WO2013103138A1

WO2013103138A1 - Biomass saccharification method and device, method and device for producing sugar, and method and device for producing ethanol

Info

Publication number: WO2013103138A1
Application number: PCT/JP2012/084143
Authority: WO
Inventors: 北野　誠; 佐藤　健治; 健太郎成相; 典充金子; 重雄蔦木
Original assignee: 株式会社Ihi
Priority date: 2012-01-06
Filing date: 2012-12-28
Publication date: 2013-07-11

Abstract

Provided are a method and device for producing sugar and ethanol efficiently and inexpensively wherein the amount of enzyme and the treatment time are reduced during the production of ethanol by saccharification enzyme reaction and fermentation using plant waste as the starting material for biomass ethanol. Particulate biomass is prepared to a water content of 80 to 90 mass%, biomass and saccharification enzyme are introduced from one end of a reactor that extends substantially horizontally, and biomass and saccharification enzyme are moved in succession vertically toward the other end of the reactor while being agitated by a turning operation wherein the vertical direction of the reactor serves as the center axis. As a result, saccharification of the biomass proceeds as the biomass moves vertically. Saccharified liquid is gradually produced by hydrolysis of cellulose and recovered from the other end of the reactor, while the solid residue recovered from the other end is re-introduced from the one end to the reactor. The saccharification enzyme contained in the solid residue is thereby reused. The resulting saccharified liquid is used for ethanol fermentation.

Description

Biomass saccharification method and saccharification device, saccharide production method and saccharide production device, ethanol production method and ethanol production device

The present invention relates to a saccharification method and saccharification apparatus for biomass, a saccharide production method and a saccharide production apparatus using the same, an ethanol production method and an ethanol production apparatus, and more specifically, lignocellulosic waste plant materials such as wood and wheat straw. TECHNICAL FIELD The present invention relates to a saccharification method and saccharification device for saccharifying cellulose by an enzymatic reaction when biomass ethanol is produced as a biomass, and a saccharide production method and a saccharide production device, an ethanol production method and an ethanol production device using the same. .

Lignocellulosic biomass is a renewable energy source derived from woody plants, agricultural wastes and other similar non-food crops and contains mainly cellulose, hemicellulose and lignin and is called a cellulosic resource. In recent years, biomass ethanol, which produces ethanol by fermentation of microorganisms using plant matter, has attracted attention as a solution to the depletion of petroleum resources, and various processes have been proposed as its production technology.

Cellulose is a glucose polymer connected to each other by β-1,4 bonds, and generally exists in a proportion of 30 to 70% by mass, although it varies depending on the type of plant. Hydrolysis of cellulose biomass by enzymes is a complex phenomenon that is influenced by the content of cellulose, hemicellulose and lignin that make up cellulosic resources, microstructure, and reaction conditions of the enzyme. Requires a long time and a large amount of energy, and the production cost is high.

Patent Document 1 below describes a method for producing a biomass ethanol product, which uses lignin-treated waste materials such as waste paper containing about 80% cellulose to produce glucose by a cellulase enzyme, followed by fermentation. A method for obtaining ethanol is disclosed.

Further, Patent Document 2 below discloses a saccharification reaction tank, which discloses a saccharification reaction tank in which a separation chamber made of a mesh or punching metal for separating foreign matters mixed in a cellulosic material is provided.

Furthermore, Patent Document 3 below describes an ethanol production apparatus, which discloses a reaction tank that performs enzymatic saccharification and ethanol fermentation in the same reaction zone.

Japanese Unexamined Patent Publication No. 2006-88136 Japanese Unexamined Patent Publication No. 2010-268705 International Publication No. 2008/047679 Pamphlet

The treatments used in the production of biomass ethanol include physical treatments that promote degradation by hydrothermal treatment, chemical treatments that promote reactions such as hydrolysis using acids, bases, catalysts, etc., saccharification enzymes and fermentation microorganisms. There are biochemical treatments that can be used, and catalysts and fermenting microorganisms can be recovered and reused. However, enzymes are generally water-soluble and are difficult to recover. In addition, since saccharifying enzymes are inactivated with the passage of time of use, supplementation of saccharifying enzymes is necessary for sufficient saccharification. In particular, β-glucosidase contained in cellulose saccharifying enzyme is inhibited by glucose that is finally produced in saccharification, so that there is a problem that the production rate decreases according to the production of glucose, and β- It is necessary to add an additional glucosidase. For this reason, the quantity of the saccharifying enzyme used for manufacture of biomass ethanol increases, and production cost becomes high. In order to produce ethanol at low cost while suppressing production costs, it is important to reduce the amount of saccharifying enzyme used. Furthermore, since the saccharification by enzymatic reaction requires a processing time, it is also important to shorten the processing time in order to produce ethanol efficiently at a low cost.

In general, a reaction system for performing an enzyme reaction is a water system containing a substrate and an enzyme. When a large amount of water is used in such a reaction system, a large amount of water is used in distillation for finally purifying the obtained ethanol. Heat energy will be consumed. Therefore, it is desirable that the amount of water used is small.

An object of the present invention is to provide a saccharification method, a saccharification device, a saccharide production method, and a saccharide production device for biomass, which solve the above-mentioned problems, have a high efficiency of cellulose decomposition reaction by saccharifying enzyme, and can reduce the amount of enzyme used. It is to provide an efficient ethanol production method and ethanol production apparatus using the same.

Another object of the present invention is to provide lignocellulosic biomass in which at least a part of the enzyme can be recovered and reused from the saccharification stage where it is difficult to recover the enzyme, and an amount of water that is a burden in subsequent ethanol purification is not used. The saccharification method, saccharification apparatus, saccharide production method and saccharide production apparatus are provided, and the ethanol production method and ethanol production apparatus capable of efficiently producing biomass ethanol are realized.

In order to solve the above-mentioned problems, the present inventors have conducted extensive research and as a result, devised a device structure that allows the saccharification reaction to proceed, thereby enabling efficient progress of the enzyme reaction and the use of water. The amount was reduced, and it was found that a part of the enzyme used could be recovered, and the present invention was completed.

According to one aspect of the present invention, a biomass saccharification method prepares particulate biomass in a water-containing state, and inputs the biomass and saccharifying enzyme from one end side of a reaction tank that extends in a substantially horizontal direction. The biomass and the saccharifying enzyme are agitated by a rotating operation with the longitudinal direction of the reaction tank as the central axis while sequentially moving in the longitudinal direction toward the other end side, thereby moving the biomass along with the movement of the biomass in the longitudinal direction. The gist is that saccharification proceeds. The moisture-containing biomass can have a moisture content (percentage of moisture mass relative to the total mass) of 90% by mass or less, preferably 80 to 90% by mass.

