WO2011021399A1

WO2011021399A1 - Preparation method for monosaccharide, disaccharide, and/or oligosaccharide

Info

Publication number: WO2011021399A1
Application number: PCT/JP2010/005141
Authority: WO
Inventors: 泰司山田; 恵悟花木
Original assignee: 花王株式会社
Priority date: 2009-08-21
Filing date: 2010-08-20
Publication date: 2011-02-24
Also published as: JP2011062196A; MY169490A

Abstract

Provided is a preparation method for a monosaccharide, a disaccharide, and/or an oligosaccharide in which a polysaccharide is heat treated at 140°C to 300°C in the presence of a C_6-12 fatty acid and water.

Description

Method for producing monosaccharide, disaccharide and / or oligosaccharide

The present invention relates to a method for producing polysaccharides, particularly monosaccharides, disaccharides, and / or oligosaccharides (hereinafter collectively referred to as “decomposed sugars”) from biomass.

In recent years, development of technology for producing useful substances such as ethanol and lactic acid from cellulose-based, starch-based, or saccharide-based biomass in place of fossil resources has been desired. In particular, there is a growing interest in technologies that make effective use of cellulosic biomass, which is a non-food resource.
Production of ethanol or the like from biomass can be performed by decomposing biomass into sugar in the saccharification step and then converting it to ethanol or the like in the fermentation step. Saccharification is roughly divided into acid saccharification using sulfuric acid or the like and enzyme saccharification.

Enzymatic saccharification is advantageous in that it can be hydrolyzed under mild conditions compared to acid saccharification and has a high saccharification rate. It is necessary to pre-process. As this pretreatment method, a sulfuric acid method, an organic solvent method, a hydrothermal treatment and the like have been studied.
For example, a method in which a raw material mixture containing lignocellulosic biomass, a weak acid and water is treated under heating and pressure conditions and decomposed into monosaccharides (Patent Document 1); under high-temperature and high-pressure conditions in which oleic acid is added In other words, a method for treating cellulose with oligosaccharide to obtain oligosaccharides, cellobiose, glucose and fructose (Non-patent Document 1) has been reported.

Meanwhile, a decomposition method using a supercritical fluid or a subcritical fluid has been proposed. For example, a method of hydrolyzing and / or thermally decomposing a natural or synthetic polymer compound using water in a supercritical state or a subcritical state ( Patent Document 2): A method of using a mixture of a water-insoluble solvent and water and decomposing the pulverized powder of wood-based waste material in a supercritical state or a subcritical state in which both or one of the water-insoluble solvent and water is in a supercritical state (Patent Document 2) 3) etc. have been reported.

JP 2009-22239 A Japanese Patent Laid-Open No. 5-31000 JP 2007-31476 A

The present invention provides a method for producing monosaccharides, disaccharides and / or oligosaccharides, in which a polysaccharide is subjected to a heat treatment at 140 to 300 ° C. in the presence of a fatty acid having 6 to 12 carbon atoms and water.

FIG. 1 is a diagram illustrating an example of a flow reactor that performs heat treatment.

In the conventional method using water in a supercritical state or subcritical state or the method using weak acid or oleic acid in the pretreatment step of enzymatic saccharification, the generated sugar is excessively decomposed, and the amount of sugar produced as a whole It has been found that there may be fewer cases. In particular, since hydroxymethylfurfural (HMF) produced by the excessive decomposition of sugar may inhibit the fermentation of sugar to ethanol, etc. in the fermentation process, the production of useful substances such as ethanol is generally controlled. It is important for efficiency improvement. In addition, when a weak acid is added in the pretreatment step of enzymatic saccharification, the weak acid is water-soluble, so that it is difficult to remove after the treatment and a neutralization operation is required, and the operation becomes complicated.
On the other hand, if the pretreatment conditions for enzymatic saccharification are too gentle, there is a problem that hydrolysis does not proceed sufficiently.

Therefore, the present invention relates to a method capable of efficiently producing a decomposed sugar from a polysaccharide while suppressing excessive decomposition of the sugar.

