Study on the calcination of DD3R zeolite membrane and reduce the nanometric cracks to improve its separation performance

In this study, the DD3R zeolite powder and membrane were synthesized via a secondary growth method. The XRD and SEM analyses show the successful synthesis of the DD3R zeolite powder and membrane. The calcination of the membrane was carried out at 500 ◦C with a heating rate of 0.2 ◦C/ min. The N2 gas permeation test was carried out at different temperature steps simultaneously with increasing the temperature. The results show that after 425 ◦C, N2 permeation increases by about 100 times, which indicates thermal shock and creating non-zeolite pores with size in nanometric range in the membrane. The calcination of another membrane at 500 ◦C with a heating rate of 0.1 ◦C/ min also was resulted in defects of the membrane. Finally, the calcination of the DD3R membrane at 425 ◦C with a heating rate of 0.2 ◦C/min prevented thermal shock, and then the defects were minimized in the membrane. So that, the perm-selectivity of CO2/CH4 and N2/CH4 were measured 10-11 and 4-5, respectively.