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Sample records for temperature steam electrolysis

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Bio-Fuel Production Assisted with High Temperature Steam Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Grant Hawkes; James O' Brien; Michael McKellar

    2012-06-01

    Two hybrid energy processes that enable production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure are presented. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), these two hybrid energy processes have the potential to provide a significant alternative petroleum source that could reduce dependence on imported oil. The first process discusses a hydropyrolysis unit with hydrogen addition from HTSE. Non-food biomass is pyrolyzed and converted to pyrolysis oil. The pyrolysis oil is upgraded with hydrogen addition from HTSE. This addition of hydrogen deoxygenates the pyrolysis oil and increases the pH to a tolerable level for transportation. The final product is synthetic crude that could then be transported to a refinery and input into the already used transportation fuel infrastructure. The second process discusses a process named Bio-Syntrolysis. The Bio-Syntrolysis process combines hydrogen from HTSE with CO from an oxygen-blown biomass gasifier that yields syngas to be used as a feedstock for synthesis of liquid synthetic crude. Conversion of syngas to liquid synthetic crude, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model

  3. Systems Engineering Provides Successful High Temperature Steam Electrolysis Project

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. High Temperature Electrolysis

    DEFF Research Database (Denmark)

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

    2015-01-01

    High temperature electrolysis of carbon dioxide, or co-electrolysis of carbon dioxide and steam, has a great potential for carbon dioxide utilisation. A solid oxide electrolysis cell (SOEC), operating between 500 and 900. °C, is used to reduce carbon dioxide to carbon monoxide. If steam is also...... input to the cell then hydrogen is produced giving syngas. This syngas can then be further reacted to form hydrocarbon fuels and chemicals. Operating at high temperature gives much higher efficiencies than can be achieved with low temperature electrolysis. Current state of the art SOECs utilise a dense...

  5. LIQUID BIO-FUEL PRODUCTION FROM NON-FOOD BIOMASS VIA HIGH TEMPERATURE STEAM ELECTROLYSIS

    Energy Technology Data Exchange (ETDEWEB)

    G. L. Hawkes; J. E. O' Brien; M. G. McKellar

    2011-11-01

    Bio-Syntrolysis is a hybrid energy process that enables production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), bio-syntrolysis has the potential to provide a significant alternative petroleum source that could reduce US dependence on imported oil. Combining hydrogen from HTSE with CO from an oxygen-blown biomass gasifier yields syngas to be used as a feedstock for synthesis of liquid transportation fuels via a Fischer-Tropsch process. Conversion of syngas to liquid hydrocarbon fuels, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. 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. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-blown 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

  6. High Temperature Co-electrolysis of Steam and CO2 in an SOC stack: Performance and Durability

    DEFF Research Database (Denmark)

    Chen, Ming; Høgh, Jens Valdemar Thorvald; Nielsen, Jens Ulrik

    2012-01-01

    units can be used for co-electrolysis of steam and CO2 to produce synthesis gas (CO+H2), which can be further processed to a variety of synthetic fuels such as methane, methanol or DME [2]. Previously we have shown at stack level that Ni/YSZ electrode supported SOEC cells can be operated at 850 o......C and -0.5 A/cm2 with no long term degradation, as long as the inlet gases to the Ni/YSZ electrode were cleaned [3]. In this work, co-electrolysis of steam and carbon dioxide was studied in a TOFC® 10-cell stack, containing 3 different types ofNi/YSZ electrode supported cells with a footprint of 12X12 cm2......High temperature electrolysis based on solid oxide electrolysis cells (SOECs) is a very promising technology for energy storage or production of synthetic fuels. By electrolysis of steam, the SOEC provides an efficient way of producing high purity hydrogen and oxygen [1]. Furthermore, the SOEC...

  7. Evaluation of the high temperature electrolysis of steam to produce hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Youngjoon; Park, Wonseok; Chang, Jonghwa; Park, Jongkuen [Korea Atomic Energy Research Institute, 150 Dukjin-dong, Yuseong-gu, Daejeon (Korea)

    2007-07-15

    A very high temperature gas-cooled reactor (VHTR) can be effectively used for hydrogen production through several CO{sub 2}-free alternative technologies, such as the Sulfur-Iodine (SI) cycle, the high temperature electrolysis of steam (HTES), and others. In our current study, the electrochemical thermodynamic properties and the overall thermal efficiency of the VHTR-assisted hydrogen production system by using the HTES technology have been calculated as a function of the operating temperature in the range of 600-1000 {sup circle} C. On the other hand, the effect of not only the gas turbine efficiency but also the recovery of waste heat for the overall hydrogen production thermal efficiency has also been evaluated. The thermal efficiency defined by a high heat value of the produced hydrogen (HHV) divided by the total energy of the heat and the electricity required to produce the hydrogen was adopted in our evaluation scheme. As a result, a maximized overall thermal efficiency of about 48% can be anticipated at 1000 {sup circle} C. Compared with a thermal efficiency of 27% by a conventional alkaline solution electrolysis at lower temperatures, a hydrogen production by the VHTR-assisted HTES can save on the required energy by about 2 times. The sensitivity of the operating temperature for the overall thermal efficiency defined by {delta}{eta}{sub {delta}} {sub T}/{eta}{sub T} is about 14.3% in the range of 600 to 1000 {sup circle} C. From the aspect of a conservative gas turbine efficiency and a reasonable recovery of the waste heat, an overall feasible efficiency of 46% is anticipated at 850 {sup circle} C. (author)

  8. Durability of Solid Oxide Electrolysis Cell and Interconnects for Steam Electrolysis

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

    2013-01-01

    Durability of a solid oxide electrolysis cell tested at -1.5A / cm2 for high temperature steam electrolysis was investigated in the present work under stack relevant conditions. Detailed electrochemical and microstructural analyses were carried out. The results show that both the hydrogen...... and interconnects on cell degradation under harsh electrolysis conditions is further discussed....

  9. Process Modeling Results of Bio-Syntrolysis: Converting Biomass to Liquid Fuel with High Temperature Steam Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    G. L. Hawkes; M. G. McKellar; R. Wood; M. M. Plum

    2010-06-01

    A new process called Bio-Syntrolysis is being researched at the Idaho National Laboratory (INL) investigating syngas production from renewable biomass that is assisted with high temperature steam electrolysis (HTSE). The INL is the world leader in researching HTSE and has recently produced hydrogen from high temperature solid oxide cells running in the electrolysis mode setting several world records along the way. A high temperature (~800°C) heat source is necessary to heat the steam as it goes into the electrolytic cells. Biomass provides the heat source and the carbon source for this process. Syngas, a mixture of hydrogen and carbon monoxide, can be used for the production of synthetic liquid fuels via Fischer-Tropsch processes. This concept, coupled with fossil-free electricity, provides a possible path to reduced greenhouse gas emissions and increased energy independence, without the major infrastructure shift that would be required for a purely hydrogen-based transportation system. Furthermore, since the carbon source is obtained from recyclable biomass, the entire concept is carbon-neutral

  10. Highly efficient high temperature electrolysis

    DEFF Research Database (Denmark)

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

    2008-01-01

    High temperature electrolysis of water and steam may provide an efficient, cost effective and environmentally friendly production of H-2 Using electricity produced from sustainable, non-fossil energy sources. To achieve cost competitive electrolysis cells that are both high performing i.e. minimum...... electrolysis is favourable from a thermodynamic point of view, because a part of the required energy can be supplied as thermal heat, and the activation barrier is lowered increasing the H-2 production rate. Only two types of cells operating at high temperature (above 200 degrees C) have been described...... electrolysis using SOECs is competitive to H-2 production from fossil fuels at electricity prices below 0.02-0.03 is an element of per kWh. Though promising SOEC results on H-2 production have been reported a substantial R&D is still required to obtain inexpensive, high performing and long-term stable...

  11. High Temperature Co‐Electrolysis of Steam and CO2 in an SOC Stack: Performance and Durability

    DEFF Research Database (Denmark)

    Chen, Ming; Høgh, Jens Valdemar Thorvald; Nielsen, J. U.

    2013-01-01

    In this work, co‐electrolysis of steam and carbon dioxide was studied in a Topsoe Fuel Cell (TOFC®) 10‐cell stack, containing three different types of Ni/yttria stabilized zirconia (YSZ) electrode supported solid oxide electrolysis cells with a footprint of 12 × 12 cm. The stack was operated at 800...... °C and –0.75 A cm–2 with 60% conversion for a period of 1,000 h. One type of the cells showed no long term degradation but actually activation during the entire electrolysis period, while the other two types degraded. The performance and durability of the different cell types is discussed...... with respect to cell material composition and microstructure. The results of this study show that long term electrolysis is feasible without notable degradation at 800 °C and a current density of –0.75 A cm–2....

  12. Status on the Component Models Developed in the Modelica Framework: High-Temperature Steam Electrolysis Plant & Gas Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Suk Kim, Jong [Idaho National Lab. (INL), Idaho Falls, ID (United States); McKellar, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bragg-Sitton, Shannon M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boardman, Richard D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-10-01

    This report has been prepared as part of an effort to design and build a modeling and simulation (M&S) framework to assess the economic viability of a nuclear-renewable hybrid energy system (N-R HES). In order to facilitate dynamic M&S of such an integrated system, research groups in multiple national laboratories have been developing various subsystems as dynamic physics-based components using the Modelica programming language. In fiscal year (FY) 2015, Idaho National Laboratory (INL) performed a dynamic analysis of two region-specific N-R HES configurations, including the gas-to-liquid (natural gas to Fischer-Tropsch synthetic fuel) and brackish water reverse osmosis desalination plants as industrial processes. In FY 2016, INL has developed two additional subsystems in the Modelica framework: a high-temperature steam electrolysis (HTSE) plant and a gas turbine power plant (GTPP). HTSE has been proposed as a high priority industrial process to be integrated with a light water reactor (LWR) in an N-R HES. This integrated energy system would be capable of dynamically apportioning thermal and electrical energy (1) to provide responsive generation to the power grid and (2) to produce alternative industrial products (i.e., hydrogen and oxygen) without generating any greenhouse gases. A dynamic performance analysis of the LWR/HTSE integration case was carried out to evaluate the technical feasibility (load-following capability) and safety of such a system operating under highly variable conditions requiring flexible output. To support the dynamic analysis, the detailed dynamic model and control design of the HTSE process, which employs solid oxide electrolysis cells, have been developed to predict the process behavior over a large range of operating conditions. As first-generation N-R HES technology will be based on LWRs, which provide thermal energy at a relatively low temperature, complementary temperature-boosting technology was suggested for integration with the

  13. Status Report on the High-Temperature Steam Electrolysis Plant Model Developed in the Modelica Framework (FY17)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Suk [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bragg-Sitton, Shannon M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boardman, Richard D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-08-29

    This report has been prepared as part of an effort to design and build a modeling and simulation (M&S) framework to assess the economic viability of a nuclear-renewable hybrid energy system (N-R HES). In order to facilitate dynamic M&S of such an integrated system, research groups in multiple national laboratories have been developing various subsystems as dynamic physics-based components using the Modelica programming language. In fiscal year 2015 (FY15), Idaho National Laboratory (INL) performed a dynamic analysis of two region-specific N-R HES configurations, including the gas-to-liquid (natural gas to Fischer-Tropsch synthetic fuel) and brackish water reverse osmosis desalination plants as industrial processes. In FY16, INL developed two additional subsystems in the Modelica framework: (1) a high-temperature steam electrolysis (HTSE) plant as a high priority industrial plant to be integrated with a light water reactor (LWR) within an N-R HES and (2) a gas turbine power plant as a secondary energy supply. In FY17, five new components (i.e., a feedwater pump, a multi-stage compression system, a sweep-gas turbine, flow control valves, and pressure control valves) have been incorporated into the HTSE system proposed in FY16, aiming to better realistically characterize all key components of concern. Special attention has been given to the controller settings based on process models (i.e., direct synthesis method), aiming to improve process dynamics and controllability. A dynamic performance analysis of the improved LWR/HTSE integration case was carried out to evaluate the technical feasibility (load-following capability) and safety of such a system operating under highly variable conditions requiring flexible output. The analysis (evaluated in terms of the step response) clearly shows that the FY17 model resulted in superior output responses with much smaller settling times and less oscillatory behavior in response to disturbances in the electric load than those

  14. Production of Hydrogen and Synthesis Gas by High Temperature Electrolysis

    DEFF Research Database (Denmark)

    Ebbesen, Sune; Høgh, Jens Valdemar Thorvald; Mogensen, Mogens Bjerg

    2009-01-01

    Electrolysis of steam and co-electrolysis of steam and carbon dioxide was studied in stacks composed of Ni/YSZ electrode supported Solid Oxide Electrolysis Cells. The results of this study show that long term electrolysis is feasible in these solid oxide electrolysis stacks. The degradation...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    Bi, Lei; Boulfrad, Samir; Traversa, Enrico

    2014-12-21

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

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

    KAUST Repository

    Bi, Lei

    2014-01-01

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

  18. HIGH-TEMPERATURE ELECTROLYSIS FOR HYDROGEN PRODUCTION FROM NUCLEAR ENERGY

    Energy Technology Data Exchange (ETDEWEB)

    James E. O& #39; Brien; Carl M. Stoots; J. Stephen Herring; Joseph J. Hartvigsen

    2005-10-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (~140 µm thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1 - 0.6), gas flow rates (1000 - 4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 90 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate.

  19. High temperature electrolysis for syngas production

    Science.gov (United States)

    Stoots, Carl M [Idaho Falls, ID; O'Brien, James E [Idaho Falls, ID; Herring, James Stephen [Idaho Falls, ID; Lessing, Paul A [Idaho Falls, ID; Hawkes, Grant L [Sugar City, ID; Hartvigsen, Joseph J [Kaysville, UT

    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. THE PRODUCTION OF SYNGAS VIA HIGH TEMPERATURE ELECTROLYSIS AND BIO-MASS GASIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    M. G. McKellar; G. L. Hawkes; J. E. O' Brien

    2008-11-01

    A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to improve the hydrogen production efficiency of the steam electrolysis process. Hydrogen from electrolysis allows a high utilization of the biomass carbon for syngas production. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon dioxide 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.

  1. Results Of Recent High Temperature Co-Electrolysis Studies At The Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    C. M. Stoots; James E. O' Brien; Joseph J. Hartvigsen

    2007-11-01

    For the past several years, the Idaho National Laboratory and Ceramatec, Inc. have been studying the feasibility of high temperature solid oxide electrolysis for large-scale, nuclear-powered hydrogen production. Parallel to this effort, the INL and Ceramatec have been researching high temperature solid oxide co-electrolysis of steam/CO2 mixtures to produce syngas, the raw material for synthetic fuels production. When powered by nuclear energy, high temperature co-electrolysis offers a carbon-neutral means of syngas production while consuming CO2. The INL has been conducting experiments to characterize the electrochemical performance of co-electrolysis, as well as validate INL-developed computer models. An inline methanation reactor has also been tested to study direct methane production from co-electrolysis products. Testing to date indicate that high temperature steam electrolysis cells perform equally well under co-electrolysis conditions. Process model predictions compare well with measurements for outlet product compositions. The process appears to be a promising technique for large-scale syngas production.

  2. Degradation in Solid Oxide Cells During High Temperature Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Manohar Sohal

    2009-05-01

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

  3. Performance Assessment of Single Electrode-Supported Solid Oxide Cells Operating in the Steam Electrolysis Mode

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-01

    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. Results presented in this paper were obtained from single cells, with an active area of 16 cm{sup 2} per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes ({approx}10 {mu}m thick), nickel-YSZ steam/hydrogen electrodes ({approx}1400 {mu}m thick), and modified LSM or LSCF air-side electrodes ({approx}90 {mu}m thick). The purpose of the present study is 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 voltage-current (VI) sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-term testing, first in the fuel cell mode, then in the electrolysis mode. Results generally 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 an improved single-cell test apparatus developed specifically for these experiments.

  4. High temperature and pressure alkaline electrolysis

    DEFF Research Database (Denmark)

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

    2013-01-01

    for immobilization of aqueous KOH solutions. Electrolysis cells with this electrolyte and metal foam based gas diffusion electrodes were successfully demonstrated at temperatures up to 250 °C at 40 bar. Different electro-catalysts were tested in order to reduce the oxygen and hydrogen overpotentials. Current...... the operational temperature and pressure to produce pressurized hydrogen at high rate (m3 H2·h-1·m-2 cell area) and high electrical efficiency. This work describes an exploratory technical study of the possibility to produce hydrogen and oxygen with a new type of alkaline electrolysis cell at high temperatures...... densities of 1.1 A cm-2 and 2.3 A cm-2 have been measured at a cell voltage of 1.5 V and 1.75 V, respectively, without noble metal catalysts. Electrical efficiencies of almost 99 % at 1.1 A cm-2 and 85 % at 2.3 A cm-2 were obtained....

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. New Construction and Catalyst Support Materials for Water Electrolysis at Elevated Temperatures

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey

    Proton exchange membrane (PEM) water electrolysis presents an attractive technology allowing to produce hydrogen for further use as a renewable energy source in the "Hydrogen cycle". Electrolysis of water steam at elevated temperatures has several advantages over the low temperature process....... However, at the same time it involves increased demands to dimensional and chemical stability of components against corrosion environment. Therefore, materials utilized in low temperature PEM electrolyzers cannot be used in systems operating above 100 °C and new candidates should be tested. The materials...... gives an introduction into the subject and Chapter 2 subsequently presents the theoretical background of the topic and describes techniques used to characterize catalysts and construction materials. Chapter 3 presents general principles and overview of materials used for PEM water electrolysis. Chapter...

  7. High Temperature and Pressure Alkaline Electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank

    temperatures and pressures. Aqueous potassium hydroxide immobilized electrolyte in porous SrTiO3 was used in those cells. Electrolysis cells with metal foam based gas diffusion electrodes and the immobilized electrolyte were successfully demonstrated at temperatures up to 250 °C and 40 bar. Different electro-catalysts...... were tested in order to reduce the oxygen and hydrogen overpotentials. Current densities of 1.1 A cm-2 and 2.3 A cm-2 have been measured at a cell voltage of 1.5 V and 1.75 V, respectively, without using expensive noble metal catalysts. Electrical efficiencies of almost 99 % at 1.1 A cm-2 and 85 % at 2...... against conventional technologies for hydrogen production, such as natural gas reforming, the production and investment costs have to be reduced. A reduction of the investment costs may be achieved by increasing the operational pressure and temperature of the electrolyzer, as this will result in: 1...

  8. High Temperature Electrolysis using Electrode-Supported Cells

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Recent Progress At The Idaho National Laboratory In High Temperature Electrolysis For Hydrogen And Syngas Production

    Energy Technology Data Exchange (ETDEWEB)

    C. Stoots; J. O' Brien; J. Herring; J. Hartvigsen

    2008-11-01

    This paper presents the most recent results of experiments conducted at the Idaho National Laboratory (INL) studying electrolysis of steam and coelectrolysis of steam / carbon dioxide in solid-oxide electrolysis stacks. Single button cell tests as well as multi-cell stack testing have been conducted. Multi-cell stack testing used 10 x 10 cm cells (8 x 8 cm active area) supplied by Ceramatec, Inc (Salt Lake City, Utah, USA) and ranged from 10 cell short stacks to 240 cell modules. Tests were conducted either in a bench-scale test apparatus or in a newly developed 5 kW Integrated Laboratory Scale (ILS) test facility. Gas composition, operating voltage, and operating temperature were varied during testing. The tests were heavily instrumented, and outlet gas compositions were monitored with a gas chromatograph. The ILS facility is currently being expanded to 15 kW testing capacity (H2 production rate based upon lower heating value).

  11. Durable SOC stacks for production of hydrogen and synthesis gas by high temperature electrolysis

    DEFF Research Database (Denmark)

    Ebbesen, Sune Dalgaard; Høgh, Jens Valdemar Thorvald; Nielsen, Karsten Agersted

    2011-01-01

    Electrolysis of steam and co-electrolysis of steam and carbon dioxide was studied in Solid Oxide Electrolysis Cell (SOEC) stacks composed of Ni/YSZ electrode supported SOECs. The results of this study show that long-term electrolysis is feasible without notable degradation in these SOEC stacks....... The degradation of the electrolysis cells was found to be influenced by the adsorption of impurities from the applied inlet gases, whereas the application of chromium containing interconnect plates and glass sealings do not seem to influence the durability when operated at 850 °C. Cleaning the inlet gases...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  13. Corrosion behaviour of construction materials for high temperature steam electrolysers

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Christensen, Erik

    2011-01-01

    Different types of commercially available stainless steels, Ni-based alloys as well as titanium and tantalum were evaluated as possible metallic bipolar plates and construction materials. The corrosion resistance was measured under simulated conditions corresponding to the conditions in high...... to corrosion under strong anodic polarisation. Among alloys, Ni-based showed the highest corrosion resistance in the simulated PEM electrolyser medium. In particular, Inconel 625 was the most promising among the tested corrosion-resistant alloys for the anodic compartment in high temperature steam electrolysis...

  14. PEM steam electrolysis at 130 °C using a phosphoric acid doped short side chain PFSA membrane

    DEFF Research Database (Denmark)

    Hansen, Martin Kalmar; Aili, David; Christensen, Erik

    2012-01-01

    Steam electrolysis test with a phosphoric acid doped Aquivion™ membrane was successfully conducted and current densities up to 775 mA cm-2 at 1.8 V was reached at 130 ºC and ambient pressure. A new composite membrane system using a perfluorosulfonic acid membrane (Aquivion™) as matrix and phospho......Steam electrolysis test with a phosphoric acid doped Aquivion™ membrane was successfully conducted and current densities up to 775 mA cm-2 at 1.8 V was reached at 130 ºC and ambient pressure. A new composite membrane system using a perfluorosulfonic acid membrane (Aquivion™) as matrix...

  15. Electrolysis

    DEFF Research Database (Denmark)

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

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

  16. High-temperature electrolysis of synthetic seawater using solid oxide electrolyzer cells

    Science.gov (United States)

    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.

  17. PEM Water Electrolysis at Elevated Temperatures

    DEFF Research Database (Denmark)

    Hansen, Martin Kalmar

    100 °C. It was found that the gas diffusion layer on the anode side played an important role for the electrolyser performance. Different thicknesses and types, i.e. a single layer- and double layer type, were tested. Chapter 5 presents a characterisation of the gas diffusion layers, using parameters...... ternary composite membrane. The durability, on the other hand, was greatly improved and test was run for approximately 70 hours (constant voltage of 1.7 V) with a 0.17 mA·h-1 decline in performance. Finally, a new class of perfluorosulfonic acid (PFSA) membranes were tested. This was Aquivion™, which...... and development of a more sophisticated anode electrode structure. Only when this parameter is optimised and performing at a high level, will it be possible to really quantify the importance of the other parameters under full single cell electrolysis tests....

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-01

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

  19. Durability of the Solid Oxide Cells for Co-Electrolysis of Steam and Carbon Dioxide under High Current Densities

    DEFF Research Database (Denmark)

    Tao, Youkun

    Production of hydrogen and syngas (CO + H2) using solid oxide electrolysis cells (SOECs) has become increasingly attractive due to high oil price, the capability for conversion and storage of intermittent energy from renewable sources and the general interest in hydrogen energy and carbon-neutral...... occurred during co-electrolysis of steam and CO2 at |i| ≥ 2.0 A/cm2. Gas diffusion limitations contribute to the dramatic increase of cell voltage and a very reducing atmosphere at the interface.......Production of hydrogen and syngas (CO + H2) using solid oxide electrolysis cells (SOECs) has become increasingly attractive due to high oil price, the capability for conversion and storage of intermittent energy from renewable sources and the general interest in hydrogen energy and carbon......-electrolysis of steam and CO2. Two types of Ni-YSZ supported cells, the LSM cell and LSCF cell, respectively with a LSM-YSZ or a LSCF-CGO oxygen electrode were tested using a setup with albite glass as sealing material, and using the gasses as received or in an setup using a glass with less known impurities...

  20. The Concept and Analytical Investigation of CO2 and Steam Co-Electrolysis for Resource Utilization in Space Exploration

    Science.gov (United States)

    McKellar, Michael G.; Stoots, Carl M.; Sohal, Manohar S.; Mulloth, Lila M.; Luna, Bernadette; Abney, Morgan B.

    2010-01-01

    CO2 acquisition and utilization technologies will have a vital role in designing sustainable and affordable life support and in situ fuel production architectures for human and robotic exploration of Moon and Mars. For long-term human exploration to be practical, reliable technologies have to be implemented to capture the metabolic CO2 from the cabin air and chemically reduce it to recover oxygen. Technologies that enable the in situ capture and conversion of atmospheric CO2 to fuel are essential for a viable human mission to Mars. This paper describes the concept and mathematical analysis of a closed-loop life support system based on combined electrolysis of CO2 and steam (co-electrolysis). Products of the coelectrolysis process include oxygen and syngas (CO and H2) that are suitable for life support and synthetic fuel production, respectively. The model was developed based on the performance of a co-electrolysis system developed at Idaho National Laboratory (INL). Individual and combined process models of the co-electrolysis and Sabatier, Bosch, Boudouard, and hydrogenation reactions are discussed and their performance analyses in terms of oxygen production and CO2 utilization are presented.

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

    Science.gov (United States)

    Licht, Stuart; Cui, Baochen; Wang, Baohui; Li, Fang-Fang; Lau, Jason; Liu, Shuzhi

    2014-08-08

    The Haber-Bosch process to produce ammonia for fertilizer currently relies on carbon-intensive steam reforming of methane as a hydrogen source. We present an electrochemical pathway in which ammonia is produced by electrolysis of air and steam in a molten hydroxide suspension of nano-Fe2O3. At 200°C in an electrolyte with a molar ratio of 0.5 NaOH/0.5 KOH, ammonia is produced at 1.2 volts (V) under 2 milliamperes per centimeter squared (mA cm(-2)) of applied current at coulombic efficiency of 35% (35% of the applied current results in the six-electron conversion of N2 and water to ammonia, and excess H2 is cogenerated with the ammonia). At 250°C and 25 bar of steam pressure, the electrolysis voltage necessary for 2 mA cm(-2) current density decreased to 1.0 V. Copyright © 2014, American Association for the Advancement of Science.

  2. The beneficial effects of straight open large pores in the support on steam electrolysis performance of electrode-supported solid oxide electrolysis cell

    Science.gov (United States)

    Lin, Jie; Chen, Long; Liu, Tong; Xia, Changrong; Chen, Chusheng; Zhan, Zhongliang

    2018-01-01

    This study is aimed at improving the electrochemical performance of electrode-supported solid oxide electrolysis cells (SOECs) by optimizing the pore structure of the supports. Two planar NiO-8 mol% yttria-stabilized zirconia supports are prepared, one by the phase-inversion tape casting, and the other by conventional tape casting method using graphite as the pore former. The former contains finger-like straight open large pores, while the latter contains randomly distributed and tortuous pores. The steam electrolysis of the cells with different microstructure cathode supports is measured. The cell supported on the cathode with straight pores shows a high current density of 1.42 A cm-2 and a H2 production rate of 9.89 mL (STP) cm-2 min-1 at 1.3 V and 50 vol % humidity and 750 °C, while the cell supported on the cathode with tortuous pores shows a current density of only 0.91 A cm-2 and a H2 production rate of 6.34 mL cm-2min-1. It is concluded that the introduction of large straight open pores into the cathode support allows fast gas phase transport and thus minimizes the concentration polarization. Furthermore, the straight pores could provide better access to the reaction site (the electrode functional layer), thereby reducing the activation polarization as well.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    Co-electrolysis of H2O and CO2 was studied in solid oxide cells (SOCs) supported by nickel-/yittria-stabilized zirconia (Ni/YSZ) electrode. Polarization characterization indicates that electrochemical reduction of both CO2 and H2O occurs during co-electrolysis. In parallel with the electrochemical...

  4. Oxygen Handling and Cooling Options in High Temperature Electrolysis Plants

    Energy Technology Data Exchange (ETDEWEB)

    Manohar S. Sohal; J. Stephen Herring

    2008-07-01

    Idaho National Laboratory is working on a project to generate hydrogen by high temperature electrolysis (HTE). In such an HTE system, safety precautions need to be taken to handle high temperature oxygen at ~830°C. This report is aimed at addressing oxygen handling in a HTE plant.. Though oxygen itself is not flammable, most engineering material, including many gases and liquids, will burn in the presence of oxygen under some favorable physicochemical conditions. At present, an absolute set of rules does not exist that can cover all aspects of oxygen system design, material selection, and operating practices to avoid subtle hazards related to oxygen. Because most materials, including metals, will burn in an oxygen-enriched environment, hazards are always present when using oxygen. Most materials will ignite in an oxygen-enriched environment at a temperature lower than that in air, and once ignited, combustion rates are greater in the oxygen-enriched environment. Even many metals, if ignited, burn violently in an oxygen-enriched environment. However, these hazards do not preclude the operations and systems involving oxygen. Oxygen can be safely handled and used if all the materials in a system are not flammable in the end-use environment or if ignition sources are identified and controlled. In fact, the incidence of oxygen system fires is reported to be low with a probability of about one in a million. This report is a practical guideline and tutorial for the safe operation and handling of gaseous oxygen in high temperature electrolysis system. The intent is to provide safe, practical guidance that permits the accomplishment of experimental operations at INL, while being restrictive enough to prevent personnel endangerment and to provide reasonable facility protection. Adequate guidelines are provided to govern various aspects of oxygen handling associated with high temperature electrolysis system to generate hydrogen. The intent here is to present acceptable

  5. Intermediate Temperature Steam Electrolysis with Phosphate-Based Electrolytes

    DEFF Research Database (Denmark)

    Prag, Carsten Brorson

    the synthesis of Sn0.9In0.1P2O7 in order to establish a reproducible synthesis procedure. The synthesis used in this work required two heat treatment steps. Fourier transform infrared spectroscopy (FT-IR) shows an O-H band in the IR spectrum from 1500 cm-1 to 3800 cm-1 strongly dependent on the first heat...... treatment step of the synthesis. It was found that initial heating of the synthesis precursors to 270 _C gave a high quality sample in a reproducible fashion. Investigations of two additional novel phosphates was attempted. These were phosphoric acid treated Nb5P7O30 and a mixture of Bi2P4O13, BiPO4 and 2...... of tantalum was used to protect stainless steel components from the highly oxidative environment of the oxygen side of the electrolyser. While such protection should not be necessary on the hydrogen side, it was found that the best results were obtained using tantalum coated stainless steel flow plates...

  6. Degradation of solid oxide cells during co-electrolysis of steam and carbon dioxide at high current densities

    DEFF Research Database (Denmark)

    Tao, Youkun; Ebbesen, Sune Dalgaard; Mogensen, Mogens Bjerg

    2016-01-01

    In this work, the durability of Ni–YSZ based solid oxide cells was investigated during co-electrolysis of steam and carbon dioxide (45% H2O + 45% CO2 + 10% H2) at current density of −1.5 or −2.0 A cm−2. The cell consists of ∼300 μm Ni–YSZ support, ∼10 μm Ni–YSZ electrode, ∼10 μm YSZ electrolyte...... and ∼15 μm LSM–YSZ oxygen electrode. The gas conversion was 45% at −1.5 A cm−2 and 60% at −2.0 A cm−2, and the operating durations were up to 700 h. The detailed electrochemical analysis revealed significant increase of the ohmic resistance, oxide ion transport resistance in the Ni–YSZ composite...

  7. Improvement of steam temperature control in supercritical once thru boilers

    OpenAIRE

    黒石, 卓司; 藤川, 卓爾

    2009-01-01

     New steam temperature control logic for supercritical once thru boilers was developed from the view point of simplicity similar to that of the conventional sub-critical drum type boilers. Water wall outlet steam temperature can be controlled more easily due to larger specific heat capacity of steam than super heater outlet steam temperature. By dividing temperature control into two parts, one at water wall outlet by fuel flow and the other at SH(super heater) outlet by SH spray flow, boiler ...

  8. DESIGN OF A COMPACT HEAT EXCHANGER FOR HEAT RECUPERATION FROM A HIGH TEMPERATURE ELECTROLYSIS SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    G. K. Housley; J.E. O' Brien; G.L. Hawkes

    2008-11-01

    Design details of a compact heat exchanger and supporting hardware for heat recuperation in a high-temperature electrolysis application are presented. The recuperative heat exchanger uses a vacuum-brazed plate-fin design and operates between 300 and 800°C. It includes corrugated inserts for enhancement of heat transfer coefficients and extended heat transfer surface area. Two recuperative heat exchangers are required per each four-stack electrolysis module. The heat exchangers are mated to a base manifold unit that distributes the inlet and outlet flows to and from the four electrolysis stacks. Results of heat exchanger design calculations and assembly details are also presented.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

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

    2017-11-01

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

  11. Thermoneutral Operation of Solid Oxide Electrolysis Cells in Potentiostatic Mode

    DEFF Research Database (Denmark)

    Chen, Ming; Sun, Xiufu; Chatzichristodoulou, Christodoulos

    2017-01-01

    High temperature electrolysis based on solid oxide electrolysis cells (SOECs) is a promising technology for energy storage and synthetic fuel production. In recent years extensive efforts have been devoted to improving performance and durability of SOEC cells and stacks. Due to historical reasons...... and the convenience of doing constant current tests, (almost) all the reported SOEC tests have been galvanostatic. In this work, we report test results on two types of SOEC cells operated for electrolysis of steam in potentiostatic mode at 1.29 V. Both cells are Ni/YSZ fuel electrode supported type with different...... cause of the degradation. Operation strategies were further proposed for electrolysis operation in potentiostatic mode....

  12. AUTOMATIC CONTROL SYSTEM OF THE DRUM BOILER SUPERHEATED STEAM TEMPERATURE.

    Directory of Open Access Journals (Sweden)

    Juravliov A.A.

    2006-04-01

    Full Text Available The control system of the temperature of the superheated steam of the drum boiler is examined. Main features of the system are the PI-controller in the external control loop and introduction of the functional component of the error signal of the external control loop with the negative feedback of the error signal between the prescribed value of steam flowrate and the signal of the steam flowrate in the exit of the boiler in the internal control loop.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. The Concept and Experimental Investigation of CO2 and Steam Co-electrolysis for Resource Utilization in Space Exploration

    Science.gov (United States)

    Stoots, Carl; Mulloth, Lila M.; Luna, Bernadette; Varghese, Mini M.

    2009-01-01

    CO2 acquisition and utilization technologies will have a vital role in determining sustained and affordable life support and in-situ fuel production architectures for human and robotic exploration of Moon and Mars. For long-term human exploration to be practical, reliable technologies have to be implemented to capture and chemically reduce the metabolic CO2 from the cabin air to restitute oxygen consumption. Technologies that facilitate the in-situ capture and conversion of atmospheric CO2 to fuel are essential for a viable human mission to Mars and their demonstration on the moon is critical as well. This paper describes the concept and experimental investigation of a CO2 capture and reduction system that comprises an adsorption compressor and a CO2 and steam co-electrolysis unit. The process products include oxygen for life support and Syngas (CO and H2) for synthetic fuel production. Electrochemical performance in terms of CO2 conversion, oxygen production, and power consumption of a system with a capacity to process 1kg CO2 per day (1-person equivalent) will be discussed.

  15. Estimation of Temperature Influence on Creep Rate of High-Temperature Elements in Steam Turbines and Steam Pipelines

    Directory of Open Access Journals (Sweden)

    A. G. Gerasimova

    2011-01-01

    Full Text Available The paper considers a high temperature influence on strength characteristics of steam pipelines and steam turbine parts of high and medium pressure. The charts showing a decisive temperature importance in diffuse creep have been presented in the paper. The paper contains a calculation of steel self-diffusion coefficient. Dependence Dsd = f(t for more accurate assessment of  resource characteristics of the applied steel has been proposed in the paper.

  16. The relationship between surface temperature, tissue temperature, microbubble formation, and steam pops.

    Science.gov (United States)

    Thompson, Nathaniel; Lustgarten, Daniel; Mason, Bryan; Mueller, Enkhtuyaa; Calame, James; Bell, Stephen; Spector, Peter

    2009-07-01

    It has been proposed that microbubble (MB) monitoring can be used to safely titrate radiofrequency (RF) power. However, MB formation has been found to be an insensitive indicator of tissue temperature during RF delivery. We hypothesized that MB formation corresponds to surface-not tissue--temperature, and therefore would be an insensitive predictor of steam pops. An in vitro bovine heart model was used to measure surface and tissue temperatures during RF delivery under conditions designed to cause steam pops. Sensitivity of type II MB (MBII) formation as a predictor of steam pops and for surface temperatures more than 80 degrees C was calculated. Of 105 lesions delivered, 99 steam pops occurred. Twenty-one steam pops were preceded by MBII. MBII were seen in 26 lesions, five of which were not associated with steam pop. Surface temperature at onset of MBII was 87 +/- 9 degrees C versus a tissue temperature of 78 +/- 23 degrees C (P = 0.044). Surface temperature at the time of steam pops was 71 +/- 17 degrees C versus a tissue temperature of 102 +/- 17 degrees C (P surface temperature in excess of 80 degrees C. MBII correlated better with surface temperature than with tissue temperature; steam pops, on the other hand, correlated better with tissue temperature. MBII was an insensitive marker of steam pops and surface temperature in excess of 80 degrees C. Therefore, MBII should not be used to titrate RF power.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    A new type of alkaline electrolysis cells with nickel foam based gas diffusion electrodes and KOH (aq) immobilized in mesoporous SrTiO3 has been developed and tested at temperatures and pressures up to 250 °C and 42 bar, respectively. Current densities of 1.0 A cm−2 have been measured at a cell...

  18. Nonuniformity of Temperatures in Microwave Steam Heating of Lobster Tail.

    Science.gov (United States)

    Fleischman, Gregory J

    2016-11-01

    The biennial Conference for Food Protection provides a formal process for all interested parties to influence food safety guidance. At a recent conference, an issue was raised culminating in a formal request to the U.S. Food and Drug Administration to change its Food Code recommendation for safe cooking of seafood using microwave energy when steaming was also employed. The request was to treat microwave steam cooked seafood as a conventionally cooked raw animal product rather than a microwave cooked product, for which the safe cooking recommendation is more extensive owing to the complex temperature distributions in microwave heating. The request was motivated by a literature study that revealed a more uniform temperature distribution in microwave steam cooked whole lobster. In that study, single-point temperatures were recorded in various sections of the whole lobster, but only one temperature was recorded in the tail, although the large size of the tail could translate to multiple hot and cold points. The present study was conducted to examine lobster tail specifically, measuring temperatures at multiple points during microwave steam cooking. Large temperature differences, greater than 60°C at times, were found throughout the heating period. To compensate for such differences, the Food Code recommends a more extensive level of cooking when microwave energy, rather than conventional heat sources, is used. Therefore, a change in the Food Code regarding microwave steam heating cannot be recommended.

  19. Electrolysis test of different composite membranes at elevated temperatures

    DEFF Research Database (Denmark)

    Hansen, Martin Kalmar

    sprayed directly onto the gas diffusion layers (GDLs). For the anode side GDL a tantalum covered stainless steel felt was used, whereas on the cathode side, the GDLs were wet-proofed carbon cloth. The composite membranes were prepared from commercial available Nafion® membranes. They were treated over.......7V for a Nafion® 115 treated with both H3PO4 and ZrP. Variations of the GDL on the anode side were tested. Different kinds of stainless steel felts were examined to find the best candidate for the final electrolysis setup. The felts differed in both tread thickness and overall thickness. The felts...... were covered with tantalum to protect the stainless steel. The felts were covered either once or twice to obtain different thicknesses of the tantalum. Experiments with PTFE treated felt was also preformed to examine if wet-proofing the anode GDL would improve the overall performance of the cell...

  20. New high temperature steels for steam power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hald, J.; Nath, B.

    1998-07-01

    Development of high efficiency ultra supercritical (USC) steam power plant is based on the availability of improved high temperature steels for key components in the steam cycle i.e: Thick section boiler components and steam lines; turbine rotors, casings, valves and bolts; superheaters; furnace panels. New martensitic high creep strength 9--12%Cr steels like the P91, P92 and P122 allow increased steam parameters in steam headers and steam lines, and similar martensitic steels are used for rotors, casings and valves of advanced steam turbines. The development of these steels have included demonstration of fabricability like welding and bending, fabrication of demonstration components built into existing plants, and the validation of long term creep properties with testing times of more than 30,000 hours. The development work has been made in international projects like the EPRI RP1403, COST 501 and ECCC. The first use of the new steels have followed in USC plants in Europe and Japan, leading to plant efficiencies up to 47%. Superheater steels must have high corrosion and oxidation resistance, and a number of new austenitic steels have been developed for this purpose. Tests are currently running to obtain long term corrosion and oxidation data for design of superheaters in the new steels. Steels for furnace panels need to be welded without post weld heat treatment, and also for this purpose new ferritic and martensitic steels are available. With the materials development described above it is today possible to construct a USC plant with steam parameters 325bar/610 C/630 C/630 C and an efficiency approaching 50%. Future developments in the European THERMIE demonstration project ``Advanced (700 C) PF Power Plant'' will address the use of nickel or cobalt base superalloys for boilers, steam lines and turbines. This may lead to efficiencies in the range 52--55%.

  1. Steam temperature control of essential oil extraction system using ...

    African Journals Online (AJOL)

    This research proposed a closed-loop temperature control using a self-tuning fuzzy fractional-order PI (FOPI) controller to overcome the problem. The controller will regulate the steam temperature at a desired level to protect the oil from excessive heat. Self capability of fuzzy rules was found to facilitate the tuning using only ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  3. Mathematical modelling of steam generator and design of temperature regulator

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanovic, S.S. [EE Institute Nikola Tesla, Belgrade (Yugoslavia)

    1999-07-01

    The paper considers mathematical modelling of once-through power station boiler and numerical algorithm for simulation of the model. Fast and numerically stable algorithm based on the linearisation of model equations and on the simultaneous solving of differential and algebraic equations is proposed. The paper also presents the design of steam temperature regulator by using the method of projective controls. Dynamic behaviour of the system closed with optimal linear quadratic regulator is taken as the reference system. The desired proprieties of the reference system are retained and solutions for superheated steam temperature regulator are determined. (author)

  4. A Demonstration of Carbon-Assisted Water Electrolysis

    Directory of Open Access Journals (Sweden)

    Olalekan D. Adeniyi

    2013-03-01

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

  5. Potential use of high-temperature and low-temperature steam ...

    African Journals Online (AJOL)

    The treatment methods included a high-pressure steam treatment (HPST; 19 bar, 3 min), treating the products with sodium hydroxide, sulphuric acid plus an enzyme mixture, or low-temperature steam treatment (LTST) under different conditions. Gas production (GP), two-step in vitro digestibility (IVD) and in situ degradability ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Linkous, C.A.; Kopitzke, R.W. [Florida Solar Energy Center, Cape Canaveral, FL (United States)

    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. Development of solid electrolytes for water electrolysis at higher temperature

    Energy Technology Data Exchange (ETDEWEB)

    Linkous, C.A. [Florida Solar Energy Center, Cocoa, FL (United States)

    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.

  9. CHALLENGES IN GENERATING HYDROGEN BY HIGH TEMPERATURE ELECTROLYSIS USING SOLID OXIDE CELLS

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-01

    Idaho National Laboratory’s (INL) high temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells is presented in this paper. The research results reported here have been obtained in a laboratory-scale apparatus. These results and common scale-up issues also indicate that for the technology to be successful in a large industrial setting, several technical, economical, and manufacturing issues have to be resolved. Some of the issues related to solid oxide cells are stack design and performance optimization, identification and evaluation of cell performance degradation parameters and processes, integrity and reliability of the solid oxide electrolysis (SOEC) stacks, life-time prediction and extension of the SOEC stack, and cost reduction and economic manufacturing of the SOEC stacks. Besides the solid oxide cells, balance of the hydrogen generating plant also needs significant development. These issues are process and ohmic heat source needed for maintaining the reaction temperature (~830°C), high temperature heat exchangers and recuperators, equal distribution of the reactants into each cell, system analysis of hydrogen and associated energy generating plant, and cost optimization. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a cost of $3.23/kg of hydrogen assuming an internal rate of return of 10%. These issues need interdisciplinary research effort of federal laboratories, solid oxide cell manufacturers, hydrogen consumers, and other such stakeholders. This paper discusses research and development accomplished by INL on such issues and highlights associated challenges that need to

  10. Long-term operation of a solid oxide cell stack for coelectrolysis of steam and CO2

    DEFF Research Database (Denmark)

    Agersted, Karsten; Chen, Ming; Blennow, Peter

    2016-01-01

    High temperature electrolysis based on solid oxide electrolysis cells (SOECs) is a promising technology for production of synthetic fuels. The SOEC units can be used for co-electrolysis of steam and CO2 to produce synthesis gas (syngas, CO+H2), which can be further processed to a variety...... of synthetic fuels such as methane, methanol or DME. Previously we have reported electrolysis operation of solid oxide cell stacks for periods up to about 1000 hours. In this work, operation of a Haldor Topsoe 8-cell stack (stack design of 2014) in co-electrolysis mode for 6000 hours is reported. The stack...

  11. Microstructure characterisation of solid oxide electrolysis cells operated at high current density

    DEFF Research Database (Denmark)

    Bowen, Jacob R.; Bentzen, Janet Jonna; Chen, Ming

    High temperature solid oxide cells can be operated either as fuel cells or electrolysis cells for efficient power generation or production of hydrogen from steam or synthesis gas (H2 + CO) from steam and CO2 respectively. When operated under harsh conditions, they often exhibit microstructural......, microstructure evolution of the Ni-yttria stabilized zirconia (YSZ) is followed as a function of galvanostatic steam electrolysis testing at current densities between -0.5 and -1.0 A cm-2 for periods of up to 750 hours at 800 °C. The volume fraction and size of the percolating Ni particles was statistically...... quantified using the mean linear intercept method as a function of current density and correlated to increases in serial resistance. The above structural changes are then compared in terms of electrode degradation observed during the co-electrolysis of steam and CO2 at current densities up to -1.5 A cm-2...

  12. Critical Causes of Degradation in Integrated Laboratory Scale Cells during High Temperature Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    M.S. Sohal; J.E. O' Brien; C.M. Stoots; J. J. Hartvigsen; D. Larsen; S. Elangovan; J.S. Herring; J.D. Carter; V.I. Sharma; B. Yildiz

    2009-05-01

    An ongoing project at Idaho National Laboratory involves generating hydrogen from steam using solid oxide electrolysis cells (SOEC). This report describes background information about SOECs, the Integrated Laboratory Scale (ILS) testing of solid-oxide electrolysis stacks, ILS performance degradation, and post-test examination of SOECs by various researchers. The ILS test was a 720- cell, three-module test comprised of 12 stacks of 60 cells each. A peak H2 production rate of 5.7 Nm3/hr was achieved. Initially, the module area-specific resistance ranged from 1.25 Ocm2 to just over 2 Ocm2. Total H2 production rate decreased from 5.7 Nm3/hr to a steady state value of 0.7 Nm3/hr. The decrease was primarily due to cell degradation. Post test examination by Ceramatec showed that the hydrogen electrode appeared to be in good condition. The oxygen evolution electrode does show delamination in operation and an apparent foreign layer deposited at the electrolyte interface. Post test examination by Argonne National Laboratory showed that the O2-electrode delaminated from the electrolyte near the edge. One possible reason for this delamination is excessive pressure buildup with high O2 flow in the over-sintered region. According to post test examination at the Massachusetts Institute of Technology, the electrochemical reactions have been recognized as one of the prevalent causes of their degradation. Specifically, two important degradation mechanisms were examined: (1) transport of Crcontaining species from steel interconnects into the oxygen electrode and LSC bond layers in SOECs, and (2) cation segregation and phase separation in the bond layer. INL conducted a workshop October 27, 2008 to discuss possible causes of degradation in a SOEC stack. Generally, it was agreed that the following are major degradation issues relating to SOECs: • Delamination of the O2-electrode and bond layer on the steam/O2-electrode side • Contaminants (Ni, Cr, Si, etc.) on reaction sites

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

    Directory of Open Access Journals (Sweden)

    Tetsuhiko Maeda

    2016-01-01

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

  14. Thermosyphon Method for Cooling the Rotor Blades of High-Temperature Steam Turbines

    Directory of Open Access Journals (Sweden)

    Bogomolov Alexander R.

    2016-01-01

    Full Text Available The design scheme of closed two-phase thermosyphon were suggested that can provide standard thermal operation of blades of high-temperature steam turbine. The method for thermosyphon calculation is developed. The example of thermal calculation was implemented, it showed that to cool the steam turbine blades at their heating by high-temperature steam, the heat can be removed in the rear part of the blades by air with the temperature of about 440°C.

  15. A review of high temperature co-electrolysis of H2O and CO2to produce sustainable fuels using solid oxide electrolysis cells (SOECs): advanced materials and technology.

    Science.gov (United States)

    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 CO 2 emissions, enable large-scale energy storage/conversion and facilitate the integration of renewable energies into the electric grid. Exciting new research has focused on CO 2 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 CO 2 conversion and utilization. Here, we discuss in detail the approaches of CO 2 conversion, the developmental history, the basic principles, the economic feasibility of CO 2 /H 2 O 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 CO 2 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.

