CONVERSION OF BIOMASS INTO ETHANOL

• US 20100196979A1
• Filed: 07/28/2009
• Published: 08/05/2010
• Est. Priority Date: 07/30/2008
• Status: Active Grant

• Current Assignee: D3MAX, LLC
• Original Assignee: BBI International Inc.
• Inventors: Lindeman, Chris, Yancey, Mark, Spooner, Jesse, Duff, Brian, Birkmire, Scott
• Granted Patent: US 8,288,138 B2
• Time in Patent Office: Days
• US Class Current: 435/161
• CPC Class Codes: C08H 8/00 Macromolecular compounds derived from lignocellulosic materials pretreatment thereof B27N
• CPC Class Codes: C12N 1/22 Processes using, or culture media containing, cellulose or hydrolysates thereof
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• 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

A process and system for the conversion of biomass, such as spent brewers grain, into ethanol and other commercial products, such as pelletized fuel, biogas, fertilizer, and livestock feed, is disclosed. The method may include biomass pretreatment, hydrolysis, fermentation, distillation, and dehydration phases.

Claims

1. A process for converting spent brewers grain into ethanol, comprising:

pretreating spent brewers grain with acid and heat to degrade hemicellulosic material within the grain;

hydrolyzing the pretreated spent brewers grain with an enzyme to convert starch and cellulosic material to simple sugars;

fermenting the simple sugars into ethanol with an ethanol-producing microbe;

distilling the ethanol;

dehydrating the ethanol to remove water; and

recovering whole stillage as a pelletized biomass fuel precursor.

2. The process of claim 1, wherein pretreating spent brewers grain includes an in-line processing system, comprising:

treating spent brewers grains with sulfuric acid to form an acidified grain material;

steam-heating the acidified grain material in a pressurized pipe, to a temperature of between about 325°

F. to about 375°

F. and a pressure of between about 80 to about 170 psig;

flowing the heated and acidified grain material through a throttle valve into a reaction vessel slightly above atmospheric pressure;

neutralizing the grain material in the reaction vessel;

adding a liquid brewery feedstock or water to provide a mixed material stream; and

cooling the mixed material stream to a temperature of between about 130°

F. to about 150°

F. with an in-line pipe heat exchanger.

3. The process of claim 1, wherein distilling the ethanol comprises:

distilling the ethanol with a single distillation column to provide an ethanol/water mixture of between about 35% to about 60% w/w ethanol;

and wherein dehydrating the ethanol comprises;

flowing the ethanol/water mixture from the single distillation column through a series of three pervaporative membranes to remove water from the ethanol.

4. The process of claim 1, wherein distilling the ethanol comprises:

distilling the ethanol with a single distillation column to provide an ethanol/water mixture of between about 35% to about 60% w/w ethanol;

and wherein dehydrating the ethanol comprises;

treating the ethanol/water mixture with molecular sieves to remove water from the ethanol.

5. The process of claim 1, further comprising:

denaturing the dehydrated ethanol for the production of fuel ethanol.

6. The process of claim 1, further comprising:

subjecting a centrate from the whole stillage to anaerobic digestion with mesophilic or thermophilic microorganisms to produce methane-containing biogas.

7. The process of claim 1, further comprising:

obtaining an ethanol-producing microbe, selected from at least one of;

yeast, Zymomonas mobilis, Saccharomyces cerevisiae, Escherichia coli, Bacillus subtilis, or Pichia pastoris, to add to the hydrolyzed spent brewers grain.

8. A process for converting spent brewers grain into ethanol, comprising:

pretreating spent brewers grain with an acid and heat to degrade hemicellulosic material within the grain;

hydrolyzing the pretreated spent brewers grain with an enzyme to convert starch and cellulosic material to simple sugars;

fermenting the simple sugars into ethanol with an ethanol-producing microbe;

distilling the ethanol;

dehydrating the ethanol to remove water; and

subjecting whole stillage to anaerobic digestion with mesophilic or thermophilic microorganisms to produce methane-containing biogas.

9. The process of claim 8, wherein pretreating spent brewers grain includes an in-line processing system comprising:

treating spent brewers grains with sulfuric acid to form an acidified grain material;

steam-heating the acidified grain material in a pressurized pipe, to a temperature of between about 325°

F. to about 375°

F. and a pressure of between about 80 to about 170 psig;

flowing the heated and acidified grain material through a throttle valve into a reaction vessel slightly above atmospheric pressure;

neutralizing the grain material in the reaction vessel;

adding a liquid brewery feedstock or water to provide a mixed material stream; and

cooling the mixed material stream to a temperature of between about 130°

F. to about 150°

F. with an in-line pipe heat exchanger.

10. The process of claim 8, wherein distilling the ethanol comprises:

distilling the ethanol with a single distillation column to provide an ethanol/water mixture of between about 35% to about 60% w/w ethanol;

and wherein dehydrating the ethanol comprises;

flowing the ethanol/water mixture from the single distillation column through a series of three pervaporative membranes to remove water from the ethanol.

11. The process of claim 8, wherein distilling the ethanol comprises:

distilling the ethanol with a single distillation column to provide an ethanol/water mixture of between about 35% to about 60% w/w ethanol;

and wherein dehydrating the ethanol comprises;

treating the ethanol/water mixture with molecular sieves to remove water from the ethanol.

12. The process of claim 8, further comprising:

denaturing the dehydrated ethanol for the production of fuel ethanol.

13. The process of claim 8, further comprising:

obtaining an ethanol-producing microbe, selected from at least one of;

yeast, Zymomonas mobilis, Saccharomyces cerevisiae, Escherichia coli, Bacillus subtilis, or Pichia pastoris, to add to the hydrolyzed spent brewers grain.

14. A system for converting spent brewers grain into ethanol, comprising:

a pretreatment apparatus that treats spent brewers grain with an acid and heat;

a hydrolysis reactor that converts the pretreated spent brewers grain into simple sugars;

a fermentation tank that converts the sugars into ethanol;

a single distillation column to convert the ethanol to an ethanol/water mixture of between about 35% to about 60% w/w ethanol; and

a dehydration reactor using a series of three pervaporative membranes to remove water from the ethanol.

15. The system of claim 14, further comprising:

a pelletization apparatus to convert whole stillage into a pelletized biomass fuel.

16. The system of claim 14, further comprising:

an anaerobic digester to convert whole stillage to produce methane-containing biogas.

17. The system of claim 14, further comprising:

a connection to a brewery, to allow sharing of common utilities chosen from;

steam, electricity, water, power generation, and waste water treatment.

18. The system of claim 14, further comprising:

a denaturing reactor to denature the dehydrated ethanol for the production of fuel ethanol.

19. The system of claim 14, further comprising:

a preparation vessel to add an ethanol-producing microbe to the hydrolyzed spent brewers grain.

20. The system of claim 14, wherein the pretreatment apparatus is an in-line pretreatment apparatus, comprising:

an acid injection apparatus to treat spent brewers grains with sulfuric acid to form an acidified grain material;

a steam-heating apparatus to heat the acidified grain material in a pressurized pipe, to a temperature of between about 325°

F. to about 375°

F. and a pressure of between about 80 to about 170 psig;

a throttle valve to transfer the heated and acidified grain material into a reaction vessel slightly above atmospheric pressure;

a reaction vessel in which to neutralize the grain material;

a dilution apparatus to add a liquid brewery feedstock or water to the grain material to provide a mixed material stream; and

a cooling apparatus to cool the mixed material stream to a temperature of between about 130°

F. to about 150°

F.