Moreover, according to one aspect of the present invention, in the method for producing sugar, a saccharified solution is gradually generated by hydrolysis of cellulose contained in biomass by the saccharification method, and the saccharified solution and the solid residue are removed from the reaction vessel. Recovering each from the other end side, charging the solid residue recovered from the other end side of the reaction vessel into the reaction vessel again from one end side, and reusing the saccharifying enzyme contained in the solid residue To do.
Furthermore, according to one aspect of the present invention, the gist of a method for producing ethanol is to produce ethanol by microbial fermentation of the sugar obtained by the sugar producing method.

Moreover, according to one aspect of the present invention, a saccharification apparatus includes a reaction tank that extends in a substantially horizontal direction, and water-containing particulate biomass having a high solids concentration from one end side to the other end of the reaction tank. Biomass supply means for supplying from the one end side of the reaction tank to the inside so as to sequentially move in the longitudinal direction toward the side, enzyme addition means for adding a saccharifying enzyme to the biomass supplied from one end side of the reaction tank, A stirrer that stirs the biomass and saccharifying enzyme by a rotation operation with the longitudinal direction of the reaction tank as a central axis, and a saccharified solution generated by the progress of saccharification of biomass that moves in the longitudinal direction in the reaction tank. The gist of the present invention is to have a discharge means for collecting from the other end of the reaction vessel.

Furthermore, according to one aspect of the present invention, a saccharification apparatus includes the saccharification apparatus and a solid residue separated from a saccharified solution produced by hydrolysis of cellulose contained in biomass in a reaction tank of the saccharification apparatus. The gist of the present invention is to have a reflux system that recovers from the other end side of the reaction tank and re-enters the reaction tank from one end side of the reaction tank to reuse the saccharifying enzyme contained in the solid residue.

According to another aspect of the present invention, a saccharification apparatus further proceeds the hydrolysis reaction by the saccharification enzyme contained in the saccharification apparatus and the saccharification solution discharged from the reaction tank of the saccharification apparatus. The gist is to have a secondary saccharification apparatus that sufficiently saccharifies the saccharified solution.

Moreover, according to one aspect of the present invention, an ethanol production apparatus is produced by the above sugar production apparatus, a fermentation apparatus that produces ethanol by microbial fermentation of the sugar produced by the sugar production apparatus, and the fermentation apparatus. And a distillation apparatus for purifying the ethanol to be purified.

According to the present invention, a saccharification method, a saccharification method that allows an enzymatic reaction to proceed efficiently in a state where the amount of water used in the enzymatic degradation of cellulose by a saccharifying enzyme is reduced, and that a part of the used enzyme can be recovered and reused. Thus, a saccharification apparatus and a sugar production apparatus capable of efficiently producing sugar are provided, and an ethanol production method and an ethanol production apparatus using the same are realized. As a result, the amount of enzyme used in the saccharification reaction in the production of biomass ethanol is reduced, the production cost is reduced, and the energy load in the final ethanol purification can be reduced. Therefore, it is economically advantageous, the use of plant waste as biomass is promoted, and it is useful for solving energy resource problems and waste disposal problems.

Schematic which shows one Embodiment of the sugar manufacturing apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram for demonstrating the saccharification method concerning this invention and the manufacturing method of sugar along the structure of a sugar manufacturing apparatus. The schematic block diagram which shows the modification of the sugar manufacturing apparatus of FIG. The schematic block diagram which shows the other modification of the sugar manufacturing apparatus of FIG.

In the production of biomass ethanol using plant waste (lignocellulosic biomass), saccharified product obtained by hydrolysis of cellulose and / or hemicellulose is ethanol-fermented. Saccharification of cellulose and hemicellulose includes enzymatic reactions using saccharifying enzymes (cellulase and hemicellulase) and catalytic reactions that hydrolyze using a catalyst. Enzymatic reactions are effective for the production of bioethanol. This is a useful reaction.

Enzyme reaction is usually carried out by adding the enzyme to water containing a substrate and homogenizing it by stirring and mixing. In biomass saccharification treatment, biomass raw materials such as particulate wood are preliminarily hydrothermally treated to remove lignin and hemicellulose, and then the cellulosic solid particles are dispersed in water. A saccharifying enzyme is allowed to act. When reacting using a batch-type reaction vessel, reducing the amount of water and increasing the concentration of solid particles lowers the fluidity. Therefore, it is difficult to reduce the water content to the extent that the fluidity is lower than that of the slurry.

In the present invention, by adopting an elongated horizontal reaction tank as a saccharification apparatus for performing an enzyme reaction, the enzyme reaction is efficiently advanced in a state where the amount of water is reduced. Specifically, as an enzyme reaction apparatus, a reaction tank extended in the horizontal direction (horizontal direction) is used, and high-concentration biomass (cellulose raw material) and a saccharifying enzyme are introduced from one end of the reaction tank to the other end. The enzyme reaction is advanced while moving in the reaction tank in the direction, and the reaction product and the reaction residue are discharged from the other end of the reaction tank. By gently stirring perpendicularly to the moving direction of the raw material (longitudinal direction of the apparatus), the vertical movement (rising and falling) and the lateral movement are combined to act on the raw material, and there are parts that are not mixed with the raw material. It can be prevented from occurring. By gently stirring, the movement and diffusion of the reaction product and the movement of the saccharifying enzyme are promoted, but the plug flow of the biomass in the reaction vessel is substantially maintained, so the cellulose is moved along with the movement of the biomass in the longitudinal direction. Degradation saccharification proceeds, and a liquid saccharification product is generated accordingly. Therefore, as the raw material moves in the longitudinal direction, the amount of the liquid material increases and the product becomes a slurry, and unreacted or in-process biomass is separated from the liquid portion as a solid residue. The liquid saccharified product contains glucose, a water-soluble oligosaccharide having a polymerization degree of 2 to 6, and a suspension polysaccharide which is a partially decomposed product having a polymerization degree of 7 to 3000, and becomes a viscous fluid liquid. The saccharification enzyme adheres to the solid residue of the unreacted cellulose, and the saccharification enzyme contained in the solid residue can be recovered and reused by separating and recovering the saccharification enzyme and throwing it into the saccharification reaction again. This configuration can also be used when hemicellulase acts as an enzyme on hemicellulose, or when cellulase and hemicellulase act as enzymes on a mixed system of cellulose and hemicellulose, and lignocellulose such as a woody material. The present invention can be widely applied in the case of performing an enzyme reaction on a system material.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the following description, a specific description will be given when cellulose is saccharified with cellulase. However, the present invention is not limited to this and is naturally applicable to saccharification of lignocellulosic materials such as hemicellulose.

