Prearation And Application Of ZSM-5 Zeolites By Sodium-free Method In Rotating Packed Bed

ZSM-5 zeolite has a typical MFI topology and a unique two-dimensional channel system,and can be modified by adjusting the preparation conditions to change the Si/Al ratio of zeolite products,so as to be suitable for different catalytic demands of industrial production.ZSM-5 zeolites have been widely used as solid acid catalyst in industry due to its unique pore structure and more acidic active centers.In recent decades,ZSM-5 zeolites play an important role in catalytic reactions in petrochemical industry,such as shape selection catalysis,alkylation,aromatization and so on.In this paper,ZSM-5 zeolites were prepared by mixing and hydrothermal method without sodium in a stirred reactor and a high gravity reactor.The effects of organic amines on the physical and chemical properties of ZSM-5 zeolite products were screened,and the effects of various parameters in STR and RPB on the acidity of ZSM-5zeolites were systematically studied.The main contents are as follows:1.The preparation of ZSM-5 zeolites by premixed hydrothermal method without sodium in a stirred reactor was studied in this paper.The effects of the variety of organic amine,organic amine content,aging,crystallization temperature and time,Si/Al ratio in operating conditions on the ZSM-5 zeolite morphology,yield,molecular sieve framework acid properties and the influence law of aluminum content,and optimize the process parameters,to explore the organic amine without sodium preparation Al entered the ZSM-5 zeolites framework.The optimum preparation conditions of ZSM-5 zeolites were obtained through experiments,and better organic amines were further screened under the optimum conditions.The results showed that ethanolamine and isopropanolamine were more favorable to the formation of framework Al in ZSM-5 zeolites synthesis than the other two organic amines,that is,the acidic site,with more acid content and better catalytic performance.2.In this paper,on the basis of the preparation of ZSM-5zeolites in stirred reactor,the preparation of ZSM-5 zeolites in rotating packed bed reactor premixed hydrothermal method without sodium was studied.Examines the RPB premixed speed,premixed time,and under the condition of RPB blends the types of organic amine and organic amine content and so on various parameters on the synthesis of ZSM-5 zeolites morphology,yield,and the influence law of molecular sieve physico-chemical properties,such as acid properties,and optimize the process parameters,and with the STR synthesized under the condition of premixed ZSM-5 zeolites acidity qualitative comparison,The influence of RPB premixing on aluminum entering framework in the process of sodium free synthesis of ZSM-5 zeolite was investigated.Under the optimum synthesis condition,compares four different organic amine synthesis of ZSM-5 zeolites on the various physical and chemical properties of different,four kinds of samples with high number of weak acid center and types of organic amine acid in synthesis of molecular sieves products properties have great influence,the sample of the synthesis of isopropanolamine acid quantity highest,reached 2.3309mmol·g^-1.3.Under the optimal technological conditions,the ZSM-5 zeolites with the most acid content was synthesized without sodium,and the organic probe catalytic reaction of benzaldehyde and ethylene glycol acetal was carried out.The catalytic performance of ZSM-5 zeolites synthesized by various organic amines was compared with the properties of ZSM-5 acid and the content of framework Al.The experimental results show that the ZSM-5 zeolite synthesized by RPB premix isopropanolamine as ammonia source without sodium has the highest catalytic performance,and the conversion rate of benzaldehyde can reach77.63%.