The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform
Yutaka Tamaura - One of the best experts on this subject based on the ideXlab platform.
-
Development of Reactive Ceramics for Conversion of Concentrated Solar Heat Into Solar Hydrogen With Two-Step Water-Splitting Reaction
Journal of Solar Energy Engineering, 2010Co-Authors: Hiroshi Kaneko, N Hasegawa, S. Taku, Y. Naganuma, Toshihiko Ishihara, Yutaka TamauraAbstract:The reactive ceramics suitable for the rotary-type Solar reactor (proposed by Tokyo Institute of Technology, Tokyo) with two-step water-splitting reaction were developer. It is confirmed that O 2 gas is evolved in the two-step water-splitting reaction with the reactive ceramics vigorously by rapid Heating (α-O 2 -releasing reaction). The α-O 2 -releasing reaction is due to the formation of interstitial defect and the conversion of lattice oxygen into O 2 gas at a nonequilibrium state. Reactive ceramics (NiFe 2 O 4 and yttria stabilized zirconia (YSZ)-NiFe 2 O 4 solid solution) can absorb Solar thermal energy and convert thermal energy into chemical energy under high O 2 partial pressure atmosphere in the α-O 2 -releasing reaction. Repetitive evolutions of O 2 gas were observed in the two-step water-splitting reaction with YSZ-Fe 3 O 4 solid solution and cerium based metal oxides (CeO 2 ―NiO, CeO 2 ―ZrO 2 , and CeO 2 ―Ta 2 O 5 ) at high O 2 partial pressure. The CeO 2 ―Ta 2 O 5 (Ce: Ta = 90: 10) released a large amount of O 2 gas (3.95 cm 3 /g) in the α-O 2 releasing reaction in the flow of air.
-
Solar thermochemical process for hydrogen production using ferrites
Energy, 2005Co-Authors: Hiroshi Kaneko, Nobuyuki Gokon, N Hasegawa, Yutaka TamauraAbstract:A two-step water splitting process using the ZnFe2O4/Zn/Fe3O4 reaction system was proposed for H2 generation utilizing Concentrated Solar Heat. The mixture of Zn and Fe3O4 was Heated to 873K in flowing steam with an Ar carrier gas, and the H2 gas was generated at 93.4% of the theoretical yield for the reaction of 3Zn+2Fe3O4+4H2O=3ZnFe2O4+4H2 (H2 generation step). The XRD and Mossbauer spectroscopy showed that the Zn‐submitted ferrite (ZnxFe3−xO4; 0.2≤x≤1) (main solid product) and ZnO (minor) were formed in the solid products after the H2 generation reaction. The ZnFe2O4 product, which was formed after the H2 generation step during the two-step water splitting process with the ZnFe2O4/Zn/Fe3O4 system, could be decomposed into Zn (and ZnO) and Fe3O4 by the Xe beam irradiation at 1900K after 3min with a 67.8% yield for the reaction of 3ZnFe2O4=3Zn+2Fe3O4+2O2 (O2 releasing step=Solar thermal step).
