Academic literature on the topic 'Oxygen conducting membrane'
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Journal articles on the topic "Oxygen conducting membrane"
1
Araki, Sadao. "Membrane Reactors Using Mixed Ionic–electric Conducting Oxygen–permeable Membranes." MEMBRANE 46, no. 3 (2021): 148–55. http://dx.doi.org/10.5360/membrane.46.148.
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Arratibel Plazaola, Alba, Aitor Cruellas Labella, Yuliang Liu, Nerea Badiola Porras, David Pacheco Tanaka, Martin Sint Annaland, and Fausto Gallucci. "Mixed Ionic-Electronic Conducting Membranes (MIEC) for Their Application in Membrane Reactors: A Review." Processes 7, no. 3 (March 1, 2019): 128. http://dx.doi.org/10.3390/pr7030128.
Full textAbstract:
Mixed ionic-electronic conducting membranes have seen significant progress over the last 25 years as efficient ways to obtain oxygen separation from air and for their integration in chemical production systems where pure oxygen in small amounts is needed. Perovskite materials are the most employed materials for membrane preparation. However, they have poor phase stability and are prone to poisoning when subjected to CO2 and SO2, which limits their industrial application. To solve this, the so-called dual-phase membranes are attracting greater attention. In this review, recent advances on self-supported and supported oxygen membranes and factors that affect the oxygen permeation and membrane stability are presented. Possible ways for further improvements that can be pursued to increase the oxygen permeation rate are also indicated. Lastly, an overview of the most relevant examples of membrane reactors in which oxygen membranes have been integrated are provided.
3
Ma, Teng, Ning Han, Bo Meng, Naitao Yang, Zhonghua Zhu, and Shaomin Liu. "Enhancing Oxygen Permeation via the Incorporation of Silver Inside Perovskite Oxide Membranes." Processes 7, no. 4 (April 8, 2019): 199. http://dx.doi.org/10.3390/pr7040199.
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As a possible novel cost-effective method for oxygen production from air separation, ion-conducting ceramic membranes are becoming a hot research topic due to their potentials in clean energy and environmental processes. Oxygen separation via these ion-conducting membranes is completed via the bulk diffusion and surface reactions with a typical example of perovskite oxide membranes. To improve the membrane performance, silver (Ag) deposition on the membrane surface as the catalyst is a good strategy. However, the conventional silver coating method has the problem of particle aggregation, which severely lowers the catalytic efficiency. In this work, the perovskite oxide La0.8Ca0.2Fe0.94O3−a (LCF) and silver (5% by mole) composite (LCFA) as the membrane starting material was synthesized using one-pot method via the wet complexation where the metal and silver elements were sourced from their respective nitrate salts. LCFA hollow fiber membrane was prepared and comparatively investigated for air separation together with pure LCF hollow fiber membrane. Operated from 800 to 950 °C under sweep gas mode, the pure LCF membrane displayed the fluxes from 0.04 to 0.54 mL min−1 cm−2. Compared to pure LCF, under similar operating conditions, the flux of LCFA membrane was improved by 160%.
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Ivanov, Ivan L., Petr O. Zakiryanov, Vladimir V. Sereda, Maxim O. Mazurin, Dmitry A. Malyshkin, Andrey Yu Zuev, and Dmitry S. Tsvetkov. "Nonstoichiometry, Defect Chemistry and Oxygen Transport in Fe-Doped Layered Double Perovskite Cobaltite PrBaCo2−xFexO6−δ (x = 0–0.6) Membrane Materials." Membranes 12, no. 12 (November 28, 2022): 1200. http://dx.doi.org/10.3390/membranes12121200.
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Mixed conducting cobaltites PrBaCo2−xFexO6−δ (x = 0–0.6) with a double perovskite structure are promising materials for ceramic semi-permeable membranes for oxygen separation and purification due to their fast oxygen exchange and diffusion capability. Here, we report the results of the detailed study of an interplay between the defect chemistry, oxygen nonstoichiometry and oxygen transport in these materials as a function of iron doping. We show that doping leads to a systematic variation of both the thermodynamics of defect formation reactions and oxygen transport properties. Thus, iron doping can be used to optimize the performance of mixed conducting oxygen-permeable double perovskite membrane materials.
5
Blond, E., and N. Richet. "Thermomechanical modelling of ion-conducting membrane for oxygen separation." Journal of the European Ceramic Society 28, no. 4 (January 2008): 793–801. http://dx.doi.org/10.1016/j.jeurceramsoc.2007.07.024.
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Świerczek, Konrad, Hailei Zhao, Zijia Zhang, and Zhihong Du. "MIEC-type ceramic membranes for the oxygen separation technology." E3S Web of Conferences 108 (2019): 01021. http://dx.doi.org/10.1051/e3sconf/201910801021.
Full textAbstract:
Mixed ionic-electronic conducting ceramic membrane-based oxygen separation technology attracts great attention as a promising alternative for oxygen production. The oxygen-transport membranes should not only exhibit a high oxygen flux but also show good stability under CO2-containing atmospheres. Therefore, designing and optimization, as well as practical application of membrane materials with good CO2 stability is a challenge. In this work, apart from discussion of literature data, authors’ own results are provided, which are focused on materia - related issues, including development of electrode materials exhibiting high ionic and electronic conductivities.
7
Chua, J., C. Li, and J. Sunarso. "Pure oxygen separation from air using dual-phase SDC-SCFZ disc membrane: A modelling approach." IOP Conference Series: Materials Science and Engineering 1195, no. 1 (October 1, 2021): 012060. http://dx.doi.org/10.1088/1757-899x/1195/1/012060.
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Abstract Novel Ce0.8Sm0.2O1.9-SrCo0.4Fe0.55Zr0.05O3-δ (SDC-SCFZ) disc membranes consist of 25 wt.% SDC fluorite ionic conducting phase and 75 wt.% SCFZ perovskite mixed conducting phase, which is more promising than perovskite oxide SCFZ single-phase membrane in terms of the oxygen permeation flux. This work features a modelling approach to simulate the oxygen permeation fluxes of the SDC-SCFZ membrane. Simplified model equations from the Zhu model and Xu-Thomson model based on the limiting cases of surface exchange reactions and bulk diffusion are compared. The Zhu model is found to be more applicable for the membranes with overall good correlation and low sum of squared error. Furthermore, modelling studies revealed that the oxygen transport is limited by surface exchange reactions from 700 to 850 °C and a mixture of both limiting cases above 850 up to 950 °C. It is concluded that the membranes exhibit high oxygen permeation flux of up to 2×10−6 mol s−1 cm−2 at 950 °C with Pair of 5 atm and Po 2 of 0.005 atm. The optimum range of operating conditions of the membrane are found to be at 950 °C with minimum Pair of 1 atm and P11 2 lower than 0.025 atm.
