Method for promoting Beta molecular sieve synthesis

A molecular sieve and accelerator technology, applied in the field of catalytic chemistry, can solve the problems of low product yield, cumbersome preparation process, low preparation reproducibility, etc., and achieve the effects of excellent catalytic performance, simple preparation method and low crystallization temperature

Inactive Publication Date: 2018-06-29
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] To sum up, there are still some problems in the rapid synthesis method of Beta molecular sieve reported so far: such as complicated preparation process, low preparation reproducibility, low product yield, etc., which limit its industrial production to a certain extent.

Method used

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  • Method for promoting Beta molecular sieve synthesis
  • Method for promoting Beta molecular sieve synthesis
  • Method for promoting Beta molecular sieve synthesis

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] Under stirring conditions, 5.3g of white carbon black (95.0wt.% SiO 2 , 5.0wt.%H 2 O), 0.4g sodium aluminate (49.0wt.%Al 2 o 3 , 38.0 wt.% Na 2 O, 13.0 wt.% H 2 O), 0.13g sodium hydroxide (96.0wt.% NaOH), 22.3g tetraethylammonium hydroxide aqueous solution (TEAOH, purity ≥ 35wt.%), 16.7g N-methyl-2 pyrrolidone (NMP, ≥ 99wt. %), 9g deionized water are added in the reactor in a certain order. The molar composition of the raw material mixture is: SiO 2 / Al 2 o 3 =43.5,Na 2 O / SiO 2 = 0.048, TEA + / SiO 2 =0.636, NMP / SiO 2 = 2.0, H 2 O / SiO 2=16. Stir for 30 minutes to make it fully mixed and seal the synthesis kettle. Directly crystallize dynamically (30 rpm) at 140°C for 0-60h. The reaction was quenched with tap water and centrifuged to obtain a solid product. Then wash with deionized water until neutral. Dry overnight at 80°C to obtain molecular sieve powder.

[0037] figure 1 It is the change curve of the crystallinity of the crystallization product wi...

Embodiment 2

[0043] Under stirring condition, 19.5g water glass (26wt.%SiO 2 , 8.2 wt.% Na 2 O, 65.8 wt.% H 2 O), 5.6g aluminum sulfate (≥99wt.%), 1.9g potassium hydroxide (≥99wt.%), 25g tetraethylammonium chloride aqueous solution (TEACl, purity ≥35wt.%), 16.7g N-methyl -2 Pyrrolidone is added to the reaction kettle in a certain order. The molar composition of the raw material mixture is: SiO 2 / Al 2 o 3 =10,K 2 O / SiO 2 = 0.2, TEA + / SiO 2 =0.636, NMP / SiO 2 = 2.0, H 2 O / SiO 2 =16. Stir for 30 minutes to make it fully mixed and seal the synthesis kettle. Directly crystallize dynamically (100 rpm) at 95°C for 60h. The reaction was quenched with tap water and centrifuged to obtain a solid product. Then wash with deionized water until neutral. Dry overnight at 80°C to obtain molecular sieve powder. The XRD spectrum pattern of gained Beta product and figure 1 Similar, the particle size is about 346nm, N 2 The BET surface area of ​​the adsorption and desorption test is 721m ...

Embodiment 3

[0045] Under stirring conditions, mix 17.4g ethyl orthosilicate (≥99wt.%), 0.2g aluminum chloride (≥99wt.%), 2.7g sodium hydroxide, 3.5g tetraethylammonium hydroxide aqueous solution, 9.5g N-ethyl-2-pyrrolidone (NEP, ≥99wt.%) and 9 g of deionized water were added into the reaction kettle in a certain order. The molar composition of the raw material mixture is: SiO 2 / Al 2 o 3 =200,Na 2 O / SiO 2 = 0.4, TEA + / SiO 2 =0.1, NEP / SiO 2 = 1.0, H 2 O / SiO 2 =16. Stir for 30 minutes to make it fully mixed and seal the synthesis kettle. Directly crystallize dynamically (80 rpm) at 120°C for 18h. The reaction was quenched with tap water and centrifuged to obtain a solid product. Then wash with deionized water until neutral. Dry overnight at 80°C to obtain molecular sieve powder. The XRD spectrum pattern of gained Beta product and figure 1 Similar, the particle size is about 389nm, N 2 The BET surface area of ​​the adsorption and desorption test is 692m 2 / g, the total pore...

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Abstract

The invention provides a method for promoting Beta molecular sieve synthesis. According to the method, a silicon source, an aluminum source, inorganic alkali, a microporous template agent and crystalgrowth promoters R are sufficiently mixed; the obtained gel is subjected to short-time hydrothermal crystallization for fast preparing a Beta molecular sieve. The synthesized product is formed by stacking and connecting primary nanometer particles; the primary particle diameter is 10 to 30nm; the synthesis process is fast; the materials can be directly crystallized for 10 to 60 hours at the propertemperature; the crystal growth promoters are 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or N-isopropyl-2-pyrrolidone or a mixture of the 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone. The cheap crystal growth promoters are used for fast preparing the Beta molecular sieve by a one-step method; the conventional crystal seed method is replaced for fast obtaining the Beta molecular sieve; the method belongs to the economic and fast Beta molecular sieve obtaining method. In addition, the prepared Beta molecular sieve also has the excellent catalyst performance; high isobutene conversion rate and tert-butylamine selectivity are shown in the isobutene amination reaction.

Description

technical field [0001] The invention belongs to the technical field of catalytic chemistry, and in particular relates to a method for promoting the synthesis of Beta molecular sieves. Background technique [0002] Beta molecular sieve is a medium-pore zeolite with a unique cage-free three-dimensional twelve-membered ring macropore system, good catalytic stability, thermal stability and hydrothermal stability. Along the [100] and [010] orientation linear channel, the pore diameter is about 0.77×0.67nm; along the [001] direction is a curved channel through the straight channel, the pore diameter is about 0.56×0.56nm. Beta molecular sieve has a wide range of industrial application value, mainly used in the catalytic conversion process of hydrocarbons, such as: alkylation of benzene and olefins (production of ethylbenzene, cumene), transalkylation of heavy aromatics, hydrocarbon cracking, Hydroisomerization, etc. [0003] Although Beta molecular sieve has many potential cataly...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B39/48B01J29/70C07C209/60C07C211/07
CPCB01J29/7007C01B39/48C01P2002/72C01P2002/80C01P2004/03C01P2004/62C01P2006/12C01P2006/14C07C209/60C07C211/07
Inventor 徐龙伢赵东璞辛文杰刘盛林楚卫锋安杰朱向学谢素娟
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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