Sulfite pretreatment for biorefining biomass

Patent metadata

Field	Value
Publication number	US-9090915-B2
Application number	US-42577309-A
Country	US
Kind code	B2
Filing date	Apr 17, 2009
Priority date	Apr 22, 2008
Publication date	Jul 28, 2015
Grant date	Jul 28, 2015

Abstract

The present invention relates to a method using sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL). More specifically, it relates to a sulfite-based chemical process for pretreating biomass in solutions to reduce access barriers of enzymes to the lignocellulose, resulting in efficient conversion through enzymatic saccharification.

First claim

What is claimed:

1. A method for treating a cellulose-containing material to produce sugars comprising the steps of:
(a) providing cellulose-containing woody biomass comprising hemicellulose and lignin;
(b) treating the woody biomass of step (a) for 0.1 to 120 minutes with a solution comprising a base of sulfite or bisulfite adjusted to have an initial pH of from about 1.5 to 5.0, wherein said treating is at a temperature of about 150 to 250° C., wherein sulfite or bisulfite charge (w/w), based on oven dried woody biomass, is no more than 9%, but greater than 0, and wherein treating removes hemicellulose and produces only partial delignification; and
(c) enzymatically hydrolyzing the resultant treated biomass of step (b) to produce sugars,
wherein the woody biomass is mechanically size-reduced or treated by steam explosion prior to or during step (a) or (b).

2. The method of claim 1 , wherein the temperature of step (b) is about 150 to 220° C.

3. The method of claim 1 , wherein the sulfite or bisulfite base further comprises sulfur dioxide.

4. The method of claim 1 , wherein the mass ratio between the sulfite or bisulfite base and the woody biomass in step (b) is about 1:100 to about 1:10.

5. The method of claim 1 , wherein the bisulfite is sodium bisulfite, magnesium bisulfite, ammonium bisulfite, calcium bisulfite, or potassium bisulfite.

6. The method of claim 1 , wherein the mechanical size reduction comprises disk milling or hammer milling.

7. The method of claim 1 , wherein step (b) takes place in a feeder coupled to a device used for the mechanical size reduction.

8. The method of claim 1 , wherein the method comprises treating the woody biomass with steam explosion at the same time as step (b).

9. The method of claim 1 , where the method further comprises fermenting the sugars into ethanol.

10. The method of claim 1 , wherein the method further comprises chemically converting the sugars to a biofuel or a biochemical.

11. The method of claim 1 , wherein the biomass ratio between the sulfite or bisulfite base and the woody biomass in step (b) is about 1:40 to about 1:15.

Assignees

• Wang Gaosheng
• Pan Xuejun
• Zhu Jun Yong
• Gleisner Roland L
• Wisconsin Alumni Res Found
• Us Agriculture

Inventors

• Wang Gaosheng
• Pan Xuejun
• Zhu Jun Yong
• Gleisner Roland L

Classifications

• Y02E50/16

  Cross-Sectional Technologies · mapped topic

• D21C5/022

  Chemicals therefor · CPC title

• C12P7/10 Primary

  substrate containing cellulosic material · CPC title

• C07G1/00

  Low-molecular-weight derivatives of lignin (high-molecular-weight derivatives of lignin {C08H6/00}) · CPC title

• C13K1/02

  obtained by saccharification of cellulosic materials (manufacture of fodder A23K10/32) · CPC title