Method of modifying a phosphorus-containing zeolite catalyst

Patent metadata

Field	Value
Publication number	US-9278342-B2
Application number	US-201213540022-A
Country	US
Kind code	B2
Filing date	Jul 2, 2012
Priority date	Jul 2, 2012
Publication date	Mar 8, 2016
Grant date	Mar 8, 2016

Abstract

A method of modifying a phosphorus-treated zeolite catalyst is carried out by contacting an unbound and calcined phosphorus-treated pentasil zeolite with water in a water treatment wherein at least a portion of the water is in a liquid phase. The water treatment is sufficient to remove at least 80% by weight or more of phosphorus from the phosphorus-treated zeolite and provide an increase in the pore volume of the zeolite by at least 50% prior to the water treatment to form a modified phosphorus-treated zeolite catalyst. A zeolite catalyst is also provided in the form of a phosphorus-containing pentasil zeolite having a phosphorus content of 7.5% or less by weight of zeolite and a 27 Al MAS NMR peak at 50 ppm that is greater than any other 27 Al MAS NMR and a pore volume of 0.2 ml/g or more.

First claim

I claim:

1. A method of modifying a phosphorus-treated zeolite catalyst comprising:
contacting an unbound and calcined phosphorus-treated pentasil zeolite with water at a temperature of 70° C. to 120° C. in a water treatment to form a modified phosphorus-treated zeolite catalyst;
wherein the zeolite has a pore volume prior to water treatment; and
wherein at least a portion of the water is in a liquid phase to facilitate removal of at least 70% by weight or more of phosphorus from the phosphorus-treated zeolite and to provide an increase in the pore volume of the zeolite by at least 50%.

2. The method of claim 1 , wherein:
the phosphorus-treated zeolite has a phosphorus content of from 1% to 25% by weight of the zeolite prior to the water treatment.

3. The method of claim 1 , wherein:
the phosphorus-treated zeolite has a phosphorus content of from 5% to 15% by weight of the zeolite prior to the water treatment.

4. The method of claim 1 , wherein:
the modified phosphorus-treated zeolite catalyst exhibits an increase in any 27 Al MAS NMR peak at 50 ppm compared to the phosphorus-treated zeolite prior to the water treatment.

5. The method of claim 1 , wherein:
the zeolite has a silica/alumina molar ratio of at least 25 or more.

6. The method of claim 1 , wherein:
the zeolite has a silica/alumina molar ratio of at least 200 or more.

7. The method of claim 1 , further comprising stirring during the water treatment.

8. The method of claim 1 , wherein:
the final phosphorus content of the modified phosphorus-treated zeolite catalyst is from 3% or less by weight of the zeolite.

9. The method of claim 1 , wherein:
the final phosphorus content of the modified phosphorus-treated zeolite catalyst is from 0.5% to 2% by weight of the zeolite.

10. The method of claim 1 , wherein:
the modified phosphorus-treated zeolite catalyst has a pore volume of 0.2 ml/g or more.

11. The method of claim 1 , wherein:
the water of the water treatment is saturated steam or a mixture of liquid water and gas.

12. The method of claim 1 , wherein:
the water of the water treatment is in a slurry.

13. The method of claim 1 , wherein:
the phosphorus-treated zeolite is steamed with superheated steam prior to the water treatment.

14. A method of preparing a zeolite catalyst comprising:
treating a pentasil zeolite with a phosphorus compound prior to combining with any optional binder with the zeolite to form a phosphorus-treated zeolite having a phosphorus content of 5% or more by weight of the zeolite;
calcining the unbound phosphorus-treated zeolite;
contacting the unbound and calcined phosphorus-treated zeolite with water at a temperature of 70° C. to 120° C. in a water treatment to form a modified phosphorus-treated zeolite catalyst;
wherein the zeolite has a pore volume prior to water treatment; and
wherein at least a portion of the water is in a liquid phase to facilitate removal of at least 80% by weight or more of phosphorus from the phosphorus-treated zeolite and to provide an increase the pore volume of the zeolite by at least 50%.

15. The method of claim 14 , wherein:
the phosphorus-treated zeolite has a phosphorus content of from 1% to 25% by weight of the zeolite prior to the water treatment.

16. The method of claim 14 , wherein:
the phosphorus-treated zeolite has a phosphorus content of from 5% to 15% by weight of the zeolite prior to the water treatment.

17. The method of claim 14 , wherein:
the modified phosphorus-treated zeolite catalyst exhibits an increase in any 27 Al MAS NMR peak at 50 ppm compared to the phosphorus-treated zeolite prior to the water treatment.

18. The method of claim 14 , wherein:
the zeolite has a silica/alumina molar ratio of at least 25 or more.

19. The method of claim 14 , wherein:
the zeolite has a silica/alumina molar ratio of at least 200 or more.

20. The method of claim 14 , further comprising stirring during the water treatment.

21. The method of claim 14 , wherein:
the final phosphorus content of the modified phosphorus-treated zeolite catalyst is from 3% or less by weight of the zeolite.

22. The method of claim 14 , wherein:
the final phosphorus content of the modified phosphorus-treated zeolite catalyst is from 0.5% to 2% by weight of the zeolite.

23. The method of claim 14 , wherein:
the modified phosphorus-treated zeolite catalyst has a pore volume of 0.2 ml/g or more.

24. The method of claim 14 , wherein:
the water of the water treatment is saturated steam or a mixture of liquid water and gas.

25. The method of claim 14 , wherein:
the water of the water treatment is in a slurry.

26. The method of claim 14 , wherein:
the phosphorus-treated zeolite is steamed with superheated steam prior to the water treatment.

27. The method of claim 14 , wherein:
the unbound phosphorus-treated zeolite is calcined at a temperature of 400° C. or higher prior to the water treatment.

Assignees

• Ghosh Ashim Kumar
• Saudi Basic Ind Corp

Inventors

• Ghosh Ashim Kumar

Classifications

• B01J29/40 Primary

  of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively · CPC title

• B01J2229/37

  Acid treatment · CPC title

• B01J2229/186

  not in framework positions · CPC title

• B01J35/1047

  Operations & Transport · mapped topic

• B01J2229/40

  Special temperature treatment, i.e. other than just for template removal · CPC title