FIG. 1 is a schematic view showing an embodiment of a sugar production apparatus for carrying out the saccharification method according to the present invention. A sugar production apparatus 1 is connected to an elongated cylindrical reaction tank 2 installed so as to extend in the lateral direction, and an upper end on one end side of the reaction tank 2 in order to put the raw material (and saccharifying enzyme) into the reaction tank 2. Hopper 3, piping 4 for recovering solid residue of unreacted cellulose from the bottom of the other end of the reaction tank 2, and saccharified liquid produced in the reaction tank 2 is discharged from the side of the other end of the reaction tank 2. Pipe 5 and an introduction pipe 6 connected to one end of the reaction tank 2 in order to recirculate the recovered solid residue to the reaction tank 2 and introduce it again. The enzyme contained in the solid residue is recycled. A reflux system for use is constituted by the pipe 5 and the introduction pipe 6. The wall portion of the reaction tank 2 is formed in a laminated structure in which a heat insulating material is incorporated in order to keep the interior at a temperature suitable for the enzyme reaction, and the inner wall surface is made of a material that does not inhibit the enzyme reaction, such as stainless steel or PTFE. It is made of iron or the like protected with a fluororesin. In order to adjust the reaction temperature, a heating device may be attached as necessary. For example, the reaction tank 2 may be covered with a double jacket that keeps warm water by passing warm water of about 80 ° C. It is effective to install so as to cover the lower half of 2 (the part where the inner wall surface is in contact with the raw material). The reaction tank 2 has a stirring device 7 for stirring and mixing the raw material and the saccharifying enzyme, and the rotating shaft 8 of the stirring device 7 is disposed in the longitudinal direction so as to coincide with the central axis of the reaction tank 2 and rotates. It is pivotally supported at both ends. By rotating or reciprocatingly rotating the rotating shaft 8 of the stirrer 7 by the motor 10 attached to the end of the reaction tank 2, a rod-shaped paddle 9 erected in the radial direction from the rotating shaft 8 is formed in the reaction tank 2. Are rotated or swung in a concentric manner. By this operation, the raw material and the enzyme are stirred and moved up and down. Each of the pipes 4, 5 and the introduction pipe 6 is provided with on-off

valves

11, 12, 13 for controlling the flow rate. In addition, a supply pipe 14 for replenishing the saccharifying enzyme to the raw material on the way in the reaction tank 2 is connected to the upper part of the reaction tank 2.

In saccharifying biomass with the sugar production apparatus of FIG. 1, the biomass raw material prepared in a granular or powder form having a particle size of about 5 mm or less is preliminarily subjected to hydrothermal treatment or the like, and then the moisture content (water mass relative to the total mass) Is prepared in a sludge-like water-containing state with a high concentration of about 90% by mass or less, preferably 80 to 90% by mass, and charged into the reaction tank 2 from the hopper 3 together with the saccharifying enzyme. The saccharifying enzyme is generally available as an aqueous liquid having a protein mass of about 1% or less, and is generally added at a ratio of about 10 parts by mass of the enzyme solution to 100 parts by mass of cellulose, and the amount of enzyme recovered together with the solid residue. It is recommended to reduce to the minimum required amount according to the situation. The addition form of the enzyme may be continuous or intermittent. The raw material and the saccharifying enzyme that have fallen into the tank are gently stirred by the stirring device 7, and the raw material and enzyme mixture are sequentially pushed out from one end side to the other end side of the reaction tank 2 by continuing the charging of the raw material. Move gradually in the longitudinal direction. During this time, the enzymatic reaction proceeds and the cellulose is gradually saccharified and liquefied to form a slurry-like mixture of unreacted raw material and saccharified liquid, and separation of the solid residue and saccharified liquid proceeds as the saccharified liquid increases. When reaching the other end of the reaction tank 2, the solid residue and the saccharified solution are discharged from the pipes 4 and 5, respectively. In order for the movement and stirring of the raw material in the reaction tank 2 to proceed efficiently and smoothly, it is preferable that a space exists on the raw material in the reaction tank 2. Specifically, the filling rate of the raw material in the reaction tank 2 Is preferably adjusted so that the feed rate is about 40 to 70% by volume. At that time, the balance between the raw material input amount and the saccharified liquid and solid residue discharge amount is adjusted so that the raw material in the reaction tank 2 moves at a constant speed. Since the optimum temperature of the enzyme reaction varies depending on the type of cellulase used, the temperature in the reaction vessel 2 is determined according to the optimum temperature of the cellulase, and the reaction time is about 30 to 70 ° C. for about 24 to 60 hours, preferably It is adjusted according to the time during which the raw material stays in the reaction tank 2 so that it is about 24 to 48 hours at 40 to 60 ° C. That is, the raw material residence time is adjusted by the raw material charging speed, the saccharified liquid, and the solid residue discharging speed so as to be the above reaction time. This achieves a saccharification rate of 85 to 90% based on the amount of glucose produced from cellulose. In order to recover a part of the saccharifying enzyme, the reaction time is set so that the saccharification rate falls within the above range, and the solid residue is intentionally left. By extending the reaction time, a further saccharification rate is possible and complete saccharification is possible.

Cellulase is generally known as an assembly of multiple types of saccharifying enzymes, and contains β-glucanase as a main component. β-glucanase is known as a saccharifying enzyme that hydrolyzes cellulose into water-soluble oligosaccharides (dimer to hexamer of glucose). Others include endoglucanase, cellobiohydrolase, etc. Is different. Therefore, reaction efficiency is good when a suitable type of saccharifying enzyme is allowed to act depending on the progress stage of the enzyme reaction. The sugar production apparatus of the present invention is configured so that a saccharification enzyme can be added to a raw material in the course of reaction by a supply pipe 14, and using this, an enzyme to be added at the initial stage of the reaction and an enzyme to be supplied from the supply pipe 14 Can be adjusted to different types or different content ratios. Further, it may be used for the purpose of adding / supplementing in consideration of inactivation of the enzyme or adjusting the addition time so that the enzyme is uniformly dispersed.

