JP2010284120A - System and method for treating biomass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for treating biomass, capable of removing fermentation-inhibiting components without creating a reduction in productivity and increase in production cost. <P>SOLUTION: This system for treating biomass is configured to include a hydrolyzing device for producing a hydrolysate containing glucose, the fermentation-inhibiting components and biomass residues by hydrolyzing a wood-based biomass, a solid-liquid-separating device for performing the solid-liquid separation of the hydrolysate to separate it into a sugar solution containing the glucose and fermentation-inhibiting components and a solid material containing the biomass residues, a gas liquid-contacting device for removing the fermentation-inhibiting components from the sugar solution by a gas liquid-contacting method and a fermenting device for producing ethanol by fermenting the treated liquid obtained after the removal of the fermentation-inhibiting components. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a biomass processing system and method.

  In recent years, biomass, which is a carbon neutral resource, has attracted attention as an alternative resource for fossil resources such as oil. As one of the uses of such biomass, there is known a technique for producing glucose by saccharifying and hydrolyzing cellulose contained in woody biomass, and further producing bioethanol by subjecting this glucose to alcohol fermentation. ing.

  In the process of producing bioethanol from woody biomass as described above, volatile fermentation-inhibiting components such as formic acid, acetic acid and phenol produced when saccharifying and hydrolyzing cellulose cause a decrease in ethanol fermentation rate. Problems have been pointed out. For such a problem, for example, in Patent Document 1 below, hydrolysis is performed by treating a hydrolyzed product obtained by saccharification / hydrolysis (treated product containing glucose and fermentation inhibiting components) with a wood-based carbide. A technique for removing a fermentation-inhibiting component contained in a processed product by adsorbing it on a wood-based carbide is disclosed.

JP 2005-270056 A

  When using wood-based carbide as an adsorbent or catalyst for removing fermentation-inhibiting components as in the technique disclosed in Patent Document 1, in order to maintain the removal performance of fermentation-inhibiting components, it is necessary to maintain a certain period of time. In addition, it is necessary to exchange these adsorbents or catalysts, which causes a problem that the process is temporarily interrupted and the production efficiency is lowered. In addition, a new adsorbent or catalyst is required for each replacement operation, resulting in an increase in production cost.

 This invention is made | formed in view of the situation mentioned above, and provides the biomass processing system and method which can remove a fermentation inhibitory component, without causing the fall of production efficiency and the increase in production cost. Objective.

In order to solve the above-described problem, the biomass treatment system according to the first aspect of the present invention hydrolyzes woody biomass to produce a hydrolyzed product containing glucose, fermentation-inhibiting components, and biomass residues. A solid-liquid separation device that separates the hydrolyzed product into a solid solution containing the glucose residue and the biomass residue by solid-liquid separation of the hydrolyzed product and a solid product containing the biomass residue; A gas-liquid contact device that removes the fermentation-inhibiting component from the sugar solution, and a fermentation device that produces ethanol by fermenting a treatment liquid obtained after the fermentation-inhibiting component is removed.
Moreover, in the biomass processing system according to the first aspect, the fermentation apparatus supplies carbon dioxide generated in the process of producing the ethanol to the gas-liquid contact apparatus, and the gas-liquid contact apparatus includes the fermentation apparatus. The fermentation-inhibiting component is removed from the sugar solution by the gas-liquid contact method using the carbon dioxide supplied from the sugar solution.

In addition, the biomass treatment system according to the second aspect of the present invention combines a gas-liquid contact method with a hydrolysis treatment of woody biomass to produce a hydrolysis-treated product containing glucose, fermentation-inhibiting components, and biomass residues. A hydrolysis apparatus that removes the fermentation-inhibiting components from the hydrolyzed product, and a solid solution that separates the hydrolyzed product into a solid solution containing the glucose solution and the biomass residue by solid-liquid separation. It is provided with a liquid separator and a fermenter which produces ethanol by fermenting the sugar solution.
Moreover, the biomass processing system which concerns on the said 2nd aspect WHEREIN: The said fermentation apparatus supplies the carbon dioxide generated in the process of producing | generating the said ethanol to the said hydrolysis apparatus, and the said hydrolysis apparatus is supplied from the said fermentation apparatus. The fermentation inhibiting component is removed from the hydrolyzed product by the gas-liquid contact method using the carbon dioxide.

