paper presents the local institutional and organizational development insights from a five-year ongoing interdisciplinary research project focused on advancing the implementation of sustainable urban water management. While it is broadly acknowledged that the inertia associated with administrative systems is possibly the most significant obstacle to advancing sustainable urban water management, contemporary research still largely prioritizes investigations at the technological level. This research is explicitly concerned with critically informing the design of methodologies for mobilizing and overcoming the administrative inertia of traditional urban water management practice. The results of fourteen in-depth case studies of local government organizations across Metropolitan Sydney primarily reveal that (i) the political institutionalization of environmental concern and (ii) the commitment to local leadership and organizational learning are key corporate attributes for enabling sustainable management. A typology of five organizational development phases has been proposed as both a heuristic and capacity benchmarking tool for urban water strategists, policy makers, and decision makers that are focused on improving the level of local implementation of sustainable urban water management activity. While this investigation has focused on local government, these findings do provide guideposts for assessing the development needs of future capacity building programs across a range of different institutional contexts.

  15. [Occurrence and distribution of volatile organic compounds in conventional and advanced drinking water treatment processes].

    PubMed

    Chen, Xi-Chao; Luo, Qian; Chen, Hu; Wei, Zi; Wang, Zi-Jian; Xu, Ke-Wen

    2013-12-01

    A series of experiments were conducted to study the occurrence and distribution of volatile organic compounds (VOCs) in conventional and advanced drinking water treatment processes of 3 water treatment plants in Lianyungang City. Results showed that 30 compounds of 3 classes were detected from 67 kinds of VOCs in all the samples collected. The concentrations of carbonyl compounds, halogenated hydrocarbons and benzenes detected were in the ranges of 0.04-61.27, 0.02-35.61 and 0.07-2.33 microg x L(-1) respectively. Comparing the changes of different VOCs in three drinking water treatment plants, conventional chlorination process could effectively remove benzenes but meanwhile produced trihalomethanes (THMs). Additional advanced treatment ozonation-biological activated carbon process could decrease the formation of THMs during pre-chlorination but produced new risky contaminants like carbonyl compounds. The changes of VOCs in tap water were also investigated. It was found that carbonyl compounds produced by ozonation could be further transformed to THMs with residual chlorine. However, the health risks of all detected compounds in tap water were at a low level, except that the carcinogenic risk of crotonaldehydes (9.3 x 10(-5)-2.2 x 10(-4)) was slightly higher than the US EPA threshold (10(-6)-10(-4)).

  16. Drinking water treatment of priority pesticides using low pressure UV photolysis and advanced oxidation processes.

    PubMed

    Sanches, Sandra; Barreto Crespo, Maria T; Pereira, Vanessa J

    2010-03-01

    This study reports the efficiency of low pressure UV photolysis for the degradation of pesticides identified as priority pollutants by the European Water Framework Directive 2000/60/EC. Direct low pressure UV photolysis and advanced oxidation processes (using hydrogen peroxide and titanium dioxide) experiments were conducted in laboratory grade water, surface water, and groundwater. LP direct photolysis using a high UV fluence (1500 mJ/cm(2)) was found to be extremely efficient to accomplish the degradation of all pesticides except isoproturon, whereas photolysis using hydrogen peroxide and titanium dioxide did not significantly enhance their removal. In all matrices tested the experimental photolysis of the pesticides followed the same trend: isoproturon degradation was negligible, alachlor, pentachlorophenol, and atrazine showed similar degradation rate constants, whereas diuron and chlorfenvinphos were highly removed. The degradation trend observed for the selected compounds followed the decadic molar absorption coefficients order with exception of isoproturon probably due to its extremely low quantum yield. Similar direct photolysis rate constants were obtained for each pesticide in the different matrices tested, showing that the water components did not significantly impact degradation. Extremely similar photolysis rate constants were also obtained in surface water for individual compounds when compared to mixtures. The model fluence and time-based rate constants reported were very similar to the direct photolysis experimental results obtained, while overestimating the advanced oxidation results. This model was used to predict how degradation of isoproturon, the most resilient compound, could be improved.

  17. Relocation of Advanced Water Vapor Radiometer 1 to Deep Space Station 55

    NASA Technical Reports Server (NTRS)

    Oswald, J.; Riley, L.; Hubbard, A.; Rosenberger, H.; Tanner, A.; Keihm, S.; Jacobs, C.; Lanyi, G.; Naudet, C.

    2005-01-01

    In June of 2004, the Advanced Water Vapor Radiometer (AWVR) unit no. 1 was relocated to the Deep Space Station (DSS) 55 site in Madrid, Spain, from DSS 25 in Goldstone, California. This article summarizes the relocation activity and the subsequent operation and data acquisition. This activity also relocated the associated Microwave Temperature Profiler (MTP) and Surface Meteorology (SurfMET) package that collectively comprise the Cassini Media Calibration System (MCS).

  18. Relocation of Advanced Water Vapor Radiometer 1 to Deep Space Station 55

    NASA Astrophysics Data System (ADS)

    Oswald, J.; Riley, L.; Hubbard, A.; Rosenberger, H.; Tanner, A.; Keihm, S.; Jacobs, Christopher S.; Lanyi. G. E.; Naudet, C. J.

    2005-11-01

    In June of 2004, the Advanced Water Vapor Radiometer (AWVR) unit no. 1 was relocated to the Deep Space Station (DSS) 55 site in Madrid, Spain, from DSS 25 in Goldstone, California. This article summarizes the relocation activity and the subsequent operation and data acquisition. This activity also relocated the associated Microwave Temperature Profiler (MTP) and Surface Meteorology (SurfMET) package that collectively comprise the Cassini Media Calibration System (MCS).

  19. Advanced Light Water Reactor Program: Program management and staff review methodology

    SciTech Connect

    Moran, D.H.

    1986-12-01

    This report summarizes the NRC/EPRI coordinated effort to develop design requirements for a standardized advanced light water reactor (ALWR) and the procedures for screening and applying new generic safety issues to this program. The end-product will be an NRC-approved ALWR Requirements Document for use by the nuclear industry in generating designs of LWRs to be constructed for operation in the 1990s and beyond.

  20. Assessing the Influence of Human Activities on Global Water Resources Using an Advanced Land Surface Model

    NASA Astrophysics Data System (ADS)

    Pokhrel, Y.; Hanasaki, N.; Koirala, S.; Kanae, S.; Oki, T.

    2010-12-01

    In order to examine the impact of human intervention on the global hydrological cycle, a Land Surface Model was enhanced with schemes to assess the anthropogenic disturbance on the natural water flow at the global scale. Four different schemes namely; reservoir operation, crop growth, environmental flow, and anthropogenic water withdrawal modules from a state-of-the-art global water resources assessment model called H08 were integrated into an offline version of LSM, Minimal Advance Treatment of Surface Interaction and Runoff (MATSIRO). MATSIRO represents majority of the hydrological processes of water and energy exchange between the land surface and the atmosphere on a physical basis and is designed to be coupled with GCM. The integrated model presented here thus has the capability to simulate both natural and anthropogenic flows of water globally at a spatial resolution of 1°x1°, considering dam operation, domestic, industrial and agricultural water withdrawals and environmental flow requirements. The model can also be coupled with climate models to assess the impact of human activities on the climate system. A simple groundwater scheme was also incorporated and the model can be used to assess the change in water table due to groundwater pumping for irrigation. The model was validated by comparing simulated soil moisture, river discharge and Terrestrial Water Storage Anomaly (TWSA) with observations. The model performs well in simulating TWSA as compared to GRACE observation in different river basins ranging from very wet to very dry. Soil moisture cannot be validated globally because of the lack of validation datasets. For Illinois region, where long term soil moisture observations are available, the model captures the seasonal variation quite well. The simulated global potential irrigation demand is about 1100km3/year, which is within the range of previously published estimates based on various water balance models and LSMs. The model has an advanced option

  1. In-Situ Propellant Production on Mars: A Sabatier/Electrolysis Demonstration Plant

    NASA Astrophysics Data System (ADS)

    Clark, David L.

    1997-01-01

    An efficient, reliable propellant production plant has been developed for use on Mars. Using a Sabatier reactor in conjunction with a water electrolysis system, a complete demonstration plant has produced methane and liquid oxygen from simulated Martian atmosphere. The production plant has demonstrated high efficiency, extended duration production and autonomous operations. This paper presents the results and conclusions relating to eventual use in a Mars sample return mission. This work was funded by the Jet Propulsion Laboratory (JPL). The production plant was built and tested at the Propulsion Center of Lockheed Martin at the Denver Colorado facility.

  2. Production of anhydrous aluminum chloride composition and process for electrolysis thereof

    DOEpatents

    Vandegrift, George F.; Krumpelt, Michael; Horwitz, E. Philip

    1983-01-01

    A process for producing an anhydrous aluminum chloride composition from a water-based aluminous material such as a slurry of aluminum hydroxide in a multistage extraction process in which the aluminum ion is first extracted into an organic liquid containing an acidic extractant and then extracted from the organic phase into an alkali metal chloride or chlorides to form a melt containing a mixture of chlorides of alkali metal and aluminum. In the process, the organic liquid may be recycled. In addition, the process advantageously includes an electrolysis cell for producing metallic aluminum and the alkali metal chloride or chlorides may be recycled for extraction of the aluminum from the organic phase.

  3. A screening level fate model of organic contaminants from advanced water treatment in a potable water supply reservoir.

    PubMed

    Hawker, Darryl W; Cumming, Janet L; Neale, Peta A; Bartkow, Michael E; Escher, Beate I

    2011-01-01

    Augmentation of potable water sources by planned indirect potable reuse of wastewater is being widely considered to address growing water shortages. Environmental buffers such as lakes and dams may act as one of a series of barriers to potable water contamination stemming from micropollutants in wastewater. In South-East Queensland, Australia, current government policy is to begin indirect potable reuse of water from reverse osmosis equipped advanced water treatment plants (AWTPs) when the combined capacity of its major storages is at 40% capacity. A total of 15 organic contaminants including NDMA and bisphenol A have been publically reported as detected in recycled water from one of South-East Queensland's AWTPs, while another 98 chemicals were analysed for, but found to be below their detection limit. To assess the natural attenuation in Lake Wivenhoe, a Level III fugacity based evaluative fate model was constructed using the maximum concentrations of these contaminants detected as input data. A parallel aquivalence based model was constructed for those contaminants, such as dichloroacetic acid, dalapon and triclopyr, which are ionised in the environment of Lake Wivenhoe. A total of 247 organic chemicals of interest, including disinfection by-products, pesticides, pharmaceuticals and personal care products, xenoestrogens and industrial chemicals, were evaluated with the model to assess their potential for natural attenuation. Out of the 15 detected chemicals, trihalomethanes are expected to volatilise with concentrations in the outflow from the dam approximately 400 times lower than influent from the AWTPs. Transformation processes in water are likely to be more significant for NDMA and pharmaceuticals such as salicylic acid and paracetamol as well as for caffeine and the herbicides dalapon and triclopyr. For hydrophobic contaminants such as cholesterol and phenolic xenoestrogens such as 4-nonylphenol, 4-t-octylphenol and bisphenol A, equilibrium between water

  4. Modeling Degradation in Solid Oxide Electrolysis Cells

    SciTech Connect

    Manohar S. Sohal; Anil V. Virkar; Sergey N. Rashkeev; Michael V. Glazoff

    2010-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic no equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, , within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, no equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  5. Methanogenesis in membraneless microbial electrolysis cells.

    PubMed

    Clauwaert, Peter; Verstraete, Willy

    2009-04-01

    Operation of microbial electrolysis cells (MECs) without an ion exchange membrane could help to lower the construction costs while lowering the ohmic cell resistance and improving MEC conversion rates by minimizing the pH gradient between anode and cathode. In this research, we demonstrate that membraneless MECs with plain graphite can be operated for methane production without pH adjustment and that the ohmic cell resistance could be lowered with approximately 50% by removing the cation exchange membrane. As a result, the current production increased from 66 +/- 2 to 156 +/- 1 A m(-3) MEC by removing the membrane with an applied voltage of -0.8 V. Methane was the main energetic product despite continuous operation under carbonate-limited and slightly acidified conditions (pH 6.1-6.2). Our results suggest that continuous production of hydrogen in membraneless MECs will be challenging since methane production might not be avoided easily. The electrical energy invested was not always completely recovered under the form of an energy-rich biogas; however, our results indicate that membraneless MECs might be a viable polishing step for the treatment of the effluent of anaerobic digesters as methane was produced under low organic loading conditions and at room temperature.

  6. Recent experimental advances on hydrophobic interactions at solid/water and fluid/water interfaces.

    PubMed

    Zeng, Hongbo; Shi, Chen; Huang, Jun; Li, Lin; Liu, Guangyi; Zhong, Hong

    2015-03-15

    Hydrophobic effects play important roles in a wide range of natural phenomena and engineering processes such as coalescence of oil droplets in water, air flotation of mineral particles, and folding and assembly of proteins and biomembranes. In this work, the authors highlight recent experimental attempts to reveal the physical origin of hydrophobic effects by directly quantifying the hydrophobic interaction on both solid/water and fluid/water interfaces using state-of-art nanomechanical techniques such as surface forces apparatus and atomic force microscopy (AFM). For solid hydrophobic surfaces of different hydrophobicity, the range of hydrophobic interaction was reported to vary from ∼10 to >100 nm. With various characterization techniques, the very long-ranged attraction (>100 nm) has been demonstrated to be mainly attributed to nonhydrophobic interaction mechanisms such as pre-existing nanobubbles and molecular rearrangement. By ruling out these factors, intrinsic hydrophobic interaction was measured to follow an exponential law with decay length of 1-2 nm with effective range less than 20 nm. On the other hand, hydrophobic interaction measured at fluid interfaces using AFM droplet/bubble probe technique was found to decay with a much shorter length of ∼0.3 nm. This discrepancy of measured decay lengths is proposed to be attributed to inherent physical distinction between solid and fluid interfaces, which impacts the structure of interface-adjacent water molecules. Direct measurement of hydrophobic interaction on a broader range of interfaces and characterization of interfacial water molecular structure using spectroscopic techniques are anticipated to help unravel the origin of this rigidity-related mismatch of hydrophobic interaction and hold promise to uncover the physical nature of hydrophobic effects. With improved understanding of hydrophobic interaction, intrinsic interaction mechanisms of many biological and chemical pathways can be better

  7. Treatment of concentrated industrial wastewaters originating from oil shale and the like by electrolysis polyurethane foam interaction

    DOEpatents

    Tiernan, Joan E.

    1991-01-01

    Highly concentrated and toxic petroleum-based and synthetic fuels wastewaters such as oil shale retort water are treated in a unit treatment process by electrolysis in a reactor containing oleophilic, ionized, open-celled polyurethane foams and subjected to mixing and l BACKGROUND OF THE INVENTION The invention described herein arose in the course of, or under, Contract No. DE-AC03-76SF00098 between the U.S. Department of Energy and the University of California.

  8. Electrolysis products in a system formed by Na/sub 2/SO/sub 4/ solution with Al (OH)/sub 3/ hydrogel

    SciTech Connect

    Epifanov, Y.V.; Kul'skii, L.A.; Matskevich, E.S.

    1985-11-01

    This paper examines the dissolution of aluminum hydroxide gel on the electrolysis of aqueous electrolyte solutions and determine the compositions of the resulting compounds and the current yields. The authors used sodium sulfate to provide equivalent production of acid or alkali in the anode and cathode chambers. There is close correspondence between the anolyte and catholyte potentiometric and conductometric titration curves, which means that the methods can be used to analyze the electrolysis products in electrochemical coagulant regeneration. Data presented for determining the contents of the soluble aluminum compounds in the anolyte and catholyte in relation to the amount of electricity passed. It is shown that electrolysis in the system Na/sub 2/SO/sub 4/ solution + Al (OH)/sub 3/ hydrogel in a diaphragmed electrolyzer provides water-soluble aluminum compounds: aluminum sulfate as intermediate and basic salts in the anolyte and an alkaline solution of sodium aluminate in the catholyte.

