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Effect of particle size and silicon to aluminium ratio on the hydrothermal stablity of polycrystalline zeolite beta

หน่วยงาน จุฬาลงกรณ์มหาวิทยาลัย

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ชื่อเรื่อง : Effect of particle size and silicon to aluminium ratio on the hydrothermal stablity of polycrystalline zeolite beta
นักวิจัย : Usnee Toophorm
คำค้น : Zeolites , Polycrystals
หน่วยงาน : จุฬาลงกรณ์มหาวิทยาลัย
ผู้ร่วมงาน : Piyasan Praserthdam , Chulalongkorn University. Faculty of Engineering
ปีพิมพ์ : 2545
อ้างอิง : 9741724926 , http://cuir.car.chula.ac.th/handle/123456789/1279
ที่มา : -
ความเชี่ยวชาญ : -
ความสัมพันธ์ : -
ขอบเขตของเนื้อหา : -
บทคัดย่อ/คำอธิบาย :

Thesis (M.Eng.)--Chulalongkorn University, 2002

Polycrystalline zeolite betas have been synthesized by hydrothermal method at various conditions. The particle sizes in the range of 0.2 to 0.9 micrometer were obtained. The samples were treated at 800 oC with 10 mole percent of water for 30 min. The changes of each size of zeolite beta before and after treatment were observed by 27Al MAS NMR spectrometer, BET surface area measurement and X-ray diffraction. It was found that hydrothermal treatment caused dealumination. The relative area of tetrahedral 27Al MAS NMR decreased similarly in accordance with the BET surface area while the crystallinity obtained from XRD was slightly changed for all sizes. It was found that change of the small particle size was easily occurred than that of the large one. However, the silicon to aluminium ratio in the zeolite framework of the sample after treatment decreased to constant values. The fresh catalysts for small particle size showed higher activity than that for large one but a significant change of activity with time on stream was pronounced. However, the similar activity for both size after hydrothermal treatment was observed. In addition, it was also observed that for the same particle size sample, extent of dealumination of the high Si/Al ratio is lower than that of the low one.

บรรณานุกรม :
Usnee Toophorm . (2545). Effect of particle size and silicon to aluminium ratio on the hydrothermal stablity of polycrystalline zeolite beta.
    กรุงเทพมหานคร : จุฬาลงกรณ์มหาวิทยาลัย.
Usnee Toophorm . 2545. "Effect of particle size and silicon to aluminium ratio on the hydrothermal stablity of polycrystalline zeolite beta".
    กรุงเทพมหานคร : จุฬาลงกรณ์มหาวิทยาลัย.
Usnee Toophorm . "Effect of particle size and silicon to aluminium ratio on the hydrothermal stablity of polycrystalline zeolite beta."
    กรุงเทพมหานคร : จุฬาลงกรณ์มหาวิทยาลัย, 2545. Print.
Usnee Toophorm . Effect of particle size and silicon to aluminium ratio on the hydrothermal stablity of polycrystalline zeolite beta. กรุงเทพมหานคร : จุฬาลงกรณ์มหาวิทยาลัย; 2545.