A kind of modification method of Y-type molecular sieve

Abstract

The invention discloses a modification method of Y-type molecular sieve, which includes the following contents: (1) roasting the Y-type molecular sieve at high temperature, then contacting unsaturated olefins with the roasted Y-type molecular sieve, and roasting in an oxygen-free atmosphere Carbon deposition reaction; (2) Under stirring conditions, add the Y-type molecular sieve after carbon deposition into the pressure-resistant container of the sodium hydroxide solution, seal the system, raise the pressure to 0.2~0.8MPa, and then raise the temperature to 50~ 90°C, constant temperature treatment for 0.5 to 3 hours, pressure relief, suction filtration, drying and roasting to obtain modified Y-type molecular sieve. The Y-type molecular sieve prepared by this method has a larger size mesopore distribution, which can provide more reaction space for macromolecules and improve the catalytic performance of the molecular sieve.

Description

technical field

[0001] The invention relates to a method for modifying a Y-type molecular sieve. The Y-type molecular sieve prepared by the method has more mesoporous structure distribution, which is beneficial to the diffusion of reactants and products in the reaction process. Background technique

[0002] Y-type molecular sieve is formed by octahedral molecular sieve cages interpenetrating with each other along three crystal axis directions through twelve-membered rings. It is an excellent catalyst active component, not only has high cracking activity, but also has good selectivity. Therefore, the discovery and use of Y-type molecular sieve has epoch-making significance in the field of catalysis.

[0003] Since Y-type molecular sieves with a low silicon-aluminum ratio (the molar ratio of silicon oxide to aluminum oxide is between 3 and 4.2) do not have good hydrothermal stability, they have not been widely studied and widely used in the actual synthesis process and applica...

Examples

Embodiment 1

[0023] (1) Roast the Y-1 molecular sieve at 550°C for 4 hours, then contact the unsaturated olefin with the roasted Y-type molecular sieve, and roast it at 500°C for 2 hours in a nitrogen atmosphere to carry out the carbon deposition reaction. Obtain the Y-type molecular sieve after carbon deposition;

[0024] (2) Under stirring conditions, add the Y-type molecular sieve after carbon deposition into the pressure-resistant container of 0.50mol / L sodium hydroxide solution, the mass ratio of molecular sieve addition to water in the solution is 1:8, and Seal the system, feed nitrogen to control the system pressure to 0.4MPa, then raise the temperature to 70°C, treat at a constant temperature for 2 hours, release the pressure, filter with suction until the pH value is less than 9, dry at 120°C for 12 hours, and finally bake at 550°C After 4 hours, a modified Y-type molecular sieve was obtained. The specific properties of molecular sieves are shown in Table 1.

Embodiment 2

[0026] (1) Roast the Y-1 molecular sieve at 450°C for 6 hours, then contact the unsaturated olefin with the roasted Y-type molecular sieve, and roast it at 550°C for 2 hours in a nitrogen atmosphere to carry out the carbon deposition reaction. Obtain the Y-type molecular sieve after carbon deposition;

[0027] (2) Under stirring conditions, add the Y-type molecular sieve after the carbon deposition into the pressure-resistant container of 0.80mol / L sodium hydroxide solution, the mass ratio of the molecular sieve to the water in the solution is 1:15, and Seal the system, feed air to control the system pressure to 0.6MPa, then raise the temperature to 80°C, treat at a constant temperature for 1 hour, release the pressure, filter with suction until the pH value is less than 9, dry at 110°C for 18 hours, and finally bake at 580°C After 4 hours, a modified Y-type molecular sieve was obtained. The specific properties of molecular sieves are shown in Table 1.

