Permeation properties of hydrogen and water vapor through porous silica membranes at high temperatures

Tsuru, Toshinori; Igi, Ryousuke; Kanezashi, Masakoto; Yoshioka, Tomohisa; Fujisaki, Shinji; Iwamoto, Yuji

doi:10.1002/aic.12298

Cited by 102 publications

(76 citation statements)

References 49 publications

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“…This result suggested that the Co doped into the silica existed as not only Co3O4 crystalline powder, but also as noncrystalline compounds, such as extremely fine particles that are undetectable by XRD or as Co composites with silica. XRD peaks of Co-doped silica powders fired at 19) in air, and at 600 in steamed air, had approximately the same peak intensities, suggesting that Codoped silica had good hydrothermal stability. The effect of Co composition on XRD pattern revealed that the Co3O4 peak intensities increased with the Co content in the range of from 0 to 30 Co mol%; at Co atomic composition greater than 30 mol%, the peak intensity remained relatively constant.…”

Section: Fabrication and Characterization Of Metal Doped Sio2 Membmentioning

confidence: 66%

“…Figure 5 shows the TEM cross-sectional image of the top layer with 10 μm depth of a Co-doped silica membrane, which was observed using a TOPCON (Model EM002b, Tokyo, Japan) 19) . The sample was prepared using a focused ion beam (FIB) and tungsten was deposited on the surface of the top layer.…”

Section: Fabrication and Characterization Of Metal Doped Sio2 Membmentioning

confidence: 99%

“…・Pa -1 ) with a H2/N2 permeance ratio of 730 19) . Figure 5 shows the TEM cross-sectional image of the top layer with 10 μm depth of a Co-doped silica membrane, which was observed using a TOPCON (Model EM002b, Tokyo, Japan) 19) .…”

Section: Fabrication and Characterization Of Metal Doped Sio2 Membmentioning

confidence: 99%

“…The sample was prepared using a focused ion beam (FIB) and tungsten was deposited on the surface of the top layer. The Co- 19) doped silica membrane showed a composite membrane structure, consisting of an α-alumina substrate that was prepared using α-alumina particles of several μms in size (pore size: 1 μm), an intermediate layer prepared using α-alumina fine particles (200 nm in diameter), a SiO2 _ ZrO2 layer, and a Co-doped silica top layer for hydrogen separation according to the preparation procedure. It should be noted that the hydrothermal stability of an intermediate layer is as important as that of silica for hydrogen separation, and improved hydrothermally stability of γ-alumina intermediate layers were prepared by doping metal such as lanthanum into boehmite sols 28)～30) or using phosphorus 29) .…”

Section: Fabrication and Characterization Of Metal Doped Sio2 Membmentioning

confidence: 99%

“…Among the metals, Ni was the first reported to be effective in improving hydrothermal stability 11),17) . We also reported improved hydrothermal stability by doping Co into silica with different Si/Co compositions by sol-gel processing, and applied this method to hydrogen separation 18), 19) . The Co-doped silica with improved hydro thermal stability was also investigated by other research groups based on permeation experiments 20) .…”

Section: Introductionmentioning

confidence: 99%

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Development of Metal-doped Silica Membranes for Increased Hydrothermal Stability and Their Applications to Membrane Reactors for Steam Reforming of Methane

Tsuru

2011

J. Jpn. Petrol. Inst.

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Hydrothermal stability is one of the most important technical challenges for hydrogen separation silica membranes. Metal doping into silica matrix was proposed, and it was found that Ni and Co were effective to improve the hydrothermal stability. Co-doped silica membranes showed a high permeance of 1.8 10 -7 mol/(m 2 ・s・Pa) and H2/N2 permeance ratio of 730 with hydrothermal stability (500 , steam partial pressure 300 kPa). Using hydrothermally stable silica membranes, permeation properties of helium, hydrogen and water vapor were examined based on the activation energy of permeation. The activation energy of H2 permeation correlated well with the permeance ratio of He/H2. The permeance ratios of H2/H2O of silica membranes are always larger than unity, although the kinetic diameter of hydrogen (0.289 nm) is larger than that of water (0.265 nm). Silica membranes were applied to bimodal catalytic membranes, which consisted of microporous silica top layer for selective permeation of hydrogen and a bimodal catalytic support layer where catalysts such as Ni were impregnated inside a bimodal support consisting of mesopores (γ-alumina) and macropores (α-alumina). Increased performance for production of hydrogen was confirmed by catalytic membranes for steam reforming of methane.

