The Experts below are selected from a list of 978 Experts worldwide ranked by ideXlab platform
Abdessamad Faik - One of the best experts on this subject based on the ideXlab platform.
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corrosion aspects of Molten Nitrate Salt based nanofluids for thermal energy storage applications
Solar Energy, 2019Co-Authors: Udayashankar Nithiyanantham, Yaroslav Grosu, Abdelali Zaki, Luis Gonzalezfernandez, J M Igartua, Abdessamad FaikAbstract:Abstract Efficient energy storage is a bottleneck for nearly every renewable energy technology. Thermal energy storage (TES) is widely considered as a relatively simple and reliable method, particularly for concentrated solar power (CSP) plants. Currently, considerable scientific effort is focused on the development of new Molten Salt-based nanofluids as storage materials with enhanced thermophysical properties and lower cost for TES purpose. However, an understanding of the effect of nanoparticles on the corrosivity of such nanofluids is practically absent. In the present work, using nanofluids based on eutectic mixture of NaNO3-KNO3 we demonstrate that nanoparticles doping has complex effects on the corrosion rates of carbon steel. In particular, if the negative effect of microbubbles of air trapped between the nanoparticles is not predominant, one can obtain reduced corrosion rates due to the incorporation of the nanoparticles into the oxidation layer. The obtained results are important both for expanding the very limited knowledge on the corrosion aspects of Molten Salts-based nanofluids, as well as for comprehensive evaluation of the feasibility of such nanofluids for TES applications.
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A simple method for the inhibition of the corrosion of carbon steel by Molten Nitrate Salt for thermal storage in concentrating solar power applications
npj Materials Degradation, 2018Co-Authors: Yaroslav Grosu, Udayashankar Nithiyanantham, Abdelali Zaki, Abdessamad FaikAbstract:Corrosion is an important issue in high-temperature applications such as Concentrated Solar Power (CSP) technology, playing a crucial role in the long-term use of storage tanks, heat exchanger and piping materials which account for a considerable component of the investment costs. While there are many studies regarding the corrosion rates of container materials under the conditions of CSP, there is little progress in the field of their degradation prevention by anticorrosion methods. This work presents an analysis of the corrosion mechanisms between the most economical construction material—carbon steel—and Molten Nitrate Salt. A method to protect the carbon steel against corrosion by Molten Salt at high temperature was proposed, involving the formation of a calcium carbonate layer on the carbon steel surface. The stability of the layer was tested under isothermal and temperature cycling conditions up to 500 °C, in both inert and air atmospheres in the presence or absence of humidity. The protection method proposed has potential to reduce investment costs for CSP technology. Spraying a thin coat of graphite on carbon steel can significantly improve their resistance to Nitrate Salts at high temperatures. A team led by Yaroslav Grosu and Abdessemad Faik from CIC Energigune in Spain used spray graphitization to coat the surface of a carbon steel before burying it in a Nitrate Salt mixture and heating it above 300 °C. Whether in air or in an inert atmosphere, and whether held above 300 °C in humidity or thermally cycled for 500 h up to 500 °C, the sprayed graphite consistently promoted the formation of stable calcium carbonate crystals at the steel surface. This protective calcium carbonate layer stopped the steel from oxidising. Inhibiting steel corrosion when in contact with Molten Salts can help optimise materials for concentrated solar power technology and other high-temperature applications.
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new insights into the corrosion mechanism between Molten Nitrate Salts and ceramic materials for packed bed thermocline systems a case study for steel slag and solar Salt
Solar Energy, 2018Co-Authors: Inigo Ortegafernandez, Yaroslav Grosu, Ainhoa Ocio, P L Arias, Javier Rodriguezaseguinolaza, Abdessamad FaikAbstract:Abstract Thermal energy storage (TES) systems based on packed bed arrangements are proven to be a very promising route to decrease the levelized cost of electricity (LCOE) in concentrated solar power (CSP) plants. However, the compatibility between the TES material and the heat transfer fluid (HTF), which operate in direct contact, is known to be a major limitation for such configuration. In this regard, the compatibility between a Molten Nitrate Salt (Solar Salt) and a ceramic by-product from the steel production, the steel slag, is investigated in this work. The obtained results show that the standard criteria used for determining any chemical incompatibility phenomena like the formation of a corrosion layer or the appearance of structural modifications, are not enough to draw a conclusion on the materials compatibility. A deep analysis of the TES material and the HTF chemical compositions revealed a migration of cations from the slag to the Salt, and the formation of nitrites in the latter boosted by the presence of the slag. These two mechanisms lead to the modification of the thermo-physical properties of the Salt.
