JP2009269260A - Surface structure control method for woody resource, manufacturing method for bio-ethanol, and manufacturing method for artificial lumber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface structure control method capable of controlling surface structures in woody resources in a state suitable for saccharification or the like. <P>SOLUTION: This surface structure control method controls the surface structures in the woody resources. A cellulose microfibril is broken fiber-likely by carrying out a refining operation of beating and tearing off the woody resource, and extremely micro-refining work is executed thereafter under the condition where a fiber characteristic is maintained in a refiner. The refining operation is carried out by rotating a rod provided eccentrically to the center axis of a cylindrical container in the container, and by feeding a woody resource chip, using wind power. The woody resource brought into "a feather-like beat fibrous state" is used, for example, as a raw material for bio-ethanol or a raw material (reinforcement material) of an artificial lumber. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel surface structure control method capable of controlling the surface structure of woody resources such as thinned wood and waste wood to be “fluffed fibrous”, and further, bioethanol as an application thereof. A manufacturing method and a manufacturing method of artificial wood are provided.

  In order to prevent global warming caused by mass consumption of fossil fuels or to secure renewable alternative energy sources, measures for effective utilization of unused biomass are being studied. For example, bioethanol obtained by saccharification and fermentation of woody biomass can be used as an alternative fuel as it is, or can be used as a fuel for a fuel cell.

  About 50% of the dry weight of woody biomass such as thinned wood and waste wood is made of cellulose, which is a glucose polymer, and can be converted into useful substances such as bioethanol by decomposing it into glucose. However, since cellulose forms crystalline fibers with β-1,4-bonded glucose, it is a very stable polymer compared to α-1,4-bonded starch, which is the same glucose polymer, and its degradation is reduced. Have difficulty. In addition, cellulose in wood has a structure that is physically, chemically, and enzymatically stable because lignin and hemicellulose tightly cover steel as if it were reinforcing steel. Decomposition is made more difficult (see, for example, Non-Patent Document 1). Therefore, in order to efficiently produce bioethanol, decomposition of woody biomass into glucose becomes a major issue.

  From such a situation, in order to obtain glucose by saccharifying wood and the like, usually, after taking out cellulose through a pretreatment step of delignification and dehemicellulose by acid and alkali treatment under high temperature and high pressure, Hydrolysis is performed with acid or enzyme cellulase (see, for example, Non-Patent Document 2).

  It is common knowledge of many researchers that hemicellulose and lignin surrounding cellulose fibers should be removed in advance in order to efficiently decompose cellulose derived from woody biomass. Conventionally, in order to achieve this, wood chips or the like have been subjected to acid or alkali treatment. However, pretreatment by this method requires not only a large-scale apparatus but also requires large investment energy. Furthermore, it is necessary to construct a system for recovering and reusing the acid and alkali to be used (see, for example, Non-Patent Document 3), and processing problems such as waste liquid generated in large quantities and exhaust gas with strong odor must be considered. I must. In addition, significant reductions in saccharification efficiency due to cellulase inhibitors produced as a by-product from wood due to acid and alkali treatment, and further degradation of the resulting monosaccharides by acid (see, for example, Non-Patent Document 4) It has become.

  For this reason, pulverizing woody biomass by mechanical treatment and supplying it as a raw material for bioethanol has also been studied (see Patent Document 2 and Patent Document 3). For example, Patent Document 2 discloses a pulverizing apparatus that pulverizes a wood material with a pulverizing medium in a pulverizing cylinder under vibration of a pulverizing cylinder supported by a spring. By using the pulverization apparatus described in Patent Document 2, it is said that the wood material can be pulverized to a powder having a particle size of 100 μm or less and can be effectively used as a raw material for biomass.

Similarly, Patent Document 3 discloses that a thick circular plate having a cylindrical container that is horizontally vibrated and has protrusions linearly in a plurality of thickness directions on its outer peripheral surface is caused to vibrate vertically and rotate in the cylinder. A high-impact pulverizer for pulverizing woody biomass, in which a plurality of movable gaps are inserted, the outer surface of the cylindrical vessel is cooled, and woody biomass chips are supplied to the gap between the cylindrical vessel and the thick disc Has been. By using the pulverizer described in Patent Document 3, it is said that a powder having a high saccharification rate can be produced in a short pulverization process.
"Cellulase" (1987) Kodansha Scientific TRENDS in Biotechnology (2006) 24: 549-556 Nikkei Biobusiness 2002 No.9 p55-56 Appl.Microbiol. Biotechnol. (2006) 69: 627-642 JP 2006-136263 A JP 2004-188339 A JP 2008-93590 A

  As mentioned above, for example, the saccharification process of woody biomass requires a large-scale plant equipped with a large decomposition reaction system and waste recovery and treatment facilities, and an energy investment sufficient to operate it. This is a major obstacle to commercialization. A wood saccharification system using cellulase that hydrolyzes cellulose under mild conditions is desirable, but the presence of lignin and hemicellulose, which are characteristic of woody biomass, makes it difficult to access and decompose cellulase to the substrate cellulose. However, no technology has been developed that gives the desired results.

