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ZSM-5 molecular sieve modified catalyst and its preparation method and application

A ZSM-5, molecular sieve technology, used in molecular sieve catalysts, chemical instruments and methods, physical/chemical process catalysts, etc., can solve the problem of difficulty in obtaining high-selectivity catalysts, high concentration of dilute ethanol solutions, and uneven molecular sieve crystal forms. The problem is that the catalytic activity does not decrease, the ethylene selectivity and yield are high, and the activity is stable.

Inactive Publication Date: 2007-08-01
JIANGSU POLYTECHNIC UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Chinese patent ZL1340485 is the method for synthesizing ZSM-5 molecular sieve under the condition that replaces organic template with inorganic ammonium, promptly in Na 2 O-Al 2 o 3 -SiO 2 -NH 3 ·H 2 O-H 2 Synthesize ZSM-5 in the O system, but the synthesized molecular sieve particles are small and have the disadvantage of uneven molecular sieve crystal form, so it is difficult to obtain a highly selective catalyst
[0007] The ZSM-5 molecular sieve used in the prior art has a silicon-aluminum ratio difference of less than 10% between the body and the surface, and the low-concentration ethanol dehydration catalyst prepared after ammonium salt ion exchange has high temperature and poor selectivity in the catalytic reaction process. High concentration of dilute ethanol solution and many by-products

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  • ZSM-5 molecular sieve modified catalyst and its preparation method and application
  • ZSM-5 molecular sieve modified catalyst and its preparation method and application

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Experimental program
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Effect test

Embodiment 1

[0031] 750 grams of water glass, 71.6 grams of aluminum sulfate octadecahydrate are substrates (wherein SiO 2 / Al 2 o 3 =30,H 2 O / SiO 2 =34,Na 2 O / Al 2 o 3 =9), 32.9 grams of 98% concentrated sulfuric acid, add 1390 grams of water, stir in the stainless steel autoclave of 5 liters of volume after being stirred for 10 minutes, add 62.5 grams of ethylamine (65% weight concentration) again, rear sealing, 170 It was crystallized at ℃ for 60 hours, and then the crystallized product was filtered out, washed with water several times and then dried. It was identified as ZSM-5 molecular sieve by phase identification.

[0032] d(A) 11.4 10.3 3.9 3.8 3.7

[0033] I / I 0 strong strong strong strong strong

[0034] The silicon-aluminum ratio of the obtained molecular sieve is 29.6 in bulk and 17.0 in the surface, with a difference of 42.6%; the crystal size is 1-3 microns. The synthesized sodium form ZSM-5 was exchanged into ammonium form by conventional methods.

[0035] Ge...

Embodiment 2

[0037] 750 grams of water glass, 57.5 grams of aluminum sulfate octadecahydrate are matrix (wherein SiO 2 / Al 2 o 3 =50,H 2 O / SiO 2 =33, Na 2 O / Al 2 o 3 =12), 31 grams of 98% concentrated sulfuric acid, add 1375 grams of water and mix uniformly, then 7.5 grams of ZSM-5 crystal powder synthesized by the method of the present invention is added to the above-mentioned system, and after stirring for 10 minutes, transfer to a 5 liter volume container In the stainless steel autoclave, add 37.5 grams of ethylamine (65% by weight), then seal the can, crystallize at 170°C for 80 hours, then filter out the crystallized product, wash it with water for several times, and dry it. ZSM-5 molecular sieve. The synthesized sodium-form ZSM-5 was exchanged into ammonium form by conventional methods, and the silicon-aluminum ratio of bulk was 36.5, and the surface silicon-aluminum ratio was 24.7, with a difference of 32.3%; the crystal size was 2-5 microns.

[0038] Get 80 grams of ammoniu...

Embodiment 3

[0040] 750 grams of water glass and 98.3 grams of aluminum sulfate octadecahydrate are substrates (wherein SiO 2 / Al 2 o 3 =100,H 2 O / SiO 2 =34,Na 2 O / Al 2 o 3 =15), 34.9 grams of 98% concentrated sulfuric acid, add 1402 grams of water and mix uniformly, then 8.0 grams of ZSM-5 crystal powder synthesized by the method of the present invention is added to the above-mentioned system, and after stirring for 10 minutes, transfer to 5 liters of volume In the stainless steel autoclave, add 72.5 grams of ethylamine (65% weight concentration), then seal the can, crystallize at 170°C for 60 hours, then filter out the crystallized product, wash it with water for several times, and then dry it. It is a ZSM-5 molecular sieve, and the silicon-aluminum ratio of the obtained molecular sieve is 58.6 in bulk and 38.1 in the surface, with a difference of 35%; the crystal size is 3-6 microns. The synthesized sodium form ZSM-5 was exchanged into ammonium form by conventional methods.

[0...

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Abstract

The invention involves preparation of ZSM-5 molecular sieve modified catalysts and the technology of using said catalysts in low concentration ethanol dehydration reaction, specifically a method uses ZSM-5 molecular sieve as carrier and prepares load modified catalysts through group grafting and surface modification, and a preparation method is used for preparing ethane through low concentration alcohol dehydration on fixed bed reactor. The low concentration alcohol dehydration catalyst prepared by load modified ZSM-5 molecular sieve in the invention has characteristics of high catalytic activity, high selectivity and it is easy to regenerate. When it is operated for low concentration alcohol dehydration art through fixed-bed reactor device long time and continuously, it displays advantages of low reaction temperature, low energy consumption, high conversion rate of ethanol, high ethylene selectivity and yield, stable catalyst activity, convenient regeneration and smooth operation.

Description

technical field [0001] The invention relates to a ZSM-5 molecular sieve modified catalyst, its preparation method and its use in low-concentration ethanol dehydration reaction. Specifically, it uses ZSM-5 molecular sieve as a carrier, and is a loaded modified catalyst made by group grafting and surface modification. , used in fixed-bed reactors for the dehydration of low-concentration ethanol to produce ethylene. Background technique [0002] Ethanol dehydration reaction is one of the common reactions. It can convert ethanol into ethylene which is more widely used. Usually, industrial ethanol is used as raw material, and ethylene is dehydrated at 350-400°C under the action of a catalyst. However, using industrial ethanol as a raw material not only has high reaction temperature and high energy consumption, but also is uneconomical. Therefore, someone proposed a new process of dehydration preparation using low-concentration ethanol as a raw material, so that the fermented etha...

Claims

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Application Information

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IPC IPC(8): B01J29/40C07C1/24C07C11/04
CPCY02P20/52Y02P20/584
Inventor 张跃严生虎刘建武沈介发马锦国
Owner JIANGSU POLYTECHNIC UNIVERSITY
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