JP2004083482A - Method for effectively utilizing lignocellulose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for effectively utilizing lignocellulose by manufacturing a levulinic ester and levulinic acid by the solvolysis of lignocellulose and concurrently manufacturing a polyol compound applicable as a raw material of a chemical. <P>SOLUTION: The method for effectively utilizing lignocellulose comprises solvolysis of lignocellulose using a decomposition reagent, a water treatment of the decomposition product, fractionation of the decomposition product into a water-soluble portion and a water-insoluble portion, separation of the levulinic ester or levulinic acid from the water-soluble portion, and separation of the polyol compound from the water-insoluble portion. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for effectively utilizing lignocellulose for decomposing lignocellulose to produce levulinic acid or a levulinic acid ester and a polyol compound which are useful chemical raw materials.
[0002]
[Prior art]
Effective use of wood-based substances such as wood, bark, waste paper, and plant-based resources (collectively referred to as lignocellulose) mainly composed of lignocellulose such as agricultural products such as rice straw, firs, bagasse, and their wastes. The development of the law is expected. In recent years, in particular, from the viewpoint of promoting the recycling of waste, development of an effective use method of lignocellulose such as construction waste material and waste paper is urgent. As one of them, there is an attempt to decompose these lignocelluloses in an organic solvent and use them effectively. When lignocellulose is treated in an organic solvent, the used organic solvent decomposes while binding to the lignocellulose, so this decomposition reaction is called solvolysis.
[0003]
Solvolysis of lignocellulose is mainly used in wood pulping technology. Pulping is a technique for separating lignin from lignocellulose such as wood to obtain cellulose as a raw material for papermaking. At this time, a solvolysis reaction is used in the step of decomposing and eluting lignin. These pulping techniques are called organosolve pulping, solvent pulping, or solvolysis pulping. The history of pulping using this kind of solvolysis reaction is old, and various studies have been made, including the study of alcohol-based pulping in the 1930s (US Pat. No. 3,585,104, US Pat. Japanese Patent No. 4100016). Sano et al. Have developed a technique for obtaining pulp by treating with an aqueous solvent of a high-boiling organic solvent (JP-A-2001-89986). The solvolysis of lignocellulose in pulping as seen in these existing technologies is a technology that efficiently solvolyzes and separates lignin and obtains cellulose as pulp without decomposition. Does not solvolyze and eventually produce levulinic acid.
[0004]
Levulinic acid is an organic compound obtained by decomposing a hexasaccharide such as glucose under acidic conditions. As early as Tollens et al. Reported in 1875 that saccharides produce levulinic acid by acid degradation. Levulinic acid can be produced by acid-hydrolyzing cellulose or starch, which is a polymer having a continuous glucose skeleton, and then subjecting it to glucose and then heat-decomposing it under acidic conditions. The method for producing levulinic acid relating to acid hydrolysis of these saccharides is also reported in Shimizu et al.'S report on the production of levulinic acid from sucrose in 1949 (Shimizu et al., Agricultural Chemistry, No. 23). Recently, Fitzpatrick has developed an apparatus for producing levulinic acid in high yield from saccharide-containing substances such as lignocellulose (US Pat. No. 5,608,105). However, in the technology of obtaining levulinic acid using these acid hydrolysis treatments, lignin by-produced when lignocellulose such as wood is used as a raw material has properties that are difficult to use as chemical products. There are no reports of use other than incineration and use as a heat source because the use is difficult.
[0005]
There is also a method for synthesizing levulinic acid using raw materials other than sugars. For example, Farnleitner et al. Produce levulinic acid having storage stability by saponifying acetylsuccinate with an aqueous mineral acid (Japanese Patent No. 2844382). Gazette). However, industrially, it is considered economically advantageous to use lignocellulose, which has a large amount as a biological resource, as a raw material.
