Production of monomers from lignin during depolymerization of lignocellulose-containing composition

1. A method for producing fragments from lignin via depolymerization comprising the steps of:

a) providing a lignocellulose-containing composition,

b) heating the composition of step a) under acidic conditions together with an aldehyde, boronic acid, or a compound selected from 2-methoxypropene, dimethyl carbonate, and 2,2-dimethoxypropane to form a mixture; and

c) separating fragments of lignin from the mixture of step b),

wherein step c) comprises the sub-steps:

c1) partitioning the mixture to form a fragments of lignin-containing phase and a residue;

c2) neutralizing the fragments of lignin-containing phase and removing solvent from the neutralized fragments of lignin-containing phase to form a fragment-containing product; and

c3) treating the fragment-containing product of step c2) with a treatment solvent and removing insoluble parts, and

wherein the lignocellulose-containing composition and the aldehyde, boronic acid or compound selected from 2-methoxypropene, dimethyl carbonate and 2,2-dimethoxypropane are present in a weight ratio of 25:1 to 1:1, wherein the aldehyde, the boronic acid or the compound selected from 2-methoxypropene, dimethyl carbonate and 2,2-dimethoxypropane weight is based on the weight of formaldehyde.

2. The method according to claim 1 , wherein step b) comprises heating the composition of step a) under acidic conditions together with an aldehyde.

3. The method according to claim 1 , wherein the lignocellulose-containing composition has a lignin content of 20-40 wt. %.

4. The method according to claim 1 , wherein step a) comprises suspending the lignocellulose-containing composition in an organic solvent.

5. The method according to claim 4 , wherein the organic solvent is an ether containing less than 50% v/v of water.

6. The method according to claim 1 , wherein step b) comprises applying a temperature of 50° C. to 120° C. for 1 to 8 hours.

7. The method according to claim 1 , wherein the acidic conditions of step b) are achieved by addition of 1 to 10 mmol mineral acid per gram of the lignocellulose-containing composition.

8. The method according to claim 1 , wherein the aldehyde is an aldehyde according to the formula R—COH, wherein R is an aliphatic residue with 1 to 6 carbon atoms.

9. The method according to claim 1 , wherein the aldehyde is formaldehyde.

10. The method according to claim 1 , wherein step c) further comprises additionally obtaining fragments of xylan.

11. The method according to claim 10 , wherein the xylan fragments contain diformyl-xylose.

12. The method according to claim 1 further comprising the step:

d) converting the fragments of lignin of step c) into monomers.

13. The method according to claim 12 , wherein step d) further comprises submitting the fragments of lignin of step c) to hydrogenolysis.

14. The method according to claim 12 , wherein the monomers from lignin are selected from Formulae M1 to M24:

15. The method of claim 12 , wherein the monomers of lignin are used for the production of resins, transportation fuels, or monomers for polymer production.

16. A method for producing fragments of xylan via depolymerization comprising the steps of:

a) providing a lignocellulose-containing composition;

b) heating the composition of step a) under acidic conditions together with an aldehyde, boronic acid, or a compound selected from 2-methoxypropene, dimethyl carbonate, and 2,2-dimethoxypropane; and

c) separating fragments of xylan from the mixture of step b) ,

wherein step c) comprises the sub-steps:

c1) partitioning the fragments of xylan to form a fragments of xylan-containing phase and a residue;

c2) neutralizing the fragments of xylan-containing phase and removing solvent from the neutralized fragments of xylan-containing phase to form a fragment-containing product; and

c3) treating the fragment-containing product of step c2) with a treatment solvent and removing insoluble parts, and

wherein the lignocellulose-containing composition and the aldehyde, boronic acid or compound selected from 2-methoxypropene, dimethyl carbonate and 2,2-dimethoxypropane are present in a weight ratio of 25:1 to 1:1, wherein the aldehyde, the boronic acid or the compound selected from 2-methoxypropene, dimethyl carbonate and 2,2-dimethoxypropane weight is based on the weight of formaldehyde.

17. The method according to claim 16 , wherein step b) comprises heating the composition of step a) under acidic conditions together with an aldehyde.

18. The method according to claim 17 , wherein the aldehyde is formaldehyde.