METHOD FOR PREPARING AN AQUEOUS ACRYLAMIDE SOLUTION HAVING A LOW ACRYLIC ACID CONCENTRATION

• US 20170283840A1
• Filed: 09/30/2015
• Published: 10/05/2017
• Est. Priority Date: 09/30/2014
• Status: Active Grant

• Current Assignee: Solenis Technologies LP (Innovative Water Care, LLC)
• Original Assignee: BASF SE
• Inventors: BRAUN, Michael, DAEUWEL, Juergen, LANG, Hans-Juergen, OEDMAN, Peter, BALDENIUS, Kai-Uwe, KLEINER, Matthias, KIEFER, Michael, FREYER, Stephan, BUDDE, Michael
• Granted Patent: US 10,227,621 B2
• Time in Patent Office: Days
• CPC Class Codes: C07C 233/09 with carbon atoms of carboxamide groups bound to carbon atoms of an acyclic unsaturated carbon skeleton
• CPC Class Codes: C08F 20/56 Acrylamide; Methacrylamide
• CPC Class Codes: C08L 2201/54 Aqueous solutions or dispersions
• CPC Class Codes: C08L 33/26 Homopolymers or copolymers of acrylamide or methacrylamide
• CPC Class Codes: C09K 8/588 characterised by the use of specific polymers polymeric surfactants C09K8/584
• CPC Class Codes: C12P 13/02 Amides, e.g. chloramphenicol or polyamides; Imides or polyimides; Urethanes, i.e. compounds comprising N-C=O structural element or polyurethanes peptides C12P21/00 or C07K
• CPC Class Codes: C12Y 402/01084 Nitrile hydratase (4.2.1.84)
• CPC Class Codes: D21H 17/375 Poly(meth)acrylamide

Abstract

The present invention relates to methods for preparing an aqueous acrylamide solution having a low acrylic acid concentration. In addition, the present invention relates to methods for reducing the acrylic acid concentration of an aqueous acrylamide solution. The methods involve a bioconversion of acrylonitrile to acrylamide in the presence of a biocatalyst, wherein during the bioconversion the content of acrylonitrile is maintained at 0.3 w/w % or more referred to the total weight of the composition in the reactor. Also provided is an aqueous acrylamide solution which is obtained by the methods of the present invention. Furthermore, the present invention is related to an acrylamide homopolymer or copolymer obtained by polymerizing the acrylamide of the aqueous solution.

Claims

1. A method for preparing an aqueous acrylamide solution, the method comprising:

(a) adding acrylonitrile, water, and a biocatalyst capable of converting acrylonitrile to acrylamide to a reactor to obtain a composition for bioconversion;

(b) performing a bioconversion of the acrylonitrile to acrylamide in the reactor; and

(c) adding further acrylonitrile such that a content of acrylonitrile during the bioconversion is maintained at 0.3 w/w % or more, relative to the total weight of the composition in the reactor, for 10 minutes to 48 hours.

4. The method according to claim 1, wherein an acrylic acid concentration of the composition at the end of the bioconversion is 1500 ppm or less, relative to the total weight of the composition at the end of the bioconversion.

6. The method of claim 1, wherein a weight ratio of the biocatalyst, acrylonitrile and water added during the (a) to (c) is 0.001 to 0.5 w/w % of the biocatalyst, 22 to 45 w/w % of acrylonitrile and a balance to 100 w/w % of water, relative to the total weight (100 w/w %) of the combined weights of the biocatalyst, acrylonitrile and water added during the (a) to (c).

7. The method of claim 1, wherein the bioconversion is performed at a temperature of from 5°

C. to 40°

C. for 10 minutes to 48 hours.

8. The method of claim 1, wherein the content of acrylonitrile during the bioconversion is maintained at 6 w/w % or less, relative to the total weight of the composition in the reactor.

9. The method of claim 1, wherein the adding of further acrylonitrile comprises:

(i) maintaining an acrylonitrile content in a first range for a first period of time;

(ii) decreasing the acrylonitrile content from the first range to a second range; and

(iii) maintaining an acrylonitrile content in the second range for a second period of time.

