JP2010279255A - Method for saccharifying biomass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for saccharifying a biomass, by which a monosaccharide can be obtained in a high yield in a short time. <P>SOLUTION: The first pressurizing hot water treatment 110 is performed for a biomass 1. The obtained treatment product is subjected to a solid-liquid separation. The obtained solution is a treated solution A1, and the obtained solid content is a residue B1. The second pressurizing hot water treatment 120 is performed for the residue B1. The obtained treatment product is subjected to a solid-liquid separation. The obtained solution is a treated solution A2, and the obtained solid content is a residue B2. A first catalyst monosaccharification treatment 210 for contacting a solid acid catalyst with the treated solution A1 is performed. The reaction conditions at this time are, for example, a temperature of ≥120 to ≤180°C, a pressure of a saturated steam pressure or higher at the temperature, and a reaction time of ≥30 min to ≤12h. The treated solution A2 is subjected to an enzymatic monosaccharification treatment 220 using an enzyme to obtain the monosaccharide 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a biomass saccharification method.

In recent years, the use of biomass, which is renewable energy, has attracted attention from the viewpoint of environmental protection, and in particular, the development of a method for producing ethanol from cellulosic biomass has been promoted. To produce ethanol from cellulosic biomass, first saccharify cellulosic biomass to produce monosaccharides such as glucose and xylose (saccharification), and then produce ethanol by allowing fermentation enzymes to act on the monosaccharides. To do.
Known methods for saccharifying biomass include, for example, hydrolysis using a liquid acid (such as sulfuric acid), steam explosion, enzymatic reaction, and pressurized hot water treatment. Recently, a technique using a solid acid catalyst has been proposed.

Of these, pressurized hot water treatment is preferably used because it uses high-temperature and high-pressure water and does not discharge environmentally hazardous substances (see, for example, Non-Patent Documents 1 and 2). Since it is difficult to decompose cellulose into monosaccharides by the pressurized hot water treatment, it is generally performed to hydrolyze biomass to oligosaccharides and then to monosaccharide by enzymatic saccharification.
Moreover, a solid acid catalyst is used suitably from the point that a waste acid process is unnecessary and can reduce reaction temperature and time (for example, patent documents 1-4). Moreover, the selectivity of saccharide | sugar is high compared with the above-mentioned pressurized hot water process and the process using a liquid acid.

International Publication No. 2008/001696 JP 2006-129735 A JP 2006-88041 A JP 2007-196174 A

Bioresource Technology, 96 (2005), 1959-1966 & Bioresource Technology, 96 (2005), 2026-2032 Bioresource Technology, 96 (2005), 1986-1993

However, when the enzymatic saccharification treatment is performed after the pressurized hot water treatment as in Non-Patent Literatures 1 and 2, the enzymatic saccharification treatment takes a long time (72 hours in Non-Patent Literature 1 and Non-Patent Literature 2). 48 hours), the efficiency is low, which causes a reduction in economic efficiency.
Moreover, in the saccharification process using a solid acid catalyst, since reaction with a solid cellulose biomass raw material becomes solid, there existed a problem that reaction did not advance easily. Therefore, even if the solid acid catalyst described in Patent Documents 1 to 4 is used, the yield of monosaccharide is insufficient, and further improvement is required.

  The objective of this invention is providing the saccharification method of biomass which can obtain a monosaccharide with a high yield in a short time.

  The biomass saccharification method of the present invention comprises a pressurized hydrothermal treatment step for performing pressurized hydrothermal treatment of biomass in the absence of a catalyst, and a catalyst unit for bringing a treatment solution obtained in the pressurized hot water treatment step into contact with a solid acid catalyst. And a saccharification step.

In this invention (referred to as Invention 1), a treatment solution in which biomass is hydrolyzed to oligosaccharides is generated by pressurized hot water treatment. When the solid acid catalyst is brought into contact with this treatment solution in the subsequent catalytic saccharification step, it is a liquid-solid reaction, so that the activity of the solid acid catalyst is easily developed, and the oligosaccharide in the treatment solution is efficiently hydrolyzed. Thus, a monosaccharide can be obtained.
In addition, the catalytic monosaccharification step using a solid acid catalyst can obtain a monosaccharide with a high yield in a short reaction time because the solid acid catalyst has high monosaccharide selectivity.
Furthermore, the environmentally hazardous substance is not discharged in the pressurized hot water treatment process and the catalyst monosaccharification process.

  In the biomass saccharification method of the invention 1, the pressurized hot water treatment step includes a first pressurized hot water treatment step in which treatment is performed with pressurized hot water having a temperature of 180 ° C. or higher and 230 ° C. or lower (referred to as Invention 2). Is preferred.

In the first pressurized hot water treatment step, hemicellulose can be mainly hydrolyzed. There exists a possibility that hemicellulose may not fully decompose | disassemble that temperature is less than 180 degreeC. On the other hand, when the temperature exceeds 230 ° C., C ₅ oligosaccharides and monosaccharides hemicellulose is produced is hydrolyzed is over-decomposed fear.

