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Core-shell structural dibasic composite zeolite and preparation method thereof

A binary composite, core-shell structure technology, applied in the directions of crystalline aluminosilicate zeolite, mercerized crystalline aluminosilicate zeolite, chemical instruments and methods, etc. The effect of the discharge of waste

Inactive Publication Date: 2010-06-16
TAIYUAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In order to utilize the respective advantages and disadvantages of mordenite and Beta zeolite, and utilize the interaction between the two to obtain high-performance catalytic materials, Liu Xiyao et al. (CN1397493) synthesized Beta zeolite with a twelve-membered ring structure in one step. -Mordenite, Beta zeolite-ZSM-12 and Mordenite-ZSM-12; this two-phase symbiotic molecular sieve is a two-phase mixed crystal state, and the ratio of the two phases is difficult to control

Method used

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  • Core-shell structural dibasic composite zeolite and preparation method thereof
  • Core-shell structural dibasic composite zeolite and preparation method thereof

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Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0020] Step 1: Mix 17.4g of tetraethylammonium bromide, 6ml of concentrated ammonia water, 2.26g of sodium metaaluminate, 0.5g of NaOH, 31ml of silica sol, and 34ml of distilled water into a uniform white jelly, and put it into a 100ml stainless steel reaction kettle , crystallized at 140°C for 10 days and taken out for use. The original material molar ratio of Beta zeolite is: 2.2Na 2 O: 20SiO 2 : Al 2 o 3 : 4.6 (TEA) 2 O: 4.6 (NH 4 ) 2 O: 440H 2 O.

[0021] The second step: add 0.6g sodium metaaluminate and 0.5g sodium hydroxide to the Beta solid-liquid mixture synthesized above, and the total molar ratio of materials is: 2.49Na 2 O:Al 2 o 3 : 15.64SiO2 2 : 3.60 (TEA) 2 O: 3.74 (NH 4 ) 2 O: 348H 2 O. Then mix and stir evenly, put it into a 100ml stainless steel reaction kettle, crystallize at 165°C for 72 hours, take it out, wash until the solution is neutral, and then dry it. Through X-ray diffraction analysis, the crystal phase is mercerized and Beta binary...

Embodiment approach 2

[0023] Step 1: Mix 17.4g of tetraethylammonium bromide, 6ml of concentrated ammonia water, 2.26g of sodium metaaluminate, 0.5g of NaOH, 31ml of silica sol, and 34ml of distilled water into a uniform white jelly, and put it into a 100ml stainless steel reaction kettle , crystallized at 140°C for 11 days and taken out for use. The molar ratio of the original material of Beta zeolite is: 2.2Na 2 O: 20SiO 2 : Al 2 o 3 : 4.6 (TEA) 2 O: 4.6 (NH 4 ) 2 O: 440H 2 O.

[0024] The second step: add 0.6g sodium metaaluminate and 1.0g sodium hydroxide to the Beta solid-liquid mixture synthesized above, and the total molar ratio of materials is: 2.74Na 2 O:Al 2 o 3 : 8.55SiO2 2 : 2.04 (TEA) 2 O: 2.04 (NH 4 ) 2 O: 253H 2 O. Mix and stir to form a uniform white substance, put it into a 100ml stainless steel reaction kettle, crystallize at 170°C for 54 hours, take it out, wash until the solution is neutral, and then dry it. The crystal phase is mercerite and Beta binary composite...

Embodiment approach 3

[0026] Step 1: Mix 17.4g of tetraethylammonium bromide, 6ml of concentrated ammonia water, 2.26g of sodium metaaluminate, 0.5g of NaOH, 31ml of silica sol, and 34ml of distilled water into a uniform white jelly, and put it into a 100ml stainless steel reaction kettle crystallized at 140°C for 13 days and taken out for use. The molar ratio of the original material of Beta zeolite is: 2.2Na 2 O: 20SiO 2 : Al 2 o 3 : 4.6 (TEA) 2 O: 4.6 (NH 4 )2 O: 440H 2 O.

[0027] The second step: add 1.0g pseudo-boehmite and 1.2g sodium hydroxide in the Beta solid-liquid mixture synthesized above, and the total molar ratio of materials is: 2.97Na 2 O:Al 2 o 3 : 13.3SiO2 2 : 3.06 (TEA) 2 O: 3.18 (NH 4 ) 2 O: 296H 2 O. Mix and stir to form a uniform white substance, put it into a 100ml stainless steel reaction kettle, crystallize at 175°C for 18 hours, take it out, wash until the solution is neutral, and then dry it. The crystal phase is mercerite and Beta binary composite zeolite ...

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Abstract

The invention relates to a binary composite zeolite with core-shell structure and the preparation method of the zeolite, in particular to a binary composite zeolite with Beta core and mordenite zeolite shell structure and the preparation method, belonging to the field of inorganic synthesis and catalyst preparation. The prepared composite material contains two phases of Beta core and mordenite zeolite shell structure simultaneously, and the proportion of the two phases and the surface L / B acid are adjustable. The preparation method is two-step crystallization method, that is, synthesizing thebeta zeolite firstly, then replenishing aluminum, organic templates of tetraethylammonium bromide and alkali; the beta zeolite is used as the silica source for the mordenite zeolite synthesis, and thebinary composite zeolite material with two micropore core-shell structure is prepared and then is converted into hydrogen form after amine-exchange, and then is used as catalyst for preparing dimethyl etherfor by means of methanol conversion, the transformation rate of the methanol is kept above 80% and the selectivity of the dimethyl ether is above 99% after reacting for 72h, under the conditionthat the weight airspeed is 2.26 (g / g) h<-1>, the partial pressure of the methanol is 11.4Kpa and the reaction temperature is 300 DEG C.

Description

1. Technical field [0001] The invention relates to a binary composite zeolite with a core-shell structure and a preparation method thereof, belonging to the field of inorganic synthesis and catalyst preparation. Specifically, it relates to a binary composite zeolite with a Beta core and a mordenite shell structure and a preparation method thereof. 2. Background technology [0002] As we all know, mordenite has a large twelve-membered ring straight-through pore system, because it can provide sufficient and strong acid sites in the catalytic reaction, as well as good heat and acid resistance, in hydrocarbons Cracking, hydrocracking, dewaxing of heavy oil, etc. have been well applied, and the synthesis cost is low. However, due to the defects in the structure and pore size, carbon deposits in the one-dimensional straight-through channels of mordenite are easy to cause the catalyst to lose activity rapidly, which makes it difficult to be used in reactions with harsh conditions,...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B39/00C01B39/26B01J29/04
Inventor 李瑞丰郑家军张喜文马静红孙万付凌凤香
Owner TAIYUAN UNIV OF TECH