METHOD OF OBTAINING AN ORGANIC SALT OR ACID FROM AN AQUEOUS SUGAR STREAM

• US 20080041366A1
• Filed: 07/06/2007
• Published: 02/21/2008
• Est. Priority Date: 08/18/2006
• Status: Active Grant

• Current Assignee: Iogen Energy Corporation (Iogen Corporation)
• Original Assignee: Iogen Energy Corporation (Iogen Corporation)
• Inventors: Wahnon, Daphne
• Granted Patent: US 7,718,070 B2
• Time in Patent Office: Days
• US Class Current: 127/37
• CPC Class Codes: B01D 15/1821 Simulated moving beds
• CPC Class Codes: B01D 15/363 Anion-exchange
• CPC Class Codes: B01J 41/05 in the strongly basic form
• CPC Class Codes: B01J 41/07 in the weakly basic form
• CPC Class Codes: B01J 49/07 containing anionic exchangers
• CPC Class Codes: C07C 51/47 by solid-liquid treatment; by chemisorption
• 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: C07H 3/00 Compounds containing only hydrogen atoms and saccharide radicals having only carbon, hydrogen, and oxygen atoms preparation by hydrolysis of di-or polysaccharides C13; separation or purification of sucrose, glucose, fructose, lactose or maltose C13
• CPC Class Codes: C07H 7/033 Uronic acids
• CPC Class Codes: G01N 30/461 with serial coupling of separation columns

Abstract

A process for obtaining one or more than one salt of an organic acid(s), or organic acid(s), from an aqueous sugar stream comprising one or more than one mineral acid and the organic acid(s) is provided. The process comprises introducing the aqueous sugar stream to a separation system comprising one or more beds of anion exchange resin and obtaining a stream therefrom comprising the sugar. The one or more beds of anion exchange resin are then regenerated in one or more stages to produce at least one product stream comprising the organic acid, a salt of the organic acid, or a combination thereof, and a separate outlet stream comprising the mineral acid, a salt of the mineral acid, or a combination thereof. The product stream is then recovered. The separation may be conducted with two separation units, or using a single anion exchange unit.

Claims

1. A process for obtaining one or more than one organic salt or organic acid from an aqueous sugar stream comprising one or more than one mineral acid, one or more than one organic acid, and a sugar selected from the group consisting of xylose, glucose, arabinose, galactose, mannose and a combination thereof, said process comprising:

(i) introducing the aqueous sugar stream to a first anion exchange unit comprising one or more than one bed comprising an anion exchange resin, wherein the mineral acid, an anion of the mineral acid, or a combination thereof, binds to the resin;

(ii) producing an effluent stream comprising the sugar and the organic acid from the first anion exchange unit and regenerating the anion exchange resin with one or more regenerants, thereby producing one or more outlet streams comprising the mineral acid, a salt of the mineral acid or a combination thereof;

(iii) feeding the effluent stream comprising the sugar and the organic acid to a second anion exchange unit comprising one or more than one bed comprising an anion exchange resin, wherein the organic acid or an anion of the organic acid binds to the resin;

(iv) obtaining a stream from the second anion exchange unit comprising the sugar, which stream is substantially free of the mineral acid and the organic acid and regenerating the second anion exchange unit with one or more regenerants, thereby producing one or more product streams comprising a salt of the organic acid, the organic acid or a combination thereof; and

(v) recovering the one or more product streams.

2. The process according to claim 1 further comprising a step of recovering the mineral acid, the salt of the mineral acid or a combination thereof.

3. The process according to claim 1, wherein, in the step of feeding (step (iii)), at least about 70% of the organic acid present in the aqueous sugar stream is fed to the second anion exchange unit.

4. The process according to claim 1, wherein the anion exchange resin in the first anion exchange unit, the second anion exchange unit or both the first and the second anion exchange unit comprises a weak base anion exchange resin.

5. The process according to claim 4, wherein the anion exchange resin in both the first and the second anion exchange unit comprises a weak base anion exchange resin.

6. The process according to claim 1, wherein the anion exchange resin in the first anion exchange unit, the second anion exchange unit or both the first and the second anion exchange unit comprises a strong base anion exchange resin.

7. The process according to claim 1, wherein the mineral acid is selected from the group consisting of sulfuric acid, hydrochloric acid, sulfurous acid, phosphoric acid and a combination thereof.

