JP2015157261A - Catalyst for saccharification and bioethanol producing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst for saccharification which facilitates separation and recovery of saccharified solution and also promotes saccharification reaction sufficiently.SOLUTION: A catalyst for saccharification comprises a carrier and an active site. The carrier comprises a particle size of 0.2-5 mm and a specific surface area of 100-1200 m/g. The active site is provided on the surface of the carrier.

Description

  Embodiments described herein relate generally to a saccharification catalyst and a bioethanol production apparatus.

  Biomass is a biological resource excluding fossil fuels and is abundant in nature. Biomass includes, for example, cellulose, which is the main component of wood, grass, rice straw, etc., amylose contained in wheat, corn, rice, etc., crustacean exoskeleton, mollusk shell skin, fungal cell walls And polysaccharides such as chitin, which are main components such as These polysaccharides are contained in large amounts in food waste, sewage sludge, waste paper, cardboard, and the like, and effective use is required. In particular, these polysaccharides have potential for industrial applications such as fuels such as bioethanol and petroleum substitute materials.

  Biomass is used for bioethanol production, for example, by saccharification and fermentation. However, woody materials and the like as biomass are abundant in nature, but have a strong structure and contain impurities that are difficult to remove such as lignin. For this reason, when using a wood material etc. as biomass, much energy is required for saccharification etc., and the efficiency of saccharification etc. is not necessarily high.

  When bioethanol is produced using a woody material or the like as biomass, it is preferably produced in a large amount in order to reduce production costs. For example, it is preferable to manufacture about 100,000 to 200,000 kiloliters per year in order to reduce manufacturing costs. However, when producing a large amount of bioethanol, it is necessary to collect woody materials and the like as biomass from a wide range, and the collection cost increases. For this reason, it is considered to construct a large-scale manufacturing apparatus overseas and manufacture and import bioethanol there.

  However, from the viewpoint of effective use of biomass, so-called local production for local consumption in which the biomass is consumed in an area where the biomass is produced is preferable. Local production for local consumption requires small and highly efficient manufacturing equipment. In the case of a small-scale manufacturing apparatus, the manufacturing apparatus can be distributed in various places, and the collection cost of biomass can be reduced. In addition, in the case of a highly efficient production apparatus, more bioethanol can be produced from the same amount of biomass as before, and as a result, production costs can be reduced. Therefore, according to the small-scale and highly efficient manufacturing apparatus, biomass can be locally produced and consumed locally.

  When bioethanol is produced from celluloses, pretreatment, saccharification treatment, fermentation treatment, concentration treatment, and the like are performed. Among these, saccharification treatment requires the most energy and high efficiency is required.

  As a saccharification treatment method, a method using a strong acid or strong alkali, a method using an enzyme, a method using an ionic liquid, or a method combining these has been studied. In recent years, among these, methods using enzymes have been studied. However, when an enzyme is used, a pretreatment such as pulverization or a low crystallization treatment is required to efficiently react the enzyme, and this pretreatment requires a lot of energy. Moreover, when using an enzyme, since the price of an enzyme is high, it is not easy to suppress manufacturing cost.

  As a saccharification treatment method, a method using a solid catalyst has also been studied. In the case of a solid catalyst, since it can be repeatedly used for the saccharification treatment, the production cost can be reduced compared to the case of an enzyme. However, the particle diameter of the solid catalyst is as small as several tens of μm or less. For this reason, for example, after the saccharification treatment, the solid catalyst floats in the saccharification solution obtained by the saccharification treatment, and it is not easy to separate and recover only the saccharification solution from the saccharification solution containing the solid catalyst. Centrifugation may be performed for separation and recovery of the saccharified solution, but additional energy is required to perform centrifugation. The solid catalyst is also required to be saccharified under conditions of low temperature, low pressure and short time.

International Publication No. 2008/001696 JP 2013-006142 A JP 2013-188739 A

  The problem to be solved by the present invention is to provide a saccharification catalyst and a bioethanol production apparatus capable of easily separating and recovering a saccharified solution and sufficiently promoting a saccharification reaction.

The saccharification catalyst of the embodiment has a carrier and an active site. The carrier has a particle size of 0.2-5 mm and a specific surface area of 100-1200 m ² / g. The active site is provided on the surface of the carrier.