  16. Molybdenum Disilicide Oxidation Kinetics in High Temperature Steam

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Elizabeth Sooby [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parker, Stephen Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nelson, Andrew Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-07

    The Fuel Cycle Research and Development program’s Advanced Fuels Campaign is currently supporting a range of experimental efforts aimed at the development and qualification of ‘accident tolerant’ nuclear fuel forms. One route to enhance the accident tolerance of nuclear fuel is to replace the zirconium alloy cladding, which is prone to rapid oxidation in steam at elevated temperatures, with a more oxidation-resistant cladding. Several cladding replacement solutions have been envisaged. The cladding can be completely replaced with a more oxidation resistant alloy, a layered approach can be used to optimize the strength, creep resistance, and oxidation tolerance of various materials, or the existing zirconium alloy cladding can be coated with a more oxidation-resistant material. Molybdenum is one candidate cladding material favored due to its high temperature creep resistance. However, it performs poorly under autoclave testing and suffers degradation under high temperature steam oxidation exposure. Development of composite cladding architectures consisting of a molybdenum core shielded by a molybdenum disilicide (MoSi2) coating is hypothesized to improve the performance of a Mo-based cladding system. MoSi2 was identified based on its high temperature oxidation resistance in O2 atmospheres (e.g. air and “wet air”). However, its behavior in H2O is less known. This report presents thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and x-ray diffraction (XRD) results for MoSi2 exposed to 670-1498 K water vapor. Synthetic air (80-20%, Ar-O2) exposures were also performed, and those results are presented here for a comparative analysis. It was determined that MoSi2 displays drastically different oxidation behavior in water vapor than in dry air. In the 670-1498 K temperature range, four distinct behaviors are observed. Parabolic oxidation is exhibited in only 670

  17. Syntrophic interactions drive the hydrogen production from glucose at low temperature in microbial electrolysis cells

    KAUST Repository

    Lu, Lu

    2012-11-01

    H2 can be obtained from glucose by fermentation at mesophilic temperatures, but here we demonstrate that hydrogen can also be obtained from glucose at low temperatures using microbial electrolysis cells (MECs). H2 was produced from glucose at 4°C in single-chamber MECs at a yield of about 6mol H2mol-1 glucose, and at rates of 0.25±0.03-0.37±0.04m3 H2m-3d-1. Pyrosequencing of 16S rRNA gene and electrochemical analyses showed that syntrophic interactions combining glucose fermentation with the oxidization of fermentation products by exoelectrogens was the predominant pathway for current production at a low temperature other than direct glucose oxidization by exoelectrogens. Another syntrophic interaction, methanogenesis and homoacetogenesis, which have been found in 25°C reactors, were not detected in MECs at 4°C. These results demonstrate the feasibility of H2 production from abundant biomass of carbohydrates at low temperature in MECs. © 2012 Elsevier Ltd.

  18. Syntrophic interactions drive the hydrogen production from glucose at low temperature in microbial electrolysis cells.

    Science.gov (United States)

    Lu, Lu; Xing, Defeng; Ren, Nanqi; Logan, Bruce E

    2012-11-01

    H(2) can be obtained from glucose by fermentation at mesophilic temperatures, but here we demonstrate that hydrogen can also be obtained from glucose at low temperatures using microbial electrolysis cells (MECs). H(2) was produced from glucose at 4°C in single-chamber MECs at a yield of about 6 mol H(2)mol(-1) glucose, and at rates of 0.25±0.03-0.37±0.04 m(3) H(2)m(-3)d(-1). Pyrosequencing of 16S rRNA gene and electrochemical analyses showed that syntrophic interactions combining glucose fermentation with the oxidization of fermentation products by exoelectrogens was the predominant pathway for current production at a low temperature other than direct glucose oxidization by exoelectrogens. Another syntrophic interaction, methanogenesis and homoacetogenesis, which have been found in 25°C reactors, were not detected in MECs at 4°C. These results demonstrate the feasibility of H(2) production from abundant biomass of carbohydrates at low temperature in MECs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. NARX-based BPSO modelling for time-varying steam temperature of ...

    African Journals Online (AJOL)

    This paper focuses on a nonlinear modelling for a time-varying process of steam temperature by employing a polynomial Nonlinear Auto-Regressive with Exogenous Input (NARX) structure based on Binary Particle Swarm Optimization (BPSO) algorithm. The system identification time-varying steam temperature data was ...

  20. Primary collector wall local temperature fluctuations in the area of water-steam phase boundary

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O.; Klinga, J.; Simo, T. [Energovyzkum Ltd., Brno (Switzerland)

    1995-12-31

    A limited number of temperature sensors could be installed at the primary collector surface in the area of water - steam phase boundary. The surface temperatures as well WWER 440 steam generator process data were measured and stored for a long time and off-line evaluated. Selected results are presented in the paper. (orig.). 2 refs.

  1. Investigation of operational temperature conditions of steam generating surfaces with critical heat flux

    Energy Technology Data Exchange (ETDEWEB)

    Remizov, O.V.

    1978-01-01

    The design and construction of reliable once-through steam generators requires a knowledge of temperature conditions along the entire length of the steam generating surface including regions affected by deteriorated heat transfer and dryout. Experimental and calculated data on temperatures in these regions are presented and compared. (LCL)

  2. Hydrogen Production Performance of a 10-Cell Planar Solid-Oxide Electrolysis Stack

    Energy Technology Data Exchange (ETDEWEB)

    James O& #39; Brien; Carl Stoots; Steve Herring; J. Hartvigsen

    2005-05-01

    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 electrolytesupported, 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 100 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate.

  3. Steam-air fluidized bed gasification of distillers grains: Effects of steam to biomass ratio, equivalence ratio and gasification temperature.

    Science.gov (United States)

    Kumar, Ajay; Eskridge, Kent; Jones, David D; Hanna, Milford A

    2009-03-01

    In this study, thermochemical biomass gasification was performed on a bench-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Distillers grains, a non-fermentable byproduct of ethanol production, were used as the biomass feedstock for the gasification. The goal was to investigate the effects of furnace temperature, steam to biomass ratio and equivalence ratio on gas composition, carbon conversion efficiency and energy conversion efficiency of the product gas. The experiments were conducted using a 3x3x3 full factorial design with temperatures of 650, 750 and 850 degrees C, steam to biomass ratios of 0, 7.30 and 14.29 and equivalence ratios of 0.07, 0.15 and 0.29. Gasification temperature was found to be the most influential factor. Increasing the temperature resulted in increases in hydrogen and methane contents, carbon conversion and energy efficiencies. Increasing equivalence ratio decreased the hydrogen content but increased carbon conversion and energy efficiencies. The steam to biomass ratio was optimal in the intermediate levels for maximal carbon conversion and energy efficiencies.

  4. Idaho National Laboratory Experimental Research In High Temperature Electrolysis For Hydrogen And Syngas Production

    Energy Technology Data Exchange (ETDEWEB)

    Carl M. Stoots; James E. O' Brien; J. Stephen Herring; Joseph J. Hartvigsen

    2008-09-01

    The Idaho National Laboratory (Idaho Falls, Idaho, USA), in collaboration with Ceramatec, Inc. (Salt Lake City, Utah, USA), is actively researching the application of solid oxide fuel cell technology as electrolyzers for large scale hydrogen and syngas production. This technology relies upon electricity and high temperature heat to chemically reduce a steam or steam / CO2 feedstock. Single button cell tests, multi-cell stack, as well as multi-stack testing has been conducted. Stack testing used 10 x 10 cm cells (8 x 8 cm active area) supplied by Ceramatec and ranged from 10 cell short stacks to 240 cell modules. Tests were conducted either in a bench-scale test apparatus or in a newly developed 5 kW Integrated Laboratory Scale (ILS) test facility. Gas composition, operating voltage, and operating temperature were varied during testing. The tests were heavily instrumented, and outlet gas compositions were monitored with a gas chromatograph. The ILS facility is currently being expanded to ~15 kW testing capacity (H2 production rate based upon lower heating value).

  5. Application of displacement monitoring system on high temperature steam pipe

    Science.gov (United States)

    Ghaffar, M. H. A.; Husin, S.; Baek, J. E.

    2017-10-01

    High-energy piping systems of power plants such as Main Steam (MS) pipe or Hot Reheat (HR) pipe are operating at high temperature and high pressure at base and cyclic loads. In the event of transient condition, a pipe can be deflected dramatically and caused high stress in the pipe, yielding to failure of the piping system. Periodic monitoring and walk down can identify abnormalities but limitations exist in the standard walk down practice. This paper provides a study of pipe displacement monitoring on MS pipe of coal-fired power plant to continuously capture the pipe movement behaviour at different load using 3-Dimensional Displacement Measuring System (3DDMS). The displacement trending at Location 5 and 6 (north and south) demonstrated pipes displace less than 25% to that of design movement. It was determined from synchronisation analysis that Location 7 (north) and Location 8 (south) pipe actual movement difference has exceeded the design movement difference. Visual survey at specified locations with significant displacement trending reveals issues of hydraulic snubber and piping interferences. The study demonstrated that the displacement monitoring is able to capture pipe movement at all time and allows engineer to monitor pipe movement behaviour, aids in identifying issue early for remedy action.

  6. Trehalose enhancing microbial electrolysis cell for hydrogen generation in low temperature (0 °C).

    Science.gov (United States)

    Xu, Linji; Liu, Wenzong; Wu, Yining; Lee, Poheng; Wang, Aijie; Li, Shuai

    2014-08-01

    This work explored the feasibility of a method combining physical (sonication and base) and biological (partial fermentation) processes for sludge treatment and the effects of trehalose on the hydrogen generation of microbial electrolysis cell at 0 °C. The results demonstrated that the above pretreatment method was favorable, which promoted organics decomposing into lower molecular weight matter. The promotion of trehalose for MEC efficiency was obvious and the optimal concentration of trehalose was 50 mmol/L. With this concentration, the highest hydrogen recovery rate was 0.25 m(3)-H₂/-m(3)-reactor per day. Coulomb efficiency and energy recovery efficiency were 46.4% and 203%, respectively. Further, the consumption order of mixed substances was VFAs>proteins>carbohydrates. For microorganism community, SEM photographs illustrated that the selectivity of environmental temperature for the species of anode bacteria was strong and denaturing gradient gel electrophoresis indicated that Microbacterium and Proteobacteria were the two main species and Proteobacteria may be one of the species that produced electrons. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. High Temperature Electrolysis for Hydrogen Production from Nuclear Energy – TechnologySummary

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-01

    The Department of Energy, Office of Nuclear Energy, has requested that a Hydrogen Technology Down-Selection be performed to identify the hydrogen production technology that has the best potential for timely commercial demonstration and for ultimate deployment with the Next Generation Nuclear Plant (NGNP). An Independent Review Team has been assembled to execute the down-selection. This report has been prepared to provide the members of the Independent Review Team with detailed background information on the High Temperature Electrolysis (HTE) process, hardware, and state of the art. The Idaho National Laboratory has been serving as the lead lab for HTE research and development under the Nuclear Hydrogen Initiative. The INL HTE program has included small-scale experiments, detailed computational modeling, system modeling, and technology demonstration. Aspects of all of these activities are included in this report. In terms of technology demonstration, the INL successfully completed a 1000-hour test of the HTE Integrated Laboratory Scale (ILS) technology demonstration experiment during the fall of 2008. The HTE ILS achieved a hydrogen production rate in excess of 5.7 Nm3/hr, with a power consumption of 18 kW. This hydrogen production rate is far larger than has been demonstrated by any of the thermochemical or hybrid processes to date.

  8. High Temperature Air/Steam Gasification (HTAG). Technical report no. 2: High Temperature Air/Steam Gasification of biomass and wastes - Stage 2

    Energy Technology Data Exchange (ETDEWEB)

    Blasiak, W.; Kalisz, S.; Szewczyk, D.; Lucas, C.; Abeyweera, R. [Royal Inst. of Technology, Stockholm (Sweden). Dep of Materials Science and Engineering

    2005-02-01

    This report aims to provide information on activity of Division of Energy and Furnace Technology, Royal Inst. of Technology in the field of solid biomass conversion into fuel gas within year 2003. Contrary to the conventional gasification, in this work highly preheated air and steam is used as a gasifying agent and supplied to newly designed continuous gasifier. Preheating of air and steam is realised by means of the modern high-cycle regenerative Air/steam preheater. Maximum temperature of preheated air or steam is raised up to 1600 deg C. In this work the laboratory test facility called High Temperature Air/steam Gasification (HTAG) plant with flow rate of preheated air or steam up to 110 Nm{sup 3}/h is used. Use of highly preheated gasifying media provides additional energy into the gasification, which enhances the thermal decomposition of solids being gasified. Together with continuous operation mode of the new gasifier, a stable process producing relatively clean fuel gas is reported. High Temperature Air/steam Gasification has very clear economical and environmental benefits. It will increase consumption of biomass (like wood pellets) thus decreases CO{sub 2} emissions from energy intensive industries. Apart from CO{sub 2} reduction possibility, the new process, High Temperature Gasification of wastes, fulfils all new regulations proposed by European Commission on wastes incineration since: no landfilling of ash residues is required, no need to treat ashes from gasification since there is no ash produced but slag which is non leachable and can be used as building material, clean gas for combustion and production of heat or electricity. In this work only gasification of wood pellets is reported but all efforts are targeted on later continuous gasification of other kinds of biomass and wastes.

  9. Design and operating experience of 1000MW high-temperature steam turbine

    Energy Technology Data Exchange (ETDEWEB)

    Matsukuma, Masaharu; Magoshi; Ryotaro; Nakano, Takashi; Tashiro; Hikaru; Tanaka, Yoshinori

    1999-07-01

    The applicable steam conditions for large-capacity fossil-fuel thermal power plants over 500 MW in Japan have conventionally been 24.2MPa and 538/566 C. Mitsubishi Heavy Industries, Ltd. (MHI) has established, through wide-scale development programs, the technologies for design and materials of steam turbines with steam temperature 593 C, and has applied the steam conditions of 24.2MPa and 538/593 C to the large-capacity 700 MW turbine, Hekinan No. 3 Unit for Chubu Electric Power Co., Inc. According to the further development of high-temperature design, MHI has successfully developed and manufactured the 1000 MW turbine, Matsuura No. 2 Unit, Electric Power Development Co., Ltd. with a steam condition of 600 C class main steam and reheating steam temperature for the first time in the world. The unit, that was first rolled with steam in January 1997, started commercial operation in July 1997. This paper describes the features of design and operating experience of this unit after about one year's commercial operation.

  10. Analysis of Precooling Injection Transient of Steam Generator for High Temperature Gas Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-01-01

    Full Text Available After a postulated design basis accident leads high temperature gas cooled reactor to emergency shutdown, steam generator still remains with high temperature level and needs to be cooled down by a precooling before reactor restarts with clearing of fault. For the large difference of coolant temperature between inlet and outlet of steam generator in normal operation, the temperature distribution on the components of steam generator is very complicated. Therefore, the temperature descending rate of the components in steam generator needs to be limited to avoid the potential damage during the precooling stage. In this paper, a pebble-bed high temperature gas cooled reactor is modeled by thermal-hydraulic system analysis code and several postulated precooling injection transients are simulated and compared to evaluate their effects, which will provide support for the precooling design. The analysis results show that enough precooling injection is necessary to satisfy the precooling requirements, and larger mass flow rate of precooling water injection will accelerate the precooling process. The temperature decrease of steam generator is related to the precooling injection scenarios, and the maximal mass flow rate of the precooling injection should be limited to avoid the excessively quick temperature change of the structures in steam generator.

  11. Inactivation of Mold Spores from Moist Carpet Using Steam Vapor: Contact Time and Temperature.

    Science.gov (United States)

    Ong, Kee-Hean; Emo, Brett; Lewis, Roger D; Kennedy, Jason; Thummalakunta, Laxmi N A; Elliott, Michael

    2015-01-01

    Steam vapor has been shown to reduce viable mold spores in carpet, but the minimal effective temperature and contact time has not been established. This study evaluated the effectiveness of steam vapor in reducing the number of viable mold spores in carpet as a function of temperature and contact time. Seventy carpet samples were inoculated with a liquid suspension of Cladosporium sphaerospermum and incubated over a water-saturated foam carpet pad for 24 hr. Steam was applied to the samples as the temperature was measured from the carpet backing. Contact time was closely monitored over seven time intervals: 0, 2, 4, 8, 12, 16, and 20 sec. Following steam vapor treatment, mold spores were extracted from the carpet samples and the extract was plated on DG-18 plates at 1:1, 1:10, 1:100 dilutions followed by one week of incubation. Raw colony forming units were determined using an automated colony counter and adjusted based on dilution factor, extraction volume, and plated volume. Analysis of variance and linear regression were used to test for statistically significant relationships. Steam contact time exhibited a linear relationship to observed temperature of carpet backing (F = 90.176, R(2) = 0.609). Observed temperature of carpet backing had a positive relationship to percent reduction of mold (F = 76.605, R(2) = 0.569). Twelve seconds of steam vapor contact time was needed to achieve over 90% mold reduction on moist carpet.

  12. Linear parameter-varying modeling and control of the steam temperature in a Canadian SCWR

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Peiwei, E-mail: sunpeiwei@mail.xjtu.edu.cn; Zhang, Jianmin; Su, Guanghui

    2017-03-15

    Highlights: • Nonlinearity of Canadian SCWR is analyzed based on step responses and Nyquist plots. • LPV model is derived through Jacobian linearization and curve fitting. • An output feedback H{sub ∞} controller is synthesized for the steam temperature. • The control performance is evaluated by step disturbances and wide range operation. • The controller can stabilize the system and reject the reactor power disturbance. - Abstract: The Canadian direct-cycle Supercritical Water-cooled Reactor (SCWR) is a pressure-tube type SCWR under development in Canada. The dynamics of the steam temperature have a high degree of nonlinearity and are highly sensitive to reactor power disturbances. Traditional gain scheduling control cannot theoretically guarantee stability for all operating regions. The control performance can also be deteriorated when the controllers are switched. In this paper, a linear parameter-varying (LPV) strategy is proposed to solve such problems. Jacobian linearization and curve fitting are applied to derive the LPV model, which is verified using a nonlinear dynamic model and determined to be sufficiently accurate for control studies. An output feedback H{sub ∞} controller is synthesized to stabilize the steam temperature system and reject reactor power disturbances. The LPV steam temperature controller is implemented using a nonlinear dynamic model, and step changes in the setpoints and typical load patterns are carried out in the testing process. It is demonstrated through numerical simulation that the LPV controller not only stabilizes the steam temperature under different disturbances but also efficiently rejects reactor power disturbances and suppresses the steam temperature variation at different power levels. The LPV approach is effective in solving control problems of the steam temperature in the Canadian SCWR.

  13. Temperature conditions and state of a steam-generating tube surface

    Energy Technology Data Exchange (ETDEWEB)

    Remizov, O.V.; Starkov, O.V.; Korotaev, S.K.; Shevchenko, N.N.

    1987-02-01

    The authors conduct a methodological study of the relationship between temperature and scale and corrosion behavior on the heat-transfer surface of reactor steam generator tubing made of 10Kh2M steel. Chemical compositions of the deposits are found to consist primarily of the oxides of iron, chromium, nickel, calcium, magnesium, and silicon. The corrosive effects of steam and water are assessed on the basis of crystal-phase transformations induced in the steel.

  14. High Temperature Ultrasonic Probe and Pulse-Echo Probe Mounting Fixture for Testing and Blind Alignment on Steam Pipes

    Science.gov (United States)

    Bar-Cohen, Yoseph (Inventor); Badescu, Mircea (Inventor); Lih, Shyh-Shiuh (Inventor); Sherrit, Stewart (Inventor); Takano, Nobuyuki (Inventor); Ostlund, Patrick N. (Inventor); Lee, Hyeong Jae (Inventor); Bao, Xiaoqi (Inventor)

    2017-01-01

    A high temperature ultrasonic probe and a mounting fixture for attaching and aligning the probe to a steam pipe using blind alignment. The high temperature ultrasonic probe includes a piezoelectric transducer having a high temperature. The probe provides both transmitting and receiving functionality. The mounting fixture allows the high temperature ultrasonic probe to be accurately aligned to the bottom external surface of the steam pipe so that the presence of liquid water in the steam pipe can be monitored. The mounting fixture with a mounted high temperature ultrasonic probe are used to conduct health monitoring of steam pipes and to track the height of condensed water through the wall in real-time.

  15. Generation of high-temperature steam from unused thermal energy by a novel adsorption heat pump

    Science.gov (United States)

    Nakaso, Koichi; Eshima, Shotaro; Fukai, Jun

    2017-01-01

    For the effective utilization of unused thermal energy, the novel adsorption heat pump system for generating high-temperature steam is proposed. This system adopts a direct heat exchange method to the adsorption heat pump to increase heat transfer rate between adsorbent and heat transfer fluid. The heat pump system consists of two processes: steam generation process and regeneration process. In the steam generation process, water is directly introduced to the adsorbent. In the regeneration process, dry gas is introduced to the adsorbent. In this study, the performance of the system is numerically evaluated. The efficiency of the heat pump system is calculated by the ratio of enthalpy of product steam to input energy. To calculate the enthalpy of steam, mass of steam generated is estimated based on the progress of the regeneration process. Input energy of the heat pump system consists of the blower power to introduce dry gas and the thermal energy to heat dry gas. The effect of the operating condition on the performance of the steam generation process is studied. It is found there is the appropriate regeneration time to maximize the efficiency of the heat pump system.

  16. Performance of Single Electrode-Supported Cells Operating in the Electrolysis Mode

    Energy Technology Data Exchange (ETDEWEB)

    J. E. O' Brien; G. K. Housley; D. G. Milobar

    2009-11-01

    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 over a temperature range of 800 to 900ºC. 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. The experiments were performed over a range of steam inlet mole fractions (0.1 – 0.6), gas flow rates, and current densities (0 to 0.6 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. On a molar basis, the steam consumption rate is equal to the hydrogen production rate. Cell performance was evaluated by performing DC potential sweeps at 800, 850, and 900°C. The voltage-current characteristics are presented, along with values of area-specific resistance as a function of current density. Long-term cell performance is also assessed to evaluate cell degradation. Details of the custom single-cell test apparatus developed for these experiments are also presented.

  17. Thermal analysis of heat and power plant with high temperature reactor and intermediate steam cycle

    Directory of Open Access Journals (Sweden)

    Fic Adam

    2015-03-01

    Full Text Available Thermal analysis of a heat and power plant with a high temperature gas cooled nuclear reactor is presented. The main aim of the considered system is to supply a technological process with the heat at suitably high temperature level. The considered unit is also used to produce electricity. The high temperature helium cooled nuclear reactor is the primary heat source in the system, which consists of: the reactor cooling cycle, the steam cycle and the gas heat pump cycle. Helium used as a carrier in the first cycle (classic Brayton cycle, which includes the reactor, delivers heat in a steam generator to produce superheated steam with required parameters of the intermediate cycle. The intermediate cycle is provided to transport energy from the reactor installation to the process installation requiring a high temperature heat. The distance between reactor and the process installation is assumed short and negligable, or alternatively equal to 1 km in the analysis. The system is also equipped with a high temperature argon heat pump to obtain the temperature level of a heat carrier required by a high temperature process. Thus, the steam of the intermediate cycle supplies a lower heat exchanger of the heat pump, a process heat exchanger at the medium temperature level and a classical steam turbine system (Rankine cycle. The main purpose of the research was to evaluate the effectiveness of the system considered and to assess whether such a three cycle cogeneration system is reasonable. Multivariant calculations have been carried out employing the developed mathematical model. The results have been presented in a form of the energy efficiency and exergy efficiency of the system as a function of the temperature drop in the high temperature process heat exchanger and the reactor pressure.

  18. Thermal analysis of heat and power plant with high temperature reactor and intermediate steam cycle

    Science.gov (United States)

    Fic, Adam; Składzień, Jan; Gabriel, Michał

    2015-03-01

    Thermal analysis of a heat and power plant with a high temperature gas cooled nuclear reactor is presented. The main aim of the considered system is to supply a technological process with the heat at suitably high temperature level. The considered unit is also used to produce electricity. The high temperature helium cooled nuclear reactor is the primary heat source in the system, which consists of: the reactor cooling cycle, the steam cycle and the gas heat pump cycle. Helium used as a carrier in the first cycle (classic Brayton cycle), which includes the reactor, delivers heat in a steam generator to produce superheated steam with required parameters of the intermediate cycle. The intermediate cycle is provided to transport energy from the reactor installation to the process installation requiring a high temperature heat. The distance between reactor and the process installation is assumed short and negligable, or alternatively equal to 1 km in the analysis. The system is also equipped with a high temperature argon heat pump to obtain the temperature level of a heat carrier required by a high temperature process. Thus, the steam of the intermediate cycle supplies a lower heat exchanger of the heat pump, a process heat exchanger at the medium temperature level and a classical steam turbine system (Rankine cycle). The main purpose of the research was to evaluate the effectiveness of the system considered and to assess whether such a three cycle cogeneration system is reasonable. Multivariant calculations have been carried out employing the developed mathematical model. The results have been presented in a form of the energy efficiency and exergy efficiency of the system as a function of the temperature drop in the high temperature process heat exchanger and the reactor pressure.

  19. System Evaluation and Life-Cycle Cost Analysis of a Commercial-Scale High-Temperature Electrolysis Hydrogen Production Plant

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-01

    Results of a system evaluation and lifecycle cost analysis are presented for a commercial-scale high-temperature electrolysis (HTE) central hydrogen production plant. The plant design relies on grid electricity to power the electrolysis process and system components, and industrial natural gas to provide process heat. The HYSYS process analysis software was used to evaluate the reference central plant design capable of producing 50,000 kg/day of hydrogen. The HYSYS software performs mass and energy balances across all components to allow optimization of the design using a detailed process flow sheet and realistic operating conditions specified by the analyst. The lifecycle cost analysis was performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes Microsoft Excel spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. The results of the lifecycle analyses indicate that for a 10% internal rate of return, a large central commercial-scale hydrogen production plant can produce 50,000 kg/day of hydrogen at an average cost of $2.68/kg. When the cost of carbon sequestration is taken into account, the average cost of hydrogen production increases by $0.40/kg to $3.08/kg.

  20. A high-temperature gas-and-steam turbine plant operating on combined fuel

    Science.gov (United States)

    Klimenko, A. V.; Milman, O. O.; Shifrin, B. A.

    2015-11-01

    A high-temperature gas-steam turbine plant (GSTP) for ultrasupercritical steam conditions is proposed based on an analysis of prospects for the development of power engineering around the world and in Russia up to 2040. The performance indicators of a GSTP using steam from a coal-fired boiler with a temperature of 560-620°C with its superheating to 1000-1500°C by firing natural gas with oxygen in a mixingtype steam superheater are analyzed. The thermal process circuit and design of a GSTP for a capacity of 25 MW with the high- and intermediate-pressure high-temperature parts with the total efficiency equal to 51.7% and the natural gas utilization efficiency equal to 64-68% are developed. The principles of designing and the design arrangement of a 300 MW GSTP are developed. The effect of economic parameters (the level and ratio of prices for solid fuel and gas, and capital investments) on the net cost of electric energy is determined. The net cost of electric energy produced by the GSTP is lower than that produced by modern combined-cycle power plants in a wide variation range of these parameters. The components of a high-temperature GSTP the development of which determines the main features of such installations are pointed out: a chamber for combusting natural gas and oxygen in a mixture with steam, a vacuum device for condensing steam with a high content of nondensables, and a control system. The possibility of using domestically available gas turbine technologies for developing the GSTP's intermediate-pressure high-temperature part is pointed out. In regard of its environmental characteristics, the GSTP is more advantageous as compared with modern condensing power plants: it allows a flow of concentrated carbon dioxide to be obtained at its outlet, which can be reclaimed; in addition, this plant requires half as much consumption of fresh water.

  1. High Temperature Steam Corrosion of Cladding for Nuclear Applications: Experimental

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kevin M; Garnier, John E; Sergey Rashkeev; Michael V. Glazoff; George W. Griffith; Shannong M. Bragg-Sitton

    2013-01-01

    Stability of cladding materials under off-normal conditions is an important issue for the safe operation of light water nuclear reactors. Metals, ceramics, and metal/ceramic composites are being investigated as substitutes for traditional zirconium-based cladding. To support down-selection of these advanced materials and designs, a test apparatus was constructed to study the onset and evolution of cladding oxidation, and deformation behavior of cladding materials, under loss-of-coolant accident scenarios. Preliminary oxidation tests were conducted in dry oxygen and in saturated steam/air environments at 1000OC. Tube samples of Zr-702, Zr-702 reinforced with 1 ply of a ß-SiC CMC overbraid, and sintered a-SiC were tested. Samples were induction heated by coupling to a molybdenum susceptor inside the tubes. The deformation behavior of He-pressurized tubes of Zr-702 and SiC CMC-reinforced Zr-702, heated to rupture, was also examined.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-05-30

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

  3. Influence of Superheated Steam Temperature Regulation Quality on Service Life of Boiler Steam Super-Heater Metal

    Directory of Open Access Journals (Sweden)

    G. T. Kulakov

    2009-01-01

    Full Text Available The paper investigates influence of change in quality of superheated steam temperature regulations on service life of super-heater metal. А dependence between metal service life and dispersion value for different steel grades has been determined in the paper. Numerical values pertaining to increase of super-heater metal service life in case of transferring from manual regulation to standard system of automatic regulation (SAR have been determined and in case of transferring from standard SAR to improved SAR. The analysis of tabular data and plotted dependencies makes it possible to conclude that any change in conditions of convection super-heater metal work due to better quality of the regulation leads to essential increase of time period which is left till the completion of the service life of a super-heater heating surface.

  4. In-situ experimental characterization of the clamping pressure effects on low temperature polymer electrolyte membrane electrolysis International Journal of Hydrogen Energy

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Cui, Xiaoti; Frensch, Steffen Henrik

    2017-01-01

    The recent acceleration in hydrogen production’s R&D will lead the energy transition. Low temperature polymer electrolyte membrane electrolysis (LT-PEME) is one of the most promising candidate technologies to produce hydrogen from renewable energy sources, and for synthetic fuel production. LT-PE...

  5. Express Electrolysis.

    Science.gov (United States)

    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)

  6. In-situ experimental characterization of the clamping pressure effects on low temperature polymer electrolyte membrane electrolysis

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Cui, Xiaoti; Frensch, Steffen Henrik

    2017-01-01

    The recent acceleration in hydrogen production’s R&D will lead the energy transition. Low temperature polymer electrolyte membrane electrolysis (LT-PEME) is one of the most promising candidate technologies to produce hydrogen from renewable energy sources, and for synthetic fuel production. LT......-PEME splits water into hydrogen and oxygen when the voltage is applied between anode and cathode. Electrical current forces the positively charged ions to migrate to negatively charged cathode through PEM, where hydrogen is produced. Meanwhile, oxygen is produced at the anode side electrode and escapes...... as a gas with the circulating water. The effects of clamping pressure (Pc) on the LT-PEME cell performance, polarization resistances, and hydrogen and water crossover through the membrane, and hydrogen and oxygen production rate are studied. A 50 cm2 active area LT-PEME cell designed and manufactured...

  7. Glow discharge electrolysis plasma initiated preparation of temperature/pH dual sensitivity reed hemicellulose-based hydrogels.

    Science.gov (United States)

    Zhang, Wenming; Zhu, Sha; Bai, Yunping; Xi, Ning; Wang, Shaoyang; Bian, Yang; Li, Xiaowei; Zhang, Yucang

    2015-05-20

    The temperature/pH dual sensitivity reed hemicellulose-based hydrogels have been prepared through glow discharge electrolysis plasma (GDEP). The effect of different discharge voltages on the temperature and pH response performance of reed hemicellulose-based hydrogels was inspected, and the formation mechanism, deswelling behaviors of reed hemicellulose-based hydrogels were also discussed. At the same time, infrared spectroscopy (FT-IR), scanning differential thermal analysis (DSC) and scanning electron microscope (SEM) were adopted to characterize the structure, phase transformation behaviors and microstructure of hydrogels. It turned out to be that all reed hemicellulose-based hydrogels had a double sensitivity to temperature and pH, and their phase transition temperatures were all approximately 33 °C, as well as the deswelling dynamics met the first model. In addition, the hydrogel (TPRH-3), under discharge voltage 600 V, was more sensitive to temperature and pH and had higher deswelling ratio. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Bias polarization study of steam electrolysis by composite oxygen electrode Ba0.5Sr0.5Co0.8Fe0.2O3-δ/BaCe0.4Zr0.4Y0.2O3-δ

    Science.gov (United States)

    Yang, Tao; Shaula, Aliaksandr; Pukazhselvan, D.; Ramasamy, Devaraj; Deng, Jiguang; da Silva, E. L.; Duarte, Ricardo; Saraiva, Jorge A.

    2017-12-01

    The polarization behavior of Ba0.5Sr0.5Co0.8Fe0.2O3-δ-BaCe0.4Zr0.4Y0.2O3-δ (BSCF-BCZY) electrode under steam electrolysis conditions was studied in detail. The composite oxygen electrode supported by BCZY electrolyzer has been assessed as a function of temperature (T), water vapor partial pressures (pH2O), and bias polarization voltage for electrodes of comparable microstructure. The Electrochemical impedance spectra show two depressed arcs in general without bias polarization. And the electrode resistance became smaller with the increase of the bias polarization under the same water vapor partial pressures. The total resistance of the electrode was shown to be significantly affected by temperature, with the same level of pH2O and bias polarization voltage. This result highlights BSCF-BCZY as an effective oxygen electrode under moderate polarization and pH2O conditions.

  9. Corrosion behavior of construction materials for intermediate temperature steam electrolysers

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Jensen, Jens Oluf

    2013-01-01

    Different corrosion resistant stainless steels, nickel-based alloys, pure nickel, Ta-coated stainless steel (AISI 316L), niobium, platinum and gold rods were evaluated as possible materials for use in the intermediate temperature (200-400 °C) acidic water electrolysers. The corrosion resistance w...

  10. The performance of a temperature cascaded cogeneration system producing steam, cooling and dehumidification

    KAUST Repository

    Myat, Aung

    2013-02-01

    This paper discusses the performance of a temperature-cascaded cogeneration plant (TCCP), equipped with an efficient waste heat recovery system. The TCCP, also called a cogeneration system, produces four types of useful energy-namely, (i) electricity, (ii) steam, (iii) cooling and (iv) dehumidification-by utilizing single fuel source. The TCCP comprises a Capstone C-30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste-heat-activated devices, namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption chiller and (iv) a multi-bed desiccant dehumidifier. The performance analysis was conducted under different operation conditions such as different exhaust gas temperatures. It was observed that energy utilization factor could be as high as 70% while fuel energy saving ratio was found to be 28%. © 2013 Desalination Publications.

  11. High-temperature Oxidation of Fe-Cr Steels in Steam Condition – A Review

    Directory of Open Access Journals (Sweden)

    Tedi Kurniawan

    2016-05-01

    Full Text Available The development of supercritical (SC and ultra-supercritical (USC power plants requires materials with better corrosion properties. Deep understanding on the oxidation mechanism in the boiler environment is one of the important factors to support this development. In this work, high temperature oxidation of Fe-Cr steels in steam condition is reviewed.  Several mechanisms that explain the effect of water vapor in the oxidation behavior the steel were presented.

  12. Performance of a pilot scale microbial electrolysis cell fed on domestic wastewater at ambient temperatures for a 12 month period.

    Science.gov (United States)

    Heidrich, Elizabeth S; Edwards, Stephen R; Dolfing, Jan; Cotterill, Sarah E; Curtis, Thomas P

    2014-12-01

    A 100-L microbial electrolysis cell (MEC) was operated for a 12-month period fed on raw domestic wastewater at temperatures ranging from 1°C to 22°C, producing an average of 0.6 L/day of hydrogen. Gas production was continuous though decreased with time. An average 48.7% of the electrical energy input was recovered, with a Coulombic efficiency of 41.2%. COD removal was inconsistent and below the standards required. Limitations to the cell design, in particular the poor pumping system and large overpotential account for many of the problems. However these are surmountable hurdles that can be addressed in future cycles of pilot scale research. This research has established that the biological process of an MEC will to work at low temperatures with real wastewater for prolonged periods. Testing and demonstrating the robustness and durability of bioelectrochemical systems far beyond that in any previous study, the prospects for developing MEC at full scale are enhanced. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Multitechnique characterisation of 304L surface states oxidised at high temperature in steam and air atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Mamede, Anne-Sophie, E-mail: anne-sophie.mamede@ensc-lille.fr [University Lille, CNRS, ENSCL, Centrale Lille, University Artois, UMR 8181 – UCCS – Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Nuns, Nicolas, E-mail: nicolas.nuns@univ-lille1.fr [University Lille, CNRS, ENSCL, Centrale Lille, University Artois, UMR 8181 – UCCS – Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Cristol, Anne-Lise, E-mail: anne-lise.cristol@ec-lille.fr [University Lille, CNRS, Centrale Lille, Arts et Métiers Paris Tech, FRE 3723 – LML – Laboratoire de Mécanique de Lille, F-59000 Lille (France); Cantrel, Laurent, E-mail: laurent.cantrel@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, PSN-RES, Cadarache, Saint Paul lez Durance, 13115 (France); Laboratoire de Recherche Commun IRSN-CNRS-Lille 1: «Cinétique Chimique, Combustion, Réactivité» (C3R), Cadarache, Saint Paul lez Durance, 13115 (France); Souvi, Sidi, E-mail: sidi.souvi@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, PSN-RES, Cadarache, Saint Paul lez Durance, 13115 (France); Laboratoire de Recherche Commun IRSN-CNRS-Lille 1: «Cinétique Chimique, Combustion, Réactivité» (C3R), Cadarache, Saint Paul lez Durance, 13115 (France); and others

    2016-04-30

    Graphical abstract: - Highlights: • Mutitechnique characterisation of oxidised 304L. • Oxidation at high temperature under steam and air conditions of 304L stainless steel. • Chromium and manganese oxides formed in the outer layer. • Oxide profiles differ in air or steam atmosphere. - Abstract: In case of a severe accident occurring in a nuclear reactor, surfaces of the reactor coolant system (RCS), made of stainless steel (304L) rich in Cr (>10%) and Ni (8–12%), are oxidised. Fission products (FPs) are released from melt fuel and flow through the RCS. A part of them is deposited onto surfaces either by vapour condensation or by aerosol deposition mechanisms. To be able to understand the nature of interactions between these FPs and the RCS surfaces, a preliminary step is to characterize the RSC surface states in steam and air atmosphere at high temperatures. Pieces of 304L stainless steel have been treated in a flow reactor at two different temperatures (750 °C and 950 °C) for two different exposition times (24 h and 72 h). After surfaces analysing by a unique combination of surface analysis techniques (XPS, ToF-SIMS and LEIS), for 304L, the results show a deep oxide scale with multi layers and the outer layer is composed of chromium and manganese oxides. Oxide profiles differ in air or steam atmosphere. Fe{sub 2}O{sub 3} oxide is observed but in minor proportion and in all cases no nickel is detected near the surface. Results obtained are discussed and compared with the literature data.

  14. Application of Flexible Micro Temperature Sensor in Oxidative Steam Reforming by a Methanol Micro Reformer

    Directory of Open Access Journals (Sweden)

    Yi-Man Lo

    2011-02-01

    Full Text Available Advances in fuel cell applications reflect the ability of reformers to produce hydrogen. This work presents a flexible micro temperature sensor that is fabricated based on micro-electro-mechanical systems (MEMS technology and integrated into a flat micro methanol reformer to observe the conditions inside that reformer. The micro temperature sensor has higher accuracy and sensitivity than a conventionally adopted thermocouple. Despite various micro temperature sensor applications, integrated micro reformers are still relatively new. This work proposes a novel method for integrating micro methanol reformers and micro temperature sensors, subsequently increasing the methanol conversion rate and the hydrogen production rate by varying the fuel supply rate and the water/methanol ratio. Importantly, the proposed micro temperature sensor adequately controls the interior temperature during oxidative steam reforming of methanol (OSRM, with the relevant parameters optimized as well.

  15. Application of Flexible Micro Temperature Sensor in Oxidative Steam Reforming by a Methanol Micro Reformer

    Science.gov (United States)

    Lee, Chi-Yuan; Lee, Shuo-Jen; Shen, Chia-Chieh; Yeh, Chuin-Tih; Chang, Chi-Chung; Lo, Yi-Man

    2011-01-01

    Advances in fuel cell applications reflect the ability of reformers to produce hydrogen. This work presents a flexible micro temperature sensor that is fabricated based on micro-electro-mechanical systems (MEMS) technology and integrated into a flat micro methanol reformer to observe the conditions inside that reformer. The micro temperature sensor has higher accuracy and sensitivity than a conventionally adopted thermocouple. Despite various micro temperature sensor applications, integrated micro reformers are still relatively new. This work proposes a novel method for integrating micro methanol reformers and micro temperature sensors, subsequently increasing the methanol conversion rate and the hydrogen production rate by varying the fuel supply rate and the water/methanol ratio. Importantly, the proposed micro temperature sensor adequately controls the interior temperature during oxidative steam reforming of methanol (OSRM), with the relevant parameters optimized as well. PMID:22319407

  16. Application of flexible micro temperature sensor in oxidative steam reforming by a methanol micro reformer.

    Science.gov (United States)

    Lee, Chi-Yuan; Lee, Shuo-Jen; Shen, Chia-Chieh; Yeh, Chuin-Tih; Chang, Chi-Chung; Lo, Yi-Man

    2011-01-01

    Advances in fuel cell applications reflect the ability of reformers to produce hydrogen. This work presents a flexible micro temperature sensor that is fabricated based on micro-electro-mechanical systems (MEMS) technology and integrated into a flat micro methanol reformer to observe the conditions inside that reformer. The micro temperature sensor has higher accuracy and sensitivity than a conventionally adopted thermocouple. Despite various micro temperature sensor applications, integrated micro reformers are still relatively new. This work proposes a novel method for integrating micro methanol reformers and micro temperature sensors, subsequently increasing the methanol conversion rate and the hydrogen production rate by varying the fuel supply rate and the water/methanol ratio. Importantly, the proposed micro temperature sensor adequately controls the interior temperature during oxidative steam reforming of methanol (OSRM), with the relevant parameters optimized as well.

  17. Hydrogen-rich gas production by steam gasification of char from biomass fast pyrolysis in a fixed-bed reactor: influence of temperature and steam on hydrogen yield and syngas composition.

    Science.gov (United States)

    Yan, Feng; Luo, Si-yi; Hu, Zhi-quan; Xiao, Bo; Cheng, Gong

    2010-07-01

    Steam gasification experiments of biomass char were carried out in a fixed-bed reactor. The experiments were completed at bed temperature of 600-850 degrees C, a steam flow rate of 0-0.357 g/min/g of biomass char, and a reaction time of 15min. The aim of this study is to determine the effects of bed temperature and steam flow rate on syngas yield and its compositions. The results showed that both high gasification temperature and introduction of proper steam led to higher yield of dry gas and higher carbon conversion efficiency. However, excessive steam reduced gas yield and carbon conversion efficiency. The maximum dry gas yield was obtained at the gasification temperature of 850 degrees C and steam flow rate of 0.165 g/min/g biomass char. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  18. Durability of solid oxide electrolysis cells for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-05-15

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

  19. Lifetime evaluation of superheater tubes exposed to steam oxidation, high temperature corrosion and creep

    Energy Technology Data Exchange (ETDEWEB)

    Henriksen, N. [Elsamprojekt A/S, Faelleskemikerne, Fredericia (Denmark); Hede Larsen, O.; Blum, R. [I/S Fynsvaerket, Faelleskemikerne, Odense (Denmark)

    1996-12-01

    Advanced fossil fired plants operating at high steam temperatures require careful design of the superheaters. The German TRD design code normally used in Denmark is not precise enough for the design of superheaters with long lifetimes. The authors have developed a computer program to be used in the evaluation of superheater tube lifetime based on input related to tube dimensions, material, pressure, steam temperature, mass flux, heat flux and estimated corrosion rates. The program is described in the paper. As far as practically feasible, the model seems to give a true picture of the reality. For superheaters exposed to high heat fluxes or low internal heat transfer coefficients as is the case for superheaters located in fluidized bed environments or radiant environments, the program has been extremely useful for evaluation of surface temperature, oxide formation and lifetime. The total uncertainty of the method is mainly influenced by the uncertainty of the determination of the corrosion rate. More precise models describing the corrosion rate as a function of tube surface temperature, fuel parameters and boiler parameters need to be developed. (au) 21 refs.

  20. Corrosion and Creep of Candidate Alloys in High Temperature Helium and Steam Environments for the NGNP

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary; Jones, J. W.

    2013-06-21

    This project aims to understand the processes by which candidate materials degrade in He and supercritical water/steam environments characteristic of the current NGNP design. We will focus on understanding the roles of temperature, and carbon and oxygen potential in the 750-850 degree C range on both uniform oxidation and selective internal oxidation along grain boundaries in alloys 617 and 800H in supercritical water in the temperature range 500-600 degree C; and examining the application of static and cyclic stresses in combination with impure He environments in the temperature rang 750-850 degree C; and examining the application of static and cyclic stresses in combination with impure He environments in the temperature range 750-850 degree C over a range of oxygen and carbon potentials in helium. Combined, these studies wil elucidate the potential high damage rate processes in environments and alloys relevant to the NGNP.

  1. Corrosion of cermet anodes during low temperature electrolysis of alumina. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kozarek, R.L.; Ray, S.P.; Dawless, R.K.; LaCamera, A.F.

    1997-09-26

    Successful development of inert anodes to replace carbon anodes in Hall cells has the potential benefits of lower energy consumption,lower operating costs, and reduced CO{sub 2} and CO emissions. Using inert anodes at reduced current density and reduced operating temperature (800 C) has potential for decreasing the corrosion rate of inert anodes. It may also permit the use of new materials for containment and insulation. This report describes the fabrication characteristics and the corrosion performance of 5324-17% Cu Cermet anodes in 100 hour tests. Although some good results were achieved, the corrosion rate at low temperature (800 C) is varied and not significantly lower than typical results at high temperature ({approximately} 960 C). This report also describes several attempts at 200 hour tests, with one anode achieving 177 hours of continuous operation and another achieving a total of 235 hours but requiring three separate tests of the same anode. The longest run did show a lower wear rate in the last test; but a high resistance layer developed on the anode surface and forced an unacceptably low current density. It is recommended that intermediate temperatures be explored as a more optimal environment for inert anodes. Other electrolyte chemistries and anode compositions (especially high conductivity anodes) should be considered to alleviate problems associated with lower temperature operation.

  2. Experimental and Numerical Study of Low Temperature Methane Steam Reforming for Hydrogen Production

    Directory of Open Access Journals (Sweden)

    Martin Khzouz

    2017-12-01

    Full Text Available Low temperature methane steam reforming for hydrogen production, using experimental developed Ni/Al2O3 catalysts is studied both experimentally and numerically. The catalytic activity measurements were performed at a temperature range of 500–700 °C with steam to carbon ratio (S/C of 2 and 3 under atmospheric pressure conditions. A mathematical analysis to evaluate the reaction feasibility at all different conditions that have been applied by using chemical equilibrium with applications (CEA software and in addition, a mathematical model focused on the kinetics and the thermodynamics of the reforming reaction is introduced and applied using a commercial finite element analysis software (COMSOL Multiphysics 5.0. The experimental results were employed to validate the extracted simulation data based on the yields of the produced H2, CO2 and CO at different temperatures. A maximum hydrogen yield of 2.7 mol/mol-CH4 is achieved at 700 °C and S/C of 2 and 3. The stability of the 10%Ni/Al2O3 catalyst shows that the catalyst is prone to deactivation as supported by Thermogravimetric Analysis TGA results.

  3. High temperature oxidation of alumina forming cast austenitic stainless steels within an environment of pure steam

    Science.gov (United States)

    Prenzlow, Elmer A.

    Steam cracking of hydrocarbons in the petrochemical industry is a multibillion dollar industry. The processes performed in these plants create byproducts that negatively affect the integrity of stainless steel piping through high temperature corrosion. Alloys used presently in industry rely on the formation of chromium oxide (chromia) as a protective layer between the bulk metal pipe and chemical byproducts. However, chromia can become susceptible to attack from aggressive species such as carbon, water vapor, and sulfur compounds, thus creating a need for a better protection method. A new series of austenitic stainless steels have been developed in recent years that, rather than forming chromia, create a protective layer of aluminum oxide (alumina) under oxidative conditions. These alloys have high nickel content for the stabilization of the austenitic phase, and a more thermodynamically stable oxide layer relative to the traditional chromia formers. Consequently, alumina forming alloys have been proposed as replacements for chromia forming alloys in the petrochemical industry. General oxidation testing has been performed on alumina forming alloys under dry and 10% water vapor conditions. However, oxidation conditions in industry resemble a 100% steam environment. Therefore, test methods to mimic such conditions are needed so that alloys can be tested and developed further for these applications. Four alloys with aluminum contents ranging from 2.6 to 3.9 wt% were cut from centrifugally cast pipes and subjected to oxidation in an environment of pure steam for up to 30 hours, at temperatures of 800 °C and 950 °C. Samples were analyzed using Raman, SEM, and EDS and showed a continuous alumina layer free of cracks. The alumina layer thickness increased with time. Additionally, larger thicknesses were observed in samples oxidized at 950 °C from those of 800 °C. Thickness measurements were used to calculate parabolic and non-parabolic oxidation rate constants

  4. High Temperature Monitoring the Height of Condensed Water in Steam Pipes

    Science.gov (United States)

    Bar-Cohen, Yoseph; Lih, Shyh-Shiuh; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Widholm, Scott; Ostlund, Patrick; Blosiu, Julian

    2011-01-01

    An in-service health monitoring system is needed for steam pipes to track through their wall the condensation of water. The system is required to measure the height of the condensed water inside the pipe while operating at temperatures that are as high as 250 deg. C. The system needs to be able to make real time measurements while accounting for the effects of cavitation and wavy water surface. For this purpose, ultrasonic wave in pulse-echo configuration was used and reflected signals were acquired and auto-correlated to remove noise from the data and determine the water height. Transmitting and receiving the waves is done by piezoelectric transducers having Curie temperature that is significantly higher than 250 deg. C. Measurements were made at temperatures as high as 250 deg. C and have shown the feasibility of the test method. This manuscript reports the results of this feasibility study.

