Modified Y molecular sieve and preparation method and use thereof, supported catalyst, and hydrocracking method

Patent metadata

Field	Value
Publication number	US-10112840-B2
Application number	US-201514930707-A
Country	US
Kind code	B2
Filing date	Nov 3, 2015
Priority date	Nov 3, 2014
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

The present invention discloses a modified Y molecular sieve, a preparation method and a use of the modified Y molecular sieve, a supported catalyst, and a hydrocracking method. The silica-alumina mole ratio in the surface layer of the modified Y molecular sieve is 20-100:1, and the silica-alumina mole ratio in the body phase of the modified Y molecular sieve is 8-30:1. When a hydrocracking catalyst prepared from the modified Y molecular sieve is used for hydrocracking, the hydrocracking catalyst has higher reactivity and higher nitrogen tolerance. The hydrocracking catalyst prepared from the modified Y molecular sieve is suitable for use for increasing the yield of diesel oil, increasing the yield of chemical materials, and catalyzed hydrogenation conversion of diesel oil, etc.

First claim

What is claimed is:

1. A modified Y molecular sieve, having a silica-alumina mole ratio in a surface layer of the modified Y molecular sieve of 20-100:1, a silica-alumina mole ratio in a bulk of the modified Y molecular sieve of 8-30:1, and the silica-alumina mole ratio in the surface layer of the modified Y molecular sieve is at least 10 times higher than the silica-alumina mole ratio in the bulk of the modified Y molecular sieve.

2. The modified Y molecular sieve according to claim 1 , wherein the silica-alumina mole ratio in the surface layer of the modified Y molecular sieve is 20-70 times higher than the silica-alumina mole ratio in the bulk of the modified Y molecular sieve.

3. The modified Y molecular sieve according to claim 1 , wherein the silica-alumina mole ratio in the surface layer is 30-80:1.

4. The modified Y molecular sieve according to claim 1 , wherein a thickness of the surface layer is 10-200 nm.

5. The modified Y molecular sieve according to claim 1 , wherein the surface layer is formed by in-situ dealumination, and a grain size of the modified Y molecular sieve is 0.4-1.2 μm.

6. The modified Y molecular sieve according to claim 1 , wherein an acid content measured by near infrared spectrometry (NIS) in the modified Y molecular sieve is 0.3-1.5 mmol/g; a specific surface area of the modified Y molecular sieve is 600-900 m 2 /g; a pore volume is 0.2-0.7 ml/g; a relative crystallinity is 60-130%; a crystal cell constant of the modified Y molecular sieve is 2.425-2.455 nm.

7. A method for preparing a modified Y molecular sieve of claim 1 , comprising:
(1) treating Na—Y zeolite by ammonium exchange, till the Na content calculated in Na 2 O in the Y molecular sieve obtained through ammonium exchange is not higher than 3 wt %;
(2) treating the Y molecular sieve obtained through ammonium exchange in the step (1) by primary dealumination, so that the silica-alumina mole ratio in the obtained Y molecular sieve is increased by 2-8;
(3) treating the Y molecular sieve treated by primary dealumination in the step (2) by carbon deposition treatment, so that 60-90 vol % of pores and channels in the Y molecular sieve treated by primary dealumination are filled;
(4) treating the product obtained in the step (3) by secondary dealumination, to form a surface layer of the modified Y molecular sieve, in which the silica-alumina mole ratio is increased by 10-80 compared with the silica-alumina mole ratio in the Y molecular sieve treated by primary dealumination;
(5) treating the Y molecular sieve obtained in the step (4) by carbon burning.

8. The method according to claim 7 , wherein in the Na—Y zeolite, the silica-alumina mole ratio is 3-6, and the content of Na 2 O is 6-15 wt %; the ammonium exchange is carried in a water solution of ammonium salt, and the concentration of the water solution of ammonium salt is 0.3-6 mol/L; the temperature of the ammonium exchange is 60-120° C., and the time of the ammonium exchange is 1-3 h.

9. The method according to claim 7 , wherein the primary dealumination treatment is one or more of hydrothermal treatment, acid treatment, aluminum salt treatment, and ammonium fluosilicate treatment.