  In the biomass saccharification method of the invention 1 or the invention 2, the catalytic saccharification step comprises treating the treatment solution obtained in the pressurized hot water treatment step with a temperature of 120 ° C. or higher and 180 ° C. or lower and a saturated vapor pressure or higher at the temperature. It is preferable to contact with the solid acid catalyst for 30 minutes or more and 12 hours or less under pressure (referred to as invention 3).

  If the catalytic saccharification step is carried out in the above temperature range and reaction time, the oligosaccharide in the treatment solution obtained in the pressurized hot water treatment step is saccharified and hyperdegradation hardly proceeds. When the pressure is lower than the saturated vapor pressure at the temperature, water may be evaporated and scattered, which is not preferable.

  In the biomass saccharification method of the invention 2 or the invention 3, in the pressurized hot water treatment step, the residue obtained in the first pressurized hot water treatment step is treated with pressurized hot water having a temperature of 230 ° C. or higher and 300 ° C. or lower. And a second saccharification treatment step of saccharifying the sugar content in the treatment solution obtained in the second pressurized hot water treatment step using an enzyme or a solid acid catalyst. (Referred to as invention 4).

In the second pressurized hot water treatment step, cellulose can be mainly hydrolyzed. If the temperature is lower than 230 ° C, the cellulose may not be sufficiently decomposed. On the other hand, when the temperature exceeds 300 ° C., the C ₆ oligosaccharide or monosaccharide produced by hydrolysis of cellulose may be excessively decomposed.
After hydrolysis in the first pressurized hot water treatment step and the second pressurized hot water treatment step, solid-liquid separation is performed by a known method to separate the residue and the treatment solution. Since each treatment solution contains an oligosaccharide, it can be decomposed into a monosaccharide using an enzyme or a solid acid catalyst. Mainly C ₅ monosaccharides are obtained when the treatment solution obtained in the first pressurized hot water treatment step to monosaccharification primarily C ₆ monosaccharides When the treatment solution obtained in the second pressurized hot water treatment step to monosaccharification Is obtained.
In the invention 4, the catalyst monosaccharification step is performed on the treatment solution obtained in the first pressurized hot water treatment step, and the enzyme or the saccharification step is carried out on the treatment solution obtained in the second pressurized hot water treatment step. Monosaccharification is carried out using a solid acid catalyst. Therefore, a high yield of monosaccharide can be obtained by each monosaccharide treatment.

  In the biomass saccharification method of the invention 2 or the invention 3, in the pressurized hot water treatment step, the residue obtained in the first pressurized hot water treatment step is treated with pressurized hot water having a temperature of 230 ° C. or higher and 300 ° C. or lower. And a second pressurized hot water treatment step, wherein the treatment solution obtained in the first pressurized hot water treatment step and the treatment solution obtained in the second pressurized hot water treatment step are combined. It is preferable to carry out the catalyst monosaccharification step (referred to as invention 5).

In the invention 5, the catalyst saccharification step is performed on the solution obtained by combining the treatment solution obtained in the first pressurized hot water treatment step and the treatment solution obtained in the second pressurized hot water treatment step. That is, monosaccharification using a solid acid catalyst which can simultaneously monosaccharification the C ₅ and C ₆ oligosaccharides. According to this, there exists an advantage that a monosaccharification process can be reduced in the whole process.
In addition, in the invention 4 or the invention 5, a step of bringing the residue obtained in the second pressurized hot water treatment step into contact with a solid acid catalyst may be further provided. The residue obtained by the second pressurized hot water treatment contains an aqueous solution containing unhydrolyzed cellulose, C ₆ oligosaccharides, and C ₆ monosaccharides. Therefore, by implementing the hydrolysis step using a solid acid catalyst for such residues, it can be obtained more C ₆ monosaccharide.

  In the biomass saccharification method of the invention 2 or the invention 3, it is preferable that the biomass saccharification method further comprises a catalyst hydrolysis step in which the residue obtained in the first pressurized hot water treatment step is brought into contact with a solid acid catalyst (referred to as invention 6).

Since the residue obtained in the first pressurized hot water treatment step contains cellulose in which crystals are broken, the hydrolysis effect of the solid acid catalyst is likely to appear significantly. As a result, more C ₆ oligosaccharides and C ₆ monosaccharides can be obtained than when cellulose is brought into contact with untreated biomass that retains a large amount of crystal components.

The biomass saccharification method of the invention 6 preferably comprises a mono-saccharification treatment step (invention 7) for mono-saccharifying the sugar in the treatment solution obtained in the catalytic hydrolysis step using an enzyme or a solid acid catalyst. .
Further, in the biomass saccharification method according to the sixth aspect of the present invention, for the combined solution of the treatment solution obtained in the first pressurized hydrothermal treatment step and the treatment solution obtained by solid-liquid separation after completion of the catalyst hydrolysis step It is preferable to carry out the catalyst monosaccharification step (referred to as Invention 8).
According to this, there can exist an effect similar to invention 4 and 5.

