METHODS OF REDUCING LIGNIN AND PRODUCTS THEREOF

CROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application 61/235,276, filed August 19, 2009, which application is incorporated herein by reference. BACKGROUND OF THE INVENTION

[0002] Biomass means biological material that is used for industrial production (e.g., to generate chemical compounds). Sources of biomass includes, but is not limited to, trees, shrubs, grasses, wheat, wheat straw, sugar cane bagasse, corn, corn husks, corn kernel including fiber from kernels, products and by-products from milling of grains. Lignin comprises about 15% to about 30% the weight of dry wood.

SUMMARY OF THE INVENTION

[0003] Described herein are compositions and methods for converting lignin, including purified lignin, into small molecule substituted phenyl compounds. The small molecule substituted phenyl compounds are then optionally converted into further desired products, including 2-methoxyphenol, catechol, phenol, muconic acid, adipic acid, butadiene, acrylic acid, methanol, 2-aminophenol, aniline, cyclohexyl carboxylic acid, caprolactam, ortho- phenylenediamine. Either the conversion of lignin into the small molecule substituted phenyl compounds or the conversion of the small molecule substituted phenyl compounds into further desired products involves at least one reduction step.

[0004] Also described herein are the aforementioned desired products that are prepared from lignin, including purified lignin.

[0005] Provided in specific embodiments herein is a method of obtaining 4-(3- hydroxypropyl)benzene-l,2-diol from lignin, comprising: subjecting lignin to reductive conditions sufficient to produce 4-(3-hydroxypropyl)benzene-l,2-diol. In more specific embodiments, the method comprises subjecting lignin to a second set of reductive conditions sufficient to produce 4-(3-hydroxypropyl)benzene-l,2-diol. In certain embodiments, the lignin is isolated from biomass. In some embodiments, the lignin is not isolated from biomass. In some embodiments, the method comprises contacting lignin with hydrogen. In certain embodiments, the method comprises contacting lignin with hydrogen gas (i.e., H ₂ ), hydrazine (e.g., N ₂ H ₄ ), dihydronaphthalene (e.g., C ₁₀ H ₁₀ ), dihydroanthracene (e.g., C ₁₄ H ₁₂ ), isopropanol (e.g., C3H7OH), formic acid (e.g., CH ₂ O ₂ ), or combinations thereof. In some embodiments, the method comprises contacting lignin with (a) hydrogen; and (b) a catalyst. In certain embodiments, the method comprises contacting lignin with (a) hydrogen; and (b) a metal catalyst. In specific embodiments, the method comprises contacting lignin with (a) hydrogen, and (b) platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), Raney nickel (e.g., NiAl), Urushibara catalysts (e.g., U-Ni-A; U-Ni-B), Wilkinson's catalyst (e.g., RhCl(PPh ₃ ) ₃ ), Crabtree's catalyst (e.g., C ₃ IH ₅₀ F ₆ IrNP ₂ ), RhCl ₃ /TPPTS, Lindlar catalyst, Adam's Catalyst (e.g., PtO ₂ ), Palladium Black, or combinations thereof. In some embodiments, the method comprises contacting lignin with (a) hydrogen; and (b) an enzyme. In specific embodiments, the method comprises contacting lignin with (a) hydrogen; and (b) an hydrogenase, hydrogenase mimic, or both. In some embodiments, the method comprises contacting lignin with (a) hydrogen; (b) a catalyst; and (c) a proton source. In specific embodiments, the method comprises contacting lignin with (a) hydrogen; (b) a catalyst; and (c) an inorganic acid. In certain embodiments, the method comprises contacting lignin with (a) hydrogen; (b) a catalyst; and (c) hydrogen chloride. In some embodiments, the method comprises contacting lignin with hydrogen in the presence of heat. In certain embodiments, the method comprises contacting lignin with hydrogen and super critical water, near critical water, or combinations thereof. In some embodiments, provided herein is 4-(3-hydroxypropyl)benzene-l,2-diol obtained by any method described herein.

[0006] Provided in certain embodiments herein is a method of obtaining γ-butyrolactone from lignin, comprising: (a) subjecting lignin to reductive conditions sufficient to produce 4-(3-hydroxypropyl)benzene-l,2-diol; and (b) subjecting 4-(3-hydroxypropyl)benzene-l,2- diol to conditions sufficient to convert 4-(3-hydroxypropyl)benzene-l,2-diol to γ- butyrolactone. In specific embodiments, the lignin is isolated from biomass, and in other embodiments, the lignin is not isolated from biomass. In certain embodiments, the method comprises oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol. In some embodiments, provided herein is γ-butyrolactone obtained by any method described herein.

[0007] Provided in some embodiments herein is a method of obtaining succinic acid from lignin, comprising: (a) subjecting lignin to reductive conditions sufficient to produce 4-(3- hydroxypropyl)benzene- 1 ,2-diol; and (b) subj ecting 4-(3 -hydroxypropyl)benzene- 1 ,2-diol to conditions sufficient to convert 4-(3-hydroxypropyl)benzene-l,2-diol to succinic acid. In specific embodiments, the lignin is isolated from biomass, and in other embodiments, the lignin is not isolated from biomass. In some embodiments, the method comprises oxidizing

-?- 4-(3-hydroxypropyl)benzene-l,2-diol. In certain embodiments, the method comprises contacting 4-(3-hydroxypropyl)benzene-l,2-diol with (a) an oxidizing agent that converts a primary alcohol to a carboxylic acid; and (b) a) reacting 4-(3-hydroxypropyl)benzene-l,2- diol with an oxidizing agent that converts a primary alcohol (e.g., a hydroxypropyl group) to a carboxylic acid; and (b) an oxidizing agent that converts an aryl group to a carboxylic acid. In some embodiments, the method comprises contacting 4-(3-hydroxypropyl)benzene- 1 ,2-diol with (a) an oxidizing agent that converts a primary alcohol to a carboxylic acid; and (b) reacting 4-(3-hydroxypropyl)benzene-l,2-diol with (i) an oxidizing agent that converts a primary alcohol (e.g., a hydroxypropyl group) to a carboxylic acid; and (ii) an oxidizing agent that converts an aryl group to a carboxylic acid. In certain embodiments, the method comprises contacting 4-(3-hydroxypropyl)benzene-l,2-diol with (a) an oxidizing agent that converts a primary alcohol to a carboxylic acid; and (b) reacting 4-(3- hydroxypropyl)benzene-l,2-diol with (i) chromic acid; and (ii) perfluoroacetic peracid. In some embodiments, provided herein is succinic acid obtained by any method described herein.

