The Experts below are selected from a list of 6000 Experts worldwide ranked by ideXlab platform
Anders Lyngfelt - One of the best experts on this subject based on the ideXlab platform.
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Chemical Looping Combustion: Status and Development Challenges
Energy & Fuels, 2020Co-Authors: Anders LyngfeltAbstract:Because the CO2 capture is inherent in Chemical Looping Combustion (CLC), thus ideally avoiding costly gas separation, this process has potential for uniquely low costs of CO2 capture. The review r...
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Chemical-Looping Combustion of biomass in a 100 kW pilot
2017Co-Authors: Carl Johan Linderholm, Anders Lyngfelt, Magnus Rydén, Matthias SchmitzAbstract:Chemical-Looping Combustion (CLC) is an innovative carbon-capture technology with potential to drastically reduce the cost of capture. By using a circulating bed material to transfer oxygen from the Combustion air to the fuel, air and fuel are never mixed and the CO 2 can be obtained as a separate flue gas stream, undiluted by N 2 . In other words, in contrast to other capture technologies, which are burdened with a significant energy penalty, carbon capture is inherent to the CLC process. Chemical-Looping Combustion of biomass in combination with carbon capture and storage would lead to so called negative emissions. Manganese ores are highly promising oxygen-carrier candidates due to high reactivity and high availability. Here, we present findings from a 100 kW Chemical-Looping combustor for solid fuels, using a sintered manganese ore called “Sinaus” as oxygen carrier and two kinds of wood pellets as fuel. Preliminary results from 6 h of operation with steam-exploded wood pellets show fuel conversion up to 75%, and essentially complete CO 2 capture. The expected lifetime of the oxygen carrier particles was found to be 100-400 hours.
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Chemical-Looping Combustion of solid fuels
Calcium and Chemical Looping Technology for Power Generation and Carbon Dioxide (CO2) Capture, 2015Co-Authors: Carl Johan Linderholm, Anders LyngfeltAbstract:Chemical-Looping Combustion (CLC) of solid fuels is a novel Combustion technology with the potential to drastically reduce the costs associated with CO2 capture. In this chapter, the costs and energy penalty of CO2 capture using CLC with solid fuel are compared with corresponding costs using other capture technologies. Furthermore, the operational experience in continuous units reported in the literature is explored: principal layout of reactor systems, fuels and oxygen carriers used in these systems, time of operation, and fuel-reactor temperature. The chapter also looks at the CLC process from a fuel perspective-how does the choice of fuel affect the process?
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Chemical Looping Combustion of solid fuels status of development
Applied Energy, 2014Co-Authors: Anders LyngfeltAbstract:Chemical-Looping Combustion (CLC) of solid fuels is a technology with the potential of reducing the costs and energy penalty dramatically for CO2 capture. The potential for low costs is based on the similarity to coal Combustion in fluidized beds. However, this assumes reaching high performance with respect to fuel and gas conversion, or that inadequate performance can be readily mitigated by downstream options. There are uncertainties with respect to the performance that can be reached in large-scale units, as well as with the extra costs needed to compensate for inadequate performance. Performance will be dependent on both reactor design and oxygen carrier properties. The status of Chemical-Looping Combustion of solid fuels is discussed with respect to performance and experiences from pilot operation.
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Chemical-Looping Combustion of solid fuels – Status of development
Applied Energy, 2014Co-Authors: Anders LyngfeltAbstract:Chemical-Looping Combustion (CLC) of solid fuels is a technology with the potential of reducing the costs and energy penalty dramatically for CO2 capture. The potential for low costs is based on the similarity to coal Combustion in fluidized beds. However, this assumes reaching high performance with respect to fuel and gas conversion, or that inadequate performance can be readily mitigated by downstream options. There are uncertainties with respect to the performance that can be reached in large-scale units, as well as with the extra costs needed to compensate for inadequate performance. Performance will be dependent on both reactor design and oxygen carrier properties. The status of Chemical-Looping Combustion of solid fuels is discussed with respect to performance and experiences from pilot operation.
