ZSM-5 was synthesized from water glass as the silica source and Al(OH) 3 as Al source. Water glass is an inexpensive silica source, but controlling the reactant composition was difficult because of the high alkali content in water glass. Considering environmental and economic concerns, we propose a new alkali extraction method using methanol to remove the alkali ingredients from water glass. When the MeOH/SiO 2 molar ratio was 3, the maximum extraction of alkali components occurred. After extracting with MeOH, the filtrates were analyzed by UV spectroscopy and titration methods, and we determined the Al 2O 3:SiO 2:Na 2O: H 2O molar ratio to be 1:58:7.55:1510. Crystallization by hydrothermal synthesis was performed at various reaction temperatures and times. Characterizations were carried out by means of XRD and SEM. ZSM-5 display a characteristic MFI peak in its XRD pattern and its crystals have planar shapes and 1~2 μm particle sizes. Alkali extraction using methanol in a template-free system is a better method for controling the level of Na 2O in water glass used for ZSM-5 synthesis.
|Number of pages||8|
|Journal||Journal of Industrial and Engineering Chemistry|
|Publication status||Published - 2004 Jul 1|
- Hydrothermal synthesis
- Water glass
ASJC Scopus subject areas
- Chemical Engineering(all)