Process for treating biomass to produce materials useful for biofuels

• US 9,873,665 B2
• Filed: 08/13/2015
• Issued: 01/23/2018
• Est. Priority Date: 08/14/2014
• Status: Active Grant

• Current Assignee: Shell USA Incorporated (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Blackbourn, Robert Lawrence, Weider, Paul Richard, Boriski, Dennis Shane
• Primary Examiner(s): Carlson, Karen Cochrane
• Assistant Examiner(s): Tichy, Jennifer M. H.
• Application Number:
  US14/825,337
• Publication Number:
  US 20160046567A1
• Time in Patent Office: 894 Days
• Field of Search: None
• CPC Class Codes: C07C 309/08 containing hydroxy groups bound to the carbon skeleton
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: C13K 13/00 Sugars not otherwise provided for in this class
• CPC Class Codes: C13K 13/002 Xylose
• CPC Class Codes: D21C 1/04 with acid reacting compounds
• CPC Class Codes: D21C 3/04 with acids, acid salts or acid anhydrides D21C3/003 and D21C3/222 take precedence
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel

Abstract

Since biomass is always accompanied by caustic inorganic materials, we have found that the formation of the anion salt of α-hydroxysulfonic acid represent the largest “loss” of the α-hydroxysulfonic acid in the potential reversible acid pretreatment process. By titrating the α-hydroxysulfonic acid salt with strong mineral acid and then reverting the alfa-hydroxysulfonic acid as its primary components, the acid components can be recovered substantially quantitatively.

Claims

1. A method for recovering α

-hydroxysulfonic acid in a biomass treatment process comprising;

(a) providing a biomass containing polysaccharides;

(b) contacting the biomass with a solution containing at least one α

-hydroxysulfonic acid thereby hydrolyzing the biomass to produce a product stream containing at least one fermentable sugar, α

-hydroxysulfonic acid, and at least one salt of α

-hydroxysulfonic acid;

(c) contacting at least a portion of the salt of α

-hydroxysulfonic acid with a mineral acid forming α

-hydroxysulfonic acid and a salt of the mineral acid;

(d) separating at least a portion of the α

-hydroxysulfonic acid from the mineral acid by heating and/or reducing pressure and recovering the α

-hydroxysulfonic acid in its component form; and

(e) recovering from the product stream an acid-removed product containing at least one fermentable sugar.

2. The method of claim 1 wherein the α

-hydroxysulfonic acid is recovered by removing at least a portion of the α

-hydroxysulfonic acid in its component form from the product by heating and/or reducing pressure to produce an acid-removed product containing at least one fermentable sugar.

3. The method of claim 1 wherein the mineral acid is present in an amount from 0.1 equivalent to 1.2 equivalent to the salt of α

-hydroxysulfonic acids in step (c).

4. The method of claim 3 wherein the mineral acid is provided to step (c).

5. The method of claim 1 wherein the α

-hydroxysulfonic acid is present in an amount of from about 1% wt. to about 55% wt., based on the solution.

6. The method of claim 1 wherein the α

-hydroxysulfonic acid is produced from (a) a carbonyl compound or a precursor to a carbonyl compound with (b) sulfur dioxide or a precursor to sulfur dioxide and (c) water.

7. The method of claim 1 wherein the α

-hydroxysulfonic acid is in-situ generated.

8. The method of claim 5 wherein step (b) is carried out at a temperature within the range of about 50°

C. to about 150°

C. and a pressure within the range of 0.5 bara to about 11 bara.

9. The method of claim 1 wherein the mineral acid is selected from the group consisting of sulfuric acid, phosphoric acid, hydrochloric acid, and mixtures thereof.

10. The method of claim 9 wherein step (b) is carried out at a temperature within the range of about 50°

C. to about 150°

C. and a pressure within the range of 0.5 bara to about 11 bara.

11. The method of claim 1 wherein step (c) is carried out at a temperature within the range from about 50°

C. to about 150°

C.

