Comprehensive study of Mn–Fe–Al oxygen-carriers for chemical-looping with oxygen uncoupling (CLOU)

Azimi, Golnar; Mattisson, Tobias; Leion, Henrik; Rydén, Magnus; Lyngfelt, Anders

doi:10.1016/j.ijggc.2014.12.022

Cited by 33 publications

(29 citation statements)

References 44 publications

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“…Additionally, owing to the low cost of both Fe and Mn, the bimetallic Fe-Mn oxide can be considered as a very competitive oxygen carrier for the chemical looping process [104]. Moreover, both Fe-Mn-O and Ni-Mn-O systems have oxygen uncoupling properties, as a result, Fe x Mn (1−x) O and NiMn 2 O 4 can be used as oxygen carriers for the CLOU process [105,106,107]. …”

Section: Improvements To Oxygen Carriersmentioning

confidence: 99%

Advanced Chemical Looping Materials for CO2 Utilization: A Review

Galvita

Poelman

et al. 2018

Materials

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Combining chemical looping with a traditional fuel conversion process yields a promising technology for low-CO2-emission energy production. Bridged by the cyclic transformation of a looping material (CO2 carrier or oxygen carrier), a chemical looping process is divided into two spatially or temporally separated half-cycles. Firstly, the oxygen carrier material is reduced by fuel, producing power or chemicals. Then, the material is regenerated by an oxidizer. In chemical looping combustion, a separation-ready CO2 stream is produced, which significantly improves the CO2 capture efficiency. In chemical looping reforming, CO2 can be used as an oxidizer, resulting in a novel approach for efficient CO2 utilization through reduction to CO. Recently, the novel process of catalyst-assisted chemical looping was proposed, aiming at maximized CO2 utilization via the achievement of deep reduction of the oxygen carrier in the first half-cycle. It makes use of a bifunctional looping material that combines both catalytic function for efficient fuel conversion and oxygen storage function for redox cycling. For all of these chemical looping technologies, the choice of looping materials is crucial for their industrial application. Therefore, current research is focused on the development of a suitable looping material, which is required to have high redox activity and stability, and good economic and environmental performance. In this review, a series of commonly used metal oxide-based materials are firstly compared as looping material from an industrial-application perspective. The recent advances in the enhancement of the activity and stability of looping materials are discussed. The focus then proceeds to new findings in the development of the bifunctional looping materials employed in the emerging catalyst-assisted chemical looping technology. Among these, the design of core-shell structured Ni-Fe bifunctional nanomaterials shows great potential for catalyst-assisted chemical looping.

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Section: Improvements To Oxygen Carriersmentioning

confidence: 99%

Advanced Chemical Looping Materials for CO2 Utilization: A Review

Galvita

Poelman

et al. 2018

Materials

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“…It can be speculated that the material, at the beginning of the oxygen release experiment, contained phases, e.g., (Mn,Fe) 2 O 3 (bixbyite), that provided a temperature-dependent oxygen release. However, once these phases released oxygen and were reduced, e.g., to (Mn,Fe) 3 O 4 (spinel), the temperature in the air reactor was too high as to thermodynamically favor oxidation to (Mn,Fe) 2 O 3 [37,38]. The recorded data suggests that oxidation is possible at lower temperature, i.e., during cool-down respectively warm-up, though the high number of elements identified in the ore makes it difficult to support these observations with thermodynamic data.…”

Section: Oxygen Releasementioning

confidence: 99%

Chemical-looping combustion of synthetic biomass-volatiles with manganese-ore oxygen carriers

