Process for reducing the light oligomer content of polypropylene oils

Patent metadata

Field	Value
Publication number	US-9951158-B2
Application number	US-201615235145-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Aug 12, 2016
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Disclosed herein are dual catalyst compositions containing an unbridged metallocene compound, a bridged metallocene compound, a chemically-treated solid oxide, and an optional co-catalyst. These catalyst compositions can be used for the oligomerization of propylene to produce an oligomer product. For example, a heavy propylene oligomer can be recovered from the oligomer product, and the heavy propylene oligomer can be characterized by a high flash point and viscosity index, and a low pour point.

First claim

We claim:

1. An oligomerization process comprising:
contacting an olefin feedstock comprising propylene with a catalyst composition comprising:
(i) catalyst component I comprising an unbridged zirconium or hafnium based metallocene compound containing two cyclopentadienyl groups, two indenyl groups, or a cyclopentadienyl and an indenyl group;
(ii) catalyst component II comprising a single atom bridged, zirconium or hafnium based metallocene compound containing two unsubstituted cyclopentadienyl groups;
(iii) a chemically-treated solid oxide; and
(iv) optionally, a co-catalyst;

to form an oligomer product under oligomerization conditions; and
isolating a heavy propylene oligomer by removing unreacted propylene and at least a portion of light propylene oligomers from the oligomer product using one or more separation steps, wherein the heavy propylene oligomer is characterized by a pour point in a range from about 0 to about −55° C.

2. The process of claim 1 , wherein the heavy propylene oligomer is characterized by:
a flash point in a range from about 140 to about 300° C.; and
a viscosity index in a range from about 75 to about 200.

3. The process of claim 1 , wherein the heavy propylene oligomer is characterized by:
a flash point in a range from about 140 to about 260° C.;
a viscosity index in a range from about 80 to about 130; and
a pour point in a range from about −5 to about −30° C.

4. The process of claim 1 , wherein the heavy propylene oligomer is characterized by:
a Mw in a range from about 1500 to about 5000 g/mol;
a ratio of Mw/Mn in a range from about 1.8 to about 4.5;
a ratio of Mz/Mw in a range from about 1.9 to about 5;
a kinematic viscosity at 40° C. in a range from about 200 to about 1500 cSt; and
a kinematic viscosity at 100° C. in a range from about 14 to about 50 cSt.

5. The process of claim 1 , wherein a flash point of the heavy propylene oligomer is greater than that of a heavy propylene oligomer prepared using the same catalyst composition without catalyst component I, and greater than that of a heavy propylene oligomer prepared using the same catalyst composition without catalyst component II, under the same processing conditions.

6. The process of claim 1 , wherein the olefin feedstock comprising propylene is contacted with the catalyst composition in the presence of hydrogen.

7. The process of claim 1 , wherein:
the catalyst composition comprises a co-catalyst; and
the chemically-treated solid oxide comprises a fluorided solid oxide and/or a sulfated solid oxide.

8. The process of claim 1 , wherein catalyst component I comprises an unbridged metallocene compound having formula (I):

wherein:
M 1 is Zr or Hf;
Cp A and Cp B independently are a cyclopentadienyl group or an indenyl group; and
each X independently is a monoanionic ligand.

9. The process of claim 8 , wherein:
M 1 is Zr;
Cp A and Cp B independently are a cyclopentadienyl group or an indenyl group, either unsubstituted or with one C 1 to C 18 hydrocarbyl substituent; and
each X is Cl.

10. The process of claim 1 , wherein catalyst component II comprises a bridged metallocene compound having formula (II):

wherein:
M 2 is Zr or Hf;
Cp C and Cp D independently are an unsubstituted cyclopentadienyl group;
E is C or Si;
each R 1 independently is H or a C 1 to C 18 hydrocarbyl group; and
each X independently is a monoanionic ligand.

11. The process of claim 10 , wherein:
M 2 is Zr;
each R 1 independently is a phenyl group, a C 1 to C 8 alkyl group, or a C 3 to C 8 alkenyl group; and
each X independently is a halide or C 1 to C 18 hydrocarbyl or hydrocarbylaminyl group.

12. The process of claim 1 , wherein:
the chemically-treated solid oxide comprises a solid oxide treated with an electron-withdrawing anion, and wherein the solid oxide comprises silica, alumina, silica-alumina, silica-coated alumina, or a combination thereof; and the electron-withdrawing anion comprises sulfate, fluoride, chloride, or a combination thereof; and
a weight ratio of catalyst component I to catalyst component II is in a range from about 2:1 to about 1:2.

13. The process of claim 1 , wherein:
the oligomer product is formed in a reaction system comprising a fixed bed reactor, a stirred tank reactor, a plug flow reactor, a loop slurry reactor, or a combination thereof; and
an activity of the catalyst composition is at least about 25,000 grams of the oligomer product per gram of catalyst component I and catalyst component II per hour.

14. The process of claim 1 , wherein the catalyst composition comprises a co-catalyst and wherein said co-catalyst is an organoaluminum co-catalyst.

15. The process of claim 14 , wherein the chemically-treated solid oxide comprises fluorided alumina, sulfated alumina, fluorided silica-alumina, sulfated silica-alumina, fluorided silica-coated alumina, fluorided-chlorided silica-coated alumina, sulfated silica-coated alumina, or any combination thereof.

16. The process of claim 14 , wherein:
catalyst component I comprises an unbridged metallocene compound having formula (I):

and
catalyst component II comprises a bridged metallocene compound having formula (II):

wherein:
M 1 and M 2 are Zr;
Cp A and Cp B independently are an unsubstituted cyclopentadienyl group or an indenyl group;
Cp C and Cp D independently are a cyclopentadienyl group;
E is C or Si;
each R 1 independently is H or a C 1 to C 18 hydrocarbyl group; and
each X independently is a monoanionic ligand.

17. The process of claim 16 , wherein the heavy propylene oligomer comprises at least about 98 mol % propylene units.

18. The process of claim 16 , wherein the process further comprises a step of hydrogenating the heavy propylene oligomer to produce a hydrogenated heavy propylene oligomer.

19. The process of claim 18 , wherein:
a flash point of the hydrogenated heavy propylene oligomer is greater than that of a hydrogenated heavy propylene oligomer prepared using the same catalyst composition without catalyst component I, and greater than that of a hydrogenated heavy propylene oligomer prepared using the same catalyst composition without catalyst component II, under the same processing conditions; and wherein
the hydrogenated heavy propylene oligomer is characterized by:
a flash point in a range from about 140 to about 260° C.;
a viscosity index in a range from about 80 to about 130;
a pour point in a range from about −5 to about −30° C.;
a kinematic viscosity at 40° C. in a range from about 200 to about 1500 cSt; and
a kinematic viscosity at 100° C. in a range from about 10 to about 100 cSt.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Lief Graham R
• Kilgore Uriah J
• Haschke Eric J

Classifications

• B01J21/12 Primary

  Silica and alumina · CPC title

• C07C5/03

  of non-aromatic carbon-to-carbon double bonds · CPC title

• B01J31/1633

  covalent linkages via silicon containing groups · CPC title

• B01J2231/20

  Olefin oligomerisation or telomerisation · CPC title

• B01J2531/48

  Zirconium · CPC title