It is the schematic of the bioethanol manufacturing apparatus of embodiment.

  Hereinafter, embodiments of the present invention will be described.

The saccharification catalyst of the embodiment is used for saccharification treatment of biomass and promotes saccharification reaction of biomass. The saccharification catalyst of the embodiment has a carrier and an active site. The carrier has a particle size of 0.2-5 mm and a specific surface area of 100-1200 m ² / g. The active site is provided on the surface of the carrier.

  The surface of the carrier includes not only the surface exposed to the outside (outer surface) but also the surface of the pores (inner surface) opening to the outside. The active point may be provided on at least one selected from the above-described outer surface and inner surface, but is preferably provided on both the outer surface and the inner surface.

According to the saccharification catalyst of the embodiment, since the particle diameter of the carrier is as large as 0.2 to 5 mm, for example, when the carrier is allowed to stand after the saccharification treatment, the saccharification liquid is easily settled and deposited in the lower part. Thereby, it becomes easy to separate and collect only the saccharified solution from the saccharified solution containing the saccharification catalyst after the saccharification treatment. This also reduces the energy required for separation and recovery. In general, when the particle size of the carrier is increased, the specific surface area of the carrier is reduced, so that the active sites are reduced. However, according to the saccharification catalyst of the embodiment, the specific surface area of the carrier is as large as 100 to 1200 m ² / g due to pores due to the porous structure, etc., so that the active site can be sufficiently secured, and the saccharification reaction of biomass can be performed. It can be promoted sufficiently.

  The carrier has, for example, a porous structure and a spherical shape. When the particle diameter of the carrier is less than 0.2 mm, it is not easy to separate and recover only the saccharified solution from the saccharified solution containing the saccharification catalyst after the saccharification treatment. When the particle diameter of the carrier is 0.2 mm or more, for example, the saccharification catalyst settles in the saccharified solution and easily deposits in the lower part. Therefore, the carrier is separated into an upper saccharified solution and a lower saccharification catalyst. By collecting the saccharified solution, only the saccharified solution can be collected from the saccharified solution containing the saccharification catalyst. From the viewpoint of easy separation and recovery of the saccharified solution, the carrier particle diameter is preferably 0.5 mm or more, more preferably 1.0 mm or more, and further preferably 1.5 mm or more. Moreover, when the particle diameter of a support | carrier exceeds 5 mm, a specific surface area tends to become small and, thereby, an active point tends to reduce. From the viewpoint of securing the specific surface area and active sites, the particle size of the carrier is preferably 4.8 mm or less, more preferably 4.5 mm or less, and even more preferably 4.3 mm or less. The particle size is measured by, for example, particle size distribution measurement or sieving.

When the specific surface area of the carrier is less than 100 m ² / g, the active sites are reduced. From the viewpoint of securing the active sites, the specific surface area of the support is preferably from 200 meters ² / g or more, more preferably at least ^{300m 2 / g, 400m 2 /} g or more and more preferably, 500 meters ² / g or more is particularly preferable. Further, when the specific surface area of the carrier exceeds 1200 m ² / g, the particle size of the carrier tends to be small, and it is not easy to separate and recover only the saccharified solution from the saccharified solution containing the saccharification catalyst after the saccharification treatment. Separation of sugar solution, from the viewpoint of recovery is facilitated, specific surface area of the support is preferably 1000 m ² / g or less, more preferably 800 m ² / g, more preferably 600 meters ² / g or less. The specific surface area is measured by a nitrogen adsorption method.

The pore volume of the support is preferably 0.2 cm ³ / g or more, more preferably 0.4 cm ³ / g or more, and 0.6 cm ³ / g or more from the viewpoint of increasing the specific surface area and increasing the active sites. Further preferred. Further, the pore volume of the support, from the viewpoint of ensuring the strength of the carrier and the like, is preferably from 2.0 cm ³ / g, more preferably not more than 1.8 cm ³ / g, more preferably 1.5 cm ³ / g or less . The pore volume is measured by a nitrogen adsorption method.

  The constituent material of the carrier is preferably an inorganic material and more preferably an inorganic oxide because it has good thermal stability, mechanical strength, and the like. In particular, the constituent material of the carrier preferably contains at least one selected from aluminum oxide, silicon oxide, zirconium oxide, titanium oxide, and zeolite.