-
Hydrogen Production Through Two-Step Water Splitting Using YSZ (Ni,Fe) System for Solar Hydrogen Production
Solar Energy, 2005Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, T. Yokoyama, Akinori Fuse, Yutaka TamauraAbstract:The two-step water splitting with the solid solution of YSZ (Yttrium stabilized Zirconia) and Ni-ferrite (NiFe2 O4 ) was studied for Solar hydrogen production. The sample of YSZ/Ni-ferrite solid solution was prepared by calcination of the mixture of the YSZ balls and Ni-ferrite (NiFe2 O4 ) powder. The two-step water splitting process composed of O2 -releasing reaction (T = 1773K) in Ar gas flow and H2 -generation reaction (T = 1473K) in Ar gas and steam flow with the YSZ/Ni-ferrite solid solution were repeated ten times, and the molar ratio of the released O2 gas and the generated H2 gas was nearly equal to 1:2 in each cycle, indicating that the two-step water splitting process proceeded stoichiometrically. The lattice constants of the YSZ/Ni-ferrite solid solution products after each step of the water splitting process were varied, therefore it was assumed that the oxidation and reduction of the iron ions proceeded in the YSZ phase. It is confirmed that the YSZ/Ni-ferrite was the solid solution and reactive ceramics of high thermal stability. The contents of iron ions determined by the atomic absorption spectroscopy indicated that the YSZ/Ni-ferrite solid solution Heated at 1773K contained the only 36% of iron loaded initially. The generated O2 gas was 42% of the theoretical yield. These suggest that YSZ/Ni-ferrite solid solution is more effective reactive ceramics which has the ability to split water with Concentrated Solar Heat than Ni-ferrite.Copyright © 2005 by ASME
-
Two-step water splitting for Solar H2 production with ZnII–MnII,III–FeIII spinel structure using Concentrated Solar Heat
Solid State Ionics, 2004Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, Hirofumi Aoki, Akio Suzuki, Yutaka TamauraAbstract:Abstract Two-step water splitting with the MnFe 2 O 4 /ZnO/H 2 O system which can be applied for the Solar hydrogen production has been studied. The water splitting reaction with the MnFe 2 O 4 /ZnO/H 2 O system generates H 2 at 1273 K, and the Zn II –Mn II,III –Fe III spinel type compound is produced. The amount of the H 2 generation was 1.7 ml per 2/3 mmol of MnFe 2 O 4 , which is 23% of the theoretical yield. The Zn II –Mn II,III –Fe III spinel type compound releases the O 2 gas in the air flow condition at 1800K, and is decomposed into the stoichiometric MnFe 2 O 4 and the fine particle of the ZnO phase. The fine particle of ZnO was deposited on the surface of the reaction cell wall and formed a thin layer by the back reaction between the metal Zn vapor and the O 2 gas. The cyclic process for the two-step water splitting of this system (the MnFe 2 O 4 /ZnO/H 2 O system) was confirmed from the experimental result that the O 2 releasing step was carried out using the solid sample obtained after the H 2 generation step with the MnFe 2 O 4 /ZnO/H 2 O system.
-
two step water splitting for Solar h2 production with znii mnii iii feiii spinel structure using Concentrated Solar Heat
Solid State Ionics, 2004Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, Hirofumi Aoki, Akio Suzuki, Yutaka TamauraAbstract:Abstract Two-step water splitting with the MnFe 2 O 4 /ZnO/H 2 O system which can be applied for the Solar hydrogen production has been studied. The water splitting reaction with the MnFe 2 O 4 /ZnO/H 2 O system generates H 2 at 1273 K, and the Zn II –Mn II,III –Fe III spinel type compound is produced. The amount of the H 2 generation was 1.7 ml per 2/3 mmol of MnFe 2 O 4 , which is 23% of the theoretical yield. The Zn II –Mn II,III –Fe III spinel type compound releases the O 2 gas in the air flow condition at 1800K, and is decomposed into the stoichiometric MnFe 2 O 4 and the fine particle of the ZnO phase. The fine particle of ZnO was deposited on the surface of the reaction cell wall and formed a thin layer by the back reaction between the metal Zn vapor and the O 2 gas. The cyclic process for the two-step water splitting of this system (the MnFe 2 O 4 /ZnO/H 2 O system) was confirmed from the experimental result that the O 2 releasing step was carried out using the solid sample obtained after the H 2 generation step with the MnFe 2 O 4 /ZnO/H 2 O system.
Hiroshi Kaneko - One of the best experts on this subject based on the ideXlab platform.
-
Development of Reactive Ceramics for Conversion of Concentrated Solar Heat Into Solar Hydrogen With Two-Step Water-Splitting Reaction
Journal of Solar Energy Engineering, 2010Co-Authors: Hiroshi Kaneko, N Hasegawa, S. Taku, Y. Naganuma, Toshihiko Ishihara, Yutaka TamauraAbstract:The reactive ceramics suitable for the rotary-type Solar reactor (proposed by Tokyo Institute of Technology, Tokyo) with two-step water-splitting reaction were developer. It is confirmed that O 2 gas is evolved in the two-step water-splitting reaction with the reactive ceramics vigorously by rapid Heating (α-O 2 -releasing reaction). The α-O 2 -releasing reaction is due to the formation of interstitial defect and the conversion of lattice oxygen into O 2 gas at a nonequilibrium state. Reactive ceramics (NiFe 2 O 4 and yttria stabilized zirconia (YSZ)-NiFe 2 O 4 solid solution) can absorb Solar thermal energy and convert thermal energy into chemical energy under high O 2 partial pressure atmosphere in the α-O 2 -releasing reaction. Repetitive evolutions of O 2 gas were observed in the two-step water-splitting reaction with YSZ-Fe 3 O 4 solid solution and cerium based metal oxides (CeO 2 ―NiO, CeO 2 ―ZrO 2 , and CeO 2 ―Ta 2 O 5 ) at high O 2 partial pressure. The CeO 2 ―Ta 2 O 5 (Ce: Ta = 90: 10) released a large amount of O 2 gas (3.95 cm 3 /g) in the α-O 2 releasing reaction in the flow of air.
