JP2016079169A - Producing method of sugar alcohol, and sugar solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method producing sugar alcohol efficiently by using sugar solution provided with a simple and easy technique without high purifying cost from non-edible biomass, and to provide the sugar solution used as raw material.SOLUTION: A producing method of sugar alcohol includes: a saccharization step gaining saccharized liquid by saccharifying non-edible biomass; a removal step removing reaction inhibitors in the saccharized liquid and gaining processed saccharized liquid; and a hydrogenation step making the processed saccharized liquid contact with a metal catalyst in hydrogen atmosphere. Sugar alcohol is produced from sugar in the hydrogenation step.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a sugar alcohol using non-edible biomass.

  Sugar alcohol is a useful compound that is used not only as a food additive, sweetener, heat storage material, etc., but also as a monomer constituting a functional polymer, or as a raw material that is converted into another monomer. Commonly used sugar alcohols include sorbitol and xylitol, which are known to be obtained by hydrogenating glucose and xylose, respectively. For example, sorbitol usually uses glucose obtained from starch, which is edible biomass, as a raw material (Non-Patent Document 1).

  However, when these edible biomass-derived saccharides are used as raw materials for the above-described process, there is a concern about competition with food, and therefore active use of non-edible biomass is required.

  As a method for obtaining a saccharide as a raw material for sugar alcohol from non-edible biomass, a method is known in which cellulose or hemicellulose contained in non-edible biomass is hydrolyzed to a monosaccharide such as hexose such as glucose or pentose such as xylose. . Patent Document 1 discloses that cellulose or hemicellulose in biomass is hydrolyzed using concentrated sulfuric acid to generate a liquid containing sugars such as hexose and pentose.

  On the other hand, Patent Documents 2 and 3 disclose a method for hydrolyzing and hydrogenating cellulose in the presence of a metal catalyst as a method for obtaining a sugar alcohol from sugar. However, these are reactions starting from commercially available powdered cellulose that has undergone purification in multiple stages such as solvent washing, chlorination, and aqueous sodium hydroxide washing.

Japanese National Patent Publication No. 11-506934 JP 2012-41335 A JP 2012-41336 A

Muroi Takagi, "Industrial Precious Metal Catalysts" Koshobo, May 26, 2003, p. 283

  In Patent Documents 2 and 3, high-purity cellulose such as α-cellulose that has undergone multi-stage purification is used as a raw material, but purification is performed in comparison with the case of using non-edible biomass that can be used industrially such as bagasse. Cost is high and not practical. Therefore, there is a demand for a method for producing a sugar alcohol using a sugar solution obtained from non-edible biomass by a simple method as a raw material.

According to the study of the present inventors, sugar alcohol is produced using a saccharified solution obtained by saccharification of non-edible biomass using a hydrogenation catalyst as described in Patent Documents 2 and 3 above. It was found that when done, the activity of the catalyst was reduced and the target sugar alcohol yield was significantly reduced. In the process of hydrolyzing the non-edible biomass disclosed in Patent Document 1 to obtain a liquid containing monosaccharides, it is considered that various impurities such as a sugar decomposition product are contained. Problems may occur in the chemical conversion process.

  The problem of the present invention has been found by the above knowledge, and a method for efficiently producing a sugar alcohol using a sugar solution obtained by a simple technique without incurring purification costs from non-edible biomass, Another object is to provide a sugar solution used as a raw material.

In response to the above problem, the present inventor performs a treatment for removing reaction inhibitors in a saccharified solution obtained by saccharifying non-edible biomass, and performs a hydrogenation reaction using the obtained saccharide solution as a raw material. The present inventors have found that sugar alcohol can be efficiently produced, and have completed the present invention.
That is, the gist of the present invention is as follows.

[1] A saccharification step of saccharifying non-edible biomass to obtain a saccharified solution;
A removal step of obtaining a treated saccharified solution by performing a treatment for removing the reaction inhibitor in the saccharified solution;
A hydrogenation reaction step of bringing the treated saccharified solution into contact with a metal catalyst under a hydrogen atmosphere,
A method for producing a sugar alcohol, comprising producing a sugar alcohol from sugar in the hydrogenation reaction step.
[2] The method for producing a sugar alcohol according to [1], wherein the saccharified solution contains glucose and / or xylose.
[3] The method for producing a sugar alcohol according to [1] or [2], wherein in the removing step, the saccharified solution is treated with a carbon-based porous material and / or a metal oxide.
[4] The treated saccharified solution obtained after the removing step contains sulfur (S) atoms contained in the sulfur-containing organic compound in a range of more than 0 ppm and not more than 10 ppm, according to any one of [1] to [3]. A method for producing a sugar alcohol.
[5] The method for producing a sugar alcohol according to any one of [1] to [4], wherein the treated saccharified solution obtained after the removing step contains formic acid in a range of more than 0 ppm and 1500 ppm or less.
[6] The method for producing a sugar alcohol according to any one of [1] to [5], wherein the treated saccharified solution obtained after the removing step contains nitrogen (N) atoms in a range of more than 0 ppm and 350 ppm or less. [7] The method for producing a sugar alcohol according to any one of [1] to [6], wherein the treated saccharified solution obtained after the removing step contains chlorine (Cl) atoms in a range of 5 ppm to 1000 ppm.
[8] The metal catalyst according to any one of [1] to [7], wherein the metal catalyst includes at least one metal element selected from Group 8, Group 9, Group 10, and Group 11 of the periodic table. A method for producing a sugar alcohol.
[9] The method for producing a sugar alcohol according to any one of [1] to [8], wherein the metal catalyst contains ruthenium.
[10] The method for producing a sugar alcohol according to any one of [1] to [9], wherein the sugar alcohol is sorbitol and / or xylitol.
[11] A sugar solution comprising chlorine (Cl) atoms in a range of 5 ppm or more and 1000 ppm or less and containing sulfur (S) atoms contained in the sulfur-containing organic compound in a range of more than 0 ppm and 10 ppm or less.
[12] A sugar solution containing chlorine (Cl) atoms in a range of 5 ppm to 1000 ppm and formic acid in a range of more than 0 ppm and 1500 ppm or less.
[13] A sugar solution comprising chlorine (Cl) atoms in a range of 5 ppm or more and 1000 ppm or less, and nitrogen (N) atoms in a range of more than 0 ppm and 350 ppm or less.
[14] A sugar solution containing a chlorine (Cl) atom and at least one of a sulfur (S) atom, formic acid, and a nitrogen (N) atom contained in the sulfur-containing organic compound,
The chlorine (Cl) atom is 5 ppm or more and 1000 ppm or less, the sulfur (S) atom contained in the sulfur-containing organic compound is more than 0 ppm, 10 ppm or less, the formic acid is more than 0 ppm, 1500 ppm or less, and the nitrogen (N) atom is 0 ppm. A sugar solution characterized by containing in a range of more than 350 ppm.

According to the method for producing a sugar alcohol of the present invention, a sugar alcohol can be efficiently produced at low cost by using a sugar solution obtained from non-edible biomass by a simple method as a raw material.
Moreover, the sugar liquid of this invention can manufacture sugar alcohol with a high yield, without reducing the activity of a catalyst by using it as the raw material of hydrogenation reaction.
From these facts, it is possible to design a process with excellent production efficiency in the production of sugar alcohol.

