Reduced Polymer Formation For Selective Ethylene Oligomerizations

Patent metadata

Field	Value
Publication number	US-2017342001-A1
Application number	US-201615167009-A
Country	US
Kind code	A1
Filing date	May 27, 2016
Priority date	May 27, 2016
Publication date	Nov 30, 2017
Grant date	—

Abstract

Disclosed 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 comprising (a) a chromium component comprising an N 2 -phosphinyl amidine chromium compound complex, an N 2 -phosphinyl formamidine chromium compound complex, an N 2 -phosphinyl guanidine chromium compound complex, or any combination thereof, and (b) an aluminoxane. A C 3+ olefin can be present in the reaction zone for a period of time, where the C 3+ olefin is not an ethylene oligomer formed in-situ within the reaction zone.

First claim

What is claimed is:

1 . A process comprising:
a) contacting i) ethylene, ii) a catalyst system comprising (a) a chromium component comprising an N 2 -phosphinyl amidine chromium compound complex, an N 2 -phosphinyl formamidine chromium compound complex, an N 2 -phosphinyl guanidine chromium compound complex, or any combination thereof, and (b) an aluminoxane, iii) an organic reaction medium (any described herein), and iv) optionally hydrogen in a reaction zone; b) forming an ethylene oligomer product in the reaction zone; wherein ethylene, the catalyst system, and an organic reaction medium are introduced into the reaction zone, and for a C 3+ olefin/ethylene feed period of time a C 3+ olefin is introduced into the reaction zone, wherein over a reaction zone period of time the reaction zone has a C 3+ olefin:ethylene weight ratio that decreases from a value of at least 0.5:1 to a value less than 0.2:1, wherein the C 3+ olefin in the reaction zone and the C 3+ olefin of the reaction zone C 3+ olefin:ethylene weight ratio is not an ethylene oligomer formed in-situ within the reaction zone.

2 . The process of claim 1 , wherein over the C 3+ olefin/ethylene feed period of time the C 3+ olefin:ethylene weight ratio fed to the reaction zone decreases from a value of at least 0.5:1 to a value less than 0.2:1.

3 . The process of claim 2 , wherein ethylene and the C 3+ olefin are separately introduced to the reaction zone.

4 . The process of claim 2 , wherein ethylene, the C 3+ olefin, and the organic reaction medium are contacted to form a feedstock mixture and the feedstock mixture is introduced into the reaction zone.

5 . The process of claim 1 , wherein the C 3+ olefin comprises 1-hexene, 1-octene, or 1-hexene and 1-octene.

6 . The process of claim 1 , wherein after the C 3+ olefin/ethylene feed period of time, ethylene and the organic reaction medium are contacted to form a feedstock mixture prior to ethylene contacting the catalyst system.

7 . The process of claim 1 , wherein the ethylene oligomer product comprises hexenes and/or octenes.

8 . The process of claim 1 , wherein a mass of polymer per mass of oligomer in the reaction zone is less than the mass of polymer per mass of oligomer in the reaction zone in an otherwise similar process where the C 3+ olefin is not introduced to the reaction zone.

9 . The process of claim 1 , having a productivity greater than a productivity in an otherwise similar process where the C 3+ olefin is not introduced to the reaction zone.

10 . A process comprising:
a) introducing into a reaction zone containing a C 3+ olefin and optionally an organic reaction medium wherein the reaction zone is substantially devoid of ethylene;
i) ethylene
ii) a catalyst system comprising (a) a chromium component comprising an N 2 -phosphinyl amidine chromium compound complex, an N 2 -phosphinyl formamidine chromium compound complex, an N 2 -phosphinyl guanidine chromium compound complex, or any combination thereof, and (b) an aluminoxane,
iii) an organic reaction medium, and
iv) optionally hydrogen; and
b) forming an ethylene oligomer product in the reaction zone; wherein over a period of time the reaction zone has a C 3+ olefin:ethylene weight ratio which decreases from a value of at least 0.5:1 to a value less than 0.2:1, wherein the C 3+ olefin in the reaction zone and the C 3+ olefin of the reaction zone C 3+ olefin:ethylene weight ratio is not an ethylene oligomer formed in-situ within the reaction zone.

