Process for producing aqueous polyacrylamide solutions

Patent metadata

Field	Value
Publication number	US-11634516-B2
Application number	US-201816759223-A
Country	US
Kind code	B2
Filing date	Oct 18, 2018
Priority date	Oct 25, 2017
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the manufacturing steps are allocated to two different locations A and B and the process comprises the step of transporting an aqueous polyacrylamide gel hold in a transportable polymerization unit from a location A to a location B. Modular, relocatable plant for manufacturing aqueous polyacrylamide solutions wherein the units of the plant are located at two different locations A and B.

First claim

The invention claimed is:

1. A process for producing an aqueous polyacrylamide solution comprising polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, characterized in that the process comprises at least the following steps:
[1] preparing an aqueous monomer solution comprising at least water and 5% to 45% by weight—relating to the total of all components of the aqueous monomer solution—of water-soluble, monoethylenically unsaturated monomers at a location A, wherein said water-soluble, monoethylenically unsaturated monomers comprise at least acrylamide,
[2] inerting and radically polymerizing the aqueous monomer solution prepared in step [1] in the presence of suitable initiators for radical polymerization under adiabatic conditions at a location A, wherein
the polymerization is performed in a transportable polymerization unit having a volume of 1 m 3 to 40 m 3 ,
the aqueous monomer solution has a temperature T 1 not exceeding 30° C. before the onset of polymerization, and
the temperature of the polymerization mixture raises in course of polymerization—due to the polymerization heat generated—to a temperature T 2 of at least 45° C.,

thereby obtaining an aqueous polyacrylamide gel having a temperature T 2 which is held in the transportable polymerization unit,
[3] transporting the transportable polymerization unit filled with the aqueous polyacrylamide gel from location A to a different location B,
[4] removing the aqueous polyacrylamide gel from the transportable polymerization unit at the location B,
[5] comminuting and dissolving the aqueous polyacrylamide gel in an aqueous liquid at the location B, thereby obtaining an aqueous polyacrylamide solution.

2. The process according to claim 1 , wherein the acrylamide is obtained by hydrolyzing acrylonitrile in water in the presence of a biocatalyst capable of converting acrylonitrile to acrylamide.

3. The process according to claim 1 , wherein the process comprises an additional step [0] conducted at location A comprising hydrolyzing acrylonitrile in water in the presence of a biocatalyst capable of converting acrylonitrile to acrylamide, thereby obtaining an aqueous acrylamide solution, and wherein said aqueous acrylamide solution is used for step [1].

4. The process according to claim 3 , wherein step [0] is performed in a relocatable bioconversion unit.

5. The process according to claim 1 , wherein step [1] is performed in a relocatable monomer make-up unit.

6. The process according to claim 1 , wherein step [2] is performed in a transportable polymerization unit having a volume from 5 m 3 to 40 m 3 .

7. The process according to claim 1 , wherein the initiators for radical polymerization to be used in course of step [2] comprise at least one redox initiator and at least one azo initiator.

8. The process according to claim 1 , wherein T 1 is from −5° C. to +5° C. and T 2 is from 50° C. to 70° C.

9. The process according to claim 8 , wherein the monomer concentration is from 15 to 24.9% by weight.

10. The process according to claim 1 , wherein the monomer solution furthermore comprises at least one stabilizer for the prevention of polymer degradation.

11. The process according to claim 10 , wherein the stabilizers are non-polymerizable stabilizers selected from the group of sulfur compounds, sterically hindered amines, N-oxides, nitroso compounds, aromatic hydroxyl compounds and ketones.

12. The process according to claim 11 , wherein the amount of non-polymerizable stabilizers is from 0.1% to 2% by weight, relating to the sum of all monomers in the aqueous monomer solution.

13. The process according to claim 1 , wherein step [2] is performed in a transportable polymerization unit P1 comprising a cylindrical upper part having a length of 4 m to 6 m and a diameter from 1.5 m to 2.5 m, a conical part at its lower end having a conus angle from 15° to 90°, feeds for the aqueous monomer solution, a bottom opening having a diameter from 0.2 to 0.8 m for removing the polyacrylamide gel, and means allowing to deploy the unit P1 in a vertical manner.

14. The process according to claim 13 , wherein the volume of the polymerization unit P1 is from 20 m 3 to 30 m 3 .

15. The process according to claim 1 , wherein the aqueous polyacrylamide gel is removed from the transportable polymerization unit in course of step [4] by applying pressure onto the gel and pressing it through an opening in the polymerization unit, wherein the pressure onto the gel is applied by
(i) means of gases, selected from the group of
air, nitrogen, and argon
and/or
(ii) by means of aqueous fluids.

16. The process according to claim 15 , wherein a polymerization unit P1 is used, and the aqueous polyacrylamide gel is removed through the bottom opening.

17. The process according to claim 1 , wherein comminuting the aqueous polyacrylamide gel in course of step [5] is carried out by conveying the aqueous polyacrylamide gel through at least one comminuting unit thereby yielding pieces of aqueous polyacrylamide gel.

18. The process according to claim 17 , wherein the aqueous polyacrylamide gel is conveyed through the at least one comminuting unit together with an aqueous liquid thereby yielding a mixture of pieces of aqueous polyacrylamide gel in an aqueous polyacrylamide solution.

19. The process according to claim 17 wherein the comminution unit comprises means for comminuting aqueous polymer gels selected from static cutting devices, moving cutting devices, perforated plates, static mixers, water-jet cutting devices and combinations thereof.

20. The process according to claim 17 , wherein at least one of the comminuting units is a water-jet cutting device.

21. The process according to claim 1 , wherein dissolution in course of step [5] is performed in a dissolution unit comprising at least a dissolution vessel and means for mixing the aqueous polyacrylamide gel with the aqueous liquid.

22. The process according to claim 21 , wherein the dissolution unit is a relocatable dissolution unit.

23. The process according to claim 22 , wherein the relocatable dissolution unit comprises at least a dissolution vessel, at least one stirrer, means for filling the dissolution unit with aqueous liquid and pieces of aqueous polyacrylamide gel and means for removing aqueous polyacrylamide solution.

24. The process according to claim 21 wherein at least two relocatable dissolution units are connected in series.

25. The process according to claim 1 , wherein the aqueous polyacrylamide solution obtained in course of step [5] is transported from location B to a site-of-use which is distant from location B in a transport unit and removed from the transport unit at the site-of-use.

26. The process according to claim 25 , wherein the aqueous polyacrylamide solution is transported in the transport unit is a concentrate having a concentration of 2.1% to 14.9% by weight.

27. The process according to claim 26 , wherein—before use—the concentrate is further diluted with an aqueous liquid at the site-of-use.

28. A process for producing an aqueous polyacrylamide solution comprising polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, char

Assignees

• Basf Se

Inventors

• Loesch Dennis
• Zimmermann Tobias Joachim
• Sprafke Hazel
• Meckelnburg Dirk
• Ostermayr Markus
• El-Toufaili Faissal-Ali

Classifications

• E21B43/16

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• E21B21/00

  Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor (freeing objects stuck in boreholes by flushing E21B31/03) · CPC title

• C08F220/56

  Acrylamide; Methacrylamide · CPC title

• C08F20/56 Primary

  Acrylamide; Methacrylamide · CPC title

• E21B21/003

  Means for stopping loss of drilling fluid (plastering the borehole wall E21B33/138) · CPC title