As such a carrier, those produced by various methods can be used as long as the particle diameter, specific surface area, pore volume and the like are satisfied. Moreover, a commercial item can also be used as such a support | carrier. Examples of commercially available products include porous silica particles (particle diameter 2 to 4 mm, specific surface area 550 m ² / g, pore volume 0.6 cm ³ / g) manufactured by Fuji Silysia Chemical Ltd. The porous silica particles are particularly preferable as a carrier for a saccharification catalyst because cracks generated when immersed in water or the like are suppressed.

  The active sites are provided on the surface of the carrier to promote biomass saccharification reaction. The active point may be provided on at least one selected from the surface exposed to the outside (outer surface) and the surface of the pores opening to the outside (inner surface), but is provided on both the outer surface and the inner surface. It is preferable. By being provided on both the outer surface and the inner surface, the saccharification reaction of biomass can be effectively promoted. Moreover, it is preferable that many active sites are provided on both the outer surface and the inner surface.

  The active site is not particularly limited as long as it has a function of promoting a saccharification reaction, but an acidic site (acid site) is preferable. The acid point preferably has a functional group chemically bonded to the surface of the carrier, and particularly preferably has a sulfo group as the functional group. When it has a sulfo group, it becomes a solid acid and exhibits super strong acidity. Thereby, a proton can be donated to biomass with high efficiency, and a saccharification reaction can be effectively promoted.

  The sulfo group is preferably obtained by chemically bonding a functional group other than the sulfo group to the surface of the carrier and oxidizing the functional group. Functional groups other than sulfo groups are chemically bonded to, for example, hydroxyl groups present on the surface of the support. As the functional group other than the sulfo group, for example, a thiol group is preferable. In the case of a sulfo group obtained by oxidation of a thiol group, the bond between the support and the sulfo group becomes very strong, and therefore, the release of the sulfo group from the support during the saccharification reaction of biomass can be suppressed.

  Introduction of a sulfo group is performed as follows, for example. First, a support | carrier is dried at 100-120 degreeC for several hours using a drying furnace. Separately, a modification liquid is prepared by sufficiently dissolving the surface modifier in an organic solvent. As the organic solvent, for example, toluene, methanol, ethanol, isopropyl alcohol, butanol and the like are used. As the surface modifier, for example, a silane coupling agent having a thiol group such as 3-mercaptopropyltrimethoxysilane is used.

  Thereafter, the carrier is immersed in the modifying solution. At this time, it is preferable to perform vacuum deaeration so that the modification solution also contacts the surface of the pores of the carrier. After immersion, stirring is performed at room temperature to about 95 ° C. for 3 to 48 hours. Depending on the temperature, the modifying liquid volatilizes, so that the modifying liquid is prevented from volatilizing using a reflux tube as necessary.

  After the stirring, the modifying solution may be removed or stirred until the modifying solution evaporates. Thereby, the hydroxyl group of a support | carrier and the terminal of a surface modifier are couple | bonded, and the support | carrier with which the thiol group was couple | bonded with the surface is obtained. The carrier having a thiol group bonded to the surface is washed with pure water as necessary in order to remove the modification solution.

  The carrier having a thiol group bonded to the surface is, for example, immersed in an oxidizing agent and stirred at 50 to 100 ° C. for 1 to 12 hours. Examples of the oxidizing agent include aqueous solutions of hydrogen peroxide, nitric acid, hydrochloric acid, and the like. Thereby, the support | carrier with which the thiol group was converted into the sulfo group and the sulfo group was couple | bonded with the surface is obtained. The carrier having a sulfo group bonded to the surface is washed with pure water as necessary in order to remove the oxidizing agent. In addition, the carrier having a sulfo group bonded to the surface is dried at room temperature to about 105 ° C. for about 12 to 96 hours, if necessary. Thereby, the catalyst for saccharification is obtained.

  The saccharification catalyst preferably has a sulfo group obtained by oxidation of the thiol group as described above from the viewpoint of effectively accelerating the saccharification reaction of biomass. For example, the carrier is simply treated with sulfuric acid or phosphoric acid. What is obtained by immersing in the solution to contain may be sufficient.