[0008] Provided in certain embodiments herein is a method of obtaining 1,4- butadiolbutane-diol from lignin, comprising: (a) subjecting lignin to reductive conditions sufficient to produce 4-(3-hydroxypropyl)benzene-l,2-diol; (b) subjecting 4-(3- hydroxypropyl)benzene-l,2-diol to conditions sufficient to convert 4-(3- hydroxypropyl)benzene-l,2-diol to γ-butyrolactone; and (c) subjecting γ-butyrolactone to conditions sufficient to convert γ-butyrolactone to 1,4-butadionebutane-diol. In some embodiments, the lignin is isolated from biomass. In other embodiments, the lignin is not isolated from biomass. In certain embodiments, the method comprises oxidizing 4-(3- hydroxypropyl)benzene-l,2-diol. In some embodiments, the method comprises contacting 4-(3-hydroxypropyl)benzene-l,2-diol with (a) an oxidizing agent that converts a primary alcohol to a carboxylic acid; and (b) reacting 4-(3-hydroxypropyl)benzene-l,2-diol with (i) an oxidizing agent that converts a primary alcohol (e.g., a hydroxypropyl group) to a carboxylic acid; and (ii) an oxidizing agent that converts an aryl group to a carboxylic acid. In certain embodiments, the method comprises contacting 4-(3-hydroxypropyl)benzene-l,2- diol with (a) an oxidizing agent that converts a primary alcohol to a carboxylic acid; and (b) reacting 4-(3-hydroxypropyl)benzene-l,2-diol with (i) chromic acid; and (ii) perfluoroacetic peracid. In some embodiments, the method comprises contacting γ-butyrolactone with a reducing agent. In some embodiments, the method comprises contacting γ-butyrolactone with hydrogen. In certain embodiments, the method comprises contacting γ-butyrolactone with hydrogen gas (i.e., H ₂ ), hydrazine (e.g., N ₂ H ₄ ), dihydronaphthalene (e.g., C ₁₀ H ₁₀ ), dihydroanthracene (e.g., Ci ₄ Hi ₂ ), isopropanol (e.g., C3H7OH), formic acid (e.g., CH ₂ O ₂ ), or combinations thereof. In some embodiments, the method comprises contacting γ- butyrolactone with (a) hydrogen; and (b) a catalyst. In certain embodiments, the method comprises contacting γ-butyrolactone with (a) hydrogen; and (b) a metal catalyst. In some embodiments, the method comprises contacting γ-butyrolactone with (a) hydrogen; and (b) an enzyme. In certain embodiments, the method comprises contacting γ-butyrolactone with (a) hydrogen; (b) a catalyst; and (c) a proton source. In some embodiments, the method comprises contacting γ-butyrolactone with hydrogen in the presence of heat. In certain embodiments, the method comprises contacting γ-butyrolactone with hydrogen and super critical water, near critical water, or combinations thereof. In some embodiments, provided herein is 1 ,4-butane-diol obtained by any method described herein.

DETAILED DESCRIPTION OF THE INVENTION

I. Certain Definitions

[0009] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which the claimed subject matter belongs.

[0010] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of any subject matter claimed. In this application, the use of the singular includes the plural unless specifically stated otherwise. It must be noted that, as used in the specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It should also be noted that use of "or" means "and/or" unless stated otherwise. Furthermore, use of the term "including" as well as other forms, (e.g., "include", "includes", and "included") is not limiting.

[0011] As used herein, "isolated," refers to separating and removing a component of interest from components not of interest. Isolated lignin can be in either a dry or semi-dry state, or in solution, including but not limited to an aqueous solution. By way of example only, lignin is "isolated" when it is free of at least some of the components (e.g., cellulose and hemicellulose) with which it is associated in the natural state. [0012] As used herein, "purified" refers to lignin which is at least 85% pure, at least 90% pure, at least 95% pure, at least 99% or greater pure.

[0013] As used herein, "biomass" means biological material that is used for industrial production (e.g., to generate chemical compounds). In some embodiments, biomass is virgin biomass, non-virgin biomass (e.g., agricultural biomass, commercial organics, and yard waste); or blended biomass. Biomass includes, but is not limited to, trees, shrubs, grasses, wheat, wheat straw, sugar cane bagasse, corn, corn husks, corn kernel including fiber from kernels, products and by-products from milling of grains such as corn (including wet milling and dry milling). In some embodiments, biomass is used as collected from the field. In some embodiments, biomass is processed, for example by milling, grinding, shredding, etc. In some embodiments, biomass is treated by chemical or physical means prior to use, for example by heating, drying, freezing, or by ensiling (storing for period of time at high moisture content).

[0014] As used herein, "agricultural biomass" includes branches, bushes, canes, corn and corn husks, energy crops, forests, fruits, flowers, grains, grasses, herbaceous crops, leaves, bark, needles, logs, roots, saplings, short rotation woody corps, shrubs, switch grasses, trees, vegetables, vines, and hard and soft woods (not including woods with deleterious materials). Generally, the substrate is of high lignocellulose content, including corn stover, corn fiber, Distiller's dried grains, rice straw, hay, sugarcane bagasse, wheat, oats, barley malt and other agricultural biomass, switchgrass, forestry wastes, poplar wood chips, pine wood chips, sawdust, yard waste, and the like, including any combination of substrate.

[0015] As used herein, "blended biomass" means any mixture or blend of virgin and non- virgin biomass, preferably having about 5-95% by weight non-virgin biomass.

[0016] As used herein, "lignin" means a water-insoluble macromolecule comprised of three monolignol monomers: p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol.

/?-coumaryl alcohol coniferyl alcohol sinapyl alcohol In certain instances, /?-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol randomly assemble to form the copolycondensate lignin. In certain instances, lignin further comprises additional monomeric units. In certain instances, lignin comprises about 15% to about 30% the weight of dry wood. In some embodiments, lignin is isolated from a lignin source (i.e., any source of lignin; e.g., unprocessed biomass and processed biomass). In some embodiments, lignin is not isolated from a lignin source.

[0017] As used herein, "cellulose" means a polysaccharide consisting of a linear chain of about 7,000 to about 15,000 β(l→4) linked D-glucose units. In certain instances, cellulose comprises about 30% to about 50% the weight of dry wood.

[0018] As used herein, "hemicellulose" means a heteropolymer consisting of a branched chain of about 500 to about 3000 sugar (e.g., glucose, xylose, mannose, galactose, rhamnose, and arabinose) units. In certain instances, hemicellulose comprises about 10% to about 35% the weight of dry wood.

[0019] As used herein, "post-translationally modified" means any modification of an amino acid which occurs after such an amino acid has been translationally incorporated into a polypeptide chain. Such modifications include, but are not limited to, co-translational in vivo modifications, co-translational in vitro modifications (such as in a cell-free translation system), post-translational in vivo modifications, and post-translational in vitro

modifications.

[0020] As used herein, "pure" means a substance that is substantially free of other components.

II. Purification of Lignin from Biomass

[0021] Disclosed herein, in some embodiments, is a method of obtaining an aromatic compound from lignin.

[0022] In some embodiments, the lignin is obtained from any suitable source. In some embodiments, the lignin is obtained from biomass. In some embodiments, lignin is obtained from biomass comprising a lignin-carbohydrate complex. In some embodiments, the lignin is obtained from lignocellulose. In some embodiments, the lignin is obtained from biomass that has been treated by a pretreatment process of the paper, pulp or biofuel industries (e.g., Kraft process, acid hydrolysis, steam explosion, ammonia fiber explosion, ammonia recycle percolation, soaking in aqueous ammonia, lime (with or without oxygen) treatment, alkaline wet oxidation and ozono lysis). [0023] In some embodiments, obtaining lignin from biomass comprises: a. contacting the biomass with an enzyme that cleaves at least one

covalent bond binding lignin to a carbohydrate; and

b. separating lignin from the biomass.

A. Characteristics of Lignin Utilized Herein

[0024] In some embodiments, the lignin utilized in a method described herein is substantially intact. As used herein, "substantially intact" means that the lignin comprises coumaryl alcohol, coniferyl alcohol and sinapyl alcohol condensation moieties that have not been substantially or significantly modified by a process described herein (e.g., the coumaryl alcohol, coniferyl alcohol and sinapyl alcohol condensation moieties of the lignin are substantially in their natural state).

