Multiple reactor and multiple zone polyolefin polymerization

Patent metadata

Field	Value
Publication number	US-11845815-B2
Application number	US-202318094792-A
Country	US
Kind code	B2
Filing date	Jan 9, 2023
Priority date	Dec 27, 2018
Publication date	Dec 19, 2023
Grant date	Dec 19, 2023

Abstract

Apparatuses and processes that produce multimodal polyolefins, and in particular, polyethylene resins, are disclosed herein. This is accomplished by using two reactors in series, where one of the reactors is a multi-zone circulating reactor that can circulate polyolefin particles through two polymerization zones optionally having two different flow regimes so that the final multimodal polyolefin has improved product properties and improved product homogeneity.

First claim

What is claimed is:

1. An apparatus for producing a multimodal polyolefin, comprising:
a first reactor configured to produce a first polyolefin;
a second reactor configured to produce a second polyolefin and a third polyolefin, where the second reactor comprises:
a riser configured to produce the second polyolefin;
an upper conduit having an end fluidly connected to a top portion of the riser;
a separator fluidly connected to an opposite end of the upper conduit;
a downcomer configured to produce the third polyolefin, wherein a top portion of the downcomer is fluidly connected to the separator, optionally via a liquid barrier in the top portion of the downcomer; and
a lower conduit having an end fluidly connected to a bottom portion of the downcomer and an opposite end fluidly connected to a bottom portion of the riser, wherein:
the second reactor is configured to receive the first polyolefin from the first reactor, or,
the first reactor is configured to receive the second polyolefin and the third polyolefin from the second reactor.

2. The apparatus of claim 1 , further comprising:
a product discharge conduit fluidly connected to i) a bottom portion of the downcomer, or ii) the first reactor; and
a heater having an end fluidly connected to the product discharge conduit and configured to receive a product mixture from the product discharge conduit and to add heat to the product mixture.

3. The apparatus of claim 1 , wherein the heater is further configured to discharge a polymer product in the product mixture at a temperature i) of about 130° F. to about 220° F., or ii) below a melting point of the polymer product.

4. The apparatus of claim 1 , further comprising:
a product discharge conduit fluidly connected to i) a bottom portion of the downcomer or ii) the first reactor,
wherein the product discharge conduit further comprises a continuous take-off valve.

5. The apparatus of claim 4 , wherein the continuous take-off valve has a flow channel diameter greater than a maximum expected polymer particle size when the continuous take-off valve is 20-25% open.

6. The apparatus of claim 1 , further comprising:
a product discharge conduit fluidly connected to i) a bottom portion of the downcomer, or ii) the first reactor; and
a separation vessel fluidly connected to the product discharge conduit, wherein the separation vessel is configured to separate the product mixture into a plurality of streams, each of the plurality of streams comprising a vapor, a polymer product, or both the vapor and the polymer product.

7. The apparatus of claim 6 , further comprising:
a monomer recovery system configured to recover one or more of a monomer, a comonomer, and a diluent from at least one of the plurality of streams comprising the vapor and configured to recycle one or more of the monomer, the comonomer, and the diluent to the first reactor, the second reactor, or both the first reactor and the second reactor.

8. The apparatus of claim 6 , further comprising:
a degassing vessel configured to receive the polymer product from the separation vessel and to remove at least a portion of a hydrocarbon entrained within the polymer product.

9. The apparatus of claim 7 , further comprising:
a degassing vessel configured to receive the polymer product from the separation vessel and to remove at least a portion of a hydrocarbon entrained within the polymer product.

10. The apparatus of claim 1 , wherein the separator comprises a cyclone.

11. The apparatus of claim 10 , wherein the riser is configured to produce a riser product mixture comprising solid particles and a gas mixture, wherein the cyclone is configured to receive the riser product mixture via the upper conduit, wherein the cyclone is a high efficiency cyclone configured to separate 99 wt % or more of the solid particles which have a size of about 2 μm or more from the gas mixture.

12. The apparatus of claim 10 , wherein the cyclone is configured to have a cone angle with respect to horizontal of about 45° to about 80°.

13. The apparatus of claim 10 , wherein the cyclone is configured to have a tangential entrance angle of 0° to 15°.

14. The apparatus of claim 10 , wherein the cyclone is configured to have a tangential entrance velocity of 50 ft/sec to 100 ft/sec.

15. The apparatus of claim 10 , wherein an angle with respect to horizontal of the opposite end of the upper conduit which fluidly connects to the cyclone is about 0° to about 15°.

16. The apparatus of claim 10 , wherein the opposite end of the upper conduit connects to the cyclone at a location about ft to about 20 ft below a top of the cyclone.

17. The apparatus of claim 1 , further comprising:
a reactor deactivation system in the second reactor, wherein the reactor deactivation system is configured to moderate or kill polymerization reactions in the riser, the downcomer, or both the riser and the downcomer.

18. The apparatus of claim 1 , further comprising one or more anti-static agent feed lines configured to inject an anti-static agent into the second reactor.

19. The apparatus of claim 18 , wherein the one or more anti-static agent lines are configured to inject a mixture comprising the anti-static agent and a carrier fluid and wherein a concentration of the anti-static agent in each of the one or more anti-static agent feed lines is about 1 ppm to about 50 ppm based on weight of the carrier fluid in each of the one or more anti-static agent feed lines.

20. The apparatus of claim 18 , wherein a concentration of the anti-static agent in the second reactor is about 1 ppm to about 50 ppm based on weight of the carrier fluid in the second reactor.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Curren Joseph A
• Gonzales Rebecca A
• Kufeld Scott E
• Mutchler Joel A
• Netemeyer Eric J
• Sutherland Jamie N
• Deslauriers Paul J
• Fodor Jeffrey S

Classifications

• C08F10/02 Primary

  Ethene · CPC title

• B01J8/0055

  using cyclones · CPC title

• B01J8/1827

  the fluidising gas being a reactant · CPC title

• B01J8/1836

  Heating and cooling the reactor (B01J8/42 takes precedence) · CPC title

• B01J8/1863

  followed by a downward movement outside the reactor and subsequently re-entering it · CPC title