Preparation, Characterization And Properties Of SAPO - 34 Zeolite Membrane

The synthesis methods of SAPO-34 molecular sieve membrane and composite membrane were studied in this paper.Through the appropriate synthetic conditions selected, the SAPO-34 sieve membrane and SAPO-34 zeolite/carbon composite membranes with good separation performance and high repetition rate were successfully prepared. Mainly research on following parts:First, secondary crystallization method, alkalinereflux and microwave heating synthesis method were investigated in order to get proper SAPO-34 molecular sieve seed. Though pure SAPO-34 molecular sieve can be got by all three methods, morphology and size of SAPO-34 molecular sieve are very different. SAPO-34 molecular sieve prepared by microwave heating manner is flaky and the size is 200~400nm, which is suitable for the preparation of seed layer. Besides, smear method, dipping method, the pre-coat layer of mesoporous silicon dioxide were studied for the preparation of the seed layer on the support surface. The results indicated that the seed layer in best quality can be get by the pre-coated silicon oxide layer.Second, the synthesis conditions of SAPO-34 molecular sieve membrane were investigated, such as the kinds of templates, silica to alumina ratio, synthesis temperature, synthesis time and coating times for getting densty membrane. Moreover, conventional heating, homogeneous heating and microwave heating were also studied. The result showed that the SAPO-34 zeolite membrane getted by conventional heating and microwave heating arrived at 26 and 35 of the CO2 selectivity respectively. After silane treatment modified, the CO2 selectivity increased, yet permeability is almost indecreased.Finally, SAPO-34 zeolite/carbon composite membrane was prepared by dip-coating method. Phenolic resin concentration, the content of zeolite, molecular sieve particle size, the degree of dispersion of molecular sieve, the degree of vacuum, thira times were also investigated respectively. CO2/CH4 separation selectivities were as high as 57, and the CO2 permeances was 8.9x10-8(mol m-2pa-1s-1) at 0.2 MPa。...