[0025] In some embodiments, the lignin utilized in a method described herein is substantially free of carbohydrates. As used herein, "substantially free of carbohydrates" means that the lignin is substantially free of carbohydrate units (e.g., unbound carbohydrate impurities and/or covalently bound carbohydrate units). In some embodiments, the lignin comprises less than about 10%, 5%, 3%, 2%, 1%, 0.1% or 0.01% by weight of bound or unbound carbohydrate.

[0026] In some embodiments, the lignin-carbohydrate complex comprises lignin and at least one carbohydrate. In some embodiments, the complex between lignin (L) and a carbohydrate (C) includes at least one at least one covalent bond (X) through which the lignin (L) and the carbohydrate (C) are connected (i.e.: L-X-C). In some embodiments, the covalent bond (X) comprises at least one chemical moiety, such as a hydroxycinnamic acid moiety. In some embodiments, a single lignin structure may be covalently linked to more than one carbohydrate, may be covalently linked to the same carbohydrate in more than one location, or combinations thereof.

[0027] In some embodiments, the carbohydrate is a polysaccharide. In some

embodiments, the carbohydrate is selected from cellulose, hemicellulose or combinations thereof. In some embodiments, the carbohydrate comprises carbohydrate monomeric units selected from glucose, arabinose, xylose, mannose, galactose or combinations thereof. B. Method of Obtaining Lignin from Biomass

[0028] In some embodiments, obtaining lignin from biomass comprises:

a. contacting the biomass with an enzyme that cleaves at least one

covalent bond binding lignin to a carbohydrate; and b. separating lignin from the biomass.

i. Enzymatic Cleavage of at least one Covalent Bond Binding Lignin to a Carbohydrate [0029] In some embodiments, an enzyme used for recovering lignin from biomass is an enzyme that cleaves at least one covalent bond linking lignin to a carbohydrate (i.e., the "first enzyme"). As used herein, reference to an enzyme that cleaves at least one covalent bond linking lignin to a carbohydrate includes an enzyme that cleaves at least one covalent bond linking lignin to a carbohydrate and/or to a carbohydrate fragment/segment. In some embodiments, the first enzyme is a xylanase, an arabinase, a glucanase, a mannanase, a galactanase, or combinations thereofor combinations thereof. In some embodiments, the first enzyme is a xylanase (e.g., endoxylanase). In some embodiments, the first enzyme is an arabinase. In some embodiments, the first enzyme is a xylanase and an arabinase. In some embodiments, the first enzyme is immobilized.

[0030] Where the first enzyme comprises a combination of enzymes, the biomass is combined with the enzymes concurrently, or sequentially. In some embodiments, the biomass is combined with a xylanase and subsequently combined with an arabinase. In some embodiments, the biomass is combined with an arabinase and subsequently combined with a xylanase. In some embodiments, the biomass is concurrently combined with an arabinase and a xylanase.

[0031] In some embodiments, the first enzyme is an isolated enzyme. In some embodiments, the first enzyme is not an isolated enzyme. In some embodiments, the first enzyme has been post-translationally modified. In some embodiments, the first enzyme is produced by fermentation methods and/or recombinant methods.

[0032] In some embodiments, xylanases are selected from, by way of non- limiting example, xylanases extracted from Aspergillus niger, Clostridium thermocellum,

Trichoderma reesi, F 'enicillium janthinellum, species of Bacillus, species ofStreptomyces, Thermomonospora fusca, Thermomonospora fusca KW3, Thermomonospora fusca MT816, or combinations thereofor combinations thereof. In some embodiments, such xylanases are produced by fermentation methods and/or recombinant methods. In some embodiments, the xylanases are modified forms of the aforementioned xylanases and/or have been selected from a library of naturally-occurring and/or modified xylanases.

[0033] In some embodiments, arabinases are selected from, by way of non- limiting example, arabinases extracted from Aspergillus niger, Aspergillus niger var. tubigensis, Aspergillus aculeatis, Dichotomitus scualens, Corticium rolfsii, Rhodotorula flava or combinations thereofor combinations thereof. In some embodiments, such arabinases are produced by fermentation methods and/or recombinant methods. In some embodiments, the arabinases are modified forms of the aforementioned arabinases and/or have been selected from a library of naturally-occurring and/or modified arabinases.

[0034] In some embodiments, glucanases are selected from, by way of non-limiting example, glucanases extracted from Aspergillus aculeatus , Tήchoderma longibrachiatum, Tήchoderma viride, Humicola insolens or combinations thereofor combinations thereof. In some embodiments, such arabinases are produced by fermentation methods and/or recombinant methods. In some embodiments, the arabinases are modified forms of the aforementioned arabinases and/or have been selected from a library of naturally-occurring and/or modified arabinases.

[0035] In some embodiments, mannanases are selected from, by way of non- limiting example, mannanases extracted from Bacillus stearothermophilus, Trichoderma reesei, Bacillus sp. strain JAMB-602, Bacillus licheniformis WL-12 or combinations thereofor combinations thereof. In some embodiments, such mannanases are produced by

fermentation methods and/or recombinant methods. In some embodiments, the mannanases are modified forms of the aforementioned mannanases and/or have been selected from a library of naturally-occurring and/or modified mannanases.

[0036] In some embodiments, galactanases are selected from, by way of non-limiting example, galactanases extracted from Aspergillus aculeatus, Humicola insolens,

Myceliophthora thermophilum, Meripilus giganteus, Pseudomonas fluorescens, Bacillus subtilis or combinations thereof. In some embodiments, such galactanases are produced by fermentation methods and/or recombinant methods. In some embodiments, the galactanases are modified forms of the aforementioned galactanases and/or have been selected from a library of naturally-occurring and/or modified galactanases.

[0037] In some embodiments, a second enzyme is used for recovering lignin from biomass. In some embodiments, the second enzyme is an enzyme that cleaves a covalent bond linking a first segment of the carbohydrate to a second segment of the carbohydrate. As such, in some embodiments, lignin or purified lignin described herein has terminal units that comprise one or more carbohydrate units (e.g., monomeric carbohydrate units or oligomeric carbohydrate units). In other embodiments, the lignin or purified lignin does not possess any carbohydrate containing terminal units. In some embodiments, the second enzyme is immobilized. [0038] In some embodiments, the covalent bond through which the lignin and a carbohydrate are connected comprises at least one hydroxycinnamic acid moiety. In some embodiments, the at least one hydroxycinnamic acid moiety is selected from, by way of non-limiting example, at least one ferulic acid moiety (including, e.g., diferulic bridges), at least one coumaric acid moiety, or combinations thereof.

[0039] In some embodiments, the second enzyme is selected from an enzyme that degrades at least one hydroxycinnamic acid moiety. In some embodiments, the second enzyme is /?-coumaroyl esterase, a feruloyl esterase, or combinations thereof. In a specific embodiment, the enzyme that degrades at least one hydroxycinnamic acid moiety is a feruloyl esterase. In a more specific embodiment, the enzyme that degrades at least one hydroxycinnamic acid moiety is a/?-coumaroyl and feruloyl esterase.

[0040] Where the second enzyme comprises a combination of enzymes, the biomass is combined with the enzymes concurrently, or sequentially. In some embodiments, the biomass is combined with a/?-coumaroyl and subsequently combined with a feruloyl esterase. In some embodiments, the biomass is combined with a feruloyl esterase and subsequently combined with a/?-coumaroyl. In some embodiments, the biomass is concurrently combined with a/?-coumaroyl and a feruloyl esterase.

[0041] In some embodiments, the second enzyme is an isolated enzyme. In some embodiments, the second enzyme is not an isolated enzyme. In some embodiments, the second enzyme has been post-translationally modified. In some embodiments, the second enzyme is produced by fermentation methods and/or recombinant methods.