  Hereinafter, the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention.

<Method for producing sugar alcohol>
The production method of the present invention includes a saccharification step for saccharifying non-edible biomass to obtain a saccharified solution, a removing step for obtaining a treated saccharified solution by removing a reaction inhibitor in the saccharified solution, and the treated saccharification A hydrogenation reaction step in which the liquid is brought into contact with a metal catalyst to form a hydrogen atmosphere.
Hereinafter, it will be described in detail for each process.

(Saccharification process)
The saccharification step performed by the production method of the present invention is not limited as long as the polysaccharide contained in the non-edible biomass can be decomposed (saccharified) into its constituent unit saccharide to obtain a saccharified solution containing oligosaccharide or monosaccharide. The saccharification method is not particularly limited, and a known method can be used.
For example, cellulose or hemicellulose is hydrolyzed to a monosaccharide such as hexose typified by glucose or pentose typified by xylose using concentrated sulfuric acid, or after pretreatment to improve the reactivity of polysaccharides, Examples thereof include a hydrolysis method using an enzyme reaction, subcritical water, supercritical water, or the like.

(Saccharified solution)
A saccharification liquid is a liquid containing the monosaccharide produced | generated by saccharifying at least one part of the polysaccharide contained in non-edible biomass. The saccharified solution may contain saccharides other than monosaccharides, and may contain polysaccharides, oligosaccharides, and the like.
Usually, organic acids such as formic acid, lactic acid, acetic acid, butyric acid, pyruvic acid, gluconic acid and amino acids; aldehydes such as furfural, hydroxymethylfurfural, formaldehyde and hydroxyaldehyde; inorganic acid ions such as sulfate ion and nitrate ion A halogen element such as chlorine and fluorine; an alkali metal element such as potassium and sodium; an alkaline earth metal element such as magnesium and calcium; a silicon element; and compounds other than sugars derived from non-edible biomass such as lignin. Here, the form in which the above-described elements are present in the saccharified solution is not particularly limited, and may be, for example, a part of the elements constituting the compounds or ions in the saccharified solution.

(Sugar)
The saccharide contained in the saccharified solution used in the present invention is not particularly limited as long as it contains a monosaccharide derived from non-edible biomass, and so-called saccharides in general can be used.
Specifically, monosaccharides having 3 carbon atoms (triose) such as glyceraldehyde; monosaccharides having 4 carbon atoms (tetrose) such as erythrose, threose, erythrulose; ribose, lyxose, xylose, arabinose, deoxyribose, xylulose, ribulose Monosaccharides having 5 carbon atoms (pentose) such as allose, talose, growth, glucose, altrose, mannose, galactose, idose, fucose, fucose, rhamnose, psicose, fructose, sorbose, tagatose, etc. (Hexose); monosaccharide having 7 carbon atoms (heptose) such as sedoheptulose. Among these monosaccharides, hexose and pentose are preferable. This is because they are abundant because they are constituents of nature and plants, and it is easy to obtain raw materials.
The saccharified solution used in the present invention may contain one kind of the above monosaccharides alone or may contain two or more kinds.

  As said hexose, glucose, fructose, mannose, and galactose are preferable, and glucose is more preferable. As pentose, xylose and arabinose are preferable, and xylose is more preferable. Since glucose and xylose are the main constituents of nature and plants, it is easy to obtain raw materials. Therefore, it is particularly preferable that the saccharified solution contains glucose and / or xylose.

  The saccharified solution may contain a saccharide that has not been hydrolyzed to a monosaccharide in the saccharification step. For example, disaccharides such as sucrose, lactose, maltose, trehanose, turanose, cellobiose; raffinose, melezitose, maltotriose Trisaccharides such as fructooligosaccharide, galactooligosaccharide, manna-oligosaccharide and the like; polysaccharides such as starch, dextrin, cellulose, hemicellulose, glucan and pentosan may be included.

(Non-edible biomass)
The non-edible biomass is not particularly limited as long as it contains a polysaccharide containing the above-mentioned saccharide as a constituent component, and examples thereof include plants containing cellulose and hemicellulose.
Specific examples of non-edible biomass include bagasse, switchgrass, napiergrass, Eliansus, corn stover, rice straw, straw, rice bran, vegetable oil residue, sasa, bamboo, pulp, waste paper, food waste, marine products Examples include residues and livestock waste. Moreover, the molasses remaining after recovering sugar from the molasses generated in the sugar production process can also be used as non-edible biomass.
Unlike the edible biomass, the non-edible biomass mentioned above does not compete with edible use, and is usually discarded or incinerated, so that stable supply and effective use of resources can be achieved. Is preferable.

  Among these, herbaceous biomass is preferable from the viewpoint of easy aggregation of raw materials. Among them, rice plants such as rice, wheat, corn, sorghum, sugar cane, switchgrass, bamboo, and sugar, and beans with nitrogen-fixing ability. Biomass derived from a family plant is preferred. Particularly preferred are sugarcane-derived bagasse, corn-derived corn stover, and switchgrass, which are concentrated in large quantities.

  The total concentration of saccharides contained in the saccharified solution used in the present invention (hereinafter referred to as “sugar concentration”) varies greatly depending on the origin of the saccharified solution, the type of sugar contained, and the like, and is not particularly limited, but usually 3 masses. % Or more, preferably 5% by mass or more, usually 60% by mass or less, preferably 50% by mass or less. It is preferable to use a saccharified solution having a saccharide concentration equal to or higher than the lower limit because the productivity of the hydrogenation reaction step is improved, and it is preferable to use a saccharified solution lower than the upper limit because the saccharified solution can be easily handled.

(Removal process)
The removal step performed in the present invention is a step of obtaining a treated saccharified solution by performing a treatment for removing reaction inhibitors in the saccharified solution obtained in the saccharification step.
The saccharified solution obtained by saccharifying non-edible biomass in the above saccharification step contains various compounds other than saccharides derived from non-edible biomass. The inventors have found that some of these compounds inhibit the hydrogenation reaction and reduce the sugar alcohol production efficiency. Therefore, a processed saccharified solution in which a compound that inhibits the hydrogenation reaction in the saccharified solution is selectively removed by carrying out the removing step without going through a process of obtaining high-purity saccharides through multi-stage purification. As a result, the inventors succeeded in obtaining a sugar solution as a raw material capable of efficiently producing a sugar alcohol.

(Reaction inhibitor)
The reaction inhibitor refers to a substance that inhibits the hydrogenation reaction in the hydrogenation reaction step that follows the removal step. As a result of investigations by the inventors, these reaction inhibitors reduce the catalytic activity by poisoning the metal catalyst used in the hydrogenation reaction or covering the surface of the catalyst. It has been found that the yield is reduced.

  In the production method of the present invention, what is contained in the saccharified solution and becomes a reaction inhibitor is, for example, a sulfur-containing organic compound that is thought to be derived from thiol or sulfide contained in non-edible biomass; nitrogen derived from amino acids (N ) Compounds containing atoms; organic acids such as formic acid, lactic acid, butyric acid and acetic acid are conceivable. Furthermore, the organic polymer derived from saccharide may physically cover the catalyst surface and reduce the activity of the catalyst.

