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

International Nuclear Information System (INIS)

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

2010-01-01

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

Optimized Flow Sheet for a Reference Commercial-Scale Nuclear-Driven High-Temperature Electrolysis Hydrogen Production Plant

International Nuclear Information System (INIS)

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

2007-01-01

This report presents results from the development and optimization of a reference commercial scale high-temperature electrolysis (HTE) plant for hydrogen production. The reference plant design is driven by a high-temperature helium-cooled reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540 C and 900 C, respectively. The electrolysis unit used to produce hydrogen consists of 4.176 - 10 6 cells with a per-cell active area of 225 cm2. A nominal cell area-specific resistance, ASR, value of 0.4 Ohm-cm2 with a current density of 0.25 A/cm2 was used, and isothermal boundary conditions were assumed. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The overall system thermal-to-hydrogen production efficiency (based on the low heating value of the produced hydrogen) is 49.07% at a hydrogen production rate of 2.45 kg/s with the high-temperature helium-cooled reactor concept. The information presented in this report is intended to establish an optimized design for the reference nuclear-driven HTE hydrogen production plant so that parameters can be compared with other hydrogen production methods and power cycles to evaluate relative performance characteristics and plant economics

High Temperature Electrolysis

DEFF Research Database (Denmark)

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

2015-01-01

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

HYFIRE: fusion-high temperature electrolysis system

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Dang, V.D.; Horn, F.; Isaacs, H.; Lazareth, O.; Makowitz, H.; Usher, J.

1980-01-01

The Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constitutents, H 2 and O 2 , electrical input is required. Power cycle efficiencies of approx. 40% require He cooling for steam superheat. Fourteen hundred degree steam coupled with 40% power cycle efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

HYFIRE: a tokamak-high-temperature electrolysis system

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Horn, F.; Isaacs, H.; Lazareth, O.W.; Makowitz, H.; Usher, J.

1980-01-01

Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 0 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constituents, H 2 and O 2 , electrical input is required. Fourteen hundred degree steam coupled with 40% power efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

HYFIRE: a tokamak-high-temperature electrolysis system

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Horn, F.; Isaacs, H.; Lazareth, O.W.; Makowitz, H.; Usher, J.

1980-01-01

Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 0 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constituents, H 2 and O 2 , electrical input is required. Fourteen hundred degree steam coupled with 40% power cycle efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

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)

Parametric Evaluation of Large-Scale High-Temperature Electrolysis Hydrogen Production Using Different Advanced Nuclear Reactor Heat Sources

International Nuclear Information System (INIS)

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

2009-01-01

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

Preconceptual design of hyfire. A fusion driven high temperature electrolysis plant

International Nuclear Information System (INIS)

Varljen, T.C.; Chi, J.W.H.; Karbowski, J.S.

1983-01-01

Brookhaven National Laboratory has been engaged in a scoping study to investigate the potential merits of coupling a fusion reactor with a high temperature blanket to a high temperature electrolysis (HTE) process to produce hydrogen and oxygen. Westinghouse is assisting this study in the areas of systems design integration, plasma engineering, balance of plant design and electrolyzer technology. The aim of the work done in the past year has been to focus on a reference design point for the plant, which has been designated HYFIRE. In prior work, the STARFIRE commercial tokamak fusion reactor was directly used as the fusion driver. This report describes a new design obtained by scaling the basic STARFIRE design to permit the achievement of a blanket power of 6000 MWt. The high temperature blanket design employs a thermally insulated refractory oxide region which provides high temperature (>1000 deg. C) steam at moderate pressures to high temperature electrolysis units. The electrolysis process selected is based on the high temperature, solid electrolyte fuel cell technology developed by Westinghouse. An initial process design and plant layout has been completed; component cost and plant economics studies are now underway to develop estimates of hydrogen production costs and to determine the sensitivity of this cost to changes in major design parameters. (author)

High Temperature Electrolysis for Hydrogen Production from Nuclear Energy - Technology Summary

International Nuclear Information System (INIS)

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

2010-01-01

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.

Economic Analysis of the Reference Design for a Nuclear-Driven High-Temperature-Electrolysis Hydrogen Production Plant

International Nuclear Information System (INIS)

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

2008-01-01

A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen production concepts. The reference plant design is driven by a high-temperature helium-cooled reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540 C and 900 C, respectively. The electrolysis unit used to produce hydrogen consists of 4,009,177 cells with a per-cell active area of 225 cm2. A nominal cell area-specific resistance, ASR, value of 0.4 Ohm-cm2 with a current density of 0.25 A/cm2 was used, and isothermal boundary conditions were assumed. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating current, AC, to direct current, DC, conversion is 96%. The overall system thermal-to-hydrogen production efficiency (based on the low heating value of the produced hydrogen) is 47.12% at a hydrogen production rate of 2.356 kg/s. An economic analysis of the plant was also performed using the H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost using realistic financial and cost estimating assumptions. A required cost of $3.23 per kg of hydrogen produced was calculated assuming an internal rate of return of 10%. Approximately 73% of this cost ($2.36/kg) is the result of capital costs associated with

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-06-01

This paper presents an overview of the high-temperature electrolysis research and development program at the Idaho National Laboratory, with selected observations of electrolysis cell degradation at the single-cell, small stack and large facility scales. The objective of the INL program is to address the technical and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for hydrogen production from steam. In the envisioned application, high-temperature electrolysis would be coupled to an advanced nuclear reactor for efficient large-scale non-fossil non-greenhouse-gas hydrogen production. The program supports a broad range of activities including small bench-scale experiments, larger scale technology demonstrations, detailed computational fluid dynamic modeling, and system modeling. A summary of the current status of these activities and future plans will be provided, with a focus on the problem of cell and stack degradation.

System Evaluation and Economic Analysis of a HTGR Powered High-Temperature Electrolysis Hydrogen Production Plant

International Nuclear Information System (INIS)

McKellar, Michael G.; Harvego, Edwin A.; Gandrik, Anastasia A.

2010-01-01

A design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322 C and 750 C, respectively. The power conversion unit will be a Rankine steam cycle with a power conversion efficiency of 40%. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 40.4% at a hydrogen production rate of 1.75 kg/s and an oxygen production rate of 13.8 kg/s. An economic analysis of this plant was performed with 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 $3.67/kg of hydrogen assuming an internal rate of return, IRR, of 12% and a debt to equity ratio of 80%/20%. A second analysis shows that if the power cycle efficiency increases to 44.4%, the hydrogen production efficiency increases to 42.8% and the hydrogen and oxygen production rates are 1.85 kg/s and 14.6 kg/s respectively. At the higher power cycle efficiency and an IRR of 12% the cost of hydrogen production is $3.50/kg.

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.

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.

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Study and modelling of an industrial plant for hydrogen production by High Temperature Steam Electrolysis

International Nuclear Information System (INIS)

Bertier, L.

2012-01-01

HTSE field (High Temperature Steam Electrolysis) is moving from the research phase to development phase. It's now necessary to prove and to possibly improve the technology competitiveness. Therefore we need a tool able to allow communication between hydrogen producers and electrolysis cell stack designers. Designers seek where their efforts have to focus, for example by searching what are the operating best conditions for HTSE (voltage, temperature). On the contrary, the producer wants to choose the most suitable stack for its needs and under the best conditions: hydrogen has to be produced at the lowest price. Two main constraints have been identified to reach this objective: the tool has to be inserted into a process simulation software and needs to be representative of the cell and stack used technology. These constraints are antagonistic. Making an object model in a process simulation usually involves a highly simplified representation of it. To meet these constraints, we have built a model chain starting from the electrode models and leading to a representative model of the HTSE technology used process. Work and added value of this thesis mainly concern a global and local energy optimization approach. Our model allows at each scale an appropriate analysis of the main phenomena occurring in each object and a quantification of the energy and economic impacts of the technology used. This approach leads to a tool able to achieve the technical and economic optimization of a HTSE production unit. (author) [fr

Techno-economic study of hydrogen production by high temperature electrolysis and coupling with different thermal energy sources

International Nuclear Information System (INIS)

Rivera-Tinoco, R.

2009-03-01

This work focuses on the techno-economic study of massive hydrogen production by the High Temperature Electrolysis (HTE) process and also deals with the possibility of producing the steam needed in the process by using different thermal energy sources. Among several sources, those retained in this study are the biomass and domestic waste incineration units, as well as two nuclear reactors (European Pressurised water Reactor - EPR and Sodium Fast Reactor - SFR). Firstly, the technical evaluation of the steam production by each of these sources was carried out. Then, the design and modelling of the equipments composing the process, specially the electrolysers (Solid Oxides Electrolysis Cells), are presented. Finally, the hydrogen production cost for each energy sources coupled with the HTE process is calculated. Moreover, several sensibility studies were performed in order to determine the process key parameter and to evaluate the influence of the unit size effect, the electric energy cost, maintenance, the cells current density, their investment cost and their lifespan on the hydrogen production cost. Our results show that the thermal energy cost is much more influent on the hydrogen production cost than the steam temperature at the outlet stream of the thermal source. It seems also that the key parameters for this process are the electric energy cost and the c ells lifespan. The first one contributes for more than 70% of the hydrogen production cost. From several cell lifespan values, it seems that a 3 year value, rather than 1 year, could lead to a hydrogen production cost reduced on 34%. However, longer lifespan values going from 5 to 10 years would only lead to a 8% reduction on the hydrogen production cost. (author)

Fusion reactors for hydrogen production via electrolysis

International Nuclear Information System (INIS)

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

1979-01-01

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

High Temperature and Pressure Alkaline Electrolysis

DEFF Research Database (Denmark)

Allebrod, Frank

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

Operational Modelling of High Temperature Electrolysis (HTE)

International Nuclear Information System (INIS)

Patrick Lovera; Franck Blein; Julien Vulliet

2006-01-01

Solid Oxide Fuel Cells (SOFC) and High Temperature Electrolysis (HTE) work on two opposite processes. The basic equations (Nernst equation, corrected by a term of over-voltage) are thus very similar, only a few signs are different. An operational model, based on measurable quantities, was finalized for HTE process, and adapted to SOFCs. The model is analytical, which requires some complementary assumptions (proportionality of over-tensions to the current density, linearization of the logarithmic term in Nernst equation). It allows determining hydrogen production by HTE using a limited number of parameters. At a given temperature, only one macroscopic parameter, related to over-voltages, is needed for adjusting the model to the experimental results (SOFC), in a wide range of hydrogen flow-rates. For a given cell, this parameter follows an Arrhenius law with a satisfactory precision. The prevision in HTE process is compared to the available experimental results. (authors)

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

Experiment Plan of High Temperature Steam and Carbon dioxide Co-electrolysis for Synthetic Gas Production

International Nuclear Information System (INIS)

Yoon, Duk-Joo; Ko, Jae-Hwa

2008-01-01

Currently, Solid oxide fuel cells (SOFC) come into the spotlight in the middle of the energy technologies of the future for highly effective conversion of fossil fuels into electricity without carbon dioxide emission. The SOFC is a reversible cell. By applying electrical power to the cell, which is solid oxide electrolysis cell (SOEC), it is possible to produce synthetic gas (syngas) from high temperature steam and carbon dioxide. The produced syngas (hydrogen and carbon monoxide) can be used for synthetic fuels. This SOEC technology can use high temperature from VHTRs for high efficiency. This paper describes KEPRI's experiment plan of high temperature steam and carbon co-electrolysis for syngas production using SOEC technology

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1985-05-30

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

Hydrogen Generation by Koh-Ethanol Plasma Electrolysis Using Double Compartement Reactor

Science.gov (United States)

Saksono, Nelson; Sasiang, Johannes; Dewi Rosalina, Chandra; Budikania, Trisutanti

2018-03-01

This study has successfully investigated the generation of hydrogen using double compartment reactor with plasma electrolysis process. Double compartment reactor is designed to achieve high discharged voltage, high concentration, and also reduce the energy consumption. The experimental results showed the use of double compartment reactor increased the productivity ratio 90 times higher compared to Faraday electrolysis process. The highest hydrogen production obtained is 26.50 mmol/min while the energy consumption can reach up 1.71 kJ/mmol H2 at 0.01 M KOH solution. It was shown that KOH concentration, addition of ethanol, cathode depth, and temperature have important effects on hydrogen production, energy consumption, and process efficiency.

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

KAUST Repository

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

2012-01-01

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

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)

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

NARCIS (Netherlands)

Logan, B.E.; Call, D.; Cheng, S.; Hamelers, H.V.M.; Sleutels, T.H.J.A.; Jeremiasse, A.W.; Rozendal, R.A.

2008-01-01

The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few

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.

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

KAUST Repository

Logan, Bruce E.

2008-12-01

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

High Temperature Electrolysis using Electrode-Supported Cells

International Nuclear Information System (INIS)

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

2010-01-01

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

Hydrogen production by alkaline water electrolysis

OpenAIRE

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

2013-01-01

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

System Evaluations and Life-Cycle Cost Analyses for High-Temperature Electrolysis Hydrogen Production Facilities

Energy Technology Data Exchange (ETDEWEB)

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

2012-05-01

This report presents results of system evaluations and lifecycle cost analyses performed for several different commercial-scale high-temperature electrolysis (HTE) hydrogen production concepts. The concepts presented in this report rely on grid electricity and non-nuclear high-temperature process heat sources for the required energy inputs. The HYSYS process analysis software was used to evaluate both central plant designs for large-scale hydrogen production (50,000 kg/day or larger) and forecourt plant designs for distributed production and delivery at about 1,500 kg/day. The HYSYS software inherently ensures mass and energy balances across all components and it includes thermodynamic data for all chemical species. The optimized designs described in this report are based on analyses of process flow diagrams that included realistic representations of fluid conditions and component efficiencies and operating parameters for each of the HTE hydrogen production configurations analyzed. As with previous HTE system analyses performed at the INL, a custom electrolyzer model was incorporated into the overall process flow sheet. This electrolyzer model allows for the determination of the average Nernst potential, cell operating voltage, gas outlet temperatures, and electrolyzer efficiency for any specified inlet steam, hydrogen, and sweep-gas flow rates, current density, cell active area, and external heat loss or gain. The lifecycle cost analyses were performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. There are standard default sets of assumptions that the methodology uses to ensure consistency when comparing the cost of different production or plant design options. However, these assumptions may also be varied within the

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-04-01

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

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

International Nuclear Information System (INIS)

Bellanger, Gilbert

1992-01-01

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

PEM Water Electrolysis at Elevated Temperatures

DEFF Research Database (Denmark)

Hansen, Martin Kalmar

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

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

International Nuclear Information System (INIS)

Yilmaz, Ceyhun; Kanoglu, Mehmet

2014-01-01

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

Microbial electrolysis cells as innovative technology for hydrogen production

International Nuclear Information System (INIS)

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

2011-01-01

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

Fusion reactors-high temperature electrolysis (HTE)

International Nuclear Information System (INIS)

Fillo, J.A.

1978-01-01

Results of a study to identify and develop a reference design for synfuel production based on fusion reactors are given. The most promising option for hydrogen production was high-temperature electrolysis (HTE). The main findings of this study are: 1. HTE has the highest potential efficiency for production of synfuels from fusion; a fusion to hydrogen energy efficiency of about 70% appears possible with 1800 0 C HTE units and 60% power cycle efficiency; an efficiency of about 50% possible with 1400 0 C HTE units and 40% power cycle efficiency. 2. Relative to thermochemical or direct decomposition methods HTE technology is in a more advanced state of development, 3. Thermochemical or direct decomposition methods must have lower unit process or capital costs if they are to be more attractive than HTE. 4. While design efforts are required, HTE units offer the potential to be quickly run in reverse as fuel cells to produce electricity for restart of Tokamaks and/or provide spinning reserve for a grid system. 5. Because of the short timescale of the study, no detailed economic evaluation could be carried out.A comparison of costs could be made by employing certain assumptions. For example, if the fusion reactor-electrolyzer capital installation is $400/(KW(T) [$1000/KW(E) equivalent], the H 2 energy production cost for a high efficiency (about 70 %) fusion-HTE system is on the same order of magnitude as a coal based SNG plant based on 1976 dollars. 6. The present reference design indicates that a 2000 MW(th) fusion reactor could produce as much at 364 x 10 6 scf/day of hydrogen which is equivalent in heating value to 20,000 barrels/day of gasoline. This would fuel about 500,000 autos based on average driving patterns. 7. A factor of three reduction in coal feed (tons/day) could be achieved for syngas production if hydrogen from a fusion-HTE system were used to gasify coal, as compared to a conventional syngas plant using coal-derived hydrogen

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

Can high temperature steam electrolysis function with geothermal heat?

International Nuclear Information System (INIS)

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

2007-01-01

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

Hydrogen production methods efficiency coupled to an advanced high temperature accelerator driven system

International Nuclear Information System (INIS)

Rodríguez, Daniel González; Lira, Carlos Alberto Brayner de Oliveira

2017-01-01

The hydrogen economy is one of the most promising concepts for the energy future. In this scenario, oil is replaced by hydrogen as an energy carrier. This hydrogen, rather than oil, must be produced in volumes not provided by the currently employed methods. In this work two high temperature hydrogen production methods coupled to an advanced nuclear system are presented. A new design of a pebbled-bed accelerator nuclear driven system called TADSEA is chosen because of the advantages it has in matters of transmutation and safety. For the conceptual design of the high temperature electrolysis process a detailed computational fluid dynamics model was developed to analyze the solid oxide electrolytic cell that has a huge influence on the process efficiency. A detailed flowsheet of the high temperature electrolysis process coupled to TADSEA through a Brayton gas cycle was developed using chemical process simulation software: Aspen HYSYS®. The model with optimized operating conditions produces 0.1627 kg/s of hydrogen, resulting in an overall process efficiency of 34.51%, a value in the range of results reported by other authors. A conceptual design of the iodine-sulfur thermochemical water splitting cycle was also developed. The overall efficiency of the process was calculated performing an energy balance resulting in 22.56%. The values of efficiency, hydrogen production rate and energy consumption of the proposed models are in the values considered acceptable in the hydrogen economy concept, being also compatible with the TADSEA design parameters. (author)

Hydrogen production methods efficiency coupled to an advanced high temperature accelerator driven system

Energy Technology Data Exchange (ETDEWEB)

Rodríguez, Daniel González; Lira, Carlos Alberto Brayner de Oliveira [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Fernández, Carlos García, E-mail: danielgonro@gmail.com, E-mail: mmhamada@ipen.br [Instituto Superior de Tecnologías y Ciencias aplicadas (InSTEC), La Habana (Cuba)

2017-07-01

The hydrogen economy is one of the most promising concepts for the energy future. In this scenario, oil is replaced by hydrogen as an energy carrier. This hydrogen, rather than oil, must be produced in volumes not provided by the currently employed methods. In this work two high temperature hydrogen production methods coupled to an advanced nuclear system are presented. A new design of a pebbled-bed accelerator nuclear driven system called TADSEA is chosen because of the advantages it has in matters of transmutation and safety. For the conceptual design of the high temperature electrolysis process a detailed computational fluid dynamics model was developed to analyze the solid oxide electrolytic cell that has a huge influence on the process efficiency. A detailed flowsheet of the high temperature electrolysis process coupled to TADSEA through a Brayton gas cycle was developed using chemical process simulation software: Aspen HYSYS®. The model with optimized operating conditions produces 0.1627 kg/s of hydrogen, resulting in an overall process efficiency of 34.51%, a value in the range of results reported by other authors. A conceptual design of the iodine-sulfur thermochemical water splitting cycle was also developed. The overall efficiency of the process was calculated performing an energy balance resulting in 22.56%. The values of efficiency, hydrogen production rate and energy consumption of the proposed models are in the values considered acceptable in the hydrogen economy concept, being also compatible with the TADSEA design parameters. (author)

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

International Nuclear Information System (INIS)

James O'Brien; Carl Stoots; Steve Herring; J. Hartvigsen

2005-01-01

An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900 C. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte supported, with scandia-stabilized zirconia electrolytes (∼140 (micro)m thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1-0.6), gas flow rates (1000-4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 100 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate

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.

Design Configurations and Coupling High Temperature Gas-Cooled Reactor and Hydrogen Plant

International Nuclear Information System (INIS)

Chang H. Oh; Eung Soo Kim; Steven Sherman

2008-01-01

The US Department of Energy is investigating the use of high-temperature nuclear reactors to produce hydrogen using either thermochemical cycles or high-temperature electrolysis. Although the hydrogen production processes are in an early stage of development, coupling either of these processes to the high-temperature reactor requires both efficient heat transfer and adequate separation of the facilities to assure that off-normal events in the production facility do not impact the nuclear power plant. An intermediate heat transport loop will be required to separate the operations and safety functions of the nuclear and hydrogen plants. A next generation high-temperature reactor could be envisioned as a single-purpose facility that produces hydrogen or a dual-purpose facility that produces hydrogen and electricity. Early plants, such as the proposed Next Generation Nuclear Plant (NGNP), may be dual-purpose facilities that demonstrate both hydrogen and efficient electrical generation. Later plants could be single-purpose facilities. At this stage of development, both single- and dual-purpose facilities need to be understood

Computational model for a high temperature electrolyzer coupled to a HTTR for efficient nuclear hydrogen production

International Nuclear Information System (INIS)

Gonzalez, Daniel; Rojas, Leorlen; Rosales, Jesus; Castro, Landy; Gamez, Abel; Brayner, Carlos; Garcia, Lazaro; Garcia, Carlos; Torre, Raciel de la; Sanchez, Danny

2015-01-01

High temperature electrolysis process coupled to a very high temperature reactor (VHTR) is one of the most promising methods for hydrogen production using a nuclear reactor as the primary heat source. However there are not references in the scientific publications of a test facility that allow to evaluate the efficiency of the process and other physical parameters that has to be taken into consideration for its accurate application in the hydrogen economy as a massive production method. For this lack of experimental facilities, mathematical models are one of the most used tools to study this process and theirs flowsheets, in which the electrolyzer is the most important component because of its complexity and importance in the process. A computational fluid dynamic (CFD) model for the evaluation and optimization of the electrolyzer of a high temperature electrolysis hydrogen production process flowsheet was developed using ANSYS FLUENT®. Electrolyzer's operational and design parameters will be optimized in order to obtain the maximum hydrogen production and the higher efficiency in the module. This optimized model of the electrolyzer will be incorporated to a chemical process simulation (CPS) code to study the overall high temperature flowsheet coupled to a high temperature accelerator driven system (ADS) that offers advantages in the transmutation of the spent fuel. (author)

Computational model for a high temperature electrolyzer coupled to a HTTR for efficient nuclear hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, Daniel; Rojas, Leorlen; Rosales, Jesus; Castro, Landy; Gamez, Abel; Brayner, Carlos, E-mail: danielgonro@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Garcia, Lazaro; Garcia, Carlos; Torre, Raciel de la, E-mail: lgarcia@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Sanchez, Danny [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil)

2015-07-01

High temperature electrolysis process coupled to a very high temperature reactor (VHTR) is one of the most promising methods for hydrogen production using a nuclear reactor as the primary heat source. However there are not references in the scientific publications of a test facility that allow to evaluate the efficiency of the process and other physical parameters that has to be taken into consideration for its accurate application in the hydrogen economy as a massive production method. For this lack of experimental facilities, mathematical models are one of the most used tools to study this process and theirs flowsheets, in which the electrolyzer is the most important component because of its complexity and importance in the process. A computational fluid dynamic (CFD) model for the evaluation and optimization of the electrolyzer of a high temperature electrolysis hydrogen production process flowsheet was developed using ANSYS FLUENT®. Electrolyzer's operational and design parameters will be optimized in order to obtain the maximum hydrogen production and the higher efficiency in the module. This optimized model of the electrolyzer will be incorporated to a chemical process simulation (CPS) code to study the overall high temperature flowsheet coupled to a high temperature accelerator driven system (ADS) that offers advantages in the transmutation of the spent fuel. (author)

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.

In situ x-ray diffraction study of crystal structure of Pd during hydrogen isotope loading by solid-state electrolysis at moderate temperatures 250−300 °C

Energy Technology Data Exchange (ETDEWEB)

Fukada, Yoshiki, E-mail: yoshiki_fukada@mail.toyota.co.jp [Toyota Motor Corporation, 1200 Mishuku, Susono-shi, Shizuoka-ken, 410-1193 (Japan); Hioki, Tatsumi; Motohiro, Tomoyoshi [Toyota Central R& D Labs.,Inc, 41-1, Yokomichi, Nagakute, Aichi, 480-1192 (Japan); Green Mobility Collaborative Research Center & Graduate School of Engineering Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603 (Japan); Ohshima, Shigeki [Toyota Central R& D Labs.,Inc, 41-1, Yokomichi, Nagakute, Aichi, 480-1192 (Japan)

2015-10-25

Hydrogen isotopes and metal interaction with respect to Pd under high hydrogen isotope potential at moderate temperature region around 300 °C was studied. A dry electrolysis technique using BaZr{sub 1−x} Y{sub x}O{sub 3} solid state electrolyte was developed to generate high hydrogen isotope potential. Hydrogen or deuterium was loaded into a 200 nm thick Pd cathode. The cathode is deposited on SiO{sub 2} substrate and covered with the solid state electrolyte and a Pd anode layer. Time resolved in situ monochromatic x-ray diffraction measurement was performed during the electrolysis. Two phase states of the Pd cathodes with large and small lattice parameters were observed during the electrolysis. Numerous sub-micron scale voids in the Pd cathode and dendrite-like Pd precipitates in the solid state electrolyte were found from the recovered samples. Hydrogen induced super-abundant-vacancy may take role in those phenomena. The observed two phase states may be attributed to phase separation into vacancy-rich and vacancy-poor states. The voids formed in the Pd cathodes seem to be products of vacancy coalescence. Isotope effects were also observed. The deuterium loaded samples showed more rapid phase changes and more formation of voids than the hydrogen doped samples. - Highlights: • High amount hydrogen loading into Pd by all solid-state electrolysis was performed. • Two phase states with large and small lattice parameters were observed. • Lattice contractions were observed suggesting formations of super-abundant-vacancy. • The absence of mechanical pressure might stimulate the formation of the vacancy. • Sub-micron void formations were found in the Pd from recovered samples.

In situ x-ray diffraction study of crystal structure of Pd during hydrogen isotope loading by solid-state electrolysis at moderate temperatures 250−300 °C

International Nuclear Information System (INIS)

Fukada, Yoshiki; Hioki, Tatsumi; Motohiro, Tomoyoshi; Ohshima, Shigeki

2015-01-01

Hydrogen isotopes and metal interaction with respect to Pd under high hydrogen isotope potential at moderate temperature region around 300 °C was studied. A dry electrolysis technique using BaZr 1−x Y x O 3 solid state electrolyte was developed to generate high hydrogen isotope potential. Hydrogen or deuterium was loaded into a 200 nm thick Pd cathode. The cathode is deposited on SiO 2 substrate and covered with the solid state electrolyte and a Pd anode layer. Time resolved in situ monochromatic x-ray diffraction measurement was performed during the electrolysis. Two phase states of the Pd cathodes with large and small lattice parameters were observed during the electrolysis. Numerous sub-micron scale voids in the Pd cathode and dendrite-like Pd precipitates in the solid state electrolyte were found from the recovered samples. Hydrogen induced super-abundant-vacancy may take role in those phenomena. The observed two phase states may be attributed to phase separation into vacancy-rich and vacancy-poor states. The voids formed in the Pd cathodes seem to be products of vacancy coalescence. Isotope effects were also observed. The deuterium loaded samples showed more rapid phase changes and more formation of voids than the hydrogen doped samples. - Highlights: • High amount hydrogen loading into Pd by all solid-state electrolysis was performed. • Two phase states with large and small lattice parameters were observed. • Lattice contractions were observed suggesting formations of super-abundant-vacancy. • The absence of mechanical pressure might stimulate the formation of the vacancy. • Sub-micron void formations were found in the Pd from recovered samples

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)

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.

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.

Comparative costs of hydrogen produced from photovoltaic electrolysis and from photoelectrochemical processes

International Nuclear Information System (INIS)

Block, D.L.

1998-01-01

The need for hydrogen produced from renewable energy sources is the key element to the world's large-scale usage of hydrogen and to the hydrogen economy envisioned by the World Hydrogen Energy Association. Renewables-produced hydrogen is also the most technically difficult problem to be solved. Hydrogen will never achieve large-scale usage until it can be competitively produced from renewable energy. One of the important questions that has to be addressed is: What are the economics of present and expected future technologies that will be used to produce hydrogen from renewables? The objective of this study is to give an answer to this question by determining the cost of hydrogen (in U.S.$/MBtu) from competing renewable production technologies. It should be noted that the costs and efficiencies assumed in this paper are assumptions of the author, and that the values are expected to be achieved after additional research on photoelectrochemical process technologies. The cost analysis performed is for three types of hydrogen (H 2 ) produced from five different types of renewable processes: photovoltaic (PV) electrolysis, three photoelectrochemical (PEC) processes and higher temperature electrolysis (HTE). The costs and efficiencies for PV, PEC and HTE processes are established for present day, and for expected costs and efficiencies 10 years into the future. A second objective of this analysis is to set base case costs of PV electrolysis. For any other renewable process, the costs for PV electrolysis, which is existing technology, sets the numbers which the other processes must better. (author)

Hydrogen by water electrolysis

International Nuclear Information System (INIS)

Anon.

1995-01-01

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

Development of Hydrogen Electrodes for Alkaline Water Electrolysis

DEFF Research Database (Denmark)

Kjartansdóttir, Cecilía Kristín

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

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

DEFF Research Database (Denmark)

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

2016-01-01

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

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

International Nuclear Information System (INIS)

Schalenbach, Maximilian; Stolten, Detlef

2015-01-01

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

High temperature fast reactor for hydrogen production in Brazil

International Nuclear Information System (INIS)

Nascimento, Jamil A. do; Ono, Shizuca; Guimaraes, Lamartine N.F.

2008-01-01

The main nuclear reactors technology for the Generation IV, on development phase for utilization after 2030, is the fast reactor type with high temperature output to improve the efficiency of the thermo-electric conversion process and to enable applications of the generated heat in industrial process. Currently, water electrolysis and thermo chemical cycles using very high temperature are studied for large scale and long-term hydrogen production, in the future. With the possible oil scarcity and price rise, and the global warming, this application can play an important role in the changes of the world energy matrix. In this context, it is proposed a fast reactor with very high output temperature, ∼ 1000 deg C. This reactor will have a closed fuel cycle; it will be cooled by lead and loaded with nitride fuel. This reactor may be used for hydrogen, heat and electricity production in Brazil. It is discussed a development strategy of the necessary technologies and some important problems are commented. The proposed concept presents characteristics that meet the requirements of the Generation IV reactor class. (author)

High hydrogen production from glycerol or glucose by electrohydrogenesis using microbial electrolysis cells

KAUST Repository

Selembo, Priscilla A.; Perez, Joe M.; Lloyd, Wallis A.; Logan, Bruce E.

