| Owing to benefits of efficient use of energy and equipment, maneuverability and excellent permeability etc., membrane separation as a new separation technology is widely investigated in recent years. Due to the absence of Al atom, Silicalite-1 membrane is highly hydrophobic and an important potential application is to extract organics from low-concentration aqueous solutions. Silicalite-1 zeolite membrane has a good alcohol/water separation performance, which is used fermentation of biomass fuel ethanol and fuel butanol. A lower alcohol concentration in fermentation broths is maintained, can effectively ensure the continuity of the fermentation process, which can overcome the deficiencies of traditional methods of separation, to change the traditional batch fermentation process.In this dissertation, the Silicalite-1 crystals with different sizes are synthesized with the traditional hydrothermal method and the effect of crystallization temperature and H2O/TEOS on the growth of the Silicalite-1 are studied. Different thickness and performance of Silicalite-1 membranes are prepared on tubularα-Al2O3 and mullite supports and with in situ hydrothermal synthesis and secondary growth method, respectively. Based on the research of conventional hydrothermal synthesis, liquid phase oxidation and low-temperature calcination method for organic template removal from Silicalite-1 membrane is used. Then hydrophobic Silicalite-1 membranes are prepared with two silicon source by secondary growth method. Lastly, the as-prepared membranes are applied to pervaporation for alcohol/water mixture and acetone/water mixture. Moreover, a good separation performance for ethanol/water mixture is obtained.The main conclusions achieved are as follows:Firstly, the influence of H2O/TEOS and crystallization temperature on the preparation of Silicalite-1 crystals was investigated respectively and Silicalite-1 seed with the size of 0.2μm-2μm were prepared for an appropriate seed layer. The seed layer integrating with the supports closely prepared by vacuum seeding method played a role in transition.Secondly, liquid phase oxidation and low-temperature calcination method for organic template removal from Silicalite-1 membrane was explored. Cracks produced by high temperature calcinations and cost of the zeolite membranes were reduced effectively.Good gas permeability and pervaporation performance of the Silicalite-1 menbranes were obtained by the removal of template method.The permeance of N2 is 8.16×10-7 mol·m-2·s-1·Pa-1 and the ideal selectivity of N2/i-C4H10 is up to 425 at 293 K and ideal selectivity of CO2/N2is 2.89 at 428 K. The fluxes of Silicalite-1 membrane at 333 K is 0.831 kg·m-2·h-1 towards ethanol/H2O mixtures, and the corresponding separation factor is 40.3.Thirdly, synthesis of Silicalite-1 membrane with two silicon source (ETES and TEOS) by secondary growth method was studied for the first time. The effects of synthesis parameters (i.e. [ETES] content, crystallization time, and crystallization temperature) on the membranes thickness and pervaporation performance were investigated for Silicalite-1 membranes grown onto seeded supports. The results indicated that the as-synthesized membranes were typical MFI-type zeolite membranes and the ETES promoted crystal growth of the Silicalite-1 membranes. The molar composition (TEOS:[0.02-0.04]ETES), more than 16 h crystallization time at low-temperature (413 K) were better for obtaining a dense and continuous Silicalite-1 membranes with a good pervaporation performance for acetone/H2O, butanol/H2O and ethanol/H2O mixtures, respectively.Lastly, synthesis and properties of organic-functionalized Silicalite-1 membranes with two silicon source were described. It was demonstrated that the presence of organic functional groups in the liquid phase oxidation and low-temperature calcinated Silicalite-1 membranes could enhanc the hydrophobicity of the membranes. They showed good pervaporation performance toward ethanol/H2O mixtures.
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