  For example, if the pulverization apparatus (pulverizer) described in Patent Document 2 or Patent Document 3 is used, it is possible to obtain a raw material powder by mechanical treatment, but if the powder is simply powdered, the particle surface becomes fluffy. Therefore, every time a fuzzy surface is saccharified, it is necessary to perform ultrafine processing or homogenization operation (stirring or the like), and the fact is that efficient saccharification cannot always be performed. In order to advance the saccharification reaction efficiently, the surface structure of the extremely fine woody resources is important. When the pulverization apparatus (pulverizer) described in Patent Document 2 or Patent Document 3 is used, Insufficient points.

  The present invention has been proposed in view of the above-described problems of the prior art, and provides a method for controlling the surface structure of a wood resource capable of controlling the surface structure of the wood resource to a state suitable for saccharification and the like. For the purpose. Furthermore, the present invention has an object to provide a bioethanol production method capable of producing bioethanol with excellent saccharification efficiency and high productivity by applying the method for controlling the surface structure of the woody resource. It is an object of the present invention to provide a method for producing an artificial wood that can produce an artificial wood having excellent bonding properties with a resin and excellent strength and flexibility.

  In a sustainable society that is desired in the future, it is essential to build an environment-friendly and energy-saving bioethanol production system. Considering this point, saccharification by an enzymatic method is most desirable. Here, the problem that the enzymatic saccharification method has is derived from the characteristics of the surface structure of, for example, woody biomass. That is, since hemicellulose and lignin tightly surround the cellulose, if the fibrous cellulose microfibrils exposed on the surface of the wood microparticles are decomposed by cellulase, further saccharification becomes difficult.

  The present inventors have made various studies over a long period of time in order to solve such problems. As a result, it is possible to make the wood resource extremely fine by combining the defibrating operation to hit and tear the wood resource and the refiner using the refiner, and to maintain the fluffy fibrous form. I came to find it.

  The present invention has been completed on the basis of the above-described knowledge, and is a surface structure control method for controlling the surface structure of a wood resource, and is performed by performing a defibrating operation by striking and tearing the wood resource. After the cellulose microfibrils are broken, ultrafine processing is performed while maintaining the fiber characteristics by a refiner. The bioethanol production method of the present invention is characterized in that the wood resources treated by the surface structure control method are saccharified with a hydrolase and subjected to ethanol fermentation. Furthermore, the method for producing artificial wood according to the present invention is characterized in that a wood resource treated by the surface structure control method is mixed with a resin.

  For example, when a wood resource is destroyed by impact of a collision with a ball mill or the like to make it extremely fine, cells are not destroyed and the surface is only fluffed. Therefore, for example, if this is to be saccharified, every time the fuzzy surface is saccharified, it is necessary to carry out ultrafine processing again, resulting in a large manufacturing cost.

  On the other hand, when the wood resources are crushed into fibers by smashing and tearing and then refined with a refiner, the fibrous form is maintained even after the refinement. When a wood resource that has been extremely refined and maintained in a fibrous form is subjected to saccharification, for example, in the production of bioethanol, saccharification is continuously performed, and the burden of production cost is greatly reduced. In addition, the surface structure of the extremely fine wood resources is “fluffy fibrous”, and it becomes the same size as the molecular structure of the resin due to the microminiaturization, so it becomes easy to bond with the resin. It also has the feature.

  According to the surface structure control method of the present invention, it is possible to finely process a wood resource to a micro level while destroying cellulose microfibrils in the form of fibers and retaining fiber characteristics. Cellulose microfibrils are the most sustainable resources produced on the earth in large quantities. As described above, the present invention can be applied to reduce the amount of wood resources and control the surface structure in various fields. Effective use becomes possible, and the environmental load related to production and disposal can be made extremely small.

  In addition, according to the bioethanol production method of the present invention, it is possible to saccharify wood resources continuously and efficiently under mild conditions in which pretreatment with acid or alkali is not performed, and saccharification efficiency with respect to input energy Improvement can be expected. In addition, according to the present invention, it is possible to perform saccharification in a simple facility because it does not require the use of an acid or an alkali and the operation under high temperature and high pressure. Furthermore, since it is not necessary to use acid and alkali, the cost required for collecting them can be reduced, and environmental problems such as waste liquid and bad odor generated can be alleviated.