In the biomass saccharification method of the inventions 1 to 8, the solid acid catalyst is a sulfonated organic material obtained by sulfonating an organic material having a BET specific surface area of 200 m ² / g or more, a temperature of 150 ° C. to 250 ° C., and a pressure of 1 MPa to 5 MPa. It is preferable that the amount of sulfo groups in the sulfonated organic substance is 0.1 mmol / g or more and less than 1.0 mmol / g (referred to as Invention 9).
In this invention, when a sulfonated organic substance is used as the solid acid catalyst and used under the above conditions, the monosaccharide can be obtained in high yield because the selectivity of the monosaccharide is high and the hyperdegradation product is not easily generated.

The flowchart which shows the saccharification method of biomass concerning 1st Embodiment of this invention. The flowchart which shows the saccharification method of biomass concerning the modification of the said 1st Embodiment. The flowchart which shows the saccharification method of biomass concerning the modification of the said 1st Embodiment. The flowchart which shows the saccharification method of biomass concerning 2nd Embodiment of this invention. The flowchart which shows the saccharification method of biomass concerning the modification of the said 2nd Embodiment. The flowchart which shows the saccharification method of biomass concerning the modification of the said 2nd Embodiment. The flowchart which shows the saccharification method of biomass concerning the modification of the said 2nd Embodiment.

Hereinafter, although embodiment of this invention is described, this invention is not limited to this.
[First Embodiment]
1st Embodiment demonstrates the saccharification method of biomass based on FIG. In addition, the various apparatuses used here can use what is generally used.
[1. material]
First, biomass 1 used as a raw material will be described. The biomass 1 is not particularly limited as long as it is a cellulosic biomass containing hemicellulose and cellulose. Examples include paper resources, woody and herbaceous biomass. Among these, it is preferable to use herbaceous biomass.
Biomass 1 is in a state of being pulverized in order to improve saccharification efficiency. The size after pulverization is not particularly limited, but can be appropriately adjusted within a range that does not affect the operation of the slurry pump used in the pressurized hot water treatment described below.

[2. Pressurized hot water treatment]
A pressurized hot water treatment is performed on the biomass 1 (pressurized hot water treatment step). The pressurized hot water treatment is performed in a two-stage process including a first pressurized hot water treatment 110 and a second pressurized hot water treatment 120.
[2-1. First pressurized hot water treatment]
First, water is added to biomass 1 to a slurry concentration of 10% by mass or more, and the slurry is supplied to the first pressurized hot water treatment apparatus by a slurry pump. The first pressurized hot water treatment apparatus is set within a temperature range of 180 ° C. or higher and 230 ° C. or lower and a pressure equal to or higher than the saturated vapor pressure within this temperature range, and the treatment is performed within 60 minutes. The slurry concentration can be appropriately adjusted within a range that does not affect the operation of the slurry pump. Thereby, hemicellulose is mainly decomposed to the oligosaccharide level.
The processed product obtained by the first pressurized hot water treatment 110 is subjected to solid-liquid separation, and the obtained solution is defined as a treatment solution A1, and the obtained solid content is defined as a residue B1. Here, primarily include C ₅ oligosaccharides and monosaccharides processing solution A1.

[2-2. Second pressurized hot water treatment]
A pressurized hot water treatment is performed on the residue B1 obtained by the first pressurized hot water treatment. Specifically, water is added to the residue B1 to a slurry concentration of 10% by mass or more, and the slurry is supplied to the second pressurized hot water treatment apparatus by a slurry pump. The second pressurized hot water treatment apparatus is set to a pressure in the temperature range of 230 ° C. or higher and 300 ° C. or lower and the saturated vapor pressure in the temperature range, and the pressurized hot water treatment is performed within 30 minutes. The slurry concentration can be appropriately adjusted within a range that does not affect the operation of the slurry pump. This mainly breaks down cellulose to the molecular level that is greater than oligosaccharides or oligosaccharides.
The processed product obtained by the second pressurized hot water treatment 120 is subjected to solid-liquid separation, and the obtained solution is defined as a treatment solution A2, and the obtained solid content is defined as a residue B2. Here, the treatment solution A2 contains C ₆ oligosaccharides and monosaccharides. Residue B2 contains lignin and is widely used as various fuels.

