Method for producing ethanol and co-products from cellulosic biomass

• US 9,335,043 B2
• Filed: 08/24/2010
• Issued: 05/10/2016
• Est. Priority Date: 08/24/2009
• Status: Expired due to Fees

• Current Assignee: Abengoa Bioenergy New Technologies, LLC (Abengoa SA)
• Original Assignee: Abengoa Bioenergy New Technologies, Inc. (Abengoa SA)
• Inventors: Nguyen, Quang A.
• Primary Examiner(s): Afremova, Vera
• Application Number:
  US13/056,074
• Publication Number:
  US 20110262984A1
• Time in Patent Office: 2,086 Days
• Field of Search: None
• US Class Current: 1/1
• 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 7/10 substrate containing cellulosic material
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: C13K 13/002 Xylose
• CPC Class Codes: D21C 1/00 Pretreatment of the finely-divided materials before digesting of waste paper D21C5/02
• CPC Class Codes: D21C 1/04 with acid reacting compounds
• CPC Class Codes: F23C 13/02 characterised by arrangements for starting the operation, e.g. for heating the catalytic material to operating temperature
• CPC Class Codes: F23D 14/64 with injectors
• CPC Class Codes: F23D 14/66 Preheating the combustion air or gas
• CPC Class Codes: F23N 1/027 using mechanical means
• CPC Class Codes: F23N 2221/06 Preheating gaseous fuel
• CPC Class Codes: F23N 2221/08 Preheating the air
• CPC Class Codes: F23N 2225/20 entrant temperature
• CPC Class Codes: F23N 2237/20 one or more bypass conduits
• CPC Class Codes: Y02E 20/34 Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

The present invention generally relates to processes for production of ethanol from cellulosic biomass. The present invention also relates to production of various co-products of preparation of ethanol from cellulosic biomass. The present invention further relates to improvements in one or more aspects of preparation of ethanol from cellulosic biomass including, for example, improved methods for cleaning biomass feedstocks, improved acid impregnation, and improved steam treatment, or “steam explosion.”

Claims

1. A method for pretreatment of virgin cellulosic biomass feedstock comprising cellulose, hemicellulose, lignin, and sand, the method comprising:

dry cleaning the virgin cellulosic biomass feedstock in a fine particulate separation zone comprising at least one classifying screen having openings of from U.S. Sieve No. 20 (840 μ

m) to U.S. Sieve No. 100 (150 μ

m) to recover a cleaned biomass feedstock on the at least one classifying screen and remove a fine particulate fraction therefrom, the fine particulate fraction having passed through the classifying screen wherein the fine particulate fraction has an ash content of at least about 30 wt. %, wherein said dry cleaning is done in the absence of the addition of liquid to the virgin cellulosic biomass feedstock for the purpose of removing contaminants;

contacting in an acid impregnation vessel the cleaned biomass feedstock and an acidic aqueous liquid medium containing less than 5 wt % acid to form an acid-impregnated cellulosic biomass feedstock;

removing an aqueous liquid fraction from the acid-impregnated cellulosic biomass feedstock to form an acid-impregnated feedstock having a reduced sand content and an acidic aqueous liquid fraction comprising sand;

removing a sand-rich product from the acidic aqueous liquid fraction; and

introducing at least a portion of the acidic aqueous liquid fraction having the sand-rich product removed therefrom into the acid impregnation vessel.

2. The method of claim 1 wherein the cleaned biomass feedstock and the acidic aqueous liquid medium are contacted by soaking the cleaned biomass feedstock in the acidic liquid medium.

3. The method of claim 1 wherein the acidic aqueous liquid fraction having the sand rich product removed therefrom and the acidic aqueous liquid medium are combined prior to introduction into the acid-impregnation vessel.

4. The method of claim 1 wherein the cellulosic biomass feedstock comprises particles having a particle size distribution such that at least 50 wt % of the feedstock particles have a size in their largest dimension of from about 0.6 cm (0.25 inches) to about 4 cm (1.5 inches).

5. The method of claim 1 wherein the acidic aqueous liquid medium includes the acid at a concentration of from about 0.7 wt % to about 3.5 wt %.

6. The method of claim 1 wherein the acidic aqueous liquid medium includes the acid at a concentration of from about 1.0 wt % to about 3.0 wt %.

7. The method of claim 1 wherein the cleaned biomass feedstock is contacted with at least 0.005 kg acid (acid weight basis) per kg cellulosic biomass feedstock (dry weight basis).

8. The method of claim 1 wherein the cleaned biomass feedstock is contacted with from about 0.01 kg to about 0.05 kg acid (acid weight basis) per kg cellulosic biomass feedstock (dry weight basis).

9. The method of claim 1 wherein the acidic aqueous liquid medium comprises a surfactant (wetting agent).

10. The method of claim 1 wherein the temperature of the acidic aqueous liquid medium is from about 20°

C. to about 95°

C.

11. The method of claim 1 further comprising heating during contact of the cleaned biomass feedstock with the acidic aqueous liquid medium.

12. The method of claim 1 wherein the cleaned biomass feedstock and acidic aqueous liquid medium are contacted at a temperature of from about 30°

C. to about 90°

C.

13. The method of claim 1 wherein the acid-impregnated cellulosic biomass feedstock has a moisture content of from about 20 wt % to about 70 wt %.

14. The method of claim 1 wherein the acid-impregnated cellulosic biomass feedstock has a moisture content of from about 30 wt % to about 70 wt %.

15. The method of claim 1 wherein the temperature of the acid impregnated cellulosic biomass feedstock is from about 40°

C. to about 80°

C.

16. The method of claim 1 wherein the cleaned biomass feedstock is contacted with the acidic aqueous liquid medium in the acid impregnation vessel and the acid-impregnated cellulosic biomass feedstock is removed from the acid impregnation vessel and held in a second vessel, the residence time of the acid-impregnated cellulosic biomass feedstock in the second vessel being from about 1 to about 60 minutes.

17. The method of claim 1 wherein the cleaned biomass feedstock is contacted with the acidic aqueous liquid medium by spraying the acidic liquid medium onto the cellulosic biomass feedstock.

18. The method of claim 17 wherein the cleaned biomass feedstock is contacted with the acidic aqueous liquid medium in an acid impregnation vessel comprising counter-rotating shafts having flights mounted thereon for agitation of the biomass.

19. The method of claim 18 wherein the cleaned biomass feedstock is agitated for from about 2 to about 5 minutes.

20. The method of claim 18 wherein the cleaned biomass feedstock is agitated at an intensity of from about 2 kWh/ton biomass to about 10 kWh/ton biomass.

21. The method of claim 18 wherein the cleaned biomass feedstock is contacted with the acidic aqueous liquid medium in the acid impregnation vessel for from about 2 to about 35 minutes.

22. The method of claim 1 wherein the fine particulate fraction has a moisture content of less than 20 wt. %.

23. The method of claim 1 wherein the cleaned biomass feedstock has a moisture content of less than 20 wt. %.

24. The method of claim 1 wherein the moisture content of the cleaned biomass feedstock and of the virgin cellulosic biomass feedstock vary by no more than about 10 wt. %.

25. The method of claim 1 wherein the moisture content of the cleaned biomass feedstock and of the virgin cellulosic biomass feedstock vary by no more than about 5 wt. %.

26. The method of claim 1 wherein the moisture content of the cleaned biomass feedstock and of the virgin cellulosic biomass feedstock vary by no more than about 3 wt. %.