On the other hand, the biomass treatment method according to the first aspect of the present invention produces a hydrolyzed product containing glucose, fermentation-inhibiting components, and biomass residues by hydrolyzing the woody biomass. Separation into a sugar solution containing the glucose and fermentation inhibiting component and a solid substance containing the biomass residue by solid-liquid separation, removing the fermentation inhibiting component from the sugar solution by a gas-liquid contact method, and the fermentation inhibiting component It is characterized in that ethanol is produced by fermenting a treatment liquid obtained after removal of.
Moreover, in the biomass treatment method according to the first aspect, the fermentation-inhibiting component is removed from the sugar solution by the gas-liquid contact method using carbon dioxide generated in the process of producing the ethanol. .

Moreover, the biomass treatment method according to the second aspect of the present invention combines a gas-liquid contact method with a hydrolysis treatment of woody biomass to produce a hydrolyzed product containing glucose, fermentation inhibiting components and biomass residues. The fermentation-inhibited components are removed from the hydrolyzed product, and the hydrolyzed product is separated into a solid solution containing the glucose residue and the biomass residue by solid-liquid separation. It is characterized by producing ethanol by fermentation.
Moreover, in the biomass treatment method according to the second aspect, the fermentation-inhibiting component is removed from the hydrolyzed product by the gas-liquid contact method using carbon dioxide generated in the process of producing the ethanol. And

 In the present invention, it is not necessary to use an adsorbent or a catalyst for removing fermentation-inhibiting components contained in the hydrolyzed product as in the prior art, so there is no need to perform these replacement operations and the process is temporarily suspended. Continuous processing is possible without any problems. Therefore, according to the present invention, it is possible to remove fermentation-inhibiting components without causing a decrease in production efficiency and an increase in production cost.

It is a block diagram of biomass processing system 1 concerning a 1st embodiment of the present invention. It is the schematic of the hydrolysis apparatus 12 in the biomass processing system 1. FIG. It is a block diagram of biomass processing system 1 concerning a 2nd embodiment of the present invention. It is the schematic of the hydrolysis apparatus 22 in the biomass processing system 2. FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing a system configuration of a biomass processing system 1 according to the first embodiment. As shown in FIG. 1, the biomass processing system 1 according to the first embodiment is a bioethanol using woody biomass containing cellulose, hemicellulose, and lignin as main components, such as wood chips and waste building materials, which are a kind of biomass. Is a chemical plant system that includes a pretreatment device 11, a hydrolysis device 12, a solid-liquid separation device 13, a stripping tower (gas-liquid contact device) 14, and a bioreactor (fermentation device) 15.

In addition, the cellulose contained in the woody biomass is a polysaccharide represented by the chemical formula (C ₆ H ₁₀ O ₅ ) _n as is well known, and is a highly polymerized glucose (monosaccharide) containing 6 carbon atoms. It is a molecular compound. Hemicellulose is a polymer compound obtained by polymerizing monosaccharides other than glucose (mainly monosaccharides containing 5 carbon atoms). Lignin is a polymer compound that has a three-dimensional grain structure and forms wood by surrounding the cellulose and hemicellulose.

Cellulose in woody biomass exists mainly as crystallized fibers. In addition, cellulose is covered with hemicellulose and lignin, and it is difficult to perform saccharification (hydrolysis) as it is. Therefore, the pretreatment device 11 is a hydrolysis device 12 to be described later, such as cutting or non-crystallization of cellulose fibers contained in the woody biomass and decomposition / dissolution of hemicellulose and lignin as pretreatment of the woody biomass supplied as a raw material. To promote the glucose formation reaction (cellulose saccharification reaction) by hydrolysis (specifically, crushing or cooking woody biomass, steaming, hydrothermal treatment, alkali treatment, acid treatment, etc.) .
After the pretreatment as described above, the pretreatment device 11 supplies the pretreated woody biomass (hereinafter referred to as pretreated biomass) to the hydrolysis device 12.

