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Yucheng Wu - One of the best experts on this subject based on the ideXlab platform.

  • Composite cathode La0.4Sr0.4TiO3−δ–Ce0.8Sm0.2O2−δ impregnated with Ni for High-Temperature Steam Electrolysis
    Journal of Power Sources, 2020
    Co-Authors: Shigang Chen, Dehua Dong, Yan Wang, Yucheng Wu
    Abstract:

    Abstract Composite Ni–SDC (Samaria doped Ceria) cathodes are able to operate in strong reducing atmospheres for Steam Electrolysis, and composite cathodes based on redox-stable La 0.4 Sr 0.4 TiO 3 (LSTO) have demonstrated promising performances without the reducing gas flow. However, the electro-catalytic activity of cathodes based on LSTO is insufficient for the efficient electrochemical reduction of Steam or carbon oxide. In this work, catalytic-active Ni nanoparticles were loaded on a La 0.4 Sr 0.4 TiO 3− δ –Ce 0.8 Sm 0.2 O 2− δ cathode (Ni-loaded LSTO–SDC) via an impregnation method to improve the electrode performances for direct Steam Electrolysis. The synergetic effect of catalytically-active Ni nanoparticles and the redox-stable LSTO–SDC skeleton contributed to the improved performances and the excellent stability of the cathode for direct Steam Electrolysis. The current efficiency with a Ni-loaded cathode was enhanced by 3% and 17% compared to the values with a bare LSTO–SDC cathode under 2.0 V of applied voltage at 800 °C with a flow of 3% H 2 O/5% H 2 /Ar and 3% H 2 O/Ar to cathodes, respectively.

  • Composite manganate oxygen electrode enhanced with iron oxide nanocatalyst for high temperature Steam Electrolysis in a proton-conducting solid oxide electrolyzer
    International Journal of Hydrogen Energy, 2015
    Co-Authors: Huaxin Li, Shigang Chen, Xiaoli Chen, Yucheng Wu
    Abstract:

    Abstract Composite electrode based on La0.8Sr0.2MnO3-δ (LSM) can be utilized in a proton-conducting solid oxide electrolyzer for Steam Electrolysis; however, the insufficient electro-catalytic activity of LSM still restricts the electrode performance and Faraday current efficiency. In this work, catalytic-active iron oxide nanoparticles are loaded on the surface of LSM composite oxygen electrode to improve electro-catalytic performance as well as extend the three-phase boundaries. SEM and EDS results together confirm the loading of Fe2O3 nanoparticles with the size of approximately 20–40 nm on the surface of LSM composite oxygen electrode. The effects on electrode performance due to different contents of Fe2O3 are loaded into LSM composite electrodes are systemically studied using symmetric cells. The electrical property of LSM is investigated and correlated to the electrochemical performance of the composite oxygen electrode in Electrolysis cells. The maximum Faraday current efficiency is approximately 65% with the Fe2O3-loaded LSM composite electrode for Steam Electrolysis in a proton-conducting solid oxide electrolyzer at 800 °C.

  • A composite cathode based on scandium-doped chromate for direct High-Temperature Steam Electrolysis in a symmetric solid oxide electrolyzer
    Journal of Power Sources, 2015
    Co-Authors: Shigang Chen, Yong Zhang, Dehua Dong, Huaxin Li, Yucheng Wu
    Abstract:

    Composite cathodes based on La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCM) are promising candidates for direct Steam Electrolysis while their insufficient electro-catalytic activity still restricts Faradic efficiency and electrode performance. In this work, scandium is doped into LSCM (LSCMS) to enhance the performance of the composite cathode. The combined characterization of XRD, TEM, TGA and XPS indicates successful partial replacement of Cr/Mn by scandium in the B site of chromate. The doping of scandium remarkably improves ionic conductivity while accordingly decreases the mixed conductivity. Electrochemical measurements demonstrate the decreased electrode polarizations of LSCMS cathodes. The Faradic efficiencies are accordingly enhanced by 20% and 50% compared with the electrolyzer with LSCM cathode for high temperature Steam Electrolysis by exposing cathode to 5%H2O/5%H2/Ar and 5%H2O/Ar, respectively.

