Reduced polymer formation for selective ethylene oligomerizations

Patent metadata

Field	Value
Publication number	US-10774015-B2
Application number	US-201916546583-A
Country	US
Kind code	B2
Filing date	Aug 21, 2019
Priority date	May 27, 2016
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

Disclosed herein are processes, systems, and reaction systems for the oligomerization of ethylene to form an ethylene oligomer product in a reaction zone using a catalyst system having i) a chromium component comprising a heteroatomic ligand chromium compound complex of the type disclosed herein, and ii) an aluminoxane. A C3+ olefin can be present in the reaction zone for a period of time, where the C3+ olefin is not an ethylene oligomer formed in-situ within the reaction zone.

First claim

What is claimed is:

1. A reaction system comprising:
a reaction zone configured to form an oligomer product, the reaction zone comprising ethylene, an organic reaction medium, a catalyst system, a C 3+ olefin, and optionally hydrogen;
a first reaction zone inlet connected to the reaction zone and configured to introduce the catalyst system comprising i) a chromium component comprising a heteroatomic ligand chromium compound complex, and ii) an aluminoxane to the reaction zone;
a second reaction zone inlet connected to the reaction zone and configured to introduce a feedstock mixture comprising ethylene, at least a portion of the organic reaction medium, and optionally hydrogen to the reaction zone;
a C 3+ olefin feed line in fluid communication with the first reaction zone inlet, the second reaction zone inlet, or a third reaction zone inlet, wherein the C 3+ olefin feed line is configured to introduce the C 3+ olefin to the reaction zone;
an ethylene feed line comprising ethylene and optionally hydrogen; and
an organic reaction medium feed line comprising the organic reaction medium, wherein the ethylene feed line and the organic reaction medium feed line are configured to combine to form a feedstock mixture line comprising the feedstock mixture, wherein the feedstock mixture line is connected to or coupled to the second reaction zone inlet;
a mixing device positioned between i) the joining of the ethylene feed line and the organic reaction medium feed line and ii) the second reaction zone inlet, configured to disperse the ethylene and the organic reaction medium in the feedstock mixture prior to the feedstock mixture entering the reaction zone; and
one or more reaction zone outlets connected to the reaction zone and configured to discharge a reaction zone effluent comprising an ethylene oligomer product from the reaction zone;
wherein the heteroatomic ligand chromium compound complex has the formula

where
each X 1s is independently selected from the group consisting of N, P, O, and S;
L 1s is a C 1 to C 20 organylene linking group, a C 1 to C 30 amin-di-yl group, or a C 1 to C 30 phosphin-di-yl group linking X 1s s;
each m is independently 1 or 2;
each R 1s is independently a C 1 to C 20 organyl group;
X is a halide, a C 1 to C 20 carboxylate, a C 1 to C 20 β-diketonate, or a C 1 to C 20 hydrocarboxide; and
p is from 2 to 6.

2. The reaction system of claim 1 , further comprising:
a catalyst system feed line connected to the first reaction zone inlet and configured to flow the catalyst system to the first reaction zone inlet.

3. The reaction system of claim 2 , wherein the C 3+ olefin feed line is connected to the catalyst system feed line.

4. The reaction system of claim 1 , wherein the reaction zone has a C 3+ olefin:ethylene weight ratio that decreases from a value of equal to or greater than 0.5:1 to a value less than 0.2:1 over a period of time, wherein the C 3+ olefin in the reaction zone that is used to determine the C 3+ olefin:ethylene weight ratio in the reaction zone is not an ethylene oligomer formed in-situ within the reaction zone.

5. The reaction system of claim 1 , wherein the C 3+ olefin feed line is connected to the organic reaction medium feed line.

