Method for producing ethanol and solvents from lignocellulosic biomass including the recirculation of a butyl wine obtained by fermenting pentoses

• US 9,453,245 B2
• Filed: 04/04/2012
• Issued: 09/27/2016
• Est. Priority Date: 04/14/2011
• Status: Active Grant

• Current Assignee: IFP Energies Nouvelles
• Original Assignee: IFP Energies Nouvelles
• Inventors: Dastillung, Rejane, Ropars, Marcel, Aymard, Caroline, Marchal, Remy, Menir, Sandra, Clement, Benjamin
• Primary Examiner(s): HOLLAND, PAUL J
• Application Number:
  US14/110,713
• Publication Number:
  US 20140065683A1
• Time in Patent Office: 1,637 Days
• Field of Search: None
• US Class Current: 1/1
• 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 7/16 Butanols
• CPC Class Codes: C12P 7/28 Acetone-containing products
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

This invention describes a process for the production of second generation alcohols and/or solvents starting from cellulosic or lignocellulosic biomass wherein the lignocellulosic or cellulosic biomass undergoes a pretreatment before being converted into ethanol after an enzymatic hydrolysis and an ethylic fermentation, wherein glucidic polymers of the pretreated plant are hydrolyzed by cellulases; microorganisms that primarily use hexoses and preferably glucose and mannose are used for the ethylic fermentation; wines, with or without separation of materials in suspension are extracted by distillation; pentoses in the vinasses are fermented by a solventogenic microorganism into a butyl wine, and at least one portion of the butyl wine is recycled upstream from enzymatic hydrolysis.

Claims

1. A process for the production of alcohols, solvents, or both starting from cellulosic or lignocellulosic biomass comprising the following steps:

a) pretreating a cellulosic or lignocellulosic substrate by thermochemical pretreatment to produce a pretreated substrate;

b) optionally washing said pretreated substrate and adjusting the pH of said pretreated substrate;

c) hydrolyzing said pretreated, optionally washed, substrate, with cellulolytic and/or hemicellulolytic enzymes, wherein an aqueous stream comprising a hydrolysate and a water-insoluble residue is produced;

d) fermenting hexoses contained in said hydrolysate obtained from step c) in the presence of an alcohologenic microorganism of the genus Saccharomyces to produce an ethyl wine comprising ethanol and solvents;

e) extracting said ethyl wine of step d), said extracting comprising

e1) separating and purifying ethanol and/or solvents obtained from step d), and

e2) separating a solid cake containing said water-insoluble residue to produce vinasses;

f) fermenting pentoses contained in said vinasses obtained from step e2) in the presence of a solventogenic microorganism of the genus Clostridium to produce a butyl wine, wherein said butyl wine comprises a mixture of solvents comprising acetone, butanol, and ethanol, or comprises a mixture of solvents comprising isopropanol, butanol, and ethanol;

g) recycling at least a portion of said butyl wine upstream from at least one of step c) and/or step d), wherein after said recycling of at least a portion of said butyl wine said aqueous stream in step c) contains between 0.1 and 20 g/L of solvents, and a butanol portion of said solvents is present in a concentration of between 0.1 and 15 g/L.

2. The process of claim 1, wherein said pentoses fermented in step f) are obtained both from said vinasses from step e2) and a stream that is extracted directly after step a).

3. The process of claim 1, wherein steps c) and d) are carried out simultaneously at a temperature range of 30°

to 45°

C., and at a pH range of 4 to 6.

4. The process of claim 1, wherein said separating said solid cake of step e2) is carried out downstream from step c) and/or step d) and is optionally coupled to a washing cycle of said solid cake.

5. The process of claim 1, wherein said vinasses sent to said fermenting in step f) have a concentration range of 30 to 90 g/L of sugars or fermentable products.

6. The process of claim 1, wherein said vinasses are sent downstream from said pretreating in step a) before being sent to said fermenting in step f).

7. The process of claim 1, wherein a portion of said butyl wine that is not recycled upstream from at least one of step c) and/or step d) is subjected to a water/solvent separation before being sent to said extracting step e).

8. The process of claim 7, wherein said ethyl and butyl wines subjected to said extracting step e) contain 10 to 150 g/L of ethanol and 0.1 to 20 g/L of solvents, wherein said solvents comprise 0.1 to 15 g/L of butanol.