-
Solar thermochemical process for hydrogen production using ferrites
Energy, 2005Co-Authors: Hiroshi Kaneko, Nobuyuki Gokon, N Hasegawa, Yutaka TamauraAbstract:A two-step water splitting process using the ZnFe2O4/Zn/Fe3O4 reaction system was proposed for H2 generation utilizing Concentrated Solar Heat. The mixture of Zn and Fe3O4 was Heated to 873K in flowing steam with an Ar carrier gas, and the H2 gas was generated at 93.4% of the theoretical yield for the reaction of 3Zn+2Fe3O4+4H2O=3ZnFe2O4+4H2 (H2 generation step). The XRD and Mossbauer spectroscopy showed that the Zn‐submitted ferrite (ZnxFe3−xO4; 0.2≤x≤1) (main solid product) and ZnO (minor) were formed in the solid products after the H2 generation reaction. The ZnFe2O4 product, which was formed after the H2 generation step during the two-step water splitting process with the ZnFe2O4/Zn/Fe3O4 system, could be decomposed into Zn (and ZnO) and Fe3O4 by the Xe beam irradiation at 1900K after 3min with a 67.8% yield for the reaction of 3ZnFe2O4=3Zn+2Fe3O4+2O2 (O2 releasing step=Solar thermal step).
-
Hydrogen Production Through Two-Step Water Splitting Using YSZ (Ni,Fe) System for Solar Hydrogen Production
Solar Energy, 2005Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, T. Yokoyama, Akinori Fuse, Yutaka TamauraAbstract:The two-step water splitting with the solid solution of YSZ (Yttrium stabilized Zirconia) and Ni-ferrite (NiFe2 O4 ) was studied for Solar hydrogen production. The sample of YSZ/Ni-ferrite solid solution was prepared by calcination of the mixture of the YSZ balls and Ni-ferrite (NiFe2 O4 ) powder. The two-step water splitting process composed of O2 -releasing reaction (T = 1773K) in Ar gas flow and H2 -generation reaction (T = 1473K) in Ar gas and steam flow with the YSZ/Ni-ferrite solid solution were repeated ten times, and the molar ratio of the released O2 gas and the generated H2 gas was nearly equal to 1:2 in each cycle, indicating that the two-step water splitting process proceeded stoichiometrically. The lattice constants of the YSZ/Ni-ferrite solid solution products after each step of the water splitting process were varied, therefore it was assumed that the oxidation and reduction of the iron ions proceeded in the YSZ phase. It is confirmed that the YSZ/Ni-ferrite was the solid solution and reactive ceramics of high thermal stability. The contents of iron ions determined by the atomic absorption spectroscopy indicated that the YSZ/Ni-ferrite solid solution Heated at 1773K contained the only 36% of iron loaded initially. The generated O2 gas was 42% of the theoretical yield. These suggest that YSZ/Ni-ferrite solid solution is more effective reactive ceramics which has the ability to split water with Concentrated Solar Heat than Ni-ferrite.Copyright © 2005 by ASME
-
Two-step water splitting for Solar H2 production with ZnII–MnII,III–FeIII spinel structure using Concentrated Solar Heat
Solid State Ionics, 2004Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, Hirofumi Aoki, Akio Suzuki, Yutaka TamauraAbstract:Abstract Two-step water splitting with the MnFe 2 O 4 /ZnO/H 2 O system which can be applied for the Solar hydrogen production has been studied. The water splitting reaction with the MnFe 2 O 4 /ZnO/H 2 O system generates H 2 at 1273 K, and the Zn II –Mn II,III –Fe III spinel type compound is produced. The amount of the H 2 generation was 1.7 ml per 2/3 mmol of MnFe 2 O 4 , which is 23% of the theoretical yield. The Zn II –Mn II,III –Fe III spinel type compound releases the O 2 gas in the air flow condition at 1800K, and is decomposed into the stoichiometric MnFe 2 O 4 and the fine particle of the ZnO phase. The fine particle of ZnO was deposited on the surface of the reaction cell wall and formed a thin layer by the back reaction between the metal Zn vapor and the O 2 gas. The cyclic process for the two-step water splitting of this system (the MnFe 2 O 4 /ZnO/H 2 O system) was confirmed from the experimental result that the O 2 releasing step was carried out using the solid sample obtained after the H 2 generation step with the MnFe 2 O 4 /ZnO/H 2 O system.
