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Hiroshi Kaneko - One of the best experts on this subject based on the ideXlab platform.
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oxygen releasing step of znfe2o4 zno fe3o4 system in air using Concentrated Solar Energy for Solar hydrogen production
Solar Energy, 2005Co-Authors: Yutaka Tamaura, Hiroshi KanekoAbstract:Abstract The oxygen-releasing step of the ZnFe 2 O 4 /(ZnO + Fe 3 O 4 )-system for Solar hydrogen production with two-step water splitting using Concentrated Solar Energy was studied under the air-flow condition by irradiation with Concentrated Xe lamp beams from a Solar simulator. The spinel-type compound of ZnFe 2 O 4 (Zn-ferrite) releases O 2 gas under the air-flow condition at 1800 K and then decomposes into Fe 3 O 4 ( = Fe II Fe 2 III O 4 ) and ZnO with a nearly 100% yield (ZnFe 2 O 4 = ZnO + 2/3Fe 3 O 4 + 1/6O 2 ). The ZnO was deposited as the thin layer on the surface of the reaction cell wall. A thermodynamic study showed that the ZnO was produced by the reaction between the O 2 gas in the air and the metal Zn vapor generated from ZnFe 2 O 4 . With the combined process of the present study on the O 2 -releasing step and the previous one on the H 2 generation step (ZnO + 2/3Fe 3 O 4 + 1/3H 2 O = ZnFe 2 O 4 + 1/3H 2 ) for the ZnFe 2 O 4 /(ZnO + Fe 3 O 4 )-system, Solar H 2 production was demonstrated by one cycle of the ZnFe 2 O 4 /(ZnO + Fe 3 O 4 )-system, where the O 2 -releasing step had been carried out in air at 1800 K and the H 2 generation step at 1100 K.
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Oxygen-releasing step of ZnFe2O4/(ZnO + Fe3O4)-system in air using Concentrated Solar Energy for Solar hydrogen production
Solar Energy, 2005Co-Authors: Yutaka Tamaura, Hiroshi KanekoAbstract:Abstract The oxygen-releasing step of the ZnFe 2 O 4 /(ZnO + Fe 3 O 4 )-system for Solar hydrogen production with two-step water splitting using Concentrated Solar Energy was studied under the air-flow condition by irradiation with Concentrated Xe lamp beams from a Solar simulator. The spinel-type compound of ZnFe 2 O 4 (Zn-ferrite) releases O 2 gas under the air-flow condition at 1800 K and then decomposes into Fe 3 O 4 ( = Fe II Fe 2 III O 4 ) and ZnO with a nearly 100% yield (ZnFe 2 O 4 = ZnO + 2/3Fe 3 O 4 + 1/6O 2 ). The ZnO was deposited as the thin layer on the surface of the reaction cell wall. A thermodynamic study showed that the ZnO was produced by the reaction between the O 2 gas in the air and the metal Zn vapor generated from ZnFe 2 O 4 . With the combined process of the present study on the O 2 -releasing step and the previous one on the H 2 generation step (ZnO + 2/3Fe 3 O 4 + 1/3H 2 O = ZnFe 2 O 4 + 1/3H 2 ) for the ZnFe 2 O 4 /(ZnO + Fe 3 O 4 )-system, Solar H 2 production was demonstrated by one cycle of the ZnFe 2 O 4 /(ZnO + Fe 3 O 4 )-system, where the O 2 -releasing step had been carried out in air at 1800 K and the H 2 generation step at 1100 K.
A.j. Vázquez - One of the best experts on this subject based on the ideXlab platform.