  • Electrochemical Investigation of La0.2Sr0.8TiO3+δ-Ce0.8Sm0.2O2-δ Composite Cathode for the Direct High Temperature Steam Electrolysis
    Advanced Materials Research, 2014
    Co-Authors: Guojian Wu, Yucheng Wu
    Abstract:

    This paper investigates a composite cathode La0.2Sr0.8TiO3+δ-Ce0.8Sm0.2O2-δ (LSTO-SDC) for the direct Steam Electrolysis in an oxide-ion-conducting solid oxide electrolyzer. The dependences of electrical conductivity of the reduced LSTO on temperature and oxygen partial pressure are studied and further correlated to the electrochemical properties of the cathode in symmetric cell LSTO-SDC/YSZ/LSTO-SDC and solid oxide electrolyzer LSTO-SDC/YSZ/LSM-SDC, respectively. Current efficiencies of the solid oxide electrolyzer with LSTO-SDC cathode were found to be 92.38% and 91.17% with or without reducing gas flowing over them under the applied voltage of 1.8 V at 800 °C, respectively.

  • Composite titanate cathode enhanced with in situ grown nickel nanocatalyst for direct Steam Electrolysis
    New Journal of Chemistry, 2014
    Co-Authors: Jun Zhang, Yong Zhang, Guojian Wu, Bin Ding, Yucheng Wu
    Abstract:

    This paper investigates the reversible exsolution of a Ni nanocatalyst anchored on the surface of La0.3Sr0.7TiO3−δ (LSTO) for enhancing the electrocatalytic activity of the composite cathode. The metallic Ni nanoparticles significantly enhance the electrode performance and elevate the current efficiency of the electrode in High-Temperature Steam Electrolysis. The combination of XRD, SEM, EDS and XPS results confirms that the exsolution and dissolution of the Ni nanoparticles are completely reversible in redox cycles. The electrical conductivities of the Ni-loaded samples accordingly improved as well. The synergetic effects of the Ni nanocatalyst and redox-stable titanate contribute to the excellent stability and improved performance for direct Steam Electrolysis. The current efficiencies with Ni-anchored LSTO can be accordingly enhanced by 20% in contrast to the bare cathode with or without reducing gas flowing over the cathode under the applied voltage of 2.0 V at 800 °C.

Oliver Posdziech - One of the best experts on this subject based on the ideXlab platform.

  • Power-to-Gas through thermal integration of High-Temperature Steam Electrolysis and carbon dioxide methanation - Experimental results
    Fuel Processing Technology, 2018
    Co-Authors: Manuel Gruber, Petra Weinbrecht, Linus Biffar, Stefan Harth, Jorg Brabandt, Oliver Posdziech, Dimosthenis Trimis, Robert Blumentritt
    Abstract:

    This article presents the experimental results of a novel Power-to-Gas (PtG) concept combining a pressurized High-Temperature Steam Electrolysis (SOEC) and a CO2-methanation module in stand-alone and thermally integrated operation. For the electrolyser, Steam conversion and energy demands at pressures up to 15 bar were examined. In terms of the methanation module, cooling performance, Steam production and product gas quality were of main interest. Additionally, temperature profiles inside the fixed beds were gathered by a multipoint thermocouple at pressures up to 30 bar and load modulations from 20 to 100%. With less than 2 vol% H2 and over 97 vol% CH4 in the finally produced synthetic natural gas (SNG), it can be directly injected into the existing German natural gas grid without further gas cleaning and without capacity limitations. The achieved overall PtG efficiency of 76% is significantly higher than state of the art plants and has the potential to reach 80% in industrial scale.

  • heat management method in a high temperature Steam Electrolysis soec solid oxide fuel cell sofc and or reversible high temperature fuel cell rsoc and high temperature Steam Electrolysis soec solid oxide fuel cell sofc and or reversible high temperatu
    2015
    Co-Authors: Dietmar Ruger, Jorg Brabandt, Oliver Posdziech
    Abstract:

    The invention relates to a heat management method in a High-Temperature Steam Electrolysis [SOEC] (fig. 1), to solid oxide fuel cells [SOFCs] (fig. 2) and/or to a reversible High-Temperature fuel cell having the SOEC and SOFC modes of operation [rSOC] (fig. 1/2), wherein Steam required (1) is supplied from at least one external source and at least one offgas stream (4, 12, 12a) is cooled at least once (3, 11, 18, 35) downstream of the cell [SOEC, SOFC, rSOC] (5, 5a), wherein internal generation of Steam required (1, 38) is effected by internal recuperative heating of externally supplied water (47, 48, 51), wherein the energy from the at least one cooling operation (3, 11, 18, 35) of the at least one offgas stream to be cooled (4, 4a, 12, 12a, 17, 20, 34, 36) is used for this purpose, and at the same time the external Steam supply (1, 38) is reduced or shut down. The invention further relates to a High-Temperature Steam Electrolysis [SOEC] arrangement, solid oxide fuel cell [SOFC] arrangement and/or reversible High-Temperature fuel cell arrangement with the SOEC and SOFC modes of operation [rSOC], each having an Electrolysis/fuel cell (5, 5a), two gas supply conduits (8, 15), two gas outlet conduits (4, 12/12a), wherein at least one water evaporation arrangement (18, 35, 53), a Steam generator and/or heat exchanger for Steam generation is arranged in at least one gas outlet conduit (4, 12, 12a) in order to generate Steam (1, 38) from water (47, 48, 51).