-
two step water splitting for Solar h2 production with znii mnii iii feiii spinel structure using Concentrated Solar Heat
Solid State Ionics, 2004Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, Hirofumi Aoki, Akio Suzuki, Yutaka TamauraAbstract:Abstract Two-step water splitting with the MnFe 2 O 4 /ZnO/H 2 O system which can be applied for the Solar hydrogen production has been studied. The water splitting reaction with the MnFe 2 O 4 /ZnO/H 2 O system generates H 2 at 1273 K, and the Zn II –Mn II,III –Fe III spinel type compound is produced. The amount of the H 2 generation was 1.7 ml per 2/3 mmol of MnFe 2 O 4 , which is 23% of the theoretical yield. The Zn II –Mn II,III –Fe III spinel type compound releases the O 2 gas in the air flow condition at 1800K, and is decomposed into the stoichiometric MnFe 2 O 4 and the fine particle of the ZnO phase. The fine particle of ZnO was deposited on the surface of the reaction cell wall and formed a thin layer by the back reaction between the metal Zn vapor and the O 2 gas. The cyclic process for the two-step water splitting of this system (the MnFe 2 O 4 /ZnO/H 2 O system) was confirmed from the experimental result that the O 2 releasing step was carried out using the solid sample obtained after the H 2 generation step with the MnFe 2 O 4 /ZnO/H 2 O system.
N Hasegawa - One of the best experts on this subject based on the ideXlab platform.
-
Development of Reactive Ceramics for Conversion of Concentrated Solar Heat Into Solar Hydrogen With Two-Step Water-Splitting Reaction
Journal of Solar Energy Engineering, 2010Co-Authors: Hiroshi Kaneko, N Hasegawa, S. Taku, Y. Naganuma, Toshihiko Ishihara, Yutaka TamauraAbstract:The reactive ceramics suitable for the rotary-type Solar reactor (proposed by Tokyo Institute of Technology, Tokyo) with two-step water-splitting reaction were developer. It is confirmed that O 2 gas is evolved in the two-step water-splitting reaction with the reactive ceramics vigorously by rapid Heating (α-O 2 -releasing reaction). The α-O 2 -releasing reaction is due to the formation of interstitial defect and the conversion of lattice oxygen into O 2 gas at a nonequilibrium state. Reactive ceramics (NiFe 2 O 4 and yttria stabilized zirconia (YSZ)-NiFe 2 O 4 solid solution) can absorb Solar thermal energy and convert thermal energy into chemical energy under high O 2 partial pressure atmosphere in the α-O 2 -releasing reaction. Repetitive evolutions of O 2 gas were observed in the two-step water-splitting reaction with YSZ-Fe 3 O 4 solid solution and cerium based metal oxides (CeO 2 ―NiO, CeO 2 ―ZrO 2 , and CeO 2 ―Ta 2 O 5 ) at high O 2 partial pressure. The CeO 2 ―Ta 2 O 5 (Ce: Ta = 90: 10) released a large amount of O 2 gas (3.95 cm 3 /g) in the α-O 2 releasing reaction in the flow of air.