6. The reaction system of claim 1 , wherein the C 3+ olefin feed line is connected to the ethylene feed line.

7. The reaction system of claim 1 , wherein the C 3+ olefin feed line is connected to the feedstock mixture line.

8. The reaction system of claim 1 , further comprising:
a pump located in the organic reaction medium feed line.

9. The reaction system of claim 8 , wherein the C 3+ olefin feed line is connected to a dispersed line formed by passing the feedstock mixture through the mixing device prior to flowing to the reaction zone via the second reaction zone inlet.

10. The reaction system of claim 1 , wherein the organic reaction medium is an aliphatic hydrocarbon.

11. The reaction system of claim 1 , wherein the C 3+ olefin comprises hexene, 1-octene, or a combination thereof; and wherein the ethylene oligomer product comprises hexenes and/or octenes.

12. A reaction system comprising:
a reaction zone configured to form an oligomer product, the reaction zone comprising ethylene, an organic reaction medium, a catalyst system, a C 3+ olefin, and optionally hydrogen;
a first reaction zone inlet connected to the reaction zone and configured to introduce the catalyst system comprising i) a chromium component comprising a heteroatomic ligand chromium compound complex, and ii) an aluminoxane to the reaction zone;
a second reaction zone inlet connected to the reaction zone and configured to introduce ethylene and optionally hydrogen to the reaction zone;
a third reaction zone inlet connected to the reaction zone and configured to introduce at least a portion of the organic reaction medium to the reaction zone;
a C 3+ olefin feed line in fluid communication with the first reaction zone inlet, the third reaction zone inlet, or a fourth reaction zone inlet, wherein the C 3+ olefin feed line is configured to introduce the C 3+ olefin to the reaction zone; and
one or more reaction zone outlets connected to the reaction zone and configured to discharge a reaction zone effluent comprising an ethylene oligomer product from the reaction zone,
wherein the heteroatomic ligand chromium compound complex has the formula

where
each X 1s is independently selected from the group consisting of N, P, O, and S;
L 1s is a C 1 to C 20 organylene linking group, a C 1 to C 30 amin-di-yl group, or a C 1 to C 30 phosphin-di-yl group linking X 1s s;
each m is independently 1 or 2;
each R 1s is independently a C 1 to C 20 organyl group;
X is a halide, a C 1 to C 20 carboxylate, a C 1 to C 20 β-diketonate, or a C 1 to C 20 hydrocarboxide; and
p is from 2 to 6.

13. The reaction system of claim 12 , further comprising:
a catalyst system feed line connected to the first reaction zone inlet and configured to flow the catalyst system to the first reaction zone inlet;
an ethylene feed line connected to the second reaction zone inlet and comprising the ethylene and optionally hydrogen, wherein the ethylene feed line is configured to flow ethylene and optionally hydrogen to the reaction zone via the second reaction zone inlet; and
an organic reaction medium feed line connected to the third reaction zone inlet and comprising the organic reaction medium and configured to flow the at least a portion of the organic reaction medium to the reaction zone via the third reaction zone inlet,
where the C 3+ olefin feed line is connected to the catalyst system feed line, the organic reaction medium feed line, or the fourth reaction zone inlet.

14. The reaction system of claim 12 , wherein the reaction zone has a C 3+ olefin:ethylene weight ratio that decreases from a value of equal to or greater than 0.5:1 to a value less than 0.2:1 over a period of time, wherein the C 3+ olefin in the reaction zone that is used to determine the C 3+ olefin:ethylene weight ratio in the reaction zone is not an ethylene oligomer formed in-situ within the reaction zone.

15. A reaction system comprising:
a reaction zone configured to form an oligomer product, the reaction zone comprising ethylene, an organic reaction medi

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Fern Jared T
• Sydora Orson L
• Kilgore Uriah J
• Bischof Steven M
• Fernandez Eric R

Classifications

• Y02P20/52

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

• C07C2/36 Primary

  as phosphines, arsines, stilbines or bismuthines · CPC title

• C07C2531/24

  Phosphines · CPC title

• B01J31/143

  of aluminium · CPC title

• C07C2531/12

  containing organo-metallic compounds or metal hydrides · CPC title