10. The method according to claim 7 , wherein in the step (3), the carbon deposition treatment is carried out in the following Approach A and/or Approach B:
Approach A:
(I) impregnating the Y molecular sieve treated by primary dealumination in a liquid carbon source, so that the liquid carbon source is filled into the pores and channels in the Y molecular sieve treated by primary dealumination, wherein the liquid carbon source is a C 5 -C 15 hydrocarbon solvent;
(II) removing the liquid carbon source partially by volatilization, so that 60-90 vol % of pores and channels in the Y molecular sieve treated by primary dealumination are filled by the liquid carbon source;
Approach B:
(I′) contacting the Y molecular sieve treated by primary dealumination with a carbon source, so that the carbon source is filled into the pores and channels in the Y molecular sieve treated by primary dealumination, wherein the carbon source is C 2 -C 10 normal or isomeric monoene, or dialkene;
(II′) carrying out a carbon deposition reaction in an oxygen-bearing atmosphere, so that the carbon source in the Y molecular sieve treated by primary dealumination is converted into carbon;
(III′) removing the carbon partially, so that 60-90 vol % of pores and channels in the Y molecular sieve treated by primary dealumination are filled by carbon.

11. The method according to claim 10 , wherein
in the Approach A, the liquid carbon source is selected from at least one of paraffin hydrocarbon, petroleum ether, carbon tetrachloride, benzene, methyl benzene, ethyl benzene, and dimethyl benzene; the impregnation is saturated impregnation, and the impregnation time is 1-5 h; the liquid carbon source is removed partially by volatilization implemented by evaporating the solvent;
in the Approach B, the carbon source is at least one of butadiene, pentylene, hexadiene, butylene, pentene, heptylene, and nonylene; the Y molecular sieve treated by primary dealumination is controlled to contact with the carbon source fully by placing the Y molecular sieve treated by primary dealumination in an enclosed atmosphere that contains the gas of the carbon source or in a liquid that contains the carbon source; the carbon is removed partially by calcination at a temperature of 400-600° C.

12. The method according to claim 11 , wherein
in the Approach A, the evaporation for removing the solvent is heat drying, the temperature of heat drying is higher than the boiling point of the hydrocarbon solvent, and the time of heat drying is 1-60 min.;
in the Approach B, when the carbon source is in gas state at room temperature, the Y molecular sieve treated by primary dealumination is contacted with the carbon source by holding the Y molecular sieve treated by primary dealumination in an enclosed atmosphere that contains the gas of the carbon source at 0.1-1.0 MPa pressure for 0.1-2 h; when the carbon source is in liquid state at room temperature, the Y molecular sieve treated by primary dealumination is contacted with the carbon source by impregnating the Y molecular sieve treated by primary dealumination in a liquid that contains the carbon source fully to contact at 0.1-1.0 MPa pressure for 0.5-4 h.

13. The method according to claim 10 , wherein in the Approach B, the carbon deposition reaction happens in an oxygen-bearing atmosphere, in which the oxygen content is 10-100 vol %; the temperature of the carbon deposition reaction is 50-500° C., and the time of the carbon deposition reaction is 1-50 h.

14. The method according to claim 7 , wherein in the step (4), the secondary dealumination treatment is an acid dealumination process and/or ammonium fluosilicate dealumination and silicon reinsertion process.

15. The method according to claim 7 , wherein in the step (5), the carbon burning treatment is implemented by calcination the Y molecular sieve treated by secondary dealumination at 400-600° C. for 2-4 h.

16. A supported catalyst, comprising a hydrogenation active component and a support, wherein the support comprises the modified Y molecular sieve according to claim 1 .

17. The supported catalyst according to claim 16 , wherein a specific surface area of the supported catalyst is 200-400 m 2 /g, and a pore volume of the supported catalyst is 0.2-0.5 ml/g.

18. The supported catalyst according to claim 16 , wherein a content of the modified Y molecular sieve in the support is 15-90 wt %.

Assignees

• China Petroleum & Chem Corp
• Fushun Res Institute Of Petroleum And Petrochemicals Sinopec Corp
• Fushun Res Institute Of Petroleum And Petrochemicals Sinopec Corp

Inventors

• Liu Wei
• Guan Minghua
• Du Yanze
• Wang Fenglai
• Liu Chang
• Qin Bo

Classifications

• C10G47/16

  Crystalline alumino-silicate carriers · CPC title

• B01J23/888

  Tungsten · CPC title

• B01J29/166

  Y-type faujasite · CPC title

• B01J37/0207

  Pretreatment of the support · CPC title

• B01J29/084 Primary

  Y-type faujasite · CPC title