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X molecular sieve and preparation method thereof

A technology of molecular sieve and molar ratio, applied in octahedral crystalline aluminosilicate zeolite, crystalline aluminosilicate zeolite, etc., can solve the problems of high silica/alumina molar ratio and difficulty in synthesis

Active Publication Date: 2021-04-13
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The X molecular sieve synthesized by the above two methods has a high silica / alumina molar ratio, and it is difficult to synthesize an X molecular sieve with a lower silica / alumina molar ratio

Method used

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  • X molecular sieve and preparation method thereof
  • X molecular sieve and preparation method thereof
  • X molecular sieve and preparation method thereof

Examples

Experimental program
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Effect test

preparation example Construction

[0016] The preparation method of X molecular sieve of the present invention comprises the following steps:

[0017] (1) Mix silicon source, aluminum source, water and sodium hydroxide, and the molar ratio of each material is SiO 2 / Al 2 o 3 =10~25,Na 2 O / SiO 2 =0.6~1.8,H 2 O / SiO 2 =10~50, aged at 0~60°C for 1~72 hours, made into a directing agent,

[0018] (2) Sodium hydroxide, aluminum source, silicon source, the directing agent prepared in step (1), sodium polycarboxylate and water are mixed uniformly to form a molecular sieve synthesis system, wherein the molar ratio of each material is: SiO 2 / Al 2 o 3 =2.5~3.2,Na 2 O / SiO 2 =1.5~2.5,H 2 O / SiO 2 =50~100, sodium polycarboxylate / Al 2 o 3 =0.03~0.3, Al contained in the added directing agent 2 o 3 and Al contained in the molecular sieve synthesis system 2 o 3 The molar ratio is 0.01~1.0%,

[0019] (3) The molecular sieve synthesis system in step (2) is hydrothermally crystallized at 90-150° C. for 2-48 hours,...

example 1

[0039] (1) Preparation of aluminum source

[0040] Add 200kg of aluminum hydroxide, 232.15kg of sodium hydroxide and 652.33kg of deionized water into the reactor, heat to 100°C, and stir for 6 hours to form a clear and transparent low-alkalinity sodium metaaluminate solution as an aluminum source. Al in the aluminum source 2 o 3 The content is 11.87% by mass, Na 2 O content is 16.59% by mass, Na 2 O and Al 2 o 3 The molar ratio is 2.3.

[0041] (2) Preparation of directing agent

[0042] Under stirring condition, the aluminum source of 3.81kg sodium hydroxide, 8.86kg deionized water, 4.48kg (1) step preparation and the water glass of 23.24kg (SiO in water glass 2 The content is 20.17% by mass, Na 2 O content is 6.32 mass %, the same below) is added in the reactor, wherein the molar ratio of each material is SiO 2 / Al 2 o 3 =15,Na 2 O / SiO 2 =1.07,H 2 O / SiO 2 =21, and then stood still at 35° C. for 16 hours to obtain a directing agent.

[0043] (3 prepare X molec...

example 2

[0051] Prepare X molecular sieve by the method for example 1, difference is in (3) step, under stirring condition, with the water glass of 69.44kg deionized water, 3.74kg sodium hydroxide, 20.20kg aluminum source, 20.50kg, 0.27kg ( 2) The directing agent and 0.47kg sodium oxalate prepared in the first step are added in the reaction kettle to obtain the X molecular sieve synthesis system, wherein the molar ratio of each material is SiO 2 / Al 2 o 3 =2.95,Na 2 O / SiO 2 =1.76,H 2 O / SiO 2 =80, sodium oxalate / Al 2 o 3 =0.15, Al contained in the directing agent 2 o 3 Al contained in the synthesis system with X molecular sieve 2 o 3 The molar ratio is 0.15%. Transfer the molecular sieve synthesis system to a closed reaction kettle, undergo hydrothermal crystallization, filter, wash with deionized water, and dry to obtain X molecular sieve a 2, the grain size is 0.8 microns, using 29 The content of various structural tetrahedrons in the framework structure obtained by Si so...

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Abstract

The invention relates to an X molecular sieve. The SiO2 / Al2O3 molar ratio of the X molecular sieve is 2.1-2.6, and in the skeleton structure, the content of tetrahedrons with a Si(OSI)(OAl)3 structure is 30-60 mol%, and there is no tetrahedron with a Si(OSI)4 structure. The X molecular sieve is used for adsorbing and separating a para-disubstituted benzene isomer from a disubstituted benzene compound, and has relatively high adsorption selectivity and adsorption capacity.

Description

technical field [0001] The invention relates to a silicon-aluminum molecular sieve and a preparation method thereof, in particular to an X molecular sieve and a preparation method thereof. Background technique [0002] Molecular sieves are a class of crystalline materials with a special skeleton structure. Due to their uniform micropore channels, adjustable acidity and good ion exchange performance, they are widely used in the fields of separation and catalysis. At present, X molecular sieves are mostly used in the industry as the active component of mixed C8 aromatics adsorption and separation adsorbents. The properties of X molecular sieves, the chemical composition of the skeleton structure, the grain size, and the internal pore structure will significantly affect the adsorption capacity of the adsorbent. Adsorption selectivity and mass transfer performance. [0003] CN1191199C discloses a method for preparing a small-grain X molecular sieve. The method uses a directing ...

Claims

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Application Information

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IPC IPC(8): C01B39/22
CPCC01B39/22C01P2004/62C01P2004/61C01P2002/72C01P2002/86
Inventor 高宁宁王辉国刘宇斯杨彦强
Owner CHINA PETROLEUM & CHEM CORP