The inventors of the present invention have intensively studied in view of the above-mentioned problems. As a result, the polysaccharide is subjected to heat treatment in the presence of a fatty acid having 6 to 12 carbon atoms and water, thereby efficiently decomposing the sugar while suppressing excessive decomposition of the sugar. It was found that can be manufactured.

According to the present invention, it is possible to efficiently produce a decomposed sugar while suppressing excessive decomposition of the sugar. The method of the present invention can also be applied to biomass containing polysaccharides, and can be expected as a technique for improving the production efficiency of useful substances such as ethanol from biomass.

Examples of the polysaccharide used in the present invention include cellulose, hemicellulose, xyloglucan, pectin, starch, mannan, glucomannan, galactomannan, chitin, chitosan, inulin, alginic acid, agar, fucoidan, laminarin, β-glucan, pullulan. Natural polysaccharides such as these or derivatives thereof. These can be used alone or in combination of two or more. Of these, cellulose, hemicellulose, chitin, and chitosan are preferable, and cellulose and hemicellulose are particularly preferable because they are inexpensive and can be converted into useful substances by fermentation production after decomposition. The molecular weight of the polysaccharide used in the present invention is not particularly limited, but generally it is preferably 1,000 or more and 5,000,000 or less.

Moreover, the raw material containing the said polysaccharide, for example, biomass, can also be used as a polysaccharide in this invention. Biomass is an organic resource derived from living organisms, excluding fossil resources. Examples of the biomass include cellulose-based, starch-based, and saccharide-based biomass, and these can be used alone or in combination of two or more.
Especially, it is preferable to use the cellulose biomass containing a cellulose from the point of effective utilization of resources.

Cellulose biomass is mainly composed of cellulose, hemicellulose, and lignin. For example, cotton, wood pulp, kenaf, hemp, small-diameter wood, thinned wood, sawdust, wood waste, waste paper, newspaper, wrapping paper, tissue paper Woody materials such as toilet paper and cardboard; plant biomass such as bagasse, switchgrass, elephant grass, rice straw and wheat straw. Examples of the starch-based biomass include rice, wheat, corn, and potato, and examples of the saccharide-based biomass include sugar-based biomass such as sugar cane, sugar beet, seaweed, shrimp shell, and crab shell.

When using biomass as the polysaccharide, it is preferable from the viewpoint of improving the decomposition rate to perform pretreatment such as drying, pulverization, shredding, etc. prior to heat treatment. For example, a ventilation type band dryer, a shelf type hot air dryer, etc. can be used for drying. For the pulverization and chopping, for example, a known rotating ball mill, planetary ball mill, disk mill, rod mill or the like can be used.

The method for heat-treating the polysaccharide is not particularly limited, and a known method can be applied. For example, a batch method, a semi-batch method, a flow reaction method and the like can be mentioned. Among these, the flow-type reaction method is preferable in that the reaction time can be easily controlled.

In the present invention, the heat treatment of the polysaccharide is performed in the presence of a fatty acid having 6 to 12 carbon atoms and water.
Here, examples of the fatty acid having 6 to 12 carbon atoms include linear or branched saturated or unsaturated fatty acids. In particular, a saturated fatty acid having 6 to 12 carbon atoms is preferable, and a saturated fatty acid having 6 to 10 carbon atoms is more preferable from the viewpoint of suppressing the excessive decomposition of sugar and improving the decomposition rate.
Specific examples of the fatty acid include caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid and the like. Of these, caprylic acid is preferable. Since fatty acids having 6 or more carbon atoms are low in water solubility, they can be easily separated from the reaction solution, and on the other hand, the yield of sugar can be improved by using fatty acids having 12 or less carbon atoms. Fatty acids having a number of 12 or less are easy to handle because of their relatively low melting points.

The amount of the fatty acid having 6 to 12 carbon atoms used for the heat treatment is preferably 0.01 to 0.5 as a mass ratio with respect to water from the viewpoint of suppressing the excessive decomposition of sugar and improving the decomposition rate. 0.02-0.4, particularly 0.05-0.3 is preferred.