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natural and by product materials for thermocline based thermal energy storage system at csp plant compatibility with mineral oil and Molten Nitrate Salt
Applied Thermal Engineering, 2018Co-Authors: Yaroslav Grosu, Inigo Ortegafernandez, Juan Miguel Lopez Del Amo, Abdessamad FaikAbstract:Abstract The use of thermal energy storage (TES) systems at concentrated solar power (CSP) plants is one of the main ways of increasing the dispatchability and hence the competitiveness among other renewable energies. The thermocline packed bed TES technology is particularly attractive in terms of cost-effectiveness. This is due to the single-tank configuration and the possibility of using low cost filler materials as TES working body. One of the main concerns for packed bed TES systems is the thermal and chemical stability of a filler material in direct contact with the heat transfer fluid. With these regards, the compatibility of previously evaluated filler materials with paraffinic mineral oil and with Molten HitecXL Salt heat transfer fluids is reported in this work. The most promising material will be selected for its implementation in the packed bed TES unit deployed at the 1 MWel pilot CSP plant and its 1/100 scale prototype constructed in the framework of the H2020 ORC-Plus project.
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unexpected effect of nanoparticles doping on the corrosivity of Molten Nitrate Salt for thermal energy storage
Solar Energy Materials and Solar Cells, 2018Co-Authors: Yaroslav Grosu, Luis Gonzalezfernandez, Nithiyanantham Udayashankar, Oleksandr Bondarchuk, Abdessamad FaikAbstract:Abstract Molten Nitrate Salts are currently the most common mature solution for thermal energy storage at the concentrated solar power (CSP) plants. Enhancing heat capacity and thermal conductivity of Molten Salts via doping by inorganic nanoparticles has attracted an explosively increasing interest due to the possibility of a considerable decrease of the investment costs for CSP technology. However, to the best of our knowledge there is almost no information on the effect of such doping on the corrosivity of the Molten Salts. In this work we demonstrate that adding small amounts of nanoparticles into the Molten Nitrate HitecXL Salt considerably increases its corrosivity and modifies the corrosion mechanisms. A set of advanced techniques such as SEM-EDX, XPS and XRD are applied to get insights into the effect of inorganic nano-additives on the corrosion phenomenon.
Yaroslav Grosu - One of the best experts on this subject based on the ideXlab platform.
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corrosion aspects of Molten Nitrate Salt based nanofluids for thermal energy storage applications
Solar Energy, 2019Co-Authors: Udayashankar Nithiyanantham, Yaroslav Grosu, Abdelali Zaki, Luis Gonzalezfernandez, J M Igartua, Abdessamad FaikAbstract:Abstract Efficient energy storage is a bottleneck for nearly every renewable energy technology. Thermal energy storage (TES) is widely considered as a relatively simple and reliable method, particularly for concentrated solar power (CSP) plants. Currently, considerable scientific effort is focused on the development of new Molten Salt-based nanofluids as storage materials with enhanced thermophysical properties and lower cost for TES purpose. However, an understanding of the effect of nanoparticles on the corrosivity of such nanofluids is practically absent. In the present work, using nanofluids based on eutectic mixture of NaNO3-KNO3 we demonstrate that nanoparticles doping has complex effects on the corrosion rates of carbon steel. In particular, if the negative effect of microbubbles of air trapped between the nanoparticles is not predominant, one can obtain reduced corrosion rates due to the incorporation of the nanoparticles into the oxidation layer. The obtained results are important both for expanding the very limited knowledge on the corrosion aspects of Molten Salts-based nanofluids, as well as for comprehensive evaluation of the feasibility of such nanofluids for TES applications.