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Lei, Song, Ao Wang, Jian Xue, and Haihui Wang. "Catalytic ceramic oxygen ionic conducting membrane reactors for ethylene production." Reaction Chemistry & Engineering 6, no. 8 (2021): 1327–41. http://dx.doi.org/10.1039/d1re00136a.
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Catalytic ceramic oxygen ionic conducting membrane reactors have great potential in the production of high value-added chemicals as they can couple chemical reactions with separation within a single unit, allowing process intensification.
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Zeng, Pingying, Ran Ran, Zhihao Chen, Hongxia Gu, Zongping Shao, and Shaomin Liu. "Novel mixed conducting SrSc0.05Co0.95O3-δ ceramic membrane for oxygen separation." AIChE Journal 53, no. 12 (2007): 3116–24. http://dx.doi.org/10.1002/aic.11334.
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Christoffersen, R., S. Kim, Y. L. Yang, and A. J. Jacobson. "Analytical TEM and EPMA Study of Decomposition Reactions in an Oxygen-Separation Membrane Material." Microscopy and Microanalysis 3, S2 (August 1997): 745–46. http://dx.doi.org/10.1017/s1431927600010618.
Full textAbstract:
Mixed-conducting oxides with appropriate values of electronic and ionic conductivity have the potential to be used as ceramic “membranes” for the separation of oxygen from other gases. The separation is based on oxygen transport from an O2-rich, and hence oxidizing, gas reservoir on one side of the membrane to an O2-lean, and hence reducing, take-up reservoir on the membrane's other side. The oxide Sr(Co1-xFex)O3-δ (SCFO), which has a cubic perovskite structure, is one such potential membrane material. Although the permeation flux of oxygen through SCFO membranes has been mea-sured, the microstructural evolution of SCFO membranes during permeation has been little studied in comparison to other potential membrane oxides. Several of these other systems do show segregation and/or decomposition phenomena that potentially may affect membrane properties. Here we report preliminary results of a systematic microanalytical study of SCFO membranes using scanning electron microscopy and microanalysis in an electron probe microanalyzer (EPMA), as well as transmission electron microscopy in an analytical TEM.
Dissertations / Theses on the topic "Oxygen conducting membrane"
1
Akin, Figen Tulin. "Ionic Conducting Ceramic Membrane Reactor for Partial Oxidation of Light Hydrocarbons." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1021991903.
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Girdauskaite, Egle. "Thermodynamische und kinetische Untersuchungen zum Sauerstoffaustausch in perowskitischen Mischoxiden auf Basis von Ferriten und Cobaltiten." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1195658113234-25483.
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Oxidkeramische Materialien sind zunehmend von praktischem Interesse für neue Technologien, die in Brennstoffzellen, Sensoren und Ionentransport-Membranen Anwendung finden. Einige dieser Oxide mit Perowskitstruktur ABO3 zeigen hohe Ionen- und Elektronenleitung, ausreichende chemische Stabilität sowie thermisch-mechanische Eigenschaften, wie sie für die Anwendung als Sauerstofftransportmembran benötigt werden. Oxidionentransport erfolgt über einen Oxidionen-Leerstellenmechanismus. Die charakteristische Schwierigkeit für die Anwendung solcher Materialien besteht aber darin, dass die gestellten Forderungen wie hoher Ionentransport und hohe Stabilität sich diametral gegenüberstehen. In dieser Arbeit wurde eine systematische Untersuchung der Beziehungen zwischen Zusammensetzung, Struktur und Stöchiometrie der ferritischer und cobaltitischer Mischoxide und den Transporteigenschaften sowie der thermischen Ausdehnung durchgeführt. Erstmalig wurden thermodynamische und kinetische Parameter von Reihen von Oxiden in einem weiten Bereich von Temperatur und Sauerstoffpartialdruck systematisch bestimmt. Aus den Ergebnissen konnten Empfehlungen gegeben werden für die Zusammensetzung von Perowskitoxiden, die zum Aufbau von Sauerstofftransportmembranen unter bestimmten pO2/T-Bedingungen geeignet sind.
3
Seeharaj, Panpailin. "Mixed-conducting LSC/CGO and Ag/CGO composites for passive oxygen separation membranes." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/5724.
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Dense ceramic oxygen separation membranes can pass oxygen perm-selectively at elevated temperature and have potential for improving the performance and reducing the cost of several industrial processes: such as the conversion of natural gas to syngas, or to separate oxygen from air for oxy-fuel combustion in electricity generation (to reduce NOx emissions and facilitate CO2 sequestration). These pressure-driven solid state membranes are based on fast oxygen-ion conducting ceramics, but also need a compensating flow of electrons. Dual-phase composites are attractive since they provide an extra degree of freedom, compared with single phase membranes, for optimising the overall membrane performance. In this study, composites containing gadolinia doped ceria (CGO, Ce0.9Gd0.1O2- ) and either strontium-doped lanthanum cobaltite (LSC, La0.9Sr0.1CoO3- or La0.6Sr0.4CoO3- ) or silver (Ag) were investigated for possible application as oxygen separation membranes in oxy-fuel combustion system. These should combine the high oxygen ion conductivity of CGO with the high electronic conductivity and fast oxygen surface exchange of LSC or silver. Dense mixed-conducting composite materials of LSC/CGO (prepared by powder mixing and sintering) and Ag/CGO composites (prepared by silver plus copper oxide infiltration method) showed high relative density (above 95%), low background gas leakage and also good electrical conduction. The percolation threshold of the electronic conducting component was determined to be approximately 20 vol.% for both LSC compositions and 14 vol.% for Ag. Isotopic exchange and depth profiling by secondary ion mass spectrometry was used to investigated the oxygen tracer diffusion (D*) and surface exchange coefficient (k*) of the composites. Composites just above the electronic percolation threshold exhibited high solid state oxygen diffusivity, fast surface exchange activity moderate thermal expansion and sufficient mechanical strength thus combining the benefits of their constituent materials. The preliminary work on oxygen permeation measurement showed that the reasonable magnitude of oxygen fluxes is possible to be achieved. This indicates that the composites of LSC/CGO and Ag/CGO are promising for further development as passive oxygen separation membranes.
4
Armstrong, Tad John. "Oxygen permeation properties of perovskite-related intergrowth oxides exhibiting mixed ionic-electronic conduction /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Cai, Andrew. "CHEMICAL EXPANSIVITY IN CERAMIC OXYGEN TRANSPORT MATERIALS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case159439738367673.
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Alqaheem, Yousef S. Y. A. H. Yousef. "Impact of sulphur contamination on the performance of mixed ionic-electronic conducting membranes for oxygen separation and hydrogen production." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/3129.