Julie Mougin - One of the best experts on this subject based on the ideXlab platform.

  • High Temperature Steam Electrolysis Stack with Enhanced Performance and Durability
    Energy Procedia, 2020
    Co-Authors: Julie Mougin, Marie Petitjean, André Chatroux, Magali Reytier, Georges Gousseau, K. Couturier, Florence Lefebvre-joud
    Abstract:

    Abstract High Temperature Steam Electrolysis (HTSE) is one of the most promising ways for hydrogen production. If coupled to a CO2-free electricity and low cost heat sources, this process is liable to a high efficiency. The present study describes recent promising results obtained in terms of performance and durability in stack environment, thanks to the use of protective coatings on one hand, and of advanced cells on the other hand. As for Solid Oxide Fuel Cells, it has been demonstrated that the integration of protective coatings was mandatory to decrease the degradation rate in HTSE stacks, and that with optimized coatings, (CoMn)3O4 in the present case, the same durability as the one of the single cell tested in a ceramic housing could be reached. The type of cell was also shown to play a major role on the degradation rate. With advanced cells, degradations below 2%/kh could be reached. The higher is the current density, the higher is the degradation rate, with a mostly reversible effect. These degradation rates are close to the objectives, even if a bit higher than in SOFC mode. Finally a low-weight stack has been designed, targeting high performance and durability while reducing the cost by the use of thin interconnects. An electrochemical performance similar to the previous stack design has been obtained for a 3-cell stack (-1 A/cm 2 at 1.3 V at 800 °C), with degradation rates below 3%/1000 h in the testing conditions. The thermal cyclability of stacks has been demonstrated, from 800 °C to 20 °C, as well as electrical load cycling. The results showed that the HTSE stacks considered in the present study can cycle very rapidly, and that the cycles considered do not induce any degradation. Therefore it can be concluded that these results makes HTSE technology getting closer to the objectives of performance, durability, thermal and electrical cyclability and cost, and that HTSE is a candidate to produce hydrogen as a mean to store renewable intermittent energies.

  • Stack performances in high temperature Steam Electrolysis and co-Electrolysis
    International Journal of Hydrogen Energy, 2015
    Co-Authors: Magali Reytier, Jérôme Aicart, Marie Petitjean, Silvana Di Iorio, André Chatroux, Julie Cren, Myriam De Saint Jean, Julie Mougin
    Abstract:

    Abstract High Temperature Steam Electrolysis (HTSE), based on solid oxide Electrolysis cells (SOE) is a promising way to produce massively hydrogen with high efficiencies. This technology also allows producing syngas (H 2  + CO) by co-electrolyzing a mix of Steam and CO 2 . This syngas constitutes the basis to obtain further synthetic fuels. For both HTSE and co-Electrolysis, durability and cost are still key points, but additionally for co-Electrolysis the outlet H 2 /CO gas composition has to be tailored to fit with the targeted fuels. Previous works have been carried out to develop a stack design suitable for both applications. Here experiments at stack level in both Electrolysis and co-Electrolysis modes have been carried out. A 10-cell stack and a 25-cell stack have been tested in Electrolysis mode, respectively producing 0.6 Nm 3 /h and 1.7 Nm 3 /h of hydrogen at 800 °C below the thermoneutral voltage (1.3 V) for all the cells and a Steam conversion around 50%, with a small scattering between the different cells. Gas tightness of the stacks has also been evaluated. Moreover, the operation in co-Electrolysis has been validated. Finally a cost analysis of this stack design has been performed and shows all the economical potentialities of this technology.