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A simple method for the inhibition of the corrosion of carbon steel by Molten Nitrate Salt for thermal storage in concentrating solar power applications
npj Materials Degradation, 2018Co-Authors: Yaroslav Grosu, Udayashankar Nithiyanantham, Abdelali Zaki, Abdessamad FaikAbstract:Corrosion is an important issue in high-temperature applications such as Concentrated Solar Power (CSP) technology, playing a crucial role in the long-term use of storage tanks, heat exchanger and piping materials which account for a considerable component of the investment costs. While there are many studies regarding the corrosion rates of container materials under the conditions of CSP, there is little progress in the field of their degradation prevention by anticorrosion methods. This work presents an analysis of the corrosion mechanisms between the most economical construction material—carbon steel—and Molten Nitrate Salt. A method to protect the carbon steel against corrosion by Molten Salt at high temperature was proposed, involving the formation of a calcium carbonate layer on the carbon steel surface. The stability of the layer was tested under isothermal and temperature cycling conditions up to 500 °C, in both inert and air atmospheres in the presence or absence of humidity. The protection method proposed has potential to reduce investment costs for CSP technology. Spraying a thin coat of graphite on carbon steel can significantly improve their resistance to Nitrate Salts at high temperatures. A team led by Yaroslav Grosu and Abdessemad Faik from CIC Energigune in Spain used spray graphitization to coat the surface of a carbon steel before burying it in a Nitrate Salt mixture and heating it above 300 °C. Whether in air or in an inert atmosphere, and whether held above 300 °C in humidity or thermally cycled for 500 h up to 500 °C, the sprayed graphite consistently promoted the formation of stable calcium carbonate crystals at the steel surface. This protective calcium carbonate layer stopped the steel from oxidising. Inhibiting steel corrosion when in contact with Molten Salts can help optimise materials for concentrated solar power technology and other high-temperature applications.
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new insights into the corrosion mechanism between Molten Nitrate Salts and ceramic materials for packed bed thermocline systems a case study for steel slag and solar Salt
Solar Energy, 2018Co-Authors: Inigo Ortegafernandez, Yaroslav Grosu, Ainhoa Ocio, P L Arias, Javier Rodriguezaseguinolaza, Abdessamad FaikAbstract:Abstract Thermal energy storage (TES) systems based on packed bed arrangements are proven to be a very promising route to decrease the levelized cost of electricity (LCOE) in concentrated solar power (CSP) plants. However, the compatibility between the TES material and the heat transfer fluid (HTF), which operate in direct contact, is known to be a major limitation for such configuration. In this regard, the compatibility between a Molten Nitrate Salt (Solar Salt) and a ceramic by-product from the steel production, the steel slag, is investigated in this work. The obtained results show that the standard criteria used for determining any chemical incompatibility phenomena like the formation of a corrosion layer or the appearance of structural modifications, are not enough to draw a conclusion on the materials compatibility. A deep analysis of the TES material and the HTF chemical compositions revealed a migration of cations from the slag to the Salt, and the formation of nitrites in the latter boosted by the presence of the slag. These two mechanisms lead to the modification of the thermo-physical properties of the Salt.
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natural and by product materials for thermocline based thermal energy storage system at csp plant compatibility with mineral oil and Molten Nitrate Salt
Applied Thermal Engineering, 2018Co-Authors: Yaroslav Grosu, Inigo Ortegafernandez, Juan Miguel Lopez Del Amo, Abdessamad FaikAbstract:Abstract The use of thermal energy storage (TES) systems at concentrated solar power (CSP) plants is one of the main ways of increasing the dispatchability and hence the competitiveness among other renewable energies. The thermocline packed bed TES technology is particularly attractive in terms of cost-effectiveness. This is due to the single-tank configuration and the possibility of using low cost filler materials as TES working body. One of the main concerns for packed bed TES systems is the thermal and chemical stability of a filler material in direct contact with the heat transfer fluid. With these regards, the compatibility of previously evaluated filler materials with paraffinic mineral oil and with Molten HitecXL Salt heat transfer fluids is reported in this work. The most promising material will be selected for its implementation in the packed bed TES unit deployed at the 1 MWel pilot CSP plant and its 1/100 scale prototype constructed in the framework of the H2020 ORC-Plus project.