  5. High Temperatures Health Monitoring of the Condensed Water Height in Steam Pipe Systems

    Science.gov (United States)

    Lih, Shyh-Shiuh; Bar-Cohen, Yoseph; Lee, Hyeong Jae; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Takano, Nobuyuki; Ostlund, Patrick; Blosiu, Julian

    2013-01-01

    Ultrasonic probes were designed, fabricated and tested for high temperature health monitoring system. The goal of this work was to develop the health monitoring system that can determine the height level of the condensed water through the pipe wall at high temperature up to 250 deg while accounting for the effects of surface perturbation. Among different ultrasonic probe designs, 2.25 MHz probes with air backed configuration provide satisfactory results in terms of sensitivity, receiving reflections from the target through the pipe wall. A series of tests were performed using the air-backed probes under irregular conditions, such as surface perturbation and surface disturbance at elevated temperature, to qualify the developed ultrasonic system. The results demonstrate that the fabricated air-backed probes combined with advanced signal processing techniques offer the capability of health monitoring of steam pipe under various operating conditions.

  6. Coupling of high temperature nuclear reactor with chemical plant by means of steam loop with heat pump

    Directory of Open Access Journals (Sweden)

    Kopeć Mariusz

    2017-01-01

    Full Text Available High temperature nuclear reactors (HTR can be used as an excellent, emission-free source of technological heat for various industrial applications. Their outlet helium temperature (700°-900°C allows not only for heat supply to all processes below 600°C (referred to as “steam class”, but also enables development of clean nuclear-assisted hydrogen production or coal liquefaction technologies with required temperatures up to 900°C (referred to as “chemical class”. This paper presents the results of analyses done for various configurations of the steam transport loop coupled with the high-temperature heat pump designed for “chemical class” applications. The advantages and disadvantages as well as the key issues are discussed in comparison with alternative solutions, trying to answer the question whether the system with the steam loop and the hightemperature heat pump is viable and economically justified.

  7. Multitechnique characterisation of 304L surface states oxidised at high temperature in steam and air atmospheres

    Science.gov (United States)

    Mamede, Anne-Sophie; Nuns, Nicolas; Cristol, Anne-Lise; Cantrel, Laurent; Souvi, Sidi; Cristol, Sylvain; Paul, Jean-François

    2016-04-01

    In case of a severe accident occurring in a nuclear reactor, surfaces of the reactor coolant system (RCS), made of stainless steel (304L) rich in Cr (>10%) and Ni (8-12%), are oxidised. Fission products (FPs) are released from melt fuel and flow through the RCS. A part of them is deposited onto surfaces either by vapour condensation or by aerosol deposition mechanisms. To be able to understand the nature of interactions between these FPs and the RCS surfaces, a preliminary step is to characterize the RSC surface states in steam and air atmosphere at high temperatures. Pieces of 304L stainless steel have been treated in a flow reactor at two different temperatures (750 °C and 950 °C) for two different exposition times (24 h and 72 h). After surfaces analysing by a unique combination of surface analysis techniques (XPS, ToF-SIMS and LEIS), for 304L, the results show a deep oxide scale with multi layers and the outer layer is composed of chromium and manganese oxides. Oxide profiles differ in air or steam atmosphere. Fe2O3 oxide is observed but in minor proportion and in all cases no nickel is detected near the surface. Results obtained are discussed and compared with the literature data.

  8. Recycling of automobile shredder residue with a microwave pyrolysis combined with high temperature steam gasification.

    Science.gov (United States)

    Donaj, Pawel; Yang, Weihong; Błasiak, Włodzimierz; Forsgren, Christer

    2010-10-15

    Presently, there is a growing need for handling automobile shredder residues--ASR or "car fluff". One of the most promising methods of treatment ASR is pyrolysis. Apart of obvious benefits of pyrolysis: energy and metals recovery, there is serious concern about the residues generated from that process needing to be recycled. Unfortunately, not much work has been reported providing a solution for treatment the wastes after pyrolysis. This work proposes a new system based on a two-staged process. The ASR was primarily treated by microwave pyrolysis and later the liquid and solid products become the feedstock for the high temperature gasification process. The system development is supported within experimental results conducted in a lab-scale, batch-type reactor at the Royal Institute of Technology (KTH). The heating rate, mass loss, gas composition, LHV and gas yield of producer gas vs. residence time are reported for the steam temperature of 1173 K. The sample input was 10 g and the steam flow rate was 0.65 kg/h. The conversion reached 99% for liquids and 45-55% for solids, dependently from the fraction. The H(2):CO mol/mol ratio varied from 1.72 solids and 1.4 for liquid, respectively. The average LHV of generated gas was 15.8 MJ/Nm(3) for liquids and 15 MJ/Nm(3) for solids fuels. 2010 Elsevier B.V. All rights reserved.

  9. High-temperature hydrogen-air-steam detonation experiments in the BNL small-scale development apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Ciccarelli, G.; Ginsburg, T.; Boccio, J.; Economos, C.; Finfrock, C.; Gerlach, L. [Brookhaven National Lab., Upton, NY (United States); Sato, K.; Kinoshita, M. [Nuclear Power Engineering Corp., Tokyo (Japan)

    1994-08-01

    The Small-Scale Development Apparatus (SSDA) was constructed to provide a preliminary set of experimental data to characterize the effect of temperature on the ability of hydrogen-air-steam mixtures to undergo detonations and, equally important, to support design of the larger scale High-Temperature Combustion Facility (HTCF) by providing a test bed for solution of a number of high-temperature design and operational problems. The SSDA, the central element of which is a 10-cm inside diameter, 6.1-m long tubular test vessel designed to permit detonation experiments at temperatures up to 700K, was employed to study self-sustained detonations in gaseous mixtures of hydrogen, air, and steam at temperatures between 300K and 650K at a fixed initial pressure of 0.1 MPa. Hydrogen-air mixtures with hydrogen composition from 9 to 60 percent by volume and steam fractions up to 35 percent by volume were studied for stoichiometric hydrogen-air-steam mixtures. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air gas mixture temperature, in the range 300K-650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm inside diameter SSDA test vessel, based upon the onset of single-head spin, decreased from 15 percent hydrogen at 300K down to between 9 and 10 percent hydrogen at 650K. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments.

  10. High Temperature Steam Oxidation Testing of Candidate Accident Tolerant Fuel Cladding Materials

    Energy Technology Data Exchange (ETDEWEB)

    Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nelson, Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parker, Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parkison, Adam [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2013-12-23

    The Fuel Cycle Research and Development (FCRD) program’s Advanced Fuels Campaign has initiated a multifold effort aimed at facilitating development of accident tolerant fuels in order to overcome the inherent shortcomings of light water reactor (LWR) fuels when exposed to beyond design basis accident conditions. The campaign has invested in development of experimental infrastructure within the Department of Energy complex capable of chronicling the performance of a wide range of concepts under prototypic accident conditions. This report summarizes progress made at Oak Ridge National Laboratory (ORNL) and Los Alamos National Laboratory (LANL) in FY13 toward these goals. Alternative fuel cladding materials to Zircaloy for accident tolerance and a significantly extended safety margin requires oxidation resistance to steam or steam-H2 environments at ≥1200°C for short times. At ORNL, prior work focused attention on SiC, FeCr and FeCrAl as the most promising candidates for further development. Also, it was observed that elevated pressure and H2 additions had minor effects on alloy steam oxidation resistance, thus, 1 bar steam was adequate for screening potential candidates. Commercial Fe-20Cr-5Al alloys remain protective up to 1475°C in steam and CVD SiC up to 1700°C in steam. Alloy development has focused on Fe-Cr-Mn-Si-Y and Fe-Cr-Al-Y alloys with the aluminaforming alloys showing more promise. At 1200°C, ferritic binary Fe-Cr alloys required ≥25% Cr to be protective for this application. With minor alloy additions to Fe-Cr, more than 20%Cr was still required, which makes the alloy susceptible to α’ embrittlement. Based on current results, a Fe-15Cr-5Al-Y composition was selected for initial tube fabrication and welding for irradiation experiments in FY14. Evaluations of chemical vapor deposited (CVD) SiC were conducted up to 1700°C in steam. The reaction of H2O with the alumina reaction tube at 1700°C resulted in Al(OH)3

  11. Non-syngas direct steam reforming of methanol to hydrogen and carbon dioxide at low temperature.

    Science.gov (United States)

    Yu, Kai Man Kerry; Tong, Weiyi; West, Adam; Cheung, Kevin; Li, Tong; Smith, George; Guo, Yanglong; Tsang, Shik Chi Edman

    2012-01-01

    A non-syngas direct steam reforming route is investigated for the conversion of methanol to hydrogen and carbon dioxide over a CuZnGaO(x) catalyst at 150-200 °C. This route is in marked contrast with the conventional complex route involving steam reformation to syngas (CO/H2) at high temperature, followed by water gas shift and CO cleanup stages for hydrogen production. Here we report that high quality hydrogen and carbon dioxide can be produced in a single-step reaction over the catalyst, with no detectable CO (below detection limit of 1 ppm). This can be used to supply proton exchange membrane fuel cells for mobile applications without invoking any CO shift and cleanup stages. The working catalyst contains, on average, 3-4 nm copper particles, alongside extremely small size of copper clusters stabilized on a defective ZnGa2O4 spinel oxide surface, providing hydrogen productivity of 393.6 ml g(-1)-cat h(-1) at 150 °C.

  12. Water electrolysis

    Science.gov (United States)

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

    1992-01-01

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

  13. Solid oxide electrolysis cells - Performance and durability

    Energy Technology Data Exchange (ETDEWEB)

    Hauch, A.

    2007-10-15

    In this work H2 electrode supported solid oxide cells (SOC) produced at Risoe National Laboratory, DTU, have been used for steam electrolysis. Electrolysis tests have been performed at temperatures from 650AeC to 950AeC, p(H2O)/p(H2) from 0.99/0.01 to 0.30/0.70 and current densities from -0.25 A/cm2 to -2 A/cm2. The solid oxide electrolysis cells (SOEC) have been characterised by iV curves and electrochemical impedance spectroscopy (EIS) at start and end of tests and by EIS under current load during electrolysis testing. The tested SOCs have shown the best initial electrolysis performance reported in literature to date. Area specific resistances of 0.26 Oecm2 at 850AeC and 0.17 Oecm2 at 950AeC were obtained from electrolysis iV curves. The general trend for the SOEC tests was: 1) a short-term passivation in first few hundred hours, 2) then an activation and 3) a subsequent and underlying long-term degradation. The transient phenomenon (passivation/activation) was shown to be a set-up dependent artefact caused by the albite glass sealing with a p(Si(OH)4) of 1.10-7 atm, leading to silica contamination of the triple-phase boundaries (TPBs) of the electrode. The long-term degradation for the SOECs was more pronounced than for fuel cell testing of similar cells. Long-term degradation of 2%/1000 h was obtained at 850AeC, p(H2O)/p(H2) = 0.5/0.5 and -0.5 A/cm2, whereas the degradation rate increased to 6%/1000h at 950AeC, p(H2O)/p(H2) = 0.9/0.1 and -1.0 A/cm2. Both the short-term passivation and the long-term degradation appear mainly to be related to processes in the H2 electrode. Scanning electron microscopy micrographs show that only limited changes occur in the Ni particle size distribution and these are not the main degradation mechanism for the SOECs. Micro and nano analysis using energy dispersive spectroscopy in combination with transmission electron microscopy (TEM) and scanning TEM reveals that glassy phase impurities have accumulated at the TPBs as a result of

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-05-29

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

  15. Cascade control of superheated steam temperature with neuro-PID controller.

    Science.gov (United States)

    Zhang, Jianhua; Zhang, Fenfang; Ren, Mifeng; Hou, Guolian; Fang, Fang

    2012-11-01

    In this paper, an improved cascade control methodology for superheated processes is developed, in which the primary PID controller is implemented by neural networks trained by minimizing error entropy criterion. The entropy of the tracking error can be estimated recursively by utilizing receding horizon window technique. The measurable disturbances in superheated processes are input to the neuro-PID controller besides the sequences of tracking error in outer loop control system, hence, feedback control is combined with feedforward control in the proposed neuro-PID controller. The convergent condition of the neural networks is analyzed. The implementation procedures of the proposed cascade control approach are summarized. Compared with the neuro-PID controller using minimizing squared error criterion, the proposed neuro-PID controller using minimizing error entropy criterion may decrease fluctuations of the superheated steam temperature. A simulation example shows the advantages of the proposed method. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

  16. Fuzzy modeling and predictive control of superheater steam temperature for power plant.

    Science.gov (United States)

    Wu, Xiao; Shen, Jiong; Li, Yiguo; Lee, Kwang Y

    2015-05-01

    This paper develops a stable fuzzy model predictive controller (SFMPC) to solve the superheater steam temperature (SST) control problem in a power plant. First, a data-driven Takagi-Sugeno (TS) fuzzy model is developed to approximate the behavior of the SST control system using the subspace identification (SID) method. Then, an SFMPC for output regulation is designed based on the TS-fuzzy model to regulate the SST while guaranteeing the input-to-state stability under the input constraints. The effect of modeling mismatches and unknown plant behavior variations are overcome by the use of a disturbance term and steady-state target calculator (SSTC). Simulation results for a 600 MW power plant show that an offset-free tracking of SST can be achieved over a wide range of load variation. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Abstract of report on increasing the oil yield in low temperature carbonization by the addition of catalyst and superheated steam

    Energy Technology Data Exchange (ETDEWEB)

    1943-04-29

    In a letter dated February 2, 1943, Hydro-works Poelitz stated that in practical operation, as well as in the laboratory, an increased oil yield in low-temperature carbonization had been obtained by the simultaneous addition of superheated steam and sulfur. Other experiments with the same objective were later performed at Gelsenberg, Scholven, and Ludwigshafen. The laboratory experimental results and operating experimental results were discussed in this report. Poelitz found that it could increase its yield from 71.5% to 79.3% by the addition of 1.2% sulfur and an increase in the steam from 150 kg/hr to 320 kg/hr when carbonizing centrifuge residue from coal and, at the time, increased the throughput in the ball kiln from 3.5 to 3.8 tons/hr. Some properties of the heavy oils were given. The use of these results in mass production depended on two factors. The first was the extent to which the quantity of steam could be increased without too great an increase in the dust content of the precooler oil. The second factor was the economy of increased steam consumption and the cost of catalysts. Most of the beneficial effect of the additions seemed to be due to the steam, but the catalyst added some effect to that of the steam; without the use of steam, catalyst alone seemed to have essentially no effect. Replacement of part of the sulfur in the catalyst by small amounts of sodium sulfide and soda seemed to give the same effect as the sulfur alone, and the alkaline addition seemed to have the additional benefit of preventing the kiln residue from becoming plastic.

  18. Analysis of Possible Application of High-Temperature Nuclear Reactors to Contemporary Large-Output Steam Power Plants on Ships

    Directory of Open Access Journals (Sweden)

    Kowalczyk T.

    2016-04-01

    Full Text Available This paper is aimed at analysis of possible application of helium to cooling high-temperature nuclear reactor to be used for generating steam in contemporary ship steam-turbine power plants of a large output with taking into account in particular variable operational parameters. In the first part of the paper types of contemporary ship power plants are presented. Features of today applied PWR reactors and proposed HTR reactors are discussed. Next, issues of load variability of the ship nuclear power plants, features of the proposed thermal cycles and results of their thermodynamic calculations in variable operational conditions, are presented.

  19. The effect of saturated steam vapor temperature on heat consumption in the process of color modification of acacia wood

    Science.gov (United States)

    Dzurenda, Ladislav

    2017-09-01

    This paper presents the heat consumption on the process of colour modification of acacia timber with measures 30 x 55 x 500 mm in pressure autoclaves AZ 240 using saturated water steam with temperatures from t = 110 to 140 °C following the regimes of colour homogenisation of I., II. and III. degree. The dependance of the heat consumption normative QTFS on the temparature of saturated water steam in the process of colour homogenisation of acacia timber following these regimes describes the equation: QTFS = 1.1122.t -13.903 kWh.m-3.

  20. Analyzing the temperature control of steam purging of 660mw ultra-supercritical once-through boiler with pressure-reducing method

    Science.gov (United States)

    Wu, Ying; Zhong, Yong-lu; Liu, Fa-sheng; Chen, Wen; Gui, Liang-ming; Xia, Yong-jun; Wan, Zhong-hai; Yan, Tao

    2017-11-01

    This paper generally introduced the process of steam purging of the ultra-supercritical once-through boiler of Jiangxi Xinchang 2×660MW Power Plant with the pressure-reducing method. In this paper, the key-points of steam temperature control was importantly analyzed and summarized. The success experience can provide the reference for preventing steam overtemp of the similar ultra-supercritical once-through boilers with pressure-reducing method.

  1. Co-Fe-Si Aerogel Catalytic Honeycombs for Low Temperature Ethanol Steam Reforming

    Directory of Open Access Journals (Sweden)

    Montserrat Domínguez

    2012-09-01

    Full Text Available Cobalt talc doped with iron (Fe/Co~0.1 and dispersed in SiO2 aerogel was prepared from silica alcogel impregnated with metal nitrates by supercritical drying. Catalytic honeycombs were prepared following the same procedure, with the alcogel synthesized directly over cordierite honeycomb pieces. The composite aerogel catalyst was characterized by X-ray diffraction, scanning electron microscopy, focus ion beam, specific surface area and X-ray photoelectron spectroscopy. The catalytic layer is about 8 µm thick and adheres well to the cordierite support. It is constituted of talc layers of about 1.5 µm × 300 nm × 50 nm which are well dispersed and anchored in a SiO2 aerogel matrix with excellent mass-transfer properties. The catalyst was tested in the ethanol steam reforming reaction, aimed at producing hydrogen for on-board, on-demand applications at moderate temperature (573–673 K and pressure (1–7 bar. Compared to non-promoted cobalt talc, the catalyst doped with iron produces less methane as byproduct, which can only be reformed at high temperature, thereby resulting in higher hydrogen yields. At 673 K and 2 bar, 1.04 NLH2·mLEtOH(l−1·min−1 are obtained at S/C = 3 and W/F = 390 g·min·molEtOH−1.

  2. Instrumental system for the quick relief of surface temperatures in fumaroles fields and steam heated soils

    Science.gov (United States)

    Diliberto, Iole; Cappuzzo, Santo; Inguaggiato, Salvatore; Cosenza, Paolo

    2014-05-01

    We present an instrumental system to measure and to map the space variation of the surface temperature in volcanic fields. The system is called Pirogips, its essential components are a Pyrometer and a Global Position System but also other devices useful to obtain a good performance of the operating system have been included. In the framework of investigation to define and interpret volcanic scenarios, the long-term monitoring of gas geochemistry can improve the resolution of the scientific approaches by other specific disciplines. Indeed the fluid phase is released on a continuous mode from any natural system which produces energy in excess respect to its geological boundaries. This is the case of seismic or magmatic active areas where the long-term geochemical monitoring is able to highlight, and to follow in real time, changes in the rate of energy release and/or in the feeding sources of fluids, thus contributing to define the actual behaviour of the investigated systems (e.g. Paonita el al., 2013; 2002; Taran, 2011; Zettwood and Tazieff, 1973). The demand of pirogips starts from the personal experience in long term monitoring of gas geochemistry (e.g. Diliberto I.S, 2013; 2011; et al., 2002; Inguaggiato et al.,2012a, 2012b). Both space and time variation of surface temperature highlight change of energy and mass release from the deep active system, they reveal the upraise of deep and hot fluid and can be easily detected. Moreover a detailed map of surface temperature can be very useful for establishing a network of sampling points or installing a new site for geochemical monitoring. Water is commonly the main component of magmatic or hydrothermal fluid release and it can reach the ground surface in the form of steam, as in the high and low temperature fumaroles fields, or it can even condense just below the ground surface. In this second case the water disperses in pores or circulates in the permeable layers while the un-condensable gases reach the surface (e

  3. Flexural Fatigue Behavior of an EBC CMC Composite System In Air and Steam at High Temperature

    Science.gov (United States)

    Jaskowiak, Martha; Bur, Michael; Harder, Bryan; Gorican, Daniel

    2017-01-01

    Both coated and uncoated SiCSiC ceramic matrix composite (CMC) samples were tested in flexure under sustained peak low cycle fatigue (SPLCF) conditions in air or steam at elevated temperatures. The SiCSiC composites were reinforced with 2-D plies of boron nitride coated Hi-Nicalon Type-S SiC fibers which were woven as 5 harness satin (5HS) cloth. The composites were densified by chemical vapor infiltration (CVI) followed by slurry melt infiltration (SMI). A multilayer barium strontium aluminosilicate (BSAS) coating was applied to the samples by a plasma spray method. Fatigue loading limits were determined from monotonic flexure tests at room temperature and 1200oC. Stress levels under the proportional limit of the composite material were selected for the SPLCF tests. After cyclic testing, the composites were evaluated to determine crack propagation and failure modes in the coated and uncoated composites. Microstructural examination was used to identify coating degradation and failure modes of the EBCCMC system.

  4. Aluminium Alloy AA6060 surface treatment with high temperature steam containing chemical additives

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Tabrizian, Naja; Jellesen, Morten S.

    2015-01-01

    The steam treatment process was employed to produce a conversion coating on aluminium alloy AA6060. The changes in microstructure and its effect on corrosion resistance properties were investigated. Various concentrations of KMnO4 containing Ce(NO3)3 was injected into the steam and its effect...

  5. Solid Oxide Electrolysis Cells: Microstructure and Degradation of the Ni/Yttria-Stabilized Zirconia Electrode

    DEFF Research Database (Denmark)

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

    2008-01-01

    Solid oxide fuel cells produced at Risø DTU have been tested as solid oxide electrolysis cells for steam electrolysis by applying an external voltage. Varying the sealing on the hydrogen electrode side of the setup verifies that the previously reported passivation over the first few hundred hours...

  6. Fracture-mechanics investigations at materials for steam power plants with live steam temperatures from 500 to 650 C; Bruchmechanische Untersuchungen an Werkstoffen fuer Dampfkraftwerke mit Frischdampftemperaturen von 500 bis 650 C

    Energy Technology Data Exchange (ETDEWEB)

    Mikulova, L.

    2005-07-01

    The higher steam temperatures and pressures in advanced supercritical steam turbines require the use of steels with improved creep rupture strength. The tempered martensitic steel P92 is a creep resistant material used for the production of components for live steam with operating temperature 550-630 C. For the application of these steels is essentially necessary to know the impact of different test atmospheres and temperatures on the crack growth rate. In the present work, the influence of atmosphere (air, vacuum, simulated live steam), proof-temperature, hold time, thermal exposure on the crack growth has been studied at temperatures between 500 and 600 C. The influence of proof-temperature and atmosphere has been reflected on micrographs of fracture surface. SEM-micrographs of the principal crack and also optical micrographs coming from the cross sections perpendicular to the plane of a crack propagation (secondary cracks) show changes in the character of a crack propagation dependent of the loading cycle and temperature. By fatigue crack growth tests has been enhancement of crack growth due to the aggressive atmosphere (air) noted. The fatigue crack growth rates in air are at least one order of magnitude faster than those in vacuum (inert atmosphere). The effects of air, vacuum, simulated live steam on creep crack growth of P92 was also studied. A hold time leads to a higher crack growth rate compared with pure creep crack growth tests. The results from crack growth tests demonstrated, that steam oxidation plays a important role among the three factor, creep crack growth, fatigue crack growth and oxidation, in crack growth of these steel in superheated steam. In this work was also effect of side-grooves on the local stress and crack growth rate experimentally examined. (orig.)

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

    Science.gov (United States)

    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.

  8. Durable Cu composite catalyst for hydrogen production by high temperature methanol steam reforming

    Science.gov (United States)

    Matsumura, Yasuyuki

    2014-12-01

    Durable catalysts are necessitated for the high temperature methanol steam reforming in compact hydrogen processors. The high durability at 400 °C can be obtained with a composite Cu catalyst where a small amount of Cu-ZnO-ZrO2-Y2O3-In2O3 is coprecipitated on a zirconia support. The lifetime of the composite catalyst containing 3 wt.% Cu is estimated to be as long as 53 × 102 h at 400 °C to produce the full conversion at a contact time of 250 g h m-3. The deactivation rate empirically relates to the cube of the activity. The gradual deactivation is caused by the gradual reduction of the Cu surface amount and also by the reduction of the surface activity which is believed to decrease with an increase in the Cu particle size. The interaction between the thin layer of the coprecipitate and the support surface probably suppresses the aggregation of the coprecipitate leading to Cu sintering.

  9. Hydrogen from biomass gas steam reforming for low temperature fuel cell: energy and exergy analysis

    Directory of Open Access Journals (Sweden)

    A. Sordi

    2009-03-01

    Full Text Available This work presents a method to analyze hydrogen production by biomass gasification, as well as electric power generation in small scale fuel cells. The proposed methodology is the thermodynamic modeling of a reaction system for the conversion of methane and carbon monoxide (steam reforming, as well as the energy balance of gaseous flow purification in PSA (Pressure Swing Adsorption is used with eight types of gasification gases in this study. The electric power is generated by electrochemical hydrogen conversion in fuel cell type PEMFC (Proton Exchange Membrane Fuel Cell. Energy and exergy analyses are applied to evaluate the performance of the system model. The simulation demonstrates that hydrogen production varies with the operation temperature of the reforming reactor and with the composition of the gas mixture. The maximum H2 mole fraction (0.6-0.64 mol.mol-1 and exergetic efficiency of 91- 92.5% for the reforming reactor are achieved when gas mixtures of higher quality such as: GGAS2, GGAS4 and GGAS5 are used. The use of those gas mixtures for electric power generation results in lower irreversibility and higher exergetic efficiency of 30-30.5%.

  10. Two-stage steam gasification of waste biomass in fluidized bed at low temperature: parametric investigations and performance optimization.

    Science.gov (United States)

    Xiao, Xianbin; Meng, Xianliang; Le, Duc Dung; Takarada, Takayuki

    2011-01-01

    Steam gasification of waste biomass has been studied in a two-stage fluidized bed reactor, which has the primary pyrolysis fluidized bed using silica sand as bed material and the secondary reforming fixed bed with catalyst. The main objectives are parametric investigation and performance improvement especially at low temperature of around 600 °C using the wood chip and the pig manure compost as feedstock. Main operating variables studied are pyrolysis temperature, catalytic temperature, steam/biomass-C ratio, space velocity and different catalyst. Reaction temperatures and steam/C ratio have important role on the gasification process. About 60 vol.% H2 (dry and N2 free) and about 2.0 Nm3/kg biomass (dry and ash free basis) can be obtained under good conditions. Compared to Ni/Al2O3, Ni/BCC (Ni-loaded brown coal char) has a better ability and a hopeful prospect for the stability with coking resistance. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Steam generators secondary side chemical cleaning at Point Lepreau using the Siemens high temperature process

    Energy Technology Data Exchange (ETDEWEB)

    Verma, K.; MacNeil, C. [New Brunswick Power Corp., Lepreau (Canada); Odar, S.; Kuhnke, K. [Siemens AG, Erlangen (Germany)

    1997-02-01

    This paper describes the chemical cleaning of the four steam generators at the Point Lepreau facility, which was accomplished as a part of a normal service outage. The steam generators had been in service for twelve years. Sludge samples showed the main elements were Fe, P and Na, with minor amounts of Ca, Mg, Mn, Cr, Zn, Cl, Cu, Ni, Ti, Si, and Pb, 90% in the form of Magnetite, substantial phosphate, and trace amounts of silicates. The steam generators were experiencing partial blockage of broached holes in the TSPs, and corrosion on tube ODs in the form of pitting and wastage. In addition heat transfer was clearly deteriorating. More than 1000 kg of magnetite and 124 kg of salts were removed from the four steam generators.

  12. Creep of Hi-Nicalon S Ceramic Fiber Tows at Elevated Temperature in Air and in Steam

    Science.gov (United States)

    2012-03-22

    primarily driven by the need of the gas turbine generator industry for materials capable of withstanding higher temperatures than the nickel based...applications, including aircraft jet engines, gas turbines for electrical power/steam cogeneration, as well as nuclear power plant components. It is...9. WAIT 1 HOUR FOR EPOXY TO CURE Wait an hour to detach specimens from the fixture board. Use a razor blade to cut the excess fiber tow against the

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Operating results of 700MW coal fired supercritical once-through steam generator for Hekinan power station No.3 boiler, Chubu Electric Power Co. Inc. with elevated reheat steam temperature of 596{degree}C

    Energy Technology Data Exchange (ETDEWEB)

    Ando, S.; Ozawa, M.; Yamamoto, T.; Kuwahara, M. [Ishikawajima-Harima Heavy Indutries Co. Ltd., Tokyo (Japan)

    1995-01-01

    The demonstration test results of the 700 MW coal fired supercritical once-through steam generator for Hekinan Power Station, Chubu Electric Power Co., Inc. were reported which generator is featured by highest reheat steam temperature of 596{degree}C among commercial boilers. On static characteristics, both gross and net thermal efficiencies were higher than the design values in a load range of 30-100%, and higher by nearly 1% than those under conventional steam conditions. The metal temperature distribution of each portion was desirable, and the reheater could be well regulated below 610{degree}C lower than the design value (619{degree}C) without arrival on the alarm setting (650{degree}C). The load change of 5%/min in a high load zone and 3%/min in a low one was allowable for each coal type keeping stable steam temperature. Unburned carbon contents in fly ash was less than 2%, while NOx emission was less than 150 ppm at a boiler outlet. In addition, the unit start characteristics equivalent to those of oil fired boilers were obtained proving the possible boiler technology at 596{degree}C in reheater steam temperature. 7 figs.

  15. (Fe, Cr)3O4 Spinel Layer as the Key to Solving the Accelerated Oxidation of High Cr Iron Alloy in High-temperature Steam

    National Research Council Canada - National Science Library

    Murata, Yoshinori; Minai, Hideyuki; Nagai, Kensuke; Shiraki, Atsuhiro; Morinaga, Masahiko

    2008-01-01

    ...)3O4 spinel layer formed on the alloy surface. This result is related closely to the fact that oxidation of high Cr ferritic steels is accelerated remarkably by the existence of steam at elevated temperatures...

  16. Avoiding chromium transport from stainless steel interconnects into contact layers and oxygen electrodes in intermediate temperature solid oxide electrolysis stacks

    Science.gov (United States)

    Schlupp, Meike V. F.; Kim, Ji Woo; Brevet, Aude; Rado, Cyril; Couturier, Karine; Vogt, Ulrich F.; Lefebvre-Joud, Florence; Züttel, Andreas

    2014-12-01

    We investigated the ability of (La0.8Sr0.2)(Mn0.5Co0.5)O3-δ (LSMC) and La(Ni0.6Fe0.4)O3-δ (LNF) contact coatings to avoid the transport of Cr from steel interconnects to solid oxide electrolysis electrodes, especially to the anode. The transport of chromium from commercial Crofer 22 APU (ThyssenKrupp) and K41X (AISI441, Aperam Isbergues) steels through LSMC and LNF contact coatings into adjacent (La0.8Sr0.2)MnO3-δ (LSM) oxygen electrodes was investigated in an oxygen atmosphere at 700 °C. Chromium concentrations of up to 4 atom% were detected in the contact coatings after thermal treatments for 3000 h, which also lead to the presence of chromium in adjacent LSM electrodes. Introduction of a dense (Co,Mn)3O4 coating between steel and contact coating was necessary to prevent the diffusion of chromium into contact coatings and electrodes and should lead to extended stack performance and lifetime.

  17. Impacts of vegetation and temperature on the treatment of domestic sewage in constructed wetlands incorporated with Ferric-Carbon micro-electrolysis material.

    Science.gov (United States)

    Zhou, Qingwei; Zhu, Hui; Bañuelos, Gary; Yan, Baixing; Liang, Yinxiu; Yu, Jing; Li, Huai

    2017-10-03

    Ferric-Carbon Micro-Electrolysis (Fe/C-M/E) material had been widely used for the pretreatment of wastewater. Therefore, we hypothesized that Fe/C-M/E material could enhance the treatment of domestic sewage when it was integrated into constructed wetlands (CWs). In this study, CWs integrated with Fe/C-M/E material were developed. Druing the experiment of effect of vegetation on the performance of CWs, percentages of NH4+-N, NO3--N, total nitrogen (TN), and Chemical Oxygen Demand (COD) removed in polyculture (W1) were up to 91.8%, 97.0%, 92.3%, and 85.4%, respectively, which were much higher than those in Lythrum salicaria monoculture (W2) and Canna indica monoculture (W3). In the experiment of temperature influences on the removal efficiency of CWs, temperature substantially influenced the performance of CWs. For example, NO3--N removal percentages of W1, W2, and W3 at high temperature (25.5°C and 19.8°C) were relatively stable and greater than 85.4%. At 8.9°C, however, a sharp decline of NO3--N removal percentage was observed in all CWs. Temperature also influenced the Chemical Oxygen Demand (COD) removal and soil microbial activity and biomass. Overall, the polyculture (Lythrum salicaria +Canna indica) showed the best performance during most of the operating time, at an average temperature ≥ 19.8°C, due to the functional complementarity between vegetation. All the CWs consistently achieved high removal efficiency (above 96%) for TP in all experiments, irrespective of vegetation types, phosphorous loadings, and temperatures. In conclusion, polyculture was an attractive solution for the treatment of domestic sewage during most of the operating time (average temperature ≥ 19.8°C). Furthermore, CWs with Fe/C-M/E material were ideally suitable for domestic sewage treatment, especially for TP removal.

  18. An attempt to minimize the temperature gradient along a plug-flow methane/steam reforming reactor by adopting locally controlled heating zones

    Science.gov (United States)

    Mozdzierz, M.; Brus, G.; Sciazko, A.; Komatsu, Y.; Kimijima, S.; Szmyd, J. S.

    2014-08-01

    Plug flow reactors are very common in the chemical process industry, including methane/steam reforming applications. Their operation presents many challenges, such as a strong dependence of temperature and composition distribution on the inlet conditions. The strongly endothermic methane/steam reforming reaction might result in a temperature drop at the inlet of the reactor and consequently the occurrence of large temperature gradients. The strongly non-uniform temperature distribution due to endothermic chemical reaction can have tremendous consequences on the operation of the reactor, such as catalyst degradation, undesired side reactions and thermal stresses. To avoid such unfavorable conditions, thermal management of the reactor becomes an important issue. To carry out thermal management properly, detailed modeling and corresponding numerical analyses of the phenomena occurring inside the reforming system is required. This paper presents experimental and numerical studies on the methane/steam reforming process inside a plug-flow reactor. To optimize the reforming reactors, detailed data about the entire reforming process is required. In this study the kinetics of methane/steam reforming on the Ni/YSZ catalyst was experimentally investigated. Measurements including different thermal boundary conditions, the fuel flow rate and the steam- to-methane ratios were performed. The reforming rate equation derived from experimental data was used in the numerical model to predict gas composition and temperature distribution along the steam-reforming reactor. Finally, an attempt was made to control the temperature distribution by adopting locally controlled heating zones.

  19. Performance and durability of solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Hauch, Anne; Jensen, Søren H; Ramousse, Severine

    2006-01-01

    Solid oxide fuel cells produced at Riso National Laboratory have been tested as electrolysis cells by applying an external voltage. Results on initial performance and durability of such reversible solid oxide cells at temperatures from 750 to 950 degrees C and current densities from -0.25 A/cm(2......) to -0.50 A/cm(2) are reported. The full cells have an initial area specific resistance as low as 0.27 Omega cm(2) for electrolysis operation at 850 degrees C. During galvanostatic long-term electrolysis tests, the cells were observed to passivate mainly during the first similar to 100 h of electrolysis....... Cells that have been passivated during electrolysis tests can be partly activated again by operation in fuel cell mode or even at constant electrolysis conditions after several hundred hours of testing....

  20. Magma Electrolysis: An update

    Science.gov (United States)

    Colson, Russell O.; Haskin, Larry A.

    1991-01-01

    Electrolytic extraction of O2 from molten lunar soil is conceptually simple and thus a candidate process for producing O2 on the Moon. Possible container and electrode materials are being tested for durability in corrosive high-temperature silicate melts and looking for complications that might increase energy requirements. Gaseous oxygen is being produced by electrolysis of 1-2 gram quantities of silicate melts in spinel (MgAl2O4) crucibles; in these melts, spinel is a stable phase. The concentration of FeO was kept low because FeO decrease O2 production efficiency. Platinum electrodes were placed about 0.5 cm apart in the melt. The spinel crucible was still intact after 40 minutes of electrolysis, when the experiment was halted for examination. The Pt anode was also intact; its Pt was maintained in a dynamci state in which the anode was continuously oxidized but quickly reduced again by the silicate melt, inhibiting migration of Pt away from the anode. In melts with low concentrations of Al2O3 + SiO2 (2 wt percent), the energy of resistance heating was only approximately equal to 10 to 20 percent of the theoretical amount required to produce O2. In melts substantially more concentrated in Al2O3 + SiO2, higher melt viscosity resulted in frothing that, in the worst case, caused high enough melt resistivities to raise the energy requirements to nearly 10 times theoretical. Both Fe and Si are produced at the cathode; in iron-rich melts, a- and c-iron and molten ferrosilicon were observed. Production was also observed at the cathode of a previously unrecognized gas; which is not yet identified. The solubility of metallic species was measured in silicate melts. They are too low to reduce significantly the efficiency of O2 production.

  1. Anodes for alkaline electrolysis

    Science.gov (United States)

    Soloveichik, Grigorii Lev [Latham, NY

    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.

  2. Electrolysis of coal slurries

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, K.E.; Tran, T.; Swinkels, D.

    1984-01-01

    The major aims of the project were: to verify early reports of the American workers and demonstrate the feasibility of the concept of electrolysis of coal slurries; investigate reaction mechanisms and the stoichiometry; measure the reducing power and oxidation kinetics of selected Australian coals; investigate some process variables, and demonstrate an electrolysis cell with practical electrode geometry.

  3. Improving carbon tolerance of Ni-YSZ catalytic porous membrane by palladium addition for low temperature steam methane reforming

    Science.gov (United States)

    Lee, Sang Moon; Won, Jong Min; Kim, Geo Jong; Lee, Seung Hyun; Kim, Sung Su; Hong, Sung Chang

    2017-10-01

    Palladium was added on the Ni-YSZ catalytic porous membrane by wet impregnation and electroless plating methods. Its surface morphology characteristics and carbon deposition properties for the low temperature steam methane reforming were investigated. The addition of palladium could obviously be enhanced the catalytic activity as well as carbon tolerance of the Ni-YSZ porous membrane. The porous membranes were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR), CH4 temperature-programmed reduction (CH4-TPR), and O2 temperature-programmed oxidation (O2-TPO). It was found that the Pd-Ni-YSZ catalytic porous membrane showed the superior stability as well as the deposition of carbon on the surface during carbon dissociation adsorption at 650 °C was also suppressed.

  4. High temperature corrosion in straw-fired power plants: Influence of steam/metal temperature on corrosion rates for TP347H

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Biede, O; Larsen, OH

    2002-01-01

    The corrosion in straw-fired boilers has been investigated at various straw-fired power plants in Denmark. Water/air-cooled probes, a test superheater and test sections removed from the actual superheater have been utilised to characterise corrosion and corrosion rates. This paper describes...... the corrosion rates measured for the TP347H type steel. The corrosion morphology at high temperature consists of grain boundary attack and selective attack of chromium. The corrosion rate increases with calculated metal temperature (based on steam temperature), however there is great variation within...... these results. In individual superheaters, there are significant temperature variations i.e. higher temperature in middle banks compared to the outer banks, higher temperature in leading tubes, which have a high impact on corrosion. In a single loop the assumption that heat uptake (and heat flux) is linear...

  5. Creep of polycrystalline yttrium aluminum garnet (YAG) at elevated temperature in air and in steam

    Energy Technology Data Exchange (ETDEWEB)

    Armani, C.J. [Air Force Institute of Technology, Wright-Patterson Air Force Base, OH 45433-7765 (United States); Ruggles-Wrenn, M.B., E-mail: marina.ruggles-wrenn@afit.edu [Air Force Institute of Technology, Wright-Patterson Air Force Base, OH 45433-7765 (United States); Hay, R.S.; Fair, G.E. [Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433-7817 (United States); Keller, K.A. [UES Inc., Dayton, OH 45432 (United States)

    2014-01-01

    Compressive creep of high-purity polycrystalline yttrium aluminum garnet (YAG, Y{sub 3}Al{sub 5}O{sub 12}) was investigated at 1300 °C and 50–200 MPa in air and in steam. Compressive creep behavior of silica-doped polycrystalline YAG (Y{sub 3}Al{sub 5}O{sub 12}–0.14 wt% SiO{sub 2}) was also studied. Creep specimens were microstructurally characterized by optical microscopy and TEM before and after creep. Steam slightly increased creep rates of material with grain size less than 1 μm (the undoped YAG), but otherwise had little effect. The flow stress exponent was n≈1 for both SiO{sub 2}-doped YAG and undoped YAG. Creep rates and microstructural observations are consistent with the Nabarro-Herring creep mechanism, with creep rate limited by lattice diffusion of yttrium cations (Y{sup 3+}). Silica-doped YAG had a larger grain size of 2.41 μm and lower creep rates than undoped YAG with 0.92 μm grain size. However, creep rates normalized by grain size for Nabarro-Herring creep were higher in SiO{sub 2}-doped YAG. Possible effects of SiO{sub 2} doping and steam on creep of YAG are discussed.

  6. Lunar production of oxygen by electrolysis

    Science.gov (United States)

    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. In situ Growth of NixCu1-x Alloy Nanocatalysts on Redox-reversible Rutile (Nb,Ti)O4 Towards High-Temperature Carbon Dioxide Electrolysis

    Science.gov (United States)

    Wei, Haoshan; Xie, Kui; Zhang, Jun; Zhang, Yong; Wang, Yan; Qin, Yongqiang; Cui, Jiewu; Yan, Jian; Wu, Yucheng

    2014-01-01

    In this paper, we report the in situ growth of NixCu1-x (x = 0, 0.25, 0.50, 0.75 and 1.0) alloy catalysts to anchor and decorate a redox-reversible Nb1.33Ti0.67O4 ceramic substrate with the aim of tailoring the electrocatalytic activity of the composite materials through direct exsolution of metal particles from the crystal lattice of a ceramic oxide in a reducing atmosphere at high temperatures. Combined analysis using XRD, SEM, EDS, TGA, TEM and XPS confirmed the completely reversible exsolution/dissolution of the NixCu1-x alloy particles during the redox cycling treatments. TEM results revealed that the alloy particles were exsolved to anchor onto the surface of highly electronically conducting Nb1.33Ti0.67O4 in the form of heterojunctions. The electrical properties of the nanosized NixCu1-x/Nb1.33Ti0.67O4 were systematically investigated and correlated to the electrochemical performance of the composite electrodes. A strong dependence of the improved electrode activity on the alloy compositions was observed in reducing atmospheres at high temperatures. Direct electrolysis of CO2 at the NixCu1-x/Nb1.33Ti0.67O4 composite cathodes was investigated in solid-oxide electrolysers. The CO2 splitting rates were observed to be positively correlated with the Ni composition; however, the Ni0.75Cu0.25 combined the advantages of metallic nickel and copper and therefore maximised the current efficiencies. PMID:24889679

  8. Development of Refractory Ceramics for The Oxygen Evolution Reaction (OER) Electrocatalyst Support for Water Electrolysis at elevated temperatures

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Prag, Carsten Brorson; Polonsky, J.

    2012-01-01

    Commercial TaC and Si3N4 powders were tested as possible electrocatalyst support materials for the Oxygen Evolution Reaction (OER) for PEM water electrolysers, operating at elevated temperatures. TaC and Si3N4 were characterised by thermogravimmetric and differential thermal analysis for their th......Commercial TaC and Si3N4 powders were tested as possible electrocatalyst support materials for the Oxygen Evolution Reaction (OER) for PEM water electrolysers, operating at elevated temperatures. TaC and Si3N4 were characterised by thermogravimmetric and differential thermal analysis...

  9. Design of steam turbine for 593[degree]C reheat temperature. Sainetsu joki ondo 593[degree]C turbine no keikaku

    Energy Technology Data Exchange (ETDEWEB)

    Matsukuma, M.; Fujikawa, T.; Takayanagi, K. (Mitsubishi Heavy Industries, Ltd., Tokyo (Japan))

    1993-02-15

    Following the successful completion of the first stage operation with main/reheat steam temperature of 593/593 centigrade for the Wakamatsu high temperature 50MW turbine of Electric Power Development Co., the large high temperature steam turbines for the hot reheat temperature of 593 centigrade are currently being realized for the first time in Japan. Namely, the Hekinan No.3 unit of Chubu Electric Power Company is being constructed, which has 246kg/cm[sup 2], 538/593 centigrade 700MW turbine, and the design of the Nanao-Ohta No.1 unit of Hokuriku Electric Power Company is in progress, which has 246kg/cm[sup 2], 566/593 centigrade 500MW turbine. The present paper describes the results of demonstration tests of the Wakamatsu high temperature turbine conducted for three years and three months from 1986 to 1990, and introduces outline of development, features in the design, and problems to be considered of these high temperature steam turbines designed for the 593 centigrade hot reheat steam temperature. 15 figs., 2 tabs.

  10. Simplify heat recovery steam generator evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. (ABCO Industries, Abilene, TX (US))

    1990-03-01

    Heat recovery steam generators (HRSGs) are widely used in process and power plants, refineries and in several cogeneration/combined cycle systems. They are usually designed for a set of gas and steam conditions but often operate under different parameters due to plant constraints, steam demand, different ambient conditions (which affect the gas flow and exhaust gas temperature in a gas turbine plant), etc. As a result, the gas and steam temperature profiles in the HRSG, steam production and the steam temperature differ from the design conditions, affecting the entire plant performance and economics. Also, consultants and process engineers who are involved in evaluating the performance of the steam system as a whole, often would like to simulate the performance of an HRSG under different gas flows, inlet gas temperature and analysis, steam pressure and feed water temperature to optimize the entire steam system and select proper auxiliaries such as steam turbines, condensers, deaerators, etc.

  11. Anti-corrosive Conversion Coating on Aluminium Alloys Using High Temperature Steam

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    and heterogeneity of native oxide layer does not provide long time corrosion resistance and adhesion of organic coating for a particular function in different environments. In order to enhance the corrosion resistance and adhesion of organic coating, the aluminium native oxide layer is treated to transform...... or convert to a functional conversion coating. In the last several decades chromate conversion coating (CrCCs) have been the most common conversion coatings used for aluminium alloys. Due to the toxicity of the hexavalent chrome, however, environmental friendly alternatives to CrCCs have been investigated...... extensively. Despite the intense research no equivalent substitute for (CrCCs) has been found. For these reasons, alternative conversion coatings are sought for substituting existing ones. Aluminium alloys AA 1090, Peraluman 706, and AA 6060 were subjected to high pressure steam treatment and various...

  12. Apparatus for and Method of Monitoring Condensed Water in Steam Pipes at High Temperature

    Science.gov (United States)

    Lih, Shyh-Shiuh (Inventor); Lee, Hyeong Jae (Inventor); Bar-Cohen, Yoseph (Inventor); Bao, Xiaoqi (Inventor)

    2016-01-01

    A system and method for monitoring the properties of a fluid, such as water, in a steam pipe without mechanically penetrating the wall of the pipe. The system uses a piezoelectric transducer to launch an ultrasonic probe signal into the pipe. Reflected ultrasonic signals are captured in a transducer, which can be the same transducer that launched the probe signal. The reflected signals are subjected to data processing, which can include filtering, amplification, analog-to-digital conversion and autocorrelation analysis. A result is extracted which is indicative of a property of the fluid, such as a height of the condensed fluid, a cavitation of the condensed fluid, and a surface perturbation of the condensed fluid. The result can be recorded, displayed, and/or transmitted to another location. One embodiment of the system has been constructed and tested based on a general purpose programmable computer using instructions recorded in machine-readable non-volatile memory.

