Prospects and problems of dense oxygen permeable membranes

Hendriksen, Peter Vang; Larsen, Peter H.; Mogensen, Mogens Bjerg; Poulsen, F.W.; Wiik, Kjell

doi:10.1016/s0920-5861(99)00286-2

Cited by 167 publications

(95 citation statements)

References 25 publications

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“…However, this may not be easy to achieve in practice. Candidate membrane materials belonging to the general class La 1-x Sr x Fe 1-y Co y O 3 have TEC values 11 in the range from 12 to 20·10 -6 K -1 (100 -900 o C) strongly depending on the Sr and Co-content (increasing with both), whereas cheap strong ceramics which could be candidates for the support typically have lower TEC values. Alumina and Zirconia for instance have TEC values in the range from 8 -11·10 -6 K -1 in the same temperature interval.…”

Section: Development Of Surface Cracks Due To Tec Mismatchesmentioning

confidence: 99%

“…The concentration of vacancies depends on the surrounding oxygen activity. When such materials are used as membranes, where they are exposed to different oxygen activities on the two sides, a vacancy concentration profile will be established inside the material, the detailed shape of which depends on the membrane thickness as well as the rates of the oxygen exchange processes on the two surfaces 3 . In general there is a volume change associated with a change in vacancy concentration in the material -the materials expand on reduction 3, , , 14 15 16 This is illustrated in Fig.…”

Section: Materials Expansion On Reductionmentioning

confidence: 99%

See 1 more Smart Citation

Failure Modes of Thin Supported Membranes

Hendriksen

Høgsberg

Kjeldsen

et al. 2008

Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 4

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Four different failure modes relevant to tubular supported membranes (thin dense films on a thick porous support) were analyzed. The failure modes were: 1) Structural collapse due to external pressure 2) burst of locally unsupported areas, 3) formation of surface cracks in the membrane due to TEC-mismatches, and finally 4) delamination between membrane and support due to expansion of the membrane on use. Design criteria to minimize risk of failure by the four different modes are discussed. The theoretical analysis of the two last failure modes is compared to failures observed on actual components.

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Section: Development Of Surface Cracks Due To Tec Mismatchesmentioning

confidence: 99%

Section: Materials Expansion On Reductionmentioning

confidence: 99%

Failure Modes of Thin Supported Membranes

Hendriksen

Høgsberg

Kjeldsen

et al. 2008

Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 4

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show abstract

“…[1][2][3][4] To improve their performance, it is important to understand the electrochemical reaction mechanisms, including the rate-determining step (e.g., oxide ion diffusion and electron redox) during device operation. The reaction around electrodes is believed to consist of various elementary steps.…”

Section: Introductionmentioning

confidence: 99%

Direct Observation of Rate Determining Step for Nd2NiO4+^|^delta; SOFC Cathode Reaction by operando Electrochemical XAS

et al. 2014

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The oxygen chemical potential of dense Nd 2 NiO 4+δ thin films on Zr 0.92 Y 0.08 O 1.96 electrolyte was investigated by operando X-ray absorption spectroscopy (XAS) measurements. Operando XAS at the Ni K-edge was measured under an applied voltage and various oxygen partial pressures at high temperature to simulate the operating conditions of solid oxide fuel cells (SOFCs). The absorption edge energy under various polarizations is similar to those measured under equivalent oxygen partial pressures under open circuit condition. Thus, the oxygen chemical potential changes drastically at the electrode/gas interface and the rate-determining step of this model system is the surface reaction. This study provides direct evidence for the rate-determining step of the SOFC cathode reaction.

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“…In fact, La 2 NiO 4+δ exhibit highest oxygen permeation fluxes known for alkaline-earth metal cation-free membrane materials, except for some dual-phase composites. As the performance of OMCMs is improved by reducing the thickness with an appropriate surface modification [1,44,45], the dense membrane layer was assumed to be coated onto a porous support (Fig. 4), which partially protects the membrane surface due to mass transport limitations in the pores and to CO 2 displacement from the pores by oxygen transported through the dense layer.…”

Section: Introductionmentioning

confidence: 99%

“…4. One should note that the deposition of porous exchange catalysts is necessary for most mixedconducting materials [40,42,44,[47][48][49][50], in particular for relatively thin membrane layers [45]. This solution leads to a lower oxygen permeation, which stems from a decreased pore size and higher mass-transfer resistance.…”

Section: Introductionmentioning

confidence: 99%

Simulation of a mixed-conducting membrane-based gas turbine power plant for CO2 capture: system level analysis of operation stability and individual process unit degradation

Colombo

Хартон

Viskup

et al. 2010

J Solid State Electrochem

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A gas turbine power plant for CO 2 capture, based on oxygen-permeable membranes with mixed ionicelectronic conductivity, was analysed with respect to longterm stability by means of numerical simulation. Due to the attractive transport and physicochemical properties of mixed-conducting La 2 NiO 4+δ , this nickelate was selected as a prototype membrane material for this application. Experiments showed very slow degradation of La 2 NiO 4+δ membranes at oxygen chemical potentials close to atmospheric conditions, which are associated with kinetic demixing and other microstructure-related factors. Interaction with CO 2 in the intermediate temperature range also leads to lower oxygen permeation, whilst increasing oxygen pressure may cause partial phase decomposition and microstructural changes, thus again limiting the range of possible operation conditions. The relevant operational constraints were included in a detailed membrane-based gas turbine power plant model. The membrane performance degradation with time was approximated by a linear function with average rate of 3.3% per 1,000 operation hours. Furthermore, performance deterioration of the gas turbine compressor and turbine were also considered. Simulations revealed that the power plant is substantially affected by degradation of the ceramic membranes and turbomachinery components. The already rather small operating window was further narrowed when compared with a conventional gas turbine power plant. Two different designs of the membrane-based power plant were analysed: (1) with and (2) without additional combustors (afterburners) between the membrane reactor and the gas turbine. Afterburners increase thermal efficiency as well as power output, but also lead to non-negligible CO 2 emissions. In order to have a frame of comparison, results for a conventional gas turbine power plant with degradation of turbomachinery components are also presented. Simulations representing changes in ambient temperature and fuel composition as well as failure incidents were executed to analyse the susceptibility of the gas turbine power plant to external and internal changes.

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Prospects and problems of dense oxygen permeable membranes

Cited by 167 publications

References 25 publications

Failure Modes of Thin Supported Membranes

Failure Modes of Thin Supported Membranes

Direct Observation of Rate Determining Step for Nd2NiO4+^|^delta; SOFC Cathode Reaction by operando Electrochemical XAS

Simulation of a mixed-conducting membrane-based gas turbine power plant for CO2 capture: system level analysis of operation stability and individual process unit degradation

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