Magnesium modified Y-type molecular sieve, preparation thereof and catalyst comprising the same

Patent metadata

Field	Value
Publication number	US-11053129-B2
Application number	US-201816484880-A
Country	US
Kind code	B2
Filing date	Feb 12, 2018
Priority date	Feb 21, 2017
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

A magnesium modified Y-type molecular sieve has a rare earth oxide content of about 4% to about 11% by weight, a magnesium oxide content of about 0.1% to about 4% by weight, a sodium oxide content of about 0.3% to about 0.8% by weight, a total pore volume of about 0.33 mL/g to about 0.39 mL/g, a percentage of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of the modified Y-type molecular sieve of about 10% to about 30%, a lattice constant of about 2.440 nm to about 2.455 nm, a percentage of non-framework aluminum content to the total aluminum content of the modified Y-type molecular sieve of no more than about 20%, and a lattice collapse temperature of not lower than about 1045° C.

First claim

The invention claimed is:

1. A modified Y-type molecular sieve, having a rare earth oxide content of about 4% to about 11% by weight, a magnesium oxide content of about 0.1% to about 4% by weight, a sodium oxide content of about 0.3% to about 0.8% by weight, a total pore volume of about 0.33 mL/g to about 0.39 mL/g, a percentage of a pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of the modified Y-type molecular sieve of about 10% to about 30%, a lattice constant of about 2.440 nm to about 2.455 nm, a percentage of non-framework aluminum content to the total aluminum content of the modified Y-type molecular sieve of no more than about 20%, and a lattice collapse temperature of not lower than about 1045° C.,
wherein the modified Y-type molecular sieve has a framework structure of zeolite Y.

2. The modified Y-type molecular sieve according to claim 1 , wherein the modified Y-type molecular sieve has a percentage of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of about 15-25%.

3. The modified Y-type molecular sieve according to claim 1 , wherein the modified Y-type molecular sieve has a percentage of non-framework aluminum content to the total aluminum content of about 13-19%, and a framework silica-alumina ratio of about 7 to about 14 calculated on the basis of SiO 2 /Al 2 O 3 molar ratio.

4. The modified Y-type molecular sieve according to claim 1 , wherein the modified Y-type molecular sieve has a lattice collapse temperature of about 1045-1075° C.

5. The modified Y-type molecular sieve according to claim 1 , wherein the magnesium oxide content is from about 0.5% to about 3% by weight.

6. The modified Y-type molecular sieve according to claim 1 , wherein the modified Y-type molecular sieve shows a relative crystallinity retention of about 30% or more after aging at 800° C. under atmospheric pressure in 100% steam atmosphere for 17 hours.

7. The modified Y-type molecular sieve according to claim 1 , wherein the modified Y-type molecular sieve has a relative crystallinity of about 55% to about 68%.

8. The modified Y-type molecular sieve according to claim 1 , wherein the modified Y-type molecular sieve has a rare earth oxide content of about 4.5% to about 10% by weight, a sodium oxide content of about 0.4% to about 0.6% by weight, a lattice constant of 2.442-2.451 nm, and a framework silica-alumina ratio of about 8.5 to about 12.6 calculated on the basis of SiO 2 /Al 2 O 3 molar ratio.

9. A method for the preparation of a modified Y-type molecular sieve according to claim 1 , comprising the steps of:
(1) contacting a NaY molecular sieve with a rare earth salt solution for ion-exchange reactional to obtain a Y type molecular sieve containing rare earth elements and having a reduced sodium oxide content;
(2) calcining the Y-type molecular sieve obtained in the step (1) at a temperature of about 350-480° C. in an atmosphere containing about 30 vol % to about 90 vol % of steam for about a time of 4.5 hours to about 7 hours to obtain a Y-type molecular sieve having a reduced lattice constant;
(3) contacting and reacting the Y-type molecular sieve obtained in the step (2) with gaseous silicon tetrachloride to obtain a high-silica ultra-stable Y-type molecular sieve under the following conditions: a weight ratio of SiCl 4 :the Y-type molecular sieve on a dry basis of about 0.1:1 to about 0.7:1, a reaction temperature of about 200° C. to about 650° C., and a reaction time of about 10 minutes to about 5 hours; and
(4) subjecting the high-silica ultra-stable Y-type molecular sieve obtained in the step (3) to modification with a magnesium compound to obtain the modified Y-type molecular sieve.