The reaction tank 2 in the sugar production apparatus 1 of FIG. 1 has a cylindrical shape, but any shape that allows stirring to work uniformly may be used. Therefore, if the lower half of the reaction tank 2 is a semicylindrical shape, It is not limited, You may comprise an upper part in a semi-elliptical column shape or a polygonal column shape.

Saccharifying enzyme is hydrophilic and diffuses uniformly in a large amount of water, but cellulose also has hydrophilicity, and because saccharifying enzyme has an adsorptive power to the surface of cellulosic material, if the amount of water is extremely reduced, The saccharification enzyme is in close contact with the raw material cellulose and easily comes into contact. The contacted saccharifying enzyme easily adheres to cellulose, and hydrolysis proceeds at that site to cut the cellulose fiber. In order for the reaction to proceed further, it is necessary to move the enzyme so that it can be decomposed and cleaved at other sites. However, the movement distance may be short, and rather the movement near the raw material is preferable, so that vigorous stirring at high speed is not necessary. In addition, since the raw material sequentially moves in the reaction tank 2 in the longitudinal direction, the movement in the longitudinal direction and the movement in the vertical and lateral directions perpendicular thereto are performed in gentle stirring at about 4 rpm or less, preferably about 1 to 3 rpm. It can mix suitably and can be mixed well and can advance an enzyme reaction favorably. For a semi-solid raw material with extremely low fluidity, high-speed stirring is not suitable because it only remains local stirring.

Slow agitation with high solids concentration also acts as a pressing or shear stress on the raw material, facilitating the raw material particles to absorb the surrounding liquid and release the internal liquid to the outside Since it has an effect, it facilitates the entry of enzymes into the raw material particles and the separation and release of decomposition products. Therefore, the high solids concentration at which the raw material particles are in contact with each other is very advantageous in this respect. In addition, the saccharified liquid droplets gradually generated by the reaction are collected to easily form a saccharified liquid phase, and the solid residue and the saccharified liquid are easily separated at the other end of the reaction tank 2. Stirring may be continuous or intermittent, and the paddle distribution density may be decreased toward the other end so as to reduce the frequency of stirring as the reaction proceeds (see FIG. 2). Even slow stirring is sufficiently effective in eliminating the non-uniformity of the temperature distribution, and can be maintained within ± 5 ° C. even if a local temperature change occurs. The shape of the paddle is not particularly limited as long as it can be stirred to perform appropriate mass transfer as described above, and a rod-shaped paddle as shown in the figure is suitable.

FIG. 2 shows another embodiment of the sugar production apparatus according to the present invention, which employs a cylindrical reaction tank 21 extending in the lateral direction, as in FIG. In this figure, the structure is schematically shown in order to explain the process of the saccharification method and the progress of the enzyme reaction. In this embodiment, a secondary saccharification device 40 for further saccharification treatment is connected to the saccharification solution obtained by the saccharide production device 20. Therefore, even when the ratio of oligosaccharides or suspension polysaccharides in the saccharified solution obtained by the saccharification apparatus 20 is high, the saccharification enzyme in the saccharification apparatus 20 can be sufficiently saccharified by the secondary saccharification apparatus 40. Since the amount used can be further reduced and the saccharification reaction time can be shortened, it is possible to further promote the suppression of the discharge of the enzyme to the outside of the apparatus and the recycling of the enzyme.

In saccharification of lignocellulosic biomass, granular or powdery biomass raw material is appropriately subjected to hydrothermal treatment or the like in advance, and the water content (percentage of water mass with respect to the total mass) is 90% by mass or less, preferably 80 to 90% by mass The biomass is prepared as a cellulose raw material B in a sludge-like water-containing state having a high concentration, and the processing is started. First, the control valve 23 is opened, the raw material B is pumped by the pump 22, supplied to one end of the cylindrical reaction tank 21 from the pipe L1, and charged from above. At this time, the control valve 36 is opened, and the saccharifying enzyme contained in the container 24 is added to the raw material B. In this embodiment, the control valve 36 is switched so that the saccharification enzyme can be supplied to either the reaction tank 21 or the biomass material B in the pipe L1. You may supply and mix in a tank. In the reaction tank 21, the rotating shaft 27 of the stirring device 25 is rotated by driving the motor 26, and the raw material B and the saccharifying enzyme are stirred and mixed by rotating or reciprocating the radial paddle 28 erected on the rotating shaft 27. Is done. By introducing the raw material B into the reaction tank 21 at a constant speed, the raw material B moves in the reaction tank 21 in the longitudinal direction. During this time, the enzymatic reaction gradually proceeds to produce saccharified liquid P, the amount of which gradually increases, and the amount of solid residue R that is unreacted raw material B gradually decreases. The paddle 28 of the stirrer 25 is provided so as to be large at one end side of the reaction tank 21 into which the raw material B is charged and small at the other end side, and in the initial stage of the enzyme reaction, the reaction is carried out by relatively frequently stirring. When the saccharified liquid is generated by the progress of the reaction, the stirring frequency is decreased to facilitate the precipitation and separation of the solid residue.

On the other end side of the reaction tank 21, the discharge of the solid residue R at the bottom is controlled by the

control valves

30 and 35, and the solid residue R discharged from the reaction tank 21 is pumped by a pump 38 provided in the pipe L3. The enzymes contained in the solid residue are reused by being supplied from the lines L2 and L3 via the switching valve 31 to the reaction tank 21 through the line L1. The saccharified liquid P in the reaction tank 21 is discharged from the suction pipe 29 through the pipe L4, and the discharge of the saccharified liquid P is controlled by the

control valves

32 and 33. The saccharified liquid P discharged from the reaction tank 21 is supplied from the line L4 to the secondary saccharification device 40 via the switching valve 31 from the line L4. Or if the control valve 33 is closed, it can extract | collect from the extraction port 34 through the pipe line L6.