Embodiment 3

[0029] (1) Roast the Y-1 molecular sieve at 600°C for 2 hours, then contact the unsaturated olefin with the roasted Y-type molecular sieve, and roast it at 480°C for 6 hours in a nitrogen atmosphere to carry out the carbon deposition reaction. Obtain the Y-type molecular sieve after carbon deposition;

[0030] (2) Under stirring conditions, add the carbon-deposited Y-type molecular sieve into a pressure-resistant container of 0.60mol / L sodium hydroxide solution. The mass ratio of the amount of molecular sieve added to the water in the solution is 1:10, and Seal the system, feed nitrogen to control the system pressure to 0.2 MPa, then raise the temperature to 60°C, treat at a constant temperature for 3 hours, release the pressure, filter with suction until the pH value is less than 9, dry at 100°C for 24 hours, and finally roast at 520°C After 4 hours, a modified Y-type molecular sieve was obtained. The specific properties of molecular sieves are shown in Table 1.

technical field

[0001] The invention relates to a method for modifying a Y-type molecular sieve. The Y-type molecular sieve prepared by the method has more mesoporous structure distribution, which is beneficial to the diffusion of reactants and products in the reaction process. Background technique

[0002] Y-type molecular sieve is formed by octahedral molecular sieve cages interpenetrating with each other along three crystal axis directions through twelve-membered rings. It is an excellent catalyst active component, not only has high cracking activity, but also has good selectivity. Therefore, the discovery and use of Y-type molecular sieve has epoch-making significance in the field of catalysis.

[0003] Since Y-type molecular sieves with a low silicon-aluminum ratio (the molar ratio of silicon oxide to aluminum oxide is between 3 and 4.2) do not have good hydrothermal stability, they have not been widely studied and widely used in the actual synthesis process and applica...

Examples

Embodiment 1

[0023] (1) Roast the Y-1 molecular sieve at 550°C for 4 hours, then contact the unsaturated olefin with the roasted Y-type molecular sieve, and roast it at 500°C for 2 hours in a nitrogen atmosphere to carry out the carbon deposition reaction. Obtain the Y-type molecular sieve after carbon deposition;

[0024] (2) Under stirring conditions, add the Y-type molecular sieve after carbon deposition into the pressure-resistant container of 0.50mol / L sodium hydroxide solution, the mass ratio of molecular sieve addition to water in the solution is 1:8, and Seal the system, feed nitrogen to control the system pressure to 0.4MPa, then raise the temperature to 70°C, treat at a constant temperature for 2 hours, release the pressure, filter with suction until the pH value is less than 9, dry at 120°C for 12 hours, and finally bake at 550°C After 4 hours, a modified Y-type molecular sieve was obtained. The specific properties of molecular sieves are shown in Table 1.

Embodiment 2

[0026] (1) Roast the Y-1 molecular sieve at 450°C for 6 hours, then contact the unsaturated olefin with the roasted Y-type molecular sieve, and roast it at 550°C for 2 hours in a nitrogen atmosphere to carry out the carbon deposition reaction. Obtain the Y-type molecular sieve after carbon deposition;

[0027] (2) Under stirring conditions, add the Y-type molecular sieve after the carbon deposition into the pressure-resistant container of 0.80mol / L sodium hydroxide solution, the mass ratio of the molecular sieve to the water in the solution is 1:15, and Seal the system, feed air to control the system pressure to 0.6MPa, then raise the temperature to 80°C, treat at a constant temperature for 1 hour, release the pressure, filter with suction until the pH value is less than 9, dry at 110°C for 18 hours, and finally bake at 580°C After 4 hours, a modified Y-type molecular sieve was obtained. The specific properties of molecular sieves are shown in Table 1.

Embodiment 3

[0029] (1) Roast the Y-1 molecular sieve at 600°C for 2 hours, then contact the unsaturated olefin with the roasted Y-type molecular sieve, and roast it at 480°C for 6 hours in a nitrogen atmosphere to carry out the carbon deposition reaction. Obtain the Y-type molecular sieve after carbon deposition;

[0030] (2) Under stirring conditions, add the carbon-deposited Y-type molecular sieve into a pressure-resistant container of 0.60mol / L sodium hydroxide solution. The mass ratio of the amount of molecular sieve added to the water in the solution is 1:10, and Seal the system, feed nitrogen to control the system pressure to 0.2 MPa, then raise the temperature to 60°C, treat at a constant temperature for 3 hours, release the pressure, filter with suction until the pH value is less than 9, dry at 100°C for 24 hours, and finally roast at 520°C After 4 hours, a modified Y-type molecular sieve was obtained. The specific properties of molecular sieves are shown in Table 1.

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