Particle size control of supported chromium catalysts in loop slurry polymerization reactors

Patent metadata

Field	Value
Publication number	US-11512154-B2
Application number	US-202217716027-A
Country	US
Kind code	B2
Filing date	Apr 8, 2022
Priority date	Dec 8, 2020
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 μm, and less than 10 wt. % has a particle size less than 10 μm, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 μm per five grams of the ethylene polymer.

First claim

We claim:

1. A supported chromium catalyst comprising a solid oxide and from 0.1 to 15 wt. % chromium, wherein the supported chromium catalyst is characterized by:
(A1) an amount of the supported chromium catalyst with a particle size greater than 100 μm of less than or equal to 3 wt. %;
(A2) a particle size span ((d90−d10)/d50) in a range from 0.5 to 1.4; and
(A3) a d10 particle size in a range from 11 to 22 μm.

2. The catalyst of claim 1 , wherein the solid oxide is silica, silica-alumina, silica-coated alumina, silica-titania, silica-titania-magnesia, silica-zirconia, silica-magnesia, silica-boria, aluminophosphate-silica, or any combination thereof.

3. The catalyst of claim 2 , wherein the catalyst comprises from 0.5 to 2 wt. % chromium.

4. The catalyst of claim 3 , wherein the solid oxide is silica and/or silica-titania.

5. The catalyst of claim 1 , wherein the particle size span is from 0.6 to 1.35.

6. The catalyst of claim 1 , wherein the particle size span is from 0.7 to 1.1.

7. The catalyst of claim 1 , wherein the catalyst contains less than or equal to 3 wt. % carbon.

8. The catalyst of claim 1 , wherein at least 80 wt. % of the chromium is present in an oxidation state of three or less.

9. The catalyst of claim 1 , wherein at least 60 wt. % of the chromium is present in an oxidation state of six (Cr+6).

10. The catalyst of claim 1 , wherein the catalyst is further characterized by:
a d50 average particle size from 15 to 60 μm; and
a ratio of d80/d20 from 1.3 to 2.8.

11. The catalyst of claim 1 , wherein the catalyst is further characterized by:
a d50 average particle size from 17 to 32 μm; and
a d95 particle size from 30 to 55 μm.

12. The catalyst of claim 1 , wherein less than or equal to 1 wt. % of the supported chromium catalyst has a particle size greater than 100 μm.

13. The catalyst of claim 1 , wherein:
the solid oxide is silica, silica-alumina, silica-coated alumina, silica-titania, silica-titania-magnesia, silica-zirconia, silica-magnesia, silica-boria, aluminophosphate-silica, or any combination thereof; and
at least 80 wt. % of the chromium is present in an oxidation state of three or less.

14. The catalyst of claim 13 , wherein the catalyst is further characterized by:
a d50 average particle size from 15 to 60 μm; and
a ratio of d80/d20 from 1.3 to 2.8.

15. The catalyst of claim 13 , wherein the particle size span is from 0.6 to 1.35.

16. The catalyst of claim 13 , wherein:
the catalyst comprises from 0.5 to 2 wt. % chromium; and
the solid oxide is silica, silica-coated alumina, or silica-titania.

17. The catalyst of claim 16 , wherein:
less than or equal to 1 wt. % of the supported chromium catalyst has a particle size greater than 100 μm; and
less than or equal to 3 wt. % of the supported chromium catalyst has a particle size less than 10 μm.

18. The catalyst of claim 16 , wherein the particle size span is from 0.7 to 1.1.

19. The catalyst of claim 16 , wherein the catalyst is further characterized by:
a d50 average particle size from 17 to 32 μm; and
a d95 particle size from 30 to 55 μm.

20. The catalyst of claim 16 , wherein the catalyst contains, independently, less than 0.1 ppm of Mg, V, Ti, Zr, or Hf.

21. The catalyst of claim 1 , wherein:
the solid oxide is silica, silica-alumina, silica-coated alumina, silica-titania, silica-titania-magnesia, silica-zirconia, silica-magnesia, silica-boria, aluminophosphate-silica, or any combination thereof; and
at least 60 wt. % of the chromium is present in an oxidation state of six (Cr+6).

22. The catalyst of claim 21 , wherein the catalyst is further characterized by:
a d50 average particle size from 15 to 60 μm; and
a ratio of d80/d20 from 1.3 to 2.8.

23. The catalyst of claim 21 , wherein the particle size span is from 0.6 to 1.35.

24. The catalyst of claim 21 , wherein:
the catalyst comprises from 0.5 to 2 wt. % chromium; and
the solid oxide is silica, silica-coated alumina, or silica-titania.

25. The catalyst of claim 24 , wherein:
less than or equal to 1 wt. % of the supported chromium catalyst has a particle size greater than 100 μm; and
less than or equal to 3 wt. % of the supported chromium catalyst has a particle size less than 10 μm.

26. The catalyst of claim 24 , wherein the particle size span is from 0.7 to 1.1.

27. The catalyst of claim 24 , wherein the catalyst is further characterized by:
a d50 average particle size from 17 to 32 μm; and
a d95 particle size from 30 to 55 μm.

28. The catalyst of claim 24 , wherein the catalyst contains, independently, less than 0.1 ppm of Mg, V, Ti, Zr, or Hf.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Mcdaniel Max P
• Ash Carlton E
• Clear Kathy S
• Schwerdtfeger Eric D
• Cruz Carlos A
• Praetorius Jeremy M

Classifications

• B01J8/08

  with moving particles (with fluidised particles B01J8/18) · CPC title

• C08F10/02 Primary

  Ethene · CPC title

• C08F2410/06

  Catalyst characterized by its size · CPC title

• C08F210/16

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08F110/02 Primary

  Ethene · CPC title