Moreover, the water used in the case of heat processing will not be restrict | limited especially if it is the water under a high temperature / high pressure state, As a water, a tap water, distilled water, ion-exchange water, and purified water are illustrated.
When the heat treatment is performed by a flow reaction method, the polysaccharide is preferably used after being dispersed in water to form a slurry. The content of the polysaccharide in the water slurry is preferably 1 to 200 g / L, more preferably 5 to 150 g / L, and particularly preferably 8 to 100 g / L from the viewpoint of fluidity.
When the heat treatment is carried out by a batch method, the polysaccharide content in the water slurry is preferably 1 to 400 g / L, more preferably 5 to 300 g / L, and particularly preferably 8 to 200 g / L.

The temperature of the heat treatment is 140 to 300 ° C., preferably 160 to 250 ° C., particularly preferably 180 to 230 ° C. from the viewpoint of suppressing the excessive decomposition of sugar and improving the decomposition rate. Examples of the heating means include water vapor and electricity.

Also, the pressure during the heat treatment is preferably set to be equal to or higher than the saturated vapor pressure of water, and is preferably 0.3 to 10 MPa, more preferably 0.9 to 8 MPa, particularly 1.3 to 6 MPa, and particularly preferably 2 to 6 MPa. Examples of the gas used for pressurization include inert gas, water vapor, nitrogen gas, and helium gas. You may adjust by a back pressure valve, without using gas.

The heat treatment time (average residence time) varies depending on the reaction method and the type of polysaccharide, but from the viewpoint of the decomposition rate and production efficiency, for example, in the case of the flow reaction method, it is 0 after the slurry reaches the set temperature. 5 to 30 minutes are preferable, 1 to 15 minutes are more preferable, and 1 to 8 minutes are particularly preferable.
The heat treatment time (average residence time) is calculated by dividing the volume of the high-temperature and high-pressure part of the reactor by the slurry supply rate.

After the heat treatment, the reaction solution may be cooled to 100 ° C. or lower, preferably 60 ° C. or lower, and the solution containing the decomposed sugar and the fatty acid may be separated. The method for separating the solution containing the decomposed sugar and the fatty acid is not particularly limited, and can be performed, for example, by centrifugation or decantation. The recovered fatty acid may be reused.

Thus, examples of monosaccharides obtained by heat treatment include glucose, fructose, mannose, galactose, xylose, and arabinose. Examples of the disaccharide include cellobiose, maltose, di-N-acetylchitobiose and the like, and examples of the oligosaccharide include those having 3 to 10 monosaccharide units, such as cellotriose, cellotetraose, Cellopentaose, cellohexaose, maltotriose, maltotetraose, maltopentaose, maltohexaose, tri-N-acetylchitotriose, tetra-N-acetylchitotetraose, penta-N-acetylchitopentaose And hexa-N-acetylchitohexaose.

An example of a flow reactor used in the production method of the present invention is shown in FIG. The flow reactor includes a water slurry tank (11) containing a polysaccharide, a water slurry supply tank (13), a fatty acid supply tank (21), a reactor (31) provided with a heating furnace (32), and a cooler (41 ), A filter (51), and a reaction liquid recovery tank (61). The reactor (31) is equipped with a pressure gauge and a thermometer. For example, the pressure during the heat treatment is adjusted by a back pressure valve.

First, water slurry is supplied to the water slurry supply tank (13) from the water slurry tank (11) containing polysaccharides using the supply pump (12). Subsequently, the water slurry is supplied to the reactor (31) pressurized and heated to a predetermined temperature and pressure by the heating furnace (32), and the fatty acid supplied from the fatty acid supply tank (21) using the supply pump (22). In the presence of water, the polysaccharide in the water slurry is hydrolyzed under high temperature and high pressure.
The flow rate of the water slurry supplied from the water slurry supply tank (13) varies depending on the volume of the reactor. For example, when the reactor volume is 100 mL, it is preferably 3.3 to 200 mL / min, particularly 6.7 to 100 mL / min is preferred.
The flow rate of the fatty acid supplied from the fatty acid supply tank (21) is preferably 0.03 to 100 mL / min, particularly preferably 0.15 to 60 mL / min.

