Green Synthesis Of Beta Zeolite And Pentasil Zeolites

Zeolites, as solid acid catalysts, are widely used in various chemical fields. ZSM-5/ZSM-11 composite zeolites and Beta zeolite have broad and important applications in the petrochemical industry. However, the use of large amount of organic templates in conventional synthetic methods of the two zeolites not only increases the cost of zeolites synthesis, but also results in producing harmful substances. The seeds-directed synthesis method can greatly reduce the application of organic templates in zeolite preparation, or even completely avoid the use of organic templates.In this study, we successfully obtained the ZSM-5/ZSM-11 composite zeolites by adding ethanol to the synthesis system of ZSM-11 zeolite as a supporting agent. The turning of ethanol amount was used to adjust the proportion of MFI topology in the composite zeolite. We have synthesized ZSM-5/ZSM-11 composite zeolites with SiO2/Al2O3 ratios of 30,120 and 400.By optimizing the synthetic conditions for Beta zeolite in template-free and seeds-directed system, the product yield was successfully increased to 85% when the crystallization was carried out at 120℃ for 6 days with the gel compositions of SiO2:0.1Al2O3:0.2Na2O:7.5H2O:10%(wt)Beta-seeds. The obtained results indicates the potential of this seeding technique for industrial application.