[3. Monosaccharification treatment]
Next, monosaccharification treatment is performed on the treatment solutions A1 and A2 obtained by the pressurized hot water treatment (the first pressurized hot water treatment 110 and the second pressurized hot water treatment 120).
[3-1. Catalytic monosaccharide treatment]
A first catalytic monosaccharification treatment 210 is performed in which the solid acid catalyst is brought into contact with the treatment solution A1 (catalyst monosaccharification step). The reaction conditions at this time are, for example, a temperature of 120 ° C. or higher and 180 ° C. or lower, and a pressure of a saturated vapor pressure or higher at the temperature and a reaction time of 30 minutes or longer and 12 hours or shorter. When the reaction temperature is too low (less than 120 ° C.) or when the reaction time is short (less than 30 minutes), hydrolysis from oligosaccharide to monosaccharide hardly proceeds. In addition, when the reaction temperature is high (above 180 ° C.) or when the reaction time is long (exceeding 12 hours), the oligosaccharide is excessively decomposed and the yield of monosaccharide may be reduced.

The solid acid catalyst is not particularly limited. For example, zeolite, alumina, silica alumina, activated carbon, cation exchange resin, sulfonated activated carbon, sulfonated mesoporous silica, sulfonated carbon material, zirconia sulfate, zirconia tungstate, phosphoric acid Zirconium etc. are mentioned. Among these, it is preferable to use a monosaccharide having a selectivity of 80% or more, and it is preferable to use a sulfonated activated carbon.
Sulfonated activated carbon is obtained by sulfonating activated carbon. A method for adjusting the sulfonated activated carbon will be described below.
Although it does not specifically limit as a raw material of activated carbon, It is preferable that a BET specific surface area is 200 m < ² > / g or more from the point that reactivity is high. For example, a commercially available product can be used, and it may be produced by carbonizing and activating carbon materials such as coconut shell, petroleum pitch, coal, and phenol resin.

Such activated carbon is well dispersed in concentrated sulfuric acid or fuming sulfuric acid, and heated and stirred to produce sulfonated activated carbon. The heating temperature is 100 ° C. to 250 ° C., and the reaction time is 30 minutes to 24 hours. Concentrated sulfuric acid or fuming sulfuric acid is used in an amount of 10 ml to 30 ml with respect to 1 g of activated carbon.
Here, the concentration of concentrated sulfuric acid is preferably 90% by mass or more, and more preferably 95% by mass or more. When the concentration of concentrated sulfuric acid is less than 90% by mass, sulfonation of activated carbon may be insufficient. Moreover, when using fuming sulfuric acid, the density | concentration is not specifically limited, For example, what has a content rate of 30 to 60% of sulfur trioxide can be used.

  The amount of sulfo group in the obtained sulfonated activated carbon is preferably 0.1 mmol / g or more, more preferably 0.1 mmol / g or more and 1.0 mmol / g or less with respect to 1 g of activated carbon. . If the amount of the sulfo group is less than 0.1 mmol / g, the activity becomes insufficient and the yield of monosaccharides may be reduced.

Next, the sulfonated activated carbon is washed and filtered using water or hot water.
Sulfonated activated carbon is removed in advance by hydrothermal treatment because sulfo groups loosely bonded to the surface may be eliminated during the reaction. For example, the sulfonated activated carbon is added to water having a temperature of 100 ° C. or more and 250 ° C. or less, and treated under hydrothermal conditions of a pressure of 1 MPa or more and 5 MPa or less. The treatment time is 30 minutes or more and 5 hours or less. After the hydrothermal treatment is finished, the solution is filtered and dried.

When the sulfonated activated carbon that has been subjected to such treatment is added to the treatment solution A1, elution of sulfate ions can be suppressed, and excessive decomposition can be suppressed.
In addition, the addition amount of the sulfonated activated carbon (solid acid catalyst) is preferably in the range of 0.01 g to 5 g with respect to 1 g of the oligosaccharide. If the added amount of the catalyst is less than 0.01 g, monosaccharification may be insufficient. Moreover, even if the addition amount of a catalyst exceeds 5 g, an improvement in sugar yield cannot be obtained.
The sulfonated activated carbon (solid acid catalyst) used in the catalyst monosaccharide treatment 210 is recovered by solid-liquid separation of the treatment liquid after the treatment is completed, and may be reused in the next catalyst monosaccharide treatment 210. It may be reused as fuel.

[3-2. Enzymatic saccharification treatment]
The monosaccharification of the treatment solution A2 is performed by an enzyme monosaccharification treatment 220 with an enzyme.
The enzyme is not particularly limited as long as it can hydrolyze an oligosaccharide into a monosaccharide, and examples thereof include polysaccharide-degrading enzymes such as cellulase and xylanase. Specifically, there are products such as “ACCELLERASE 1000” (manufactured by Genencor) as cellulase.
In the enzyme saccharification treatment 220, an appropriate amount of cellulase is added to the treatment solution A2, and left for a certain period of time until the reaction is completed. Here, the reaction is performed by treating a reaction solution obtained by adding treatment solution A2 and cellulase to a buffer solution adjusted to pH 3.5 or more and 5.5 or less with a buffer at a temperature of 45 ° C. or more and 55 ° C. or less for 24 hours or more. Done.
And the filtrate obtained by filtering the process solution after reaction is collect | recovered. This filtrate mainly contains glucose which is monosaccharide 3.

