Advanced biorefinery process

• US 8,414,771 B2
• Filed: 02/08/2012
• Issued: 04/09/2013
• Est. Priority Date: 09/01/2006
• Status: Expired due to Fees

• Current Assignee: RA Energy
• Original Assignee: RA Energy
• Inventors: Stuart, Earnest
• Primary Examiner(s): BARRY, CHESTER T
• Application Number:
  US13/368,813
• Publication Number:
  US 20120201947A1
• Time in Patent Office: 426 Days
• Field of Search: 210/606, 210/173
• US Class Current: 210/606
• CPC Class Codes: C12P 7/06 Ethanol, i.e. non-beverage
• CPC Class Codes: C12P 7/16 Butanols
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

The present invention is a method for refining native biomass to extremely fine and highly disrupted particles using high shear and/or cavitation in combination with high temperature and high or low pH conditions which dissolve biomass to a high percentage. The method of the present invention results in a high percentage of hydrolysis, in many cases near theoretical levels, in short residence times while minimizing inputs over other methods, using low chemical inputs, and optionally with no chemical inputs in certain stages compared to existing processes. The method of the present invention also uses minimal electrical energy inputs and conserves heat energy within the process and reduces equipment requirements while producing concentrated products.

Claims

1. A method of refining lignocellulosic biomass comprising cellulose and hemicellulose fractions, the cellulose and hemicellulose fractions comprising cells having structure, the method comprising the steps of:

(a) applying high shear and cavitation to a slurry containing the biomass to disrupt the cellular structure of the cellulose and hemicellulose fractions of the biomass;

(b) subsequent to step a, removing native biomass protein from the slurry; and

(c) subsequent to step b, heating the slurry to a temperature of between 150°

C. and 300°

C. for a duration sufficient to hydrolyze a high percentage of the biomass.

2. The method of claim 1, wherein the protein removal step comprises adding protease enzymes to the slurry.

3. The method of claim 1, wherein the protein removal step comprises adding potassium chloride to the slurry.

4. The method of claim 1, wherein the protein removal step comprises adding acid to the slurry.

5. The method of claim 1, wherein the protein removal step comprises adding a base to the slurry.

6. The method of claim 1, wherein the protein removal step comprises subjecting the slurry to high temperature extraction and coagulation.

7. The method of claim 1, wherein the protein removal step further comprises removing amino acids from the slurry.

8. The method of claim 1, wherein step (c) further comprises applying high shear and cavitation to the heated slurry.

9. The method of claim 1, wherein the application of high shear and cavitation in step (a) comprises passing the biomass slurry through a high shear and cavitating device with nozzle holes less than 2 mm in diameter, and operating at a tip speed of at least 120 feet per second.

10. The method of claim 9, wherein the application of high shear and cavitation in step (a) comprises passing the biomass slurry through a high shear and cavitating device with nozzle holes less than 2 mm in diameter, and operating at a tip speed of at least 140 feet per second.

11. The method of claim 10, wherein the application of high shear and cavitation in step (a) comprises passing the biomass slurry through a high shear and cavitating device with nozzle holes less than 1.5 mm in diameter, and operating at a tip speed of at least 150 feet per second.

12. The method of claim 10, wherein the high shear and cavitating device operates at a tip speed of at least 200 feet per second.

13. The method of claim 1, further including a step of adding a chemical to the biomass slurry prior to or during step (c) to accelerate the hydrolysis of the biomass.

14. The method of claim 13 wherein the chemical is selected from the group consisting of mineral acids, anhydrous ammonia, ammonium hydroxide, and alkaline mineral chemicals.

15. The method of claim 14, wherein a mineral acid is added to the biomass slurry to produce an acid loading of less than 2% to accelerate the hydrolysis of the biomass.

16. The method of claim 1 wherein the biomass slurry is heated to a temperature of at least 200°

C.

17. The method of claim 1 wherein the biomass comprises hemicellulose, and none of the following chemicals are added to the slurry:

mineral acids, mineral bases, anhydrous ammonia, ammonium hydroxide, and alkaline mineral chemicals.

18. The method of claim 1 wherein no chemical is added to the biomass slurry during step (c).

19. The method of claim 8 wherein step (c) is performed for less than five minutes.