  13. In-Service Monitoring of Steam Pipe Systems at High Temperatures

    Science.gov (United States)

    Bar-Cohen, Yoseph (Inventor); Lih, Shyh-Shiuh (Inventor); Badescu, Mircea (Inventor); Bao, Xiaoqi (Inventor); Sherrit, Stewart (Inventor); Scott, James Samson (Inventor); Blosiu, Julian O. (Inventor); Widholm, Scott E. (Inventor)

    2014-01-01

    A system and method for monitoring the properties of a fluid, such as water, in a steam pipe without mechanically penetrating the wall of the pipe. The system uses a piezoelectric transducer to launch an ultrasonic probe signal into the pipe. Reflected ultrasonic signals are captured in a transducer, which can be the same transducer that launched the probe signal. The reflected signals are subjected to data processing, which can include filtering, amplification, analog-to-digital conversion and autocorrelation analysis. A result is extracted which is indicative of a property of the fluid, such as a height of the condensed fluid, a cavitation of the condensed fluid, and a surface perturbation of the condensed fluid. The result can be recorded, displayed, and/or transmitted to another location. One embodiment of the system has been constructed and tested based on a general purpose programmable computer using instructions recorded in machine-readable non-volatile memory.

  14. High-temperature oxidation of advanced FeCrNi alloy in steam environments

    Science.gov (United States)

    Elbakhshwan, Mohamed S.; Gill, Simerjeet K.; Rumaiz, Abdul K.; Bai, Jianming; Ghose, Sanjit; Rebak, Raul B.; Ecker, Lynne E.

    2017-12-01

    Alloys of iron-chromium-nickel are being explored as alternative cladding materials to improve safety margins under severe accident conditions. Our research focuses on non-destructively investigating the oxidation behavior of the FeCrNi alloy ;Alloy 33; using synchrotron-based methods. The evolution and structure of oxide layer formed in steam environments were characterized using X-ray diffraction, hard X-ray photoelectron spectroscopy, X-ray fluorescence methods and scanning electron microscopy. Our results demonstrate that a compact and continuous oxide scale was formed consisting of two layers, chromium oxide and spinel phase (FeCr2O4) oxides, wherein the concentration of the FeCr2O4 phase decreased from the surface to the bulk-oxide interface.

  15. J-resistance curves for Inconel 690 and Incoloy 800 nuclear steam generators tubes at room temperature and at 300 °C

    Science.gov (United States)

    Bergant, Marcos A.; Yawny, Alejandro A.; Perez Ipiña, Juan E.

    2017-04-01

    The structural integrity of steam generator tubes is a relevant issue concerning nuclear plant safety. In the present work, J-resistance curves of Inconel 690 and Incoloy 800 nuclear steam generator tubes with circumferential and longitudinal through wall cracks were obtained at room temperature and 300 °C using recently developed non-standard specimens' geometries. It was found that Incoloy 800 tubes exhibited higher J-resistance curves than Inconel 690 for both crack orientations. For both materials, circumferential cracks resulted into higher fracture resistance than longitudinal cracks, indicating a certain degree of texture anisotropy introduced by the tube fabrication process. From a practical point of view, temperature effects have found to be negligible in all cases. The results obtained in the present work provide a general framework for further application to structural integrity assessments of cracked tubes in a variety of nuclear steam generator designs.

  16. A comparative study of ethylene oxide gas, hydrogen peroxide gas plasma, and low-temperature steam formaldehyde sterilization.

    Science.gov (United States)

    Kanemitsu, Keiji; Imasaka, Takayuki; Ishikawa, Shiho; Kunishima, Hiroyuki; Harigae, Hideo; Ueno, Kumi; Takemura, Hiromu; Hirayama, Yoshihiro; Kaku, Mitsuo

    2005-05-01

    To compare the efficacies of ethylene oxide gas (EOG), hydrogen peroxide gas plasma (PLASMA), and low-temperature steam formaldehyde (LTSF) sterilization methods. The efficacies of EOG, PLASMA, and LTSF sterilization were tested using metal and plastic plates, common medical instruments, and three process challenge devices with narrow lumens. All items were contaminated with Bacillus stearothermophilus spores or used a standard biological indicator. EOG and LTSF demonstrated effective killing of B. stearothermophilus spores, with or without serum, on plates, on instruments, and in process challenge devices. PLASMA failed to adequately sterilize materials on multiple trials in several experiments, including two of three plates, two of three instruments, and all process challenge devices. Our results suggest that PLASMA sterilization may be unsuccessful under certain conditions, particularly when used for items with complex shapes and narrow lumens. Alternatively, LTSF sterilization demonstrates excellent efficacy and is comparable to EOG sterilization. LTSF could potentially act as a substitute if EOG becomes unavailable due to environmental concerns.

  17. A study on the paste boronizing treatment of 12%Cr steel for steam turbine nozzle and high temperature surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J. H.; Son, G. S.; Yoon, J. H. [Changwon Univ., Changwon (Korea, Republic of); Kim, H. S. [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of); Lee, S. H.; Byon, E. S. [Korea Institute of Machine and Metals, Changwon (Korea, Republic of); Lee, E. Y. [Andong Univ., Andong (Korea, Republic of); Kim, I. S. [Doosan Heavy Co., Ltd., Changwon (Korea, Republic of)

    2003-02-01

    12% Cr steel used for a nozzle in steam turbine was paste-boronized and its surface properties at high temperature were evaluated. Typical tooth structure, which consisted of outer layer of FeB and inner layer of Fe{sub 2}B, was observed at the boronized layer of the specimen and its activation energy was 286.7kJ/mole. Cracks due to the difference of thermal expansion coefficient and brittleness of FeB layer were observed. Voids were also observed at tip area of tooth structure. Weight of the specimen exposed at 740 .deg. C increased rapidly from the initial stage of oxidation. Iron oxide was mixed in chromium oxide at outer layer of the oxidized specimen, but chromium oxide and molybdenum were mixed in iron oxide at inner layer. Boronized specimen has shown excellent erosion resistance up to 20 times higher than that of non-treated specimen.

  18. Study of oxide and α-Zr(O) growth kinetics from high temperature steam oxidation of Zircaloy-4 cladding

    Energy Technology Data Exchange (ETDEWEB)

    Sawarn, Tapan K., E-mail: sawarn@barc.gov.in; Banerjee, Suparna, E-mail: sup@barc.gov.in; Samanta, Akanksha, E-mail: akanksha@barc.gov.in; Rath, B.N., E-mail: bibhur@barc.gov.in; Kumar, Sunil, E-mail: sunilkmr@barc.gov.in

    2015-12-15

    Oxidation kinetics of Zircaloy-4 cladding of fuel pins of Indian pressurized heavy water reactors (IPHWRs) under a simulated loss of coolant accident (LOCA) condition was investigated. The kinetic rate constants for the oxide and oxygen stabilized α-Zr phase growth were established from the isothermal metal-steam reaction at high temperatures (900–1200 °C) with soaking periods in the range of 60–900 s. Oxide and α-Zr(O) layer thickness were measured to derive the respective growth rates. The observed rates obeyed a parabolic law and Arrhenius expressions of rate constants were established. Percentage equivalent clad reacted (%ECR) was calculated using Baker-Just equation. Hydrogen estimation was carried out on the oxidized samples using inert gas fusion technique. The hydrogen pick up was found to be in the range 10–30 ppm. The measured values of oxide and α-Zr(O) layer thickness were compared with the results obtained using OXYCON, an indigenously developed model. The model predicts the oxide growth reasonably well but under predicts the α-Zr(O) growth significantly at thickness values higher than 80 μm. - Highlights: • Steam oxidation kinetics of IPHWR fuel cladding material, Zircaloy-4 in the temperature range 900–1200 °C has been studied. • The growth kinetics of the oxide and α-Zr(O) were established from the microstructural analysis. • An indigenously developed model, OXYCON has been validated against the experimental data. • The hydrogen pick up in the cladding during oxidation was observed to be in the range 10–30 ppm.

  19. Optimization of High Temperature and Pressurized Steam Modified Wood Fibers for High-Density Polyethylene Matrix Composites Using the Orthogonal Design Method

    Directory of Open Access Journals (Sweden)

    Xun Gao

    2016-10-01

    Full Text Available The orthogonal design method was used to determine the optimum conditions for modifying poplar fibers through a high temperature and pressurized steam treatment for the subsequent preparation of wood fiber/high-density polyethylene (HDPE composites. The extreme difference, variance, and significance analyses were performed to reveal the effect of the modification parameters on the mechanical properties of the prepared composites, and they yielded consistent results. The main findings indicated that the modification temperature most strongly affected the mechanical properties of the prepared composites, followed by the steam pressure. A temperature of 170 °C, a steam pressure of 0.8 MPa, and a processing time of 20 min were determined as the optimum parameters for fiber modification. Compared to the composites prepared from untreated fibers, the tensile, flexural, and impact strength of the composites prepared from modified fibers increased by 20.17%, 18.5%, and 19.3%, respectively. The effect on the properties of the composites was also investigated by scanning electron microscopy and dynamic mechanical analysis. When the temperature, steam pressure, and processing time reached the highest values, the composites exhibited the best mechanical properties, which were also well in agreement with the results of the extreme difference, variance, and significance analyses. Moreover, the crystallinity and thermal stability of the fibers and the storage modulus of the prepared composites improved; however, the hollocellulose content and the pH of the wood fibers decreased.

  20. High-temperature steam oxidation testing of select advanced replacement alloys for potential core internals

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-05-19

    Coupons from a total of fourteen commercial and custom fabricated alloys were exposed to 1 bar full steam with ~10 ppb oxygen content at 600 and 650°C. The coupons were weighed at 500-h intervals with a total exposure time of 5,000 h. The fourteen alloys are candidate alloys selected under the ARRM program, which include three ferritic steels (Grade 92, 439, and 14YWT), three austenitic stainless steels (316L, 310, and 800), seven Ni-base superalloys (X750, 725, C22, 690, 625, 625 direct-aging, and 625- plus), and one Zr-alloy (Zr–2.5Nb). Among the alloys, 316L and X750 are served as reference alloys for low- and high-strength alloys, respectively. The candidate Ni-base superalloy 718 was procured too late to be included in the tests. The corrosion rates of the candidate alloys can be approximately interpreted by their Cr, Ni and Fe content. The corrosion rate was significantly reduced with increasing Cr content and when Ni content is above ~15 wt%, but not much further reduced when Fe content is less than ~55 wt%. Simplified thermodynamics analyses of the alloy oxidation provided reasonable indications for the constituents of oxide scales formed on the alloys and explanations for the porosity and exfoliation phenomena because of the nature of specific types of oxides.

  1. Heat and fuel coupled operation of a high temperature polymer electrolyte fuel cell with a heat exchanger methanol steam reformer

    Science.gov (United States)

    Schuller, G.; Vázquez, F. Vidal; Waiblinger, W.; Auvinen, S.; Ribeirinha, P.

    2017-04-01

    In this work a methanol steam reforming (MSR) reactor has been operated thermally coupled to a high temperature polymer electrolyte fuel cell stack (HT-PEMFC) utilizing its waste heat. The operating temperature of the coupled system was 180 °C which is significantly lower than the conventional operating temperature of the MSR process which is around 250 °C. A newly designed heat exchanger reformer has been developed by VTT (Technical Research Center of Finland LTD) and was equipped with commercially available CuO/ZnO/Al2O3 (BASF RP-60) catalyst. The liquid cooled, 165 cm2, 12-cell stack used for the measurements was supplied by Serenergy A/S. The off-heat from the electrochemical fuel cell reaction was transferred to the reforming reactor using triethylene glycol (TEG) as heat transfer fluid. The system was operated up to 0.4 A cm-2 generating an electrical power output of 427 Wel. A total stack waste heat utilization of 86.4% was achieved. It has been shown that it is possible to transfer sufficient heat from the fuel cell stack to the liquid circuit in order to provide the needed amount for vaporizing and reforming of the methanol-water-mixture. Furthermore a set of recommendations is given for future system design considerations.

  2. Geometric Characteristics of Methane Steam Reforming with Low Temperature Heat Source

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Gahui; Yun, Jinwon; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

    2016-12-15

    In a hybrid fuel cell system, low-temperature reforming technology, which uses waste heat as a heat source, is applied to improve system efficiency. A low temperature reformer is required to optimize geometry in low thermal conditions so that the reformer can achieve the proper methane conversion rate. This study analyzed internal temperature distributions and the reaction patterns of a reformer by considering the change of the shape factor on the limited heat supply condition. Unlike the case of a high temperature reformer, analysis showed that the reaction of a low temperature reformer takes place primarily in the high temperature region of the reactor exit. In addition, it was confirmed that the efficiency can be improved by reducing the GHSV (gas hourly space velocity) or increasing the heat transfer area in the radial direction. Through reacting characteristic analysis, according to change of the aspect ratio, it was confirmed that a low temperature reformer can improve the efficiency by increasing the heat transfer in the radial direction, rather than in the longitudinal direction.

  3. Deactivation Studies of Rh/Ce0.8Zr0.2O2 Catalysts in Low Temperature Ethanol Steam Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Platon, Alex; Roh, Hyun-Seog; King, David L.; Wang, Yong

    2007-10-30

    Rapid deactivation of Rh/Ce0.8Zr0.2O2 catalysts in low temperature ethanol steam reforming was studied. A significant build-up of carbonaceous intermediate, instead of carbon deposit, was observed at a lower reaction temperature which was attributed to the rapid catalyst deactivation. Co-feed experiments indicated that acetone and ethylene caused more severe catalyst deactivation than other oxygenates such as acidic acid and acetaldehyde.

  4. Understand steam generator performance

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. (ABCO Industries, Abilene, TX (United States))

    1994-12-01

    Several variables affect the design and performance of packaged steam generators. Engineers should understand these parameters and their effects so that they can select cost-effective design options and write good specifications. Knowing how the steam parameters and efficiency vary with load can also help plant engineers plan their operation better. This article discusses the effects of such variables as excess air, fuel type, exit gas temperature, load, and emissions on generator design and operation. It also discusses some of the potential benefits of customized steam generators over standard, prepackaged designs, which often compromise on overall performance. The focus of the article is limited to gaseous and oil fuels.

  5. High performance steam development

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, T.; Schneider, P. [Solar Turbines Inc., San Diego, CA (United States)

    1995-10-01

    Over 30 years ago U.S. industry introduced the world`s highest temperature (1200{degrees}F at 5000 psig) and most efficient power plant, the Eddystone coal-burning steam plant. The highest alloy material used in the plant was 316 stainless steel. Problems during the first few years of operation caused a reduction in operating temperature to 1100{degrees}F which has generally become the highest temperature used in plants around the world. Leadership in high temperature steam has moved to Japan and Europe over the last 30 years.

  6. Procedure of calculation of the spatial distribution of temperatures and heat fluxes in the steam generator of a nuclear power installation with an RBEC fast-neutron reactor

    Science.gov (United States)

    Frolov, A. A.; Sedov, A. A.

    2016-08-01

    A method for combined 3D/1D-modeling of thermohydraulics of a once-through steam generator (SG) based on the joint analysis of three-dimensional thermo- and hydrodynamics of a single-phase heating coolant in the intertube space and one-dimensional thermohydraulics of steam-generating channels (tubes) with the use of well-known friction and heat-transfer correlations under various boiling conditions is discussed. This method allows one to determine the spatial distribution of temperatures and heat fluxes of heat-exchange surfaces of SGs with a single-phase heating coolant in the intertube space and with steam generation within tubes. The method was applied in the analytical investigation of typical operation of a once-through SG of a nuclear power installation with an RBEC fast-neutron heavy-metal reactor that is being designed by Kurchatov Institute in collaboration with OKB GIDROPRESS and Leipunsky Institute of Physics and Power Engineering. Flow pattern and temperature fields were obtained for the heavy-metal heating coolant in the intertube space. Nonuniformities of heating of the steam-water coolant in different heat-exchange tubes and nonuniformities in the distribution of heat fluxes at SG heat-exchange surfaces were revealed.

  7. Higher Efficiency and Temperature Reliability of Steam Generators at Thermal Power Stations

    Directory of Open Access Journals (Sweden)

    R. F. Kelbaliev

    2010-01-01

    Full Text Available Methods for higher power unit efficiency and decrease of specific fuel consumption for electric-power generation have been considered in the paper. The paper reveals that a heat exchange intensification makes a positive effect on efficiency and temperature reliability of power engineering equipment while using coil and artificially turbulized (contoured pipes. Results of experimental investigations on metal temperature at various mode parameters are proposed in the paper. The paper contains equations for determination of conditions initiating heat-transfer drop.

  8. Steam reforming of light oxygenates

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Resasco, Daniel E; Jensen, Anker Degn

    2013-01-01

    Steam reforming (SR) of ethanol, acetic acid, acetone, acetol, 1-propanol, and propanal has been investigated over Ni/MgAl2O4 at temperatures between 400 and 700 degrees C and at a steam-to-carbon-ratio (S/C) of 6. The yield of H-2 and conversion increased with temperature, while the yield of by...

  9. Creep of Hi-Nicalon S Fiber Tows at Elevated Temperature in Air and in Steam

    Science.gov (United States)

    2013-03-01

    the 1920’s. In the 1930’s and 1940’s, honeycomb structures, powder metallurgy , and glass reinforced plastic were the advanced structural materials...materials to bear the service loads and conditions are not available. Whatever the field may be, the final limitation on advancement depends on... Steel . “consequence of INtermittent Exposure to Moisture and Salt Fog on the High-Temperature Fatigue Durability of Several Ceramic-Matrix Composites

  10. Effects of temperature and pressure on the performance of a solid oxide fuel cell running on steam reformate of kerosene

    Energy Technology Data Exchange (ETDEWEB)

    Chick, Lawrence A.; Marina, Olga A.; Coyle, Christopher A.; Thomsen, Edwin C.

    2013-08-15

    A button solid oxide fuel cell with a La0.6Sr0.4Co0.2Fe0.8O3 cathode and a nickel-YSZ anode was tested over a range of temperatures from 650 to 800°C and a range of pressures from 101 to 724 kPa. The fuel was simulated steam-reformed kerosene and the oxidant was air. The observed increases in open circuit voltages (OCV) were accurately predicted by the Nernst equation. Kinetics also increased, although the power boost due to kinetics was about two thirds as large as the boost due to OCV. The total power boost in going from 101 to 724 kPa at 750°C and 0.8 volts was 66%. Impedance spectroscopy demonstrated a significant decrease in electrodic losses at elevated pressures. Complex impedance spectra were dominated by a combination of low frequency processes that decreased markedly with increasing pressure. A composite of high-frequency processes also decreased with pressure, but to a lesser extent. An empirical algorithm that accurately predicts the increased fuel cell performance at elevated pressures was developed for our results and was also suitable for some, but not all, data reported in the literature.

  11. Apparatus and methods of reheating gas turbine cooling steam and high pressure steam turbine exhaust in a combined cycle power generating system

    Science.gov (United States)

    Tomlinson, Leroy Omar; Smith, Raub Warfield

    2002-01-01

    In a combined cycle system having a multi-pressure heat recovery steam generator, a gas turbine and steam turbine, steam for cooling gas turbine components is supplied from the intermediate pressure section of the heat recovery steam generator supplemented by a portion of the steam exhausting from the HP section of the steam turbine, steam from the gas turbine cooling cycle and the exhaust from the HP section of the steam turbine are combined for flow through a reheat section of the HRSG. The reheated steam is supplied to the IP section inlet of the steam turbine. Thus, where gas turbine cooling steam temperature is lower than optimum, a net improvement in performance is achieved by flowing the cooling steam exhausting from the gas turbine and the exhaust steam from the high pressure section of the steam turbine in series through the reheater of the HRSG for applying steam at optimum temperature to the IP section of the steam turbine.

  12. K-Based Geopolymer from metakaolin: roles of K/Al ratio and water or steam Curing at different temperatures

    Directory of Open Access Journals (Sweden)

    Tawfik, A.

    2016-06-01

    Full Text Available K-based geopolymer binder was prepared by reacting metakaolin with alkaline solutions having different potassium contents and by water curing at room temperature and 80 °C as well as steam curing at 150 and 180 °C. The phase formation, microstructure and Al and Si nearest neighbor environments were studied using XRD, TEM and 27Al and 29Si MAS NMR spectroscopy, respectively. The results revealed that amorphous alumino-silicates were predominant in geopolymer prepared by curing up to 28 days at room temperature or at 80 °C. The amorphous alumino-silicates persisted after hydrothermal treatment at 150 °C/48 hrs and even at 180 °C/30 hrs. However, the samples cured hydrothermally at 180 °C/48 hrs revealed formation of crystalline potassium aluminum silicate and chabazite phases. The Al nearest neighbor environments was not significantly affected by increasing the K/Al ratio up to 1.55 or by the curing temperatures. On the other hand, the geopolymer reaction appears to have increased when cured at 80 °C or steam cured at 150° and 180 °C and crystalline aluminosilicates resulted when the geopolymer sample was hydrothermally treated at 180 °C/48 hrs.Se prepararon geopolímeros por reacción de metacaolín con disoluciones alcalinas con diferentes contenidos de potasio. Se realizó un curado con agua a temperatura ambiente y a 80 °C, y con vapor de agua a 150 y 180 °C. La formación de las diferentes fases así como la microestructura y entornos del Al y Si se estudiaron mediante DRX, TEM y espectroscopia de RMN MAS de 27Al y 29Si. Los aluminosilicatos amorfos fueron predominantes en aquellos geopolímeros sometidos a curado de hasta 28 días a temperatura ambiente o a 80 °C. Los aluminosilicatos amorfos persistieron tras el tratamiento hidrotermal a 150 °C/48 horas e incluso a 180 °C/30 h. Sin embargo, las muestras curadas hidrotermalmente a 180 °C/48 h revelaron la formación de fases cristalinas de silicatos de aluminio y potasio, as

  13. Low Temperature and H2 Selective Catalysts for Ethanol Steam Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Hyun-Seog; Wang, Yong; King, David L.; Platon, Alex; Chin, Ya-Huei

    2006-04-01

    Supported Rh catalysts have been developed for selective H2 production at low temperatures. Ethanol dehydration is favorable over either acidic or basic supports such as γ-Al2O3 and MgAl2O4, while ethanol dehydrogenation is more favorable over neutral supports. A series of CeO2-ZrO2 supports with various CeO2/ZrO2 ratios were prepared by a co-precipitation method and Rh was impregnated on the as-synthesized support to achieve a strong metal to support interaction (SMSI). 2%Rh/Ce0.8Zr0.2O2 catalyst exhibited the highest H2 yield at 450oC among the various supported Rh catalysts evaluated in this study. This is mainly due to a favored reaction pathway via ethanol dehydrogenation to form the acetaldehyde intermediate, and both the strong interaction between Rh and Ce0.8Zr0.2O2 and the high oxygen storage capacity of Ce0.8Zr0.2O2 which favors oxidation of acetaldehyde decomposition products

  14. Operating results of Hekinan power station No. 3 unit with elevated reheat steam temperature 593[degree]C. Koon sainen joki ondo 593[degree]C Hekinan karyoku 3 goki no shiunten jisseki

    Energy Technology Data Exchange (ETDEWEB)

    Ohara, H. (Chubu Electric Power Co. Inc., Nagoya (Japan)); Ishimoto, R.; Kuwahara, M. (Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)); Ichimura, T.; Minami, Y. (Mitsubishi Heavy Industries, Ltd., Tokyo (Japan))

    1994-05-15

    This paper introduces the Japan's first large-capacity coal fired thermal power plant that uses elevated reheat steam temperature of 593[degree]C as a commercial power plant. This unit is characterized by the high efficiency (adoption of titanium alloy 40-inch blades in the steam turbine and the reaction stage that has been designed by analyzing three-dimensional flows), high operational characteristics (achievement in high load fluctuation rate and improvement in actuation characteristics), and low pollution (suppressed NOx emission). Considerations given in adopting the high steam temperature conditions included the following: optimization in heat conduction arrangement of reheaters on the boiler side; adequate selection of high-temperature materials; measures against high-temperature corrosion and steam oxidization; assurance of reliability in accessories to the high-temperature components; discussions on the improved 12 Cr forged rotor material on the turbine side; and search of an appropriate medium-pressure turbine rotor cooling method and high-performance high-reliability reaction blades. Results exceeding the planned values were obtained on the plant efficiency, the turbine efficiency and the boiler efficiency. Good values were acquired on the reheated steam temperature control range as the static boiler characteristics and the temperature distribution in the reheater metal. Safety was identified in the steam turbine vibration characteristics. 7 refs., 17 figs., 3 tabs.

  15. Long-Term Degradation Testing of High-Temperature Electrolytic Cells

    Energy Technology Data Exchange (ETDEWEB)

    C.M. Stoots; J.E. O' Brien; J.S. Herring; G.K. Housley; D.G. Milobar; M.S. Sohal

    2009-08-01

    The Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cell for large-scale hydrogen production from steam over a temperature range of 800 to 900ºC. The INL has been testing various solid oxide cell designs to characterize their electrolytic performance operating in the electrolysis mode for hydrogen production. Some results presented in this report were obtained from cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with ~10 µm thick yttria-stabilized zirconia (YSZ) electrolytes, ~1400 µm thick nickel-YSZ steam-hydrogen electrodes, and manganite (LSM) air-oxygen electrodes. The experiments were performed over a range of steam inlet mole fractions (0.1 to 0.6), gas flow rates, and current densities (0 to 0.6 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. On a molar basis, the steam consumption rate is equal to the hydrogen production rate. Cell performance was evaluated by performing DC potential sweeps at 800, 850, and 900°C. The voltage-current characteristics are presented, along with values of area-specific resistance as a function of current density. Long-term cell performance is also assessed to evaluate cell degradation. Details of the custom single-cell test apparatus developed for these experiments are also presented. NASA, in conjunction with the University of Toledo, has developed a new cell concept with the goals of reduced weight and high power density. This report presents results of the INL's testing of this new solid oxide cell design as an electrolyzer. Gas composition, operating voltage, and other parameters were varied during testing. Results to date show the NASA cell to be a promising design for both high power-to-weight fuel cell and electrolyzer applications.

  16. Gadolinia-Doped Ceria Cathodes for Electrolysis of CO2

    Science.gov (United States)

    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

  17. Catalyst Deactivation and Regeneration in Low Temperature Ethanol Steam Reforming with Rh/CeO2-ZrO2 Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Hyun-Seog; Platon, Alex; Wang, Yong; King, David L.

    2006-08-01

    Rh/CeO2-ZrO2 catalysts with various CeO2/ZrO2 ratios have been applied to H2 production from ethanol steam reforming at low temperatures. The catalysts all deactivated with time on stream (TOS) at 350 C. The addition of 0.5% K has a beneficial effect on catalyst stability, while 5% K has a negative effect on catalytic activity. The catalyst could be regenerated considerably even at ambient temperature and could recover its initial activity after regeneration above 200 C with 1% O2. The results are most consistent with catalyst deactivation due to carbonaceous deposition on the catalyst.

  18. A Decade of Solid Oxide Electrolysis Improvements at DTU Energy

    DEFF Research Database (Denmark)

    Hauch, Anne; Brodersen, Karen; Chen, Ming

    2017-01-01

    Solid oxide electrolysis cells (SOECs) can efficiently convert electrical energy (e.g. surplus wind power) to energy stored in fuels such as hydrogen or other synthetic fuels. Performance and durability of the SOEC has increased orders of magnitudes within the last decade. This paper presents....... All together, these improvements have led to a decrease in long-term degradation rate from ∼40 %/kh to ∼0.4 %/kh for steam electrolysis at -1 A/cm2, while the initial area specific resistance has been decreased from 0.44 Ωcm2 to 0.15 Ωcm2 at -0.5 A/cm2 and 750 °C....

  19. Materials for higher steam temperatures (up to 600 deg C) in biomass and waste fired plant. A review of present knowledge; Material foer hoegre aangtemperaturer (upp till 600 grader C) i bio- och avfallseldade anlaeggningar

    Energy Technology Data Exchange (ETDEWEB)

    Staalenheim, Annika; Henderson, Pamela

    2011-02-15

    A goal for the Swedish power industry is to build a demonstration biomass-fired plant with 600 deg C steam data in 2015. Vaermeforsk also has a goal to identify materials that can be used in such a plant. This project involves a survey of present knowledge and published articles concerning materials that are suitable for use in biomass and wastefired plants with steam data up to 600 deg C. The information has been gathered from plants presently in operation, and from field tests previously performed with probes. Plants firing only household waste are excluded. The components considered are waterwalls/furnace walls (affected because of higher steam pressures) and superheaters. Fireside corrosion and steam-side oxidation are dealt with. Candidate materials (or coatings) are suggested and areas for further research have been identified. The purpose of this project is to give state-of-the-art information on what materials could be used in biomass and waste-fired plant to reach a maximum steam temperature of 600 deg C. This report is aimed at suppliers of boilers and materials, energy utility companies and others involved in building new plant with higher steam data. In accordance with the goals of this project: - Materials suitable for use at higher steam temperatures (up to 600 deg C steam) in wood-based biomass and waste-fired plant have been identified. Austenitic stainless steels HR3C, TP 347 HFG and AC66 all have adequate strength, steam-side oxidation and fireside corrosion resistance for use as superheaters. AC66 and HR3C have better steam-side oxidation resistance than TP 347 HFG , but TP 347 HFG has better fireside corrosion resistance. It is recommended that TP 347 HFG be shot-peened on the inside to improve the oxidation resistance if in service with steam temperatures above 580 deg C. - Furnace walls coated with Ni-based alloys or a mixture of Ni- alloy and ceramic show good corrosion resistance at lower temperatures and should be evaluated at higher

  20. Steam explosion studies review

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Moon Kyu; Kim, Hee Dong

    1999-03-01

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  1. Thermodynamic properties of dissociated steam

    Science.gov (United States)

    Aminov, R. Z.; Gudym, A. A.

    2017-11-01

    In connection with the development of hydrogen technologies and the generation of dissociated steam as a result of the oxidation of hydrogen in an oxygen environment, it became necessary to determine the calorific parameters of dissociated steam. In the existing tables, the caloric parameters of dissociated steam are presented at a reference temperature of 0 K. By contrast, the authors have developed tables of dissociated steam using a reference temperature of 0°C, within the pressure range 0.01–20.0 MPa and the temperature range 1250–4000 K, along with a system of equations for the industrial calculation of the properties of dissociated steam within the temperature range 1250–2300 K and pressure range 0.01–10.0 MPa, followed by a temperature range of 2200–3600 K. During the dissociation of steam, a mixture of eight components are formed including hydrogen H, oxygen O, radicals OH and HO2, molecules of hydrogen H2, oxygen O2, steam H2O, and hydrogen peroxide H2O2. All existing tables of the properties of dissociated steam are based on a mixture of six components: H2, O2, OH, H, O, and H2O. For evaluate whether this is an oversimplification, the composition of the mixture comprising all eight components was calculated, taking into account additional chemical reactions for the formation of HO2 and H2O2. At a pressure of 0.01 MPa, the maximum mole fraction of HO2 was 2.8·10‑5 at a temperature of 3000 K, and at a pressure of 10 MPa, the maximum mole fraction was 5·10‑5 at a temperature of 4000 K. The mole fraction of H2O2 was much lower. Thus at temperatures up to 3000 K, calculations of the properties of dissociated steam are restricted to six components.

  2. Data bank on hydrodynamics, thermal tests and tube temperature regimes of PGV-4 and PVG-1000 natural steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Ageev, A.G.; Vasileva, R.V.; Nigmatulin, B.I.; Titov, V.F.; Tarankov, G.N. [EREC Electrogorsk Research and Engineering Centre of Nuclear Plants Safety, Moscow (Russian Federation)

    1995-12-31

    The data bank was prepared by EREC, OKB `Hydropress` using results of static and dynamic tests of PGV-4 and PGV- 1000 natural steam generators cared out at Kolskaya, Novo-Voronezhskaya, Ugno-Ukrainskaya, Balakov-skaya and Hmelnitskaya NPP within period of 1974-1993. It is destined for making calculation codes verification. (authors).

  3. Operating results of 700MW coal fired supercritical once-through steam generator for Hekinan power station No. 3 boiler, Chubu Electric Power Co. , Inc. with elevated reheat steam temperature: 596[degree]C. Chubu denryoku kabushiki kaisha Hekinan karyoku hatsudensho 3 go boiler (koon sainetsu joki ondo: 596[degree]C) no shiunten jisseki

    Energy Technology Data Exchange (ETDEWEB)

    Ishimoto, R.; Ozawa, M.; Yamamoto, T.; Kuwahara, M. (Ishikawajima-Harima Heavy Industries, Co. Ltd., Tokyo (Japan))

    1994-03-01

    The IHI-FW 700 MW coal fired supercritical variable pressure once-through reheat type steam generator at Hekinan Power Station No. 3 boiler of Chubu Electric Power Co., Inc. started commercial operation in April 1993. This paper describes an outline of the operating results of commissioning stage, focusing on the evaluation of elevated reheat steam temperature. The boiler was the first to achieve reheat steam temperature of 596 centigrade in Japan. The evaporation of boiler is 2,250 t/h at the maximum continuous load. The boiler has advanced special merits, such as cyclic operation, environmental technology to achieve low NOx emissions, high efficiency plant due to the elevated steam temperature, etc. During commissioning, these special merits were confirmed to be satisfactory. The plant efficiencies at the generating end and the sending end were higher than those as designed. In addition, the steam temperature characteristics as designed were obtained. The metal temperature distribution of the reheater was lower than that as designed. 7 figs.

  4. The effect of microstructural stability on long-term creep behaviour of 11 %Cr steels for steam power plants with operating steam temperatures up to 650 C

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Scholz, A.; Berger, C. [Technische Univ. Darmstadt (DE). Inst. fuer Werkstoffkunde (IFW); Kauffmann, F.; Maile, K. [Stuttgart Univ. (DE). Materialpruefungsanstalt (MPA); Mayer, K.H. [Alstom Power, Nuernberg (Germany)

    2010-07-01

    The investigations of advanced ferritic/martensitic steels for 650 C power plant components focus on the improvement of high-temperature creep properties with respect to chemical composition. This study deals with the development of new heat resistant 11-12%Cr ferritic-martensitic steels with sufficient creep and oxidation resistance up to 650 application by using basic principles and concepts of physical metallurgy. The highest creep strength could be achieved with a 0.04% Nb alloyed 11%CrWCoMoVB melt, which is in addition alloyed with a higher C and B content as well as with lower W and Co portions. The microstructure evolution during creep of this newly developed steel was investigated in comparison to a sister alloy which comprises 0.06% Ta instead of the Nb. (orig.)

  5. Magnetic Resonance Imaging of Electrolysis.

    Science.gov (United States)

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

    2015-01-01

    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. PMID:25659942

  6. Membrane Cells for Brine Electrolysis.

    Science.gov (United States)

    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)

  7. BLAST: a digital computer program for the dynamic simulation of the high temperature gas cooled reactor reheater-steam generator module

    Energy Technology Data Exchange (ETDEWEB)

    Hedrick, R.A.; Cleveland, J.C.

    1976-06-24

    BLAST simulates the high temperature gas cooled reactor reheater-steam generator module with a multi-node, fixed boundary, homogenous flow model. The time dependent conservation of energy, mass, and momentum equations are solved by an implicit integration technique. The code contains equation of state formulations for both helium and water as well as heat transfer and friction factor correlations. Normal operational transients and more severe transients such as those resulting in low and/or reverse flow can be simulated. The code calculates helium and water temperature, pressure, flow rate, and tube bulk and wall temperatures at various points within the reheater-steam generator module during the transients. BLAST predictions will be compared with dynamic test results obtained from the Fort St. Vrain reactor owned by Public Service of Colorado, and, based on these comparisons, appropriate improvements will be made in BLAST. BLAST is written in FORTRAN IV for the IBM 360/91 computer at the Oak Ridge National Laboratory.

  8. Performance of iron–chromium–aluminum alloy surface coatings on Zircaloy 2 under high-temperature steam and normal BWR operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Weicheng; Mouche, Peter A.; Han, Xiaochun [University of Illinois, Department of Nuclear, Radiological, and Plasma Engineering, Urbana, IL 61801 (United States); Heuser, Brent J., E-mail: bheuser@illinois.edu [University of Illinois, Department of Nuclear, Radiological, and Plasma Engineering, Urbana, IL 61801 (United States); Mandapaka, Kiran K.; Was, Gary S. [University of Michigan, Department of Nuclear Engineering and Radiological Sciences, Ann Arbor, MI 48109 (United States)

    2016-03-15

    Iron-chromium-aluminum (FeCrAl) coatings deposited on Zircaloy 2 (Zy2) and yttria-stabilized zirconia (YSZ) by magnetron sputtering have been tested with respect to oxidation weight gain in high-temperature steam. In addition, autoclave testing of FeCrAl-coated Zy2 coupons under pressure-temperature-dissolved oxygen coolant conditions representative of a boiling water reactor (BWR) environment has been performed. Four different FeCrAl compositions have been tested in 700 °C steam; compositions that promote alumina formation inhibited oxidation of the underlying Zy2. Parabolic growth kinetics of alumina on FeCrAl-coated Zy2 is quantified via elemental depth profiling. Autoclave testing under normal BWR operating conditions (288 °C, 9.5 MPa with normal water chemistry) up to 20 days demonstrates observable weight gain over uncoated Zy2 simultaneously exposed to the same environment. However, no FeCrAl film degradation was observed. The 900 °C eutectic in binary Fe–Zr is addressed with the FeCrAl-YSZ system. - Graphical abstract: Weight gain normalized to total sample surface area versus time during 700 °C steam exposure for FeCrAl samples with different composition (A) and Fe/Cr/Al:62/4/34 (B). In both cases, the responses of uncoated Zry2 (Zry2-13A and Zry2-19A) are shown for comparison. This uncoated Zry2 response shows the expected pre-transition quasi-cubic kinetic behavior and eventual breakaway (linear) kinetics. Highlights: • FeCrAl coatings deposited on Zy2 have been tested with respect to oxidation in high-temperature steam. • FeCrAl compositions promoting alumina formation inhibited oxidation of Zy2 and delay weight gain. • Autoclave testing to 20 days of coated Zy2 in a simulated BWR environment demonstrates minimal weight gain and no film degradation. • The 900 °C eutectic in binary Fe-Zr is addressed with the FeCrAl-YSZ system.

  9. Oxidation behavior of Ti2AlC in the temperature range of 1400 °C-1600 °C in steam

    Science.gov (United States)

    Tang, Chongchong; Steinbrück, Martin; Große, Mirco; Bergfeldt, Thomas; Seifert, Hans Jürgen

    2017-07-01

    The oxidation behavior of bulk Ti2AlC ceramic in steam has been investigated in the temperature range of 1400 °C-1600 °C. The oxidation kinetics followed a sub-parabolic law at the early stage of oxidation, then tended to be a linear law beyond 18 h at 1400 °C, and obeyed a linear law during the whole exposure up to 24 h at 1500 °C. At the initial stage of oxidation at 1400 °C and 1500 °C, randomly Al2TiO5 isolated islands with large elongated grains were observed on the surface. A continuous inner α-Al2O3 layer with a thin discontinuous outer layer of Al2TiO5 formed with prolonged exposure time. Outward diffusion of Ti and C through grain boundaries of the α-Al2O3 scale during steady-state oxidation result in segregation of TiO2 at the grain boundaries of α-Al2O3 and formation of gaseous CO and CO2, respectively. The scale adhesion was reduced in steam compared to that in air due to the accumulation of stresses, and generation of voids at the scale/substrate interface. The mechanical disruption of the oxide scale to relief the stresses contribute to the breakaway oxidation of Ti2AlC at 1400 °C and to the non-protective effect at 1500 °C. The sample was rapidly and completely consumed during isothermal oxidation at 1600 °C accompanied by release of heat and hydrogen. The maximum tolerant temperature of Ti2AlC in steam was approximate 1555 °C, which can be extended via a tailored pre-oxidation process.

  10. Determination of Three Dimensional Microstructure Parameters from a Solid Oxide Ni/YSZ Electrode after Electrolysis Operation

    DEFF Research Database (Denmark)

    Jørgensen, Peter Stanley; Bowen, Jacob R.

    2011-01-01

    The interface structure of a Ni/YSZ electrode tested for 1300 hours in steam electrolysis mode is analyzed. We break down the electrode interface structure measurements into total phase interfaces (e.g. total pore surface area), two-phase interfaces (e.g. Ni/YSZ interface area) and triple...

  11. Calculate the moisture content of steam

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. (ABCO Industries, Inc., Abilene, TX (United States))

    1993-08-01

    Water droplets in steam can create serious problems. For example, if the steam is being used to drive turbines, droplets can damage the turbine blades. It is important, therefore, for an engineer to know if steam contains moisture, especially if the steam is generated in low-pressure boilers (under 500 psia). Unlike larger boilers, these units don't have internal separation devices such as cyclones. Calculating the steam's moisture content, or quality, can be complicated procedure. Now, a simple chart can be used to get the data from one temperature reading. The paper explains the procedure.

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

    Science.gov (United States)

    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.

  13. Additional considerations on electrolysis in electromembrane extraction

    OpenAIRE

    Šlampová, A. (Andrea); Kubáň, P. (Pavel); Boček, P. (Petr)

    2016-01-01

    Additional considerations on quantitative aspects of electrolysis in EME have been evaluated. The most likely reasons for back-extraction of analytes during EMEs have been examined and efficient approaches for electrolysis elimination have been proposed.

  14. ULTRA-SUPERCRITICAL STEAM CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, G.R.; Alman, D.E.; Bullard, S.B.; Covino, B.S., Jr.; Cramer, S.D.; Ziomek-Moroz, M.

    2003-04-22

    Efficiency increases in fossil energy boilers and steam turbines are being achieved by increasing the temperature and pressure at the turbine inlets well beyond the critical point of water. To allow these increases, advanced materials are needed that are able to withstand the higher temperatures and pressures in terms of strength, creep, and oxidation resistance. As part of a larger collaborative effort, the Albany Research Center (ARC) is examining the steam-side oxidation behavior for ultrasupercritical (USC) steam turbine applications. Initial tests are being done on six alloys identified as candidates for USC steam boiler applications: ferritic alloy SAVE12, austenitic alloy Super 304H, the high Cr-high Ni alloy HR6W, and the nickel-base superalloys Inconel 617, Haynes 230, and Inconel 740. Each of these alloys has very high strength for its alloy type. Three types of experiments are planned: cyclic oxidation in air plus steam at atmospheric pressure, thermogravimetric ana lysis (TGA) in steam at atmospheric pressure, and exposure tests in supercritical steam up to 650 C (1202 F) and 34.5 MPa (5000 psi). The atmospheric pressure tests, combined with supercritical exposures at 13.8, 20.7, 24.6, and 34.5 MPa (2000, 3000, 4000, and 5000 psi) should allow the determination of the effect of pressure on the oxidation process.

  15. Life Time Performance Characterization of Solid Oxide Electrolysis Cells for Hydrogen Production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

    2015-01-01

    Solid oxide electrolysis cells (SOECs) offer a promising technological solution for efficient energy conversion and production of hydrogen or syngas. The commercialization of the SOEC technology can be promoted if SOECs can be operated at high current density with stable performance over ~5 years...... - 3 years (continuous operation, setting 1.5 V as the upper voltage defining “end of life”). The results provide technological input to future design of electrolysis plants for hydrogen production. © 2015 ECS - The Electrochemical Society....... In this work, long-term durability of Ni/yttria stabilized zirconia (YSZ) supported planar SOECs was investigated at 800 oC for electrolysis of steam at different current densities from 0 to -1.25 A/cm2. The SOEC cells are able to be operated at current density up to ~-1 A/cm2, with a predicted life time of 2...

  16. Effective utilization of by-product oxygen from electrolysis hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Takeyoshi; Kubota, Mitsuhiro; Kobayashi, Noriyuki; Suzuoki, Yasuo [Nagoya University (Japan)

    2005-11-01

    To avoid fossil-fuel consumption and greenhouse-gas emissions, hydrogen should be produced by renewable energy resources. Water electrolysis using proton exchange membrane (PEM) is considered a promising hydrogen-production method, although the cost of the hydrogen from PEM would be very high compared with that from other mature technologies, such as steam methane reforming (SMR). In this study, we focus on the effective utilization of by-product oxygen from electrolysis hydrogen production and discuss the potential demand for it, as well as evaluating its contribution to improving process efficiency. Taking as an example the utilization of by-product oxygen for medical use, we compare the relative costs of hydrogen production by means of PEM electrolysis and SMR. (author)

  17. Influence of the reheat temperature on the efficiency of the wet-steam turbines of thermal power plants that operate under variable conditions

    Science.gov (United States)

    Tarelin, A. A.

    2017-04-01

    A brief analysis of the existing methods for controlling the operating conditions of the turbine units that operate at variable loads is presented. In practice, the outdated rule of operation is most frequently used that states that the higher the parameters of the live and reheat steam and the lower the condenser pressure are, the higher is the efficiency of the turbine unit. However, in the technical literature, there is sufficiently substantiated evidence that this approach is not always correct, especially under low loads. This applies to both the regulation of the initial and final pressure and reheat temperature t r. In the article, particular stress is laid on the controllable parameter t r, the effect of which in the operational practices, according to the results of the analysis, is underestimated. The causes are considered that constrain more effective use of reheat temperature t r as a process variable. The results of field trials to investigate the influence of t r on the efficiency of turbine units of various capacities, viz., of 210, 250, 300, and 325 MW, during operation at varying loads are presented. It is shown that a decrease in t r to an optimal value of 10-30°C, depending on the load and the condenser pressure, increases the thermal efficiency by 1-2%. The following general pattern has been set: the lower the load, the lower the optimal reheat temperature. The main causes and factors that result in more efficient use of the heat phase transition in the steam path of the low-pressure cylinder and increased efficiency of the unit under rational choice of the reheat temperature are studied.

  18. Electrolysis Propulsion for Spacecraft Applications

    Science.gov (United States)

    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.

  19. Electrolysis Performance Improvement and Validation Experiment

    Science.gov (United States)

    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.

  20. On-board reforming of biodiesel and bioethanol for high temperature PEM fuel cells: Comparison of autothermal reforming and steam reforming

    Science.gov (United States)

    Martin, Stefan; Wörner, Antje

    2011-03-01

    In the 21st century biofuels will play an important role as alternative fuels in the transportation sector. In this paper different reforming options (steam reforming (SR) and autothermal reforming (ATR)) for the on-board conversion of bioethanol and biodiesel into a hydrogen-rich gas suitable for high temperature PEM (HTPEM) fuel cells are investigated using the simulation tool Aspen Plus. Special emphasis is placed on thermal heat integration. Methyl-oleate (C19H36O2) is chosen as reference substance for biodiesel. Bioethanol is represented by ethanol (C2H5OH). For the steam reforming concept with heat integration a maximum fuel processing efficiency of 75.6% (76.3%) is obtained for biodiesel (bioethanol) at S/C = 3. For the autothermal reforming concept with heat integration a maximum fuel processing efficiency of 74.1% (75.1%) is obtained for biodiesel (bioethanol) at S/C = 2 and λ = 0.36 (0.35). Taking into account the better dynamic behaviour and lower system complexity of the reforming concept based on ATR, autothermal reforming in combination with a water gas shift reactor is considered as the preferred option for on-board reforming of biodiesel and bioethanol. Based on the simulation results optimum operating conditions for a novel 5 kW biofuel processor are derived.

  1. Modeling Degradation in Solid Oxide Electrolysis Cells

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Steam drum design for direct steam generation

    Science.gov (United States)

    Willwerth, Lisa; Müller, Svenja; Krüger, Joachim; Succo, Manuel; Feldhoff, Jan Fabian; Tiedemann, Jörg; Pandian, Yuvaraj; Krüger, Dirk; Hennecke, Klaus

    2017-06-01

    For the direct steam generation in solar fields, the recirculation concept has been demonstrated in several installations. Water masses in the solar field vary during transient phases, such as passing clouds. The volume of the steam drum can serve as a buffer during such transients by taking in excess water and providing water storage. The saturated steam mass flow to the superheating section or the consumer can be maintained almost constant during short transients; therefore the steam drum plays a key role for constant steam supply. Its buffer effect depends on the right sizing of the steam drum for the prevailing situations. Due to missing experiences, steam drums have been sized under conservative assumptions and are thereby usually oversized. With this paper, experiences on the steam drum of the 5 MWel TSE1 power plant are discussed for optimized future plant design. The results are also of relevance for process heat installations, in which saturated steam is produced by the solar field.

  3. Investigation of Relative Time Constant Influence of Inertial Part of Superheater on Quality of Steam Temperature Control Behind Boiler in Broad Band of Loading Variations

    Directory of Open Access Journals (Sweden)

    G. T. Kulakov

    2008-01-01

    Full Text Available The paper is devoted to computational investigation of influence relative time constant of an object which changes in broad band on quality of steam temperature control behind a boiler with due account of value of regulating action in the system with PI- and PID- regulator. The simulation has been based on a single-loop automatic control system (ACS. It has been revealed that the less value of the relative time constant of an object leads to more integral control error in system with PID- regulator while operating external ACS perturbation. Decrease of numerical value of relative time constant of an object while operating external perturbation causes decrease of relative time concerning appearance of maximum dynamic control error from common relative control time.

  4. Microstructural Degradation of Ni/YSZ Electrodes in Solid Oxide Electrolysis Cells under High Current

    DEFF Research Database (Denmark)

    Chen, Ming; Liu, Yi-Lin; Bentzen, Janet Jonna

    2013-01-01

    Ni/yttria stabilized zirconia (YSZ) supported solid oxide electrolysis cells (SOECs) were exposed to long-term galvanostatic electrolysis tests, under different testing conditions (temperature, gas composition, current density etc.) with an emphasis on high current density (above −1 A/cm2...... of Ni-YSZ interfacial reactions, taking place under the conditions prevailing under strong polarization. A mechanism for the formation of ZrO2 nano-particles on the Ni surface under the electrolysis cell testing is proposed and the possibility of Ni-YSZ interfacial reactions under such conditions (T, p...

