Unified cooling in multiple polyolefin polymerization reactors

Patent metadata

Field	Value
Publication number	US-9310137-B2
Application number	US-201313872746-A
Country	US
Kind code	B2
Filing date	Apr 29, 2013
Priority date	Apr 29, 2013
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A system and method for a polyolefin reactor temperature control system having a first reactor temperature control path, a second reactor temperature control path, and a shared temperature control path. The shared temperature control path is configured to combine and process coolant return streams, and to provide coolant supply for the first reactor temperature control path and the second reactor temperature control path.

First claim

What is claimed is:

1. A polyolefin reactor temperature control system comprising:
(a) a first reactor temperature control path for:
a first control feed stream to split into at least (1) a first cooler zone feed stream to pass through a first cooler zone to produce a first cooler zone output stream and (2) a first cooler zone bypass stream;
a first treated stream having a first treated stream temperature and comprising the first cooler zone output stream and the first cooler zone bypass stream; and
a first recycle stream comprising the first treated stream after the first treated stream has exchanged energy with a first polyolefin reactor;

(b) a second reactor temperature control path for:
a second control feed stream to split into at least (1) a second cooler feed stream to pass through a second cooler zone to produce a second cooler zone output stream and (2) a second cooler zone bypass stream;
a second treated stream having a second treated stream temperature and comprising the second cooler zone output stream and the second cooler zone bypass stream; and
a second recycle stream comprising the second treated stream after the second treated stream has exchanged energy with a second polyolefin reactor; and

(c) a shared temperature control path configured to:
combine the first and second recycle streams to form a combined recycle stream;
process the combined recycle stream through shared system equipment to form a shared output stream; and
split the shared output stream into the first control feed stream and the second control feed stream.

2. The reactor temperature control system of claim 1 , further comprising a first treated stream control system configured to adjust the first treated stream temperature by manipulating flow rates of one or more of the following: the first cooler zone feed stream, the first cooler zone output stream, or the first cooler zone bypass stream.

3. The reactor temperature control system of claim 1 , further comprising a second treated stream control system configured to adjust the second treated stream temperature by manipulating flow rates of one or more of the following: the second cooler zone feed stream, the second zone output stream, or the second cooler zone bypass stream.

4. The reactor control system of claim 1 , wherein the first control feed stream is further configured to be split into a first heater zone feed stream to pass through a first heater zone to produce a first heater zone output stream, and wherein the first treated stream further comprises the first heater zone output stream.

5. The reactor temperature control system of claim 4 , further comprising a first treated stream control system configured to adjust the first treated stream temperature by manipulating flow rates of one or more of the following: the first cooler zone feed stream, first cooler zone output stream, the first cooler zone bypass stream, the first heater zone feed stream, or the first heater zone output stream.

6. The reactor control system of claim 4 , wherein the first heater zone comprises a sparger or a shell-and-tube exchanger, or a combination thereof.

7. The reactor control system of claim 1 , wherein the second control feed is further configured to be split into a second heater zone feed stream configured to pass through a second heater zone to produce a second heater zone output stream, and wherein the second treated stream further comprises the second heater zone output stream.

8. The reactor temperature control system of claim 7 , further comprising a second treated stream control system configured to adjust the second treated stream temperature by manipulating flow rates of one or more of the following: the second cooler zone feed stream, the second cooler zone output stream, the second cooler zone bypass stream, the second heater zone feed stream, or the second heater zone output stream.

9. The reactor control system of claim 1 , wherein the first reactor temperature control path is further configured to route the first cooler zone bypass stream through a first heater zone.

10. The reactor control system of claim 9 , wherein the first reactor temperature control path is configured to further split the first control feed stream into a first secondary bypass stream through a flow control valve, and wherein the first treated stream further comprises the first secondary bypass stream.

11. The reactor control system of claim 1 , wherein the second reactor temperature control path is configured to route the second cooler zone bypass stream through a second heater zone.

12. The reactor control system of claim 11 , wherein the second reactor temperature control path is configured to further split the second control feed stream into a second secondary bypass stream to through a flow control valve, and wherein the second treated stream further comprises the second secondary bypass stream.

13. The reactor temperature control system of claim 1 , wherein the first reactor temperature control path is configured to pass the first control feed stream through a first heater zone before being split into at least the first cooler zone feed stream and the first cooler zone bypass stream.

14. The reactor temperature control system of claim 1 , wherein the second reactor temperature control path is configured to pass the second control feed stream through a second heater zone before being split into at least the second cooler zone feed stream and the second cooler zone bypass stream.

15. The reactor temperature control system of claim 1 , wherein the shared system equipment comprises a coolant pump configured to provide the shared output stream.

16. The reactor temperature control system of claim 15 , wherein the coolant pump is a centrifugal pump.

17. The reactor temperature control system of claim 1 , wherein the shared system equipment comprises a coolant pump configured to simultaneously provide the first control feed and the second control feed.

18. The reactor temperature control system of claim 1 , wherein the shared system equipment comprises a surge tank fluidically connected to a coolant pump.

19. The reactor temperature control system of claim 1 , wherein the first control feed stream comprises water.

20. The reactor temperature control system of claim 1 , wherein the first reactor temperature is controlled within 0.5° F. of a first reactor temperature set point.

21. The reactor temperature control system of claim 1 , wherein the first reactor temperature is controlled within 0.25° F. of a first reactor temperature set point.

22. The reactor temperature control system of claim 1 , wherein the first cooler zone comprises at least two coolers.

23. The reactor temperature control system of claim 1 , wherein the first cooler zone comprises at least four coolers.

24. The reactor temperature control system of claim 1 , wherein the first recycle stream and the first treatment stream have a temperature difference of at least 10° F.

25. The reactor temperature control system of claim 1 , wherein the first recycle stream and the first treatment stream have a temperature difference of at least 25° F.

26. The reactor temperature control system of claim 1 , wherein the first recycle stream and the first treatment stream have a temperature difference of at least 40° F.

27. The reactor temperature control system of claim 1 , wherein the first reactor has a first re

Assignees

• Chevron Phillips Chemical Co

Inventors

• Odi Timothy O
• Gupta Anurag
• Romig Ralph W

Classifications

• F28D15/00 Primary

  Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls {; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies (F28D17/00, F28D19/00, F28D20/00 take precedence)} · CPC title

• C08F2/01 Primary

  characterised by special features of the polymerisation apparatus used · CPC title

• C08F2/001

  Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer (C08F295/00, C08F297/00 take precedence) · CPC title

• B01J2219/00094

  Jackets · CPC title

• B01J19/1862

  placed in series · CPC title