[0042] In some embodiments, feruloyl esterases include, by way of non-limiting example, feruloyl esterases extracted from Aspergillus niger (e.g., FAEA and FAEB), Psudomonas fluorescens, Phanerochaete chrysosporium Penicillium funiculosum, Talaromyces stipitatus, or combinations thereof. In some embodiments, such feruloyl esterases are produced by fermentation methods and/or recombinant methods. In some embodiments, the feruloyl esterases are modified forms of the aforementioned feruloyl esterases and/or have been selected from a library of naturally-occurring and/or modified feruloyl esterases.

[0043] In some embodiments, /?-coumaroyl esterases include, by way of non- limiting example, /?-coumaroyl esterases extracted from Aspergillus awamori, Penicillium pinophilum, Neocallimastix, or combinations thereof. In some embodiments, such/?- coumaroyl esterases are produced by fermentation methods and/or recombinant methods. In some embodiments, the /?-coumaroyl esterases are modified forms of the aforementioned p- coumaroyl esterases and/or have been selected from a library of naturally-occurring and/or modified /?-coumaroyl esterases.

[0044] In some embodiments, an enzyme used for recovering lignin from biomass comprises a first enzyme that cleaves a bond between carbohydrate monomeric units and a second enzyme that degrades at least one hydroxycinnamic acid moiety. In a specific embodiment, the first enzyme is a xylanase and the second enzyme is a feruloyl esterase. In a specific embodiment, the first enzyme is an arabinase and the second enzyme is a feruloyl esterase. In a more specific embodiment, the first enzyme is a xylanase and an arabinase, and the second enzyme is a feruloyl esterase.

[0045] Where a first enzyme and a second enzyme are used to obtain lignin from biomass, the biomass is combined with the first enzyme and the second enzyme

concurrently, or with the first enzyme and the second enzyme sequentially. In some embodiments, the biomass is combined with a first enzyme and subsequently combined with the second enzyme.

[0046] In some embodiments, the biomass and the enzyme are contacted under conditions that instigate or maximize the cleavage of lignin and a carbohydrate. In some embodiments, the biomass and the enzyme are contacted under heating, pressurizing and/or agitating (e.g., stirring or mixing). In some embodiments, heating a biomass/enzyme combination includes, by way of non-limiting example, heating to at least room

temperature, at least 25° C, at least 35° C, at least 50° C, at least 70° C, at least 80° C, at least 90° C, or at least 100° C.

ii. Separating Lignin from Enzymatically Processed Biomass

[0047] In some embodiments, the lignin is separated from the enzymatically processed biomass by any method suitable.

[0048] In some embodiments, the lignin is extracted from the enzymatically processed biomass by use of a solvent. In some embodiments, the lignin is extracted from the enzymatically processed biomass by use of a solvent in which the lignin is soluble and the remaining biomass material is either insoluble or sparingly soluble. In some embodiments, the lignin is extracted from enzymatically processed biomass by use of a solvent in which lignin is either insoluble or sparingly soluble. In some embodiments, the solvent and the soluble components are separated from the insoluble components by any suitable method (e.g., filtration). Where the lignin is soluble, in some embodiments, the lignin is precipitated from the solvent. In some embodiments, the method comprises washing the lignin with a second solvent to further remove impurities. In some embodiments, the solvent with which the purified lignin is extracted is a tunable solvent, such as a gas-expanded liquid, iii. Use of a Reactor

[0049] In some embodiments, the biomass is contacted with an enzyme in a reactor. In some embodiments, the lignin is separated from the biomass in a reactor. In some embodiments, the reactor is, by way of non- limiting example, a flow reactor (e.g., a batch- flow reactor and a continuous flow reactor). In some embodiments, the reactor is a large scale industrial reactor.

III. Reduction of Lignin into 4-(3-hydroxypropyDbenzene-l.,2-diol

[0050] Disclosed herein, in certain embodiments, is 4-(3-hydroxypropyl)benzene-l,2- diol obtained from lignin. Further disclosed herein, in certain embodiments, is a method of obtaining 4-(3-hydroxypropyl)benzene-l,2-diol from lignin. It is to be understood that provided in various embodiments herein are both (a) 4-(3-hydroxypropyl)benzene-l,2-diol prepared according to any of the processes described herein; and (b) methods for obtaining 4-(3-hydroxypropyl)benzene-l,2-diol from a lignin source.

4-(3-hydroxypropyl)benzene- 1 ,2-diol

[0051] Disclosed herein, in certain embodiments, is a method of obtaining 4-(3- hydroxypropyl)benzene-l,2-diol from lignin, comprising: subjecting lignin to reductive conditions sufficient to produce 4-(3-hydroxypropyl)benzene-l,2-diol. In some

embodiments, the lignin is isolated from biomass (e.g., lignocellulose biomass) by any method disclosed herein. In some embodiments, the lignin is not isolated from biomass.

[0052] In some embodiments, the reductive conditions include heating, pressurizing and/or agitating (e.g., stirring or mixing). In some embodiments, heating a lignin containing combination includes, by way of non-limiting example, heating to at least room

temperature, at least 25° C, at least 35° C, at least 50° C, at least 70° C, at least 80° C, at least 90° C, or at least 100° C.

[0053] Disclosed herein, in certain embodiments, is a method of obtaining 4-

(3-hydroxypropyl)benzene-l,2-diol from lignin, comprising: subjecting lignin to reductive conditions sufficient to produce 4-(3-hydroxypropyl)benzene-l,2-diol. In some embodiments, the method comprises contacting lignin with hydrogen. In some

embodiments, the method comprises contacting lignin with hydrogen gas (i.e., H ₂ ), hydrazine e.g., N ₂ H ₄ ), dihydronaphthalene e.g., C ₁₀ H ₁₀ ), dihydroanthracene (e.g., Ci ₄ Hi ₂ ), isopropanol (e.g., C ₃ H ₇ OH), formic acid (e.g., CH ₂ O ₂ ), or combinations thereof. In some embodiments, the method comprises contacting lignin with hydrogen gas (i.e., H ₂ ). In some embodiments, the lignin is subjected to reductive conditions once. In some embodiments, lignin is subjected to reductive conditions more than once. In some embodiments, lignin is subjected to reductive conditions twice.

[0054] In some embodiments, the method comprises contacting lignin with hydrogen (i.e., H ₂ ) and a catalyst. In some embodiments, the method comprises contacting lignin with hydrogen (i.e., H ₂ ) and a metal catalyst. In some embodiments, the method comprises contacting lignin with hydrogen (i.e., H ₂ ) and platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), Raney nickel (NiAl), Urushibara catalysts (e.g., U-Ni-A; U- Ni-B), Wilkinson's catalyst (e.g., RhCl(PPh ₃ ) ₃ ), Crabtree's catalyst (e.g., C ₃ 1H ₅₀ F ₆ IrNP ₂ ), RhCl ₃ /TPPTS, Lindlar catalyst, Adam's Catalyst (e.g., PtO ₂ ), Palladium Black, or combinations thereof. In some embodiments, the method comprises contacting lignin with hydrogen (i.e., H ₂ ) and palladium (e.g., palladium on carbon).

[0055] In some embodiments, the method comprises contacting lignin with hydrogen (i.e., H ₂ ) and a catalyst. In certain embodiments, the catalyst is an enzyme. In some embodiments, the method comprises contacting lignin with hydrogen (i.e., H ₂ ) and an hydrogenase, an hydrogenase mimic, or a combination thereof.