The secondary saccharification device 40 is constituted by a batch type vertical reaction tank having a stirring device, and the contents are stirred by rotating a vertical rotation shaft 41 of the stirring device by a motor 42. Therefore, it is suitable for the treatment of a fluid liquid having a low viscosity, and the saccharified solution P supplied from the reaction tank 21 can be suitably treated.
In order to continuously supply the raw material B to the reaction tank 21, it is necessary to always use the pipe line L1. In consideration of this point, an example in which the saccharified solution P and the solid residue R are discharged and transferred in the saccharide production apparatus 20 of FIG. 2 so as to be suitable for continuous processing is shown in FIGS. Since the configuration other than the discharge / transfer mode of the saccharified solution P and the solid residue R is the same as that in FIG. 2, the description thereof will be omitted in the description of the sugar production apparatus in FIGS. 3 and 4 below.
In the sugar producing apparatus 20A of FIG. 3, a pipe L8 for supplying the solid residue R discharged from the other end of the reaction tank 21 to the one end of the reaction tank 21 separately from the raw material B is provided separately from the pipe L1. The transfer path of the saccharified liquid P does not intersect with the transfer path of the solid residue R. Specifically, the saccharified solution P discharged from the reaction tank 21 by the suction pipe 29 is supplied to the secondary saccharification device 40 through the pipe line L7, and the supply is controlled by the control valve 50. The solid residue R in the reaction tank 21 is returned alone to one end of the reaction tank 21 through a pipe L8 from a sludge chamber 60 provided at the bottom of the other end of the reaction tank 21, and the enzyme contained in the solid residue R is reused. The Therefore, the supply of the raw material B through the pipe L1 is not interfered by the reflux of the solid residue R, and the continuous supply of the raw material B can be stably performed. When the solid residue R is supplied to the sludge chamber 60, the saccharified liquid accompanying the solid residue R is separated as a supernatant, and the solid residue R is deposited. The sludge chamber 60 is provided with an interface meter 51 for detecting an internal liquid-solid interface. A pipe L8 is connected to the lower end outlet of the sludge chamber 60, and a control valve 52 for opening and closing the pipe L8 is provided. Provided. The interface meter 51 is electrically connected to the control valve 52 so that the control valve 52 is opened when the interface of the solid residue R deposited in the sludge chamber 60 reaches a predetermined level, and is closed when the interface is below the predetermined level. Is activated. It is preferable to set the predetermined level so that the volume of the solid residue is maintained to be less than about 50%, preferably less than about 20% of the internal volume of the sludge chamber 60 by opening the control valve 52. As the interface meter 51, for example, an interface meter that detects an interface using an elastic wave such as a vibration wave or a sound wave such as a vibration level switch, a tuning fork limit switch for liquid, and an ultrasonic level meter is preferably used. it can. The solid residue R discharged from the sludge chamber 60 is pumped through the line L8 by the pump 53, and is returned to the reaction tank 21 or switched from the line L8 by switching the

control valves

54 and 55. It is supplied to the tank through the path L9. In the state in which saccharification proceeds suitably in the saccharide production apparatus 20A of FIG. 3, the control valve 52 is intermittently opened, and the solid residue R is returned to the reaction tank 21 from the pipe L8 and saccharified again, and the enzyme contained in the residue (Cellulase) is reused. If the percentage of undegraded product increases significantly due to the decrease in the activity of the enzyme, the liquid-solid interface in the sludge chamber 60 will continuously exceed a predetermined level even if the control valve 52 is opened. In order to avoid such a situation, when the saccharification rate decreases, the solid residue R in the sludge chamber 60 is switched to be transferred to the tank once without returning to the reaction tank 21, and the solid residue in the tank 56 is opened, and the pump 57 is driven to pump the solid-liquid separator 58 through the line L10. In the solid-liquid separator 58, the saccharified liquid contained in the solid residue is separated, and the saccharified liquid is supplied to the secondary saccharification apparatus 40 through the line L11, and the solid residue is discharged from the line 12 to be boiler fuel. Effectively used as a source. In FIG. 3, the saccharifying enzyme in the container 24 is described as being added to the raw material B of the pipe L1 as in FIG. 2, but the sugar producing apparatus 20A is also added to the solid residue to be refluxed. May be configured.
When the amount of enzyme added to the raw material B is sufficient, or when the residual rate of the solid residue R is low because the pretreatment state of the raw material B is good, saccharification proceeds sufficiently, Since the main component is a non-saccharified substance such as lignin, the necessity of returning to the reaction tank 21 is low. In such a case, a sugar production apparatus 20B as shown in FIG. 4 can be used. In the sugar production apparatus 20B of FIG. 4, the pipe for returning the solid residue R separated in the sludge chamber 60 to the reaction vessel 21 is omitted, and the solid residue R is always stored in the tank through the pipe L13. Except for this, the configuration of the sugar manufacturing apparatus 20B is the same as that of the sugar manufacturing apparatus 20A of FIG.

As the reaction conditions in the above-described configuration, for example, the reaction is performed in the secondary saccharification apparatus 40 by reacting in the reaction vessel 21 at 30 to 70 ° C. for 12 to 48 hours, preferably at 40 to 60 ° C. for 12 to 24 hours. A saccharified solution in a state where it can be stirred and mixed is obtained, and this is allowed to react in the secondary saccharification apparatus 40 at 30 to 70 ° C. for 12 to 48 hours, preferably at 40 to 60 ° C. for 12 to 24 hours. A saccharification rate of 85 to 90% can be achieved. For adjusting the reaction temperature, it is useful to cover the reaction tank 21 with a heat insulation or heating jacket using warm water as a heat medium as in the sugar production apparatus of FIG. In the manufacturing apparatus, it is preferable to use a heat retaining or heating system using such a jacket.

Cellulase is generally known as an assembly of a plurality of types of saccharifying enzymes, and contains β-glucanase as a main component. Β-glucanase converts cellulose into a water-soluble oligosaccharide (a dimer to hexamer of glucose). ) Is known as a saccharifying enzyme that hydrolyzes. A part of the water-soluble oligosaccharide is decomposed into glucose by β-glucosidase contained in cellulase. That is, cellulases include multiple types of enzymes that act at different stages in the monosaccharification process. Since each enzyme has substrate specificity and is adsorbed to the raw material B according to the specificity, the enzyme that acts in the initial stage of the monosaccharide process is easily joined to the raw material B, and the enzyme that acts in the late stage is partially It is easy to be joined to the degraded suspension polysaccharide, and the solid residue R and the saccharified solution P may be biased in enzyme distribution. Therefore, by recovering and reusing the solid residue R from the reaction tank 21, a relatively large amount of enzyme that acts in the initial stage of saccharification is recovered and reused, while being supplied to the secondary saccharification apparatus 40. The saccharified solution P contains a relatively large amount of an enzyme that acts in the later stage of saccharification, and is advantageous in completing the saccharification reaction. The saccharification apparatus of FIG. 2 can divide the saccharification process into two parts, and a part of the saccharification process can be performed by the secondary saccharification apparatus 40. Therefore, the saccharification rate in the saccharide production apparatus 20 can be set lower than the above. Specifically, the reaction time and enzyme addition amount are set so that the saccharification rate in the saccharide production apparatus 20 is about 50 to 90%, and the saccharified solution containing the suspension polysaccharide and the water-soluble oligosaccharide by partial decomposition Can be completely saccharified using the secondary saccharification apparatus 40. As a result, the ratio of the enzyme contained in the slurry-like solid residue R to be collected and reused is increased, which is useful for increasing the enzyme collection and reuse rate.