  The saccharification catalyst preferably has a surface acid amount of, for example, 0.1 to 5.0 mmol / g. By having such a surface acid amount, the saccharification reaction of biomass can be effectively promoted. The surface acid amount is more preferably 1.5 to 5.0 mmol / g, and further preferably 2.0 to 5.0 mmol / g.

The specific surface area of the saccharification catalyst is preferably at least 100 m ² / g, more preferably at least 200 meters ² / g, more preferably more than ^{300m 2 / g, 400m 2 /} g or more is particularly preferable. The specific surface area of the saccharification catalyst is preferably 1200 m ² / g or less, more preferably 1000 m ² / g, more preferably 800 m ² / g or less, and particularly preferably 600m ² / g.

The pore volume of the saccharification catalyst is preferably 0.2 cm ³ / g or more, more preferably 0.4 cm ³ / g or more, and further preferably 0.6 cm ³ / g or more. Further, the pore volume of the saccharification catalyst is preferably at most 1.8 cm ³ / g, more preferably not more than 1.2 cm ³ / g, more preferably 1.0 cm ³ / g or less.

Next, production of bioethanol using the saccharification catalyst will be described.
Bioethanol is produced, for example, by performing pretreatment, saccharification treatment, fermentation treatment, filtration treatment, and concentration treatment in this order.

  Biomass used for the production of bioethanol is a biological resource, excluding fossil fuels. Examples of biomass include cellulose or hemicellulose that constitutes waste paper, cardboard, wood, herbs, amylose or amylopectin that constitutes starch, crustacean exoskeleton, mollusk shell, surface of fungi Examples include polysaccharides such as chitin or chitosan.

  From biomass, soluble saccharides such as monosaccharides and oligosaccharides, low molecular weight polysaccharides and the like are obtained. Monosaccharides are also referred to as simple sugars and are not further hydrolyzed. Examples of monosaccharides include glucose, fructose, and xylose. Oligosaccharides are saccharides (also called oligosaccharides), which are compounds in which monosaccharides are linked by glycosidic bonds and have a molecular weight that is not as great as that of polysaccharides. The oligosaccharide is, for example, a saccharide in which 2 or more and less than 10 monosaccharides are bound. The oligosaccharide is a saccharide having a molecular weight of about 300 to 3000, for example. Examples of oligosaccharides include maltose, sucrose, cellobiose, and trehalose. The polysaccharide is a saccharide excluding monosaccharides and oligosaccharides and having a molecular weight larger than these.

  For example, cellulose is a chain polymer compound formed by β-l, 4 glycosidic bonds between many glucose molecules. In cellulose, a number of glucoses are bonded together by dehydration condensation between the hydroxyl group at the 1-position of one glucose and the hydroxyl group at the 4-position of another glucose. In addition, in cellulose, a hydrogen bond is formed between celluloses to form a very strong structure. When cellulose is saccharified, 1,4-glycosidic bonds are cleaved to produce soluble saccharides such as monosaccharides and oligosaccharides, and low molecular weight polysaccharides.

  The pretreatment is not necessarily required, but is performed according to the components of the biomass as necessary. For example, in the case of a wood material containing lignin or the like, it is preferable to perform a pretreatment such as a pulverization treatment or an alkali treatment using ammonia or sodium hydroxide. By performing the pretreatment, the saccharification reaction in the subsequent saccharification treatment is promoted. On the other hand, in the case of used paper, cardboard, etc. with a high cellulose content, saccharification may be performed without performing pretreatment.

  The energy required for the pretreatment is less when the saccharification catalyst is used for the saccharification treatment than when the enzyme is used for the saccharification treatment. When the crystallinity of cellulose is high, or when it contains a large amount of components such as lignin, the saccharification reaction does not proceed easily when an enzyme is used. On the other hand, when a saccharification catalyst is used, the saccharification reaction easily proceeds because the catalytic activity at the active site is high. For this reason, by using the saccharification catalyst for the saccharification treatment, the energy required for the pretreatment can be reduced as compared with the case of using an enzyme for the saccharification treatment.

  Here, the saccharification reaction proceeds as the contact between the saccharification catalyst (particularly the active site) and the biomass increases. Therefore, as a pretreatment method, it is preferable to employ a method according to the constituent components of the biomass so that the contact between the saccharification catalyst and the biomass increases and the saccharification reaction proceeds even with a small amount of energy.

