Oligomerization catalyst system activation and related ethylene oligomerization processes and reaction systems

Patent metadata

Field	Value
Publication number	US-11267909-B2
Application number	US-202016929204-A
Country	US
Kind code	B2
Filing date	Jul 15, 2020
Priority date	Jul 15, 2020
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

Disclosed herein are oligomerization processes in which ethylene and a catalyst system are first combined for a suitable residence time in an activation vessel, prior to introduction into a reaction zone to oligomerize ethylene to form a desired oligomer product, such as 1-hexene and/or 1-octene. Related oligomerization reaction systems that include the activation vessel also are disclosed. In these oligomerization processes and reaction systems, the catalyst system can be fully activated as it leaves the activation vessel and enters the reaction zone, thus providing greater catalyst utilization and less catalyst waste.

First claim

We claim:

1. A process comprising:
a) forming a first mixture in an activation vessel, the first mixture comprising:
1) ethylene,
2) a catalyst system comprising i) a heteroatomic ligand chromium compound complex and an organoaluminum compound, or ii) a heteroatomic ligand, a chromium compound, and an organoaluminum compound,
3) optionally, a first organic reaction medium, and
4) optionally, hydrogen;

b) maintaining the first mixture in the activation vessel for an average residence time;
c) introducing into a reaction zone:
i) ethylene,
ii) the first mixture from step b),
iii) a second organic reaction medium, and
iv) optionally, hydrogen; and

d) forming an oligomer product in the reaction zone;
wherein the average residence time of the first mixture in the activation vessel is in a range from 10 sec up to a period of time sufficient to form an amount of a first oligomer product in the activation vessel equal to 5% of an amount of the oligomer product formed in the reaction zone.

2. The process of claim 1 , wherein i) the heteroatomic ligand chromium compound complex and the organoaluminum compound are, or ii) at least one of the heteroatomic ligand, the chromium compound, and the organoaluminum compound is, separately introduced into the activation vessel.

3. The process of claim 1 , wherein a catalyst system mixture comprising:
(a) i) the heteroatomic ligand chromium compound complex and the organoaluminum compound, or ii) the heteroatomic ligand, the chromium compound, and the organoaluminum compound, and
(b) a catalyst system organic medium comprising an aromatic hydrocarbon,
is formed and then introduced into the activation vessel.

4. The process of claim 3 , wherein the catalyst system mixture further comprises at least a portion of the first organic reaction medium.

5. The process of claim 1 , wherein, in step c), a second feed stream comprising ethylene, at least a portion of the second organic reaction medium, and hydrogen is introduced into the reaction zone separate from the first mixture from step b).

6. The process of claim 1 , wherein the first organic reaction medium and the second organic reaction medium independently comprise a cyclic aliphatic hydrocarbon, an acyclic aliphatic hydrocarbon, an aromatic hydrocarbon, or any combination thereof.

7. The process of claim 1 , wherein:
the first organic reaction medium and the second organic reaction medium comprise cyclohexane;
in step c), the first mixture from step b) and the ethylene are introduced separately into the reaction zone; and
the oligomer product comprises C 6 and/or C 8 olefins.

8. The process of claim 1 , wherein hydrogen is present in step c) and not present in step a).

9. The process of claim 1 , wherein:
a conversion of ethylene in the activation vessel is less than or equal to 5 mol % of a total ethylene utilized in step a) and step c); or
a catalyst system productivity in the activation vessel is less than or equal to 5% of a catalyst system mixture productivity in the reaction zone; or
a fouling rate in the activation vessel is less than or equal to 0.065 mg/cm 2 -hr; or
an oligomer product discharge rate from the activation vessel is less than or equal to 0.15 lb/gal/hr, and an oligomer product discharge rate from the reaction zone is in a range from 0.75 to 6 lb/gal/hr; or
a ΔT from an inlet of the activation vessel to an outlet of the activation vessel is less than or equal to 5° C.; or
an amount of ethylene introduced into the activation vessel is less than 50% of an amount of ethylene introduced into the reaction zone; or
step b) is performed at an activation temperature and an activation pressure, and the first mixture in the activation vessel is below the bubble point at the activation temperature and the activation pressure; or
any combination thereof.

