Journal ArticleDOI
La0.8Sr0.2Co0.2Fe0.8O3−δ as a potential oxygen carrier in a chemical looping type reactor, an in-situ powder X-ray diffraction study
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TLDR
In this article, in-situ powder X-ray diffraction was used to study the La1−xSrxCo1−yFeyO3−δ system and found that for samples with high iron content a hexagonal/orthorhombic to cubic phase transition was observed upon heating in a reductive atmosphere and that the cationic lattice is maintained upon reduction.Abstract:
Perovskite type materials which can change oxygen content quickly under changing oxygen partial pressures are believed to be suitable materials for chemical looping of natural gas. In order to investigate the oxidation/reduction of these materials in-situ powder X-ray diffraction was used to study the La1−xSrxCo1−yFeyO3−δ system. It was found that for samples with high iron content a hexagonal/orthorhombic to cubic phase transition was observed upon heating in a reductive atmosphere and that the cationic lattice is maintained upon reduction. On the other hand, the samples with high cobalt content were unstable with respect to heating in a reductive atmosphere as they decomposed to form La2O3, Co and at least one additional phase. Once a suitable candidate had been obtained a chemical looping experiment was carried out using H2 as a model fuel, again using in-situ powder X-ray diffraction.read more
Citations
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Journal ArticleDOI
Progress in chemical-looping combustion and reforming technologies
TL;DR: A comprehensive review of the Chemical-Looping Combustion (CLC) and ChemicalLooping Reforming (CLR) processes reporting the main advances in these technologies up to 2010 is presented in this article.
Journal ArticleDOI
Chemical-looping combustion (CLC) for inherent CO2 separations—a review
Mohammad M. Hossain,Hugo de Lasa +1 more
TL;DR: In this article, a review of recent advances on chemical-looping combustion (CLC) is presented, which is a promising technology for fossil fuel combustion preventing CO 2 dilution with flue gases, mainly nitrogen.
Journal ArticleDOI
Novel oxygen-carrier materials for chemical-looping combustion and chemical-looping reforming; LaxSr1−xFeyCo1−yO3−δ perovskites and mixed-metal oxides of NiO, Fe2O3 and Mn3O4
TL;DR: In this article, a fixed-bed quartz reactor at 900oC was examined by reducing with CH4 and oxidation with air, and it was found that LaxSr1−xFeO3−δ perovskites provided very high selectivity towards CO/H2 and should be well suited for chemical-looping reforming.
Journal ArticleDOI
Present status and overview of Chemical Looping Combustion technology
TL;DR: A review of the chemical looping combustion (CLC) technology can be found in this paper, which is based on the transfer of oxygen from air to fuel by means of a metal-based oxygen carrier and this process is blessed with inherent sequestration of CO2.
Journal ArticleDOI
Perovskite-type oxides LaFe1−xCoxO3 for chemical looping steam methane reforming to syngas and hydrogen co-production
TL;DR: In this article, the influence of Co doping on the characteristics and the stabilities of perovskite-type oxides were investigated by means of X-ray diffraction (XRD), Xray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H2-TPR), Brunauer-Emmett-Teller (BET) surface area and fixed-bed experiments.
References
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Journal ArticleDOI
Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides
TL;DR: The effective ionic radii of Shannon & Prewitt [Acta Cryst. (1969), B25, 925-945] are revised to include more unusual oxidation states and coordinations as mentioned in this paper.
Journal ArticleDOI
Structure and electrical properties of La1−xSrxCo1−yFeyO3. Part 1. The system La0.8Sr0.2Co1−yFeyO3
TL;DR: In this article, the electrical conductivity and Seebeck coefficient as a function of the Co Fe ratio and temperature were investigated in the La0.8Sr0.2Co1−yFeyO3 with 0 ≤ y ≤ 1.
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Structure and electrical properties of La1 − xSrxCo1 − yFeyO3. Part 2. The system La1 − xSrxCo0.2Fe0.8O3
TL;DR: In this paper, a semi-empirical model was developed which took into account the thermally activated disproportionation of Co 3+ ions into Co 4+ and Co 2+ pairs, and the ionic compensation of oxygen vacancies formed at high temperatures.
Journal ArticleDOI
The use of iron oxide as an oxygen carrier in chemical-looping combustion of methane with inherent separation of CO2
TL;DR: In this paper, the feasibility of using Fe 2 O 3 as an oxygen carrier has been investigated in a fixed bed quartz reactor, where the iron oxide was exposed to repeated cycles of air and methane at 950 ° C, with the outlet gas concentrations measured.
Journal ArticleDOI
Crystal Structure and Metal–Insulator Transition of La1−xSrxCoO3
TL;DR: In this article, the crystal structure of perovskite La{sub 1-x}Sr{sub x}CoO{sub 3} (0.0, 0.25) was determined by powder X-ray Rietveld analysis, and its correlation with the electrical properties was discussed.
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