The hydrolysis apparatus 12 hydrolyzes the pretreated biomass supplied from the pretreatment apparatus 11 using a dilute sulfuric acid method. Specifically, as shown in FIG. 2, hydrolysis treatment is performed by heating pretreated biomass and dilute sulfuric acid while stirring and mixing in a tank. By this hydrolysis treatment, a saccharification reaction of cellulose contained in the pretreated biomass occurs, and the cellulose is decomposed into glucose which is a kind of hexasaccharide. In addition, volatile fermentation inhibiting components such as formic acid, acetic acid and phenol and biomass residues such as lignin are also produced by this hydrolysis treatment.
The hydrolysis apparatus 12 supplies the solid-liquid separation apparatus 13 with the hydrolyzed product containing glucose, fermentation inhibition components, and biomass residues generated as described above. The hydrolysis treatment method is not limited to the dilute sulfuric acid method, and an enzymatic saccharification method, a concentrated sulfuric acid method, a hydrochloric acid method, a mechanochemical method, and the like can be used. In the case of a process using an acid such as sulfuric acid or hydrochloric acid, it is necessary to carry out a neutralization treatment at a later stage.

  The solid-liquid separation device 13 separates the hydrolysis-treated product supplied from the hydrolysis device 12 into a solid solution containing glucose and a fermentation residue, and a solid matter containing a biomass residue by solid-liquid separation. The sugar solution is fed to the top of the stripping tower 14. As such a solid-liquid separation device 13, a tank / decanter device can be used. Water is stored in the tank of this tank / decanter device, the hydrolyzed product produced by the hydrolyzing device 12 is supplied into the water, and glucose and fermentation-inhibiting components in the hydrolyzed product are dissolved in water. To do. Since the biomass residue, which is a solid material, accumulates in the lower part of the tank, the solid material can be separated and discharged by opening and closing the valve.

As a method of solid-liquid separation, water is sprayed and washed on the hydrolyzed product, and a sugar solution obtained by dissolving glucose and fermentation inhibiting components in water is collected and supplied to the stripping tower 14. The remaining solid material may be separated and discharged by a conveying device such as a conveyor or a feeder.
Moreover, you may employ | adopt the method of isolate | separating a hydrolysis processed material into a sugar solution and a solid substance using filtration / separation apparatuses, such as a filter press.

  The stripping tower 14 is a gas-liquid contact device that removes fermentation inhibiting components from a sugar solution by a stripping method (a kind of gas-liquid contact method) using carbon dioxide supplied from a bioreactor 15 described later as a stripping gas. Function. That is, the sugar solution generated by the solid-liquid separator 13 is supplied to the top of the stripping tower 14, and the carbon dioxide generated in the process of ethanol fermentation by the bioreactor 15 is supplied to the bottom of the stripping tower 14. Is done.

The sugar solution and carbon dioxide supplied to the stripping tower 14 in this way are in gas-liquid contact in the tower, and impurities (fermentation-inhibiting components) contained in the sugar solution move into the gas (carbon dioxide), and fermentation is performed. A gas containing an inhibitory component is discharged from the top of the column. That is, the fermentation inhibiting component can be removed from the sugar solution by gas-liquid contact between the sugar solution and carbon dioxide. The stripping tower 14 supplies the bioreactor 15 with a stripping solution (sugar solution from which the fermentation inhibitory component has been removed) obtained after the fermentation inhibitory component is removed.
In addition, since the fermentation inhibiting component discharged from the stripping tower 14 is mainly a hydrocarbon compound, the hydrocarbon compound is burned in a stack and exhausted, or collected and concentrated with an adsorbent or the like to be reused as fuel. You may provide the process to utilize. Further, the gas-liquid contact method is not limited to the stripping method, and a bubbling method or the like may be used.

The bioreactor 15 adds ethanol-fermenting microorganisms such as yeast and nutrient sources such as nitrogen and phosphorus to the stripping solution supplied from the above-described stripping tower 14, under appropriate conditions such as temperature and pH. Bioethanol is produced by culturing microorganisms and fermenting a stripping solution (sugar solution containing glucose) with alcohol. As the ethanol fermentation microorganism, various known microorganisms such as Saccharomyces yeast can be used.
Here, although the stripping treatment liquid supplied from the stripping tower 14 contains glucose, but does not contain any fermentation-inhibiting components, there is no problem of causing a decrease in the ethanol fermentation rate.