[0056] In some embodiments, the method comprises contacting lignin with hydrogen (i.e., H ₂ ), a catalyst, and a proton source. In some embodiments, the method comprises contacting lignin with hydrogen (i.e., H ₂ ), a catalyst, and an inorganic acid. In some embodiments, the method comprises contacting lignin with hydrogen (i.e., H ₂ ), a catalyst, and hydrogen chloride (HCl).

[0057] In some embodiments, the contacting occurs under heating, pressurizing and/or agitating (e.g., stirring or mixing). In some embodiments, the contacting occurs in the presence of heating. In some embodiments, the contacting occurs in the presence of super critical water. As used herein, "supercritical water" is water heated to about 400° C and at about 23 MPa. In some embodiments, the contacting occurs in the presence of near-critical water. As used herein, "near critical water" is water that has a temperature and/or pressure about 1% less than, about 2% less than, about 3% less than, about 5% less than, about 10% less than, or about 15% less than is necessary for the water to become supercritical. In some embodiments, the lignin is subjected to reduction and heating simultaneously. In some embodiments, the lignin is subjected to reduction and then heating. In some embodiments, the lignin is subjected to heating and then reduction.

[0058] In some embodiments, the lignin is subjected to reduction and then heating. In some embodiments, the lignin is subjected to reduction, heating, and a second reduction. In some embodiments, the lignin is subjected to (a) reduction; and (b) heating and a second reduction concurrently.

[0059] In some embodiments, methanol is produced from the reduction of lignin. In some embodiments, methanol is isolated from the reaction mixture.

Isolation of 4-(3-hydroxypropyl)benzene-l ,2-diol

[0060] In some embodiments, the 4-(3-hydroxypropyl)benzene-l,2-diol is isolated from the remaining lignin. In some embodiments, 4-(3-hydroxypropyl)benzene-l,2-diol is isolated by any method suitable.

[0061] In some embodiments, the 4-(3-hydroxypropyl)benzene-l,2-diol is separated from the lignin by use of a solvent. In some embodiments, the 4-(3-hydroxypropyl)benzene- 1,2-diol is separated from the lignin by use of a solvent in which the 4-(3- hydroxypropyl)benzene-l,2-diol is soluble and the lignin is either insoluble or sparingly soluble. In some embodiments, the 4-(3-hydroxypropyl)benzene-l,2-diol is separated from the lignin by use of a solvent in which 4-(3-hydroxypropyl)benzene- 1 ,2-diol is either insoluble or sparingly soluble and lignin is soluble. In some embodiments, the solvent and the soluble components are separated from the insoluble components by any suitable method (e.g., filtration). Where the 4-(3-hydroxypropyl)benzene-l,2-diol is soluble, in some embodiments, the 4-(3-hydroxypropyl)benzene-l,2-diol is precipitated from the solvent. In some embodiments, the method comprises washing the 4-(3-hydroxypropyl)benzene-l,2- diol with a second solvent to further remove impurities. In some embodiments, the solvent with which the purified 4-(3-hydroxypropyl)benzene-l,2-diol is extracted is a tunable solvent, such as a gas-expanded liquid.

[0062] In some embodiments, the 4-(3-hydroxypropyl)benzene-l,2-diol/residual lignin material is washed with a first solvent in which 4-(3-hydroxypropyl)benzene-l,2-diol is either insoluble or sparingly soluble and subsequently washed with a second solvent in which 4-(3-hydroxypropyl)benzene-l,2-diol is soluble. [0063] In some embodiments, (a) 4-(3-hydroxypropyl)benzene-l,2-diol and the residual lignin material are washed with a first solvent; (b) the first solvent is removed (e.g., by evaporation or filtration); and (c) the 4-(3-hydroxypropyl)benzene-l,2-diol is further purified (i) by washing the 4-(3-hydroxypropyl)benzene-l,2-diol with a second solvent in which the 4-(3-hydroxypropyl)benzene-l,2-diol is insoluble (or sparingly soluble) and in which at least some of the contaminants are at least partially soluble, (ii) by dissolving the 4-(3-hydroxypropyl)benzene-l,2-diol in a second solvent in which at least some of the contaminants are insoluble (or sparingly soluble), and/or (iii) by dissolving the 4-(3- hydroxypropyl)benzene-l,2-diol and at least some of the contaminants in a second solvent and selectively precipitating 4-(3 -hydroxypropyl)benzene- 1 ,2-diol and/or the various contaminants from the second solvent.

D. Use of a Reactor

[0064] In some embodiments, the biomass is contacted with an enzyme in a reactor. In some embodiments, the lignin is separated from the biomass in a reactor. In some embodiments, the reactor is, by way of non- limiting example, a flow reactor (e.g., a batch- flow reactor and a continuous flow reactor). In some embodiments, the reactor is a large scale industrial reactor.

IV. End-Products

A. y-Butyrolactone

[0065] Disclosed herein, in certain embodiments, is γ-butyrolactone obtained from lignin. Further disclosed herein, in certain embodiments, is a method of obtaining γ- butyrolactone from lignin. It is to be understood that provided in various embodiments herein are both (a) γ-butyrolactone prepared according to any of the methods described herein; and (b) methods for preparing γ-butyrolactone from lignin.

γ-Butyrolactone

[0066] Disclosed herein, in certain embodiments, is a method of obtaining γ- butyrolactone from lignin, comprising: (a) subjecting lignin to reductive conditions sufficient to produce 4-(3-hydroxypropyl)benzene-l,2-diol, and (b) subjecting 4-(3- hydroxypropyl)benzene-l,2-diol to conditions sufficient to convert 4-(3- hydroxypropyl)benzene-l,2-diol to 2 γ-butyrolactone. In some embodiments, lignin is converted to 4-(3-hydroxypropyl)benzene-l,2-diol by any method disclosed herein.

[0067] In some embodiments, the lignin is isolated from biomass (e.g., lignocellulose biomass) by any method disclosed herein. In some embodiments, the lignin is not isolated from biomass.

[0068] In some embodiments, the reductive conditions include heating, pressurizing and/or agitating (e.g., stirring or mixing). In some embodiments, heating a lignin containing combination includes, by way of non-limiting example, heating to at least room

temperature, at least 25° C, at least 35° C, at least 50° C, at least 70° C, at least 80° C, at least 90° C, or at least 100° C.

i. Conversion of 4-(3-hydroxypropyl)benzene- 1 ,2-diol to γ-Butyrolactone

[0069] In some embodiments, converting 4-(3-hydroxypropyl)benzene-l,2-diol to γ- butyrolactone comprises oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol. In some embodiments, converting 4-(3-hydroxypropyl)benzene-l,2-diol to γ-butyrolactone comprises oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol that has been isolated from any residual lignin. In some embodiments, converting 4-(3-hydroxypropyl)benzene-l,2-diol to γ-butyrolactone comprises oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol that has not been isolated from any residual lignin.

[0070] In some embodiments, oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol comprises contacting 4-(3-hydroxypropyl)benzene-l,2-diol with a metal catalyst and an oxidant. In certain embodiments, the metal catalyst is a ruthenium (Ru) catalyst. In some embodiments, the oxidant is peroxide (e.g., hydrogen peroxide), periodate, electrochemical oxidation, or the like. In certain embodiments, the oxidant is an organic peracid (aka: a peroxy acid) under conditions that instigate or maximize the reaction. In some

embodiments, oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol comprises contacting 4-(3- hydroxypropyl)benzene-l,2-diol with perfluoroacetic peracid (e.g., trifluoroacetic acid; e.g., CF ₃ CO ₂ H), acetic peracid (e.g., peracetic acid; e.g., C ₂ H ₄ O ₃ ), or both under conditions that instigate or maximize the reaction.