The saccharification enzyme for replenishing the reaction tank 21 is accommodated in the container 37, and can be used for replenishing the enzyme that is insufficient due to inactivation or the like. In addition, an enzyme solution containing a large amount of enzyme acting in the early stage of saccharification and a saccharified solution containing a large amount of enzyme acting in the late stage of saccharification are stored separately in

containers

24 and 37, and the enzyme is supplied according to the reaction stage. May be performed.

In the sugar production apparatus as shown in FIGS. 1 and 2, a stirring blade may be provided at the tip or in the middle of the paddle of the stirring device, and it becomes easy to apply a pressing force to the raw material on the stirring blade, thereby bringing the enzyme into contact with the raw material. Invasion of the enzyme into the raw material particles and release / diffusion of the decomposition product from the raw material particles are promoted.

In addition, if the longitudinal axis of the reaction tank is slightly inclined and the other end side from which the saccharified liquid is discharged is arranged slightly higher than the one end side where the raw material is charged, Therefore, the reaction vessel may be installed at an inclination angle of about 3 ° or less, preferably about 1 to 2 °.

One embodiment of constituting an ethanol production apparatus using the sugar production apparatus described above will be described below.

The ethanol production apparatus includes a monosaccharide production apparatus that saccharifies biomass to produce a monosaccharide, a fermentation apparatus that ferments a saccharification product to produce ethanol, and a distillation apparatus that distills the fermentation product to purify ethanol. The monosaccharide production apparatus is composed of a pressurized hot water reactor that promotes selective hydrolysis of hemicellulose, a solid-liquid separator that separates hemicellulose-derived degradation products, and saccharifies cellulose by an enzymatic reaction. It comprises using an enzyme reaction apparatus. As the enzyme reaction apparatus, a sugar production apparatus as shown in FIG. 1 or FIG. 2 is used, biomass is supplied to a pressurized hot water reaction apparatus of a monosaccharide production apparatus, and hemicellulose is selectively hydrolyzed and liquefied to form a solid liquid. After separation by the separation device, the solid residue which is a cellulose raw material is supplied to the sugar production device of FIG. 1 or FIG. 2 and saccharified by an enzymatic reaction. When saccharification is completely performed by an enzymatic reaction, the obtained monosaccharide is directly introduced into a fermentation apparatus to produce ethanol, and ethanol may be generated by a distillation apparatus. In the case where saccharification is not carried out completely by an enzymatic reaction, for example, a catalytic reaction device using a solid acid catalyst may be attached, and a partially decomposed polysaccharide or oligosaccharide may be hydrolyzed by the catalytic reaction device to be monosaccharide. In addition, since the liquefied product produced by selective hydrolysis of hemicellulose is a partially decomposed product containing oligosaccharides derived from hemicellulose and xylose, in order to use this for the production of ethanol, a catalytic reactor using a solid acid catalyst And a fermentation apparatus using a microorganism having xylose fermentation ability. The catalytic reaction with a solid acid catalyst is also effective for monosaccharideization of oligosaccharides derived from hemicellulose.

A method for producing ethanol from lignocellulosic biomass using the ethanol production apparatus as described above will be described.

The biomass B used as a raw material may be any cellulosic material, for example, woody materials such as wood, thinned wood, bark, herbs such as rice straw, wheat straw, rice husks, pulp, waste paper, cotton cloth, linen, Examples thereof include fiber materials such as artificial cellulose materials. In particular, plant materials such as wood materials containing hemicellulose can be efficiently saccharified and fermented. From the viewpoint of reaction efficiency, it is preferable to pulverize such biomass B in advance, and it is preferable to prepare particles having a particle size of about 5 mm or less.

In a pressurized hot water reactor, a certain amount of biomass supplied as a raw material is accommodated from the outside, and is prepared using a heater, a pump, etc., at about 200 to 230 ° C., pressure of about 2 to 2.5 MPa (subcriticality) Supply pressurized hot water in the state). When pressurized hot water is added to and acts on biomass, hemicellulose contained in the biomass is selectively hydrolyzed and solubilized. The woody material is a cellulosic biomass mainly composed of cellulose and containing hemicellulose and lignin. When hydrolyzed with pressurized hot water, cellulose requires a temperature of about 240 to 300 ° C. Since it is easily decomposed and solubilized at a temperature lower than that of cellulose at about 200 to 230 ° C., the reaction product obtained by treating the wood material with a pressurized hydrothermal reactor is a polysaccharide containing an oligosaccharide partially decomposed and solubilized from hemicellulose. The solid-liquid mixture containing the water-containing liquid and the solid residue of cellulose and lignin that do not decompose. Pressurized hot water may be supplied either continuously or batchwise. In the case of continuous water supply, the water flow rate is adjusted so that the residence time in the tank is 5 to 120 minutes. And react for about 10 to 120 minutes. When pressurized hot water of about 120 to 200 ° C. is allowed to act before supplying the above-mentioned hot water of about 200 to 230 ° C., lignin is easily separated and the decomposition of hemicellulose at 200 ° C. or higher is promoted.

The reaction product of the pressurized hot water reactor is supplied to a solid-liquid separator and separated into a liquid portion of a hemicellulose decomposition product and a solid residue containing cellulose and lignin.

