Synthetic method of ZSM-5 zeolites

Abstract

The invention belongs to the synthesis field of aluminosilicate ZMS (Zeolite Molecular Sieve), and relates to a synthetic method of ZSM-5 zeolite molecular sieves. ZSM-5 zeolites are high-silicon micro-porous zeolites with unique three-dimensional ten-membered ring crossing aperture passages, the diameters of the aperture passages are close to the sizes of benzene rings, and the ZSM-5 zeolites can be widely applied to petroleum refining, petrochemical industry and fine chemicals synthesis. Particularly, nano-sized ZSM-5 zeolites achieve larger external surface area and higher intracrystalline diffusion rate, and have higher activity and selectivity as well as strong coking deactivation-resisting capability in hydrocarbons catalysis conversion reactions. The synthetic method regulates the polymerization degrees of silicon sources and aluminum sources respectively by adding acid and alkali so as to obtain highly reactive reactants, and can rapidly achieve nucleus formation in large quantities in a system so as to obtain nano-sized zeolites. The synthetic method is not limited by the types of the silicon sources and the aluminum sources, has strong applicability to raw materials, changes the activity of the raw materials through simple regulation, and can rapidly synthesize products of the nano-sized ZSM-5 zeolites with well crystallinity under the dosage conditions of no template and low-cost templates.

Description

technical field [0001] The invention belongs to the field of synthesis of aluminosilicate zeolite, and relates to a synthesis method of ZSM-5 zeolite. Background technique [0002] The ZSM-5 zeolite (USP 3702886) invented by Mobil Petroleum Company of the United States has become a very important shape-selective catalytic material due to its unique pore structure and good catalytic performance. The well-known processes developed with ZSM-5 zeolite are: Mobil middle distillate dewaxing process (MDDW), lubricating oil dewaxing process (MLDW), catalytic reforming process, selective reforming of gasoline and M-reforming process, from light Cyclar process (LPG BTX) for synthesis of aromatics from hydrocarbons, Mobil-Badger synthesis of ethylbenzene process, toluene gasification process (MTDP), xylene isomerization process (MVPI), methanol to gasoline process (MTG) and p-ethylbenzene Synthetic process (PET). [0003] The following patents and documents all involve the applicatio...

AI Technical Summary

Problems solved by technology

The material with ZSM-5 zeolite mesoporous composite structure can improve the diffusion performance of the product, make up for the deficiency of microporous molecular sieves, and provide a favorable spatial configuration for macromolecular reactions, but its acidity is weak and its hydrothermal stability is relatively Lower problems persist

[0058] The above inorganic methods successfully overcome various problems of organic templates, but the synthesis of ZSM-5 zeolite silica-alumina by inorganic methods is relatively low, and the crystallinity is relatively poor in most cases, and the product performance is not as good as that synthesized by organic templates.

[0059] From the perspective of patent literature, the synthesis of nano ZSM-5 zeolite is still a challenge

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