  Furthermore, according to the method for producing artificial wood of the present invention, it is possible to produce artificial wood having excellent strength and flexibility. This is because, by making the woody resources extremely fine to the micro level, the workability of the material is greatly improved, for example, the strength is increased, and high-speed superplasticity that enables high-speed processing to complex shaped products with a small force is achieved.

  Hereinafter, embodiments of a method for controlling the surface structure of a wood resource to which the present invention is applied, a method for producing bioethanol, and a method for producing artificial wood will be described in detail.

  FIG. 1 shows an example of a wood resource surface structure control system (miniaturization system) to which the present invention is applied. The system includes a special rod mill 1 that performs a defibrating operation for tapping and tearing chip-shaped wood resources, a belt conveyor 2 that transports the fibrillated fibrous wood resources, and a pulper 3 that accommodates the transferred fibrous wood resources, Crushing pump 4 and conical refiner 5 for ultrafine fiber wood resources supplied from the pulper 3, drum type concentrator 6 for dewatering ultrafine wood resource fine powder, high concentration for transferring wood resource fine powder It comprises a transfer pump 7 and a storage tank 8 that contains fine powder of wood resources whose surface structure is controlled.

  Here, the special rod mill 1 is composed of an inlet 11 into which a chip-like wood resource as a raw material is introduced, a cylindrical container 12 and a rod 13 installed in the cylindrical container 12. The rod 13 is installed in a state where its central axis is eccentric from the central axis of the cylindrical container 12. By rotating this rod, the rod 13 is struck against the inner wall of the cylindrical container 12, and the injected chip-like wood resource is cylindrical. A defibrating operation is performed in which the container 12 and the rod 13 are struck and torn.

  In the special rod mill 1, chip-like wood resources are supplied and transferred in the cylindrical container 12 using wind power. A blower (not shown) is installed in the vicinity of the inlet 11, and chip-like wood resources are supplied from the inlet 11 into the cylindrical container 12 by the wind from the fan. The chip-like wood resources supplied into the cylindrical container 12 are moved toward the discharge port side by the wind force, and are struck by the rod 13 and the inner wall of the cylindrical container 12 in the process of movement.

  The supply of the raw material by the wind force and the transfer in the cylindrical container 12 are advantageous in classifying the fibrous wooden resources after the defibrating operation. That is, the fibrous wooden resources defibrated in the cylindrical container 12 are discharged from the outlet of the cylindrical container 12, but among the fibrous wooden resources blown by wind power, those having a relatively large size are discharged. Falling near the exit, small ones are thrown far away. Using this, it is possible to classify fibrillated woody resources. Of the classified fibrous woody resources, only small ones are supplied to the next ultra-miniaturization. Among the classified fibrous wood resources, those having a relatively large size can be reused by being input again from the input port 11.

  The pulper 3 is provided with a rotor for generating a spiral gyration on the bottom surface, and a strainer is disposed below the rotor. In the pulper 3, the fibrous wood resources are hydrated, disaggregated and discharged from the strainer.

  The conical refiner 5 is a device that mechanically taps and grinds fibrous wood resources in the presence of water. By treating the fibrous woody resources with this conical refiner 5, the fibers are disaggregated, cut, hydrated, swollen, entangled, etc., and are refined to the micro level.

  Next, the surface structure control of the wood resource by the wood resource surface structure control system having the above configuration will be described. In order to control the surface structure of the wood resource, first, the chip-like wood resource (wood resource chip MC) is supplied from the inlet 11 of the special rod mill 1 by a blower. The wood resources to be treated are, for example, thinned wood and waste wood, and can be applied to so-called woody biomass in general.

  The chip-shaped wood resource MC that has been input is crushed into fibers by breaking and tearing in the special rod mill 1 to become a fiber-like wood resource. Of these fibrous wooden resources, a small one is transferred to the pulper 3 by the belt conveyor 2 and hydrated, disaggregated, and sorted in the pulper 3. For the large size, the defibrating operation is performed again in the special rod mill 1. The fibrous wood resource that has been hydrated or the like in the pulper 3 is then transferred to the conical refiner 5 by the crushing pump 4 and subjected to ultrafine processing in the conical refiner 5. In the conical refiner 5, ultrafine processing is performed by so-called beating, and ultrafine processing is performed down to the micro level while leaving the fiber characteristics. The very fine woody material is conveyed to the drum type concentrator 6, dehydrated, separated by the agitator 9, and conveyed to the storage tank 9 by the high concentration transfer pump 7. The aqueous phase separated from the solid content (wood resource fine powder) in the drum type concentrator 6 is recovered by the recovery tank 10 and returned to the pulper 3.

