Synthesis of ZSM-5-type zeolite membranes on, porous disks loaded with different amounts of seed

Dincer, Eser
Kalıpçılar, Halil
Culfaz, Ali
ZSM-5-type zeolite membranes were synthesized at 130 degrees C on alumina supports coated with seed crystals by vacuum seeding. Compact and uniform ZSM-5 layers were formed on the support surfaces when the amount of seed was less than 1 mg/cm(2). Higher loading of seed crystals resulted in an asymmetric structure with a compact and uniform ZSM-5 layer on top, the support at the bottom, and the seed layer in between. Fifty-one membranes were prepared on supports coated with different amounts of seed. About 70% of the membranes synthesized on seeded supports were impermeable to nitrogen before calcination, whereas all nine membranes synthesized on plain supports were permeable to nitrogen before calcination. One-third of the membranes synthesized on seeded supports had N-2/SF6 ideal selectivity higher than the quality criterion of 40 after calcination. Membranes with high N-2/SF6 ideal selectivity also showed high n-C4H10/i-C4H10 separation selectivity.


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Oezcan, Aysenur; Kalıpçılar, Halil (American Chemical Society (ACS), 2006-07-05)
A method is presented for the hydrothermal synthesis of binderless zeolite A bars and tubes with high purity from amorphous aluminosilicate extrudates. The solid that was separated from a hydrogel was mixed with an aqueous solution of hydroxyethyl cellulose to obtain a paste, which was extruded into bars and tubes. After calcination, amorphous bars and tubes were converted to zeolite A in the liquid phase that was separated from the hydrogel. The zeolite bars and tubes were composed of cubic zeolite A cryst...
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Soydas, Belma; Culfaz, Ali; Kalıpçılar, Halil (Informa UK Limited, 2009-01-01)
MFI-type zeolite membranes were hydrothermally synthesized as a thin layer on macroporous -alumina discs coated with 1m MFI-type seed crystals as seed. The effect of soda (Na2O) concentration on the morphology of the membranes was investigated. Soda concentration, and thus the hydroxyl ion concentration, was changed between 0.25 and 6.5 mol/mol gel. At low soda concentrations the crystals forming the layer exhibited mostly (h0h)/c-axis orientation, but at high soda concentrations a membrane layer formed fro...
Synthesis of alpha-Fe2O3/TiO2 heterogeneous composites by the sol-gel process and their photocatalytic activity
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alpha-Fe2O3/TiO2 heterogeneous composites were synthesized by the sol-gel process to increase the photocatalytic activity of TiO2. The structural, morphological, and optical characteristics of the composites were determined by X-ray diffraction, scanning electron microscope, and UV-vis diffuse reflectance spectroscopy. Results revealed that the incorporation of alpha-Fe2O3 to TiO2 widened the visible light absorption ability of TiO2. It was realized that the calcination temperature plays a crucial role in m...
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Soydas, Belma; Kalıpçılar, Halil; Culfaz, Ali (American Chemical Society (ACS), 2010-06-02)
Thin zeolite membranes of MFI type were prepared on alpha-Al2O3 supports by midsynthesis addition of silica in a recirculating flow system at 95 degrees C The synthesis was started with the batch composition of 80SiO(2): 30TPAOH:1500H(2)O which was changed to 80SiO(2)center dot 9TPAOH:1500H(2)O by addition of silica Mkt 24, 48, or 72 h Compared to synthesis at constant composition. it is possible to affect the rates of nucleation and crystal growth to obtain membranes with better quality by changing the ove...
Synthesis and Characterization of Aluminum Containing Silica Aerogel Catalysts for Degradation of PLA
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Citation Formats
E. Dincer, H. Kalıpçılar, and A. Culfaz, “Synthesis of ZSM-5-type zeolite membranes on, porous disks loaded with different amounts of seed,” INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, pp. 4743–4749, 2008, Accessed: 00, 2020. [Online]. Available: