Method for producing ethanol from lignocellulosic raw material

Patent metadata

Field	Value
Publication number	US-11773415-B2
Application number	US-201917274775-A
Country	US
Kind code	B2
Filing date	Sep 10, 2019
Priority date	Sep 10, 2018
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

Abstract

The present invention provides a method for efficiently producing ethanol from a lignocellulosic raw material. More specifically, the present invention provides a method for producing ethanol from a lignocellulosic raw material, which comprises a step of performing multiple parallel fermentation while continuously or intermittently adding an additional saccharification enzyme to a fermentation liquid comprising a lignocellulosic raw material, a saccharification enzyme and a yeast so that the physical property value of the fermentation liquid itself is maintained within a preset range.

First claim

The invention claimed is:

1. A method for producing ethanol from a lignocellulosic raw material, comprising:
a step of performing multiple parallel fermentation to produce ethanol while continuously or intermittently adding an additional amount of a saccharification enzyme to a fermentation liquid comprising a lignocellulosic raw material, a saccharification enzyme and a yeast so that the viscosity of the fermentation liquid is maintained within a range of 300 cP or less,
wherein the multiple parallel fermentation is a continuous system or is a semi-batch system or a batch system,
wherein the viscosity is measured with a viscometer at 25° C. and atmospheric pressure,
wherein
when the multiple parallel fermentation is a continuous system, addition of the additional saccharification enzyme to the fermentation liquid is started when the viscosity of the fermentation liquid exceeds 140 cP, and
when the multiple parallel fermentation is a semi-batch system or a batch system, the addition of the additional saccharification enzyme to the fermentation liquid is started when the viscosity of the fermentation liquid exceeds 4 cP.

2. The method for producing ethanol according to claim 1 , wherein the ethanol concentration in the fermentation liquid is maintained at 80% or more relative to the ethanol concentration after 12 to 240 hours from the start of fermentation.

3. The method for producing ethanol according to claim 1 , wherein the additional saccharification enzyme is added so that an enzyme basic unit in the fermentation liquid is maintained at 0.1 to 30% relative to the enzyme basic unit after 1 to 12 hours from the start of fermentation.

4. The method for producing ethanol according to claim 1 , wherein a mass ratio of the addition amount of the additional saccharification enzyme per day to the initial content of the saccharification enzyme in the fermentation liquid is 1:10 to 1:100.

5. The method for producing ethanol according to claim 1 , wherein the additional saccharification enzyme is added to the fermentation liquid in an amount of 20 U/L or less.

6. The method for producing ethanol according to claim 1 , wherein the additional saccharification enzyme is intermittently added every 2 to 192 hours.

7. The method for producing ethanol according to claim 1 , wherein the concentration of the lignocellulosic raw material in the fermentation liquid is adjusted so as to be maintained at 5 to 30% by mass.

8. The method for producing ethanol according to claim 1 , wherein the multiple parallel fermentation is performed in at least two reaction tanks connected to each other.

9. The method for producing ethanol according to claim 8 , wherein the at least two reaction tanks are connected in series.

10. The method for producing ethanol according to claim 8 , wherein the at least two reaction tanks comprise a first reaction tank which stores the fermentation liquid and in which additional lignocellulosic raw material is continuously fed.

11. The method for producing ethanol according to claim 8 , wherein the at least two reaction tanks comprise a first reaction tank and a second reaction tank, wherein a part of the fermentation liquid is continuously transferred from the first reaction tank to the second reaction tank.

12. The method for producing ethanol according to claim 1 , which further comprises the following steps:
a solid-liquid separation of an aqueous ethanol solution from the fermentation liquid to produce a solid content concentrated fermentation liquid, and
transferring the solid content concentrated fermentation liquid to a reaction tank after separating the aqueous ethanol solution.

13. The method for producing ethanol according to claim 2 , wherein the additional saccharification enzyme is added so that an enzyme basic unit in the fermentation liquid is maintained at 0.1 to 30% relative to the enzyme basic unit after 1 to 12 hours from the start of fermentation.

14. The method for producing ethanol according to claim 2 , wherein a mass ratio of the addition amount of the additional saccharification enzyme per day to the initial content of the saccharification enzyme in the fermentation liquid is 1:10 to 1:100.

15. The method for producing ethanol according to claim 2 , wherein the additional saccharification enzyme is added to the fermentation liquid in an amount of 20 U/L or less.

16. The method for producing ethanol according to claim 2 , wherein the additional saccharification enzyme is intermittently added every 2 to 192 hours.

Assignees

• Eneos Corp
• Oji Holdings Corp

Inventors

• Takahashi Yuichi
• Ide Kohei
• Niwa Masahiro
• KANEZAWA Miyuki
• Ikemizu Shoichi
• FURUJO Atsushi
• Azumi Naoya
• Tsukamoto Akira
• Sekizawa Shingo

Classifications

• C12P7/08 Primary

  produced as by-product or from waste or cellulosic material substrate · CPC title

• C12P7/10 Primary

  substrate containing cellulosic material · CPC title

• C12P19/02

  Monosaccharides (2-ketogulonic acid C12P7/60) · CPC title

• C12P19/14

  produced by the action of a carbohydrase {(EC 3.2.x)}, e.g. by alpha-amylase {, e.g. by cellulase, hemicellulase} · CPC title

• Y02E50/10

  Biofuels, e.g. bio-diesel · CPC title