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Mixed ionic-electronic conducting (MIEC) membranes are a promising technology for oxygen separation but they are not commercialised yet due to sealing issue and sensitivity to impurities in feedstock. In this study, La0.6Sr0.4Co0.2Fe0.8O3- (LSCF6428) was successfully sealed for long-term operation of 963 h using a gold-glass-ceramic sealant. The membrane was then tested for air separation in presence of hydrogen sulphide for 100 h and results showed that the impurity caused a drop in oxygen flux to zero within few hours. The flux could not be fully restored after hydrogen sulphide removal and only 6 to 35% was recovered. It was proposed that hydrogen sulphide was adsorbed on the membrane in the form of sulphur and it occupied oxygen vacancies. With time, strontium segregates toward sulphur to form irreversible layer of strontium sulphate. To restore the damaged surface, the membrane was treated by 1% (mol) of hydrogen for 20 h and the recovery improved from 6 to 12%. It was discovered that the poisoning mechanism is a function of oxygen partial pressure and change of partial pressure from 0.21 to 0.01 bar resulted in 90% recovery and this can be used as a strategy to reduce the damage. The next step was to test the membrane for hydrogen production using 1% (mol) of methane and results showed that methane conversion was steady at 33% for 350 h. Methane oxidation was also carried in presence of hydrogen sulphide but it resulted in drop of conversion to 8%. However, the conversion was slowly regenerating with time and it reached a constant value of 15%. This recovery was interpreted by the reaction of methane with hydrogen sulphide or methane decomposition and the membrane acted as a catalyst for these reactions. After hydrogen sulphide removal from the feed, the conversion kept on decreasing and this was linked to the change of membrane properties and therefore the membrane could not provide the sites for methane-oxygen reaction. For better stability under hydrogen sulphide, the membrane was modified by adding a powder of LSCF6428 material over the dense membrane. This dual layer membrane was stable for air separation under hydrogen for 33 h and the flux was only reduced by 5%.
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Balaguer, Ramírez María. "New solid state oxygen and hydrogen conducting materials. Towards their applications as high temperature electrochemical devices and gas separation membranes." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/31654.
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Los materiales conductores mixtos de electrones e iones (oxígeno o
protones) son capaces de separar oxígeno o hidrógeno de los gases de combustión
o de corrientes de reformado a alta temperatura. La selectividad de este proceso
es del 100%. Estos materiales, óxidos sólidos densos, pueden usarse en la
producción de electricidad a partir de combustibles fósiles, así como formar parte
de los procesos que forman parte del sistema de captura y almacenamiento de
CO2. Las membranas de transporte de oxígeno (MTO) se pueden utilizar en las
plantas energéticas con procesos de oxicombustión, así como en reactores
catalíticos de membrana (RCM), mientras que las membranas de transporte de
hidrógeno (MTH) se aplican en procesos de precombustión. Además, estos
materiales encuentran aplicación en componentes de sistemas energéticos, como
electrodos o electrolitos de pilas de combustible de óxido sólido, de ambas clases
iónicas y protónicas (SOFC y PC-SOFC).
Los procesos mencionados implican condiciones de operación muy
severas, como altas temperaturas y grandes gradientes de presión parcial de
oxígeno (pO2), probablemente combinadas con la presencia de CO2 and SO2. Los
materiales más que mayor rendimiento de separación presentan y más
ampliamente investigados en este campo son inestables en estas condiciones. Por
tanto, existe la necesidad de encontrar nuevos materiales inorgánicos estables que
proporcionen alta conductividad electrónica e iónica.
La presente tesis propone una búsqueda sistemática de nuevos
conductores iónicos-electrónicos mixtos (MIEC, del inglés) con diferente
estructura cristalina y/o diferente composición, variando la naturaleza de los
elementos y la estequiometría del cristal. La investigación ha dado lugar a materiales capaces de transportar iones oxígeno, protones o cargas electrónicas y
que son estables en las condiciones de operación.
La caracterización de una amplia serie de cerias (CeO2) dopadas con
lantánidos proporciona una comprensión general de las propiedades estructurales
y de transporte, así como la relación entre ellas. Además, se estudia el efecto de la
adición de cobalto a dicho sistema. Se ha completado el análisis con la
optimización de las propiedades de trasporte a partir de la microestructura. Todo
esto permite hacer una clasificación inicial de los materiales basada en el
comportamiento de transporte principal y permite adecuar la estructura y las
condiciones de operación para obtener las propiedades deseadas para cada
aplicación.
Algunos de los materiales extraídos de este estudio alcanzaron las
expectativas. Las familias de materiales basadas en Ce1-x
Tbx
O2-¿
y Ce1-x
Tbx
O2-¿
+2 mol% Co proporcionan flujos de oxígeno bajos pero competitivos, ya que son
estables en atmósferas con CO2. Además, la inclusión de estos materiales en
membranas de dos fases aumenta el flujo de oxígeno. La combinación con una
espinela libre de cobalto y de metales alcalinotérreos como es el Fe2
NiO4, ha
dado lugar a un material prometedor en cuanto a flujo de oxígeno y estabilidad en
CO2 y en SO2, que podría ser integrado en el proceso de oxicombustión.
Por otra parte, se ha añadido metales como codopantes en el sistema
Ce0.9-x
Mx
Gd0.1O1.95. Estos materiales, en combinación con la perovskita La1-
x
Srx
MnO3 usada comúnmente como cátodo de SOFC, han sido capaces de
disminuir la resistencia de polarización del cátodo. La mejora es consecuencia de
la introducción de conductividad iónica por parte de la ceria.
Las perovskitas dopadas basadas en CaTiO3 forman el segundo grupo de
materiales investigados. La dificultad de obtener perovskitas estables y que presenten conducción mixta iónica y electrónica se ha hecho evidente. De entre
los dopantes utilizados, el hierro y la combinación hierro-magnesio han sido los
mejores candidatos. Ambos materiales presentan conductividad principalmente
iónica a alta temperatura, mientras que a baja predomina la conductividad
electrónica tipo p. CaTi0.73Fe0.18Mg0.09O3-¿ se ha mostrado como un material
competente en la fabricación de membranas de oxígeno, que proporciona flujos
adecuados a la par que estabilidad en CO2.