  Among the reaction inhibitory substances, particularly when a sulfur-containing organic compound is present in the saccharified solution, the sulfur (S) atom is coordinated to the metal of the catalyst, and the catalytic activity is significantly reduced. Examples of the sulfur-containing organic compound include organic substances having a thiol group having a divalent S atom, a sulfide group, and a sulfoxide group having a tetravalent S atom. As sulfur-containing organic compounds contained in saccharified liquid derived from non-edible biomass, there are many organic substances mainly having thiol groups and sulfide groups having divalent S atoms. For example, cysteine and methionine are amino acids. Can be mentioned. Even if these amino acids themselves are not present, the hydrogenation reaction is also inhibited by the presence of organic substances derived from cysteine and methionine. In particular, sulfur-containing organic compounds having divalent and tetravalent S atoms are considered to be reaction inhibitory substances that easily coordinate to the catalyst metal because the S atoms have unpaired electrons and cause poisoning of the catalyst. .

On the other hand, even if a hexavalent S atom contained in an inorganic acid such as sulfuric acid is present in the saccharified solution, the hydrogenation reaction is not affected because it has no unpaired electrons.
Regarding the amount of S atoms contained in the sulfur-containing organic compound, the amount of S atoms measured by water-soluble ion chromatography analysis from the amount of all S atoms measured by combustion absorption ion chromatography analysis (the amount of hexavalent S atoms) It is calculated by subtracting
Here, the form in which the divalent or tetravalent S atom contained in the sulfur-containing organic compound is present in the saccharified solution is not particularly limited, and usually constitutes a compound present in the saccharified solution. Present as part of the element.

  The amount of S atom contained in the sulfur-containing organic compound in the treated saccharified liquid obtained by carrying out the removal step is 1000 ppm or less, preferably 100 ppm or less, more preferably 10 ppm or less, more preferably as S atoms with respect to the weight of the saccharified liquid. It is desirable that the content be 5 ppm or less, most preferably 1 ppm or less. Although it is considered preferable that the content of divalent or tetravalent S atoms contained in the sulfur-containing organic compound is small, it is large in carrying out the hydrogenation reaction step even if it is contained within the above range. It doesn't matter. When a saccharified solution containing no divalent or tetravalent S atom is used in the hydrogenation reaction step, isomerization of the sugar proceeds, hydrogenolysis proceeds because the reactivity of the catalyst is too high, etc. A compound other than the target product may be produced, and the selectivity of the reaction tends to decrease.

Nitrogen (N) atoms contained in the saccharified solution may also coordinate with the metal of the catalyst, reducing the catalytic activity. N atoms in the saccharified solution are mainly brought from various amino acids and their polymers.
The amount of N atom in the treated saccharified solution obtained by carrying out the removing step is 2000 ppm or less, preferably 1000 ppm or less, more preferably 400 ppm or less, more preferably 350 ppm or less, more preferably as N atoms based on the weight of the saccharified solution. It is desirable to set it to 100 ppm or less, most preferably 10 ppm or less. It is particularly preferable that no N atom is contained, but if it is within the above range, even if it is contained, it does not cause a big problem in carrying out the hydrogenation reaction step.
Here, the form in which the N atom is present in the saccharified solution is not particularly limited, and is usually present as a part of an element constituting a compound or ion present in the saccharified solution. Hereinafter, a compound containing an N atom may be referred to as an N atom-containing component.

The organic acid contained in the saccharified solution can inhibit the hydrogenation reaction. Organic acids are produced when saccharifying non-edible biomass, such as formic acid, lactic acid, acetic acid, butyric acid, pyruvic acid, and gluconic acid. In particular, when formic acid is present, it acts on the metal catalyst and reduces the catalytic activity.
Therefore, the amount of formic acid in the treated saccharified solution obtained by carrying out the removing step is 30000 ppm or less, preferably 3000 ppm or less, more preferably 1500 ppm or less, more preferably 1000 ppm or less, and even more preferably 500 ppm with respect to the saccharified solution mass. Most preferably, the content is 100 ppm or less. It is particularly preferable that formic acid is not contained at all, but if it is within the above range, even if it is contained, it does not cause a big problem in carrying out the hydrogenation reaction step.

(Processed saccharified solution)
The treated saccharified solution has been subjected to a treatment for removing the reaction inhibitor and is a sugar solution from which at least a part of the reaction inhibitor has been removed. The content of the reaction inhibitor is as described above. The treated saccharified solution is useful as a saccharide solution that is a raw material for producing a sugar alcohol with high production efficiency.
It mainly contains saccharides such as monosaccharides and disaccharides, and may contain other compounds than sugars derived from non-edible biomass. For example, halogen elements such as chlorine and fluorine; alkali metal elements such as potassium and sodium; alkaline earth metal elements such as magnesium and calcium; silicon elements; sulfate ions, nitrate ions, and the like may be included. Here, the form in which the above-described elements are present in the treated saccharified solution is not particularly limited. For example, even if a part of the elements constituting the compound or ion in the treated saccharified solution is used. Good.

A compound containing a chlorine (Cl) atom is usually included in a saccharified liquid derived from non-edible biomass and not removed by the removal treatment. According to the inventor's study, even a saccharified solution containing Cl atoms did not have an inhibitory effect on the hydrogenation reaction, and therefore Cl atoms may be included in the treated saccharified solution. Cl atoms are contained in a saccharified solution obtained by saccharification of non-edible biomass. In particular, the efficiency of sugar alcohol production can be improved by combining a specific reaction inhibitor removal process with the saccharified solution containing Cl atoms. There is a tendency to improve.
The amount of Cl atom in the treated saccharified solution obtained by carrying out the removing step may be 5 ppm or more, and in some cases 50 ppm or more, preferably 1000 ppm or less, more preferably 500 ppm or less as Cl atoms with respect to the weight of the saccharified solution. Is desirable.
Here, the form in which the Cl atom is present in the saccharified solution is not particularly limited. The Cl atom is present as a part of an element constituting a compound or ion present in the saccharified solution, or alone, Cl ions. May exist as

(Removal processing method)
In the removal step of the production method of the present invention, as a treatment method for removing the reaction inhibitor, a method of removing it by adsorbing to an adsorbent such as a carbon-based porous material or metal oxide (hereinafter referred to as adsorption treatment). A) cation exchange resin, a method of removing by contacting with an anion exchange resin, a method of removing from a mother liquor when obtaining glucose or xylose by crystallization from a sugar solution, a method of removing by reacting with a reducing agent, etc. There is a method of removing physical properties by distillation. In particular, the method of adsorbing with an adsorbent is preferable because the operation is simple without greatly changing the pH sugar concentration of the saccharified solution. More preferably, the saccharified solution is treated using a carbon-based porous material and / or a metal oxide.