  9. Advanced Signal Processing for High Temperatures Health Monitoring of Condensed Water Height in Steam Pipes

    NASA Technical Reports Server (NTRS)

    Lih, Shyh-Shiuh; Bar-Cohen, Yoseph; Lee, Hyeong Jae; Takano, Nobuyuki; Bao, Xiaoqi

    2013-01-01

    An advanced signal processing methodology is being developed to monitor the height of condensed water thru the wall of a steel pipe while operating at temperatures as high as 250deg. Using existing techniques, previous study indicated that, when the water height is low or there is disturbance in the environment, the predicted water height may not be accurate. In recent years, the use of the autocorrelation and envelope techniques in the signal processing has been demonstrated to be a very useful tool for practical applications. In this paper, various signal processing techniques including the auto correlation, Hilbert transform, and the Shannon Energy Envelope methods were studied and implemented to determine the water height in the steam pipe. The results have shown that the developed method provides a good capability for monitoring the height in the regular conditions. An alternative solution for shallow water or no water conditions based on a developed hybrid method based on Hilbert transform (HT) with a high pass filter and using the optimized windowing technique is suggested. Further development of the reported methods would provide a powerful tool for the identification of the disturbances of water height inside the pipe.

  10. Effects of advanced oxidation pretreatment on residual aluminum control in high humic acid water purification.

    PubMed

    Wang, Wendong; Li, Hua; Ding, Zhenzhen; Wang, Xiaochang

    2011-01-01

    Due to the formation of disinfection by-products and high concentrations of Al residue in drinking water purification, humic substances are a major component of organic matter in natural waters and have therefore received a great deal of attention in recent years. We investigated the effects of advanced oxidation pretreatment methods usually applied for removing dissolved organic matters on residual Al control. Results showed that the presence of humic acid increased residual Al concentration notably. With 15 mg/L of humic acid in raw water, the concentrations of soluble aluminum and total aluminum in the treated water were close to the quantity of Al addition. After increasing coagulant dosage from 12 to 120 mg/L, the total-Al in the treated water was controlled to below 0.2 mg/L. Purification systems with ozonation, chlorination, or potassium permanganate oxidation pretreatment units had little effects on residual Al control; while UV radiation decreased Al concentration notably. Combined with ozonation, the effects of UV radiation were enhanced. Optimal dosages were 0.5 mg O3/mg C and 3 hr for raw water with 15 mg/L of humic acid. Under UV light radiation, the combined forces or bonds that existed among humic acid molecules were destroyed; adsorption sites increased positively with radiation time, which promoted adsorption of humic acid onto polymeric aluminum and Al(OH)3(s). This work provides a new solution for humic acid coagulation and residual Al control for raw water with humic acid purification.

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

    SciTech Connect

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

    2010-06-01

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

  12. High Temperature Electrolysis using Electrode-Supported Cells

    SciTech Connect

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

    2010-07-01

    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 µm thick), nickel-YSZ steam/hydrogen electrodes (~1400 µm thick), and manganite (LSM) air-side electrodes (~90 µm 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.

  13. Gadolinia-Doped Ceria Cathodes for Electrolysis of CO2

    NASA Technical Reports Server (NTRS)

    Adler, Stuart B.

    2009-01-01

    Gadolinia-doped ceria, or GDC, (Gd(0.4)Ce(0.6)O(2-delta), where the value of delta in this material varies, depending on the temperature and oxygen concentration in the atmosphere in which it is being used) has shown promise as a cathode material for high-temperature electrolysis of carbon dioxide in solid oxide electrolysis cells. The polarization resistance of a GDC electrode is significantly less than that of an otherwise equivalent electrode made of any of several other materials that are now in use or under consideration for use as cathodes for reduction of carbon dioxide. In addition, GDC shows no sign of deterioration under typical temperature and gas-mixture operating conditions of a high-temperature electrolyzer. Electrolysis of CO2 is of interest to NASA as a way of generating O2 from the CO2 in the Martian atmosphere. On Earth, a combination of electrolysis of CO2 and electrolysis of H2O might prove useful as a means of generating synthesis gas (syngas) from the exhaust gas of a coal- or natural-gas-fired power plant, thereby reducing the emission of CO2 into the atmosphere. The syngas a mixture of CO and H2 could be used as a raw material in the manufacture, via the Fisher-Tropsch process, of synthetic fuels, lubrication oils, and other hydrocarbon prod

  14. Hollow Fiber Spacesuit Water Membrane Evaporator Development and Testing for Advanced Spacesuits

    NASA Technical Reports Server (NTRS)

    Bue, Grant C.; Trevino, Luis A.; Tsioulos, Gus; Settles, Joseph; Colunga, Aaron; Vogel, Matthew; Vonau, Walt

    2010-01-01

    The spacesuit water membrane evaporator (SWME) is being developed to perform the thermal control function for advanced spacesuits to take advantage of recent advances in micropore membrane technology in providing a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. Principles of a sheet membrane SWME design were demonstrated using a prototypic test article that was tested in a vacuum chamber at JSC in July 1999. The Membrana Celgard X50-215 microporous hollow fiber (HoFi) membrane was selected after recent contamination tests as the most suitable candidate among commercial alternatives for HoFi SWME prototype development. A design that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape, was developed into a full-scale prototype consisting 14,300 tube bundled into 30 stacks, each of which are formed into a chevron shape and separated by spacers and organized into three sectors of ten nested stacks. Vacuum chamber testing has been performed characterize heat rejection as a function of inlet water temperature and water vapor backpressure and to show contamination resistance to the constituents expected to be found in potable water produced by the distillation processes. Other tests showed the tolerance to freezing and suitability to reject heat in a Mars pressure environment.

  15. Systematic Discrimination of Advanced Hydrogen Production Technologies

    SciTech Connect

    Charles V. Park; Michael W. Patterson

    2010-07-01

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

  16. Anion Recognition in Water: Recent Advances from a Supramolecular and Macromolecular Perspective

    PubMed Central

    Langton, Matthew J.

    2015-01-01

    Abstract The recognition of anions in water remains a key challenge in modern supramolecular chemistry, and is essential if proposed applications in biological, medical, and environmental arenas that typically require aqueous conditions are to be achieved. However, synthetic anion receptors that operate in water have, in general, been the exception rather than the norm to date. Nevertheless, a significant step change towards routinely conducting anion recognition in water has been achieved in the past few years, and this Review highlights these approaches, with particular focus on controlling and using the hydrophobic effect, as well as more exotic interactions such as C−H hydrogen bonding and halogen bonding. We also look beyond the field of small‐molecule recognition into the macromolecular domain, covering recent advances in anion recognition based on biomolecules, polymers, and nanoparticles. PMID:26612067

  17. Overview of the Consortium for the Advanced Simulation of Light Water Reactors (CASL)

    NASA Astrophysics Data System (ADS)

    Kulesza, Joel A.; Franceschini, Fausto; Evans, Thomas M.; Gehin, Jess C.

    2016-02-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) was established in July 2010 for the purpose of providing advanced modeling and simulation solutions for commercial nuclear reactors. The primary goal is to provide coupled, higher-fidelity, usable modeling and simulation capabilities than are currently available. These are needed to address light water reactor (LWR) operational and safety performance-defining phenomena that are not yet able to be fully modeled taking a first-principles approach. In order to pursue these goals, CASL has participation from laboratory, academic, and industry partners. These partners are pursuing the solution of ten major "Challenge Problems" in order to advance the state-of-the-art in reactor design and analysis to permit power uprates, higher burnup, life extension, and increased safety. At present, the problems being addressed by CASL are primarily reactor physics-oriented; however, this paper is intended to introduce CASL to the reactor dosimetry community because of the importance of reactor physics modelling and nuclear data to define the source term for that community and the applicability and extensibility of the transport methods being developed.

  18. Advances in the application of the SWAT model for water resources management

    NASA Astrophysics Data System (ADS)

    Jayakrishnan, R.; Srinivasan, R.; Santhi, C.; Arnold, J. G.

    2005-02-01

    Developments in computer technology have revolutionized the study of hydrologic systems and water resources management. Several computer-based hydrologic/water quality models have been developed for applications in hydrologic modelling and water resources studies. Distributed parameter models, necessary for basin-scale studies, have large input data requirements. Geographic information systems (GIS) and model-GIS interfaces aid the efficient creation of input data files required by such models. One such model available for the water resources professional is the Soil and Water Assessment Tool (SWAT), a distributed parameter model developed by the United States Department of Agriculture. This paper describes some recent advances made in the application of SWAT and the SWAT-GIS interface for water resources management. Four case studies are presented. The Hydrologic Unit Model for the United States (HUMUS) project used SWAT to conduct a national-scale analysis of the effect of management scenarios on water quantity and quality. Integration of the SWAT model with rainfall data available from the WSR-88D radar network helps us to incorporate the spatial variability of rainfall into the modelling process. This study demonstrates the usefulness of radar rainfall data in distributed hydrologic studies and the potential of SWAT for application in flood analysis and prediction. A hydrologic modelling study of the Sondu river basin in Kenya using SWAT indicates the potential for application of the model in African watersheds and points to the need for development of better model input data sets in Africa, which are critical for detailed water resources studies. The application of SWAT for water quality analysis in the Bosque river basin, Texas demonstrates the strength of the model for analysing different management scenarios to minimize point and non-point pollution, and its potential for application in total maximum daily load (TMDL) studies.

  19. Process and apparatus for electrolysis of hydrochloric acid

    SciTech Connect

    Minz, F.; Wiechers, H.

    1980-12-02

    In the production of chlorine and hydrogen from hydrochloric acid by electrolysis in an electrolysis cell comprising a plurality of vertically arranged bipolar electrodes, a diaphragm arranged between each two electrodes to divide the electrolysis chambers formed between them into an anolyte chamber and a catholyte chamber, and outlet and inlet devices for the electrolyte, the improvement which comprises electrolyzing the hydrochloric acid in at least two successive stages, and degassing the hydrochloric acid. Advantageously the hydrochloric acid moves from bottom to top, first through an upper stage and then through a lower stage. As a result less electrode surface is needed, a higher current density and/or voltage is possible so existing apparatus can be modified to connect more bipolar electrodes in series.

  20. Dewaterability characteristics of sludge conditioned with surfactants pretreatment by electrolysis.

    PubMed

    Yuan, Haiping; Zhu, Nanwen; Song, Fanyong

    2011-02-01

    The potential benefits of electrolysis-conditioned sludge dewaterability treatments with surfactants were investigated in this study. Capillary suction time (CST) and specific resistance of filtration (SRF) were used to evaluate the sludge dewaterability. Extracellular polymeric substance (EPS) content, viscosity and zeta potential were determined in an attempt to explain the observed changes in the conditioning process. The results indicated that SDS (Sodium Dodecyl Sulphate) and Triton X-100 have negative effect on the dewaterability of sludge pretreated both with and without electrolysis. However, with a combination of CTAB (Cetyl Trimethyl Ammonium Bromide) and electrolysis pretreatment presented clear advantages over surfactant conditioning alone for improving sludge dewaterability. The optimal dosage of CTAB to give maximal dewaterability was found to be 2000 mg/L, which generated sludge with optimal EPS concentration (150-300 mg/L), viscosity (55-62 mpa s) and zeta potential (-2.12 to -1.19 mV).

  1. From Oxygen Generation to Metals Production: In Situ Resource Utilization by Molten Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Khetpal, Deepak; Ducret, Andrew C.; Sadoway, Donald R.

    2003-01-01

    For the exploration of other bodies in the solar system, electrochemical processing is arguably the most versatile technology for conversion of local resources into usable commodities: by electrolysis one can, in principle, produce (1) breathable oxygen, (2) silicon for the fabrication of solar cells, (3) various reactive metals for use as electrodes in advanced storage batteries, and (4) structural metals such as steel and aluminum. Even so, to date there has been no sustained effort to develop such processes, in part due to the inadequacy of the database. The objective here is to identify chemistries capable of sustaining molten oxide electrolysis in the cited applications and to examine the behavior of laboratory-scale cells designed to generate oxygen and to produce metal. The basic research includes the study of the underlying high-temperature physical chemistry of oxide melts representative of lunar regolith and of Martian soil. To move beyond empirical approaches to process development, the thermodynamic and transport properties of oxide melts are being studied to help set the limits of composition and temperature for the processing trials conducted in laboratory-scale electrolysis cells. The goal of this investigation is to deliver a working prototype cell that can use lunar regolith and Martian soil to produce breathable oxygen along with metal by-product. Additionally, the process can be generalized to permit adaptation to accommodate different feedstock chemistries, such as those that will be encountered on other bodies in the solar system. The expected results of this research include: (1) the identification of appropriate electrolyte chemistries; (2) the selection of candidate anode and cathode materials compatible with electrolytes named above; and (3) performance data from a laboratory-scale cell producing oxygen and metal. On the strength of these results it should be possible to assess the technical viability of molten oxide electrolysis for in

  2. Simulation of isoelectro focusing processes. [stationary electrolysis of charged species

    NASA Technical Reports Server (NTRS)

    Palusinski, O. A.

    1980-01-01

    This paper presents the computer implementation of a model for the stationary electrolysis of two or more charged species. This has specific application to the technique of isoelectric focussing, in which the stationary electrolysis of ampholytes is used to generate a pH gradient useful for the separation of proteins, peptides and other biomolecules. The fundamental equations describing the process are given. These equations are transformed to a form suitable for digital computer implementation. Some results of computer simulation are described and compared to data obtained in the laboratory.

  3. Experimental study of the electrolysis of silicate melts

    NASA Technical Reports Server (NTRS)

    Keller, Rudolf

    1992-01-01

    Melting and electrolyzing lunar silicates yields oxygen gas and potentially can be practiced in situ to produce oxygen. With the present experiments conducted with simulant oxides at 1425-1480 C, it was ascertained that oxygen can be obtained anodically at feasible rates and current efficiencies. An electrolysis cell was operated with platinum anodes in a sealed vessel, and the production of gas was monitored. In these electrolysis experiments, stability of anodes remained a problem, and iron and silicon did not reduce readily into the liquid silver cathode.

  4. Installation of Ohio's First Electrolysis-Based Hydrogen Fueling Station

    NASA Technical Reports Server (NTRS)

    Scheidegger, Brianne T.; Lively, Michael L.

    2012-01-01

    This paper describes progress made towards the installation of a hydrogen fueling station in Northeast Ohio. In collaboration with several entities in the Northeast Ohio area, the NASA Glenn Research Center is installing a hydrogen fueling station that uses electrolysis to generate hydrogen on-site. The installation of this station is scheduled for the spring of 2012 at the Greater Cleveland Regional Transit Authority s Hayden bus garage in East Cleveland. This will be the first electrolysis-based hydrogen fueling station in Ohio.

  5. Reduction of organic trace compounds and fresh water consumption by recovery of advanced oxidation processes treated industrial wastewater.

    PubMed

    Bierbaum, S; Öller, H-J; Kersten, A; Klemenčič, A Krivograd

    2014-01-01

    Ozone (O(3)) has been used successfully in advanced wastewater treatment in paper mills, other sectors and municipalities. To solve the water problems of regions lacking fresh water, wastewater treated by advanced oxidation processes (AOPs) can substitute fresh water in highly water-consuming industries. Results of this study have shown that paper strength properties are not impaired and whiteness is slightly impaired only when reusing paper mill wastewater. Furthermore, organic trace compounds are becoming an issue in the German paper industry. The results of this study have shown that AOPs are capable of improving wastewater quality by reducing organic load, colour and organic trace compounds.

  6. Application of electrolysis for inactivation of an antiviral drug that is one of possible selection pressure to drug-resistant influenza viruses.

    PubMed

    Kobayashi, Toyohide; Hirose, Jun; Wu, Hong; Sano, Kouichi; Katsumata, Takahiro; Tsujibo, Hiroshi; Nakano, Takashi

    2013-12-01

    The recent development of antiviral drugs has led to concern that the release of the chemicals in surface water due to expanded medical use could induce drug-resistant mutant viruses in zoonosis. Many researchers have noted that the appearance of an oseltamivir (Tamiflu(®))-resistant avian influenza mutant virus, which may spread to humans, could be induced by oseltamivir contamination of surface water. Although past studies have reported electrolysis as a possible method for degradation of antineoplastics and antibacterials in water, the validity of the method for treatment of antiviral drugs is unknown. In this study, electrolysis was used to degrade an antiviral prodrug, oseltamivir, and a stable active form, oseltamivir carboxylate, and the degradation process was monitored with HPLC-UV and the neuraminidase inhibitory assay. HPLC-UV-detectable oseltamivir and oseltamivir carboxylate were decomposed by electrolysis within 60 min, and inhibitory activity of neuraminidase decreased below the detection limit of the assay used. Cytotoxic and genotoxic activity were not detected in electrolyzed fluid. These results indicate that electrolysis is a possible treatment for inactivation of the antiviral drug oseltamivir.

