METHOD FOR PRODUCING ETHANOL FROM LIGNOCELLULOSIC BIOMASS

• US 20120220005A1
• Filed: 09/02/2009
• Published: 08/30/2012
• Est. Priority Date: 09/02/2009
• Status: Abandoned Application

• Current Assignee: Kawasaki Jukogyo Kabushiki Kaisha, University of Tokushima
• Original Assignee: Kawasaki Jukogyo Kabushiki Kaisha, University of Tokushima
• Inventors: Kumagai, Chikanori, Taniyama, Noriyuki, Nakamura, Yoshitoshi
• Application Number:
  US13/393,518
• Publication Number:
  US 20120220005A1
• Time in Patent Office: Days
• US Class Current: 435/161
• CPC Class Codes: C12M 45/02 by mechanical forces; Stirring; Trituration; Comminuting crushing, pulverizing, disintegrating in general B02C
• CPC Class Codes: C12M 45/20 Heating; Cooling heating or cooling apparatus for laboratory uses B01L7/00
• 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: C12P 7/14 Multiple stages of fermentation; Multiple types of microorganisms or re-use of microorganisms
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

An object of the invention is to provide an inexpensive and efficient ethanol production method using lignocellulosic biomass as a raw material.

The method for producing ethanol from lignocellulosic biomass of the present invention includes

• • a lignocellulose decomposition step of subjecting lignocellulosic biomass to a steam explosion treatment or hydrolysis in a subcritical state followed by a flash treatment;
  • a lignin removal step of immersing a solid residue resulting from the decomposition step in ethanol to remove lignin; and
  • a C6 saccharification/simultaneous fermentation step of saccharifying the solid residue resulting from the lignin removal step with an enzyme and further fermenting the resulting product into ethanol with a C6 fermentation microorganism.

By combining the steam explosion treatment and the lignin removal process by ethanol immersion, higher rates are achieved for the saccharification and fermentation of the biomass.

Claims

1. A method for producing ethanol from lignocellulosic biomass, the method comprising:

a lignocellulose decomposition step of subjecting lignocellulosic biomass to a steam explosion treatment or hydrolysis in a subcritical state;

a lignin removal step of removing lignin by ethanol immersion of the solid residue resulting from the decomposition step;

a C6 saccharification/simultaneous fermentation step of saccharifying the solid residue resulting from the lignin removal step with an enzyme and further fermenting the resulting product into ethanol with a C6 fermentation microorganism.

2. The method according to claim 1, further comprising a C5 fermentation step of carrying out ethanol fermentation of C5 sugars with a C5 fermentation microorganism after the liquid phase resulting from the decomposition step was concentrated.

3. The method according to claim 2, wherein after separating the fermentation microorganism from a C5 fermented liquid resulting from the C5 fermentation step, the C5 fermented liquid is supplied to the C6 saccharification/simultaneous fermentation step.

4. The method according to claim 3, wherein the C5 fermentation microorganism separated from the C5 fermented liquid is reused.

5. The method according to claim 1, further comprising an immersion step of immersing the lignocellulosic biomass in aqueous ammonia or ethanol prior the decomposition step.

6. The method according to claim 1, wherein the C6 fermentation microorganism is separated from the C6 fermented liquid resulting from the C6 saccharification/simultaneous fermentation step and reused.

7. The method according to claim 2, wherein in place of the C5 fermentation microorganism and the C6 fermentation microorganism, a fermentation microorganism displaying C5 enzyme and C6 enzyme on the surface thereof and capable of utilizing glucose and xylose to give ethanol.