  5. Hydrogen Production by Steam Reforming of Ethanol over Nickel Catalysts Supported on Sol Gel Made Alumina: Influence of Calcination Temperature on Supports.

    Science.gov (United States)

    Yaakob, Zahira; Bshish, Ahmed; Ebshish, Ali; Tasirin, Siti Masrinda; Alhasan, Fatah H

    2013-05-30

    Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/AlS.G.) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel made supports on catalyst activity was tested in ethanol reforming reaction. The characteristics of the sol gel alumina supports and Ni catalysts were affected by the calcination temperature of the supports. The structure of the sol gel made alumina supports was transformed in the order of γ → (γ + θ) → θ-alumina as the calcination temperature of the supports increased from 600 °C to 1000 °C. Both hydrogen yield and ethanol conversion presented a volcano-shaped behavior with maximum values of 4.3 mol/mol ethanol fed and 99.5%, respectively. The optimum values were exhibited over Ni/AlS.G800 (Ni catalyst supported on sol gel made alumina calcined at 800 °C). The high performance of the Ni/AlS.G800 catalyst may be attributed to the strong interaction of Ni species and sol gel made alumina which lead to high nickel dispersion and small particle size.

  6. Steam Reforming of Ethylene Glycol over Ni/Al{sub 2}O{sub 3} Catalysts: Effect of the Preparation Method and Reduction Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Dong Hyuck; Park, Jung Eun; Park, Eun Duck [Ajou University, Suwon (Korea, Republic of)

    2015-02-15

    The effect of preparation method on the catalytic activities of the Ni/Al{sub 2}O{sub 3} catalysts on steam reforming of ethylene glycol was investigated. The catalysts were prepared with various preparation methods such as an incipient wetness impregnation, wet impregnation, and coprecipitation method. In the case of coprecipitation method, various precipitants such as KOH, K{sub 2}CO{sub 3}, and NH{sub 4}OH were compared. The prepared catalysts were characterized by using N{sub 2} physisorption, inductively coupled plasma-atomic emission spectroscopy, X-ray diffraction, temperature programmed reduction, pulsed H{sub 2} chemisorption, temperature-programmed oxidation, scanning electron microscopy, and thermogravimetric analysis. Among the catalysts reduced at 773 K, the Ni/Al{sub 2}O{sub 3} catalyst prepared by a coprecipitation with KOH or K{sub 2}CO{sub 3} as precipitants showed the best catalytic performance. The preparation method affected the particle size of Ni, reducibility of nickel oxides, catalytic performance (activity and stability), and types of coke formed during the reaction. The Ni/Al{sub 2}O{sub 3} catalyst prepared by a coprecipitation with KOH showed the increasing catalytic activity with an increase in the reduction temperature from 773 to 1173 K because of an increase in the reduction degree of Ni oxide species even though the particle size of Ni increased with increasing reduction temperature.

  7. Research and Development of Heat-Resistant Materials for Advanced USC Power Plants with Steam Temperatures of 700 °C and Above

    Directory of Open Access Journals (Sweden)

    Fujio Abe

    2015-06-01

    Full Text Available Materials-development projects for advanced ultra-supercritical (A-USC power plants with steam temperatures of 700 °C and above have been performed in order to achieve high efficiency and low CO2 emissions in Europe, the US, Japan, and recently in China and India as well. These projects involve the replacement of martensitic 9%−12% Cr steels with nickel (Ni-base alloys for the highest temperature boiler and turbine components in order to provide sufficient creep strength at 700°C and above. To minimize the requirement for expensive Ni-base alloys, martensitic 9%−12% Cr steels can be applied to the next highest temperature components of an A-USC power plant, up to a maximum of 650°C. This paper comprehensively describes the research and development of Ni-base alloys and martensitic 9%−12% Cr steels for thick section boiler and turbine components of A-USC power plants, mainly focusing on the long-term creep-rupture strength of base metal and welded joints, strength loss in welded joints, creep-fatigue properties, and microstructure evolution during exposure at elevated temperatures.

  8. 2nd Generation Alkaline Electrolysis

    DEFF Research Database (Denmark)

    Yde, Lars; Kjartansdóttir, Cecilia Kristin; Allebrod, Frank

    This report provides the results of the 2nd Generation Alkaline Electrolysis project which was initiated in 2008. The project has been conducted from 2009-2012 by a consortium comprising Århus University Business and Social Science – Centre for Energy Technologies (CET (former HIRC)), Technical...

  9. Electrolysis Bubbles Make Waterflow Visible

    Science.gov (United States)

    Schultz, Donald F.

    1990-01-01

    Technique for visualization of three-dimensional flow uses tiny tracer bubbles of hydrogen and oxygen made by electrolysis of water. Strobe-light photography used to capture flow patterns, yielding permanent record that is measured to obtain velocities of particles. Used to measure simulated mixing turbulence in proposed gas-turbine combustor and also used in other water-table flow tests.

  10. Redox-Reversible Iron Orthovanadate Cathode for Solid Oxide Steam Electrolyzer.

    Science.gov (United States)

    Gan, Lizhen; Ye, Lingting; Ruan, Cong; Chen, Shigang; Xie, Kui

    2016-02-01

    A redox-reversible iron orthovanadate cathode is demonstrated for a solid oxide electrolyser with up to 100% current efficiency for steam electrolysis. The iron catalyst is grown on spinel-type electronic conductor FeV2O4 by in situ tailoring the reversible phase change of FeVO4 to Fe+FeV2O4 in a reducing atmosphere. Promising electrode performances have been obtained for a solid oxide steam electrolyser based on this composite cathode.

  11. Method of steam reforming methanol to hydrogen

    Science.gov (United States)

    Beshty, Bahjat S.

    1990-01-01

    The production of hydrogen by the catalyzed steam reforming of methanol is accomplished using a reformer of greatly reduced size and cost wherein a mixture of water and methanol is superheated to the gaseous state at temperatures of about 800.degree. to about 1,100.degree. F. and then fed to a reformer in direct contact with the catalyst bed contained therein, whereby the heat for the endothermic steam reforming reaction is derived directly from the superheated steam/methanol mixture.

  12. Fixation of compressive deformation in wood by pre-steaming

    Science.gov (United States)

    M. Inoue; N. Sekino; T. Morooka; R.M. Rowell; M. Norimoto

    2008-01-01

    Wood block specimens pre-steamed at 120-220 °C for 5-20 min were compressed in the radial direction. The recovery of set decreased with increasing pre-steaming temperature and time. The reduction of set recovery correlated with the amount of weight loss in steaming irrespective of pre-steaming temperature and time. The weight loss for the highest level of...

  13. An integrated systems calculation of a steam generator tube rupture in a modular prismatic HTGR (high-temperature gas-cooled reactor) conceptual design using ATHENA (Advanced Thermal-Hydraulic Energy Network Analyzer)

    Energy Technology Data Exchange (ETDEWEB)

    Beelman, R.J. (Idaho National Engineering Laboratory, Idaho Falls (USA))

    1989-11-01

    The capability to perform integrated systems calculations of modular high-temperature gas-cooled reactor (MHTGR) transients has been developed at the Idaho National Engineering Laboratory (INEL) using the Advanced Thermal-Hydraulic Energy Network Analyzer (ATHENA) computer code. A scoping calculation of a steam generator tube rupture (SGTR) water ingress event in a prismatic 2 {times} 350-MW(thermal) MHTGR conceptual design has been completed at INEL using ATHENA. The proposed MHTGR design incorporates dual, graphite-moderated, helium-cooled, 350-MW(thermal), annular prismatic core concept reactor plants, each configured with an individual helical once-through steam generator steaming a common 280-MW(electric) turbine generator set.

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

    Science.gov (United States)

    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.

  15. Electrolysis of carbon dioxide in Solid Oxide Electrolysis Cells

    DEFF Research Database (Denmark)

    Ebbesen, Sune; Mogensen, Mogens Bjerg

    2009-01-01

    Carbon dioxide electrolysis was studied in Ni/YSZ electrode supported Solid Oxide Electrolysis Cells (SOECs) consisting of a Ni-YSZ support, a Ni-YSZ electrode layer, a YSZ electrolyte, and a LSM-YSZ O2 electrode (YSZ = Yttria Stabilized Zirconia). The results of this study show that long term CO2...... electrolysis is possible in SOECs with nickel electrodes.The passivation rate of the SOEC was between 0.22 and 0.44 mV h−1 when operated in mixtures of CO2/CO = 70/30 or CO2/CO = 98/02 (industrial grade) at 850 °C and current densities between −0.25 and −0.50 A cm−2. The passivation rate was independent...... in the gas stream, most likely sulphur, adsorbing on some specific nickel sites in the cathode of the SOEC. Activation can be carried out by hydrogen reacting with adsorbed sulphur to form the volatile compound H2S. Because adsorption of sulphur is site specific, only a part of the nickel sites were...

  16. Hydrogen production by alkaline water electrolysis

    Directory of Open Access Journals (Sweden)

    Diogo M. F. Santos

    2013-01-01

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

  17. Desulfurization from Bauxite Water Slurry (BWS) Electrolysis

    Science.gov (United States)

    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.

  18. Detection and evaluation of corrosion zones at high temperature in steam generators; Deteccion y evaluacion de zonas de corrosion en alta temperatura de generadoras de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Villafane, Alberto; Chacon Nava, Jose G.; Huerta Espino, Mario; Mojica Calderon, Cecilio; Castillo Viveros, Antonio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    This paper presents the methodology for the detection and evaluation of high corrosion zones at high temperature. The results found up to now, show a critical zone in the Babcock Hitachi design, specifically in the high temperature reheater in the zone nearby the outlet header. In the normalized design CE (Mitsubishi) of 300 MW and CE (Canada) of 300 MW, the results found in recent years show small thickness reduction, therefore a good operation of these steam generators is recognized. [Espanol] En este trabajo se presenta la metodologia para la deteccion y evaluacion de zonas de corrosion en alta temperatura. Los resultados encontrados hasta el momento muestran una zona critica en el diseno Babcock Hitachi, especificamente en el recalentador de alta temperatura en la zona cercana al cabezal de salida. En el diseno normalizado CE (Mitsubishi) de 300 MW y CE (Canada) de 300 MW, los resultados encontrados en anos recientes muestran poca disminucion de espesor, por lo que se considera una buena operacion de estos generadores de vapor.

  19. Electrical impedance tomography of electrolysis.

    Science.gov (United States)

    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.

  20. Electrical impedance tomography of electrolysis.

    Directory of Open Access Journals (Sweden)

    Arie Meir

    Full Text Available The primary goal of this study is to explore the hypothesis that changes in pH during electrolysis can be detected with Electrical Impedance Tomography (EIT. The study has relevance to real time control of minimally invasive surgery with electrolytic ablation. To investigate the hypothesis, we compare EIT reconstructed images to optical images acquired using pH-sensitive dyes embedded in a physiological saline agar gel phantom treated with electrolysis. We further demonstrate the biological relevance of our work using a bacterial E.Coli model, grown on the phantom. The results demonstrate the ability of EIT to image pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E.coli model. The results are promising, and invite further experimental explorations.

  1. Hydrogen production by alkaline water electrolysis

    OpenAIRE

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

    2013-01-01

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

  2. Generating steam efficiently

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. [ABCO Industries, Abilene, TX (United States)

    1997-12-31

    This paper outlines a few methods or options for generating steam efficiently in cogeneration plants when using conventional steam generators (boilers) and gas turbine Heat Recovery Steam Generators (HRSGS). By understanding the performance characteristics of these systems and operating them at their most efficient loads, steam can be generated at low cost. Suggestions are also made to improve the efficiency of existing HRSGS.

  3. Transient nanobubbles in short-time electrolysis.

    Science.gov (United States)

    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.

  4. Development of a static feed water electrolysis system

    Science.gov (United States)

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

    1982-01-01

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

  5. Polybenzimidazole membranes for zero gap alkaline electrolysis cells

    DEFF Research Database (Denmark)

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

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

  6. Steam coal forecaster

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This quarterly forecasting service provides a short-term analysis and predictions of the international steam coal trade. Sections are entitled: market review; world steam coal at a glance; economics/foreign exchange; demand (reviewing the main purchasing companies country-by-country); supply (country-by-country information on the main producers of steam coal); and freight. A subscription to Steam Coal Forecaster provides: a monthly PDF of McCloskey's Steam Coal Forecaster sent by email; access to database of stories in Steam Coal Forecaster via the search function; and online access to the latest issue of Steam Coal.

  7. Some Aspects of PDC Electrolysis

    Science.gov (United States)

    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.

  8. Steam Digest 2002

    Energy Technology Data Exchange (ETDEWEB)

    2003-11-01

    Steam Digest 2002 is a collection of articles published in the last year on steam system efficiency. DOE directly or indirectly facilitated the publication of the articles through it's BestPractices Steam effort. Steam Digest 2002 provides a variety of operational, design, marketing, and program and program assessment observations. Plant managers, engineers, and other plant operations personnel can refer to the information to improve industrial steam system management, efficiency, and performance.

  9. Halogen acid electrolysis in solid polymer electrolyte cells

    Energy Technology Data Exchange (ETDEWEB)

    Balko, E.N.; McElroy, J.F.; LaConti, A.B.

    1981-01-01

    The use of solid polymer electrolyte systems has been extended to the electrolysis of aqueous HCl and HBr. The reduced internal losses in these cells permits the production of hydrogen and the halogen at an energy consumption considerably less than that reported previously. Data are presented for the operational characteristics of the solid polymer electrolyte acid electrolysers operating over a range of current densities, pressures, feedstock compositions, and temperatures.

  10. 7 CFR 305.23 - Steam sterilization treatment schedules.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Steam sterilization treatment schedules. 305.23... Steam sterilization treatment schedules. Treatment schedule Temperature( °F) Pressure Exposure period (minutes) Directions T303-b-1 10 lbs 20 Use 28″ vacuum. Steam sterilization is not practical for treatment...

  11. The Effect of Steaming on the Glucosinolate Content in Broccoli

    NARCIS (Netherlands)

    Verkerk, R.; Knol, J.J.; Dekker, M.

    2010-01-01

    Total and individual glucosinolates were measured after different duration of steaming broccoli (Brassica oleracea L. var. italica). During steaming, the temperature profile, cell lysis and inactivation of myrosinase were assessed as well. Steaming resulted in high retention of total aliphatic and

  12. Creep of Sylramic-iBN Fiber Tows at Elevated Temperature in Air and in Silicic Acid-Saturated Steam

    Science.gov (United States)

    2015-06-01

    fairly chemically inert, but has little to no mobility of dislocations, resulting in no plastic deformation. Because plastic deformation is an energy...ancient Egyptians, where their renowned straw -reinforced clay-bricks trumped over the traditional clay brick. The straw acted as a reinforcement medium...crystalline ceramic, stress concentrations cannot be relieved by plastic deformation (except, to some degree, at high temperatures) and thus the

  13. The role of metal-support interaction for CO-free hydrogen from low temperature ethanol steam reforming on Rh-Fe catalysts.

    Science.gov (United States)

    Choong, Catherine K S; Chen, Luwei; Du, Yonghua; Schreyer, Martin; Daniel Ong, S W; Poh, Chee Kok; Hong, Liang; Borgna, Armando

    2017-02-08

    Rh-Fe catalysts supported on Ca-Al2O3, MgO and ZrO2 were evaluated in ethanol steam reforming at 623 K and compared to Rh catalysts on the same supports without iron promotion. The metal-support interaction among the three entities, i.e. Rh ↔ Fe2O3 ← support (ZrO2, MgO and Ca-Al2O3) was investigated using H2-chemisorption, TEM, XPS and in situ techniques such as DRIFTS, temperature-resolved XRD and XAS. As compared to the unpromoted Rh catalysts on the same supports, the CO selectivity is depressed in the presence of iron on Rh/MgO and Rh/Ca-Al2O3, the latter being significantly superior. The role of metal-support interaction for CO-free hydrogen generation was unravelled using a combination of techniques. It was found that the reducibility of iron oxide determines the extent of the strong metal support interaction between Rh and Fe2O3 and the reducibility of iron oxide was affected by the support. On Rh-Fe/Ca-Al2O3, a good balance of the interaction between Rh, Fe2O3 and Ca-Al2O3 prevents strong metal support interaction between Rh and Fe2O3 and thus promotes CO elimination via water-gas-shift reaction on Rh-FexOy sites.

  14. Study of the response of Zircaloy- 4 cladding to thermal shock during water quenching after double sided steam oxidation at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sawarn, Tapan K., E-mail: sawarn@barc.gov.in; Banerjee, Suparna; Kumar, Sunil

    2016-05-15

    This study investigates the failure of embrittled Zircaloy-4 cladding in a simulated loss of coolant accident condition and correlates it with the evolved stratified microstructure. Isothermal steam oxidation of Zircaloy-4 cladding at high temperatures (900–1200 °C) with soaking periods in the range 60–900 s followed by water quenching was carried out. The combined oxide + oxygen stabilized α-Zr layer thickness and the fraction of the load bearing phase (recrystallised α-Zr grains + prior β-Zr or only prior β-Zr) of clad tube specimens were correlated with the %ECR calculated using Baker-Just equation. Average oxygen concentration of the load bearing phase corresponding to different oxidation conditions was calculated from the average microhardness using an empirical correlation. The results of these experiments are presented in this paper. Thermal shock sustainability of the clad was correlated with the %ECR, combined oxide+α-Zr(O) layer thickness, fraction of the load bearing phase and its average oxygen concentration. - Highlights: • Response of the embrittled Zircaloy-4 clad towards thermal shock, simulated under LOCA condition was investigated. • Thermal shock sustainability of the clad was correlated with its evolved stratified microstructure. • Cladding fails at %ECR value ≥ 29. • To resist the thermal shock, clad should have load bearing phase fraction > 0.44 and average oxygen concentration < 0.69 wt%.

  15. Reactor modeling to simulate catalytic partial oxidation and steam reforming of methane. Comparison of temperature profiles and strategies for hot spot minimization

    Energy Technology Data Exchange (ETDEWEB)

    Barrio, V.L.; Cambra, J.F.; Arias, P.L.; Gueemez, M.B. [School of Engineering (UPV/EHU), c/Alameda Urquijo s/n, 48013 Bilbao (Spain); Schaub, G.; Rohde, M. [Engler-Bunte-Institut, Universitaet Karlsruhe, Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Rabe, S.; Vogel, F. [Paul Scherrer Institute, Laboratory for Energy and Materials Cycles, CH-5232 Villigen PSI (Switzerland)

    2007-07-15

    Catalytic partial oxidation (CPO) reactions of methane in the presence of steam (low temperature CPO, LTCPO) over a noble metal catalyst were investigated. A quasi-homogeneous one-dimensional model was developed in order to model a lab-scale fixed-bed reactor to produce syngas. These model calculations can contribute to the optimization of the process with respect to the formation of important hot spots ({delta} T{>=}130 ). These useful data can enable the model development in order to study the influence of the space velocity, product composition and other variables. Furthermore, a feed splitting study was performed. In the heat balance an overall heat transport term was included to account for small heat losses/gains along the reactor. The agreement between simulations and the degree of detail in the model is appropriate for the amount and kind of experimental data available. Thus, this model can also assist in a pilot reactor design, materials and further scale-up. (author)

  16. Temperature control of a steam generator by means of an hybrid system PID-RLC; Control de las temperaturas de un generador de vapor mediante un sistema hibrido PID-RLC

    Energy Technology Data Exchange (ETDEWEB)

    Palomares Gonzalez, Daniel; Garcia Mendoza, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    A description is made of the design and evaluation of an hybrid control system, formed by a quadratic gaussian linear regulator (QLR) and proportional integral derivative (PID) type regulators. This scheme is used to control the reheater and secondary superheater steam temperatures of a steam generator model with a maximum capacity of 2,150,000 pounds per hour. Once applied to the model of a 300 MW steam power plant, this system showed better results than the traditional schemes and inclusively better than some modern control schemes. This fact characterizes it as a high potential system to be applied to steam power plants. [Espanol] Se describe el diseno y la evaluacion de un sistema de control hibrido, formado por un regulador lineal cuadratico gaussiano (RLC) y reguladores tipo proporcional integral derivativo (PID). Este esquema se utiliza para controlar las temperaturas de vapor del recalentador y sobrecalentador secundario del modelo de un generador de vapor con capacidad maxima de 2,150,000 libras por hora. Una vez aplicado al modelo de una unidad termoelectrica de 300 MW, este sistema produjo mejores resultados que los esquemas tradicionales e incluso mejores que algunos esquemas de control moderno. Esto lo caracteriza como un sistema con un alto potencial para aplicarse a unidades termoelectricas.

  17. Direct LiT Electrolysis in a Metallic Fusion Blanket

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Luke [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-30

    A process that simplifies the extraction of tritium from molten lithium-based breeding blankets was developed. The process is based on the direct electrolysis of lithium tritide using a ceramic Li ion conductor that replaces the molten salt extraction step. Extraction of tritium in the form of lithium tritide in the blankets/targets of fusion/fission reactors is critical in order to maintain low concentrations. This is needed to decrease the potential tritium permeation to the surroundings and large releases from unforeseen accident scenarios. Extraction is complicated due to required low tritium concentration limits and because of the high affinity of tritium for the blanket. This work identified, developed and tested the use of ceramic lithium ion conductors capable of recovering hydrogen and deuterium through an electrolysis step at high temperatures.

  18. Direct Lit Electrolysis In A Metallic Lithium Fusion Blanket

    Energy Technology Data Exchange (ETDEWEB)

    Colon-Mercado, H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Babineau, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Elvington, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Garcia-Diaz, B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Teprovich, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Vaquer, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    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

  19. Minimization of steam requirements and enhancement of water-gas shift reaction with warm gas temperature CO2 removal

    Science.gov (United States)

    Siriwardane, Ranjani V; Fisher, II, James C

    2013-12-31

    The disclosure utilizes a hydroxide sorbent for humidification and CO.sub.2 removal from a gaseous stream comprised of CO and CO.sub.2 prior to entry into a water-gas-shift reactor, in order to decrease CO.sub.2 concentration and increase H.sub.2O concentration and shift the water-gas shift reaction toward the forward reaction products CO.sub.2 and H.sub.2. The hydroxide sorbent may be utilized for absorbtion of CO.sub.2 exiting the water-gas shift reactor, producing an enriched H.sub.2 stream. The disclosure further provides for regeneration of the hydroxide sorbent at temperature approximating water-gas shift conditions, and for utilizing H.sub.2O product liberated as a result of the CO.sub.2 absorption.

  20. Nickel and its alloys as perspective materials for intermediate temperature steam electrolysers operating on proton conducting solid acids as electrolyte

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Jensen, Jens Oluf

    2012-01-01

    Several stainless steels, nickel-based alloys, Ta-coated stainless steel, niobium, nickel, platinum and gold were evaluated as possible materials for use in the intermediate temperature water electrolysers. The corrosion resistance was measured in molten KH2PO4 as simulated conditions corresponding...... plates and cell housing. It was shown, that nickel, high-nickel alloys and austenitic stainless steels containing small amounts of Ti have high corrosion resistance in this media. © The Electrochemical Society....... to protonconducting solid acids or transition metal phosphates as electrolytes. It was shown that Au is subject to corrosion in molten KH 2PO4 during polarisation. However, Ni and Ta-coated stainless steel (AISI 316L) demonstrated high corrosion stability and can be recommended as a construction material for bipolar...

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

    Directory of Open Access Journals (Sweden)

    Y. Kirosa

    2017-03-01

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

  2. Steam Digest 2001

    Energy Technology Data Exchange (ETDEWEB)

    2002-01-01

    Steam Digest 2001 chronicles BestPractices Program's contributions to the industrial trade press for 2001, and presents articles that cover technical, financial and managerial aspects of steam optimization.

  3. Electrolysis of a molten semiconductor

    Science.gov (United States)

    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

  4. Understand the basics of packaged steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. [ABCO Industries, Abilene, TX (United States)

    1997-07-01

    Oil- and gas-fired packaged steam generators are widely used in chemical plants, refineries and cogeneration systems. They form an important part of the total steam system in any plant and are available in capacities up to 250,000 lb/h at pressures ranging from 150 to 1,500 psig and temperatures from saturated steam to 1,000 F. They are expected to last about 25 years, and, therefore, cost-effectively generate steam. However, when making purchasing decisions, plant engineers, consultants and engineering firms spend little time on important aspects such as long-term performance and operating costs and often recommend standard, off-the-shelf designs that have several limitations. Here are important design and performance aspects of packaged steam generators and recent trends in their design that engineers should be familiar with.

  5. The Invisibility of Steam

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2014-01-01

    Almost everyone "knows" that steam is visible. After all, one can see the cloud of white issuing from the spout of a boiling tea kettle. In reality, steam is the gaseous phase of water and is invisible. What you see is light scattered from the tiny droplets of water that are the result of the condensation of the steam as its temperature…

  6. Steam Digest Volume IV

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-07-01

    This edition of the Steam Digest is a compendium of 2003 articles on the technical and financial benefits of steam efficiency, presented by the stakeholders of the U.S. Department of Energy's BestPractices Steam effort.

  7. Steam Digest: Volume IV

    Energy Technology Data Exchange (ETDEWEB)

    2004-07-01

    This edition of the Steam Digest is a compendium of 2003 articles on the technical and financial benefits of steam efficiency, presented by the stakeholders of the U.S. Department of Energy's BestPractices Steam effort.

  8. Attenuated Allergenic Activity of Ovomucoid After Electrolysis

    Science.gov (United States)

    Kido, Jun

    2015-01-01

    Ovomucoid (OMC) is the most prominent allergen causing hen's egg allergy, containing disulfide (S-S) bonds that may be responsible for its allergic action. As S-S bonds may be reduced during electrolysis, this study was undertaken to evaluate modulation of the allergic action of OMC after electrolysis. Electrolysis was carried out for 1% OMC containing 1% sodium chloride for 30 minutes with a voltage difference of 90 V, 0.23 A (30 mA/cm2). Protein assays, amino acid measurement, and mass spectrometry in untreated OMC and OMC on both the anode and cathode sides after electrolysis were performed. Moreover, 21 patients with IgE-mediated hen's egg allergy were evaluated by using the skin prick test (SPT) for untreated OMC and OMC after electrolysis. The allergic action of OMC was reduced after electrolysis on both the anode and cathode sides when evaluated by the SPT. The modifications of OMC on electrolysis caused the loss of 2 distinct peptide fragments (57E-63K and 123H-128R) as seen on matrix-associated laser desorption/ionization time-of-flight mass spectrometry. The total free SH groups in OMC were increased on the cathode side. Although the regions of S-S broken bonds were not determined in this study, the change in S-S bonds in OMC on both the anode and cathode sides may reduce the allergenic activity. PMID:26333707

  9. Production of HBR from bromine and steam for off-peak electrolytic hydrogen generation

    Energy Technology Data Exchange (ETDEWEB)

    Schlief, R.E.; Hanrahan, R.J.; Stoy, M.A. [Univ. of Florida, Gainesville, FL (United States)] [and others

    1995-09-01

    Progress is reported on the development of a renewable energy source based solar-electrolytic system for production of hydrogen and oxygen. It employs water, bromine, solar energy and supplemental electrical power. The concept is being developed by Solar Reactor Technologies, Inc., (SRT), with the U.S. Department of Energy (DOE). An overview of the nature and objectives of this program is provided here, and technical progress made during the first (three-month) performance period of the Phase I work effort is reported. The SRT concept entails (1) absorption of concentrated solar radiation by bromine vapor Br{sub 2(g)} in a high-temperature reactor producing Br{sub (g)} atoms, (2) reaction of Br{sub (g)} with water yielding hydrogen bromide (HBr), and (3) electrolysis of stored hydrogen bromide for production of H{sub 2(g)} and recovery of Br{sub 2(I)}. Incorporation of solar radiation in the primary photochemical step (1) reduces by 50 - 70% the electrical power required to split water. The SRT concept is very attractive from an economic viewpoint as well. The reversible fuel cell, employed in the SRT electrolysis concept is capitalized via its use in load leveling by the utility. A 1 kW solar reactor was designed and constructed during the first three-month performance period by SRT personnel at the University of Florida, Gainesville. It was employed in taking survey data of the reaction between bromine and steam at temperatures between 900 and 1300 K. This reaction was run under purely thermal conditions, i.e. in the absence of solar photons. The experimental data are reported and interpreted employing concomitant thermodynamic calculations. The anticipated improvement is discussed briefly as well as the effect of a photochemical boost to the reaction. The amount of this enhancement will be studied in the next three month performance period.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

  11. ELECTROLYSIS OF THORIUM AND URANIUM

    Science.gov (United States)

    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.

  12. An Improved Steam Injection Model with the Consideration of Steam Override

    Directory of Open Access Journals (Sweden)

    He Congge

    2017-01-01

    Full Text Available The great difference in density between steam and liquid during wet steam injection always results in steam override, that is, steam gathers on the top of the pay zone. In this article, the equation for steam override coefficient was firstly established based on van Lookeren’s steam override theory and then radius of steam zone and hot fluid zone were derived according to a more realistic temperature distribution and an energy balance in the pay zone. On this basis, the equation for the reservoir heat efficiency with the consideration of steam override was developed. Next, predicted results of the new model were compared with these of another analytical model and CMG STARS (a mature commercial reservoir numerical simulator to verify the accuracy of the new mathematical model. Finally, based on the validated model, we analyzed the effects of injection rate, steam quality and reservoir thickness on the reservoir heat efficiency. The results show that the new model can be simplified to the classic model (Marx-Langenheim model under the condition of the steam override being not taken into account, which means the Marx-Langenheim model is corresponding to a special case of this new model. The new model is much closer to the actual situation compared to the Marx-Langenheim model because of considering steam override. Moreover, with the help of the new model, it is found that the reservoir heat efficiency is not much affected by injection rate and steam quality but significantly influenced by reservoir thickness, and to ensure that the reservoir can be heated effectively, the reservoir thickness should not be too small.

  13. Steam-water relative permeability

    Energy Technology Data Exchange (ETDEWEB)

    Ambusso, W.; Satik, C.; Home, R.N. [Stanford Univ., CA (United States)

    1997-12-31

    A set of relative permeability relations for simultaneous flow of steam and water in porous media have been measured in steady state experiments conducted under the conditions that eliminate most errors associated with saturation and pressure measurements. These relations show that the relative permeabilities for steam-water flow in porous media vary approximately linearly with saturation. This departure from the nitrogen/water behavior indicates that there are fundamental differences between steam/water and nitrogen/water flows. The saturations in these experiments were measured by using a high resolution X-ray computer tomography (CT) scanner. In addition the pressure gradients were obtained from the measurements of liquid phase pressure over the portions with flat saturation profiles. These two aspects constitute a major improvement in the experimental method compared to those used in the past. Comparison of the saturation profiles measured by the X-ray CT scanner during the experiments shows a good agreement with those predicted by numerical simulations. To obtain results that are applicable to general flow of steam and water in porous media similar experiments will be conducted at higher temperature and with porous rocks of different wetting characteristics and porosity distribution.

  14. Ni-Based Catalysts for Low Temperature Methane Steam Reforming: Recent Results on Ni-Au and Comparison with Other Bi-Metallic Systems

    Directory of Open Access Journals (Sweden)

    Anna M. Venezia

    2013-06-01

    Full Text Available Steam reforming of light hydrocarbons provides a promising method for hydrogen production. Ni-based catalysts are so far the best and the most commonly used catalysts for steam reforming because of their acceptably high activity and significantly lower cost in comparison with alternative precious metal-based catalysts. However, nickel catalysts are susceptible to deactivation from the deposition of carbon, even when operating at steam-to-carbon ratios predicted to be thermodynamically outside of the carbon-forming regime. Reactivity and deactivation by carbon formation can be tuned by modifying Ni surfaces with a second metal, such as Au through alloy formation. In the present review, we summarize the very recent progress in the design, synthesis, and characterization of supported bimetallic Ni-based catalysts for steam reforming. The progress in the modification of Ni with noble metals (such as Au and Ag is discussed in terms of preparation, characterization and pretreatment methods. Moreover, the comparison with the effects of other metals (such as Sn, Cu, Co, Mo, Fe, Gd and B is addressed. The differences of catalytic activity, thermal stability and carbon species between bimetallic and monometallic Ni-based catalysts are also briefly shown.

  15. Highly energetic phenomena in water electrolysis.

    Science.gov (United States)

    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.

  16. Highly energetic phenomena in water electrolysis

    Science.gov (United States)

    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.

  17. Methanogenesis in membraneless microbial electrolysis cells.

    Science.gov (United States)

    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.

  18. Customizing pays off in steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. (ABCO Industries, Inc., Abilene, TX (United States))

    1995-01-01

    Packaged steam generators are the workhorses of chemical process plants, power plants and cogeneration systems. They are available as oil- or gas-fired models, and are used to generate either high-pressure superheated steam (400 to 1,200 psig, at 500 to 900 F) or saturated steam at low pressures (100 to 300 psig). In today's emission- and efficiency- conscious environment, steam generators have to be custom designed. Gone are the days when a boiler supplier--or for that matter an end user--could look up a model number from a list of standard sizes and select one for a particular need. Thus, before selecting a system, it is desirable to know the features of oil- and gas-fired steam generators, and the important variables that influence their selection, design and performance. It is imperative that all of these data are supplied to the boiler supplier so that the engineers may come up with the right design. Some of the parameters which are discussed in this paper are: duty, steam temperature, steam purity, emissions, and furnace design. Superheaters, economizers, and overall performance are also discussed.

  19. Economic comparison of hydrogen production using sulfuric acid electrolysis and sulfur cycle water decomposition. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Farbman, G.H.; Krasicki, B.R.; Hardman, C.C.; Lin, S.S.; Parker, G.H.

    1978-06-01

    An evaluation of the relative economics of hydrogen production using two advanced techniques was performed. The hydrogen production systems considered were the Westinghouse Sulfur Cycle Water Decomposition System and a water electrolysis system employing a sulfuric acid electrolyte. The former is a hybrid system in which hydrogen is produced in an electrolyzer which uses sulfur dioxide to depolarize the anode. The electrolyte is sulfuric acid. Development and demonstration efforts have shown that extremely low cell voltages can be achieved. The second system uses a similar sulfuric acid electrolyte technology in water electrolysis cells. The comparative technoeconomics of hydrogen produced by the hybrid Sulfur Cycle and by water electrolysis using a sulfuric acid electrolyte were determined by assessing the performance and economics of 380 million SCFD plants, each energized by a very high temperature nuclear reactor (VHTR). The evaluation concluded that the overall efficiencies of hydrogen production, for operating parameters that appear reasonable for both systems, are approximately 41% for the sulfuric acid electrolysis and 47% for the hybrid Sulfur Cycle. The economic evaluation of hydrogen production, based on a 1976 cost basis and assuming a developed technology for both hydrogen production systems and the VHTRs, indicated that the hybrid Sulfur Cycle could generate hydrogen for a total cost approximately 6 to 7% less than the cost from the sulfuric acid electrolysis plant.

  20. Thermodynamic analysis of synthetic hydrocarbon fuel production in pressurized solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Jensen, Søren Højgaard

    2012-01-01

    A promising way to store wind and solar electricity is by electrolysis of H2O and CO2 using solid oxide electrolysis cells (SOECs) to produce synthetic hydrocarbon fuels that can be used in existing fuel infrastructure. Pressurized operation decreases the cell internal resistance and enables...... hydrocarbon fuel and avoiding damage to the cells. The main parameters of cell operating temperature, pressure, inlet gas composition and reactant utilization are varied to examine how they influence cell thermoneutral and reversible potentials, in situ formation of methane and carbon at the Ni–YSZ electrode...

  1. Thermography of flame during diesel fuel combustion with steam gasification

    Science.gov (United States)

    Anufriev, I. S.; Arsentyev, S. S.; Agafontsev, M. V.; Kopyev, E. P.; Loboda, E. L.; Shadrin, E. Yu; Sharypov, O. V.

    2017-11-01

    The paper represents a study concerning the combustion of liquid hydrocarbon fuel in a perspective burner device with the controlled forced supply of overheated steam into the combustion zone, using diesel fuel. The thermal imaging measurements are conducted for the outer flame of the burner device in the wide range of regime parameters (flow rate and temperature of steam). A thermal imaging camera (FLIR, JADE J530SB) is used in the experiments. The effective emissivity coefficient of flame is obtained versus the flow rate of steam supplied. The steam parameters are found to influence on the temperature in the outer flame of the burner device.

  2. High-temperature nuclear reactor power plant cycle for hydrogen and electricity production – numerical analysis

    Directory of Open Access Journals (Sweden)

    Dudek Michał

    2016-01-01

    Full Text Available High temperature gas-cooled nuclear reactor (called HTR or HTGR for both electricity generation and hydrogen production is analysed. The HTR reactor because of the relatively high temperature of coolant could be combined with a steam or gas turbine, as well as with the system for heat delivery for high-temperature hydrogen production. However, the current development of HTR’s allows us to consider achievable working temperature up to 750°C. Due to this fact, industrial-scale hydrogen production using copper-chlorine (Cu-Cl thermochemical cycle is considered and compared with high-temperature electrolysis. Presented calculations show and confirm the potential of HTR’s as a future solution for hydrogen production without CO2 emission. Furthermore, integration of a hightemperature nuclear reactor with a combined cycle for electricity and hydrogen production may reach very high efficiency and could possibly lead to a significant decrease of hydrogen production costs.

  3. An Isothermal Steam Expander for an Industrial Steam Supplying System

    OpenAIRE

    Chen-Kuang Lin; Guang-Jer Lai; Yoshiyuki Kobayashi; Masahiro Matsuo; Min-Chie Chiu

    2015-01-01

    Steam is an essential medium used in the industrial process. To ensure steam quality, small and middle scale boilers are often adopted. However, because a higher steam pressure (compared to the necessary steam pressure) is generated, the boiler’s steam pressure will be reduced via a pressure regulator before the steam is directed through the process. Unfortunately, pressure is somewhat wasted during the reducing process. Therefore, in order to promote energy efficiency, a pressure regulator i...

  4. Mathematical modeling of control system for the experimental steam generator

    Directory of Open Access Journals (Sweden)

    Podlasek Szymon

    2016-01-01

    Full Text Available A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units – quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

  5. Mathematical modeling of control system for the experimental steam generator

    Science.gov (United States)

    Podlasek, Szymon; Lalik, Krzysztof; Filipowicz, Mariusz; Sornek, Krzysztof; Kupski, Robert; Raś, Anita

    2016-03-01

    A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units - quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics) are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

  6. Diagnosis of a cathode-supported solid oxide electrolysis cell by electrochemical impedance spectroscopy

    NARCIS (Netherlands)

    Nechache, A.; Mansuy, A.; Petitjean, M.; Mougin, J.; Mauvy, F.; Boukamp, Bernard A.; Cassir, M.; Ringuede, A.

    2016-01-01

    High-temperature electrolysis (HTSE) is a quite recent topic where most of the studies are focused on performance measurements and degradation observations, mainly achieved by polarization curve. However, it mainly leads to the overall cell behaviour. To get more specific knowledge on the operation

  7. Equations for calculating the properties of dissociated steam

    Science.gov (United States)

    Aminov, R. Z.; Gudym, A. A.

    2017-08-01

    The equations of state for dissociated steam have been developed in the temperature and pressure ranges of 1250-2300 K and 0.01-10.00 MPa for calculating thermodynamic processes in thermal power units operating on high-temperature steam. These equations are based on the property tables for dissociated steam derived at a reference temperature of 0 K. It is assumed that the initial substance is steam, the dissociation of which—in accordance with the most likely chemical reactions—results in formation of molecules of hydrogen, oxygen, steam, hydroxyl, and atoms of oxygen and hydrogen. Differential thermodynamic correlations, considering a change in the chemical potential and the composition of the mixture, during the steam dissociation are used. A reference temperature of 0.01°C used in the calculation of parameters of nondissociated steam has been adopted to predict processes in thermal power units without matching the reference temperatures and to account for transformation of dissociated steam into its usual form for which there is the international system of equations with the water triple point of 0.01°C taken as the reference. In the investigated region, the deviation of dissociated steam properties from those of nondissociated steam, which increases with decreasing the pressure or increasing the temperature, was determined. For a pressure of 0.02 MPa and a temperature of 2200 K, these deviations are 512 kJ/kg for the enthalpy, 0.2574 kJ/(kg K) for the entropy, and 3.431 kJ/(kg K) for the heat capacity at constant pressure. The maximum deviation of the dissociated steam properties calculated by the developed equations from the handbook values that these equations are based on does not exceed 0.03-0.05%.

  8. The use of isotropic and anisotropic concepts of damage to the calculation of the long-term strength of steam turbine rotor under conditions of high temperature creep

    OpenAIRE

    Гораш, Є. М.

    2006-01-01

    Within the framework of the research work two typical material models describing isotropic and anisotropic creep-damage processes in metals and alloys are applied to the simulation of the mechanical behaviour of a steam turbine rotor in its service conditions. Numerical solutions of the initial-boundary value problems have been obtained by FEM using solid axisymmetrical type finite elements. For the purpose of adequate long-term strength analysis both isotropic and anisotropic creep-damage mo...

  9. Oxygen-hydrogen torch is a small-scale steam generator

    Science.gov (United States)

    Maskell, C. E.

    1966-01-01

    Standard oxygen-hydrogen torch generates steam for corrosion-rate analysis of various metals. The steam is generated through local combustion inside a test chamber under constant temperature and pressure control.

  10. Steam reforming of ethanol

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Dahl, Søren; Jensen, Anker Degn

    2013-01-01

    Steam reforming (SR) of oxygenated species like bio-oil or ethanol can be used to produce hydrogen or synthesis gas from renewable resources. However, deactivation due to carbon deposition is a major challenge for these processes. In this study, different strategies to minimize carbon deposition...... on Ni-based catalysts during SR of ethanol were investigated in a flow reactor. Four different supports for Ni were tested and Ce0.6Zr0.4O2 showed the highest activity, but also suffered from severe carbon deposition at 600 °C or below. Operation at 600 °C or above were needed for full conversion...... of ethanol over the most active catalysts at the applied conditions. At these temperatures the offgas composition was close to the thermodynamical equilibrium. Operation at high temperatures, 700 °C and 750 °C, gave the lowest carbon deposition corresponding to 30–60 ppm of the carbon in the feed ending...

  11. Steampunk: Full Steam Ahead

    Science.gov (United States)

    Campbell, Heather M.

    2010-01-01

    Steam-powered machines, anachronistic technology, clockwork automatons, gas-filled airships, tentacled monsters, fob watches, and top hats--these are all elements of steampunk. Steampunk is both speculative fiction that imagines technology evolved from steam-powered cogs and gears--instead of from electricity and computers--and a movement that…

  12. STEAM by Design

    Science.gov (United States)

    Keane, Linda; Keane, Mark

    2016-01-01

    We live in a designed world. STEAM by Design presents a transdisciplinary approach to learning that challenges young minds with the task of making a better world. Learning today, like life, is dynamic, connected and engaging. STEAM (Science, Technology, Environment, Engineering, Art, and Math) teaching and learning integrates information in…

  13. Safety Picks up "STEAM"

    Science.gov (United States)

    Roy, Ken

    2016-01-01

    This column shares safety information for the classroom. STEAM subjects--science, technology, engineering, art, and mathematics--are essential for fostering students' 21st-century skills. STEAM promotes critical-thinking skills, including analysis, assessment, categorization, classification, interpretation, justification, and prediction, and are…

  14. Steam generator specifications

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. [ABCO Industries, Abilene, TX (United States)

    1996-12-31

    This paper describes some of the recent trends in steam generator designs and how engineers should develop specifications for them. Purchasing a steam generator based on standard designs available in the form of tabular data or based on square feet of surface can lead to a poor selection as will be explained later. Several aspects such as emissions, steam parameters, special plant requirements can affect the design and configuration of steam generators. A custom designed steam generator is the best choice as it has several advantages over standard design. Also, to arrive at the optimum design one has to consider not only the initial costs but also the operating costs. Going by thumb rules or misleading and outdated surface area norms should be avoided.

  15. An Isothermal Steam Expander for an Industrial Steam Supplying System

    Directory of Open Access Journals (Sweden)

    Chen-Kuang Lin

    2015-01-01

    Full Text Available Steam is an essential medium used in the industrial process. To ensure steam quality, small and middle scale boilers are often adopted. However, because a higher steam pressure (compared to the necessary steam pressure is generated, the boiler’s steam pressure will be reduced via a pressure regulator before the steam is directed through the process. Unfortunately, pressure is somewhat wasted during the reducing process. Therefore, in order to promote energy efficiency, a pressure regulator is replaced by a steam expander. With this steam expander, the pressure will be transformed into mechanical energy and extracted during the expansion process. A new type of isothermal steam expander for an industrial steam supplying system will be presented in the paper. The isothermal steam expander will improve the energy efficiency of a traditional steam expander by replacing the isentropic process with an isothermal expansion process. With this, steam condensation will decrease, energy will increase, and steam quality will be improved. Moreover, the mathematical model of the isothermal steam expander will be established by using the Schmidt theory, the same principle used to analyze Stirling engines. Consequently, by verifying the correctness of the theoretical model for the isothermal steam expander using experimental data, a prototype of 100 c.c. isothermal steam expander is constructed.

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

    Science.gov (United States)

    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.

  17. 21 CFR 886.4250 - Ophthalmic electrolysis unit.

    Science.gov (United States)

    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 destroy...

  18. Ultra supercritical turbines--steam oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R.; Covino, Bernard S., Jr.; Bullard, Sophie J.; Cramer, Stephen D.; Ziomek-Moroz, Margaret; Alman, David E.

    2004-01-01

    Ultra supercritical (USC) power plants offer the promise of higher efficiencies and lower emissions, which are goals of the U.S. Department of Energy?s Advanced Power Systems Initiatives. Most current coal power plants in the U.S. operate at a maximum steam temperature of 538?C. However, new supercritical plants worldwide are being brought into service with steam temperatures of up to 620?C. Current Advanced Power Systems goals include coal generation at 60% efficiency, which would require steam temperatures of up to 760?C. This research examines the steamside oxidation of advanced alloys for use in USC systems, with emphasis placed on alloys for high- and intermediate-pressure turbine sections. Initial results of this research are presented.

  19. Durable solid oxide electrolysis cells and stacks

    Energy Technology Data Exchange (ETDEWEB)

    Ming Chen

    2010-08-15

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

  20. Steam atmosphere drying concepts using steam exhaust recompression

    Energy Technology Data Exchange (ETDEWEB)

    DiBella, F.A. (TECOGEN, Inc., Waltham, MA (United States))

    1992-08-01

    In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg[sub evap] to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

  1. Steam atmosphere drying concepts using steam exhaust recompression

    Energy Technology Data Exchange (ETDEWEB)

    DiBella, F.A. [TECOGEN, Inc., Waltham, MA (United States)

    1992-08-01

    In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg{sub evap} to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

  2. Modeling Degradation in Solid Oxide Electrolysis Cells - Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Manohar Motwani

    2011-09-01

    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 non-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, non-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.

  3. High-temperature process-steam application at the Southern Union Refining Company, Hobbs, New Mexico (solar energy in the oil patch). Phase I design. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-31

    Southern Union Refining Company's Famariss Energy Refinery has worked diligently with Monument Solar Corporation in the conceptual and detail design for this unique application of solar generated steam. An area closely adjacent to the refinery and fronting New Mexico State Highway No. 18 has been designated for the solar collector array. Space planned for the demonstration parabolic trough array is sufficiently large to handle an array of 25,200 square feet in size - an array more than twice the size of the 10,080 square feet proposed originally. The conceptual design, performance, safety, environmental impact, and economic analysis are described. Engineering drawings are included. (WHK)

  4. Steam boiler technology

    Energy Technology Data Exchange (ETDEWEB)

    Teir, S.

    2003-07-01

    This book is the published version of the e-book with the same name. The interactive lecture slides, which accompany most chapters, exist only in the online version and on the attached CD-Rom. The Steam Boiler Technology e-book is the main course book for the course on steam boiler technology provided by the Laboratory of Energy Engineering and Environmental Protection at Helsinki University of Technology. The steam boiler technology e-Book is provided by the Laboratory of Energy Engineering and Environmental Protection at Helsinki University of Technology. The book covers the basics and the history of steam generation, modern boilers types and applications, steam/water circulation design, feedwater and steam systems components, heat exchangers in steam boilers, boiler calculations, thermal design of heat exchangers. The chapters of the second edition have been corrected based on reader and reviewer comments, and four new chapters have been added. The user interface of the electronic version has also been updated. The password for the online book will be changed once a year. If you have problems accessing the online book, or need a new password, please contact sebastian.teir@hut.fi.

  5. Development of the process of energy transfer from a nuclear Power Plant to an intermediate temperature electrolyse; Desarrollo del proceso de transferencia de energia desde una central nuclear a un electrolizador de temperatura intermedia

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Cervantes, A.; Cuadrado Garcia, P.; Soraino Garcia, J.

