Method and apparatus for conversion of cellulosic material to ethanol

• US 9,284,383 B2
• Filed: 05/01/2015
• Issued: 03/15/2016
• Est. Priority Date: 07/19/2005
• Status: Active Grant

• Current Assignee: Inbicon A/S
• Original Assignee: Inbicon A/S
• Inventors: Christensen, Borge Holm, Gerlach, Lena Holm
• Primary Examiner(s): DRODGE, JOSEPH W
• Application Number:
  US14/702,210
• Publication Number:
  US 20150232579A1
• Time in Patent Office: 319 Days
• Field of Search: 127 34- 37, 127/42, 127/43, 127/65, 100/38, 100 73- 75, 100/92, 162/9, 162/18, 162/19, 162/24, 210632-634, 210/760, 210/766, 210/770, 210/774, 210/806, 210/808, 443/07, 444/50, 445/89, 445/90, 446/05, 446/06, 446/20, 435132-136, 435161-165, 422/600, 422/608, 422/616, 422/618, 422/630, 422/638, 422/642, 422/644, 422/646
• US Class Current: 1/1
• CPC Class Codes: B01J 19/245 placed in series
• CPC Class Codes: B01J 2219/00006 Large-scale industrial plants
• CPC Class Codes: C08B 1/003 Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids solutions used in the manufacture of monocomponent artificial filaments or cellulose or derivatives thereof D01F2/02
• CPC Class Codes: C08B 15/00 Preparation of other cellulose derivatives or modified cellulose , e.g. complexes
• CPC Class Codes: C08B 37/0057 beta-D-Xylans, i.e. xylosaccharide, e.g. arabinoxylan, arabinofuronan, pentosans; (beta-1,3)(beta-1,4)-D-Xylans, e.g. rhodymenans; Hemicellulose; Derivatives thereof
• CPC Class Codes: C08H 6/00 Macromolecular compounds derived from lignin, e.g. tannins, humic acids
• CPC Class Codes: C08H 8/00 Macromolecular compounds derived from lignocellulosic materials pretreatment thereof B27N
• CPC Class Codes: C12M 21/12 for producing fuels or solvents C12M21/04 takes precedence; liquid carbonaceous fuels C10L1/00, solid fuels C10L5/00
• CPC Class Codes: C12M 45/02 by mechanical forces; Stirring; Trituration; Comminuting crushing, pulverizing, disintegrating in general B02C
• CPC Class Codes: C12M 45/04 Phase separators; Separation of non fermentable material; Fractionation
• CPC Class Codes: C12M 45/09 by enzymatic treatment
• CPC Class Codes: C12M 45/20 Heating; Cooling heating or cooling apparatus for laboratory uses B01L7/00
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• CPC Class Codes: C12P 19/14 produced by the action of a carbohydrase (EC 3.2.x), e.g. by alpha-amylase , e.g. by cellulase, hemicellulase
• CPC Class Codes: C12P 21/00 Preparation of peptides or proteins single cell protein C12N1/00
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: C12P 2203/00 Fermentation products obtained from optionally pretreated or hydrolyzed cellulosic or lignocellulosic material as the carbon source ethanol C12P7/10
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C12P 7/14 Multiple stages of fermentation; Multiple types of microorganisms or re-use of microorganisms
• CPC Class Codes: C12P 7/56 Lactic acid
• CPC Class Codes: C13B 20/165 : using membranes, e.g. osmosis, ultrafiltration electrodialysis C13B20/18
• CPC Class Codes: C13K 1/02 : obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: D21C 9/18 : De-watering de-watering in general F26B; Elimination of cooking or pulp-treating liquors from the pulpD21C9/002, D21C9/02 take precedence; paper-making machines D21F; strainers in digesters D21C7/00; presses in general B30B
• CPC Class Codes: Y02E 50/10 : Biofuels, e.g. bio-diesel

