Method to produce biomass-derived compounds using a co-solvent system containing gamma-valerolactone

1. A method to produce an aqueous solution of carbohydrates comprising C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof, the process comprising:

reacting biomass or a biomass-derived reactant comprising lignin with a solvent system comprising

(i) an organic solvent selected from the group consisting of polar aprotic solvents,

(ii) an organic co-solvent, and

(iii) water;

in the presence of an acid, for a time, at a pressure, and at a temperature to yield a product mixture wherein at least a portion of water-insoluble C6-sugar-containing polymers or oligomers, or water-insoluble C5-sugar-containing polymers or oligomers, if present in the biomass or biomass-derived reactant, are converted to water-soluble C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof, and

at least 10% of the lignin present in the biomass or biomass-derived reactant is present in the product mixture as a precipitate.

2. The method of claim 1 , wherein the organic solvent is miscible with water at ambient temperature.

3. The method of claim 1 , wherein the organic solvent is a polar aprotic solvent selected from the group consisting of cyclic ethers, beta-, gamma-, and delta-lactones, and combinations thereof.

4. The method of claim 1 , wherein the organic solvent is gamma-valerolactone (GVL).

5. The method of claim 1 , wherein the organic solvent is present in a mass ratio with the water (organic solvent:water ratio) ranging from about 60:40 to about 99:1.

6. The method of claim 1 , wherein the acid is homogeneous or heterogeneous, and if the acid is homogeneous it is present in a concentration not greater than 100 mM based on volume of the solvent system, and if the acid is heterogeneous it is present in a concentration not greater than 1.0 wt % based on weight of the solvent system.

7. The method of claim 6 , wherein the acid is a mineral acid or an organic acid.

8. The method of claim 6 , wherein the acid is a solid acid selected from the group consisting of a solid Brønsted acid, a solid Lewis acid catalysts, and combinations thereof.

9. The method of claim 1 , wherein the biomass or a biomass-derived reactant is reacted at a temperature range from about 100° C. to about 300° C.

10. The method of claim 1 , wherein the biomass or a biomass-derived reactant is reacted at a dynamic temperature range.

11. The method of claim 10 , wherein the dynamic temperature range ramps from a first temperature to a second temperature that is higher than the first temperature.

12. The method of claim 10 , wherein the dynamic temperature range changes from a first temperature to a second temperature in a linear fashion or a non-linear fashion.

13. The method of claim 1 , wherein the biomass or a biomass-derived reactant comprises water-insoluble glucose-containing polymers or oligomers, or water-insoluble xylose-containing polymers or oligomers, or any combination thereof, and these, if present, are converted to water-soluble glucose-containing oligomers, glucose monomers, water-soluble xylose-containing oligomers, xylose monomers, or any combination thereof.

14. The method of claim 1 , wherein in step (a), residence time of the reaction ranges from 1 min to 24 hours.

15. A method to produce an aqueous solution of carbohydrates comprising C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof, the process comprising:

reacting biomass or a biomass-derived reactant with a solvent system comprising:

(i) an organic solvent selected from the group consisting of polar aprotic solvents,

(ii) an organic co-solvent, wherein the organic co-solvent is selected from the group consisting of linear, branched or cyclic alkanes; linear, branched or cyclic alkenes; linear, branched or cyclic ketones; linear, branched or cyclic alcohols; aromatic hydrocarbons; and substituted or unsubstituted phenols, and

(iii) water;

in the presence of an acid, for a time, at a pressure, and at a temperature to yield a product mixture wherein at least a portion of water-insoluble C6-sugar-containing polymers or oligomers, or water-insoluble C5-sugar-containing polymers or oligomers, if present in the biomass or biomass-derived reactant, are converted to water-soluble C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof; and

at least 10% of lignin, if present in the biomass or biomass-derived reactant, is present in the product mixture as a precipitate.

16. A method to produce an aqueous solution of carbohydrates comprising C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof, the process comprising:

reacting biomass or a biomass-derived reactant with a solvent system comprising:

(i) an organic solvent, wherein the organic solvent is gamma-valerolactone (GVL),

(ii) an organic co-solvent which is an aromatic hydrocarbon, and

(iii) water;

in the presence of an acid, for a time, at a pressure, and at a temperature to yield a product mixture wherein at least a portion of water-insoluble C6-sugar-containing polymers or oligomers, or water-insoluble C5-sugar-containing polymers or oligomers, if present in the biomass or biomass-derived reactant, are converted to water-soluble C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof; and

at least 10% of lignin, if present in the biomass or biomass-derived reactant, is present in the product mixture as a precipitate.

