System and process for producing polyethylene

Patent metadata

Field	Value
Publication number	US-9834624-B2
Application number	US-201415027587-A
Country	US
Kind code	B2
Filing date	Oct 7, 2014
Priority date	Oct 11, 2013
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

Systems and processes for generating polyethylene are provided. A process includes performing a first reaction with methane and oxygen to produce a first product; performing a second reaction with the first product to produce a second product; separating components from the second product; returning ethane from the second product and performing a reaction simultaneous to the first reaction; performing a third reaction to produce a third product including polyethylene and vented methane; and returning the vented methane to a feed to the first reaction.

First claim

We claim:

1. A process for producing polyethylene from methane, comprising:
receiving a first feed comprising methane and oxygen;
performing a first reaction in the presence of a first oxidation catalyst to produce a first product comprising methane, ethylene, hydrogen, ethane, propane, propylene, carbon monoxide, carbon dioxide, and water;
performing a second reaction in the presence of a second catalyst to produce a second product comprising methane, ethylene, ethane, propane, propylene, carbon dioxide, and water;
separating off ethane, propane, propylene, carbon dioxide, and water from the second product;
receiving a second feed comprising ethane separated from the second product and oxygen and performing a reaction simultaneous to the first reaction;
performing a third reaction to produce a third product comprising polyethylene and vented methane; and
returning the vented methane to the first feed.

2. The process of claim 1 , wherein the performing a first, second, and third reactions takes place in different reaction chambers.

3. The process of claim 1 , wherein the performing a first reaction comprises maintaining a temperature of about 700° C. to about 950° C.

4. The process of claim 1 , wherein the first oxidation catalyst comprises a sodium-manganese oxide-based mixed silicon dioxide compound.

5. The process of claim 1 , wherein the performing a second reaction comprises maintaining a temperature of about 100° C. to about 200° C.

6. The process of claim 1 , wherein the performing a second reaction comprises removing carbon monoxide from the first product.

7. The process of claim 1 , further comprising substantially separating water and carbon dioxide from the second product to create a second product intermediary, and then separating ethane, propane, and propylene from the second product intermediary.

8. The process of claim 1 , wherein the reaction simultaneous to the first reaction comprises oxidative dehydrogenation of ethane.

9. The process of claim 1 , wherein the first reaction takes place in a first reactor and second feed comprising ethane separated from the second product and oxygen is fed to a lower portion of the first reactor.

10. The process of claim 8 , wherein the first reaction takes place in a first reactor at a first set of conditions and wherein the oxidative dehydrogenation of ethane takes place in the first reactor at the first set of conditions.

11. The process of claim 1 , further comprising feeding a co-monomer to the third reaction.

12. The process of claim 1 , further comprising feeding hydrogen to the third reaction.

13. The process of claim 1 , wherein methane and ethylene, fed from the second product to the third reaction, comprises about 10% to about 80% methane and about 20% to about 90% ethylene by weight.

14. The process of claim 1 , wherein the performing a third reaction comprises maintaining a temperature of about 100° C. and a pressure of about 2 MegaPascals.

15. A system for generating polyethylene, comprising:
an inlet line to feed a first reactor;
a first reactor, coupled to the inlet line, configured to perform a reaction in the presence of a first oxidation catalyst to produce a first product comprising methane, ethylene, hydrogen, ethane, propane, propylene, carbon monoxide, carbon dioxide, and water;
a first feed line, coupled to the first reactor, to feed the first product;
a second reactor, coupled to the first feed line, configured to perform a reaction in the presence of a second catalyst to produce a second product comprising methane, ethylene, ethane, propane, propylene, carbon dioxide, and water;
an outlet line to separate off ethane, propane, propylene, carbon dioxide, and water from the second product;
a second feed line to feed ethane separated from the second product and oxygen to the first reactor;
a third reactor, configured to perform a reaction to produce a third product comprising polyethylene;
a third feed line coupled to the third reactor to feed methane and ethylene from the second product to the third reactor;
and
a second outlet line, coupled to the third reactor, to allow methane to vent from the third reactor, the second outlet line configured to return methane vented from the third reactor to the first feed.

16. The system of claim 15 , further comprising separation units, coupled to the outlet line, to separate off ethane, propane, propylene, carbon dioxide, and water from the second product.

17. The system of claim 16 , wherein the separation units comprise a propylene refrigeration cold box.

18. The system of claim 15 , wherein the third reactor comprises a venting unit.

19. The system of claim 15 , further comprising a fourth feed line, coupled to the third feed line, to feed a co-monomer to the third reactor.

20. The system of claim 15 , wherein the second feed line is coupled to a lower portion of the first reactor.

Assignees

• Saudi Basic Ind Corp

Inventors

• Mamedov Aghaddin
• Abdelghani Mohamed Sabri

Classifications

• C08F10/02 Primary

  Ethene · CPC title

• C07C2/84

  catalytic · CPC title

• C07C5/48

  with oxygen as an acceptor · CPC title

• B01J8/1818

  Feeding of the fluidising gas (B01J8/44 takes precedence) · CPC title

• C07C2/78 Primary

  Processes with partial combustion · CPC title