NaY-type molecular sieves and preparation method thereof

Abstract

The invention discloses microcrystal NaY-type molecular sieves and a preparation method thereof. In the microcrystal NaY-type molecular sieves, the molar ratio of SiO2 to Al2O3 is 4.0 to 6.0, and the average particle size is 100 to 700 nanometers. The microcrystal NaY-type molecular sieves are prepared by a method combining low-temperature synthesis directing agent, low-temperature synthesis gel and two-stage variable-temperature dynamic crystallization. The NaY-type molecular sieves have a relative crystallinity of over 80 percent after being roasted in the air at 600 DEG C for 3 hours or after undergoing hydrothermal treatment with vapor at 650 DEG C for 1 hour, as well as high thermostability and hydrothermal stability.

Description

technical field

[0001] The invention relates to a Y-type molecular sieve and a preparation method thereof, in particular to a preparation method of a small-grain NaY-type molecular sieve. Background technique

[0002] At present, molecular sieves that can be used as cracking active components in the field of heavy oil cracking include Y-type, β-type and ZSM, among which Y-type molecular sieves are most commonly used. At present, the methods for industrially producing Y-type molecular sieves basically adopt the directing agent method proposed by GRACE Company of the United States in USP 3639099 and USP 4166099. The crystal grains of the obtained common Y-type molecular sieves are generally about 1000nm, and the crystal grains are relatively large. The pores are relatively long, and the diffusion resistance is high. It is difficult for macromolecules to enter the pores for reaction, and it is also difficult for the products after the reaction to diffuse out. Therefore, the cra...

Examples

preparation example Construction

[0030] In the preparation method of small grain NaY type molecular sieve of the present invention, in the high alkali sodium metaaluminate solution described in step (1), Na 2 O content is 260~320g / L, Al 2 o 3 The content is 30-50g / L, the solution is clear, does not contain floc or sediment, and can be prepared by conventional methods. Na in the low-alkali sodium metaaluminate solution described in step (2) 2 O content is 100~130g / L, Al 2 o 3 The content is 60-90g / L, the solution is clear, does not contain floc or sediment, and can be prepared by conventional methods. Al in the aluminum sulfate solution described in step (2) 2 o 3 The content is 80~100g / L. SiO in the water glass described in step (2) 2 The content is 200~300g / L, and the modulus is 2.8~3.5.

[0031] The preparation method of small grain NaY type molecular sieve of the present invention specifically comprises the following steps:

[0032] (1) Prepare the directing agent at low temperature.

[0033] Ac...

Embodiment 1

[0044] (1) Preparation of directing agent: Slowly add 1200ml of water glass into 800ml of peralkaline sodium metaaluminate under stirring condition at 10°C, and stir at constant temperature for 40 minutes after adding the water glass. Stirring was stopped, and the mixed solution was sealed in a container, and aged at a temperature of 5°C for 12 hours at a constant temperature. After the constant temperature is finished, add 667ml of clean water to the mixed solution as a guiding agent.

[0045] (2) Preparation of the gel: Add 59.4ml of aluminum sulfate, 62.7ml of low sodium metaaluminate and 42.2ml of directing agent to 208ml of water glass under stirring conditions at a temperature of 5°C, then stir at a constant temperature and speed for 1.5 Hours, then the resulting synthetic solution was statically aged at the above temperature for 8 hours to obtain a gel.

[0046] (3) Crystallization: Under stirring conditions, raise the gel in the synthesis kettle to 70°C within 20 minu...

Embodiment 2

[0048] (1) Preparation of the directing agent: slowly add 1200ml of water glass to 800ml of peralkaline sodium metaaluminate under stirring conditions at 8°C, and stir at constant temperature and speed for 40 minutes after adding the water glass. Stirring was stopped, and the mixed solution was sealed in a container, and aged at a constant temperature for 12 hours at a temperature of 8°C. After the constant temperature is finished, add 667ml of clean water to the mixed solution as a guiding agent.

