Method of recovering unreacted ethylene in ethylene oligomerization process

Patent metadata

Field	Value
Publication number	US-11952339-B2
Application number	US-202017629158-A
Country	US
Kind code	B2
Filing date	Jul 22, 2020
Priority date	Jul 24, 2019
Publication date	Apr 9, 2024
Grant date	Apr 9, 2024

Abstract

Provided is a method of recovering unreacted ethylene in an ethylene oligomerization process and reusing the ethylene as a raw material, and more particularly, to a method of recovering unreacted ethylene with an increased recovery rate of reuse. When the method of the present invention is used, most of unreacted ethylene may be dissolved in a solvent to be recovered without loss, and a low boiling point reaction product which is not dissolved in the solvent is removed to prevent an unreacted product from being concentrated in a reactor.

First claim

The invention claimed is:

1. A method of recovering unreacted ethylene in an ethylene oligomerization process, the method comprising:
in the ethylene oligomerization process,
mixing a first recovery stream comprising the unreacted ethylene and a low boiling point reaction product separated in a second separation device in a latter stage of a reactor with a solvent introduced to a reaction raw material;
transferring the mixture to a first separation device, wherein an oligomerization catalyst introduced to a reaction raw material is introduced to the first separation device;
separating the mixture into a first upper effluent comprising the low boiling point reaction product and a first lower effluent comprising the ethylene and the solvent in the first separation device;
transferring the first lower effluent in the first separation device to the reactor and performing an ethylene oligomerization reaction; and
transferring a first reactant reacted in the reactor to the second separation device and recovering the first recovery stream comprising the unreacted ethylene and the low boiling point reaction product as a second upper effluent and separating a reactant comprising C4 or higher olefin oligomers and the solvent as a second lower effluent.

2. The method of recovering unreacted ethylene of claim 1 , wherein the ethylene introduced to a reaction raw material is introduced to the first separation device or the reactor.

3. The method of recovering unreacted ethylene of claim 1 , wherein the low boiling point reaction product comprises any one or more selected from methane, ethane, carbon monoxide (CO), nitrogen (N 2 ), hydrogen (H 2 ), and oxygen (O 2 ).

4. The method of recovering unreacted ethylene of claim 1 , wherein the first separation device and the second separation device are any one selected from a flash drum and a distillation column or a combination thereof, respectively.

5. The method of recovering unreacted ethylene of claim 1 , wherein the solvent introduced to a reaction raw material is any one selected from toluene, benzene, ethylbenzene, cumene, xylene, hexane, octane, cyclohexane, methyl cyclohexane, diethyl ether, and tetrahydrofuran, or a mixed solvent of two or more thereof.

6. The method of recovering unreacted ethylene of claim 1 , wherein a content of the solvent introduced to a reaction raw material satisfies the following Relation 1:

0.02
≤

W
e

/

W
s

≤
1.0

[

Relation
⁢

⁢
1

]

wherein W e is a content of unreacted ethylene in the first recovery stream, and W s is a content of the solvent introduced to a reaction raw material.

7. The method of recovering unreacted ethylene of claim 1 , wherein operation conditions of the first separation device are performed under conditions satisfying the following Relations 2 and 3:

0.0005
≤

RS
1

/

(

RS
1

+

W
S

)

×
100

≤
5

[

Relation
⁢

⁢
2

]

2
≤

RS
e

/

(

RS
e

+

W
S

)

×
100

≤
60

[

Relation
⁢

⁢
3

]

wherein RS 1 is a content of the low boiling point reaction product dissolved in the solvent in the first separation device, Rs e is a content of the unreacted ethylene dissolved in the solvent in the first separation device, and W s is a content of the solvent introduced to the reaction raw material.

8. The method of recovering unreacted ethylene of claim 7 , wherein the operation conditions of the first separation device are performed under conditions satisfying the following Relations 4 and 5:

RS
1

/

R
1

×
100

≤
90

[

Relation
⁢

⁢
4

]

Assignees

• Sk Innovation Co Ltd
• Sk Geo Centric Co Ltd

Inventors

• Park Chansaem
• Bang Jinhwan
• Son Sungreal
• Song Inhyoup
• Jung Woosung
• Han Eol

Classifications

• C07C7/04 Primary

  by distillation · CPC title

• B01D3/06

  Flash distillation · CPC title

• B01D3/143

  by two or more of a fractionation, separation or rectification step · CPC title

• C07C2/08

  Catalytic processes · CPC title

• B01J19/0046 Primary

  Sequential or parallel reactions, e.g. for the synthesis of polypeptides or polynucleotides; Apparatus and devices for combinatorial chemistry or for making molecular arrays (synthesis methods per se C40B50/00) · CPC title