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The use of Concentrated Solar Energy for the reduction of CuO in H2
Solar Energy, 2019Co-Authors: Maria A. Arenas, A.j. Vázquez, J. I. Robla, Isabel Padilla, Aurora López-delgadoAbstract:Abstract The reduction of copper (II) oxide was carried out under Concentrated Solar radiation in a stream of gaseous mixture 5/95 v/v H2/N2 in a 1.5 kW thermal power vertical axis parabolic concentrator at the PROMES-CNRS Solar facility (Odeillo-Font Romeu, France). Experiments were performed using a commercial oxide in two different forms, powdered and compacted specimens. The reduction of CuO to elemental Cu was more effective for compacted specimen yielding a dendrite microstructured metallic copper with an electrochemical behavior similar to that exhibited by the commercial metal. In the case of powdered specimen, a composite metal/oxide (Cu/Cu2O) block was obtained as a macroporous material. The reduction process of CuO under Concentrated Solar Energy tracks through the formation of Cu2O as the only intermediate phase, which was evidenced by X-ray diffraction and scanning electron microscopy.
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High melting point metals welding by Concentrated Solar Energy
Solar Energy, 2013Co-Authors: Alejandra Huertas Romero, Ignacio García, Maria A. Arenas, Víctor López, A.j. VázquezAbstract:Abstract Sound welding of high melting point metals, namely H13 tool steel and AISI 316L stainless steel, have been achieved by means of Concentrated Solar Energy. Longitudinal weld track on 2 and 5 mm steel sheets with a thickness up to 60 mm, under argon atmosphere, has been performed on a variety of geometrical configurations. This work has been carried out in a 2 kW thermal power vertical axis parabolic concentrator at the PROMES–CNRS Solar facility (Odeillo-Font-Romeu, southeast France). Cross sections of welded specimens were characterized by optical microscopy, scanning electron microscopy, EDS analysis, and microhardness measurements. Various microstructures were observed in the melted zone, partially melted zone, and heat-affected zone due to the several metallurgical transformations (such as melting, solidification, solution and partial solution) induced by welding. Defect-free welded beads for both materials have been obtained by optimizing the geometrical configuration, Solar radiation and tracking speed.
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Magnetite Production from Steel Wastes with Concentrated Solar Energy
steel research international, 2012Co-Authors: Íñigo Ruiz-bustinza, Inmaculada Canadas, Jose Rodriguez, Luis Felipe Verdeja, Javier Mochón, F. García-carcedo, A.j. VázquezAbstract:In order to achieve a balanced development in the application of materials for structural or functional purposes, one of the priority objectives of future work is to achieve the goal of ‘‘zero waste’’ in the different production lines. As would be expected from what was agreed in the Kyoto Protocol and the meetings of Copenhagen 2009 and Cancun 2010, the production of clean Energy will be strongly encouraged in the future, and indeed that is already the case now. Taking that into consideration, while the promotion of clean Energy production is mainly directed toward electricity, Solar thermal is quite interesting because of its direct application to metal mining and the chemical processes used in the sustainable development of materials. The combination of both objectives, ‘‘zero waste’’ and ‘‘clean Energy,’’ may pose an interesting challenge in the development of primary iron and steel, as well as in other areas of metal production and even in the field of mining. The help of Solar thermal Energy, which can be Concentrated to reach high temperatures, is a tool that could support both the direct production and the recycling of waste steel, in particular waste which is physically and chemically the worst for the environment. This would mean that the environment itself, Solar Energy, is in fact the key to environmental protection.
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NiAl coatings on carbon steel by self-propagating high-temperature synthesis assisted with Concentrated Solar Energy: mass influence on adherence and porosity
Solar Energy Materials and Solar Cells, 2005Co-Authors: C. Sierra, A.j. VázquezAbstract:NiAl have been produced by a self-propagating high-temperature synthesis (SHS). The power source that ignite the SHS reaction is Concentrated Solar Energy. NiAl coatings are obtained in few seconds and the processes are economic and environment friendly. Three different NiAl mass are tested: 0.3; 0.6 y 1.7 g. Coating porosity and adherence to substrate depends on the NiAl mass. Pores are large in samples with 1.7 g while the other specimens have small pores. Coating adherence is better when the amount of reactive powder is larger.