  • Degradation study by 3D reconstruction of a nickel–yttria stabilized zirconia cathode after high temperature Steam Electrolysis operation
    Journal of Power Sources, 2014
    Co-Authors: E. Lay-grindler, Julie Mougin, Jérôme Laurencin, Julie Villanova, Peter Cloetens, Pierre Bleuet, A. Mansuy, Gérard Delette
    Abstract:

    Abstract Microstructural evolution of a Solid Oxide Electrolyser Cell (SOEC) Ni–YSZ cermet cathode is investigated using three dimensional electrode characterisations. 3D reconstructions are obtained on a reference and two long-term tested cells, which were maintained at −0.5 and −0.8 A cm−2 for 1000 h at 800 °C. During the long term tests, air was fed at the anode and a mixture of 10% H2–90% H2O was fed at the cathode. In this framework, reconstructions have been obtained from synchrotron X-ray nano-tomography technique. Microstructural properties extracted from the 3D reconstructions exhibit an evolution during the tests. Triple Phase Boundary length is decreasing from 10.49 ± 1.18 μm−2 for the reference cell to 6.18 ± 0.6 μm−2 for the long term tested cell at −0.8 A cm−2. Evolutions of morphological parameters were introduced in an in-house multi-scale model to evaluate their impacts on the electrode degradation, and hence, on the global SOEC performance.

  • Enhanced performance and durability of a high temperature Steam Electrolysis stack
    Fuel Cells, 2013
    Co-Authors: Julie Mougin, Marie Petitjean, André Chatroux, Magali Reytier, Georges Gousseau, Aurore Mansuy, Fabrice Mauvy
    Abstract:

    High temperature Steam Electrolysis (HTSE) is one of the most promising ways for hydrogen mass production. If coupled to a CO2-free electricity and a low cost heat source, this process is liable to a high efficiency. High levels of performance and durability, in association with cost-effective stack and system components are the key points. To reach such goals, a low-weight stack has been designed, keeping the advantages of the high performing and robust stack previously validated in terms of performance, durability, and cyclability [1], but aiming at reducing the cost by the use of thin interconnects. This low-weight stack has demonstrated at the scale of a 3-cell stack a good performance of -1.0 A cm-2 at 1.3 V at 800 °C. Before performing the durability test, preliminary studies at the cell level have been carried out to highlight the effect of two major operating parameters that are the current density and the Steam conversion (SC) ratio, those studies being carried out at one temperature, 800 °C. Based on these results, optimized operating parameters have been defined to perform the durability test on the stack, that is -0.5 A cm-2 and a SC ratio of 25%. Degradation rates around 3-4% 1,000 h-1 have been measured. The thermal cyclability of this stack has also been demonstrated with one thermal cycle. Therefore it can be concluded that these results make HTSE technology getting closer to the objectives of performance, durability, thermal cyclability, and cost.

  • Enhanced Performances of Structured Oxygen Electrodes for High Temperature Steam Electrolysis
    Fuel Cells, 2013
    Co-Authors: Tiphaine Ogier, Marie Petitjean, Jean-claude Grenier, Fabrice Mauvy, K. Couturier, Jean-marc Bassat, Sébastien Fourcade, Julie Mougin
    Abstract:

    The present study is focused on alternative structured oxygen electrodes for solid oxide Electrolysis cells (SOEC). The Ln2NiO4+δ (Ln = La or Pr) nickelate oxides were selected as innovative electrode materials with respect to their mixed electronic and ionic conductivity. A thin interfacial ceria-based layer was added in between the electrode and the zirconia-based electrolyte to improve mechanical and electrochemical properties and to limit the chemical reactivity. These structured cells were characterized by electrochemical impedance spectroscopy on symmetrical cells, under zero dc conditions and anodic polarization. Low polarization resistance RP and improved anodic overpotential ηA versus current density curves were obtained for the Pr2NiO4+δ electrode with Ce0.8Y0.2O2-δ interlayer: RP is decreased down to 0.06 Ω cm2 at 800 °C, under air and zero dc conditions. Then, complete hydrogen electrode-supported cells including Pr2NiO4+δ as oxygen electrode were electrochemically characterized. At 800 °C, when the inlet gas composition is 90 vol.% H2O-10 vol.% H2 at the hydrogen electrode, air being swept at the oxygen electrode, the current density determined at 1.28 V reaches -0.9 A cm-2, the corresponding Steam to hydrogen conversion ratio being 58%. These results are compared to those obtained with a reference cell including the oxygen deficient perovskite La0.6Sr0.4Fe0.8Co0.2O3-δ as oxygen electrode.

Robert Blumentritt - One of the best experts on this subject based on the ideXlab platform.