    2013-07-01

    Fifty million tons of hydrogen are consumed annually in the world in various industrial processes. Among them, the ammonia production, oil refining and the production of methanol. One of the methods to produce it is the electrolysis of water, oxygen and hydrogen. This process needs electricity and steam which a central nuclear It can be your source; Hence the importance of developing the transfer process energy between the two. The objective of the study is to characterize the process of thermal energy transfer from a nuclear power plant to an electrolyzer of intermediate temperature (ITSE) already defined. The study is limited to the intermediate engineering process, from the central to the cell.

  6. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  7. Steam reforming catalyst

    Science.gov (United States)

    Kramarz, Kurt W.; Bloom, Ira D.; Kumar, Romesh; Ahmed, Shabbir; Wilkenhoener, Rolf; Krumpelt, Michael

    2001-01-01

    A method of forming a hydrogen rich gas from a source of hydrocarbon fuel. A vapor of the hydrocarbon fuel and steam is brought in contact with a two-part catalyst having a dehydrogenation powder portion and an oxide-ion conducting powder portion at a temperature not less than about 770.degree.C. for a time sufficient to generate the hydrogen rich. The H.sub.2 content of the hydrogen gas is greater than about 70 percent by volume. The dehydrogenation portion of the catalyst includes a group VIII metal, and the oxide-ion conducting portion is selected from a ceramic oxide from the group crystallizing in the fluorite or perovskite structure and mixtures thereof. The oxide-ion conducting portion of the catalyst is a ceramic powder of one or more of ZrO.sub.2, CeO.sub.2, Bi.sub.2 O.sub.3, (BiVO).sub.4, and LaGaO.sub.3.

  8. Steam turbines with a low-boiling working agent

    OpenAIRE

    Morozov, N.; Karasev, V.

    2010-01-01

    The subject of the article is the assembly of a steam-generator plant with a natural working agent. A method of calculation for steam turbines with a low-boiling working agent is offered, which accounts for the correlation between the adiabatic curve indication, pressure and temperature in the overheated vapor area.

  9. Methane Steam Reforming Kinetics for a Rhodium-Based Catalyst

    DEFF Research Database (Denmark)

    Jakobsen, Jon Geest; Jakobsen, M.; Chorkendorff, Ib

    2010-01-01

    Methane steam reforming is the key reaction to produce synthesis gas and hydrogen at the industrial scale. Here the kinetics of methane steam reforming over a rhodium-based catalyst is investigated in the temperature range 500-800 A degrees C and as a function of CH4, H2O and H-2 partial pressures...

  10. Kinetic simulation model for steam pyrolysis of shale oil feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Kavianian, H.R.; Yesavage, V.F.; Dickson, P.F.; Peters, R.W. (Argonne National Lab., Argonne, IL (US))

    1990-04-01

    Steam pyrolysis of shale oil feedstocks for the production of chemical intermediates was studied in a bench-scale tubular reactor. The results have been correlated as a function of temperature, residence time, and pyrolysis severity. The experimental results obtained upon pyrolysis of shale oil indicate that shale oil should make an excellent feedstock for steam pyrolysis.

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

    Science.gov (United States)

    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

  12. New ferritic steels for advanced steam plants

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K.H; Koenig, H. [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1998-12-31

    During the last 15-20 years ferritic-martensitic 9-12 % chromium steels have been developed under international research programmes which permit inlet steam temperatures up to approx. 625 deg C and pressures up to about 300 bars, thus leading to improvements in thermal efficiency of around 8 % and a CO{sub 2} reduction of about 20 % versus conventional steam parameters. These new steels are already being applied in 13 European and 34 Japanese power stations with inlet steam temperature up to 610 deg C. This presentation will give an account of the content, scope and results of the research programmes and of the experience gained during the production of components which have been manufactured from the new steels. (orig.) 13 refs.

  13. Combining Electrolysis and Electroporation for Tissue Ablation.

    Science.gov (United States)

    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. © The Author(s) 2014.

  14. Transient nanobubbles in short-time electrolysis

    NARCIS (Netherlands)

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

    2013-01-01

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

  15. Steam Properties Database

    Science.gov (United States)

    SRD 10 NIST/ASME Steam Properties Database (PC database for purchase)   Based upon the International Association for the Properties of Water and Steam (IAPWS) 1995 formulation for the thermodynamic properties of water and the most recent IAPWS formulations for transport and other properties, this updated version provides water properties over a wide range of conditions according to the accepted international standards.

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

    Science.gov (United States)

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

    1988-01-01

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

  17. Temperature and thermal power measurements for a helical-coil steam generator in a thermal storage tank of molten solar salt

    Science.gov (United States)

    Marakkos, Costas; Stiliaris, Efstathios; Guillen, Elena; Montenon, Alaric; Papanicolas, Costas

    2017-06-01

    The steam power output of a helical-col generator is both experimentally and numerically examined using Nusselt number correlations from literature. Validation studies of the correlation models examined herein are performed for a mass flux G of 84 kg.s-1.m-2, power output Q of 15.5 kW, supply pressure P of 0.81 MPa and internal tube-diameter to coil-diameter ratio Di/Dc of 0.027. Existing two-phase models applied with Newton's Law of cooling, lead to an under-prediction of the coil size, namely, the tube length requirement for a specified power output by about 20%.

  18. An numerical analysis of high-temperature helium reactor power plant for co-production of hydrogen and electricity

    Science.gov (United States)

    Dudek, M.; Podsadna, J.; Jaszczur, M.

    2016-09-01

    In the present work, the feasibility of using a high temperature gas cooled nuclear reactor (HTR) for electricity generation and hydrogen production are analysed. The HTR is combined with a steam and a gas turbine, as well as with the system for heat delivery for medium temperature hydrogen production. Industrial-scale hydrogen production using copper-chlorine (Cu-Cl) thermochemical cycle is considered and compared with high temperature electrolysis. Presented cycle shows a very promising route for continuous, efficient, large-scale and environmentally benign hydrogen production without CO2 emissions. The results show that the integration of a high temperature helium reactor, with a combined cycle for electric power generation and hydrogen production, may reach very high efficiency and could possibly lead to a significant decrease of hydrogen production costs.

  19. Solar production of industrial process steam ranging in temperature from 300/sup 0/F to 550/sup 0/F (Phase I). Volume 1. Final report, September 30, 1978-June 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-30

    This section summarizes the Foster Wheeler Development Corporation/Dow Chemical Company Phase I solar industrial process steam system and includes a system schematic, a brief system description, general specifications of the major system components, expected system performance, and a cost estimate summary for Phases II and III. The objectives of Phase I are: (1) design a cost-effective solar steam generating system, using state-of-the-art components and technology, to supply steam for Dow Chemical Company's Dalton, Georgia, plant; (2) predict the performance of the solar process steam plant; (3) conduct a safety evaluation and an environmental impact assessment of the solar steam system; (4) conduct an economic analysis to determine the potential economic benefits of a solar-augmented process steam production system compared with an existing fossil-fuel-fired steam generator; and (5) promote the project extensively to make it visible to industry and the general public.

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

    Science.gov (United States)

    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.

  1. 2nd Generation alkaline electrolysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-03-15

    The overall purpose of this project has been to contribute to this load management by developing a 2{sup nd} generation of alkaline electrolysis system characterized by being compact, reliable, inexpensive and energy efficient. The specific targets for the project have been to: 1) Increase cell efficiency to more than 88% (according to the higher heating value (HHV)) at a current density of 200 mA /cm{sup 2}; 2) Increase operation temperature to more than 100 degree Celsius to make the cooling energy more valuable; 3) Obtain an operation pressure more than 30 bar hereby minimizing the need for further compression of hydrogen for storage; 4) Improve stack architecture decreasing the price of the stack with at least 50%; 5) Develop a modular design making it easy to customize plants in the size from 20 to 200 kW; 6) Demonstrating a 20 kW 2{sup nd} generation stack in H2College at the campus of Arhus University in Herning. The project has included research and development on three different technology tracks of electrodes; an electrochemical plating, an atmospheric plasma spray (APS) and finally a high temperature and pressure (HTP) track with operating temperature around 250 deg. C and pressure around 40 bar. The results show that all three electrode tracks have reached high energy efficiencies. In the electrochemical plating track a stack efficiency of 86.5% at a current density of 177mA/cm{sup 2} and a temperature of 74.4 deg. C has been shown. The APS track showed cell efficiencies of 97%, however, coatings for the anode side still need to be developed. The HTP cell has reached 100 % electric efficiency operating at 1.5 V (the thermoneutral voltage) with a current density of 1. 1 A/cm{sup 2}. This track only tested small cells in an externally heated laboratory set-up, and thus the thermal loss to surroundings cannot be given. The goal set for the 2{sup nd} generation electrolyser system, has been to generate 30 bar pressure in the cell stack. An obstacle to be

  2. Hydrogen production from biomass over steam gasification

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, R.; Potetz, A.; Hofbauer, H. [Vienna Univ. of Technology (Austria). Inst. of Chemical Engineering; Weber, G. [Bioenergy 2020+, Guessing (Austria)

    2010-12-30

    Renewable hydrogen is one option for a clean energy carrier in the future. There were several research programs in the past, to produce hydrogen on a renewable basis by electrolysis, direct conversion of water or by gasification of biomass. None of these options were developed to a stage, that they could be used on a commercial basis. At the moment almost all hydrogen is produced from fossil fuels and one main consumer of hydrogen are refineries. So a good option to demonstrate the production of renewable hydrogen and bring it later into the market is over refineries. The most economic option to produce renewable hydrogen at the moment is over gasification of biomass. In Austria an indirect gasification system was developed and is demonstrated in Guessing, Austria. The biomass CHP Guessing uses the allothermal steam dual fluidised bed gasifier and produces a high grade product gas, which is used at the moment for the CHP in a gas engine. As there is no nitrogen in the product gas and high hydrogen content, this gas can be also used as synthesis gas or for production of hydrogen. The main aim of this paper is to present the experimental and simulation work to convert biomass into renewable hydrogen. The product gas of the indirect gasification system is mainly hydrogen, carbon monoxide, carbon dioxide and methane. Within the ERA-Net project ''OptiBtLGas'' the reforming of methane and the CO-shift reaction was investigated to convert all hydrocarbons and carbon monoxide to hydrogen. On basis of the experimental results the mass- and energy balances of a commercial 100 MW fuel input plant was done. Here 3 different cases of complexity of the overall plant were simulated. The first case was without reforming and CO-shift, only by hydrogen separation. The second case was by including steam - reforming and afterwards separation of hydrogen. The third case includes hydrocarbon reforming, CO-shift and hydrogen separation. In all cases the off-gases (CO

  3. Treatment of Paper and Pulp Mill Wastewater by Ozonation Combined with Electrolysis

    National Research Council Canada - National Science Library

    KISHIMOTO, Naoyuki; NAKAGAWA, Takahiro; OKADA, Hirokazu; MIZUTANI, Hiroshi

    2010-01-01

    Ozonation combined with electrolysis (ozone-electrolysis), ozonation alone and electrolysis alone were applied to the treatment of a paper and pulp mill wastewater for the decolorization and removal of chemical oxygen demand (COD...

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

    Science.gov (United States)

    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.

  5. Modifikasi Alat Steam untuk Pembengkokan Rotan

    Directory of Open Access Journals (Sweden)

    Eustasia Sri Murwati

    2016-04-01

    distribution of steam because there are no spaces between rattans besides contact with rust stains from tube steamer. The purpose of this study was to modify steamer that is designed multi-purpose steam, can soften rattan with wet steam in a steamer tube, can also be sprayed with dry steam on the rattan surfaces. The method is carried out field survey and literature, design planning, procurement of materials, manufacturing equipment, testing equipment, finishing equipment, evaluation and reporting. The test tool with rattan variable crosssection of 2,4 cm, 2,8 cm 3,2 cm and a steaming rattan 5 minutes, 10 minutes, and 15 minutes, with boiler and steamer tube temperature 110° C, 2 bar maximum pressure (kg / cm2. Results obtained in the form of 1 unit Steam Tool For Bending Rattan consists of: Heating, Steam boiler stainless steel base material JIS G 3116-2000 standard specifications, 118 liter of volume, steam tube SUS 340 Grade, soaking tub and bending table. The trial results are best with a steaming time of 15 minutes, rattan is not broken, no cracking or not deflated, for all variable diameter. Can bend U shape rattan, Ω, semi-circular and spiral. Dry steam trials with great results at the time of spraying is greater than 20 minutes.Keywords: steamer, furniture, bending, rattan

  6. Performance improvement in thermal power plants. ; Design of 700MW coal-fired boiler with elevated reheat steam temperature for Hekinan No. 3 unit, Chubu Electric Power Co. Ltd. Karyoku hatsudensho no seino kojo taisaku. ; Chubu denryoku (kabu) Hekinan karyoku hatsudensho 3 go unit muke koon sainetsu joki ondo (596 degree C)saiyo boiler no keikaku

    Energy Technology Data Exchange (ETDEWEB)

    Kuwahara, M.; Kajigaya, I.; Umaki, H.; Kunihiro, T. (Ishikawajima-Harima Heavy Industries, Co. Ltd., Tokyo (Japan))

    1991-07-15

    The 700 MW coal fired super critical boiler with elevated reheat steam temperature for variable pressure operation was outlined which is under development for the Hekinan No. 3 unit, Chubu Electric Power Co., Inc. Its steam temperature was designed to be 596{degree}C at a reheater outlet and 593{degree}C at an intermediate pressure turbine inlet in the range from 35 to 100% of maximum continuous evaporation. For such high temperature steam conditions, the arrangement of reheater heating surfaces was optimized by examining both static and dynamic characteristics. Tubing materials for the reheater outlet were carefully selected in consideration of coal ash corrosion and steam side oxidation, and modified 9Cr-1Mo steel was widely adopted for high temperature parts. The seam-welded modified 9Cr-1Mo steel pipe was, in particular, adopted for hot reheat pipes, and the bending fabricability and weldability of such steel plate were tested extensively on a full-scale mock-up model to ensure a plant reliability. 1 ref., 15 figs., 4 tabs.

  7. Alkaline Ammonia Electrolysis on Electrodeposited Platinum for Controllable Hydrogen Production.

    Science.gov (United States)

    Gwak, Jieun; Choun, Myounghoon; Lee, Jaeyoung

    2016-02-19

    Ammonia is beginning to attract a great deal of attention as an alternative energy source carrier, because clean hydrogen can be produced through electrolytic processes without the emission of COx . In this study, we deposited various shapes of Pt catalysts under potentiostatic mode; the electrocatalytic oxidation behavior of ammonia using these catalysts was studied in alkaline media. The electrodeposited Pt was characterized by both qualitative and quantitative analysis. To discover the optimal structure and the effect of ammonia concentration, the bulk pH value, reaction temperature, and applied current of ammonia oxidation were investigated using potential sweep and galvanostatic methods. Finally, ammonia electrolysis was conducted using a zero-gap cell, producing highly pure hydrogen with an energy efficiency over 80 %. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  9. Electrolysis activities at FCH Test Center

    DEFF Research Database (Denmark)

    Ravn Nielsen, Eva; Nygaard, Frederik Berg

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

  10. Electrolysis cell for the manufacture of persulfates

    Science.gov (United States)

    Cueto, J. M.

    1986-01-01

    A cell for the electrolytic generation of persulfates, characterized by the fact that a housing acts as cathode, is made of metal, and consists of a lower electrolytically active section and an upper electrolytically inactive section. It is designed so that there is produced the greatest possible current density suited to produce the desired electrolysis effect. This invention, compared to the devices used until now, exhibits considerable advantages whereby it is particularly suited for the production of potassium persulfate.

  11. Specifications and measurements of alternative diaphragms for the industrial advanced alkaline electrolysis

    Science.gov (United States)

    Bardin, J. C.

    Increasing the operating temperature of an alkaline electrolysis cell to improve cell efficiency leads to a requirement for replacing the asbestos diaphragm used in conventional cells with new separator materials. The present paper discusses means for the evaluation of alternative material performance and formulates a set of specifications for diaphragm characteristics. The measurements to be made are in the areas of sample porosity, mechanical behavior, and wettability, with final selection to be on the basis of tests of the operating characteristics of a water electrolysis monocell at a temperature of 120 to 200 C, pressure of 60 bar, current density of 1 A/sq cm and active surface of 0.2 x 0.5 m.

  12. STEAM GENERATOR GROUP PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Clark, R. A.; Lewis, M

    1985-09-01

    This report is a summary of progress in the Surry Steam Generator Group Project for 1984. Information is presented on the analysis of two baseline eddy current inspections of the generator. Round robin series of tests using standard in-service inspection techniques are described along with some preliminary results. Observations are reported of degradation found on tubing specimens removed from the generator, and on support plates characterized in-situ. Residual stresses measured on a tubing specimen are reported. Two steam generator repair demonstrations are described; one for antivibration bar replacement, and one on tube repair methods. Chemical analyses are shown for sludge samples removed from above the tube sheet.

  13. Solid Oxide Electrolysis for Oxygen Production in an ARS Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Paragon Space Development Corporation proposes an innovative, efficient and practical concept that utilizes Solid Oxide Electrolysis for regenerative air...

  14. A Vivens Ex Vivo Study on the Synergistic Effect of Electrolysis and Freezing on the Cell Nucleus.

    Science.gov (United States)

    Lugnani, Franco; Zanconati, Fabrizio; Marcuzzo, Thomas; Bottin, Cristina; Mikus, Paul; Guenther, Enric; Klein, Nina; Rubinsky, Liel; Stehling, Michael K; Rubinsky, Boris

    2015-01-01

    Freezing-cryosurgery, and electrolysis-electrochemical therapy (EChT), are two important minimally invasive surgery tissue ablation technologies. Despite major advantages they also have some disadvantages. Cryosurgery cannot induce cell death at high subzero freezing temperatures and requires multiple freeze thaw cycles, while EChT requires high concentrations of electrolytic products-which makes it a lengthy procedure. Based on the observation that freezing increases the concentration of solutes (including products of electrolysis) in the frozen region and permeabilizes the cell membrane to these products, this study examines the hypothesis that there could be a synergistic effect between freezing and electrolysis in their use together for tissue ablation. Using an animal model we refer to as vivens ex vivo, which may be of value in reducing the use of animals for experiments, combined with a Hematoxylin stain of the nucleus, we show that there are clinically relevant protocols in which the cell nucleus appears intact when electrolysis and freezing are used separately but is affected by certain combinations of electrolysis and freezing.

  15. Energy efficient thermochemical conversion of very wet biomass to biofuels by integration of steam drying, steam electrolysis and gasification

    DEFF Research Database (Denmark)

    Clausen, Lasse Røngaard

    2017-01-01

    by thermodynamic modelling and the analysis shows that the system can handle mechanically dried biomasses with a water content of 70 wt% and an ash content of up to 50 wt% (dry basis). A high tolerable ash content is an advantage because very wet biomasses, such as sewage sludge and manure, have a high ash content....... The analysis shows that the total efficiency of the novel system is 69–70% depending on the biomass ash content, while the biomass to SNG energy ratio is 165%, which is near the theoretical maximum because electrolytic hydrogen is supplied to the synthesis gas. It is proposed to combine the novel system...

  16. Analysis regarding steam generator furnace's incident heat, temperature and composition of combustion gases; Analisis de calor incidente, temperatura y composicion de gases de combustion en hornos de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Diego Marin, Antonio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2006-07-01

    In order to obtain more precise evaluations of the combustion process in the furnace of a steam generator a suction pyrometer has been integrated to measure the temperature of the combustion gases; an ellipsoidal radiometer to measure the incident heat by thermal radiation in the water walls; a water cooled probe to determine the particle concentration, as well as a water cooled probe to determine the composition of the combustion gases present. This document clarifies the form of use of these instruments and their engineering specifications, simultaneously presenting an analysis that considers, unlike others, the internal conditions of the furnace to obtain a more precise evaluation of the efficiency that the combustion process presents and bases for the taking of preventive actions in specific zones of the furnace. Thus, the present work exhibits instruments and techniques of analysis to study the phenomena occurring within a steam generator. [Spanish] Con el fin de obtener evaluaciones mas precisas del proceso de combustion en el horno de un generador de vapor, se ha integrado un pirometro de succion para medir la temperatura de los gases de combustion; un radiometro elipsoidal para medir el calor incidente por radiacion termica en las paredes del agua; una sonda enfriada con agua para determinar la concentracion de particulas, asi como una sonda refrigerada con agua para determinar la composicion de los gases de combustion presentes. Este documento aclara la forma de uso de estos instrumentos y sus especificaciones tecnicas, a la vez que presenta un analisis que considera, a diferencia de otros, las condiciones internas del horno para obtener una evaluacion mas precisa sobre la eficiencia del proceso de combustion y bases para la toma de acciones preventivas en zonas especificas del horno. Asi, el presente trabajo exhibe instrumentos y tecnicas de analisis para estudiar los fenomenos que ocurren dentro de un generador de vapor.

  17. Degradation of Solid Oxide Electrolysis Cells Operated at High Current Densities

    DEFF Research Database (Denmark)

    Tao, Youkun; Ebbesen, Sune Dalgaard; Mogensen, Mogens Bjerg

    2014-01-01

    In this work the durability of solid oxide cells for co-electrolysis of steam and carbon dioxide (45 % H2O + 45 % CO2 + 10 % H2) at high current densities was investigated. The tested cells are Ni-YSZ electrode supported, with a YSZ electrolyte and either a LSM-YSZ or LSCF-CGO oxygen electrode....... A current density of -1.5 and -2.0 A/cm2 was applied to the cell and the gas conversion was 45 % and 60 %, respectively. The cells were operated for a period of up to 700 hours. The electrochemical analysis revealed significant performance degradation for the ohmic process, oxygen ion interfacial transfer...

  18. High Temperature Gas-Cooled Reactor Projected Markets and Preliminary Economics

    Energy Technology Data Exchange (ETDEWEB)

    Larry Demick

    2011-08-01

    This paper summarizes the potential market for process heat produced by a high temperature gas-cooled reactor (HTGR), the environmental benefits reduced CO2 emissions will have on these markets, and the typical economics of projects using these applications. It gives examples of HTGR technological applications to industrial processes in the typical co-generation supply of process heat and electricity, the conversion of coal to transportation fuels and chemical process feedstock, and the production of ammonia as a feedstock for the production of ammonia derivatives, including fertilizer. It also demonstrates how uncertainties in capital costs and financial factors affect the economics of HTGR technology by analyzing the use of HTGR technology in the application of HTGR and high temperature steam electrolysis processes to produce hydrogen.

  19. Mediated water electrolysis in biphasic systems.

    Science.gov (United States)

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

    2017-08-30

    The concept of efficient electrolysis by linking photoelectrochemical biphasic H2 evolution and water oxidation processes in the cathodic and anodic compartments of an H-cell, respectively, is introduced. Overpotentials at the cathode and anode are minimised by incorporating light-driven elements into both biphasic reactions. The concepts viability is demonstrated by electrochemical H2 production from water splitting utilising a polarised water-organic interface in the cathodic compartment of a prototype H-cell. At the cathode the reduction of decamethylferrocenium cations ([Cp2*Fe(III)]+) to neutral decamethylferrocene (Cp2*Fe(II)) in 1,2-dichloroethane (DCE) solvent takes place at the solid electrode/oil interface. This electron transfer process induces the ion transfer of a proton across the immiscible water/oil interface to maintain electroneutrality in the oil phase. The oil-solubilised proton immediately reacts with Cp2*Fe(II) to form the corresponding hydride species, [Cp2*Fe(IV)(H)]+. Subsequently, [Cp2*Fe(IV)(H)]+ spontaneously undergoes a chemical reaction in the oil phase to evolve hydrogen gas (H2) and regenerate [Cp2*Fe(III)]+, whereupon this catalytic Electrochemical, Chemical, Chemical (ECC') cycle is repeated. During biphasic electrolysis, the stability and recyclability of the [Cp2*Fe(III)]+/Cp2*Fe(II) redox couple were confirmed by chronoamperometric measurements and, furthermore, the steady-state concentration of [Cp2*Fe(III)]+ monitored in situ by UV/vis spectroscopy. Post-biphasic electrolysis, the presence of H2 in the headspace of the cathodic compartment was established by sampling with gas chromatography. The rate of the biphasic hydrogen evolution reaction (HER) was enhanced by redox electrocatalysis in the presence of floating catalytic molybdenum carbide (Mo2C) microparticles at the immiscible water/oil interface. The use of a superhydrophobic organic electrolyte salt was critical to ensure proton transfer from water to oil, and not

  20. Sorption enhanced reaction process for direct production of fuel-cell grade hydrogen by low temperature catalytic steam-methane reforming

    Science.gov (United States)

    Beaver, Michael G.; Caram, Hugo S.; Sircar, Shivaji

    New experimental data are reported to demonstrate that a sorption enhanced reaction (SER) concept can be used to directly produce fuel-cell grade H 2 (concept. Mathematical simulations of a cyclic two-step SER concept showed that the H 2 productivity of the process (moles of essentially pure H 2 produced per kg of catalyst-chemisorbent admixture in the reactor per cycle) is much higher at a reaction temperature of 590 °C than that at 550 or 520 °C. On the other hand, the conversion of feed CH 4 to high purity H 2 product is relatively high (>99+%) at all three temperatures. The conversion is much higher than that in a conventional catalyst-alone reactor at these temperatures, and it increases only moderately (<1%) as the reaction temperature is increased from 520 to 590 °C. These results are caused by complex interactions of four phenomena. They are (a) favorable thermodynamic equilibrium of the highly endothermic SMR reaction at the higher reaction temperature, (b) faster kinetics of SMR reaction at higher temperatures, (c) favorable removal of CO 2 from the reaction zone at lower temperatures, and (d) higher cyclic working capacity for CO 2 chemisorption at higher temperature.

  1. Steam turbine materials and corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, G.R.; Ziomek-Moroz, M.

    2007-01-01

    Ultra supercritical (USC) power plants offer the promise of higher efficiencies and lower emissions. Current goals of the U.S. Department of Energy’s Advanced Power Systems Initiatives include coal generation at 60% efficiency, which would require steam temperatures of up to 760°C. This research examines the steamside oxidation of alloys for use in USC systems, with emphasis placed on applications in high- and intermediate-pressure turbines. The list of alloys being examined is discussed, including the addition of new alloys to the study. These include alloy 625, selected because of its use as one of the two alloys used for turbine rotors, valves, casings, blading and bolts in the European AD700 full-scale demonstration plant (Scholven Unit F). The other alloy, alloy 617, is already one of the alloys currently being examined by this project. Other new alloys to the study are the three round robin alloys in the UK-US collaboration: alloys 740, TP347HFG, and T92. Progress on the project is presented on cyclic oxidation in 50% air – 50% water vapor, furnace exposures in moist air, and thermogravimetric analysis in argon with oxygen saturated steam. An update on the progress towards obtaining an apparatus for high pressure exposures is given.

  2. Predicting efficiency of solar powered hydrogen generation using photovoltaic-electrolysis devices

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, Thomas L.; Kelly, Nelson A. [General Motors Research and Development Center, Chemical Science and Material Systems Laboratory, Mail Code 480-106-269, 30500 Mound Road, Warren, MI 48090-9055 (United States)

    2010-02-15

    Hydrogen fuel for fuel cell vehicles can be produced by using solar electric energy from photovoltaic (PV) modules for the electrolysis of water without emitting carbon dioxide or requiring fossil fuels. In the past, this renewable means of hydrogen production has suffered from low efficiency (2-6%), which increased the area of the PV array required and therefore, the cost of generating hydrogen. A comprehensive mathematical model was developed that can predict the efficiency of a PV-electrolyzer combination based on operating parameters including voltage, current, temperature, and gas output pressure. This model has been used to design optimized PV-electrolyzer systems with maximum solar energy to hydrogen efficiency. In this research, the electrical efficiency of the PV-electrolysis system was increased by matching the maximum power output and voltage of the photovoltaics to the operating voltage of a proton exchange membrane (PEM) electrolyzer, and optimizing the effects of electrolyzer operating current, and temperature. The operating temperature of the PV modules was also an important factor studied in this research to increase efficiency. The optimized PV-electrolysis system increased the hydrogen generation efficiency to 12.4% for a solar powered PV-PEM electrolyzer that could supply enough hydrogen to operate a fuel cell vehicle. (author)

  3. Catalytic steam reforming of model biogas

    Energy Technology Data Exchange (ETDEWEB)

    Philipp Kolbitsch; Christoph Pfeifer; Hermann Hofbauer [Vienna University of Technology, Vienna (Austria). Institute of Chemical Engineering

    2008-05-15

    Catalytic steam reforming of a model biogas (CH{sub 4}/CO{sub 2} = 60/40) is investigated to produce H{sub 2}-rich synthesis gas. Gas engines benefit from synthesis gas fuel in terms of higher efficiency and lower NOx production when compared to raw biogas or CH{sub 4}. The process is realized in a fixed bed reactor with a Ni-based catalyst on CaO/Al{sub 2}O{sub 3} support. To optimize the performance, the reactor temperature and the amount of excess steam are varied. The experimental results are compared to the theoretical values from thermodynamic calculation and the main trends of CH{sub 4} conversion and H{sub 2} yield are analyzed and verified. Finally, optimal reactor temperature is pointed out and a range of potential steam to methane ratios is presented. The experimental results will be applied to design a steam reformer at an existing anaerobic biomass fermentation plant in Strem, Austria. 20 refs., 8 figs., 4 tabs.

  4. Steam-chemical reactivity for irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; McCarthy, K.A.; Oates, M.A.; Petti, D.A.; Pawelko, R.J.; Smolik, G.R. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental investigation to determine the influence of neutron irradiation effects and annealing on the chemical reactivity of beryllium exposed to steam. The work entailed measurements of the H{sub 2} generation rates for unirradiated and irradiated Be and for irradiated Be that had been previously annealed at different temperatures ranging from 450degC to 1200degC. H{sub 2} generation rates were similar for irradiated and unirradiated Be in steam-chemical reactivity experiments at temperatures between 450degC and 600degC. For irradiated Be exposed to steam at 700degC, the chemical reactivity accelerated rapidly and the specimen experienced a temperature excursion. Enhanced chemical reactivity at temperatures between 400degC and 600degC was observed for irradiated Be annealed at temperatures of 700degC and higher. This reactivity enhancement could be accounted for by the increased specific surface area resulting from development of a surface-connected porosity in the irradiated-annealed Be. (author)

  5. Steam injections wells: topics to consider in casing design of steam injection wells; Revestimento para pocos de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Antonio Carlos Farias [PETROBRAS, Recife, PE (Brazil). Gerencia de Perfuracao do Nordeste. Div. de Operacoes

    1994-07-01

    Steam injection is one of the processes used to increase production from very viscous oil reservoirs. A well is completed at a temperature of about 110 deg F and during steam injection that temperature varies around 600 deg F. Strain or breakdowns may occur to the casing, due to the critical conditions generated by the change of temperature. The usual casing design methods, do not take into account special environmental conditions, such as those which exist for steam injection. From the results of this study we come up to the conclusion that casing grade K-55, heavy weight with premium connections, without pre-stressing and adequately heated, is the best option for steam injection well completion for most of the fields in Brazil. (author)

  6. Research and Development of Heat-Resistant Materials for Advanced USC Power Plants with Steam Temperatures of 700 °C and Above

    National Research Council Canada - National Science Library

    Abe, Fujio

    2015-01-01

    .... These projects involve the replacement of martensitic 9%−12% Cr steels with nickel (Ni)-base alloys for the highest temperature boiler and turbine components in order to provide sufficient creep strength at 700°C and above...

  7. Steam generators in cogeneration plants

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. [Abco Industries, Inc., Abilene, TX (United States)

    1994-12-31

    This paper addresses the performance aspects of packaged steam generators and small to medium sized single pressure gas turbine heat recovery steam generators (HRSGs) used in cogeneration plants. HRSGs in combined cycle plants are not addressed here as they usually involve multiple steam pressure operation and comparison with steam generators, which operate at single pressure, would be difficult. Also,the paper deals with simple Brayton cycles with heat recovery for cogeneration only and hence discussions on steam turbines is avoided. The paper addresses the behavior of the steam generators with respect to load with emphasis on fuel utilization, efficiency and performance. The information, it is hoped, would be of interest to plant engineers who would like to operate the steam generators at their best efficiency points.

  8. Long Term Testing of Solid Oxide Electrolysis Cells Under Co-Electrolysis Conditions

    DEFF Research Database (Denmark)

    Rao, Megha; Sun, Xiufu; Hagen, Anke

    2017-01-01

    SOECs consisting of a nickel-yttria stabilized zirconia (Ni-YSZ) fuel electrode, YSZ electrolyte and lanthanum strontium cobalt ferrite-gadolinium doped ceria (LSCF-GDC) composite oxygen electrode were tested under co-electrolysis (H2O+CO2) conditions. The aim in this study was to compare the SOEC...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and an immobilized electrolyte allow for reversible operation as electrolysis cell or fuel...

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

    Science.gov (United States)

    Kamata, Masahiro; Yajima, Seiko

    2013-01-01

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

  11. Prospects for Martensitic 12 % Cr Steels for Advanced Steam Power Plants

    DEFF Research Database (Denmark)

    Hald, John

    2016-01-01

    and FB2 are now used in power plants up to 600–620 °C steam temperature. For higher steam temperatures up to 650 °C steels with 11–12 % Cr are needed for better resistance against steam oxidation. However, fine V and Nb based nitrides may transform to coarse Z-phase [Cr(V,Nb)N] nitrides in steels...

  12. The Dilemma of Supporting Electrolytes for Electroorganic Synthesis: A Case Study on Kolbe Electrolysis.

    Science.gov (United States)

    Stang, Carolin; Harnisch, Falk

    2016-01-08

    Remarkably, coulombic efficiency (CE, about 50 % at 1 Farad equivalent), and product composition resulting from aqueous Kolbe electrolysis are independent of reactor temperature and initial pH value. Although numerous studies on Kolbe electrolysis are available, the interrelations of different reaction parameters (e.g., acid concentration, pH, and especially electrolytic conductivity) are not addressed. A systematic analysis based on cyclic voltammetry reveals that solely the electrolytic conductivity impacts the current-voltage behavior. When using supporting electrolytes, not only their concentration, but also the type is decisive. We show that higher concentrations of KNO3 result in reduced CE and thus in significant increase in electric energy demand per converted molecule, whereas Na2 SO4 allows improved space-time yields. Pros and cons of adding supporting electrolytes are discussed in a final cost assessment. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

    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.

  14. Steam as turbine blade coolant: Experimental data generation

    Energy Technology Data Exchange (ETDEWEB)

    Wilmsen, B.; Engeda, A.; Lloyd, J.R. [Michigan State Univ., East Lansing, MI (United States)

    1995-10-01

    Steam as a coolant is a possible option to cool blades in high temperature gas turbines. However, to quantify steam as a coolant, there exists practically no experimental data. This work deals with an attempt to generate such data and with the design of an experimental setup used for the purpose. Initially, in order to guide the direction of experiments, a preliminary theoretical and empirical prediction of the expected experimental data is performed and is presented here. This initial analysis also compares the coolant properties of steam and air.

  15. Experimental characterization and modeling of an ethanol steam reformer

    DEFF Research Database (Denmark)

    Mandø, Matthias; Bovo, Mirko; Nielsen, Mads Pagh

    2006-01-01

    This work describes the characterization of an ethanol reforming system for a high temperature PEM fuel cell system. High temperature PEM fuel cells are well suited for operation on reformate gas due to the superior CO tolerance compared with low temperature PEM. Steam reforming of liquid biofuels...

  16. Features of steam turbine cooling by the example of an SKR-100 turbine for supercritical steam parameters

    Science.gov (United States)

    Arkadyev, B. A.

    2015-10-01

    Basic principles of cooling of high-temperature steam turbines and constructive solutions used for development of the world's first cooled steam turbine SKR-100 (R-100-300) are described. Principal differences between the thermodynamic properties of cooling medium in the steam and gas turbines and the preference of making flow passes of cooled cylinders of steam turbines as reactive are shown. Some of its operation results and their conclusions are given. This turbine with a power of 100 MW, initial steam parameters approximately 30 MPa and 650°C, and back pressure 3 MPa was made by a Kharkov turbine plant in 1961 and ran successfully at a Kashira GRES (state district power plant) up to 1979, when it was taken out of use in a still fully operating condition. For comparison, some data on construction features and operation results of the super-high pressure cylinder of steam turbines of American Philo 6 (made by General Electric Co.) and Eddystone 1 (made by Westinghouse Co.) power generating units, which are close to the SKR-100 turbine by design initial steam parameters and the implementation time, are given. The high operational reliability and effectiveness of the cooling system that was used in the super-high pressure cylinder of the SKR-100 turbine of the power-generating unit, which were demonstrated in operation, confirms rightfulness and expediency of principles and constructive solutions laid at its development. As process steam temperatures are increased, the realization of the proposed approach to cooling of multistage turbines makes it possible to limit for large turbine parts the application of new, more expensive high-temperature materials, which are required for making steam boilers, and, in some cases, to do completely away with their utilization.

  17. A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater

    Directory of Open Access Journals (Sweden)

    Ruihong Yang

    2016-04-01

    Full Text Available Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to be an initial pH value of 3, reaction time of 80 min, and 0.05 mol/L Na2SO4 additive concentration. The reaction mechanism of the treatment of oil refinery wastewater by Fe/C/Al micro-electrolysis was investigated. The process of the treatment of oil refinery wastewater with multiple micro-electrolysis conforms to the third-order reaction kinetics. The gas chromatography–mass spectrometry (GC–MS used to analyze the organic compounds of the oil refinery wastewater before and after treatment and the Ultraviolet–visible spectroscopy (UV–VIS absorption spectrum analyzed the degradation process of organic compounds in oil refinery wastewater. The treatment effect of Fe/C/Al multiple micro-electrolysis was examined in the continuous experiment under the optimum conditions, which showed high organic compound removal and stable treatment efficiency.

  18. A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater.

    Science.gov (United States)

    Yang, Ruihong; Zhu, Jianzhong; Li, Yingliu; Zhang, Hui

    2016-04-29

    Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to be an initial pH value of 3, reaction time of 80 min, and 0.05 mol/L Na₂SO₄ additive concentration. The reaction mechanism of the treatment of oil refinery wastewater by Fe/C/Al micro-electrolysis was investigated. The process of the treatment of oil refinery wastewater with multiple micro-electrolysis conforms to the third-order reaction kinetics. The gas chromatography-mass spectrometry (GC-MS) used to analyze the organic compounds of the oil refinery wastewater before and after treatment and the Ultraviolet-visible spectroscopy (UV-VIS) absorption spectrum analyzed the degradation process of organic compounds in oil refinery wastewater. The treatment effect of Fe/C/Al multiple micro-electrolysis was examined in the continuous experiment under the optimum conditions, which showed high organic compound removal and stable treatment efficiency.

  19. Tunable microbubble generator using electrolysis and ultrasound

    Directory of Open Access Journals (Sweden)

    Younes Achaoui

    2017-01-01

    Full Text Available This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant that may modify the composition of the host fluid. It impacts across a broad range of scientific domains from bioengineering, sensing to environment.

  20. Highly energetic phenomena in water electrolysis

    OpenAIRE

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

    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 gr...

  1. Model studies of the vertical steam generator thermal-hydraulic characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Desyatun, V.F.; Moskvichev, V.F.; Ulasov, V.M.; Morozov, V.G.; Burkov, V.K.; Grebennikov, V.N.

    1984-03-01

    Results of investigations conducted to clarify the calculation technique and to test the workability of the main elements and units of the PGV-250 vertical steam generator of saturated steam are considered. The steam generating capacity of the plant is 1486 t/h, thermal power is 792 MW. Steam generation follows a multiple circulation scheme. The heat surface comprises 330-shields. The investigations are carried out with a model which reproduces all the main elements of the steam generator excluding the economizer section. The flow rates of feed water, generated steam and coolant of the first circuit as well as temperature, pressure and humidity of the generated steam past the separator are determined. The average heat transfer factors of the heat surface are calculated on the base of the data obtained and a conclusion is drawn on the correctness of the thermohydraulic calculation technique used in development of the PGV-250 steam generator design. Temperature pulsations and heat surface steaming are not observed. The steam humidity at the outlet and steam capture into sinking tubes are within permissible values.

  2. Steam condenser developments

    Science.gov (United States)

    Lang, H. V.

    Factors determining condenser size and tube arrangement are reviewed, including steam side pressure drop; incondensible blanketing; effect of incondensibles on heat transfer; vent requirements; deaeration; condensate depression; cooling water velocity; tube material and diameter selection; fouling; and enhanced heat transfer tubes. Tube nest shapes and condenser concepts are described. Thermal design, and condenser acceptance testing are treated; field test results on "Church Window'' condensers are reported.

  3. Solar steam generation by heat localization.

    Science.gov (United States)

    Ghasemi, Hadi; Ni, George; Marconnet, Amy Marie; Loomis, James; Yerci, Selcuk; Miljkovic, Nenad; Chen, Gang

    2014-07-21

    Currently, steam generation using solar energy is based on heating bulk liquid to high temperatures. This approach requires either costly high optical concentrations leading to heat loss by the hot bulk liquid and heated surfaces or vacuum. New solar receiver concepts such as porous volumetric receivers or nanofluids have been proposed to decrease these losses. Here we report development of an approach and corresponding material structure for solar steam generation while maintaining low optical concentration and keeping the bulk liquid at low temperature with no vacuum. We achieve solar thermal efficiency up to 85% at only 10 kW m(-2). This high performance results from four structure characteristics: absorbing in the solar spectrum, thermally insulating, hydrophilic and interconnected pores. The structure concentrates thermal energy and fluid flow where needed for phase change and minimizes dissipated energy. This new structure provides a novel approach to harvesting solar energy for a broad range of phase-change applications.

  4. Steam generated conversion coating on aluminium alloys

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    into functional conversion coatings in order to enhance corrosion resistance and adhesion to paint systems. Chromium based conversion coatings have been extensively used on aluminium alloys to improve adhesion of subsequent paint layers and corrosion resistance. However, the use of hexavalent chromium is strictly...... regulated due to its toxic nature and suspected carcinogenicity. So, it is highly imperative to develop other alternatives for chrome conversion coatings. Treatment of aluminium with natural water at elevated temperatures results in the formation of different forms of aluminium oxide (γ-AlO(OH) , Al(OH)3...... pressure steam produced by an autoclave at a temperature of 107 – 121 °C and pressure of 15 -17 psi for 10 minutes to produce a thin coating of aluminium oxide. The aim of this study is to understand the effect of high pressure steam with and without different chemical additives on surface morphology...

  5. A Numerical Study on the Supersonic Steam Ejector Use in Steam Turbine System

    Directory of Open Access Journals (Sweden)

    Lin Cai

    2013-01-01

    Full Text Available Supersonic steam ejector is widely used in steam energy systems such as refrigeration, wood drying equipment, papermaking machine, and steam turbine. In this paper the Computational Fluids Dynamics (CFD method was employed to simulate a supersonic steam ejector, SST k-w turbulence model was adopted, and both real gas model and ideal gas model for fluid property were considered and compared. The mixing chamber angle, throat length, and nozzle exit position (NXP primary pressure and temperature effects on entrainment ratio were investigated. The results show that performance of the ejector is underestimated using ideal gas model, and the entrainment ratio is 20%–40% lower than that when using real gas model. There is an optimum mixing chamber angel and NXP makes the entrainment ratio achieve its maximum; as throat length is decreased within a range, the entrainment ratio remains unchanged. Primary fluid pressure has a critical value, and the entrainment ratio reaches its peak at working critical pressure; when working steam superheat degree increases, the entrainment ratio is increased.

  6. Steam Oxidation Testing in the Severe Accident Test Station

    Energy Technology Data Exchange (ETDEWEB)

    Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    After the March 2011 accident at Fukushima Daiichi, Oak Ridge National Laboratory (ORNL) began conducting high temperature steam oxidation testing of candidate materials for accident tolerant fuel (ATF) cladding in August 2011 [1-11]. The ATF concept is to enhance safety margins in light water reactors (LWR) during severe accident scenarios by identifying materials with 100× slower steam oxidation rates compared to current Zr-based alloys. In 2012, the ORNL laboratory equipment was expanded and made available to the entire ATF community as the Severe Accident Test Station (SATS) [4,12]. Compared to the current UO2/Zr-based alloy fuel system, an ATF alternative would significantly reduce the rate of heat and hydrogen generation in the core during a coolant-limited severe accident [13-14]. The steam oxidation behavior of candidate materials is a key metric in the evaluation of ATF concepts and also an important input into models [15-17]. However, initial modeling work of FeCrAl cladding has used incomplete information on the physical properties of FeCrAl. Also, the steam oxidation data being collected at 1200°-1700°C is unique as no prior work has considered steam oxidation of alloys at such high temperatures. Also, because many accident scenarios include steadily increasing temperatures, the required data are not traditional isothermal exposures but exposures with varying “ramp” rates. In some cases, the steam oxidation behavior has been surprising and difficult to interpret. Thus, more fundamental information continues to be collected. In addition, more work continues to focus on commercially-manufactured tube material. This report summarizes recent work to characterize the behavior of candidate alloys exposed to high temperature steam, evaluate steam oxidation behavior in various ramp scenarios and continue to collect integral data on FeCrAl compared to conventional Zr-based cladding.

  7. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  8. Oxidation of alloys for advanced steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R.; Covino, Bernard S., Jr.; Bullard, Sophie J.; Ziomek-Moroz, M.; Alman, David E.

    2005-01-01

    Ultra supercritical (USC) power plants offer the promise of higher efficiencies and lower emissions. Current goals of the U.S. Department of Energy’s Advanced Power Systems Initiatives include coal generation at 60% efficiency, which would require steam temperatures of up to 760°C. This research examines the steamside oxidation of advanced alloys for use in USC systems, with emphasis placed on alloys for high- and intermediate-pressure turbine sections.

  9. Thermal steam plasma decomposition of organochlorine compounds

    Science.gov (United States)

    Surov, A. V.; Subbotin, D. I.; Popov, V. E.; Popov, S. D.; Litvyikova, A. I.; Nakonechniy, Gh V.; Serba, E. O.; Obraztsov, N. V.

    2017-11-01

    For the almost complete processing of organochlorine compounds are required a high temperature, hydrogen to produce hydrogen chloride and a high degree of mixing. Reforming chlorobenzene by steam and carbon dioxide in the presence of methane using a three-phase AC plasma torch was carried out. Soot composition was analyzed by energy dispersive X-ray analysis. The yield of soot was 0.84% wt. of raw materials, the content of chlorine in the soot was 2.08% by wt.

  10. Incorporating supercritical steam turbines into molten-salt power tower plants :

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, James Edward; Wolf, Thorsten; Muley, Nishant

    2013-03-01

    Sandia National Laboratories and Siemens Energy, Inc., examined 14 different subcritical and supercritical steam cycles to determine if it is feasible to configure a molten-salt supercritical steam plant that has a capacity in the range of 150 to 200 MWe. The effects of main steam pressure and temperature, final feedwater temperature, and hot salt and cold salt return temperatures were determined on gross and half-net efficiencies. The main steam pressures ranged from 120 bar-a (subcritical) to 260 bar-a (supercritical). Hot salt temperatures of 566 and 600ÀC were evaluated, which resulted in main steam temperatures of 553 and 580ÀC, respectively. Also, the effects of final feedwater temperature (between 260 and 320ÀC) were evaluated, which impacted the cold salt return temperature. The annual energy production and levelized cost of energy (LCOE) were calculated using the System Advisory Model on 165 MWe subcritical plants (baseline and advanced) and the most promising supercritical plants. It was concluded that the supercritical steam plants produced more annual energy than the baseline subcritical steam plant for the same-size heliostat field, receiver, and thermal storage system. Two supercritical steam plants had the highest annual performance and had nearly the same LCOE. Both operated at 230 bar-a main steam pressure. One was designed for a hot salt temperature of 600ÀC and the other 565ÀC. The LCOEs for these plants were about 10% lower than the baseline subcritical plant operating at 120 bar-a main steam pressure and a hot salt temperature of 565ÀC. Based on the results of this study, it appears economically and technically feasible to incorporate supercritical steam turbines in molten-salt power tower plants.

  11. Control system pre-feedbacked for the super heated steam temperature in heat recovering units; Sistema de control pre-retroalimentado para la temperatura de vapor sobrecalentado en recuperadores de calor

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Alvarez, Hilario; Madrigal Espinosa, Guadalupe [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The study that is presented corresponds to the analysis, design and development of a pre-feedbacked control system for the superheated steam temperature regulation in the heat recovery units of a combined cycle thermoelectric power plant. The designs of the feedback controller and the pre-feedback control system were implemented based in a linear model of the tempering zone. This linear model was obtained through the application of parametric identification techniques to the non-linear mathematical model of a combined cycle power plant. [Espanol] El estudio que se presenta corresponde al analisis, diseno y desarrollo de un sistema de control pre-retroalimentado para regular la temperatura de vapor sobrecalentado en los recuperadores de calor de una central termoelectrica de ciclo combinado. Los disenos del controlador retroalimentado y del sistema de control prealimentado se realizaron con base en un modelo lineal de la zona de atemperacion. Este modelo lineal se obtuvo aplicando tecnicas de identificacion parametrica al modelo matematico no-lineal de una central de ciclo combinado.

  12. Carbon assisted water electrolysis for hydrogen generation

    Science.gov (United States)

    Sabareeswaran, S.; Balaji, R.; Ramya, K.; Rajalakshmi, N.; Dhathathereyan, K. S.