12. The method of claim 11 wherein step (d) is carried out at a temperature within the range from about 50°

C. to about 150°

C. and a pressure within the range from about 0.1 bara to about 5 bara.

13. The method of claim 12 wherein the mineral acid is selected from the group consisting of sulfuric acid, phosphoric acid, hydrochloric acid, and mixtures thereof.

14. The method of claim 13 wherein up to about an equivalent molar amount of mineral acid to the amount of the salt of α

-hydroxysulfonic acid is provided to step (c).

15. The method of claim 1 wherein the mineral acid is provided to step (b).

16. The method of claim 1 wherein the at least one fermentable sugar comprises at least one pentose and/or at least one hexose.

17. The method of claim 1 further comprising separating a liquid stream containing said fermentable sugar and a wet solid stream containing remaining biomass from the acid-removed product.

18. The method of claim 17 wherein at least a portion of the liquid stream is recycled to step (b).

19. The method of claim 18 wherein the mineral acid is provided to the recycle of the liquid stream.

20. The method of claim 17 further comprising hydrolyzing the wet solid stream thereby producing a sugar stream.

21. The method of claim 20 further comprising fermenting the sugar stream thereby producing fermented products.

22. The method of claim 2 further comprising hydrolyzing and fermenting the stream containing fermentable sugar thereby producing fermented products.

23. The method of claim 1 wherein the recovered α

-hydroxysulfonic acid is recycled to step (b) as components or in its recombined form.

24. The method of claim 9 wherein the recovered α

-hydroxysulfonic acid is recycled to step (b) as components or in its recombined form.

25. The method of claim 13 wherein the recovered α

-hydroxysulfonic acid as components is recycled to step (b) as components or in its recombined form.

26. The process of claim 13 wherein the biomass is contacted with the α

-hydroxysulfonic acid at a temperature of 120°

C. or less.

32. The method of claim 1 wherein the acid-removed product is further processed to produce at least one organic compound.

27. A method for recovering α

-hydroxysulfonic acid in a biomass treatment process comprising;

(a) providing a biomass containing polysaccharides;

(b) contacting the biomass with a solution containing at least one α

-hydroxysulfonic acid in an amount of from about 1% wt. to about 55% wt., based on the solution, at a temperature within the range of about 50°

C. to about 150°

C. and a pressure within the range of 0.5 bara to about 11 bara thereby hydrolyzing the biomass to produce a product stream containing at least one fermentable sugar, α

-hydroxysulfonic acid, and at least one salt of α

-hydroxysulfonic acid;

(c) contacting at least a portion of the salt of α

-hydroxysulfonic acid with a mineral acid in an amount from about 0.1 equivalent to about 1.2 equivalent amount of mineral acid to the salt of α

-hydroxysulfonic acid, said mineral acid is selected from the group consisting of sulfuric acid, phosphoric acid, hydrochloric acid, and mixtures thereof, at a temperature within the range from about 50°

C. to about 150°

C. forming α

-hydroxysulfonic acid and a salt of the mineral acid;

(d) separating at least a portion of the α

-hydroxysulfonic acid from the mineral acid at a temperature within the range from about 50°

C. to about 150°

C. and a pressure within the range from about 0.1 bara to about 5 bara with the proviso that (i) the temperature is higher than step (b), (ii) the pressure is less than step or (iii) the temperature is higher and pressure is lower than step (b), and recovering the α

-hydroxysulfonic acid in its component form; and

(e) recovering from the product stream an acid-removed product containing at least one fermentable sugar.

28. The method of claim 27 wherein the mineral acid is phosphoric acid.

29. The method of claim 27 wherein the mineral acid is sulfuric acid.

30. The method of claim 27 wherein the mineral acid is hydrochloric acid.

31. The method of claim 27 wherein the acid-removed product is further processed to produce at least one organic compound.