[4. Effects of First Embodiment]
As described above, in the present embodiment, the following operational effects can be achieved.
(1) In the above-described embodiment, after the first pressurized hot water treatment 110 is performed on the biomass 1, the catalyst monosaccharification treatment 210 in which the sulfonated activated carbon (solid acid catalyst) is brought into contact with the treatment solution A1 is performed. To obtain monosaccharide 3.
According to this, the first pressurized hydrothermal treatment 110 hydrolyzes the hemicellulose in the biomass 1 to oligosaccharide, and at the same time, the cellulose and lignin contained in the biomass 1 are removed, and the oligosaccharide is hydrolyzed in a subsequent step. Cheap. In addition, since the reaction between the hydrolyzed treatment solution and the sulfonated activated carbon is a liquid-solid reaction, the activity of the sulfonated activated carbon, which is a catalyst, easily develops, and the oligosaccharide in the treatment solution A1 is efficiently hydrolyzed. Can be disassembled. In addition, the solid acid catalyst has high selectivity for monosaccharides. Therefore, a high yield of monosaccharide 3 can be obtained in a short reaction time (30 minutes to 12 hours).

(2) Moreover, in the said embodiment, the 2nd pressurized hot water process 120 is performed with respect to the residue B1 produced | generated by the 1st pressurized hot water process 110. FIG. According to this, the cellulose which was not hydrolyzed by the 1st pressurized hot water process 110 can be hydrolyzed even to an oligosaccharide. And since the enzyme monosaccharide | saccharification process 220 is performed with respect to the hydrolyzed process solution A2, the monosaccharide 3 can be obtained with a higher yield. Monosaccharide saccharification treatment with an enzyme requires a longer time than the catalytic monosaccharide saccharification treatment 210 with a solid acid catalyst, but monosaccharide 3 can be obtained in a high yield because of high monosaccharide selectivity.

(3) Further, in the above embodiment, the first pressurized hot water treatment 110 and the second pressurized hot water treatment 120 are performed in the absence of a catalyst. By performing the first pressurized hot water treatment 110 in the absence of a catalyst, the biomass 1 can be effectively hydrolyzed into oligosaccharides. In addition, the crystal structure of the solid cellulose residue contained in the residue B1 can be destroyed. Therefore, in the process of the second pressurized hydrothermal treatment 120, hydrolysis of cellulose proceeds, the concentration of C ₆ oligosaccharide and monosaccharide in the treatment solution A2 is increased, and the enzyme monosaccharification treatment 220 has a high yield. To obtain monosaccharide 3.

(4) In the above embodiment, sulfonated activated carbon is used as the solid acid catalyst of the first catalyst monosaccharification treatment 210. When the sulfonation activity is used, monosaccharide 3 can be obtained in high yield because the selectivity of monosaccharide is high and it is difficult to produce a hyperdegradation product.
(5) Moreover, in the said embodiment, since all the processes of a pressurized hot water process, the catalyst monosaccharification process by a solid acid catalyst, and an enzyme monosaccharification process have little load with respect to an environment, their usefulness is high.
(6) Furthermore, in the said embodiment, after using a solid acid catalyst (sulfonated activated carbon), since it can recycle | reuse by the catalyst monosaccharide | saccharification process 210 or can be reused as a fuel, its usefulness is high. When reusing as fuel, it can be used as fuel together with residue B2 such as lignin. Further, the mixture of the residue B2 and the used solid acid catalyst can be reused as a raw material for the activated carbon catalyst (solid acid catalyst) used in the present embodiment.

[5. Modification of First Embodiment]
Note that the first embodiment may be configured as follows.
For example, in the above embodiment, the enzyme monosaccharification treatment 220 was performed on the treatment solution A2 obtained by the second pressurized hot water treatment 120, but as shown in FIG. 2, the solid acid catalyst was treated on the treatment solution A2. The second catalytic monosaccharification treatment 230 may be performed. According to this, the reaction time can be further shortened by the second catalytic monosaccharification treatment 230.
Moreover, as shown in FIG. 3, the treatment solution A1 obtained by the first pressurized hot water treatment 110 and the treatment solution A2 obtained by the second pressurized hot water treatment 120 are mixed, and a solid is added to this mixed solution. You may perform the 3rd catalyst monosaccharification process 240 by an acid catalyst. According to this, the catalyst saccharification treatment may be carried out once, so that it can be carried out with few facilities.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIG. In the second embodiment, only the process is different and the details of each process are the same as those in the first embodiment, and therefore only the process will be described.
In the second embodiment, the pressurized hot water treatment for the biomass 1 is performed in a one-step process of only the first pressurized hot water treatment 110. When the first pressurized hot water treatment 110 is performed, the treated product is subjected to solid-liquid separation, and the obtained solution is designated as a treatment solution A1, and the obtained solid content is designated as a residue B1.
Next, the first catalytic monosaccharide treatment 210 is performed on the treatment solution A1 to obtain monosaccharide 3.