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Surface transformation hardening on steels treated with Solar Energy in central tower and heliostats field
Solar Energy Materials and Solar Cells, 1995Co-Authors: G.p. Rodríquez, Víctor López, J. De Damborenea, A.j. VázquezAbstract:The possibility of surface hardening on AISI 4140 steel treated with Concentrated Solar Energy in Solar installations for electricity production has been studied. The samples were slides from a 35 mm diameter steel bar and their height was 35 mm. The quenching was made in water but also was considered the possibility of self-quenching by cooling in air. The amount of the surface hardness and the different structures obtained in both cases are presented, and some discussion is made with reference to the surface hardness, the hardness profiles and the structures obtained. The heating of steel with Concentrated Solar Energy may produce similar hardening to that obtained with more conventional techniques of surface hardening.
D. I. Pantelis - One of the best experts on this subject based on the ideXlab platform.
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Titanium Alloys Thin Sheet Welding with the Use of Concentrated Solar Energy
Journal of Materials Engineering and Performance, 2017Co-Authors: D. I. Pantelis, M. Kazasidis, P. N. KarakizisAbstract:The present study deals with the welding of titanium alloys thin sheets 1.3 mm thick, with the use of Concentrated Solar Energy. The experimental part of the work took place at a medium size Solar furnace at the installation of the Centre National de la Recherche Scientifique, at Odeillo, in Southern France, where similar and dissimilar defect-free welds of titanium Grades 4 and 6 were achieved, in the butt joint configuration. After the determination of the appropriate welding conditions, the optimum welded structures were examined and characterized microstructurally, by means of light optical microscopy, scanning electron microscopy, and microhardness testing. In addition, test pieces extracted from the weldments were tested under uniaxial tensile loading aiming to the estimation of the strength and the ductility of the joint. The analysis of the experimental results and the recorded data led to the basic concluding remarks which demonstrate increased hardness distribution inside the fusion area and severe loss of ductility, but adequate yield and tensile strength of the welds.
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Experimental and numerical investigation of AA6082-T6 thin plates welding using Concentrated Solar Energy (CSE)
Solar Energy Materials and Solar Cells, 2017Co-Authors: D. I. Pantelis, D.g. Karalis, M. Kazasidis, P. N. Karakizis, J. RodrıguezAbstract:Abstract In the present study Concentrated Solar Energy (CSE) was used in order to weld thin plates (3 mm thickness) of the 6082 aluminum alloy in the T6 condition. A specially designed vacuum chamber and a cooling system were utilized in order to create the inert atmosphere and the heat dissipation required, respectively. The experiments resulted in the production of a sound butt weld between the aluminum plates which presented a 23% and 32% reduction of the microhardness and the Ultimate Tensile Strength (UTS) respectively compared to the base metal but are in good correlation with other fusion welding methods of the same material. Finally, based on the experimental results, a finite element 3D thermal model of the process was developed that can be used for the design and optimization of welds of aluminum alloys using the same experimental set-up.
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Surface alloying of pre-deposited molybdenum-based powder on 304L stainless steel using Concentrated Solar Energy
Solar Energy Materials and Solar Cells, 2005Co-Authors: D. I. Pantelis, A. Griniari, C.i. SarafoglouAbstract:Abstract The application of Concentrated Solar Energy on the surface alloying of molybdenum-based powder on 304L stainless steel is attempted in this work. The treated surfaces are thoroughly examined by means of optical and scanning electron microscopy (SEM) and characterized by electron dispersive spectroscopy (EDS). The characteristics of the obtained surface alloys (depth, microstructure, chemical composition, hardness) are related to the type of the heating process applied and to the main experimental parameters: heating rate, maximum temperature ( T max ), duration of maintenance ( t maint ) at T max and total time of exposure ( t total ).