2009-01-01

The use of glycerol for hydrogen gas production was examined via electrohydrogenesis using microbial electrolysis cells (MECs). A hydrogen yield of 3.9 mol-H2/mol was obtained using glycerol, which is higher than that possible by fermentation

Economical hydrogen production by electrolysis using nano pulsed DC

Energy Technology Data Exchange (ETDEWEB)

Dharmaraj, C.H. [Tangedco, Tirunelveli, ME Environmental Engineering (India); Adshkumar, S. [Department of Civil Engineering, Anna University of Technology Tirunelveli, Tirunelveli - 627007 (India)

2012-07-01

Hydrogen is an alternate renewable eco fuel. The environmental friendly hydrogen production method is electrolysis. The cost of electrical energy input is major role while fixing hydrogen cost in the conventional direct current Electrolysis. Using nano pulse DC input makes the input power less and economical hydrogen production can be established. In this investigation, a lab scale electrolytic cell developed and 0.58 mL/sec hydrogen/oxygen output is obtained using conventional and nano pulsed DC. The result shows that the nano pulsed DC gives 96.8 % energy saving.

Hydrogen Generation From Electrolysis

Energy Technology Data Exchange (ETDEWEB)

Steven Cohen; Stephen Porter; Oscar Chow; David Henderson

2009-03-06

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

Hydrogen electrolysis using a NASICON solid protonic conductor

Energy Technology Data Exchange (ETDEWEB)

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

1988-09-01

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

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-03-01

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

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

DEFF Research Database (Denmark)

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

2013-01-01

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

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...

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)

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

International Nuclear Information System (INIS)

Saji, Genn

2014-01-01

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

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)

Carbon dioxide and water vapor high temperature electrolysis

Science.gov (United States)

Isenberg, Arnold O.; Verostko, Charles E.

1989-01-01

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

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.

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

International Nuclear Information System (INIS)

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

2003-01-01

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

CFD Model Of A Planar Solid Oxide Electrolysis Cell For Hydrogen Production From Nuclear Energy

International Nuclear Information System (INIS)

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

2005-01-01

A three-dimensional computational fluid dynamics (CFD) model has been created to model high temperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). The model represents a single cell as it would exist in an electrolysis stack. Details of the model geometry are specific to a stack that was fabricated by Ceramatec2, Inc. and tested at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean model results are shown to compare favorably with experimental results obtained from an actual ten-cell stack tested at INL

Water electrolysis for hydrogen production in Brazilian perspective

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

A new type of hydrogen generator-HHEG (high-compressed hydrogen energy generator)

International Nuclear Information System (INIS)

Harada, H.; Tojima, K.; Takeda, M.; Nakazawa, T.

2004-01-01

'Full text:' We have developed a new type of hydrogen generator named HHEG (High-compressed Hydrogen Energy Generator). HHEG can produce 35 MPa high-compressed hydrogen for fuel cell vehicle without any mechanical compressor. HHEG is a kind of PEM(proton exchange membrane)electrolysis. It was well known that compressed hydrogen could be generated by water electrolysis. However, the conventional electrolysis could not generate 35 MPa or higher pressure that is required for fuel cell vehicle, because electrolysis cell stack is destroyed in such high pressure. In HHEG, the cell stack is put in high-pressure vessel and the pressure difference of oxygen and hydrogen that is generated by the cell stack is always kept at nearly zero by an automatic compensator invented by Mitsubishi Corporation. The cell stack of HHEG is not so special one, but it is not broken under such high pressure, because the automatic compensator always offsets the force acting on the cell stack. Hydrogen for fuel cell vehicle must be produce by no emission energy such as solar and atomic power. These energies are available as electricity. So, water electrolysis is the only way of producing hydrogen fuel. Hydrogen fuel is also 35 MPa high-compressed hydrogen and will become 70 MPa in near future. But conventional mechanical compressor is not useful for such high pressure hydrogen fuel, because of the short lifetime and high power consumption. Construction of hydrogen station network is indispensable in order to come into wide use of fuel cell vehicles. For such network contraction, an on-site type hydrogen generator is required. HHEG can satisfy above these requirements. So we can conclude that HHEG is the only way of realizing the hydrogen economy. (author)

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.

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.

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

International Nuclear Information System (INIS)

Ferrero, Domenico; Santarelli, Massimo

2017-01-01

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

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.

High hydrogen production from glycerol or glucose by electrohydrogenesis using microbial electrolysis cells

KAUST Repository

Selembo, Priscilla A.

2009-07-01

The use of glycerol for hydrogen gas production was examined via electrohydrogenesis using microbial electrolysis cells (MECs). A hydrogen yield of 3.9 mol-H2/mol was obtained using glycerol, which is higher than that possible by fermentation, at relatively high rates of 2.0 ± 0.4 m3/m3 d (Eap = 0.9 V). Under the same conditions, hydrogen was produced from glucose at a yield of 7.2 mol-H2/mol and a rate of 1.9 ± 0.3 m3/m3 d. Glycerol was completely removed within 6 h, with 56% of the electrons in intermediates (primarily 1,3-propanediol), with the balance converted to current, intracellular storage products or biomass. Glucose was removed within 5 h, but intermediates (mainly propionate) accounted for only 19% of the electrons. Hydrogen was also produced using the glycerol byproduct of biodiesel fuel production at a rate of 0.41 ± 0.1 m3/m3 d. These results demonstrate that electrohydrogenesis is an effective method for producing hydrogen from either pure glycerol or glycerol byproducts of biodiesel fuel production. © 2009 International Association for Hydrogen Energy.

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

International Nuclear Information System (INIS)

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

1978-01-01

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

Development of Non-Platinum Catalysts for Intermediate Temperature Water Electrolysis

DEFF Research Database (Denmark)

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

2014-01-01

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

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

Large-scale hydrogen production using nuclear reactors

Energy Technology Data Exchange (ETDEWEB)

Ryland, D.; Stolberg, L.; Kettner, A.; Gnanapragasam, N.; Suppiah, S. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

2014-07-01

For many years, Atomic Energy of Canada Limited (AECL) has been studying the feasibility of using nuclear reactors, such as the Supercritical Water-cooled Reactor, as an energy source for large scale hydrogen production processes such as High Temperature Steam Electrolysis and the Copper-Chlorine thermochemical cycle. Recent progress includes the augmentation of AECL's experimental capabilities by the construction of experimental systems to test high temperature steam electrolysis button cells at ambient pressure and temperatures up to 850{sup o}C and CuCl/HCl electrolysis cells at pressures up to 7 bar and temperatures up to 100{sup o}C. In parallel, detailed models of solid oxide electrolysis cells and the CuCl/HCl electrolysis cell are being refined and validated using experimental data. Process models are also under development to assess options for economic integration of these hydrogen production processes with nuclear reactors. Options for large-scale energy storage, including hydrogen storage, are also under study. (author)

Estimating Hydrogen Production Potential in Biorefineries Using Microbial Electrolysis Cell Technology

Energy Technology Data Exchange (ETDEWEB)

Borole, Abhijeet P [ORNL; Mielenz, Jonathan R [ORNL

2011-01-01

Microbial electrolysis cells (MECs) are devices that use a hybrid biocatalysis-electrolysis process for production of hydrogen from organic matter. Future biofuel and bioproducts industries are expected to generate significant volumes of waste streams containing easily degradable organic matter. The emerging MEC technology has potential to derive added- value from these waste streams via production of hydrogen. Biorefinery process streams, particularly the stillage or distillation bottoms contain underutilized sugars as well as fermentation and pretreatment byproducts. In a lignocellulosic biorefinery designed for producing 70 million gallons of ethanol per year, up to 7200 m3/hr of hydrogen can be generated. The hydrogen can either be used as an energy source or a chemical reagent for upgrading and other reactions. The energy content of the hydrogen generated is sufficient to meet 57% of the distillation energy needs. We also report on the potential for hydrogen production in existing corn mills and sugar-based biorefineries. Removal of the organics from stillage has potential to facilitate water recycle. Pretreatment and fermentation byproducts generated in lignocellulosic biorefinery processes can accumulate to highly inhibitory levels in the process streams, if water is recycled. The byproducts of concern including sugar- and lignin- degradation products such as furans and phenolics can also be converted to hydrogen in MECs. We evaluate hydrogen production from various inhibitory byproducts generated during pretreatment of various types of biomass. Finally, the research needs for development of the MEC technology and aspects particularly relevant to the biorefineries are discussed.

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

Science.gov (United States)

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

1984-01-01

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

Hydrogen production system based on high temperature gas cooled reactor energy using the sulfur-iodine (SI) thermochemical water splitting cycle

International Nuclear Information System (INIS)

Garcia, L.; Gonzalez, D.

2011-01-01

Hydrogen production from water using nuclear energy offers one of the most attractive zero-emission energy strategies and the only one that is practical on a substantial scale. Recently, strong interest is seen in hydrogen production using heat of a high-temperature gas-cooled reactor. The high-temperature characteristics of the modular helium reactor (MHR) make it a strong candidate for producing hydrogen using thermochemical or high-temperature electrolysis (HTE) processes. Eventually it could be also employ a high-temperature gas-cooled reactor (HTGR), which is particularly attractive because it has unique capability, among potential future generation nuclear power options, to produce high-temperature heat ideally suited for nuclear-heated hydrogen production. Using heat from nuclear reactors to drive a sulfur-iodine (SI) thermochemical hydrogen production process has been interest of many laboratories in the world. One of the promising approaches to produce large quantity of hydrogen in an efficient way using the nuclear energy is the sulfur-iodine (SI) thermochemical water splitting cycle. Among the thermochemical cycles, the sulfur iodine process remains a very promising solution in matter of efficiency and cost. This work provides a pre-conceptual design description of a SI-Based H2-Nuclear Reactor plant. Software based on chemical process simulation (CPS) was used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. (Author)

Assessment of MHR-based hydrogen energy systems

International Nuclear Information System (INIS)

Richards, Matthew; Shenoy, Arkal; Schultz, Kenneth; Brown, Lloyd; Besenbruch, Gottfried; Handa, Norihiko; Das, Jadu

2004-01-01

Process heat from a high-temperature nuclear reactor can be used to drive a set of chemical reactions, with the net result of splitting water into hydrogen and oxygen. For example, process heat at temperatures in the range 850degC to 950degC can drive the sulfur-iodine (SI) thermochemical process to produce hydrogen with high efficiency. The SI process produces highly pure hydrogen and oxygen, with formation, decomposition, regeneration, and recycle of the intermediate chemical reagents and low-temperature heat as the only waste product. Electricity can also be used directly to split water, using conventional, low-temperature electrolysis (LTE). Hydrogen can also be produced with hybrid processes that use both process heat and electricity to generate hydrogen. An example of a hybrid process is high-temperature electrolysis (HTE), in which process heat is used to generate steam, which is then supplied to an electrolyzer to generate hydrogen. This process is of interest because the efficiency of electrolysis increases with temperature. Because of its high-temperature capability, advanced of development relative to other high-temperature reactor concepts, and passive-safety features, the Modular Helium Reactor (MHR) is well suited for producing hydrogen using nuclear energy. In this paper we investigate concepts for coupling the MHR to the SI process, LTE, and HTE. These concepts are referred to as the H2-MHR. (author)

US work on technical and economic aspects of electrolytic, thermochemical, and hybrid processes for hydrogen production at temperatures below 550 deg. C

International Nuclear Information System (INIS)

Petri, M.C.; Yyldyz, B.; Klickman, A.E.

2006-01-01

Hydrogen demand is increasing, but there are few options for affordable hydrogen production free of greenhouse gas emissions. Nuclear power is one of the most promising options. Most research is focused on high-temperature electrolytic and thermochemical processes for nuclear-generated hydrogen, but it will be many years before very high temperature reactors become commercially available. For light water reactors or supercritical reactors, low-temperature water electrolysis is a currently available technology for hydrogen production. Higher efficiencies may be gained through thermo-electrochemical hydrogen production cycles, but there are only a limited number that have heat requirements consistent with the lower temperatures of light-water reactor technology. Indeed, active research is ongoing for only three such cycles in the USA. Reductions in electricity and system costs would be needed (or the imposition of a carbon tax) for low-temperature water electrolysis to compete with today's costs for steam methane reformation. The interactions between hydrogen and electricity markets and hydrogen and electricity producers are complex and will evolve as the markets evolve. (author)

Production price of hydrogen from grid connected electrolysis in a power market with high wind penetration

International Nuclear Information System (INIS)

Joergensen, Claus; Ropenus, Stephanie

2008-01-01

In liberalized power markets, there are significant power price fluctuations due to independently varying changes in demand and supply, the latter being substantial in systems with high wind power penetration. In such systems, hydrogen production by grid connected electrolysis can be cost optimized by operating an electrolyzer part time. This paper presents a study on the minimization of the hydrogen production price and its dependence on estimated power price fluctuations. The calculation of power price fluctuations is based on a parameterization of existing data on wind power production, power consumption and power price evolution in the West Danish power market area. The price for hydrogen is derived as a function of the optimal electrolyzer operation hours per year for four different wind penetration scenarios. It is found to amount to 0.41-0.45 EUR/Nm 3 . The study further discusses the hydrogen price sensitivity towards investment costs and the contribution from non-wind power sources. (author)

Production price of hydrogen from grid connected electrolysis in a power market with high wind penetration

Energy Technology Data Exchange (ETDEWEB)

Joergensen, Claus [Materials Research Department, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Ropenus, Stephanie [Systems Analysis Department, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

2008-10-15

In liberalized power markets, there are significant power price fluctuations due to independently varying changes in demand and supply, the latter being substantial in systems with high wind power penetration. In such systems, hydrogen production by grid connected electrolysis can be cost optimized by operating an electrolyzer part time. This paper presents a study on the minimization of the hydrogen production price and its dependence on estimated power price fluctuations. The calculation of power price fluctuations is based on a parameterization of existing data on wind power production, power consumption and power price evolution in the West Danish power market area. The price for hydrogen is derived as a function of the optimal electrolyzer operation hours per year for four different wind penetration scenarios. It is found to amount to 0.41-0.45 EUR/Nm{sup 3}. The study further discusses the hydrogen price sensitivity towards investment costs and the contribution from non-wind power sources. (author)

Production price of hydrogen from grid connected electrolysis in a power market with high wind penetration.

Energy Technology Data Exchange (ETDEWEB)

Joergensen, Claus [Materials Research Department, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Ropenus, Stephanie [Systems Analysis Department, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

2008-10-15

In liberalized power markets, there are significant power price fluctuations due to independently varying changes in demand and supply, the latter being substantial in systems with high wind power penetration. In such systems, hydrogen production by grid connected electrolysis can be cost optimized by operating an electrolyzer part time. This paper presents a study on the minimization of the hydrogen production price and its dependence on estimated power price fluctuations. The calculation of power price fluctuations is based on a parameterization of existing data on wind power production, power consumption and power price evolution in the West Danish power market area. The price for hydrogen is derived as a function of the optimal electrolyzer operation hours per year for four different wind penetration scenarios. It is found to amount to 0.41-0.45 EUR/Nm{sup 3}. The study further discusses the hydrogen price sensitivity towards investment costs and the contribution from non-wind power sources. (author)

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

Science.gov (United States)

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

2016-01-01

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

Root cause study on hydrogen generation and explosion through radiation-induced electrolysis in the Fukushima Daiichi accident

Energy Technology Data Exchange (ETDEWEB)

Saji, Genn, E-mail: sajig@bd5.so-net.ne.jp

2016-10-15

Highlights: • Reviewed how LWRs have coped with “water radiolysis”, during normal operation to severe accidents. • Concluded “water radiolysis” is not likely a route course of the hydrogen explosions at Fukushima. • Performed modeling studies based on “radiation-induced electrolysis” on Unit 1–Unit 4. • Generation of several tens of thousands cubic meters hydrogen gas is predicted before the hydrogen explosions. • Upon SBO, early safe disposal of hydrogen from RPVs is indispensable in BWRs. - Abstract: Since the scientific cause for a series of hydrogen explosions during the Fukushima accident has not been established, the author investigated his basic theory named “radiation-induced electrolysis (RIE)” by applying the estimation of the amounts of H{sub 2} generation during the active phase of the Fukushima accident. The author's theory was originally developed by including Faraday's law of electrolysis into the basic time-dependent material balance equation of radiation-chemical species for his study on accelerated corrosion phenomena which is widely observed in aged plants. As such this theory applies to the early phase of the accident before the loss of water levels in the reactor cores, although the simulations were performed from the time of seismic reactor trip to the hydrogen explosions in this paper. Through this mechanism as much as 29,400 m{sup 3}-STP of hydrogen gas is estimated to be accumulated inside the PCV just prior to the hydrogen explosion which occurred one day after the reactor trip in 1F1. With this large volume of hydrogen gas the explosion was a viable possibility upon the “venting” operation. In view of this observation, hydrogen generation from the spent fuel pools was also investigated. For the investigation of the 1F4 SFP, the pool water temperature and flow velocity due to natural circulation were changed widely to identify conditions of large hydrogen generation. During the trial calculations

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....

Seven harmonic susceptibility in oxygen and hydrogen loading of sintered YBCO by μs pulsed electrolysis in an aqueous solution at room temperature

International Nuclear Information System (INIS)

Tripodi, P.; Di Gioacchino, D.; Celani, F.

1996-09-01

The complex AC susceptibility of high T c superconducting materials has been described in terms of the first seven harmonic component of Fourier series. Has been measured the χ' n and χ n (n=1,7) of sintered YBa 2 Cu 3 O 7-x (YBCO) bulk oxygen and hydrogen loaded samples versus amplitude and frequency of AC magnetic field at fixed temperature. The sample have been loaded by μs current pulses electrolysis in an aqueous solution (0.3N LiOH+H 2 O) at room temperature. In addition to the simplicity of the experimental setup, this procedure allows to obtain extremely high equivalent hydrogen/oxygen gas pressure on the surface of the electrodes. The YBCO electrode is polarized by short pulse width (0.5-10 μs) and high power (120 W) peaks with a variable repetition rate (0.1-10000 Hz). The pulses are obtained by an home.made pulse generator. The difference in the behavior of the susceptibilities harmonic component between the deficiency and oxygen or hydrogen loaded samples give us the possibility to connect the susceptibilities with variations of the flux pinning in respect to normal losses in the superconducting materials. The loading can be a good probe to have information on the mechanism of the processes that sustain the critical current density Jc in this situation these affects appear strongly dependent on the loading conditions. By comparison of this measurements has been observed drastic change in behavior of susceptibility

High Temperature Oxidation of Ferritic Steels for Solid Oxide Electrolysis Stacks

DEFF Research Database (Denmark)

Molin, Sebastian; Chen, Ming; Bentzen, Janet Jonna

2013-01-01

atmospheres at 800°C. Four commercially available alloys: Crofer 22 APU, Crofer 22 H, AL29-4, E-Brite were characterized in humidified hydrogen. One alloy, Crofer 22 APU was also characterized in pure oxygen both in the as-prepared state and after application of a protective coating. Best corrosion resistance......Oxidation rates of ferritic steels used as interconnector plates in Solid Oxide Electrolysis Stacks are of concern as they may be determining for the life time of the technology. In this study oxidation experiments were carried out for up to 1000 hours in hydrogen-side and oxygen-side simulated...... in humidified hydrogen atmosphere was observed for Crofer 22 APU and Crofer 22 H alloys. Corrosion rates for Crofer 22 APU measured in humidified hydrogen are similar to the corrosion rates measured in air. Both coatings of plasma sprayed LSM and dual layer coatings (Co3O4/LSM-Co3O4) applied by wet spraying...

Hydrogen production from steam methane reforming and electrolysis as part of a near-term hydrogen infrastructure

International Nuclear Information System (INIS)

Roberts, K.

2003-01-01

Building a complete hydrogen infrastructure for a transportation system based on Fuel Cells (FC) and hydrogen is a risky and expensive ordeal, especially given that it is not known with complete certainty that Fuel Cells will indeed replace the gasoline ICE. But how can we expect the diffusion of an automotive technology if there is no infrastructure to support its fuel needs? This gives rise to a chicken and egg type problem. One way to get around this problem is to produce hydrogen when and where it is needed. This solves the problems of high costs associated with expensive pipeline distribution networks, the high energy-intensities associated with liquefaction of hydrogen and the high costs of cryogenic equipment. This paper will consider the advantages and disadvantages of two such hydrogen production mechanisms, namely, onsite production of hydrogen from Electrolysis and onsite production of hydrogen from Steam Methane Reforming (SMR). Although SMR hydrogen may be more economical due to the availability and low cost of methane, under certain market and technological conditions onsite electrolytic hydrogen can be more attractive. The paper analyses the final price of delivered hydrogen based on its sensitivity to market conditions and technology developments. (author)

Hydrogen Production by Water Electrolysis Via Photovoltaic Panel

Directory of Open Access Journals (Sweden)

Hydrogen Production by Water Electrolysis Via Photovoltaic Panel

2016-07-01

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

Hydrogen generation through static-feed water electrolysis

Science.gov (United States)

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

1975-01-01

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

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

KAUST Repository

Nam, Joo-Youn

2012-05-01

Hydrogen gas can be electrochemically produced in microbial reverse-electrodialysis electrolysis cells (MRECs) using current derived from organic matter and salinity-gradient energy such as river water and seawater solutions. Here, it is shown that ammonium bicarbonate salts, which can be regenerated using low-temperature waste heat, can also produce sufficient voltage for hydrogen gas generation in an MREC. The maximum hydrogen production rate was 1.6 m3 H2/m3·d, with a hydrogen yield of 3.4 mol H2/mol acetate at a salinity ratio of infinite. Energy recovery was 10% based on total energy applied with an energy efficiency of 22% based on the consumed energy in the reactor. The cathode overpotential was dependent on the catholyte (sodium bicarbonate) concentration, but not the salinity ratio, indicating high catholyte conductivity was essential for maximizing hydrogen production rates. The direction of the HC and LC flows (co- or counter-current) did not affect performance in terms of hydrogen gas volume, production rates, or stack voltages. These results show that the MREC can be successfully operated using ammonium bicarbonate salts that can be regenerated using conventional distillation technologies and waste heat making the MREC a useful method for hydrogen gas production from wastes. © 2012 American Chemical Society.

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

Science.gov (United States)

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

2016-10-29

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

Seven harmonic susceptibility in oxygen and hydrogen loading of sintered YBCO by {mu}s pulsed electrolysis in an aqueous solution at room temperature

Energy Technology Data Exchange (ETDEWEB)

Tripodi, P.; Di Gioacchino, D.; Celani, F. [Istituto Nazionale di Fisica Nucleare, Frascati (Italy). Lab. Nazionale di Frascati

1996-09-01

The complex AC susceptibility of high T{sub c} superconducting materials has been described in terms of the first seven harmonic component of Fourier series. Has been measured the {chi}{sub n} (n=1,7) of sintered YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) bulk oxygen and hydrogen loaded samples versus amplitude and frequency of AC magnetic field at fixed temperature. The sample have been loaded by {mu}s current pulses electrolysis in an aqueous solution (0.3N LiOH+H{sub 2}O) at room temperature. In addition to the simplicity of the experimental setup, this procedure allows to obtain extremely high equivalent hydrogen/oxygen gas pressure on the surface of the electrodes. The YBCO electrode is polarized by short pulse width (0.5-10 {mu}s) and high power (120 W) peaks with a variable repetition rate (0.1-10000 Hz). The pulses are obtained by an home.made pulse generator. The difference in the behavior of the susceptibilities harmonic component between the deficiency and oxygen or hydrogen loaded samples give us the possibility to connect the susceptibilities with variations of the flux pinning in respect to normal losses in the superconducting materials. The loading can be a good probe to have information on the mechanism of the processes that sustain the critical current density Jc in this situation these affects appear strongly dependent on the loading conditions. By comparison of this measurements has been observed drastic change in behavior of susceptibility.

Evaluation of two processes of hydrogen production starting from energy generated by high temperature nuclear reactors; Evaluacion de dos procesos de produccion de hidrogeno a partir de energia generada por reactores nucleares de alta temperatura

Energy Technology Data Exchange (ETDEWEB)

Valle H, J., E-mail: jvalle@upmh.edu.mx [Universidad Politecnica Metropolitana de Hidalgo, Boulevard Acceso a Tolcayuca 1009, Ex-Hacienda San Javier, 43860 Tolcayuca, Hidalgo (Mexico)

2013-10-15

In this work an evaluation to two processes of hydrogen production using energy generated starting from high temperature nuclear reactors (HTGR's) was realized. The evaluated processes are the electrolysis of high temperature and the thermo-chemistry cycle Iodine-Sulfur. The electrolysis of high temperature, contrary to the conventional electrolysis, allows reaching efficiencies of up to 60% because when increasing the temperature of the water, giving thermal energy, diminishes the electric power demand required to separate the molecule of the water. However, to obtain these efficiencies is necessary to have water vapor overheated to more than 850 grades C, temperatures that can be reached by the HTGR. On the other hand the thermo-chemistry cycle Iodine-Sulfur, developed by General Atomics in the 1970 decade, requires two thermal levels basically, the great of them to 850 grades C for decomposition of H{sub 2}SO{sub 4} and another minor to 360 grades C approximately for decomposition of H I, a high temperature nuclear reactor can give the thermal energy required for the process whose products would be only hydrogen and oxygen. In this work these two processes are described, complete models are developed and analyzed thermodynamically that allow to couple each hydrogen generation process to a reactor HTGR that will be implemented later on for their dynamic simulation. The obtained results are presented in form of comparative data table of each process, and with them the obtained net efficiencies. (author)

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

DEFF Research Database (Denmark)

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

degradation of cell components in relation to the loss of electrochemical performance specific to the mode of operation. Thus descriptive microstructure characterization methods are required in combination with electrochemical characterization methods to decipher degradation mechanisms. In the present work......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...... 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...

Advanced Intermediate Heat Transport Loop Design Configurations for Hydrogen Production Using High Temperature Nuclear Reactors

International Nuclear Information System (INIS)

Chang Oh; Cliff Davis; Rober Barner; Paul Pickard

2005-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2002-01-01

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

Reversibility of the SOFC for the hydrogen production by high temperature electrolysis

International Nuclear Information System (INIS)

Brisse, A.; Marrony, M.; Perednis, D.; Schefold, J.; Jose-Garcia, M.; Zahid, M.

2007-01-01

The behaviour of two SOFC cells in electrolysis mode is studied. The performances of these solid oxide cells, reversible at 800 C and for current densities between 0 and -0.42 A/cm 2 , are presented. A weaker polarisation resistance has been measured for the cell containing a mixed conductor as oxygen electrode. For each cell, a limitation by gaseous diffusion has been observed under current. This phenomenon appears for current densities which are higher for the mixed conductor cell as oxygen electrode. (O.M.)

Screening analysis of solar thermochemical hydrogen concepts.

Energy Technology Data Exchange (ETDEWEB)

Diver, Richard B., Jr.; Kolb, Gregory J.

2008-03-01

A screening analysis was performed to identify concentrating solar power (CSP) concepts that produce hydrogen with the highest efficiency. Several CSP concepts were identified that have the potential to be much more efficient than today's low-temperature electrolysis technology. They combine a central receiver or dish with either a thermochemical cycle or high-temperature electrolyzer that operate at temperatures >600 C. The solar-to-hydrogen efficiencies of the best central receiver concepts exceed 20%, significantly better than the 14% value predicted for low-temperature electrolysis.

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

. 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...

Electrochemical performances of LSM/YSZ composite electrode for high temperature steam electrolysis

International Nuclear Information System (INIS)

Kyu-Sung Sim; Ki-Kwang Bae; Chang-Hee Kim; Ki-Bae Park

2006-01-01

The (La 0.8 Sr 0.2 ) 0.95 MnO 3 /Yttria-stabilized Zirconia composite electrodes were investigated as anode materials for high temperature steam electrolysis using X-ray diffractometry, scanning electron microscopy, galvano-dynamic and galvano-static polarization method. For this study, the LSM perovskites were fabricated in powders by the co-precipitation method and then were mixed with 8 mol% YSZ powders in different molar ratios. The LSM/YSZ composite electrodes were deposited on 8 mol% YSZ electrolyte disks by screen printing method, followed by sintering at temperature above 1100 C. From the experimental results, it is concluded that the electrochemical properties of pure and composite electrodes are closely related to their micro-structure and operating temperature. (authors)

Comparative Analysis of Hydrogen Production Methods with Nuclear Reactors

International Nuclear Information System (INIS)

Morozov, Andrey

2008-01-01

Hydrogen is highly effective and ecologically clean fuel. It can be produced by a variety of methods. Presently the most common are through electrolysis of water and through the steam reforming of natural gas. It is evident that the leading method for the future production of hydrogen is nuclear energy. Several types of reactors are being considered for hydrogen production, and several methods exist to produce hydrogen, including thermochemical cycles and high-temperature electrolysis. In the article the comparative analysis of various hydrogen production methods is submitted. It is considered the possibility of hydrogen production with the nuclear reactors and is proposed implementation of research program in this field at the IPPE sodium-potassium eutectic cooling high temperature experimental facility (VTS rig). (authors)

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

Science.gov (United States)

1975-01-01

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

A hydrogen production experiment by the thermo-chemical and electrolytic hybrid hydrogen production in lower temperature range. System viability and preliminary thermal efficiency estimation

International Nuclear Information System (INIS)

Takai, Toshihide; Nakagiri, Toshio; Inagaki, Yoshiyuki

2008-10-01

A new experimental apparatus by the thermo-chemical and electrolytic Hybrid-Hydrogen production in Lower Temperature range (HHLT) was developed and hydrogen production experiment was performed to confirm the system operability. Hydrogen production efficiency was estimated and technical problems were clarified through the experimental results. Stable operation of the SO 3 electrolysis cell and the sulfur dioxide solution electrolysis cell were confirmed during experimental operation and any damage which would be affected solid operation was not detected under post operation inspection. To improve hydrogen production efficiency, it was found that the reduction of sulfuric acid circulation and the decrease in the cell voltage were key issues. (author)

The Economic Potential of Nuclear-Renewable Hybrid Energy Systems Producing Hydrogen

Energy Technology Data Exchange (ETDEWEB)

Ruth, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cutler, Dylan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Flores-Espino, Francisco [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stark, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-04-01

This report is one in a series of reports that Idaho National Laboratory and the Joint Institute for Strategic Energy Analysis are publishing that address the technical and economic aspects of nuclear-renewable hybrid energy systems (N-R HESs). This report discusses an analysis of the economic potential of a tightly coupled N-R HES that produces electricity and hydrogen. Both low and high temperature electrolysis options are considered in the analysis. Low-temperature electrolysis requires only electricity to convert water to hydrogen. High temperature electrolysis requires less electricity because it uses both electricity and heat to provide the energy necessary to electrolyze water. The study finds that, to be profitable, the examined high-temperature electrosis and low-temperature electrosis N-R HES configurations that produce hydrogen require higher electricity prices, more electricity price volatility, higher natural gas prices, or higher capacity payments than the reference case values of these parameters considered in this analysis.

