Methods for increasing polymer production rates with halogenated hydrocarbon compounds

Patent metadata

Field	Value
Publication number	US-10167353-B2
Application number	US-201815960624-A
Country	US
Kind code	B2
Filing date	Apr 24, 2018
Priority date	Jun 9, 2016
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

Methods for controlling the productivity of an olefin polymer in a polymerization reactor system using a halogenated hydrocarbon compound are disclosed. The productivity of the polymer can be increased via the addition of the halogenated hydrocarbon compound.

First claim

We claim:

1. A process for producing an ethylene polymer at a target productivity, the process comprising:
(a) contacting a metallocene-based catalyst system with ethylene and an optional α-olefin comonomer in a polymerization reactor system under polymerization conditions; and
(b) controlling an amount of a halogenated hydrocarbon compound introduced into the polymerization reactor system to produce the ethylene polymer at the target productivity;
wherein the metallocene-based catalyst system comprises at least one metallocene compound.

2. The process of claim 1 , wherein:
the metallocene-based catalyst system comprises one or two metallocene compounds, an activator, and an optional co-catalyst; and
the activator comprises an aluminoxane compound, an organoboron or organoborate compound, an ionizing ionic compound, an activator-support, or any combination thereof.

3. The process of claim 1 , wherein:
the metallocene-based catalyst system comprises one or two metallocene compounds, an activator, and an organoaluminum co-catalyst; and
the activator comprises an aluminoxane compound, an organoboron or organoborate compound, an ionizing ionic compound, an activator-support, or any combination thereof.

4. The process of claim 3 , wherein the activator comprises the activator-support, the activator-support comprising a fluorided solid oxide, a sulfated solid oxide, or a combination thereof.

5. The process of claim 1 , wherein:
a productivity of the ethylene polymer increases as the amount of the halogenated hydrocarbon compound added to the polymerization reactor system increases;
the halogenated hydrocarbon compound comprises a halogenated aromatic compound, a halogenated alkane compound, or a combination thereof; and
the ethylene polymer comprises an ethylene homopolymer, an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octene copolymer.

6. The method of claim 1 , wherein the polymerization reactor system comprises multiple reactors.

7. The method of claim 1 , wherein the polymerization reactor system comprises:
a loop slurry reactor and a gas phase reactor;
multiple loop slurry reactors; or
multiple gas phase reactors.

8. A method of controlling a polymerization reaction in a polymerization reactor system, the method comprising:
(i) contacting a transition metal-based catalyst system with ethylene and an optional α-olefin comonomer in the polymerization reactor system under polymerization conditions to produce an ethylene polymer, wherein the polymerization reactor system comprises a loop slurry reactor; and
(ii) introducing an amount of a halogenated hydrocarbon compound into the polymerization reactor system to increase a productivity of the ethylene polymer;
wherein the halogenated hydrocarbon compound is a liquid under the polymerization conditions in the loop slurry reactor, and has a boiling point, at standard temperature and pressure, in a range from 25° C. to 100° C.

9. The method of claim 8 , wherein the halogenated hydrocarbon compound comprises perfluorohexane, hexafluorobenzene, or both.

10. The method of claim 8 , wherein the transition metal-based catalyst system is a chromium-based catalyst system, a Ziegler-Natta based catalyst system, a metallocene-based catalyst system, or a combination thereof.

11. The method of claim 8 , wherein:
the introduction of the halogenated hydrocarbon compound into the polymerization reactor system increases the productivity of the ethylene polymer by from about 10% to about 150%; and
the transition metal-based catalyst system is contacted with ethylene and a comonomer comprising 1-butene, 1-hexene, 1-octene, or a mixture thereof.

12. The method of claim 8 , wherein:
the transition metal-based catalyst system is a Ziegler-Natta based catalyst system; and
the ethylene polymer comprises an ethylene homopolymer, an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octene copolymer.

13. The method of claim 8 , wherein the polymerization reactor system comprises multiple reactors.

14. The method of claim 13 , wherein the transition metal-based catalyst system is a Ziegler-Natta based catalyst system.

15. The method of claim 12 , wherein the introduction of the halogenated hydrocarbon compound into the polymerization reactor system increases the productivity of the ethylene polymer by from about 20% to about 250%.

16. A method of controlling a polymerization reaction in a polymerization reactor system, the method comprising:
(i) contacting a transition metal-based catalyst system with ethylene and an optional α-olefin comonomer in the polymerization reactor system under polymerization conditions to produce an ethylene polymer; and
(ii) introducing an amount of a halogenated hydrocarbon compound into the polymerization reactor system to increase a productivity of the ethylene polymer;
wherein:
the polymerization reactor system comprises a loop slurry reactor;
the transition metal-based catalyst system is a chromium-based catalyst system; and
the halogenated hydrocarbon compound is a liquid under the polymerization conditions in the loop slurry reactor.

17. The method of claim 16 , wherein the polymerization reactor system comprises multiple reactors.

18. The method of claim 16 , wherein the introduction of the halogenated hydrocarbon compound into the polymerization reactor system increases the productivity of the ethylene polymer by from about 10% to about 100%.

19. The method of claim 16 , wherein the ethylene polymer comprises an ethylene homopolymer, an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octene copolymer.

20. The method of claim 16 , wherein the halogenated hydrocarbon compound comprises perfluorohexane, hexafluorobenzene, or both.

21. The method of claim 16 , wherein the percent solids in the loop slurry reactor are in a range from about 30 wt. % to about 55 wt. %.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Ding Errun
• Beaulieu William B

Classifications

• C08F10/00

  Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond · CPC title

• B01J2219/24

  Stationary reactors without moving elements inside · CPC title

• C08F110/14 Primary

  Monomers containing five or more carbon atoms · CPC title

• C08F4/65925

  two cyclopentadienyl rings being mutually non-bridged · CPC title

• C08F2/01 Primary

  characterised by special features of the polymerisation apparatus used · CPC title