  In the saccharification treatment, the polysaccharide contained in the biomass is converted to a saccharide having a lower molecular weight. Specifically, a saccharide having a molecular weight lower than that due to hydrolysis of the polysaccharide is used. The saccharification treatment is performed, for example, by stirring the biomass in the presence of moisture and a saccharification catalyst. By saccharification treatment, a saccharified solution containing soluble saccharides such as monosaccharides and oligosaccharides, low molecular weight polysaccharides and the like is obtained. In particular, the saccharified solution preferably contains at least one selected from monosaccharides to hexasaccharides.

  The temperature of the saccharification treatment is preferably 30 to 220 ° C. When temperature is 30 degreeC or more, saccharification reaction advances easily. The temperature is more preferably 50 ° C. or higher because the saccharification reaction easily proceeds. A temperature of 220 ° C. is sufficient as the temperature, and if it is less than this, the amount of energy used is reduced, and the production cost is reduced, which is preferable. The temperature is more preferably 200 ° C. or less, and more preferably 150 ° C. or less, because production costs can be reduced.

  The saccharification treatment time is preferably 1 to 300 hours. When the time is 1 hour or more, the production rate of soluble saccharides such as monosaccharides and oligosaccharides increases. The time is more preferably 20 hours or longer because the production rate of soluble saccharides such as monosaccharides and oligosaccharides increases. A time of 300 hours is sufficient, and if it is less than this, the amount of energy used is reduced, which is preferable because the manufacturing cost can be reduced. Since the manufacturing cost can be suppressed, the time is more preferably 200 hours or less, and even more preferably 100 hours or less.

  In the saccharification treatment, a catalyst other than this may be used together with a predetermined saccharification catalyst. However, since it is easy to separate and recover the saccharified solution after the saccharification treatment, it is preferable to use only a predetermined saccharification catalyst as the catalyst. In the saccharification treatment, a plurality of saccharification catalysts can be used simultaneously. In this case, the carrier in each saccharification catalyst may have the same particle diameter, specific surface area, or the like, or may be different from each other.

  In the saccharification treatment, first, the biomass comes into contact with active sites existing on the surface (outer surface) exposed to the outside of the saccharification catalyst, so that the biomass is decomposed and reduced in molecular weight, such as monosaccharides and oligosaccharides. Soluble saccharides and low molecular weight polysaccharides are produced. For example, in the case of cellulose, a part of the cellulose comes into contact with an active site existing on the outer surface of the saccharification catalyst, whereby a polysaccharide having a molecular weight lower than that is generated. The reduced molecular polysaccharide further contacts the active sites present on the outer surface of the saccharification catalyst or the active sites present on the surface of the pores opening to the outside (inner surface), Soluble saccharides such as oligosaccharides are produced.

  In the saccharification treatment, a hyperdegradation reaction may occur in which soluble saccharides such as monosaccharides and oligosaccharides are decomposed to produce organic acids and carbides. In order to suppress the excessive decomposition reaction, it is preferable to lower the temperature of the saccharification treatment and shorten the time of the saccharification treatment. Moreover, the production | generation ratio of soluble saccharides, such as a monosaccharide and an oligosaccharide, changes according to the temperature of saccharification processing, time, the catalyst for saccharification, the quantity of moisture, etc. Therefore, it is preferable to appropriately select the saccharification treatment temperature, time, saccharification catalyst, amount of water, and the like according to the desired production rate.

  After the saccharification treatment, only the saccharified solution is separated and recovered from the saccharified solution containing the saccharification catalyst. For example, when stirring in the saccharification treatment is stopped, the saccharification catalyst sinks in the saccharified solution and accumulates in the lower part. Thus, when it isolate | separates into an upper saccharification liquid and a lower saccharification catalyst, only a saccharification liquid can be collect | recovered from the saccharification liquid containing a saccharification catalyst by collect | recovering upper saccharification liquids. Further, it is preferable that the saccharification catalyst is left without being recovered because biomass, moisture and the like can be supplied and used as it is.