Finalmente, la perovskita La0.87Sr0.13CrO3 (LSC) ha sido dopada con el
objetivo de aumentar la conductividad mixta protónica electrónica. Este estudio
ha llevado al desarrollo de una nueva generación de ánodos para PC-SOFC
basadas en electrolitos de LWO. Las perovskitas dopadas con Ce en el sitio del
La (LSCCe) y con Ni en el sitio del Cr (LSCN) son estables en condiciones de
operación reductoras, así como en contacto con el electrolito. El uso de ambos
materiales como ánodo disminuye la resistencia de polarización con respecto al
LSC. El LSCCe está limitado por los procesos que ocurren a baja frecuencia
(BF), relacionados con los procesos superficiales, y que son atenuados en el caso
del LSCN debido a la formación de nanopartículas de Ni metálico en la
superficie. La infiltración posterior con nanopartículas de Ni permite disminuir la
resistencia a BF lo que sugiere que la reacción superficial de oxidación del H2
está siendo catalizada. La infiltración más concentrada en Ni (5Ni) elimina
completamente la resistencia a BF en ambos ánodos, de forma que los procesos
que ocurren a altas frecuencias son ahora limitantes. El ánodo constituido por
LSCNi20+5Ni dio una resistencia de polarización de 0.26 ¿·cm
2
at 750 ºC en H2
húmedo.Mixed ionic (oxygen ions or protons) and electronic conducting materials (MIEC) separate oxygen or hydrogen from flue gas or reforming streams at high temperature in a process 100% selective to the ion. These solid oxide materials may be used in the production of electricity from fossil fuels (coal or natural gas), taking part of the CO2 separation and storage system. Dense oxygen transport membranes (OTM) can be used in oxyfuel combustion plants or in catalytic membrane reactors (CMR), while hydrogen transport membranes (HTM) would be applied in precombustion plants. Furthermore, these materials may also be used in components for energy systems, as advanced electrodes or electrolytes for solid oxide fuel cells (SOFC) and proton conducting solid oxide fuel cells (PCSOFC) working at high and moderate temperature. The harsh working conditions stablished by the targeted processes include high temperatures and low O2 partial pressures (pO2), probably combined with CO2 and SO2 containing gases. The instability disadvantages presented by the most widely studied materials for these purposes make them impractical for application to gas separation. Thus, the need to discover new stable inorganic materials providing high electronic and ionic conductivity is still present. This thesis presents a systematic search for new mixed ionic-electronic conductors. It includes different crystalline structures and/or composition of the crystal lattice, varying the nature of the elements and the stoichiometry of the crystal. The research has yielded new materials capable to transport oxygen ions or protons and electronic carriers that are stable in the working condition to which they are submitted.
Balaguer Ramírez, M. (2013). New solid state oxygen and hydrogen conducting materials. Towards their applications as high temperature electrochemical devices and gas separation membranes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31654
TESIS
Premiado
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Schmidt, Marek Wojciech, and Marek Schmidt@rl ac uk. "Phase formation and structural transformation of strontium ferrite SrFeOx." The Australian National University. Research School of Physical Sciences and Engineering, 2001. http://thesis.anu.edu.au./public/adt-ANU20020708.190055.
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Non-stoichiometric strontium iron oxide is described by an abbreviated formula SrFeOx (2.5 ≤ x ≤ 3.0) exhibits a variety of interesting physical and chemical properties over a broad range of temperatures and in different
gaseous environments. The oxide contains a mixture of iron in the trivalent and the rare tetravalent state. The material at elevated temperature is a mixed oxygen conductor and it, or its derivatives,can have practical
applications in oxygen conducting devices such as pressure driven oxygen
generators, partial oxidation reactors in electrodes for solid oxide fuel cells
(SOFC).
¶
This thesis examines the behaviour of the material at ambient and elevated temperatures using a broad spectrum of solid state experimental
techniques such as: x-ray and neutron powder diffraction,thermogravimetric and calorimetric methods,scanning electron microscopy and Mossbauer
spectroscopy. Changes in the oxide were induced using conventional thermal
treatment in various atmospheres as well as mechanical energy (ball milling).
The first experimental chapter examines the formation of the ferrite from
a mixture of reactants.It describes the chemical reactions and phase transitions that lead to the formation of the oxide. Ball milling of the reactants prior to annealing was found to eliminate transient phases from the reaction route and to increase the kinetics of
the reaction at lower temperatures.
Examination of the thermodynamics of iron oxide (hematite) used for the
reactions led to a new route of synthesis of the ferrite frommagnetite and
strontium carbonate.This chapter also explores the possibility of synthesis
of the material at room temperature using ball milling.
¶
The ferrite strongly interacts with the gas phase so its behaviour was studied under different pressures of oxygen and in carbon dioxide.The changes in ferrite composition have an equilibrium character and depend on temperature and oxygen concentration in the
atmosphere. Variations of the oxygen
content x were described as a function of temperature and oxygen partial
pressure, the results were used to plot an equilibrium composition diagram.
The heat of oxidation was also measured as a function of temperature and oxygen partial pressure.
¶
Interaction of the ferrite with carbon dioxide below a critical temperature
causes decomposition of the material to strontium carbonate and SrFe12O19 .
The critical temperature depends on the partial pressure of CO2 and above
the critical temperature the carbonate and SrFe12O19 are converted back into
the ferrite.The resulting SrFe12O19 is very resistant towards carbonation and
the thermal carbonation reaction does not lead to a complete decomposition
of SrFeOx to hematite and strontium carbonate.
¶
The thermally induced oxidation and carbonation reactions cease at room
temperature due to sluggish kinetics however,they can be carried out at ambient temperature using ball milling.The reaction routes for these processes are different from the thermal routes.The mechanical oxidation induces two
or more concurrent reactions which lead to samples containing two or more
phases. The mechanical carbonation on the other hand produces an unknown
metastable iron carbonate and leads a complete decomposition of the ferrite
to strontiumcarbonate and hematite.
¶
Thermally and mechanically oxidized samples were studied using Mossbauer
spectroscopy. The author proposes a new interpretation of the Sr4Fe4O11
(x=2.75) and Sr8Fe8O23 (x=2.875)spectra.The interpretation is based
on the chemistry of the compounds and provides a simpler explanation of
the observed absorption lines.The Mossbauer results froma range of compositions
revealed the roomtemperature phase behaviour of the ferrite also
examined using x-ray diffraction.
¶
The high-temperature crystal structure of the ferrite was examined using
neutron powder diffraction.The measurements were done at temperatures
up to 1273K in argon and air atmospheres.The former atmosphere protects
Sr2Fe2O5 (x=2.5) against oxidation and the measurements in air allowed
variation of the composition of the oxide in the range 2.56 ≤ x ≤ 2.81.
Sr2Fe2O5 is an antiferromagnet and undergoes phase transitions to the paramagnetic
state at 692K and from the orthorhombic to the cubic structure
around 1140K.The oxidized formof the ferrite also undergoes a transition
to the high-temperature cubic form.The author proposes a new structural
model for the cubic phase based on a unit cell with the Fm3c symmetry.
The new model allows a description of the high-temperature cubic form of
the ferrite as a solid solution of the composition end members.The results
were used to draw a phase diagramfor the SrFeOx system.
¶
The last chapter summarizes the findings and suggests directions for further research.
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Capoen, Édouard. "Étude de composés oxydes conducteurs mixtes, anioniques et électroniques, pour leur utilisation en tant que matériaux membranaires pour la séparation sélective de l'oxygène de l'air." Lille 1, 2002. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2002/50376-2002-235.pdf.