Hongguang Jin - One of the best experts on this subject based on the ideXlab platform.
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Development of Chemical Looping Combustion Power Systems at the Chinese Academy of Sciences
Energy & Fuels, 2020Co-Authors: Hui Hong, Hao Zhang, Qiongqiong Jiang, Xiangyu Liu, Hongguang JinAbstract:A power system with Chemical Looping Combustion (CLC) has been an effective method to realize efficient energy conversion and CO2 capture with zero energy penalty. Over the past 30 years, CLC power...
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A Looping Material of (CoO+1.0% PtO2)/CoAl2O4 for Dimethyl Ether Chemical-Looping Combustion in a Cellular Reactor
Energy Procedia, 2017Co-Authors: Hui Hong, Tao Han, Hao Zhang, Hongguang JinAbstract:Abstract Chemical-Looping Combustion (CLC) is considered as one of innovative technologies for CO 2 capture. In this paper, an oxygen carrier of (CoO+1.0% PtO 2 )/CoAl 2 O 4 is synthesized for the mid-temperature Chemical-Looping Combustion of di-methyl ether (DME). Experiments are implemented to investigate the reactivity, the carbon deposition behavior and the redox stability. Experimental results indicate that the Looping material shows a good reactivity at reduction temperature of 673 K. Furthermore, we propose a cellular combustor reactor which has a potential of eliminating the gas-solid separation and avoiding the abrasion of solid Looping material. Our study has provided the possibility for the integration of the mid-temperature solar thermal energy with the Chemical-Looping Combustion of DME, and offering a new approach of developing the combustor reactor of the Chemical-Looping Combustion.
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A Solar-Hybrid Power Plant Integrated With Ethanol Chemical-Looping Combustion
Volume 3: Controls Diagnostics and Instrumentation; Education; Electric Power; Microturbines and Small Turbomachinery; Solar Brayton and Rankine Cycle, 2011Co-Authors: Hui Hong, Tao Han, Pan Ying, Xiaosong Zhang, Shuo Peng, Hongguang JinAbstract:In this paper, a new solar hybrid gas turbine cycle integrating ethanol-fueled Chemical-Looping Combustion (CLC) has been proposed, and the system was investigated with the aid of the Energy-Utilization Diagram (EUD). Chemical-Looping Combustion consists of two successive reactions: first, ethanol fuel is oxidized by metal oxide (NiO) as an oxygen carrier (reduction of metal oxide); secondly, the reduced metal (Ni) is successively oxidized by Combustion air (the oxidation of metal). The reduction of NiO with ethanol requires a relative low-grade thermal energy at 150–200°C. Then concentrated solar thermal energy at approximately 200–300°C can be utilized to provide the process heat for this reaction. The integration of solar thermal energy and CLC could make the exergy efficiency and the net solar-to-electric efficiency of the system more than 54% and 28% at a turbine inlet temperature (TIT) of 1288°C, respectively. At the same time, the variation in the overall thermal efficiency (η) of the system with varying key parameters was analyzed, such as Turbine Inlet Temperature, pressure ratio (π) and the temperature of reduction reactor. Additionally, preliminary experiments on ethanol-fueled Chemical-Looping Combustion are carried out to verify the feasibility of the key process. The promising results obtained here indicate that this novel gas turbine cycle with ethanol-fueled Chemical-Looping Combustion could provide a promising approach of both efficient use of alternative fuel and low-temperature solar thermal and offer a technical probability of combining the Chemical-Looping Combustion with inherent CO2 capture for the alternative fuel.© 2011 ASME
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An Innovative Gas Turbine Cycle With Methanol-Fueled Chemical-Looping Combustion