When a saccharification catalyst is used, the carrier particle size is as large as 0.2 to 5 mm. Therefore, the saccharification catalyst easily sinks in the saccharified solution and accumulates in the lower part. From the saccharified solution containing the saccharification catalyst to the saccharified solution It becomes easy to separate and recover only the water. Moreover, since the specific surface area of a support | carrier is as large as 100-1200 m < ² > / g, an active site can be ensured and a saccharification reaction can fully be accelerated | stimulated. Furthermore, when the active site has a chemically bonded functional group, the functional group is prevented from being detached from the carrier during the saccharification reaction, and the decrease in activity when repeatedly used is suppressed. In particular, when the functional group is a sulfo group obtained by oxidation of a thiol group, the saccharification reaction is effectively promoted.

  Further, when a saccharification catalyst is used, energy required for saccharification treatment can be reduced. Specifically, the temperature and pressure of saccharification treatment can be reduced. The temperature of saccharification processing can be made into 30-220 degreeC, for example. The pressure for the saccharification treatment can be, for example, normal pressure (0.1001325 MPa) to 1 MPa. In this way, the saccharification reaction can be effectively promoted, the temperature and pressure can be reduced, and the saccharified solution can be easily recovered. Therefore, a small-scale and highly efficient production apparatus can be realized, and the local production and consumption of biomass can be reduced. It becomes possible.

In the fermentation process, ethanol is produced by fermenting the saccharide obtained by the saccharification process.
Yeast is used for the fermentation treatment. The yeast should just be able to ferment the saccharide obtained by saccharification, and the thing suitable for the saccharide obtained by saccharification is selected suitably.

  Depending on the treatment time, the saccharide obtained by saccharification treatment may contain polysaccharides that are lower in molecular weight than cellulose but exist as solids, in addition to soluble saccharides such as monosaccharides and oligosaccharides. is there. In this case, by using an appropriate enzyme or the like, ethanol can be produced while promoting the decomposition of the polysaccharide into a monosaccharide.

  For example, as an enzyme, exo-type cellobiohydrolase (CBH) that releases cellobiose from the end of crystalline cellulose, crystalline cellulose cannot be decomposed, but endo-type endoglucanase (EG) that cleaves amorphous cellulose chains, cellobiose, There are three types of exo-type β-glucosidase (BGL) that produces glucose from the end of a short chain (cellooligosaccharide). By using these effectively, ethanol can be produced efficiently.

  A filtration process isolate | separates and collect | recovers yeast from the fermented liquor obtained by the fermentation process. The fermented liquid obtained by the fermentation treatment contains yeast used for the fermentation treatment. For this reason, it is preferable to isolate | separate and collect | recover only yeast from the fermented liquor containing yeast. Known methods are appropriately employed for separating and collecting the yeast.

  The concentration process increases the concentration of ethanol in the fermentation broth. The fermented liquor is usually obtained as an aqueous ethanol solution containing water used for saccharification and fermentation, and ethanol obtained by the fermentation. For this reason, it is preferable to remove the water and increase the concentration of ethanol. As a method for improving the concentration of ethanol, a distillation method is also known. However, the amount of energy used increases and the production cost tends to increase. For this reason, it is preferable to use the separation membrane of ethanol and water as what can use the energy little and can suppress manufacturing cost.

Next, a bioethanol production apparatus using a saccharification catalyst will be described.
FIG. 1 is a schematic view showing an embodiment of a bioethanol production apparatus.

  The bioethanol production apparatus 10 includes, for example, a pretreatment unit 20, a saccharification treatment unit 30, a fermentation treatment unit 40, a filtration treatment unit 50, and a concentration treatment unit 60.

  The pretreatment unit 20 is provided as necessary to promote the saccharification reaction, and performs pretreatment of biomass. The preprocessing unit 20 is, for example, a ball mill as illustrated. Specifically, the pretreatment unit 20 includes a pretreatment tank 21, and biomass 22, moisture 23, and media 24 are input into the pretreatment tank 21, and the biomass 22 is crushed by the moisture 23 and the media 24. To do. The pretreatment unit 20 is not limited to the ball mill as shown in the figure, and can perform various treatments according to the constituent components of the biomass.