[0006]
Levulinic acid is a useful chemical raw material that can be converted into various compounds. Leonard reports that levulinic acid can be converted into various compounds as a chemical raw material (Industrial and Engineering Chemistry, Vol 48, No 8, 1330-1341, 1956). Recently, Bozell et al. Of the National Institute of Renewable Energy of the US Department of Energy have reported on the use of levulinic acid as a useful chemical raw material from the viewpoint of effective use of lignocellulosic resources. Thus, the chemistry of utilizing levulinic acid has received attention (Resources, Conservation and Recycling, 28, 227-239, 2000). There have been many reports on aminolevulinic acid that can be derived from levulinic acid as a raw material (Japanese Patent No. 3124692, Japanese Patent No. 2994949, etc.). It has been reported that 5-aminolevulinic acid is used as a bioactive agent in herbicide components (Japanese Patent No. 2623312). As mentioned above, there are reports on the use of levulinic acid, but there is no report of producing levulinic acid using a solvolysis reaction and simultaneously using lignin as a useful chemical raw material.
[0007]
There is a report on the application of cyclic carbonates to woody substances by the present inventors (JP-A-11-80367). Here, a technique is described in which lignocellulose is treated with a cyclic carbonate (corresponding to a cyclic carbonate) to obtain a resin raw material composition. Japanese Patent No. 301,296 describes a technique for preparing a resin raw material by making a polyhydric alcohol act on lignocellulose to form a liquid solution. However, these technologies aim to liquefy the entire lignocellulose and apply the product as a resin raw material to resin raw materials such as moldings and adhesives, and to isolate useful compounds such as levulinic acid. It is not about.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide a technique for producing levulinic acid ester and levulinic acid by solvolysis of lignocellulose to produce a polyol compound having properties applicable as a raw material for chemical products, and to effectively utilize lignocellulose. Is what you do.
[0009]
[Means for Solving the Problems]
The present invention provides a method for solvolyzing lignocellulose using a decomposing reagent, treating the decomposed product with water, fractionating the degraded product into a water-soluble part and a water-insoluble part, and levulinic acid ester or levulinic acid from the water-soluble part. And a method for effectively utilizing lignocellulose, comprising separating a polyol compound from a water-insoluble portion.
The present invention also relates to the above-mentioned method for effectively utilizing lignocellulose, which comprises subjecting lignocellulose to solvolysis using an acid and a decomposition reagent.
In the present invention, the decomposition reagent used for the solvolysis is at least one compound selected from cyclic carbonates and alcohols, and the compound is solvolyzed by heating in a temperature range from the melting point to the boiling point of the decomposition reagent. The present invention relates to a method for effectively utilizing the lignocellulose.
The present invention also relates to the above-mentioned method for effectively utilizing lignocellulose, wherein the alcohol is a dihydric alcohol having a boiling point of 100 to 400 ° C.
The present invention also relates to the above-mentioned method for effectively utilizing lignocellulose, wherein the cyclic carbonate is ethylene carbonate.
The present invention also relates to the above-mentioned method for effectively utilizing lignocellulose for separating levulinic acid from a water-soluble portion by using an ion-exchange resin to separate a decomposition reagent and levulinic acid.
The present invention also relates to the above-mentioned method for effectively utilizing lignocellulose, which recovers the decomposition reagent in the water-soluble portion and uses the same again for solvolysis of lignocellulose.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is an explanatory view showing the production steps of the method for effectively utilizing lignocellulose of the present invention.
In the present invention, a solvolysis reaction is used as a method for producing levulinic acid from lignocellulose. Through the solvolysis reaction, sugar components such as cellulose in lignocellulose are promptly converted into levulinic acid esters. In the solvolysis reaction, the used decomposition reagent binds to lignocellulose and decomposes it at the same time, so that the solvolysis product is greatly denatured by the decomposition reagent. This modification is a great advantage for lignin utilization. That is, while the conventional acid hydrolysis treatment highly condenses and produces lignin with low activity, the solvolysis reaction of the present invention introduces a large number of alcoholic hydroxyl groups derived from a decomposition reagent into lignin. Therefore, the production of lignin with a low degree of condensation and high activity is achieved simultaneously with the acquisition of levulinic acid or levulinic acid ester. Introduction of the alcoholic hydroxyl group prevents lignin itself from undergoing high-order acid condensation and becoming a substance having low activity, and a polyol compound useful as a raw material for chemical products can be obtained. Therefore, in the present invention, a lignin-derived residue that is difficult to use as produced by a hydrolysis-based technique is not produced, and lignocellulose can be used effectively. Further, the decomposition reagent obtained in the step of separating and purifying levulinic acid can be recovered and reused in the solvolysis reaction.
