Screening the bulk properties and reducibility of Fe-doped Mn2O3 from first principles calculations

Баженова, Е. А.; Honkala, Karoliina

doi:10.1016/j.cattod.2017.02.004

Cited by 12 publications

(11 citation statements)

References 49 publications

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“…An oxygen carrier with high reactivity towards H , CO and CH will reduce the amount of unburned gaseous products escaping from the fuel reactor and, therefore, the oxygen demand. Elemental studies based on density functional theory calculations (DFT) can be found in literature [203][204][205][206][207]). They analyze some aspects regarding the theoretical reactivity of oxygen carriers, such as the effect of metal oxide or the relevance of dopants addition.…”

Section: Relevance Of the Oxygen Carriermentioning

confidence: 99%

Chemical looping combustion of solid fuels

Adánez

Abad

Mendiara

et al. 2018

Progress in Energy and Combustion Science

487

321

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Chemical Looping Combustion (CLC) has arisen during last years as a very promising combustion technology for power plants and industrial applications, with inherent CO 2 capture which avoids the energy penalty imposed on other competing technologies. The use of solid fuels in CLC has been highly developed in the last decade and currently stands at a technical readiness level (TRL) of 6. In this paper, experience gained during CLC operation in continuous units is reviewed and appraised, focusing mainly on technical and environmental issues relating to the use of solid fuels. Up to now, more than 2700 hours of operational experience has been reported in 19 pilot plants ranging from 0.5 kW th to 4 MW th. When designing a CLC unit, the preferred configuration for the scale-up of CLC of solid fuels is a two circulating fluidized beds (CFB) system. Coal has been the most commonly used solid fuel in CLC, but biomass has recently emerged as a very promising option to achieve negative emissions using bioenergy with carbon capture and storage (BECCS). Mostly low cost iron and manganese materials have been used as oxygen carriers in the so called in-situ gasification CLC (iG-CLC). The development of Chemical Looping with oxygen uncoupling (CLOU) makes a qualitative step forward in the solid fuel combustion, due to the use of materials able to release oxygen. The performance and environmental issues of CLC of solid fuels is evaluated here. Regarding environmental aspects, the pollutant emissions (SO 2 , NO x , etc.) released into the atmosphere from the air reactor are no cause of concern for the environment. However, the presence of SO 2 , NO x and Hg at the exit of the fuel reactor affects CO 2 quality, which must be taken into account during the later compression and purification stages. The effect of the main variables affecting CLC performance is evaluated for fuel conversion, CO 2 capture rate, and combustion efficiency obtained in different CLC 3 units. Solid fuel conversion is normally not complete during operation, due to the undesired loss of char. A methodology is presented to extrapolate the current information to what could be expected in a larger CLC system. CO 2 capture near 100% has been reported using a highly efficient carbon stripper, highly reactive fuels (such as lignites and biomass, etc.) or by the CLOU process. Operational experience in iG-CLC has showed that it is not possible to reach complete fuel combustion, making an additional oxygen polishing step necessary. For the further scale-up, it is essential to reduce the unburnt compounds at the fuel reactor outlet. Proposals to achieve this reduction already exist and include both improvement to the gas-oxygen carrier contact, or new design concepts based on the current scheme for iG-CLC. In addition, CLOU based on copper materials has shown that complete fuel combustion could be achieved. Main challenges for the future development and scale-up of CLC technology have been also identified. A breakthrough in the future development of CLC technology for ...

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Section: Relevance Of the Oxygen Carriermentioning

confidence: 99%

Chemical looping combustion of solid fuels

Adánez

Abad

Mendiara

et al. 2018

Progress in Energy and Combustion Science

487

321

View full text Add to dashboard Cite

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Section: Advanced Experimental and Computational Techniques For Undermentioning

confidence: 99%

“…Additional computational tools and high resolution spectroscopic techniques should be brought to the field to provide more mechanistic insights on how metal doping is influencing reactions kinetics or stabilizing the microstructure of the redox materials. Density functional theory (DFT) has been successfully used in sister fields such as thermochemical solar-to-fuel , production or chemical looping combustion, assessing redox behavior of similar type of oxides. Incorporation of advanced in situ/operando spectroscopy techniques, such as Raman, X-ray photoelectron spectroscopy (XPS), or X-ray adsorption spectroscopy, to the already explored use of in situ XRD would be crucial for obtaining valuable information on temperature-resolved materials crystallographic ordering, phenomena occurring at the oxide surface, and oxidation state transition taking place during the redox trade.…”

