Method for preparing sugar, bioethanol or microbial metabolite from lignocellulosic biomass

Patent metadata

Field	Value
Publication number	US-10329589-B2
Application number	US-201414991209-A
Country	US
Kind code	B2
Filing date	Jun 9, 2014
Priority date	Jul 9, 2013
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

The present invention relates to a method for preparing bioethanol from lignocellulosic biomass. The method of the present invention is capable of: minimizing the impurity content of an enzymatic saccharification raw material, by extracting biomass using hot water, before pretreatment, and removing extractable substances such as inorganic salts; suppressing, to the greatest extent, the production of overdecomposition products of sugar, by pretreating the biomass, from which the hot water extractable substances have been removed, in a condition for maximizing xylan yield; preparing fermentable sugar at a low cost, without washing a pretreated solid obtained from subsequent solid-liquid separation, but by only concentrating a sugar solution obtained after enzymatic saccharification, using a separation film; and preparing bioethanol therefrom in high yield.

First claim

What is claimed is:

1. A method of producing fermentable sugar, the method comprising the steps of:
performing liquid hot water pretreatment of a lignocellulosic biomass at 160 to 230° C. temperature to produce a pretreatment product;
treating said pretreatment product with an aqueous alkali solution at pH 11 or higher and 80 to 105° C. temperature;
adjusting pH to 5.0+0.1 by adding a base having at least two hydroxyl groups, wherein the base is present in a form of an aqueous solution or a colloidal suspension having an average diameter of 0.001 to 10 μm, wherein the base forms a salt by neutralization reaction with acetic add produced by hydrolysis of the pretreatment product, and a dissolution constant (pKa 2 ) of a second acetyl group of the resulting salt is 8.0 or more;
contacting the pretreatment product after said adjusting with a cellulose hydrolyzing enzyme, and producing fermentable sugar solution having at least 9±1% acetic add by weight, relative to total sum of glucose, other sugars, acetic acid, 5-hydroxymethyl-2-furaldehyde (HMF), and furfural in the fermentable sugar solution.

2. The production method according to claim 1 , wherein the pretreatment product used in the step of treating with an aqueous alkali solution is selected from the group consisting of:
a) both a liquid and solid obtained after performing the liquid hot water pretreatment of the lignocellulosic biomass;
b) a solid obtained by a solid-liquid separation step performed after the liquid hot water pretreatment of the lignocellulosic biomass; and
c) a liquid pretreatment product obtained after performing the liquid hot water pretreatment of the lignocellulosic biomass.

3. The production method according to claim 1 , wherein the liquid hot water pretreatment is performed at 160 to 230° C. for 1 to 60 minutes.

4. The production method according to claim 1 , wherein the base is calcium hydroxide, barium hydroxide or magnesium hydroxide.

5. A method for fermentation comprising the steps of:
1) providing the fermentable sugar produced by the method according to claim 1 ; and
2) fermenting the fermentable sugar using at least one microorganism selected from the group consisting of: genus Escherichia , genus Sacharomyces , genus Serratia , genus Lactobacillus , genus Lactococcus , genus Leuconostoc , genus Corynebacterium , genus Brevibacterium or genus Clostridium.

6. The method according to claim 1 , further comprising the step of:
maintaining pH at 5.0±0.1 and temperature at 50±1° C.

7. The method according to claim 4 , wherein the base is calcium hydroxide.

8. The method according to claim 5 , wherein the at least one microorganism is Saccharomyces cerevisiae.

Assignees

• Korea Res Inst Chemical Tech

Inventors

• Yu Ju Hyun
• Jung Chan Duck
• Eom In Yong
• Lee Seung Hwan
• Hong Kyung Sik
• Kim In-Chul
• Jegal Jong Geon
• Song Bong Keun

Classifications

• C07H1/06

  Separation; Purification · 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

• C12P7/065

  with microorganisms other than yeasts · CPC title

• C07H3/02

  Monosaccharides · CPC title

• Y02E50/16

  Cross-Sectional Technologies · mapped topic