Synthesis and characterization of W-type zeolite membrane:effect of synthesis temprature

In this paper, effects of synthesis temperature on synthesis of W-type zeolite membrane were investigated. Experiments were carried out at these levels of synthesis temperature: 165, 185 and 200 °C and synthesis time: 12. Permeation measurements 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 synthesized zeolite W membrane. This behavior was attributed to the effect of synthesis temperature on selectivity. More zeolite crystals are deposited, and larger crystals are formed at higher synthesis temperatures. Formation of larger crystals increases zeolite layer integration rate, which is responsible for gas separation, in one hand and reduces deposited zeolite layer density, due to the more void formation, on the other hand. In the optimum condition, W-type zeolite membrane was synthesized at 185 °C for 12 h with a high separation factor of 12.

W-type zeolite membrane, Gas separation, Optimum synthesis condition, effect of synthesis temptature.