Section: Thermochemical Heat Storage Based On Redox Cycles Of Metal O...mentioning

confidence: 99%

Solar Energy on Demand: A Review on High Temperature Thermochemical Heat Storage Systems and Materials

et al. 2019

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Among renewable energies, wind and solar are inherently intermittent and therefore both require efficient energy storage systems to facilitate a round-the-clock electricity production at global scale. In this context, concentrated solar power (CSP) stands out among other sustainable technologies because it offers the interesting possibility of storing energy collected from the sun as heat, by sensible, latent or thermochemical means. Accordingly, continuous electricity generation in the power block is possible even during off-sun periods, providing CSP plants with a remarkable dispatchability. Sensible heat storage has been already incorporated to commercial CSP plants. However, due to its potentially higher energy storage density, thermochemical heat storage (TCS) systems emerge as an attractive alternative for the design of next generation power plants, which are expected to operate at higher temperatures. Through these systems, thermal energy is used to drive endothermic chemical reactions, which can subsequently release the stored energy when needed through a reversible exothermic step. This review analyzes the status 2 of this prominent energy storage technology, its major challenges and future perspectives, covering in detail the numerous strategies proposed for the improvement of materials and thermochemical reactors. Thermodynamic calculations allow selecting high energy density systems, but experimental findings indicate that sufficiently rapid kinetics and long-term stability trough continuous cycles of chemical transformation are also necessary for practical implementation. In addition, selecting easy to handle materials with reduced cost and limited toxicity is crucial for large-scale deployment of this technology. In this work, the possible utilization of materials as diverse as metal hydrides, hydroxides or carbonates for thermochemical storage is discussed. Furthermore, especial attention is paid to the development of redox metal oxides, such as Co3O4/CoO, Mn2O3/Mn3O4 and perovskites of different compositions, as an auspicious new class of TCS materials due to the advantage of working with atmospheric air as reactant, avoiding the need of gas storage tanks. Current knowledge about the structural, morphological and chemical modifications of these solids, either caused during redox transformations, or induced wittingly as a way to improve their properties, is revised in detail. In addition, the design of new reactors concepts proposed for the most efficient use of TCS in concentrated solar facilities is also critically considered. Finally, strategies for the harmonic integration of these units in functioning solar power plants, as well as the economic aspects are also briefly assessed.

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“…In addition to changing the supports, the introduction of promoters could improve the performance of Mn-based oxygen carriers. Bazhenova et al [317] theoretically explained and analyzed the influence of Fe doping on Mn 2 O 3 at the atomic level by DFT calculations. Since Fe-O bonds were more stable than Mn-O bonds, the addition of Fe made the oxides more stable and changed the electronic structure of the oxides.…”

Section: Other Oxygen Carriermentioning

confidence: 99%

Chemical looping reforming: process fundamentals and oxygen carriers

et al. 2022

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Chemical looping reforming (CLR) provides a viable process intensification approach for clean and efficient syngas production from carbonaceous fuel with inherent gas–gas separation. The rational design of metal oxide-based oxygen carriers and the scale-up of associated CLR reactor systems play important roles in CLR process development. This review first introduces the concept and advantages of CLR as well as its historical development. The process fundamentals, including basic schemes, reaction stoichiometry, thermodynamics, kinetics and reactor system design, are reviewed. The integral approach for CLR process development is illustrated, showing that the design and compatibility of oxygen carriers and reactor systems are critical for CLR performance. The reaction principle during the reduction of oxygen carriers is discussed, followed by strategies for improving the redox reactivity and stability. We further review and discuss the latest exciting advances on this subject with the purpose of illustrating factors that govern fundamental mechanisms in the redox reaction chemistry of oxygen carriers and their design principles for sustained chemical looping reactor applications. It is expected that these new advances will inspire more effective oxygen carriers and efficient reactor systems for the development and deployment of various CLR processes.

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Screening the bulk properties and reducibility of Fe-doped Mn2O3 from first principles calculations

Cited by 12 publications

References 49 publications

Chemical looping combustion of solid fuels

Chemical looping combustion of solid fuels

Solar Energy on Demand: A Review on High Temperature Thermochemical Heat Storage Systems and Materials

Chemical looping reforming: process fundamentals and oxygen carriers

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