[0071] In some embodiments, oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol comprises contacting 4-(3-hydroxypropyl)benzene-l,2-diol with an organic peracid and heating the combination. In some embodiments, the organic peracid/4-(3- hydroxypropyl)benzene-l,2-diol combination is heated to about 200° C, about 250° C, about 300° C, about 350° C, or about 350° C. In some embodiments, decarboxylating 4-(3- hydroxypropyl)benzene-l,2-diol comprises contacting 4-(3-hydroxypropyl)benzene-l,2-diol with super critical or near critical water,

ii. Isolation of γ-Butyrolactone

[0072] In some embodiments, the γ-butyro lactone is isolated from any remaining impurities (e.g., lignin and/or 4-(3-hydroxypropyl)benzene-l,2-diol). In some embodiments, γ-butyrolactone is isolated by any method suitable.

[0073] In some embodiments, the γ-butyrolactone is isolated from any remaining impurities (e.g., lignin and/or 4-(3-hydroxypropyl)benzene-l,2-diol) by use of a solvent. In some embodiments, the γ-butyrolactone is isolated from any remaining impurities by use of a solvent in which one or more of the impurities is soluble and the γ-butyrolactone is either insoluble or sparingly soluble. In some embodiments, any impurities are separated from the γ-butyrolactone by use of a solvent in which the impurities are either insoluble or sparingly soluble and γ-butyrolactone is soluble. In some embodiments, the solvent and the soluble components are separated from the insoluble components by any suitable method (e.g., filtration). Where the γ-butyrolactone is soluble, in some embodiments, the γ-butyrolactone is precipitated from the solvent. In some embodiments, the method comprises washing the γ-butyrolactone with a second solvent to further remove impurities. In some embodiments, the solvent with which the purified γ-butyrolactone is extracted is a tunable solvent, such as a gas-expanded liquid.

[0074] In some embodiments, the reaction mixture is washed with a first solvent in which γ-butyrolactone is either insoluble or sparingly soluble and subsequently washed with a second solvent in which γ-butyrolactone is soluble.

[0075] In some embodiments, (a) γ-butyrolactone and any residual impurities are washed with a first solvent; (b) the first solvent is removed (e.g., by evaporation or filtration); and (c) the γ-butyrolactone is further purified (i) by washing the γ-butyrolactone with a second solvent in which the γ-butyrolactone is insoluble (or sparingly soluble) and in which at least some of the impurities are at least partially soluble, (ii) by dissolving the γ- butyrolactone in a second solvent in which at least some of the impurities are insoluble (or sparingly soluble), and/or (iii) by dissolving the γ-butyrolactone and at least some of the contaminants in a second solvent and selectively precipitating γ-butyrolactone and/or the various impurities from the second solvent,

iii. Use of a Reactor [0076] In some embodiments, the biomass is contacted with an enzyme in a reactor. In some embodiments, the lignin is separated from the biomass in a reactor. In some embodiments, the reactor is, by way of non- limiting example, a flow reactor (e.g., a batch- flow reactor and a continuous flow reactor). In some embodiments, the reactor is a large scale industrial reactor.

B. Succinic Acid

[0077] Disclosed herein, in certain embodiments, is succinic acid obtained from lignin. Further disclosed herein, in certain embodiments, is a method of obtaining succinic acid from lignin. It is to be understood that provided in various embodiments herein are both (a) succinic acid prepared according to any of the methods described herein; and (b) methods for preparing succinic acid from lignin.

Succinic Acid

[0078] Disclosed herein, in certain embodiments, is a method of obtaining succinic acid from lignin, comprising: (a) subjecting lignin to reductive conditions sufficient to produce 4-(3-hydroxypropyl)benzene-l,2-diol, and (b) subjecting 4-(3-hydroxypropyl)benzene-l,2- diol to conditions sufficient to convert 4-(3-hydroxypropyl)benzene-l,2-diol to succinic acid. In some embodiments, lignin is converted to 4-(3-hydroxypropyl)benzene-l,2-diol by any method disclosed herein.

[0079] In some embodiments, the lignin is isolated from biomass (e.g., lignocellulose biomass) by any method disclosed herein. In some embodiments, the lignin is not isolated from biomass.

[0080] In some embodiments, the reductive conditions include heating, pressurizing and/or agitating (e.g., stirring or mixing). In some embodiments, heating a lignin containing combination includes, by way of non-limiting example, heating to at least room

temperature, at least 25° C, at least 35° C, at least 50° C, at least 70° C, at least 80° C, at least 90° C, or at least 100° C.

i. Conversion of 4-(3-hydroxypropyl)benzene-l,2-diol to succinic acid

[0081] In some embodiments, converting 4-(3-hydroxypropyl)benzene-l,2-diol to succinic acid comprises oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol. In some embodiments, converting 4-(3-hydroxypropyl)benzene-l,2-diol to succinic acid comprises oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol that has been isolated from any residual lignin. In some embodiments, converting 4-(3-hydroxypropyl)benzene-l,2-diol to succinic acid comprises oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol that has not been isolated from any residual lignin.

[0082] In some embodiments, oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol comprises contacting 4-(3-hydroxypropyl)benzene-l,2-diol with a metal catalyst and an oxidant. In certain embodiments, the metal catalyst is a ruthenium (Ru) catalyst. In some embodiments, the oxidant is peroxide (e.g., hydrogen peroxide), periodate, electrochemical oxidation, or the like. In certain embodiments, the oxidant is an organic peracid (aka: a peroxy acid) under conditions that instigate or maximize the reaction. In some

embodiments, oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol comprises contacting 4-(3- hydroxypropyl)benzene-l,2-diol with perfluoroacetic peracid (e.g., trifluoroacetic acid; e.g., CF3CO2H), acetic peracid (e.g., peracetic acid; e.g., C2H4O3), or both under conditions that instigate or maximize the reaction.

[0083] In some embodiments, the method of obtaining succinic acid from lignin comprises (a) reacting 4-(3-hydroxypropyl)benzene-l,2-diol with an oxidizing agent that converts a primary alcohol (e.g., a hydroxypropyl group) to a carboxylic acid, generating 3- (3,4-dihydroxyphenyl)propanoic acid; and (b) reacting 3-(3,4-dihydroxyphenyl)propanoic acid with an oxidizing agent that converts an aryl group to a carboxylic acid. In some embodiments, (a) reacting 4-(3-hydroxypropyl)benzene-l,2-diol with an oxidizing agent that converts a primary alcohol (e.g., a hydroxypropyl group) to a carboxylic acid; and (b) reacting 3-(3,4-dihydroxyphenyl)propanoic acid with an oxidizing agent that converts an aryl group to a carboxylic acid occurs sequentially or concurrently. In some embodiments, (a) reacting 4-(3-hydroxypropyl)benzene-l,2-diol with an oxidizing agent that converts a primary alcohol (e.g., a hydroxypropyl group) to a carboxylic acid occurs before (b) reacting 3-(3,4-dihydroxyphenyl)propanoic acid with an oxidizing agent that converts an aryl group to a carboxylic acid.

[0084] In some embodiments, the method of obtaining succinic acid from lignin comprises (a) reacting 4-(3-hydroxypropyl)benzene-l,2-diol with chromic acid, generating 3-(3,4-dihydroxyphenyl)propanoic acid; and (b) reacting 3-(3,4-dihydroxyphenyl)propanoic acid with an organic peracid (e.g., perfluoroacetic peracid and/or acetic peracid). It is to be understood that as used throughout, treatment with an organic peracid includes treatment with a combination of the corresponding organic acid and hydrogen peroxide.

