Recovery of organic acids

• US 8,048,655 B2
• Filed: 08/26/2009
• Issued: 11/01/2011
• Est. Priority Date: 01/29/2004
• Status: Expired due to Fees

• Current Assignee: ZeaChem, Inc.
• Original Assignee: ZeaChem, Inc.
• Inventors: Verser, Dan W., Eggeman, Timothy J.
• Primary Examiner(s): OH, TAYLOR V
• Application Number:
  US12/548,312
• Publication Number:
  US 20100187472A1
• Time in Patent Office: 797 Days
• Field of Search: 560/179, 562/589, 562/508, 562/584, 435/135, 435/139, 435/140, 435/141, 435/142, 435/144
• US Class Current: 435/135
• CPC Class Codes: C07C 51/02 from salts of carboxylic acids
• CPC Class Codes: C07C 51/48 by liquid-liquid treatment
• CPC Class Codes: C07C 51/487 by treatment giving rise to chemical modification by chemisorption C07C51/47
• CPC Class Codes: C07C 53/02 Formic acid
• CPC Class Codes: C07C 53/08 Acetic acid pyroligneous acid C10C; preparation of vinegar C12J
• CPC Class Codes: C07C 53/122 Propionic acid
• CPC Class Codes: C07C 53/124 Acids containing four carbon atoms
• CPC Class Codes: C07C 55/10 Succinic acid
• CPC Class Codes: C07C 59/06 Glycolic acid
• CPC Class Codes: C07C 59/08 Lactic acid
• CPC Class Codes: C07C 59/10 Polyhydroxy carboxylic acids
• CPC Class Codes: C07C 59/265 Citric acid
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO₂ are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

Claims

1. A method for producing a product from biomass, the method comprising:

a. fermenting biomass to produce a solution comprising at least one salt of a carboxylic acid, the cation of which forms an insoluble carbonate salt;

b. introducing into the solution a tertiary amine selected from the group consisting of tributylamine and dicyclohexyl methylamine, and a weak acidulant to form an acid/amine complex and the insoluble carbonate salt;

c. contacting the acid/amine complex with a water immiscible solvent capable of forming an ester with the acid, to form a reaction phase; and

d. forming a product of the acid and the water immiscible solvent.

2. The method of claim 1, wherein the carboxylic acid is selected from the group consisting of acetic acid, lactic acid, propionic acid, butyric acid, succinic acid, citric acid, 3-hydroxypropionic acid, glycolic acid, and formic acid.

3. The method of claim 1, wherein the insoluble carbonate salt is calcium carbonate.

4. The method of claim 1, wherein the weak acidulant is CO₂.

5. The method of claim 1, wherein the water immiscible solvent is an alcohol.

6. The method of claim 1, wherein the water immiscible solvent is an alcohol selected from the group consisting of n-octanol, n-hexanol, n-pentanol, and n-butanol.

7. The method of claim 1, wherein the step of forming a product comprises continuously drying the reaction phase.

8. The method of claim 1, wherein the product is an ester.

9. A method for producing an ester from a complex of an organic acid and a tertiary amine selected from the group consisting of tributylamine and dicyclohexyl methylamine, the method comprising:

a. contacting the acid/amine complex with a water immiscible solvent capable of forming an ester with the acid, so that the acid/amine complex is extracted into the water immiscible solvent forming a reaction phase; and

b. forming an ester between the acid and the water immiscible solvent.

10. The method of claim 9, wherein the water immiscible solvent is an alcohol.

11. The method of claim 9, wherein the water immiscible solvent is an alcohol selected from the group consisting of n-octanol, n-hexanol, n-pentanol, and n-butanol.

12. The method of claim 9, wherein the step of forming a product comprises continuously drying the reaction phase.

13. A method for producing an ester from a solution comprising an aqueous phase and a reaction phase, wherein the reaction phase comprises a water immiscible solvent and a complex of an organic acid and a tertiary amine selected from the group consisting of tributylamine and dicyclohexyl methylamine, the method comprising:

a. separating the reaction phase from the aqueous phase; and

b. forming an ester of the acid and the water immiscible solvent.

14. The method of claim 13, wherein the water immiscible solvent is an alcohol.

15. The method of claim 13, wherein the water immiscible solvent is an alcohol selected from the group consisting of n-octanol, n-hexanol, n-pentanol, and n-butanol.

16. The method of claim 13, wherein the acid/amine complex comprises acetate.

17. The method of claim 13, wherein the acid/amine complex is tributylammonium acetate.

18. The method of claim 13, wherein the step of forming a product comprises continuously drying the reaction phase.

19. A method for producing an ester, the method comprising:

a. obtaining a solution comprising a water immiscible solvent and a complex between an organic acid and a tertiary amine selected from the group consisting of tributylamine and dicyclohexyl methyl amine;

b. forming an ester of the acid and the solvent by continuously drying the solution; and

c. recovering the ester.

20. The method of claim 19, wherein the water immiscible solvent is an alcohol.

21. The method of claim 19, wherein the water immiscible solvent is an alcohol selected from the group consisting of n-octanol, n-hexanol, n-pentanol, and n-butanol.

22. The method of claim 19, wherein the product is tributylammonium acetate.

23. The method of claim 19, further comprising:

d. decomposing the ester to form an organic acid and a tertiary amine.