Moldenhauer

Sundqvist

Mattisson

et al. 2018

International Journal of Greenhouse Gas Control

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Carbon capture and storage of CO 2 from combustion of biomass, i.e., bio-energy carbon capture and storage (BECCS), makes it possible to obtain so-called negative emissions-the atmosphere is cleansed from carbon dioxide. The purpose of the present study was to investigate the suitability of different manganese ores as oxygen carriers in chemical-looping combustion of biomass fuels. For this screening study, a laboratory-scale, circulating fluidized-bed CLC system with a nominal fuel input of 300 W th was used. The primary focus was to investigate the reactivity of these oxygen carriers towards biomass fuels, and find a reactive oxygen carrier with sufficient mechanical stability that could be suitable for large-scale chemical-looping combustion of biomass. A synthetic "biomass volatiles" gas was used to study how the different gas components react with the oxygen-carrier particles. Additional experiments were conducted with methane and a syngas. Parameter studies concerning temperature and specific fuelreactor bed mass (bed mass per fuel thermal power in kg/MW th) were carried out. With the synthetic biomass volatiles, conversion of fuel carbon to CO 2 as high as 97.6 % was achieved. For a majority of the investigated ores, essentially all C2 and C3 hydrocarbons were converted, as well as a very high fraction of the CO. Reactivity towards CH 4 was generally lower, but improved at higher temperatures. The resistance of the oxygen carriers towards mechanical degradation was measured in a jet-cup attrition test rig. The measured attrition was estimated as "intermediate" for four of the five tested materials, while one of the ores displayed high attrition.

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“…In the fuel reactor, CO 2 generated from the oxidation reaction can be captured with 100% efficiency from the outlet of the reactor by simply condensing the steam, another reaction product, without engaging complex CO 2 separation schemes. [6][7][8][9][10][11] Among these oxygen carriers, iron oxide is very attractive since it is relatively inexpensive, readily available from large natural reserves and also environmentally safe. 3 This technology has been developed into a chemical looping partial oxidation (CLPO) process for direct syngas production from methane with significant economic attraction compared to the conventional approaches.…”

Section: Introductionmentioning

confidence: 99%

Methane adsorption and dissociation on iron oxide oxygen carriers: the role of oxygen vacancies

Cheng

Qin

Guo

et al. 2016

Phys. Chem. Chem. Phys.

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We performed ab initio DFT+U calculations to explore the interaction between methane and iron oxide oxygen carriers for chemical looping reaction systems. The adsorption of CH4 and CHx (x = 0-3) radicals on α-Fe2O3(001), and the influence of oxygen vacancies at the top surface and on the subsurface on the adsorption properties of the radicals was investigated. The adsorption strength for CH4 and C radicals at the top of the α-Fe2O3(001) surface in the presence of oxygen vacancies is lower than that on the stoichiometric surface. However, for methyl (CH3), methylene (CH2) and methine (CH) radicals, it is correspondingly higher. In contrast, the oxygen vacancy formation on the subsurface not only increases the adsorption strength of CH3, CH2 and CH radicals, but also facilitates C radical adsorption. We found that oxygen vacancies significantly affect the adsorption configuration of CHx radicals, and determine the probability of finding an adsorbed species in the stoichiometric region and the defective region at the surface. With the obtained adsorption geometries and energetics of these species adsorbed on the surface, we extend the analysis to CH4 dissociation under chemical looping reforming conditions. The distribution of adsorbed CH4 and CHx (x = 0-3) radicals is calculated and analyzed which reveals the relationship between adsorbed CHx radical configuration and oxygen vacancies in iron oxide. Also, the oxygen vacancies can significantly facilitate CH4 activation by lowering the dissociation barriers of CH3, CH2 and CH radicals. However, when the oxygen vacancy concentration reaches 2.67%, increasing the oxygen vacancy concentration cannot continue to lower the CH dissociation barrier. The study provides fundamental insights into the mechanism of CH4 dissociation on iron based oxygen carriers and also provide guidance to design more efficient oxygen carriers.

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Comprehensive study of Mn–Fe–Al oxygen-carriers for chemical-looping with oxygen uncoupling (CLOU)

Cited by 33 publications

References 44 publications

Advanced Chemical Looping Materials for CO2 Utilization: A Review

Advanced Chemical Looping Materials for CO2 Utilization: A Review

Chemical-looping combustion of synthetic biomass-volatiles with manganese-ore oxygen carriers

Methane adsorption and dissociation on iron oxide oxygen carriers: the role of oxygen vacancies

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