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On the investigation of 7075 aluminum alloy welding using Concentrated Solar Energy
Solar Energy Materials and Solar Cells, 2005Co-Authors: D.g. Karalis, D. I. Pantelis, V.j. PapazoglouAbstract:The application of Concentrated Solar Energy for the welding of aluminum alloy 7075 was attempted in the present work, by employing the installation of the CNRS Solar Furnace at Odeillo, Pyrenees, southeast France. The characteristics of the Solar treated specimens (microstructure, hardness, SEM-EDS analysis) were fully investigated and correlated with thermal numerical results using the finite element method.
Luis Felipe Verdeja - One of the best experts on this subject based on the ideXlab platform.
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the treatment of basic oxygen furnace bof slag with Concentrated Solar Energy
Solar Energy, 2019Co-Authors: D Fernandezgonzalez, J Prazuch, I Ruizbustinza, C Gonzalezgasca, J Pinuelanoval, Luis Felipe VerdejaAbstract:Abstract Basic Oxygen Furnace (BOF) slag is one of the sub-products generated in the steelmaking process. This waste is characterized by its free lime and free magnesia contents that limit its application in construction. Moreover, the iron content in BOF slag of 14–30 wt% is a quantity which is problematic in the manufacture of cements. On the other hand, BOF slag is a source of available iron in the steelmaking industry. Concentrated Solar Energy offers a great potential in high temperature applications, so we used it to treat BOF slag. In this way, the slag was treated to stabilize it combining the free lime and free magnesia to give other phases (silicates, aluminates, and complex oxides), but also to transform iron into a magnetic phase that could be recovered through magnetic methods. The results demonstrate that the free lime and free magnesia reacted with silicates, aluminates, and ferrites to form stable phases which are not hydrated in the presence of water. Due to this, the treated BOF slag might find application in the construction industry. Furthermore, the iron was transformed into magnetite/maghemite, i.e. phases with magnetic properties.
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Transformations in the Mn-O-Si system using Concentrated Solar Energy
Solar Energy, 2019Co-Authors: D. Fernández-gonzález, J Prazuch, Íñigo Ruiz-bustinza, Carmen González-gasca, J. Piñuela-noval, Luis Felipe VerdejaAbstract:Abstract Energy consumption and carbon dioxide emissions are a problem in the metallurgical industries. The synthesis of manganese and silicomanganese using Concentrated Solar Energy is proposed in this paper. Mixtures of oxide of manganese (IV) and silicon (50 wt% and 75 wt%) were treated in a 1.5 kW Solar furnace located in Odeillo. Results demonstrated that mixtures of manganese and silicon, but also silicomanganese, are obtained after treatment even in the less favorable situation: without iron, which reduces the liquidus temperature, and without slag-forming reagents.
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Silicomanganese and Ferromanganese Slags Treated with Concentrated Solar Energy
Proceedings, 2018Co-Authors: D. Fernández-gonzález, Juan Piñuela-noval, Luis Felipe VerdejaAbstract:Solar Energy when properly Concentrated offers a great potential in high temperature applications as those required in metallurgical processes. Even when Concentrated Solar Energy cannot compete with conventional metallurgical processes, it could find application in the treatment of wastes from these processes. These by-products are characterized by their high metallic contents, which make them interesting as they could be a raw material available in the own factory. Slags are one of these by-products. Slags are most of them disposed in controlled landfill with environmental impact, but also with economic impact associated to the storing costs and the metallic losses. Here we propose the treatment of ferromanganese and silicomanganese slags with Concentrated Solar Energy with the purpose of evaluating the recovery of manganese from these slags.