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

Science.gov (United States)

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

2016-01-01

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

Breaking through the hydrogen cost barrier by using electrolysis loads to access ancillary services and demand response programs

International Nuclear Information System (INIS)

Wilson, D.; McGillivray, R.

2009-01-01

This presentation described the use of hydrogen electrolysis as a load resource for handling grid instability resulting from the increased penetration of intermittent renewable power. In particular, it focused on Hydrogenics, the leading global supplier of industrial scale electrolysis equipment and fuel cells. The presentation included an overview of the current incentive and market value of ancillary services provided by the company and demand responses in a number of grids around the world. There is a link between the amount of ancillary services required by the grid and the penetration level of renewable energy power such as wind and solar. The ability of hydrogen generation from electrolysis to satisfy all the requirements of ancillary services markets was also demonstrated. The economic analysis of hydrogen generation was discussed with particular reference to the cost of hydrogen fully loading all capital, energy and operating costs. The resulting reduction in the cost of hydrogen was compared to the existing markets for hydrogen, including use of hydrogen as a fuel for municipal bus fleets relative to the existing cost of fossil fuel fleets. Current industrial hydrogen merchant and bulk market prices were also compared

Coupling the modular helium reactor to hydrogen production processes

International Nuclear Information System (INIS)

Richards, M.B.; Shenoy, A.S.; Schultz, K.R.

2004-01-01

Steam reforming of natural gas (methane) currently produces the bulk of hydrogen gas used in the world today. Because this process depletes natural gas resources and generates the greenhouse gas carbon dioxide as a by-product, there is a growing interest in using process heat and/or electricity generated by nuclear reactors to generate hydrogen by splitting water. Process heat from a high temperature nuclear reactor can be used directly to drive a set of chemical reactions, with the net result of splitting water into hydrogen and oxygen. For example, process heat at temperatures in the range 850 deg C to 950 deg C can drive the sulphur-iodine (S-I) thermochemical process to produce hydrogen with high efficiency. The S-I process produces highly pure hydrogen and oxygen, with formation, decomposition, regeneration, and recycle of the intermediate chemical reagents. Electricity can also 1)e used directly to split water, using conventional, low-temperature electrolysis (LTE). Hydrogen can also be produced with hybrid processes that use both process heat and electricity to generate hydrogen. An example of a hybrid process is high-temperature electrolysis (HTE), in which process heat is used to generate steam, which is then supplied to an electrolyzer to generate hydrogen. This process is of interest because the efficiency of electrolysis increases with temperature. Because of its high temperature capability, advanced stage of development relative to other high-temperature reactor concepts, and passive-safety features, the modular helium reactor (MHR) is well suited for producing hydrogen using nuclear energy. In this paper we investigate the coupling of the MHR to the S-I process, LTE, and HTE. These concepts are referred to as the H2-MHR. (author)

Study of the effect of pressure on electrolysis of H2O and co-electrolysis of H2O and CO2 at high temperature

International Nuclear Information System (INIS)

Bernadet, Lucile

2016-01-01

This thesis work investigates the behavior of a solid oxide cell operating under pressure in high temperature steam electrolysis and co-electrolysis mode (H 2 O and CO 2 ). The experimental study of single cell associated with the development of multi-physical models have been set up. The experiments, carried out using an original test bench developed by the CEA-Grenoble on two types of cells between 1 and 10 bar and 700 to 800 C, allowed to identify in both operating modes that the pressure has a positive or negative effect on performance depending on the cell operating point (current, voltage). In addition, gas analyzes performed in co-electrolysis led to detect in situ CH 4 production under pressure. These pressure effects were simulated by models calibrated at atmospheric pressure. Simulations analysis helped identify the pressure dependent mechanisms and propose operating conditions thanks to the establishment of operating maps. (author) [fr

Once-through hybrid sulfur process for nuclear hydrogen production

International Nuclear Information System (INIS)

Jeong, Y. H.

2008-01-01

Increasing concern about the global climate change spurs the development of low- or zero-carbon energy system. Nuclear hydrogen production by water electrolysis would be the one of the short-term solutions, but low efficiency and high production cost (high energy consumption) is the technical hurdle to be removed. In this paper the once-through sulfur process composed of the desulfurization and the water electrolysis systems is proposed. Electrode potential for the conventional water electrolysis (∼2.0 V) can be reduced significantly by the anode depolarization using sulfur dioxide: down to 0.6 V depending on the current density This depolarized electrolysis is the electrolysis step of the hybrid sulfur process originally proposed by the Westinghouse. However; recycling of sulfur dioxide requires a high temperature heat source and thus put another technical hurdle on the way to nuclear hydrogen production: the development of high temperature nuclear reactors and corresponding sulfuric acid decomposition system. By the once-through use of sulfur dioxide rather than the closed recycle, the hurdle can be removed. For the sulfur feed, the desulfurization system is integrated into the water electrolysis system. Fossil fuels include a few percent of sulfur by weight. During the refinement or energy conversion, most of the sulfur should be separated The separated sulfur can be fed to the water electrolysis system and the final product would be hydrogen and sulfuric acid, which is number one chemical in the world by volume. Lowered electrode potential and additional byproduct, the sulfuric acid, can provide economically affordable hydrogen. In this study, the once-through hybrid sulfur process for hydrogen production was proposed and the process was optimized considering energy consumption in electrolysis and sulfuric acid concentration. Economic feasibility of the proposed process was also discussed. Based on currently available experimental data for the electrode

Hydrogen production by electrolysis of a phosphate solution on a stainless steel cathode

International Nuclear Information System (INIS)

De Silva Munoz, L.; Bergel, A.; Basseguy, R.; Feron, D.

2010-01-01

The catalytic properties of phosphate species, already shown on the reduction reaction in anaerobic corrosion of steels, are exploited here for hydrogen production. Phosphate species work as a homogeneous catalyst that enhances the cathodic current at mild pH values. A voltammetric study of the hydrogen evolution reaction is performed using phosphate solutions at different concentrations on 316L stainless steel and platinum rotating disk electrodes. Then, hydrogen is produced in an electrolytic cell using a phosphate solution as the catholyte. Results show that 316L stainless steel electrodes have a stable behaviour as cathodes in the electrolysis of phosphate solutions. Phosphate (1 M, pH 4. 0/5. 0) as the catholyte can equal the performance of a KOH 25%w solution with the advantage of working at mild pH values. The use of phosphate and other weak acids as catalysts of the hydrogen evolution reaction could be a promising technology in the development of electrolysis units that work at mild pH values with low-cost electrodes and construction materials. (authors)

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-01

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

Efficient STEP (solar thermal electrochemical photo) production of hydrogen - an economic assessment

Energy Technology Data Exchange (ETDEWEB)

Licht, Stuart [Department of Chemistry, George Washington University, Ashburn, VA 20147 (United States); Solar Institute, George Washington University, Washington, DC 20052 (United States); Chitayat, Olivia; Bergmann, Harry; Dick, Andrew; Ayub, Hina [Solar Institute, George Washington University, Washington, DC 20052 (United States); Ghosh, Susanta [Department of Chemistry, George Washington University, Ashburn, VA 20147 (United States); Department of Chemistry, Visva-Bharati, Santiniketan (India)

2010-10-15

A consideration of the economic viability of hydrogen fuel production is important in the STEP (Solar Thermal Electrochemical Photo) production of hydrogen fuel. STEP is an innovative way to decrease costs and increase the efficiency of hydrogen fuel production, which is a synergistic process that can use concentrating photovoltaics (CPV) and solar thermal energy to drive a high temperature, low voltage, electrolysis (water-splitting), resulting in H{sub 2} at decreased energy and higher solar efficiency. This study provides evidence that the STEP system is an economically viable solution for the production of hydrogen. STEP occurs at both higher electrolysis and solar conversion efficiencies than conventional room temperature photovoltaic (PV) generation of hydrogen. This paper probes the economic viability of this process, by comparing four different systems: (1) 10% or (2) 14% flat plate PV driven aqueous alkaline electrolysis H{sub 2} production, (3) 25% CPV driven molten electrolysis H{sub 2} production, and (4) 35% CPV driven solid oxide electrolysis H{sub 2} production. The molten and solid oxide electrolysers are high temperature systems that can make use of light, normally discarded, for heating. This significantly increases system efficiency. Using levelized cost analysis, this study shows significant cost reduction using the STEP system. The total price per kg of hydrogen is shown to decrease from 5.74 to 4.96 to 3.01 to 2.61 with the four alternative systems. The advanced STEP plant requires less than one seventh of the land area of the 10% flat cell plant. To generate the 216 million kg H{sub 2}/year required by 1 million fuel cell vehicles, the 35% CPV driven solid oxide electrolysis requires a plant only 9.6 mi{sup 2} in area. While PV and electrolysis components dominate the cost of conventional PV generated hydrogen, they do not dominate the cost of the STEP-generated hydrogen. The lower cost of STEP hydrogen is driven by residual distribution and

Hydrogen - High pressure production and storage

International Nuclear Information System (INIS)

Lauretta, J.R

2005-01-01

The development of simple, safe and more and more efficient technologies for the production and the storage of hydrogen is necessary condition for the transition towards the economy of hydrogen.In this work the hydrogen production studies experimentally to high pressure by electrolysis of alkaline solutions without the intervention of compressing systems and its direct storage in safe containers.The made tests show that the process of electrolysis to high pressure is feasible and has better yield than to low pressure, and that is possible to solve the operation problems, with relatively simple technology.The preliminary studies and tests indicate that the system container that studied is immune to the outbreak and can have forms and very different sizes, nevertheless, to reach or to surpass the efficiency of storage of the conventional systems the investments necessary will be due to make to be able to produce aluminum alloy tubes of high resistance

Test Plan for Long-Term Operation of a Ten-Cell High Temperature Electrolysis Stack

International Nuclear Information System (INIS)

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

2008-01-01

This document defines a test plan for a long-term (2500 Hour) test of a ten-cell high-temperature electrolysis stack to be performed at INL during FY09 under the Nuclear Hydrogen Initiative. This test was originally planned for FY08, but was removed from our work scope as a result of the severe budget cuts in the FY08 NHI Program. The purpose of this test is to evaluate stack performance degradation over a relatively long time period and to attempt to identify some of the degradation mechanisms via post-test examination. This test will be performed using a planar ten-cell Ceramatec stack, with each cell having dimensions of 10 cm x 10 cm. The specific makeup of the stack will be based on the results of a series of shorter duration ten-cell stack tests being performed during FY08, funded by NGNP. This series of tests was aimed at evaluating stack performance with different interconnect materials and coatings and with or without brazed edge rails. The best performing stack from the FY08 series, in which five different interconnect/coating/edge rail combinations were tested, will be selected for the FY09 long-term test described herein

High temperature fast reactor for hydrogen production in Brazil; Reator nuclear rapido de altissima temperatura para producao de hidrogenio no Brasil

Energy Technology Data Exchange (ETDEWEB)

Nascimento, Jamil A. do; Ono, Shizuca; Guimaraes, Lamartine N.F. [Centro Tecnico Aeroespacial (CTA-IEAv), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados]. E-mail: jamil@ieav.cta.br

2008-07-01

The main nuclear reactors technology for the Generation IV, on development phase for utilization after 2030, is the fast reactor type with high temperature output to improve the efficiency of the thermo-electric conversion process and to enable applications of the generated heat in industrial process. Currently, water electrolysis and thermo chemical cycles using very high temperature are studied for large scale and long-term hydrogen production, in the future. With the possible oil scarcity and price rise, and the global warming, this application can play an important role in the changes of the world energy matrix. In this context, it is proposed a fast reactor with very high output temperature, {approx} 1000 deg C. This reactor will have a closed fuel cycle; it will be cooled by lead and loaded with nitride fuel. This reactor may be used for hydrogen, heat and electricity production in Brazil. It is discussed a development strategy of the necessary technologies and some important problems are commented. The proposed concept presents characteristics that meet the requirements of the Generation IV reactor class. (author)

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

DEFF Research Database (Denmark)

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

2016-01-01

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

Hydrogen production from electrolysis in LHD-type helical reactor FFHR

International Nuclear Information System (INIS)

Yamada, S.; Sagara, A.; Imagawa, S.; Mito, T.; Motojima, O.

2007-01-01

The LHD-type helical power reactor, FFHR, is proposed by the National Institute for Fusion Science on the basis of the engineering achievements and confinement properties of the LHD. The output of the thermal power and electric power of the FFHR2m2 are optimized to 3 GW and 1 GW, respectively. To assess the technical potential of the FFHR2m2 operation style, hydrogen production from electrolysis is investigated in this report. Gaseous hydrogen of 700 tons per day can be produced by the electric power of 1 GW. The steam of 6,354 tons per day at 150 degree C is necessary in this case. Required heating power to produce the stem from the water at 20 degree C is 198 MW. In FFHR2m2, about 450 MW of thermal power is delivered via the scrape-off layer plasma to the divertors with double-null structure. The divertor may be one of the potential heat sources to produce the steam for the electrolysis. Hydrogen has to be packaged by compression or liquefaction, transported by trailer or pipeline, stored, and transferred to the end users. The four different styles of plant outputs were estimated: (A) 1 GW of power generation, (B) pressurized hydrogen gas of 625 tons per day, (C) liquid hydrogen of 574 tons per day, and (D) 0.824 GW of electricity plus 100 tons per day of liquid hydrogen. Case (A) is suitable for a largely constant level of power demand as well as a nuclear fission power plant. Case (B) and case (C) are dedicated hydrogen production and these cases are desirable as the infrastructure for the future fuel cell society. Case (D) has the flexibility in plant operation. Electrical power to the grid can be modulated if the excess electricity were used for the hydrogen production, at the constant power generation. This fraction rate of case (D) is appropriate for the levelization between on-peak and off-peak demand. Energy conversion efficiencies of these four cases are also discussed in this paper. (authors)

HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER

Energy Technology Data Exchange (ETDEWEB)

BROWN,LC; BESENBRUCH,GE; LENTSCH,RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

2003-06-01

OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from

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

Science.gov (United States)

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

2014-03-01

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

Hydrogen generation using the modular helium reactor

International Nuclear Information System (INIS)

Richards, M.; Shenoy, A.

2004-01-01

Process heat from a high-temperature nuclear reactor can be used to drive a set of chemical reactions, with the net result of splitting water into hydrogen and oxygen. For example, process heat at temperatures in the range 850 deg.C to 950 deg.C can drive the sulfur-iodine (SI) thermochemical process to produce hydrogen with high efficiency. Electricity can also be used to split water, using conventional, low-temperature electrolysis. An example of a hybrid process is high-temperature electrolysis (HTE), in which process heat is used to generate steam, which is then supplied to an electrolyser to generate hydrogen. In this paper we investigate the coupling of the Modular Helium Reactor (MHR) to the SI process and HTE. These concepts are referred to as the H2-MHR. Optimization of the MHR core design to produce higher coolant outlet temperatures is also discussed. The use of fixed orifices to control the flow distribution is a promising design solution for increasing the coolant outlet temperature without increasing peak fuel temperatures significantly

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

International Nuclear Information System (INIS)

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

2016-01-01

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

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

KAUST Repository

Bi, Lei; Boulfrad, Samir; Traversa, Enrico

2014-01-01

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

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.

Silicon Carbide-Based Hydrogen Gas Sensors for High-Temperature Applications

Directory of Open Access Journals (Sweden)

Sangchoel Kim

2013-10-01

Full Text Available We investigated SiC-based hydrogen gas sensors with metal-insulator-semiconductor (MIS structure for high temperature process monitoring and leak detection applications in fields such as the automotive, chemical and petroleum industries. In this work, a thin tantalum oxide (Ta2O5 layer was exploited with the purpose of sensitivity improvement, because tantalum oxide has good stability at high temperature with high permeability for hydrogen gas. Silicon carbide (SiC was used as a substrate for high-temperature applications. We fabricated Pd/Ta2O5/SiC-based hydrogen gas sensors, and the dependence of their I-V characteristics and capacitance response properties on hydrogen concentrations were analyzed in the temperature range from room temperature to 500 °C. According to the results, our sensor shows promising performance for hydrogen gas detection at high temperatures.

Tritium separation from heavy water using electrolysis

International Nuclear Information System (INIS)

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

2001-01-01

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

Collection of summaries of Sunshine Program achievement reports for fiscal 1982. Hydrogen energy; 1982 nendo sunshine keikaku seika hokokusho gaiyoshu. Suiso energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1983-04-01

The collection includes achievements of research relating to hydrogen energy. In the research on hydrogen production by electrolysis, electrolysis of water using an acid-type solid polymer electrolyte and electrolysis of water using an alkali-type solid polymer electrolyte are taken up. In the research on hydrogen production by thermochemical methods, studies are conducted on the iodine-based cycle, the bromine-based cycle, materials for devices for the iodine-based cycle, and the mixed cycle. Hydrogen production using high-temperature direct thermolysis and solar radiation is also studied. In the research on hydrogen transportation and storage, use of metallic hydrides in these processes are taken up. In the research on the application of hydrogen, techniques of hydrogen combustion and hydrogen-fueled engines are discussed. In the research on hydrogen safety measures, technologies for the prevention of hydrogen explosions and of hydrogen embrittlement of materials in use with hydrogen are studied. In addition, a study is conducted of a hydrogen energy total system, and research and development is carried out for a plant that produces hydrogen by high-temperature high-pressure electrolysis of water. (NEDO)

Development of new electrode materials for hydrogen production by water electrolysis

International Nuclear Information System (INIS)

Rozain, Caroline

2013-01-01

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

Processes of hydrogen production, coupled with nuclear reactors: Economic perspectives

International Nuclear Information System (INIS)

Werkoff, Francois; Avril, Sophie; Mansilla, Christine; Sigurvinsson, Jon

2006-01-01

Hydrogen production, using nuclear power is considered from a technic-economic (TE) point of view. Three different processes are examined: Alkaline electrolysis, High-temperature steam electrolysis (HTE) and the thermochemical Sulphur-Iodine (S/I) cycle. The three processes differ, in the sense that the first one is operational and both last ones are still at demonstration stages. For them, it is at present only possible to identify key points and limits of competitiveness. The cost of producing hydrogen by alkaline electrolysis is analysed. Three major contributions to the production costs are examined: the electricity consumption, the operation and maintenance expenditures and the depreciation capital expenditures. A technic-economic evaluation of hydrogen production by HTE coupled to a high-temperature reactor (HTR) is presented. Key points appear to be the electrolyser and the high temperature heat exchangers. The S/I thermochemical cycle is based on the decomposition and the re-composition of H 2 SO 4 and HI acids. The energy consumption and the recovery of iodine are key points of the S/I cycle. With the hypothesis that the hydrogen energy will progressively replace the fossil fuels, we give a first estimate of the numbers of nuclear reactors (EPR or HTR) that would be needed for a massive nuclear hydrogen production. (authors)

Hydrogen production profiles using furans in microbial electrolysis cells.

Science.gov (United States)

Catal, Tunc; Gover, Tansu; Yaman, Bugra; Droguetti, Jessica; Yilancioglu, Kaan

2017-06-01

Microbial electrochemical cells including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are novel biotechnological tools that can convert organic substances in wastewater or biomass into electricity or hydrogen. Electroactive microbial biofilms used in this technology have ability to transfer electrons from organic compounds to anodes. Evaluation of biofilm formation on anode is crucial for enhancing our understanding of hydrogen generation in terms of substrate utilization by microorganisms. In this study, furfural and hydroxymethylfurfural (HMF) were analyzed for hydrogen generation using single chamber membrane-free MECs (17 mL), and anode biofilms were also examined. MECs were inoculated with mixed bacterial culture enriched using chloroethane sulphonate. Hydrogen was succesfully produced in the presence of HMF, but not furfural. MECs generated similar current densities (5.9 and 6 mA/cm 2 furfural and HMF, respectively). Biofilm samples obtained on the 24th and 40th day of cultivation using aromatic compounds were evaluated by using epi-fluorescent microscope. Our results show a correlation between biofilm density and hydrogen generation in single chamber MECs.

Summary of the FY 1989 Sunshine Project results. Hydrogen energy; 1989 nendo sunshine keikaku seika hokokusho gaiyoshu. Suiso energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-04-01

Outlined herein are the results of researches on hydrogen energy as part of the FY 1989 Sunshine Project results. Researches on the techniques for producing hydrogen by electrolysis of water using a polymer electrolyte include those on the SPE electrolysis at high temperature and current density, and basic studies on the electrolysis using an OH ion conducting type polymer electrolyte. Researches on the techniques for producing hydrogen by electrolysis with hot steam include development of the materials, techniques for processing these materials, and electrolysis performance tests. Researches on the techniques for transporting hydrogen by metal hydrides include development of hydrogen-occluding alloys of high bulk density, and techniques for evaluating characteristics of metal hydrides. Researches on the techniques for storing hydrogen include those on hydrogen-storing metallic materials, alloy molding/processing techniques, and new hydrogen-storing materials. Researches on the techniques for utilizing hydrogen include those on energy conversion techniques using hydrogen-occluding alloys, and hydrogen-fueled motors. Researches on the techniques for safety-related measures include those on prevention of embrittlement of the system materials by hydrogen. (NEDO)

Research Progress of Hydrogen Production fromOrganic Wastes in Microbial Electrolysis Cell(MEC

Directory of Open Access Journals (Sweden)

YU Yin-sheng

2015-08-01

Full Text Available Microbial electrolysis cell(MECtechnology as an emerging technology, has achieved the target of hydrogen production from different substrates such as waste water, forestry wastes, activated sludge by simultaneous enzymolysis and fermentation, which can effectively improve the efficiency of resource utilization. This paper described the working principle of MEC and analyzed these factors influencing the process of hydrogen production from organic waste in MEC.

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

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.

Long-Term Degradation Testing of High-Temperature Electrolytic Cells

International Nuclear Information System (INIS)

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

2009-01-01

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 900 C. 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 ∼m thick yttria-stabilized zirconia (YSZ) electrolytes, ∼1400 (micro)m 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.

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

International Nuclear Information System (INIS)

Millet, P.

2006-01-01

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

Heat transfer problems for the production of hydrogen from geothermal energy

International Nuclear Information System (INIS)

Sigurvinsson, J.; Mansilla, C.; Arnason, B.; Bontemps, A.; Marechal, A.; Sigfusson, T.I.; Werkoff, F.

2006-01-01

Electrolysis at low temperature is currently used to produce Hydrogen. From a thermodynamic point of view, it is possible to improve the performance of electrolysis while functioning at high temperature (high temperature electrolysis: HTE). That makes it possible to reduce energy consumption but requires a part of the energy necessary for the dissociation of water to be in the form of thermal energy. A collaboration between France and Iceland aims at studying and then validating the possibilities of producing hydrogen with HTE coupled with a geothermal source. The influence of the exit temperature on the cost of energy consumption of the drilling well is detailed. To vaporize the water to the electrolyser, it should be possible to use the same technology currently used in the Icelandic geothermal context for producing electricity by using a steam turbine cycle. For heating the steam up to the temperature needed at the entrance of the electrolyser three kinds of heat exchangers could be used, according to specific temperature intervals

Potential for greenhouse gas emission reductions using surplus electricity in hydrogen, methane and methanol production via electrolysis

International Nuclear Information System (INIS)

Uusitalo, Ville; Väisänen, Sanni; Inkeri, Eero; Soukka, Risto

2017-01-01

Highlights: • Greenhouse gas emission reductions using power-to-x processes are studied using life cycle assessment. • Surplus electricity use led to greenhouse gas emission reductions in all studied cases. • Highest reductions can be achieved by using hydrogen to replace fossil based hydrogen. • High reductions are also achieved when fossil transportation fuels are replaced. - Abstract: Using a life cycle perspective, potentials for greenhouse gas emission reductions using various power-to-x processes via electrolysis have been compared. Because of increasing renewable electricity production, occasionally surplus renewable electricity is produced, which leads to situations where the price of electricity approach zero. This surplus electricity can be used in hydrogen, methane and methanol production via electrolysis and other additional processes. Life cycle assessments have been utilized to compare these options in terms of greenhouse gas emission reductions. All of the power-to-x options studied lead to greenhouse gas emission reductions as compared to conventional production processes based on fossil fuels. The highest greenhouse gas emission reductions can be gained when hydrogen from steam reforming is replaced by hydrogen from the power-to-x process. High greenhouse gas emission reductions can also be achieved when power-to-x products are utilized as an energy source for transportation, replacing fossil transportation fuels. A third option with high greenhouse gas emission reduction potential is methane production, storing and electricity conversion in gas engines during peak consumption hours. It is concluded that the power-to-x processes provide a good potential solution for reducing greenhouse gas emissions in various sectors.

High temperature hydrogenation of CaC6

International Nuclear Information System (INIS)

Srinivas, G.; Howard, C.A.; Skipper, N.T.; Bennington, S.M.; Ellerby, M.

2009-01-01

The structure and superconducting properties of high temperature hydrogenated calcium-graphite intercalation compound, CaC 6 have been investigated using room temperature X-ray diffraction, and temperature and field dependence of magnetisation. It is found that the hydrogenation can only decompose the CaC 6 phase, and generate a mixture of CaH 2 and graphite as the final compound. The hydrogenation of CaC 6 also reveals a degradation of its superconducting properties. The experimental results are discussed in detail and it is found that the formation of stable CaH 2 and deintercalation are the main source for observed phase separation and suppression in superconductivity.

High temperature equation of state of metallic hydrogen

International Nuclear Information System (INIS)

Shvets, V. T.

2007-01-01

The equation of state of liquid metallic hydrogen is solved numerically. Investigations are carried out at temperatures from 3000 to 20 000 K and densities from 0.2 to 3 mol/cm 3 , which correspond both to the experimental conditions under which metallic hydrogen is produced on earth and the conditions in the cores of giant planets of the solar system such as Jupiter and Saturn. It is assumed that hydrogen is in an atomic state and all its electrons are collectivized. Perturbation theory in the electron-proton interaction is applied to determine the thermodynamic potentials of metallic hydrogen. The electron subsystem is considered in the randomphase approximation with regard to the exchange interaction and the correlation of electrons in the local-field approximation. The proton-proton interaction is taken into account in the hard-spheres approximation. The thermodynamic characteristics of metallic hydrogen are calculated with regard to the zero-, second-, and third-order perturbation theory terms. The third-order term proves to be rather essential at moderately high temperatures and densities, although it is much smaller than the second-order term. The thermodynamic potentials of metallic hydrogen are monotonically increasing functions of density and temperature. The values of pressure for the temperatures and pressures that are characteristic of the conditions under which metallic hydrogen is produced on earth coincide with the corresponding values reported by the discoverers of metallic hydrogen to a high degree of accuracy. The temperature and density ranges are found in which there exists a liquid phase of metallic hydrogen

Thermodynamic Analysis of Three Compressed Air Energy Storage Systems: Conventional, Adiabatic, and Hydrogen-Fueled

Directory of Open Access Journals (Sweden)

Hossein Safaei

2017-07-01

Full Text Available We present analyses of three families of compressed air energy storage (CAES systems: conventional CAES, in which the heat released during air compression is not stored and natural gas is combusted to provide heat during discharge; adiabatic CAES, in which the compression heat is stored; and CAES in which the compression heat is used to assist water electrolysis for hydrogen storage. The latter two methods involve no fossil fuel combustion. We modeled both a low-temperature and a high-temperature electrolysis process for hydrogen production. Adiabatic CAES (A-CAES with physical storage of heat is the most efficient option with an exergy efficiency of 69.5% for energy storage. The exergy efficiency of the conventional CAES system is estimated to be 54.3%. Both high-temperature and low-temperature electrolysis CAES systems result in similar exergy efficiencies (35.6% and 34.2%, partly due to low efficiency of the electrolyzer cell. CAES with high-temperature electrolysis has the highest energy storage density (7.9 kWh per m3 of air storage volume, followed by A-CAES (5.2 kWh/m3. Conventional CAES and CAES with low-temperature electrolysis have similar energy densities of 3.1 kWh/m3.

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

KAUST Repository

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

2012-01-01

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

Repression of hydrogen uptake using conjugated oligoelectrolytes in microbial electrolysis cells

KAUST Repository

Hou, Huijie

2014-11-01

Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. DSBN+, a conjugated oligoelectrolyte (COE), was added to microbial electrolysis cells (MECs) to improve hydrogen recovery. The volume of hydrogen gas recovered in a fedbatch cycle of mixed culture MECs increased by 126× compared to controls (no COE addition), mainly by preventing the loss of hydrogen to methane production. Performance in pure culture MECs fed with Geobacter sulfurreducens increased by factors of 10.5 in terms of energy yield, 2.1 in COD removal, and 11.8 in hydrogen yield. Hydrogen gas recycling was reduced, and the volume of hydrogen gas recovered increased by 6.5× compared to controls. Minimal methane production and a lack of hydrogen gas uptake by G. sulfurreducens suggested that the COEs increased hydrogen recoveries by interfering with hydrogen uptake by hydrogenotrophic methanogens but also by exoelectrogenic bacteria. COEs may therefore be useful for inhibiting the activities of certain hydrogenases, although the mechanism of inhibition needs further investigation.

Repression of hydrogen uptake using conjugated oligoelectrolytes in microbial electrolysis cells

KAUST Repository

Hou, Huijie; Chen, Xiaofen; Liu, Jia; Zhu, Xiuping; Bazan, Guillermo C.; Logan, Bruce E.

2014-01-01

Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. DSBN+, a conjugated oligoelectrolyte (COE), was added to microbial electrolysis cells (MECs) to improve hydrogen recovery. The volume of hydrogen gas recovered in a fedbatch cycle of mixed culture MECs increased by 126× compared to controls (no COE addition), mainly by preventing the loss of hydrogen to methane production. Performance in pure culture MECs fed with Geobacter sulfurreducens increased by factors of 10.5 in terms of energy yield, 2.1 in COD removal, and 11.8 in hydrogen yield. Hydrogen gas recycling was reduced, and the volume of hydrogen gas recovered increased by 6.5× compared to controls. Minimal methane production and a lack of hydrogen gas uptake by G. sulfurreducens suggested that the COEs increased hydrogen recoveries by interfering with hydrogen uptake by hydrogenotrophic methanogens but also by exoelectrogenic bacteria. COEs may therefore be useful for inhibiting the activities of certain hydrogenases, although the mechanism of inhibition needs further investigation.

