High-pressure polymerization process of ethylenically unsaturated monomers in a tubular reactor

Patent metadata

Field	Value
Publication number	US-9631037-B2
Application number	US-201615240084-A
Country	US
Kind code	B2
Filing date	Aug 18, 2016
Priority date	Jul 23, 2015
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

The present technology relates to a process for polymerizing or copolymerizing ethylenically unsaturated monomers in the presence of free-radical polymerization initiators, wherein the polymerization is carried out in a continuously operated tubular reactor at temperatures from 100° C. to 350° C. and pressures from 180 MPa to 340 MPa, with a specific reactor surface area A sp of 2 m 2 /(t/h) to 5.5 m 2 /(t/h), and the tubular reactor has a specific ratio RD sp of 0.0050 MPa −1 to 0.0069 MPa −1 and an inner surface which has a surface roughness Ra of 2 μm or less.

First claim

What is claimed is:

1. A tubular reactor for polymerizing or copolymerizing ethylenically unsaturated monomers, comprising a pipe having:
a length ranging from 0.5 km to 5 km, an inner diameter d i ranging from 50 mm to 120 mm, and a length-to-diameter ratio ranging from 1000 to 50000;
an inner surface which has a surface roughness Ra of 2 μm or less, determined according to DIN EN ISO 4287:2010; and
an inlet and at least two spatially separated initiator injection points downstream of the inlet.

2. The tubular reactor of claim 1 , wherein the pipe has a specific ratio RD sp ranging from 0.0050-0.0069 MPa −1 , RD sp being the ratio of an outer diameter d o to the inner diameter d i divided by a design pressure p des according to the equation:

RD
sp

=

d
o

d
i

*

p
des

.

3. The tubular reactor of claim 2 , wherein the design pressure p des of the tubular reactor ranges from 240 MPa to 400 MPa.

4. The tubular reactor of claim 1 , wherein the pipe has a ratio of an outer diameter d o to the inner diameter d i ranging from 1.2 to 2.76.

5. The tubular reactor of claim 1 , wherein the pipe has a specific reactor surface area A sp ranging from 2 m 2 /(t/h) to 5.5 m 2 /(t/h), the specific reactor surface area A sp being a ratio of an area of the inner surface of the tubular polymerization reactor to a design feed rate of reaction gas composition to the pipe.

6. The tubular reactor of claim 5 , wherein the design feed rate of the reaction gas composition to the tubular reactor ranging from 80 t/h to 210 t/h.

7. The tubular reactor of claim 1 , wherein the pipe is comprised of plurality of tubes, wherein each of the tubes has an individual length ranging from 5 m to 25 m.

8. The tubular reactor of claim 1 , wherein the pipe has a tensile strength R m of at least 1100 N/mm 2 , determined according to EN ISO 6892-1:2009.

9. The tubular reactor of claim 1 , wherein an outer diameter d o and the inner diameter d i of the pipe is essentially the same over the length of the pipe.

10. The tubular reactor of claim 1 , wherein an outer diameter d o of the pipe, the inner diameter d i of the pipe, or both of the outer diameter d o and the inner diameter d i varies over the length of the pipe.

11. A process for polymerizing or copolymerizing ethylenically unsaturated monomers, comprising:
feeding a reaction gas into a tubular reactor having an inner surface which has a surface roughness Ra of 2 μm or less, determined according to DIN EN ISO 4287:2010;
feeding an initiator into the tubular reactor in a concentration ranging from 0.1 mol/t to 50 mol/t; and
polymerizing the reaction gas in the tubular reactor at a temperature ranging from 100° C. to 350° C. and a pressure ranging from 180 MPa to 340 MPa.

12. The process of claim 11 , wherein the tubular reactor has a specific ratio RD sp ranging from 0.0050-0.0069 MPa −1 , RD sp being the ratio of the outer diameter d o to the inner diameter d i divided by the design pressure p des according to the equation:

RD
sp

=

d
o

d
i

*

p
des

.

13. The process of claim 11 , further comprising:
feeding a 30-90% by weight portion of the reaction gas to an inlet of the tubular reactor; and
feeding a 10-70% by weight portion of the reaction gas to one or more side streams of the tubular reactor downstream of the inlet of the tubular reactor.

14. The process of claim 11 , wherein the surface roughness Ra is between 2 μm and 0.4 μm, determined according to DIN EN ISO 4287:2010.

15. The process of claim 11 , wherein the tubular reactor has a specific reactor surface area A sp ranging from 2 m 2 /(t/h) to 5.5 m 2 /(t/h), the specific reactor surface area A sp being a ratio of an area of the inner surface of the tubular polymerization reactor to a design feed rate of reaction gas composition to the pipe.

16. A tubular reactor for use in a high-pressure polymerization process of ethylenically unsaturated monomers; comprising:
a plurality of tubes, each of the tubes having a length ranging from 5 m to 25 m, an inner diameter d i ranging from 50 mm to 120 mm, a ratio of the outer diameter d o to the inner diameter d i ranging from 1.2 to 2.76, and an inner surface which has a surface roughness Ra of 2 μm or less, determined according to DIN EN ISO 4287:2010;
a plurality of bends connecting the plurality of tubes; and
the plurality of tubes and plurality of bends having a design pressure p des ranging from 240 MPa to 400 MPa and a tensile strength R m of at least 1100 N/mm 2 , determined according to EN ISO 6892-1:2009.

17. The tubular reactor of claim 16 , wherein the plurality of tubes have a specific ratio RD sp ranging from 0.0050-0.0069 MPa −1 , RD sp being the ratio of the outer diameter d o to the inner diameter d i divided by the design pressure p des according to the equation:

RD
sp

=

d
o

d
i

*

p
des

.

18. The tubular reactor of claim 16 , wherein the tube has a specific reactor surface area A sp ranging from 2 m 2 /(t/h) to 5.5 m 2 /(t/h), the specific reactor surface area A sp being a ratio of an area of the inner surface of the tubular polymerization reactor to a design feed rate of reaction gas composition to the pipe.

19. The tubular reactor of claim 16 , wherein each of the plurality of bends has a bend angle of 180°.

20. The tubular reactor of claim 16 , wherein each of the plurality of bends has a bend ratio R/do of 4 or less, in which R is the radius of curvature of the bending and do is the outer diameter of the bend.

Assignees

• Basell Polyolefine Gmbh

Inventors

• Littmann Dieter
• Mohrbutter Jurgen Peter
• Mei Giulia
• Finette Andre-Armand
• Wolfram Sven Georg
• Deuerling Michael
• Khayrullin Danir
• Groos Georg
• Wolf Christoph

Classifications

• C08F2500/12

  Melt flow index or melt flow ratio · CPC title

• C08F2/34

  Polymerisation in gaseous state · CPC title

• C08F2/00

  Processes of polymerisation · CPC title

• C08F110/02 Primary

  Ethene · CPC title

• C08F2500/26

  Use as polymer for film forming · CPC title