A method for synthesizing zeolite molecular sieves with chabazite structure

A technology of zeolite molecular sieve and chabazite, which is applied in the direction of crystalline aluminosilicate zeolite, etc., can solve problems such as difficult scale-up production, and achieve the effects of simple implementation conditions, convenient operation, and wide adjustable range

Active Publication Date: 2018-05-08
北方稀土华凯高科技河北有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The above-mentioned synthetic methods of various aluminosilicate zeolites with chabazite structure have their own difficulties and limitations in the process of industrial production
K-G, D and R molecular sieves are carried out in a highly alkaline hydrogel system, and their crystallization process is controlled by kinetics, which is very sensitive to parameters such as chemical composition, volume, stirring rate of raw materials and related factors such as mass transfer and heat transfer. Difficult to scale up production

Method used

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  • A method for synthesizing zeolite molecular sieves with chabazite structure
  • A method for synthesizing zeolite molecular sieves with chabazite structure
  • A method for synthesizing zeolite molecular sieves with chabazite structure

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Embodiment 1

[0027] 4.0 grams of sodium hydroxide, 6.6 grams of potassium hydroxide (85%) and 75 grams of deionized water were prepared into a solution, 0.75 grams of 25% tetraethylammonium hydroxide solution was added, and 1.35 grams of aluminum powder was put in for dissolution. After the temperature of the solution dropped to room temperature, 12.0 g of white carbon black was added and stirred for half an hour until the hydrogel was evenly mixed. The molar ratio of the material for synthesizing the hydrogel is 0.05TEAOH (tetraethylammonium hydroxide): 2.0Na 2 O: 2.0K 2 O: Al 2 o 3 : 8SiO 2 : 150H 2 O. The mixture was left to stand at room temperature for half an hour, then transferred to a Teflon-lined stainless steel sealed kettle, heated to 85°C, and left to stand for three days. Then cool to room temperature, open the sealed kettle, pour off the supernatant, recover the white solid, and wash it three times with clear water. The resulting white powder was dried at 80°C.

[002...

Embodiment 2

[0031] Dissolve 4.0 g of sodium hydroxide and 19.7 g of 85% potassium hydroxide in 45.0 g of deionized water, add 2.5 g of ethylenediamine, and add 6.66 g of aluminum sulfate octadecahydrate to dissolve. Then, 60.0 g of 40% silica sol was slowly added while stirring, and the hydrogel was mixed evenly and stirred evenly, and then left to stand at room temperature for 12 hours. The molar ratio of the material for synthesizing the hydrogel is 8.0EDA (ethylenediamine): 10.0Na 2 O: 30.0K 2 O: Al 2 o 3: 80SiO 2 : 800H 2 O. The aged mixture was sealed in a Teflon-lined stainless steel autoclave, heated to 150 °C and allowed to stand for 5 days. Cool to room temperature, open the sealed kettle, pour off the supernatant, recover the white solid, and wash with water three times. The resulting white powder was dried at 80°C.

[0032] attached Figure 1-2 It is the powder X-ray diffraction pattern of the product obtained in this embodiment, and it can be known that the product is...

Embodiment 3

[0034] Dissolve 2.65 grams of potassium hydroxide in 12.0 grams of deionized water, add 1.0 grams of 25% tetrapropylammonium hydroxide solution, and add 0.82 grams of sodium metaaluminate to dissolve. Slowly add 7.5 grams of 40% silica sol under stirring, stir well to obtain a hydrogel, and the molar ratio of the material for synthesizing the hydrogel is 0.25TPAOH (tetrapropylammonium hydroxide): 1.0Na 2 O: 4.0K 2 O: Al 2 o 3 : 10SiO 2 : 190H 2 O. Without aging, directly transfer to a stainless steel kettle lined with Teflon, heat to 120 degrees Celsius, and turn the stainless steel kettle at a speed of 1 revolution per minute. Keep it for 12 hours, then cool to room temperature, open the sealed kettle, pour off the supernatant, recover the white solid, and wash it three times with water. The resulting white powder was dried at 80°C.

[0035] attached Figure 1-3 It is the powder X-ray diffraction pattern of the product obtained in this embodiment, and it can be known ...

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Abstract

The invention provides a method for synthesizing a zeolite molecular sieve with a chabasite structure. The preparation method includes the step of adding organic weak base to obtain the aluminosilicate zeolite molecular sieve with the chabasite structure without adding organic template agents or chabasite seed crystals in chabasite synthesizing reaction under hydrothermal conditions. The molar ratio of framework silicon-aluminum atoms ranges from 4 to 40, and reaction raw materials are prepared according to the molar ratio of Na2O:K2O:the organic weak base Al2O3:SiO2:H2O=(1-20):(2-30):(0.05-8.0):1:(8-80):(150-800). According to the method, the zeolite molecular sieve with the chabasite structure can be stably synthesized without the template agents, fluorinated compounds and the seed crystals.

Description

technical field [0001] The invention belongs to the field of preparation of zeolite molecular sieves, in particular to a method for synthesizing zeolite molecular sieves with a chabazite structure. Background technique [0002] The chabazite structure refers to the skeleton topological structure of a specific microporous zeolite molecular sieve, which is characterized by [8 6 6 2 4 12 ] Large cages, each cage is connected by an 8-membered ring window. Natural chabazite has a chabazite structure and its general chemical composition is Ca 6 Al 12 Si 24 o 72 , is an aluminosilicate zeolite molecular sieve with a molar ratio of silicon to aluminum atoms of 2. In addition, several artificially synthesized aluminosilicate zeolite molecular sieves also have a chabazite structure, including the K-G molecular sieve published by R.Barrer in J.Chem.Soc., 1956, 2892, with a silicon-aluminum ratio of 2.3 to 4.15; British patent 868846 (1961) published the D-type molecular sieve w...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B39/02
CPCC01B39/02C01P2002/72C01P2002/88
Inventor 杨晓波赵向云肖剑鸣
Owner 北方稀土华凯高科技河北有限公司
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