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

DEFF Research Database (Denmark)

Zhang, Yifeng; Angelidaki, Irini

2014-01-01

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

Nickel-based electrodeposits as potential cathode catalysts for hydrogen production by microbial electrolysis

Science.gov (United States)

Mitov, M.; Chorbadzhiyska, E.; Nalbandian, L.; Hubenova, Y.

2017-07-01

The development of cost-effective cathodes, operating at neutral pH and ambient temperatures, is a crucial challenge for the practical application of microbial electrolysis cell (MEC) technology. In this study, NiW and NiMo co-deposits produced by electroplating on Ni-foam are explored as cathodes in MEC. The fabricated electrodes exhibit higher corrosion stability and enhanced electrocatalytic activity towards hydrogen evolution reaction in neutral electrolyte compared to the bare Ni-foam. NiW/Ni-foam electrodes possess six times higher intrinsic catalytic activity, estimated from data obtained by linear voltammetry and chronoamperometry. The newly developed electrodes are applied as cathodes in single-chamber membrane-free MEC reactors, inoculated with wastewater and activated sludge from a municipal wastewater treatment plant. Cathodic hydrogen recovery of 79% and 89% by using NiW and NiMo cathodes, respectively, is achieved at applied voltage of 0.6 V. The obtained results reveal potential for practical application of used catalysts in MEC.

Sustainable hydrogen production

Energy Technology Data Exchange (ETDEWEB)

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

1996-01-01

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

Fusion Energy for Hydrogen Production

Energy Technology Data Exchange (ETDEWEB)

Fillo, J. A.; Powell, J. R.; Steinberg, M.; Salzano, F.; Benenati, R.; Dang, V.; Fogelson, S.; Isaacs, H.; Kouts, H.; Kushner, M.; Lazareth, O.; Majeski, S.; Makowitz, H.; Sheehan, T. V.

1978-09-01

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

Hydrogen production with effluent from an ethanol–H2-coproducing fermentation reactor using a single-chamber microbial electrolysis cell

KAUST Repository

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

2009-01-01

Hydrogen can be produced by bacterial fermentation of sugars, but substrate conversion to hydrogen is incomplete. Using a single-chamber microbial electrolysis cell (MEC), we show that additional hydrogen can be produced from the effluent

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.

Solid oxide electrolysis cell for decomposition of tritiated water

International Nuclear Information System (INIS)

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

1984-01-01

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

Research on hydrogen production system

International Nuclear Information System (INIS)

Nakagiri, Toshio

2002-07-01

Hydrogen is closely watched for environmental issues in recent years. In this research, hydrogen production systems and production techniques are widely investigated, and selected some hydrogen production process which have high validity for FBR system. Conclusions of the investigation are shown below. (1) Water-electrolysis processes and steam reform processes at low temperatures are already realized in other fields, so they well be easily adopted for FBR system. FBR system has no advantage when compared with other systems, because water-electrolysis processes can be adopted for other electricity generation system. On the other hand, FBR system has an advantage when steam reforming processes at low temperatures will be adopted, because steam reforming processes at 550-600degC can't be adopted for LWR. (2) Thermochemical processes will be able to adopted for FBR when process temperature will be lowered and material problems solved, because their efficiencies are expected high. Radiolysis processes which use ray (for example, gamma rya) emitted in reactor can be generate hydrogen easily, so they will be able to be adopted for FBR if splitting efficiency will be higher. Further investigation and R and D to realize these processes are considered necessary. (author)

Fiscal 1975 Sunshine Project research report. General research on hydrogen energy subsystems and their peripheral technologies (Research on peripheral technologies around hydrogen); 1975 nendo suiso riyo subsystem no sogoteki kento to shuhen gijutsu ni kansuru kenkyu seika hokokusho. Suiso no shuhen gijutsu ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-03-01

This report summarizes the fiscal 1975 research result on peripheral and seed technologies for hydrogen energy systems. Chapter 1 'Evaluation method for thermochemical techniques' reports critical study on qualitative evaluation method, estimation method for thermal efficiencies, and trial cost calculation example. Chapter 2 'Current state and problems of water electrolysis and hybrid technique composed of electrolysis and thermochemical technique' reports general survey on current water electrolysis and new technologies under development to clarify possible electrolytic voltage drop, from the practical viewpoint. Chapter 3 'Use of a high- temperature gas cooling reactor for hydrogen production' reports survey on the current and future reactors, and characteristics of such nuclear reactors, from the viewpoint that study on thermochemical technique is dependent on use of a high-temperature gas cooling reactor. Chapter 4 'Hydrogen transport and storage technology using organic compounds including oxygen' reports that acetone-isopropanol system is better for hydrogen storage. Chapter 5 'Water electrolysis using photo-semiconducting electrode' reports the additional survey. (NEDO)

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.

Direct LiT Electrolysis in a Metallic Fusion Blanket

International Nuclear Information System (INIS)

Olson, Luke

2016-01-01

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

Collection of summaries of Sunshine Program achievement reports for fiscal 1981. Hydrogen energy; 1981 nendo sunshine keikaku seika hokokusho gaiyoshu. Suuiso energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1982-04-01

The collection includes research on hydrogen production through the electrolysis of water using an acid-type solid polymer electrolyte, electrolysis of water using an alkali-type solid polymer electrolyte, thermochemical method using an iodine-based cycle, thermochemical method using a bromine-based cycle, thermochemical method using a mixed cycle, high-temperature direct thermolysis, and the utilization of solar radiation. Furthermore, it includes a study of materials to build a iodine-based cycle apparatus. In a research on the transportation and storage of hydrogen, technologies of hydrogen transportation and storage using metallic hydrides are taken up. In a research on the application of hydrogen, technologies of hydrogen combustion and hydrogen-fueled engines are discussed. In a research on hydrogen safety measures, technologies for the prevention of hydrogen explosion disasters and of hydrogen embrittlement of materials in use with hydrogen are studied. In addition, a study is conducted of a hydrogen energy total system, and research and development is carried out of a plant that produces hydrogen by means of the high-temperature high-pressure electrolysis of water. (NEDO)

Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell

KAUST Repository

Wang, Aijie; Sun, Dan; Cao, Guangli; Wang, Haoyu; Ren, Nanqi; Wu, Wei-Min; Logan, Bruce E.

2011-01-01

Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs

Nuclear energy for sustainable Hydrogen production

International Nuclear Information System (INIS)

Gyoshev, G.

2004-01-01

There is general agreement that hydrogen as an universal energy carrier could play increasingly important role in energy future as part of a set of solutions to a variety of energy and environmental problems. Given its abundant nature, hydrogen has been an important raw material in the organic chemical industry. At recent years strong competition has emerged between nations as diverse as the U.S., Japan, Germany, China and Iceland in the race to commercialize hydrogen energy vehicles in the beginning of 21st Century. Any form of energy - fossil, renewable or nuclear - can be used to generate hydrogen. The hydrogen production by nuclear electricity is considered as a sustainable method. By our presentation we are trying to evaluate possibilities for sustainable hydrogen production by nuclear energy at near, medium and long term on EC strategic documents basis. The main EC documents enter water electrolysis by nuclear electricity as only sustainable technology for hydrogen production in early stage of hydrogen economy. In long term as sustainable method is considered the splitting of water by thermochemical technology using heat from high temperature reactors too. We consider that at medium stage of hydrogen economy it is possible to optimize the sustainable hydrogen production by high temperature and high pressure water electrolysis by using a nuclear-solar energy system. (author)

Solid oxide electrolysis cell for decomposition of tritiated water

International Nuclear Information System (INIS)

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

1986-01-01

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

The impact of anode acclimation strategy on microbial electrolysis cell treating hydrogen fermentation effluent

DEFF Research Database (Denmark)

Li, Xiaohu; Zhang, Ruizhe; Qian, Yawei

2017-01-01

The impact of different anode acclimation methods for enhancing hydrogen production in microbial electrolysis cell (MEC) was investigated in this study. The anodes were first acclimated in microbial fuel cells using acetate, butyrate and corn stalk fermentation effluent (CSFE) as substrate before...

Nuclear hydrogen - possibilities for Brazil; Hidrogenio nuclear - possibilidades para o Brasil

Energy Technology Data Exchange (ETDEWEB)

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

2008-07-01

The energy vector hydrogen represents a good possibility to replace fossil fuels. One of the main renewable sources of interest for hydrogen is water, which is abundant and can be decomposed directly into pure H{sub 2} and O{sub 2}. This water splitting can be performed by the following methods: electrolysis, thermal decomposition, and thermochemical cycles. The thermochemical cycles and high temperature electrolysis (HTE) are often thought to be feasible methods to be associated with a High Temperature Gas cooled Reactor (HTGR). Both routines have high efficiency at temperature range of 700-950 deg C. In this work, is presented an attainable proposal for Brazilian production of hydrogen based on a HTGR followed by HTE system. A research group at Fuel Cell and Hydrogen Center - CCCH at IPEN/CNEN-SP has elaborated a working plan for 10 years, where it is proposed a R and D line for hydrogen production based on nuclear energy supplied by HTGR. So, in this work, a Brazilian program for researching in this area is proposed inviting potential cooperation. (author)

18th world hydrogen energy conference 2010. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

This CD-ROM contains lectures, power points slides and posters presented on the 18th World Hydrogen Energy Conference. The topics of the conference are: (A). Fuel Cell Basics: 1. Electrochemistry of PEM Fuell Cells; 2. PEM/HT-PEM Fuel Cells: Electrolytes, Stack Components; 3. Direct Fuel Cells; 4. High-Temperature Fuel Cells; 5. Advanced Modelling (B). Existing and Emerging Markets: 1. Off-Grid Power Supply and Premium Power Generation; 2. Space and Aeronautic Applications; 3. APUs for LDV, Trucks, Ships and Airplanes; 4. Portable Applications and Light Traction. (C). Stationary Applications: 1. High-Temperature Fuel Cells; 2. Fuell Cells for Buildings. (D). Transportation Applications: 1. Fuel-Cell Power Trains; 3. Hydrogen Internal Combustion Engines; 4. Systems Analysis and Well-to-Wheel Studies; 5. Demonstration Projects, Costs and Market Introduction; 6 Electrification in Transportation Systems. (E). Fuel Infrastructures: 1. Hydrogen Distribution Technologies; 2. Hydrogen Deployment; 3. Fuel Provision for Early Market Applications. (G). Hydrogen Production Technologies: 1a. Photobiological Hydrogen Production; 1b. Fermentative Hydrogen Production; 1c. The HYVOLUTION Project. (H). Thermochemical Cycles: 3a. Hydrogen from Renewable Electricity; 3b. High-Temperature Electrolysis; 3c Alcaline Electrolysis; 3d PEM Electrolysis; 4a Reforming and Gasification-Fossil Energy Carriers; 4b Reforming and Gasification-Biomass; 5. Hydrogen-Separation Membranes; 6. Hydrogen Systems Assessment;.7. Photocatalysis (I). Storages: 1. Physical Hydrogen Storage; 2a. Metal Hydrides; 2b. Complex Hydrides; 3. Adsorption Technologies; (J). Strategic Analyses: 1. Research + Development Target and Priorities; 2. Life-Cycle Assessment and Economic Impact; 3. Socio-Economic Studies; 4. Education and Public Awareness; 5. Market Introduction; 7. Regional Activities; 8. The Zero Regio Project. (K). Safety Issues: 1. Vehicle and Infrastructural Safety; 2. Regulations, Codes, Standards and Test

18th world hydrogen energy conference 2010. Proceedings

International Nuclear Information System (INIS)

2010-01-01

This CD-ROM contains lectures, power points slides and posters presented on the 18th World Hydrogen Energy Conference. The topics of the conference are: (A). Fuel Cell Basics: 1. Electrochemistry of PEM Fuell Cells; 2. PEM/HT-PEM Fuel Cells: Electrolytes, Stack Components; 3. Direct Fuel Cells; 4. High-Temperature Fuel Cells; 5. Advanced Modelling (B). Existing and Emerging Markets: 1. Off-Grid Power Supply and Premium Power Generation; 2. Space and Aeronautic Applications; 3. APUs for LDV, Trucks, Ships and Airplanes; 4. Portable Applications and Light Traction. (C). Stationary Applications: 1. High-Temperature Fuel Cells; 2. Fuell Cells for Buildings. (D). Transportation Applications: 1. Fuel-Cell Power Trains; 3. Hydrogen Internal Combustion Engines; 4. Systems Analysis and Well-to-Wheel Studies; 5. Demonstration Projects, Costs and Market Introduction; 6 Electrification in Transportation Systems. (E). Fuel Infrastructures: 1. Hydrogen Distribution Technologies; 2. Hydrogen Deployment; 3. Fuel Provision for Early Market Applications. (G). Hydrogen Production Technologies: 1a. Photobiological Hydrogen Production; 1b. Fermentative Hydrogen Production; 1c. The HYVOLUTION Project. (H). Thermochemical Cycles: 3a. Hydrogen from Renewable Electricity; 3b. High-Temperature Electrolysis; 3c Alcaline Electrolysis; 3d PEM Electrolysis; 4a Reforming and Gasification-Fossil Energy Carriers; 4b Reforming and Gasification-Biomass; 5. Hydrogen-Separation Membranes; 6. Hydrogen Systems Assessment;.7. Photocatalysis (I). Storages: 1. Physical Hydrogen Storage; 2a. Metal Hydrides; 2b. Complex Hydrides; 3. Adsorption Technologies; (J). Strategic Analyses: 1. Research + Development Target and Priorities; 2. Life-Cycle Assessment and Economic Impact; 3. Socio-Economic Studies; 4. Education and Public Awareness; 5. Market Introduction; 7. Regional Activities; 8. The Zero Regio Project. (K). Safety Issues: 1. Vehicle and Infrastructural Safety; 2. Regulations, Codes, Standards and Test

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)

HYFIRE II: fusion/high-temperature electrolysis conceptual-design study. Annual report

International Nuclear Information System (INIS)

Fillo, J.A.

1983-08-01

As in the previous HYFIRE design study, the current study focuses on coupling a Tokamak fusion reactor with a high-temperature blanket to a High-Temperature Electrolyzer (HTE) process to produce hydrogen and oxygen. Scaling of the STARFIRE reactor to allow a blanket power to 6000 MW(th) is also assumed. The primary difference between the two studies is the maximum inlet steam temperature to the electrolyzer. This temperature is decreased from approx. 1300 0 to approx. 1150 0 C, which is closer to the maximum projected temperature of the Westinghouse fuel cell design. The process flow conditions change but the basic design philosophy and approaches to process design remain the same as before. Westinghouse assisted in the study in the areas of systems design integration, plasma engineering, balance-of-plant design, and electrolyzer technology

A comprehensive review of microbial electrolysis cells (MEC reactor designs and configurations for sustainable hydrogen gas production

Directory of Open Access Journals (Sweden)

Abudukeremu Kadier

2016-03-01

Full Text Available Hydrogen gas has tremendous potential as an environmentally acceptable energy carrier for vehicles. A cutting edge technology called a microbial electrolysis cell (MEC can achieve sustainable and clean hydrogen production from a wide range of renewable biomass and wastewaters. Enhancing the hydrogen production rate and lowering the energy input are the main challenges of MEC technology. MEC reactor design is one of the crucial factors which directly influence on hydrogen and current production rate in MECs. The rector design is also a key factor to up-scaling. Traditional MEC designs incorporated membranes, but it was recently shown that membrane-free designs can lead to both high hydrogen recoveries and production rates. Since then multiple studies have developed reactors that operate without membranes. This review provides a brief overview of recent advances in research on scalable MEC reactor design and configurations.

Electrolysis test of different composite membranes at elevated temperatures

DEFF Research Database (Denmark)

Hansen, Martin Kalmar

temperatures, phosphoric acid (H3PO4)[1] and zirconium phosphate (ZrP)[2] were introduced. These composite membranes were tested in an electrolysis setup. A typical electrolysis test was performed at 130°C with a galvanostatic load. Polarization curves were recorded under stationary conditions. Testing...... night at 150°C in a zirconium phosphate saturated 85wt% phosphoric acid solution. Different thicknesses of membranes were tested and as expected, the performance increased when the thickness of the membranes decreased. Furthermore composite membranes only treated with phosphoric acid or only treated...

Fiscal 1976 Sunshine Project research report. Interim report (hydrogen energy); 1976 nendo chukan hokokushoshu. Suiso energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-11-01

This report summarizes the Sunshine Project research interim reports on hydrogen energy of every organizations. The report includes research items, laboratories, institutes and enterprises concerned, research targets, research plans, and progress conditions. The research items are as follows. (1) Hydrogen production technology (electrolysis, high- temperature high-pressure water electrolysis, 4 kinds of thermochemical techniques, direct thermolysis). (2) Hydrogen transport and storage technology (2 kinds of solidification techniques). (3) Hydrogen use technology (combustion technology, fuel cell, solid electrolyte fuel cell, fuel cell power system, hydrogen fuel engine). (4) Hydrogen safety measures technology (disaster preventive technology for gaseous and liquid hydrogen, preventing materials from embrittlement due to hydrogen, hydrogen refining, transport and storage systems, their safety technology). (5) Hydrogen energy system (hydrogen energy system, hydrogen use subsystems, peripheral technologies). (NEDO)

Hydrogen - A new green energy

International Nuclear Information System (INIS)

Barnu, Franck

2013-01-01

A set of articles proposes an overview of the role hydrogen might have as energy in the energy transition policy, a review of different areas of research related to the hydrogen sector, and presentations of some remarkable innovations in different specific fields. Hydrogen might be an asset in energy transition because production modes (like electrolysis) result in an almost carbon-free or at least low-carbon hydrogen production. Challenges and perspectives are evoked: energy storage for intermittent energies (the MYRTE platform), the use of a hydrogen-natural mix (GRHYD program), the development of fuel cells for transport applications, and co-generation (Japan is the leader). Different French research organisations are working on different aspects and areas: the H2E program by Air Liquide, fuel cell technologies by GDF Suez, power electrolyzers and cells by Areva. Some aspects and research areas are more specifically detailed: high temperature electrolysis (higher efficiencies, synthesis of methane from hydrogen), fuel cells (using less platinum, and using ceramics for high temperatures), the perspective of solid storage solutions (hydrogen bottles in composite materials, development of 'hydrogen sponges', search for new hydrides). Innovations concern a project car, storage and production (Greenergy Box), the McPhy Energy storage system, an electric bicycle with fuel cell, easy to transport storage means by Air Liquide and Composites Aquitaine, development of energy autonomy, fuel cells for cars, electrolyzers using the Proton Exchange Membrane or PEM technology

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

Science.gov (United States)

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

2018-03-05

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

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

International Nuclear Information System (INIS)

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

2002-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-07-01

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

Improving The Efficiency Of Ammonia Electrolysis For Hydrogen Production

Science.gov (United States)

Palaniappan, Ramasamy

Given the abundance of ammonia in domestic and industrial wastes, ammonia electrolysis is a promising technology for remediation and distributed power generation in a clean and safe manner. Efficiency has been identified as one of the key issues that require improvement in order for the technology to enter the market phase. Therefore, this research was performed with the aim of improving the efficiency of hydrogen production by finding alternative materials for the cathode and electrolyte. 1. In the presence of ammonia the activity for hydrogen evolution reaction (HER) followed the trend Rh>Pt>Ru>Ni. The addition of ammonia resulted in lower rates for HER for Pt, Ru, and Ni, which have been attributed to competition from the ammonia adsorption reaction. 2. The addition of ammonia offers insight into the role of metal-hydrogen underpotential deposition (M-Hupd) on HER kinetics. In addition to offering competition via ammonia adsorption it resulted in fewer and weaker M-Hupd bonds for all metals. This finding substantiates the theory that M-Hupd bonds favor HER on Pt electrocatalyst. However, for Rh results suggest that M-Hupd bond may hinder the HER. In addition, the presence of unpaired valence shell electrons is suggested to provide higher activity for HER in the presence of ammonia. 3. Bimetals PtxM1-x (M = Ir, Ru, Rh, and Ni) offered lower overpotentials for HER compared to the unalloyed metals in the presence of ammonia. The activity of HER in the presence of ammonia follows the trend Pt-Ir>Pt-Rh>Pt-Ru>Pt-Ni. The higher activity of HER is attributed to the synergistic effect of the alloy, where ammonia adsorbs onto the more electropositive alloying metal leaving Pt available for Hupd formation and HER to take place. Additionally, this supports the theory that the presence of a higher number of unpaired electrons favors the HER in the presence of ammonia. 4. Potassium polyacrylate (PAA-K) was successfully used as a substitute for aqueous KOH for ammonia

Clean hydrogen generation through the electrocatalytic oxidation of ethanol in a Proton Exchange Membrane Electrolysis Cell (PEMEC): Effect of the nature and structure of the catalytic anode

Science.gov (United States)

Lamy, Claude; Jaubert, Thomas; Baranton, Stève; Coutanceau, Christophe

2014-01-01

The electrocatalytic oxidation of ethanol was investigated in a Proton Exchange Membrane Electrolysis Cell (PEMEC) working at low temperature (20°C) on several Pt-based catalysts (Pt/C, PtSn/C, PtSnRu/C) in order to produce very clean hydrogen by electrolysis of a biomass compound. The electrocatalytic activity was determined by cyclic voltammetry and the rate of hydrogen evolution was measured for each catalyst at different current densities. The cell voltages UEtOH were recorded as a function of time for each current density. At 100 mA cm-2, i.e. 0.5 A with the 5 cm2 surface area PEMEC used, the cell voltage did not exceed 0.9 V for an evolution rate of about 220 cm3 of hydrogen per hour and the electrical energy consumed was less than 2.3 kWh (Nm3)-1, i.e. less than one half of the energy needed for water electrolysis (4.7 kWh (Nm3)-1 at UH2O = 2 V). This result is valid for the decomposition of any organic compound, particularly those originated from biomass resource, provided that their electro-oxidation rate is sufficient (>100 mA cm-2) at a relatively low cell voltage (Ucell < 1 V) which necessitates the development of efficient electrocatalysts for the electrochemical decomposition of this compound.

Japan's Sunshine Project. 1991 Annual Summary of Hydrogen Energy R and D

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-07-01

In the study of hydrogen production, tests and experiments were conducted concerning electrolysis of water in solid polymer electrolytes and electrolysis of high-temperature steam. In the study of hydrogen storage and transportation, use of metal hydrides for these purposes was tested with attention paid to CaNi{sub 5} degradation and metal element substitution in ZrMn{sub 2}. In the study of hydrogen application, electrodes in hydrogen storage alloy-aided energy conversion were investigated and hydrogen-oxygen combustion systems were experimented. In the study of hydrogen safety, a fracture in a heat affected weld and fatigue crack propagation therein were simulated, and the effect of hydrogen on the episode was investigated. Investigated in the study of a hydrogen-fired turbine were hydrogen combustion, hydrogen-fired power generation thermal efficiency, fuel cost, power generation cost, etc. (NEDO)

Ni-Zn electrodes for hydrogen production by acid electrolysis; Eletrodos de Ni-Zn para producao de hidrogenio por eletrolise acida

Energy Technology Data Exchange (ETDEWEB)

Torres, C.S.; Malfatti, C.F., E-mail: camilator@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre (Brazil). Departamento de Metalurgia. Lab. de Pesquisa em Corrosao

2014-07-01

Hydrogen production by electrolysis of water, have an important role in countries that have great renewable potential for electricity production. The electrolysis of water has been proposed to use the excess capacity of hydroelectric plants. However, to improve process efficiency, research has been undertaken to improve the catalytic reduction reaction of hydrogen from the development of electrodes with better performance. Thus, the selection of low cost electrode materials with good electrocatalytic activity is required. In this work, the hydrogen evolution reaction (HER) employing electrodes of Ni-Zn and Ni was investigated. Morphological characterization of the electrodes was performed using SEM/ EDX and profilometry and electrochemical behavior was evaluated by cathodic polarization curves. The results showed that the addition of Zn promotes the increase the electrocatalytic activity of HER compared to nickel electrode. (author)

Electrolysis apparatus and method

International Nuclear Information System (INIS)

1975-01-01

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

Reversibility of the SOFC for the hydrogen production by high temperature electrolysis; Reversibilite des SOFC pour la production d'hydrogene par electrolyse haute temperature

Energy Technology Data Exchange (ETDEWEB)

Brisse, A.; Marrony, M.; Perednis, D.; Schefold, J.; Jose-Garcia, M.; Zahid, M. [Institut Europeen de Recherche sur l' Energie (EIFER), Karlsruhe (Germany)

2007-07-01

The behaviour of two SOFC cells in electrolysis mode is studied. The performances of these solid oxide cells, reversible at 800 C and for current densities between 0 and -0.42 A/cm{sup 2}, are presented. A weaker polarisation resistance has been measured for the cell containing a mixed conductor as oxygen electrode. For each cell, a limitation by gaseous diffusion has been observed under current. This phenomenon appears for current densities which are higher for the mixed conductor cell as oxygen electrode. (O.M.)

Japan sunshine project 1987 annual summary of Hydrogen energy R and D

Science.gov (United States)

1988-04-01

This paper presents the findings of the researches on hydrogen energy in sunshine project in FY87. A duration test of the electrolyte membrane of solid polymer fabricated by bonding Pt and Ir catalyst layers was made for seven months to produce hydrogen by the electrolysis of water. The result indicates that the electrolysis will be able to be made at high current density. The sensitivity to stress corrosion cracking of stainless steel for electrolysis of water was evaluated. Since a thin film of stabilized zirconia fabricated by sintering at a temperature of 1500 C or higher is dense and conductive, it is a promising solid electrolyte. Since an inert phase to hydrogen is developed in a high-density metallic alloy for hydrogen storage produced by sintering and partially melting Mg7Zn3-Ni, it must be improved. A heating module of hydrogenated material monolithically coated on copper tube was investigated. The application of metallic alloy for hydrogen storage to the hydrogen electrode is studied. A hydrogen-fueled prime mover system circulating an inert gas is being developed. Since the low alloy steel part is extremely embrittled by heating, the intergranular face of coarse crystal affected by the cycle of welding heat is a problem.

Intermediate Temperature Steam Electrolysis with Phosphate-Based Electrolytes

DEFF Research Database (Denmark)

Prag, Carsten Brorson

as the technological issues and challenges faced. A setup suitable for intermediate temperature electrolysis has been constructed in order to accommodate testing in the IT region. This included the evaluation of multiple generations of components such as end plates and flow plates. Chemical vapour deposition...... 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...

Technology selection for hydrogen production using nuclear energy

International Nuclear Information System (INIS)

Siti Alimah; Erlan Dewita

2008-01-01

The NPP can either be used to produce electricity, or as heat source for non-electric applications (cogeneration). High Temperature Reactor (HTR) with high outlet coolant temperature around 900~1000 o C, is a reactor type potential for cogeneration purposes such as hydrogen production and other chemical industry processes that need high heat. Considering the national energy policy that a balanced arrangement of renewable and unrenewable natural resources has to be made to keep environmental conservation for the sake of society prosperity in the future, hydrogen gas production using nuclear heat is an appropriate choice. Hydrogen gas is a new energy which is environmentally friendly that it is a prospecting alternative energy source in the future. Within the study, a comparison of three processes of hydrogen gas production covering electrolysis, steam reforming and sulfur-iodine cycle, have been conducted. The parameters that considered are the production cost, capital cost and energy cost, technological status, the independence of fossil fuel, the environmental friendly aspect, as well as the efficiency and the independence of corrosion-resistance material. The study result showed that hydrogen gas production by steam reforming is a better process compared to electrolysis and sulfur-iodine process. Therefore, steam reforming process can be a good choice for hydrogen gas production using nuclear energy in Indonesia. (author)

A microbial fluidized electrode electrolysis cell (MFEEC) for enhanced hydrogen production

KAUST Repository

Liu, Jia

2014-12-01

A microbial fluidized electrode electrolysis cell (MFEEC) was used to enhance hydrogen gas production from dissolved organic matter. Flowable granular activated carbon (GAC) particles were used to provide additional surface area for growth of exoelectrogenic bacteria. The use of this exoelectrogenic biofilm on the GAC particles with fluidization produced higher current densities and hydrogen gas recoveries than controls (no recirculation or no GAC), due to intermittent contact of the capacitive particles with the anode. The total cumulative charge of 1688C m-2 with the MFEEC reactor (a recirculation flow rate of 19 mL min-1) was 20% higher than that of the control reactor (no GAC). The highest hydrogen gas yield of 0.82 ± 0.01 mol-H2/mol-acetate (17 mL min-1) was 39% higher than that obtained without recirculation (0.59 ± 0.01 mol-H 2/mol-acetate), and 116% higher than that of the control (no GAC, without recirculation). These results show that flowable GAC particles provide a useful approach for enhancing hydrogen gas production in bioelectrochemical systems. © 2014 Elsevier B.V. All rights reserved.

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

Fiscal 1999 hydrogen utilization international clean energy system technology (WE-NET). Phase 2 R and D (Task 8) - development of hydrogen production technology; 1999 nendo suiso riyo kokusai clean energy system gijutsu (WE-NET) dainiki kenkyu kaihatsu. Task 8. Suiso seizo gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

R and D was conducted with the view of establishing hydrogen production technology based on the solid high polymer electrolyte water electrolysis method, which presumably offers higher efficiency and lower cost than conventional methods. This year, as well as implementing development of large-scale cell lamination (electrode area 2,500 cm{sup 2}, 10 cells) by using two hydrogen production methods (electroless plating method and hot press method), work was started for developing cells (electrode area 1,000 cm{sup 2}) for hydrogen stations. In the research on longterm durability improvement, with a 50 cm{sup 2} membrane electrolyte or cell, the evaluation test results were obtained of stable electrolytic performance showing more than 93% energy efficiency after 400 hour operation, under the conditions with electrolysis pressure 0.4MPa and electrolysis temperature 120 degree C. In a test of 1,000 cm{sup 2} prototype cell for hydrogen stations, the evaluation result was obtained for energy efficiency of 92% under the conditions with electrolysis pressure 0.5MPa and electrolysis temperature 120 degree C; thus, this year's target efficiency of over 90% was achieved. Further, enhancement of the quality was contrived for example by improving the electroless plating method and remodeling a roll press machine. (NEDO)

High-temperature effect of hydrogen on sintered alpha-silicon carbide

Science.gov (United States)

Hallum, G. W.; Herbell, T. P.

1986-01-01

Sintered alpha-silicon carbide was exposed to pure, dry hydrogen at high temperatures for times up to 500 hr. Weight loss and corrosion were seen after 50 hr at temperatures as low as 1000 C. Corrosion of SiC by hydrogen produced grain boundary deterioration at 1100 C and a mixture of grain and grain boundary deterioration at 1300 C. Statistically significant strength reductions were seen in samples exposed to hydrogen for times greater than 50 hr and temperatures above 1100 C. Critical fracture origins were identified by fractography as either general grain boundary corrision at 1100 C or as corrosion pits at 1300 C. A maximum strength decrease of approximately 33 percent was seen at 1100 and 1300 C after 500 hr exposure to hydrogen. A computer assisted thermodynamic program was also used to predict possible reaction species of SiC and hydrogen.

