A kind of preparation method of β-type molecular sieve

A technology of molecular sieves and precursors, which is applied in the field of preparation of β-type molecular sieves, can solve the problems of poor thermal stability, hydrothermal stability, and low crystallinity, and achieve good stability, high crystallinity, and high crystallinity.

Active Publication Date: 2018-03-16
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this method reduces the amount of template agent and increases the yield of β molecular sieve, it needs to add composite template agent and seed crystal, and when the silicon-aluminum ratio exceeds 30, the crystallinity is low, and the thermal stability and hydrothermal stability are poor.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] (1) Preparation of amorphous silicon-aluminum precursor

[0048] Prepare solid aluminum sulfate into 60mL concentration of 100g A1 2 o 3 / L aluminum sulfate working solution (a). Dilute the concentrated ammonia water with an appropriate amount of distilled water to obtain about 10wt% dilute ammonia water (b). Take SiO 2 Mass meter 28wt% sodium silicate solution, then diluted to 100mL concentration is 140g SiO 2 / L sodium silicate working solution (c). Take a 2-liter steel reaction tank, add 0.2 liter of distilled water into the reaction tank, stir and heat to 70°C, open the valves of the containers (a), (b) and (c) at the same time, control (a) and The flow rate of (c) is to keep the neutralization reaction time within 40 minutes, and the flow rate of (b) is adjusted quickly to keep the pH value of the system at 7-8, and the temperature of the system is controlled at about 60°C. After the aluminum sulfate reaction is completed, stop adding (b), and the amount of ...

Embodiment 2

[0056] (1) Preparation of amorphous silicon-aluminum precursor

[0057] Prepare solid aluminum sulfate to 100mL concentration to be 80g A1 2 o 3 / L aluminum sulfate working solution (a). Dilute the concentrated ammonia water with an appropriate amount of distilled water to obtain about 10wt% dilute ammonia water (b). Take SiO 2 Mass meter 28wt% sodium silicate solution, then diluted to 80mL concentration is 150g SiO 2 / L sodium silicate working solution (c). Take a 5-liter steel reaction tank, add 0.2 liter of distilled water into the reaction tank, stir and heat to 70°C, open the valves of the containers (a), (b) and (c) at the same time, control (a) and The flow rate of (c) is to keep the neutralization reaction time within 40 minutes, and the flow rate of (b) is adjusted quickly to keep the pH value of the system at 7-8, and the temperature of the system is controlled at about 60°C. After the aluminum sulfate reaction is completed, stop adding (b), and the amount of (...

Embodiment 3

[0065] (1) Preparation of amorphous silicon-aluminum precursor

[0066] Prepare solid aluminum chloride to make 100mL concentration be 100g A1 2 o 3 / L aluminum chloride working solution (a). Dilute the concentrated ammonia water with an appropriate amount of distilled water to obtain about 10wt% dilute ammonia water (b). Take SiO 2 Mass meter 28wt% sodium silicate solution, then diluted to 100mL concentration is 100g SiO 2 / L sodium silicate working solution (c). Take a 2-liter steel reaction tank, add 0.3 liter of distilled water into the reaction tank, stir and heat to 70°C, open the valves of the containers (a), (b) and (c) at the same time, control (a) and The flow rate of (c) is to keep the neutralization reaction time within 40 minutes, and the flow rate of (b) is adjusted quickly to keep the pH value of the system at 7-8, and the temperature of the system is controlled at about 60°C. After the aluminum chloride reaction is completed, stop adding (b), and the amo...

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Abstract

The invention discloses a preparation method of β-type molecular sieve. The preparation method includes: (1) Preparation of amorphous silicon-aluminum precursor by acid-base precipitation method; the preparation process includes acid-base neutralization to form a gel, aging, wherein silicon is introduced into the reaction system by adding an aluminum-containing compound and a precipitant Introduce part of the silicon-containing compound before neutralization and / or during the gelation process, and the remaining silicon-containing compound is introduced after the aluminum-containing compound and the precipitant are neutralized into the gel and before aging; (2), to step (1 ) into the amorphous silica-alumina precursor obtained by adding water, silicon source and template to obtain silica-alumina gel; (3), the silica-alumina gel obtained in step (2) undergoes two-step dynamic crystallization, and then is filtered, Washing to obtain Naβ molecular sieve. The method of the invention can not only reduce the usage amount of the organic template, but also can synthesize the β-type molecular sieve with high crystallinity and high silicon-aluminum ratio, and has better thermal stability and hydrothermal stability.

Description

technical field [0001] The invention relates to a method for preparing molecular sieves, in particular to a method for preparing β-type molecular sieves. Background technique [0002] In 1967, Wadlinger of Mobile Company first synthesized β molecular sieve by mixing and crystallizing sodium aluminate, silica gel, tetraethylammonium hydroxide (TEAOH) and water. β molecular sieve has a 12-membered ring intersecting channel structure, the 12-membered ring of the one-dimensional channel parallel to the (001) crystal plane has a pore size of 0.57-0.75nm, and the other 12-membered ring of the two-dimensional channel parallel to the (100) crystal plane The pore size is 0.56 ~ 0.65nm. Because of its special structure, it has both acid catalytic properties and structural selectivity. The β molecular sieve modified by various methods can be used for hydrocracking, hydrofining, and conversion of light aliphatic hydrocarbons to Aromatics, benzene alkylation, cracking, isomerization and...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B39/04
Inventor 孙晓艳樊宏飞王继锋于政敏
Owner CHINA PETROLEUM & CHEM CORP
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