10. The method of claim 9, wherein

the first range is from 1.2 w/w % to 6 w/w % relative to the total weight of the composition in the reactor,

the first period of time is from 30 minutes to 4 hours,

the second range is from 0.3 w/w % to 1.2 w/w % relative to the total weight of the composition in the reactor, and

the second period of time is from 30 minutes to 24 hours.

11. The method of claim 10, wherein

the first range is from 1.2 w/w % to 4 w/w % relative to the total weight of the composition in the reactor,

the first period of time is from 30 minutes to 3 hours,

the second range is from 0.5 w/w % to 1.1 w/w % relative to the total weight of the composition in the reactor, and

the second period of time is from 30 minutes to 12 hours.

12. The method of claim 11, wherein

the first range is from 1.3 w/w % to 3 w/w % relative to the total weight of the composition in the reactor,

the first period of time is from 30 minutes to 2 hours,

the second range is from 0.6 w/w % to 1.0 w/w % relative to the total weight of the composition in the reactor, and

the second period of time is from 1 hour to 8 hours.

13. The method of claim 1, wherein the method is carried out using a semi-batch process.

14. The method of claim 1, wherein the content of acrylonitrile is measured using Fourier Transform Infrared Spectroscopy (FTIR).

15. The method of claim 1, wherein the biocatalyst encodes the enzyme nitrile hydratase.

16. The method of claim 1, wherein the biocatalyst is at least one selected from the group consisting of Rhodococcus, Aspergillus, Acidovorax, Agrobacterium, Bacillus, Bradyrhizobium, Burkholderia, Escherichia, Geobacillus, Klebsiella, Mesorhizobium, Moraxella, Pantoea, Pseudomonas, Rhizobium, Rhodopseudomonas, Serratia, Amycolatopsis, Arthrobacter, Brevibacterium, Corynebacterium, Microbacterium, Micrococcus, Nocardia, Pseudonocardia, Trichoderma, Myrothecium, Aureobasidium, Candida, Cryptococcus, Debaryomyces, Geotrichum, Hanseniaspora, Kluyveromyces, Pichia, Rhodotorula, Comomonasz, and Pyrococcus.

17. The method of claim 16, wherein the biocatalyst is at least one selected from the group consisting of Rhodococcus, Pseudomonas, Escherichia and Geobacillus.

18. The method of claim 1, wherein the biocatalyst is at least one selected from the group consisting of Rhodococcus rhodochrous, Rhodococcus pyridinovorans, Rhodococcus erythropolis, Rhodococcus equi, Rhodococcus ruber, Rhodococcus opacus, Aspergillus niger, Acidovorax avenae, Acidovorax facilis, Agrobacterium tumefaciens, Agrobacterium radiobacter, Bacillus subtilis, Bacillus pallidus, Bacillus smithii, Bacillus sp BR449, Bradyrhizobium oligotrophicum, Bradyrhizobium diazoefficiens, Bradyrhizobium japonicum, Burkholderia cenocepacia, Burkholderia gladioli, Escherichia coli, Geobacillus sp. RAPc8, Klebsiella oxytoca, Klebsiella pneumonia, Klebsiella variicola, Mesorhizobium ciceri, Mesorhizobium opportunistum, Mesorhizobium sp F28, Moraxella, Pantoea endophytica, Pantoea agglomerans, Pseudomonas chlororaphis, Pseudomonas putida, Rhizobium, Rhodopseudomonas palustris, Serratia liquefaciens, Serratia marcescens, Amycolatopsis, Arthrobacter, Brevibacterium sp CH1, Brevibacterium sp CH2, Brevibacterium sp R312, Brevibacterium imperiale, Brevibacterium casei, Corynebacterium nitrilophilus, Corynebacterium pseudodiphteriticum, Corynebacterium glutamicum, Corynebacterium hoffmanii, Microbacterium imperiale, Microbacterium smegmatis, Micrococcus luteus, Nocardia globerula, Nocardia rhodochrous, Nocardia sp 163, Pseudonocardia thermophila, Trichoderma, Myrothecium verrucaria, Aureobasidium pullulans, Candida famata, Candida guilliermondii, Candida tropicalis, Cryptococcus flavus, Cryptococcus sp UFMG-Y28, Debaryomyces hanseii, Geotrichum candidum, Geotrichum sp JR1, Hanseniaspora, Kluyveromyces thermotolerans, Pichia kluyveri, Rhodotorula glutinis, Comomonas testosteroni, Pyrococcus abyssi, Pyrococcus furiosus, and Pyrococcus horikoshii.