[0011]
In the present invention, it is preferable to use at least one compound obtained from cyclic carbonates and alcohols as a decomposition reagent for solvolysis of lignocellulose. Preferably, an acid and a decomposition reagent are used as a mixture, and the mixture is heated preferably at a temperature not lower than the melting point of the decomposition reagent and lower than the boiling point to solvolyze the lignocellulose. At that time, it is desirable that the reaction is continued until the cellulose component in the lignocellulose is sufficiently decomposed into levulinic acid ester. The degree of decomposition of cellulose at this stage needs to be sufficient at least until it is decomposed into water-soluble glycosides. When a cyclic carbonate is used as a decomposition reagent, decomposition of cellulose and generation of levulinic acid ester are promoted. Levulinic acid can be released from the produced levulinic acid ester, but can also be obtained as a chemical raw material in the form of levulinic acid ester. During the solvolysis reaction, a part of the cyclic carbonate is decarbonated and decomposed to an alcohol-based substance.
[0012]
In the present invention, after the solvolysate obtained by the solvolysis treatment is treated with water, it is fractionated into a water-soluble part and a water-insoluble part.
[0013]
The lignin component is mainly fractionated in the water-insoluble portion. In addition, a decomposed product derived from a sugar that has reacted with a self-condensation or decomposition reagent via a furan skeleton is also fractionated into a water-insoluble portion. The water-insoluble portion has a large number of active hydroxyl groups derived from the decomposition reagent, and a polyol compound which can be applied to the production of a resin using the active hydroxyl group as a reaction point is obtained. The water-insoluble portion has the property of being soluble in general-purpose organic solvents such as methanol, ethanol, dimethyl sulfoxide, N, N-dimethylformamide, and 1,4-dioxane. Since the acid component added as a catalyst flows out as a water-soluble portion, a neutralization treatment is not required when resinification is performed using a polyol compound as a raw material.
[0014]
The water-soluble portion contains a levulinic acid ester, and when heated at a temperature not higher than the boiling point of water, levulinic acid is released from the levulinic acid ester. Since the water-soluble portion contains the acid added during the solvolysis treatment, it is not necessary to newly add an acid catalyst. The levulinic acid ester generated by the solvolysis treatment is a compound in which a decomposing reagent and levulinic acid are ester-bonded, and it is possible to release levulinic acid by decomposing this ester bond in water. This process can be omitted when levulinic acid ester is obtained as the target substance. The aqueous solution after liberation of levulinic acid is extracted using a water-insoluble organic solvent such as ether or chloroform. At this time, levulinic acid and a part of the decomposition reagent are fractionated in the organic layer. On the other hand, most of the decomposition reagent used for the solvolysis and the acid used as the catalyst are fractionated in the aqueous layer. These can be recovered and used again for solvolysis of lignocellulose.
When water is added to the organic layer containing levulinic acid and the organic solvent is removed under reduced pressure, an aqueous solution containing levulinic acid and a trace amount of a decomposition reagent is obtained.
[0015]
The aqueous solution containing levulinic acid and a trace amount of a decomposition reagent is treated using an ion exchange resin, and the decomposition reagent is separated and recovered, and at the same time, levulinic acid is purified. As the ion exchange resin, a basic anion exchange resin is used. The purification steps are performed in the following order. First, an aqueous solution containing levulinic acid and a trace amount of a decomposition reagent is brought into contact with an anion exchange resin to adsorb levulinic acid. Subsequently, the resin is washed with distilled water to completely wash away the decomposition reagent. The decomposed reagent that has been washed away can be collected and used again for solvolysis of lignocellulose. Next, levulinic acid is released from the resin using an aqueous acid such as 1N hydrochloric acid, and eluted as an aqueous acid. At this time, an alkaline aqueous solution such as a sodium hydroxide aqueous solution can be used instead of the acid aqueous solution. Levulinic acid is obtained by distilling the eluted aqueous solution or extracted from the aqueous solution using an organic solvent such as ethyl acetate.
[0016]
The lignocellulose as a starting material of the present invention is not limited, but wood flour, sawdust, wood chips, bark, woody substances such as waste paper, rice straws, agricultural substances such as bagasse, sugars, Plant-based substances such as cereals and starch are used.