Journal of Engineering for Gas Turbines and Power, 2009Co-Authors: Hongguang Jin, Hui Hong, Xiaosong Zhang, Wei HanAbstract:In this paper, a novel gas turbine cycle integrating methanol decomposition and the Chemical-Looping Combustion (CLC) is proposed. Two types of methanol-fueled power plants, including the new gas turbine cycle with CLC Combustion and a Chemically intercooled gas turbine cycle, have been investigated with the aid of the T-Q diagram. In the proposed system, methanol fuel is decomposed into syngas mainly containing H(2) and CO by recovering low-temperature thermal energy from an intercooler of the air compressor. After the decomposition of methanol, the resulting product of syngas is divided into two parts: the part reacting with Fe(2)O(3) is sent into the CLC subsystem, and the other part is introduced into a supplement combustor to enhance the inlet temperatures of the gas turbine to 1100-1500 degrees C. As a result, the new methanol-fueled gas turbine cycle with CLC had a breakthrough in thermodynamic and environmental performance. The thermal efficiency of the new system can achieve 60.6% with 70% of CO(2) recovery at a gas turbine inlet temperature of 1300 degrees C. It would be expected to be at least about 10.7 percentage points higher than that of the Chemically intercooled gas turbine cycle with the same recovery of CO(2) and is environmentally superior due to the recovery of CO(2). The promising results obtained here indicated that this novel gas turbine cycle with methanol-fueled Chemical-Looping Combustion could provide a promising approach of both effective use of alternative fuel and recovering low-temperature waste heat and offer a technical probability of blending a combination of the Chemical-Looping Combustion and the advanced gas turbine for carbon capture and storage.
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Progress of energy system with Chemical-Looping Combustion
Science Bulletin, 2009Co-Authors: Hongguang Jin, Hui Hong, Tao HanAbstract:Chemical-Looping Combustion with zero energy penalty of CO2 separation is a significant breakthrough in resolving energy and environment problems for power generation systems. This paper summarizes the research on energy systems with Chemical-Looping Combustion conducted in recent years, discloses the underlying mechanism of energy release of Chemical-Looping Combustion, describes the trends of the key technology development, and presents the proposed Chemical-Looping Combustion thermal cycles. This paper may provide a new direction to the synthesis of the next-generation energy system compatible with environment.
Masaru Ishida - One of the best experts on this subject based on the ideXlab platform.
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A new type of coal gas fueled Chemical-Looping Combustion
Fuel, 2004Co-Authors: Hongguang Jin, Masaru IshidaAbstract:A new type of coal gas fueled Chemical-Looping Combustion is experimentally investigated by means of a fixed-bed reactor operated at elevated pressure. Chemical-Looping Combustion may be carried out in two successive reactions between two reactors, a reduction reactor (coal gas with metal oxides) and an oxidation reactor (reduced metal with oxygen in the air), which may lead to a breakthrough in clean coal technology by simultaneously allowing efficient use of energy and greenhouse gas control. We have experimentally examined the kinetic behavior between solid Looping materials and coal gas in a high-pressure fixed bed reactor. On the basis of the development of suitable material and the good reactivity with the fixed bed reactor, we have identified that the coal gas fueled Chemical-Looping combustor has much better reactivity than natural gas combustors, and this phenomenon is completely different from direct Combustion with natural gas. The promising results obtained here will be valuable for the design of a practical reactor.
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Reactivity study on a novel hydrogen fueled Chemical-Looping Combustion
International Journal of Hydrogen Energy, 2001Co-Authors: Hongguang Jin, Masaru IshidaAbstract:In this paper the reactivity study on hydrogen fueled Chemical-Looping Combustion, which is capable of making breakthrough in simultaneous contribution to the efficient use of energy and being environmentally benign, has been carried out by a thermogravimetric analyzer (TGA) and a fixed bed reactor. The hydrogen fueled Chemical-Looping Combustion in the new gas turbine cycle consists of two successive reactions: hydrogen fuel is reacted with metal oxide (reduction of metal oxide), instead of air or pure oxygen, and then the reduced metal is successively oxidized by air. Here, we have developed Looping materials based on the integration of NiO, as solid reactants, with a composite metal oxide of NiAl 2 O 4 , as a binder, leading to a significant role in improving reaction rate, conversion, and regenerability in cyclic reaction in this combustor, compared with the other materials. These promising results indicated that this novel hydrogen fueled Chemical-Looping Combustion is expected to be an effective use of hydrogen energy in power generation.