(Adsorbent)
As the adsorbent that can be used for the aforementioned adsorption treatment, any adsorbent that can adsorb reaction-inhibiting substances may be used. For example, carbon-based porous materials such as activated carbon, carbon black, silicon carbide, alumina, silica, zirconia, niobia, titania. , Metal oxides such as ceria, diatomaceous earth, zeolite, and zinc oxide. In particular, activated carbon, alumina, and zinc oxide are preferable because of their high adsorptive capacity for sulfur-containing organic compounds.

  The same as the hydrogenation catalyst in which the above carbon-based porous material or metal oxide carries at least one metal component selected from Group 8, Group 9, Group 10 and Group 11 of the periodic table. May be used. The component of the supported metal catalyst is preferably palladium, ruthenium, nickel, copper, palladium, gold, platinum, iron, osmium, cobalt, rhodium, iridium, etc., and a metal supporting ruthenium or palladium element from the viewpoint of hydrogenation activity A catalyst is particularly preferred.

  The above adsorbents may be used alone or in combination of two or more. When used in combination, two types of adsorbents may be used at the same time, or one type may be used at a time.

  The activated carbon used as the adsorbent is not particularly limited, but for example, peat, lignite, lignite, anthracite, pitch coke and other coal systems, wood, sawdust, charcoal, coconut shell charcoal, palm charcoal and other vegetable systems, Petroleum residues such as petroleum residues, oil carbon, etc., synthetic resins such as phenol resin, furan resin, polyvinyl chloride, polyimide, polyacrylonitrile, polyethylene, polypropylene, etc., and waste systems such as pulp waste liquid and organic waste are used as raw materials. Activated carbon can be used. In addition, activated carbons obtained by activating these various activated carbons by a method such as a gas activation method, a steam activation method, a chemical activation method such as zinc chloride and phosphoric acid, and the like can be used. In particular, activated carbon activated by a chemical activation method such as zinc chloride is preferable because the pore volume of the activated carbon is large and the average pore diameter is large, so that the inhibitor can be easily adsorbed and removed.

  Specific examples of commercially available activated carbon include Carvone Carbon Japan Co., Ltd. Carvone CPG, Calgon CAL, Calgon SGL, Diasoap W, Diahope MS10, Diahope M010, Diahope MS16, Diahope 6MD, Diahope 6MW, Diahope 8ED, Diahope ZGN4 and CENTUR, Nippon Norit GAC, GAC PLUS, GCN PLUS, C GRAN, RO, ROX, DARCO, CN, SX, SX PLUS, SA, PK and W, Kuraray Chemical GW, GWH, GLC, 4GC, KW, PW and PK, Tsurumi Coal HC-30S, GL-30S, 4G-3S, 4GV, PA and PC, Phutamura Chemical P, W, CW, SG, SGP, S, GB, CA and K, Nippon E White birch KL, white birch W2C, white birch WH2C, white birch WH5C, white birch WH5X, white birch XS7100H-3, carborafine, white birch A, white birch C and white birch M manufactured by Viro Chemicals, and Hokuetsu CL-K manufactured by Ajinomoto Fine Techno Co., Ltd. Examples include Hokuetsu HS and Hokuetsu KS.

(Adsorption treatment)
The shape of the adsorbent is not particularly limited, but may be a powder having a diameter of about 1 μm or a granular having a diameter of about several mm. In order to separate the adsorbent and the sugar liquid after the adsorption treatment of the saccharified liquid, the operation is simple, and therefore, when used in an industrial scale operation, a granular form is preferable.
The mode of the adsorption treatment may be a batch type or a continuous type, and a continuous type is preferable from the viewpoint of efficiency.

  The amount of the adsorbent used in the adsorption treatment is not particularly limited as long as the reaction inhibitor contained in the saccharified solution is sufficiently adsorbed, and is appropriately adjusted depending on the amount of the reaction inhibitor contained in the saccharified solution. However, it is usually 0.01% by mass or more, preferably 0.1% by mass or more and 10% by mass or less, preferably 1% by mass or less, based on the saccharified solution. If it is above the lower limit, reaction inhibitors can be removed sufficiently, and if it is below the upper limit, the amount of sugar absorbed by the adsorbent can be suppressed, and the sugar alcohol recovery rate can be kept high. Is preferable.

  The temperature during the treatment in the adsorption treatment is not particularly limited, but is usually 0 ° C. or higher, preferably 10 ° C. or higher, 100 ° C. or lower, preferably 60 ° C. or lower. Usually, the saccharified solution contains water, and if the temperature is lower than the above range, there is a fear of freezing, and if it is higher than the above range, it may boil.

  The treatment time in the adsorption treatment is not particularly limited, but is usually 10 minutes or more, preferably 30 minutes or more, and is usually 6 hours or less, preferably 2 hours or less. Since the porous material is used, if the processing time is short, the saccharified solution may not sufficiently penetrate into the inside. Long processing times are disadvantageous in terms of productivity.

  The separation method of the adsorbent and the treatment liquid in the adsorption treatment is not particularly limited, but usually filtration using filter paper, filter cloth, membrane filter; decantation; centrifugation is used. Separation by filtration is preferred. Any method may be used for filtration, such as a guard column type tower or a centle batch type.

  The adsorbent used in the adsorption process may be subjected to a regeneration process after the adsorption process. As the regeneration treatment, washing treatment with water or an organic solvent; acid treatment with sulfuric acid or nitric acid; reduction treatment with formic acid or alcohol; heat treatment in the presence of nitrogen, oxygen, hydrogen gas, steam, or the like is used. In particular, when the heat treatment is performed on the carbon-based porous material, a temperature range in which the carbonaceous material is not burned off and the attached organic substances are removed is desirable. Specifically, it is 100 ° C. or higher and 600 ° C. or lower, more preferably 200 ° C. or higher and 500 ° C. or lower.

(Hydrogenation reaction process)
The hydrogenation reaction step performed in the production method of the present invention is a step in which the treated saccharified solution is brought into contact with a metal catalyst in a hydrogen atmosphere to reduce sugar in the treated sugar solution to sugar alcohol. If the sugar can be hydrogenated to a sugar alcohol, the reaction procedure is not particularly limited, and a known method can be used. Hereinafter, preferred embodiments will be described.

(Metal catalyst)
The metal component of the metal catalyst used in the hydrogenation reaction step of the production method of the present invention is not particularly limited as long as it can hydrogenate a saccharide to a sugar alcohol, but usually ruthenium, nickel, copper, palladium, gold, platinum Further, metals such as iron, osmium, cobalt, rhodium and iridium can be used. Among them, it is preferable to include at least one metal element selected from Group 8, Group 9, Group 10 and Group 11 of the periodic table as a material that exhibits hydrogenation ability, and particularly has high hydrogenation ability. Therefore, it is preferable to contain at least one metal element selected from Group 8, Group 9 and Group 10 of the periodic table, and ruthenium, rhodium, nickel, palladium and platinum are particularly preferable because of high selectivity. In particular, ruthenium and nickel are more preferable because of their high hydrogenation ability of the carbonyl group.

The metal catalyst used in the hydrogenation reaction step may use one kind of metal or two or more kinds.
When two or more kinds of metals are used, the combination is not particularly limited. Even if each metal has catalytic activity (cocatalyst), it can improve the catalytic activity of one or more metals (cocatalyst). Of these, promoters are preferred.