[0017]
Decomposition reagents used in the solvolysis of the present invention include cyclic carbonates such as ethylene carbonate and propylene carbonate, and alcohols such as butyl alcohol and aliphatic and aromatic monohydric alcohols such as benzyl alcohol. Aliphatic and aromatic dihydric alcohols such as ethylene glycol, polyethylene glycol, 1,3-butanediol and 1,4-butanediol, aliphatic and aromatic trihydric alcohols such as glycerin, and pentaerythritol And other tetravalent alcohols. The above decomposition reagents can be used alone or as a mixture.
As the cyclic carbonate, ethylene carbonate is preferably used, and as the alcohol, a dihydric alcohol having a boiling point of preferably 100 to 400 ° C., for example, ethylene glycol, polyethylene glycol or the like is used.
The decomposition reagent is preferably used in an amount of 300 to 3,000 parts by weight based on 100 parts by weight of lignocellulose.
[0018]
Examples of the acid used as a catalyst in the solvolysis of the present invention include mineral acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; Bronsted acids such as organic acids such as formic acid, acetic acid, and p-toluenesulfonic acid; Examples thereof include Lewis acids such as boron, aluminum chloride, and stannic chloride, and ethers, alcohols, and phenol complexes thereof. The use ratio is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the decomposition reagent.
[0019]
As the reaction apparatus used for the solvolysis of the present invention, an acid-resistant normal-pressure reaction vessel can be used. It is desirable that a stirrer is provided to make the solvolysis reaction uniform. The solvolysis is preferably performed at 120 to 180 ° C., preferably 10 to 180 minutes, until the lignocellulose is decomposed into levulinic acid ester. The reaction conditions depend on the composition of the decomposition reagent. When the amount of the cyclic carbonate used is large, the formation of the levulinic acid ester is promoted, so that the reaction conditions can be moderate.
[0020]
After the solvolysis, the polyol compound fractionated as a water-insoluble portion can be used as a raw material for chemical products after drying. Since a large number of alcoholic hydroxyl groups are introduced into the water-insoluble portion, it has reactivity with isocyanates and epoxies, and the reaction product with them has the property of becoming a polymer resin substance by catalyst or heating. And can be used as a raw material for molded articles, adhesives and the like. The hydroxyl value of this polyol compound is preferably 100 to 1,000 KOH mg / g, and the weight average molecular weight is preferably 1,000 to 100,000.
[0021]
The release treatment of levulinic acid in the levulinic acid releasing step can use an acid-resistant reaction vessel for normal pressure, and the reaction vessel used for solvolysis may be used as it is. The release treatment of levulinic acid is performed within the temperature range from the melting point to the boiling point of water, but it is desirable to boil the water by attaching a cooling device to the upper part of the reaction vessel. The release treatment of levulinic acid is carried out at a temperature of preferably 80 to 100 ° C., preferably for 10 to 120 minutes. The aqueous solution after liberation of levulinic acid is extracted using an organic solvent. A low-polarity water-insoluble solvent such as diethyl ether or chloroform can be used as the organic solvent for extraction.
[0022]
The ion exchange resin used in the separation / purification step is not particularly limited as long as it is a basic anion exchange resin, and examples thereof include the following products. Anion exchange resins such as IRA-400, IRA-410, IRA-96SB of Amberlite (manufactured by Rohm and Haas). Anion exchange resin such as SAION, PA series, HPA series, WA series of Diaion (manufactured by Mitsubishi Chemical Corporation). An anion exchange resin series of Duolite (manufactured by Rohm and Haas) and the like are used.
[0023]
The method for introducing the aqueous solution containing the released levulinic acid and a trace amount of the decomposition reagent into the ion exchange resin is not particularly limited, but the aqueous solution containing the levulinic acid and the trace amount of the decomposition reagent is passed through a column filled with the ion exchange resin. And a method of immersing the ion exchange resin in an aqueous solution containing levulinic acid and a trace amount of a decomposition reagent. By introducing an aqueous solution containing levulinic acid and a trace amount of a decomposition reagent into the ion exchange resin, free levulinic acid is adsorbed on the ion exchange resin. In order to prevent contamination of the ion exchange resin, an aqueous solution containing levulinic acid and a trace amount of a decomposition reagent can be treated with activated carbon before being introduced into the ion exchange resin to remove components having low polarity.