The bioreactor 15 supplies carbon dioxide generated in the process of producing the bioethanol, that is, the glucose fermentation process, to the bottom of the stripping tower 14. In addition, following (1) Formula is reaction formula which shows that a carbon dioxide is produced | generated by alcohol fermentation.
_{C 6 H 12 O 6 → 2C} 2 H 5 OH + 2CO 2 ... (1)

  As mentioned above, in the biomass processing system 1 which concerns on 1st Embodiment, since it is not necessary to use the adsorption agent or catalyst for removing the fermentation inhibition component contained in a hydrolysis processed material like the past, these There is no need to perform replacement work, and continuous processing is possible without temporarily interrupting the process. Therefore, according to this embodiment, it is possible to remove the fermentation-inhibiting component without causing a decrease in production efficiency and an increase in production cost.

In the first embodiment, the case where carbon dioxide generated in the process of alcohol fermentation in the bioreactor 15 is used as the stripping gas in the stripping tower 14 is described as an example. However, air or water vapor is used as the stripping gas. May be supplied to the stripping tower 14 from the outside.
The following two points can be cited as merits of using carbon dioxide generated in the process of alcohol fermentation as the stripping gas.

(1) For example, when air is supplied from the compressor to the stripping tower 14, there is a problem that the liquid amount and temperature of the sugar solution in the stripping tower 14 are reduced due to evaporation of water of saturated steam. Since carbon dioxide obtained from the bioreactor 15 contains saturated steam, such a problem does not occur. Further, when steam is used, a heat source for steam is required, which increases costs. However, when carbon dioxide generated in the process of alcohol fermentation is used, the bioreactor 15 originally provided is used, which increases costs. Will not be invited.

(2) When neutral hydrolysis is performed, the sugar solution is acidified by supplying carbon dioxide to the stripping tower 14 to liberate organic acids, thereby facilitating volatilization and removal of fermentation inhibiting components. can do. The following formula (2) represents the ionization formula of acetic acid, and the following formula (3) represents the ionization formula of phenol.
CH ₃ C00 ⁻ + H ⁺ ⇔CH ₃ COOH (2)
C ₆ H ₅ O ⁻ + H ⁺ ⇔ C ₆ H ₅ OH (3)

[Second Embodiment]
FIG. 3 is a block diagram showing a system configuration of the biomass processing system 2 according to the second embodiment. As shown in FIG. 3, the biomass processing system 2 according to the second embodiment includes a pretreatment device 21, a hydrolysis device 22, a solid-liquid separation device 23, and a bioreactor 24.

  As in the first embodiment, the pretreatment device 21 promotes a glucose production reaction (cellulose saccharification reaction) by hydrolysis in a hydrolysis device 22 described later as a pretreatment of woody biomass supplied as a raw material. After the treatment is performed, the woody biomass (pretreated biomass) after the pretreatment is supplied to the hydrolysis device 22.

The hydrolysis apparatus 22 hydrolyzes the pretreated biomass supplied from the pretreatment apparatus 21 using a dilute sulfuric acid method and removes fermentation-inhibiting components from the hydrolyzed product by combining a gas-liquid contact method. To do. Specifically, as shown in FIG. 4, pretreatment biomass and dilute sulfuric acid are heated while being stirred and mixed in a tank to perform a hydrolysis treatment, and from the bioreactor 24, carbon dioxide generated by ethanol fermentation. Carbon is introduced into the tank by supplying carbon to a gas pipe installed at the bottom of the tank. Thereby, the fermentation inhibiting component produced | generated by the hydrolysis process is volatilized and removed by the gas-liquid contact reaction.
The hydrolysis device 22 supplies the hydrolyzed product (including glucose and biomass residue) after removing the fermentation-inhibiting components to the solid-liquid separation device 23 in this way.

  The solid-liquid separation device 23 separates the hydrolyzed product after removal of the fermentation inhibiting component supplied from the hydrolysis device 22 into a solid solution containing glucose and a sugar solution containing biomass by solid-liquid separation. The sugar solution is supplied to the bioreactor 24. As such a solid-liquid separation device 23, a tank / decanter device or the like can be used as in the first embodiment.

As in the first embodiment, the bioreactor 24 adds an ethanol-fermenting microorganism such as yeast and a nutrient source such as nitrogen and phosphorus to the sugar solution supplied from the solid-liquid separation device 23. Bioethanol is produced by culturing microorganisms under conditions such as temperature and pH and subjecting a sugar solution (sugar solution containing glucose) to alcohol fermentation. The bioreactor 24 supplies the hydrolyzer 22 with carbon dioxide generated in the process of producing the bioethanol, that is, the glucose fermentation process.
Here, although the sugar solution supplied from the solid-liquid separator 23 contains glucose, it does not contain a fermentation-inhibiting component, so that there is no problem of causing a decrease in the ethanol fermentation rate.