  7. Variations in AOC and microbial diversity in an advanced water treatment plant

    NASA Astrophysics Data System (ADS)

    Yang, B. M.; Liu, J. K.; Chien, C. C.; Surampalli, R. Y.; Kao, C. M.

    2011-10-01

    SummaryThe objective of this study was to evaluate the variations in assimilable organic carbon (AOC) and microbial diversities in an advanced water treatment plant. The efficiency of biofiltration on AOC removal using anthracite and granular activated carbon (GAC) as the media was also evaluated through a pilot-scale column experiment. Effects of hydrological factors (seasonal effects and river flow) on AOC concentrations in raw water samples and hydraulic retention time (HRT) of biofiltration on AOC treatment were also evaluated. Results show that AOC concentrations in raw water and clear water of the plant were about 138 and 27 μg acetate-C/L, respectively. Higher AOC concentrations were observed in wet seasons probably due to the resuspension of organic-contained sediments and discharges of non-point source (NPS) pollutants from the upper catchment. This reveals that seasonal effect played an important role in the variations in influent AOC concentrations. Approximately 82% and 70% of AOC removal efficiencies were observed in GAC and anthracite columns, respectively. Results from column experiment reveal that the applied treatment processes in the plant and biofiltration system were able to remove AOC effectively. Microbial colonization on GAC and anthracite were detected via the observation of scanning electron microscopic (SEM) images. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal significant decrease in microbial diversities after the ozonation process. Higher HRT caused higher microbial contact time, and thus, more microbial colonies and higher microbial diversity were observed in the latter part of the biofilters. Some of the dominant microbial species in the biofiltration columns belonged to the beta- proteobacterium, which might contribute to the AOC degradation. Results of this study provide us insight into the variations in AOC and microbial diversity in the advanced

  8. Experimental design, operation, and results of a 4 kW high temperature steam electrolysis experiment

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoyu; O'Brien, James E.; Tao, Greg; Zhou, Can; Housley, Gregory K.

    2015-11-01

    High temperature steam electrolysis (HTSE) is a promising technology for large-scale hydrogen production. However, research on HTSE performance above the kW level is limited. This paper presents the results of 4 kW HTSE long-term test completed in a multi-kW test facility recently developed at the Idaho National Laboratory (INL). The 4 kW HTSE unit consisted of two solid oxide electrolysis stacks electrically connected in parallel, each of which included 40 electrode-supported planar cells. A current density of 0.41 A cm-2 was used for the long-term operating at a constant current mode, resulting in a theoretical hydrogen production rate about 23 slpm. A demonstration of 830 h stable operation was achieved with a degradation rate of 3.1% per 1000 h. The paper also includes detailed descriptions of the piping layout, steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. This successful demonstration of multi-kW scale HTSE unit will help to advance the technology toward near-term commercialization.

  9. Ammonia synthesis. Ammonia synthesis by N₂ and steam electrolysis in molten hydroxide suspensions of nanoscale Fe₂O₃.

    PubMed

    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.

  10. LONG-TERM PERFORMANCE OF SOLID OXIDE STACKS WITH ELECTRODE-SUPPORTED CELLS OPERATING IN THE STEAM ELECTROLYSIS MODE

    SciTech Connect

    J. E. O'Brien; R. C. O'Brien; X. Zhang; G. Tao; B. J. Butler

    2011-11-01

    Performance characterization and durability testing have been completed on two five-cell high-temperature electrolysis stacks constructed with advanced cell and stack technologies. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. The per-cell active area is 100 cm2. The stack is internally manifolded with compliant mica-glass seals. Treated metallic interconnects with integral flow channels separate the cells. Stack compression is accomplished by means of a custom spring-loaded test fixture. Initial stack performance characterization was determined through a series of DC potential sweeps in both fuel cell and electrolysis modes of operation. Results of these sweeps indicated very good initial performance, with area-specific resistance values less than 0.5 ?.cm2. Long-term durability testing was performed with A test duration of 1000 hours. Overall performance degradation was less than 10% over the 1000-hour period. Final stack performance characterization was again determined by a series of DC potential sweeps at the same flow conditions as the initial sweeps in both electrolysis and fuel cell modes of operation. A final sweep in the fuel cell mode indicated a power density of 0.356 W/cm2, with average per-cell voltage of 0.71 V at a current of 50 A.

  11. Game Changing Development Program - Next Generation Life Support Project: Oxygen Recovery From Carbon Dioxide Using Ion Exchange Membrane Electrolysis Technology

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jiao, Feng

    2016-01-01

    This report summarizes the Phase I research and development work performed during the March 13, 2015 to July 13, 2016 period. The proposal for this work was submitted in response to NASA Research Announcement NNH14ZOA001N, "Space Technology Research, Development, Demonstration, and Infusion 2014 (SpaceTech-REDDI-2014)," Appendix 14GCD-C2 "Game Changing Development Program, Advanced Oxygen Recovery for Spacecraft Life Support Systems Appendix" The Task Agreement for this Phase I work is Document Control Number: GCDP-02-TA-15015. The objective of the Phase I project was to demonstrate in laboratories two Engineering Development Units (EDU) that perform critical functions of the low temperature carbon dioxide electrolysis and the catalytic conversion of carbon monoxide into carbon and carbon dioxide. The low temperature carbon dioxide electrolysis EDU was built by the University of Delaware with Dr. Feng Jiao as the principal investigator in charge of this EDU development (under NASA Contract NNC15CA04C). The carbon monoxide catalytic conversion EDU was built by the NASA Glenn Research Center with Kenneth Burke as the principal investigator and overall project leader for the development of both EDUs. Both EDUs were successfully developed and demonstrated the critical functions for each process. The carbon dioxide electrolysis EDU was delivered to the NASA Johnson Space Center and the carbon monoxide catalytic conversion EDU was delivered to the NASA Marshall Spaceflight Center.

  12. An exergetic/energetic/economic analysis of three hydrogen production processes - Electrolysis, hybrid, and thermochemical

    NASA Astrophysics Data System (ADS)

    Funk, J. E.; Eisermann, W.

    This paper presents the results of a combined first and second law analysis, along with capital and operating costs, for hydrogen production from water by means of electrolytic, hybrid, and thermochemical processes. The processes are SPE and Lurgi electrolysis with light water reactor power generation and sulfur cycle hybrid, thermochemical and SPE electrolysis with a very high temperature reactor primary energy source. Energy and Exergy (2nd law) flow diagrams for the process are shown along with the location and magnitude of the process irreversibilities. The overall process thermal (1st law) efficiencies vary from 25 to 51% and the exergetic (2nd law) efficiencies, referred to the fuel for the primary energy source, vary from 22 to 45%. Capital and operating costs, escalated to 1979 dollars, are shown for each process for both the primary energy source and the hydrogen production plant. All costs were taken from information available in the open literature and are for a plant capacity of 100 x 10 to the 6th SCF/day. Production costs vary from 10 to 18 $/GJ, based on the higher heating value of hydrogen, and are based on a 90% plant operating factor with a 21% annual charge on total capital costs.

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

    PubMed

    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 <480 mV in alkaline pH possess the best chance to achieve 100 % oxygen/hydrogen selectivity. NiFe layered double hydroxide is shown to satisfy this criterion at pH 13 in 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.

  14. Estimating Hydrogen Production Potential in Biorefineries Using Microbial Electrolysis Cell Technology

    SciTech Connect

    Borole, Abhijeet P; Mielenz, Jonathan R

    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.

  15. Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell.

    PubMed

    Huang, Xiao; Qu, Yan; Cid, Clément A; Finke, Cody; Hoffmann, Michael R; Lim, Keahying; Jiang, Sunny C

    2016-04-01

    The paucity of proper sanitation facilities has contributed to the spread of waterborne diseases in many developing countries. The primary goal of this study was to demonstrate the feasibility of using a wastewater electrolysis cell (WEC) for toilet wastewater disinfection. The treated wastewater was designed to reuse for toilet flushing and agricultural irrigation. Laboratory-scale electrochemical (EC) disinfection experiments were performed to investigate the disinfection efficiency of the WEC with four seeded microorganisms (Escherichia coli, Enterococcus, recombinant adenovirus serotype 5, and bacteriophage MS2). In addition, the formation of organic disinfection byproducts (DBPs) trihalomethanes (THMs) and haloacetic acids (HAA5) at the end of the EC treatment was also investigated. The results showed that at an applied cell voltage of +4 V, the WEC achieved 5-log10 reductions of all four seeded microorganisms in real toilet wastewater within 60 min. In contrast, chemical chlorination (CC) disinfection using hypochlorite [NaClO] was only effective for the inactivation of bacteria. Due to the rapid formation of chloramines, less than 0.5-log10 reduction of MS2 was observed in toilet wastewater even at the highest [NaClO] dosage (36 mg/L, as Cl2) over a 1 h reaction. Experiments using laboratory model waters showed that free reactive chlorine generated in situ during EC disinfection process was the main disinfectant responsible for the inactivation of microorganisms. However, the production of hydroxyl radicals [OH], and other reactive oxygen species by the active bismuth-doped TiO2 anode were negligible under the same electrolytic conditions. The formation of THMs and HAA5 were found to increase with higher applied cell voltage. Based on the energy consumption estimates, the WEC system can be operated using solar energy stored in a DC battery as the sole power source.

  16. Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell

    PubMed Central

    Huang, Xiao; Qu, Yan; Cid, Clément A.; Finke, Cody; Hoffmann, Michael R.; Lim, Keahying; Jiang, Sunny C.

    2016-01-01

    The paucity of proper sanitation facilities has contributed to the spread of waterborne diseases in many developing countries. The primary goal of this study was to demonstrate the feasibility of using a wastewater electrolysis cell (WEC) for toilet wastewater disinfection. The treated wastewater was designed to reuse for toilet flushing and agricultural irrigation. Laboratory-scale electrochemical (EC) disinfection experiments were performed to investigate the disinfection efficiency of the WEC with four seeded microorganisms (Escherichia coli, Enterococcus, recombinant adenovirus serotype 5, and bacteriophage MS2). In addition, the formation of organic disinfection byproducts (DBPs) trihalomethanes (THMs) and haloacetic acids (HAA5) at the end of the EC treatment was also investigated. The results showed that at an applied cell voltage of +4 V, the WEC achieved 5-log10 reductions of all four seeded microorganisms in real toilet wastewater within 60 min. In contrast, chemical chlorination (CC) disinfection using hypochlorite [NaClO] was only effective for the inactivation of bacteria. Due to the rapid formation of chloramines, less than 0.5-log10 reduction of MS2 was observed in toilet wastewater even at the highest [NaClO] dosage (36 mg/L, as Cl2) over a 1 h reaction. Experiments using laboratory model waters showed that free reactive chlorine generated in situ during EC disinfection process was the main disinfectant responsible for the inactivation of microorganisms. However, the production of hydroxyl radicals [•OH], and other reactive oxygen species by the active bismuth-doped TiO2 anode were negligible under the same electrolytic conditions. The formation of THMs and HAA5 were found to increase with higher applied cell voltage. Based on the energy consumption estimates, the WEC system can be operated using solar energy stored in a DC battery as the sole power source. PMID:26854604

  17. Using advanced oxidation treatment for biofilm inactivation by varying water vapor content in air plasma

    NASA Astrophysics Data System (ADS)

    Ryota, Suganuma; Koichi, Yasuoka

    2015-09-01

    Biofilms are caused by environmental degradation in food factories and medical facilities. The inactivation of biofilms involves making them react with chemicals including chlorine, hydrogen peroxide, and ozone, although inactivation using chemicals has a potential problem because of the hazardous properties of the residual substance and hydrogen peroxide, which have slow reaction velocity. We successfully performed an advanced oxidation process (AOP) using air plasma. Hydrogen peroxide and ozone, which were used for the formation of OH radicals in our experiment, were generated by varying the amount of water vapor supplied to the plasma. By varying the content of the water included in the air, the main product was changed from air plasma. When we increased the water content in the air, hydrogen peroxide was produced, while ozone peroxide was produced when we decreased the water content in the air. By varying the amount of water vapor, we realized a 99.9% reduction in the amount of bacteria in the biofilm when we discharged humidified air only. This work was supported by JSPS KAKENHI Grant Number 25630104.

  18. Utility leadership in reopening the nuclear option with advanced light water reactors

    SciTech Connect

    Marston, T.U.; Layman, W.H. )

    1992-01-01

    Since 1981, the Electric Power Research Institute (EPRI) has been pursing the development of the advanced light water reactor (ALWR). The ALWR Program is comprised of five phases and are described in the paper. In order to meet the anticipated baseline power generation requirements in the US, the Nuclear Power Oversight Committee (NPOC) has developed a strategic plan for ALWR implementation in order to regain the nuclear option in the United States. The paper also covers the policies behind the utility requirements, the status of ALWR developments in the United States, the electricity demands during the period 1990-2010, and some of the innovative features of the passive plants presently under design.

  19. TRAC-PF1: an advanced best-estimate computer program for pressurized water reactor analysis

    SciTech Connect

    Liles, D.R.; Mahaffy, J.H.

    1984-02-01

    The Transient Reactor Analysis Code (TRAC) is being developed at the Los Alamos National Laboratory to provide advanced best-estimate predictions of postulated accidents in light water reactors. The TRAC-PF1 program provides this capability for pressurized water reactors and for many thermal-hydraulic experimental facilities. The code features either a one-dimensional or a three-dimensional treatment of the pressure vessel and its associated internals; a two-phase, two-fluid nonequilibrium hydrodynamics model with a noncondensable gas field; flow-regime-dependent constitutive equation treatment; optional reflood tracking capability for both bottom flood and falling-film quench fronts; and consistent treatment of entire accident sequences including the generation of consistent initial conditions. This report describes the thermal-hydraulic models and the numerical solution methods used in the code. Detailed programming and user information also are provided.

  20. Lunar Water Resource Demonstration

    NASA Technical Reports Server (NTRS)

    Muscatello, Anthony C.

    2008-01-01

    In cooperation with the Canadian Space Agency, the Northern Centre for Advanced Technology, Inc., the Carnegie-Mellon University, JPL, and NEPTEC, NASA has undertaken the In-Situ Resource Utilization (ISRU) project called RESOLVE. This project is a ground demonstration of a system that would be sent to explore permanently shadowed polar lunar craters, drill into the regolith, determine what volatiles are present, and quantify them in addition to recovering oxygen by hydrogen reduction. The Lunar Prospector has determined these craters contain enhanced hydrogen concentrations averaging about 0.1%. If the hydrogen is in the form of water, the water concentration would be around 1%, which would translate into billions of tons of water on the Moon, a tremendous resource. The Lunar Water Resource Demonstration (LWRD) is a part of RESOLVE designed to capture lunar water and hydrogen and quantify them as a backup to gas chromatography analysis. This presentation will briefly review the design of LWRD and some of the results of testing the subsystem. RESOLVE is to be integrated with the Scarab rover from CMIJ and the whole system demonstrated on Mauna Kea on Hawaii in November 2008. The implications of lunar water for Mars exploration are two-fold: 1) RESOLVE and LWRD could be used in a similar fashion on Mars to locate and quantify water resources, and 2) electrolysis of lunar water could provide large amounts of liquid oxygen in LEO, leading to lower costs for travel to Mars, in addition to being very useful at lunar outposts.