Abstract

The present invention provides an apparatus and a method for conversion of cellulosic material, such as chopped straw and corn stover, and household waste, to ethanol and other products. The cellulosic material is subjected to continuous hydrothermal pre-treatment without addition of chemicals, and a liquid and a fiber fraction are produced. The fiber fraction is subjected to enzymatic liquefaction and saccharification. The method of the present invention comprises:

• • performing the hydrothermal pre-treatment by subjecting the cellulosic material to at least one soaking operation, and conveying the cellulosic material through at least one pressurized reactor, and subjecting the cellulosic material to at least one pressing operation, creating a fiber fraction and a liquid fraction;
  • selecting the temperature and residence time for the hydrothermal pretreatment, so that the fibrous structure of the feedstock is maintained and at least 80% of the lignin is maintained in the fiber fraction.

Claims

1. A method for treatment of cellulosic material comprising the steps of:

exposing said cellulosic material to a first temperature or pressure condition in a first reactor section having an inlet and an outlet,

separating a liquid fraction from a solid fraction following the first temperature or pressure condition by pressing a solid fraction of the cellulosic material at the outlet of the first reactor section, wherein the liquid fraction is subsequently subjected to fermentation, and

exposing said solid fraction to a second temperature or pressure condition in a second reactor section following said separation of a liquid fraction from the solid fraction.

2. The method of claim 1, wherein a subsequent liquid fraction is separated from said solid fraction following exposure to said second temperature or pressure condition.

3. The method of claim 2, wherein the concentration of lignin in the solid fraction following exposure to the second temperature or pressure condition and separation of said subsequent liquid fraction is higher than the lignin concentration in the cellulosic material prior to exposure to said first temperature or pressure condition.

4. The method of claim 1, wherein the severity of the second temperature or pressure condition is higher than the severity of the first temperature or pressure condition.

5. The method of claim 1, wherein the first temperature or pressure condition comprises exposing said cellulosic material to a temperature between 170°

C. and 230°

C.

6. The method of claim 1, wherein the cellulosic material is soaked at ambient pressures at temperatures up to 100°

C. prior to exposure to the first set of temperature or pressure conditions.

7. The method of claim 6, wherein a liquid fraction is separated from the cellulosic material after said soaking and prior to exposure of the first set of temperature or pressure conditions.

8. The method of claim 1, wherein said first and second temperature or pressure conditions take place in separate zones of a single reactor.

9. The method of claim 1 wherein said first and second temperature or pressure conditions take place in separate reactors.

10. The method of claim 1, wherein said treatment method is continuous.

11. The method of claim 1, wherein said treatment occurs at increased pressure when compared to atmospheric pressure.

12. The method of claim 11, wherein said increased pressure is not released until after said second temperature or pressure condition.

13. The method of claim 1, wherein the pressing is accomplished under pressurized conditions.

14. The method of claim 13 wherein the pressing under pressurized conditions is accomplished using a screw press.

15. The method of claim 1, wherein the solid fraction is subsequently subject to enzymatic liquefaction and saccharification.

16. The method of claim 15, wherein the solid fraction is further fermented to produce ethanol following enzymatic liquefaction and saccharification.

17. The method of claim 1, wherein the solid fraction is cooled by a counter current wash stage prior to exposure to said second set of temperature or pressure conditions.

18. The method of claim 1, wherein said fermentation converts C5 sugars of the liquid fraction to ethanol.

19. The method of claim 1 wherein the feedstock is wheat straw, bagasse, corn stover, or cereal straw.

20. The method of claim 1, wherein the second temperature or pressure condition comprises a higher temperature and pressure than the temperature and pressure of the first temperature or pressure condition.

21. The method of claim 1, wherein the liquid fraction undergoes hydrolysis following said separating of a liquid fraction and prior to subjecting the liquid fraction to fermentation.

22. The method of claim 21, wherein the pH of the liquid fraction is adjusted prior to subjecting the liquid fraction to fermentation.

23. The method of claim 1, wherein the pH of the liquid fraction is adjusted prior to subjecting the liquid fraction to fermentation.