-
Solar thermochemical process for hydrogen production using ferrites
Energy, 2005Co-Authors: Hiroshi Kaneko, Nobuyuki Gokon, N Hasegawa, Yutaka TamauraAbstract:A two-step water splitting process using the ZnFe2O4/Zn/Fe3O4 reaction system was proposed for H2 generation utilizing Concentrated Solar Heat. The mixture of Zn and Fe3O4 was Heated to 873K in flowing steam with an Ar carrier gas, and the H2 gas was generated at 93.4% of the theoretical yield for the reaction of 3Zn+2Fe3O4+4H2O=3ZnFe2O4+4H2 (H2 generation step). The XRD and Mossbauer spectroscopy showed that the Zn‐submitted ferrite (ZnxFe3−xO4; 0.2≤x≤1) (main solid product) and ZnO (minor) were formed in the solid products after the H2 generation reaction. The ZnFe2O4 product, which was formed after the H2 generation step during the two-step water splitting process with the ZnFe2O4/Zn/Fe3O4 system, could be decomposed into Zn (and ZnO) and Fe3O4 by the Xe beam irradiation at 1900K after 3min with a 67.8% yield for the reaction of 3ZnFe2O4=3Zn+2Fe3O4+2O2 (O2 releasing step=Solar thermal step).
-
Hydrogen Production Through Two-Step Water Splitting Using YSZ (Ni,Fe) System for Solar Hydrogen Production
Solar Energy, 2005Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, T. Yokoyama, Akinori Fuse, Yutaka TamauraAbstract:The two-step water splitting with the solid solution of YSZ (Yttrium stabilized Zirconia) and Ni-ferrite (NiFe2 O4 ) was studied for Solar hydrogen production. The sample of YSZ/Ni-ferrite solid solution was prepared by calcination of the mixture of the YSZ balls and Ni-ferrite (NiFe2 O4 ) powder. The two-step water splitting process composed of O2 -releasing reaction (T = 1773K) in Ar gas flow and H2 -generation reaction (T = 1473K) in Ar gas and steam flow with the YSZ/Ni-ferrite solid solution were repeated ten times, and the molar ratio of the released O2 gas and the generated H2 gas was nearly equal to 1:2 in each cycle, indicating that the two-step water splitting process proceeded stoichiometrically. The lattice constants of the YSZ/Ni-ferrite solid solution products after each step of the water splitting process were varied, therefore it was assumed that the oxidation and reduction of the iron ions proceeded in the YSZ phase. It is confirmed that the YSZ/Ni-ferrite was the solid solution and reactive ceramics of high thermal stability. The contents of iron ions determined by the atomic absorption spectroscopy indicated that the YSZ/Ni-ferrite solid solution Heated at 1773K contained the only 36% of iron loaded initially. The generated O2 gas was 42% of the theoretical yield. These suggest that YSZ/Ni-ferrite solid solution is more effective reactive ceramics which has the ability to split water with Concentrated Solar Heat than Ni-ferrite.Copyright © 2005 by ASME
-
Two-step water splitting for Solar H2 production with ZnII–MnII,III–FeIII spinel structure using Concentrated Solar Heat
Solid State Ionics, 2004Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, Hirofumi Aoki, Akio Suzuki, Yutaka TamauraAbstract:Abstract Two-step water splitting with the MnFe 2 O 4 /ZnO/H 2 O system which can be applied for the Solar hydrogen production has been studied. The water splitting reaction with the MnFe 2 O 4 /ZnO/H 2 O system generates H 2 at 1273 K, and the Zn II –Mn II,III –Fe III spinel type compound is produced. The amount of the H 2 generation was 1.7 ml per 2/3 mmol of MnFe 2 O 4 , which is 23% of the theoretical yield. The Zn II –Mn II,III –Fe III spinel type compound releases the O 2 gas in the air flow condition at 1800K, and is decomposed into the stoichiometric MnFe 2 O 4 and the fine particle of the ZnO phase. The fine particle of ZnO was deposited on the surface of the reaction cell wall and formed a thin layer by the back reaction between the metal Zn vapor and the O 2 gas. The cyclic process for the two-step water splitting of this system (the MnFe 2 O 4 /ZnO/H 2 O system) was confirmed from the experimental result that the O 2 releasing step was carried out using the solid sample obtained after the H 2 generation step with the MnFe 2 O 4 /ZnO/H 2 O system.