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A novel gas turbine cycle with hydrogen-fueled Chemical-Looping Combustion
International Journal of Hydrogen Energy, 2000Co-Authors: Hongguang Jin, Masaru IshidaAbstract:Abstract In this paper we have proposed a novel gas turbine cycle with hydrogen-fueled Chemical-Looping Combustion, and the system study on two hydrogen-fueled power plants, the new gas turbine cycle and an advanced gas turbine cycle with H2/O2 Combustion, has been investigated with the aid of exergy principle (EUD methodology). The hydrogen fueled Chemical-Looping Combustion in the new gas turbine cycle consists of two successive reactions: hydrogen fuel is reacted with metal oxide (reduction of metal oxide), and then instead of air or pure oxygen, the reduced metal is successively oxidized by the saturated air. As a result, the new hydrogen-fueled gas turbine cycle has a breakthrough performance, with at least about 12 percentage-point higher efficiency compared to the gas turbine cycle with H2/O2 Combustion, and will be environmentally superior due to complete elimination of NOx formation. The promising results obtained here indicated that this novel gas turbine cycle with hydrogen-fueled Chemical Looping Combustion could make a breakthrough in efficient use of hydrogen energy in power plants.
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development of a novel Chemical Looping Combustion synthesis of a solid Looping material of nio nial2o4
Industrial & Engineering Chemistry Research, 1999Co-Authors: Hongguang Jin, Toshihiro Okamoto, Masaru IshidaAbstract:A new kind of solid Looping material, NiO/NiAl2O4, was synthesized based on integration of NiO, as solid reactant, with a composite metal oxide of NiAl2O4, as a binder, for applying it to Chemical-Looping Combustion. The Chemical Looping Combustion including reduction (fuel with metal) and oxidation (air with the reduced metal oxide) could make a breakthrough in simultaneous contribution to both energy and environmental issues. The reactivity of the reduction and oxidation was investigated by TGA (thermogravimetrical analysis). The results obtained here indicated that the new Looping material, NiO/NiAl2O4, might significantly improve reaction rate, conversion, and regenerability in cyclic reaction, compared with the other materials. In addition, the carbon deposition can be completely avoided by addition of water vapor at a ratio of H2O/CH4 = 2.0. These results suggest that this new Looping material of NiO/NiAl2O4 may play a vital role in developing Chemical-Looping Combustion.
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Development of a Novel Chemical-Looping Combustion: Synthesis of a Solid Looping Material of NiO/NiAl2O4
Industrial & Engineering Chemistry Research, 1999Co-Authors: Hongguang Jin, Toshihiro Okamoto, Masaru IshidaAbstract:A new kind of solid Looping material, NiO/NiAl2O4, was synthesized based on integration of NiO, as solid reactant, with a composite metal oxide of NiAl2O4, as a binder, for applying it to Chemical-Looping Combustion. The Chemical Looping Combustion including reduction (fuel with metal) and oxidation (air with the reduced metal oxide) could make a breakthrough in simultaneous contribution to both energy and environmental issues. The reactivity of the reduction and oxidation was investigated by TGA (thermogravimetrical analysis). The results obtained here indicated that the new Looping material, NiO/NiAl2O4, might significantly improve reaction rate, conversion, and regenerability in cyclic reaction, compared with the other materials. In addition, the carbon deposition can be completely avoided by addition of water vapor at a ratio of H2O/CH4 = 2.0. These results suggest that this new Looping material of NiO/NiAl2O4 may play a vital role in developing Chemical-Looping Combustion.