  Examples of the metal catalyst used in the hydrogenation reaction step include an alloy catalyst and a supported metal catalyst in which a catalytically active species is supported on a support.

  The alloy catalyst is not particularly limited, but an alloy of a metal such as ruthenium, nickel, copper, palladium, gold, or platinum is used. Specific examples include Raney catalysts that are generally known and copper chromium catalysts.

  The supported metal catalyst is not particularly limited, but a supported catalyst in which an active metal species is supported on various supports described later may be used, facilitating separation from the reaction solution, and easy reuse of the catalyst. From the point of view, it is preferable to use a supported catalyst.

The carrier is not particularly limited, and examples thereof include carbon-based carriers such as activated carbon, carbon black, and silicon carbide; metal oxide carriers such as alumina, silica, zirconia, niobia, titania, ceria, diatomaceous earth, and zeolite. Among them, it is preferable to use at least one selected from activated carbon, silica and alumina as a carrier from the viewpoint of reaction activity expression and stabilization of catalyst activity.

  The content of the metal in the metal catalyst used in the hydrogenation reaction step is not particularly limited, but is usually a mass percentage in terms of metal, usually 0.5% by mass or more based on the total mass of the support and the metal, preferably It is 1 mass% or more, and is usually 50 mass% or less, preferably 20 mass% or less, more preferably 10 mass% or less. By setting the metal content within the above range, sufficient catalytic activity can be obtained. In the following description of the catalyst, the value described as mass% represents the metal content relative to the total mass of the catalyst support and metal.

The surface area of the support used for the metal catalyst is not particularly limited, but is usually 1 to 2000 m ² / g.
Preferably, it is 10-1500 m < ² > / g. Use of a material having the lower limit value or more is preferable in that the metal can be supported on the support with a high degree of dispersion, and sufficient catalytic activity is obtained. In addition, it is preferable to use a material having the upper limit value or less because the pores of the carrier can be effectively used. In particular, when activated carbon is used as the carrier, the surface area is more preferably 500 to 1500 m ² / g in order to obtain high productivity.

  The method for producing the metal catalyst used in the hydrogenation reaction step is not particularly limited as long as the active component functions as a catalyst in the metal state in the reduction reaction carried out in the present invention. A compound or the like is used after reduction treatment.

  When using a supported metal catalyst, the manufacturing method is not specifically limited, It can manufacture by combining a general method suitably. Usually, a metal compound as a metal source is supported on a carrier, subjected to treatments such as drying, washing and firing, and then converted into a metal state by reduction treatment.

  The method for supporting the metal compound on the carrier is not particularly limited, and known methods commonly used for the preparation of a supported metal catalyst, such as an impregnation method, an ion exchange method, a spray method, and a coprecipitation method, can be used. By subjecting the carrier on which the metal compound is supported to a reduction treatment, the metal compound supported on the carrier is converted into a metal, whereby a target catalyst is obtained.

The reduction treatment can be performed in either a liquid phase or a gas phase, but a gas phase reduction using a reducing gas such as hydrogen or a liquid phase reduction using an alcohol, formic acid or the like is preferable.

  The reduction temperature in the reduction treatment is not particularly limited, but the reduction is usually 20 ° C. or higher, preferably 100 ° C. or higher, more preferably 250 ° C. or higher, usually 600 ° C. or lower, preferably 500 ° C. or lower.

  The shape of the metal catalyst used in the hydrogenation reaction step is not particularly limited, and can be appropriately selected and used depending on the type of reaction performed using the metal catalyst. Specific examples of the shape of the metal catalyst include shapes such as powder, particles, and pellets. Among these, particles and pellets are preferable from the viewpoint of improving operability.

  Further, the particle diameter of the metal catalyst used in the hydrogenation reaction step is not particularly limited, and can be appropriately selected and used depending on the type of reaction performed using the metal catalyst. A catalyst having a size of 100 μm or more and 20 mm or less is used.

(Hydrogenation reaction conditions)
The reduction reaction performed in the present invention is performed in a hydrogen atmosphere.
The hydrogen source in the embodiment of the present invention is not particularly limited, but it is desirable to use gaseous hydrogen that does not require separation and purification after completion of the reaction.

The hydrogen pressure is not particularly limited, but is usually carried out in the presence of hydrogen under pressurized conditions. The pressure of the hydrogenation reaction is not particularly limited, but is usually 0.1 MPa or more, preferably 0.3 MPa or more, more preferably 0.4 MPa or more, usually 10 MPa or less, preferably 5 MPa or less, more preferably 3 MPa or less. .
Generally, when the reaction pressure is increased, hydrogen supply to the metal catalyst is promoted, and the reaction rate is improved. On the other hand, in order to carry out at a high reaction pressure, equipment such as a reactor having a particularly high pressure resistance is required, and hydrocracking may proceed due to increased hydrogenation capacity.
The hydrogen concentration in the hydrogen atmosphere is not particularly limited, but is usually 70% by volume or more, preferably 80% by volume or more, more preferably 90% by volume or more, and the upper limit is usually 100% by volume, preferably 95%. % By volume or less.

  When the solvent is used in the reduction reaction performed in the hydrogenation reaction step, the specific solvent is not particularly limited, but usually water; methanol, ethanol, 1,4 butanediol, 2,3-butanediol, 1, Alcohols such as 2-butanediol and 1,3-butenediol; ethers such as tetrahydrofuran, dioxane, diethylene glycol dimethyl ether and triethylene glycol dimethyl ether; hydrocarbons such as hexane and decalin; These solvents can be used alone or as a mixed solvent of two or more. The saccharified solution obtained from non-edible biomass often contains water, and it is preferable in terms of efficiency to use water as a solvent as it is.

  The reaction temperature of the reduction reaction performed in the hydrogenation reaction step is not particularly limited, but is usually 20 ° C. or higher, preferably 50 ° C. or higher, more preferably 90 ° C. or higher, usually 350 ° C. or lower, preferably 250 ° C. or lower, more preferably. Is 150 ° C. or lower, more preferably 120 ° C. or lower. When the reaction temperature is within the above range, the conversion of saccharides to other than the target product is suppressed, the reduction reaction proceeds sufficiently, and the yield is improved.

  The reaction time of the reduction reaction is not particularly limited, but is not particularly limited as long as the saccharide to be used reacts to sufficiently obtain the target sugar alcohol. Usually 30 minutes or longer, preferably 1 hour or longer, more preferably 3 hours or longer, usually 24 hours or shorter, preferably 12 hours or shorter, more preferably 5 hours or shorter.

  The reaction apparatus used in the hydrogenation reaction step is not particularly limited, but usually an autoclave capable of high pressure reaction is used. It is also possible to use a continuous reactor, and it is possible to select the reaction by filling the reactor with a catalyst and circulating the raw material liquid and hydrogen. In the case of a continuous reactor, a catalyst separation step is unnecessary, and a continuous reactor is more desirable for mass production.