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unexpected effect of nanoparticles doping on the corrosivity of Molten Nitrate Salt for thermal energy storage
Solar Energy Materials and Solar Cells, 2018Co-Authors: Yaroslav Grosu, Luis Gonzalezfernandez, Nithiyanantham Udayashankar, Oleksandr Bondarchuk, Abdessamad FaikAbstract:Abstract Molten Nitrate Salts are currently the most common mature solution for thermal energy storage at the concentrated solar power (CSP) plants. Enhancing heat capacity and thermal conductivity of Molten Salts via doping by inorganic nanoparticles has attracted an explosively increasing interest due to the possibility of a considerable decrease of the investment costs for CSP technology. However, to the best of our knowledge there is almost no information on the effect of such doping on the corrosivity of the Molten Salts. In this work we demonstrate that adding small amounts of nanoparticles into the Molten Nitrate HitecXL Salt considerably increases its corrosivity and modifies the corrosion mechanisms. A set of advanced techniques such as SEM-EDX, XPS and XRD are applied to get insights into the effect of inorganic nano-additives on the corrosion phenomenon.
Dan Addison - One of the best experts on this subject based on the ideXlab platform.
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Rechargeable-battery chemistry based on lithium oxide growth through Nitrate anion redox
Nature Chemistry, 2019Co-Authors: Vincent Giordani, Dylan Tozier, Hongjin Tan, Gregory V. Chase, Betar M Gallant, Jasim Uddin, Bryan D Mccloskey, Julia R Greer, Dan AddisonAbstract:Phase-forming conversion chemistry, like that observed in Li–S and Li–O_2 batteries, shows great promise, but these systems suffer some drawbacks, such as practically low cathode areal capacities and electrolyte decomposition. Now, high-energy conversion battery chemistry—based on Nitrate/nitrite redox where one of the products is soluble—has been enabled by using nanoparticulate Ni/NiO electrocatalysts.AbstractNext-generation lithium-battery cathodes often involve the growth of lithium-rich phases, which enable specific capacities that are 2−3 times higher than insertion cathode materials, such as lithium cobalt oxide. Here, we investigated battery chemistry previously deemed irreversible in which lithium oxide, a lithium-rich phase, grows through the reduction of the Nitrate anion in a lithium Nitrate-based Molten Salt at 150 °C. Using a suite of independent characterization techniques, we demonstrated that a Ni nanoparticle catalyst enables the reversible growth and dissolution of micrometre-sized lithium oxide crystals through the effective catalysis of Nitrate reduction and nitrite oxidation, which results in high cathode areal capacities (~12 mAh cm^–2). These results enable a rechargeable battery system that has a full-cell theoretical specific energy of 1,579 Wh kg^–1, in which a Molten Nitrate Salt serves as both an active material and the electrolyte.
Vincent Giordani - One of the best experts on this subject based on the ideXlab platform.
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Rechargeable-battery chemistry based on lithium oxide growth through Nitrate anion redox
Nature Chemistry, 2019Co-Authors: Vincent Giordani, Dylan Tozier, Hongjin Tan, Gregory V. Chase, Betar M Gallant, Jasim Uddin, Bryan D Mccloskey, Julia R Greer, Dan AddisonAbstract:Phase-forming conversion chemistry, like that observed in Li–S and Li–O_2 batteries, shows great promise, but these systems suffer some drawbacks, such as practically low cathode areal capacities and electrolyte decomposition. Now, high-energy conversion battery chemistry—based on Nitrate/nitrite redox where one of the products is soluble—has been enabled by using nanoparticulate Ni/NiO electrocatalysts.AbstractNext-generation lithium-battery cathodes often involve the growth of lithium-rich phases, which enable specific capacities that are 2−3 times higher than insertion cathode materials, such as lithium cobalt oxide. Here, we investigated battery chemistry previously deemed irreversible in which lithium oxide, a lithium-rich phase, grows through the reduction of the Nitrate anion in a lithium Nitrate-based Molten Salt at 150 °C. Using a suite of independent characterization techniques, we demonstrated that a Ni nanoparticle catalyst enables the reversible growth and dissolution of micrometre-sized lithium oxide crystals through the effective catalysis of Nitrate reduction and nitrite oxidation, which results in high cathode areal capacities (~12 mAh cm^–2). These results enable a rechargeable battery system that has a full-cell theoretical specific energy of 1,579 Wh kg^–1, in which a Molten Nitrate Salt serves as both an active material and the electrolyte.
Udayashankar Nithiyanantham - One of the best experts on this subject based on the ideXlab platform.