The solid residue is prepared in a high-concentration sludge-like water-containing state with a water content of about 90% by mass or less, preferably about 80 to 90% by mass, and used as a cellulose raw material as an enzyme reaction device, that is, the sugar of FIG. Supplied to manufacturing equipment. At that time, cellulase enzyme solution (protein mass of about 1% or less) is added at a ratio of about 10 parts by mass with respect to 100 parts by mass of cellulose, and as described above, the raw material is continuously supplied and the raw material in the reaction vessel is elongated. Stir slowly while moving in the direction. The reaction tank is maintained at an enzyme-active temperature, and cellulose in the solid residue is decomposed by the action of cellulase. Cellulose (a dimer of glucose), which is a water-soluble oligosaccharide, is mainly used as a saccharified solution of cellulose. A decomposition product is obtained. The saccharified solution contains a water-soluble oligosaccharide and a water-insoluble suspension polysaccharide, and is a fluid liquid in which the suspension polysaccharide is dispersed in a water-containing oligosaccharide-containing liquid. Saccharifies into glucose. Suspension polysaccharide is a partial decomposition product of cellulose, which is a hexamer or higher glucose polymer or cellohexaose crystal, which is a hexamer of glucose, and can be hydrolyzed to glucose by a solid acid catalytic reaction. is there.

As the saccharifying enzyme used in the enzyme reaction, a commercially available saccharifying enzyme can be used, and a commercially available saccharifying enzyme can also be used. Ordinary saccharifying enzymes have maximum enzyme activity at about 40 to 50 ° C., and thermostable enzymes have maximum enzyme activity at about 70 to 90 ° C. Therefore, the temperature of the enzyme reaction apparatus depends on the saccharifying enzyme used. Accordingly, it is adjusted as appropriate so as to obtain an appropriate enzyme activity. In order to facilitate the temperature control of the enzyme reaction, a cooler for reducing the temperature of the solid residue after the pressurized hot water reaction may be provided as necessary.

When the saccharified solution of cellulose produced in the enzyme reaction contains an oligosaccharide or a polysaccharide, it can be supplied to a catalytic reaction device to be saccharified. The catalytic reaction proceeds by mixing and stirring with a solid acid catalyst at a temperature of 90 ° C. or higher and lower than 120 ° C. using a solid acid catalyst, and oligosaccharides and suspension polysaccharides are hydrolyzed well by the action of the solid acid catalyst. It is decomposed to produce glucose (monosaccharide constituting cellulose). Examples of the solid acid catalyst include inorganic solid acids such as carbon-based, zeolite, alumina, and silica, and those obtained by introducing acidic groups by sulfonation treatment of organic materials such as resins. A powdered or particulate solid acid catalyst may be used. In particular, a sulfonated carbon-based material obtained by carbonization treatment of an organic carbon material and then a sulfonation treatment is preferable, and the sulfonated carbon-based solid acid catalyst is an inert material such as nitrogen or woody organic carbon material. Amorphous black solid (carbide) obtained by heat treatment in a gas atmosphere is heated in concentrated sulfuric acid or fuming sulfuric acid to add a sulfone group to the skeleton of the carbide and obtained by hot water washing. . The use amount of the solid acid catalyst is preferably 400 to 500 g / L as the packing density. The reaction time may generally be about 5 to 15 hours. A solid acid catalyst in the reaction product is settled and separated, and a saccharified solution containing glucose as a main component is obtained as a supernatant. The solid acid catalyst separated and separated is recovered and then returned to the mixing apparatus to be used again.

The saccharified solution obtained from cellulose is adjusted to the appropriate amount of water and pH so that the conditions are suitable for fermentation. The fermented microorganism is ingested in the fermenter to prepare a fermentation stock solution, and glucose is converted into ethanol by the action of the fermented microorganism. Convert. As a fermentation microorganism used for ethanol fermentation, known ethanol fermentation microorganisms such as yeast can be used. Examples include Zymomonas mobilis and Kluyveromyces marxianus. Moreover, you may utilize the bacterium which introduce | transduced the enzyme gene which has the conversion ability to ethanol by gene recombination. The use of flocculent yeast is advantageous in solid-liquid separation after fermentation because of good sedimentation, and it is advantageous for yeast to use amino acids and the like degraded by hydrolyzing enzymes of surrounding microorganisms as nutrient sources. Since it is also a form, it is useful for improving fermentation efficiency. During fermentation, it is preferable to add a nutrient source necessary for the propagation and activity of the fermenting microorganisms and adjust to an optimum pH. In order for yeast to be active and proliferating, essential nutrients such as phosphorus, nitrogen and vitamins, and required trace elements such as Co, Ni, and Zn are necessary, and yeast used for the production of biomass ethanol is The ability to synthesize vitamins or amino acids may be low or lacking. As a nutrient source for fermentation microorganisms to which such necessary components are added from the outside, yeast extract, polypeptone and the like can be generally used. Alternatively, plant waste such as tea husk and coffee husk and algal crushed material may be used, and components contained in these cell protoplasts can be used as the nutrient source.

The saccharified (glucose) concentration of the fermentation stock solution is adjusted to be about 1 to 20% by mass, preferably about 10% by mass. The addition amount of the nutrient source for microorganisms (in terms of dry matter) is appropriately adjusted according to the type of fermenting microorganism, and is generally set to about 0.1 to 1% by mass, preferably about 0.2 to 0.5% by mass. Good. The pH of the fermentation stock solution is adjusted to about 2.5 to 5.5, preferably about 3.0 to 5.5, inoculated with fermenting microorganisms at a rate of about 1 to 30 g / L, and a temperature of 30 to 37 ° C. The fermentation proceeds by holding for about 2 to 48 hours. For example, ethanol can be produced at a rate of about 20 to 25 g-ethanol / (L · h) using a fermentation stock solution having a glucose concentration of about 10% by mass.

The purified fermentation product is obtained by distilling the fermentation product that has undergone fermentation, if necessary, after removing solids (lignin, fermentation microorganisms, etc.) by filtration or the like. You may distill as it is, without removing solid content from a fermentation product. The solid matter separated from the fermentation product may be introduced into the biomass saccharification step.

On the other hand, the saccharified solution derived from hemicellulose is hydrolyzed and monosaccharided by a catalytic reaction using the same solid acid catalyst as described above using a catalytic reaction apparatus. The reaction conditions may be the same as described above. Monosaccharides including xylose, arabinose (pentose sugar constituting hemicellulose) and the like are generated from hemicellulose-derived oligosaccharides.