[0049] (2) Preparation of gel: Add 59.4ml of aluminum sulfate, 62.7ml of low sodium metaaluminate and 56.3ml of directing agent to 208ml of water glass under stirring conditions at a temperature of 2°C, and then stir at a constant temperature and speed After 1.5 hours, the obtained synthetic solution was statically aged at the above temperature for 8 hours to obtain a gel.

[0050] (3) Crystallization: Under stirring conditions, within 20 minutes, the temperature of the gel in the...

technical field

[0001] The invention relates to a Y-type molecular sieve and a preparation method thereof, in particular to a preparation method of a small-grain NaY-type molecular sieve. Background technique

[0002] At present, molecular sieves that can be used as cracking active components in the field of heavy oil cracking include Y-type, β-type and ZSM, among which Y-type molecular sieves are most commonly used. At present, the methods for industrially producing Y-type molecular sieves basically adopt the directing agent method proposed by GRACE Company of the United States in USP 3639099 and USP 4166099. The crystal grains of the obtained common Y-type molecular sieves are generally about 1000nm, and the crystal grains are relatively large. The pores are relatively long, and the diffusion resistance is high. It is difficult for macromolecules to enter the pores for reaction, and it is also difficult for the products after the reaction to diffuse out. Therefore, the cra...

Examples

preparation example Construction

[0030] In the preparation method of small grain NaY type molecular sieve of the present invention, in the high alkali sodium metaaluminate solution described in step (1), Na 2 O content is 260~320g / L, Al 2 o 3 The content is 30-50g / L, the solution is clear, does not contain floc or sediment, and can be prepared by conventional methods. Na in the low-alkali sodium metaaluminate solution described in step (2) 2 O content is 100~130g / L, Al 2 o 3 The content is 60-90g / L, the solution is clear, does not contain floc or sediment, and can be prepared by conventional methods. Al in the aluminum sulfate solution described in step (2) 2 o 3 The content is 80~100g / L. SiO in the water glass described in step (2) 2 The content is 200~300g / L, and the modulus is 2.8~3.5.

[0031] The preparation method of small grain NaY type molecular sieve of the present invention specifically comprises the following steps:

[0032] (1) Prepare the directing agent at low temperature.

[0033] Ac...

Embodiment 1

[0044] (1) Preparation of directing agent: Slowly add 1200ml of water glass into 800ml of peralkaline sodium metaaluminate under stirring condition at 10°C, and stir at constant temperature for 40 minutes after adding the water glass. Stirring was stopped, and the mixed solution was sealed in a container, and aged at a temperature of 5°C for 12 hours at a constant temperature. After the constant temperature is finished, add 667ml of clean water to the mixed solution as a guiding agent.

[0045] (2) Preparation of the gel: Add 59.4ml of aluminum sulfate, 62.7ml of low sodium metaaluminate and 42.2ml of directing agent to 208ml of water glass under stirring conditions at a temperature of 5°C, then stir at a constant temperature and speed for 1.5 Hours, then the resulting synthetic solution was statically aged at the above temperature for 8 hours to obtain a gel.

[0046] (3) Crystallization: Under stirring conditions, raise the gel in the synthesis kettle to 70°C within 20 minu...

Embodiment 2

[0048] (1) Preparation of the directing agent: slowly add 1200ml of water glass to 800ml of peralkaline sodium metaaluminate under stirring conditions at 8°C, and stir at constant temperature and speed for 40 minutes after adding the water glass. Stirring was stopped, and the mixed solution was sealed in a container, and aged at a constant temperature for 12 hours at a temperature of 8°C. After the constant temperature is finished, add 667ml of clean water to the mixed solution as a guiding agent.

[0049] (2) Preparation of gel: Add 59.4ml of aluminum sulfate, 62.7ml of low sodium metaaluminate and 56.3ml of directing agent to 208ml of water glass under stirring conditions at a temperature of 2°C, and then stir at a constant temperature and speed After 1.5 hours, the obtained synthetic solution was statically aged at the above temperature for 8 hours to obtain a gel.

[0050] (3) Crystallization: Under stirring conditions, within 20 minutes, the temperature of the gel in the...

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