-
two step water splitting for Solar h2 production with znii mnii iii feiii spinel structure using Concentrated Solar Heat
Solid State Ionics, 2004Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, Hirofumi Aoki, Akio Suzuki, Yutaka TamauraAbstract:Abstract Two-step water splitting with the MnFe 2 O 4 /ZnO/H 2 O system which can be applied for the Solar hydrogen production has been studied. The water splitting reaction with the MnFe 2 O 4 /ZnO/H 2 O system generates H 2 at 1273 K, and the Zn II –Mn II,III –Fe III spinel type compound is produced. The amount of the H 2 generation was 1.7 ml per 2/3 mmol of MnFe 2 O 4 , which is 23% of the theoretical yield. The Zn II –Mn II,III –Fe III spinel type compound releases the O 2 gas in the air flow condition at 1800K, and is decomposed into the stoichiometric MnFe 2 O 4 and the fine particle of the ZnO phase. The fine particle of ZnO was deposited on the surface of the reaction cell wall and formed a thin layer by the back reaction between the metal Zn vapor and the O 2 gas. The cyclic process for the two-step water splitting of this system (the MnFe 2 O 4 /ZnO/H 2 O system) was confirmed from the experimental result that the O 2 releasing step was carried out using the solid sample obtained after the H 2 generation step with the MnFe 2 O 4 /ZnO/H 2 O system.
Hongguang Jin - One of the best experts on this subject based on the ideXlab platform.
-
Isothermal versus two-temperature Solar thermochemical fuel synthesis: A comparative study
Applied Energy, 2018Co-Authors: Hui Kong, Yong Hao, Hongguang JinAbstract:Abstract Metal-oxide based, two-step thermochemical cycling is a promising means of harvesting Solar energy, in which water or carbon dioxide is dissociated to synthesize fuels via successive reduction and oxidation half-reactions driven by Concentrated Solar Heat. Isothermal thermochemical cycling has recently emerged as an important special case of two-step Solar TC with distinct advantages of easier Heat recovery and potentially high efficiencies, and criteria for the design of oxide materials of isothermal thermochemical cycling are talked about recently. However, the pros and cons of isothermal versus two-temperature (i.e. two-T) TC are under debate. In this work, the two approaches are compared by exploring the influence of temperature, reduction pressure and thermodynamic properties of materials on Solar-to-fuel efficiencies. Through the analysis, isothermal cycling is shown to work much better on CO2 splitting for easily reducible materials than two-T cycling; even for materials conventionally considered good for two-T cycling, isothermal cycling could still excel (over two-T cycling) under certain operating conditions. General principles for materials screening are also explored. There are many factors that favour isothermal thermochemical cycling over two-T cycling, such as high temperature, high Heat recovery rate, small reduction enthalpy or splitting of CO2 instead of water. In addition, materials with large specific Heat, which are unfavorable for two-T cycling, may be suitable for isothermal cycling. At high temperatures or with high Heat recovery rates, isothermal thermochemical cycling exhibits excellent performance even for H2O splitting. The theoretical Solar-to-fuel efficiency of ∼28% (for CO2 splitting at 1650 °C and pO2 = 10−5 atm, without Heat recovery) of isothermal cycling may indicate a meaningful route to effective Solar thermochemical fuel production.
-
performance assessment of hybrid Solar energy and coal fired power plant based on feed water preHeating
Energy, 2017Co-Authors: Hui Hong, Shuo Peng, Hao Zhang, Jie Sun, Hongguang JinAbstract:Abstract Hybridizing Solar energy and coal-fired steam power plant is one of most attractive approaches of cost-efficient Solar electricity in the present. By using the Concentrated Solar Heat at around 300 °C to replace the bleed steam of the turbine for preHeating feed-water of coal-fired steam cycle, higher Solar-to-power efficiency is possibly achieved in that the conversion of Solar to power can utilize higher-temperature steam cycle. In this paper, with the aid of exergy methodology, we derive expressions of the conversion of Solar energy into power for such kind of Solar hybrid plant, especially an explicit correlation is obtained for explaining Solar-to-power efficiency. By using the derived expressions, we examine a typical hybrid Solar system with 330 MW coal-fired power plant and evaluate thermal performance of Solar-to-power. In addition, the influences of key operation parameters on the Solar thermal performance are disclosed such as Solar irradiation, incident angle and turbine load. The results obtained here would be expected to provide a possibility for designing and evaluating practical hybrid Solar and coal-fired power plant.
