JP2003212888A - Method for producing glucose and/or water-soluble cellooligosaccharide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new method for efficiently producing glucose and/or a water-soluble cellooligosaccharide from a cellulosic material. <P>SOLUTION: This method for producing glucose and/or the water-soluble cellooligosaccharide comprises hydrolyzing cellulose ≥100 in mean degree of polymerization by contact reaction with supercritical or subcritical water for 0.01-5 s, cooling and then further contact reaction with subcritical water for 1 s to 10 min. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel glucose and / or water-soluble cellooligosaccharide capable of efficiently producing glucose and / or water-soluble cellooligosaccharide from a cellulose-containing material. The present invention relates to a method for producing sugar. [0002] Cellulose constituting cellulose is glucose, and cellooligosaccharides and further glucose can be obtained by hydrolyzing cellulose. Glucose is an important food material by itself, and ethanol can be obtained by fermentation, or sugars such as fructose, organic acids such as citric acid, and sugar alcohols such as sorbitol can be obtained by fermentation, or microorganisms or enzymes or chemical conversion. And other materials. In addition, water-soluble cellooligosaccharides, like various oligosaccharides, have been revealed in physiological functions and are expected as functional food materials. Here, the water-soluble cellooligosaccharide is glucose 2
Means up to about 12 polymers. Hitherto, many studies have been made to obtain water-soluble cellooligosaccharides and glucose from cellulose.
Initially, acid hydrolysis was attempted. For example, in the method using concentrated sulfuric acid, hemicellulose was separated and decomposed by pretreatment, then the cellulose was hydrolyzed with 80% sulfuric acid, and then post-treated with dilute sulfuric acid to remove glucose. What you get.
However, this method has the disadvantages that the equipment is corroded by the acid, the cost of recovering sulfuric acid is high, and the glucose is further decomposed by the acid, and the improvement thereof has been attempted. Not reached. JP-A-5-31000 discloses a method for hydrolyzing and / or pyrolyzing natural or synthetic polymers in addition to cellulose using water in a supercritical or subcritical state as a solvent. . However, in this method, the yield of glucose is limited to 20% to 30%. The reason is that if the reaction conditions are severe to promote hydrolysis, the thermal decomposition of glucose itself will proceed,
On the other hand, if the reaction conditions are moderated to suppress thermal decomposition, insoluble cellulose will remain. To solve these problems, Japanese Patent Laid-Open No.
JP-A-01-95594 discloses that cellulose is temporarily solubilized with supercritical water or subcritical water, and an enzyme treatment with cellulase is carried out while a decomposition product of cellulose is dissolved in a reaction solution, so that glucose and water are dissolved. Methods for obtaining sex cellooligosaccharides are disclosed. The yield of glucose and water-soluble cellooligosaccharides obtained by this method is 75 to 85%, which is a useful method, but requires about 30 minutes to 20 hours for the enzyme treatment time, and the productivity is extremely low. [0006] JP-A-10-327900 discloses a method of producing water-soluble oligosaccharides by contacting cellulose with subcritical water at a temperature of 200 to 300 ° C, and then saccharifying and decomposing them with an enzyme to produce glucose. Is disclosed.