  1. Numerical Evaluation of Fluid Mixing Phenomena in Boiling Water Reactor Using Advanced Interface Tracking Method

    NASA Astrophysics Data System (ADS)

    Yoshida, Hiroyuki; Takase, Kazuyuki

    Thermal-hydraulic design of the current boiling water reactor (BWR) is performed with the subchannel analysis codes which incorporated the correlations based on empirical results including actual-size tests. Then, for the Innovative Water Reactor for Flexible Fuel Cycle (FLWR) core, an actual size test of an embodiment of its design is required to confirm or modify such correlations. In this situation, development of a method that enables the thermal-hydraulic design of nuclear reactors without these actual size tests is desired, because these tests take a long time and entail great cost. For this reason, we developed an advanced thermal-hydraulic design method for FLWRs using innovative two-phase flow simulation technology. In this study, a detailed Two-Phase Flow simulation code using advanced Interface Tracking method: TPFIT is developed to calculate the detailed information of the two-phase flow. In this paper, firstly, we tried to verify the TPFIT code by comparing it with the existing 2-channel air-water mixing experimental results. Secondary, the TPFIT code was applied to simulation of steam-water two-phase flow in a model of two subchannels of a current BWRs and FLWRs rod bundle. The fluid mixing was observed at a gap between the subchannels. The existing two-phase flow correlation for fluid mixing is evaluated using detailed numerical simulation data. This data indicates that pressure difference between fluid channels is responsible for the fluid mixing, and thus the effects of the time average pressure difference and fluctuations must be incorporated in the two-phase flow correlation for fluid mixing. When inlet quality ratio of subchannels is relatively large, it is understood that evaluation precision of the existing two-phase flow correlations for fluid mixing are relatively low.

  2. HIGH-TEMPERATURE CO-ELECTROLYSIS OF H2O AND CO2 FOR SYNGAS PRODUCTION

    SciTech Connect

    Stoots, C.M.

    2006-11-01

    Worldwide, the demand for light hydrocarbon fuels like gasoline and diesel oil is increasing. To satisfy this demand, oil companies have begun to utilize oil deposits of lower hydrogen content (an example is the Athabasca Oil Sands). Additionally, the higher contents of sulfur and nitrogen of these resources requires processes such as hydrotreating to meet environmental requirements. In the mean time, with the price of oil currently over $50 / barrel, synthetically-derived hydrocarbon fuels (synfuels) have become economical. Synfuels are typically produced from syngas – hydrogen (H2) and carbon monoxide (CO) -- using the Fischer-Tropsch process, discovered by Germany before World War II. South Africa has used synfuels to power a significant number of their buses, trucks, and taxicabs. The Idaho National Laboratory (INL), in conjunction with Ceramatec Inc. (Salt Lake City, USA) has been researching for several years the use of solid-oxide fuel cell technology to electrolyze steam for large-scale nuclear-powered hydrogen production. Now, an experimental research project is underway at the INL to investigate the feasibility of producing syngas by simultaneously electrolyzing at high-temperature steam and carbon dioxide (CO2) using solid oxide fuel cell technology. The syngas can then be used for synthetic fuel production. This program is a combination of experimental and computational activities. Since the solid oxide electrolyte material is a conductor of oxygen ions, CO can be produced by electrolyzing CO2 sequestered from some greenhouse gas-emitting process. Under certain conditions, however, CO can further electrolyze to produce carbon, which can then deposit on cell surfaces and reduce cell performance. The understanding of the co-electrolysis of steam and CO2 is also complicated by the competing water-gas shift reaction. Results of experiments and calculations to date of CO2 and CO2/H2O electrolysis will be presented and discussed. These will include

  3. Spacesuit Water Membrane Evaporator; An Enhanced Evaporative Cooling Systems for the Advanced Extravehicular Mobility Unit Portable Life Support System

    NASA Technical Reports Server (NTRS)

    Bue, Grant C.; Makinen, Janice V.; Miller, Sean.; Campbell, Colin; Lynch, Bill; Vogel, Matt; Craft, Jesse; Petty, Brian

    2014-01-01

    Spacesuit Water Membrane Evaporator - Baseline heat rejection technology for the Portable Life Support System of the Advanced EMU center dot Replaces sublimator in the current EMU center dot Contamination insensitive center dot Can work with Lithium Chloride Absorber Radiator in Spacesuit Evaporator Absorber Radiator (SEAR) to reject heat and reuse evaporated water The Spacesuit Water Membrane Evaporator (SWME) is being developed to replace the sublimator for future generation spacesuits. Water in LCVG absorbs body heat while circulating center dot Warm water pumped through SWME center dot SWME evaporates water vapor, while maintaining liquid water - Cools water center dot Cooled water is then recirculated through LCVG. center dot LCVG water lost due to evaporation (cooling) is replaced from feedwater The Independent TCV Manifold reduces design complexity and manufacturing difficulty of the SWME End Cap. center dot The offset motor for the new BPV reduces the volume profile of the SWME by laying the motor flat on the End Cap alongside the TCV.

  4. HIGH-TEMPERATURE ELECTROLYSIS FOR HYDROGEN PRODUCTION FROM NUCLEAR ENERGY

    SciTech Connect

    James E. O'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.

  5. Synergistic Combination of Electrolysis and Electroporation for Tissue Ablation

    PubMed Central

    Mikus, Paul; Klein, Nina; Rubinsky, Liel; Rubinsky, Boris

    2016-01-01

    Electrolysis, electrochemotherapy with reversible electroporation, nanosecond pulsed electric fields and irreversible electroporation are valuable non-thermal electricity based tissue ablation technologies. This paper reports results from the first large animal study of a new non-thermal tissue ablation technology that employs “Synergistic electrolysis and electroporation” (SEE). The goal of this pre-clinical study is to expand on earlier studies with small animals and use the pig liver to establish SEE treatment parameters of clinical utility. We examined two SEE methods. One of the methods employs multiple electrochemotherapy-type reversible electroporation magnitude pulses, designed in such a way that the charge delivered during the electroporation pulses generates the electrolytic products. The second SEE method combines the delivery of a small number of electrochemotherapy magnitude electroporation pulses with a low voltage electrolysis generating DC current in three different ways. We show that both methods can produce lesion with dimensions of clinical utility, without the need to inject drugs as in electrochemotherapy, faster than with conventional electrolysis and with lower electric fields than irreversible electroporation and nanosecond pulsed ablation. PMID:26866693

  6. Three-Man Solid Electrolyte Carbon Dioxide Electrolysis Breadboard

    NASA Astrophysics Data System (ADS)

    Isenberg, Arnold O.

    1989-06-01

    The development of the Three-Man (2.2 lb CO2/man-day) Solid Electrolyte CO2 Electrolysis Breadboard consisted of a Phase 1 and 2 effort. The Phase 1 effort constituted fabrication of three electrolysis cell types and performing parametric testing, off-design testing, and cell life testing. The Phase 2 consisted of the preliminary design, incorporation of palladium (Pd) tubes for hydrogen separation from the electrolyzer cathode feed gases, design support testing, final design, fabrication, and performance testing of the breadboard system. The results of performance tests demonstrated that CO2 electrolysis in an oxygen reclamation system for long duration space-based habitats is feasible. Closure of the oxygen system loop, therefore, can be achieved by CO2 electrolysis. In a two step process the metabolic CO2 and H2O vapor are electrolyzed into O2, H2, and CO. The CO can subsequently be disproportionated into carbon and CO2 in a carbon deposition reactor and the CO2 in turn be recycled and electrolyzed for total O2 recovery. The development effort demonstrated electrolyzer system can be designed and built to operate safely and reliably and the incorporation of Pd tubes for hydrogen diffusion can be integrated safely with predictable performance.

  7. Hydrogen generation by electrolysis of aqueous organic solutions

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Valdez, Thomas I. (Inventor)

    2002-01-01

    A device for electrolysis of an aqueous solution of an organic fuel. The electrolyte is a solid-state polymer membrane with anode and cathode catalysts on both surfaces for electro-oxidization and electro-reduction. A low-cost and portable hydrogen generator can be made based on the device with organic fuels such as methanol.

  8. Oxygen from the lunar soil by molten silicate electrolysis

    NASA Technical Reports Server (NTRS)

    Colson, Russell O.; Haskin, Larry A.

    1992-01-01

    Accepting that oxygen, rather than gigantic gems or gold, is likely to make the Moon's Klondike, the extraction of oxygen from the lunar soil by molten silicate electrolysis has chosen to be investigated. Process theory and proposed lunar factory are addressed.

  9. Hydrogen generation by electrolysis of aqueous organic solutions

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Valdez, Thomas I. (Inventor)

    2006-01-01

    A device for electrolysis of an aqueous solution of an organic fuel. The electrolyte is a solid-state polymer membrane with anode and cathode catalysts on both surfaces for electro-oxidization and electro-reduction. A low-cost and portable hydrogen generator can be made based on the device with organic fuels such as methanol.

  10. Production of aluminum metal by electrolysis of aluminum sulfide

    DOEpatents

    Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

    1982-04-01

    Metallic aluminum may be produced by the electrolysis of Al/sub 2/S/sub 3/ at 700 to 800/sup 0/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.

  11. Production of aluminum metal by electrolysis of aluminum sulfide

    DOEpatents

    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.

  12. PEM Electrolysis H2A Production Case Study Documentation

    SciTech Connect

    James, Brian; Colella, Whitney; Moton, Jennie; Saur, G.; Ramsden, T.

    2013-12-31

    This report documents the development of four DOE Hydrogen Analysis (H2A) case studies for polymer electrolyte membrane (PEM) electrolysis. The four cases characterize PEM electrolyzer technology for two hydrogen production plant sizes (Forecourt and Central) and for two technology development time horizons (Current and Future).

  13. Three-Man Solid Electrolyte Carbon Dioxide Electrolysis Breadboard

    NASA Technical Reports Server (NTRS)

    Isenberg, Arnold O.

    1989-01-01

    The development of the Three-Man (2.2 lb CO2/man-day) Solid Electrolyte CO2 Electrolysis Breadboard consisted of a Phase 1 and 2 effort. The Phase 1 effort constituted fabrication of three electrolysis cell types and performing parametric testing, off-design testing, and cell life testing. The Phase 2 consisted of the preliminary design, incorporation of palladium (Pd) tubes for hydrogen separation from the electrolyzer cathode feed gases, design support testing, final design, fabrication, and performance testing of the breadboard system. The results of performance tests demonstrated that CO2 electrolysis in an oxygen reclamation system for long duration space-based habitats is feasible. Closure of the oxygen system loop, therefore, can be achieved by CO2 electrolysis. In a two step process the metabolic CO2 and H2O vapor are electrolyzed into O2, H2, and CO. The CO can subsequently be disproportionated into carbon and CO2 in a carbon deposition reactor and the CO2 in turn be recycled and electrolyzed for total O2 recovery. The development effort demonstrated electrolyzer system can be designed and built to operate safely and reliably and the incorporation of Pd tubes for hydrogen diffusion can be integrated safely with predictable performance.

  14. Synergistic Combination of Electrolysis and Electroporation for Tissue Ablation.

    PubMed

    Stehling, Michael K; Guenther, Enric; Mikus, Paul; Klein, Nina; Rubinsky, Liel; Rubinsky, Boris

    2016-01-01

    Electrolysis, electrochemotherapy with reversible electroporation, nanosecond pulsed electric fields and irreversible electroporation are valuable non-thermal electricity based tissue ablation technologies. This paper reports results from the first large animal study of a new non-thermal tissue ablation technology that employs "Synergistic electrolysis and electroporation" (SEE). The goal of this pre-clinical study is to expand on earlier studies with small animals and use the pig liver to establish SEE treatment parameters of clinical utility. We examined two SEE methods. One of the methods employs multiple electrochemotherapy-type reversible electroporation magnitude pulses, designed in such a way that the charge delivered during the electroporation pulses generates the electrolytic products. The second SEE method combines the delivery of a small number of electrochemotherapy magnitude electroporation pulses with a low voltage electrolysis generating DC current in three different ways. We show that both methods can produce lesion with dimensions of clinical utility, without the need to inject drugs as in electrochemotherapy, faster than with conventional electrolysis and with lower electric fields than irreversible electroporation and nanosecond pulsed ablation.

  15. The Use of Advanced Hydroelectric Turbines to Improve Water Quality and Fish Populations

    SciTech Connect

    Brookshier, P A; Cada, G F; Flynn, J V; Rinehart, B N; Sale, M J; Sommers, G L

    1999-09-20

    Hydroelectric power contributes about 10 percent of the electrical energy generated in the United States, and nearly 20 percent of the world's electrical energy. It is a renewable energy source that can contribute significantly to reduction of greenhouse gases by offsetting conventional carbon-based electricity generation. However, rather than growing in importance, hydroelectric generation has actually declined in recent years, often as a consequence of environmental concerns centering around (1) restriction of upstream and downstream fish passage by the dam, and (2) alteration of water quality and river flows by the impoundment. The Advanced Hydropower Turbine System (AHTS) Program of the U.S. Department of Energy is developing turbine technology which would help to maximize global hydropower resources while minimizing adverse environmental effects. Major technical goals for the Program are (1) the reduction of mortality among turbine-passed fish to 2 percent or less, compared to current levels ranging up to 30 percent or greater; and (2) development of aerating turbines that would ensure that water discharged from reservoirs has a dissolved oxygen concentration of at least 6 mg/L. These advanced, "environmentally friendly" turbines would be suitable both for new hydropower installations and for retrofitting at existing dams. Several new turbine designs that have been developed in the initial phases of the AHTS program are described.

  16. Advanced, Environmentally Friendly Hydroelectric Turbines for the Restoration of Fish and Water Quality

    SciTech Connect

    Brookshier, P.A.; Cada, G.F.; Flynn, J.V.; Rinehart, B.N.; Sale, M.J.; Sommers, G.L.

    1999-09-06

    Hydroelectric power contributes about 10 percent of the electrical energy generated in the United States, and nearly 20 percent of the world�s electrical energy. The contribution of hydroelectric generation has declined in recent years, often as a consequence of environmental concerns centering around (1) restriction of upstream and downstream fish passage by the dam, and (2) alteration of water quality and river flows by the impoundment. The Advanced Hydropower Turbine System (AHTS) Program of the U.S. Department of Energy is developing turbine technology which would help to maximize global hydropower resources while minimizing adverse environmental effects. Major technical goals for the Program are (1) the reduction of mortality among turbine-passed fish to 2 percent or less, compared to current levels ranging up to 30 percent or greater; and (2) development of aerating turbines that would ensure that water discharged from reservoirs has a dissolved oxygen concentration of at least 6 mg/L. These advanced, �environmentally friendly� turbines would be suitable both for new hydropower installations and for retrofitting at existing dams. Several new turbine designs that have been he AHTS program are described.

  17. Homogenous VUV advanced oxidation process for enhanced degradation and mineralization of antibiotics in contaminated water.

    PubMed

    Pourakbar, Mojtaba; Moussavi, Gholamreza; Shekoohiyan, Sakine

    2016-03-01

    This study was aimed to evaluate the degradation and mineralization of amoxicillin(AMX), using VUV advanced process. The effect of pH, AMX initial concentration, presence of water ingredients, the effect of HRT, and mineralization level by VUV process were taken into consideration. In order to make a direct comparison, the test was also performed by UVC radiation. The results show that the degradation of AMX was following the first-order kinetic. It was found that direct photolysis by UVC was able to degrade 50mg/L of AMX in 50min,while it was 3min for VUV process. It was also found that the removal efficiency by VUV process was directly influenced by pH of the solution, and higher removal rates were achieved at high pH values.The results show that 10mg/L of AMX was completely degraded and mineralized within 50s and 100s, respectively, indicating that the AMX was completely destructed into non-hazardous materials. Operating the photoreactor in contentious-flow mode revealed that 10mg/L AMX was completely degraded and mineralized at HRT values of 120s and 300s. it was concluded that the VUV advanced process was an efficient and viable technique for degradation and mineralization of contaminated water by antibiotics.

  18. Degradation of estrone in water and wastewater by various advanced oxidation processes.

    PubMed

    Sarkar, Shubhajit; Ali, Sura; Rehmann, Lars; Nakhla, George; Ray, Madhumita B

    2014-08-15

    A comprehensive study was conducted to determine the relative efficacy of various advanced oxidation processes such as O3, H2O2, UV, and combinations of UV/O3, UV/H2O2 for the removal of estrone (E1) from pure water and secondary effluent. In addition to the parent compound (E1) removal, performance of the advanced oxidation processes was characterized using removal of total organic carbon (TOC), and estrogenicity of the effluent. Although E1 removal was high for all the AOPs, intermediates formed were more difficult to degrade leading to slow TOC removal. Energy calculations and cost analysis indicated that, although UV processes have low electricity cost, ozonation is the least cost option ($ 0.34/1000 gallons) when both capital and operating costs were taken into account. Ozonation also is superior to the other tested AOPs due to higher removal of TOC and estrogenicity. The rate of E1 removal decreased linearly with the background TOC in water, however, E1 degradation in the secondary effluent from a local wastewater treatment plant was not affected significantly due to the low COD values in the effluent.