[0024]
The ion exchange resin after the adsorption is washed with distilled water. The decomposition reagent used for solvolysis flows out into the washing solution, and after concentration, can be used again as a solvolysis reagent for lignocellulose. Next, the ion-exchange resin is washed with an acid solution such as 0.1-5 N hydrochloric acid to release levulinic acid adsorbed on the ion-exchange resin. The acid used at this time is not particularly limited, but a mineral acid solution such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid is used.
[0025]
As an organic solvent used for extracting levulinic acid released from the acid solution obtained by washing the ion exchange resin, ethyl acetate, chloroform, diethyl ether and the like are used. The acid component remaining in the aqueous layer can be recovered and reused when liberating levulinic acid from the ion exchange resin. The ion-exchange resin can be regenerated by bringing it into contact with a 0.1 to 1 N sodium hydroxide solution and used again in the levulinic acid purification step.
[0026]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples of the present invention, but the present invention is not limited to these Examples.
[0027]
Example 1
As a solvolysis reactor, a 300 ml three-necked flask equipped with a stirrer, a condenser, and a thermometer was used. As a solvolysis reagent, 40 g of ethylene carbonate and 10 g of ethylene glycol were mixed and filled in a flask. 1.5 g of concentrated sulfuric acid was introduced into the flask as a catalyst, and the mixture was stirred and mixed with the decomposition reagent. Next, 10 g of the dried cedar wood flour was weighed out, quantitatively inserted into the flask, and mixed well by stirring. The solvolysis reaction was performed by immersing the flask in an oil bath and stirring at 140 ° C. for 30 minutes. After the reaction, the reaction was stopped by immersing the flask in water.
The product in the flask was washed out with distilled water, quantitatively transferred into a funnel equipped with a glass filter (manufactured by Advantech, GA100), and the water-insoluble portion was filtered. The water-insoluble portion was weighed after drying to obtain 4.87 g of a water-insoluble portion. The water-insoluble portion is a polyol compound having a hydroxyl value of 310 KOH mg / g and a weight average molecular weight of 21,000, and can be used as a raw material for synthesizing a resin such as a polyurethane resin.
[0028]
The water-soluble part was transferred to a 500 ml Erlenmeyer flask equipped with a cooling tube and heated with stirring at 100 ° C. for 90 minutes using a hot plate with a magnetic stirrer. Next, the operation of transferring the aqueous solution in the Erlenmeyer flask to a separating funnel and adding 300 ml of chloroform to separate an aqueous layer and an organic layer was repeated several times. Most of the decomposition reagent and the acid were fractionated in the aqueous layer, and were concentrated and stored for use in solvolysis again. After adding 200 ml of distilled water to the chloroform layer, chloroform was recovered with a rotary evaporator to obtain an aqueous solution containing free levulinic acid.
An anion exchange resin Amberlite IRA96SBAG manufactured by Rohm and Haas was used as the ion exchange resin. The ion exchange resin was reversely regenerated with 1N hydrochloric acid and then regenerated to the OH form with a 1N aqueous sodium hydroxide solution. This operation is performed only when the resin is used for the first time. After packing the ion exchange resin in the OH form into a cylindrical column, the above aqueous solution containing free levulinic acid was introduced into the column and allowed to stand for 2 hours. Then, after washing the column with distilled water, the washing solution was concentrated, and the decomposition reagent was recovered. This was also mixed with the above aqueous layer and stored for use in solvolysis again. Next, 1N hydrochloric acid was introduced into the column to release levulinic acid adsorbed on the ion exchange resin. The column was regenerated by treatment with 1N sodium hydroxide solution and prepared for the next use. The eluted hydrochloric acid solution of levulinic acid was transferred to a separating funnel, and ethyl acetate was added thereto to separate into an aqueous layer and an ethyl acetate layer. The aqueous layer was recovered and converted into 1 N hydrochloric acid to be used again as the solvent for the ion exchange resin. The ethyl acetate layer was distilled under reduced pressure after removing ethyl acetate to obtain 1.09 g of levulinic acid.