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corrosion aspects of Molten Nitrate Salt based nanofluids for thermal energy storage applications
Solar Energy, 2019Co-Authors: Udayashankar Nithiyanantham, Yaroslav Grosu, Abdelali Zaki, Luis Gonzalezfernandez, J M Igartua, Abdessamad FaikAbstract:Abstract Efficient energy storage is a bottleneck for nearly every renewable energy technology. Thermal energy storage (TES) is widely considered as a relatively simple and reliable method, particularly for concentrated solar power (CSP) plants. Currently, considerable scientific effort is focused on the development of new Molten Salt-based nanofluids as storage materials with enhanced thermophysical properties and lower cost for TES purpose. However, an understanding of the effect of nanoparticles on the corrosivity of such nanofluids is practically absent. In the present work, using nanofluids based on eutectic mixture of NaNO3-KNO3 we demonstrate that nanoparticles doping has complex effects on the corrosion rates of carbon steel. In particular, if the negative effect of microbubbles of air trapped between the nanoparticles is not predominant, one can obtain reduced corrosion rates due to the incorporation of the nanoparticles into the oxidation layer. The obtained results are important both for expanding the very limited knowledge on the corrosion aspects of Molten Salts-based nanofluids, as well as for comprehensive evaluation of the feasibility of such nanofluids for TES applications.
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A simple method for the inhibition of the corrosion of carbon steel by Molten Nitrate Salt for thermal storage in concentrating solar power applications
npj Materials Degradation, 2018Co-Authors: Yaroslav Grosu, Udayashankar Nithiyanantham, Abdelali Zaki, Abdessamad FaikAbstract:Corrosion is an important issue in high-temperature applications such as Concentrated Solar Power (CSP) technology, playing a crucial role in the long-term use of storage tanks, heat exchanger and piping materials which account for a considerable component of the investment costs. While there are many studies regarding the corrosion rates of container materials under the conditions of CSP, there is little progress in the field of their degradation prevention by anticorrosion methods. This work presents an analysis of the corrosion mechanisms between the most economical construction material—carbon steel—and Molten Nitrate Salt. A method to protect the carbon steel against corrosion by Molten Salt at high temperature was proposed, involving the formation of a calcium carbonate layer on the carbon steel surface. The stability of the layer was tested under isothermal and temperature cycling conditions up to 500 °C, in both inert and air atmospheres in the presence or absence of humidity. The protection method proposed has potential to reduce investment costs for CSP technology. Spraying a thin coat of graphite on carbon steel can significantly improve their resistance to Nitrate Salts at high temperatures. A team led by Yaroslav Grosu and Abdessemad Faik from CIC Energigune in Spain used spray graphitization to coat the surface of a carbon steel before burying it in a Nitrate Salt mixture and heating it above 300 °C. Whether in air or in an inert atmosphere, and whether held above 300 °C in humidity or thermally cycled for 500 h up to 500 °C, the sprayed graphite consistently promoted the formation of stable calcium carbonate crystals at the steel surface. This protective calcium carbonate layer stopped the steel from oxidising. Inhibiting steel corrosion when in contact with Molten Salts can help optimise materials for concentrated solar power technology and other high-temperature applications.
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A simple method for the inhibition of the corrosion of carbon steel by Molten Nitrate Salt for thermal storage in concentrating solar power applications
Nature Publishing Group, 2018Co-Authors: Yaroslav Grosu, Udayashankar Nithiyanantham, Abdelali Zaki, Abdessamad FaikAbstract:Carbon steels: graphite spraying improves high-temperature corrosion in Molten Nitrate Salts Spraying a thin coat of graphite on carbon steel can significantly improve their resistance to Nitrate Salts at high temperatures. A team led by Yaroslav Grosu and Abdessemad Faik from CIC Energigune in Spain used spray graphitization to coat the surface of a carbon steel before burying it in a Nitrate Salt mixture and heating it above 300 °C. Whether in air or in an inert atmosphere, and whether held above 300 °C in humidity or thermally cycled for 500 h up to 500 °C, the sprayed graphite consistently promoted the formation of stable calcium carbonate crystals at the steel surface. This protective calcium carbonate layer stopped the steel from oxidising. Inhibiting steel corrosion when in contact with Molten Salts can help optimise materials for concentrated solar power technology and other high-temperature applications