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Section: Fabrication and Characterization Of Metal Doped Sio2 Membmentioning

confidence: 66%

Section: Fabrication and Characterization Of Metal Doped Sio2 Membmentioning

confidence: 99%

Section: Fabrication and Characterization Of Metal Doped Sio2 Membmentioning

confidence: 99%

Section: Fabrication and Characterization Of Metal Doped Sio2 Membmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Development of Metal-doped Silica Membranes for Increased Hydrothermal Stability and Their Applications to Membrane Reactors for Steam Reforming of Methane

Tsuru

2011

J. Jpn. Petrol. Inst.

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In situ Electrical Impedance Tomography for Visualizing Water Transportation in Hygroscopic Aerogels

Tang,

Zhong,

et al. 2024

Advanced Science

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The global water crisis demands immediate attention, and atmospheric water harvesting (AWH) provides a viable alternative. However, studying the real‐time subtle relationship between water absorption, diffusion, and internal structure for hygroscopic materials is challenging. Herein, a dynamic visualization technique is proposed that utilizes an in situ electrical impedance tomography (EIT) system and a precise reconstruction algorithm to achieve real‐time monitoring of the water sorption process within aerogels from an internal microstructural perspective. These results can be inferred that composites' pore sizes affecting the kinetics of their moisture absorption. In addition, the diffusion path of moisture absorption and the distribution of stored moisture inside aerogels exhibit intrinsic self‐selective behavior, where the fiber skeleton of the aerogel plays a crucial role. In summary, this work proposes a generic EIT‐based technique for the in situ and dynamic monitoring of the hygroscopic process, pointing to an entirely new approach regarding research on AWH materials.

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Effects of water vapor on gas permeation and separation properties of MFI zeolite membranes at high temperatures

Wang

Lin

2011

AIChE Journal

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in Wiley Online Library (wileyonlinelibrary.com).Understanding the effects of water vapor on gas permeation and separation properties of MFI zeolite membranes, especially at high temperatures, is important to the applications of these zeolite membranes for chemical reactions and separation involving water vapor. The effects of water vapor on H 2 and CO 2 permeation and separation properties of ZSM-5 (Si/Al $ 80) zeolite and aluminum-free silicalite membranes were studied by comparing permeation properties of H 2 and CO 2 with the feed of equimolar H 2 /CO 2 binary and H 2 /CO 2 /H 2 O ternary mixtures in 300-550 C. For both membranes, the presence of water vapor lowers H 2 and CO 2 permeance to the same extent, resulting in negligible effect on the H 2 /CO 2 separation factor. The suppression effect of water vapor on H 2 and CO 2 permeation is larger for the less hydrophobic ZSM-5 zeolite membrane than for the hydrophobic silicalite membrane, and, for both membranes, is stronger at lower temperatures and higher water vapor partial pressures.

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Permeation properties of hydrogen and water vapor through porous silica membranes at high temperatures

Cited by 102 publications

References 49 publications

Development of Metal-doped Silica Membranes for Increased Hydrothermal Stability and Their Applications to Membrane Reactors for Steam Reforming of Methane

Development of Metal-doped Silica Membranes for Increased Hydrothermal Stability and Their Applications to Membrane Reactors for Steam Reforming of Methane

In situ Electrical Impedance Tomography for Visualizing Water Transportation in Hygroscopic Aerogels

Effects of water vapor on gas permeation and separation properties of MFI zeolite membranes at high temperatures

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