Stability analysis of high temperature superconducting coil in liquid hydrogen

International Nuclear Information System (INIS)

Nakayama, T.; Yagai, T.; Tsuda, M.; Hamajima, T.

2007-01-01

Recently, it is expected that hydrogen plays an important role in energy source including electric power in near future. Liquid hydrogen has high potential for cooling down superconducting coil wound with high temperature superconductors (HTS), such as BSCCO, YBCO. In this paper, we study stabilities of the coils wound with BSCCO tapes, which are immersed in the liquid hydrogen, and compare stability results with those cooled by liquid helium. We treat a minimum propagation zone (MPZ) theory to evaluate the coil stability considering boiling heat flux of the liquid hydrogen, and specific heat, heat conduction and resistivity of HTS materials as a function of temperature. It is found that the coil cooled by the liquid hydrogen has higher stability margin than that cooled by the liquid helium. We compare the stability margins of both coils wound with Bi-2223/Ag tape and Bi-2212/Ag tape in liquid hydrogen. As a result, it is found that the stability of Bi-2212 coil is equivalent to that of Bi-2223 coil in low and high magnetic field, while the maximum current of Bi-2212 coil exceeds a little bit that of Bi-2223 coil in both magnetic fields

Hydrogenation and high temperature oxidation of Zirconium claddings

International Nuclear Information System (INIS)

Novotny, T.; Perez-Feró, E.; Horváth, M.

2015-01-01

In the last few years a new series of experiments started for supporting the new LOCA criteria, considering the proposals of US NRC. The effects which can cause the embrittlement of VVER fuel claddings were reviewed and evaluated in the framework of the project. The purpose of the work was to determine how the fuel cladding’s hydrogen uptake under normal operating conditions, effect the behavior of the cladding under LOCA conditions. As a first step a gas system equipment with gas valves and pressure gauge was built, in which the zirconium alloy can absorb hydrogen under controlled conditions. In this apparatus E110 (produced by electrolytic method, currently used at Paks NPP) and E110G (produced by a new technology) alloys were hydrogenated to predetermined hydrogen contents. According the results of ring compression tests the E110G alloys lose their ductility above 3200 ppm hydrogen content. This limit can be applied to determine the ductile-brittle transition of the nuclear fuel claddings. After the hydrogenation, high temperature oxidation experiments were carried out on the E110G and E110 samples at 1000 °C and 1200 °C. 16 pieces of E110G and 8 samples of E110 with 300 ppm and 600 ppm hydrogen content were tested. The oxidation of the specimens was performed in steam, under isothermal conditions. Based on the ring compression tests load-displacement curves were recorded. The main objective of the compression tests was to determine the ductile-brittle transition. These results were compared to the results of our previous experiments where the samples did not contain hydrogen. The original claddings showed more ductile behavior than the samples with hydrogen content. The higher hydrogen content resulted in a more brittle mechanical behavior. However no significant difference was observed in the oxidation kinetics of the same cladding types with different hydrogen content. The experiments showed that the normal operating hydrogen uptake of the fuel claddings

Facile preparation of graphene by high-temperature electrolysis and its application in supercapacitor.

Science.gov (United States)

Jiao, Chen-Xu; Xing, Bao-Yan; Zhao, Jian-Guo; Geng, Yu; Li, Zuo-Peng

2014-01-01

Graphene is well known owing to its astonishing properties: stronger than diamond, more conductive than copper and more flexible than rubber. Because of its potential uses in industry, researchers have been searching for less toxicity ways to make graphene in large amount with lower cost. We demonstrated an efficient method to prepare graphene by high temperature electrolysis technique. High resolution scanning electron microscopy and raman spectroscopy were used to characterize the microstructure of graphene. Graphene was assembled into the supercapacitor and its performance of electrochemical capacitor was investigated by constant current charge and discharge, cyclic voltammetry and AC impedance. The results showed that the micro-morphology of the prepared graphene was multilayer and it was favorable when the electrolytic voltage was 1.5 V. When the current density is 1 mA/cm(2), the specific capacitance of the graphene supercapacitor can reach 78.01 F/g in 6 mol/L KOH electrolyte, which was an increase of 114% compared with 36.43 F/g of conventional KOH electrolyte.

Hydrogen: The Fuel that Drill Bits Cannot Reach

International Nuclear Information System (INIS)

Miller, Alistair I.; Duffey, Romney B.

2006-01-01

As realization grows of the damaging cumulative effects of CO 2 on our biosphere, the prospect of substituting hydrogen for oil-based fuels attracts growing attention. Japan provides a leading example of remedial action with the expectation of five million fuel-cell-powered vehicles in operation by 2020. But where will the fuel for these and the rest of a 'Hydrogen Age' come from? The hydrogen market used to be straightforward: small-scale or high-purity markets were supplied relatively expensively by electrolysis; the other 95% was supplied much more cheaply by reforming hydrocarbons -- mostly using steam-methane reforming (SMR) and low-cost natural gas. The recent rise in the price of hydrocarbons -- natural gas as well as oil -- plus the need to sequester CO 2 has disrupted this scenario. It seems likely that this is a permanent shift driven by growing demand for limited low-cost sources of fluid hydrocarbons. So the traditional SMR route to hydrogen will be in competition with reforming of heavier hydrocarbons (particularly coal and residual oils) as well as with electrolysis based on electricity produced from low-CO 2 -emitting sources. By 2025, new high-temperature thermochemical or thermo-electrolytic sources based on high-temperature nuclear reactors could be in contention. This paper assesses the economics of all these potential sources of hydrogen and their price sensitivities. It also considers their environmental footprints. Is hydrogen from 'clean coal' or other lower value hydrocarbons cost-effective if it is also CO 2 -free? Is intermittent low-temperature electrolysis based on nuclear- and wind-produced electricity (NuWind C ) the best way or does the hydrogen future belong to thermochemistry or thermo-electrolytic sources? How can one produce hydrogen to upgrade Canada's vast oil sands resources without the detraction of a large CO 2 processing penalty? Fortunately for our planet, switching to hydrogen is no more than a technical challenge with a

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

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....... The stack was operated at 800 oC and -0.75 A/cm2 with 60% conversion for a period of 1000 hours. 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 also at lower temperature (800 oC) and higher current density (-0.75 A/cm2)....

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

International Nuclear Information System (INIS)

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

2010-01-01

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

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

Science.gov (United States)

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

1977-01-01

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

Precursors-Derived Ceramic Membranes for High-Temperature Separation of Hydrogen

OpenAIRE

Yuji, Iwamoto

2007-01-01

This review describes recent progress in the development of hydrogen-permselective ceramic membranes derived from organometallic precursors. Microstructure and gas transport property of microporous amorphous silica-based membranes are briefly described. Then, high-temperature hydrogen permselectivity, hydrothermal stability as well as hydrogen/steam selectivity of the amorphous silica-based membranes are discussed from a viewpoint of application to membrane reactors for conversion enhancement...

Nuclear Reactor/Hydrogen Process Interface Including the HyPEP Model

International Nuclear Information System (INIS)

Steven R. Sherman

2007-01-01

The Nuclear Reactor/Hydrogen Plant interface is the intermediate heat transport loop that will connect a very high temperature gas-cooled nuclear reactor (VHTR) to a thermochemical, high-temperature electrolysis, or hybrid hydrogen production plant. A prototype plant called the Next Generation Nuclear Plant (NGNP) is planned for construction and operation at the Idaho National Laboratory in the 2018-2021 timeframe, and will involve a VHTR, a high-temperature interface, and a hydrogen production plant. The interface is responsible for transporting high-temperature thermal energy from the nuclear reactor to the hydrogen production plant while protecting the nuclear plant from operational disturbances at the hydrogen plant. Development of the interface is occurring under the DOE Nuclear Hydrogen Initiative (NHI) and involves the study, design, and development of high-temperature heat exchangers, heat transport systems, materials, safety, and integrated system models. Research and development work on the system interface began in 2004 and is expected to continue at least until the start of construction of an engineering-scale demonstration plant

Detonation cell size measurements in high-temperature hydrogen-air-steam mixtures at the BNL high-temperature combustion facility

International Nuclear Information System (INIS)

Ciccarelli, G.; Ginsberg, T.; Boccio, J.L.

1997-11-01

The High-Temperature Combustion Facility (HTCF) was designed and constructed with the objective of studying detonation phenomena in mixtures of hydrogen-air-steam at initially high temperatures. The central element of the HTCF is a 27-cm inner-diameter, 21.3-m long cylindrical test vessel capable of being heating to 700K ± 14K. A unique feature of the HTCF is the 'diaphragmless' acetylene-oxygen gas driver which is used to initiate the detonation in the test gas. Cell size measurements have shown that for any hydrogen-air-steam mixture, increasing the initial mixture temperature, in the range of 300K to 650K, while maintaining the initial pressure of 0.1 MPa, decreases the cell size and thus makes the mixture more detonable. The effect of steam dilution on cell size was tested in stoichiometric and off-stoichiometric (e.g., equivalence ratio of 0.5) hydrogen-air mixtures. Increasing the steam dilution in hydrogen-air mixtures at 0.1 MPa initial pressure increases the cell size, irrespective of initial temperature. It is also observed that the desensitizing effect of steam diminished with increased initial temperature. A 1-dimensional, steady-state Zel'dovich, von Neumann, Doring (ZND) model, with full chemical kinetics, has been used to predict cell size for hydrogen-air-steam mixtures at different initial conditions. Qualitatively the model predicts the overall trends observed in the measured cell size versus mixture composition and initial temperature and pressure. It was found that the proportionality constant used to predict detonation cell size from the calculated ZND model reaction zone varies between 10 and 100 depending on the mixture composition and initial temperature. 32 refs., 35 figs

Development and Verification of Tritium Analyses Code for a Very High Temperature Reactor

International Nuclear Information System (INIS)

Oh, Chang H.; Kim, Eung S.

2009-01-01

A tritium permeation analyses code (TPAC) has been developed by Idaho National Laboratory for the purpose of analyzing tritium distributions in the VHTR systems including integrated hydrogen production systems. A MATLAB SIMULINK software package was used for development of the code. The TPAC is based on the mass balance equations of tritium-containing species and a various form of hydrogen (i.e., HT, H2, HTO, HTSO4, and TI) coupled with a variety of tritium source, sink, and permeation models. In the TPAC, ternary fission and neutron reactions with 6Li, 7Li 10B, 3He were taken into considerations as tritium sources. Purification and leakage models were implemented as main tritium sinks. Permeation of HT and H2 through pipes, vessels, and heat exchangers were importantly considered as main tritium transport paths. In addition, electrolyzer and isotope exchange models were developed for analyzing hydrogen production systems including both high-temperature electrolysis and sulfur-iodine process. The TPAC has unlimited flexibility for the system configurations, and provides easy drag-and-drops for making models by adopting a graphical user interface. Verification of the code has been performed by comparisons with the analytical solutions and the experimental data based on the Peach Bottom reactor design. The preliminary results calculated with a former tritium analyses code, THYTAN which was developed in Japan and adopted by Japan Atomic Energy Agency were also compared with the TPAC solutions. This report contains descriptions of the basic tritium pathways, theory, simple user guide, verifications, sensitivity studies, sample cases, and code tutorials. Tritium behaviors in a very high temperature reactor/high temperature steam electrolysis system have been analyzed by the TPAC based on the reference indirect parallel configuration proposed by Oh et al. (2007). This analysis showed that only 0.4% of tritium released from the core is transferred to the product hydrogen

A rationale for large inertial fusion plants producing hydrogen for powering low emission vehicles

International Nuclear Information System (INIS)

Logan, B.G.

1993-01-01

Inertial Fusion Energy (IFE) has been identified in the 1991 National Energy Strategy, along with Magnetic Fusion Energy (MFE), as one of only three inexhaustible energy sources for long term energy supply (past 2025), the other alternatives being fission and solar energy. Fusion plants, using electrolysis, could also produce hydrogen to power low emission vehicles in a potentially huge future US market: > 500 GWe would be needed for example, to replace all foreign oil imports with equal-energy hydrogen, assuming 70%-efficient electrolysis. Any inexhaustible source of electricity, including IFE and MFE reactors, can thus provide a long term renewable source of hydrogen as well as solar, wind and biomass sources. Hydrogen production by both high temperature thermochemical cycles and by electrolysis has been studied for MFE, but avoiding trace tritium contamination of the hydrogen product would best be assured using electrolysis cells well separated from any fusion coolant loops. The motivations to consider IFE or MFE producing renewable hydrogen are: (1) reducing US dependence on foreign oil imports and the associated trade deficient; (2) a hydrogen-based transportation system could greatly mitigate future air pollution and greenhouse gases; (3) investments in hydrogen pipelines, storage, and distribution systems could be used for a variety of hydrogen sources; (4) a hydrogen pipeline system could access and buffer sufficiently large markets that temporary outages of large (>> 1 GWe size) fusion hydrogen units could be tolerated

Generation of Hydrogen, Lignin and Sodium Hydroxide from Pulping Black Liquor by Electrolysis

Directory of Open Access Journals (Sweden)

Guangzai Nong

2015-12-01

Full Text Available Black liquor is generated in Kraft pulping of wood or non-wood raw material in pulp mills, and regarded as a renewable resource. The objective of this paper was to develop an effective means to remove the water pollutants by recovery of both lignin and sodium hydroxide from black liquor, based on electrolysis. The treatment of a 1000 mL of black liquor (122 g/L solid contents consumed 345.6 kJ of electric energy, and led to the generation of 30.7 g of sodium hydroxide, 0.82 g of hydrogen gas and 52.1 g of biomass solids. Therefore, the recovery ratios of elemental sodium and biomass solids are 80.4% and 76%, respectively. Treating black liquor by electrolysis is an environmentally friendly technology that can, in particular, be an alternative process in addressing the environmental issues of pulping waste liquor to the small-scale mills without black liquor recovery.

Testing And Performance Analysis Of NASA 5 CM BY 5 CM Bi-Supported Solid Oxide Electrolysis Cells Operated In Both Fuel Cell And Steam Electrolysis Modes

International Nuclear Information System (INIS)

O'Brien, R.C.; O'Brien, J.E.; Stoots, C.M.; Zhang, X.; Farmer, S.C.; Cable, T.L.; Setlock, J.A.

2011-01-01

A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

Alternate applications of fusion power: development of a high-temperature blanket for synthetic-fuel production

International Nuclear Information System (INIS)

Howard, P.A.; Mattas, R.F.; Krajcinovic, D.; DePaz, J.; Gohar, Y.

1981-11-01

This study has shown that utilization of the unique features of a fusion reactor can result in a novel and potentially economical method of decomposing steam into hydrogen and oxygen. Most of the power of fusion reactors is in the form of energetic neutrons. If this power could be used to produce high temperature uncontaminated steam, a large fraction of the energy needed to decomposee the steam could be supplied as thermal energy by the fusion reaction. Proposed high temperature electrolysis processes require steam temperature in excess of 1000 0 C for high efficiency. The design put forth in this study details a system that can accomplish that end

Innovative anode materials and architectured cells for high temperature steam electrolysis operation

International Nuclear Information System (INIS)

Ogier, Tiphaine

2012-01-01

In order to improve the electrochemical performances of cells for high temperature steam electrolysis (HTSE), innovative oxygen electrode materials have been studied. The compounds Ln_2NiO_4_+_δ (Ln = La, Pr or Nd), Pr_4Ni_3O_1_0_±_δ and La_0_,_6S_r0_,_4Fe_0_,_8Co_0_,_2O_3_-_δ have been selected for their mixed electronic and ionic conductivity. First, their physical and chemical properties have been investigated. Then, the electrodes were shaped on symmetrical half cells,adding a thin ceria-based interlayer between the electrode and the yttria doped zirconia-based electrolyte. These architectured cells lead to low polarization resistances (RP≤ 0.1 Ω.cm"2 at 800 C) as well as reduced anodic over potentials. An electrochemical model has been developed in order to describe and analyze the experimental polarization curves.The electrode with the lower overpotential, i.e. Pr_2NiO_4_+δ, has been selected and characterized into complete cermet-supported cells. Under HTSE operation, at 800 C, a high current density was measured, close to i = -0.9 A.cm"-"2 for a cell voltage equals to 1.3 V, the conversion rate being about 60%. (author) [fr

The Modular Helium Reactor for Hydrogen Production

International Nuclear Information System (INIS)

E. Harvego; M. Richards; A. Shenoy; K. Schultz; L. Brown; M. Fukuie

2006-01-01

For electricity and hydrogen production, an advanced reactor technology receiving considerable international interest is a modular, passively-safe version of the high-temperature, gas-cooled reactor (HTGR), known in the U.S. as the Modular Helium Reactor (MHR), which operates at a power level of 600 MW(t). For hydrogen production, the concept is referred to as the H2-MHR. Two concepts that make direct use of the MHR high-temperature process heat are being investigated in order to improve the efficiency and economics of hydrogen production. The first concept involves coupling the MHR to the Sulfur-Iodine (SI) thermochemical water splitting process and is referred to as the SI-Based H2-MHR. The second concept involves coupling the MHR to high-temperature electrolysis (HTE) and is referred to as the HTE-Based H2-MHR

High-temperature oxidation of Zircaloy in hydrogen-steam mixtures

International Nuclear Information System (INIS)

Chung, H.M.; Thomas, G.R.

1982-09-01

Oxidation rates of Zircaloy-4 cladding tubes have been measured in hydrogen-steam mixtures at 1200 to 1700 0 C. For a given isothermal oxidation temperature, the oxide layer thicknesses have been measured as a function of time, steam supply rate, and hydrogen overpressure. The oxidation rates in the mixtures were compared with similar data obtained in pure steam and helium-steam environments under otherwise identical conditions. The rates in pure steam and helium-steam mixtures were equivalent and comparable to the parabolic rates obtained under steam-saturated conditions and reported in the literature. However, when the helium was replaced with hydrogen of equivalent partial pressure, a significantly smaller oxidation rate was observed. For high steam-supply rates, the oxidation kinetics in a hydrogen-steam mixture were parabolic, but the rate was smaller than for pure steam or helium-steam mixtures. Under otherwise identical conditions, the ratio of the parabolic rate for hydrogen-steam to that for pure steam decreased with increasing temperature and decreasing steam-supply rate

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

DEFF Research Database (Denmark)

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

2013-01-01

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

Transition metal carbides (WC, Mo₂C, TaC, NbC) as potential electrocatalysts for the hydrogen evolution reaction (HER) at medium temperatures

DEFF Research Database (Denmark)

Meyer, Simon; Nikiforov, Aleksey V.; Petrushina, Irina M.

2015-01-01

One limitation for large scale water electrolysis is the high price of the Pt cathode catalyst. Transition metal carbides, which are considered as some of the most promising non-Pt catalysts, are less active than Pt at room temperature. The present work demonstrates that the situation is different......C > TaC. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved....

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

Directory of Open Access Journals (Sweden)

Jan Christian Koj

2017-06-01

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

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.

Durable solid oxide electrolysis cells for hydrogen production

DEFF Research Database (Denmark)

Sun, Xiufu; Chen, Ming; Hendriksen, Peter Vang

2014-01-01

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...... that except for the first 250 hours fast initial degradation, for the rest of the testing period, the cell showed rather stable performance with an moderate degradation rate of around 25 mV/1000 h. The electrochemical impedance spectra show that both serial resistance and polarization resistance of the cell...... and changing of porosity inside the active layer. The degree of these microstructural changes becomes less and less severe along the hydrogen-steam flow path. The present test results show that this type of cell can be used for early demonstration electrolysis at 1A/cm2. Future work should be focus on reducing...

Meeting the near-term demand for hydrogen using nuclear energy in competitive power markets

International Nuclear Information System (INIS)

Miller, Alistair I.; Duffey, Romney B.

2004-01-01

Hydrogen is becoming the reference fuel for future transportation and, in the USA in particular, a vision for its production from advanced nuclear reactors has been formulated. Fulfillment of this vision depend on its economics in 2020 or later. Prior to 2020, hydrogen needs to gain a substantial foothold without incurring excessive costs for the establishment of the distribution network for the new fuel. Water electrolysis and steam-methane reforming (SMR) are the existing hydrogen-production technologies, used for small-scale and large-scale production, respectively. Provided electricity is produced at costs expected for nuclear reactors of near-term design, electrolysis appears to offer superior economics when the SMR-related costs of distribution and sequestration (or an equivalent emission levy) are included. This is shown to hold at least until several percentage points of road transport have been converted to hydrogen. Electrolysis has large advantages over SMRs in being almost scale-independent and allowing local production. The key requirements for affordable electrolysis are low capital cost and relatively high utilization, although the paper shows that it should be advantageous to avoid the peaks of electricity demand and cost. The electricity source must enable high utilization as well as being itself low-cost and emissions-free. By using off-peak electricity, no extra costs for enhanced electricity distribution should occur. The longer-term supply of hydrogen may ultimately evolve away from low-temperature water electrolysis but it appears to be an excellent technology for early deployment and capable of supplying hydrogen at prices not dissimilar from today's costs for gasoline and diesel provided the vehicle's power unit is a fuel cell. (author)

Enhanced hydrogen generation using a saline catholyte in a two chamber microbial electrolysis cell

KAUST Repository

Nam, Joo-Youn

2011-11-01

High rates of hydrogen gas production were achieved in a two chamber microbial electrolysis cell (MEC) without a catholyte phosphate buffer by using a saline catholyte solution and a cathode constructed around a stainless steel mesh current collector. Using the non-buffered salt solution (68 mM NaCl) produced the highest current density of 131 ± 12 A/m3, hydrogen yield of 3.2 ± 0.3 mol H2/mol acetate, and gas production rate of 1.6 ± 0.2 m3 H2/m 3·d, compared to MECs with catholytes externally sparged with CO2 or containing a phosphate buffer. The salinity of the catholyte achieved a high solution conductivity, and therefore the electrode spacing did not appreciably affect performance. The coulombic efficiency with the cathode placed near the membrane separating the chambers was 83 ± 4%, similar to that obtained with the cathode placed more distant from the membrane (84 ± 4%). Using a carbon cloth cathode instead of the stainless steel mesh cathode did not significantly affect performance, with all reactor configurations producing similar performance in terms of total gas volume, COD removal, rcat and overall energy recovery. These results show MEC performance can be improved by using a saline catholyte without pH control. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Basic study on high temperature gas cooled reactor technology for hydrogen production

International Nuclear Information System (INIS)

Chang, Jong Hwa; Lee, W. J.; Lee, H. M.

2003-01-01

The annual production of hydrogen in the world is about 500 billion m 3 . Currently hydrogen is consumed mainly in chemical industries. However hydrogen has huge potential to be consumed in transportation sector in coming decades. Assuming that 10% of fossil energy in transportation sector is substituted by hydrogen in 2020, the hydrogen in the sector will exceed current hydrogen consumption by more than 2.5 times. Currently hydrogen is mainly produced by steam reforming of natural gas. Steam reforming process is chiefest way to produce hydrogen for mass production. In the future, hydrogen has to be produced in a way to minimize CO2 emission during its production process as well as to satisfy economic competition. One of the alternatives to produce hydrogen under such criteria is using heat source of high-temperature gas-cooled reactor. The high-temperature gas-cooled reactor represents one type of the next generation of nuclear reactors for safe and reliable operation as well as for efficient and economic generation of energy

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.

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

DEFF Research Database (Denmark)

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

2014-01-01

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

Achievement report for 1st phase (fiscal 1974-80) Sunshine Program research and development - Hydrogen energy. Research on hydrogen production technology using electrolysis; 1974-1980 nendo suiso energy seika hokokusho. Denki bunkaiho ni yoru suiso seizo gijutsu no kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

The electrolysis of water is a hydrogen production technology known since early days. But the efficiency of a commercial electrolytic bath is found at 60-70%, which is too low to prepare for future energy systems. A high-temperature high-pressure water electrolysis process is being studied for improving on the efficiency. For the realization of energy efficiency of 90% or higher, the conventional operating conditions of 90 degrees C or lower, 20A/dm{sup 2}, and 1.8-2.0V bath operating voltage will be improved to be higher than 120 degrees C, 20kg/cm{sup 2}, and 40A/dm{sup 2}, and the electrodes will be modified to work down at 1.65V. The tasks to discharge involve the materials (of diaphragms etc.) for constituting electrolytic baths, electrode catalysts, and electrode shapes. Tests are under way using a test plant capable of producing hydrogen at a rate of 4m{sup 3}/hr. In the analysis of water in a solid polymeric electrolyte, a combination of a cation exchange membrane and a catalytic electrode directly junctioned to the membrane operates as a unit cell. Development is under way with a view to realizing a bath operating voltage of 1.65V or lower at 100A/dm{sup 2}. Since this process still wants much basic research and the materials for bath construction for the process are expensive, further development endeavors will have to be exerted. (NEDO)

Japan's New Sunshine Project. 1998 Annual summary of hydrogen energy R and D

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

Summarized herein are the reports on R and D efforts on hydrogen energy, as part of the FY 1998 New Sunshine Project. For production of hydrogen, characteristics related to transport number were investigated for steam electrolysis at high temperature, in which a sintered ceramic powder was used as the electrolyte and the cell was equipped with platinum electrodes. For utilization of hydrogen, energy conversion techniques were investigated using hydrogen occluding alloys for testing methods for alloy microstructures and hydrogenation characteristics, and preparation of and performance testing methods for the cathodes charged with the aid of hydrogen gas. For analysis/assessment for development of hydrogen-related techniques, the investigated items included water electrolysis with solid polymer electrolytes, hydrogen transport techniques using metal hydrides, hydrogen storing techniques using metal hydrides, hydrogen engines, and techniques for preventing hydrogen embrittlement. Analysis/assessment for development of hydrogen turbines was also investigated as one of the 12 R and D themes reported herein. (NEDO)

High Performance, Low Cost Hydrogen Generation from Renewable Energy

Energy Technology Data Exchange (ETDEWEB)

Ayers, Katherine [Proton OnSite; Dalton, Luke [Proton OnSite; Roemer, Andy [Proton OnSite; Carter, Blake [Proton OnSite; Niedzwiecki, Mike [Proton OnSite; Manco, Judith [Proton OnSite; Anderson, Everett [Proton OnSite; Capuano, Chris [Proton OnSite; Wang, Chao-Yang [Penn State University; Zhao, Wei [Penn State University

2014-02-05

Renewable hydrogen from proton exchange membrane (PEM) electrolysis is gaining strong interest in Europe, especially in Germany where wind penetration is already at critical levels for grid stability. For this application as well as biogas conversion and vehicle fueling, megawatt (MW) scale electrolysis is required. Proton has established a technology roadmap to achieve the necessary cost reductions and manufacturing scale up to maintain U.S. competitiveness in these markets. This project represents a highly successful example of the potential for cost reduction in PEM electrolysis, and provides the initial stack design and manufacturing development for Proton’s MW scale product launch. The majority of the program focused on the bipolar assembly, from electrochemical modeling to subscale stack development through prototyping and manufacturing qualification for a large active area cell platform. Feasibility for an advanced membrane electrode assembly (MEA) with 50% reduction in catalyst loading was also demonstrated. Based on the progress in this program and other parallel efforts, H2A analysis shows the status of PEM electrolysis technology dropping below $3.50/kg production costs, exceeding the 2015 target.

Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrodeless Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

OpenAIRE

Gavare, Zanda; Revalde, Gita; Skudra, Atis

2010-01-01

The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-α diagonal band (d3Πu−→a3∑g+ electronic transition; Q-branch with v=v′=2) to determine the temperature of hydrogen containing high-frequency electrodeless lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied curren...

Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrode less Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

International Nuclear Information System (INIS)

Gavare, Z.; Revalde, G.; Skudra, A.

2011-01-01

The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-a diagonal band (d3η u- a3Σg + electronic transition; Q-branch with ν=ν=2) to determine the temperature of hydrogen containing high-frequency electrode less lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied current. The results have been compared with the method of temperature derivation from Doppler profiles of He 667.8 nm and Ar 772.4 nm lines. The results of both methods are in good agreement, showing that the method of gas temperature determination from the intensity distribution in the hydrogen Fulcher-a (2-2)Q band can be used for the hydrogen containing HFEDLs. It was observed that the admixture of 10% hydrogen in the argon HFEDLs significantly reduces the gas temperature

A review of the potential for the use of nuclear reactors for hydrogen production

International Nuclear Information System (INIS)

Worley, N.G.

1977-01-01

The possibilities of using reactors to carry out high temperature chemical processes are considered briefly. The relevant characteristics of the high temperature gas cooled reactor and fast breeder reactors are summarized. The use of 'off-peak' electricity to produce hydrogen by the electrolysis of water is considered. Various problems, political, social, organizational and technical are discussed. (U.K.)

Hydrogen production and storage: R & D priorities and gaps

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-05-04

This review of priorities and gaps in hydrogen production and storage R & D has been prepared by the IEA Hydrogen Implementing Agreement in the context of the activities of the IEA Hydrogen Co-ordination Group. It includes two papers. The first is by Trygve Riis, Elisabet F. Hagen, Preben J.S. Vie and Oeystein Ulleberg. This offers an overview of the technologies for hydrogen production. The technologies discussed are reforming of natural gas; gasification of coal and biomass; and the splitting of water by water-electrolysis, photo-electrolysis, photo-biological production and high-temperature decomposition. The second paper is by Trygve Riis, Gary Sandrock, Oeystein Ulleberg and Preben J.S. Vie. The objective of this paper is to provide a brief overview of the possible hydrogen storage options available today and in the foreseeable future. Hydrogen storage can be considered for onboard vehicular, portable, stationary, bulk, and transport applications, but the main focus of this paper is on vehicular storage, namely fuel cell or ICE/electric hybrid vehicles. 7 refs., 24 figs., 14 tabs.

TESTING AND PERFORMANCE ANALYSIS OF NASA 5 CM BY 5 CM BI-SUPPORTED SOLID OXIDE ELECTROLYSIS CELLS OPERATED IN BOTH FUEL CELL AND STEAM ELECTROLYSIS MODES

Energy Technology Data Exchange (ETDEWEB)

R. C. O' Brien; J. E. O' Brien; C. M. Stoots; X. Zhang; S. C. Farmer; T. L. Cable; J. A. Setlock

2011-11-01

A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

Study on in-situ electrochemical impedance spectroscopy measurement of anodic reaction in SO_2 depolarized electrolysis process

International Nuclear Information System (INIS)

Xue Lulu; Zhang Ping; Chen Songzhe; Wang Laijun

2014-01-01

SO_2 depolarized electrolysis (SDE) is the pivotal reaction in hybrid sulfur process, one of the most promising approaches for mass hydrogen production without CO_2 emission. The net result of hybrid sulfur process is to split water into hydrogen and oxygen at a relatively low voltage, which will dramatically decrease the energy consumption for the production of hydrogen. The potential loss of SDE process could be separated into four components, i.e. reversible cell potential, anode overpotential, cathode overpotential and ohmic loss. So far, it has been identified that the total cell potential for the SO_2 depolarized electrolyzer is dominantly controlled by sulfuric acid concentration of the anolyte and electrolysis temperature of the electrolysis process. In this work, an in-situ Electrochemical Impedance Spectroscopy (EIS) measurement of the anodic SDE reaction was conducted. Results show that anodic overpotential is mainly resulted from the SO_2 oxidation reaction other than ohmic resistance or mass transfer limitation. This study extends the understanding to SDE process and gives suggestions for the further improvement of the SDE performance. (author)

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.