  • Power-to-Gas through thermal integration of High-Temperature Steam Electrolysis and carbon dioxide methanation - Experimental results
    Fuel Processing Technology, 2018
    Co-Authors: Manuel Gruber, Petra Weinbrecht, Linus Biffar, Stefan Harth, Jorg Brabandt, Oliver Posdziech, Dimosthenis Trimis, Robert Blumentritt
    Abstract:

    This article presents the experimental results of a novel Power-to-Gas (PtG) concept combining a pressurized High-Temperature Steam Electrolysis (SOEC) and a CO2-methanation module in stand-alone and thermally integrated operation. For the electrolyser, Steam conversion and energy demands at pressures up to 15 bar were examined. In terms of the methanation module, cooling performance, Steam production and product gas quality were of main interest. Additionally, temperature profiles inside the fixed beds were gathered by a multipoint thermocouple at pressures up to 30 bar and load modulations from 20 to 100%. With less than 2 vol% H2 and over 97 vol% CH4 in the finally produced synthetic natural gas (SNG), it can be directly injected into the existing German natural gas grid without further gas cleaning and without capacity limitations. The achieved overall PtG efficiency of 76% is significantly higher than state of the art plants and has the potential to reach 80% in industrial scale.

James E. O'brien - One of the best experts on this subject based on the ideXlab platform.

  • Integrated Operation of the INL HYTEST System and High-Temperature Steam Electrolysis for Synthetic Natural Gas Production
    Nuclear Technology, 2020
    Co-Authors: Carl M Stoots, Lee Shunn, James E. O'brien
    Abstract:

    The primary feedstock for synthetic fuel production is syngas, a mixture of carbon monoxide and hydrogen. Current hydrogen production technologies rely upon fossil fuels and produce significant quantities of greenhouse gases as a byproduct. This is not a sustainable means of satisfying future hydrogen demands, given the current projections for conventional world oil production and future targets for carbon emissions. For the past six years, the Idaho National Laboratory has been investigating the use of High-Temperature Steam Electrolysis (HTSE) to produce the hydrogen feedstock required for synthetic fuel production. High-Temperature Electrolysis water-splitting technology, combined with non-carbon-emitting energy sources, can provide a sustainable, environmentally-friendly means of large-scale hydrogen production. Additionally, laboratory facilities are being developed at the INL for testing hybrid energy systems composed of several tightly-coupled chemical processes (HYTEST program). The first such test involved the coupling of HTSE, CO2 separation membrane, reverse shift reaction, and methanation reaction to demonstrate synthetic natural gas production from a feedstock of water and either CO or a simulated flue gas containing CO2. This paper will introduce the initial HTSE and HYTEST testing facilities, overall coupling of the technologies, testing results, and future plans.

  • Experimental design, operation, and results of a 4 kW high temperature Steam Electrolysis experiment
    Journal of Power Sources, 2015
    Co-Authors: Xiaoyu Zhang, James E. O'brien, Can Zhou, G. K. Housley
    Abstract:

    High temperature Steam Electrolysis (HTSE) is a promising technology for large-scale hydrogen production. However, research on HTSE performance above the kW level is limited. This paper presents the results of 4 kW HTSE long-term test completed in a multi-kW test facility recently developed at the Idaho National Laboratory (INL). The 4 kW HTSE unit included two solid oxide Electrolysis stacks operating in parallel, each of which included 40 electrode-supported planar cells. A current density of 0.41 A/cm2 was used for the long-term operation, resulting in a hydrogen production rate about 25 slpm. A demonstration of 920 hours stable operation was achieved. The paper also includes detailed descriptions of the piping layout, Steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. As a result, this successful demonstration of multi-kW scale HTSE unit will help to advance the technology toward near-term commercialization.

  • High Temperature Electrolysis 4 kW Experiment Design, Operation, and Results
    2012
    Co-Authors: James E. O'brien, Xiaoyu Zhang, K. Dewall, L. Moore-mcateer
    Abstract:

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

  • Bio-Fuel Production Assisted with High Temperature Steam Electrolysis
    2012
    Co-Authors: Grant L Hawkes, James E. O'brien, Michael G. Mckellar
    Abstract:

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

  • Thermodynamics and Transport Phenomena in High Temperature Steam Electrolysis Cells
    Journal of Heat Transfer-transactions of The Asme, 2012
    Co-Authors: James E. O'brien
    Abstract:

    Hydrogen can be produced from water splitting with relatively high efficiency using high temperature Electrolysis. This technology makes use of solid-oxide cells, running in the Electrolysis mode to produce hydrogen from Steam, while consuming electricity and high temperature process heat. The overall thermal-to-hydrogen efficiency for high temperature Electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature Electrolysis. Current large-scale hydrogen production is based almost exclusively on Steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. An overview of high temperature Electrolysis technology will be presented, including basic thermodynamics, experimental methods, heat and mass transfer phenomena, and computational fluid dynamics modeling.