-
proposal of a Solar coal power plant on off design operation
Journal of Solar Energy Engineering-transactions of The Asme, 2013Co-Authors: Yawen Zhao, Hui Hong, Hongguang JinAbstract:In a Solar hybrid system, the intermittent Solar radiation seriously effects the Solar-to-electricity conversion. In this paper, the energy-level mechanism between the Concentrated Solar Heat and the thermal cycle was discussed. The system analysis was taken on a 200 MW coal-fired power plant hybridized with Solar Heat at approximately 300 degrees C, where the middle-temperature Solar thermal energy was used to preHeat the feed water before entering the boiler. With changing Solar radiation in typical days, the Solar share, the work output and the net Solar-to-electricity efficiency of this Solar hybrid system were evaluated. The net Solar-to-electricity efficiency would be increased by 3-7% points compared to that in a Solar-only power plant. An off-design parallel configuration of this hybrid system was proposed, achieving the net annual Solar-to-electricity efficiency of 18%. It would expected to be an attractive approach to develop the scale-up mid-temperature Solar thermal power technology in the short and midterm.
-
operational performance of the development of a 15 kw parabolic trough mid temperature Solar receiver reactor for hydrogen production
Applied Energy, 2012Co-Authors: Hui Hong, Qibin Liu, Hongguang JinAbstract:Abstract In this paper, we report the operational performance and energy conversion efficiency of a developed 15 kW Solar chemical receiver/reactor for hydrogen production. A Concentrated Solar Heat of around 200–300 °C was utilized to provide process Heat to drive methanol steam reforming. A modified 15 kW direct-irradiation Solar reactor coupled with a linear receiver positioned along the focal line of a one-axis parabolic trough concentrator was used. The experiments were conducted from 200 to 300 °C under a mean Solar flux of 300–800 W/m 2 and a reactant feeding rate of 6 kg/h. Reactants were continuously fed, and the attained conversion rate of methanol was more than 70% at 700 W/m 2 . The typical Solar thermochemical efficiency of Solar thermal energy converted into chemical energy was in the 20–28% range. The overall energy efficiency of input Solar power conversion into chemical energy reached up to 17% and may be further increased by improving Solar field efficiency. Hydrogen production exceeding 80% was achieved. In addition, preliminary economic evaluation was performed, and methods for further improvement were proposed. This paper proves that Solar hydrogen production is feasible by combining Solar thermal energy with alternative fuel at around 200–300 °C, which is much lower than the temperature of other Solar thermochemical processes. This may offer an economic approach to Solar fuel production and extend the application of mid-temperature Solar thermal energy.
-
Operational performance of the development of a 15 kW parabolic trough mid-temperature Solar receiver/reactor for hydrogen production
Applied Energy, 2012Co-Authors: Hui Hong, Qibin Liu, Hongguang JinAbstract:Abstract In this paper, we report the operational performance and energy conversion efficiency of a developed 15 kW Solar chemical receiver/reactor for hydrogen production. A Concentrated Solar Heat of around 200–300 °C was utilized to provide process Heat to drive methanol steam reforming. A modified 15 kW direct-irradiation Solar reactor coupled with a linear receiver positioned along the focal line of a one-axis parabolic trough concentrator was used. The experiments were conducted from 200 to 300 °C under a mean Solar flux of 300–800 W/m 2 and a reactant feeding rate of 6 kg/h. Reactants were continuously fed, and the attained conversion rate of methanol was more than 70% at 700 W/m 2 . The typical Solar thermochemical efficiency of Solar thermal energy converted into chemical energy was in the 20–28% range. The overall energy efficiency of input Solar power conversion into chemical energy reached up to 17% and may be further increased by improving Solar field efficiency. Hydrogen production exceeding 80% was achieved. In addition, preliminary economic evaluation was performed, and methods for further improvement were proposed. This paper proves that Solar hydrogen production is feasible by combining Solar thermal energy with alternative fuel at around 200–300 °C, which is much lower than the temperature of other Solar thermochemical processes. This may offer an economic approach to Solar fuel production and extend the application of mid-temperature Solar thermal energy.
Hideyuki Ishihara - One of the best experts on this subject based on the ideXlab platform.