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

Science.gov (United States)

Yi, Xuenong; Wang, Yulin

2017-06-01

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

Questioning hydrogen

International Nuclear Information System (INIS)

Hammerschlag, Roel; Mazza, Patrick

2005-01-01

As an energy carrier, hydrogen is to be compared to electricity, the only widespread and viable alternative. When hydrogen is used to transmit renewable electricity, only 51% can reach the end user due to losses in electrolysis, hydrogen compression, and the fuel cell. In contrast, conventional electric storage technologies allow between 75% and 85% of the original electricity to be delivered. Even when hydrogen is extracted from gasified coal (with carbon sequestration) or from water cracked in high-temperature nuclear reactors, more of the primary energy reaches the end user if a conventional electric process is used instead. Hydrogen performs no better in mobile applications, where electric vehicles that are far closer to commercialization exceed fuel cell vehicles in efficiency, cost and performance. New, carbon-neutral energy can prevent twice the quantity of GHG's by displacing fossil electricity than it can by powering fuel cell vehicles. The same is true for new, natural gas energy. New energy resources should be used to displace high-GHG electric generation, not to manufacture hydrogen

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

Science.gov (United States)

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

2017-02-01

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

High-temperature electrolysis of CO2-enriched mixtures by using fuel-electrode supported La0.6Sr0.4CoO3/YSZ/Ni-YSZ solid oxide cells

Science.gov (United States)

Kim, Si-Won; Bae, Yonggyun; Yoon, Kyung Joong; Lee, Jong-Ho; Lee, Jong-Heun; Hong, Jongsup

2018-02-01

To mitigate CO2 emissions, its reduction by high-temperature electrolysis using solid oxide cells is extensively investigated, for which excessive steam supply is assumed. However, such condition may degrade its feasibility due to massive energy required for generating hot steam, implying the needs for lowering steam demand. In this study, high-temperature electrolysis of CO2-enriched mixtures by using fuel-electrode supported La0.6Sr0.4CoO3/YSZ/Ni-YSZ solid oxide cells is considered to satisfy such needs. The effect of internal and external steam supply on its electrochemical performance and gas productivity is elucidated. It is shown that the steam produced in-situ inside the fuel-electrode by a reverse water gas shift reaction may decrease significantly the electrochemical resistance of dry CO2-fed operations, attributed to self-sustaining positive thermo-electrochemical reaction loop. This mechanism is conspicuous at low current density, whereas it is no longer effective at high current density in which total reactant concentrations for electrolysis is critical. To overcome such limitations, a small amount of external steam supply to the CO2-enriched feed stream may be needed, but this lowers the CO2 conversion and CO/H2 selectivity. Based on these results, it is discussed that there can be minimum steam supply sufficient for guaranteeing both low electrochemical resistance and high gas productivity.

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

International Nuclear Information System (INIS)

Ciccarelli, G.; Ginsburg, T.; Boccio, J.; Economos, C.; Finfrock, C.; Gerlach, L.; Sato, K.; Kinoshita, M.

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

Study on hydrogen production using the fast breeder reactors (FBR)

International Nuclear Information System (INIS)

Kani, Yoshio

2003-01-01

As the fast breeder reactor (FBR) can effectively convert uranium-238 difficult to carry out nuclear fission at thermal neutron reactors to nuclear fissionable plutonium-239 to use it remarkable upgrading of application on uranium can be performed, to be expected for sustainable energy source. And, by reuse minor actinides of long half-life nuclides in reprocessed high level wasted solutions for fuels of nuclear reactors, reduction of radioactive poison based on high level radioactive wastes was enabled. As high temperature of about 800 centigrade was required on conventional hydrogen production, by new hydrogen production technique even at operation temperature of sodium-cooled FBR it can be enabled. Here were described for new hydrogen production methods applicable to FBR on palladium membrane hydrogen separation method carrying out natural gas/steam modification at reaction temperature of about 500 centigrade, low temperature thermo-chemical method expectable simultaneous simplification of production process, and electrolysis method expected on power load balancing. (G.K.)

Fabrication and characterization of Cu/YSZ cermet high-temperature electrolysis cathode material prepared by high-energy ball-milling method

International Nuclear Information System (INIS)

Lee, Sungkyu; Kang, Kyoung-Hoon; Kim, Jong-Min; Hong, Hyun Seon; Yun, Yongseung; Woo, Sang-Kook

2008-01-01

Cu/YSZ composites (40 and 60 vol.% Cu powder with balance YSZ) was successfully fabricated by high-energy ball-milling of Cu and YSZ powders at 400 rpm for 24 h, pressing into pellets (O 13 mm x 2 mm) and subsequent sintering process at 900 deg. C under flowing 5%-H 2 /Ar gas for use as cermet cathode material of high-temperature electrolysis (HTE) of water vapor in a more economical way compared with conventional Ni/YSZ cermet cathode material. The Cu/YSZ composite powders thus synthesized and sintered were characterized using various analytical tools such as XRD, SEM, and laser diffraction and scattering method. Electrical conductivity of sintered Cu/YSZ cermet pellets thus fabricated was measured using 4-probe technique and compared with that of Ni/YSZ cermets. The effect of composites composition on the electrical conductivity was investigated and marked increase in electrical conductivity for copper contents greater than 40 vol.% in the composite was explained by percolation threshold

Advanced alkaline water electrolysis

International Nuclear Information System (INIS)

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

2012-01-01

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

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

International Nuclear Information System (INIS)

Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.; Finfrock, C.; Gerlach, L.; Sato, K.

1994-01-01

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 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 temperature between 300K and 650K at a fixed pressure of 0.1 MPa. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air gas mixture temperature, in the range 300K to 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 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. Experiments were conducted to measure the rate of hydrogen oxidation in the absence of ignition sources at temperatures of 500K and 650K, for hydrogen-air mixtures of 15% and 50%, and for a mixture of equimolar hydrogen-air and 30% steam at 650K. The rate of hydrogen oxidation was found to be significant at 650K. Reduction of hydrogen concentration by chemical reaction from 50 to 44% hydrogen, and from 15 to 11% hydrogen, were observed on a time frame of minutes. The DeSoete rate equation predicts the 50% experiment very well, but greatly underestimates the reaction rate of the lean mixtures

The impact of anode acclimation strategy on microbial electrolysis cell treating hydrogen fermentation effluent.

Science.gov (United States)

Li, Xiaohu; Zhang, Ruizhe; Qian, Yawei; Angelidaki, Irini; Zhang, Yifeng

2017-07-01

The impact of different anode acclimation methods for enhancing hydrogen production in microbial electrolysis cell (MEC) was investigated in this study. The anodes were first acclimated in microbial fuel cells using acetate, butyrate and corn stalk fermentation effluent (CSFE) as substrate before moving into MECs, respectively. Subsequently, CSFE was used as feedstock in all the three MECs. The maximum hydrogen yield with the anode pre-acclimated with butyrate (5.21±0.24L H 2 /L CSFE) was higher than that pre-acclimated with acetate (4.22±0.19L H 2 /L CSFE) and CSFE (4.55±0.14L H 2 /L CSFE). The current density (480±11A/m 3 ) and hydrogen production rate (4.52±0.13m 3 /m 3 /d) with the anode pre-acclimated with butyrate were also higher that another two reactors. These results demonstrated that the anode biofilm pre-acclimated with butyrate has significant advantages in CSFE treatment and could improve the performance of hydrogen production in MEC. Copyright © 2017 Elsevier Ltd. All rights reserved.

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...... severe percolation loss of Ni particles. The blocking of the Ni-YSZ TPBs by impurities (e.g. SiOx) also contributed to the fast degradation of SOECs in the initial test period. However, the post-test observation revealed dominating SiOx inclusions inside the Ni grain close to the electrolyte, instead...

Hydrogen production from biomass pyrolysis gas via high temperature steam reforming process

International Nuclear Information System (INIS)

Wongchang, Thawatchai; Patumsawad, Suthum

2010-01-01

Full text: The aim of this work has been undertaken as part of the design of continuous hydrogen production using the high temperature steam reforming process. The steady-state test condition was carried out using syngas from biomass pyrolysis, whilst operating at high temperatures between 600 and 1200 degree Celsius. The main reformer operating parameters (e.g. temperature, resident time and steam to biomass ratio (S/B)) have been examined in order to optimize the performance of the reformer. The operating temperature is a key factor in determining the extent to which hydrogen production is increased at higher temperatures (900 -1200 degree Celsius) whilst maintaining the same as resident time and S/B ratio. The effects of exhaust gas composition on heating value were also investigated. The steam reforming process produced methane (CH 4 ) and ethylene (C 2 H 4 ) between 600 to 800 degree Celsius and enhanced production ethane (C 2 H 6 ) at 700 degree Celsius. However carbon monoxide (CO) emission was slightly increased for higher temperatures all conditions. The results show that the use of biomass pyrolysis gas can produce higher hydrogen production from high temperature steam reforming. In addition the increasing reformer efficiency needs to be optimized for different operating conditions. (author)

Platinum Group Metal-free Catalysts for Hydrogen Evolution Reaction in Microbial Electrolysis Cells.

Science.gov (United States)

Yuan, Heyang; He, Zhen

2017-07-01

Hydrogen gas is a green energy carrier with great environmental benefits. Microbial electrolysis cells (MECs) can convert low-grade organic matter to hydrogen gas with low energy consumption and have gained a growing interest in the past decade. Cathode catalysts for the hydrogen evolution reaction (HER) present a major challenge for the development and future applications of MECs. An ideal cathode catalyst should be catalytically active, simple to synthesize, durable in a complex environment, and cost-effective. A variety of noble-metal free catalysts have been developed and investigated for HER in MECs, including Nickel and its alloys, MoS 2 , carbon-based catalysts and biocatalysts. MECs in turn can serve as a research platform to study the durability of the HER catalysts. This personal account has reviewed, analyzed, and discussed those catalysts with an emphasis on synthesis and modification, system performance and potential for practical applications. It is expected to provide insights into the development of HER catalysts towards MEC applications. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Summary of the FY 1988 Sunshine Project results. Hydrogen energy; 1988 nendo sunshine keikaku seika hokokusho gaiyoshu. Suiso energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-04-01

Outlined herein are the results of researches on hydrogen energy as part of the FY 1988 Sunshine Project results. Researches on the techniques for producing hydrogen by electrolysis of water using a polymer electrolyte include development of power-supplying materials for electrolysis at high current density, and basic studies on the electrolysis using an OH ion conducting type polymer electrolyte. Researches on the techniques for producing hydrogen by electrolysis with hot steam include development of the materials, techniques for processing these materials, and electrolysis performance tests. Researches on the techniques for transporting hydrogen by metal hydrides include development of hydrogen-occluding alloys of high bulk density, and techniques for evaluating characteristics of metal hydrides. Researches on the techniques for storing hydrogen include those on alloy molding/processing techniques, hydrogen-storing metallic materials, and new hydrogen-storing materials. Researches on the techniques for utilizing hydrogen include those on energy conversion techniques using hydrogen-occluding alloys, and hydrogen-fueled motors. Researches on the techniques for safety-related measures include those on prevention of embrittlement of the system materials by hydrogen. (NEDO)

High temperature and pressure alkaline electrolysis

DEFF Research Database (Denmark)

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

2013-01-01

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

Hydrogen Production by Geobacter Species and a Mixed Consortium in a Microbial Electrolysis Cell

KAUST Repository

Call, D. F.

2009-10-09

A hydrogen utilizing exoelectrogenic bacterium (Geobacter sulfurreducens) was compared to both a nonhydrogen oxidizer (Geobacter metallireducens) and a mixed consortium in order to compare the hydrogen production rates and hydrogen recoveries of pure and mixed cultures in microbial electrolysis cells (MECs). At an applied voltage of 0.7 V, both G. sulfurreducens and the mixed culture generated similar current densities (ca. 160 A/m3), resulting in hydrogen production rates of ca. 1.9 m3 H2/m 3/day, whereas G. metallireducens exhibited lower current densities and production rates of 110 ± 7 A/m3 and 1.3 ± 0.1 m3 H2/m3/day, respectively. Before methane was detected in the mixed-culture MEC, the mixed consortium achieved the highest overall energy recovery (relative to both electricity and substrate energy inputs) of 82% ± 8% compared to G. sulfurreducens (77% ± 2%) and G. metallireducens (78% ± 5%), due to the higher coulombic efficiency of the mixed consortium. At an applied voltage of 0.4 V, methane production increased in the mixed-culture MEC and, as a result, the hydrogen recovery decreased and the overall energy recovery dropped to 38% ± 16% compared to 80% ± 5% for G. sulfurreducens and 76% ± 0% for G. metallireducens. Internal hydrogen recycling was confirmed since the mixed culture generated a stable current density of 31 ± 0 A/m3 when fed hydrogen gas, whereas G. sulfurreducens exhibited a steady decrease in current production. Community analysis suggested that G. sulfurreducens was predominant in the mixed-culture MEC (72% of clones) despite its relative absence in the mixed-culture inoculum obtained from a microbial fuel cell reactor (2% of clones). These results demonstrate that Geobacter species are capable of obtaining similar hydrogen production rates and energy recoveries as mixed cultures in an MEC and that high coulombic efficiencies in mixed culture MECs can be attributed in part to the recycling of hydrogen into current. Copyright �

Hydrogen Production by Geobacter Species and a Mixed Consortium in a Microbial Electrolysis Cell▿

Science.gov (United States)

Call, Douglas F.; Wagner, Rachel C.; Logan, Bruce E.

2009-01-01

A hydrogen utilizing exoelectrogenic bacterium (Geobacter sulfurreducens) was compared to both a nonhydrogen oxidizer (Geobacter metallireducens) and a mixed consortium in order to compare the hydrogen production rates and hydrogen recoveries of pure and mixed cultures in microbial electrolysis cells (MECs). At an applied voltage of 0.7 V, both G. sulfurreducens and the mixed culture generated similar current densities (ca. 160 A/m3), resulting in hydrogen production rates of ca. 1.9 m3 H2/m3/day, whereas G. metallireducens exhibited lower current densities and production rates of 110 ± 7 A/m3 and 1.3 ± 0.1 m3 H2/m3/day, respectively. Before methane was detected in the mixed-culture MEC, the mixed consortium achieved the highest overall energy recovery (relative to both electricity and substrate energy inputs) of 82% ± 8% compared to G. sulfurreducens (77% ± 2%) and G. metallireducens (78% ± 5%), due to the higher coulombic efficiency of the mixed consortium. At an applied voltage of 0.4 V, methane production increased in the mixed-culture MEC and, as a result, the hydrogen recovery decreased and the overall energy recovery dropped to 38% ± 16% compared to 80% ± 5% for G. sulfurreducens and 76% ± 0% for G. metallireducens. Internal hydrogen recycling was confirmed since the mixed culture generated a stable current density of 31 ± 0 A/m3 when fed hydrogen gas, whereas G. sulfurreducens exhibited a steady decrease in current production. Community analysis suggested that G. sulfurreducens was predominant in the mixed-culture MEC (72% of clones) despite its relative absence in the mixed-culture inoculum obtained from a microbial fuel cell reactor (2% of clones). These results demonstrate that Geobacter species are capable of obtaining similar hydrogen production rates and energy recoveries as mixed cultures in an MEC and that high coulombic efficiencies in mixed culture MECs can be attributed in part to the recycling of hydrogen into current. PMID:19820150

High temperature cathodic charging of hydrogen in zirconium alloys and iron and nickel base alloys

International Nuclear Information System (INIS)

John, J.T.; De, P.K.; Gadiyar, H.S.

1990-01-01

These investigations lead to the development of a new technique for charging hydrogen into metals and alloys. In this technique a mixture of sulfates and bisulfates of sodium and potassium is kept saturated with water at 250-300degC in an open pyrex glass beaker and electrolysed using platinum anode and the material to be charged as the cathode. Most of the studies were carried out on Zr alloys. It is shown that because of the high hydrogen flux available at the surface and the high diffusivity of hydrogen in metals at these temperatures the materials pick up hydrogen faster and more uniformly than the conventional electrolytic charging at room temperature and high temperature autoclaving in LiOH solutions. Chemical analysis, metallographic examination and XRD studies confirm this. This technique has been used to charge hydrogen into many iron and nickel base austentic alloys, which are very resistant to hydrogen pick up and to H-embrittlement. Since this involved a novel method of electrolysing water, the hydrogen/deuterium isotopic ratio has been studied. At this temperatures the D/H ratio in the evolved hydrogen gas was found to be closer to the value in the liquid water, which means a smaller separation factor. This confirm the earlier observation that separation factor decreases with increase of temperature. (author). 16 refs., 21 fi gs., 6 tabs

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

International Nuclear Information System (INIS)

Shimizu, Saburo; Ueno, Shuichi

2004-01-01

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

Modeling and optimization of a novel solar chimney cogeneration power plant combined with solid oxide electrolysis/fuel cell

International Nuclear Information System (INIS)

Joneydi Shariatzadeh, O.; Refahi, A.H.; Abolhassani, S.S.; Rahmani, M.

2015-01-01

Highlights: • Proposed a solar chimney cogeneration power plant combined with solid oxide fuel cell. • Conducted single-objective economic optimization of cycle by genetic algorithm. • Stored surplus hydrogen in season solarium to supply electricity in winter by SOFC. - Abstract: Using solar chimney in desert areas like El Paso city in Texas, USA, with high intensity solar radiation is efficient and environmental friendly. However, one of the main challenges in terms of using solar chimneys is poor electricity generation at night. In this paper, a new power plant plan is proposed which simultaneously generates heat and electricity using a solar chimney with solid oxide fuel cells and solid oxide electrolysis cells. In one hand, the solar chimney generates electricity by sunlight and supplies a part of demand. Then, additional electricity is generated through the high temperature electrolysis which produces hydrogen that is stored in tanks and converted into electricity by solid oxide fuel cells. After designing and modeling the cycle components, the economic aspect of this power plant is considered numerically by means of genetic algorithm. The results indicate that, 0.28 kg/s hydrogen is produced at the peak of the radiation. With such a hydrogen production rate, this system supplies 79.26% and 37.04% of the demand in summer and winter respectively in a district of El Paso city.

Hydrogen desorption from mechanically milled carbon micro coils hydrogenated at high temperature

International Nuclear Information System (INIS)

Yoshio Furuya; Shuichi Izumi; Seiji Motojima; Yukio Hishikawa

2005-01-01

Carbon micro coils (CMC) have been prepared by the catalytic pyrolysis of acetylene at 750-800 C. The as grown coils have an almost amorphous structure and contain about 1 mass% hydrogen. They have 0.1 - 10 mm coil length, 1-5 μm coil diameter, 0.1-0.5 μm coil pitch and about 100 m 2 /g specific surface area. They were graphitized, as maintaining the morphology of the coils, by heat-treating at a higher temperature than 2500 C in Ar atmosphere. The layer space (d) of graphitized CMC was determined to be 0.341 nm, forming a 'herringbone' structure with an inclination of 10-40 degree versus the coiled fiber axis, having a specific surface area of about 8 m 2 /g. The hydrogen absorption behaviors of CMC were investigated from RT to 1200 C by a thermal desorption spectrometry (TDS) using a quadrupole mass analyzer. In TDS measurements, pre-existing hydrogen, which was due to the residual acetylene incorporated into CMC on its growing, desorbed from 700 C and peaked at about 900 C. The increment in the main peak of desorbed hydrogen in the as-grown CMC heat-treated at 500 C for 1 h under high pressure of hydrogen gas (1.9 or 8.9 MPa) was not remarkable as is shown in Fig.1. While, in the CMC samples milled mechanically for 1 h at RT using a planetary ball mill, the increase of desorbed hydrogen became to be great with the hydrogen pressure (up to 8.9 MPa) on heat-treating at 500 C, as is shown in Fig.2. In these CMC samples, the building up temperature of the hydrogen desorption was shifted to a lower one and the temperature range of desorption became to be wider than those in the as-grown CMC because of the appearance of another desorption peak at about 600 C in addition to the peak ranging from 850 C to 900 C. The same kind of peak was also slightly observed in as-grown CMC (Fig.1). It is clear that this desorption at about 600 C has contributed to the remarkable increase of desorbed hydrogen in the milled CMC. In this work, values of more than 2 mass% were obtained

Preliminary Cost Estimates for Nuclear Hydrogen Production: HTSE System

International Nuclear Information System (INIS)

Yang, K. J.; Lee, K. Y.; Lee, T. H.

2008-01-01

KAERI is now focusing on the research and development of the key technologies required for the design and realization of a nuclear hydrogen production system. As a preliminary study of cost estimates for nuclear hydrogen systems, the hydrogen production costs of the nuclear energy sources benchmarking GTMHR and PBMR are estimated in the necessary input data on a Korean specific basis. G4-ECONS was appropriately modified to calculate the cost for hydrogen production of HTSE (High Temperature Steam Electrolysis) process with VHTR (Very High Temperature nuclear Reactor) as a thermal energy source. The estimated costs presented in this paper show that hydrogen production by the VHTR could be competitive with current techniques of hydrogen production from fossil fuels if CO 2 capture and sequestration is required. Nuclear production of hydrogen would allow large-scale production of hydrogen at economic prices while avoiding the release of CO 2 . Nuclear production of hydrogen could thus become the enabling technology for the hydrogen economy. The major factors that would affect the cost of hydrogen were also discussed

Heat pump cycle by hydrogen-absorbing alloys to assist high-temperature gas-cooled reactor in producing hydrogen

International Nuclear Information System (INIS)

Satoshi, Fukada; Nobutaka, Hayashi

2010-01-01

A chemical heat pump system using two hydrogen-absorbing alloys is proposed to utilise heat exhausted from a high-temperature source such as a high-temperature gas-cooled reactor (HTGR), more efficiently. The heat pump system is designed to produce H 2 based on the S-I cycle more efficiently. The overall system proposed here consists of HTGR, He gas turbines, chemical heat pumps and reaction vessels corresponding to the three-step decomposition reactions comprised in the S-I process. A fundamental research is experimentally performed on heat generation in a single bed packed with a hydrogen-absorbing alloy that may work at the H 2 production temperature. The hydrogen-absorbing alloy of Zr(V 1-x Fe x ) 2 is selected as a material that has a proper plateau pressure for the heat pump system operated between the input and output temperatures of HTGR and reaction vessels of the S-I cycle. Temperature jump due to heat generated when the alloy absorbs H 2 proves that the alloy-H 2 system can heat up the exhaust gas even at 600 deg. C without any external mechanical force. (authors)

Basic study of alkaline water electrolysis

International Nuclear Information System (INIS)

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

2013-01-01

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

Nuclear hydrogen production programme in the United States

International Nuclear Information System (INIS)

Sink, C.

2010-01-01

The Nuclear Hydrogen Initiative (NHI) is focused on demonstrating the economic, commercial-scale production of hydrogen using process heat derived from nuclear energy. NHI-supported research has concentrated to date on three technologies compatible with the Next Generation Nuclear Plant (NGNP): high temperature steam electrolysis (HTE); sulphur-iodine (S-I) thermochemical; and hybrid sulphur (HyS) thermochemical. In 2009 NHI will down select to a single technology on which to focus its future development efforts, for which the next step will be a pilot-scale experiment. (author)

Engineering Design Elements of a Two-Phase Thermosyphon to Trannsfer NGNP Nuclear Thermal Energy to a Hydrogen Plant

Energy Technology Data Exchange (ETDEWEB)

Piyush Sabharwal

2009-07-01

Two hydrogen production processes, both powered by a Next Generation Nuclear Plant (NGNP), are currently under investigation at Idaho National Laboratory. The first is high-temperature steam electrolysis, which uses both heat and electricity; the second is thermo-chemical production through the sulfur iodine process primarily using heat. Both processes require a high temperature (>850°C) for enhanced efficiency; temperatures indicative of the NGNP. Safety and licensing mandates prudently dictate that the NGNP and the hydrogen production facility be physically isolated, perhaps requiring separation of over 100 m.

Upgrading of straw hydrolysate for production of hydrogen and phenols in a microbial electrolysis cell (MEC)

DEFF Research Database (Denmark)

Thygesen, Anders; Marzorati, Massimo; Boon, Nico

2011-01-01

In a microbial electrolysis cell (MEC), hydrolysate produced by hydrothermal treatment of wheat straw was used for hydrogen production during selective recovery of phenols. The average H2 production rate was 0.61 m3 H2/m3 MEC·day and equivalent to a rate of 0.40 kg COD/m3 MEC·day. The microbial...... the energy content in the consumed compounds and the cell voltage of 0.7 V. The highest hydrogen production was equivalent to 0.8 kg COD/m3 MEC·day and was obtained at pH 7–8 and 25°C. Accumulation of 53% w/v phenolic compounds in the liquor was obtained by stepwise addition of the hydrolysate during...

Optimization studies of bio-hydrogen production in a coupled microbial electrolysis-dye sensitized solar cell system.

Science.gov (United States)

Ajayi, Folusho Francis; Kim, Kyoung-Yeol; Chae, Kyu-Jung; Choi, Mi-Jin; Chang, In Seop; Kim, In S

2010-03-01

Bio-hydrogen production in light-assisted microbial electrolysis cell (MEC) with a dye sensitized solar cell (DSSC) was optimized by connecting multiple MECs to a single dye (N719) sensitized solar cell (V(OC) approx. 0.7 V). Hydrogen production occurred simultaneously in all the connected MECs when the solar cell was irradiated with light. The amount of hydrogen produced in each MEC depends on the activity of the microbial catalyst on their anode. Substrate (acetate) to hydrogen conversion efficiencies ranging from 42% to 65% were obtained from the reactors during the experiment. A moderate light intensity of 430 W m(-2) was sufficient for hydrogen production in the coupled MEC-DSSC. A higher light intensity of 915 W m(-2), as well as an increase in substrate concentration, did not show any improvement in the current density due to limitation caused by the rate of microbial oxidation on the anode. A significant reduction in the surface area of the connected DSSC only showed a slight effect on current density in the coupled MEC-DSSC system when irradiated with light.

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.

On-Board Hydrogen Gas Production System For Stirling Engines

Science.gov (United States)

Johansson, Lennart N.

2004-06-29

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

Study on the best utilization of solar energy. Experimental study of hydrogen generation by water electrolysis using solar battery; Taiyo energy no yuko riyo ni kansuru kenkyu. Taiyo denchi riyosui denki bunkai suiso hassei field test

Energy Technology Data Exchange (ETDEWEB)

Kawashima, Y; Murai, K; Nakai, T [Himeji Institute of Technology, Hyogo (Japan)

1997-11-25

Shortcomings of solar energy are that it is subject to weather and is not available in the nighttime. The weak points may be effectively made up for when solar energy collected on a fine day is stored in the form of hydrogen energy for recovery as required. In this report, power generated by solar cells is used for the electrolysis of water for the generation of hydrogen. The amounts of the thus-generated hydrogen and hydrogen energy are determined and, on the basis of the measured amount of insolation, the solar energy availability rate (hydrogen conversion performance) is calculated. The amount of hydrogen generated in fiscal 1996 is also calculated for every month. The hydrogen generation level is quite low in the TiO2 wet type solar cell, approximately 0.2% at most. The current efficiency is fairly high in hydrogen generation using electrolysis, which is approximately 96-97%. The efficiency is higher when several units of electrolyte are connected in series until the solar cell optimum voltage is attained. A linear relationship is found between the daily summation of insolation and the amount of hydrogen generated. 1 ref., 7 figs., 2 tabs.

Synthesis of Ni-YSZ cermet for an electrode of high temperature electrolysis by high energy ball milling

International Nuclear Information System (INIS)

Hong, H.S.; Chae, U.S.; Park, K.M.; Choo, S.T.

2005-01-01

Ni/YSZ composites for a cathode that can be used in high temperature electrolysis were prepared by ball milling of Ni and YSZ powder. Ball milling was performed in a dry process and in ethanol. The microstructure and electrical conductivity of the composites were examined by XRD, SEM, TEM and a 4-point probe. XRD patterns for both the dry and wet ball-milled powders showed that the composites were composed of crystalline Ni and YSZ particles. The patterns did not change with increases in the milling time up to 48 h. Dry-milling slightly increased the average particle size compared to starting Ni particles, but little change in the particle size was observed with the increase in milling time. On the other hand, the wet-milling reduced the average size and the increasing milling time induced a further decrease in the particle size. After cold-pressing and annealing at 900 C for 2 h, the dry-milled powder exhibited high stability against Ni sintering so that the particle size changed little, but the particle size increased in the wet-milled powder. The electrical conductivity increased after sintering at 900 C. Particles from the dry and wet process became denser and contacted closer after sintering, providing better electron migration paths. (orig.)

Anomalously deep penetration of hydrogen into niobium under action of pulse high temperature hydrogen plasma

International Nuclear Information System (INIS)

Didyk, A.Yu.

2011-01-01

The method of elastic recoil detection (ERD) has been used for the study of storage and redistribution processes of hydrogen atoms under the influence of pulse high temperature hydrogen plasma obtained using the 'Plasma Focus' PF-4 set-up in three high purity niobium foils. It was established that with an increase of number of PF-4 set-up pulses there occur spreading and transfer of implanted hydrogen atoms to large depths in three Nb-foils which are significantly larger than the projected range of hydrogen ions (with the velocity ∼ 10 8 cm/s). The maximum hydrogen concentration up to 60 at. % is reached in the nearest to Ph-4 surface of the third Nb-foil at 20 impulses of the Ph-4 set-up. The observed phenomenon can be described by transfer of implanted hydrogen atoms under the action of powerful shock waves, created by pulse hydrogen plasma and (or) by accelerating hydrogen atom diffusion under the influence of compression straining wave at the front of the shock wave at redistribution of hydrogen atoms at large depths. Similar behavior was discovered and described also in series of nickel, vanadium, niobium and tantalum foils (two or three foils and more in a series) including series of foils from heterogeneous (different) materials, which were studied, too

HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER FINAL RECHNICAL REPORT FOR THE PERIOD AUGUST 1, 1999 THROUGH SEPTEMBER 30, 2002 REV. 1

Energy Technology Data Exchange (ETDEWEB)

BROWN,LC; BESENBRUCH,GE; LENTSCH, RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

2003-12-01

OAK-B135 Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy [1-1,1-2]. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties [1-3,1-4]. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from fossil fuels has trace contaminants (primarily

The role of hydrogen in high wind energy penetration electricity systems: the Irish case

International Nuclear Information System (INIS)

Gonzalez, A.; McKeogh, E.; Gallachoir, B.O.