  The metal catalyst used in the hydrogenation reaction step may be regenerated and recycled. As the regeneration treatment, washing treatment with water or an organic solvent; acid treatment with sulfuric acid or nitric acid; reduction treatment with formic acid or alcohol; heat treatment in the presence of nitrogen, oxygen, hydrogen, steam, or the like is used. In particular, when the heat treatment is performed on the carbon-based porous material, a temperature range in which the carbonaceous material is not burned off and the attached organic substances are removed is desirable. Specifically, it is 100 ° C. or higher and 600 ° C. or lower, more preferably 200 ° C. or higher and 500 ° C. or lower.

The yield of the sugar alcohol obtained by the production method of the present invention is not particularly limited, but is usually 50% or more, preferably 80% or more, and the upper limit is not particularly limited, and is usually 100% or less. .
The yield was calculated by the following calculation formula.
Yield (%) = (corresponding sugar alcohol after reaction (mol) / feed raw material sugar compound (mol)) × 100

  The sugar alcohol obtained by the reduction reaction performed in the hydrogenation reaction step is separated from the reaction mixture through general separation and purification operations such as filtration, concentration, extraction, distillation, sublimation, and the like, as appropriate, after the completion of the reaction. It can refine | purify to the target purity suitably. As a purification method, in the case of a batch reactor, crystallization is generally selected after filtering the catalyst. By using a polymer film or a zeolite film, the crystallization step can be omitted or simple conditions can be used.

(Sugar alcohol)
The sugar alcohol obtained by the production method of the present invention is preferably sorbitol and / or xylitol.
These can be used as food additives, heat storage materials, and polymer materials. If sorbitol is subsequently subjected to a dehydration reaction, it can be induced to isosorbide. Isosorbide is a secondary diol and can be used as a polycarbonate monomer with excellent optical properties, so its precursor, sorbitol, is also an important monomer raw material.

<Sugar solution>
The sugar liquid of the present invention is a sugar liquid containing chlorine (Cl) atoms and at least one of sulfur (S) atoms, formic acid, and nitrogen (N) atoms contained in the sulfur-containing organic compound. The sugar solution of the present invention may contain not only chlorine (Cl) atoms but also sulfur (S) atoms, formic acid and nitrogen (N) atoms contained in the sulfur-containing organic compound, or two or more components.
For example, the sugar solution of the present invention contains chlorine (Cl) atoms in the range of 5 ppm or more and 1000 ppm or less, and contains sulfur (S) atoms contained in the sulfur-containing organic compound in the range of more than 0 ppm and 10 ppm or less.
Another sugar solution of the present invention contains chlorine (Cl) atoms in a range of 5 ppm to 1000 ppm and formic acid in a range of more than 0 ppm and 1500 ppm or less.
Another sugar solution of the present invention contains chlorine (Cl) atoms in a range of 5 ppm to 1000 ppm and nitrogen (N) atoms in a range of more than 0 ppm and 350 ppm or less.

Any sugar solution can be a raw material capable of producing a sugar alcohol with high efficiency if it is subjected to a hydrogenation reaction step because the content of the above-mentioned reaction inhibitor is reduced. On the other hand, since it contains a specific amount of chlorine (Cl) atoms that are characteristically contained in the biomass saccharified liquid, it is clearly different from the sugar liquid in which the purified saccharide is dissolved.
Any sugar solution of the present invention is useful as a raw material for sugar alcohol in the same manner as the treated saccharified solution obtained in the removing step of the production method of the present invention described above.

  In any sugar solution, the amount of Cl atom in the sugar solution may contain 5 ppm or more, in some cases 50 ppm or more, preferably 1000 ppm or less, more preferably 500 ppm or less, as Cl atoms with respect to the weight of the sugar solution. Is desirable.

  The amount of S atom in the sulfur-containing organic compound contained in the sugar liquid is 10 ppm or less, preferably 5 ppm or less, more preferably 1 ppm or less as S atoms with respect to the weight of the sugar liquid. Is desirable. Although it is considered preferable that the content of divalent or tetravalent S atoms contained in the sulfur-containing organic compound is small, it is large in carrying out the hydrogenation reaction step even if it is contained within the above range. It doesn't matter. When a saccharified solution containing no divalent or tetravalent S atom is used in the hydrogenation reaction step, isomerization of the sugar proceeds, hydrogenolysis proceeds because the reactivity of the catalyst is too high, etc. A compound other than the target product may be produced, and the selectivity of the reaction tends to decrease.

  The amount of formic acid contained in the sugar solution is desirably 1500 ppm or less, preferably 1000 ppm or less, more preferably 500 ppm or less, and even more preferably 100 m or less with respect to the weight of the sugar solution. It is particularly preferable that formic acid is not contained at all, but if it is within the above range, even if it is contained, it is not a big problem when used as a raw material for the production of sugar alcohol.

  The amount of N atom contained in the sugar solution is desirably 400 ppm or less, preferably 350 ppm or less, more preferably 50 ppm or less, and even more preferably 10 m or less as N atoms with respect to the weight of the sugar solution. It is particularly preferable that no N atom is contained, but if it is within the above range, even if it is contained, it is not a big problem when used as a raw material for the production of sugar alcohol.

(Method for producing sugar solution)
The sugar liquid of the present invention may be produced in any manner as long as it has the above composition, but is preferably obtained by saccharifying biomass. For example, it can be produced by carrying out the saccharification step and the removal step described above.

Hereinafter, the present invention will be described more specifically with reference to examples.
The high-performance liquid chromatography (hereinafter, LC) measurement conditions and ion chromatography measurement conditions of the reaction mixtures obtained in the examples are as follows.
Moreover, the combustion absorption ion chromatography measurement conditions and water-soluble ion chromatography measurement conditions for calculating the amount of S atoms contained in the sulfur-containing organic compound are shown below.

(Liquid phase chromatograph (LC) analysis)
Pump: LC-20AD manufactured by Shimadzu Corporation
Column oven: CTO-10A manufactured by Shimadzu Corporation
UV detector: Shimadzu Corporation SPD-10A
RI detector: Shimadzu Corporation RID-10A
Column: ULTRON PS-80H 8.0ID × 300 mm apparatus manufactured by Shinwa Chemical Industry Co., Ltd .: Eluent: 0.11 mass% perchloric acid solution 1.0 mL / min Detection method: UV (210 nm), RI
Injection volume: 10 μL

(Ion chromatographic analysis)
The method for measuring the amount of chlorine (Cl) atoms is as follows.
A sample was collected on a magnetic board, heated in a quartz tube furnace, and the Cl content in the combustion gas was absorbed with 0.1% hydrogen peroxide. Cl ions in the absorbing solution were measured with an ion chromatograph.
Quartz tubular furnace: AQF-2100H type manufactured by Mitsubishi Chemical Corporation In-chromatograph device: ICS-1000 type manufactured by Dionex

(Combustion absorption ion chromatography analysis)
The method for measuring the amount of S atoms is as follows.
The sample is burned in the presence of an auxiliary agent, the gas is absorbed in an aqueous solution, filtered through a filter, and then measured with an ion chromatograph.
Ion chromatograph: manufactured by Thermo Fisher Scientific
ICS-2000, DX500
Combustion device: AQF-2100M manufactured by Mitsubishi Chemical Analytech