  19. Solar-Enhanced Advanced Oxidation Processes for Water Treatment: Simultaneous Removal of Pathogens and Chemical Pollutants.

    PubMed

    Tsydenova, Oyuna; Batoev, Valeriy; Batoeva, Agniya

    2015-08-14

    The review explores the feasibility of simultaneous removal of pathogens and chemical pollutants by solar-enhanced advanced oxidation processes (AOPs). The AOPs are based on in-situ generation of reactive oxygen species (ROS), most notably hydroxyl radicals •OH, that are capable of destroying both pollutant molecules and pathogen cells. The review presents evidence of simultaneous removal of pathogens and chemical pollutants by photocatalytic processes, namely TiO2 photocatalysis and photo-Fenton. Complex water matrices with high loads of pathogens and chemical pollutants negatively affect the efficiency of disinfection and pollutant removal. This is due to competition between chemical substances and pathogens for generated ROS. Other possible negative effects include light screening, competitive photon absorption, adsorption on the catalyst surface (thereby inhibiting its photocatalytic activity), etc. Besides, some matrix components may serve as nutrients for pathogens, thus hindering the disinfection process. Each type of water/wastewater would require a tailor-made approach and the variables that were shown to influence the processes-catalyst/oxidant concentrations, incident radiation flux, and pH-need to be adjusted in order to achieve the required degree of pollutant and pathogen removal. Overall, the solar-enhanced AOPs hold promise as an environmentally-friendly way to substitute or supplement conventional water/wastewater treatment, particularly in areas without access to centralized drinking water or sewage/wastewater treatment facilities.

  20. Removal of natural organic matter from drinking water by advanced oxidation processes.

    PubMed

    Matilainen, Anu; Sillanpää, Mika

    2010-06-01

    Over the past 10-20years the amount of the natural organic matter (NOM) has been increased in raw water supplies on several areas. The presence of NOM causes many problems in drinking water treatment processes, including: (i) negative effect on water quality by colour, taste and odor problems, (ii) increased coagulant and disinfectant dose requirements (which in turn results increased sludge and potential harmful disinfection by-product formation), (iii) promoted biological growth in distribution system, and (iv) increased levels of complexed heavy metals and adsorbed organic pollutants. Thus, more efficient methods for the removal of NOM have emerged. Among these are advanced oxidation processes (AOPs). These include O(3)/H(2)O(2), O(3)/UV, UV/H(2)O(2), TiO(2)/UV, H(2)O(2)/catalyst, Fenton and photo-Fenton prosesses as well as ultrasound. In the present work, an overview of the recent research studies dealing with AOP methods for the removal of NOM and related compounds from drinking water is presented.

  1. Pilot-scale investigation of drinking water ultrafiltration membrane fouling rates using advanced data analysis techniques.

    PubMed

    Chen, Fei; Peldszus, Sigrid; Peiris, Ramila H; Ruhl, Aki S; Mehrez, Renata; Jekel, Martin; Legge, Raymond L; Huck, Peter M

    2014-01-01

    A pilot-scale investigation of the performance of biofiltration as a pre-treatment to ultrafiltration for drinking water treatment was conducted between 2008 and 2010. The objective of this study was to further understand the fouling behaviour of ultrafiltration at pilot scale and assess the utility of different foulant monitoring tools. Various fractions of natural organic matter (NOM) and colloidal/particulate matter of raw water, biofilter effluents, and membrane permeate were characterized by employing two advanced NOM characterization techniques: liquid chromatography - organic carbon detection (LC-OCD) and fluorescence excitation-emission matrices (FEEM) combined with principal component analysis (PCA). A framework of fouling rate quantification and classification was also developed and utilized in this study. In cases such as the present one where raw water quality and therefore fouling potential vary substantially, such classification can be considered essential for proper data interpretation. The individual and combined contributions of various NOM fractions and colloidal/particulate matter to hydraulically reversible and irreversible fouling were investigated using various multivariate statistical analysis techniques. Protein-like substances and biopolymers were identified as major contributors to both reversible and irreversible fouling, whereas colloidal/particulate matter can alleviate the extent of irreversible fouling. Humic-like substances contributed little to either reversible or irreversible fouling at low level fouling rates. The complementary nature of FEEM-PCA and LC-OCD for assessing the fouling potential of complex water matrices was also illustrated by this pilot-scale study.

  2. Inactivation of dinoflagellate Scripsiella trochoidea in synthetic ballast water by advanced oxidation processes.

    PubMed

    Yang, Zhishan; Jiang, Wenju; Zhang, Yi; Lim, T M

    2015-01-01

    Ship-borne ballast water contributes significantly to the transfer of non-indigenous species across aquatic environments. To reduce the risk of bio-invasion, ballast water should be treated before discharge. In this study, the efficiencies of several conventional and advanced oxidation processes were investigated for potential ballast water treatment, using a marine dinoflagellate species, Scripsiella trochoidea, as the indicator organism. A stable and consistent culture was obtained and treated by ultraviolet (UV) light, ozone (O3), hydrogen peroxide (H2O2), and their various combinations. UV apparently inactivated the cells after only 10 s of irradiation, but subsequently photo-reactivation of the cells was observed for all methods involving UV. O3 exhibited 100% inactivation efficiency after 5 min treatment, while H2O2 only achieved maximum 80% inactivation in the same duration. Combined methods, e.g. UV/O3 and UV/H2O2, were found to inhibit photo-reactivation and improve treatment efficiency to some degree, indicating the effectiveness of using combined treatment processes. The total residual oxidant (TRO) levels of the methods were determined, and the results indicated that UV and O3 generated the lowest and highest TRO, respectively. The synergic effect of combined processes on TRO generation was found to be insignificant, and thus UV/O3 was recommended as a potentially suitable treatment process for ballast water.

  3. Aquila field - advanced contracting strategies for the offshore development, in 850 meter water depth

    SciTech Connect

    Cerrito, E.; Ciprigno, M.

    1996-12-31

    Aquila oil field is located in 850 meters of water in the middle of the Otranto Channel, in the Mediterranean Sea, at about 45 km from the shore and is subject to both difficult sea and weather conditions. The many difficulties, mainly due to the very high water depth, imposed the use of advanced technology, that could be obtained only through the direct association of contractor companies, leaders in their own field. Such a solution safeguards the technological reliability and allows the maximum control of time and cost. The selection of an FPSO (Floating, Production, Storage and Offloading) comes from a feasibility study indicating this solution as the only one, allowing the economical exploitation of the Aquila field. This paper deals with a series of technical solutions and contractual agreements with a Joint-Venture embracing two leading world contractors for developing, manufacturing and installing the FPSO {open_quotes}Agip Firenze{close_quotes}, permanently anchored at a world record 850 m water depth. The system includes flowlines and control lines. The ship, has been especially redesigned and purchased by contractors. They will use the vessel to manage the field development. Agip will provide the subsea production system: christmas tree and control system with artificial lift. The Aquila field development project aims to identify an economically viable, low risk method of producing hydrocarbons from a deep water location where previously the reserves were technologically and economically out of range.

  4. Solar-Enhanced Advanced Oxidation Processes for Water Treatment: Simultaneous Removal of Pathogens and Chemical Pollutants

    PubMed Central

    Tsydenova, Oyuna; Batoev, Valeriy; Batoeva, Agniya

    2015-01-01

    The review explores the feasibility of simultaneous removal of pathogens and chemical pollutants by solar-enhanced advanced oxidation processes (AOPs). The AOPs are based on in-situ generation of reactive oxygen species (ROS), most notably hydroxyl radicals •OH, that are capable of destroying both pollutant molecules and pathogen cells. The review presents evidence of simultaneous removal of pathogens and chemical pollutants by photocatalytic processes, namely TiO2 photocatalysis and photo-Fenton. Complex water matrices with high loads of pathogens and chemical pollutants negatively affect the efficiency of disinfection and pollutant removal. This is due to competition between chemical substances and pathogens for generated ROS. Other possible negative effects include light screening, competitive photon absorption, adsorption on the catalyst surface (thereby inhibiting its photocatalytic activity), etc. Besides, some matrix components may serve as nutrients for pathogens, thus hindering the disinfection process. Each type of water/wastewater would require a tailor-made approach and the variables that were shown to influence the processes—catalyst/oxidant concentrations, incident radiation flux, and pH—need to be adjusted in order to achieve the required degree of pollutant and pathogen removal. Overall, the solar-enhanced AOPs hold promise as an environmentally-friendly way to substitute or supplement conventional water/wastewater treatment, particularly in areas without access to centralized drinking water or sewage/wastewater treatment facilities. PMID:26287222

  5. HYDROGEN GENERATION FROM ELECTROLYSIS - REVISED FINAL TECHNICAL REPORT

    SciTech Connect

    IBRAHIM, SAMIR; STICHTER, MICHAEL

    2008-07-31

    DOE GO13028-0001 DESCRIPTION/ABSTRACT This report is a summary of the work performed by Teledyne Energy Systems to understand high pressure electrolysis mechanisms, investigate and address safety concerns related to high pressure electrolysis, develop methods to test components and systems of a high pressure electrolyzer, and produce design specifications for a low cost high pressure electrolysis system using lessons learned throughout the project. Included in this report are data on separator materials, electrode materials, structural cell design, and dissolved gas tests. Also included are the results of trade studies for active area, component design analysis, high pressure hydrogen/oxygen reactions, and control systems design. Several key pieces of a high pressure electrolysis system were investigated in this project and the results will be useful in further attempts at high pressure and/or low cost hydrogen generator projects. An important portion of the testing and research performed in this study are the safety issues that are present in a high pressure electrolyzer system and that they can not easily be simplified to a level where units can be manufactured at the cost goals specified, or operated by other than trained personnel in a well safeguarded environment. The two key objectives of the program were to develop a system to supply hydrogen at a rate of at least 10,000 scf/day at a pressure of 5000psi, and to meet cost goals of $600/ kW in production quantities of 10,000/year. On these two points TESI was not successful. The project was halted due to concerns over safety of high pressure gas electrolysis and the associated costs of a system which reduced the safety concerns.

  6. Full-Scale Hollow Fiber Spacesuit Water Membrane Evaporator Prototype Development and Testing for Advanced Spacesuits

    NASA Technical Reports Server (NTRS)

    Bue, Grant; Trevino, Luis; Tsioulos, Gus; Mitchell, Keith; Dillon, Paul; Weaver, Gregg

    2009-01-01

    The spacesuit water membrane evaporator (SWME) is being developed to perform the thermal control function for advanced spacesuits to take advantage of recent advances in micropore membrane technology in providing a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. Principles of a sheet membrane SWME design were demonstrated using a prototypic test article that was tested in a vacuum chamber at JSC in July 1999. The Membrana Celgard X50-215 microporous hollow fiber (HoFi) membrane was selected after recent contamination tests as the superior candidate among commercial alternatives for HoFi SWME prototype development. Although a number of design variants were considered, one that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape, was deemed best for further development. An analysis of test data showed that eight layer stacks of the HoFi sheets that had good exposure on each side of the stack would evaporate water with high efficiency. A design that has 15,000 tubes, with 18 cm of exposed tubes between headers has been built and tested that meets the size, weight, and performance requirements of the SWME. This full-scale prototype consists of 30 stacks, each of which are formed into a chevron shape and separated by spacers and organized into three sectors of ten nested stacks. Testing has been performed to show contamination resistance to the constituents expected to be found in potable water produced by the distillation processes. Other tests showed the sensitivity to surfactants.

  7. The Detoxification and Degradation of Benzothiazole from the Wastewater in Microbial Electrolysis Cells.

    PubMed

    Liu, Xianshu; Ding, Jie; Ren, Nanqi; Tong, Qingyue; Zhang, Luyan

    2016-12-20

    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.

  8. High-temperature electrolysis of synthetic seawater using solid oxide electrolyzer cells

    NASA Astrophysics Data System (ADS)

    Lim, Chee Kuan; Liu, Qinglin; Zhou, Juan; Sun, Qiang; Chan, Siew Hwa

    2017-02-01

    A Ni-YSZ/YSZ/LSCF-GDC solid oxide electrolyzer cell (SOEC) is used to investigate the effects of seawater electrolysis for hydrogen production through electrolyzing steam produced from simulated seawater bath. Steam electrolysis using an SOEC with its fuel electrode contaminated by sea salt is also investigated. Steam produced from seawater is found to be free of contaminants, which are present in the seawater. Similar electrochemical performance is observed from the polarization curves and impedance spectra when using steam produced from pure water and seawater. Their short-term degradation rates are similar, which are registered at 15% 1000 h-1 for both cases. For the case of direct sea salt contamination in an SOEC's fuel electrode, both the uncontaminated and contaminated cells exhibit rather similar performance as observed from the polarization curves and impedance spectra. The difference in ASR values from the polarization curves and impedance spectra between the uncontaminated and contaminated cell are all within a 10% range. Rather similar short-term degradation rates of 15% 1000 h-1 and 16% 1000 h-1 are recorded for the uncontaminated and contaminated cells, respectively. Post-mortem analysis shows that the sea salt impregnated into the cell has been vaporized at a typical SOEC operating temperature of 800 °C over the period of operation.

  9. Electrolysis within anaerobic bioreactors stimulates breakdown of toxic products from azo dye treatment.

    PubMed

    Gavazza, Sávia; Guzman, Juan J L; Angenent, Largus T

    2015-04-01

    Azo dyes are the most widely used coloring agents in the textile industry, but are difficult to treat. When textile effluents are discharged into waterways, azo dyes and their degradation products are known to be environmentally toxic. An electrochemical system consisting of a graphite-plate anode and a stainless-steel mesh cathode was placed into a lab-scale anaerobic bioreactor to evaluate the removal of an azo dye (Direct Black 22) from synthetic textile wastewater. At applied potentials of 2.5 and 3.0 V when water electrolysis occurs, no improvement in azo dye removal efficiency was observed compared to the control reactor (an integrated system with electrodes but without an applied potential). However, applying such electric potentials produces oxygen via electrolysis and promoted the aerobic degradation of aromatic amines, which are toxic, intermediate products of anaerobic azo dye degradation. The removal of these amines indicates a decrease in overall toxicity of the effluent from a single-stage anaerobic bioreactor, which warrants further optimization in anaerobic digestion.

  10. Nitrate removal and microbial analysis by combined micro-electrolysis and autotrophic denitrification.

    PubMed

    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.

  11. Performance of single chamber biocatalyzed electrolysis with different types of ion exchange membranes.

    PubMed

    Rozendal, René A; Hamelers, Hubertus V M; Molenkamp, Redmar J; Buisman, Cees J N

    2007-05-01

    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). Both configurations performed comparably and produced over 0.3 m3 H2/m3 reactor liquid volume/day at 1.0 V applied voltage (overall hydrogen efficiencies around 23%). Analysis of the water that permeated through the membrane revealed that a large part of potential losses in the system were associated with a pH gradient across the membrane (CEM DeltapH=6.4; AEM DeltapH=4.4). These pH gradient associated potential losses were lower in the AEM configuration (CEM 0.38 V; AEM 0.26 V) as a result of its alternative ion transport properties. This benefit of the AEM, however, was counteracted by the higher cathode overpotentials occurring in the AEM configuration (CEM 0.12 V at 2.39 A/m2; AEM 0.27 V at 2.15 A/m2) as a result of a less effective electroless plating method for the AEM membrane electrode assembly (MEA).