2004-01-01

The deployment of wind energy is constrained by wind uncontrollability, which poses operational problems on the electricity supply system at high penetration levels, lessening the value of wind-generated electricity to a significant extent. This paper studies the viability of hydrogen production via electrolysis using wind power that cannot be easily accommodated on the system. The potential benefits of hydrogen and its role in enabling a large penetration of wind energy are assessed, within the context of the enormous wind energy resource in Ireland. The exploitation of this wind resource may in the future give rise to significant amounts of surplus wind electricity, which could be used to produce hydrogen, the zero-emissions fuel that many experts believe will eventually replace fossil fuels in the transport sector. In this paper the operation of a wind powered hydrogen production system is simulated and optimised. The results reveal that, even allowing for significant cost-reductions in electrolyser and associated balance-of-plant equipment, low average surplus wind electricity cost and a high hydrogen market price are also necessary to achieve the economic viability of the technology. These conditions would facilitate the installation of electrolysis units of sufficient capacity to allow an appreciable increase in installed wind power in Ireland. The simulation model was also used to determine the CO 2 abatement potential associated with the wind energy/hydrogen production. (author)

Hydrogen production with effluent from an ethanol–H2-coproducing fermentation reactor using a single-chamber microbial electrolysis cell

KAUST Repository

Lu, Lu

2009-06-01

Hydrogen can be produced by bacterial fermentation of sugars, but substrate conversion to hydrogen is incomplete. Using a single-chamber microbial electrolysis cell (MEC), we show that additional hydrogen can be produced from the effluent of an ethanol-type dark-fermentation reactor. An overall hydrogen recovery of 83 ± 4% was obtained using a buffered effluent (pH 6.7-7.0), with a hydrogen production rate of 1.41 ± 0.08 m3 H2/m3 reactor/d, at an applied voltage of Eap = 0.6 V. When the MEC was combined with the fermentation system, the overall hydrogen recovery was 96%, with a production rate of 2.11 m3 H2/m3/d, corresponding to an electrical energy efficiency of 287%. High cathodic hydrogen recoveries (70 ± 5% to 94 ± 4%) were obtained at applied voltages of 0.5-0.8 V due to shorter cycle times, and repression of methanogen growth through exposure of the cathode to air after each cycle. Addition of a buffer to the fermentation effluent was critical to MEC performance as there was little hydrogen production using unbuffered effluent (0.0372 m3 H2/m3/d at Eap = 0.6 V, pH 4.5-4.6). These results demonstrate that hydrogen yields from fermentation can be substantially increased by using MECs. © 2009 Elsevier B.V. All rights reserved.

Fabrication and characterization of Cu/YSZ cermet high temperature electrolysis cathode material prepared by high-energy ball-milling method

International Nuclear Information System (INIS)

Lee, Sungkyu; Kim, Jong-Min; Hong, Hyun Seon; Woo, Sang-Kook

2009-01-01

Cu/YSZ cermet (40 and 60 vol.% Cu powder with balance YSZ) is a more economical cathode material than the conventional Ni/YSZ cermet for high temperature electrolysis (HTE) of water vapor and it was successfully fabricated by high-energy ball-milling of Cu and YSZ powders, pressing into pellets (o 13 mm x 2 mm) and subsequent sintering process at 700 deg. C under flowing 5%-H 2 /Ar gas. The Cu/YSZ composite material thus fabricated was characterized using various analytical tools such as XRD, SEM, and laser diffraction and scattering method. Electrical conductivity of sintered Cu/YSZ cermet pellets thus fabricated was measured by using 4-probe technique for comparison with that of conventional Ni/YSZ cermets. The effect of composite composition on the electrical conductivity was investigated and a marked increase in electrical conductivity for copper contents greater than 40 vol.% in the composite was explained by percolation threshold. Also, Cu/YSZ cermet was selected as a candidate for HTE cathode of self-supporting planar unit cell and its electrochemical performance was investigated, paving the way for preliminary correlation of high-energy ball-milling parameters with observed physical and electrochemical performance of Cu/YSZ cermets

Summary - Advanced high-temperature reactor for hydrogen and electricity production

International Nuclear Information System (INIS)

Forsberg, Charles W.

2001-01-01

Historically, the production of electricity has been assumed to be the primary application of nuclear energy. That may change. The production of hydrogen (H 2 ) may become a significant application. The technology to produce H 2 using nuclear energy imposes different requirements on the reactor, which, in turn, may require development of new types of reactors. Advanced High Temperature reactors can meet the high temperature requirements to achieve this goal. This alternative application of nuclear energy may necessitate changes in the regulatory structure

HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS

Energy Technology Data Exchange (ETDEWEB)

Gorensek, M.

2011-07-06

Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950 C, the other 750 C. Performance was improved (over earlier flowsheets) by assuming that use of a more acid-tolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion{reg_sign}, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950 C case, dropping to 39.9% for the 750 C case.

High-temperature study of superconducting hydrogen and deuterium sulfide

Energy Technology Data Exchange (ETDEWEB)

Durajski, A.P. [Institute of Physics, Czestochowa University of Technology, Ave. Armii Krajowej 19, 42-200 Czestochowa (Poland); Szczesniak, R. [Institute of Physics, Czestochowa University of Technology, Ave. Armii Krajowej 19, 42-200 Czestochowa (Poland); Institute of Physics, Jan Dlugosz University, Ave. Armii Krajowej 13/15, 42-200 Czestochowa (Poland); Pietronero, L. [Sapienza, Universita di Roma, Dip. Fisica, P. le A. Moro 2, 00185 Roma (Italy); Institute of Complex Systems, CNR, Via dei Taurini 19 Roma (Italy); London Institute for Mathematical Sciences, South Street 22, Mayfair London (United Kingdom)

2016-05-15

Hydrogen-rich compounds are extensively explored as candidates for a high-temperature superconductors. Currently, the measured critical temperature of 203 K in hydrogen sulfide (H{sub 3}S) is among the highest over all-known superconductors. In present paper, using the strong-coupling Eliashberg theory of superconductivity, we compared in detail the thermodynamic properties of two samples containing different hydrogen isotopes H{sub 3}S and D{sub 3}S at 150 GPa. Our research indicates that it is possible to reproduce the measured values of critical temperature 203 K and 147 K for H{sub 3}S and D{sub 3}S by using a Coulomb pseudopotential of 0.123 and 0.131, respectively. However, we also discuss a scenario in which the isotope effect is independent of pressure and the Coulomb pseudopotential for D{sub 3}S is smaller than for H{sub 3}S. For both scenarios, the energy gap, specific heat, thermodynamic critical field and related dimensionless ratios are calculated and compared with other conventional superconductors. We shown that the existence of the strong-coupling and retardation effects in the systems analysed result in significant differences between values obtained within the framework of the Eliashberg formalism and the prediction of the Bardeen-Cooper-Schrieffer theory. (copyright 2015 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Effect of high hydrogen content on metallurgical and mechanical properties of zirconium alloy claddings after heat-treatment at high temperature

International Nuclear Information System (INIS)

Turque, Isabelle

2016-01-01

Under hypothetical loss-of-coolant accident conditions, fuel cladding tubes made of zirconium alloys can be exposed to steam at high temperature (HT, up 1200 C) before being cooled and then quenched in water. In some conditions, after burst occurrence the cladding can rapidly absorb a significant amount of hydrogen (secondary hydriding), up to 3000 wt.ppm locally, during steam exposition at HT. The study deals with the effect, poorly studied up to date, of high contents of hydrogen on the metallurgical and mechanical properties of two zirconium alloys, Zircaloy-4 and M5, during and after cooling from high temperatures, at which zirconium is in its β phase. A specific facility was developed to homogeneously charge in hydrogen up to ∼ 3000 wt.ppm cladding tube samples of several centimeters in length. Phase transformations, chemical element partitioning and hydrogen precipitation during cooling from the β temperature domain of zirconium were studied by using several techniques, for the materials containing up to ∼ 3000 wt.ppm of hydrogen in average: in-situ neutron diffraction upon cooling from 700 C, X-ray diffraction, μ-ERDA, EPMA and electron microscopy in particular. The results were compared to thermodynamic predictions. In order to study the effect of high hydrogen contents on the mechanical behavior of the (prior-)μ phase of zirconium, axial tensile tests were performed at various temperatures between 20 and 700 C upon cooling from the β temperature domain, on samples with mean hydrogen contents up to ∼ 3000 wt.ppm. The results show that metallurgical and mechanical properties of the (prior-)β phase of zirconium alloys strongly depend on temperature and hydrogen content. (author) [fr

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...

Hydrogen: the great debate. 'Power to Gas - how to cope with the challenge of electricity storage?; Hydrogen in energy transition: which challenges to be faced?; Hydrogen, essential today, indispensable tomorrow; Electrolytic hydrogen, a solution for energy transition?; Development of high power electrolysis systems: need and approach; Hydrogen as energy vector, Potential and stakes: a perspective; The Toyota Fuel Cell System: a new era for the automotive industry; Three key factors: production, applications to mobility, and public acceptance; Hydrogen, benevolent fairy or tempting demon

International Nuclear Information System (INIS)

Hauet, Jean-Pierre; Boucly, Philippe; Beeker, Etienne; Mauberger, Pascal; Quint, Aliette; Pierre, Helene; Lucchese, Paul; Bouillon-Delporte, Valerie; Chauvet, Bertrand; Brisse, Annabelle; Gautier, Ludmila; Hercberg, Sylvain; De Volder, Marc; Gruson, Jean-Francois; Marion, Pierre; Grellier, Sebastien; Devezeaux, Jean-Guy; Mansilla, Christine; Le Net, Elisabeth; Le Duigou, Alain; Maire, Jacques

2015-01-01

This publication proposes a set of contributions which address various issues related to the development of the use of hydrogen as an energy source. More precisely, these contributions discuss how to face the challenge of electricity storage by using the Power-to-Gas technology, the challenges to be faced regarding the role of hydrogen in energy transition, the essential current role of hydrogen and its indispensable role for tomorrow, the possible role of electrolytic hydrogen as a solution for energy transition, the need of and the approach to a development of high power electrolysis systems, the potential and stakes of hydrogen as an energy vector, the Toyota fuel cell system as a sign for new era for automotive industry, the three main factors (production, applications to mobility, and public acceptance) for the use of hydrogen in energy transition, and the role of hydrogen perceived either as a benevolent fairy or a tempting demon

Collection of outlines of achievement reports for fiscal 1976 on Sunshine Program. Hydrogen energy; 1976 nendo sunshine keikakaku seika hokokusho gaiyoshu. Suiso energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-04-01

Twenty studies are outlined, which are: Hydrogen production technology using electrolysis (Osaka National Research Institute); Hydrogen production technology using high-temperature/high-pressure electrolysis (Showa Denko K.K., and 1 other); Hydrogen production technologies using thermochemical method (4 articles - Osaka National Research Institute; Tokyo National Research Institute; Hitachi, Ltd.; Mitsubishi Heavy Industries, Ltd.); Water decomposition by thermochemical and photochemical hybrid cycle (Yokohama National University); Hydrogen production technology using direct thermolysis (Electrotechnical Laboratory); Hydrogen solidification technology (2 articles - Osaka National Research Institute; Tokyo National Research Institute); Combustion technology (Osaka National Research Institute); Materials for fuel cells (Osaka National Research Institute); Manufacture of fuel cells (Electrotechnical Laboratory); Systematization of fuel cells (Electrotechnical Laboratory); Hydrogen-fueled engine (Mechanical Engineering Laboratory); Disaster prevention technologies for gaseous and liquid hydrogen, etc. (Tokyo National Research Institute); Prevention of embrittlement of materials used with hydrogen (Chugoku National Research Institute); Refining, transportation, and storage systems, and safety techniques for hydrogen (Industrial Research Institute); Hydrogen energy total system (Electrotechnical Laboratory); Comprehensive examination of hydrogen-using subsystems and peripheral technologies (Electrochemical Society of Japan, and 6 others). (NEDO)

Metallic Membranes for High Temperature Hydrogen Separation

DEFF Research Database (Denmark)

Ma, Y.H.; Catalano, Jacopo; Guazzone, Federico

2013-01-01

membrane fabrication methods have matured over the last decades, and the deposition of very thin films (1–5 µm) of Pd over porous ceramics or modified porous metal supports is quite common. The H2 permeances and the selectivities achieved at 400–500 °C were in the order of 50–100 Nm3/m/h/bar0.5 and greater......Composite palladium membranes have extensively been studied in laboratories and, more recently, in small pilot industrial applications for the high temperature separation of hydrogen from reactant mixtures such as water-gas shift (WGS) reaction or methane steam reforming (MSR). Composite Pd...... than 1000, respectively. This chapter describes in detail composite Pd-based membrane preparation methods, which consist of the grading of the support and the deposition of the dense metal layer, their performances, and their applications in catalytic membrane reactors (CMRs) at high temperatures (400...

Hydrogen production from solar energy

Science.gov (United States)

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

1975-01-01

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

Enhanced performance of solid oxide electrolysis cells by integration with a partial oxidation reactor: Energy and exergy analyses

International Nuclear Information System (INIS)

Visitdumrongkul, Nuttawut; Tippawan, Phanicha; Authayanun, Suthida; Assabumrungrat, Suttichai; Arpornwichanop, Amornchai

2016-01-01

Highlights: • Process design of solid oxide electrolyzer integrated with a partial oxidation reactor is studied. • Effect of key operating parameters of partial oxidation reactor on the electrolyzer performance is presented. • Exergy analysis of the electrolyzer process is performed. • Partial oxidation reactor can enhance the solid oxide electrolyzer performance. • Partial oxidation reactor in the process is the highest exergy destruction unit. - Abstract: Hydrogen production without carbon dioxide emission has received a large amount of attention recently. A solid oxide electrolysis cell (SOEC) can produce pure hydrogen and oxygen via a steam electrolysis reaction that does not emit greenhouse gases. Due to the high operating temperature of SOEC, an external heat source is required for operation, which also helps to improve SOEC performance and reduce operating electricity. The non-catalytic partial oxidation reaction (POX), which is a highly exothermic reaction, can be used as an external heat source and can be integrated with SOEC. Therefore, the aim of this work is to study the effect of operating parameters of non-catalytic POX (i.e., the oxygen to carbon ratio, operating temperature and pressure) on SOEC performance, including exergy analysis of the process. The study indicates that non-catalytic partial oxidation can enhance the hydrogen production rate and efficiency of the system. In terms of exergy analysis, the non-catalytic partial oxidation reactor is demonstrated to be the highest exergy destruction unit due to irreversible chemical reactions taking place, whereas SOEC is a low exergy destruction unit. This result indicates that the partial oxidation reactor should be improved and optimally designed to obtain a high energy and exergy system efficiency.

Nanodiamond for hydrogen storage: temperature-dependent hydrogenation and charge-induced dehydrogenation.

Science.gov (United States)

Lai, Lin; Barnard, Amanda S

2012-02-21

Carbon-based hydrogen storage materials are one of hottest research topics in materials science. Although the majority of studies focus on highly porous loosely bound systems, these systems have various limitations including use at elevated temperature. Here we propose, based on computer simulations, that diamond nanoparticles may provide a new promising high temperature candidate with a moderate storage capacity, but good potential for recyclability. The hydrogenation of nanodiamonds is found to be easily achieved, in agreement with experiments, though we find the stability of hydrogenation is dependent on the morphology of nanodiamonds and surrounding environment. Hydrogenation is thermodynamically favourable even at high temperature in pure hydrogen, ammonia, and methane gas reservoirs, whereas water vapour can help to reduce the energy barrier for desorption. The greatest challenge in using this material is the breaking of the strong covalent C-H bonds, and we have identified that the spontaneous release of atomic hydrogen may be achieved through charging of hydrogenated nanodiamonds. If the degree of induced charge is properly controlled, the integrity of the host nanodiamond is maintained, which indicates that an efficient and recyclable approach for hydrogen release may be possible. This journal is © The Royal Society of Chemistry 2012

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.

Hydrogen production with nickel powder cathode catalysts in microbial electrolysis cells

KAUST Repository

Selembo, Priscilla A.

2010-01-01

Although platinum is commonly used as catalyst on the cathode in microbial electrolysis cells (MEC), non-precious metal alternatives are needed to reduce costs. Cathodes were constructed using a nickel powder (0.5-1 μm) and their performance was compared to conventional electrodes containing Pt (0.002 μm) in MECs and electrochemical tests. The MEC performance in terms of coulombic efficiency, cathodic, hydrogen and energy recoveries were similar using Ni or Pt cathodes, although the maximum hydrogen production rate (Q) was slightly lower for Ni (Q = 1.2-1.3 m3 H2/m3/d; 0.6 V applied) than Pt (1.6 m3 H2/m3/d). Nickel dissolution was minimized by replacing medium in the reactor under anoxic conditions. The stability of the Ni particles was confirmed by examining the cathodes after 12 MEC cycles using scanning electron microscopy and linear sweep voltammetry. Analysis of the anodic communities in these reactors revealed dominant populations of Geobacter sulfurreduces and Pelobacter propionicus. These results demonstrate that nickel powder can be used as a viable alternative to Pt in MECs, allowing large scale production of cathodes with similar performance to systems that use precious metal catalysts. © 2009 Professor T. Nejat Veziroglu.

Meeting the near-term demand for hydrogen using nuclear energy in competitive power markets

International Nuclear Information System (INIS)

Miller, A.I.; Duffey, R.B.

2004-01-01

Hydrogen is becoming the reference fuel for future transportation and the timetable for its adoption is shortening. However, to deploy its full potential, hydrogen production either directly or indirectly needs to satisfy three criteria: no associated emissions, including CO 2 ; wide availability; and affordability. This creates a window of great opportunity within the next 15 years for nuclear energy to provide the backbone of hydrogen-based energy systems. But nuclear must establish its hydrogen generating role long before the widespread deployment of Gen IV high-temperature reactors, with their possibility of producing hydrogen directly by heat rather than electricity. For Gen IV the major factors will be efficiency and economic cost, particularly if centralized storage is needed and/or credits for avoided emissions and/or oxygen sales. In the interim, despite its apparently lower overall efficiency, water electrolysis is the only available technology today able to meet the first and second criteria. The third criterion includes costs of electrolysis and electricity. The primary requirements for affordable electrolysis are low capital cost and high utilisation. Consequently, the electricity supply must enable high utilisation as well as being itself low-cost and emissions-free. Evolved Gen III+ nuclear technologies can produce electricity on large scales and at rates competitive with today's CO 2 -emitting, fossil-fuelled technologies. As an example of electrolytic hydrogen's potential, we show competitive deployment in a typical competitive power market. Among the attractions of this approach are reactors supplying a base-loaded market - though permitting occasional, opportunistic diversion of electricity during price spikes on the power grid - and easy delivery of hydrogen to widely distributed users. Gen IV systems with multiple product streams and higher efficiency (e.g., the SCWR) can also be envisaged which can use competitive energy markets to advantage

Electromagnetic radiation during electrolysis of heavy water

International Nuclear Information System (INIS)

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

1994-01-01

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

Hydrogen termination of CVD diamond films by high-temperature annealing at atmospheric pressure

NARCIS (Netherlands)

Seshan, V.; Ullien, D.; Castellanos-Gomez, A.; Sachdeva, S.; Murthy, D.H.K.; Savenije, T.J.; Ahmad, H.A.; Nunney, T.S.; Janssens, S.D.; Haenen, K.; Nesládek, M.; Van der Zant, H.S.J.; Sudhölter, E.J.R.; De Smet, L.C.P.M.

2013-01-01

A high-temperature procedure to hydrogenate diamond films using molecular hydrogen at atmospheric pressure was explored. Undoped and doped chemical vapour deposited (CVD) polycrystalline diamond films were treated according to our annealing method using a H2 gas flow down to ?50 ml/min (STP) at

Japan's New Sunshine Project. 1998 annual summary of hydrogen energy R and D; New sunshine keikaku 1998 nendo seika hokokusho gaiyoshu. Suiso energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-04-01

Summarized herein are the reports on R and D efforts on hydrogen energy, as part of the FY 1998 New Sunshine Project. For production of hydrogen, characteristics related to transport number were investigated for steam electrolysis at high temperature, in which a sintered ceramic powder was used as the electrolyte and the cell was equipped with platinum electrodes. For utilization of hydrogen, energy conversion techniques were investigated using hydrogen occluding alloys for testing methods for alloy microstructures and hydrogenation characteristics, and preparation of and performance testing methods for the cathodes charged with the aid of hydrogen gas. For analysis/assessment for development of hydrogen-related techniques, the investigated items included water electrolysis with solid polymer electrolytes, hydrogen transport techniques using metal hydrides, hydrogen storing techniques using metal hydrides, hydrogen engines, and techniques for preventing hydrogen embrittlement. Analysis/assessment for development of hydrogen turbines was also investigated as one of the 12 R and D themes reported herein. (NEDO)

Electrolysis: Information and Opportunities for Electric Power Utilities

Energy Technology Data Exchange (ETDEWEB)

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

2006-09-01

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

Hydrogen co-production from subcritical water-cooled nuclear power plants in Canada

Energy Technology Data Exchange (ETDEWEB)

Gnanapragasam, N.; Ryland, D.; Suppiah, S., E-mail: gnanapragasamn@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

2013-06-15

Subcritical water-cooled nuclear reactors (Sub-WCR) operate in several countries including Canada providing electricity to the civilian population. The high-temperature-steam-electrolysis process (HTSEP) is a feasible and laboratory-demonstrated large-scale hydrogen-production process. The thermal and electrical integration of the HTSEP with Sub-WCR-based nuclear-power plants (NPPs) is compared for best integration point, HTSEP operating condition and hydrogen production rate based on thermal energy efficiency. Analysis on integrated thermal efficiency suggests that the Sub-WCR NPP is ideal for hydrogen co-production with a combined efficiency of 36%. HTSEP operation analysis suggests that higher product hydrogen pressure reduces hydrogen and integrated efficiencies. The best integration point for the HTSEP with Sub-WCR NPP is upstream of the high-pressure turbine. (author)

Nanoporous, Metal Carbide, Surface Diffusion Membranes for High Temperature Hydrogen Separations

Energy Technology Data Exchange (ETDEWEB)

Way, J. Douglas [Colorado School of Mines, Golden, CO (United States). Dept. of Chemical and Biological Engineering; Wolden, Colin A. [Colorado School of Mines, Golden, CO (United States)

2013-09-30

Colorado School of Mines (CSM) developed high temperature, hydrogen permeable membranes that contain no platinum group metals with the goal of separating hydrogen from gas mixtures representative of gasification of carbon feedstocks such as coal or biomass in order to meet DOE NETL 2015 hydrogen membrane performance targets. We employed a dual synthesis strategy centered on transition metal carbides. In the first approach, novel, high temperature, surface diffusion membranes based on nanoporous Mo₂C were fabricated on ceramic supports. These were produced in a two step process that consisted of molybdenum oxide deposition followed by thermal carburization. Our best Mo₂C surface diffusion membrane achieved a pure hydrogen flux of 367 SCFH/ft² at a feed pressure of only 20 psig. The highest H₂/N₂ selectivity obtained with this approach was 4.9. A transport model using “dusty gas” theory was derived to describe the hydrogen transport in the Mo₂C coated, surface diffusion membranes. The second class of membranes developed were dense metal foils of BCC metals such as vanadium coated with thin (< 60 nm) Mo₂C catalyst layers. We have fabricated a Mo₂C/V composite membrane that in pure gas testing delivered a H₂ flux of 238 SCFH/ft² at 600 °C and 100 psig, with no detectable He permeance. This exceeds the 2010 DOE Target flux. This flux is 2.8 times that of pure Pd at the same membrane thickness and test conditions and over 79% of the 2015 flux target. In mixed gas testing we achieved a permeate purity of ≥99.99%, satisfying the permeate purity milestone, but the hydrogen permeance was low, ~0.2 SCFH/ft².psi. However, during testing of a Mo₂C coated Pd alloy membrane with DOE 1 feed gas mixture a hydrogen permeance of >2 SCFH/ft².psi was obtained which was stable during the entire test, meeting the permeance associated with

Research and development program of hydrogen production system with high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Miyamoto, Y.; Shiozawa, S.; Ogawa, M.; Inagaki, Y.; Nishihara, T.; Shimizu, S.

2000-01-01

Japan Atomic Energy Research Institute (JAERI) has been developing a hydrogen production system with a high temperature gas-cooled reactor (HTGR). While the HTGR hydrogen production system has the following advantages compared with a fossil-fired hydrogen production system; low operation cost (economical fuel cost), low CO 2 emission and saving of fossil fuel by use of nuclear heat, it requires some items to be solved as follows; cost reduction of facility such as a reactor, coolant circulation system and so on, development of control and safety technologies. As for the control and safety technologies, JAERI plans demonstration test with hydrogen production system by steam reforming of methane coupling to 30 Wt HTGR, named high temperature engineering test reactor (HTTR). Prior to the demonstration test, a 1/30-scale out-of-pile test facility is in construction for safety review and detailed design of the HTTR hydrogen production system. Also, design study will start for reduction of facility cost. Moreover, basic study on hydrogen production process without CO 2 emission is in progress by thermochemical water splitting. (orig.)

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

Is there room for hydrogen in energy transition?

International Nuclear Information System (INIS)

Beeker, Etienne

2014-08-01

As Germany decided to use hydrogen to store huge quantities of renewable energies, this report aims at assessing the opportunities associated with hydrogen in the context of energy transition. The author addresses the various techniques and technologies of hydrogen production, and proposes a prospective economic analysis of these processes: steam reforming, alkaline electrolysis, polymer electrolyte membrane (PEM) electrolysis, and other processes still at R and D level. He gives an overview of existing and potential uses of hydrogen in industry, in energy storage (power-to-gas, power-to-power, methanation) and in mobility (hydrogen-mobility could be a response to hydrocarbon shortage, but the cost is still very high, and issues like hydrogen distribution must be addressed), and also evokes their emergence potential

Nickel brittling by hydrogen. Temperature effect

International Nuclear Information System (INIS)

Lapitz, P.A; Fernandez, S; Alvarez, M.G

2006-01-01

The results of a study on the effect of different variables on the susceptibility to brittling by hydrogen and the velocity of propagation of fissures in nickel wire (99.7% purity) are described. The hydrogen load was carried out by cathodic polarization in H 2 SO 4 0.5m solution. The susceptibility to brittling by hydrogen was determined with traction tests at slow deformation speed and constant cathodic potential, and the later observation of the fracture surface by scanning electron microscopy. The variables studied were: applied cathodic overpower, speed of initial deformation and temperature. The results showed that the speed of fissure propagation in the nickel by brittleness from hydrogen is a function of the applied potential and the speed of deformation used. Without tension, the hydrogen load by cathodic polarization at room temperature leads to the formation of cavities similar to those observed when the hydrogenation is performed in the presence of gaseous hydrogen at high pressure and temperature (CW)

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

Science.gov (United States)

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

2015-01-01

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

Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell

KAUST Repository

Wang, Aijie

2011-03-01

Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs (each 25mL) connected in series to an MEC (72mL) produced a maximum of 0.43V using fermentation effluent as a feed, achieving a hydrogen production rate from the MEC of 0.48m 3 H 2/m 3/d (based on the MEC volume), and a yield of 33.2mmol H 2/g COD removed in the MEC. The overall hydrogen production for the integrated system (fermentation, MFC and MEC) was increased by 41% compared with fermentation alone to 14.3mmol H 2/g cellulose, with a total hydrogen production rate of 0.24m 3 H 2/m 3/d and an overall energy recovery efficiency of 23% (based on cellulose removed) without the need for any external electrical energy input. © 2010 Elsevier Ltd.

Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell.

Science.gov (United States)

Wang, Aijie; Sun, Dan; Cao, Guangli; Wang, Haoyu; Ren, Nanqi; Wu, Wei-Min; Logan, Bruce E

2011-03-01

Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs (each 25 mL) connected in series to an MEC (72 mL) produced a maximum of 0.43 V using fermentation effluent as a feed, achieving a hydrogen production rate from the MEC of 0.48 m(3) H(2)/m(3)/d (based on the MEC volume), and a yield of 33.2 mmol H(2)/g COD removed in the MEC. The overall hydrogen production for the integrated system (fermentation, MFC and MEC) was increased by 41% compared with fermentation alone to 14.3 mmol H(2)/g cellulose, with a total hydrogen production rate of 0.24 m(3) H(2)/m(3)/d and an overall energy recovery efficiency of 23% (based on cellulose removed) without the need for any external electrical energy input. Copyright © 2010 Elsevier Ltd. All rights reserved.

Quorum sensing alters the microbial community of electrode-respiring bacteria and hydrogen scavengers toward improving hydrogen yield in microbial electrolysis cells

International Nuclear Information System (INIS)

Cai, Weiwei; Zhang, Zhaojing; Ren, Ge; Shen, Qiuxuan; Hou, Yanan; Ma, Anzhou; Deng, Ye; Wang, Aijie; Liu, Wenzong

2016-01-01

Highlights: • Enhanced hydrogen yield has been achieved with addition of AHL. • AHL regulated exoelectrogens resulting in electrochemical activity enhancement. • Microbial community shift in cathodic biofilm inhibited hydrogen loss. - Abstract: Quorum sensing has been widely applied to enhance the energy recovery of bioelectrochemical system as a sustainable pathway to enhance communication between cells and electrodes. However, how signalling molecules (acyl-homoserine lactones, AHLs) regulate the microbial community to improve hydrogen generation in microbial electrolysis cells (MECs) is not well understood, especially the subsequent influence on interspecies relationships among not only electrode-respiring bacteria but also hydrogen scavengers. Understanding AHL regulation in a complicated and actual biofilm system will be valuable for future applications of microbial electrochemical technology. Herein, we added short-chain AHLs (3OC6) to regulate the biofilm community on bio-electrodes in MECs. As a result, hydrogen yields were enhanced with AHL addition, increasing by 5.57%, 38.68%, and 81.82% with varied external voltages (0.8 V, 0.6 V, and 0.4 V, respectively). Accordingly, overall reactor performance was enhanced, including coulombic efficiency, electron recovery efficiency, and energy efficiency. Based on an electrochemical impedance spectra analysis, the structured biofilm under simple nutrient conditions (acetate) showed a lower internal resistance with AHL addition, indicating that the microbial communities were altered to enhance electron transfer between the biofilm and electrode. The change in the cathodic microbial structure with more electrochemically active bacteria and fewer hydrogen scavengers could contribute to a higher electron recovery and hydrogen yield with AHL addition. The regulation of the microbial community structure by AHLs represents a potential strategy to enhance electron transfer and hydrogen generation in

Key Challenges to the introduction of hydrogen - European stakeholder views

International Nuclear Information System (INIS)

Seymour, E. Hugo; Murray, Luke; Fernandes, Rei

2008-01-01

Recent hydrogen policy initiatives focus on fostering the market introduction of hydrogen technologies. These initiatives include hydrogen roadmapping projects. Stakeholder involvement in strategic planning is of key importance to the successful implementation of the strategy. Thus, the views of the stakeholder group involved in the European roadmapping project HyWays are pertinent to the introduction of hydrogen in Europe. A qualitative assessment using the Key Changes and Actor Mapping (KCAM) methodology showed that on average stakeholders expect hydrogen systems to begin to be introduced over the next 15 years. Hydrogen production is expected to be based initially on steam methane reforming of natural gas and onsite electrolysis using wind power, and any hydrogen transport is likely to be by truck. The major challenges envisaged are to do with carbon capture and storage, high-temperature hydrogen production technologies and hydrogen pipeline development. (author)

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

Science.gov (United States)

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

2017-11-01

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

Performance of single chamber biocatalyzed electrolysis with different types of ion exchange membranes

NARCIS (Netherlands)

Rozendal, R.A.; Hamelers, H.V.M.; Molenkamp, R.J.; Buisman, C.J.N.

