Molecular sieve with rich aluminum on surface, preparation method and applications thereof, and isomerization reaction catalyst and applications thereof

A molecular sieve and isomerization technology, applied in the field of molecular sieve, can solve the problem that high activity and high isomeric selectivity cannot be obtained at the same time, and achieve the effects of high isomeric selectivity, good application prospect and high catalytic activity.

Active Publication Date: 2020-03-03
CHNA ENERGY INVESTMENT CORP LTD +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] The purpose of the present invention is to provide a surface aluminum-rich molecular sieve and its preparation method and application and isomerization in order to overcome the problem that high activity and high isomerization selectivity cannot be obtained at the same time when molecular sieves in the prior art are used for isomerization conversion of long-chain alkanes Reaction catalyst and its application

Method used

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  • Molecular sieve with rich aluminum on surface, preparation method and applications thereof, and isomerization reaction catalyst and applications thereof
  • Molecular sieve with rich aluminum on surface, preparation method and applications thereof, and isomerization reaction catalyst and applications thereof
  • Molecular sieve with rich aluminum on surface, preparation method and applications thereof, and isomerization reaction catalyst and applications thereof

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preparation example Construction

[0022] The present invention provides a first aspect of the present invention provides a method for preparing a surface aluminum-rich molecular sieve, the method comprising:

[0023] (1) Precursor gels A and B are prepared, the silicon-aluminum ratio of the precursor gel A is 40-100, the silicon-aluminum ratio of the precursor gel B is 100-400, and the silicon-aluminum ratio of the two is different;

[0024] (2) Carrying out the first step of crystallization of the precursor gels A and B respectively;

[0025] (3) The crystallization products of the first step prepared by the precursor gels A and B were mixed at a mass ratio of 1: (3-50) for the second step of crystallization, and finally the surface aluminum-rich molecular sieve was obtained.

[0026] Herein, the silicon-aluminum ratio refers to the molar ratio of silicon oxide to aluminum oxide.

[0027] In the present invention, the silicon-aluminum ratio of the precursor gel A can be 40, 45, 50, 55, 60, 65, 70, 75, 80, 85...

Embodiment approach

[0043] According to one embodiment, the ZSM-48 molecular sieve prepared by the method has a silicon-aluminum ratio of 150-300 as a whole of the molecular sieve, and a silicon-aluminum ratio of 40-150 within a thickness of 50 nm of the particle surface of the molecular sieve, preferably For 40-90. Here, the "within a thickness of 50 nm from the particle surface" should be understood as a thickness range of 50 nm from the particle surface.

[0044] According to one embodiment, the specific surface area of ​​the molecular sieve prepared by the method is not less than 200m 2 / g, preferably 200-1000m 2 / g; the pore diameter is 0.53-0.56nm; the pore volume is not less than 0.1cm 3 / g, preferably 0.1-1cm 3 / g.

[0045] In the present invention, the molecular sieve prepared by the method has relatively high crystallinity, and the crystallinity is above 98%.

[0046] The third aspect of the present invention provides the application of the molecular sieve described in the second a...

Embodiment 1

[0053] (1) The hexamethylammonium bromide of 7.78g, the sodium metaaluminate of 3.28g, the sodium hydroxide of 6g are dissolved in the water of 540g to form a solution; The silica sol (concentration is 30wt%) of 200g, slowly under stirring Add slowly to the solution of the above system, and stir evenly to prepare molecular sieve precursor gel A, wherein SiO 2 :Al 2 o 3 :H 2 O:OH - : The molar ratio of hexamethylammonium bromide is 1:0.02:30:0.15:0.0215;

[0054] (2) The hexamethylammonium bromide of 6.34g, the sodium metaaluminate of 0.82g, the sodium hydroxide of 5.2g are dissolved in the water of 270g to form a solution; The silica sol (concentration is 30wt%) of 200g, under stirring Slowly add to the solution of the above system, and stir evenly to prepare molecular sieve precursor gel B, wherein SiO 2 :Al 2 o 3 :H 2 O:OH - : The molar ratio of hexamethylammonium bromide is 1:0.005:15:0.13:0.0175;

[0055] (3) Put the molecular sieve precursor gels A and B into di...

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Abstract

The invention relates to the field of molecular sieves, and discloses a preparation method of a molecular sieve with rich aluminum on the surface. The method comprises the following steps: preparing two molecular sieve precursor gels with different silicon-aluminum ratios, respectively carrying out first-step crystallization on the two molecular sieve precursor gels by controlling crystallizationconditions, mixing the first-step crystallization products according to a preset ratio, and carrying out second-step crystallization to finally obtain the molecular sieve with rich aluminum on the surface. According to the invention, the obtained molecular sieve is high in crystallinity, the effective acid centers are intensively distributed on the outer surface, and the molecular sieve shows highcatalytic activity and high catalytic selectivity in a long-chain alkane isomerization catalytic reaction.

Description

technical field [0001] The invention relates to the field of molecular sieves, in particular to a surface aluminum-rich molecular sieve and its preparation method and application, an isomerization reaction catalyst and its application. Background technique [0002] Molecular sieves are often used as catalysts or catalyst supports due to their pore structure. Among them, ZSM-5, ZSM-12, ZSM-22, ZSM-23, ZSM-48 and SSZ-32 molecular sieves are widely used. ZSM-48 is a kind of high-silica zeolite, which belongs to the orthorhombic crystal structure. It has 10-membered pore openings without interlaced linear channels. The channels are connected by 5-membered rings, and the pore size is 0.53nm×0.56nm. Generally, pure silicon ZSM-48 molecular sieves have good low-carbon olefin selectivity in the reaction of syngas to olefins, while the low silicon-aluminum ratio (SiO 2 / Al 2 o 3 )'s ZSM-48 molecular sieve has good catalytic performance for heterogeneous cracking. [0003] "Synth...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J29/70B01J35/10C07C5/27C07C9/16
CPCB01J29/703B01J37/0018B01J35/1019B01J35/1023B01J35/1057C07C5/2775C07C5/2737B01J2229/18C07C9/16
Inventor 李景赵效洪朱加清艾军李浩
Owner CHNA ENERGY INVESTMENT CORP LTD
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