[Catalyst treatment]
Further, the catalyst treatment 310 is performed on the residue B1 (catalyst hydrolysis step). Here, the same solid acid catalyst as that used in the first catalyst monosaccharification treatment 210 described above can be used. Water is added to the residue B1 to make the slurry concentration 10 mass% or more, the temperature is 120 ° C. or higher and 230 ° C. or lower, and the pressure is higher than the saturated vapor pressure of the temperature and the reaction time is 30 minutes or longer and 12 hours or shorter. The product obtained by the catalyst treatment 310 is subjected to solid-liquid separation, and the resulting solution is designated as a treatment solution A3, and the resulting solid content is designated as a residue B3. The residue B3 contains lignin and is widely used as various fuels.
Next, the enzyme monosaccharification process 220 is implemented with respect to process solution A3, and the monosaccharide 3 is obtained.
Note that the solid acid catalyst used in the catalyst treatment 310 is widely reused as various fuels together with lignin and the like contained in the residue after the treatment.

[Effects of Second Embodiment]
As mentioned above, in 2nd Embodiment, there can exist the effect (1) (3) (4) (5) and the following effect of 1st Embodiment.
(6) In the second embodiment, since the catalyst treatment 310 is performed on the residue B1 obtained by the first pressurized hot water treatment 110, the cellulose that has not been hydrolyzed by the first pressurized hot water treatment 110 Can be hydrolyzed to oligosaccharides. Then, since the enzymatic monosaccharification process 220 with respect to the hydrolyzed treatment solution A3 (including the C ₆ oligosaccharide and monosaccharides), it can be obtained monosaccharide in higher yields. Since monosaccharide saccharification treatment with enzymes has higher selectivity for monosaccharides than catalytic monosaccharification treatment 210 with a solid acid catalyst, monosaccharide 3 can be obtained in high yield. Further, as described in (3), since the crystal structure of cellulose in the residue B1 is broken to some extent, the activity of the catalyst in the catalyst treatment 310 is easily developed.

[Modification of Second Embodiment]
Note that the second embodiment may be configured as follows.
For example, as shown in FIG. 5, the treatment solution A1 and the treatment solution A3 obtained in the second embodiment are mixed, and the mixture is subjected to a third catalytic monosaccharification treatment 240 using a solid acid catalyst. Also good. According to this, the catalyst saccharification treatment may be carried out once, so that it can be carried out with few facilities.
Further, as shown in FIG. 6, in the second embodiment, since the treatment solution A3 obtained by the catalyst treatment 310 has a large proportion of monosaccharides, the treatment solution A3 is further subjected to monosaccharide treatment with an enzyme or the like. You may collect | recover the monosaccharide contained in processing solution A3. According to this, since the saccharification process only needs the 1st catalyst saccharification process 210 in the whole process, the process of saccharification can be simplified.

  Furthermore, it is good also as a structure which combined the above-mentioned 1st Embodiment and 2nd Embodiment. Specifically, as shown in FIG. 7, the first pressurized hot water treatment 110 and the second pressurized hot water treatment 120 are performed on the biomass 1, and the catalyst treatment 310 is performed on the obtained residue B2. carry out. And the 1st catalyst monosaccharide | saccharification process 210 is implemented with respect to the process solution A1 obtained by the 1st pressurized hot water process 110, and the monosaccharide 3 is obtained. In addition, the enzyme monosaccharification treatment 220 is performed on the treatment solution A2 obtained by the second pressurized hot water treatment 120 to obtain the monosaccharide 3. Furthermore, the monosaccharide obtained by the catalyst treatment 310 is recovered as monosaccharide 3. According to this, since a hydrolysis process is implemented several times with respect to the residue by hydrolysis of the biomass 1, more cellulose can be hydrolyzed. Therefore, the monosaccharide 3 can be recovered with a high yield.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above embodiment, sulfonated activated carbon is used as the solid acid catalyst, but the present invention is not limited to this. Catalyst monosaccharification treatment and catalyst treatment may be performed using zeolite, alumina, silica alumina, activated carbon, cation exchange resin, sulfonated mesoporous silica, sulfonated carbon material, zirconia sulfate, zirconia tungstate, zirconium phosphate, etc. .

EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated in more detail, this invention is not restrict | limited at all to the description content of these Examples.
First, the following two types (C1, C2) of sulfonated activated carbon were prepared as solid acid catalysts.