2007-01-01

In this paper hydrogen production through biocatalyzed electrolysis was studied for the first time in a single chamber configuration. Single chamber biocatalyzed electrolysis was tested in two configurations: (i) with a cation exchange membrane (CEM) and (ii) with an anion exchange membrane (AEM).

The Feasibility of Onsite Electrolysis as Primary and Clean Production Source of Fuel Hydrogen in Brazil

International Nuclear Information System (INIS)

COSTA, Andre R

2006-01-01

In accordance with the International Monetary Fund Brazil is currently the world's 12. largest and Latin America's largest economy, with a nominal GPD in the amount of US dollars 732,078 millions. Despite the fact that energy production is still heavily based on hydrocarbons, such as oil, natural gas and coal, the country is often indicated as one of the worldwide leaders in implementing renewable energy sources, primarily due to the spread utilization of bio-ethanol in transportation and the electricity production from hydropower. The purpose of this study is to assess the feasibility of onsite electrolysis as primary and clean source of fuel hydrogen in Brazil, indicating the main advantages of this production method. A perspective of the most significant challenges and actions to be taken regarding the accomplishment of a clean Brazilian hydrogen economy will be presented herein. (author)

Status of hydrogen production by nuclear power

International Nuclear Information System (INIS)

Chang, Jong Wa; Yoo, Kun Joong; Park, Chang Kue

2001-07-01

Hydrogen production methods, such as electrolysis, thermochemical method, biological method, and photochemical method, are introduced in this report. Also reviewed are current status of the development of High Temperatrue Gas Coooled Reactor, and it application for hydrogen production

Prospect of HTGRs for hydrogen production in Indonesia

International Nuclear Information System (INIS)

Rusli, A.; Dasuki, A.S.; Rahman, M.; Nuriman; Sudarto

1997-01-01

Hydrogen energy system is interesting to many people of the world that because of hydrogen promised to save our planet earth from destroying of burning of fossil fuels. The selected development of hydrogen production from water such as electrolysis and thermochemical cycles are evaluated. These processes are allowed to split the water at lower temperature, still in the range of HTGRs' working temperature. An overview of related studies in recent years enables the development of research to be followed, studied and evaluated are mentioned. The prospect of hydrogen market in Indonesia and economic consideration based on previous studied are also analyzed and evaluated. (author). 11 refs, 5 figs, 13 tabs

Influence of hydrogen additions on high-temperature superplasticity of titanium alloys

International Nuclear Information System (INIS)

Lederich, R.J.; Sastry, S.M.L.

1982-01-01

The effects of the addition of up to 1.0 wt pct hydrogen as a transient alloying element on the superplastic formability (SPF) of fine-grained, equiaxed Ti-6Al-4V (Ti-64) and duplex-annealed Ti-6Al-2Sn-4Zr-2Mo (Ti-6242) were determined. Small amounts of internal hydrogen greatly improve the SPF of the alloys. Formability at 720-900 C was evaluated by an instrumented cone-forming test with continuous monitoring of strain with time. Argon/1 pct hydrogen and argon/4 pct hydrogen gas mixtures were used for charging the alloys with hydrogen as well as for superplastic forming. Hydrogen additions lower the beta-transus temperature of alpha-beta titanium alloys, and the proportions of the alpha and beta phases required for optimum superplasticity can thus be obtained at lower temperatures in hydrogen-modified alloys than in standard alloys. The increased amount of beta phase in the hydrogen-modified titanium alloys reduces the grain growth rates at forming temperature, thus reducing the time-dependent decrease in superplastic strain rate at constant stress or the increase in flow stress at constant strain rate. Process parameters for superplastic forming of Ti-64 and Ti-6242 using argon-hydrogen gas mixtures were determined. 8 references

Electrolysis of a nitrosyl hexafluoro-molybdate in anhydrous hydrogen fluoride

International Nuclear Information System (INIS)

Mougin, Jacques

1972-01-01

This thesis addresses the field of irradiated fuel reprocessing, and more particularly the study of the formation of molybdenum hexafluoride (MoF_6) by electrolysis of nitrosyl hexafluoro-molybdate (NOMoF_6) in solution in HF. The author presents the conditions of preparation of an electrolysis in anhydrous HF: solvent purification and control, production of a reference electrode, potential-kinetic study of the behaviour of materials selected for the electrode. The author then addresses the actual hydrolysis of the solution of nitrosyl hexafluoro-molybdate [fr

Penetration of hydrogen isotopes through EhI 698 alloy at high pressure and temperature

International Nuclear Information System (INIS)

Bystritskij, V.M.; Voznyak, Ya.; Granovskij, V.B.

1986-01-01

The paper deals with investigations of the process of hydrogen and deuterium penetration through the high-temperature alloy EhI-698 at a pressure up to 1 kbar and temperature up to 1050 K. Parameters of the process obey Sieverts's law and can be described by Arrenius's and Vant-Goff's equations. The obtained results lead to a conclusion that the alloy EhI-698 is good for vessels to be employed in hydrogen media

Hydrogen production by water dissociation from a nuclear reactor; Production d'hydrogene par dissociation de l'eau a partir d'un reacteur nucleaire

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

This memento presents the production of hydrogen by water decomposition, the energy needed for the electrolysis, the thermochemical cycles for a decomposition at low temperature and the possible nuclear reactors associated. (A.L.B.)

Ultrasonic and metallographic studies on AISI 4140 steel exposed to hydrogen at high pressure and temperature

Science.gov (United States)

Oruganti, Malavika

This thesis conducts an investigation to study the effects of hydrogen exposure at high temperature and pressure on the behavior of AISI 4140 steel. Piezoelectric ultrasonic technique was primarily used to evaluate surface longitudinal wave velocity and defect geometry variations, as related to time after exposure to hydrogen at high temperature and pressure. Critically refracted longitudinal wave technique was used for the former and pulse-echo technique for the latter. Optical microscopy and scanning electron microscopy were used to correlate the ultrasonic results with the microstructure of the steel and to provide better insight into the steel behavior. The results of the investigation indicate that frequency analysis of the defect echo, determined using the pulse-echo technique at regular intervals of time, appears to be a promising tool for monitoring defect growth induced by a high temperature and high pressure hydrogen-related attack.

Hydrogen production system coupled with high-temperature gas-cooled reactor (HTTR)

International Nuclear Information System (INIS)

Shiozawa, Shusaku

2003-01-01

On the HTTR program, R and D on nuclear reactor technology and R and D on thermal application technology such as hydrogen production and so on, are advanced. When carrying out power generation and thermal application such as hydrogen production and so on, it is, at first, necessary to supply nuclear heat safely, stably and in low cost, JAERI carries out some R and Ds on nuclear reactor technology using HTTR. In parallel to this, JAERI also carries out R and D for jointing nuclear reactor system with thermal application systems because of no experience in the world on high temperature heat of about 1,000 centigrade supplied by nuclear reactor except power generation, and R and D on thermochemical decomposition method IS process for producing hydrogen from water without exhaust of carbon dioxide. Here were described summaries on R and D on nuclear reactor technology, R and D on jointing technology using HTTR hydrogen production system, R and D on IS process hydrogen production, and comparison hydrogen production with other processes. (G.K.)

Influence of rolling direction and carbide precipitation on IGSCC susceptibility in hydrogenated high temperature water

International Nuclear Information System (INIS)

Arioka, Koji; Yamada, Takuyo; Terachi, Takumi; Chiba, Goro

2005-01-01

IGSCC growth behaviors of austenitic stainless steels in hydrogenated high temperature water were studied using compact type specimens (0.5T for cold worked materials). The effect of cold rolling direction, alloy composition and carbide precipitation on crack growth behaviors was studied in hydrogenated high temperature water. Then, to examine the effect of cold work and carbide precipitation on IGSCC behaviors, the role of grain boundary sliding studied in high temperature air using CT specimens. The similar dependences of carbide precipitation and cold work on IGSCC and creep behaviors suggest that grain boundary sliding might play an important role by itself or in conjunction with other reactions such as crack tip dissolution etc. (author)

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

KAUST Repository

Luo, Xi

2013-07-01

Waste heat can be captured as electrical energy to drive hydrogen evolution in microbial reverse-electrodialysis electrolysis cells (MRECs) by using thermolytic solutions such as ammonium bicarbonate. To determine the optimal membrane stack configuration for efficient hydrogen production in MRECs using ammonium bicarbonate solutions, different numbers of cell pairs and stack arrangements were tested. The optimum number of cell pairs was determined to be five based on MREC performance and a desire to minimize capital costs. The stack arrangement was altered by placing an extra low concentration chamber adjacent to anode chamber to reduce ammonia crossover. This additional chamber decreased ammonia nitrogen losses into anolyte by 60%, increased the coulombic efficiency to 83%, and improved the hydrogen yield to a maximum of 3.5mol H2/mol acetate, with an overall energy efficiency of 27%. These results improve the MREC process, making it a more efficient method for renewable hydrogen gas production. © 2013 Elsevier Ltd.

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-07-01

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

Hydrogen: an energy carrier of the future

Energy Technology Data Exchange (ETDEWEB)

Hamerak, K

1977-02-01

Some advantages and fields of application of hydrogen are outlined in the introduction. Hydrogen production by conventional water electrolysis, by the thermochemical iron-chlorine cycle process, and by a new water electrolysis method still in the laboratory stage are dealt with in which the electrolysis voltage is considerably reduced by the action of solar UV light on an anode consisting of p-conducting material.

Cadmium (II) removal mechanisms in microbial electrolysis cells

Energy Technology Data Exchange (ETDEWEB)

Colantonio, Natalie; Kim, Younggy, E-mail: younggy@mcmaster.ca

2016-07-05

Highlights: • Rapid removal of Cd(II) was achieved in 24 h using microbial electrolysis cells. • Cathodic reduction (electrodeposition) of Cd(II) cannot explain the rapid removal. • H{sub 2} evolution in microbial electrolysis cells increases local pH near the cathode. • High local pH induces Cd(OH){sub 2} and CdCO{sub 3} precipitation only with electric current. • Neutral pH caused by low current and depleted substrate dissolves the precipitated Cd. - Abstract: Cadmium is a toxic heavy metal, causing serious environmental and human health problems. Conventional methods for removing cadmium from wastewater are expensive and inefficient for low concentrations. Microbial electrolysis cells (MECs) can simultaneously treat wastewater, produce hydrogen gas, and remove heavy metals with low energy requirements. Lab-scale MECs were operated to remove cadmium under various electric conditions: applied voltages of 0.4, 0.6, 0.8, and 1.0 V; and a fixed cathode potential of −1.0 V vs. Ag/AgCl. Regardless of the electric condition, rapid removal of cadmium was demonstrated (50–67% in 24 h); however, cadmium concentration in solution increased after the electric current dropped with depleted organic substrate under applied voltage conditions. For the fixed cathode potential, the electric current was maintained even after substrate depletion and thus cadmium concentration did not increase. These results can be explained by three different removal mechanisms: cathodic reduction; Cd(OH){sub 2} precipitation; and CdCO{sub 3} precipitation. When the current decreased with depleted substrates, local pH at the cathode was no longer high due to slowed hydrogen evolution reaction (2H{sup +} + 2e{sup −} → H{sub 2}); thus, the precipitated Cd(OH){sub 2} and CdCO{sub 3} started dissolving. To prevent their dissolution, sufficient organic substrates should be provided when MECs are used for cadmium removal.

Hydrogen generation by nuclear power for sustainable development in the 21-st century

International Nuclear Information System (INIS)

Bilegan, Iosif Constantin; Pall, Stefan

2002-01-01

Hydrogen is the main non-polluting fuel. It is produced by natural gas steam reforming, water electrolysis and thermonuclear processes. Currently, 4% of the hydrogen world production is obtained by water electrolysis. The use of nuclear power for hydrogen production avoids the generation of greenhouse gases and the dependence of primary external energy sources. The US is currently developing a modular reactor for hydrogen production and water desalination, STAR - H 2 (Secure Transportable Autonomous Reactor for Hydrogen production) with fast neutrons, lead cooling and passive safety systems operating at a temperature of 780 deg C. Also, a Russian reactor of the same type is operated at 540 deg C. China and India joint industrial countries like France, Japan, Russia and US in recognizing that any strategies aiming at a future with clean energy implies the nuclear energy

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

. In this work, long-term durability of Ni/yttria stabilized zirconia (YSZ) supported planar SOECs were investigated at 800 oC for electrolysis of steam. The cells, which represent the state-of-the-art SOEC technology at Technical University of Denmark (DTU), have a Ni/YSZ support and active fuel electrode......, OCV) to -1.25 A/cm2. Detailed electrochemical and post-mortem characterizations were further conducted in order to clarify the cell or electrode degradation mechanisms. The cells show stable performance, with a steady-state degradation rate of up to 2 %/1000 h for electrolysis tests with current......Globally the amount of electricity generated from renewable energy sources such as wind or solar energy is increasing. To integrate high amount of fluctuating renewable energy into the existing energy grid, efficient and cost competitive conversion of electricity into other kinds of energy carriers...

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Static feed water electrolysis subsystem development

Science.gov (United States)

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

1991-01-01

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

Water electrolysis system

International Nuclear Information System (INIS)

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

1996-01-01

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

Methanol from biomass and hydrogen

International Nuclear Information System (INIS)

Anon.

1989-01-01

For Hawaii in the near term, the only liquid fuels indigenous sources will be those that can be made from biomass, and of these, methanol is the most promising. In addition, hydrogen produced by electrolysis can be used to markedly increase the yield of biomass methanol. This paper calculates cost of producing methanol by an integrated system including a geothermal electricity facility plus a plant producing methanol by gasifying biomass and adding hydrogen produced by electrolysis. Other studies cover methanol from biomass without added hydrogen and methanol from biomass by steam and carbon dioxide reforming. Methanol is made in a two-step process: the first is the gasification of biomass by partial oxidation with pure oxygen to produce carbon oxides and hydrogen, and the second is the reaction of gases to form methanol. Geothermal steam is used to generate the electricity used for the electrolysis to produce the added hydrogen

Chemically durable polymer electrolytes for solid-state alkaline water electrolysis

Science.gov (United States)

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

2018-01-01

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

Hydrogen permeation behavior through F82H at high temperature

Energy Technology Data Exchange (ETDEWEB)

Matsuda, S.; Katayama, K.; Shimozori, M.; Fukada, S. [Interdisciplinary Graduate School of Engineering Science, Kyushu University, Kyushu (Japan); Ushida, H. [Energy Science and Engineering, Faculty of Engineering, Kyushu University, Kyushu (Japan); Nishikawa, M. [Malaysia-Japan International Institute of Technology, UTM, Kuala Lumpur (Malaysia)

2015-03-15

F82H is a primary candidate of structural material and coolant pipe material in a blanket of a fusion reactor. Understanding tritium permeation behavior through F82H is important. In a normal operation of a fusion reactor, the temperature of F82H will be controlled below 550 C. degrees because it is considered that F82H can be used up to 30,000 hours at 550 C. degrees. However, it is necessary to assume the situation where F82H is heated over 550 C. degrees in a severe accident. In this study, hydrogen permeation behavior through F82H was investigated in the temperature range from 500 to 800 C. degrees. In some cases, water vapor was added in a sample gas to investigate an effect of water vapor on hydrogen permeation. The permeability of hydrogen in the temperature range from 500 to 700 C. degrees agreed well with the permeability reported by E. Serra et al. The degradation of the permeability by water vapor was not observed. After the hydrogen permeation reached in a steady state at 700 C. degrees, the F82H sample was heated to 800 C. degrees. The permeability of hydrogen through F82H sample which was once heated up to 800 C. degrees was lower than that of the original one. (authors)

High Efficiency Generation of Hydrogen Fuels Using Solar Thermochemical Splitting of Water

Energy Technology Data Exchange (ETDEWEB)

Heske, Clemens; Moujaes, Samir; Weimer, Alan; Wong, Bunsen; Siegal, Nathan; McFarland, Eric; Miller, Eric; Lewis, Michele; Bingham, Carl; Roth, Kurth; Sabacky, Bruce; Steinfeld, Aldo

2011-09-29

The objective of this work is to identify economically feasible concepts for the production of hydrogen from water using solar energy. The ultimate project objective was to select one or more competitive concepts for pilot-scale demonstration using concentrated solar energy. Results of pilot scale plant performance would be used as foundation for seeking public and private resources for full-scale plant development and testing. Economical success in this venture would afford the public with a renewable and limitless source of energy carrier for use in electric power load-leveling and as a carbon-free transportation fuel. The Solar Hydrogen Generation Research (SHGR) project embraces technologies relevant to hydrogen research under the Office of Hydrogen Fuel Cells and Infrastructure Technology (HFCIT) as well as concentrated solar power under the Office of Solar Energy Technologies (SET). Although the photoelectrochemical work is aligned with HFCIT, some of the technologies in this effort are also consistent with the skills and technologies found in concentrated solar power and photovoltaic technology under the Office of Solar Energy Technologies (SET). Hydrogen production by thermo-chemical water-splitting is a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or a combination of heat and electrolysis instead of pure electrolysis and meets the goals for hydrogen production using only water and renewable solar energy as feed-stocks. Photoelectrochemical hydrogen production also meets these goals by implementing photo-electrolysis at the surface of a semiconductor in contact with an electrolyte with bias provided by a photovoltaic source. Here, water splitting is a photo-electrolytic process in which hydrogen is produced using only solar photons and water as feed-stocks. The thermochemical hydrogen task engendered formal collaborations among two universities, three national laboratories and two private sector

The INNOHYP-CA Project: producing Hydrogen by innovative high-temperature processes

International Nuclear Information System (INIS)

Giaconia, A.; Giorgiantoni, G.; Liberatore, R.; Tarquini, P.; Vignolini, M.

2008-01-01

The Project, financed under the 6. Framework Programme, has selected a member of innovative high-temperature processes that seem promising for large-scale production of Hydrogen. ENEA has contributed to the analysis of the status of national and regional projects in the European countries and to the definition of guidelines for the future development of these technologies [it

Assessment of thermochemical hydrogen production. Project 61010 (formerly 8994) final report, July 1, 1977-March 31, 1979

Energy Technology Data Exchange (ETDEWEB)

Dafler, J.R.; Foh, S.E.; Lee, T.S.; Schreiber, J.D.

1979-05-01

The Institute of Gas Technology's (IGT) assessment of thermochemical water-splitting processes is given. Eight tasks were performed: evaluation of load-line efficiencies; hydrogen bromide electrolysis; maximum attainable thermal efficiency on a specific bromide hybrid cycle; development of electrolyzer elements for H/sub 2/SO/sub 3/; feasibility of high-temperature reference-state thermochemical cycles; interfacing characteristics - solar high-temperature heat sources; analysis of solar and solar hybrid heat sources; and laboratory assessment of cycle with high-temperature step. Engineering analyses were done on two thermochemical hydrogen production cycles - IGT's cycles B-1 and H-5. The load line efficiency for B-1 was 18.1% and for H-5 37.4%. The electrolysis of HBr (aq) on three substrates: platinum, porous graphite, and vitreous graphite was investigated. Platinum proved to be the most efficient electrode surface, with vitreous graphite showing no promise, and porous graphite showing only slightly better results. On platinum, cell voltages of under 1.0 volt were obtained at current densities up to 200 mA/cm/sup 2/. Five new members of the metal-metal oxide class of cycles were derived. The maximum attainable efficiencies of these high-temperature, two-step cycles range from 64 to 86%. Six high-temperature metal oxide-metal sulfate cycles were derived. Performance and capital costs data for a wide range of solar primary heat sources were tabulated.

Gradient Meshed and Toughened SOEC (Solid Oxide Electrolyzer Cell) Composite Seal with Self-Healing Capabilities

Energy Technology Data Exchange (ETDEWEB)

Kathy Lu; W. T. Reynolds, Jr.

2010-06-08

High-temperature electrolysis of water steam is a promising approach for hydrogen production. The potential is even more promising when abundant heat source from nuclear power reactors can be efficiently utilized. Hydrogen production through the above approach also allows for low electric consumption. Overall energy conversion efficiencies for high temperature electrolysis are in the 45-50% range compared to ~30% for the conventional electrolysis. Under such motivation, this research is focused on increasing the operation time and high temperature stability of solid oxide electrolyzer cells (SOEC) for splitting water into hydrogen. Specifically, our focus is to improve the SOEC seal thermal stability and performances by alleviating thermal stress and seal cracking issues.

Performance of CVD and CVR coated carbon-carbon in high temperature hydrogen

Science.gov (United States)

Adams, J. W.; Barletta, R. E.; Svandrlik, J.; Vanier, P. E.

As a part of the component development process for the particle bed reactor (PBR), it is necessary to develop coatings which will be time and temperature stable at extremely high temperatures in flowing hydrogen. These coatings must protect the underlying carbon structure from attack by the hydrogen coolant. Degradation which causes small changes in the reactor component, e.g. hole diameter in the hot frit, can have a profound effect on operation. The ability of a component to withstand repeated temperature cycles is also a coating development issue. Coatings which crack or spall under these conditions would be unacceptable. While refractory carbides appear to be the coating material of choice for carbon substrates being used in PBR components, the method of applying these coatings can have a large effect on their performance. Two deposition processes for these refractory carbides, chemical vapor deposition (CVD) and chemical vapor reaction (CVR), have been evaluated. Screening tests for these coatings consisted of testing of coated 2-D and 3-D weave carbon-carbon in flowing hot hydrogen at one atmosphere. Carbon loss from these samples was measured as a function of time. Exposure temperatures up to 3,000 K were used, and samples were exposed in a cyclical fashion cooling to room temperature between exposures. The results of these measurements are presented along with an evaluation of the relative merits of CVR and CVD coatings for this application.

Economics of liquid hydrogen from water electrolysis

Science.gov (United States)

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

1985-01-01

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

Study of the bipolar electrolysis of the tritiated water applied to the hydrogen isotopes separation by electrochemical permeation threw Pd-Ag alloy membranes

International Nuclear Information System (INIS)

Heinze, S.

2000-01-01

The objective of the study is to enrich waters of poor tritium concentration, by electrolysis in the same time of an hydrogen emission of low activity. In this framework the hydrogen electrochemical permeation threw Pd-Ag alloy membranes has been used. The first part of the study concerns the hydrogen and the deuterium diffusion threw these membranes. The activation and the thermal treatments influence have been studied. A relation between the membrane microstructure and the diffusion mechanism has been proposed. The second part of the study is devoted to the hydrogen gate mechanism determination in the membrane by impedance spectroscopy. The last part concerns the determination of the isotopic separation factor hydrogen-deuterium. Experimental results agree the calculated theoretical data. The operation of an operational membrane cell has been simulated and the process feasibility has been proved. (A.L.B.)

Fiscal 1974-1975 Sunshine Project research report. Hydrogen energy research results (National laboratories and institutes); 1974, 1975 nendo suiso energy kenkyu seika hokokushu. Kokuritsu shiken kenkyusho kankei

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-10-01

This report summarizes the 21 research results on hydrogen energy promoted by 3 national laboratories and 2 national institutes. (1) Tokyo National Industrial Research Institute (TNIRI): Ca-I system, Mn system, S system and hybrid cycles, and water decomposition reaction by CO as thermochemical hydrogen production technique. (2) Osaka National Industrial Research Institute (ONIRI): Fe system, Cu system and ammonia system cycles, and high-temperature high-pressure water electrolysis. (3) Electrotechnical Laboratory: high- temperature direct thermolysis hydrogen production technique. (4) TNIRI: Mg-base and transition metal-base hydrogen solidification technique. (5) ONIRI: Ti-base and rare metal- base hydrogen solidification technique. (6) Mechanical Engineering Laboratory: hydrogen-fuel engines. (7) Electrotechnical Laboratory and ONIRI: fuel cell. (8) TNIRI: disaster preventive technology for gaseous and liquid hydrogen. (9) Chugoku National Industrial Research Institute: preventing materials from embrittlement due to hydrogen. (10) Electrotechnical Laboratory: hydrogen energy system. (NEDO)

Development status of a preprototype water electrolysis subsystem

Science.gov (United States)

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

1981-01-01

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

Development status on hydrogen production technology using high-temperature gas-cooled reactor at JAEA, Japan

International Nuclear Information System (INIS)

Shiozawa, Shusaku; Ogawa, Masuro; Hino, Ryutaro

2006-01-01

The high-temperature gas-cooled reactor (HTGR), which is graphite-moderated and helium-cooled, is attractive due to its unique capability of producing high temperature helium gas and its fully inherent reactor safety. In particular, hydrogen production using the nuclear heat from HTGR (up to 900 deg. C) offers one of the most promising technological solutions to curb the rising level of CO 2 emission and resulting risk of climate change. The interests in HTGR as an advanced nuclear power source for the next generation reactor, therefore, continue to rise. This is represented by the Japanese HTTR (High-Temperature Engineering Test Reactor) Project and the Chinese HTR-10 Project, followed by the international Generation IV development program, US nuclear hydrogen initiative program, EU innovative HTR technology development program, etc. To enhance nuclear energy application to heat process industries, the Japan Atomic Energy Agency (JAEA) has continued extensive efforts for development of hydrogen production system using the nuclear heat from HTGR in the framework of the HTTR Project. The HTTR Project has the objectives of establishing both HTGR technology and heat utilization technology. Using the HTTR constructed at the Oarai Research and Development Center of JAEA, reactor performance and safety demonstration tests have been conducted as planned. The reactor outlet temperature of 950 deg. C was successfully achieved in April 2004. For hydrogen production as heat utilization technology, R and D on thermo-chemical water splitting by the 'Iodine-Sulfur process' (IS process) has been conducted step by step. Proof of the basic IS process was made in 1997 on a lab-scale of hydrogen production of 1 L/h. In 2004, one-week continuous operation of the IS process was successfully demonstrated using a bench-scale apparatus with hydrogen production rate of 31 L/h. Further test using a pilot scale facility with greater hydrogen production rate of 10 - 30 m 3 /h is planned as

Hydrogen/Oxygen Reactions at High Pressures and Intermediate Temperatures: Flow Reactor Experiments and Kinetic Modeling

DEFF Research Database (Denmark)

Hashemi, Hamid; Christensen, Jakob Munkholt; Glarborg, Peter

A series of experimental and numerical investigations into hydrogen oxidation at high pressures and intermediate temperatures has been conducted. The experiments were carried out in a high pressure laminar flow reactor at 50 bar pressure and a temperature range of 600–900 K. The equivalence ratio......, the mechanism is used to simulate published data on ignition delay time and laminar burning velocity of hydrogen. The flow reactor results show that at reducing, stoichiometric, and oxidizing conditions, conversion starts at temperatures of 750–775 K, 800–825 K, and 800–825 K, respectively. In oxygen atmosphere......, ignition occurs at the temperature of 775–800 K. In general, the present model provides a good agreement with the measurements in the flow reactor and with recent data on laminar burning velocity and ignition delay time....

Hydrogen production methods

International Nuclear Information System (INIS)

Hammerli, M.

1982-07-01

Old, present and new proceses for producing hydrogen are assessed critically. The emphasis throughout is placed on those processes which could be commercially viable before the turn of the century for large-scale hydrogen manufacture. Electrolysis of water is the only industrial process not dependent on fossil resources for large-scale hydrogen production and is likely to remain so for the next two or three decades. While many new processes, including those utilizing sunlight directly or indirectly, are presently not considered to be commercially viable for large-scale hydrogen production, research and development effort is needed to enhance our understanding of the nature of these processes. Water vapour electrolysis is compared with thermochemical processes: the former has the potential for displacing all other processes for producing hydrogen and oxygen from water

Redox-reversible perovskite ferrite cathode for high temperature solid oxide steam electrolyser

International Nuclear Information System (INIS)

Li, Zhe; Li, Shisong; Tseng, Chung-Jen; Tao, Shanwen; Xie, Kui

2017-01-01

Highlights: • Redox reversible ferrite cathode is demonstrated for solid oxide electrolyser. • Promising electrical conductivity is obtained with Pr doping in hydrogen. • High performance of steam electrolysis is achieved with ferrite cathode. - Abstract: In this work, perovskite Sr 1−x Pr x FeO 3-δ (SPF) (x = 0.02, 0.04, 0.06, 0.08 and 0.10) are investigated and employed as solid oxide steam electrolyser cathode at 800 °C. X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscopy (TEM) analysis together indicate that the Sr 1−x Pr x FeO 3-δ is redox reversible with a phase transition from cubic to orthorhombic structure in redox cycles. The doping of Pr in A site has remarkably enhanced the electronic conduction to 1.0–1.2 S cm −1 at intermediate temperatures in reducing atmosphere. Electrochemical measurements demonstrate that the polarization resistance with Sr 0.96 Pr 0.04 FeO 3-δ electrode shows the lowest values of 0.25 Ω cm 2 in symmetric cells in reducing atmosphere at 800 °C. Direct steam electrolysis with Sr 0.96 Pr 0.04 FeO 3-δ cathode shows a current density of 1.64 A cm −2 at 2.0 V when fed with 5%H 2 O/Ar. The hydrogen production rate reaches 4.73, 6.68, 8.35 and 10.23 mL min −1 cm −2 at 1.4, 1.6, 1.8, 2.0 V, respectively, while the highest Faraday efficiency is as high as 97.16% at 1.8 V.

New hydrogen technologies

International Nuclear Information System (INIS)