[0029]
Example 2
Using the decomposition reagent recovered in Example 1, solvolysis of cedar wood powder was performed again. In the same three-necked flask as in Example 1, 30 g of the recovered decomposition reagent obtained in Example 1 and 20 g of ethylene carbonate were used as a mixed decomposition reagent, and 0.6 g of concentrated sulfuric acid was further added and stirred. Mixed. Next, 10 g of the dried cedar wood flour was weighed out, quantitatively inserted into the flask, and mixed well by stirring. The solvolysis reaction was performed at 140 ° C. for 30 minutes. The solvolysate was fractionated in the same manner as in Example 1 to obtain 5.31 g of a water-insoluble portion applicable as a resin raw material and 1.31 g of levulinic acid.
[0030]
Since the recovered decomposition reagent contains a saccharide component and a water-soluble lignin component as a precursor that decomposes into levulinic acid, higher yields were obtained when the recovered decomposition reagent was used.
[0031]
Example 3
In the process of Example 1, solvolysis was carried out by a similar method using used newspaper paper cut into strips instead of cedar wood flour. The solvolysate was fractionated in the same manner as in Example 1 to obtain 4.68 g of a water-insoluble portion and 1.04 g of levulinic acid.
[0032]
Example 4
In the process of Example 1, solvolysis was carried out in the same manner using cellulose powder (alpha-cellulose, manufactured by Sigma) instead of cedar wood powder. The solvolysate was fractionated in the same manner as in Example 1 to obtain 2.36 g of a water-insoluble portion and 1.84 g of levulinic acid.
[0033]
Example 5
In the process of Example 1, a mixture of 40 g of polyethylene glycol having an average molecular weight of 400 and 10 g of ethylene glycol was used as a decomposition reagent, and cedar wood powder was subjected to solvolysis in the same manner. The solvolysis reaction temperature was 160 ° C., and the reaction time was 60 minutes. The solvolysate was fractionated in the same manner as in Example 1 to obtain 4.53 g of a water-insoluble portion and 1.01 g of levulinic acid.
[0034]
Example 6
Using the decomposition reagent recovered in Example 5, solvolysis of cedar wood powder was performed again. In the same three-necked flask as in Example 1, a mixture of 30 g of the recovered decomposition reagent obtained in Example 5, 16 g of polyethylene glycol having an average molecular weight of 400, and 4 g of ethylene glycol was used as a decomposition reagent. Further, 0.6 g of concentrated sulfuric acid was added and mixed with stirring. Next, 10 g of the dried cedar wood flour was weighed out, quantitatively inserted into the flask, and mixed well by stirring. The solvolysis reaction was performed at 160 ° C. for 60 minutes. The solvolysate was fractionated by the same treatment as in Example 1 to obtain 5.26 g of a water-insoluble portion applicable as a resin raw material and 1.22 g of levulinic acid.
[0035]
【The invention's effect】
In the present invention, levulinic acid or a levulinic acid ester, which is a useful chemical raw material, is produced by solvolysis of lignocellulose, and at the same time, lignin-derived products that were difficult to use in existing methods are also highly active polyol compounds useful as resin raw materials Lignocellulose can be used effectively. In addition, the decomposition reagent used for solvolysis can be recovered and used, which is economically advantageous.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a production process of a method for effectively utilizing lignocellulose.

Claims (7)

The lignocellulose is subjected to solvolysis using a decomposing reagent, and the decomposed product is treated with water. A method for effectively utilizing lignocellulose, comprising separating a polyol compound from a water-insoluble portion. The method for effectively utilizing lignocellulose according to claim 1, wherein the lignocellulose is subjected to solvolysis using an acid and a decomposition reagent. 3. The decomposition reagent used for solvolysis is at least one compound selected from cyclic carbonates and alcohols, and is subjected to solvolysis by heating in a temperature range from the melting point to the boiling point of the decomposition reagent. Effective use of lignocellulose. The method for effectively utilizing lignocellulose according to any one of claims 1 to 3, wherein the alcohol is a dihydric alcohol having a boiling point of 100 to 400 ° C. The method for effectively utilizing lignocellulose according to any one of claims 1 to 3, wherein the cyclic carbonate is ethylene carbonate. The method for effectively using lignocellulose according to any one of claims 1 to 5, wherein, when levulinic acid is separated from the water-soluble portion, the decomposition reagent and levulinic acid are separated using an ion exchange resin. The method for effectively utilizing lignocellulose according to any one of claims 1 to 6, wherein the decomposition reagent in the water-soluble portion is recovered and used again for solvolysis of lignocellulose.

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