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Le développement de nouveaux matériaux membranaires céramiques à base de BIMEVOX ou de familles proches pour la séparation de l'oxygène de l'air, fait l'objet de cette étude. Deux types de membranes sont envisagés : la membrane à gradient de pression partielle d'oxygène et la membrane ampérométrique. Des flux de perméation de l'oxygène ont été mesurés sur trois phases à base d'oxyde de bismuth : une phase de type delta Bi2O3 dans le binaire Bi2O3-Er2O3, une phase de type bêta2 dans le binaire Bi2O3-CaO et une phase BICOVOX. Pour les deux premières, des flux notables ont été obtenus, ils sont nettement améliorés en présence d'argent sous forme de cermet. Par contre, en absence de courant imposé, le transfert de l'oxygène dans la phase BICOVOX est difficile. L'addition d'un conducteur électronique tel que l'or n'améliore pas ce transfert alors que des flux d'oxygène importants sont observés lorsque les BIMEVOX sont employés comme membranes ampérométriques. La caractérisation de ces membranes par spectrométrie d'impédance, échange isotopique de l'oxygène et diffraction des neutrons sous courant imposé, a permis de comprendre les mécanismes de transfert de l'oxygène mis en jeu dans ces matériaux en condition de fonctionnement. La stabilité de ces membranes sur de longues durées a enfin été suivie.
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Skulimowska, Anita. "Matériaux pour électrolyseur à membrane électrolyte protonique." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20020.
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Les travaux présentés dans ce mémoire concernent les composants d'assemblages membrane-électrodes (AMEs) pour électrolyseur à membrane échangeuse de protons (PEM – proton exchange membrane) fonctionnant à moyenne température. L'électrolyse de l'eau PEM, alimentée par l'énergie électrique provenant de sources renouvelables, est une voie pour la production efficace et durable d'hydrogène de haute pureté. De nouveaux électrolytes polymère solides (un des principaux éléments de la cellule d'électrolyse) à double conduction, basés sur un réseau semi-interpénétré créé par le polybenzimidazole sulfoné et l'acide polyphosphonique, ont été étudiés. Les membranes perfluorosulfonées (PFSA) à chaîne latérale courte et le composite PFSA-phosphate de zirconium (ZrP) ont également été étudiés. Les matériaux catalytiques de l'anode à base d'oxyde d'iridium ont été préparés par hydrolyse et calcination. L'oxyde d'iridium (IrO2), les oxydes bimétalliques (Ir/Ru) et ternaires (Ir/Ru/Ta) oxydes ont été étudiés par voie électrochimique dans la gamme de températures comprises entre 20 et 120 °C. Les caractérisations physico-chimiques ont confirmé la formation de structures d'oxyde et l'absence de particules de chlorures ou de métal résiduels. On observe une diminution de la tension de cellule, quelle que soit la densité de courant, lorsque la température augmente. Le catalyseur a été déposé sur la membrane, soit par pulvérisation directe ou par transfert en utilisant un support inerte (décalque). Aucune différence significative n'a été observée en appliquant les deux méthodes de dépôt. Les performances s'améliorent lorsque la température augmente pour tous les échantillons. L'assemblage comprenant une membrane de type PFSA, Aquivion®, de masse équivalente 870 meq.g-1 et d'une épaisseur de 120 µm, a montré de meilleures performances pour l'électrolyse de l'eau à 120 °C comparé à l'assemblage comprenant une membrane composite Aquivion® / ZrP, tandis qu'une membrane de type de polybenzimidazole sulfoné à liaison éther, poly-[(1-(4,4'-diphényléther)-5-oxybenzimidazole)-benzimidazole], a montré des performances prometteuses et aucune limitation de transport jusqu'à 2 A.cm-2. Les meilleurs performances ont été observées à 120 °C pour un assemblage préparé par pulvérisation directe de IrO2 sur une membrane Aquivion®; 1,67 V à 2 A.cm-2Preparation and investigation of the main components of membrane electrode assemblies (MEAs) for medium temperature proton exchange membrane water electrolysis (PEMWE) are described in this manuscript. Moderate temperature PEMWE, nourished by electrical energy from renewable sources is a practical path to sustainable generation of hydrogen with high purity and efficiency. Novel solid polymer electrolytes (a key component of the electrolysis cell) with double functionality properties, based on highly sulfonated polybenzimidazole creating a semi-interpenetrating network with a polyphosphonic acid, were investigated. A short side chain perfluorosulfonated acid (PFSA) type membrane and PFSA-zirconium phosphate composite membrane were also studied. The anode catalyst materials based on iridium oxide were prepared using the aqueous hydrolysis method followed by calcination. IrO2, some bimetallic (Ir/Ru) and ternary (Ir/Ru/Ta) oxides were electrochemically investigated in a wide range of temperatures (20-120 °C). The physico-chemical characterisation confirmed the formation of oxide structures, absence of residual chloride or metal particles. All catalysts prepared showed decreasing voltage at any given current density with rising the temperature. Catalyst was deposited on the membrane either directly by spray deposition or by decal transfer. No significant difference was observed using both deposition method. The PEMWE performance was increasing with the temperature. The short-side-chain PFSA - Aquivion® ionomer of equivalent weight 870 meq.g-1, of thickness 120 µm, displayed higher water electrolysis performance at 120 °C than a composite membrane of Aquivion® with zirconium phosphate, while a sulfonated ether-linked polybenzimidazole, sulfonated poly-[(1-(4,4'-diphenylether)-5-oxybenzimidazole)-benzimidazole], showed promising performance and no mass transport limitations up to 2 A.cm-2. The lowest cell voltage was observed at 120 °C for an MEA prepared using spray-coating of IrO2 directly on the Aquivion® membrane, 1.67 V at 2 A.cm-2
Book chapters on the topic "Oxygen conducting membrane"
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Tong, Jianhua, and Ryan O'Hayre. "Preparation and Synthesis of Mixed Ionic and Electronic Conducting Ceramic Membranes for Oxygen Permeation." In Membranes for Membrane Reactors, 169–99. Chichester, UK: John Wiley & Sons, Ltd, 2011. http://dx.doi.org/10.1002/9780470977569.ch5.
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Carolan, Michael. "Syngas Membrane Engineering Design and Scale-Up Issues. Application of Ceramic Oxygen Conducting Membranes." In Nonporous Inorganic Membranes, 215–44. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/3527608796.ch8.
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Woolley, D. E., U. Pal, and G. B. Kenney. "Solid-Oxide Oxygen-Ion-Conducting Membrane (SOM) Technology for Production of Magnesium Metal by Direct Reduction of Magnesium Oxide." In Magnesium Technology 2000, 35–36. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118808962.ch7.
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Steele, B. C. H. "Dense Ceramic Ion Conducting Membranes." In Oxygen Ion and Mixed Conductors and their Technological Applications, 323–45. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-017-2521-7_10.