  As described above, in the biomass processing system 2 according to the second embodiment, it is not necessary to use an adsorbent or a catalyst for removing the fermentation inhibition component contained in the hydrolyzed product, as in the first embodiment. It is possible to remove the fermentation-inhibiting component without causing a decrease in production efficiency and an increase in production cost. Further, in the biomass processing system 2 according to the second embodiment, it is not necessary to provide the stripping tower 14 as in the first embodiment, which is advantageous in terms of cost.

  In the second embodiment, the case where carbon dioxide generated in the process of alcohol fermentation in the bioreactor 24 is used as a gas for removing fermentation inhibition components in the hydrolysis apparatus 22 has been described as an example. It is good also as a structure which supplies air and water vapor | steam to the hydrolysis apparatus 22 from the outside.

  DESCRIPTION OF SYMBOLS 1, 2 ... Biomass processing system 11, 21 ... Pre-processing apparatus, 12, 22 ... Hydrolysis apparatus, 13, 23 ... Solid-liquid separation apparatus, 14 ... Stripping tower (gas-liquid contact apparatus), 15, 24 ... Bio Reactor (fermenter)

Claims (8)

A hydrolysis apparatus that generates a hydrolyzed product containing glucose, fermentation-inhibiting components, and biomass residues by hydrolyzing woody biomass;
A solid-liquid separation device that separates the hydrolysis-treated product into a solid solution containing the glucose residue and the biomass residue by solid-liquid separation, and a solid matter containing the biomass residue;
A gas-liquid contact device for removing the fermentation-inhibiting component from the sugar solution by a gas-liquid contact method;
A fermentation apparatus for producing ethanol by fermenting a treatment liquid obtained after removal of the fermentation inhibiting component;
A biomass processing system comprising: The fermentation apparatus supplies carbon dioxide generated in the process of producing the ethanol to the gas-liquid contact apparatus,
The biomass treatment system according to claim 1, wherein the gas-liquid contact device removes the fermentation-inhibiting component from the sugar solution by the gas-liquid contact method using the carbon dioxide supplied from the fermentation device. . Hydrolyzing woody biomass to produce a hydrolyzed product containing glucose, fermentation-inhibiting components and biomass residues, and removing the fermentation-inhibiting components from the hydrolyzed product by combining a gas-liquid contact method Equipment,
A solid-liquid separation device for separating the hydrolyzed product into a solid solution containing the glucose residue and a solid matter containing the biomass residue by solid-liquid separation;
A fermentation apparatus for producing ethanol by fermenting the sugar solution;
A biomass processing system comprising: The fermentation apparatus supplies carbon dioxide generated in the process of producing the ethanol to the hydrolysis apparatus,
The biomass treatment according to claim 3, wherein the hydrolysis device removes the fermentation-inhibiting component from the hydrolysis-treated product by the gas-liquid contact method using the carbon dioxide supplied from the fermentation device. system. By hydrolyzing the woody biomass, a hydrolyzed product containing glucose, fermentation-inhibiting components and biomass residue is produced,
By separating the hydrolyzed product into solid and liquid, it is separated into a sugar solution containing the glucose and fermentation inhibiting components and a solid product containing the biomass residue,
Removing the fermentation inhibiting component from the sugar solution by a gas-liquid contact method,
The biomass processing method characterized by producing ethanol by fermenting the processing liquid obtained after the removal of the fermentation inhibiting component.   The biomass treatment method according to claim 5, wherein the fermentation inhibiting component is removed from the sugar solution by the gas-liquid contact method using carbon dioxide generated in the process of producing ethanol. Hydrolyzing woody biomass to produce a hydrolyzed product containing glucose, fermentation inhibiting components and biomass residues and combining the gas-liquid contact method to remove the fermentation inhibiting components from the hydrolyzed product,
The hydrolyzed product is separated into a solid solution containing the glucose residue and the biomass residue by solid-liquid separation,
A biomass processing method characterized by producing ethanol by fermenting the sugar solution.   The biomass treatment method according to claim 7, wherein the fermentation-inhibiting component is removed from the hydrolyzed product by the gas-liquid contact method using carbon dioxide generated in the process of producing the ethanol.

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