The hot reaction liquid that has exited the reactor (31) is quickly cooled by the cooler (41). In the case of the flow type, the flow rate of the reaction liquid discharged from the reactor outlet is the sum of the slurry supply flow rate and the fatty acid supply flow rate.
Next, the reaction solution is passed through the filter (51), unreacted polysaccharide is separated, and decomposed sugar is obtained in the reaction solution recovery tank (61).

The degradation sugar obtained by the production method of the present invention is preferably rich in monosaccharides typified by glucose. The concentration of monosaccharides such as glucose in the degraded sugar is preferably 60 to 99% by mass, more preferably 65 to 99% by mass, and still more preferably 70 to 99% by mass.
In addition, the reaction liquid containing the decomposition sugar preferably has a low HMF content and a monosaccharide / HMF mass ratio of 5 or more, more preferably 5 to 1000, more preferably 8 to 200, particularly 10 to 200, and particularly preferably 12 to 200. .

The decomposed saccharide obtained by the production method of the present invention can be used for usual enzymatic saccharification using cellulase or the like. Furthermore, useful substances such as ethanol, polylactic acid, amino acids, xylitol and erythritol can be produced by microbial fermentation or chemical conversion using these decomposed sugars as a sugar source. Decomposed sugar-containing compositions having a monosaccharide / HMF mass ratio of 5 or more are particularly useful for the production of these useful substances.

<Measurement of monosaccharide concentration, disaccharide concentration and oligosaccharide concentration>
Using a high performance liquid chromatograph manufactured by Hitachi, Ltd., a column Asahipak NH2P-50 4E (4.5 mmφ × 250 m) manufactured by Showa Denko was installed, and a gradient method was performed at a column temperature of 20 ° C. The mobile phase A solution was acetonitrile, and the B solution was 30% methanol water, and the solution was sent at 1.00 mL / min. The gradient conditions are as follows.
Time (min) A liquid (%) B liquid (%)
0 20 80
45 50 50
45.1 20 80
55 20 80
The sample injection amount was 5 μL, and detection was performed using a corona CAD detector manufactured by ESA Biosciences.

<Measurement of hydroxymethylfurfural (HMF) concentration>
Using a high-performance liquid chromatograph manufactured by Hitachi, Ltd., a column Inertsil ODS-3 (3.0 mmφ × 150 m) manufactured by GL Sciences Inc. was mounted, and a gradient method was performed at a column temperature of 40 ° C. The mobile phase A solution was acetonitrile and the B solution was water, and the solution was fed at 0.40 mL / min. The gradient conditions are as follows.
Time (min) A liquid (%) B liquid (%)
0 10 90
10 10 90
30 90 10
40 90 10
40.1 10 90
60 10 10
The sample injection amount was 10 μL, and detection was quantified by absorbance at a wavelength of 275 nm.

Example 1
Heat treatment was performed using the flow reactor shown in FIG.
Microcrystalline powdery cellulose (Sigma Aldrich) was dispersed in distilled water at 1.11 wt% and uniformly stirred in a water slurry supply tank. In a 100 mL stainless steel flow reactor (manufactured by Nitto Koatsu Co., Ltd.), water slurry of cellulose and caprylic acid (Wako Pure Chemical Industries, Ltd., density 0.91 g / mL (20 ° C.)) were flowed at a flow rate of 45 mL / min, respectively. It was fed at 5 mL / min and reacted at 220 ° C. (average residence time 2 minutes). The pressure was adjusted to 3 MPa with an outlet valve. The reaction solution was extracted from the reactor outlet at a flow rate of 50 mL / min, and the extracted reaction solution was cooled to room temperature (25 ° C.) and collected in a tank. The reaction solution was washed three times with the same volume of hexane to remove fatty acids, and then the monosaccharide (glucose) concentration, disaccharide (cellobiose) concentration, oligosaccharide (cellotriose) concentration, and HMF concentration were measured. The results are shown in Table 1.

Example 2
A reaction solution was obtained in the same manner as in Example 1 except that the reaction temperature was 200 ° C., and the flow rates of the cellulose slurry and caprylic acid were 22.5 mL / min and 2.5 mL / min, respectively.