  12. Application of electrolysis to stimulate microbial reductive PCE dechlorination and oxidative VC biodegradation.

    PubMed

    Lohner, Svenja T; Tiehm, Andreas

    2009-09-15

    A novel approach was applied to stimulate biodegradation of chloroethenes bya coupled bioelectro-process. In a flow-through column system, microbial dechlorination of tetrachloroethene to cis-dichloroethene, vinyl chloride, and ethene was stimulated by hydrogen produced by water electrolysis. Dechlorinating bacteria (Dehalococcoides spp. and Desulfitobacterium spp.) and also methanogens and homoacetogens were detected in the anaerobic column. Simultaneously, oxidative biodegradation of lower chlorinated metabolites (vinyl chloride) was stimulated by electrolytic oxygen formation in the corresponding aerobic column. The process was stable for more than 100 days and an average removal of approximately 23 micromol/d PCE and 72 micromo/d vinyl chloride was obtained with a current density of 0.05 mA/cm2. Abiotic electrochemical degradation of the contaminants was not observed. Microbial dechlorination correlated with the current densities in the applied range of 0.01-0.05 mA/cm2. The results are promising for environmental applications, since with electrolysis hydrogen and oxygen can be supplied continuously to chloroethene degrading microorganisms, and the supply rates can be easily controlled by adjusting the electric current.

  13. The Detoxification and Degradation of Benzothiazole from the Wastewater in Microbial Electrolysis Cells

    PubMed Central

    Liu, Xianshu; Ding, Jie; Ren, Nanqi; Tong, Qingyue; Zhang, Luyan

    2016-01-01

    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. PMID:27999421

  14. Innovative combination of electrolysis and Fe(II)-activated persulfate oxidation for improving the dewaterability of waste activated sludge.

    PubMed

    Zhen, Guang-Yin; Lu, Xue-Qin; Li, Yu-You; Zhao, You-Cai

    2013-05-01

    The feasibility of electrolysis integrated with Fe(II)-activated persulfate (S2O8(2-)) oxidation to improve waste activated sludge (WAS) dewaterability was evaluated. The physicochemical properties (sludge volume (SV), total suspended solids (TSS) and volatile suspended solids (VSS)) and extracellular polymeric substances (EPS), including slime EPS, loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) were characterized to identify their exact roles in sludge dewatering. While dewaterability negatively corresponded to LB-EPS, TB-EPS, protein (PN) and polysaccharide (PS) in LB-EPS and TB-EPS, it was independent of SV, TSS, VSS, slime EPS and PN/PS. Further study through scanning electron microscope (SEM) verified the entrapment of bacterial cells by TB-EPS, protecting them against electrolysis disruption. Comparatively, electrolysis integrated with S2O8(2-)/Fe(II) oxidation was able to effectively disrupt the protective barrier and crack the entrapped cells, releasing the water inside EPS and cells. Therefore, the destruction of both TB-EPS and cells is the fundamental reason for the enhanced dewaterability.

  15. Development of the microbial electrolysis desalination and chemical-production cell for desalination as well as acid and alkali productions.

    PubMed

    Chen, Shanshan; Liu, Guangli; Zhang, Renduo; Qin, Bangyu; Luo, Yong

    2012-02-21

    By combining the microbial electrolysis cell and the microbial desalination cell, the microbial electrolysis desalination cell (MEDC) becomes a novel device to desalinate salty water. However, several factors, such as sharp pH decrease and Cl(-) accumulation in the anode chamber, limit the MEDC development. In this study, a microbial electrolysis desalination and chemical-production cell (MEDCC) was developed with four chambers using a bipolar membrane. Results showed that the pH in the anode chamber of the MEDCC always remained near 7.0, which greatly enhanced the microbial activities in the cell. With applied voltages of 0.3-1.0 V, 62%-97% of Coulombic efficiencies were achieved from the MEDCC, which were 1.5-2.0 times of those from the MEDC. With 10 mL of 10 g/L NaCl in the desalination chamber, desalination rates of the MEDCC reached 46%-86% within 18 h. Another unique feature of the MEDCC was the simultaneous production of HCl and NaOH in the cell. With 1.0 V applied voltage, the pH values at 18 h in the acid-production chamber and cathode chamber were 0.68 and 12.9, respectively. With the MEDCC, the problem with large pH changes in the anode chamber was resolved, and products of the acid and alkali were obtained.

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

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  17. Comparing removal of trace organic compounds and assimilable organic carbon (AOC) at advanced and traditional water treatment plants.

    PubMed

    Lou, Jie-Chung; Lin, Chung-Yi; Han, Jia-Yun; Tseng, Wei-Biu; Hsu, Kai-Lin; Chang, Ting-Wei

    2012-06-01

    Stability of drinking water can be indicated by the assimilable organic carbon (AOC). This AOC value represents the regrowth capacity of microorganisms and has large impacts on the quality of drinking water in a distribution system. With respect to the effectiveness of traditional and advanced processing methods in removing trace organic compounds (including TOC, DOC, UV(254), and AOC) from water, experimental results indicate that the removal rate of AOC at the Cheng Ching Lake water treatment plant (which utilizes advanced water treatment processes, and is hereinafter referred to as CCLWTP) is 54%, while the removal rate of AOC at the Gong Yuan water treatment plant (which uses traditional water treatment processes, and is hereinafter referred to as GYWTP) is 36%. In advanced water treatment units, new coagulation-sedimentation processes, rapid filters, and biological activated carbon filters can effectively remove AOC, total organic carbon (TOC), and dissolved organic carbon (DOC). In traditional water treatment units, coagulation-sedimentation processes are most effective in removing AOC. Simulation results and calculations made using the AutoNet method indicate that TOC, TDS, NH(3)-N, and NO(3)-N should be regularly monitored in the CCLWTP, and that TOC, temperature, and NH(3)-N should be regularly monitored in the GYWTP.

  18. Treatment of concentrated industrial wastewaters originating from oil shale and the like by electrolysis polyurethane foam interaction

    DOEpatents

    Tiernan, Joan E.

    1990-01-01

    Highly concentrated and toxic petroleum-based and synthetic fuels wastewaters such as oil shale retort water are treated in a unit treatment process by electrolysis in a reactor containing oleophilic, ionized, open-celled polyurethane foams and subjected to mixing and laminar flow conditions at an average detention time of six hours. Both the polyurethane foams and the foam regenerate solution are re-used. The treatment is a cost-effective process for waste-waters which are not treatable, or are not cost-effectively treatable, by conventional process series.

  19. Removal of emerging contaminants in sewage water subjected to advanced oxidation with ozone.

    PubMed

    Ibáñez, M; Gracia-Lor, E; Bijlsma, L; Morales, E; Pastor, L; Hernández, F

    2013-09-15

    Advanced oxidation processes (AOP) based on ozone treatments, assisted by ultrasounds, have been investigated at a pilot-plant scale in order to evaluate the removal of emerging contaminants in sewage water. Around 60 emerging contaminants, mainly pharmaceuticals from different therapeutically classes and drugs of abuse, have been determined in urban wastewater samples (treated and untreated) by LC-MS/MS. In a first step, the removal efficiency of these contaminants in conventional sewage water treatment plants was evaluated. Our results indicate that most of the compounds were totally or partially removed during the treatment process of influent wastewater. Up to 30 contaminants were quantified in the influent and effluent samples analysed, being antibiotics, anti-inflammatories, cholesterol lowering statin drugs and angiotensin II receptor antagonists the most frequently detected. Regarding drugs of abuse, cocaine and its metabolite benzoylecgonine were the most frequent. In a second step, the effectiveness of AOP in the removal of emerging contaminants remaining in the effluent was evaluated. Ozone treatments have been proven to be highly efficient in the removal, notably decreasing the concentrations for most of the emerging contaminants present in the water samples. The use of ultrasounds, alone or assisting ozone treatments, has been shown less effective, being practically unnecessary.

  20. Multi-functional electrospun nanofibres for advances in tissue regeneration, energy conversion & storage, and water treatment.

    PubMed

    Peng, Shengjie; Jin, Guorui; Li, Linlin; Li, Kai; Srinivasan, Madhavi; Ramakrishna, Seeram; Chen, Jun

    2016-03-07

    Tissue regeneration, energy conversion & storage, and water treatment are some of the most critical challenges facing humanity in the 21st century. In order to address such challenges, one-dimensional (1D) materials are projected to play a key role in developing emerging solutions for the increasingly complex problems. Eletrospinning technology has been demonstrated to be a simple, versatile, and cost-effective method in fabricating a rich variety of materials with 1D nanostructures. These include polymers, composites, and inorganic materials with unique chemical and physical properties. In this tutorial review, we first give a brief introduction to electrospun materials with a special emphasis on the design, fabrication, and modification of 1D functional materials. Adopting the perspective of chemists and materials scientists, we then focus on the recent significant progress made in the domains of tissue regeneration (e.g., skin, nerve, heart and bone) and conversion & storage of clean energy (e.g., solar cells, fuel cells, batteries, and supercapacitors), where nanofibres have been used as active nanomaterials. Furthermore, this review's scope also includes the advances in the use of electrospun materials for the removal of heavy metal ions, organic pollutants, gas and bacteria in water treatment applications. Finally a conclusion and perspective is provided, in which we discuss the remaining challenges for 1D electrospun nanomaterials in tissue regeneration, energy conversion & storage, and water treatment.

  1. Advanced combined iodine dispenser and detector. [for microorganism annihilation in potable water

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    A total weight of 1.23 kg (2.7 lb), a total volume of 1213 cu m (74 cu in), and an average power consumption of 5.5W was achieved in the advanced combined iodine dispenser/detector by integrating the detector with the iodine source, arranging all iodinator components within a compact package and lowering the parasitic power to the detector and electronics circuits. These achievements surpassed the design goals of 1.36 kg (3.0 lb), 1671 cu m (102 cu in) and 8W. The reliability and maintainability were improved by reducing the detector lamp power, using an interchangeable lamp concept, making the electronic circuit boards easily accessible, providing redundant water seals and improving the accessibility to the iodine accumulator for refilling. The system was designed to iodinate (to 5 ppm iodine) the fuel cell water generated during 27 seven-day orbiter missions (equivalent to 18,500 kg (40,700 lb) of water) before the unit must be recharged with iodine crystals.

  2. Recent advances in cellulose and chitosan based membranes for water purification: A concise review.

    PubMed

    Thakur, Vijay Kumar; Voicu, Stefan Ioan

    2016-08-01

    Recently membrane technology has emerged as a new promising and pervasive technology due to its innate advantages over traditional technologies such as adsorption, distillation and extraction. In this article, some of the recent advances in developing polymeric composite membrane materials for water purification from natural polysaccharide based polymers namely cellulose derivatives and chitosan are concisely reviewed. The impact of human social, demographic and industrial evolution along with expansion through environment has significantly affected the quality of water by pollution with large quantities of pesticides, minerals, drugs or other residues. At the forefront of decontamination and purification techniques, we found the membrane materials from polymers as a potential alternative. In an attempt to reduce the number of technical polymers widely used in the preparation of membranes, many researchers have reported new solutions for desalination or retention of organic yeasts, based on bio renewable polymers like cellulose derivatives and chitosan. These realizations are presented and discussed in terms of the most important parameters of membrane separation especially water flux and retention in this article.

  3. Photoassisted electrolysis of water - Conversion of optical to chemical energy

    NASA Technical Reports Server (NTRS)

    Wrighton, M. S.; Bolts, J. M.; Kaiser, S. W.; Ellis, A. B.

    1976-01-01

    A description is given of devices, termed photoelectrochemical cells, which can, in principle, be used to directly convert light to fuels and/or electricity. The fundamental principles on which the photoelectrochemical cell is based are related to the observation that irradiation of a semiconductor electrode in an electrochemical cell can result in the flow of an electric current in the external circuit. Attention is given to the basic mechanisms involved, the energy conversion efficiency, the advantages of photoelectrochemical cells, and the results of investigations related to the study of energy conversion via photoelectrochemical cells.

  4. High pressure water electrolysis for space station EMU recharge

    NASA Technical Reports Server (NTRS)

    Lance, Nick; Puskar, Michael; Moulthrop, Lawrence; Zagaja, John

    1988-01-01

    A high pressure oxygen recharge system (HPORS), is being developed for application on board the Space Station. This electrolytic system can provide oxygen at up to 6000 psia without a mechanical compressor. The Hamilton standard HPORS based on a solid polymer electrolyte system is an extension of the much larger and succesful 3000 psia system of the U.S. Navy. Cell modules have been successfully tested under conditions beyond which spacecraft may encounter during launch. The control system with double redundancy and mechanical backups for all electronically controlled components is designed to ensure a safe shutdown.

  5. Special issue on the "Consortium for Advanced Simulation of Light Water Reactors Research and Development Progress"

    NASA Astrophysics Data System (ADS)

    Turinsky, Paul J.; Martin, William R.

    2017-04-01

    In this special issue of the Journal of Computational Physics, the research and development completed at the time of manuscript submission by the Consortium for Advanced Simulation of Light Water Reactors (CASL) is presented. CASL is the first of several Energy Innovation Hubs that have been created by the Department of Energy. The Hubs are modeled after the strong scientific management characteristics of the Manhattan Project and AT&T Bell Laboratories, and function as integrated research centers that combine basic and applied research with engineering to accelerate scientific discovery that addresses critical energy issues. Lifetime of a Hub is expected to be five or ten years depending upon performance, with CASL being granted a ten year lifetime.

  6. Evaluation of copper slag to catalyze advanced oxidation processes for the removal of phenol in water.

    PubMed

    Huanosta-Gutiérrez, T; Dantas, Renato F; Ramírez-Zamora, R M; Esplugas, S

    2012-04-30

    The aim of this work was to evaluate the use of copper slag to catalyze phenol degradation in water by advanced oxidation processes (AOPs). Copper slag was tested in combination with H(2)O(2) (slag/H(2)O(2)) and H(2)O(2)/UV (slag/H(2)O(2)/UV). The studied methods promoted the complete photocatalytic degradation of phenol. Besides, they were able to reduce about 50% the TOC content in the samples. Slag/H(2)O(2)/UV and slag/H(2)O(2) treatments have favored biodegradability increment along the reaction time. Nevertheless, the irradiated method achieved higher values of the biodegradability indicator (BOD(5)/TOC). The toxicity assessment indicated the formation of more toxic compounds in both treatments. However, the control of the reaction time would minimize the environmental impact of the effluents.

  7. A flammability and combustion model for integrated accident analysis. [Advanced light water reactors

    SciTech Connect

    Plys, M.G.; Astleford, R.D.; Epstein, M. )

    1988-01-01

    A model for flammability characteristics and combustion of hydrogen and carbon monoxide mixtures is presented for application to severe accident analysis of Advanced Light Water Reactors (ALWR's). Flammability of general mixtures for thermodynamic conditions anticipated during a severe accident is quantified with a new correlation technique applied to data for several fuel and inertant mixtures and using accepted methods for combining these data. Combustion behavior is quantified by a mechanistic model consisting of a continuity and momentum balance for the burned gases, and considering an uncertainty parameter to match the idealized process to experiment. Benchmarks against experiment demonstrate the validity of this approach for a single recommended value of the flame flux multiplier parameter. The models presented here are equally applicable to analysis of current LWR's. 21 refs., 16 figs., 6 tabs.

  8. Application of hot melt extrusion for poorly water-soluble drugs: limitations, advances and future prospects.

    PubMed

    Lu, Ming; Guo, Zhefei; Li, Yongcheng; Pang, Huishi; Lin, Ling; Liu, Xu; Pan, Xin; Wu, Chuanbin

    2014-01-01

    Hot melt extrusion (HME) is a powerful technology to enhance the solubility and bioavailability of poorly water-soluble drugs by producing amorphous solid dispersions. Although the number of articles and patents about HME increased dramatically in the past twenty years, there are very few commercial products by far. The three main obstacles limiting the commercial application of HME are summarized as thermal degradation of heat-sensitive drugs at high process temperature, recrystallization of amorphous drugs during storage and dissolving process, and difficulty to obtain products with reproducible physicochemical properties. Many efforts have been taken in recent years to understand the basic mechanism underlying these obstacles and then to overcome them. This article reviewed and summarized the limitations, recent advances, and future prospects of HME.

  9. Development of an advanced solar augmented water heater (for single family home applications)

    NASA Astrophysics Data System (ADS)

    Grunes, H.; Morrison, D.; Dewinter, F.

    1982-06-01

    A program was undertaken to design, construct and test two advanced prototype solar augmented gas water heaters. Computer analyses and experimental work were used to optimize components and characterize performance. The resulting design includes a solar preheat tank, a gas-fired backup tank, the collector loop pump and all operating controls contained in a single cylindrical package. The backup tank is positioned above the solar preheat tank. The connection between the solar and backup tanks is effectively a thermal diode which restricts heat transfer from the backup to the solar tank but allows the backup tank to become an integral part of solar storage whenever the solar tank temperature surpasses the backup tank set point temperature. Solar heat is supplied through a jacketed tank drainback system.

