Synthesis of SAPO-34/ceramic composite membranes

Porous SAPO-34 molecular sieve membranes supported on alpha-Al2O3 substrates have been successfully prepared by in-situ synthesis. It is found that several synthesis tames are needed and the placement of the substrate in the autoclave is important to prepare a defect-free SAPO-34 membrane. The best ideal selectivity of H-2/N-2 and CO2/N-2 of the membranes is 11.17 and 7.09 respectively. N-butane has a permeability of zero, indicating that the membranes are defect-free and the permeability mechanism through the membranes is molecular sieving.