However, the reaction time for obtaining a water-soluble cellooligosaccharide in a yield of 80% or more requires 15 minutes or more, and in order to obtain glucose, it takes 1 to 2 hours by enzymatic reaction. There was a problem with sex. [0007] The present invention provides a method for efficiently producing glucose and / or a water-soluble cellooligosaccharide from a cellulose-containing material. Means for Solving the Problems The present inventors have conducted intensive studies on a method for efficiently producing glucose and / or a water-soluble cellooligosaccharide from a cellulose-containing material, and as a result, have found that the method for producing glucose and / or water-soluble cellooligosaccharides with a short residence time results After performing a critical water reaction and once lowering the molecular weight of cellulose to some extent, as it is, by performing a mild hydrolysis reaction in subcritical water within a few minutes, the secondary decomposition reaction of glucose is suppressed, and The present inventors have found that glucose and / or a water-soluble cellooligosaccharide are efficiently produced, and completed the present invention. That is, in the present invention, cellulose having an average degree of polymerization of 100 or more is contact-reacted with supercritical water or subcritical water at a temperature of 250 to 450 ° C. and a pressure of 15 to 450 MPa for 0.01 to 5 seconds. And then reacting with subcritical water having a pressure of 15 MPa or more and 450 MPa or less and a temperature of 250 ° C. or more and 350 ° C. or less for 1 second or more and 10 minutes or less to hydrolyze glucose and / or
Or a method for producing cellooligosaccharides. The cellulose raw material used in the present invention is not limited as long as it is a material containing cellulose having an average degree of polymerization of 100 or more. Examples include papermaking pulp, chemical dissolving pulp, refined linter, powdered cellulose, crystalline cellulose, straw, rice straw, waste paper, wood chips, regenerated cellulose fibers, and the like. Among these, powdered cellulose and crystalline cellulose, which are powders, are preferable in handling. Plate, paper, and linear materials such as pulp waste paper, rice straw, straw, wood chips, and regenerated cellulose fibers must be cut, crushed, and other pre-processed in advance, and then subjected to acid hydrolysis and explosion. You can go. In the present invention, supercritical water is defined as water in a state of 374 ° C. or more and 22.1 MPa (critical point) or more. The subcritical water is hot water in a state near the critical point, and is 250 ° C. or more and 374 ° C. or less.
It is defined as water of not less than MPa and not more than 22.1 MPa. In the present invention, the cellulose material is used as a first step at a temperature of 250 ° C.
℃ to 450 ° C, pressure 15MPa to 450MPa
And contact with supercritical water or subcritical water of 0.01 seconds or more and 5 seconds or less, and then, as a second step, pressure 15MPa
The cellulose material is hydrolyzed, dissolved, and cooled by contacting with subcritical water having a temperature of 250 to 374 ° C. for 1 to 10 minutes. Temperature conditions greatly affect the yield and physical properties of cellulose. If the temperature is less than 250 ° C. in the first step, most of the raw material remains in the product, so that glucose and / or water-soluble cellooligosaccharide cannot be obtained in good yield.
On the other hand, when the temperature exceeds 450 ° C., hydrolysis and thermal decomposition proceed excessively, and secondary decomposition products of glucose are generated, and the yield of glucose and / or water-soluble cellooligosaccharide decreases. Preferably, the temperature is 350 ° C. or more and 400 ° C.
Hereinafter, the pressure is 25 MPa or more. The contact / reaction time with subcritical water in the second stage also has a significant effect on the yield of glucose and / or water-soluble cellooligosaccharide as the final product. If the contact time is less than 1 second, the reaction does not proceed sufficiently and water-insoluble cellulose remains in the product. If the time exceeds 10 minutes, hydrolysis and thermal decomposition proceed excessively, and the amount of decomposed glucose increases, and the yield also decreases. Preferably 1
0 seconds or more and 1 minute or less. The apparatus for performing the supercritical water or subcritical water treatment is not particularly limited, but a flow-type apparatus capable of freely controlling the reaction time is preferable. After the reaction in the first stage, a system in which the reaction is cooled in a pipe as it is and the reaction is performed in a reactor in the second stage is preferable. FIG. 1 is a schematic system diagram showing an example of a reaction apparatus preferably used in the present invention. The water in the water container 1 is raised to a predetermined pressure by the water pump 2. Then, it is heated by the heater 3 and raised to a predetermined temperature. This is designated as heated water A. on the other hand,
The raw material cellulose is mixed with water and put into a container 4 in a slurry state. The pressure is increased by the slurry pump 5. This is designated as raw material slurry B. The heated water A and the raw material slurry B are mixed and passed through the supercritical water reaction tube 6 to cause a first-stage reaction. Thereafter, the cooling water C is mixed and cooled to the reaction temperature of the second stage, and the reaction of the second stage is performed in the subcritical water reaction tube 9. Thereafter, the mixture is cooled to 50 ° C. or lower by the cooler 10, undissolved solids are removed by the filter 11, and the treated water is collected in the container 13 through the back pressure valve 12. The glucose and / or water-soluble cellooligosaccharide flowing out of the reactor can be separated and purified according to a conventional method to obtain a purified glucose product or a purified cellooligosaccharide product. Further, the aqueous solution flowing out of the reactor in the second stage may be further treated with an enzyme such as cellulase. Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples and the like. Example 1 Crystalline cellulose (Avicel (registered trademark) PH-101, manufactured by Asahi Kasei Corporation) was dispersed in water to obtain a slurry having a solid content of 4.8% by weight. Using a flow-type supercritical water reactor shown in FIG. 1, 5 parts of pre-heated and pressurized supercritical water was mixed with 1 part of the raw material slurry.
