Method and systems for processing lignin during hydrothermal digestion of cellulosic biomass solids while producing a monohydric alcohol feed

Patent metadata

Field	Value
Publication number	US-9376355-B2
Application number	US-201314067282-A
Country	US
Kind code	B2
Filing date	Oct 30, 2013
Priority date	Oct 31, 2012
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

Digestion of cellulosic biomass solids may be complicated by release of lignin therefrom. Methods for digesting cellulosic biomass solids may comprise: providing cellulosic biomass solids in the presence of a digestion solvent, molecular hydrogen, and a slurry catalyst capable of activating molecular hydrogen; at least partially converting the cellulosic biomass solids into a phenolics liquid phase comprising lignin, an aqueous phase comprising a glycol derived from the cellulosic biomass solids, and an optional light organics phase; wherein at least a portion of the slurry catalyst accumulates in the phenolics liquid phase as it forms; combining the glycol with the phenolics liquid phase, thereby forming a combined phase; and heating the combined phase in the presence of molecular hydrogen; wherein heating the combined phase reduces the viscosity of the phenolics liquid phase and transforms at least a portion of the glycol into a monohydric alcohol.

First claim

What is claimed is:

1. A method comprising:
providing cellulosic biomass solids in the presence of a digestion solvent, molecular hydrogen, and a slurry catalyst capable of activating molecular hydrogen;
at least partially converting the cellulosic biomass solids into a phenolics liquid phase comprising lignin, an aqueous phase comprising a glycol derived from the cellulosic biomass solids, and an optional light organics phase;
wherein at least a portion of the slurry catalyst accumulates in the phenolics liquid phase as it forms;
combining the glycol with the phenolics liquid phase, thereby forming a combined phase; and
heating the combined phase in the presence of molecular hydrogen;
wherein heating the combined phase reduces the viscosity of the phenolics liquid phase and transforms at least a portion of the glycol into a monohydric alcohol.

2. The method of claim 1 , wherein the glycol is formed by a catalytic reduction reaction of soluble carbohydrates, the soluble carbohydrates being derived from the cellulosic biomass solids.

3. The method of claim 1 , wherein the slurry catalyst comprises a poison-tolerant catalyst.

4. The method of claim 3 , wherein the poison-tolerant catalyst comprises a sulfided catalyst.

5. The method of claim 1 , wherein heating the combined phase in the presence of molecular hydrogen at least partially depolymerizes the lignin therein.

6. The method of claim 5 , wherein the cellulosic biomass solids are heated to a first temperature to form the phenolics liquid phase and the aqueous phase, and the combined phase is heated to a second temperature to at least partially depolymerize the lignin, the first temperature being lower than the second temperature and insufficient to at least partially depolymerize the lignin.

7. The method of claim 1 , further comprising:
separating the phenolics liquid phase from the cellulosic biomass solids before combining the glycol with the phenolics liquid phase.

8. The method of claim 7 , further comprising:
removing at least a portion of the water from the aqueous phase, thereby producing a dried glycol;
wherein the dried glycol is combined with the phenolics liquid phase.

9. The method of claim 8 , wherein removing at least a portion of the water from the aqueous phase comprises a distillation to separate at least a portion of the water from the glycol.

10. The method of claim 1 , further comprising:
separating the phenolics liquid phase from the aqueous phase; and
after separating the phenolics liquid phase from the aqueous phase, removing at least a portion of the water from the aqueous phase, thereby producing a dried glycol;
wherein the dried glycol is combined with the phenolics liquid phase.

11. The method of claim 10 , wherein removing at least a portion of the water from the aqueous phase comprises a distillation to separate at least a portion of the water from the glycol.

12. The method of claim 1 , wherein the combined phase is heated to a temperature of about 270° C. or higher.

13. The method of claim 1 , further comprising:
measuring the viscosity of the phenolics liquid phase; and
heating the combined phase until a desired viscosity has been reached.