Example 3
A reaction solution was obtained in the same manner as in Example 1 except that the concentration of the water slurry of cellulose was 1.25 wt%, the flow rate was 40 mL / min, and the caprylic acid flow rate was 10 mL / min.

Comparative Example 1
A reaction liquid was obtained in the same manner as in Example 1 except that the concentration of the cellulose slurry was 1.00 wt% and the flow rate was 50 mL / min without supplying the fatty acid.

Comparative Example 2
A reaction solution was obtained in the same manner as in Example 1 except that oleic acid (density 0.90 g / mL (20 ° C.)) was used instead of caprylic acid.

As is apparent from Table 1, in Examples 1-3 in which cellulose was heat-treated in the presence of a fatty acid having 6 to 12 carbon atoms and water, all of glucose, cellobiose and cellotriose were produced, while the amount of glucose produced was It was possible to suppress the amount of HMF produced relative to. On the other hand, in Comparative Example 1 in which no fatty acid was supplied, the production amounts of glucose, cellobiose and cellotriose were small. Further, in Comparative Example 2 in which oleic acid was supplied, the amount of HMF produced relative to the amount of glucose produced was large, although the amount of glucose, cellobiose and cellotriose produced was slightly increased compared to Comparative Example 1 in which no fatty acid was added.

Example 4
10 g of microcrystalline powder cellulose (Sigma Aldrich) and 90 g of water were mixed. This water slurry and 9 g of caprylic acid (Wako Pure Chemical Industries, density 0.91 g / mL (20 ° C.)) were placed in a batch hydrothermal apparatus (Start 200 New Quick, volume 180 mL manufactured by Nitto Koatsu), and the upper space was purged with nitrogen. Heated with stirring. The heating rate was 3.4 ° C./min. After reaching 180 ° C., it was cooled to room temperature. The time during which the slurry temperature was 180 ° C. was 3 minutes. After the reaction solution was washed three times with the same volume of hexane to remove fatty acids, the monosaccharide (glucose) concentration, disaccharide (cellobiose) concentration, oligosaccharide (cellotriose) concentration, and HMF concentration were measured. The results are shown in Table 2.

Comparative Example 3
A reaction solution was obtained in the same manner as in Example 4 except that caprylic acid was not added.

As apparent from Table 2, in Example 4 in which cellulose was heat-treated in the presence of C8 fatty acid and water, the production amount of glucose, cellobiose and cellotriose was large, while the production amount of HMF relative to the glucose production amount was We were able to keep it low. On the other hand, in Comparative Example 3 in which no fatty acid was added, the production amounts of glucose, cellobiose and cellotriose were small, and the HMF production amount was large with respect to the glucose production amount.

Water slurry tank containing polysaccharides (11)
Supply pump (12)
Water slurry supply tank (13)
Fatty acid supply tank (21)
Supply pump (22)
Reactor (31)
Heating furnace (32)
Cooler (41)
Filter (51)
Reaction liquid recovery tank (61)

Claims

A method for producing monosaccharides, disaccharides, and / or oligosaccharides, in which a polysaccharide is heated at 140 to 300 ° C. in the presence of a fatty acid having 6 to 12 carbon atoms and water.
The method for producing monosaccharides, disaccharides and / or oligosaccharides according to claim 1, wherein the mass ratio of the fatty acid having 6 to 12 carbon atoms to water is 0.01 to 0.5.
The method for producing monosaccharides, disaccharides and / or oligosaccharides according to claim 1 or 2, wherein the heat treatment is performed at a pressure equal to or higher than a saturated vapor pressure of water.
The method for producing monosaccharides, disaccharides and / or oligosaccharides according to any one of claims 1 to 3, wherein the heat treatment is performed at a pressure of 0.3 to 10 MPa.
The method for producing monosaccharides, disaccharides and / or oligosaccharides according to any one of claims 1 to 4, wherein cellulose-containing biomass is used as the polysaccharide.
Monosaccharide / disaccharide and / or oligosaccharide-containing composition having a monosaccharide / HMF mass ratio of 5 or more.