SAPO-34 membranes for separation of CO2/CH4 gas mixture were fabricated on porous α-Al2O3 substrates by seeded growth under microwave irradiation. Effects of synthesis conditions

including heating mode

seed size

aging and synthesis time

on membrane morphology and structure were investigated in order to manufacture dense and thin SAPO-34 membranes. Scanning electron microscopy (SEM)

X-ray diffraction (XRD)

and Fourier transform infrared spectroscopy (FT-IR) were used to characterize SAPO-34 membranes. 1.5 μm-thick defect-free SAPO-34 membrane could be obtained with high reproducibility at condition of 0.4 μm-sized seed

24 h aging

and 4 h microwave heating. The new membrane demonstrated an average CO2/CH4 separation selectivity at 81 and high CO2 permeability at 6.6×10-7 mol·m-2·s-1·Pa-1.