  10. Conceptual design of an advanced water/steam receiver for a solar thermal central power system

    NASA Astrophysics Data System (ADS)

    Wu, S. F.; Narayanan, T. V.; Gorman, D. N.

    1981-06-01

    This paper describes the conceptual design of an advanced water/steam receiver for a commercial-scale solar central receiver thermal power system. The objective was to develop a receiver concept featuring an optimum combination of cost, performance, and reliability. While interfaces with other major subsystems of the complete power plant were recognized, emphasis was on the design and performance of the receiver. The baseline thermal rating of this receiver was 550 MW, and the steam outlet conditions were 12,860 kPa and 516 C. After technical and economic evaluations, a quad-cavity, natural-circulation concept was selected as the preferred receiver design. It consists of four separate cavities in a single receiver unit, each cavity receiving concentrated solar energy from one quadrant of a surrounding heliostat field.

  11. Advanced Energy and Water Recovery Technology from Low Grade Waste Heat

    SciTech Connect

    Dexin Wang

    2011-12-19

    The project has developed a nanoporous membrane based water vapor separation technology that can be used for recovering energy and water from low-temperature industrial waste gas streams with high moisture contents. This kind of exhaust stream is widely present in many industrial processes including the forest products and paper industry, food industry, chemical industry, cement industry, metal industry, and petroleum industry. The technology can recover not only the sensible heat but also high-purity water along with its considerable latent heat. Waste heats from such streams are considered very difficult to recover by conventional technology because of poor heat transfer performance of heat-exchanger type equipment at low temperature and moisture-related corrosion issues. During the one-year Concept Definition stage of the project, the goal was to prove the concept and technology in the laboratory and identify any issues that need to be addressed in future development of this technology. In this project, computational modeling and simulation have been conducted to investigate the performance of a nanoporous material based technology, transport membrane condenser (TMC), for waste heat and water recovery from low grade industrial flue gases. A series of theoretical and computational analyses have provided insight and support in advanced TMC design and experiments. Experimental study revealed condensation and convection through the porous membrane bundle was greatly improved over an impermeable tube bundle, because of the membrane capillary condensation mechanism and the continuous evacuation of the condensate film or droplets through the membrane pores. Convection Nusselt number in flue gas side for the porous membrane tube bundle is 50% to 80% higher than those for the impermeable stainless steel tube bundle. The condensation rates for the porous membrane tube bundle also increase 60% to 80%. Parametric study for the porous membrane tube bundle heat transfer

  12. Radio-toxicity of spent fuel of the advanced heavy water reactor.

    PubMed

    Anand, S; Singh, K D S; Sharma, V K

    2010-01-01

    The Advanced Heavy Water Reactor (AHWR) is a new power reactor concept being developed at Bhabha Atomic Research Centre, Mumbai. The reactor retains many desirable features of the existing Pressurised Heavy Water Reactor (PHWR), while incorporating new, advanced safety features. The reactor aims to utilise the vast thorium resources available in India. The reactor core will use plutonium as the make-up fuel, while breeding (233)U in situ. On account of this unique combination of fuel materials, the operational characteristics of the fuel as determined by its radioactivity, decay heat and radio-toxicity are being viewed with great interest. Radio-toxicity of the spent fuel is a measure of potential radiological hazard to the members of the public and also important from the ecological point of view. The radio-toxicity of the AHWR fuel is extremely high to start with, being approximately 10(4) times that of the fresh natural U fuel used in a PHWR, and continues to remain relatively high during operation and subsequent cooling. A unique feature of this fuel is the peak observed in its radio-toxicity at approximately 10(5) y of decay cooling. The delayed increase in fuel toxicity has been traced primarily to a build-up of (229)Th, (230)Th and (226)Ra. This phenomenon has been observed earlier for thorium-based fuels and is confirmed for the AHWR fuel. This paper presents radio-toxicity data for AHWR spent fuel up to a period of 10(6) y and the results are compared with the radio-toxicity of PHWR.

  13. Study of plutonium disposition using the GE Advanced Boiling Water Reactor (ABWR)

    SciTech Connect

    1994-04-30

    The end of the cold war and the resulting dismantlement of nuclear weapons has resulted in the need for the U.S. to disposition 50 to 100 metric tons of excess of plutonium in parallel with a similar program in Russia. A number of studies, including the recently released National Academy of Sciences (NAS) study, have recommended conversion of plutonium into spent nuclear fuel with its high radiation barrier as the best means of providing long-term diversion resistance to this material. The NAS study {open_quotes}Management and Disposition of Excess Weapons Plutonium{close_quotes} identified light water reactor spent fuel as the most readily achievable and proven form for the disposition of excess weapons plutonium. The study also stressed the need for a U.S. disposition program which would enhance the prospects for a timely reciprocal program agreement with Russia. This summary provides the key findings of a GE study where plutonium is converted into Mixed Oxide (MOX) fuel and a 1350 MWe GE Advanced Boiling Water Reactor (ABWR) is utilized to convert the plutonium to spent fuel. The ABWR represents the integration of over 30 years of experience gained worldwide in the design, construction and operation of BWRs. It incorporates advanced features to enhance reliability and safety, minimize waste and reduce worker exposure. For example, the core is never uncovered nor is any operator action required for 72 hours after any design basis accident. Phase 1 of this study was documented in a GE report dated May 13, 1993. DOE`s Phase 1 evaluations cited the ABWR as a proven technical approach for the disposition of plutonium. This Phase 2 study addresses specific areas which the DOE authorized as appropriate for more in-depth evaluations. A separate report addresses the findings relative to the use of existing BWRs to achieve the same goal.

  14. Identification and characterization of passive safety system and inherent safety feature building blocks for advanced light-water reactors

    SciTech Connect

    Forsberg, C.W.

    1989-01-01

    Oak Ridge National Laboratory (ORNL) is investigating passive and inherent safety options for Advanced Light-Water Reactors (ALWRs). A major activity in 1989 includes identification and characterization of passive safety system and inherent safety feature building blocks, both existing and proposed, for ALWRs. Preliminary results of this work are reported herein. This activity is part of a larger effort by the US Department of Energy, reactor vendors, utilities, and others in the United States to develop improved LWRs. The Advanced Boiling Water Reactor (ABWR) program and the Advanced Pressurized Water Reactor (APWR) program have as goals improved, commercially available LWRs in the early 1990s. The Advanced Simplified Boiling Water Reactor (ASBWR) program and the AP-600 program are developing more advanced reactors with increased use of passive safety systems. It is planned that these reactors will become commercially available in the mid 1990s. The ORNL program is an exploratory research program for LWRs beyond the year 2000. Desired long-term goals for such reactors include: (1) use of only passive and inherent safety, (2) foolproof against operator errors, (3) malevolence resistance against internal sabotage and external assault and (4) walkaway safety. The acronym ''PRIME'' (Passive safety, Resilient operation, Inherent safety, Malevolence resistance, and Extended (walkaway) safety) is used to summarize these desired characteristics. Existing passive and inherent safety options are discussed in this document.

  15. Thermochemical Production of Hydrogen from Water.

    ERIC Educational Resources Information Center

    Bamberger, C. E.; And Others

    1978-01-01

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

  16. Travelers' Health: Water Disinfection for Travelers

    MedlinePlus

    ... models are still available for international use. Salt (Sodium Chloride) Electrolysis Passing a current through a simple ... pubs/dr_a/pdf/tbmed577.pdf . Lantagne DS. Sodium hypochlorite dosage for household and emergency water treatment. ...

  17. Electroepilation (electrolysis) in hirsutism. 35,000 hours' experience on the face and neck.

    PubMed

    Richards, R N; McKenzie, M A; Meharg, G E

    1986-10-01

    Physicians frequently recommend electroepilation (electrolysis) in the management of hirsutism, but there have been no English language reports of its clinical effectiveness. We performed over 35,000 hours of electroepilation (electrolysis) on two hundred eighty-one women over a 4-year period. We used conventional, commercially available electroepilation (electrolysis) equipment that produced both thermolysis and blend type currents. We found that electroepilation (electrolysis) helps control hirsutism, and 93% of the patients improved. There was no scarring. For best results electroepilation (electrolysis) must be combined with treatment of excess androgens. Instructions about good grooming and stressing that shaving is not harmful will help to maximize improvement in appearance. Electroepilation (electrolysis) is expensive and not readily available to those lacking insurance or other funding.

  18. Modeling Interfacial Glass-Water Reactions: Recent Advances and Current Limitations

    SciTech Connect

    Pierce, Eric M.; Frugier, Pierre; Criscenti, Louise J.; Kwon, Kideok D.; Kerisit, Sebastien N.

    2014-07-12

    Describing the reactions that occur at the glass-water interface and control the development of the altered layer constitutes one of the main scientific challenges impeding existing models from providing accurate radionuclide release estimates. Radionuclide release estimates are a critical component of the safety basis for geologic repositories. The altered layer (i.e., amorphous hydrated surface layer and crystalline reaction products) represents a complex region, both physically and chemically, sandwiched between two distinct boundaries pristine glass surface at the inner most interface and aqueous solution at the outer most interface. Computational models, spanning different length and time-scales, are currently being developed to improve our understanding of this complex and dynamic process with the goal of accurately describing the pore-scale changes that occur as the system evolves. These modeling approaches include geochemical simulations [i.e., classical reaction path simulations and glass reactivity in allowance for alteration layer (GRAAL) simulations], Monte Carlo simulations, and Molecular Dynamics methods. Finally, in this manuscript, we discuss the advances and limitations of each modeling approach placed in the context of the glass-water reaction and how collectively these approaches provide insights into the mechanisms that control the formation and evolution of altered layers.

  19. Modeling Interfacial Glass-Water Reactions: Recent Advances and Current Limitations

    SciTech Connect

    Pierce, Eric M.; Frugier, Pierre; Criscenti, Louise J.; Kwon, K. D.; Kerisit, Sebastien N.

    2014-07-12

    The altered layer (i.e., amorphous hydrated surface layer and crystalline reaction products)represents a complex region, both physically and chemically, sandwiched between two distinct boundaries - pristine glass surface at the inner most interface and aqueous solution at the outer most. The physico-chemical processes that control the development of this region have a significant impact on the long-term glass-water reaction. Computational models, spanning different length and time-scales, are currently being developed to improve our understanding of this complex and dynamic process with the goal of accurately describing the pore-scale changes that occur as the system evolves. These modeling approaches include Geochemical Reaction Path simulations, Glass Reactivity in Allowance for Alteration Layer simulations, Monte Carlo simulations, and Molecular Dynamics methods. Discussed in this manuscript are the advances and limitations of each modeling approach placed in the context of the glass water reaction and how collectively these approaches provide insights into the mechanisms that control the formation and evolution of altered layers; thus providing the fundamental data needed to develop pore-scale equations that enable more accurate predictions of nuclear waste glass corrosion in a geologic repository.

  20. Oxidative decomposition of p-nitroaniline in water by solar photo-Fenton advanced oxidation process.

    PubMed

    Sun, Jian-Hui; Sun, Sheng-Peng; Fan, Mao-Hong; Guo, Hui-Qin; Lee, Yi-Fan; Sun, Rui-Xia

    2008-05-01

    The degradation of p-nitroaniline (PNA) in water by solar photo-Fenton advanced oxidation process was investigated in this study. The effects of different reaction parameters including pH value of solutions, dosages of hydrogen peroxide and ferrous ion, initial PNA concentration and temperature on the degradation of PNA have been studied. The optimum conditions for the degradation of PNA in water were considered to be: the pH value at 3.0, 10 mmol L(-1) H(2)O(2), 0.05 mmol L(-1) Fe(2+), 0.072-0.217 mmol L(-1) PNA and temperature at 20 degrees C. Under the optimum conditions, the degradation efficiencies of PNA were more than 98% within 30 min reaction. The degradation characteristic of PNA showed that the conjugated pi systems of the aromatic ring in PNA molecules were effectively destructed. The experimental results indicated solar photo-Fenton process has more advantages compared with classical Fenton process, such as higher oxidation power, wider working pH range, lower ferrous ion usage, etc. Furthermore, the present study showed the potential use of solar photo-Fenton process for PNA containing wastewater treatment.

  1. Study of plutonium disposition using existing GE advanced Boiling Water Reactors

    SciTech Connect

    Not Available

    1994-06-01

    The end of the cold war and the resulting dismantlement of nuclear weapons has resulted in the need for the US to dispose of 50 to 100 metric tons of excess of plutonium in a safe and proliferation resistant manner. A number of studies, including the recently released National Academy of Sciences (NAS) study, have recommended conversion of plutonium into spent nuclear fuel with its high radiation barrier as the best means of providing permanent conversion and long-term diversion resistance to this material. The NAS study ``Management and Disposition of Excess Weapons Plutonium identified Light Water Reactor spent fuel as the most readily achievable and proven form for the disposition of excess weapons plutonium. The study also stressed the need for a US disposition program which would enhance the prospects for a timely reciprocal program agreement with Russia. This summary provides the key findings of a GE study where plutonium is converted into Mixed Oxide (MOX) fuel and a typical 1155 MWe GE Boiling Water Reactor (BWR) is utilized to convert the plutonium to spent fuel. A companion study of the Advanced BWR has recently been submitted. The MOX core design work that was conducted for the ABWR enabled GE to apply comparable fuel design concepts and consequently achieve full MOX core loading which optimize plutonium throughput for existing BWRs.

  2. Modeling Interfacial Glass-Water Reactions: Recent Advances and Current Limitations

    DOE PAGES

    Pierce, Eric M.; Frugier, Pierre; Criscenti, Louise J.; ...

    2014-07-12

    Describing the reactions that occur at the glass-water interface and control the development of the altered layer constitutes one of the main scientific challenges impeding existing models from providing accurate radionuclide release estimates. Radionuclide release estimates are a critical component of the safety basis for geologic repositories. The altered layer (i.e., amorphous hydrated surface layer and crystalline reaction products) represents a complex region, both physically and chemically, sandwiched between two distinct boundaries pristine glass surface at the inner most interface and aqueous solution at the outer most interface. Computational models, spanning different length and time-scales, are currently being developed tomore » improve our understanding of this complex and dynamic process with the goal of accurately describing the pore-scale changes that occur as the system evolves. These modeling approaches include geochemical simulations [i.e., classical reaction path simulations and glass reactivity in allowance for alteration layer (GRAAL) simulations], Monte Carlo simulations, and Molecular Dynamics methods. Finally, in this manuscript, we discuss the advances and limitations of each modeling approach placed in the context of the glass-water reaction and how collectively these approaches provide insights into the mechanisms that control the formation and evolution of altered layers.« less

  3. Realizing the potential of the CUAHSI Water Data Center to advance Earth Science

    NASA Astrophysics Data System (ADS)

    Hooper, R. P.; Seul, M.; Pollak, J.; Couch, A.

    2015-12-01

    The CUAHSI Water Data Center has developed a cloud-based system for data publication, discovery and access. Key features of this system are a semantically enabled catalog to discover data across more than 100 different services and delivery of data and metadata in a standard format. While this represents a significant technical achievement, the purpose of this system is to support data reanalysis for advancing science. A new web-based client, HydroClient, improves access to the data from previous clients. This client is envisioned as the first step in a workflow that can involve visualization and analysis using web-processing services, followed by download to local computers for further analysis. The release of the WaterML library in the R package CRAN repository is an initial attempt at linking the WDC services in a larger analysis workflow. We are seeking community input on other resources required to make the WDC services more valuable in scientific research and education.

  4. Enhancing hydrophilicity and water permeability of PET track-etched membranes by advanced oxidation process

    NASA Astrophysics Data System (ADS)

    Korolkov, Ilya V.; Mashentseva, Anastassiya A.; Güven, Olgun; Zdorovets, Maxim V.; Taltenov, Abzal A.