[0085] In some embodiments, oxidizing 4-(3-hydroxypropyl)benzene-l,2-diol comprises contacting 4-(3-hydroxypropyl)benzene-l,2-diol with an organic peracid and heating the combination. In some embodiments, the organic peracid/4-(3- hydroxypropyl)benzene-l,2-diol combination is heated to about 200° C, about 250° C, about 300° C, about 350° C, or about 350° C. In some embodiments, decarboxylating 4-(3- hydroxypropyl)benzene-l,2-diol comprises contacting 4-(3-hydroxypropyl)benzene-l,2-diol with super critical or near critical water.

ii. Isolation of Succinic acid

[0086] In some embodiments, the succinic acid is isolated from any remaining impurities (e.g., lignin and 4-(3-hydroxypropyl)benzene-l,2-diol). In some embodiments, succinic acid is isolated by any method suitable.

[0087] In some embodiments, the succinic acid is isolated from any remaining impurities (e.g., lignin or 4-(3-hydroxypropyl)benzene-l,2-diol) by use of a solvent. In some embodiments, the succinic acid is isolated from any remaining impurities by use of a solvent in which one or more of the impurities is soluble and the succinic acid is either insoluble or sparingly soluble. In some embodiments, any impurities are separated from the succinic acid by use of a solvent in which the impurities are either insoluble or sparingly soluble and succinic acid is soluble. In some embodiments, the solvent and the soluble components are separated from the insoluble components by any suitable method (e.g., filtration). Where the succinic acid is soluble, in some embodiments, the succinic acid is precipitated from the solvent. In some embodiments, the method comprises washing the succinic acid with a second solvent to further remove impurities. In some embodiments, the solvent with which the purified succinic acid is extracted is a tunable solvent, such as a gas- expanded liquid.

[0088] In some embodiments, the reaction mixture is washed with a first solvent in which succinic acid is either insoluble or sparingly soluble and subsequently washed with a second solvent in which succinic acid is soluble.

[0089] In some embodiments, (a) succinic acid and any residual impurities are washed with a first solvent; (b) the first solvent is removed (e.g., by evaporation or filtration); and (c) the succinic acid is further purified (i) by washing the succinic acid with a second solvent in which the succinic acid is insoluble (or sparingly soluble) and in which at least some of the impurities are at least partially soluble, (ii) by dissolving the succinic acid in a second solvent in which at least some of the impurities are insoluble (or sparingly soluble), and/or (iii) by dissolving the succinic acid and at least some of the contaminants in a second solvent and selectively precipitating succinic acid and/or the various impurities from the second solvent.

iii. Use of a Reactor

[0090] In some embodiments, the biomass is contacted with an enzyme in a reactor. In some embodiments, the lignin is separated from the biomass in a reactor. In some embodiments, the reactor is, by way of non- limiting example, a flow reactor (e.g., a batch- flow reactor and a continuous flow reactor). In some embodiments, the reactor is a large scale industrial reactor.

C. 1 ,4-Butane-diol

[0091] Disclosed herein, in certain embodiments, is 1 ,4-butane-diol obtained from lignin. Further disclosed herein, in certain embodiments, is a method of obtaining 1 ,4-butane-diol from lignin. It is to be understood that provided in various embodiments herein are both (a) 1 ,4-butane-diol prepared according to any of the methods described herein; and (b) methods for preparing 1 ,4-butane-diol from lignin. HO ^^ ^^

1,4-Butane-diol

[0092] Disclosed herein, in certain embodiments, is a method of obtaining 1 ,4-butane-diol from lignin, comprising: (a) subjecting lignin to reductive conditions sufficient to produce 4-(3-hydroxypropyl)benzene-l,2-diol, (b) subjecting 4-(3-hydroxypropyl)benzene-l,2-diol to conditions sufficient to convert 4-(3-hydroxypropyl)benzene-l,2-diol to γ-butyrolactone; and (c) subjecting γ-butyrolactone to conditions sufficient to convert γ-butyrolactone to 1,4- butane-diol.

[0093] In some embodiments, lignin is converted to 4-(3-hydroxypropyl)benzene-l,2-diol by any method disclosed herein. In some embodiments, 4-(3-hydroxypropyl)benzene-l,2- diol is converted to γ-butyrolactone by any suitable method.

[0094] In some embodiments, the lignin is isolated from biomass (e.g., lignocellulose biomass) by any method disclosed herein. In some embodiments, the lignin is not isolated from biomass. [0095] In some embodiments, the reductive conditions include heating, pressurizing and/or agitating (e.g., stirring or mixing). In some embodiments, heating a lignin containing combination includes, by way of non-limiting example, heating to at least room

temperature, at least 25° C, at least 35° C, at least 50° C, at least 70° C, at least 80° C, at least 90° C, or at least 100° C.

i Conversion of γ-Butyrolactone to 1 ,4-Butane-diol

[0096] In some embodiments, converting γ-butyrolactone to 1 ,4-butane-diol comprises reducing γ-butyrolactone. In some embodiments, converting γ-butyrolactone to 1,4-butane- diol comprises reducing γ-butyrolactone that has been isolated from any residual γ- butyrolactone and/or 4-(3-hydroxypropyl)benzene-l,2-diol. In some embodiments, converting γ-butyrolactone to 1 ,4-butane-diol comprises reducing γ-butyrolactone that has not been isolated from any residual γ-butyrolactone and/or 4-(3-hydroxypropyl)benzene-

1,2-diol.

[0097] In some embodiments, reducing γ-butyrolactone to 1 ,4-butane-diol comprises contacting γ-butyrolactone with hydrogen. In some embodiments, the method comprises contacting γ-butyrolactone with hydrogen gas, hydrazine, dihydronaphthalene,

dihydroanthracene, isopropanol, formic acid or combinations thereof. In some

embodiments, the method comprises contacting γ-butyrolactone with hydrogen gas (i.e., H ₂ ). In some embodiments, the γ-butyrolactone is subjected to reductive conditions once. In some embodiments, γ-butyrolactone is subjected to reductive conditions twice.

[0098] . In some embodiments, the method comprises contacting γ-butyrolactone with hydrogen gas (i.e., H ₂ ), hydrazine (e.g., N ₂ H ₄ ), dihydronaphthalene (e.g., CioHio), dihydroanthracene (e.g., Ci ₄ Hi ₂ ), isopropanol (e.g., C3H7OH), formic acid e.g., CH ₂ O ₂ ), or combinations thereof. In some embodiments, the method comprises contacting γ- butyrolactone with hydrogen gas (i.e., H ₂ ). In some embodiments, the γ-butyrolactone is subjected to reductive conditions once. In some embodiments, γ-butyrolactone is subjected to reductive conditions more than once. In some embodiments, γ-butyrolactone is subjected to reductive conditions twice.

