Method for synthesizing fine grain MCM-22 molecular sieve

A technology of MCM-22 and synthesis method, applied in the direction of crystalline aluminosilicate zeolite, etc., to achieve the effects of good reproducibility, improved crystallinity, and reduced synthesis cost

Inactive Publication Date: 2005-11-23
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

MCM-22 molecular sieve is a layered crystal. It is relatively easy to realize the grain thickness (C-axis direction) into nanoscale (<100nm), but it is still difficult to reduce the three-dimensional to the nanoscale (<100nm) scale. It is expected, but it is possible to make its X and Y directions sub-nanometer (<1μm) in the case of making the grain thickness reach the nanometer scale

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0009] Preparation of templating agent

[0010] In a serial, multi-stage, cold-shock fixed-bed reactor, a total of 280ml of hydrogenation catalyst JH-01 (produced by Dalian Chemical Industry Institute) was charged in four stages, and 70ml was installed in each of the first to fourth stages. The hydrogen was divided into four parts from the top of each stage. To enter, caprolactam is added from the top of the first section. Control the reaction temperature of each section to be 265°C, the reaction pressure to be 1.0MPa, the molar ratio of total hydrogen to caprolactam to be 90, and the liquid space velocity of total caprolactam to be 0.1h -1 . Obtain the conversion rate of caprolactam 98%, contain 82.5% (weight percent, hereinafter the same) hexamethyleneimine, 2.0% (w) caprolactam, 0.5% (w) by-product and 15.0% (w) water in the liquid product, The liquid mixture was named L.

[0011] Synthesis of MCM-22 Molecular Sieve

[0012] (1) Raw materials:

[0013] A. Sodium alumin...

Embodiment 3

[0022] In embodiment 2, add 1.7g sodium dodecylbenzene sulfonate (abbreviation DBSAS, hereinafter the same), make DBSAS / SiO 2 = 1.0, the composition of the rest of the synthetic raw materials remains unchanged, the crystallization temperature and time are 160° C. and 48 h, respectively, and the product is MCM-22 molecular sieve. The SiO was measured by XRF 2 / Al 2 o 3 It is 27.9, and its diameter is 150-300nm and thickness is 20-40nm as measured by TEM.

Embodiment 4

[0024] In embodiment 2, the add-on of sodium hydroxide solution is changed into 5.4g, the add-on of silica sol is changed into 22.6g, the add-on of deionized water is changed into 95.9g, the add-on of liquid mixture L is changed into 7.3g , and add 0.2g sodium dodecylbenzenesulfonate, all the other components remain unchanged, the molar composition of the reaction mixture is: SiO 2 / Al 2 o 3 = 20; OH - / SiO 2 =0.36;H 2 O / SiO 2 =67; R / SiO 2 = 0.63; DBSAS / SiO 2 = 0.12. The crystallization temperature and time were 154°C and 92h, respectively, and the product was MCM-22 molecular sieve. The SiO was measured by XRF 2 / Al 2 o 3 It is 16.9, and its diameter is 200-450nm and thickness is 20-40nm as measured by TEM.

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Abstract

Disclosed is a method for synthesizing fine grain MCM22 molecular sieve, wherein the templating agent employs the product yield of hexanolactam hydrogenation, and mainly comprises hexamethyleneimine, water, a small amount of byproduct and hexanolactam (reacted unconcompletely), the method comprises using silicon source, aluminium source, alkali source, templating agent and deionized water as reaction raw material, crystallizing for a finite period of time at 135-185 deg. C, untill completion of the reaction, obtaiting the needed molecular screen through hydrothermal synthesis, the invention is characterized in that organic additives can be charged into the reaction raw material, the organic additive can be sodium dodecylbenzene sulfonate, polyethylene glycol type surface active agent, or their mixture, the molecule ratio of the charged additive and the silicon dioxide in the reaction raw material is 0.01-2.5.

Description

technical field [0001] The invention relates to a preparation method of small-grain MCM-22 molecular sieves. Specifically, it is a method for synthesizing small-grain MCM-22 molecular sieves by using caprolactam catalytic hydrogenation products as templates and adding additives. Background technique [0002] MCM-22 molecular sieve is a molecular sieve containing two non-intersecting pore systems first reported by Mobil Corporation in the early 1990s (USP 4954 325). It has the dual structural characteristics of twelve-membered rings and ten-membered rings. Based on unique structural features, MCM-22 molecular sieves exhibit excellent reactivity in various catalytic reactions (such as alkylation, aromatization, isomerization, gasoline upgrading and catalytic cracking, etc.). Usually, the synthesized MCM-22 molecular sieves are micron-sized (particle diameter > 1 μm), and all use pure hexamethyleneimine as a structure-directing agent. Compared with conventional scale molec...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B39/04
Inventor 谢素娟牛雄雷徐龙伢
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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