A kind of beta zeolite containing nanopores in the crystal and its application

Abstract

The invention discloses a Beta zeolite containing intracrystalline nanopores and application thereof. The Beta zeolite is prepared through a method comprising the following steps: (1) uniformly mixing diallyl amine and acetic acid according to a mass ratio 1:(0.5-3), adding dimethyl diallyl ammonium chloride of which the mass is 2-12 times more than that of the diallyl amine, uniformly stirring, reacting at 60-120 DEG C for 1-6 hours, and cooling to obtain a high-molecular copolymer containing quaternary ammonium groups; (2) preparing a 1.0-6.0wt.% sodium hydroxide water solution, adding industrial sodium aluminate powder, stirring to form a mixed solution I, adding industrial solid silica gel into the mixed solution I, uniformly stirring, adding a small amount of Beta crystal seeds, further stirring until the temperature of the system is reduced to room temperature, finally adding the high-molecular copolymer containing quaternary ammonium groups, and further stirring for 1-10 hours; and (3) performing dynamic crystallization on the mixture obtained in the step (2) at 120-160 DEG C for 100-170 hours to obtain the Beta zeolite containing intracrystalline nanopores. The invention provides application of the Beta zeolite containing intracrystalline nanopores as a catalyst in phenanthrene alkylation reaction.

Description

[0001] (1) Technical field [0002] The invention relates to a Beta zeolite with large particles and nanopores in crystals and its application. [0003] (2) Background technology [0004] Beta zeolite was first synthesized by the American Mobile Company in 1967 through hydrothermal crystallization (US3308069). The zeolite has an open three-dimensional pore structure, strong acidity, thermal stability and hydrothermal stability. Therefore, it has important applications in petroleum refining, petrochemical and fine chemical synthesis industries. For example, Beta zeolite is the main catalyst for alkylation and isomerization in industry, and also the main additive for catalytic cracking catalyst. [0005] The synthesis of traditional Beta zeolite is generally carried out in a strong alkaline system. White carbon black or silica gel is used as the silicon source, and the small molecule template agent tetraethylammonium hydroxide (TEAOH) is used as the microporous structure-direc...

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Problems solved by technology

[0006] First, the generally obtained zeolite grains are small, at 200-300nm, solid products must be separated by high-speed centrifugation, and the finer nano-grains still exist in the mother liquor synthesized with zeolite, causing great waste and greatly Increased separation cost and production cost of the product

[0007] Second, a large amount of expensive small molecule template tetraethylammonium hydroxide (TEAOH) is used in the synthesis system, resulting in higher synthesis costs;

[0008] Third, the silicon-aluminum ratio of zeolite products generally obtained in the traditional formula system is 10-20 (silicon-aluminum atomic ratio), which cannot meet the needs of industry in most cases

[0009] Fourth, the traditional Beta zeolite only has a microporous structure (pore size less than 0.74nm), which is not conducive to the diffusion of reactant molecules

However, the silicon-aluminum ratio of the synthetic sample is relatively low (9-12)

Moreover, in the synthetic system H 2 O / SiO 2 If it is too high (50), the solid content of the synthesis system is low, and the yield of the final solid product is low

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