• Title/Summary/Keyword: Super critical drying

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Syunthesis of Silica Aerogel at Ambient Pressure and Characterization (I) (실리카에어로겔의 상압합성 및 특성연구(I))

  • 강신규;최세영
    • Journal of the Korean Ceramic Society
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    • v.33 no.12
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    • pp.1394-1402
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    • 1996
  • The Silica gel with the density of 0.2g/cm3 and porosity of 90% was synthesized. The silica wet gel was dried and heat-treated under the ambient pressure after modification of the wet gel surface by TMCS. Specific surface area total pore volume and mean pore radius of dried gel were all increased with increasing heat treatment temperature and confirmed about 1400m2/g, 4.5cc/g and 8 nm respectively after heat treatment above 25$0^{\circ}C$. But the pore size distribution of dried gel was in the range of 1-100nm and was almost indepen-dent of temperature. As the result of external shape pore characteristics and microstructure of gel using SEM similar properties were observed between the silica gel synthesized in this study and the silica aerogel through the super critical drying.

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Performance of V2O5-TiO2 Catalyst Prepared by Various Methods for Removal of Hydrogen Sulfide Emitted from Steel Smelting Process (다양한 제조방법으로 제조된 V2O5-TiO2 촉매를 이용한 제련공정에서 발생한 황화수소 제거능 비교)

  • Kim, Moon il
    • Journal of Environmental Science International
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    • v.30 no.6
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    • pp.501-505
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    • 2021
  • V2O5-TiO2 catalysts were prepared by various methods. V2O5-TiO2 were prepared by sol-gel method with different drying conditions (aerogel and xerogel), and V2O5 supported on TiO2 obtained by sol-gel method with precipitation-deposition method and impregnation method. The performance of the V2O5-TiO2 catalysts was investigated for the selective oxidation of hydrogen sulfide in the stream containing both ammonia and excess water. All the catalysts showed good dispersion of vanadium and they had high H2S conversion with no or little production of sulfur dioxide. The V2O5-TiO2 aerogel catalyst prepared by sol-gel method with drying under super critical condition had the highest surface area which led to better catalytic activity compared to those by other synthesis methods.