Preparation And Application Of Beta Zeolite Membrane

Zeolite membranes have great potential for the separator, the reactor and sensor. Zeolite membranes offer several advantages at heat transfer and mass transfer compared to conventional fixed-beds and slurry reactors.Zeolite Beta has good thermal stability, acid stability and hydrophobic because of the special structure and exhibit excellent catalytic performance in acidic catalytic cracking, isomerization, alkylation and transalkylation reactions petrochemical process.In this paper， Beta zeolite membranes was the research object, using different preparation methods, studied the effects of synthesis conditions on the load、 morphology and orientation, Evaluated the Beta zeolite membranes prepared through N2O decomposition。Firstly, we used the coating method and introduced a new coating——Sliica alumina gel coating, compared with alumina gel coating, studied the effects of the coating amount、Si/Al、crystallization time on the load and microscopic morphology。 The results show that the use of Sliica-alu-mina gel coating is better than alumina gel coating in the aspect of prepar-ing Beta zeolite membranes。Through the loading investigation we found that Beta zeolite membrane what was prepared using Sliica-alum-ina gel coating is not suitable as a reactor because the amount of load was too low.Secondly, we used secondary growth method to prepare the Beta membrane。The seed coating solution of conventional secondary growth method were mixture of an amount of seed and deionized water。Through changing the composition of the seed coating solution, add Sliica or aluminum source, we did the research about preparing Beta zeolite membrane.The new seed coating solution that mixture of an amount of seed、 deionized water and Sliica gel was prepared。By examining the composition of the seed layer silica, we found the function of Sliica gel in the coating-the role of bonding and silicon source; and synthesis conditions---crystallization time, crystallization temperature, alkalinity synthetic liquor were investigated, the results show that the introduction of silica can promote the growth of zeolite membrane and the secondary growth process is the process of shedding edge and growth; optimal crystallization temperature was140℃, low temperature is not conducive to form a film, high temperature can increased load, but there will be a mordenite impurity crystals when temperature was high; orientation membranes can be synthesized and adjusted by adjusting the basicity of the mother liquorIntroduced aluminum sol to the seed coating liquid, the aluminum content of the coating. crystallization time and crystallization temperature was investigated; results show that the crystallization process is still a growing side edge shedding process even the different seed layer; the introduction of aluminum sol can also promote the growth of zeolite membranes; proper amount of coating can be adjusted orientation membranes; the introduction of aluminum makes the crystallization temperature sol changes greatly increases the load;Finally, respectively, used Fe modified Beta zeolite membranes prepared in the fourth chapter and the fifth chapter decompose N2O, exhibited excellent catalytic activity。N2O completely decomposed at550℃when we used Beta zeolite membranes prepared by silica sol assisted; N2O conversion rate was94.0%at550℃when we used Beta zeolite membranes prepared by aluminum sol assisted; Both showed excellent catalytic activity。...