    2013-06-01

    Carbon Assisted Water Electrolysis (CAWE) is an energy efficient process in that H2 can be produced at lower applied voltage (˜1.0 V) compared to nearly 2.0 V needed for ordinary water electrolysis for the same H2 evolution rate. In this process, carbon is oxidized to oxides of carbon at the anode of an electrochemical cell and hydrogen is produced at the cathode. These gases are produced in relatively pure state and would be collected in a separate chamber. In this paper, we present the results of influence of various operating parameters on efficiency of CAWE process. The results showed that H2 can be produced at applied voltages Eo as low as 1.0V (vs. SHE) and its production rate is strongly dependent on the type of the carbon used and its concentration in the electrolyte. It has also been found that the performance of CAWE process is higher in acidic electrolyte than in alkaline electrolyte.

  13. Co-Electrolysis of Steam and Carbon Dioxide in Solid Oxide Cells

    DEFF Research Database (Denmark)

    Ebbesen, Sune Dalgaard; Knibbe, Ruth; Mogensen, Mogens Bjerg

    2012-01-01

    Reduction of H2O and CO2 as well as oxidation of H2 and CO was studied in a Ni/YSZ electrode supported Solid Oxide Cell (SOC) produced at DTU Energy conversion (former Risø DTU). Even though these Ni/YSZ based SOCs were developed and optimized for fuel cell use, they can work as reversible SOCs i...

  14. Process for purifying geothermal steam

    Science.gov (United States)

    Li, C.T.

    Steam containing hydrogen sulfide is purified and sulfur recovered by passing the steam through a reactor packed with activated carbon in the presence of a stoichiometric amount of oxygen which oxidizes the hydrogen sulfide to elemental sulfur which is adsorbed on the bed. The carbon can be recycled after the sulfur has been recovered by vacuum distillation, inert gas entrainment or solvent extraction. The process is suitable for the purification of steam from geothermal sources which may also contain other noncondensable gases.

  15. Solar energy for steam generation in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    De Carvalho, A.V. Jr.; Orlando, A. DeF.; Magnoli, D.

    1979-05-01

    Steam generation is a solar energy application that has not been frequently studied in Brazil, even though for example, about 10% of the national primary energy demand is utilized for processing heat generation in the range of 100 to 125/sup 0/C. On the other hand, substitution of automotive gasoline by ethanol, for instance, has received much greater attention even though primary energy demand for process heat generation in the range of 100 to 125/sup 0/C is of the same order of magnitude than for total automotive gasoline production. Generation of low-temperature steam is analyzed in this article using distributed systems of solar collectors. Main results of daily performance simulation of single flat-plate collectors and concentrating collectors are presented for 20/sup 0/S latitude, equinox, in clear days. Flat plate collectors considered are of the aluminum roll-bond absorber type, selective surface single or double glazing. Considering feedwater at 20/sup 0/C, saturated steam at 120/sup 0/C and an annual solar utilization factor of 50%, a total collector area of about 3,000 m/sup 2/ is necessary for the 10 ton/day plant, without energy storage. A fuel-oil back-up system is employed to complement the solar steam production, when necessary. Preliminary economic evaluation indicates that, although the case-study shows today a long payback period relative to subsidized fuel oil in the domestic market (over 20 years in the city of Rio de Janeiro), solar steam systems may be feasible in the medium term due to projected increase of fuel oil price in Brazil.

  16. Numerical Research of Steam and Gas Plant Efficiency of Triple Cycle for Extreme North Regions

    Directory of Open Access Journals (Sweden)

    Galashov Nikolay

    2016-01-01

    Full Text Available The present work shows that temperature decrease of heat rejection in a cycle is necessary for energy efficiency of steam turbine plants. Minimum temperature of heat rejection at steam turbine plant work on water steam is 15°C. Steam turbine plant of triple cycle where lower cycle of steam turbine plant is organic Rankine cycle on low-boiling substance with heat rejection in air condenser, which safely allows rejecting heat at condensation temperatures below 0°C, has been offered. Mathematical model of steam and gas plant of triple cycle, which allows conducting complex researches with change of working body appearance and parameters defining thermodynamic efficiency of cycles, has been developed. On the basis of the model a program of parameters and index cycles design of steam and gas plants has been developed in a package of electron tables Excel. Numerical studies of models showed that energy efficiency of steam turbine plants of triple cycle strongly depend on low-boiling substance type in a lower cycle. Energy efficiency of steam and gas plants net 60% higher can be received for steam and gas plants on the basis of gas turbine plant NK-36ST on pentane and its condensation temperature below 0°C. It was stated that energy efficiency of steam and gas plants net linearly depends on condensation temperature of low-boiling substance type and temperature of gases leaving reco very boiler. Energy efficiency increases by 1% at 10% decrease of condensation temperature of pentane, and it increases by 0.88% at 15°C temperature decrease of gases leaving recovery boiler.

  17. Modeling of the process of electrolysis production of caustic, chlorine and hydrogen

    Science.gov (United States)

    Shulaeva, E. A.; Shulaev, N. S.; Kovalenko, J. F.

    2017-01-01

    The present work describes the modeling parameters of an electrolyzer in production of caustic, hydrogen and chlorine by electrolysis. The dependence of temperature on the current-voltage characteristics of the electolyzer and the ratio that determines the current as a function of the design parameters were found. It is shown that an increase in the current in the electrolyzer with increased temperature is due to decreasing viscosity of the electrolyte and reducing the radii of solvated ions and sodium chloride. The yield of sodium hydroxide, chlorine and hydrogen was determined based on the technological and construction parameters of the cell. These relations are used in the developed simulation and modeling software.

  18. Diagnosis of sources of current inefficiency in industrial molten salt electrolysis cells by Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sadoway, D.R.

    1988-07-29

    The purpose of this project was to employ Raman spectroscopy in the study of industrial molten salt electrolysis cells. The objective was to improve the understanding of the chemistry and electrochemistry of the relevant melt systems and, in turn, of energy loss mechanisms in the industrial processes. On this basis new ways to improve the energy efficiency of these industrial reactors might be identified. The research plan has several principal elements. First, there was the design and construction of laboratory scale representations of industrial molten salt electrolysis cells that would at the same time serve a spectrocells. Secondly, there was the mastery of the preparation of the molten salt electrolytes, what in industry is called the ''front end.'' Thirdly, there was the adaptation of commercially available Raman instrumentation in order to facilitate the proposed studies. It is the nature of the specimens that so dramatically distinguished this work from conventional Raman studies for which commercial instrumentation is designed: first, the laboratory scale electrolysis cells are large compared to typical spectrocells; and secondly, the cells operate at, what for Raman studies are, extremely high temperatures. 4 refs., 2 figs.

  19. Methods of increasing thermal efficiency of steam and gas turbine plants

    Science.gov (United States)

    Vasserman, A. A.; Shutenko, M. A.

    2017-11-01

    Three new methods of increasing efficiency of turbine power plants are described. Increasing average temperature of heat supply in steam turbine plant by mixing steam after overheaters with products of combustion of natural gas in the oxygen. Development of this idea consists in maintaining steam temperature on the major part of expansion in the turbine at level, close to initial temperature. Increasing efficiency of gas turbine plant by way of regenerative heating of the air by gas after its expansion in high pressure turbine and before expansion in the low pressure turbine. Due to this temperature of air, entering combustion chamber, is increased and average temperature of heat supply is consequently increased. At the same time average temperature of heat removal is decreased. Increasing efficiency of combined cycle power plant by avoiding of heat transfer from gas to wet steam and transferring heat from gas to water and superheated steam only. Steam will be generated by multi stage throttling of the water from supercritical pressure and temperature close to critical, to the pressure slightly higher than condensation pressure. Throttling of the water and separation of the wet steam on saturated water and steam does not require complicated technical devices.

  20. Poisoning of Solid Oxide Electrolysis Cells by Impurities

    DEFF Research Database (Denmark)

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

    2010-01-01

    Electrolysis of H2O, CO2, and co-electrolysis of H2O and CO2 was studied in Ni/yttria-stabilized zirconia (YSZ) electrode supported solid oxide electrolysis cells (SOECs) consisting of a Ni/YSZ support, a Ni/YSZ electrode layer, a YSZ electrolyte, and an lanthanum strontium manganite (LSM......)/YSZ oxygen electrode When applying the gases as received, the cells degraded significantly at the Ni/YSZ electrode, whereas only minor (and initial) degradation was observed for either the Ni/YSZ or LSM/YSZ electrode. Application of clean gases to the Ni/YSZ electrode resulted in operation without any long...

  1. CO2 Fixation by Membrane Separated NaCl Electrolysis

    Directory of Open Access Journals (Sweden)

    Hyun Sic Park

    2015-08-01

    Full Text Available Atmospheric concentrations of carbon dioxide (CO2, a major cause of global warming, have been rising due to industrial development. Carbon capture and storage (CCS, which is regarded as the most effective way to reduce such atmospheric CO2 concentrations, has several environmental and technical disadvantages. Carbon capture and utilization (CCU, which has been introduced to cover such disadvantages, makes it possible to capture CO2, recycling byproducts as resources. However, CCU also requires large amounts of energy in order to induce reactions. Among existing CCU technologies, the process for converting CO2 into CaCO3 requires high temperature and high pressure as reaction conditions. This study proposes a method to fixate CaCO3 stably by using relatively less energy than existing methods. After forming NaOH absorbent solution through electrolysis of NaCl in seawater, CaCO3 was precipitated at room temperature and pressure. Following the experiment, the resulting product CaCO3 was analyzed with Fourier transform infrared spectroscopy (FT-IR; field emission scanning electron microscopy (FE-SEM image and X-ray diffraction (XRD patterns were also analyzed. The results showed that the CaCO3 crystal product was high-purity calcite. The study shows a successful method for fixating CO2 by reducing carbon dioxide released into the atmosphere while forming high-purity CaCO3.

  2. DEMONSTRATION BULLETIN STEAM ENHANCED REMEDIATION STEAM TECH ENVIRONMENTAL SERVICES, INC.

    Science.gov (United States)

    Steam Enhanced Remediation is a process in which steam is injected into the subsurface to recover volatile and semivolatile organic contaminants. It has been applied successfully to recover contaminants from soil and aquifers and at a fractured granite site. This SITE demonstra...

  3. Correlation Between Hue-angle and Colour Lightness of Steamed Black locust Wood

    Directory of Open Access Journals (Sweden)

    NÉMETH, Károly

    2008-01-01

    Full Text Available Black locust (Robinia pseudoacacia L. wood was steamed at wide range of temperature(75-130°C applying long (22 days steaming time. The colour change was monitored by CIE L*a*b*and L*h*c* colour co-ordinate systems. A wide range of colours from greenish yellow up to chocolatebrown were created by steaming in function of the steaming time and temperature. In spite of this widecolour range a good linear correlation was found between the lightness and the colour hue. Thislinearity had little distortion only above 100°C at a long steaming time. Accordingly, this linearcorrelation gives the possibility to follow the colour change during steaming by measuring only thelightness.

  4. Horizontal steam generator PGV-1000 thermal-hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ubra, O. [Skoda Company, Prague (Switzerland); Doubek, M. [Czech Technical Univ., Prague (Switzerland)

    1995-12-31

    A computer program for the steady state thermal-hydraulic analysis of horizontal steam generator PGV-1000 is presented. The program provides the capability to analyze steam generator PGV-1000 primary side flow and temperature distribution, primary side pressure drops, heat transfer between the primary and secondary sides and multidimensional heat flux distribution. A special attention is paid to the thermal-hydraulics of the secondary side. The code predicts 3-D distribution of the void fraction at the secondary side, mass redistribution under the submerged perforated sheet and the steam generator level profile. By means of developed computer program a detailed thermal-hydraulic study of the PGV-1000 has been carried out. A wide range of calculations has been performed and a set of important steam generator characteristics has been obtained. Some of them are presented in the paper. (orig.). 5 refs.

  5. Gas--steam turbine combined cycle power plants

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.

    1978-10-01

    The purpose of this technology evaluation is to provide performance and cost characteristics of the combined gas and steam turbine, cycle system applied to an Integrated Community Energy System (ICES). To date, most of the applications of combined cycles have been for electric power generation only. The basic gas--steam turbine combined cycle consists of: (1) a gas turbine-generator set, (2) a waste-heat recovery boiler in the gas turbine exhaust stream designed to produce steam, and (3) a steam turbine acting as a bottoming cycle. Because modification of the standard steam portion of the combined cycle would be necessary to recover waste heat at a useful temperature (> 212/sup 0/F), some sacrifice in the potential conversion efficiency is necessary at this temperature. The total energy efficiency ((electric power + recovered waste heat) divided by input fuel energy) varies from about 65 to 73% at full load to 34 to 49% at 20% rated electric power output. Two major factors that must be considered when installing a gas--steam turbine combines cycle are: the realiability of the gas turbine portion of the cycle, and the availability of liquid and gas fuels or the feasibility of hooking up with a coal gasification/liquefaction process.

  6. Catalytic glycerol steam reforming for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Monica, E-mail: monica.dan@itim-cj.ro; Mihet, Maria, E-mail: maria.mihet@itim-cj.ro; Lazar, Mihaela D., E-mail: diana.lazar@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj Napoca (Romania)

    2015-12-23

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

  7. Research of Hydrogen Preparation with Catalytic Steam-Carbon Reaction Driven by Photo-Thermochemistry Process

    Directory of Open Access Journals (Sweden)

    Xiaoqing Zhang

    2013-01-01

    Full Text Available An experiment of hydrogen preparation from steam-carbon reaction catalyzed by K2CO3 was carried out at 700°C, which was driven by the solar reaction system simulated with Xenon lamp. It can be found that the rate of reaction with catalyst is 10 times more than that without catalyst. However, for the catalytic reaction, there is no obvious change for the rate of hydrogen generation with catalyst content range from 10% to 20%. Besides, the conversion efficiency of solar energy to chemical energy is more than 13.1% over that by photovoltaic-electrolysis route. An analysis to the mechanism of catalytic steam-carbon reaction with K2CO3 is given, and an explanation to the nonbalanced [H2]/[CO + 2CO2] is presented, which is a phenomenon usually observed in experiment.

  8. Jay Carter Enterprises, Incorporated steam engine

    Science.gov (United States)

    1981-01-01

    The Small Community Solar Thermal Power Experiment (SCSE) selected an organic rankine cycle (ORC) engine driving a high speed permanent magnet alternator (PMA) as the baseline power conversion subsystem (PCS) design. The back-up conceptual PCS design is a steam engine driving an induction alternator delivering power directly to the grid. The development of the automotive reciprocating simple rankine cycle steam engine and how an engine of similar design might be incorporated into the SCSE is discussed. A description of the third generation automotive engine is included along with some preliminary test data. Tests were conducted with the third generation engine driving an induction alternator delivering power directly to the grid. The purpose of these tests is to further verify the effects of expander inlet temperature, input thermal power level, expansion ratio, and other parameters affecting engine performance to aid in the development of an SCSE PCS.

  9. Program computes turbine steam rates and properties

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. (ABCO Industries, Inc., Abilene, TX (US))

    1988-11-01

    BASIC computer program quickly evaluates steam properties and rates during expansion in a steam turbine. Engineers involved in cogeneration projects and power plant studies often need to calculate the steam properties during expansion in a steam turbine to evaluate the theoretical and actual steam rates and hence, the electrical power output. With the help of this program written in BASIC, one can quickly evaluate all the pertinent data. Correlations used for steam property evaluation are also presented.

  10. Modelling of gas diffusion limitations in Ni/YSZ electrode material in CO2 and co-electrolysis

    DEFF Research Database (Denmark)

    Duhn, Jakob Dragsbæk; Jensen, Anker Degn; Wedel, Stig

    2016-01-01

    Carbon formation during CO2 and co-electrolysis (combined electrolysis of H2O and CO2)has been observed in recent studies, under operating conditions where carbon formation,based on the bulk gas composition, should be thermodynamically unfavorable. The carboncan principally be formed by the Boudo......Carbon formation during CO2 and co-electrolysis (combined electrolysis of H2O and CO2)has been observed in recent studies, under operating conditions where carbon formation,based on the bulk gas composition, should be thermodynamically unfavorable. The carboncan principally be formed...... by the Boudouard reaction (2CO à CO2 + C(s)) or the COreduction reaction (CO+H2 à H2O + C(s)), and will disintegrate the cell structure as itgrows. It is therefore of great importance to be able to predict when the carbon is formed,and subsequently take actions to prevent formation.The literature offers...... suggestions that the carbon formation is caused by diffusionlimitations within the Ni/YSZ electrode, but this has not been verified. To do so, thediffusion has been modelled with the dusty gas model and the effect of the electrodetortuosity , porosity , temperature T, electrode thickness dc, and current...

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

    Science.gov (United States)

    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

  12. Ion cumulation by conical cathode electrolysis.

    CERN Document Server

    Grishin, V G

    2002-01-01

    Results of solid-state sodium stearate electrolysis with conical and cylindrical cathodes is presented here. Both electric measurement and conical samples destruction can be explained if a stress developing inside the conical sample is much bigger than in the cylindrical case and there is its unlimited amplification along cone slopes. OTHER KEYWORDS: ion, current, solid, symmetry, cumulation, polarization, depolarization, ionic conductor,superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, anvil, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epitaxy, sodium hydroxide, metallic substrate, crystallization, point, tip, susceptibility, ferroelectric, ...

  13. Percutaneous treatment of pulmonary tumors by electrolysis.

    Science.gov (United States)

    Samuelsson, L; Jönsson, L; Ståhl, E

    1983-06-01

    Five lung tumors in four patients were treated with electrolysis. One of the tumors was probably primary, while the others were metastases. Under local anesthesia, two or three platinum electrodes (diameter 3 mm) were introduced through the thoracic wall into the lung tumor using biplane fluoroscopy. The patient was sedated before the procedure and a chest tube was inserted into the pleural cavity. Between anode and cathode a direct current of 80 mA and 10 V was passed during 2-4 h, creating substantial electrolytic destruction mainly through chlorine liberation. Observations at autopsy, surgery, chest X-ray, and CT showed that 60%-80% of the tumor mass was destroyed. No tumor was completely destroyed. The patients tolerated the procedure well.

  14. Percutaneous treatment of pulmonary tumors by electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, L.; Joensson, L.; Stahl, E.

    1983-06-01

    Five lung tumors in four patients were treated with electrolysis. One of the tumors was probably primary, while the others were metastases. Under local anesthesia, two or three platinum electrodes (diameter 3 mm) were introduced through the thoracic wall into the lung tumor using biplane fluoroscopy. The patient was sedated before the procedure and a chest tube was inserted into the pleural cavity. Between anode and cathode a direct current of 80 mA and 10 V was passed during 2-4 h, creating substantial electrolytic destruction mainly through chlorine liberation. Observations at autopsy, surgery, chest X-ray, and CT showed that 60%-80% of the tumor mass was destroyed. No tumor was completely destroyed. The patients stood the procedure well.

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    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.

  16. Technology advancement of the static feed water electrolysis process

    Science.gov (United States)

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

    1977-01-01

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

  17. Durability of Solid Oxide Electrolysis Cells for Syngas Production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

    2013-01-01

    Performance and durability of Ni-YSZ supported solid oxide electrolysis cells (SOECs) for co-electrolysis of H2O and CO2 at high current density was investigated. The cells consist of a Ni-YSZ support, a Ni-YSZ electrode, a YSZ electrolyte, and an LSM-YSZ electrode. The durability was examined...... at 800°C and electrolysis current densities of −1 or −1.5 A/cm2 with 60% reactant (H2O + CO2) utilization. The cell voltage degradation showed a strong dependence on the electrolysis current density. Electrochemical characterization of the cells showed that the degradation was mainly related to the LSM...

  18. Solar Power Augmented Electrolysis Module for Energy Storage Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Regenerative fuel cell systems often include a dedicated electrolysis module with solar photovoltaic (PV) panels packaged as a subsystem of the larger energy storage...

  19. Studies on membrane acid electrolysis for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  20. Large Scale Inert Anode for Molten Oxide Electrolysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Molten oxide electrolysis is a demonstrated laboratory-scale process for producing oxygen from the JSC-1a lunar simulant; however, critical subsystems necessary for...

  1. Modeling a Helical-coil Steam Generator in RELAP5-3D for the Next Generation Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    Nathan V. Hoffer; Piyush Sabharwall; Nolan A. Anderson

    2011-01-01

    Options for the primary heat transport loop heat exchangers for the Next Generation Nuclear Plant are currently being evaluated. A helical-coil steam generator is one heat exchanger design under consideration. Safety is an integral part of the helical-coil steam generator evaluation. Transient analysis plays a key role in evaluation of the steam generators safety. Using RELAP5-3D to model the helical-coil steam generator, a loss of pressure in the primary side of the steam generator is simulated. This report details the development of the steam generator model, the loss of pressure transient, and the response of the steam generator primary and secondary systems to the loss of primary pressure. Back ground on High Temperature Gas-cooled reactors, steam generators, the Next Generation Nuclear Plant is provided to increase the readers understanding of the material presented.

  2. Structural Changes of Silica Mesocellular Foam Supported Amine-Functionalized CO 2 Adsorbents Upon Exposure to Steam

    KAUST Repository

    Li, Wen

    2010-11-24

    Three classes of amine-functionalized mesocellular foam (MCF) materials are prepared and evaluated as CO2 adsorbents. The stability of the adsorbents under steam/air and steam/nitrogen conditions is investigated using a Parr autoclave reactor to simulate, in an accelerated manner, the exposure that such adsorbents will see under steam stripping regeneration conditions at various temperatures. The CO2 capacity and organic content of all adsorbents decrease after steam treatment under both steam/air and steam/nitrogen conditions, primarily due to structural collapse of the MCF framework, but with additional contributions likely associated with amine degradation during treatment under harsh conditions. Treatment with steam/air is found to have stronger effect on the CO2 capacity of the adsorbents compared to steam/nitrogen. © 2010 American Chemical Society.

  3. Performance of broiler chickens offered nutritionally-equivalent diets based on two red grain sorghums with quantified kafirin concentrations as intact pellets or re-ground mash following steam-pelleting at 65 or 97°C conditioning temperatures

    Directory of Open Access Journals (Sweden)

    Ha H. Truong

    2015-09-01

    Full Text Available The Liverpool Plains is a fertile agricultural region in New South Wales, Australia. Two sorghums from the 2009 Liverpool Plains harvest, sorghums #3 and #5, were extensively characterised which included concentrations of kafirin and phenolic compounds plus rapid visco-analysis (RVA starch pasting profiles. Diets based on these two sorghums were formulated to be iso-nitrogenous and iso-energetic and were offered to male Ross 308 broiler chicks from 7 to 28 days post--hatch as either intact pellets or reground mash following steam-pelleting at conditioning temperatures of either 65 or 97°C. Thus the feeding study consisted of a 2 × 2 × 2 factorial array of dietary treatments: two sorghum varieties, two feed forms and two conditioning temperatures. Each of the eight treatments was replicated six times with six birds per replicate cage. Assessed parameters included growth performance, nutrient utilisation, apparent starch and protein (N digestibility coefficients and disappearance rates from the distal jejunum and distal ileum. Intact pellets supported higher (P < 0.001 feed intakes and weight gains by 9.83 and 9.08%, respectively, than reground mash diets. Feed conversion ratios of broilers offered diets steam-conditioned at 97°C were 2.46% inferior (P < 0.001 in comparison to 65°C diets and both apparent metabolizable energy (AME and N-corrected AME (AMEn were compromised. Broilers offered sorghum #3-based diets significantly (P < 0.001 outperformed their sorghum #5 counterparts in terms of weight gain by 3.75% (1,334 versus 1,223 g/bird, FCR by 4.81% (1.524 versus 1.601, AME by 1.06 MJ (13.61 versus 12.55 MJ/kg, ME:GE ratio (ME:GE by 4.81% (0.806 versus 0.769 and AMEn by 1.03 MJ (12.38 versus 11.35 MJ/kg. The inferiority of sorghum #5 appeared to be associated with higher concentrations of kafirin (61.5 versus 50.7 g/kg and conjugated phenolic acids, including ferulic acid (31.1 versus 25.6 µg/g. There were no significant differences in

  4. Steam generator tube integrity program

    Energy Technology Data Exchange (ETDEWEB)

    Dierks, D.R.; Shack, W.J. [Argonne National Laboratory, IL (United States); Muscara, J.

    1996-03-01

    A new research program on steam generator tubing degradation is being sponsored by the U.S. Nuclear Regulatory Commission (NRC) at Argonne National Laboratory. This program is intended to support a performance-based steam generator tube integrity rule. Critical areas addressed by the program include evaluation of the processes used for the in-service inspection of steam generator tubes and recommendations for improving the reliability and accuracy of inspections; validation and improvement of correlations for evaluating integrity and leakage of degraded steam generator tubes, and validation and improvement of correlations and models for predicting degradation in steam generator tubes as aging occurs. The studies will focus on mill-annealed Alloy 600 tubing, however, tests will also be performed on replacement materials such as thermally-treated Alloy 600 or 690. An overview of the technical work planned for the program is given.

  5. Evaluate deaerator steam requirements quickly

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. (ABCO Industries, Inc., Abilene, TX (US))

    1991-02-01

    Steam plant engineers frequently have to perform energy balance calculations around the deaerator to estimate the steam required to preheat and deaerate the make-up water and condensate returns. This calculation involves solving two sets of equations, one for mass and the other for energy balance. Reference to steam tables is also necessary. However, with the help of this program written in BASIC, one can arrive at the make-up water and steam requirements quickly, without referring to steam tables. This paper shows the mass and energy balance equations for the deaerator. This paper gives the program listing. An number of condensate returns can be handled. An example illustrates the use of the program.

  6. Optimizing the Heat Exchanger Network of a Steam Reforming System

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh; Korsgaard, Anders Risum; Kær, Søren Knudsen

    2004-01-01

    gas steam reformer along with gas purification reactors to generate clean hydrogen suited for a PEM stack. The temperatures in the various reactors in the fuel processing system vary from around 1000°C to the stack temperature at 80°C. Furthermore, external heating must be supplied to the endothermic...... steam reforming reaction and steam must be generated. The dependence of the temperature profiles on conversion in shift reactors for gas purification is also significant. The optimum heat integration in the system is thus imperative in order to minimize the need for hot and cold utilities. A rigorous 1D......Proton Exchange Membrane (PEM) based combined heat and power production systems are highly integrated energy systems. They may include a hydrogen production system and fuel cell stacks along with post combustion units optionally coupled with gas turbines. The considered system is based on a natural...

  7. Laboratory investigations of the physics of steam flow in a porous medium

    Science.gov (United States)

    Herkelrath, W.N.; Moench, A.F.

    1982-01-01

    Experiments were carried out in the laboratory to test a theory of transient flow of pure steam in a uniform porous medium. This theory is used extensively in modeling pressure-transient behavior in vapor-dominated geothermal systems. Transient, superheated steam-flow experiments were run by bringing a cylinder of porous material to a uniform initial pressure, and then making a step increase in pressure at one end of the sample, while monitoring the pressure-transient breakthrough at the other end. It was found in experiments run at 100?, 125?, and 146?C that the time required for steam-pressure transients to propagate through an unconsolidated material containing sand, silt, and clay was 10 to 25 times longer than predicted by theory. It is hypothesized that the delay in the steam-pressure transient was caused by adsorption of steam in the porous sample. In order to account for steam adsorption, a sink term was included in the conservation of mass equation. In addition, energy transfer in the system has to be considered because latent heat is released when steam adsorption occurs, increasing the sample temperature by as much as 10?C. Finally, it was recognized that the steam pressure was a function of both the temperature and the amount of adsorption in the sample. For simplicity, this function was assumed to be in equilibrium adsorption isotherm, which was determined by experiment. By solving the modified mass and energy equations numerically, subject to the empirical adsorption isotherm relationship, excellent theoretical simulation of the experiments was achieved. The experiments support the hypothesis that adsorption of steam can strongly influence steam pressure-transient behavior in porous media; the results suggest that the modified steam-flow theory, which includes steam adsorption terms, should be used in modeling steam flow in vapor-dominated geothermal systems.

  8. Electrolysis Performance Improvement Concept Study (EPICS) Flight Experiment-Reflight

    Science.gov (United States)

    Schubert, F. H.

    1997-01-01

    The Electrolysis Performance Improvement Concept Study (EPICS) is a flight experiment to demonstrate and validate in a microgravity environment the Static Feed Electrolyzer (SFE) concept which was selected for the use aboard the International Space Station (ISS) for oxygen (O2) generation. It also is to investigate the impact of microgravity on electrochemical cell performance. Electrochemical cells are important to the space program because they provide an efficient means of generating O2 and hydrogen (H2) in space. Oxygen and H2 are essential not only for the survival of humans in space but also for the efficient and economical operation of various space systems. Electrochemical cells can reduce the mass, volume and logistical penalties associated with resupply and storage by generating and/or consuming these gases in space. An initial flight of the EPICS was conducted aboard STS-69 from September 7 to 8, 1995. A temperature sensor characteristics shift and a missing line of software code resulted in only partial success of this initial flight. Based on the review and recommendations of a National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) review team a reflight activity was initiated to obtain the remaining desired results, not achieved during the initial flight.

  9. PMK-2. Experimental study on steam generator behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Ezsoel, G.; Szabados, L.; Trosztel, I. [KFKI Atomic Energy Research Inst., Budabest (Hungary)

    1995-12-31

    The PMK-2 is a full pressure scaled-down model of the Paks Nuclear Power Plant, with a 1:2070 scaling ratio for the volume and power. It has a steam generator model which is a vertical section of the horizontal steam generator. The model has hot and cold collectors similarly to the steam generators of the plant. The heat transfer tubes are horizontal tubes. There are 82 rows of tubes and the elevations, as well as the heat transfer surface distribution is the same as in the plant. The elevation of the feed water supply is similar to that of the plant. To study the temperature distribution in both the primary and the secondary side several thermocouples are built in, in addition to the overall instrumentation of the loop which has again a high number of measurement channels. Paper gives a description and results of SPE-4, with special respect to the steam generator behaviour in both steady state and transient conditions. Axial distribution of coolant and feedwater temperatures are given for the primary and the secondary side of hot and cold collectors and the temperature distribution in the centre of steam generator. (orig.).

  10. Powder metallurgy processing of Ni-Co base electrodes for application in water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Assis, O.B.G. [EMBRAPA Agricultural Instrumentation, Sao Carlos, SP (Brazil); Crnkovic, F.C.; Machado, R.; Avaca, L.A.; Ferrante, M.; Machado, S.A.S.

    1999-07-01

    Electrodes of Co, Ni and Ni{sub 50}Co{sub 50} were produced by powder metallurgy techniques aiming at their application as cathodes for water electrolysis system. Sintering was carried out in vacuum/argon atmosphere at low temperature to keep some residual porosity to enhance surface electroactivity by an increase of the geometric area. The Ni-Co alloying was obtained by mechanical synthesis, making use of the appropriated route. The final electrodes presented porosity around 12% where the electrochemical tests presented increasing in the critical peak when compared with electroplated flat samples. (orig.) 11 refs.

  11. TOF-SIMS characterization of impurity enrichment and redistribution in solid oxide electrolysis cells during operation

    DEFF Research Database (Denmark)

    Kiebach, Wolff-Ragnar; Norrman, Kion; Chatzichristodoulou, Christodoulos

    2014-01-01

    TOF-SIMS analyses of state-of-the-art high temperature solid oxide electrolysis cells before and after testing under different operating conditions were performed. The investigated cells consist of an yttria stabilized zirconia (YSZ) electrolyte, a La1-xSrxMnO3-δ composite anode and a Ni-YSZ cermet...... and Ca, increases. For Si, a concentration gradient is found from the gas inlet to the gas outlet. Additionally, a loss of Ni percolation in the active cathode is observed in the same area where the Si enrichment is found. Based on the obtained TOF-SIMS results, the influence of the operating conditions...

  12. Thermal Conductivity of Compounds Present in the Side Ledge in Aluminium Electrolysis Cells

    Science.gov (United States)

    Gheribi, Aïmen E.; Chartrand, Patrice

    2017-11-01

    This paper presents a database for the temperature-dependent thermal conductivity of compounds potentially present in the side ledge formed in aluminium electrolysis cells, between the molten electrolyte used to dissolve the alumina and the side wall. The database is given in the form of an analytical model with sets of parameters for each compound. To determine the model parameters, we considered a robust optimisation approach based on reliable models derived from fundamental physics. Where data are missing, first-principles calculations are utilized to estimate the parameters directly. For all compounds for which data are available, the model's predictions are found to be in very good agreement with reported experimental data.

  13. General purpose steam table library :

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, John H.; Belcourt, Kenneth Noel; Nourgaliev, Robert

    2013-08-01

    Completion of the CASL L3 milestone THM.CFD.P7.04 provides a general purpose tabular interpolation library for material properties to support, in particular, standardized models for steam properties. The software consists of three parts, implementations of analytic steam models, a code to generate tables from those models, and an interpolation package to interface the tables to CFD codes such as Hydra-TH. Verification of the standard model is maintained through the entire train of routines. The performance of interpolation package exceeds that of freely available analytic implementation of the steam properties by over an order of magnitude.

  14. Trends in packaged steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. [ABCO Industries, Abilene, TX (United States)

    1996-09-01

    Oil and gas-fired packaged steam generators are used in many industrial plants. They generate saturated or superheated steam up to 250,000 lb/hr, 1000 psig, and 950 F. They may be used for continuous steam generation or as standby boilers in cogeneration systems. Numerous variables affect the design of this equipment. A few important considerations should be addressed at an early point by the plant engineer specifying or evaluating equipment options. These considerations include trends such as customized designs that minimize operating costs and ensure emissions regulations are met. The paper discusses efficiency considerations first.

  15. Advanced technologies on steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Sakata, Kaoru; Nakamura, Yuuki [Mitsubishi Heavy Industry Co., Takasago (Japan); Nakamori, Nobuo; Mizutani, Toshiyuki; Uwagawa, Seiichi; Saito, Itaru [Mitsubishi Heavy Industry Co., Kobe (Japan); Matsuoka, Tsuyoshi [Mitsubishi Heavy Industry Co., Yokohama (Japan)

    1997-12-31

    The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermalhydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (orig.). 3 refs.

  16. Characterization of steam generated anti-corrosive oxide films on Aluminium alloys

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    alloy surfaces were exposed to high pressure steam produced by an autoclave at a temperature of 107 – 121 °C and pressure of 15 -17 psi for 10 minutes to produce a thin coating of aluminium oxide. The aim of this study is to understand the effect of high pressure steam with and without different...

  17. Steam generation control in Solar Invictus 53S - A parabolic dish solar collector for direct steam generation

    Science.gov (United States)

    Ali, Wajahat; Usman, Zubair; Jamil, Umer

    2017-06-01

    This paper presents a control methodology for steam generation at desired steam outlet conditions for the Solar Invictus 53S System. The system consists of a parabolic solar dish with an effective projected area of 51.6 m2 and a cavity type receiver which works as Once Through direct Solar Steam Generator (OTSSG). The challenge is to control the feedwater mass flow rate precisely in order to maintain the steam generation at desired steam conditions at the outlet of OTSSG. The controller must be robust to incorporate the varying external conditions like Direct Normal Irradiance (DNI), ambient temperature, soiling and wind speed. This paper formulates the control problem and presents a solution using two cascaded loops. In the first loop, feed forward mass flow rate to achieve the desired steam conditions is calculated. Feed forward control is implemented to give better disturbance rejection. For the mass flow rate calculated, a feedback loop is applied. The methodology is verified and tested in a simulated environment.

  18. Heat transfer during condensation of steam from steam-gas mixtures in the passive safety systems of nuclear power plants

    Science.gov (United States)

    Portnova, N. M.; Smirnov, Yu B.

    2017-11-01

    A theoretical model for calculation of heat transfer during condensation of multicomponent vapor-gas mixtures on vertical surfaces, based on film theory and heat and mass transfer analogy is proposed. Calculations were performed for the conditions implemented in experimental studies of heat transfer during condensation of steam-gas mixtures in the passive safety systems of PWR-type reactors of different designs. Calculated values of heat transfer coefficients for condensation of steam-air, steam-air-helium and steam-air-hydrogen mixtures at pressures of 0.2 to 0.6 MPa and of steam-nitrogen mixture at the pressures of 0.4 to 2.6 MPa were obtained. The composition of mixtures and vapor-to-surface temperature difference were varied within wide limits. Tube length ranged from 0.65 to 9.79m. The condensation of all steam-gas mixtures took place in a laminar-wave flow mode of condensate film and turbulent free convection in the diffusion boundary layer. The heat transfer coefficients obtained by calculation using the proposed model are in good agreement with the considered experimental data for both the binary and ternary mixtures.

  19. Electrochemical deposition of La-Mg alloys in LaCl3-MgCl2-KCl system with molten salt electrolysis process

    Directory of Open Access Journals (Sweden)

    Sahoo Kumar D.

    2014-01-01

    Full Text Available La-Mg alloys of different compositions were prepared by electrolysis of LaCl3-MgCl2-KCl melts. Different phases of La-Mg alloys were characterized by X-ray diffraction (XRD and Scanning Electron Microscopy (SEM. Energy dispersive spectrometry (EDS and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES analyses showed that chemical compositions of La-Mg alloys were consistent with phase structures of XRD pattern, and magnesium content in the alloy could be controlled by electrolysis parameters. The effects of various process parameters such as concentration of magnesium chloride in the bath, temperature of electrolysis and cathode current density on the current efficiency have been investigated. A maximum current efficiency of 85% and yield of 80% was obtained from the bath at 12.5A/cm2 current density at an operating temp 850°C.

  20. Principle and perspectives of hydrogen production through biocatalyzed electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Rozendal, Rene A.; Hamelers, Hubertus V.M.; Buisman, Cees J.N. [Sub-Department of Environmental Technology, Wageningen University, Bomenweg 2, P.O. Box 8129, 6700 EV Wageningen (Netherlands); Euverink, Gerrit J.W.; Metz, Sybrand J. [Wetsus, Centre for Sustainable Water Technology, Agora 1, P.O. Box 1113, 8900 CC Leeuwarden (Netherlands)

    2006-09-15

    Biocatalyzed electrolysis is a novel biological hydrogen production process with the potential to efficiently convert a wide range of dissolved organic materials in wastewaters. Even substrates formerly regarded to be unsuitable for hydrogen production due to the endothermic nature of the involved conversion reactions can be converted with this technology. Biocatalyzed electrolysis achieves this by utilizing electrochemically active micro-organisms that are capable of generating electrical current from the oxidation of organic matter. When this biological anode is coupled to a proton reducing cathode by means of a power supply, hydrogen is generated. In the biocatalyzed electrolysis experiments presented in this article acetate is used as a model compound. In theory, biocatalyzed electrolysis of acetate requires applied voltages that can be as low as 0.14V, while hydrogen production by means of conventional water electrolysis, in practice, requires applied voltages well above 1.6V. At an applied voltage of 0.5V the biocatalyzed electrolysis setup used in this study, produces approximately 0.02m{sup 3}H{sub 2}/m{sup 3} reactor liquid volume/day from acetate at an overall efficiency of 53+/-3.5%. This performance was mainly limited by the current design of the system, diffusional loss of hydrogen from the cathode to the anode chamber and high overpotentials associated with the cathode reaction. In this article we show that optimization of the process will allow future volumetric hydrogen production rates above 10m{sup 3}H{sub 2}/m{sup 3} reactor liquid volume/day at overall efficiencies exceeding 90% and applied voltages as low as 0.3-0.4V. In the future, this will make biocatalyzed electrolysis an attractive technology for hydrogen production from a wide variety of wastewaters. (author)

  1. High performance steam development. Final report, Phase No. 3: 1500{degree}F steam plant for industrial cogeneration prototype development tests

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, T.; Schneider, P.

    1996-01-01

    As a key part of DOE`s and industry`s R&D efforts to improve the efficiency, cost, and emissions of power generation, a prototype High Performance Steam System (HPSS) has been designed, built, and demonstrated. The world`s highest temperature ASME Section I coded power plant successfully completed over 100 hours of development tests at 1500{degrees}F and 1500 psig on a 56,000 pound per hour steam generator, control valve and topping turbine at an output power of 5500 hp. This development advances the HPSS to 400{degrees}F higher steam temperature than the current best technology being installed around the world. Higher cycle temperatures produce higher conversion efficiencies and since steam is used to produce the large majority of the world`s power, the authors expect HPSS developments will have a major impact on electric power production and cogeneration in the twenty-first century. Coal fueled steam plants now produce the majority of the United States electric power. Cogeneration and reduced costs and availability of natural gas have now made gas turbines using Heat Recovery Steam Generators (HRSG`s) and combined cycles for cogeneration and power generation the lowest cost producer of electric power in the United States. These gas fueled combined cycles also have major benefits in reducing emissions while reducing the cost of electricity. Development of HPSS technology can significantly improve the efficiency of cogeneration, steam plants, and combined cycles. Figure 2 is a TS diagram that shows the HPSS has twice the energy available from each pound of steam when expanding from 1500{degrees}F and 1500 psia to 165 psia (150 psig, a common cogeneration process steam pressure). This report describes the prototype component and system design, and results of the 100-hour laboratory tests. The next phase of the program consists of building up the steam turbine into a generator set, and installing the power plant at an industrial site for extended operation.

  2. A computationally efficient and accurate numerical representation of thermodynamic properties of steam and water for computations of non-equilibrium condensing steam flow in steam turbines

    Directory of Open Access Journals (Sweden)

    Hrubý Jan

    2012-04-01

    Full Text Available Mathematical modeling of the non-equilibrium condensing transonic steam flow in the complex 3D geometry of a steam turbine is a demanding problem both concerning the physical concepts and the required computational power. Available accurate formulations of steam properties IAPWS-95 and IAPWS-IF97 require much computation time. For this reason, the modelers often accept the unrealistic ideal-gas behavior. Here we present a computation scheme based on a piecewise, thermodynamically consistent representation of the IAPWS-95 formulation. Density and internal energy are chosen as independent variables to avoid variable transformations and iterations. On the contrary to the previous Tabular Taylor Series Expansion Method, the pressure and temperature are continuous functions of the independent variables, which is a desirable property for the solution of the differential equations of the mass, energy, and momentum conservation for both phases.

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

    Science.gov (United States)

    Eggeen, Per-Odd; Kvittingen, Lise

    2004-01-01

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

  4. Duplex tube steam reformer development program

    Energy Technology Data Exchange (ETDEWEB)

    Lewe, C K; Nieto, J M; Papadopoulos, A

    1978-09-01

    Work done in partial fulfillment of Task 7 of the Duplex Steam Reformer Development Program is described. The DSR concept acts as a double barrier between a process heat high temperature reactor plant (PNP) and a closed loop chemical heat pipe (CHP) for the long distance transport of chemical energy to a remote industrial user. The current state of the DSR design is described as well as related systems and equipment. The PNP concept presented is based upon work currently underway in the Federal Republic of Germany.

  5. Direct injection of superheated steam for continuous hydrolysis reaction

    KAUST Repository

    Wang, Weicheng

    2012-09-01

    The primary intent for previous continuous hydrolysis studies was to minimize the reaction temperature and reaction time. In this work, hydrolysis is the first step of a proprietary chemical process to convert lipids to sustainable, drop-in replacements for petroleum based fuels. To improve the economics of the process, attention is now focused on optimizing the energy efficiency of the process, maximizing the reaction rate, and improving the recovery of the glycerol by-product. A laboratory-scale reactor system has been designed and built with this goal in mind.Sweet water (water with glycerol from the hydrolysis reaction) is routed to a distillation column and heated above the boiling point of water at the reaction pressure. The steam pressure allows the steam to return to the reactor without pumping. Direct injection of steam into the hydrolysis reactor is shown to provide favorable equilibrium conditions resulting in a high quality of FFA product and rapid reaction rate, even without preheating the inlet water and oil and with lower reactor temperatures and lower fresh water demand. The high enthalpy of the steam provides energy for the hydrolysis reaction. Steam injection offers enhanced conditions for continuous hydrolysis of triglycerides to high-purity streams of FFA and glycerol. © 2012 Elsevier B.V.

  6. 4 kW Test of Solid Oxide Electrolysis Stacks with Advanced Electrode-Supported Cells

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Effects of the different atmospheric steam curing processes on the ...

    Indian Academy of Sciences (India)

    In this paper an attempt has been made to study the use of microsilica on the properties of self-compacting-concrete (SCC) such as compressive strength, splitting tensile strength, flexural strength, ultrasonic pulse velocity (UPV) and micro-hardness when exposed to different atmospheric steam curing temperatures.

  8. Hideout in steam generator tube deposits

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, P.V.; Franklin, K.J.; Turner, C.W

    1998-05-01

    Hideout in deposits on steam generator tubes was studied using tubes coated with magnetite. Hideout from sodium chloride solutions at 279 degrees C was followed using an on-line high-temperature conductivity probe, as well as by chemical analysis of solution samples from the autoclave in which the studies were done. Significant hideout was observed only at a heat flux greater than 200 kW/m{sup 2}, corresponding to a temperature drop greater than 2 degrees C across the deposits. The concentration factor resulting from the hideout increased highly non-linearly with the heat flux (varying as high as the fourth power of the heat flux). The decrease in the apparent concentration factor with increasing deposit thickness suggested that the pores in the deposit were occupied by a mixture of steam and water, which is consistent with the conclusion from the thermal conductivity measurements on deposits in a separate study. Analyses of the deposits after the hideout tests showed no evidence of any hidden-out solute species, probably due to the concentrations being very near the detection limits and to their escape from the deposit as the tests were being ended. This study showed that hideout in deposits may concentrate solutes in the steam generator bulk water by a factor as high as 2 x 10{sup 3}. Corrosion was evident under the deposit in some tests, with some chromium enrichment on the surface of the tube. Chromium enrichment usually indicates an acidic environment, but the mobility required of chromium to become incorporated into the thick magnetite deposit may indicate corrosion under an alkaline environment. An alkaline environment could result from preferential accumulation of sodium in the solution in the deposit during the hideout process. (author)

  9. Vibration Analysis for Steam Dryer of APR1400 Steam Generator

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sung-heum; Ko, Doyoung [KHNP CRI, Daejeon (Korea, Republic of); Cho, Minki [Doosan Heavy Industry, Changwon (Korea, Republic of)

    2016-10-15

    This paper is related to comprehensive vibration assessment program for APR1400 steam generator internals. According to U.S. Nuclear Regulatory Commission, Regulatory Guide 1.20 (Rev.3, March 2007), we conducted vibration analysis for a steam dryer as the second steam separator of steam generator internals. The vibration analysis was performed at the 100 % power operating condition as the normal operation condition. The random hydraulic loads were calculated by the computational fluid dynamics and the structural responses were predicted by power spectral density analysis for the probabilistic method. In order to meet the recently revised U.S. NRC RG 1.20 Rev.3, the CVAP against the potential adverse flow effects in APR1400 SG internals should be performed. This study conducted the vibration response analysis for the SG steam dryer as the second moisture separator at the 100% power condition, and evaluated the structural integrity. The predicted alternating stress intensities were evaluated to have more than 17.78 times fatigue margin compared to the endurance limit.

  10. Power to fuel using electrolysis and CO2 capture

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Graves, Christopher R.; Chatzichristodoulou, Christodoulos

    2014-01-01

    Conversion of renewable electricity to synthetic fuel using electrolysis to produce at H2 and CO, which is furtherused to form liquid or gaseous fuel, called “power to fuel” or “power2fuel” has got a lot of attention recently.This is because synthetic fuels (synfuels) in the form CO2 neutral “green......” hydrocarbon fuels seem particularlybenign to replace the fossil fuels, and electrolysis seems to be a feasible step in production of green fuels. In particular, synthetic hydrocarbon based fuel will be necessary for the heavy transportation vehicles such as airplanes, ships, and trucks. More than 65...... % of the cost of H2 produced by electrolysis originates from electricity cost. How much more depends on the actual electricity price and depends further on efficiency, investment cost and lifetime of electrolyzer. Investment costs are inversely proportional the current density at a given cell voltage...

  11. Development of Hydrogen Electrodes for Alkaline Water Electrolysis

    DEFF Research Database (Denmark)

    Kjartansdóttir, Cecilía Kristín

    will be needed. Producing hydrogen via water electrolysis using surplus, low cost, power from renewables offers the possibility of increased production capacity and load management with no greenhouse emissions. Hydrogen is a valuable energy carrier, which is able to contribute to various forms of energy, such as...... infrastructure. Alkaline water electrolysis (AWE) is the current standard (stat of the art) for industrial large-scale water electrolysis systems. One of the main criteria for industrial AWE is efficient and durable electrodes. The aim of the present PhD study was to develop electrode materials for hydrogen...... production in order to improve the efficiency and durability, and decrease the costs associated with industrial AWE. The primary effort was reserved to the hydrogen electrodes. Additionally, a new test setup for efficiency and durability measurements was to be designed and constructed. During the present Ph...

  12. Electrolysis of lunar soil to produce oxygen and metals

    Science.gov (United States)

    Colson, Russell O.; Haskin, Larry A.; Keller, R.