(Water-soluble ion chromatographic analysis)
The method for measuring the amount of hexavalent S atoms is as follows.
The sample is diluted 100 times with water, filtered with a filter, and then measured with an ion chromatograph.
Ion chromatograph: manufactured by Thermo Fisher Scientific
ICS-2000, DX500

(Trace nitrogen analysis)
The method for measuring the amount of N atoms is as follows.
The sample was burned in an oxygen atmosphere, and the generated gas was burned and measured with a trace nitrogen analyzer using a reduced pressure chemiluminescence method. At that time, an ammonia-based nitrogen standard solution manufactured by Wako Pure Chemical Industries was used as a standard sample.
Trace nitrogen analyzer: TN-05 manufactured by Mitsubishi Chemical Analytech

<Synthesis example>
(Saccharification process)
Bagasse was used as non-edible biomass. Sulfuric acid corresponding to 2% by mass of the bagasse dry mass and water in such an amount that the water content becomes 60% were added and mixed for 20 minutes with a drum mixer (Sugiyama Heavy Industries). The obtained dilute sulfuric acid treatment product was put into a hydrolysis apparatus (manufactured by Yasima Co., Ltd.), steam was put in, and steamed at 180 ° C. for 15 minutes. The water content of the obtained steamed product was 64.6%.
The steamed product was charged into a saccharification apparatus so as to have a dry weight of 200 g / L, and pH was adjusted to 6.0 by adding 10 N NaOH. To this, CTec2 (manufactured by Novozyme) for 15 FPU was added as a saccharifying enzyme, and hydrolysis was performed while stirring at a temperature of 50 ° C. and a stirring speed of 200 rpm for 72 hours. Thereafter, centrifugation was performed at 10,000 g for 10 minutes, and undegraded cellulose or lignin was separated and removed to prepare a saccharified solution. As a result of analysis by ion chromatography, the saccharified solution contained 160 ppm of Cl atoms and also contained S atoms contained in the sulfur-containing organic compound.

<Example 1>
A saccharified solution A was prepared in the same manner as in the synthesis example. As a result of LC analysis of this saccharified liquid A, glucose was 7.33% by mass, and the total of xylose and fructose was 3.95% by mass. Further, other saccharides of 0.5% by mass or more were not detected.
(Removal process)
To 12 g of saccharified solution A, 0.7 g of powdered activated carbon (FP-1 manufactured by Nippon Enviro Chemicals) was added and stirred at room temperature for 1 hour. The obtained mixture was filtered with an argon pressure filter equipped with a 1 μm membrane filter to obtain a treated saccharified solution 1.

(Hydrogenation reaction process)
After mixing 4 g of the above treated saccharified solution 1 and 0.33 g of 1.5% by mass Ru / C catalyst (manufactured by NP Chemcat) in an autoclave with an internal volume of 70 mL under an argon atmosphere using a stirrer The autoclave was sealed. Next, H ₂ was charged into the autoclave through a valve so that the H ₂ pressure was 2 MPa. The autoclave was placed in an electric furnace maintained at 120 ° C., held for 15 minutes as it was, and the time when the temperature inside the autoclave could be raised to 120 ° C. was set as the reaction start. After 1 hour from the start of the reaction, the autoclave was taken out of the electric furnace, allowed to cool to room temperature, purged with the residual pressure, and then the entire reaction mixture in the autoclave was recovered.
The recovered reaction mixture was subjected to LC analysis under the above conditions, and the sorbitol yield and xylitol yield were determined by the following formulas. The results are shown in Table 1.
Since the content of fructose in the saccharified solution is extremely small, the total amount of xylose and fructose was used to indicate the amount of xylose.
Sorbitol yield (%) = (Sorbitol amount after reaction (mol) / Glucose amount charged (mol)) × 100
Xylitol yield (%) = (xylitol amount after reaction (mol) / charged xylose amount (mol)) × 100

<Example 2>
Except that the removal treatment of the saccharified solution A in Example 1 was performed using activated carbon (4GV manufactured by Turumi Coal Co., Ltd.) pulverized so as to be a powder having a particle size of 420 μm or less, the removal step and A hydrogenation reaction step was performed. The results of LC analysis are shown in Table 1.

<Example 3>
The removal step and the hydrogenation reaction step were performed in the same manner as in Example 1 except that the removal treatment of the saccharified solution A in Example 1 was changed to powdery 5% by mass Pd / C (manufactured by NP Chemcat). . The results of LC analysis are shown in Table 1.

<Example 4>
The removal step and the hydrogenation reaction step were performed in the same manner as in Example 1 except that the removal treatment of the saccharified solution A in Example 1 was Al ₂ O ₃ (N612 made by JGC Catalysts & Chemicals). The results of LC analysis are shown in Table 1.

<Example 5>
The removal step and the hydrogenation reaction step were performed in the same manner as in Example 1 except that the removal treatment of the saccharified solution A was basic Al ₂ O ₃ (activated alumina manufactured by WAKO) in Example 1. The results of LC analysis are shown in Table 1.

<Example 6>
The removal step and the hydrogenation reaction step were performed in the same manner as in Example 1 except that the removal treatment of the saccharified solution A in Example 1 was changed to basic SiO ₂ modified by aminopropyl group (manufactured by Kanto Chemical Co., Inc.). It was. The results of LC analysis are shown in Table 1.

<Example 7>
In Example 1, 5.2 g of treated sugar solution 1, 0.104 g of sponge Ni R-2311 (as metal amount) manufactured by Nikko Rica Co., Ltd. was used instead of the Ru / C catalyst as a catalyst for the hydrogenation reaction, and reaction The removal step and the hydrogenation reaction step were performed in the same manner as in Example 1 except that the temperature was changed from 120 ° C to 90 ° C. The results of LC analysis are shown in Table 1.

<Comparative Example 1>
A hydrogenation reaction step was performed in the same manner as in Example 1 except that the removal treatment of the saccharified solution A was not performed in Example 1. The results of LC analysis are shown in Table 1.

<Comparative Example 2>
The removal step for the saccharified liquid A in Example 1 was not performed, and 0.08 g of sponge Ni R-2311 (as a metal amount) manufactured by Nikko Rica Co., Ltd. was used instead of the Ru / C catalyst as a catalyst for the hydrogenation reaction. And the hydrogenation reaction process was performed like Example 1 except having changed reaction temperature from 120 degreeC to 90 degreeC. The results of LC analysis are shown in Table 1.

Comparison between Examples 1 to 6 and Comparative Example 1 shows that the activity of the hydrogenation reaction is greatly improved by treating the saccharified solution with a carbon-based porous material or metal oxide. This is because the reaction inhibitor in the saccharified solution is reduced by the carbon-based porous material or the metal oxide adsorbent. Moreover, it is understood from the comparison between Example 7 and Comparative Example 2 that the hydrogenation reaction activity is greatly improved by treating the saccharified solution with a carbon-based porous material. This means that the effect of reducing the reaction inhibitor in the saccharified solution by the pretreatment is also observed in the alloy catalyst such as sponge Ni, like the supported metal catalyst such as Ru / C. .
This example shows that sugar alcohol can be obtained in a high yield by a simple method of treating saccharified solution with an adsorbent using bagasse, which is a herbaceous non-edible biomass, as a starting material.