[Adjustment of sulfonated activated carbon (C1)]
8.0 g of commercially available activated carbon powder (manufactured by Wako Pure Chemical Industries, Ltd.) was added to 80 mL of 95% concentrated sulfuric acid. The reaction mixture was placed in a 125 mL glass washing bottle and heated from room temperature to 150 ° C. over 30 minutes while flowing nitrogen gas at a flow rate of 80 mL / min. And the said reaction liquid mixture was made to react at 150 degreeC for 4 hours, stirring. After the reaction mixture was allowed to cool to room temperature, the sulfonated activated carbon was filtered off. The obtained activated carbon was washed with 2 L of room temperature water and 6 L of 80 ° C. distilled water. After washing, 2 g of activated carbon was added to 100 mL of water and hydrothermally treated in an autoclave at 200 ° C. and 1.6 MPa for 3 hours. The obtained sulfonated activated carbon was washed with 1 L of room temperature water and filtered, and then filtered and dried at 100 ° C. for 12 hours with a constant temperature dryer.

[Adjustment of sulfonated activated carbon (C2)]
1.0 g of commercially available activated carbon powder (Wako Pure Chemical Industries, Ltd.) was added to 20 mL of 95% concentrated sulfuric acid. The reaction mixture was put in a 50 mL test tube type glass container and heated to 150 ° C. at a rate of 5 ° C./min while flowing argon gas at a flow rate of 40 mL / min. The reaction mixture was reacted at 150 ° C. for 16 hours with stirring. After the reaction mixture was allowed to cool to room temperature, the sulfonated activated carbon was filtered off. The obtained activated carbon was washed with 3 L of distilled water at 80 ° C. Subsequently, in addition to 20 mL of water, hydrothermal treatment was performed in an autoclave at 200 ° C. and 1.6 MPa for 3 hours, and then the sulfonated activated carbon was separated by filtration and dried at 100 ° C. for 12 hours by a constant temperature dryer.

[Test 1]
It was confirmed as follows that oligosaccharides can be converted into monosaccharides by sulfonated activated carbon (C1).
2.0 g of xylo-oligosaccharide (manufactured by Wako Pure Chemical Industries), 0.5 g of sulfonated activated carbon catalyst (C1) and 50 g of ion-exchanged water are put in an autoclave, heated to 150 ° C. in 45 minutes, and reacted at 150 ° C. for 3 hours. It was. After cooling to room temperature, the contents were taken out, and the sulfonated activated carbon catalyst (C1) and the liquid after the reaction were separated by filtration. The sugar in the filtrate was measured by high performance liquid chromatography (HPLC). The measurement conditions are as follows.
Measurement conditions: Column: HITACHI-GL-W520
Eluent: 0.1% formic acid water
Flow rate: 1.0 mL / min
Detector RI (cell temperature 40 ° C)
As a result of the measurement, the remaining oligosaccharide in the total sugar of the product was 0.1% or less, and the remainder was a monosaccharide (xylose). It was also confirmed that no overdecomposed product was present in the product. That is, it can be said that the selectivity of monosaccharide is high.

[Test 2]
[Example 1]
10 g of rice straw cut to 5 mm or less and 57 g of ion-exchanged water were placed in an autoclave and subjected to pressurized hot water treatment at 190 ° C. for 10 minutes. The obtained contents were filtered to obtain a rice straw pressurized hot water treatment liquid (A1) as a filtrate. Then, 5 mL of this treatment liquid (A1) and 50 mg of the sulfonated activated carbon catalyst (C2) were placed in an autoclave and reacted at 150 ° C. for 3 hours. The solution thus obtained is designated as Solution C.

[Comparative Example 1]
In 5 mL of treatment liquid (A1), the catalyst was not put in an autoclave and reacted at 150 ° C. for 3 hours. The solution thus obtained is designated as Solution D.

For the solutions obtained in Example 1 and Comparative Example 1, the concentration of monosaccharides was measured under the following measurement conditions.
Measurement conditions: Column: shodex-SP0810
Eluent: Water
Flow rate: 1.0 mL / min
Detector RI (cell temperature 40 ° C)

[Evaluation]
The glucose (monosaccharide) concentration in the solution C of Example 1 was 16.9 times the glucose concentration in the solution D of Comparative Example 1. Moreover, the xylose (monosaccharide) concentration in the solution C of Example 1 was 5.0 times the xylose concentration in the solution D of Comparative Example 1. That is, in Example 1, a monosaccharide was obtained in high yield.

[Test 3]
[Example 2]
10 g of rice straw cut to 5 mm or less and 57 g of ion-exchanged water were placed in an autoclave and subjected to pressurized hot water treatment at 190 ° C. for 10 minutes. The obtained contents were filtered, and the treatment solution A1 as the filtrate was treated in the same manner as in Example 1.
The remaining solid (residue) was dried at 105 ° C. for 12 hours. 2 g of this residue, 0.5 g of the sulfonated activated carbon catalyst (C1) and 50 g of ion-exchanged water were placed in an autoclave and reacted at 180 ° C. for 3 hours. The product thus obtained was filtered to obtain filtrate E.

