Preparation method of beta-zeolite

Abstract

The invention relates to a preparation method of beta-zeolite. The preparation method comprises the following steps: adding tetraethyl ammonium halide, an aluminum source, and a silicon source into a sodium hydroxide solution, carrying out low-temperature aging for 2 to 16 hours at a temperature of 40 to 100 DEG C, placing the reaction mixture on a multi-layer screening plate in a reactor, adding water and an auxiliary template agent namely low-carbon organic amine into the reactor bottom, heating, carrying out crystallization for 24 to 60 hours at a temperature of 130 to 160 DEG C, filtering, washing, and drying so as to obtain the beta-zeolite. The mole ratios of the materials in the synthesis system are as follows: SiO2 / Al2O3=30-300, TEA+ / SiO2=0.05-0.30, Na2O / SiO2=0.15-0.80, and H2O / SiO2=7-15. The mole ratios of the materials in the reactor bottom are as follows: H2O / SiO2=0.5-2.0, and R / SiO2=0.08-0.18. The preparation method has the advantages of low synthesis cost and high synthesis efficiency.

Description

technical field [0001] The invention relates to a preparation method of zeolite molecular sieve, specifically, a preparation method of beta zeolite. Background technique [0002] Beta zeolite is a large-porous high-silica zeolite with a three-dimensional twelve-membered ring channel structure. Studies have shown that β zeolite exhibits good catalytic performance in petroleum refining and petrochemical processes such as hydrocracking, isomerization, alkylation, olefin hydration, cracking and dewaxing, and its application prospects are broad. Structurally speaking, the large pore size and unique topological structure of zeolite β ensure good diffusion properties of reactant and product molecules in its crystal structure and good accessibility to active sites; compositionally, β Zeolite's relatively high and adjustable silicon-aluminum ratio in a wide range ensures its good thermal and hydrothermal stability, resulting in the adjustable acidity of zeolite beta, which enables i...

AI Technical Summary

Problems solved by technology

As early as 1989, the patent USP4847055 of Mobil Corporation of the United States reported a method for synthesizing zeolite beta with tetraethylammonium bromide as a template, but a special silicon source was involved in this method, and its silicon source The processing method is relatively complicated, which complicates the synthesis process while reducing the synthesis cost

Subsequently, the patent USP5164169 of Mobil Company in 1992 reported a kind of synthetic route with tetraethylammonium hydroxide and tetraethylammonium bromide mixture as template agent again, but introduced chelating agent in this synthetic system, makes synthetic system complication

Chinese patents CN1198404A, CN1249270A and CN1249271A have reported the method for synthesizing zeolite beta with tetraethylammonium halide or / and tetraethylammonium hydroxide as template, in this method part or all replaces quaternary ammonium base with halide, reduces The synthesis cost of β zeolite is excluded, but F is introduced in this series of patents - ions, due to F - The presence of ions makes this method difficult to achieve industrial scale production

Chinese patent CN1377827A has also reported a kind of beta zeolite synthesis route that uses tetraethylammonium bromide as template agent, template agent consumption is few, crystallization time is short and does not need chelating agent in this method, but the synthesis of this method Beta zeolite silicon aluminum ratio (SiO 2 / Al 2 o 3 ) only concentrated in 10~55

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