Process for the synthesis of choline salts

1. A process for the synthesis of one or more choline salts, comprising:

(a) providing an aqueous solution of choline;

(b) combining the aqueous solution of choline with a hydrophobic organic solvent and an excess of free acid to form a first acidic solution;

(c) combining the first acidic solution with one or more alcohols to form a first extraction mixture;

(d) separating the first extraction mixture into a lower phase, a middle phase and an upper phase; and

(e) recovering the lower phase of the first extraction mixture to provide a first aqueous solution of a choline salt.

2. A process according to claim 1 further comprising:

(f) combining the first aqueous solution of choline salt with an excess of free acid and a hydrophobic organic solvent to form a second acidic solution;

(g) combining the second acidic solution with at least one alcohol and to form a second extraction mixture;

(h) separating the second extraction mixture into a lower phase, a middle phase and an upper phase; and

(i) recovering the lower phase of the second extraction mixture to provide a second aqueous solution of a choline salt.

3. A process according to claim 1 further comprising isolating the choline salt from the first aqueous solution of choline salt.

4. A process according to claim 2 further comprising isolating the choline salt from the second aqueous solution of choline salt.

5. A process according to claim 1 further comprising recycling the hydrophobic organic solvent for further use in the process.

6. A process according to claim 1 wherein the alcohol comprises at least one C 1 to C 6 alcohol.

7. A process according to claim 1 wherein the alcohol comprises ethanol, propanol or isopropanol.

8. A process according to claim 1 wherein the hydrophobic organic solvent comprises a high-boiling-point alkane.

9. A process according to claim 1 wherein the hydrophobic organic solvent comprises cyclohexane.

10. A process according to claim 1 wherein the free acid comprises an organic acid.

11. A process according to claim 1 wherein the free acid is selected from the group consisting of acetic acid, formic acid, lactic acid, pyruvic acid, glycolic acid, propionic acid, isobutyric acid, hydroxyl-butanoic acid, hydroxyl-pentanoic acid and tiglic acid.

12. A process according to claim 1 wherein the free acid comprises glycolic acid.

13. A process according to claim 1 wherein the free acid comprises hydrochloric acid.

14. A process according to claim 1 wherein the hydrophobic organic solvent comprises one or more C 6 to C 10 hydrocarbons.

15. A process according to claim 1 wherein the hydrophobic organic solvent has less than about 5% solubility in water, and/or has less than about 5% water solubility therein.

16. A process according to claim 1 wherein the free acid is selected from the group consisting of HCl, H 2 SO 4 , HF, an arsonic acid, an ascorbic acid, a barbituric acid, a carbamic acid, a carboxylic acid, a hydroxamic acid, an organosulfur acid, a peroxy acid, a phosphinic acid, a phosphonic acid, a picric acid, a squaric acid, a thiocarboxy acid and a uric acid.

17. A process according to claim 1 wherein the free acid is provided in an amount of about 5 to about 20 moles of acid per mole of choline.

18. A process according to claim 1 that is performed below the boiling point and above the crystallization or freezing point of the alcohol(s), organic solvent(s) and/or acid(s) used therein.

19. A process according to claim 1 wherein the middle phase comprises a layer; and/or the upper phase comprises the hydrophobic organic solvent.

20. A process according to claim 1 further comprising applying a washing solvent to recover, isolate and/or purify the choline salt from the aqueous solution.