[0099] In some embodiments, the method comprises contacting γ-butyrolactone with hydrogen (i.e., H ₂ ) and a catalyst. In some embodiments, the method comprises contacting γ-butyrolactone with hydrogen (i.e., H ₂ ) and a metal catalyst. In some embodiments, the method comprises contacting γ-butyrolactone with hydrogen (i.e., H ₂ ) and platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), Raney nickel (e.g., NiAl), Urushibara

-??- catalysts (e.g., U-Ni-A; U-Ni-B), Wilkinson's catalyst (e.g., RhCl(PPh ₃ ) ₃ ), Crabtree's catalyst (e.g., C ₃ IH ₅₀ F ₆ IrNP ₂ ), RhCl ₃ /TPPTS, Lindlar catalyst, Adam's Catalyst (e.g., PtO ₂ ), Palladium Black, or combinations thereof. In some embodiments, the method comprises contacting γ-butyrolactone with hydrogen (i.e., H ₂ ) and palladium (e.g., palladium on carbon).

[00100] In some embodiments, the method comprises contacting γ- butyrolactone with hydrogen (i.e., H ₂ ) and a catalyst. In certain embodiments, the catalyst is an enzyme. In some embodiments, the method comprises contacting γ-butyrolactone with hydrogen (i.e., H ₂ ) and an hydrogenase, an hydrogenase mimic, or a combination thereof.

[00101] In some embodiments, the method comprises contacting γ- butyrolactone with hydrogen (i.e., H ₂ ), a catalyst, and a proton source. In some

embodiments, the method comprises contacting γ-butyrolactone with hydrogen (i.e., H ₂ ), a catalyst, and an inorganic acid. In some embodiments, the method comprises contacting γ- butyrolactone with hydrogen (i.e., H ₂ ), a catalyst, and hydrogen chloride (HCl).

[00102] In some embodiments, the contacting occurs under heating, pressurizing and/or agitating (e.g., stirring or mixing). In some embodiments, the contacting occurs in the presence of heating. In some embodiments, the contacting occurs in the presence of super critical water. As used herein, "supercritical water" is water heated to about 400° C and at about 23 MPa. In some embodiments, the contacting occurs in the presence of near-critical water. As used herein, "near critical water" is water that has a temperature and/or pressure about 1% less than, about 2% less than, about 3% less than, about 5% less than, about 10% less than, or about 15% less than is necessary for the water to become supercritical. In some embodiments, the γ-butyrolactone is subjected to reduction and heating simultaneously. In some embodiments, the γ-butyrolactone is subjected to reduction and then heating. In some embodiments, the γ-butyrolactone is subjected to heating and then reduction.

[00103] In some embodiments, the γ-butyrolactone is subjected to reduction and then heating. In some embodiments, the γ-butyrolactone is subjected to reduction, heating, and a second reduction. In some embodiments, the γ-butyrolactone is subjected to (a) reduction; and (b) heating and a second reduction concurrently.

ii. Isolation of 1 ,4-Butane-diol

[00104] In some embodiments, the 1 ,4-butane-diol is isolated from any remaining impurities (e.g., lignin, 4-(3-hydroxypropyl)benzene-l,2-diol, and/or γ-butyrolactone). In some embodiments, 1 ,4-butane-diol is isolated by any method suitable. [00105] In some embodiments, the 1 ,4-butane-diol is isolated from any remaining impurities (e.g., lignin, 4-(3-hydroxypropyl)benzene-l,2-diol, and/or γ-butyro lactone) by use of a solvent. In some embodiments, the 1 ,4-butane-diol is isolated from any remaining impurities by use of a solvent in which one or more of the impurities is soluble and the 1,4- butane-diol is either insoluble or sparingly soluble. In some embodiments, any impurities are separated from the 1 ,4-butane-diol by use of a solvent in which the impurities are either insoluble or sparingly soluble and 1 ,4-butane-diol is soluble. In some embodiments, the solvent and the soluble components are separated from the insoluble components by any suitable method (e.g., filtration). Where the 1 ,4-butane-diol is soluble, in some

embodiments, the 1 ,4-butane-diol is precipitated from the solvent. In some embodiments, the method comprises washing the 1 ,4-butane-diol with a second solvent to further remove impurities. In some embodiments, the solvent with which the purified 1 ,4-butane-diol is extracted is a tunable solvent, such as a gas-expanded liquid.

[00106] In some embodiments, the reaction mixture is washed with a first solvent in which 1 ,4-butane-diol is either insoluble or sparingly soluble and subsequently washed with a second solvent in which 1 ,4-butane-diol is soluble.

[00107] In some embodiments, (a) 1 ,4-butane-diol and any residual impurities are washed with a first solvent; (b) the first solvent is removed (e.g., by evaporation or filtration); and (c) the 1 ,4-butane-diol is further purified (i) by washing the 1 ,4-butane-diol with a second solvent in which the 1 ,4-butane-diol is insoluble (or sparingly soluble) and in which at least some of the impurities are at least partially soluble, (ii) by dissolving the 1,4- butane-diol in a second solvent in which at least some of the impurities are insoluble (or sparingly soluble), and/or (iii) by dissolving the 1 ,4-butane-diol and at least some of the contaminants in a second solvent and selectively precipitating 1 ,4-butane-diol and/or the various impurities from the second solvent,

iii. Use of a Reactor

[00108] In some embodiments, the biomass is contacted with an enzyme in a reactor. In some embodiments, the lignin is separated from the biomass in a reactor. In some embodiments, the reactor is, by way of non- limiting example, a flow reactor (e.g., a batch- flow reactor and a continuous flow reactor). In some embodiments, the reactor is a large scale industrial reactor. EXAMPLES

Example 1 - Generation of 4-(3-hvdroxypropyl)benzene-l,2-diol

[00109] Lignin is converted into 4-(3-hydroxypropyl)benzene-l,2-diol by contacting lignin with molecular hydrogen and the metal catalyst palladium concurrently with or followed by heating (e.g., in the presence of super critical water). The intermediate product is then contacted molecular hydrogen and the metal catalyst palladium.

Example 2 - Generation of γ-Butyrolactone

oxidation

[00110] Lignin is converted into γ-butyrolactone by (1) contacting lignin with molecular hydrogen and the metal catalyst palladium concurrently with or followed by heating; and (2) contacting the intermediate product with molecular hydrogen and the metal catalyst palladium to generate 4-(3-hydroxypropyl)benzene-l,2-diol. Next, the 4-(3- hydroxypropyl)benzene-l,2-diol is isolated from the lignin. Then, the 4-(3- hydroxypropyl)benzene-l,2-diol is oxidized by contacting it with perfluoroacetic peracid. Example 3 - Generation of Succinic Acid

[00111] Lignin is converted into succinic acid by (1) contacting lignin with molecular hydrogen and the metal catalyst palladium concurrently with or followed by heating; and (2) contacting the intermediate product with molecular hydrogen and the metal catalyst palladium to generate 4-(3-hydroxypropyl)benzene-l,2-diol. Next, the 4-(3- hydroxypropyl)benzene-l,2-diol is isolated from the lignin. Then, the 4-(3- hydroxypropyl)benzene-l,2-diol is oxidized by concurrently contacting it with chromic acid and perfluoroacetic peracid.

Example 4 - Generation of 1 ,4-Butane-diol

Lignin

oxidation reduction

[00112] Lignin is converted into 1 ,4-butane-diol by first contacting lignin with molecular hydrogen and the metal catalyst palladium concurrently with or followed by heating; and (2) contacting the intermediate product with molecular hydrogen and the metal catalyst palladium to generated 4-(3-hydroxypropyl)benzene-l,2-diol. Next, the 4-(3- hydroxypropyl)benzene-l,2-diol is isolated from the lignin. Then, the 4-(3- hydroxypropyl)benzene-l,2-diol is oxidized to γ-butyrolactone by contacting it with perfluoroacetic peracid. Finally, the γ-butyrolactone is reduced to 1 ,4-butane-diol by contacting it with molecular hydrogen and palladium.