Preparation And Characterization Of Nano-structure Zeolite Beta And Its Composite Membranes

Zeolite beta (BETA) is a wide-pore and high-silica microporous material which comprising a three-dimensional system of 12-membered ring channels.zeolite beta has excellent catalyse performance because it has unique channel structure and outstanding thermal stability.It used for many petrochemical engineering process. Nano-structure and hierarchical-structure crystals can solve the diffusion of molecules to internal catalytic sites. In order to achieve the industrial applications of BETA,we must try to reduce organic template needed and reaction time in systhsis.Carbon memberane is poor and fragile which has long and tortuous channel because of its channel structure consists of turbostratic carbon structure.The channel sructure is easy on the gas molecules have a big spread of resistance. This channel structure easily generated the larger resistance in the process of gas molecules diffusion.Carbon-zeolite composite membrane prepared on support body as a novel membrane material because of it's simple and good gas separation function.carbon-zeolite composite membrane prepared study is a freshly research directions. This paper prepared beta zeolite-carbon composite membrane and investigation gas separation performance of the membrane,which can support experiments data for future industrialization application or research in inorganic membrane separation technology.Based on the research ideas, this work conducted the following experiment:Preparat the micron Beta zeolite; preparat the nano structure Beta zeolite; synthesis nano beta zeolite by microwave; use different Beta zeolite doped with phenolic resin precursor solution prepared Beta/C composite memberanes, and studied the gas separation performance of the memberanes.The main conclusions are as follows:(1) Inspected the effect of template,H2O/SiO2,the temperature and time to the synthesis of beta zeolite, fixed the optimal formulation and optimal synthesis conditions for crystallization synthesis at the end.At the formulation of Al2O3:50SiO2:1000H2O:1.5Na2O: 15TEAOH,150度for 3 days get the uniform crystal.(2) Under the conditions of increasing basicity assist rotation crystallization,obtained nano-beta zeolite which exhibit high crystallinity,dispersity and uniform particle sizes about 50nm. On this basis, by adding carbon as the second template can successfully synthesized hierarchical structure beta zeolite nanocrystal aggregation. Three kinds of carbon materials used in this article as contrast, then the productions characterized by series analysis.The results show the obtained porductions are hierarchical structure beta zeolite,their morphologies are very similar,the product from the carbon nanotubes as the second template with the greatest external surface area.Then we speculate the synthesis mechanism of the process.(3) Use microwave to synthesize nano beta zeolite, reduce synthesis time obviously from 72h to 15h. Followed by adding F- and crystal seeds, further reducing the reaction time from 15h to 5h. then reduce the particle size significantly, particle size reduction by the 1um to 300nm.(4) Select the nano-sized beta zeolite and nanocrystal aggregation beta zeolite as doping particles to prepare Beta/C composite membrane. Investigat the effect of dipping times to the synthesis of membranes. It was found that nanocrystal aggregation beta zeolite as doping particles obtained better gas seperation performance, the best dip time is 3.