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Dhallu, M., Y. Ji, and J. A. Kilner. "Oxygen Transport in Composite Materials for Oxygen Separators and Syngas Membranes." In Mixed Ionic Electronic Conducting Perovskites for Advanced Energy Systems, 253–63. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-1-4020-2349-1_24.
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Bouwmeester, H. I. M., and L. M. van der Haar. "Oxygen Permeation Through Mixed-Conducting Perovskite Oxide Membranes." In Ceramic Transactions Series, 49–57. 735 Ceramic Place, Westerville, Ohio 43081: The American Ceramic Society, 2012. http://dx.doi.org/10.1002/9781118370858.ch6.
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Wiik, Kjell, Anita Fossdal, Lise Sagdahl, Hilde L. Lein, Mohan Menon, Sonia Faaland, Ivar Wærnhus, Nina Orlovskaya, Mari-Ann Einarsrud, and Tor Grande. "LaFeO3 and LaCoO3 Based Perovskites: Preparation and Properties of Dense Oxygen Permeable Membranes." In Mixed Ionic Electronic Conducting Perovskites for Advanced Energy Systems, 75–85. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-1-4020-2349-1_6.
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Zhu, Xuefeng, and Weishen Yang. "Interfacial Phenomena in Mixed Conducting Membranes: Surface Oxygen Exchange- and Microstructure-Related Factors." In Solid State Electrochemistry II, 501–39. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2011. http://dx.doi.org/10.1002/9783527635566.ch11.
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Rodulfo-Baechler, Serbia M. "Dual Role of Perovskite Hollow Fiber Membrane in the Methane Oxidation Reactions." In Petrochemical Catalyst Materials, Processes, and Emerging Technologies, 385–430. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-9975-5.ch014.
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The Mixed Ionic and Electronic Conducting (MIEC) membrane reactors are of interest because they have the potential to produce high purity oxygen from air at lower costs and provide a continuous oxygen supply to reactions or/and industrial processes. The study of the dual role oxygen flux and catalytic performance of the unmodified and Ni-coated La0.6Sr0.4Co0.2Fe0.8O3-d hollow fibre membranes (LSCF6428 HFM) in the methane oxidation reactions (i.e., partial oxidation of methane and methane combustion) by using air on lumen side and methane on shell side are shown in this chapter. The LSCF6428 HFM participates not only in the oxygen flux but also in the methane conversion to C2. A Ni-coated LSCF6428 HFM under lean O2/CH4 gradient (i.e., 0.5) showed the production of syngas, carbon dioxide and C2 products in agreement with the thermodynamic calculation. At rich O2/CH4 gradient (i.e., 1.0), the formation of carbon dioxide was facilitated. The main catalytic pathway at lean O2/CH4 gradient and H2 reduction treatment was partial oxidation of methane to C2 and syngas.
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Smail, Manal, Sunil Rupee, Khemraj Rupee, Abla Mohammed Ahmed Ismail, Sara Sultan, Frank Christopher Howarth, Ernest A. Adeghate, and Jaipaul Singh. "Effects of Diabetes Mellitus on the Conduction System of the Heart: Mini-Review." In New Insights on Cardiomyopathy [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.109423.
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Diabetes mellitus can induce substantial damage to the conduction system of the heart, especially the sinoatrial node. This is due to hyperglycemia leading to bradyarrhythmia. DM, via the elevation of HG, generates the production of a number of insulting agents in the myocardium known as reactive oxygen species and reactive carbonyl species, which elicit direct damage to neuro-filament-M and β2-adrenergic receptors in the conducting system as well as a number of cardiac contractile, cation transporting and channel proteins. One cation channel protein is the hyperpolarization-activated cyclic nucleotide-gated potassium channel. It encodes the protein responsible for the hyperpolarizing-activated current or the “funny current” that participates in spontaneous diastolic membrane depolarization in sinoatrial node cells. Gene expression of these proteins and their physiological functions are decreased in the diabetic heart, which affects the generation of electrical impulses or action potentials resulting in increases in RR and PR intervals and QRS complex duration of the electrocardiogram. The heart rate and force of contraction of the myocardium are decreased leading to bradyarrhythmia and sudden cardiac death. This review attempts to explain the cellular mechanism(s) involved in diabetes-induced bradyarrhythmia with emphasis on cation-transporting proteins, especially the hyperpolarization-activated cyclic nucleotide-gated channels pacemaker current channels.
Conference papers on the topic "Oxygen conducting membrane"
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Lindfeldt, Erik G., and Mats O. Westermark. "An Integrated Gasification Zero Emission Plant Using Oxygen Produced in a Mixed Conducting Membrane Reactor." In ASME Turbo Expo 2006: Power for Land, Sea, and Air. ASMEDC, 2006. http://dx.doi.org/10.1115/gt2006-90183.
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Integrated gasification combined cycles (IGCCs) exhibit conditions favourable to CO2 sequestration. In this article, simulations of the Integrated Gasification Zero Emission Plant (IGZEP) concept are presented. The idea behind this concept is to use oxygen produced in a Mixed Conducting Membrane (MCM) reactor in an IGCC. Previous studies have shown that it is beneficial to integrate an MCM reactor in a natural gas fired cycle, and the objective of this article is to quantify the advantages of integrating the same type of reactor with an IGCC the way it is suggested in the IGZEP concept. The core of the membrane reactor is a ceramic membrane, which separates oxygen from air exiting the gas turbine compressor. The reactor operates at temperatures around 900 °C and is driven by a difference in oxygen partial pressure. The oxygen permeating the membrane is used in a Texaco gasifier, whereas the oxygen-depleted air is sent to a high temperature combustor. The rest of the cycle is essentially similar to a “standard” IGCC. The simulations performed resulted in a CO2 capture penalty of 6.4% points (Lower Heating Value, LHV) and a net cycle efficiency of 32.5% (LHV). Despite this quite low efficiency, the IGZEP concept is interesting since one of the main reasons for the low net efficiencies is the low efficiency of the Texaco gasifier model used. Other models for Texaco gasifiers with higher efficiency have been found in literature. Nevertheless, it is judged more interesting to compare IGZEP’s penalty for oxygen generation with that of existing competitors. It is shown that the total oxygen production penalty can be decreased from 4.9% points in the reference case to 4.3% points in IGZEP. That is, about 0.6% points in net efficiency may be gained by replacing a standard (non-integrated) cryogenic air distillation unit with an MCM reactor. Other studies have also shown that this strategy may entail lower investment and electricity production costs.
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Selimovic, Faruk, Bengt Sunde´n, Mohsen Assadi, and Azra Selimovic. "Computational Analysis of O2 Separating Membrane for a CO2-Emission-Free Power Process." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-59382.
