Converting lignocellulosic biomass to glucose using a low temperature sulfur dioxide pretreatment

Patent metadata

Field	Value
Publication number	US-11299850-B2
Application number	US-201816761180-A
Country	US
Kind code	B2
Filing date	Nov 9, 2018
Priority date	Nov 9, 2017
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

A process for converting lignocellulosic biomass to glucose or ethanol includes subjecting the lignocellulosic biomass to a SO2 pretreatment within the temperature range 110° C.-150° C. Good glucose yields have been achieved when the SO2 pretreatment is conducted for more than 90 minutes and when the total amount of SO2 available is greater than 20 wt % based on dry weight of lignocellulosic biomass.

First claim

The invention claimed is:

1. A method for converting lignocellulosic biomass to glucose comprising:
pretreating the lignocellulosic biomass to provide a pretreated material, said pretreating comprising subjecting the lignocellulosic biomass to a SO 2 pretreatment, said SO 2 pretreatment comprising heating said lignocellulosic biomass with at least one of sulfur dioxide and sulfurous acid, said heating conducted between 110° C. and 150° C. for more than 90 minutes, said SO 2 pretreatment conducted with a total amount of sulfur dioxide greater than 20 wt % based on dry weight of lignocellulosic biomass; and
hydrolyzing at least 60% of the cellulose in the pretreated material to glucose, said hydrolyzing including adding enzyme to at least a solid fraction of the pretreated material, said enzyme including a cellulase.

2. The method according to claim 1 , wherein said hydrolyzing provides a cellulose conversion of at least 80% within 72 hours.

3. The method according to claim 2 , wherein said pretreating does not include heating the lignocellulosic biomass above 150° C.

4. The method according to claim 2 , wherein said heating is conducted above 120° C. for more than 100 minutes.

5. The method according to claim 4 , wherein said heating is conducted for more than 120 minutes.

6. The method according to claim 5 , wherein said heating is conducted for more than 180 minutes.

7. The method according to claim 2 , wherein said heating is conducted between 125° C. and 135° C.

8. The method according to claim 1 , wherein the total amount of sulfur dioxide is greater than 25 wt % based on dry weight of lignocellulosic biomass.

9. The method according to claim 1 , wherein the total amount of sulfur dioxide is greater than 30 wt % based on dry weight of lignocellulosic biomass.

10. The method according to claim 1 , wherein the total amount of sulfur dioxide is greater than 40 wt % based on dry weight of lignocellulosic biomass.

11. A method for converting lignocellulosic biomass to glucose comprising:
pretreating the lignocellulosic biomass to provide a pretreated material, said pretreating comprising subjecting the lignocellulosic biomass to a SO 2 pretreatment, said SO 2 pretreatment comprising heating said lignocellulosic biomass with at least one of sulfur dioxide and sulfurous acid, said heating conducted between 110° C. and 150° C. for more than 90 minutes; and
hydrolyzing at least 60% of the cellulose in the pretreated material to glucose, said hydrolyzing including adding enzyme to at least a solid fraction of the pretreated material, said enzyme including a cellulase,
wherein said SO 2 pretreatment is conducted with a total amount of sulfur dioxide greater than 70 wt % based on dry weight of lignocellulosic biomass.

12. The method according to claim 6 , wherein the total amount of sulfur dioxide is between 20 wt % and 60 wt % based on dry weight of lignocellulosic biomass.

13. The method according to claim 2 , wherein the lignocellulosic biomass comprises at least one of wheat straw and sugar cane bagasse.

14. The method according claim 2 , wherein said adding enzyme comprises adding cellulase at a dosage of less than about 12 milligrams protein per gram of cellulose.

15. The method according to claim 2 , wherein the total amount of sulfur dioxide is sufficient to provide an initial pH less than 1.25.

16. The method according to claim 2 , wherein the total amount of sulfur dioxide is sufficient to provide an initial pH less than 1.

17. A method for converting lignocellulosic biomass to glucose comprising:
pretreating the lignocellulosic biomass to provide a pretreated material, said pretreating comprising subjecting the lignocellulosic biomass to a SO 2 pretreatment, said SO 2 pretreatment comprising heating said lignocellulosic biomass with at least one of sulfur dioxide and sulfurous acid, said heating conducted between 110° C. and 150° C. for more than 90 minutes, said SO 2 pretreatment conducted with a total amount of sulfur dioxide greater than 20 wt % based on dry weight of lignocellulosic biomass; and
hydrolyzing at least 60% of the cellulose in the pretreated material to glucose, said hydrolyzing including adding enzyme to at least a solid fraction of the pretreated material, said enzyme including a cellulase,
wherein said hydrolyzing provides a cellulose conversion of at least 80% within 72 hours, and
wherein said pretreating is conducted in the absence of added alkali.

18. A method for converting lignocellulosic biomass to glucose comprising:
pretreating the lignocellulosic biomass to provide a pretreated material, said pretreating comprising subjecting the lignocellulosic biomass to a SO 2 ; pretreatment, said SO 2 pretreatment comprising heating said lignocellulosic biomass with at least one of sulfur dioxide and sulfurous acid, said heating conducted between 110° C. and 150° C. for more than 90 minutes, said SO 2 pretreatment conducted with a total amount of sulfur dioxide greater than 20 wt % based on dry weight of lignocellulosic biomass; and
hydrolyzing at least 60% of the cellulose in the pretreated material to glucose, said hydrolyzing including adding enzyme to at least a solid fraction of the pretreated material, said enzyme including a cellulase,
wherein said hydrolyzing provides a cellulose conversion of at least 80% within 72 hours, and
wherein said pretreating is conducted in the absence of added organic solvent.

19. The method according to claim 2 , wherein pretreating the lignocellulosic biomass to provide a pretreated material comprises pretreating lignocellulosic biomass having a consistency between 10 wt % and 40 wt %.

20. The method according to claim 2 , comprising:
subjecting the pretreated material to a solid/liquid separation that provides a liquid fraction and the solid fraction, and
washing the solid fraction prior to said hydrolyzing.

21. A process for the production of an alcohol from lignocellulosic biomass, said process comprising:
feeding the lignocellulosic biomass into a pretreatment reactor;
pretreating the lignocellulosic biomass in the pretreatment reactor to provide a pretreated material, said pretreating comprising heating the lignocellulosic biomass with at least one of sulfur dioxide and sulfurous acid between 110° C. and 150° C. for more than 100 minutes, where a total amount of sulfur dioxide is greater than 20 wt % based on dry weight of lignocellulosic biomass, where alkali is added in an amount in the range from 0 to 0.5 wt % based on dry weight of incoming lignocellulosic biomass and organic solvent is added in an amount in the range from 0 to 5 wt % based on dry weight of incoming lignocellulosic biomass;
hydrolyzing at least 60% of the cellulose in the lignocellulosic biomass to glucose, said hydrolyzing including adding cellulase;
fermenting the glucose to produce the alcohol; and
recovering the alcohol.

Assignees

• Iogen Corp

Inventors

• Foody Brian
• Tolan Jeffrey S
• Macdonald Daniel G
• Martens Kristin
• Leduc Natacha
• Mackenzie Douglas A

Classifications

• 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

• C12P2201/00

  Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis · CPC title

• D21C1/04 Primary

  with acid reacting compounds · CPC title

• C08H8/00 Primary

  Macromolecular compounds derived from lignocellulosic materials {(pretreatment thereof B27N)} · CPC title

• C12P7/10

  substrate containing cellulosic material · CPC title