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Concentrated Solar Energy applications in materials science and metallurgy
Solar Energy, 2018Co-Authors: D. Fernández-gonzález, Íñigo Ruiz-bustinza, Carmen González-gasca, Juan Piñuela Noval, Javier Mochón-castaños, José Sancho-gorostiaga, Luis Felipe VerdejaAbstract:Abstract New Energy sources have been researched with the objective of achieving a reduction in the emissions of greenhouse gases as well as other polluting gases. Solar Energy is one of the options as when properly Concentrated offers a great potential in high temperature applications. This paper offers a review on all fields connected with materials where Concentrated Solar Energy has been applied. These applications include metallurgy, materials processing (welding and cladding; surface treatments; coatings and surface hardening; and, powder metallurgy), and non-metallic materials (ceramics, fullerenes, carbon nanotubes, and production of lime).
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Magnetite Production from Steel Wastes with Concentrated Solar Energy
steel research international, 2012Co-Authors: Íñigo Ruiz-bustinza, Inmaculada Canadas, Jose Rodriguez, Luis Felipe Verdeja, Javier Mochón, F. García-carcedo, A.j. VázquezAbstract:In order to achieve a balanced development in the application of materials for structural or functional purposes, one of the priority objectives of future work is to achieve the goal of ‘‘zero waste’’ in the different production lines. As would be expected from what was agreed in the Kyoto Protocol and the meetings of Copenhagen 2009 and Cancun 2010, the production of clean Energy will be strongly encouraged in the future, and indeed that is already the case now. Taking that into consideration, while the promotion of clean Energy production is mainly directed toward electricity, Solar thermal is quite interesting because of its direct application to metal mining and the chemical processes used in the sustainable development of materials. The combination of both objectives, ‘‘zero waste’’ and ‘‘clean Energy,’’ may pose an interesting challenge in the development of primary iron and steel, as well as in other areas of metal production and even in the field of mining. The help of Solar thermal Energy, which can be Concentrated to reach high temperatures, is a tool that could support both the direct production and the recycling of waste steel, in particular waste which is physically and chemically the worst for the environment. This would mean that the environment itself, Solar Energy, is in fact the key to environmental protection.
Stéphane Abanades - One of the best experts on this subject based on the ideXlab platform.
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Metal Oxides Applied to Thermochemical Water-Splitting for Hydrogen Production Using Concentrated Solar Energy
ChemEngineering, 2019Co-Authors: Stéphane AbanadesAbstract:Solar thermochemical processes have the potential to efficiently convert high-temperature Solar heat into storable and transportable chemical fuels such as hydrogen. In such processes, the thermal Energy required for the endothermic reaction is supplied by Concentrated Solar Energy and the hydrogen production routes differ as a function of the feedstock resource. While hydrogen production should still rely on carbonaceous feedstocks in a transition period, thermochemical water-splitting using metal oxide redox reactions is considered to date as one of the most attractive methods in the long-term to produce renewable H2 for direct use in fuel cells or further conversion to synthetic liquid hydrocarbon fuels. The two-step redox cycles generally consist of the endothermic Solar thermal reduction of a metal oxide releasing oxygen with Concentrated Solar Energy used as the high-temperature heat source for providing reaction enthalpy; and the exothermic oxidation of the reduced oxide with H2O to generate H2. This approach requires the development of redox-active and thermally-stable oxide materials able to split water with both high fuel productivities and chemical conversion rates. The main relevant two-step metal oxide systems are commonly based on volatile (ZnO/Zn, SnO2/SnO) and non-volatile redox pairs (Fe3O4/FeO, ferrites, CeO2/CeO2−δ, perovskites). These promising hydrogen production cycles are described by providing an overview of the best performing redox systems, with special focus on their capabilities to produce Solar hydrogen with high yields, rapid reaction rates, and thermochemical performance stability, and on the Solar reactor technologies developed to operate the solid–gas reaction systems.