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The increased demand for clean power in recent years has led to the development of various processes that include different types of CO2 capture. Several options are possible: pre-combustion concepts (fuel de-carbonization and subsequent combustion of H2), post-combustion concepts (tail-end CO2 capture solutions, such as amine scrubbing), and integrated concepts in which combustion is carried out in pure a O2 or oxygen-enriched environment instead of air. The integrated concepts involve the use of oxygen-, hydrogen-, or CO2-separating membranes resulting in exhaust gas containing CO2 and water, from which CO2 can easily be separated. In contrast to traditional oxygen pumps, where a solid oxide electrolyte is sandwiched between two gas-permeable electrodes, a dense, mixed ionic-electronic conducting membrane (MIECM) shows high potential for oxygen separation without external electrodes attached to the oxide surface. Models for oxygen transport through dense membranes have been reported in numerous recent studies. In this study, an equation for oxygen separation has been integrated into a steady-state heat and mass transfer membrane model. Oxygen transfer through a porous supporting layer of membrane is also taken into account. The developed FORTRAN code has been used for numerical investigation and performance analysis of the MIECM and the oxygen transport potential over a range of operating conditions. Preliminary results indicate that a non-uniform temperature distribution, for a given set of oxygen inlet boundary conditions has considerable impact on the oxygen flux and membrane efficiency. Since the implementation of detailed membrane models in heat and mass balance calculations for system studies would result in excessive calculation time, results from this study will be utilized for the generation of correlations describing the oxygen transfer as a function of operating parameters such as temperature and partial pressure. This modeling approach is expected to improve the accuracy of system studies.
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Eldrid, Sacheverel, Mehrdad Shahnam, Michael T. Prinkey, and Zhirui Dong. "3D Modeling of Polymer Electrolyte Membrane Fuel Cells." In ASME 2003 1st International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2003. http://dx.doi.org/10.1115/fuelcell2003-1719.
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Polymer Electrolyte Membrane (PEM) fuel cell performance can be optimized and improved by modeling the complex processes that take place in the various components of a fuel cell. Operability over a range of conditions can be assessed using a robust design methodology. Sensitivity analysis can identify critical characteristics in order to guide hardware and softgoods development. A computational model is necessary which captures the critical physical processes taking place within the cell. Such a model must be validated against experimental data before it can be used for product development. A computational model of an experimental PEM fuel cell has been developed. The model is based on the FLUENT CFD solver with the addition of user-defined functions supplied by FLUENT. These functions account for local electrochemical reactions, electrical conduction within diffusion layers and current collectors, mass and heat transfer in the diffusion layers and the flow channels along with binary gas diffusion. The results of this model are compared to experimental data. A PEM fuel cell consists of an ion conducting membrane, anode and cathode catalyst layers, anode and cathode gas diffusion layers, flow channels, and two bipolar plates. Hydrogen and oxygen are supplied to the anode and cathode respectively. As a result of hydrogen oxidation at the anode catalyst layer, hydrogen ions and electrons are produced. The hydrogen ions are conducted through the membrane to the cathode catalyst layer where they combine with oxygen and electrons to produce water and heat. Therefore, a PEM fuel cell model has to take into account: • Fluid flow, heat transfer, and mass transfer in porous anode and cathode diffusion layers; • Electrochemical reactions; • Current transport and potential field in porous anode, cathode, and solid conducting regions. FLUENT Inc. has developed such a model based on their commercially available FLUENT CFD code. This model was exercised on an experimental Plug Power fuel cell. The voltage characteristic of the model was compared to the experimentally measured values. The preliminary comparison between the predicted polarization curve and the experimental results are very favorable.
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Zeng, Pingying, Kang Wang, Ryan Falkenstein-Smith, and Jeongmin Ahn. "A Ceramic-Membrane-Based Methane Combustion Reactor With Tailored Function of Simultaneous Separation of Carbon Dioxide From Nitrogen." In ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2014 8th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fuelcell2014-6510.
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Today, industry has become more dependent on natural gases and combustion processes, creating a tremendous pressure to reduce their emissions. Although the current methods such as chemical looping combustion (CLC) and pure oxygen combustion have several advantages, there are still many limitations. A ceramic membrane based methane combustion reactor is an environmentally friendly technique for heat and power generation. This work investigates the performance of a perovskite-type SrSc0.1Co0.9O3−δ (SSC) membrane reactor for the catalytic combustion of methane. For this purpose, the mixed ionic and electronic conducting SSC oxygen-permeable planar membrane was prepared by a dry-pressing technique, and the SSC powder catalyst was spray coated on the permeation side of the membrane. Then, the prepared SSC membrane with the catalyst was used to perform the catalytic combustion of methane. The oxygen permeability of the membrane reactor was studied. Also, the methane conversion rates and CO2 selectivity at various test conditions were reported.
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Falkenstein-Smith, Ryan, Kang Wang, Pingying Zeng, and Jeongmin Ahn. "A Ceramic-Membrane-Based Methane Combustion Reactor With Tailored Function of Simultaneous Separation of Carbon Dioxide From Nitrogen." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-38283.
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Today, industry has become more dependent on natural gases and combustion processes, creating a tremendous pressure to reduce their emissions. Although the current methods such as chemical looping combustion (CLC) and pure oxygen combustion have several advantages, there are still many limitations. A ceramic membrane based methane combustion reactor is an environmentally friendly technique for heat and power generation. This work investigates the performance of a perovskite-type SrSc0.1Co0.9O3-δ (SSC) membrane reactor for the catalytic combustion of methane. For this purpose, the mixed ionic and electronic conducting SSC oxygen-permeable planar membrane was prepared by a dry-pressing technique, and the SSC powder catalyst was spray coated on the permeation side of the membrane. Then, the prepared SSC membrane with the catalyst was used to perform the catalytic combustion of methane. The oxygen permeability of the membrane reactor was studied. Also, the methane conversion rates and CO2 selectivity at various test conditions were reported.
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Sander, Frank, Sebastian Foeste, and Roland Span. "Model of an Oxygen Transport Membrane for Coal Fired Power Cycles With CO2 Capture." In ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27788.
