IP Library › Granted Patent US 12,358,939
Granted Patent B2
US 12,358,939 · App. 17/836,061 · Granted Jul 15, 2025

Method to solubilize biomass under mild conditions

Inventors: Fachuang Lu (Madison, WI); John Ralph (Madison, WI)
Assignee: Wisconsin Alumni Research Foundation
C07G1/00G01N21/31
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Quick Facts
Patent No.
US 12,358,939
App. No.
17/836,061
Granted
Jul 15, 2025
Kind
B2
Abstract

A method of completely dissolving lignocellulosic biomass. The method includes the steps of dissolving a sample of biomass in an aqueous solution of strong acid and an amine-thiol to yield a first solution. A method for measuring lignin concentration in biomass via absorbance of the first solution at a wavelength of about 283 nm by comparing the measured absorbance to a standard curve of absorbance values made from solutions of known lignin concentration.

Claims (19)

1. A method of dissolving biomass, including lignocellulosic biomass, the method comprising contacting an amount of biomass with an amount of an aqueous solution comprising a strong acid and an amine-thiol, wherein the amount of the aqueous solution is sufficient to completely dissolve the biomass.

2. The method of claim 1 , wherein the strong acid is selected from the group consisting of chloric acid (HClO 3 ), perchloric acid (HClO 4 ), hydrochloric acid (HCl), hydrobromic acid (HBr), hydroiodic acid (HI), nitric acid (HNO 3 ), phosphoric (H 3 PO 4 ), and sulfuric acid (H 2 SO 4 ).

3. The method of claim 1 , wherein the strong acid is sulfuric acid.

4. The method of claim 1 , wherein the amine-thiol is cysteine.

5. The method of claim 1 , wherein the strong acid is sulfuric acid and the amine-thiol is cysteine.

6. The method of claim 1 , wherein the method is conducted at a temperature of from about 20° C. to 30° C.

7. The method of claim 1 , wherein the aqueous solution comprises about 12 M strong acid and about 0.1 g/mL of amine-thiol.

8. The method of claim 1 , wherein the aqueous solution comprises about 12 M sulfuric acid and about 0.1 g/mL of cysteine.

9. A method of measuring lignin concentration in biomass, the method comprising:

(a) dissolving a sample of biomass suspected of containing lignocellulose in an aqueous solution comprising a strong acid and an amine-thiol to yield a first solution; and

(b) measuring absorbance of the first solution at a wavelength of about 283 nm; and

(c) determining lignin concentration in the first solution by comparing the measured absorbance in step (b) to a standard curve of absorbance values made from solutions of known lignin concentration.

10. The method of claim 9 , wherein the strong acid is selected from the group consisting of chloric acid (HClO 3 ), perchloric acid (HClO 4 ), hydrochloric acid (HCl), hydrobromic acid (HBr), hydroiodic acid (HI), nitric acid (HNO 3 ), phosphoric (H 3 PO 4 ), and sulfuric acid (H 2 SO 4 ).

11. The method of claim 9 , wherein the strong acid is sulfuric acid.

12. The method of claim 9 , wherein the amine-thiol is cysteine.

13. The method of claim 9 , wherein the strong acid is sulfuric acid and the amine-thiol is cysteine.

14. The method of claim 9 , wherein steps (a) and (b) are conducted a temperature of from about 20° C. to 30° C.

15. The method of claim 9 , wherein the aqueous solution of step (a) comprises about 12 M strong acid and about 0.1 g/mL of amine-thiol.

16. The method of claim 9 , wherein the aqueous solution of step (a) comprises about 12 M sulfuric acid and about 0.1 g/mL of cysteine.

Assignments (2)
CONFIRMATORY LICENSE Recorded Sep 2, 2022
From: UNIVERSITY OF WISCONSIN-MADISON
To: UNITED STATES DEPARTMENT OF ENERGY
Reel/Frame 061375/0763 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 13, 2022
From: RALPH, JOHN; LU, FACHUANG
To: WISCONSIN ALUMNI RESEARCH FOUNDATION
Reel/Frame 060181/0605 →
Continuity (2)
Provisional Application 63208817 · Jun 9, 2021
Related Publication 20220411453A1 · Dec 29, 2022
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