10. The method according to claim 9 , wherein the Y-type molecular sieve obtained in the step (1) has a lattice constant of about 2.465-2.472 nm, and a sodium oxide content of no more than about 9.5 wt %.

11. The method according to claim 9 , wherein the Y-type molecular sieve obtained in the step (1) has a rare earth content of about 4.5% to about 13% by weight on the basis of RE 2 O 3 , a sodium oxide content of about 5-9.5% by weight, and a lattice constant of about 2.465-2.472 nm.

12. The method according to claim 9 , wherein, in the step (1), the ion-exchange reaction of the NaY molecular sieve with the rare earth solution is carried out under the following conditions: a weight ratio of NaY molecular sieve:rare earth salt:H 2 O of about 1:0.01-0.18:5-15, an ion-exchange temperature of about 15-95° C., and an ion-exchange time of about 30-120 minutes.

13. The method according to claim 9 , wherein, in the step (2), the calcination temperature is about 380-460° C., the calcination atmosphere contains about 40-80% steam, and the calcination time is about 5-6 hours.

14. The method according to claim 9 , wherein the Y-type molecular sieve having a reduced lattice constant obtained in the step (2) has a lattice constant of about 2.450-2.462 nm, and a water content of no more than about 1% by weight.

15. The method according to claim 9 , wherein the rare earth salt is rare earth chloride, rare earth nitrate, or a mixture thereof, and the magnesium compound is magnesium chloride, magnesium nitrate, or a mixture thereof.

16. The method according to claim 9 , wherein the modification with the magnesium compound of the step (4) comprises: adding the high-silica ultra-stable Y-type molecular sieve to a solution containing a magnesium salt at a weight ratio of water to the high-silica ultra-stable Y-type molecular sieve of about 1-6, a weight ratio of the magnesium salt on the basis magnesium oxide to the high-silica ultra-stable Y-type molecular sieve of about 0.001-0.04; stirring at about 5-50° C. for about 10-120 minutes, adding ammonia water to adjust the pH of the solution to about 7.5-10, then filtering to obtain a filter cake and subjecting the filter cake to calcination at about 500-650° C. for at least about 1 hour, to obtain the modified Y-type molecular sieve.

17. A catalytic cracking catalyst, comprising the modified Y-type molecular sieve according to claim 1 .

18. The catalytic cracking catalyst according to claim 17 , wherein the catalyst comprises about 10% to about 50% by weight, on a dry basis, of the modified Y-type molecular sieve, about 10% to about 40% by weight on the basis of alumina of an alumina binder, and about 10% to about 80% by weight, on a dry basis, of clay.

19. The catalytic cracking catalyst according to claim 17 , wherein the catalyst comprises about 10% to about 50% by weight, on a dry basis, of the modified Y-type molecular sieve, about 2% to about 40% by weight on a dry basis of an additive-containing alumina and about 10% to about 80% by weight, on a dry basis, of clay; wherein on a dry basis and based on the weight of the additive-containing alumina, the additive-containing alumina comprises about 60% to about 99.5% by weight of alumina and about 0.5% to about 40% by weight of an additive, wherein the additive is one or more selected from the group consisting of compounds containing alkaline earth metal, lanthanide metal, silicon, gallium, boron, phosphorus, and mixtures thereof.

20. The catalytic cracking catalyst according to claim 19 , wherein the catalyst comprises about 25-40% by weight, on a dry basis, of the modified Y-type molecular sieve, about 2-20% by weight on a dry basis of an additive-containing alumina, about 5-30% by weight on a dry basis of an alumina binder, and about 30-50% by weight on a dry basis of clay.

Assignees

• China Petroleum & Chem Corp
• Sinopec Res Inst Petroleum

Inventors

• Zhou Lingping
• Zhang Weilin
• Xu Mingde
• Chen Zhenyu
• Tian Huiping
• Zhu Yuxia

Classifications

• C10G11/05

  Crystalline alumino-silicates, e.g. molecular sieves · CPC title

• C01B39/24 Primary

  Type Y {(C01B39/205 takes precedence)} · CPC title

• B01J29/005

  Mixtures of molecular sieves comprising at least one molecular sieve which is not an aluminosilicate zeolite, e.g. from groups B01J29/03 - B01J29/049 or B01J29/82 - B01J29/89 · CPC title

• B01J2229/186

  not in framework positions · CPC title

• B01J2229/42

  Addition of matrix or binder particles · CPC title