Tobias Mattisson - One of the best experts on this subject based on the ideXlab platform.
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Innovative Oxygen Carriers Uplifting Chemical-Looping Combustion
Energy Procedia, 2014Co-Authors: Tobias Mattisson, Juan Adánez, Karl Mayer, Frans Snijkers, Gareth Williams, Evert Wesker, Otmar Bertsch, Anders LyngfeltAbstract:This paper reports on the main results of the EU-financed project INNOCUOUS (Innovative Oxygen Carriers Uplifting Chemical-Looping Combustion). The project follows a series of successful projects with the aim of developing Chemical-Looping Combustion (CLC) with gaseous fuels rich in methane. The project has included a wide range of experimental and modelling tasks, which included i) extensive screening of spray-dried and impregnated oxygen carriers, ii) production of impregnated and spray-dried oxygen carriers at >100 kg scale, iii) operation of several oxygen carriers at industrial conditions up to 120 kW scale and iv) techno-economic study of the next-scale CLC. One area of focus in the project has been the search for viable oxygen carriers which have low or no Ni. A large portfolio of interesting metal oxide systems has been found. Two oxygen carriers of CaMnxTiyMg1-x-yO3 were successfully produced in larger amounts by spray-drying and an oxygen carrier of Fe2O3/Al2O3 was produced in similar quantity using impregnation. The Ca-based material showed excellent behavior in a 10 kW and 120 kW unit, where complete Combustion was achieved. With respect to the aim of replacing the bench-mark Ni-based material the project was thus very successful, as complete Combustion has never been achieved in these units using Ni-based material.
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Investigation of Different NiO/NiAl2O4 Particles as Oxygen Carriers for Chemical-Looping Combustion
Energy & Fuels, 2009Co-Authors: Erik Jerndal, Tobias Mattisson, Anders LyngfeltAbstract:Chemical-Looping Combustion is a Combustion technology, where CO2 is separated from the rest of the flue gases without an energy-consuming gas-separation process. The Combustion is performed in two reactors, with metal oxide particles circulating between them, transferring oxygen from the Combustion air to the fuel. Particles of NiO, supported by NiAl2O4, have been reported earlier as excellent oxygen carriers for this process. The aim of the present investigation is to verify that commercially available raw materials can be used to produce oxygen carrier particles with properties suitable for the technology. A total of 36 oxygen carrier materials were prepared by freeze granulation and investigated with respect to parameters important for Chemical-Looping Combustion. The reactivity of the particles was investigated in a small fluidized bed reactor by exposing them cyclically to CH4 and 5% O2 in N2, at 950 °C. Although defluidization occasionally occurred for some materials, it was clear that the gas conversion and the reactivity were generally high. An addition of Ca(OH)2 to the oxygen carriers increased the strength and thus reduces the risk of fragmentation and attrition in a Chemical-Looping Combustion device. An addition of MgO enhanced the fuel conversion early in reduction, which seemed to be restricted because of the limited amounts of metallic Ni. An increased sintering temperature generally resulted in harder particles of higher density; however, the risk of defluidization seemed to increase for such particles. Carbon formation was only detected when the oxygen carriers were highly reduced and the fuel conversion was incomplete, i.e., at conditions not expected in a real Chemical-Looping Combustion device. Two of the investigated particles, NOV1T1400 and NOV2T1400, displayed a combination of high reactivity and strength as well as excellent fluidization behavior and should be feasible for use in a Chemical-Looping Combustion unit.