17. A method to produce an aqueous solution of carbohydrates comprising C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof, the process comprising:

reacting biomass or a biomass-derived reactant with a solvent system comprising:

(i) an organic solvent selected from the group consisting of polar aprotic solvents,

(ii) an organic co-solvent, and

(iii) water;

in the presence of an acid, for a time, at a pressure, and at a temperature to yield a product mixture wherein at least a portion of water-insoluble C6-sugar-containing polymers or oligomers, or water-insoluble C5-sugar-containing polymers or oligomers, if present in the biomass or biomass-derived reactant, are converted to water-soluble C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof; and

at least 10% of lignin, if present in the biomass or biomass-derived reactant, is present in the product mixture as a precipitate;

wherein the organic co-solvent is present in a volume ratio with the solvent system (organic co-solvent:solvent ratio) ranging from about 5:50 to about 10:30.

18. A method to produce an aqueous solution of carbohydrates comprising C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof, the process comprising:

reacting biomass or a biomass-derived reactant with a solvent system comprising:

(i) an organic solvent selected from the group consisting of polar aprotic solvents,

(ii) an organic co-solvent, and

(iii) water;

in the presence of an acid, for a time, at a pressure, and at a temperature to yield a product mixture wherein at least a portion of water-insoluble C6-sugar-containing polymers or oligomers, or water-insoluble C5-sugar-containing polymers or oligomers, if present in the biomass or biomass-derived reactant, are converted to water-soluble C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof;

wherein the solvent system is monophasic at the temperature of the reaction and biphasic at a lower temperature; and

at least 10% of lignin, if present in the biomass or biomass-derived reactant, is present in the product mixture as a precipitate.

19. A method to produce an aqueous solution of carbohydrates comprising C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof, the process comprising:

reacting biomass or a biomass-derived reactant with a solvent system comprising

(i) an organic solvent selected from the group consisting of polar aprotic solvents,

(ii) an organic co-solvent, and

(iii) water;

in the presence of an acid, for a time, at a pressure, and at a temperature to yield a product mixture wherein at least a portion of water-insoluble C6-sugar-containing polymers or oligomers, or water-insoluble C5-sugar-containing polymers or oligomers, if present in the biomass or biomass-derived reactant, are converted to water-soluble C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof, and

wherein the solvent system is monophasic at the temperature of the reaction and biphasic at a lower temperature.

20. The method of claim 19 , wherein the solvent system is monophasic at a temperature range of about 100° C. to about 300° C., and is biphasic at temperatures below about 50° C.

21. The method of claim 19 , wherein at least 10% of lignin, if present in the biomass or biomass-derived reactant, is present in the product mixture as a precipitate.

22. The method of claim 19 , wherein the organic solvent is miscible with water at ambient temperature.

23. The method of claim 19 , wherein the organic solvent is a polar aprotic solvent selected from the group consisting of cyclic ethers, beta-, gamma-, and delta-lactones, and combinations thereof.

24. The method of claim 19 , wherein the organic solvent is gamma-valerolactone (GVL).

25. The method of claim 19 , wherein the organic co-solvent is selected from the group consisting of linear, branched or cyclic alkanes; linear, branched or cyclic alkenes; linear, branched or cyclic ketones; linear, branched or cyclic alcohols; aromatic hydrocarbons; and substituted or unsubstituted phenols.

26. The method of claim 19 , wherein the organic solvent is gamma-valerolactone (GVL) and the organic co-solvent is an aromatic hydrocarbon.

27. The method of claim 19 , wherein the organic solvent is present in a mass ratio with the water (organic solvent:water ratio) ranging from about 60:40 to about 99:1.

28. The method of claim 19 , wherein the organic co-solvent is present in a volume ratio with the solvent system (organic co-solvent:solvent ratio) ranging from about 5:50 to about 10:30.

29. The method of claim 19 , wherein the acid is homogeneous or heterogeneous, and if the acid is homogeneous it is present in a concentration not greater than 100 mM based on volume of the solvent system, and if the acid is heterogeneous it is present in a concentration not greater than 1.0 wt % based on weight of the solvent system.

30. The method of claim 29 , wherein the acid is a mineral acid or an organic acid.

31. The method of claim 29 , wherein the acid is a solid acid selected from the group consisting of a solid Brønsted acid, a solid Lewis acid catalysts, and combinations thereof.