10. The process of claim 1 , wherein the average residence time is in a range from 30 sec to 45 min.

11. The process of claim 1 , wherein the average residence time is in a range from 30 sec up to a period of time sufficient to form an amount of the first oligomer product in the activation vessel equal to 1% of the amount of the oligomer product formed in the reaction zone.

12. A process comprising:
a) forming a first mixture in an activation vessel, the first mixture comprising:
1) a first catalyst system comprising i) a first heteroatomic ligand chromium compound complex and a first organoaluminum compound, or ii) a first heteroatomic ligand, a first chromium compound, and a first organoaluminum compound,
2) a first feed comprising ethylene, a second catalyst system comprising i) a second heteroatomic ligand chromium compound complex and a second organoaluminum compound, or ii) a second heteroatomic ligand, a second chromium compound, and a second organoaluminum compound, a second organic reaction medium, a second oligomer product, and optionally hydrogen,
3) optionally, a first organic reaction medium, and
4) optionally, hydrogen;

b) maintaining the first mixture in the activation vessel for an average residence time;
c) introducing into a reaction zone:
i) ethylene,
ii) the first mixture from step b),
iii) the second organic reaction medium, and
iv) optionally, hydrogen; and

d) forming an oligomer product in the reaction zone;
wherein a portion of a reaction zone effluent is fed to the activation vessel as the first feed, and
wherein the average residence time of the first mixture in the activation vessel is in a range from 10 sec up to a period of time sufficient to form an amount of a first oligomer product in the activation vessel equal to 5% of an amount of the oligomer product formed in the reaction zone.

13. The process of claim 12 , wherein:
a conversion of ethylene in the activation vessel is less than or equal to 5 mol % of a total ethylene utilized in step a) and step c); or
a catalyst system productivity in the activation vessel is less than or equal to 5% of a catalyst system mixture productivity in the reaction zone; or
a fouling rate in the activation vessel is less than or equal to 0.065 mg/cm 2 -hr; or
an oligomer product discharge rate from the activation vessel is less than or equal to 0.15 lb/gal/hr, and an oligomer product discharge rate from the reaction zone is in a range from 0.75 to 6 lb/gal/hr; or
a ΔT from an inlet of the activation vessel to an outlet of the activation vessel is less than or equal to 5° C.; or
an amount of ethylene introduced into the activation vessel is less than 50% of an amount of ethylene introduced into the reaction zone; or
step b) is performed at an activation temperature and an activation pressure, and the first mixture in the activation vessel is below the bubble point at the activation temperature and the activation pressure; or
the average residence time is in a range from 1 min to 45 min; or
any combination thereof.

14. The process of claim 12 , wherein, in step c), a second feed stream comprising ethylene, at least a portion of the second organic reaction medium, and hydrogen is introduced into the reaction zone separate from the first mixture from step b).

15. A reaction system comprising:
(a) an activation vessel configured to form a first mixture, wherein the activation vessel is further configured for an average residence time of the first mixture in the activation vessel;
(b) one or more activation vessel inlets configured to introduce i) ethylene and a catalyst system mixture, or ii) ethylene and components of a catalyst system mixture, into the activation vessel;
(c) an activation vessel outlet configured to withdraw the first

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Bischof Steven M
• Hillier James L
• Kilgore Uriah J
• Hutchison Steve R
• Kreischer Bruce E
• Sydora Orson L

Classifications

• C07C2/36 Primary

  as phosphines, arsines, stilbines or bismuthines · CPC title

• Y02P20/52

  using catalysts, e.g. selective catalysts · CPC title

• B01J31/2438

  and further hetero atoms as ring members, excluding the positions adjacent to P · CPC title

• C07C2531/24

  Phosphines · CPC title

• C08F10/02 Primary

  Ethene · CPC title