Methods of depolymerizing lignin
AssigneeWisconsin Alumni Research Foundation
InventorsShannon Stahl, Hao Luo
Life of this patent
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Abstract
Methods of depolymerizing lignin and products obtained therefrom. The methods include reacting lignin in a liquid solvent comprising an oxidation catalyst with the solvent being in contact with 02 gas. The solvent can include aprotic polar solvents. The oxidation catalyst can include heterogeneous catalysts. The methods can be used in the oxidative catalytic fractionation of raw biomass to generate soluble aromatic monomers and a solid carbohydrate residue. Depolymerized lignin products include phenolic and benzoquinone monomers, such as p-hydroxybenzoic acid, vanillin, syringaldehyde, vanillic acid, and/or syringic acid.
Claims31
A method of depolymerizing lignin, the method comprising reacting in a liquid solvent the lignin and an oxidation catalyst with the solvent being in contact with gas comprising O2 gas.
The method of claim, further comprising after the reacting, isolating a phenolic monomer produced during the reacting from the solvent.
A method of depolymerizing lignin, the method comprising reacting in a liquid solvent the lignin and an oxidation catalyst with the solvent being in contact with gas comprising O2 gas, wherein:
- the solvent comprises an aprotic solvent selected from the group consisting of acetone, acetonitrile, and a combination thereof in an amount of at least about 90% v/v
- the solvent is devoid of protic solvent or comprises protic solvent in an amount less than about 10% v/v;
- the oxidation catalyst is a heterogeneous catalyst comprises a metal selected from the group consisting of Mn, Fe, Co, Ni, V and Cu;
- the oxidation catalyst is contained within the solvent within a porous cage;
- the gas comprises O2 gas in an amount from about 1% v/v to about 10% v/v;
- the O2 gas is present at a partial pressure from about 1 to about 3 bar;
- the reacting is conducted at a temperature from about 100° C. to about 240° C.;
- and
- the lignin is in the form of lignocellulosic biomass that has not been treated with chemical pretreatment and has not been treated with physicochemical pretreatment.
Dependencies are inferred from the claim text.