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Greenhouse gas emissions from power generation will increase in future if the demand for electrical energy does not subside. Therefore capture and storage of carbon dioxide (CO2) will become important technologies for lowering the rate of increase of global CO2 emissions, or even reducing them. A promising technology for coal fired power cycles is the integrated gasification combined cycle (IGCC), where CO2 is separated from the syngas coming from the gasifier before the syngas is combusted in a more or less conventional gas turbine. But oxygen is required for the gasification process to achieve a high carbon conversion rate. The energy demand for the cryogenic air separation unit (ASU) lowers the net power output of the IGCC cycle. An alternative way of producing the oxygen could eliminate this disadvantage of the IGCC cycle. Oxygen transport membranes (also known as mixed conducting membranes – MCM) show a high potential for such applications in power cycles. In this paper results of an investigation on an IGCC cycle with CO2 capture and an integrated oxygen transport membrane (OTM) reactor are reported. The operating conditions of the membrane reactor have been analyzed; the feed inlet temperature and the pressure differences between permeate and retentate sides of the membrane reactor have been varied. The impact on the overall IGCC cycle has been discussed. The most optimistic assumptions give an overall net efficiency close to the case without CO2 capture. In this case the net efficiency is reduced by only 3 percentage points compared to an IGCC process without CO2 capture. But these assumptions lead to very challenging conditions for the membrane reactor. A pressure difference of 14.5 bar is assumed. Less severe operating conditions for the OTM reactor, which seem closer to realization, show less promising results. For sweep stream pressures of 10 and 15 bar the net efficiency ranges from 36% to 39%. This is in the range of an IGCC process with cryogenic ASU which achieves a net efficiency of 37% to 38%. It can be concluded that the integration of an OTM reactor into the IGCC cycle is an option with good prospects if the membrane is capable of bearing the challenging operating conditions. Calculations of investment costs have not been investigated in the frame of this work. Both the total capital costs and the durability are very important aspects for the membrane technology to be realized in power cycles such as IGCC.
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Selimovic, Faruk, Jonas Eborn, Bengt Sunde´n, and Hubertus Tummescheit. "Dynamic Analysis of an O2 Separating Membrane Reactor for CO2-Emission Free Power Processes." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14226.
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The need to reduce CO2 emissions from fossil-fuel based power production creates the need for new power plant solutions where the CO2 is captured and stored or reused. Oxygen Transfer Membrane (OTM) is the key component of oxy-fuel combustion processes as pure oxygen is usually required to process reactions (e.g. Natural Gas Combined cycle NGCC, Pulverised Coal-fired power plants PC-plants, Integrated Gasification Combined Cycle IGCC). The transfer of oxygen across such OTM is limited by a number of processes, such as surface exchange and ambipolar diffusion through mixed-conducting gas separation layer. This paper shows a mathematical model of an oxygen transfer membrane incorporated into OTM reactor (OTM reactor consists of High Temperature Heat Exchanger and OTM), where transient behavior takes place. The modeling of the OTM reactor has been carried out to show the importance of optimizing OTM parameters (temperatures, oxygen partial pressures, oxygen flux) and reactor design that enables a high oxygen transfer for optimum performance of future power cycles with CO2 capture. All modeling work was carried out in the modeling language Modelica, which is an open standard for equation-based, object-oriented modeling of physical systems. The OTM reactor model has been built using the CombiPlant Library, a modeling library for combined cycle power plants which is under development.
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Arnau, Francisco, Ricardo Novella, Luis Miguel García-Cuevas, and Fabio Gutiérrez. "Adapting an Internal Combustion Engine to Oxy-Fuel Combustion With In-Situ Oxygen Production." In ASME 2021 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/icef2021-67707.
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Abstract In transport applications, reciprocating internal combustion engines still have important advantages in terms of endurance and refueling time and available infrastructure when compared against fuel cell or battery-based powertrains. Although conventional internal combustion engine configurations produce important amounts of greenhouse gases and pollutant emissions, oxyfuel combustion can be used to mitigate to a great extent such emissions, mainly producing NOx-free, CO2 and H2O exhaust gases. However, the oxygen needed for the combustion, which is mixed with flue gases before entering the cylinder, has to be stored in an additional tank, which hinders the adoption of this technology. Fortunately, the latest developments in gas separation membranes are starting to produce extremely-high selectivity and high permeability oxygen-separation membranes. Using the waste heat of the exhaust gases to heat up a mixed ionic-electronic conducting membrane, and feeding it with pressurized air, it is possible to produce all the oxygen needed by the combustion process while keeping the whole system compact. This works presents a design of an oxy-fuel combustion engine with in-situ oxygen production. The numerical simulations show also that this concept keeps a competitive brake specific fuel consumption, while the high concentration of CO2 in the exhaust gases facilitates the introduction of carbon sequestration technologies, leading to potentially carbon-neutral internal combustion engines.
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Alhussan, Khaled. "A Novel Design of Polymer Electrolyte Membrane Fuel Cell." In ASME/JSME 2007 5th Joint Fluids Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/fedsm2007-37458.
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A fuel cell is an energy conversion device that converts the chemical energy of fuel into electrical energy. Fuel cells operate continuously if they are provided with the reactant gases, not like batteries. Fuel cells can provide power in wide range. Fuel cells are environmentally friendly; the by-product of hydrogen/oxygen fuel cell is water and heat. This paper will show a numerical modeling for this spiral design of high pressurized Polymer Electrolyte Membrane fuel cell. Numerical modeling requires understanding the physical principles of fuel cells, fluid flow, heat transfer, mass transfer in porous media, electrochemical reactions, multiphase flow with phase change, transport of current and potential field in porous media and solid conducting regions, and water transport across the polymer membrane; and this will result in optimal design process. This paper will show fuel cell models that are used in this analysis. Such as; electrochemical model: predicts local current density, voltage distributions. Potential field model: predicts current and voltage in porous and solid conducting regions. Multiphase mixture model: predicts liquid water and gas flow in the porous diffusion layers. Thin film multiphase model: tracks liquid water flow in gas flow passages. The numerical results of the theoretical modeling are shown in this paper. This paper shows the contour plots of mole fraction of H2O, H2, and O2. Results in this research include the species concentration of H2O, H2, and O2. This research also shows the plot of mass concentration of H2O, H2 and O2.
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Mauer, G., R. Vaßen, and D. Stöver. "Thin and Dense Ceramic Coatings by Plasma Spraying at Very Low Pressure." In ITSC2009, edited by B. R. Marple, M. M. Hyland, Y. C. Lau, C. J. Li, R. S. Lima, and G. Montavon. ASM International, 2009. http://dx.doi.org/10.31399/asm.cp.itsc2009p0773.
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Abstract Very low pressure plasma spraying (VLPPS) processes operate at a pressure of approximately 100 Pa, where the interaction of the plasma jet with the surrounding atmosphere is very weak and, as a result, plasma velocity is almost constant over a long distance from the nozzle exit. At these low pressures, the collision frequency is distinctly reduced and the mean free path is strongly increased. As a consequence, the specific enthalpy of the plasma is substantially higher, but at lower density. These particular plasma characteristics offer enhanced possibilities to spray thin and dense ceramics compared to conventional processes which operate in the pressure range between 5 and 20 kPa. This paper presents examples of gas-tight and electrically insulating layers with thicknesses less than 50 μm for solid oxide fuel cell applications. Plasma spraying of oxygen conducting membrane materials like perovskite is also discussed.
Reports on the topic "Oxygen conducting membrane"
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Visco, Steven. CRADA Final Report: Ionically Conductive Membranes Oxygen Separation. Office of Scientific and Technical Information (OSTI), October 2001. http://dx.doi.org/10.2172/1157024.
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