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Solid fuels in Chemical-Looping Combustion
International Journal of Greenhouse Gas Control, 2008Co-Authors: Henrik Leion, Tobias Mattisson, Anders LyngfeltAbstract:The feasibility of using a number of different solid fuels in Chemical-Looping Combustion (CLC) has been investigated. A laboratory fluidized bed reactor system for solid fuel, simulating a Chemical-Looping Combustion system by exposing the sample to alternating reducing and oxidizing conditions, was used. In each reducing phase 0.2 g of fuel in the size range 180–250 μm was added to the reactor containing 40 g oxygen carrier of size 125–180 μm. Two different oxygen carriers were tested, a synthetic particle of 60% active material of Fe2O3 and 40% MgAl2O4 and a particle consisting of the natural mineral ilmenite. Effect of steam content in the fluidizing gas of the reactor was investigated as well as effect of temperature. A number of experiments were also made to investigate the rate of conversion of the different fuels in a CLC system. A high dependency on steam content in the fluidizing gas as well as temperature was shown. The fraction of volatiles in the fuel was also found to be important. Furthermore the presence of an oxygen carrier was shown to enhance the conversion rate of the intermediate gasification reaction. At 950 °C and with 50% steam the time needed to achieve 95% conversion of fuel particles with a diameter of 0.125–0.18 mm ranged between 4 and 15 min depending on the fuel, while 80% conversion was reached within 2–10 min. In almost all cases the synthetic Fe2O3 particle with 40% MgAl2O4 and the mineral ilmenite showed similar results with the different fuels.
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the use of petroleum coke as fuel in Chemical Looping Combustion
Fuel, 2007Co-Authors: Henrik Leion, Tobias Mattisson, Anders LyngfeltAbstract:Chemical Looping Combustion is a novel technique used for CO2 separation that previously has been demonstrated for gaseous fuel. This work demonstrates the feasibility of using solid fuel (petroleum coke) in Chemical-Looping Combustion (CLC). Here, the reaction between the oxygen carrier and solid fuel occurs via the gasification intermediates, primarily CO and H2. A laboratory fluidized-bed reactor system for solid fuel, simulating a CLC-system by exposing oxygen-carrying particles to alternating reducing and oxidizing conditions, has been developed. In each reducing period, 0.2 g of petroleum coke was added to 20 g of oxygen carrier composed of 60% active material of Fe2O3 and 40% inert MgAl2O4. The effect of steam and SO2 concentration in the fluidizing gas was investigated as well as effect of temperature. The rate of reaction was found to be highly dependent on the steam and SO2 concentration as well as the temperature. Also shown was that the presence of a metal oxide enhances the gasification of petroleum coke. A preliminary estimation of the oxygen carrier inventory needed in a real CLC system showed that it would be below 2000 kg/MWth.
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A 300 W laboratory reactor system for Chemical-Looping Combustion with particle circulation
Fuel, 2006Co-Authors: Eva Johansson, Anders Lyngfelt, Tobias Mattisson, Hilmer ThunmanAbstract:Abstract Chemical-Looping Combustion (CLC) is a method to burn gaseous fuels with inherent separation of carbon dioxide. A continuously operated laboratory reactor system for Chemical-Looping Combustion with two interconnected fluidized beds was designed and built. This Chemical-Looping combustor was designed to operate with a fuel flow corresponding to 100–300 W. The CLC system was operated successfully using a highly reactive nickel-based oxygen-carrier. Furthermore, tests were carried out to determine the degree of gas leakage between the reactors. Although there was some leakage between the fuel and air reactors, it is low enough to enable evaluation of the Combustion results. The Combustion tests showed a high conversion of the natural gas to carbon dioxide, indicating that the particles are suitable for Chemical-Looping Combustion. No methane was detected in the gas from the fuel reactor, and the fraction of carbon monoxide was in the range 0.5–3%.
Toshihiro Okamoto - One of the best experts on this subject based on the ideXlab platform.