  The saccharification processing unit 30 performs biomass saccharification processing. Biomass is, for example, pretreated. The saccharification processing unit 30 includes, for example, a saccharification tank 31 into which biomass (not shown), a saccharification catalyst 32, moisture necessary for biomass saccharification reaction, and the like are input. For example, the biomass is introduced into the saccharification tank 31 through a pipe 71 connected to the pretreatment unit 20. As the moisture, the moisture used in the pretreatment is used as it is, and is introduced into the saccharification tank 31 through a pipe 71 connected to the pretreatment unit 20, for example. Inside the saccharification tank 31, a stirring fin 33 for stirring biomass, a saccharification catalyst 32, moisture and the like is provided. A heater 34 for heating the saccharification tank 31 is provided around the saccharification tank 31.

  The fermentation processing unit 40 performs a fermentation process on the saccharide obtained by the saccharification process. The fermentation processing unit 40 includes, for example, a fermenter 41, and saccharides, yeasts, and the like obtained by saccharification are input into the fermenter 41. For example, the saccharide is introduced into the fermenter 41 through a pipe 72 connected to the saccharification processing unit 30. For example, the saccharide does not include the saccharification catalyst 32 but is charged into the fermenter 41 as a saccharified solution containing saccharide obtained by saccharification and water. From such a viewpoint, it is preferable that the pipe 72 is provided in the saccharification tank 31 at a position where the saccharification catalyst is not recovered and only the saccharified solution is recovered. Specifically, it is preferable that the pipe 72 is provided at a position higher than the height of the upper part of the deposition portion when the saccharification catalyst is deposited in the lower part of the saccharification tank 31. The yeast is introduced into the fermenter 41 through a pipe 73, for example. Inside the fermenter 41, stirring fins 42 are provided for stirring saccharides, yeasts and the like obtained by saccharification. In addition, a heater 43 for heating the fermenter 41 is provided around the fermenter 41.

  The filtration process part 50 isolate | separates and collect | recovers yeast from the fermented liquor obtained by the fermentation process. The filtration process part 50 has the filtration filter 51 which isolate | separates and collect | recovers yeast from a fermentation liquid, for example. For example, the fermented liquid is introduced into the filtration filter 51 through a pipe 74 connected to the fermentation processing unit 40. The separated and recovered yeast is supplied again to the fermentation processing unit 40 through the pipe 75, for example. The fermentation broth from which the yeast has been removed is supplied to the concentration processing unit 60 through the pipe 76.

  The concentration processing unit 60 increases the concentration of ethanol in the fermentation broth. The concentration process part 60 has the separation membrane 61 of ethanol and water, for example. The concentration processing unit 60 may perform distillation. However, distillation increases the amount of energy used and tends to increase production costs. For this reason, the separation membrane 61 of ethanol and water is preferable as the amount of energy used is small and the manufacturing cost can be suppressed.

(Saccharification catalyst)
After 3-mercaptopropyltrimethoxysilane as a surface modifier was dissolved in toluene as an organic solvent, a large amount of pure water was added and stirred vigorously to prepare a modification solution. This modifying solution was impregnated with porous silica particles as a carrier. In addition, the usage-amount of 3-mercaptopropyl trimethoxysilane was 0.3 by molar ratio with respect to the porous silica particle. In addition, porous silica particles manufactured by Fuji Silysia Chemical Ltd. were used as the porous silica particles. The porous silica particles have a particle diameter of 2 to 4 mm, a specific surface area of 550 m ² / g, and a pore volume of 0.6 cm ³ / g. The particle size was measured by a sieving method. Specific surface area and pore volume were measured by a nitrogen adsorption method. The surface acid amount was measured by an ammonia temperature programmed desorption method.

  The modification liquid impregnated with the porous silica particles was placed in a rotary evaporator and stirred at room temperature for 1 hour while degassing. Thereafter, the mixture was stirred at 60 ° C. for 3 hours while degassing, and further stirred at 95 ° C. for 3 hours at normal pressure. Then, it stirred while concentrating and wash | cleaned 3 times with pure water. Thereby, 3-mercaptopropyltrimethoxysilane was bonded to the surface of the porous silica particles. The porous silica particles were put into hydrogen peroxide solution and stirred at 55 ° C. for 6 hours to oxidize thiol groups on the surface to form sulfo groups. The porous silica particles having a sulfo group were washed three times with pure water and then dried at 105 ° C. for 24 hours to obtain a saccharification catalyst.