-
Hydrogen Production Through Two-Step Water Splitting Using YSZ (Ni,Fe) System for Solar Hydrogen Production
Solar Energy, 2005Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, T. Yokoyama, Akinori Fuse, Yutaka TamauraAbstract:The two-step water splitting with the solid solution of YSZ (Yttrium stabilized Zirconia) and Ni-ferrite (NiFe2 O4 ) was studied for Solar hydrogen production. The sample of YSZ/Ni-ferrite solid solution was prepared by calcination of the mixture of the YSZ balls and Ni-ferrite (NiFe2 O4 ) powder. The two-step water splitting process composed of O2 -releasing reaction (T = 1773K) in Ar gas flow and H2 -generation reaction (T = 1473K) in Ar gas and steam flow with the YSZ/Ni-ferrite solid solution were repeated ten times, and the molar ratio of the released O2 gas and the generated H2 gas was nearly equal to 1:2 in each cycle, indicating that the two-step water splitting process proceeded stoichiometrically. The lattice constants of the YSZ/Ni-ferrite solid solution products after each step of the water splitting process were varied, therefore it was assumed that the oxidation and reduction of the iron ions proceeded in the YSZ phase. It is confirmed that the YSZ/Ni-ferrite was the solid solution and reactive ceramics of high thermal stability. The contents of iron ions determined by the atomic absorption spectroscopy indicated that the YSZ/Ni-ferrite solid solution Heated at 1773K contained the only 36% of iron loaded initially. The generated O2 gas was 42% of the theoretical yield. These suggest that YSZ/Ni-ferrite solid solution is more effective reactive ceramics which has the ability to split water with Concentrated Solar Heat than Ni-ferrite.Copyright © 2005 by ASME
-
Two-step water splitting for Solar H2 production with ZnII–MnII,III–FeIII spinel structure using Concentrated Solar Heat
Solid State Ionics, 2004Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, Hirofumi Aoki, Akio Suzuki, Yutaka TamauraAbstract:Abstract Two-step water splitting with the MnFe 2 O 4 /ZnO/H 2 O system which can be applied for the Solar hydrogen production has been studied. The water splitting reaction with the MnFe 2 O 4 /ZnO/H 2 O system generates H 2 at 1273 K, and the Zn II –Mn II,III –Fe III spinel type compound is produced. The amount of the H 2 generation was 1.7 ml per 2/3 mmol of MnFe 2 O 4 , which is 23% of the theoretical yield. The Zn II –Mn II,III –Fe III spinel type compound releases the O 2 gas in the air flow condition at 1800K, and is decomposed into the stoichiometric MnFe 2 O 4 and the fine particle of the ZnO phase. The fine particle of ZnO was deposited on the surface of the reaction cell wall and formed a thin layer by the back reaction between the metal Zn vapor and the O 2 gas. The cyclic process for the two-step water splitting of this system (the MnFe 2 O 4 /ZnO/H 2 O system) was confirmed from the experimental result that the O 2 releasing step was carried out using the solid sample obtained after the H 2 generation step with the MnFe 2 O 4 /ZnO/H 2 O system.
-
two step water splitting for Solar h2 production with znii mnii iii feiii spinel structure using Concentrated Solar Heat
Solid State Ionics, 2004Co-Authors: Hideyuki Ishihara, Hiroshi Kaneko, N Hasegawa, Hirofumi Aoki, Akio Suzuki, Yutaka TamauraAbstract:Abstract Two-step water splitting with the MnFe 2 O 4 /ZnO/H 2 O system which can be applied for the Solar hydrogen production has been studied. The water splitting reaction with the MnFe 2 O 4 /ZnO/H 2 O system generates H 2 at 1273 K, and the Zn II –Mn II,III –Fe III spinel type compound is produced. The amount of the H 2 generation was 1.7 ml per 2/3 mmol of MnFe 2 O 4 , which is 23% of the theoretical yield. The Zn II –Mn II,III –Fe III spinel type compound releases the O 2 gas in the air flow condition at 1800K, and is decomposed into the stoichiometric MnFe 2 O 4 and the fine particle of the ZnO phase. The fine particle of ZnO was deposited on the surface of the reaction cell wall and formed a thin layer by the back reaction between the metal Zn vapor and the O 2 gas. The cyclic process for the two-step water splitting of this system (the MnFe 2 O 4 /ZnO/H 2 O system) was confirmed from the experimental result that the O 2 releasing step was carried out using the solid sample obtained after the H 2 generation step with the MnFe 2 O 4 /ZnO/H 2 O system.