Coagulation of biopolymers from ionic liquid solutions using CO2

Patent metadata

Field	Value
Publication number	US-9663589-B2
Application number	US-201414767841-A
Country	US
Kind code	B2
Filing date	Feb 13, 2014
Priority date	Feb 14, 2013
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

Disclosed herein are processes for providing a biopolymer from a biomass or source of chitin using ionic liquids. The processes involve contacting a biomass or source of chitin with an ionic liquid to produce a biopolymer comprising solution and precipitating the biopolymer from the solution with supercritical CO 2 , gaseous CO 2 , or combinations thereof.

First claim

What is claimed is:

1. A process for providing a biopolymer from a biomass, comprising:
a) contacting an ionic liquid with the biomass to form a biopolymer containing solution, wherein the biomass is a chitinous biomass, the biopolymer comprises chitin, the ionic liquid comprises a cation and an anion, wherein the cation is an imidazolium, and the anion is C 1 -C 6 carboxylate;
b) adding supercritical CO 2 to the solution to precipitate the biopolymer from the biopolymer containing solution; and
c) removing the CO 2 from the ionic liquid to provide a recycled ionic liquid.

2. The process of claim 1 , further comprising isolating the precipitated biopolymer.

3. The process of claim 1 , wherein the chitinous biomass comprises the shells of crustaceans.

4. The process of claim 1 , wherein the chitinous biomass is selected from the group consisting of shrimp shells, crab shells, lobster shells, crawfish shells, prawn shells, and combinations thereof.

5. The process of claim 1 , wherein the biomass is contacted with the ionic liquid at a temperature of from about 70° C. to about 130° C.

6. The process of claim 1 , wherein the biomass is dissolved or dispersed in the ionic liquid at a temperature of from about 0° C. to about 70° C.

7. The process of claim 1 , wherein in step (a) a microwave is used to heat the biopolymer containing solution.

8. The process of claim 1 , wherein a co-solvent is added to the ionic liquid.

9. The process of claim 1 , wherein an insoluble impurity is present in the biopolymer containing solution and is removed before step (b).

10. The process of claim 9 , wherein the impurity is removed by centrifugation or filtration.

11. The process of claim 1 , wherein the cation is:

where each R 1 and R 2 is, independently, a substituted or unsubstituted linear, branched, or cyclic C 1 -C 6 alkyl, or substituted or unsubstituted linear, branched, or cyclic C 1 -C 6 alkoxy; each R 3 , R 4 , and R 5 is, independently, hydrogen, substituted or unsubstituted linear, branched, or cyclic C 1 -C 6 alkyl, substituted or unsubstituted linear, branched, or cyclic C 1 -C 6 alkoxy, or substituted or unsubstituted linear or branched, C 1 -C 6 alkoxyalkyl.

12. The process of claim 1 , wherein the ionic liquid is a 3-alkyl-1-alkyl imidazolium C 1 -C 6 carboxylate.

13. The process of claim 1 , wherein the ionic liquid is 3-ethyl-1-methylimidazolium acetate.

14. The process of claim 1 , wherein step (b) is at a temperature above about 31° C. and a pressure above about 1073 psi (7400 kPa).

15. The process of claim 1 , wherein the recycled ionic liquid is used to contact the biomass.

16. The process of claim 1 , wherein removing the CO 2 from the ionic liquid comprises reducing the pressure and vaporizing the CO 2 from the ionic liquid.

17. A process of using a biopolymer, comprising:
a) contacting an ionic liquid with a biomass to form a biopolymer containing solution, wherein the biomass is a chitinous biomass and the biopolymer comprises chitin, wherein the ionic liquid comprises a cation and an anion, wherein the cation is an imidazolium, and wherein the anion is C 1 -C 6 carboxylate;
b) adding supercritical CO 2 to the solution to precipitate the biopolymer from the biopolymer containing solution;
c) casting the precipitated biopolymer into a fiber, film or bead; and
d) removing the CO 2 from the ionic liquid to provide a recycled ionic liquid.

18. The process of claim 17 , further comprising adding an additional polymer or adjunct to the biopolymer containing solution before step (b).

19. The process of claim 18 , wherein the additional polymer is poly(2-hydroxyethyl methacrylate) (poly-HEMA) and the adjunct is a pharmaceutical, herbicide, insecticide, or food ingredient.

20. The process of claim 18 , wherein the additional polymer is poly(lactic acid) (PLA) and the adjunct is a pharmaceutical, herbicide, insecticide, or food ingredient.

21. The process of claim 18 , wherein the additional polymer is polyethylterephthalate, polystyrene, polyethylene, or nylon.

Assignees

• Univ Alabama
• The Intellectual Property Office Of Inst Of Process Eng Chinese Acad Of Sciences

Inventors

• Rogers Robin D
• Barber Patrick S
• Griggs Chris S
• Gurau Gabriela
• Lu Xingmei
• Zhang Suojiang

Classifications

• C08B37/0003

  General processes for their isolation or fractionation, e.g. purification or extraction from biomass · CPC title

• C08L97/02

  Lignocellulosic material, e.g. wood, straw or bagasse {(manufacture of articles made from lignocellulosic material by dry processes B27N)} · CPC title

• C08J3/14

  by precipitation from solutions {(C08J3/122 takes precedence)} · CPC title

• Y02P20/544

  Cross-Sectional Technologies · mapped topic

• C08B15/08

  Fractionation of cellulose, e.g. separation of cellulose crystallites · CPC title