METHOD OF PRODUCING NANOCRYSTALLINE ZEOLITE BEA (VERSIONS) AND OBTAINED ZEOLITE BEA (VERSIONS) Russian patent published in 2020 - IPC C01B39/04 B82B3/00 C01B39/48 B01J29/70 B01J20/18 

FIELD: chemistry.

SUBSTANCE: group of inventions relates to synthesis of zeolites. Disclosed is a method of producing nanocrystalline zeolite of structural type BEA, comprising impregnating solid particles of silica gel with a solution of a reaction mixture to obtain a precursor characterized by a composition corresponding to the crystallization of BEA zeolite, holding the precursor in closed form at room temperature for 1.5-2 hours, precursor crystallization in the absence of free water at 130-145°C for 12-36 hours. Upon completion of crystallization, the obtained solid particles are washed and dried, which have a shape identical to that of the initial silica gel particles. Method enables to obtain BEA zeolite in the form of two modifications. Modification of BEA-I is nanocrystals of 100-200 nm in the form of strong particles with size of 0.5-5 mm. Modification of BEA-II is isolated nanocrystals with size of 200-800 nm, which are retained relative to each other due to adhesion and form particles with size of 0.5-5 mm, which break at mechanical action. To obtain a modification of BEA-I, the molar ratio of SiO₂:Al₂O₃ in precursor is 20-25; to obtain a modification of BEA-II, the molar ratio of SiO₂:Al₂O₃ in precursor is 26-60. Molar ratios of components in the precursor are the following in order to obtain BEA zeolite in form of both modifications: Me₂O:SiO₂ from 0.09 to 0.16, R:SiO₂ from 0.06 to 0.08, H₂O:SiO₂ from 2.8-3.0, where Me is an alkali metal, R is an organic template of tetraethylammonium hydroxide.

EFFECT: technical result is reduction of number of process operations, absence of liquid crystallization products, high degree of use of initial reagents and high output of BEA zeolite, reduction of water consumption and increase of crystallizer efficiency by several times, simplification of technology due to elimination of procedures for extraction of nanocrystals using high-speed centrifugation, possibility of producing nanocrystalline BEA zeolite in the form of two modifications.

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