8. The process according to claim 7, wherein the mineral acid is sulfuric acid.

9. The process according to claim 1, wherein the organic acid is selected from the group consisting of acetic acid, formic acid, glucuronic acid, galacturonic acid and a combination thereof.

10. The process according to claim 9, wherein the organic acid is acetic acid.

11. The process according to claim 1, wherein the one or more regenerants in step (ii), step (iv) or both step (ii) and step (iv) is an alkali solution selected from the group consisting of an ammonium hydroxide solution, a sodium hydroxide solution and a potassium hydroxide solution.

12. The process according to claim 11, wherein the alkali solution is an ammonium hydroxide solution.

13. The process according to claim 1, wherein the first anion exchange unit, the second anion exchange unit or both the first anion exchange unit and the second anion exchange unit is a Simulated Moving Bed (SMB) system or an Improved Simulated Moving Bed (ISMB) system.

14. The process according to claim 9, wherein the organic acid is acetic acid and further comprising recovering the acetic acid from the one or more product streams by distillation.

15. The process according to claim 9, wherein the organic acid is acetic acid and further comprising recovering the acetic acid from the one or more product streams by liquid-liquid extraction.

16. The process according to claim 9, wherein the organic acid is acetic acid and further comprising recovering the acetic acid from the one or more product streams by stripping the acetic acid with air or steam.

17. The process according to claim 14, 15 or 16, wherein the one or more product streams comprise a salt of acetic acid and further comprising adjusting the pH of the one or more product streams to about 4 or lower by the addition of a second acid prior to recovering the acetic acid.

18. The process according to claim 1, wherein the aqueous sugar stream is at a pH of about 0.4 to about 5.0.

19. The process according to claim 1, wherein the aqueous sugar stream is obtained by pretreating a lignocellulosic feedstock at a pH of about 0.4 to about 5.0 by adding one or more than one acid to the lignocellulosic feedstock to hydrolyze at least a portion of the hemicellulose in the feedstock.

20. The process according to claim 1, wherein the aqueous sugar stream is a hydrolyzate stream obtained from adding one or more than one acid to a lignocellulosic feedstock to hydrolyze both hemicellulose and cellulose present in said lignocellulosic feedstock to their respective sugar monomers.

21. The process according to claim 1, wherein one or more regenerants in step (ii), (iv) or both step (ii) and (iv) is an aqueous solution selected from an alkali solution, an acid solution or water.

22. The process according to claim 21, wherein one or more regenerants in step (ii), (iv) or both step (ii) and (iv) is an aqueous solution selected from an alkali solution or an acid solution.

23. A process for obtaining an organic salt or organic acid from an aqueous sugar stream comprising a mineral acid, an organic acid, and a sugar selected from the group consisting of xylose, glucose, arabinose, galactose, mannose and a combination thereof, said process comprising the steps of:

(i) introducing the aqueous sugar stream to a separation system comprising one or more beds of anion exchange resin and obtaining at least one stream therefrom comprising the sugar;

(ii) regenerating the one or more beds of anion exchange resin in one or more stages, thereby producing at least one stream comprising the mineral acid, a salt of the mineral acid, or a combination thereof, and at least one separate product stream comprising the organic acid, a salt of the organic acid, or a combination thereof; and

(iii) recovering the at least one product stream.

24. The process of claim 23, wherein the anion exchange system comprises a first and a second anion exchange unit.

25. The process of claim 24, wherein

said step of introducing comprises feeding the aqueous sugar stream to the first anion exchange unit, wherein the mineral acid, an anion of the mineral acid, or a combination thereof, binds to the resin of the first anion exchange unit;

said process further comprising

obtaining an effluent stream comprising the sugar and the organic acid, a salt of the organic acid, or a combination thereof, from said first anion exchange unit and then feeding the effluent stream to the second anion exchange unit and said organic acid, an anion of the organic acid, or a combination thereof, binds to the resin of the second anion exchange unit; and

wherein

said step of regenerating comprises adding at least one regenerant to the first anion exchange unit to produce the at least one stream comprising the mineral acid, a salt of the mineral acid, or a combination thereof, and adding at least one regenerant to the second anion exchange unit to produce the at least one product stream comprising the organic acid, a salt of the organic acid, or a combination thereof.

26. The process of claim 25, wherein at least about 70% of the organic acid present in the aqueous sugar stream is fed to the second anion exchange unit.