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development of a novel Chemical Looping Combustion synthesis of a solid Looping material of nio nial2o4
Industrial & Engineering Chemistry Research, 1999Co-Authors: Hongguang Jin, Toshihiro Okamoto, Masaru IshidaAbstract:A new kind of solid Looping material, NiO/NiAl2O4, was synthesized based on integration of NiO, as solid reactant, with a composite metal oxide of NiAl2O4, as a binder, for applying it to Chemical-Looping Combustion. The Chemical Looping Combustion including reduction (fuel with metal) and oxidation (air with the reduced metal oxide) could make a breakthrough in simultaneous contribution to both energy and environmental issues. The reactivity of the reduction and oxidation was investigated by TGA (thermogravimetrical analysis). The results obtained here indicated that the new Looping material, NiO/NiAl2O4, might significantly improve reaction rate, conversion, and regenerability in cyclic reaction, compared with the other materials. In addition, the carbon deposition can be completely avoided by addition of water vapor at a ratio of H2O/CH4 = 2.0. These results suggest that this new Looping material of NiO/NiAl2O4 may play a vital role in developing Chemical-Looping Combustion.
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Development of a Novel Chemical-Looping Combustion: Synthesis of a Solid Looping Material of NiO/NiAl2O4
Industrial & Engineering Chemistry Research, 1999Co-Authors: Hongguang Jin, Toshihiro Okamoto, Masaru IshidaAbstract:A new kind of solid Looping material, NiO/NiAl2O4, was synthesized based on integration of NiO, as solid reactant, with a composite metal oxide of NiAl2O4, as a binder, for applying it to Chemical-Looping Combustion. The Chemical Looping Combustion including reduction (fuel with metal) and oxidation (air with the reduced metal oxide) could make a breakthrough in simultaneous contribution to both energy and environmental issues. The reactivity of the reduction and oxidation was investigated by TGA (thermogravimetrical analysis). The results obtained here indicated that the new Looping material, NiO/NiAl2O4, might significantly improve reaction rate, conversion, and regenerability in cyclic reaction, compared with the other materials. In addition, the carbon deposition can be completely avoided by addition of water vapor at a ratio of H2O/CH4 = 2.0. These results suggest that this new Looping material of NiO/NiAl2O4 may play a vital role in developing Chemical-Looping Combustion.
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kinetic behavior of solid particle in Chemical Looping Combustion suppressing carbon deposition in reduction
Energy & Fuels, 1998Co-Authors: Masaru Ishida, Hongguang Jin, Toshihiro OkamotoAbstract:In order to apply Chemical-Looping Combustion to a practical power plant, carbon deposition on the solid particle is one of the key problems to be overcome. Six kinds of solid particles were examined to clarify the kinetic behavior of carbon deposition. The effects of the solid composition, feed gas composition, and reaction temperature on carbon deposition were investigated by TGR (thermogravimetrical reactor) on the basis of NiO/YSZ particle. From the viewpoints of both reactivity and resistance against carbon deposition, the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) was found to be a good candidate for Chemical-Looping Combustion. We have observed that carbon deposition could be completely avoided with very low concentration of water vapor. By means of a proposed model, the condition that carbon deposition would be avoided was identified.
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A Fundamental Study of a New Kind of Medium Material for Chemical-Looping Combustion
Energy & Fuels, 1996Co-Authors: Masaru Ishida, And Hongguang Jin, Toshihiro OkamotoAbstract:A new kind of medium material is developed for Chemical-Looping Combustion, in which fuel is oxidized by metallic oxide medium in a reactor and reduced metal is oxidized by air in another reactor. This scheme may yield great advantage of savings of energy and suppressing the effect on environment. Two kinds of methods, sol−gel method and dissolution method, are examined to prepare the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) as an excellent medium material from the viewpoint of Chemical kinetics and mechanical strength. The effects of reaction temperature, particle size, and gas composition are clarified experimentally. The experimental results on kinetics are interpreted by unreacted-core shrinking model. The cyclic use of the medium particle is also tested. The results obtained in this paper disclose the high potentiality that the Chemical-Looping Combustion could be applied in a practical power plant.