Raw material slurry of 0.8 wt% raw material at 400 ° C, 40MP
The reaction was allowed to stay for 0.10 seconds under the condition of a. Thereafter, room temperature water was mixed with the slurry after the reaction at 40 MPa, cooled to 280 ° C., and reacted for 45 seconds. Thereafter, the mixture was cooled to a room temperature with a cooler, filtered to remove solids by a filter, and then returned to normal pressure with a back pressure valve, and the treated aqueous solution was collected in a container. The resulting treated aqueous solution was subjected to component analysis using high performance liquid chromatography. Further, the treated aqueous solution was allowed to stand for 12 hours, and a precipitate was observed, but no precipitate was observed. Table 1 shows the results.
The glucose yield was 19.9% by weight based on the charged raw material,
Water-soluble cellulose oligomer is also 34.0% by weight.
And a total of 53.9% by weight. FIG. 2 shows the results of MALDI-TOFMS analysis of the treatment aqueous solution. MAL
DI-TOFMS is a laser ionization and time-of-flight mass spectrometer (Matrix-Assisted Lazer Desorption Ioniz)
ation-Time of Fleight Mass Spectrometer).
FIG. 2 shows, from the left, molecular weights 336.0, 528.0, 69.
0.5, 852.6, 1015.1, 1177.1, 1
339.5, 1501.1, 1663.7, 1825.
6, 19988.8, and was regularly detected from glucose dimer (cellobiose) to cellododecaose (glucose 12-mer). Example 2 Crystalline cellulose (Avicel PH-101, manufactured by Asahi Kasei Corporation) was dispersed in water to obtain a slurry having a solid content of 4% by weight. Using a flow-type supercritical water reactor shown in FIG. 1, 5 parts of pre-heated and pressurized supercritical water was mixed with 1 part of the raw material slurry. A raw material slurry of 0.67% by weight of raw material was added at 400 ° C. and 40 MPa to form a slurry.
The mixture was allowed to stay for 05 seconds to react. Thereafter, room temperature water was mixed with the slurry after the reaction at 40 MPa, cooled to 280 ° C., and reacted for 30 seconds. Thereafter, the mixture was cooled to a room temperature with a cooler, and filtered to remove a solid content by a filter. The resulting treated aqueous solution was subjected to component analysis using high performance liquid chromatography. The treated aqueous solution was allowed to stand for 12 hours, and the precipitate was observed. As a result, 11.8% by weight of a white precipitate was observed, which was an insoluble cellulose type II aggregate having a relatively high degree of polymerization. Table 1 shows the results. The glucose yield was 9.5% by weight and the water-soluble cellulose oligomer was 55.4% by weight based on the charged raw materials, for a total of 64.9% by weight. FIG. 2 shows the results of MALDI-TOFMS analysis of the treatment aqueous solution. Comparative Example 1 Crystalline cellulose (Avicel PH-101, manufactured by Asahi Kasei Corporation) was dispersed in water to obtain a slurry having a solid content of 4% by weight. Using a flow-type supercritical water reactor shown in FIG. 1, 5 parts of pre-heated and pressurized supercritical water was mixed with 1 part of the raw material slurry. A raw material slurry of 0.67% by weight of raw material was added at 400 ° C. and 40 MPa to form a slurry.