27. The process of claim 23, wherein steps (i)-(iii) are carried out in a single anion exchange unit.

28. The process of claim 25, wherein, in said step of introducing, the mineral acid, organic acid, or anions thereof, bind to the resin.

29. The process according to claim 23 further comprising a step of recovering the mineral acid, a salt of the mineral acid, or a combination thereof.

30. The process according to claim 23, wherein the separation system comprises a weak base anion exchange resin.

31. The process according to claim 23, wherein the separation system comprises a strong base anion exchange resin.

32. The process according to claim 23, wherein the mineral acid is selected from the group consisting of sulfuric acid, hydrochloric acid, sulfurous acid, phosphoric acid and a combination thereof.

33. The process according to claim 32, wherein the mineral acid is sulfuric acid.

34. The process according to claim 23, wherein the organic acid is selected from the group consisting of acetic acid, formic acid, galacturonic acid, glucuronic acid and a combination thereof.

35. The process according to claim 34, wherein the organic acid is acetic acid.

36. The process according to claim 25, wherein the organic acid is acetic acid.

37. The process according to claim 23, wherein the regeneration comprises adding one or more regenerants to the one or more resin bed to regenerate the anion exchange resin, one or more regenerants is an aqueous solution selected from an alkali solution, an acid solution, water, or a combination thereof.

38. The process according to claim 37, wherein one or more regenerants is an aqueous solution selected from an alkali solution, an acid solution or a combination thereof.

39. The process according to claim 38, wherein the alkali solution is selected from the group consisting of an ammonium hydroxide solution, a sodium hydroxide solution, a potassium hydroxide solution, and a combination thereof.

40. The process according to claim 39, wherein the alkali solution is an ammonium hydroxide solution.

41. The process according to claim 23, wherein the separation system is a Simulated Moving Bed (SMB) System or an Improved Simulated Moving Bed (ISMB) system.

42. The process according to claim 35, further comprising recovering the acetic acid from the at least one product stream by distillation.

43. The process according to claim 35, further comprising recovering the acetic acid from the at least one product stream by liquid-liquid extraction.

44. The process according to claim 35, further comprising recovering the acetic acid from the at least one product stream by stripping the acetic acid with air or steam.

45. The process according to claim 42, 43 or 44, wherein the at least one product stream comprises a salt of acetic acid and further comprising adjusting the pH of the at least one product stream to about 4 or lower by the addition of an acid prior to recovering the acetic acid.

46. The process according to claim 23, wherein the aqueous sugar stream is at a pH of about 0.4 to about 5.0.

47. The process according to claim 23, wherein the aqueous sugar stream is a hydrolyzate stream resulting from pretreating a lignocellulosic feedstock at a pH of about 0.4 to about 5.0, to hydrolyze at least a portion of hemicellulose present in the feedstock.

48. The process according to claim 23, wherein the aqueous sugar stream is a hydrolyzate stream resulting from adding an acid to a lignocellulosic feedstock, to hydrolyze both hemicellulose and cellulose present in said lignocellulosic feedstock to their respective sugar monomers.

49. A process for obtaining acetate salt, acetic acid or a combination thereof, from a lignocellulosic feedstock comprising the steps of:

(i) obtaining an aqueous sugar stream resulting from hydrolysis of the lignocellulosic feedstock, said hydrolysis comprising one or more stages of sulfuric acid addition, said sugar stream comprising acetic acid, acetate salt, or a combination thereof, sulfuric acid and one or more sugars selected from xylose, glucose, arabinose, galactose, mannose and a combination thereof;

(ii) introducing the aqueous sugar stream to a Simulated Moving Bed separation system comprising one or more beds of anion exchange resin and obtaining at least one stream therefrom comprising the one or more sugars;

(iii) regenerating the one or more beds of anion exchange resin with sulfuric acid, thereby producing at least one organic acid product stream comprising the acetic acid and, thereafter, regenerating the one or more beds of anion exchange resin with ammonium hydroxide to produce at least one separate outlet stream comprising ammonium sulfate; and

(iv) recovering the at least one product stream.

50. The process according to claim 49, wherein the sulfuric acid addition is conducted to pretreat the lignocellulosic feedstock, thereby hydrolyzing at least a portion of hemicellulose present in said lignocellulosic feedstock to sugar monomers.

51. The process according to claim 49, wherein the sulfuric acid addition is conducted to hydrolyze both hemicellulose and cellulose present in said lignocellulosic feedstock to their respective sugar monomers.