    1991-01-01

    The discussion of melt electrolysis consists of three sections. The implications of the chemistry and physics of fluxed and raw melts on melt electrolysis are discussed first. This includes discussion of the factor that influence melt resistivity, melt viscosity, oxygen production efficiency, and the theoretical energy required to produce oxygen. Second, the implications of phase equilibria and solubilities in silicate melts on the selection of materials for container and electrodes are discussed. The implications of proposed container and electrode materials on melt composition and how this effects expected resistivities, viscosities, as outlined in the first section are discussed. Finally, a general discussion of the basic features of both the fluxed and unfluxed melt electrolysis is given, including their advantages and disadvantages and how they compare with alternative processes.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    The LaNiO3 perovskite was chosen for incorporation into a nickel matrix in order to obtain a metallic composite electrode suitable for improving the oxygen evolution reaction (OER) in commercial water electrolysis at elevated temperature. The manufactured LaNiO3 + Ni composite coatings were...... deposited in a Watts type nickel electrolyte in a specially designed beaker with continuous particle circulation. Activity of the composite coatings was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and anodic potentiodynamic polarization measurements. The obtained...... results were compared to a non-catalysed Watts nickel reference sample and the electrochemical measurements confirmed that the coating decreased the OER overpotential by 70 mV. XRD furthermore revealed that a LaNiO3 + Ni composite structure was obtained. Conventional alkaline water electrolysis...

  14. Game Changing Development Program - Next Generation Life Support Project: Oxygen Recovery From Carbon Dioxide Using Ion Exchange Membrane Electrolysis Technology

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

    Keow, Alicia; Chen, Zheng

    2017-04-01

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

  17. Silicon Carbide-Derived Carbon Prepared by Fused Salt Electrolysis and Electrochemical Performance

    Directory of Open Access Journals (Sweden)

    Shuyuan Wang

    2016-01-01

    Full Text Available A number of carbide-derived carbon (CDC samples were successfully synthesized by the electrolysis of SiC powder in molten CaCl2. The electrolysis was conducted at different temperatures (850, 900, and 950°C for 48 h in argon at an applied constant voltage of 3.1 V. The structure of the resulting carbon is characterized by X-ray diffraction, Raman spectroscopy, and transmission electron microscope techniques. Cyclic voltammetry and galvanostatic charge/discharge measurements are applied to investigate electrochemical performances of the SiC-CDC material. It can be seen that the degree of order of the SiC-CDC increases monotonically along with elevation of reaction temperature, while the highest specific surface area 1137.74 m2/g together with a specific capacitance of 161.27 F/g at a current density 300 mA/g was achieved from sample synthesized at 900°C.

  18. The recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor.

    Science.gov (United States)

    Ren, Xiulian; Wei, Qifeng; Hu, Surong; Wei, Sijie

    2010-09-15

    This paper reports the optimization of the process parameters for recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor. The experiments were carried out in an ammoniacal ammonium chloride system. The influence of composition of electrolytes, pH, stirring rate, current density and temperature, on cathodic current efficiency, specific power consumption and anodic dissolution of Zn were investigated. The results indicate that the cathode current efficiency increases and the hydrogen evolution decreased with increasing the cathode current density. The partial current for electrodeposition of Zn has liner relationship with omega(1/2) (omega: rotation rate). The highest current efficiency for dissolving zinc was obtained when NH(4)Cl concentration was 53.46 g L(-1) and the anodic dissolution of zinc was determined by mass transfer rate at stirring rate 0-300 r min(-1). Increase in temperature benefits to improve CE and dissolution of Zn, and reduce cell voltage. Initial pH of electrolytes plays an important role in the deposition and anodic dissolution of Zn. The results of single factor experiment show that about 50% energy consumption was saved for electrodeposition of Zn in the anion-exchange membrane electrolysis reactor. Copyright 2010 Elsevier B.V. All rights reserved.

  19. The recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ren Xiulian [College of Ocean, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Wei Qifeng, E-mail: weiqifeng163@163.com [College of Ocean, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Hu Surong; Wei Sijie [College of Ocean, Harbin Institute of Technology at Weihai, Weihai 264209 (China)

    2010-09-15

    This paper reports the optimization of the process parameters for recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor. The experiments were carried out in an ammoniacal ammonium chloride system. The influence of composition of electrolytes, pH, stirring rate, current density and temperature, on cathodic current efficiency, specific power consumption and anodic dissolution of Zn were investigated. The results indicate that the cathode current efficiency increases and the hydrogen evolution decreased with increasing the cathode current density. The partial current for electrodeposition of Zn has liner relationship with {omega}{sup 1/2} ({omega}: rotation rate). The highest current efficiency for dissolving zinc was obtained when NH{sub 4}Cl concentration was 53.46 g L{sup -1} and the anodic dissolution of zinc was determined by mass transfer rate at stirring rate 0-300 r min{sup -1}. Increase in temperature benefits to improve CE and dissolution of Zn, and reduce cell voltage. Initial pH of electrolytes plays an important role in the deposition and anodic dissolution of Zn. The results of single factor experiment show that about 50% energy consumption was saved for electrodeposition of Zn in the anion-exchange membrane electrolysis reactor.

  20. Small Engines as Bottoming Cycle Steam Expanders for Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Rohitha Weerasinghe

    2017-01-01

    Full Text Available Heat recovery bottoming cycles for internal combustion engines have opened new avenues for research into small steam expanders (Stobart and Weerasinghe, 2006. Dependable data for small steam expanders will allow us to predict their suitability as bottoming cycle engines and the fuel economy achieved by using them as bottoming cycles. Present paper is based on results of experiments carried out on small scale Wankel and two-stroke reciprocating engines as air expanders and as steam expanders. A test facility developed at Sussex used for measurements is comprised of a torque, power and speed measurements, electronic actuation of valves, synchronized data acquisition of pressure, and temperatures of steam and inside of the engines for steam and internal combustion cycles. Results are presented for four engine modes, namely, reciprocating engine in uniflow steam expansion mode and air expansion mode and rotary Wankel engine in steam expansion mode and air expansion mode. The air tests will provide base data for friction and motoring effects whereas steam tests will tell how effective the engines will be in this mode. Results for power, torque, and p-V diagrams are compared to determine the change in performance from air expansion mode to steam expansion mode.

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

    Science.gov (United States)

    Lee, Kristopher A.

    2016-01-01

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

  2. Modern geothermal power: GeoPP with geothermal steam turbines

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.

    2017-03-01

    The first part of the review presents information on the scale and specific features of geothermal energy development in various countries. The classification of geothermal power plant (GeoPP) process flow diagrams by a phase state of the primary heat source (a geothermal fluid), thermodynamic cycle, and applicable turbines is proposed. Features of geothermal plants using methods of flashing and steam separation in the process loop and a flowsheet and thermodynamic process of a geothermal fluid heat-to-power conversion in a GeoPP of the most widespread type using a double-flash separation are considered. It is shown that, for combined cycle power units, the specific power-to-consumption geothermal fluid ratio is 20-25% higher than that for traditional single-loop GeoPP. Information about basic chemical components and their concentration range for geothermal fluids of various formations around the world is presented. Three historic stages of improving geothermal energy technologies are determined, such as development of high-temperature geothermal resources (dry, superheated steam) and application of a two-phase wet-steam geothermal fluid in GeoPP power units with one or two expansion pressures and development of binary cycle GeoPPs. A current trend of more active use of binary power plants in GeoPP technological processes is noted. Design features of GeoPP's steam turbines and steam separating devices, determined by the use of low-potential geothermal saturated steam as a working medium, which is characterized by corrosion aggressiveness and a tendency to form deposits, are considered. Most promising Russian geothermal energy projects are determined. A list of today's most advanced geothermal turbine performance technologies is presented. By an example of a 25 MW steam turbine design, made by JSC Kaluga Turbine Works, advantages of the internal moisture separation with a special turbine-separator stage are shown.

  3. Role of acidic chemistries in steam treatment of aluminium alloys

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    The effect of acidic chemistry on the accelerated growth of oxide on aluminium alloys Peraluman 706TM and AA6060 under exposure to high temperature steam was investigated. Studied chemistries were based on citrates and phosphates. Results showed that the presence of citrate and phosphate anions...... initiate doxide growth at the intermetallic particles while growth and corrosion performance of oxide was found tobe a function of anions type and their concentration. Further, steam treatment with phosphates exhibited better performance under acetic acid salt spray and filiform corrosion test whereas...

  4. Analysis and potential of once-through steam generators in line focus systems - Final results of the DUKE project

    Science.gov (United States)

    Feldhoff, Jan Fabian; Hirsch, Tobias; Pitz-Paal, Robert; Valenzuela, Loreto

    2016-05-01

    The direct steam generation in line focus systems such as parabolic troughs and linear Fresnel collectors is one option for providing `solar steam' or heat. Commercial power plants use the recirculation concept, in which the steam generation is separated from the superheating by a steam drum. This paper analyzes the once-through mode as an advanced solar field concept. It summarizes the results of the DUKE project on loop design, a new temperature control strategy, thermo-mechanical stress analysis, and an overall cost analysis. Experimental results of the temperature control concept at the DISS test facility at Plataforma Solar de Almería are presented.

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

    Science.gov (United States)

    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.

  6. Intermetallics as advanced cathode materials in hydrogen production via electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Stojic, Dragica Lj.; Marceta Kaninski, Milica P.; Maksic, Aleksandar D.; Simic, Natasa D. [Laboratory of Physical Chemistry, Vinca Institute of Nuclear Sciences, P.O. Box 522, 11001-Belgrade (Serbia and Montenegro); Grozdic, Tomislav D. [Centre for Multidisciplinary Studies, University of Belgrade, 11030-Belgrade (Serbia and Montenegro)

    2006-06-15

    Intermetallics phases along Mo-Pt phase diagram have been investigated as cathode materials for the production of hydrogen by electrolysis from water KOH solutions, in an attempt to increase the electrolytic process efficiency. These materials were compared with conventional cathodes (Fe and Ni), often used in the alkaline electrolysis, and also with the intermetallic Ti-Pt. An significant upgrade of the electrolytic efficiency using intermetallics in pure KOH electrolyte was achieved in comparison with conventional cathode materials. The effects of those cathode materials on the process efficiency were discussed in the context of transition metal features that issue from their electronic configuration. (author)

  7. Compact solar autoclave based on steam generation using broadband light-harvesting nanoparticles

    National Research Council Canada - National Science Library

    Oara Neumann; Curtis Feronti; Albert D. Neumann; Anjie Dong; Kevin Schell; Benjamin Lu; Eric Kim; Mary Quinn; Shea Thompson; Nathaniel Grady; Peter Nordlander; Maria Oden; Naomi J. Halas

    2013-01-01

    .... Here, we show the use of broadband light-absorbing nanoparticles as solar photothermal heaters, which generate high-temperature steam for a standalone, efficient solar autoclave useful for sanitation...

  8. Thermodynamic Peculiar Features of Steam Flow in Heat Pipe-Line

    Directory of Open Access Journals (Sweden)

    B. M. Khroustalev

    2008-01-01

    Full Text Available The paper contains results of the investigations pertaining to thermodynamic steam characteristics of the operating pipe-line, analysis of steam flow regimes, influence of heat losses on temperature fall along the length. The eh-diagram presents changes in e and e values which are caused by decrease of mean temperatures with the given pressure value at pipe-line inlet and outlet. The paper shows that steam enthalpy at the pipeline outlet depends on inlet enthalpy, ambient temperature and entropy difference.The constructed nomograph makes it possible to forecast steam temperature fall in the pipe-line with the purpose to ensure more efficient usage of its thermodynamic potential.

  9. Optimum steam data in bio-fuelled CHP; Optimala aangdata foer biobraensleeldade kraftvaermeverk

    Energy Technology Data Exchange (ETDEWEB)

    Steinwall, Pontus; Johansson, Kent; Svensson, Sven-Aake [Sycon Energikonsult AB, Malmoe (Sweden); Adolfson, Helene; Ekelund, Niclas [EPS Consulting AB, Vaenersborg (Sweden)

    2002-04-01

    This report deals with which steam data that gives the lowest electricity production cost in a biofuelled CHP. Three different sizes of CHP have been examined with a CFB of 30, 75 and 120 MWth. Calculations have been made to find how the investment cost depends on the steam data. The need of components, material and working time to build the boilers has been examined to find these costs. The costs for operation and maintenance are also affected by the steam data, especially the cost for high temperature corrosion at the superheaters. By data from other projects at Vaermeforsk the endurance of the superheaters has been estimated. The cost for manufacturing and changing the superheaters has been calculated with knowledge from projects carried through. The maintenance costs for the superheaters in are exponential to the steam data but rather proportional to the plant size at the same steam data. The steam data that is preferable has been examined by calculating the power production cost. The income from district heat is very important for the result why this is varied. The fuel price is 110 SEK/MWh but doesn't affect the result. Our conclusion is that in a CHP, credited with normal levels for the DH, should the steam temperature be under 500 deg C. The admission data should PN 160 or lower. High steam data are most interesting at low levels of the income from DH.

  10. Hydrogen-based power generation from bioethanol steam reforming

    Science.gov (United States)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-12-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  11. Hydrogen-based power generation from bioethanol steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Tasnadi-Asztalos, Zs., E-mail: tazsolt@chem.ubbcluj.ro; Cormos, C. C., E-mail: cormos@chem.ubbcluj.ro; Agachi, P. S. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos, Postal code: 400028, Cluj-Napoca (Romania)

    2015-12-23

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO{sub 2} emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  12. Design and Activation of a LOX/GH Chemical Steam Generator

    Science.gov (United States)

    Saunders, G. P.; Mulkey, C. A.; Taylor, S. A.

    2009-01-01

    The purpose of this paper is to give a detailed description of the design and activation of the LOX/GH fueled chemical steam generator installed in Cell 2 of the E3 test facility at Stennis Space Center, MS (SSC). The steam generator uses a liquid oxygen oxidizer with gaseous hydrogen fuel. The combustion products are then quenched with water to create steam at pressures from 150 to 450 psig at temperatures from 350 to 750 deg F (from saturation to piping temperature limits).

  13. The study of reactions influencing the biomass steam gasification process

    Energy Technology Data Exchange (ETDEWEB)

    C. Franco; F. Pinto; I. Gulyurtlu; I. Cabrita [INETI-DEECA, Lisbon (Portugal)

    2003-05-01

    Steam gasification studies were carried out in an atmospheric fluidised bed. The gasifier was operated over a temperature range of 700 900{sup o}C whilst varying a steam/biomass ratio from 0.4 to 0.85 w/w. Three types of forestry biomass were studied: Pinus pinaster (softwood), Eucalyptus globulus and holm-oak (hardwood). The energy conversion, gas composition, higher heating value and gas yields were determined and correlated with temperature, steam/biomass ratio, and species of biomass used. The results obtained seemed to suggest that the operating conditions were optimised for a gasification temperature around 830{sup o}C and a steam/biomass ratio of 0.6 0.7 w/w, because a gas richer in hydrogen and poorer in hydrocarbons and tars was produced. These conditions also favoured greater energy and carbon conversions, as well the gas yield. The main objective of the present work was to determine what reactions were dominant within the operation limits of experimental parameters studied and what was the effect of biomass type on the gasification process. As biomass wastes usually have a problem of availability because of seasonal variations, this work analysed the possibility of replacing one biomass species by another, without altering the gas quality obtained. 19 refs., 8 figs. 2 tabs.

  14. Steamed Zeolites for Heat Pump Applications and Solar Driven Thermal Adsorption Storage

    OpenAIRE

    Herzog, Thomas H.; Jänchen, Jochen; Kontogeorgopoulos, Eythymius M.; Lutz, Wolfgang

    2014-01-01

    The influence of the dealumination degree of NaY with respect to the water adsorption properties was investigated by infrared spectroscopy, thermogravimetry and isotherm measurements. The modification of the samples is a result of a steaming process at different temperatures in dependence of time. It was found that dealumination controls the hydrophilic behavior of NaY and contributes to defined low desorption temperatures. Similar to microporous SAPO's steamed Y-zeolites can be used for low ...

  15. A simplified mathematical model of vertical U-tube steam generator in MATLAB environment

    Science.gov (United States)

    Gerova, Gergana; Pasheva, Vesela

    2017-12-01

    The paper presents a vertical U-tube steam generator mathematical model which is developed in MATLAB environment. In the model is used single phase or humongous fluid and are made some simplifications in order to save computational time. After the model was build several numerical simulations were conducted. The changes of some main parameter values like primary water temperature, metal tube temperature, steam generator pressure, and so on are presented in graphs and tables.

  16. Steam jacket dynamics in underground coal gasification

    Science.gov (United States)

    Otto, Christopher; Kempka, Thomas

    2017-04-01

    Underground coal gasification (UCG) has the potential to increase the world-wide hydrocarbon reserves by utilization of deposits not economically mineable by conventional methods. In this context, UCG involves combusting coal in-situ to produce a high-calorific synthesis gas, which can be applied for electricity generation or chemical feedstock production. Apart from high economic potentials, in-situ combustion may cause environmental impacts such as groundwater pollution by by-product leakage. In order to prevent or significantly mitigate these potential environmental concerns, UCG reactors are generally operated below hydrostatic pressure to limit the outflow of UCG process fluids into overburden aquifers. This pressure difference effects groundwater inflow into the reactor and prevents the escape of product gas. In the close reactor vicinity, fluid flow determined by the evolving high reactor temperatures, resulting in the build-up of a steam jacket. Numerical modeling is one of the key components to study coupled processes in in-situ combustion. We employed the thermo-hydraulic numerical simulator MUFITS (BINMIXT module) to address the influence of reactor pressure dynamics as well as hydro-geological coal and caprock parameters on water inflow and steam jacket dynamics. The US field trials Hanna and Hoe Creek (Wyoming) were applied for 3D model validation in terms of water inflow matching, whereby the good agreement between our modeling results and the field data indicates that our model reflects the hydrothermal physics of the process. In summary, our validated model allows a fast prediction of the steam jacket dynamics as well as water in- and outflows, required to avoid aquifer contamination during the entire life cycle of in-situ combustion operations.

  17. Experimental investigation on combustion of hydrogen-oxygen and methane-oxygen mixtures in the medium of low-superheated steam

    Science.gov (United States)

    Pribaturin, N. A.; Fedorov, V. A.; Alekseev, M. V.; Bogomolov, A. R.; Sorokin, A. L.; Azikhanov, S. S.; Shevyrev, S. A.

    2016-05-01

    Experimental data are represented on the investigation of combustion of hydrogen-oxygen and methane-oxygen mixtures in the medium of low-superheated (initial temperature of approximately 150°C) steam at atmospheric pressure. The influence of the ratio of mass flows of the combustible mixture and steam on the qualitative composition of combustion products and the temperature of produced steam is revealed. Main laws for combustion of the hydrogen-oxygen mixture within the steam flow, which affect the completeness of mixture combustion, are determined. Experimental data on the influence of concentrations of the hydrogen-oxygen mixture within the flow of the steam and the combustible mixture upon the completeness of combustion are given. It is found that, when burning the hydrogen-oxygen mixture within the steam flow with a temperature of 1000-1200°C, it is possible using a variation of the combustible mixture flow. At the same time, the volume fraction of noncondensable gases in the produced steam is no more than 2%. It is revealed that there are several combustion modes of the hydrogen-oxygen mixture within the steam flow, in which, in one case, the steam always suppresses combustion and, in another one, detonation of the combustible mixture combustible mixture occurs. It is found that with the excess air factor close to unit, the combustion of the methane-oxygen mixture within steam and the vapor conversion of methane, which result in the appearance of free hydrogen in the produced high-temperature steam, are possible. The description and the principle of the operation of the experimental bench for investigation of combustion of methane-oxygen and hydrogen-oxygen mixtures in the medium of steam are given. Results of experimental investigations of burning fuel and oxygen in the medium of steam are used in the development of a steam superheater for a hightemperature steam turbine.

  18. Steam Digest 2001: Office of Industrial Technologies

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2002-01-01

    Steam Digest 2001 chronicles Best Practices Program's contributions to the industrial trade press for 2001, and presents articles that cover technical, financial and managerial aspects of steam optimization.

  19. Deuterium overloading of palladium wires by means of high power means of high power ms pulsed electrolysis and electromigration : suggestions of phase transition and related excess heat

    Energy Technology Data Exchange (ETDEWEB)

    Celani, F.; Spallone, A.; Tripodi, P.; Petrocchi, A.; Di Gioacchino, D. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Marini, P.; Di Stefani, V. [EURESIS, Rome (Italy); Pace, S. [Salerno Univ. (Italy). Dip. di Fisica; Mancini, A. [ORIM s.r.l., Macerata (Italy)

    1996-03-01

    A room-temperature hydrogen and deuterium loading of palladium wires by means of pulsed electrolysis and electromigration effect is described. The D/Pd atomic ratio has been measured by means of the dependence of the resistivity upon the D/Pd ratio. Values of the D/Pd ratio up to 0.95 or even higher have been reached in short times. A correlation between an anomalous temperature rise and a resistivity transition of the overloaded palladium clearly appears.

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

    Science.gov (United States)

    Venkatachar, Arun C.

    1985-01-01

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

  1. PEM Electrolysis H2A Production Case Study Documentation

    Energy Technology Data Exchange (ETDEWEB)

    James, Brian [Strategic Analysis Inc. (SA), Arlington, Virginia; Colella, Whitney [Strategic Analysis Inc. (SA), Arlington, Virginia; Moton, Jennie [Strategic Analysis Inc. (SA), Arlington, Virginia; Saur, G. [Strategic Analysis Inc. (SA), Arlington, Virginia; Ramsden, T. [Strategic Analysis Inc. (SA), Arlington, Virginia

    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).

  2. Synergistic Combination of Electrolysis and Electroporation for Tissue Ablation.

    Science.gov (United States)

    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.

  3. Principle and perspectives of hydrogen production through biocatalyzed electrolysis

    NARCIS (Netherlands)

    Rozendal, R.A.; Hamelers, H.V.M.; Euverink, G.J.W.; Metz, S.J.; Buisman, C.J.N.

    2006-01-01

    Biocatalyzed electrolysis is a novel biological hydrogen production process with the potential to efficiently convert a wide range of dissolved organic materials in wastewaters. Even substrates formerly regarded to be unsuitable for hydrogen production due to the endothermic nature of the involved

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

    Science.gov (United States)

    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. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Hydrogen generation by electrolysis of aqueous organic solutions

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into chemical energy in the form of hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and a liquid immobilized electrolyte allow the operation...

  7. Search for DD-fusion neutrons during heavy water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Seeliger, D.; Wiesener, K.; Meister, A.; Marten, H.; Ohms, D.; Rahner, D.; Schwierz, R.; Wustner, P. (Technische Univ., Dresden (German Democratic Republic))

    1989-07-01

    The radiation obtained by the electrolysis of heavy water with a palladium cathode was measured, using a large volume liquid scintillation detector and some other neutron and gamma-ray detectors. An indication of a weak generation of fast neutrons (0.1 s{sup -1} of about 2.5 MeV) is found. (author).

  8. Durable solid oxide electrolysis cells for hydrogen production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Hendriksen, Peter Vang

    2014-01-01

    Solid oxide cell (SOC) for electrolysis application has attracted great interest in recent years due to its high power-to-gas efficiency and capability of co-electrolysis of H2O and CO2 for syngas (H2 + CO) production. The demonstration of durable solid oxide electrolysis cell operation for fuel...... production is required for promoting commercialization of the SOEC technology. In this work, we report a recent 4400 hours test of a state-of-the-art Ni-YSZ electrode supported SOEC cell. The cell consists of a Ni-YSZ (YSZ: yttria stabilized zirconia) support and active fuel electrode, an YSZ electrolyte...... layer, a CGO (Gd doped ceria) inter-diffusion barrier layer and a LSCF-CGO (LSCF: lanthanum ferrite doped with strontium and cobalt) oxygen electrode layer. The electrolysis test was carried out at 800 °C under 1 A/cm2 with 90 % H2O + 10 % H2 supplied to Ni-YSZ electrode compartment. The results show...

  9. Oxygen from the lunar soil by molten silicate electrolysis

    Science.gov (United States)

    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.

  10. Steam Electrolysis by Proton-Conducting Solid Oxide Electrolysis Cells (SOECs) with Chemically Stable BaZrO3-Based Electrolytes

    KAUST Repository

    Bi, Lei

    2015-07-17

    BaZrO3-based material was applied as the electrolyte for proton-conducting solid oxide fuel cells (SOECs). Compared with the instability of BaCeO3-based proton-conductors, BaZrO3-based material could be a more promising candidate for proton-conducting SOECs due to its excellent chemical stability under H2O conditions, but few reports on this aspect has been made due to the processing difficulty for BaZrO3. Our recent pioneering work has demonstrated the feasibility of using BaZrO3-based electrolyte for SOECs and the fabricated cell achieves relatively high cell performance, which is comparable or even higher than that for BaCeO3-based SOECs and offers better chemical stability. Cell performance can be further improved by tailoring the electrolyte and electrode. © The Electrochemical Society.

  11. Effect of a steam foot spa on geriatric inpatients with cognitive impairment: a pilot study

    Science.gov (United States)

    Koike, Yoshihisa; Kondo, Hideki; Kondo, Satoshi; Takagi, Masayuki; Kano, Yoshio

    2013-01-01

    Purpose To investigate whether a steam foot spa improves cognitive impairment in geriatric inpatients. Methods Geriatric inpatients with cognitive impairment were given a steam foot spa treatment at 42°C for 20 minutes for 2 weeks (5 days/week). Physiological indicators such as blood pressure, percutaneous oxygen saturation, pulse, tympanic temperature, and sleep time and efficiency were assessed. Cognitive function and behavioral and psychological symptoms of dementia were assessed using the Mini-Mental State Examination, Dementia Mood Assessment Scale, and Dementia Behavior Disturbance scale. Results Significant decreases in systolic (P steam foot spas. A significant improvement was seen in the Mini-Mental State Examination score (P steam foot baths. In this study, a control group was not used. Raters and enforcers were not blinded. Conclusion The results of this pilot study suggest that steam foot spas mitigate cognitive impairment in geriatric inpatients. PMID:23717038

  12. Steam zone classification in the recovery of bitumen by SAGD technology

    Energy Technology Data Exchange (ETDEWEB)

    Thimm, H.F. [Thimm Petroleum Technologies Inc. (Canada)

    2011-07-01

    In an oil field, steam assisted gravity drainage (SAGD) is used as a thermal recovery process. The presence of gas in the steam zone can affect the ease with which the process can be simulated. The behaviour of gases in the steam zone is strongly influenced by the solubility of these gases in water. The aim of the paper is to look at the behaviour of the gases present in SAGD operations in terms of high temperature solution thermodynamics. The theoretical model was first demonstrated and then results were compared with the field results from several operations in the Athabasca and Cold Lake areas. Field calculations confirmed both the results from the theoretical model and the existence of three distinct types of steam zones in the SAGD process. This paper examined the behaviour of gases in SAGD processes and highlighted the fact that the presence of three types of steam zones has to be taken into consideration in simulations and in field operations.

  13. Methane steam reforming kinetics over Ni-YSZ anodematerials for Solid Oxide FuelCells

    DEFF Research Database (Denmark)

    Mogensen, David

    accurately predict the steam reforming rate in a stack from the rate expression obtained from the packed bed experiments. During the experiments a previously unreported long term dynamic behavior of the catalyst was observed. After startup, the initial high reactivity was slowly reduced by a factor 5-10 over...... energy. The overall efficiency of a fuel cell system operating on natural gas can be significantly improved by having part of the steam reforming take place inside the SOFC stack. In order to avoid large temperature gradients as a result of the highly endothermal steam reforming reaction, the amount...... of internal reforming has to be carefully controlled. The objective of this thesis is to make such a careful control possible by examining the rate of internal steam reforming in SOFCs. The catalytic steam reforming activity of Ni-YSZ anode material was tested both in a packed bed reactor to determine...

  14. BWR Steam Dryer Alternating Stress Assessment Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Morante, R. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hambric, S. A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ziada, S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-12-01

    This report presents an overview of Boiling Water Reactor (BWR) steam dryer design; the fatigue cracking failures that occurred at the Quad Cities (QC) plants and their root causes; a history of BWR Extended Power Uprates (EPUs) in the USA; and a discussion of steam dryer modifications/replacements, alternating stress mechanisms on steam dryers, and structural integrity evaluations (static and alternating stress).

  15. Parametric study for horizontal steam generator modelling

    Energy Technology Data Exchange (ETDEWEB)

    Ovtcharova, I. [Energoproekt, Sofia (Bulgaria)

    1995-12-31

    In the presentation some of the calculated results of horizontal steam generator PGV - 440 modelling with RELAP5/Mod3 are described. Two nodalization schemes have been used with different components in the steam dome. A study of parameters variation on the steam generator work and calculated results is made in cases with separator and branch.

  16. The quest for intensified steam cracking process

    NARCIS (Netherlands)

    Van Goethem, M.W.M.; Verheijen, P.J.T.

    2005-01-01

    In this paper the results are presented on the quest for an intensified steam cracking process. The main focus is to improve the efficiency of the steam cracking process. The first part of the investigation is to examine which of the current available processes is close to the ideal steam cracking

  17. HYDROGEN GENERATION FROM ELECTROLYSIS - REVISED FINAL TECHNICAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. New downhole steam generator tested

    Energy Technology Data Exchange (ETDEWEB)

    Bleakley, W.B.

    1981-07-01

    Completion of 2 field tests of a new-model down-hole steam generator paves the way for further evaluation and development of a system destined to increase California's heavy oil production. Current air pollution restrictions there prevent installation of conventional steam generators in several areas of interest to oil operators. The current series of tests, conducted by Chemical Oil Recovery Co. (CORCO) of Bakersfield, California, follows an earlier prototype operation conducted by Sandia National Laboratories in conjunction with the US Department of Energy. The CORCO tests were conducted on the surface with the generator's output going into Tenneco Oil Exploration and Production Co.'s overland-Riokern Well No. 80, located in the Kern River field 4 miles north of Bakersfield. The first test was concluded with just under 1000 bbl of steam injected, less than planned due to a higher-than-expected injection pressure. The unit operated at less than 25% capacity because of the air compressor limitation. Compressor output was only 285 psi, not enough to inject the desired volumes into the reservoir. Test data shows that injection amounted to 150 bpd of 90 to 95% quality steam at 225-psi wellhead pressure. After injection, the well was shut in for 3 days to allow soaking, then put on production. Initial production was 40 bopd at 175 F.

  19. The STEAM behind the Scenes

    Science.gov (United States)

    Smith, Carmen Petrick; King, Barbara; González, Diana

    2015-01-01

    There is a growing need for STEAM-based (Science, Technology, Engineering, Arts, and Mathematics) knowledge and skills across a wide range of professions (Brazell 2013). Yet students often fail to see the usefulness of mathematics beyond the classroom (Kloosterman, Raymond, and Emenaker 1996), and they do not regularly make connections between…

  20. The STEAM-Powered Classroom

    Science.gov (United States)

    Harper, Charlie

    2017-01-01

    An instructional coach argues that STEAM (science, technology, engineering, arts, and mathematics) programming combined with problem-based learning can offer rich academic experiences--and not just in science classrooms. He outlines relevant problem-based lesson ideas, and discusses ways school leaders can better support instructional practices…

  1. Steam Hydrocarbon Cracking and Reforming

    Science.gov (United States)

    Golombok, Michael

    2004-01-01

    The interactive methods of steam hydrocarbon reforming and cracking of the oil and chemical industries are scrutinized, with special focus on their resemblance and variations. The two methods are illustrations of equilibrium-controlled and kinetically-controlled processes, the analysis of which involves theories, which overlap and balance each…

  2. Catalyzed steam gasification of biomass. Phase II. Final research report

    Energy Technology Data Exchange (ETDEWEB)

    Hooverman, R.H.

    1979-05-01

    The Wright-Malta gasification process is characterized by low-temperature, catalyzed steam gasification in a pressurized rotary kiln. Fresh biomass moves slowly and continuously through the kiln, where it is gradually heated to around 1200/sup 0/F in an atmosphere of 300 psi steam. During its traverse, pyrolysis and reaction of steam with the nascent char convert nearly all of the organic solids to the gaseous phase. The volatile pyrolysis products pass through the kiln co-currently with the solids and are similarly cracked and steam-reformed within the kiln to fixed gases. Heat for the gasification process is provided by sensible heat recovered from the product gas and the wood decomposition exotherm, making the process inherently very energy-efficient. This report summarizes the work done during the experimental, laboratory-scale phase of development of the W-M biomass gasification process. Two bench-scale experimental gasifiers were constructed and tested: the ''minikiln'', a batch-feed, rotating autoclave; and the ''biogasser'', a stationary, continuous-feed, tubular reactor with zone heating and auger transport. Studies were carried out in these reactors to determine the extent of conversion of biomass solids to gas, and the makeup of the product gas, over a wide range of process conditions. The process variables that were investigated included reactor pressure and temperature, catalyst type and concentration, moisture content and type of biomass feed.

  3. Influence of the Steam Addition on Premixed Methane Air Combustion at Atmospheric Pressure

    Directory of Open Access Journals (Sweden)

    Mao Li

    2017-07-01

    Full Text Available Steam-diluted combustion in gas turbine systems is an effective approach to control pollutant emissions and improve the gas turbine efficiency. The primary purpose of the present research is to analyze the influence of steam dilution on the combustion stability, flame structures, and CO emissions of a swirl-stabilized gas turbine model combustor under atmospheric pressure conditions. The premixed methane/air/steam flame was investigated with three preheating temperatures (384 K/434 K/484 K and the equivalence ratio was varied from stoichiometric conditions to the flammability limits where the flame was physically blown out from the combustor. In order to represent the steam dilution intensity, the steam fraction Ω defined as the steam to air mass flow rate ratio was used in this work. Exhaust gases were sampled with a water-cooled emission probe which was mounted at the combustor exit. A 120 mm length quartz liner was used which enabled the flame visualization and optical measurement. Time-averaged CH chemiluminescence imaging was conducted to characterize the flame location and it was further analyzed with the inverse Abel transform method. Chemical kinetics calculation was conducted to support and analyze the experimental results. It was found that the LBO (lean blowout limits were increased with steam fraction. CH chemiluminescence imaging showed that with a high steam fraction, the flame length was elongated, but the flame structure was not altered. CO emissions were mapped as a function of the steam fraction, inlet air temperature, and equivalence ratios. Stable combustion with low CO emission can be achieved with an appropriate steam fraction operation range.

  4. A study of steam methanol reforming in a microreactor

    Science.gov (United States)

    Suh, Jeong-Se; Lee, Ming-tsang; Greif, Ralph; Grigoropoulos, Costas P.

    Steam reforming of methanol is investigated numerically considering both heat and mass transfer of the species in a packed bed microreactor. The numerical results are shown to be in good agreement with experimental data [M.T. Lee, R. Greif, C.P. Grigoropoulos, H.G. Park, F.K. Hsu, J. Power Sources Transport in, 166 (2007) 194-201] with a BASF F3-01(CuO/ZnO/Al 2O 3) catalyst. A correlation for the conversion efficiency of methanol has been obtained as a function of the operating temperature and a dimensionless time parameter which represents the ratio of the characteristic time of the methanol flow to the time for chemical reaction. The results show that for the constant wall temperature condition the steam reforming process of methanol results in a nearly uniform temperature throughout the microreactor over the range of operating conditions.

  5. Evaluation of Steam and Soil Solarization for Meloidogyne arenaria Control in Florida Floriculture Crops.

    Science.gov (United States)

    Kokalis-Burelle, Nancy; Rosskopf, Erin N; Butler, David M; Fennimore, Steven A; Holzinger, John

    2016-09-01

    Steam and soil solarization were investigated for control of the root-knot nematode Meloidogyne arenaria in 2 yr of field trials on a commercial flower farm in Florida. The objective was to determine if preplant steam treatments in combination with solarization, or solarization alone effectively controlled nematodes compared to methyl bromide (MeBr). Trials were conducted in a field with naturally occurring populations of M. arenaria. Treatments were solarization alone, steam treatment after solarization using standard 7.6-cm-diameter perforated plastic drain tile (steam 1), steam treatment following solarization using custom-drilled plastic drain tile with 1.6-mm holes spaced every 3.8 cm (steam 2), and MeBr applied at 392 kg/ha 80:20 MeBr:chloropicrin. Drain tiles were buried approximately 35 cm deep with four tiles per 1.8 by 30 m plot. Steam application followed a 4-wk solarization period concluding in mid-October. All steam was generated using a Sioux propane boiler system. Plots were steamed for sufficient time to reach the target temperature of 70°C for 20 min. Solarization plastic was retained on the plots during steaming and plots were covered with a single layer of carpet padding to provide additional insulation. The floriculture crops larkspur (Delphinium elatum and Delphinium × belladonna), snapdragon (Antirrhinum majus), and sunflower (Helianthus annuus) were produced according to standard commercial practices. One month after treatment in both years of the study, soil populations of M. arenaria were lower in both steam treatments and in MeBr compared to solarization alone. At the end of the season in both years, galling on larkspur, snapdragon, and sunflowers was lower in both steam treatments than in solarization. Both steam treatments also provided control of M. arenaria in soil at the end of the season comparable to, or exceeding that provided by MeBr. Both steam treatments also reduced M. arenaria in snapdragon roots comparable to, or exceeding

  6. Cost analysis for application of solidified waste fission product canisters in U. S. Army steam plants

    Energy Technology Data Exchange (ETDEWEB)

    Sande, W.E.; Bjorklund, W.J.; Brooks, N.A.

    1977-04-01

    The main objectives of the present study are to design steam plants using projected waste fission product canister characteristics, to analyze the overall impact and cost/benefit to the nuclear fuel cycle associated with these plants, and to develop plans for this application if the cost analysis so warrants it. The construction and operation of a steam plant fueled with waste fission product canisters would require the involvement and cooperation of various government agencies and private industry; thus the philosophies of these groups were studied. These philosophies are discussed, followed by a forecast of canister supply, canister characteristics, and strategies for Army canister use. Another section describes the safety and licensing of these steam plants since this affects design and capital costs. The discussion of steam plant design includes boiler concepts, boiler heat transfer, canister temperature distributions, steam plant size, and steam plant operation. Also, canister transportation is discussed since this influences operating costs. Details of economics of Army steam plants are provided including steam plant capital costs, operating costs, fuel reprocessor savings due to Army canister storage, and overall economics. Recommendations are made in the final section.

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

    Science.gov (United States)

    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.

  8. Steam cooling system for a gas turbine

    Science.gov (United States)

    Wilson, Ian David; Barb, Kevin Joseph; Li, Ming Cheng; Hyde, Susan Marie; Mashey, Thomas Charles; Wesorick, Ronald Richard; Glynn, Christopher Charles; Hemsworth, Martin C.

    2002-01-01

    The steam cooling circuit for a gas turbine includes a bore tube assembly supplying steam to circumferentially spaced radial tubes coupled to supply elbows for transitioning the radial steam flow in an axial direction along steam supply tubes adjacent the rim of the rotor. The supply tubes supply steam to circumferentially spaced manifold segments located on the aft side of the 1-2 spacer for supplying steam to the buckets of the first and second stages. Spent return steam from these buckets flows to a plurality of circumferentially spaced return manifold segments disposed on the forward face of the 1-2 spacer. Crossover tubes couple the steam supply from the steam supply manifold segments through the 1-2 spacer to the buckets of the first stage. Crossover tubes through the 1-2 spacer also return steam from the buckets of the second stage to the return manifold segments. Axially extending return tubes convey spent cooling steam from the return manifold segments to radial tubes via return elbows.

  9. Lignin isolated from steam-exploded eucalyptus wood chips by phase separation and its affinity to Trichoderma reesei cellulase.

    Science.gov (United States)

    Nonaka, Hiroshi; Kobayashi, Ai; Funaoka, Masamitsu

    2013-07-01

    Steam-exploded eucalyptus wood chips were treated with p-cresol and 72% sulfuric acid at ambient temperature. Steam-exploded lignin was isolated as acetone-soluble and diethyl ether-insoluble compounds from the cresol layer. The lignin extraction yield was only 47%, and the amount of cresol grafted to lignin was much less than that in the case of eucalyptus lignin without steam explosion. Clearly, the steam explosion process depolymerized native lignin, and simultaneously, promoted polymerization via labile benzyl positions. The steam-exploded eucalyptus lignin adsorbed more Trichoderma reesei cellulase; however, its enzymatic activity was less than that of eucalyptus lignin that did not undergo steam explosion. It is evident that pretreatment potentially affects the affinity between lignin and cellulase and the resultant saccharification efficiency. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Thermal conductivity of the sideledge in aluminium electrolysis cells: Experiments and numerical modelling.

    Science.gov (United States)

    Gheribi, Aïmen E; Poncsák, Sándor; Guérard, Sébastien; Bilodeau, Jean-François; Kiss, László; Chartrand, Patrice

    2017-03-21

    During aluminium electrolysis, a ledge of frozen electrolytes is generally formed, attached to the sides of the cells. This ledge acts as a protective layer, preventing erosion and chemical attacks of both the electrolyte melt and the liquid aluminium on the side wall materials. The control of the sideledge thickness is thus essential in ensuring a reasonable lifetime for the cells. The key property for modelling and predicting the sideledge thickness as a function of temperature and electrolyte composition is the thermal conductivity. Unfortunately, almost no data is available on the thermal conductivity of the sideledge. The aim of this work is to alleviate this lack of data. For seven different samples of sideledge microstructures, recovered from post-mortem industrial electrolysis cells, the thermal diffusivity, the density, and the phase compositions were measured in the temperature range of 423 K to 873 K. The thermal diffusivity was measured with a laser flash technique and the average phase compositions by X-ray diffraction analysis. The thermal conductivity of the sideledge is deduced from the present experimental thermal diffusivity and density, and the thermodynamically assessed heat capacity. In addition to the present experimental work, a theoretical model for the prediction of the effective thermal transport properties of the sideledge microstructure is also proposed. The proposed model considers an equivalent microstructure and depends on phase fractions, porosity, and temperature. The strength of the model lies in the fact that only a few key physical properties are required for its parametrization and they can be predicted with a good accuracy via first principles calculations. It is shown that the theoretical predictions are in a good agreement with the present experimental measurements.

  11. Zirconium alloys with small amounts of iron and copper or nickel show improved corrosion resistance in superheated steam

    Science.gov (United States)

    Greenberg, S.; Youngdahl, C. A.

    1967-01-01

    Heat treating various compositions of zirconium alloys improve their corrosion resistance to superheated steam at temperatures higher than 500 degrees C. This increases their potential as fuel cladding for superheated-steam nuclear-fueled reactors as well as in autoclaves operating at modest pressures.

  12. Two-dimensional modeling of water spray cooling in superheated steam

    Directory of Open Access Journals (Sweden)

    Ebrahimian Vahid

    2008-01-01

    Full Text Available Spray cooling of the superheated steam occurs with the interaction of many complex physical processes, such as initial droplet formation, collision, coalescence, secondary break up, evaporation, turbulence generation, and modulation, as well as turbulent mixing, heat, mass and momentum transfer in a highly non-uniform two-phase environment. While it is extremely difficult to systematically study particular effects in this complex interaction in a well defined physical experiment, the interaction is well suited for numerical studies based on advanced detailed models of all the processes involved. This paper presents results of such a numerical experiment. Cooling of the superheated steam can be applied in order to decrease the temperature of superheated steam in power plants. By spraying the cooling water into the superheated steam, the temperature of the superheated steam can be controlled. In this work, water spray cooling was modeled to investigate the influences of the droplet size, injected velocity, the pressure and velocity of the superheated steam on the evaporation of the cooling water. The results show that by increasing the diameter of the droplets, the pressure and velocity of the superheated steam, the amount of evaporation of cooling water increases. .

  13. Oxygen permeation through perovskitic membranes: The influence of steam in the sweep on the permeation performance

    Directory of Open Access Journals (Sweden)

    Michael Müller

    2016-08-01

    Full Text Available Experimental approaches are employed for the understanding of oxygen permeation through membranes. For the experiments, different oxygen partial pressures are applied to both sides of a BSCF5582 membrane, using synthetic air as feed and vacuum or steam/argon as sweep gas. Beside the partial pressure gradient, the permeation rate depends on the temperature and the membrane thickness. Sufficient permeation rates can be achieved by sweeping the membrane with water vapor (steam instead of a noble gas, which is optimized by ascending water content in the sweep gas. The influence of the steam content on the permeation performance as well as microstructural changes are demonstrated.

  14. Steam generator corrosion 2007; Dampferzeugerkorrosion 2007

    Energy Technology Data Exchange (ETDEWEB)

    Born, M. (ed.)

    2007-07-01

    Between 8th and 9th November, 2007, SAXONIA Standortentwicklungs- und -verwertungsgesellschaft GmbH (Freiberg, Federal Republic of Germany) performed the 3rd Freiberger discussion conference ''Fireside boiler corrosion''. The topics of the lectures are: (a) Steam generator corrosion - an infinite history (Franz W. Alvert); (b) CFD computations for thermal waste treatment plants - a contribution for the damage recognition and remedy (Klaus Goerner, Thomas Klasen); (c) Experiences with the use of corrosion probes (Siegfried R. Horn, Ferdinand Haider, Barbara Waldmann, Ragnar Warnecke); (d) Use of additives for the limitation of the high temperature chlorine corrosion as an option apart from other measures to the corrosion protection (Wolfgang Spiegel); (e) Current research results and aims of research with respect to chlorine corrosion (Ragnar Warnecke); (f) Systematics of the corrosion phenomena - notes for the enterprise and corrosion protection (Thomas Herzog, Wolfgang Spiegel, Werner Schmidl); (g) Corrosion protection by cladding in steam generators of waste incinerators (Joerg Metschke); (h) Corrosion protection and wear protection by means of thermal spraying in steam generators (Dietmar Bendix); (i) Review of thick film nickelized components as an effective protection against high-temperature corrosion (Johann-Wilhelm Ansey); (j) Fireproof materials for waste incinerators - characteristics and profile of requirement (Johannes Imle); (k) Service life-relevant aspects of fireproof linings in the thermal recycling of waste (Till Osthoevener and Wolfgang Kollenberg); (l) Alternatives to the fireproof material in the heating space (Heino Sinn); (m) Cladding: Inconal 625 contra 686 - Fundamentals / applications in boiler construction and plant construction (Wolfgang Hoffmeister); (n) Thin films as efficient corrosion barriers - thermal spray coating in waste incinerators and biomass firing (Ruediger W. Schuelein, Steffen Hoehne, Friedrich

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

    Science.gov (United States)

    Graves, Christopher Ronald

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

  16. ASPEN plus modelling of air–steam gasification of biomass with sorbent enabled CO2 capture

    Directory of Open Access Journals (Sweden)

    S. Rupesh

    2016-06-01

    Full Text Available The work deals with the modelling and simulation of carbon dioxide capture in air–steam gasification of saw dust using ASPEN Plus process simulator. The proposed quasi-steady state model incorporates pyrolysis, tar cracking and char conversion using existing experimental data. Prediction accuracy of the developed model is validated by comparing with available experimental results. Effects of CaO addition in air–steam gasification are analysed through key operating parameters such as gasification temperature, equivalence ratio, steam to biomass ratio and gasification efficiency. Maximum H2 mole fraction of 31.17% is obtained at a temperature of 900 K, equivalence ratio of 0.25, and steam to biomass ratio and sorbent to biomass ratio of unity. The H2 and CO2 mole fractions are found to be increased and decreased by 28.10% and 42.6%, respectively, when compared with the corresponding non- sorbent case.

  17. Closed loop steam cooled airfoil

    Science.gov (United States)

    Widrig, Scott M.; Rudolph, Ronald J.; Wagner, Gregg P.

    2006-04-18

    An airfoil, a method of manufacturing an airfoil, and a system for cooling an airfoil is provided. The cooling system can be used with an airfoil located in the first stages of a combustion turbine within a combined cycle power generation plant and involves flowing closed loop steam through a pin array set within an airfoil. The airfoil can comprise a cavity having a cooling chamber bounded by an interior wall and an exterior wall so that steam can enter the cavity, pass through the pin array, and then return to the cavity to thereby cool the airfoil. The method of manufacturing an airfoil can include a type of lost wax investment casting process in which a pin array is cast into an airfoil to form a cooling chamber.

  18. Flow field design for high-pressure PEM electrolysis cells

    DEFF Research Database (Denmark)

    Olesen, Anders Christian; Kær, Søren Knudsen

    micro-channels and porous media, our research group has developed an Euler-Euler model in the computational fluid dynamics modelling framework of ANSYS CFX. In addition to two-phase flow, the model accounts for turbulence, species transport in the gas phase, heat transport in all three phases (i......With the increasing interest in producing hydrogen through water electrolysis, the importance of understanding the transport phenomena governing its operation increases. To ensure optimal operating conditions for PEM electrolysis, it is particularly important to understand how the liquid feed.......e. solid, gas and liquid), as well as charge transport of electrons and ions. Our recent improvements have focused on the models ability to account for phase change and electrochemistry as well as the modelling of two-phase flow regimes. For comparison, an interdigitated and parallel channel flow field...

  19. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    Science.gov (United States)

    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.

  20. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    Energy Technology Data Exchange (ETDEWEB)

    Saksono, Nelson; Febiyanti, Irine Ayu, E-mail: irine.ayu41@ui.ac.id; Utami, Nissa; Ibrahim [Department of Chemical Engineering, Universitas Indonesia, Depok 16424, Indonesia Phone: +62217863516, Fax: +62217863515 (Indonesia)

    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.