The reaction was allowed to stay for 20 seconds. Then, water at room temperature was mixed with the slurry after the reaction, cooled to room temperature, filtered to remove solids, then returned to normal pressure with a back pressure valve, and the treated aqueous solution was collected in a container. The resulting treated aqueous solution was subjected to component analysis using high performance liquid chromatography. Further, the treated aqueous solution was allowed to stand for 12 hours, and a precipitate was observed, but no precipitate was observed. Table 1 shows the results. The glucose yield is 1 for the raw material charged.
0.5% by weight, water-soluble cellulose oligomer
2.2 wt%, for a total of 42.7 wt%. Also,
FIG. 2 shows the result of MALDI-TOFMS analysis of the treatment aqueous solution. Compared with Example 1, fragmentation of the * part (glucose ring) was in progress, and only cellooctaose (octameric glucose) was detected. Comparative Example 2 Crystalline cellulose (Avicel PH-101, manufactured by Asahi Kasei Corporation) was dispersed in water to obtain a slurry having a solid content of 4% by weight. Using the flow-type supercritical water reactor shown in FIG. 1, 5 parts of pre-heated and pressurized subcritical water was mixed with 1 part of the raw material slurry. The raw material slurry of the 0.67% by weight raw material was retained at 280 ° C. and 40 MPa for 6 minutes. Thereafter, water at room temperature was mixed with the slurry after the reaction, cooled to room temperature, filtered to remove solids, and then returned to normal pressure with a back pressure valve, and the treated aqueous solution was collected in a container. The resulting treated aqueous solution was subjected to component analysis using high performance liquid chromatography. Further, the treated aqueous solution was allowed to stand for 12 hours, and a precipitate was observed, but no precipitate was observed. Table 1 shows the results. The glucose yield was 14.8% by weight and the water-soluble cellulose oligomer was 5.6% by weight based on the charged raw materials.
0.4% by weight. On the other hand, the solid content (insoluble matter) filtered by the filter was 17.3% by weight. FIG. 2 shows the results of MALDI-TOFMS analysis of the treatment aqueous solution.
Only up to cellopentaose (a pentamer of glucose) was detected. [Table 1] According to the present invention, a method for efficiently producing glucose and / or a water-soluble cellooligosaccharide from a cellulose-containing material can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic system diagram showing an example of a supercritical water and subcritical water reactor used in the present invention. FIG. 2 shows the results of MALDI-TOFMS analysis of the treatment aqueous solutions in Examples 1 and 2 and Comparative Examples 1 and 2 of the present invention. [Description of Signs] 1 Water container 2 Water pump 3 Heater 4 Cellulose slurry container 5 Cellulose slurry pump 6 Supercritical water reaction tube 7 Water container 8 Water pump 9 Subcritical water reaction tube 10 Cooler 11 Filter 12 Back pressure valve 13 Treated water Container A Heated water B Raw material slurry C Cooling water

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Yuji Matsue             Asahi Kasei, 6-4100 Asahicho, Nobeoka City, Miyazaki Prefecture             Inside the company F term (reference) 4C057 AA30 BB02 BB04                 4C090 AA05 BA24 BD03 BD37 CA20

Claims (1)

Claims: 1. A cellulose having an average degree of polymerization of 100 or more,
Temperature 250 ° C or higher and 450 ° C or lower, pressure 15MPa or higher 4
Contact reaction with supercritical water or subcritical water of 50 MPa or less for 0.01 second or more and 5 seconds or less, and then cooling, and
MPa to 450 MPa, temperature 250 ° C to 350
A process for producing glucose and / or a water-soluble cellooligosaccharide, which is carried out by contact-reacting with subcritical water at a temperature of not more than 1 ° C. for 1 second to 10 minutes for hydrolysis.