[Example 3]
10 g of rice straw cut to 5 mm or less and 57 g of ion-exchanged water were placed in an autoclave and subjected to pressurized hot water treatment at 190 ° C. for 10 minutes. The obtained contents were filtered, and the treatment solution A1 as the filtrate was treated in the same manner as in Example 1.
The remaining solid (residue) was dried at 105 ° C. for 12 hours. To 2 g of this residue, 50 g of ion-exchanged water was added and reacted at 230 ° C. for 10 minutes in an autoclave without using a catalyst. The resulting product was filtered to obtain filtrate F.

For the filtrates obtained in Example 2 and Example 3, the monosaccharide concentration was measured under the following measurement conditions.
Measurement conditions: Column: HITACHI-GL-W520
Eluent: 0.1% formic acid water
Flow rate: 1.0 mL / min
Detector RI (cell temperature 40 ° C)

[Evaluation]
The glucose (monosaccharide) concentration in the filtrate E of Example 2 was 0.56 mg / ml, and the glucose concentration in the filtrate F of Example 3 was 0.26 mg / ml. That is, the monosaccharide was obtained in a higher yield in Example 2 using a catalyst.
In Example 3, since the saccharification of the solid residue does not use a catalytic reaction, the reaction temperature is set higher than in Example 2 and the reaction time is set shorter. On the other hand, the treatment of the filtrate A1 was performed under the same conditions in both Examples 2 and 3.

  The present invention can be used for the production of fuels, chemicals and the like using biomass as a raw material.

DESCRIPTION OF SYMBOLS 1 ... Biomass 3 ... Monosaccharide 110 ... 1st pressurized hot water process 120 ... 2nd pressurized hot water process 210 ... 1st catalyst monosaccharification process 220 ... Enzyme monosaccharification process 230 ... 2nd catalyst monosaccharification process 240 ... 1st 3 catalyst monosaccharification treatment 310 ... catalyst treatment A1, A2, A3 ... treatment solution B1, B2, B3, B4 ... residue

Claims (9)

A pressurized hot water treatment process for performing pressurized hot water treatment of biomass under no catalyst;
And a catalytic saccharification step in which the treatment solution obtained in the pressurized hot water treatment step is brought into contact with a solid acid catalyst. The biomass saccharification method according to claim 1,
The pressurized hot water treatment step includes
A biomass saccharification method comprising a first pressurized hot water treatment step of treating with pressurized hot water at a temperature of 180 ° C or higher and 230 ° C or lower. In the biomass saccharification method according to claim 1 or 2,
The catalytic saccharification step comprises
Bringing the treatment solution obtained in the pressurized hot water treatment step into contact with the solid acid catalyst at a temperature of 120 ° C. or higher and 180 ° C. or lower and a pressure of a saturated vapor pressure or higher at the temperature for 30 minutes or longer and 12 hours or shorter. A biomass saccharification method characterized. In the biomass saccharification method according to claim 2 or 3,
The pressurized hot water treatment step includes
A second pressurized hot water treatment step of treating the residue obtained in the first pressurized hot water treatment step with pressurized hot water having a temperature of 230 ° C. or higher and 300 ° C. or lower;
A biomass saccharification method comprising: a saccharification treatment step of saccharifying a sugar content in the treatment solution obtained in the second pressurized hot water treatment step using an enzyme or a solid acid catalyst. In the biomass saccharification method according to claim 2 or 3,
The pressurized hot water treatment step includes
A second pressurized hot water treatment step of treating the residue obtained in the first pressurized hot water treatment step with pressurized hot water having a temperature of 230 ° C. or higher and 300 ° C. or lower;
The catalyst monosaccharification step is performed on a solution obtained by combining the treatment solution obtained in the first pressurized hot water treatment step and the treatment solution obtained in the second pressurized hot water treatment step. To saccharify biomass. In the biomass saccharification method according to claim 2 or 3,
A biomass saccharification method, further comprising a catalytic hydrolysis step in which the residue obtained in the first pressurized hot water treatment step is brought into contact with a solid acid catalyst. In the biomass saccharification method according to claim 6,
A biomass saccharification method comprising a mono-saccharification treatment step of mono-saccharifying a sugar content in the treatment solution obtained in the catalytic hydrolysis step using an enzyme or a solid acid catalyst. In the biomass saccharification method according to claim 6,
Carrying out the catalytic monosaccharification step on a solution obtained by combining the treatment solution obtained in the first pressurized hot water treatment step and the treatment solution obtained by solid-liquid separation after the catalyst hydrolysis step is completed. A biomass saccharification method characterized. In the method for saccharification of biomass according to any one of claims 1 to 8,
The solid acid catalyst is
A sulfonated organic material obtained by sulfonating an organic material having a BET specific surface area of 200 m ² / g or more is obtained by performing hydrothermal treatment at a temperature of 150 ° C. to 250 ° C. and a pressure of 1 MPa to 5 MPa,
The biomass saccharification method, wherein a sulfo group amount in the sulfonated organic substance is 0.1 mmol / g or more and less than 1.0 mmol / g.

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