The saccharified solution derived from hemicellulose is adjusted to the appropriate amount of water and pH so that the conditions are suitable for fermentation. The fermented microorganisms are ingested in the fermentation apparatus to prepare a fermentation stock solution, and xylose is converted into ethanol by the action of the fermented microorganisms. Convert. Examples of fermenting microorganisms used for fermentation include microorganisms having xylose fermenting ability such as Saccharomyces yeast and Rhizopus oryzae. Moreover, you may utilize the bacterium which introduce | transduced the enzyme gene which has the conversion ability to ethanol by gene recombination. The use of flocculent yeast is advantageous in solid-liquid separation after fermentation because of good sedimentation, and it is advantageous for yeast to use amino acids and the like degraded by hydrolyzing enzymes of surrounding microorganisms as nutrient sources. Since it is also a form, it is useful for improving fermentation efficiency.

The fermentation product derived from hemicellulose can be purified by distillation in a distillation apparatus after removing solids (lignin, fermentation microorganisms, etc.) by filtration or the like, if necessary. You may distill as it is, without removing solid content from a fermentation product. The solid matter separated from the fermentation product may be introduced into the biomass saccharification step. The fermentation product derived from cellulose and the fermentation product derived from hemicellulose may be distilled together.

In fermentation equipment, microorganisms such as Clostridium acetobutylicum, Clostridium beigerinki, Clostridium auran butyricum, Clostridium tetanomorphum can be used to produce alcohol such as butanol and acetone by fermentation. It can be applied to the production of useful alcohols and ketones. Similarly, it can be applied to the production of hydroxymethylfurfural and furfural.

The present invention can be economically and rationally processed using resources that do not cause a rise in food prices when producing biomass ethanol from plant waste as biomass. Therefore, it is highly useful and can contribute to the promotion of recycling and environmental protection.

Claims

Prepare particulate biomass in a water-containing state,
While the biomass and saccharifying enzyme are introduced from one end side of a reaction vessel extending in a substantially horizontal direction and sequentially moved in the longitudinal direction toward the other end side, a rotation with the longitudinal direction of the reaction vessel as a central axis is performed. A biomass saccharification method in which saccharification of biomass proceeds with movement of the biomass in the longitudinal direction by stirring the biomass and saccharifying enzyme by dynamic operation.
The water-containing biomass has a moisture content of 90% by mass or less, and the stirring of the biomass is performed by rotating a stirring device having a paddle erected in a radial direction from a rotating shaft extending in the longitudinal direction of the reaction vessel. The biomass saccharification method according to claim 1, which is carried out by:
The water-containing biomass has a moisture content of 80 to 90% by mass, and the reaction vessel is disposed at an inclination angle of 3 ° or less so that one end side is lower than the other end side. 2. The method for saccharification of biomass according to 2.
The biomass saccharification method according to any one of claims 1 to 3, wherein the biomass is lignocellulosic biomass containing cellulose, and the saccharifying enzyme is cellulase.
The biomass of any one of claims 1 to 4, wherein the particulate biomass is obtained by previously hydrolyzing and removing hemicellulose contained in biomass by contacting with pressurized hot water. Saccharification method.
The biomass saccharification method according to any one of claims 1 to 4, wherein a saccharification enzyme is added while saccharification of the biomass proceeds.
A saccharified solution is gradually produced by hydrolysis of cellulose contained in the biomass by the biomass saccharification method according to any one of claims 1 to 6.
Recovering the saccharified solution and solid residue from the other end of the reaction tank,
A method for producing sugar, wherein the solid residue recovered from the other end side of the reaction tank is again charged into the reaction tank from one end side, and the saccharifying enzyme contained in the solid residue is reused.
The saccharification rate produced by the saccharified liquid from the biomass is 50 to 90%, and the saccharified liquid is further monohydrated by further proceeding with a hydrolysis reaction by a saccharifying enzyme contained in the saccharified liquid recovered from the reaction tank. Item 8. A method for producing a sugar according to Item 7.
A method for producing ethanol, wherein the sugar obtained by the method for producing sugar according to claim 7 or 8 is subjected to microbial fermentation to produce ethanol.
A reaction vessel extending in a substantially horizontal direction;
Biomass supply means for supplying water-containing particulate biomass having a high solids concentration from one end side of the reaction tank to the inside so as to sequentially move from one end side to the other end side of the reaction tank. ,
Enzyme adding means for adding saccharifying enzyme to biomass supplied from one end side of the reaction vessel;
A stirrer that stirs the biomass and saccharifying enzyme by a rotation operation with the longitudinal direction of the reaction tank as a central axis;
A saccharification apparatus comprising: discharge means for recovering a saccharified solution generated by saccharification of biomass moving in the longitudinal direction in the reaction tank from the other end side of the reaction tank.
The saccharification apparatus according to claim 10, wherein the agitation device includes a rotation shaft that is rotatably supported by extending in the longitudinal direction of the reaction tank, and a paddle that is erected in a radial direction from the rotation shaft. .
The saccharification apparatus according to claim 10 or 11, wherein the reaction tank is arranged with an inclination angle of 3 ° or less so that one end side is lower than the other end side.
The saccharification apparatus according to any one of claims 10 to 12, further comprising a replenishment means for replenishing the saccharifying enzyme to the biomass that is moving in the reaction tank.
14. A pressurized hot water reactor for bringing the particulate biomass into contact with pressurized hot water in advance to selectively hydrolyze and remove hemicellulose contained in the biomass. The saccharification apparatus of Claim 1.
A saccharification device according to any one of claims 10 to 14,
The solid residue separated from the saccharified liquid produced by hydrolysis of cellulose contained in biomass in the reaction tank of the saccharification apparatus is recovered from the other end side of the reaction tank, and charged into the reaction tank again from one end side of the reaction tank. And a reflux system for reusing the saccharifying enzyme contained in the solid residue.
Furthermore, the saccharide | sugar production apparatus of Claim 15 which has a secondary saccharification apparatus which further advances the hydrolysis reaction by the saccharification enzyme contained in the saccharification liquid discharged | emitted from the said reaction tank, and saccharifies the saccharification liquid.
A saccharification device according to any one of claims 10 to 14,
A saccharification apparatus comprising: a secondary saccharification apparatus that further saccharifies the saccharification liquid by further proceeding with a hydrolysis reaction by a saccharification enzyme contained in the saccharification liquid discharged from the reaction tank of the saccharification apparatus.
A sugar production apparatus according to any one of claims 15 to 17,
A fermentation apparatus for producing ethanol by microbial fermentation of sugar produced by the sugar production apparatus;
An ethanol production apparatus comprising: a distillation apparatus for purifying ethanol produced by the fermentation apparatus.