Study of the effects of Si/Al ratio and operating conditions in hydrothermal dealumination of Y zeolite

NaY zeolites with different framework Si/Al ratios were synthesized via hydrothermal technique. Structural characteristics of the synthesized zeolites were determined by using X-ray diffraction, X-ray fluorescence analysis, scanning electron microscopy, BET analyses. The effects of operating conditions of hydrothermal dealumination, i.e. time, temperature and partial pressure of water vapor on dealumination of the Y zeolites framework and their structure were investigated via X-ray diffraction and BET analyses. According to the experiments, hydrothermal dealumination of the Y zeolite with Si/Al=1.69 was not successful while it was satisfactorily performed for the other one with Si/Al=2.44