Chemical pulping of chitinous biomass for chitin

• US 10,100,131 B2
• Filed: 08/27/2015
• Issued: 10/16/2018
• Est. Priority Date: 08/27/2014
• Status: Active Grant

• Current Assignee: Board of Trustees of The University of Alabama (University of Alabama System)
• Original Assignee: Board of Trustees of The University of Alabama (University of Alabama System)
• Inventors: Barber, Patrick S., Griggs, Chris S., Rogers, Robin D., Gurau, Gabriela, Shamshina, Julia L.
• Primary Examiner(s): Jiang, Shaojia A
• Assistant Examiner(s): Miller, Dale R
• Application Number:
  US14/837,881
• Publication Number:
  US 20160060363A1
• Time in Patent Office: 1,146 Days
• Field of Search: None
• CPC Class Codes: C08B 37/003 Chitin, i.e. 2-acetamido-2-deoxy-(beta-1,4)-D-glucan or N-acetyl-beta-1,4-D-glucosamine; Chitosan, i.e. deacetylated product of chitin or (beta-1,4)-D-glucosamine; Derivatives thereof
• CPC Class Codes: C08L 5/08 Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof

Abstract

Methods of separating chitin from a chitinous biomass that contains chitin and non-chitin material by a chemical pulping process that uses a protic ionic liquid or a composition comprising acid and base precursor molecules are described. Also described are methods for purifying chemically pulped chitin resulting in a pure chitin material with a high molecular weight and a higher degree of acetylation in comparison to traditional pulping and ionic liquid extraction based methods.

Claims

1. A method for separating chitin from a chitinous biomass that contains chitin and non-chitin material, comprising:

contacting the chitinous biomass with a protic ionic liquid to form a mixture, wherein the protic ionic liquid comprises at least one cation chosen from hydroxylammonium and 2-hydroxyethylammonium, and at least one anion chosen from halide and a C1-C4 alkyl carboxylate;

wherein a majority of the non-chitin material from the chitinous biomass is removed from the chitinous biomass by the ionic liquid, and a majority of the chitin from the chitinous biomass is not dissolved in the ionic liquid and forms a residue;

wherein about 30 wt. % or more of the residue is chitin.

2. The method of claim 1, wherein the residue is about 70 wt. % or more chitin.

3. The method of claim 1, wherein the residue is greater than about 99 wt. % chitin.

4. The method of claim 1, wherein the chitinous biomass comprises an arthropod biomass, a fungi biomass, or a combination thereof.

5. The method of claim 4, wherein the arthropod biomass comprises the exoskeleton of an arthropod chosen from shrimp, crab, lobster, insect, and any combination thereof.

6. The method of claim 1, wherein the protic ionic liquid comprises at least one acetate anion.

7. The method of claim 1, wherein the protic ionic liquid is hydroxylammonium acetate or 2-hydroxyethylammonium acetate.

8. The method of claim 1, wherein the degree of acetylation of the chitin is 29% or more.

9. The method of claim 1, wherein the degree of acetylation of the chitin is 60% or more.

10. A method for separating chitin from a chitinous biomass that contains chitin and non-chitin material, comprising:

contacting the chitinous biomass with an acid and a base, in any order, to form a mixture,

wherein the acid is acetic acid and the base is 2-hydroxyethylamine or hydroxylamine,

wherein a majority of the non-chitin material from the chitinous biomass is removed from the chitinous biomass by the acid-base composition, and a majority of the chitin from the chitinous biomass is not dissolved in the acid-base composition and forms a residue;

wherein about 30% or more of the residue is chitin.

11. The method of claim 10, wherein the addition of the acid and base forms a protic ionic liquid.

12. The method of claim 10, wherein the residue is about 70 wt. % or more chitin.

13. The method of claim 10, wherein the residue is greater than about >

99 wt. % chitin.

14. The method of claim 10, wherein the degree of acetylation of the chitin is 29% or more.

15. The method of claim 10, wherein the degree of acetylation of the chitin is 60% or more.

16. A composition, comprising:

a chitinous biomass and a protic ionic liquid,

wherein the chitinous biomass contains chitin and non-chitin material, wherein the protic ionic liquid comprises at least one cation chosen from hydroxylammonium and 2-hydroxyethylammonium, and at least one anion chosen from halide and a C1-C4 alkyl carboxylate, wherein the composition further comprises a mixture and a residue, the mixture comprising a majority of the non-chitin material from the chitinous biomass dissolved in the protic ionic liquid, and the residue comprising a majority of the chitin from the chitinous biomass not dissolved in the protic ionic liquid.

17. The composition of claim 16, wherein the chitinous biomass comprises an arthropod biomass, a fungi biomass, or a combination thereof.

18. The composition of claim 17, wherein the arthropod biomass comprises the exoskeleton of an arthropod chosen from shrimp, crab, lobster, insect, and any combination thereof.

19. The composition of claim 16, wherein the protic ionic liquid comprises at least one acetate anion.

20. The composition of claim 16, wherein the protic ionic liquid is hydroxylammonium acetate or 2-hydroxyethylammonium acetate.

21. The composition of claim 16, wherein the chitinous biomass is present at from about 5 to about 30 wt. % or less of the composition.