19. The method of claim 18, wherein the biocatalyst is Rhodococcus rhodochrous.

20. The method of claim 18, wherein the biocatalyst is Rhodococcus pyridinovorans.

21. The method of claim 1, wherein the biocatalyst has been dried before being added to the reactor.

22. The method of claim 21, wherein the biocatalyst has been dried by freeze-drying, spray drying, heat drying, vacuum drying, fluidized bed drying, spray granulation, or a combination thereof.

23. The method of claim 21, wherein the dried biocatalyst is added to the reactor.

24. The method of claim 21, wherein the dried biocatalyst is reconstituted before being added to the reactor.

25. The method of claim 24, wherein the biocatalyst is reconstituted by suspending in an aqueous composition.

26. An aqueous acrylamide solution, obtained by the method of claim 1.

27. The aqueous acrylamide solution according to claim 26, containing 35 to 65 w/w % of acrylamide having an acrylic acid concentration of not more than 1500 ppm, relative to the total weight of the solution.

28. The aqueous acrylamide solution of claim 26, wherein the acrylamide content, the acrylic acid concentration, or both, are determined using HPLC.

29. An acrylamide homopolymer or copolymer, obtained by polymerizing acrylamide of the aqueous acrylamide solution of claim 26.

30. The acrylamide homopolymer or copolymer of claim 29, having an acrylic acid content of 60,000 ppm or less, relative to the total weight of the solid acrylamide homopolymer or copolymer.

31. The acrylamide homopolymer or copolymer of claim 29, wherein the acrylamide copolymer is a cationic polyacrylamide.

32. The acrylamide homopolymer or copolymer of claim 30, wherein the acrylic acid content is determined using NMR spectroscopy.

33. A solution, comprising:

the acrylamide homopolymer or copolymer of claim 29; and

seawater.

2. A method for preparing an aqueous acrylamide solution, the method comprising:

(a) adding acrylonitrile, water, and a biocatalyst capable of converting acrylonitrile to acrylamide to a reactor to obtain a composition for bioconversion;

(b) performing a bioconversion of the acrylonitrile to acrylamide in the reactor; and

(c) adding further acrylonitrile such that a content of acrylonitrile during the bioconversion is maintained at 0.3 w/w % or more until an acrylamide content reaches at least 20 w/w %, relative to the total weight of the composition in the reactor.

3. A method for reducing an acrylic acid concentration of an aqueous acrylamide solution prepared by converting acrylonitrile to acrylamide using a biocatalyst, the method comprising:

(a) adding acrylonitrile, water, and a biocatalyst capable of converting acrylonitrile to acrylamide to a reactor to obtain a composition for bioconversion;

(b) performing a bioconversion of the acrylonitrile to acrylamide in the reactor; and

(c) adding further acrylonitrile such that a content of acrylonitrile during the bioconversion is maintained at 0.3 w/w % or more, relative to the total weight of the composition in the reactor.

5. A method for preparing an aqueous acrylamide solution, comprising:

(a) adding acrylonitrile, water, and a biocatalyst capable of converting acrylonitrile to acrylamide to a reactor to obtain a composition for bioconversion;

(b) performing a bioconversion of the acrylonitrile to acrylamide in the reactor;

(c) adding further acrylonitrile such that a content of acrylonitrile during the bioconversion is maintained at 0.3 w/w % or more, relative to the total weight of the composition in the reactor; and

(d) obtaining a composition at the end of the bioconversion, which has an acrylic acid concentration of 1500 ppm or less, relative to the total weight of the composition at the end of the bioconversion.