With respect to this saccharification catalyst, the specific surface area, pore volume, and surface acid amount were measured. The specific surface area and pore volume were measured by a nitrogen adsorption method. The surface acid amount was measured by an ammonia temperature programmed desorption method. As a result, the specific surface area was 497 m ² / g, the pore volume was 0.34 cm ³ / g, and the surface acid amount was 4.4 mmol / g.

(Preprocessing)
Used paper (no ink) was used as biomass. This waste paper was cut into a few millimeters using a shredder and then wet-ground for 48 hours using a zirconia ball mill. By such pretreatment, the particle size of the used paper became about 25 μm.

(Saccharification treatment)
Waste paper that had been pretreated, a saccharification catalyst, and pure water were mixed. The mixing ratio was 1.0 g of saccharification catalyst and 5.0 g of pure water with respect to 0.1 g of waste paper. Thereafter, stirring was performed at 100 ° C. for 48 hours to lower the molecular weight of cellulose as a main component, and a saccharified solution containing monosaccharide (glucose) and oligosaccharide (cellobiose etc.) was obtained. The saccharified solution contained polysaccharides and impurities with reduced molecular weight as solid residues. In addition, since the saccharification catalyst was precipitated at the bottom of the saccharification liquid simultaneously with the stop of the stirring, only the saccharification liquid could be easily recovered from the saccharification liquid containing the saccharification catalyst.

(Fermentation treatment)
Yeast (Yeast) was added to the saccharified solution obtained by the saccharification treatment to make it anaerobic so that no oxygen was present, and then the mixture was stirred at 45 ° C. for 3 hours. As a result, it was confirmed that there was carbon dioxide generation by fermentation and ethanol was synthesized. The fermentation broth obtained by this fermentation treatment was an aqueous ethanol solution containing water and ethanol and having an ethanol concentration of about several percent.

(Concentration treatment)
The aqueous ethanol solution as the fermentation broth was concentrated using a separation membrane of water and ethanol. A zeolite membrane was used as the separation membrane. By this concentration treatment, an ethanol concentration of 99% or more was obtained.

 According to at least one embodiment described above, the saccharified solution can be easily separated and recovered, and the saccharification reaction can be sufficiently accelerated.

  Although several embodiments of the present invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Bioethanol manufacturing apparatus, 20 ... Pretreatment part, 21 ... Pretreatment tank, 22 ... Biomass, 23 ... Water | moisture content, 24 ... Media, 30 ... Saccharification part, 31 ... Saccharification tank, 32 ... Saccharification catalyst, 33 ... Stirring fin, 34 ... heater, 40 ... fermentation processing unit, 41 ... fermentor, 42 ... stirring fin, 43 ... heater, 50 ... filtration processing unit, 51 ... filtration filter, 60 ... concentration processing unit, 61 ... separation membrane, 71 -76 ... piping.

Claims (9)

A carrier having a particle size of 0.2 to 5 mm and a specific surface area of 100 to 1200 m ² / g;
A saccharification catalyst having active sites provided on the surface of the carrier.   The catalyst for saccharification according to claim 1, wherein the carrier contains at least one selected from aluminum oxide, silicon oxide, zirconium oxide, titanium oxide, and zeolite.   The saccharification catalyst according to claim 1, wherein the active site has a sulfo group.   A bioethanol production apparatus comprising the saccharification catalyst according to any one of claims 1 to 3. A saccharification treatment unit that has the saccharification catalyst and produces a saccharide having a molecular weight lower than that of the polysaccharide contained in the biomass;
The bioethanol production apparatus according to claim 4, further comprising: a fermentation processing unit that ferments the saccharides to produce a fermentation liquid containing ethanol.   The bioethanol production apparatus according to claim 5, wherein the saccharide includes a soluble saccharide.   The bioethanol production apparatus according to claim 6, wherein the saccharide includes at least one selected from monosaccharide to hexasaccharide.   The bioethanol production apparatus according to any one of claims 5 to 7, further comprising a pretreatment unit that performs pretreatment of the biomass.   The bioethanol production apparatus according to any one of claims 5 to 8, further comprising a concentration processing unit that increases the concentration of the ethanol in the fermentation broth.

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