Recovery of organic acids
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 CO 2 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.
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 CO 2 .
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.