In this paper, effects of synthesis parameters (synthesis temperature, synthesis time and number of layers) on W-type zeolite membranes were investigated. Experiments were carried out at these levels of synthesis temperature: 165, 185 and 200 °C; synthesis time: 6, 12 and 18 h and number of layers: 1 and 2. Permeation measurements, XRD and SEM analysis were used for characterization of the synthesized membranes. The results showed that increasing synthesis temperature from 165 up to 185 °C increases separation factor of O2/SF6, however, further increasing decreases the separation performance. The same trend was observed for synthesis time for the single layer synthesized zeolite W membrane, while for the double layer synthesized zeolite W membrane, separation factor increased with increasing synthesis time. Repetition of layering has a net positive effect on separation factor of O2/SF6, and negative effect on permeation flux through the membranes. This behavior was attributed to the dual effect of synthesis temperature and synthesis time on selectivity. More zeolite crystals are deposited and larger crystals are formed at higher synthesis temperatures and longer synthesis times. Well W-type zeolite membrane was synthesized at 185 °C for 18 h with 2 repeating layers with a high separation factor of 20.1.
کلید واژگان :Ceramic membrane, W-type zeolite membrane, gas separation, ideal selectivity of O2/SF6, effect of number of layers
ارزش ریالی : 1200000 ریال
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