  Cellulose microfibrils that form round or square cells such as pipe cross-sections are skeletal substances that occupy 50% or more of plant cell walls (plant fibers), and are nanofibers with a width of about 4 nm consisting of extended chain crystals. It is. Its elastic modulus and strength reach 140 GPa and 3 GPa, respectively. This is equivalent to aramid fiber (trade name: Kevlar), which is a typical high-strength fiber, and is more elastic than glass fiber. Therefore, the destruction of the cell wall is incomplete in the crushing by the impact of the ball mill. In the wood resource surface structure control system, the chip-like wood resources are crushed by the tapping and tearing of the chip-like wood resources in the special rod mill 1, and the fiber characteristics are left in the conical refiner 5 after being broken into fibers. Ultra-fine processing down to the micro level.

  The wood resource fine powder obtained by the above treatment is composed of “fluffy fibrous” cellulose microfibrils, and has excellent reaction with enzymes. Therefore, it is suitable as a raw material for bioethanol.

  That is, the above-mentioned surface structure control is used as a pretreatment, and a hydrolase is added to the obtained wood resource fine powder to perform conversion (decomposition) into sugars such as glucose. Cellulase or the like is used as a hydrolase for saccharification. Cellulose is broken down into glucose by enzymatic hydrolysis with cellulase. As the cellulase that is a hydrolase, for example, cellulases derived from various microorganisms can be used, but a mixture of a plurality (for example, two types) of cellulases derived from different microorganisms can also be used in combination. By coexisting two types of cellulase mixtures originating from different microorganisms, the concentration of produced glucose is improved and more efficient saccharification is realized.

  After the saccharification, ethanol fermentation is performed with yeast or the like. Alternatively, at the time of saccharification, yeast can be added together with the hydrolase to make simultaneous saccharification and fermentation. In simultaneous saccharification and fermentation, cellulase, which is a hydrolase, and yeast are allowed to act simultaneously on cellulose to obtain alcohol in a one-step reaction. Saccharification and treatments accompanying this, fermentation, and fermentation In one process, it is possible to increase the yield of ethanol products, increase the reaction rate, and the like.

  Any yeast can be used as the yeast for ethanol fermentation. By the action of the cellulase mixture of microbial origin in the presence of yeast, for example, fibrous cellulose microfibrils constituting the wood resource fine powder are saccharified and further converted into an ethanol product by ethanol fermentation.

  The woody material fine powder treated by the above surface structure control system is composed of fibrous cellulose microfibrils and is extremely miniaturized, so that it is quickly saccharified and becomes ethanol by ethanol fermentation. When saccharifying wood particles that are simply made into fine particles by a ball mill or the like, if the fuzzy surface is saccharified, it is necessary to re-fine the material again, but the wood resources processed by the previous surface structure control system When fine powder is used, there is no such need, and bioethanol can be produced efficiently.

  In addition, in the wood resource fine powder processed by the surface structure control system described above, the cellulose microfibrils refined into fibers are bundled in several or tens of bundles. A technique that can be made into a fiber-reinforced composite material excellent in mechanical properties and optical properties and that can produce such materials at low cost is remarkable.

  For example, the surface structure struck and torn by the surface structure control system is “fluffed fibrous”, and becomes the same size as the molecular structure of the resin by microminiaturization. Cellulose microfibrils and resins having the same size are easily bonded to each other, and an artificial wood excellent in strength and flexibility can be produced.

  Any resin can be used as the resin to be combined with the wood resource fine powder treated by the surface structure control system. However, when combined with a biodegradable resin such as polylactic acid, it is excellent in strength and flexibility. Rather, it will be possible to construct an artificial wood that will be the next generation for the environment.

It is a schematic diagram which shows the structural example of a surface structure control system.

Explanation of symbols

1 Special rod mill, 2 belt conveyor, 3 pulper, 4 crushing pump, 5 conical refiner, 6 drum type concentrator, 7 high concentration transfer pump, 8 storage tank, 9 stirrer, 10 recovery tank, 11 inlet, 12 cylinder Container, 13 rod

Claims (5)

  A surface structure control method for controlling the surface structure of a wood resource. After the cellulose microfibrils are broken into fibers by performing a defibration operation that strikes and tears the wood resource, the fiber properties are maintained by a refiner. A method for controlling the surface structure of a wood resource, characterized by performing ultrafine processing.   2. The defibrating operation is performed by rotating a rod installed eccentrically with respect to a central axis of the container in a cylindrical container and feeding wood resource chips using wind power. To control the surface structure of woody resources.   A method for producing bioethanol, comprising saccharifying a wood resource treated by the surface structure control method according to claim 1 or 2 with a hydrolase and performing ethanol fermentation.   A method for producing artificial wood, comprising mixing a wood resource treated by the surface structure control method according to claim 1 or 2 with a resin.   The method for producing artificial wood according to claim 4, wherein the resin is a biodegradable resin.

Images