초록 ▼

The present invention provides a method for converting lignocellulosic material into biofuel. In particular embodiments, the method comprises pre-treating lignocellulosic material by dissolving the material in ionic liquids. The pretreated lignocellulosic material can be isolated, such as by precipi

The present invention provides a method for converting lignocellulosic material into biofuel. In particular embodiments, the method comprises pre-treating lignocellulosic material by dissolving the material in ionic liquids. The pretreated lignocellulosic material can be isolated, such as by precipitation with a regenerating solvent (e.g., water), and be used directly in the formation of biofuel, including undergoing hydrolysis to form sugar and fermentation to form fuel, such as bioethanol. The ionic liquid can be recycled for further use, such as by evaporation of the water introduced during precipitation, and the recycling provides a route to a hemicellulose rich fraction and an ionic liquid of consistent quality and wood dissolution characteristics. The recovered hemicelluloses are of significant utilization potential toward commodity and specialty applications.

대표청구항 ▼

1. A method of converting a wood into biofuel comprising: (i) pre-treating the wood in its native form by dissolving in ionic liquid to form a solution of dissolved wood in ionic liquid; said dissolving comprises mixing while heating at a temperature of about 50° C. to about 150° C.(ii) precipitatin

1. A method of converting a wood into biofuel comprising: (i) pre-treating the wood in its native form by dissolving in ionic liquid to form a solution of dissolved wood in ionic liquid; said dissolving comprises mixing while heating at a temperature of about 50° C. to about 150° C.(ii) precipitating the pretreated wood from the ionic liquid to form a regenerated wood; and(iii) carrying out one or more further steps to convert the regenerated wood to a biofuel or to a reactant in the direct preparation of a biofuel. 2. The method of claim 1, wherein said dissolving is carried out in the substantial absence of water. 3. The method of claim 2, wherein said dissolving is carried out such that the ionic liquid comprises less than about 1% by weight water. 4. The method of claim 1, wherein said dissolving is carried out in the substantial absence of a nitrogen-containing base. 5. The method of claim 4, wherein said dissolving is carried out such that the ionic liquid comprises less than about 1% by weight of a nitrogen-containing base. 6. The method of claim 1, wherein the ionic liquid comprises a material formed of a cation and an anion, wherein the cation is selected from the group consisting of imidazoles, pyrazoles, thiazoles, isothiazoles, azathiozoles, oxothiazoles, oxazines, oxazolines, oxazaboroles, dithiozoles, triazoles, delenozoles, oxaphospholes, pyrroles, boroles, furans, thiophenes, phospholes, pentazoles, indoles, indolines, oxazoles, isoxazoles, isotetrazoles, tetrazoles, benzofurans, dibenzofurans, benzothiophenes, dibenzothiophenes, thiadiazoles, pyridines, pyrimidines, pyrazines, pyridazines, piperazines, piperidines, morpholones, pyrans, annolines, phthalazines, quinazolines, guanidiniums, quinxalines, choline-based analogues, derivatives thereof, and combinations thereof, and wherein the anion is selected from the group consisting of halogens, phosphates, alkylphosphates, alkenylphosphates, BF4−, PF6−, AsF6−, NO3−, N(CN)2−, N(SO3CF3)2−, amino acids, substituted or unsubstituted carboranes, perchlorates, pseudohalogens, metal chloride-based Lewis acids, C1-6 carboxylates, and combinations thereof 7. The method of claim 6, wherein the cation is selected from the group consisting of imidazoles and pyridines, and the anion is selected from the group consisting of halogens, phosphates, alkylphosphates, alkenylphosphates, and bis(trifluoromethylsulfonyl)imide. 8. The method of claim 1, wherein the wood, prior to dissolving in the ionic liquid, is in a form selected from the group consisting of ball-milled wood powder, sawdust, thermomechanical pulp fibers, wood chips, and combinations thereof. 9. The method of claim 1, wherein the precipitation step comprises adding a regenerating solvent to the solution. 10. The method of claim 1, wherein the regenerated wood has a basic structure that is at least about 95% amorphous. 11. The method of claim 1, further comprising recycling the ionic liquid after precipitation of the wood. 12. The method of claim 11, wherein said recycling comprising removing the regenerating solvent from the ionic liquid. 13. The method of claim 1, wherein said ionic liquid comprises an ionic liquid that has been recycled from a previous pre-treatment step. 14. The method of claim 1, wherein the one or more further steps comprises isolating the regenerated wood from the ionic liquid and converting the isolated regenerated wood into a sugar. 15. The method of claim 14, wherein said converting step comprises enzymatic hydrolysis in the presence of an amount of lignin present within the wood in its native form. 16. The method of claim 14, further comprising microbially converting the sugar into a biofuel. 17. The method of claim 16, wherein said microbially converting step comprises contacting the sugar with ethanol forming bacteria. 18. The method of claim 1, wherein the biofuel comprises ethanol. 19. The method of claim 1, wherein the reactant comprises glucose. 20. A method for preparing a highly porous, reactive wood substrate, the method comprising: (a) dissolving a wood in its native form in an ionic liquid to form a solution; said dissolving comprises mixing while heating at a temperature of about 50° C. to about 150° C. and(b) precipitating the dissolved wood from the ionic liquid to form the highly porous, reactive regenerated wood substrate. 21. The method of claim 20, wherein said precipitating step comprises adding a regenerating solvent to the solution. 22. A method for isolating hemicellulose from a wood, said method comprising: (a) dissolving the wood in its native form in an ionic liquid; said dissolving comprises mixing while heating at a temperature of about 50° C. to about 150° C.(b) regenerating the wood having a reduced hemicellulose content;(c) separating the regenerated wood from the ionic liquid to provide a recycled ionic liquid; and(d) isolating hemicellulose from the recycled ionic liquid. 23. The method of claim 22, wherein said isolating step comprises precipitating the hemicellulose from the ionic liquid. 24. The method of claim 23, wherein said precipitating comprises adding to the recycled ionic liquid a solvent in which the hemicellulose is not soluble.