14. The method of claim 1 , further comprising:
forming methanol from the lignin while heating the combined phase.

15. The method of claim 14 , further comprising:
separating the methanol and the monohydric alcohol from the combined phase.

16. The method of claim 15 , further comprising:
performing a condensation reaction on the methanol and the monohydric alcohol or a product derived therefrom.

17. The method of claim 1 , further comprising:
separating the monohydric alcohol from the combined phase.

18. The method of claim 17 , further comprising:
performing a condensation reaction on the monohydric alcohol or a product derived therefrom.

19. The method of claim 1 , further comprising:
separating the slurry catalyst from the combined phase after reducing the viscosity.

20. The method of claim 19 , further comprising:
returning the slurry catalyst to the cellulosic biomass solids.

21. The method of claim 1 , further comprising:
circulating at least a portion of the aqueous phase through the cellulosic biomass solids.

22. A method comprising:
providing cellulosic biomass solids in the presence of a digestion solvent, molecular hydrogen, and a slurry catalyst capable of activating molecular hydrogen;
heating the cellulosic biomass solids to a first temperature and forming a phenolics liquid phase comprising lignin, an aqueous phase comprising a glycol derived from the cellulosic biomass solids, and an optional light organics phase;
wherein at least a portion of the slurry catalyst accumulates in the phenolics liquid phase as it forms;
separating the phenolics liquid phase from the aqueous phase and the cellulosic biomass solids;
removing at least a portion of the water from the aqueous phase, thereby producing a dried glycol;
combining the dried glycol with the phenolics liquid phase, thereby forming a combined phase; and
heating the combined phase to a second temperature in the presence of molecular hydrogen, the second temperature being sufficient to reduce the viscosity of the phenolics liquid phase and transform at least a portion of the dried glycol into a monohydric alcohol;
wherein the first temperature is lower than the second temperature.

23. The method of claim 22 , wherein the glycol is formed by a catalytic reduction reaction of soluble carbohydrates, the soluble carbohydrates being derived from the cellulosic biomass solids.

24. The method of claim 22 , wherein the slurry catalyst comprises a poison-tolerant catalyst.

25. The method of claim 24 , wherein the poison-tolerant catalyst comprises a sulfided catalyst.

26. The method of claim 22 , wherein heating the combined phase to the second temperature in the presence of molecular hydrogen at least partially depolymerizes the lignin therein.

27. The method of claim 26 , wherein the first temperature is insufficient to at least partially depolymerize the lignin.

28. The method of claim 26 , wherein the second temperature is about 270° C. or higher.

29. The method of claim 28 , wherein the first temperature is about 250° C. or lower.

30. The method of claim 22 , further comprising:
measuring the viscosity of the phenolics liquid phase; and
heating the combined phase until a desired viscosity has been reached.

31. The method of claim 22 , further comprising:
forming methanol from the lignin while heating the combined phase.

32. The method of claim 31 , further comprising:
separating the methanol and the monohydric alcohol from the combined phase.

33. The method of claim 32 , further comprising:
performing a condensation reaction on the methanol and the monohydric alcohol or a product derived therefrom.

34. The method of claim 22 , further comprising:
separating the monohydric alcohol from the combined phase.

35. The method of claim 34 , further comprising:
performing a condensation reaction on the monohydric alcohol or a product derived therefrom.

36. The method of claim 22 , further comprising:
separating the slurry catalyst from the combine

Assignees

• Shell Oil Co

Inventors

• Powell Joseph Broun
• Johnson Kimberly Ann

Classifications

• C07C29/60

  by elimination of -OH groups, e.g. by dehydration (C07C29/34 takes precedence) · CPC title

• C10G2300/1014

  of vegetal origin · CPC title

• C10G3/50

  in the presence of hydrogen, hydrogen donors or hydrogen generating compounds · CPC title

• D21C3/20

  with organic solvents {or in solvent environment} · CPC title

• C10G1/002 Primary

  in combination with oil conversion- or refining processes · CPC title