Ammonium based ionic liquids useful for lignocellulosic processing

Patent metadata

Field	Value
Publication number	US-10907184-B2
Application number	US-201615778924-A
Country	US
Kind code	B2
Filing date	Nov 23, 2016
Priority date	Nov 24, 2015
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

Methods and compositions are provided for ionic liquid processing of biomass.

First claim

What is claimed is:

1. A method for treating a biomass comprising polysaccharide and lignin, the method comprising:
(i) providing a pre-treatment mixture comprising the biomass at a concentration of at least about 5% w/w, a single ionic liquid at a concentration of at least about 40% w/w, and optionally water, wherein the single ionic liquid is tetrabutylammonium hydroxide; and
(ii) maintaining the mixture under pre-treatment conditions sufficient to dissolve at least a portion of the polysaccharide present in the biomass, wherein the pre-treatment conditions comprise a temperature of from about 35° C. to about 55° C. for a duration of from about 0.5 hours to about 3 hours, and maintaining the temperature of the pre-treatment mixture with less than about 40 MT/hr of steam to process 2000 MT/day of dry biomass.

2. The method of claim 1 , wherein the pre-treatment conditions comprise conditions sufficient to remove at least 50% w/w of the lignin present in the biomass.

3. The method of claim 1 , wherein the biomass is derived from switchgrass, pine, eucalyptus, or a combination thereof.

4. The method of claim 1 , wherein the pH of the pre-treatment mixture is from about 7.5 to about 14.

5. The method of claim 1 , wherein the single ionic liquid is at a concentration of between at least about 40% and about 90% w/w.

6. The method of claim 1 , wherein providing the pre-treatment mixture comprises mechanically reducing the biomass to a smaller particle size.

7. The method of claim 1 , wherein after (ii), the method further comprises:
(iii) diluting the pre-treatment mixture with a polar solvent.

8. The method of claim 7 , wherein the polar solvent is selected from the group consisting of water, methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, heptanol, octanol and isooctanol.

9. The method of claim 7 , wherein the method comprises diluting the pre-treatment mixture with from about 2 volumes of polar solvent to about 10 volumes of polar solvent.

10. The method of claim 7 , wherein:
(a)
step (iii) further comprises reducing the pH of the pre-treatment mixture with an acid, and after diluting the pre-treatment mixture, the method comprises:
(iv) contacting the diluted pre-treated mixture with a glycoside hydrolase under conditions sufficient to hydrolyze at least a portion of glucan, thereby forming a sugar composition, wherein the sugar composition comprises at least one monosaccharide or oligosaccharide; or
(b)
wherein after diluting the pre-treatment mixture, the method comprises:
(iv) collecting pre-treated biomass solids from the mixture, wherein the pre-treated biomass solids comprise at least about 50% w/w of glucan present in the biomass provided in the pre-treatment mixture, and wherein the method optionally further comprises
(v) contacting the pre-treated biomass solids with a glycoside hydrolase under conditions sufficient to hydrolyze at least a portion of the glucan, thereby forming a sugar composition, wherein the sugar composition comprises at least one monosaccharide or oligosaccharide.

11. The method of claim 7 , wherein after diluting the pre-treatment mixture, the method comprises:
(iv) collecting pre-treated biomass solids from the mixture, wherein the pre-treated biomass solids comprise from about 90% w/w to about 95% w/w of glucan present in the biomass provided in the pre-treatment mixture.

12. The method of claim 10 , wherein the glycoside hydrolase is selected from the group consisting of a cellulase, an endoglucanase, an exoglucanase, a β-glucosidase, a xylanase, and mixtures thereof.

13. A method for preparing a sugar composition comprising:
(i) providing a pre-treatment mixture comprising biomass at a concentration of at least about 5% w/w, a single ionic liquid at a concentration of at least about 40% w/w, and optionally water, wherein the biomass comprises lignin and polysaccharide, and wherein the single ionic liquid is tetrabutylammonium hydroxide;
(ii) maintaining the mixture under pre-treatment conditions sufficient to dissolve at least a portion of the polysaccharide present in the biomass, wherein the pre-treatment conditions comprise a temperature of from about 35° C. to about 55° C. for a duration of about 0.5 hours to about 3 hours, and maintaining the temperature of the pre-treatment mixture with less than about 40 MT/hr of steam to process 2000 MT/day of dry biomass;
(iii) diluting the pre-treatment mixture with a polar solvent to form a diluted pre-treatment mixture, and optionally collecting pre-treated biomass solids from the diluted pre-treatment mixture; and
(iv) contacting the pre-treated biomass solids with a glycoside hydrolase under conditions sufficient to hydrolyze at least a portion of the polysaccharide, thereby forming a sugar composition, wherein the sugar composition comprises at least one monosaccharide or oligosaccharide,
wherein the method optionally further comprises converting the sugar composition to a fermentation product, wherein the converting comprises fermenting a mixture containing the sugar composition of step (iv).

14. The method of claim 13 , wherein the method comprises reducing the pH and the temperature of the diluted pre-treatment mixture and contacting the pre-treatment mixture with the glycoside hydrolase.

15. A method for converting a sugar composition to a fermentation product, the method comprising fermenting a mixture containing a sugar composition prepared according to the method of claim 10 .

Assignees

• Nat Tech & Eng Solutions Sandia Llc

Inventors

• Ramakrishnan Parthasarathi
• Dutta Tanmoy
• Simmons Blake
• Singh Seema

Classifications

• C13K13/002

  Xylose · CPC title

• C08B37/0057

  beta-D-Xylans, i.e. xylosaccharide, e.g. arabinoxylan, arabinofuronan, pentosans; (beta-1,3)(beta-1,4)-D-Xylans, e.g. rhodymenans; Hemicellulose; Derivatives thereof · CPC title

• C13K1/02

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

• C12P19/02

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

• C12P2201/00

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