Method for producing polyolefin and polyolefin production system

Patent metadata

Field	Value
Publication number	US-10683373-B2
Application number	US-201816114489-A
Country	US
Kind code	B2
Filing date	Aug 28, 2018
Priority date	Aug 29, 2017
Publication date	Jun 16, 2020
Grant date	Jun 16, 2020

Abstract

A polyolefin production system is provided. The polyolefin production system includes a plurality of gas-phase polymerization tanks configured to polymerize an olefin gas to form a polyolefin, a gas transfer series line connecting the plurality of the gas-phase polymerization tanks to each other in series, a compressor having an inlet and an outlet and being configured to compress an olefin-containing gas, a gas main feed line disposed at the frontmost gas-phase polymerization tank and configured to guide the gas fed from the outlet of the compressor to the frontmost gas-phase polymerization tank, a gas discharge line disposed at the rearmost gas-phase polymerization tank, and a first valve installed in the gas main feed line.

First claim

What is claimed is:

1. A polyolefin production system comprising:
a plurality of gas-phase polymerization tanks configured to polymerize an olefin gas to form a polyolefin;
a gas transfer series line connecting the plurality of the gas-phase polymerization tanks to each other in series;
a compressor comprising an inlet and an outlet and being configured to compress an olefin-containing gas;
a gas main feed line disposed at the frontmost gas-phase polymerization tank, configured to guide the gas fed from the outlet of the compressor to the frontmost gas-phase polymerization tank;
a gas discharge line disposed at the rearmost gas-phase polymerization tank; and
a first valve installed in the gas main feed line.

2. The polyolefin production system according to claim 1 , wherein the first valve is a butterfly valve or an eccentric rotary plug valve.

3. The polyolefin production system according to claim 1 , further comprising a second valve installed in the gas transfer series line connecting at least one pair of the gas-phase polymerization tanks to each other.

4. The polyolefin production system according to claim 1 , further comprising a second valve installed in the gas discharge line.

5. The polyolefin production system according to claim 3 , wherein the second valve is a butterfly valve or an eccentric rotary plug valve.

6. The polyolefin production system according to claim 1 , further comprising a gas sub-feed line connecting at least one of the gas-phase polymerization tanks other than the frontmost gas-phase polymerization tank to the outlet of the compressor without going through each of other gas-phase polymerization tanks.

7. The polyolefin production system according to claim 6 , further comprising a third valve installed in the gas sub-feed line.

8. The polyolefin production system according to claim 1 , further comprising a gas purge line connecting the gas transfer series line to the inlet of the compressor without going through each of other gas-phase polymerization tanks.

9. The polyolefin production system according to claim 8 , further comprising a fourth valve installed in the gas purge line.

10. The polyolefin production system according to claim 1 , further comprising a particle transfer series line connecting the plurality of the gas-phase polymerization tanks to each other in series.

11. The polyolefin production system according to claim 1 , comprising in each of the gas-phase polymerization tanks a cone member having a tapered slope with inner diameter thereof becoming smaller downward and an opening at the bottom end of the tapered slope, or a distributor.

12. The polyolefin production system according to claim 1 , wherein the inner diameter of the gas transfer series line is smaller than the inner diameter of each of the gas-phase polymerization tanks.

13. A method for producing a polyolefin with use of the polyolefin production system according to claim 1 , comprising:
a step of feeding an olefin-containing gas compressed by the compressor to the frontmost gas-phase polymerization tank through the gas main feed line;
a step of transferring the gas discharged from the frontmost gas-phase polymerization tank to the rearmost gas-phase polymerization tank through the gas transfer series line, sequentially;
a step of returning the gas discharged from the rearmost gas-phase polymerization tank to the compressor through the gas discharge line; and
a step of controlling the flow rate of the gas to be fed to the frontmost gas-phase polymerization tank through the gas main feed line by the first valve installed in the gas main feed line.

14. A method for producing a polyolefin with use of the polyolefin production system according to claim 3 , comprising:
a step of feeding an olefin-containing gas compressed by the compressor to the frontmost gas-phase polymerization tank through the gas main feed line;
a step of transferring the gas discharged from the frontmost gas-phase polymerization tank to the rearmost gas-phase polymerization tank through the gas transfer series line, sequentially;
a step of returning the gas discharged from the rearmost gas-phase polymerization tank to the compressor through the gas discharge line;
a step of controlling the flow rate of the gas to be fed to the frontmost gas-phase polymerization tank through the gas main feed line by the first valve installed in the gas main feed line; and
a step of controlling the aperture of the second valve in such a manner that the pressure in the upstream gas-phase polymerization tank than the second valve, the difference between the pressure in the upstream gas-phase polymerization tank than the second valve and the pressure in the further upstream gas-phase polymerization tank than the upstream gas-phase polymerization tank, or the difference between the pressure in the upstream gas-phase polymerization tank than the second valve and the pressure in the downstream gas-phase polymerization tank than the second valve is in a predetermined range.

15. A method for producing a polyolefin with use of the polyolefin production system according to claim 4 , comprising:
a step of feeding an olefin-containing gas compressed by the compressor to the frontmost gas-phase polymerization tank through the gas main feed line;
a step of transferring the gas discharged from the frontmost gas-phase polymerization tank to the rearmost gas-phase polymerization tank through the gas transfer series line, sequentially;
a step of returning the gas discharged from the rearmost gas-phase polymerization tank to the compressor through the gas discharge line;
a step of controlling the flow rate of the gas to be fed to the frontmost gas-phase polymerization tank through the gas main feed line by the first valve installed in the gas main feed line; and
a step of controlling the aperture of the second valve in such a manner that the difference between the pressure in one of the gas-phase polymerization tanks and the pressure in the downstream part than the second valve in the gas discharge line is in a predetermined range.

16. A method for producing a polyolefin with use of the polyolefin production system according to claim 6 , comprising:
a step of feeding an olefin-containing gas compressed by the compressor to the frontmost gas-phase polymerization tank through the gas main feed line;
a step of transferring the gas discharged from the frontmost gas-phase polymerization tank to the rearmost gas-phase polymerization tank through the gas transfer series line, sequentially;
a step of returning the gas discharged from the rearmost gas-phase polymerization tank to the compressor through the gas discharge line;
a step of controlling the flow rate of the gas to be fed to the frontmost gas-phase polymerization tank through the gas main feed line by the first valve installed in the gas main feed line; and
a step of feeding the olefin-containing gas compressed by the compressor to at least one of the gas-phase polymerization tanks other than the frontmost gas-phase polymerization tank through the gas sub-feed line.

17. A method for producing a polyolefin with use of the polyolefin production system according to claim 7 , comprising:
a step of feeding an olefin-containing gas compressed by the compressor to the frontmost gas-phase polymerization tank through the gas main feed line;
a step of transferring the gas discharged from the frontmost gas-phase polymerization tank to the rearmost gas-phase polymerization tank through the gas transfer series line, sequentially;
a step of returning the gas discharged f

Assignees

• Sumitomo Chemical Co

Inventors

• Itoguchi Satoshi
• Suruvu Naganjaneyulu
• Funaoka Shunpei

Classifications

• B01J19/0033

  Optimalisation processes, i.e. processes with adaptive control systems (adaptive control systems per se G05B13/00) · CPC title

• B01J8/245

  Spouted-bed technique · CPC title

• B01J19/0053

  Details of the reactor · CPC title

• C08F10/00

  Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond · CPC title

• C08F10/06 Primary

  Propene · CPC title