11 . The process of claim 10 , wherein the C 3+ olefin comprises 1-hexene, 1-octene, or a combination thereof, wherein the 1-hexene and 1-octene is not an ethylene oligomer formed in-situ within the reaction zone.

12 . The process of claim 10 , wherein, after the period of time, ethylene and the organic reaction medium are contacted to form a feedstock mixture prior to ethylene contacting the catalyst system.

13 . The process of claim 10 , wherein the ethylene oligomer product comprises hexenes and/or octenes.

14 . The process of claim 10 , wherein a mass of polymer per mass of oligomer in the reaction zone is less than the mass of polymer per mass of oligomer in the reaction zone in an otherwise similar process where ethylene is introduced into the reaction zone which does not contain the C 3+ olefin.

15 . The process of claim 10 , having a productivity greater than a productivity in an otherwise similar process where ethylene is introduced into the reaction zone which does not contain the C 3+ olefin.

16 . A reaction system comprising:
a reaction zone; a first reaction zone inlet configured to introduce a catalyst system comprising i) a chromium component comprising an N 2 -phosphinyl amidine chromium compound complex, an N 2 -phosphinyl formamidine chromium compound complex, an N 2 -phosphinyl guanidine chromium compound complex, or any combination thereof, and ii) an aluminoxane to the reaction zone; a second reaction zone inlet configured to introduce ethylene, an 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 configured to introduce a C 3+ olefin to the reaction zone; and one or more reaction zone outlets configured to discharge the reaction zone effluent comprising an ethylene oligomer product from the reaction zone.

17 . The reaction system of claim 16 , further comprising:
a catalyst system feed line flowing the catalyst system to the first reaction zone inlet; an ethylene feed line comprising the ethylene; an organic reaction medium feed line comprising the organic reaction medium, wherein the organic reaction medium feed line and the ethylene feed line combine to yield the feedstock mixture which is introduced to the reaction zone via the second reaction zone inlet, wherein the C 3+ olefin feed line combines with at least one of the catalyst system feed line, the ethylene feed line, the organic reaction medium feed line, the feedstock mixture, or a dispersed feedstock mixture formed by passing the feedstock mixture through a mixing device prior to flowing to the reaction zone via the second reaction zone inlet.

18 . The reaction system of claim 17 , further comprising:
a pump in fluid communication with the second reaction zone inlet and which is located upstream of a point where the ethylene feed line and the organic reaction medium feed line join to produce the feedstock mixture.

19 . The reaction system of claim 17 , further comprising:
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 to disperse the ethylene and the organic reaction medium prior to the feedstock mixture entering the reaction zone.

20 . The reaction system of claim 16 , wherein during steady state operation, the first reaction zone inlet is configured to periodically or continuously introduce the catalyst system to the reaction zone, the second reaction zone inlet is configured to periodically or continuously introduced the feedstock mixture to the reaction zone, and the one or more reaction zone outlets are configured to periodically or continuously discharge the reaction zone effluent from the reaction zone.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

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

Classifications

• C07F11/005

  compounds without a metal-carbon linkage · CPC title

• B01J31/143

  of aluminium · CPC title

• C07F9/6561

  containing systems of two or more relevant hetero rings condensed among themselves or condensed with a common carbocyclic ring or ring system, with or without other non-condensed hetero rings · CPC title

• B01J31/24

  Phosphines {, i.e. phosphorus bonded to only carbon atoms, or to both carbon and hydrogen atoms, including e.g. sp2-hybridised phosphorus compounds such as phosphabenzene, phosphole or anionic phospholide ligands} · CPC title

• C07C2531/34

  of chromium, molybdenum or tungsten · CPC title