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co2 valorisation based on fe3o4 feo thermochemical redox reactions using Concentrated Solar Energy
International Journal of Energy Research, 2013Co-Authors: Stéphane Abanades, Isabel VillafanvidalesAbstract:SUMMARY The Solar-driven dissociation of CO2 by thermochemical looping via Fe3O4/FeO redox reactions is considered. The process recycles and upgrades CO2 to ultimately produce chemical synthetic fuels from high-temperature Solar heat and abundant feedstock as only inputs. The two-step process encompasses the endothermic reduction of Fe3O4 to FeO and O2 using Concentrated Solar Energy as the high-temperature source for reaction enthalpy and the nonSolar exothermic oxidation of FeO with CO2 to generate CO. The resulting Fe3O4 is then recycled to the first step and carbon monoxide can be further processed to syngas and serve as the building block to synthesise various synfuels by catalytic processes. This study examines the thermodynamics and kinetics of the pertinent reactions. The high-temperature thermal reduction of Fe3O4 is realised above the oxide melting point by using Concentrated Solar thermal power. The reactivity of the synthesised FeO-rich material with CO2 at moderate temperature is then investigated by thermogravimetry. FeO conversion higher than 90% can be achieved with reaction rates depending on temperature, particle size and CO2 concentration. The Solar-produced nonstoichiometric FeO is more reactive with CO2 than commercial pure FeO. Activation energies of 57 and 68 kJ/mol are derived from a kinetic analysis of the CO2-splitting reaction in the range of 600 °C to 800 °C with Solar and commercial FeO, respectively. Copyright © 2012 John Wiley & Sons, Ltd.
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CO2 valorisation based on Fe3O4/FeO thermochemical redox reactions using Concentrated Solar Energy
International Journal of Energy Research, 2012Co-Authors: Stéphane Abanades, Isabel Villafan-vidalesAbstract:SUMMARY The Solar-driven dissociation of CO2 by thermochemical looping via Fe3O4/FeO redox reactions is considered. The process recycles and upgrades CO2 to ultimately produce chemical synthetic fuels from high-temperature Solar heat and abundant feedstock as only inputs. The two-step process encompasses the endothermic reduction of Fe3O4 to FeO and O2 using Concentrated Solar Energy as the high-temperature source for reaction enthalpy and the nonSolar exothermic oxidation of FeO with CO2 to generate CO. The resulting Fe3O4 is then recycled to the first step and carbon monoxide can be further processed to syngas and serve as the building block to synthesise various synfuels by catalytic processes. This study examines the thermodynamics and kinetics of the pertinent reactions. The high-temperature thermal reduction of Fe3O4 is realised above the oxide melting point by using Concentrated Solar thermal power. The reactivity of the synthesised FeO-rich material with CO2 at moderate temperature is then investigated by thermogravimetry. FeO conversion higher than 90% can be achieved with reaction rates depending on temperature, particle size and CO2 concentration. The Solar-produced nonstoichiometric FeO is more reactive with CO2 than commercial pure FeO. Activation energies of 57 and 68 kJ/mol are derived from a kinetic analysis of the CO2-splitting reaction in the range of 600 °C to 800 °C with Solar and commercial FeO, respectively. Copyright © 2012 John Wiley & Sons, Ltd.
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screening of water splitting thermochemical cycles potentially attractive for hydrogen production by Concentrated Solar Energy
Energy, 2006Co-Authors: Stéphane Abanades, Patrice Charvin, Gilles Flamant, Pierre NeveuAbstract:Hydrogen, a promising and clean Energy carrier, could potentially replace the use of fossil fuels in the transportation sector. Currently, no environmentally attractive, large-scale, low-cost and high-efficiency hydrogen production process is available for commercialization. Solar-driven water-splitting thermochemical cycles may constitute one of the ultimate options for CO2-free production of hydrogen. The method is environmentally friendly since it uses only water and Solar Energy. First, the potentially attractive thermochemical cycles must be identified based on a set of criteria. To reach this goal, a database that contains 280 referenced cycles was established. Then, the selection and evaluation of the promising cycles was performed in the temperature range of 900–2000°C, suitable to the use of Concentrated Solar Energy. About 30 cycles selected for further investigations are presented in this paper. The principles and basis for a thermodynamic evaluation of the cycles are also given.