    2015-12-01

    In this study we present results on the application of advanced oxidation systems for effective and non-toxic oxidation of poly(ethylene terephthalate) track-etched membranes (PET TeMs) to improve their wettability and water transport properties. Two oxidizing systems: H2O2 under UV irradiation (H2O2/UV) and Fenton system under visible light (Fenton/H2O2/Vis) were compared. The surface of functionalized PET TeMs was characterized by using colorimetric assay, contact angle measurements and X-ray photoelectron spectroscopy (XPS). Results clearly showed that water permeability of PET TeMs treated with H2O2/UV was improved by 28 ± 5% compared with etched-only membrane, the same parameter was found to increase by 13 ± 4% in the case of Fenton/H2O2/Vis treatment. The proposed oxidation technique is very simple, environment friendly and not requiring special equipment or expensive chemicals. The surface hydrophilicity of the membranes stored for 360 days in air between paper sheets was analyzed by contact angle test, colorimetric assay to measure concentration of carboxylic groups on the surface with toluidine blue and XPS analysis. The hydrophilic properties of oxidized PET TeMs were found to be stable for a long period of time.

  5. Maintenance Cycle Extension in the IRIS Advanced Light Water Reactor Plant Design

    SciTech Connect

    Galvin, Mark R.; Todreas, Neil E.; Conway, Larry E.

    2003-09-15

    New nuclear power generation in the United States will be realized only if the economic performance can be made competitive with other methods of electrical power generation. The economic performance of a nuclear power plant can be significantly improved by increasing the time spent on-line generating electricity relative to the time spent off-line conducting maintenance and refueling. Maintenance includes planned actions (surveillances) and unplanned actions (corrective maintenance) to respond to component degradation or failure. A methodology is described that can be used to resolve, in the design phase, maintenance-related operating cycle length barriers. A primary goal was to demonstrate the applicability and utility of the methodology in the context of the International Reactor, Innovative and Secure (IRIS) design. IRIS is an advanced light water nuclear power plant that is being designed to maximize this on-line generating time by increasing the operating cycle length. This is consequently a maintenance strategy paper using the IRIS plant as the example.Potential IRIS operating cycle length maintenance-related barriers, determined by modification of an earlier operating pressurized water reactor (PWR) plant cycle length analysis to account for differences between the design of IRIS and this operating PWR, are presented. The proposed methodology to resolve these maintenance-related barriers by the design process is described. The results of applying the methodology to two potential IRIS cycle length barriers, relief valve testing and emergency heat removal system testing, are presented.

  6. Critical review of electrochemical advanced oxidation processes for water treatment applications.

    PubMed

    Chaplin, Brian P

    2014-05-01

    Electrochemical advanced oxidation processes (EAOPs) have emerged as novel water treatment technologies for the elimination of a broad-range of organic contaminants. Considerable validation of this technology has been performed at both the bench-scale and pilot-scale, which has been facilitated by the development of stable electrode materials that efficiently generate high yields of hydroxyl radicals (OH˙) (e.g., boron-doped diamond (BDD), doped-SnO2, PbO2, and substoichiometic- and doped-TiO2). Although a promising new technology, the mechanisms involved in the oxidation of organic compounds during EAOPs and the corresponding environmental impacts of their use have not been fully addressed. In order to unify the state of knowledge, identify research gaps, and stimulate new research in these areas, this review critically analyses published research pertaining to EAOPs. Specific topics covered in this review include (1) EAOP electrode types, (2) oxidation pathways of select classes of contaminants, (3) rate limitations in applied settings, and (4) long-term sustainability. Key challenges facing EAOP technologies are related to toxic byproduct formation (e.g., ClO4(-) and halogenated organic compounds) and low electro-active surface areas. These challenges must be addressed in future research in order for EAOPs to realize their full potential for water treatment.

  7. Direct LiT Electrolysis in a Metallic Fusion Blanket

    SciTech Connect

    Olson, Luke

    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.

  8. Natural gas anodes for aluminium electrolysis in molten fluorides.

    PubMed

    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.

  9. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    SciTech Connect

    Saksono, Nelson; Febiyanti, Irine Ayu Utami, Nissa; Ibrahim

    2015-12-29

    Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H{sub 2}O{sub 2} amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical current throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode.

  10. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    NASA Astrophysics Data System (ADS)

    Saksono, Nelson; Febiyanti, Irine Ayu; Utami, Nissa; Ibrahim

    2015-12-01

    Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H2O2 amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical current throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode.

  11. Comparison of waste combustion and waste electrolysis - A systems analysis

    NASA Technical Reports Server (NTRS)

    Holtzapple, Mark T.; Little, Frank E.

    1989-01-01

    A steady state model of a closed environmental system has been developed which includes higher plant growth for food production, and is designed to allow wastes to be combusted or electrolyzed. The stoichiometric equations have been developed to evaluate various trash compositions, food items (both stored and produced), metabolic rates, and crew sizes. The advantages of waste electrolysis versus combustion are: (1) oxygen is not required (which reduces the load on the oxygen producing system); (2) the CO2 and H2 products are produced in pure form (reducing the load on the separators); and (3) nitrogen is converted to nitrate (which is directly usable by plants). Weight tradeoff studies performed using this model have shown that waste electrolysis reduces the life support weight of a 4-person crew by 1000 to 2000 kg.

  12. Direct Lit Electrolysis In A Metallic Lithium Fusion Blanket

    SciTech Connect

    Colon-Mercado, H.; Babineau, D.; Elvington, M.; Garcia-Diaz, B.; Teprovich, J.; Vaquer, A.

    2015-10-13

    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 fission/fusion reactors is critical in order to maintained low concentrations.  This is needed to decrease the potential tritium permeation to the surroundings and large releases from unforeseen accident scenarios. Because of the high affinity of tritium for the blanket, extraction is complicated at the required low levels. This work identified, developed and tested the use of ceramic lithium ion conductors capable of recovering the hydrogen and deuterium thru an electrolysis step at high temperatures. 

  13. Hydrogen Transport to Mars Enables the Sabatier/Electrolysis Process

    NASA Technical Reports Server (NTRS)

    Mueller, P. J.; Rapp, D.

    1997-01-01

    The Sabatier/Electrolysis (S/E) process is an attractive approach to in situ propellant production (ISPP), and a breadboard demonstration of this process at Lockheed Martin Astronautics funded by JPL performed very well, with high conversion efficiency, and reliable diurnal operation. There is a net usage of hydrogen in the S/E process, and this has been the principal problem for this approach to ISPP.

  14. Transformation of polyfluorinated compounds in natural waters by advanced oxidation processes.

    PubMed

    Anumol, Tarun; Dagnino, Sonia; Vandervort, Darcy R; Snyder, Shane A

    2016-02-01

    The presence of perfluorocarboxylic acids (PFCAs) in source and finished drinking waters is a concern with studies showing bioaccumulation and adverse toxicological effects in wildlife and potentially humans. Per/Polyfluoroalkyl substances (PFAS) such as fluorotelomer alcohols have been identified as precursors for PFCAs in biological pathways. In this study, we investigated the fate of 6:2 and 8:2 homologues of the fluorotelomer unsaturated carboxylic acids (FTUCAs) during advanced oxidation process (AOPs). Results showed 6:2 FTUCA and 8:2 FTUCA transformed into 6-C PFCA (PFHxA) and 8-C PFCA (PFOA) respectively with very little other PFCA formation for all AOPs. The degradation of 6:2 FTUCA and 8:2 FTUCA was greater in the GW compared to SW for the ozone processes but similar for UV/H2O2. The formation of n-C PFCA followed O3>O3/H2O2 at same dose and UV/H2O2 had much lower formation at the doses tested. Non-targeted analysis with the LC-MS-qTOF indicated the production of other PFCAs which contribute to the total mass balance, although no intermediate product was discovered indicating a rapid and direct transformation from the FTUCAs to the PFCAs and/or significant volatilization of intermediates. With the use of AOPs essential to water reuse treatment schemes, this work raises concerns over the risk of potential formation of PFCAs in the treatment and their adverse health effects in finished drinking water.

  15. Biologically active filters - An advanced water treatment process for contaminants of emerging concern.

    PubMed

    Zhang, Shuangyi; Gitungo, Stephen W; Axe, Lisa; Raczko, Robert F; Dyksen, John E

    2017-05-01

    With the increasing concern of contaminants of emerging concern (CECs) in source water, this study examines the hypothesis that existing filters in water treatment plants can be converted to biologically active filters (BAFs) to treat these compounds. Removals through bench-scale BAFs were evaluated as a function of media, granular activated carbon (GAC) and dual media, empty bed contact time (EBCT), and pre-ozonation. For GAC BAFs, greater oxygen consumption, increased pH drop, and greater dissolved organic carbon removal normalized to adenosine triphosphate (ATP) were observed indicating increased microbial activity as compared to anthracite/sand dual media BAFs. ATP concentrations in the upper portion of the BAFs were as much as four times greater than the middle and lower portions of the dual media and 1.5 times greater in GAC. Sixteen CECs were spiked in the source water. At an EBCT of 18 min (min), GAC BAFs were highly effective with overall removals greater than 80% without pre-ozonation; exceptions included tri(2-chloroethyl) phosphate and iopromide. With a 10 min EBCT, the degree of CECs removal was reduced with less than half of the compounds removed at greater than 80%. The dual media BAFs showed limited CECs removal with only four compounds removed at greater than 80%, and 10 compounds were reduced by less than 50% with either EBCT. This study demonstrated that GAC BAFs with and without pre-ozonation are an effective and advanced technology for treating emerging contaminants. On the other hand, pre-ozonation is needed for dual media BAFs to remove CECs. The most cost effective operating conditions for dual media BAFs were a 10 min EBCT with the application of pre-ozonation.

  16. Re-engineering an artificial sweetener: transforming sucralose residuals in water via advanced oxidation.

    PubMed

    Keen, Olya S; Linden, Karl G

    2013-07-02

    Sucralose is an artificial sweetener persistently present in wastewater treatment plant effluents and aquatic environments impacted by human activity. It has a potential to accumulate in the water cycle due to its resistance to common water and wastewater treatment processes. This study examined UV/H2O2 advanced oxidation and found that hydroxyl substitution of the chlorine atoms on the sucralose molecule can form a carbohydrate consisting of fructose and sugar alcohol, very similar to environmentally benign sucrose. The second-order reaction rate constant for loss of parent molecule via reaction with hydroxyl radical was determined to be (1.56 ± 0.03)·10(9) M(-1)s(-1). The degradation pathway involves substitution of a single chlorine by a hydroxyl group, with cyclic moiety being a preferential site for initial dechlorination. Further reaction leads to full dechlorination of the molecule, presumably via hydroxyl group substitution as well. No direct photolysis by UV wavelengths above 200 nm was observed. Because of its photostability when exposed to UV wavelengths ≥200 nm, known stability with ozone, limits of quantification by mass spectrometry close to or below environmental concentrations (<5 μg/L) without preconcentration, and otherwise stable nature, sucralose can be used as an in situ hydroxyl radical probe for UV-based and ozone-based AOP processes. As a compound safe for human consumption, sucralose makes a suitable full scale hydroxyl radical probe fit even for drinking water treatment plant applications. Its main drawback as a probe is lack of UV detection and as a result a need for mass spectrometry analysis.

  17. Advances in simulating radiance signatures for dynamic air/water interfaces

    NASA Astrophysics Data System (ADS)

    Goodenough, Adam A.; Brown, Scott D.; Gerace, Aaron

    2015-05-01

    The air-water interface poses a number of problems for both collecting and simulating imagery. At the surface, the magnitude of observed radiance can change by multiple orders of magnitude at high spatiotemporal frequency due to glinting effects. In the volume, similarly high frequency focusing of photons by a dynamic wave surface significantly changes the reflected radiance of in-water objects and the scattered return of the volume itself. These phenomena are often manifest as saturated pixels and artifacts in collected imagery (often enhanced by time delays between neighboring pixels or interpolation between adjacent filters) and as noise and greater required computation times in simulated imagery. This paper describes recent advances made to the Digital Image and Remote Sensing Image Generation (DIRSIG) model to address the simulation issues to better facilitate an understanding of a multi/hyper-spectral collection. Glint effects are simulated using a dynamic height field that can be driven by wave frequency models and generates a sea state at arbitrary time scales. The volume scattering problem is handled by coupling the geometry representing the surface (facetization by the height field) with the single scattering contribution at any point in the water. The problem is constrained somewhat by assuming that contributions come from a Snell's window above the scattering point and by assuming a direct source (sun). Diffuse single scattered and multiple scattered energy contributions are handled by Monte Carlo techniques employed previously. The model is compared to existing radiative transfer codes where possible, with the objective of providing a robust movel of time-dependent absolute radiance at many wavelengths.

  18. Biases in Total Precipitable Water Vapor Climatologies from Atmospheric Infrared Sounder and Advanced Microwave Scanning Radiometer

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Eldering, Annmarie; Aumann, Hartmut H.; Chahine, Moustafa T.

    2006-01-01

    We examine differences in total precipitable water vapor (PWV) from the Atmospheric Infrared Sounder (AIRS) and the Advanced Microwave Scanning Radiometer (AMSR-E) experiments sharing the Aqua spacecraft platform. Both systems provide estimates of PWV over water surfaces. We compare AIRS and AMSR-E PWV to constrain AIRS retrieval uncertainties as functions of AIRS retrieved infrared cloud fraction. PWV differences between the two instruments vary only weakly with infrared cloud fraction up to about 70%. Maps of AIRS-AMSR-E PWV differences vary with location and season. Observational biases, when both instruments observe identical scenes, are generally less than 5%. Exceptions are in cold air outbreaks where AIRS is biased moist by 10-20% or 10-60% (depending on retrieval processing) and at high latitudes in winter where AIRS is dry by 5-10%. Sampling biases, from different sampling characteristics of AIRS and AMSR-E, vary in sign and magnitude. AIRS sampling is dry by up to 30% in most high-latitude regions but moist by 5-15% in subtropical stratus cloud belts. Over the northwest Pacific, AIRS samples conditions more moist than AMSR-E by a much as 60%. We hypothesize that both wet and dry sampling biases are due to the effects of clouds on the AIRS retrieval methodology. The sign and magnitude of these biases depend upon the types of cloud present and on the relationship between clouds and PWV. These results for PWV imply that climatologies of height-resolved water vapor from AIRS must take into consideration local meteorological processes affecting AIRS sampling.

  19. Improving electrokinetic microdevice stability by controlling electrolysis bubbles.

    PubMed

    Lee, Hwi Yong; Barber, Cedrick; Minerick, Adrienne R

    2014-07-01

    The voltage-operating window for many electrokinetic microdevices is limited by electrolysis gas bubbles that destabilize microfluidic system causing noise and irreproducible responses above ∼3 V DC and less than ∼1 kHz AC at 3 Vpp. Surfactant additives, SDS and Triton X-100, and an integrated semipermeable SnakeSkin® membrane were employed to control and assess electrolysis bubbles from platinum electrodes in a 180 by 70 μm, 10 mm long microchannel. Stabilized current responses at 100 V DC were observed with surfactant additives or SnakeSkin® barriers. Electrolysis bubble behaviors, visualized via video microscopy at the electrode surface and in the microchannels, were found to be influenced by surfactant function and SnakeSkin® barriers. Both SDS and Triton X-100 surfactants promoted smaller bubble diameters and faster bubble detachment from electrode surfaces via increasing gas solubility. In contrast, SnakeSkin® membranes enhanced natural convection and blocked bubbles from entering the microchannels and thus reduced current disturbances in the electric field. This data illustrated that electrode surface behaviors had substantially greater impacts on current stability than microbubbles within microchannels. Thus, physically blocking bubbles from microchannels is less effective than electrode functionalization approaches to stabilize electrokinetic microfluidic systems.

  20. Thermochemical and hybrid cycles for hydrogen production - A differential economic comparison with electrolysis

    NASA Astrophysics Data System (ADS)

    Shinnar, R.; Shapira, D.; Zakal, S.

    1981-10-01

    A method for economic evaluation of new processes is presented. The method is especially suitable for evaluating new technology at a stage where much of the detailed process information is still missing. It is based on differential comparison of the new process with available technology for focusing on evaluating its advantages in dealing with stochiometric, thermodynamic, and process constraints and the interactions between them. The method is demonstrated by performing thorough evaluation of a class of processes that has been proposed for generation of hydrogen from nuclear reaction. The paper shows that one can conclude that the processes that have been proposed in the literature are inferior to electrolysis of water and that this conclusion can be obtained without any detailed process information using only available thermodynamic properties of the components involved.