  It is suggested that the reaction inhibitory substance containing sulfur (S) atoms in the saccharified liquid may be removed by performing the removal process on the saccharified liquid derived from non-edible biomass. The experiment was conducted.

<Reference synthesis example>
(Production of model sugar solution)
A model sugar solution B was prepared by dissolving 27 g of glucose and 0.06 g of methionine (600 ppm of methionine with respect to the sugar solution; 129 ppm as S contained in the sulfur-containing organic compound) in 72.8 mL of ultrapure water. When the LC analysis of the model sugar solution B under the above conditions was performed, it was 26.8% by mass of glucose.
Glucose 27 g and methionine 0.006 g (60 ppm methionine: 13 ppm as S contained in the sulfur-containing organic compound) were dissolved in 72.8 mL of ultrapure water to prepare a model sugar solution C. When LC analysis of the model sugar liquid C under the above conditions was performed, it was 26.8% by mass of glucose.

<Reference Experimental Example 1>
(Removal process)
To 12 g of model sugar solution B, 0.7 g of activated carbon (4 GV manufactured by Tsurumi Coal) was added and stirred at room temperature for 1 hour. The obtained mixture was filtered with an argon pressure filter equipped with a 1 μm membrane filter to obtain treated sugar solution 2.
(Hydrogenation reaction process)
A hydrogenation reaction step was performed in the same manner as in Example 1 except that the treated sugar solution 2 was used in Example 1 and the reaction temperature was 90 ° C. The results of LC analysis are shown in Table 2.

<Reference Comparative Example 1>
The hydrogenation reaction step was performed in the same manner as in Example 1 except that the model sugar solution B was used without treating the sugar solution in Example 1 and the reaction temperature was 90 ° C. The results of LC analysis are shown in Table 2.

<Reference Experiment Example 2>
0.02 g of zinc oxide (manufactured by Kanto Chemical Co., Inc.) was added to 12 g of model sugar solution C, and the mixture was stirred at room temperature for 1 hour. The obtained mixture was filtered with an argon pressure filter equipped with a 1 μm membrane filter to obtain treated sugar solution 3.
A hydrogenation reaction step was performed in the same manner as in Example 1 except that the treated sugar solution 3 was used in Example 1 and the reaction temperature was 90 ° C. The results of LC analysis are shown in Table 2.

<Reference Comparative Example 2>
The hydrogenation reaction step was performed in the same manner as in Example 1 except that the model sugar solution C was used without treating the sugar solution in Example 1 and the reaction temperature was 90 ° C. The results of LC analysis are shown in Table 2.

  By comparing Reference Experimental Examples 1 and 2 with Reference Comparative Examples 1 and 2, a sugar solution containing a sulfur-containing organic compound is treated with a carbon-based porous material or a metal oxide, thereby greatly increasing the activity of the hydrogenation reaction. It can be seen that it has improved. This confirms that the sulfur-containing organic compound is a reaction inhibitor and is derived from being reduced by a carbon-based porous material or a metal oxide adsorbent.

<Example 1-2, Example 3-2, Comparative Example 1-2>
About each processing saccharified liquid obtained by the removal process of Example 1, and the removal process of Example 3, and the saccharified liquid A used by the comparative example 1, content of nitrogen (N) atom was measured by the above-mentioned method. . Further, the content of formic acid was measured by the above-mentioned liquid phase chromatograph (LC) analysis. The results are shown in Table 3.

  By comparing the saccharified solution containing the N-atom-containing component and formic acid with the carbon-based porous material or the supported metal catalyst by comparing Examples 1-2 and 3-2 with Comparative Example 1-2, It can be seen that the amount of N atom and the amount of formic acid decreased. As a result, it became clear that the carbon-based porous material and the supported metal catalyst show the effect of inhibiting substance adsorption. Further, in view of the results of Examples 1 and 3, N atom-containing components and formic acid are inhibitors to the catalyst. A possibility has been shown, and it has also been shown that treatment with a carbon-based porous material or a supported metal catalyst reduces the inhibition factor of the hydrogenation reaction.

According to the method for producing a sugar alcohol of the present invention, by removing a specific substance in a saccharified solution derived from non-edible biomass by a simple method, the obtained treated saccharified solution is used as a raw material for sugar alcohol production. As a result, sugar alcohol can be produced efficiently at low cost.
Moreover, the sugar liquid of this invention can manufacture sugar alcohol with a high yield, without reducing the activity of a catalyst by using it as the raw material of hydrogenation reaction.
From these facts, it is possible to design a process with excellent production efficiency in the production of sugar alcohol.

Claims (11)

A saccharification step of saccharifying non-edible biomass to obtain a saccharified solution;
A removal step of obtaining a treated saccharified solution by performing a treatment for removing the reaction inhibitor in the saccharified solution;
A hydrogenation reaction step of bringing the treated saccharified solution into contact with a metal catalyst under a hydrogen atmosphere,
A method for producing a sugar alcohol, wherein sugar alcohol is produced from sugar in the hydrogenation reaction step.   The method for producing a sugar alcohol according to claim 1, wherein the saccharified solution contains glucose and / or xylose.   The method for producing a sugar alcohol according to claim 1 or 2, wherein in the removing step, the saccharified solution is treated with a carbon-based porous material and / or a metal oxide.   The processed saccharified solution obtained after the removing step contains the sulfur (S) atom contained in the sulfur-containing organic compound in a range of more than 0 ppm and not more than 10 ppm. Production method.   The method for producing a sugar alcohol according to any one of claims 1 to 4, wherein the treated saccharified solution obtained after the removing step contains formic acid in a range of more than 0 ppm and 1500 ppm or less.   The manufacturing method of the sugar alcohol of any one of Claims 1-5 in which the process saccharified liquid obtained after the said removal process contains nitrogen (N) atom in the range of more than 0 ppm and 350 ppm or less.   The manufacturing method of the sugar alcohol of any one of Claims 1-6 in which the process saccharified liquid obtained after the said removal process contains a chlorine (Cl) atom in 5 ppm or more and 1000 ppm or less.   The sugar alcohol according to any one of claims 1 to 7, wherein the metal catalyst contains at least one metal element selected from Group 8, Group 9, Group 10 and Group 11 of the Periodic Table. Production method.   The method for producing a sugar alcohol according to any one of claims 1 to 8, wherein the metal catalyst contains ruthenium or nickel.   The method for producing a sugar alcohol according to any one of claims 1 to 9, wherein the sugar alcohol is sorbitol and / or xylitol. A sugar solution comprising a chlorine (Cl) atom and at least one of a sulfur (S) atom, formic acid, and a nitrogen (N) atom contained in the sulfur-containing organic compound,
The chlorine (Cl) atom is 5 ppm or more and 1000 ppm or less, the sulfur (S) atom contained in the sulfur-containing organic compound is more than 0 ppm, 10 ppm or less, the formic acid is more than 0 ppm, 1500 ppm or less, and the nitrogen (N) atom is 0 ppm. A sugar solution characterized by containing in a range of more than 350 ppm.