JP2011047083A - Method for producing bast fiber and bast fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a large amount of bast fibers at a low cost by using bark of an arboreous plant as a raw material. <P>SOLUTION: The method for producing the bast fibers includes: crushing and dispersing the bark of the arboreous plant in water; carrying out a saccharification treatment with a saccharifying enzyme; then carrying out a solid-liquid separating treatment for separating a liquid containing a saccharide and a solid residue; and obtaining the bast fibers from the residue. The method for producing the bast fibers includes carrying out a fermentation treatment with a yeast subsequently to the saccharification treatment; and then carrying out the solid-liquid separating treatment. In the method for producing the bast fibers, the saccharification treatment is a treatment simultaneously carrying out fermentation with the yeast. Furthermore, the method for producing the bast fibers includes carrying out a grinding treatment before the saccharification treatment, and the method for producing the bast fibers includes carrying out a chemical treatment before the saccharification treatment. The method for producing the bast fibers includes carrying out the grinding treatment and chemical treatment successively or simultaneously before the saccharification treatment. There are provided the bast fibers obtained by the method for production. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a bast fiber using a bark of a woody plant as a raw material, and a bast fiber.

Bast fibers have been used in banknotes and Japanese paper, but in recent years they are obtained from woody biomass, which is carbon neutral and renewable resources, as well as properties such as strength and lightness and biodegradability. Attention has been focused on the use of fiber as a fiber material for fiber reinforced resin.
For example, a composite fiber material in which bast fibers are added to a polylactic acid resin has been proposed (Patent Document 1).

  In addition, as a conventional method for producing bast fibers, a method in which ramie, cannabis and flax are boiled with alkali, the fibers are loosened and then oxygen bleached or chlorine bleached to extract bast fibers (Patent Document 2). A method for producing bast fibers by cutting basts of vegetation such as kenaf, kouzo, mitsumata, soaking in an ammonium oxalate solution, defibration by stirring, washing and drying (Patent Document 3), etc. Proposed.

JP 2008-150599 A JP 2007-126809 A JP 2002-105737 A

Most of the bast fibers listed above are made from herbaceous plants such as ramie, cannabis, flax, kenaf, etc., but herbaceous plant materials are such as their storage stability and quality stability. In addition, shrubs such as kouzo and mitsumata, which are used as raw materials for Japanese paper, are also known as raw materials for bast fibers. Have difficulty.
Therefore, a method for producing bast fibers that can stably supply a large amount of bast fibers at low cost has been demanded.

In order to solve the above problems, the present inventors take the following methods (1) to (6).
(1) The bark of a woody plant is crushed and dispersed in water, saccharified with a saccharifying enzyme, and then subjected to a solid-liquid separation process for separating a liquid component containing sugar and a solid residue, and A method for producing a bast fiber, comprising obtaining a leather fiber.
(2) The method for producing a bast fiber according to (1), wherein after the saccharification treatment, a fermentation treatment with yeast is performed, followed by a solid-liquid separation treatment.
(3) The method for producing a bast fiber according to (1), wherein the saccharification treatment is a treatment for simultaneously performing fermentation with yeast.
(4) The method for producing a bast fiber according to any one of (1) to (3), wherein a grinding treatment is performed before the saccharification treatment.
(5) The method for producing a bast fiber according to any one of (1) to (3), wherein chemical treatment is performed before saccharification treatment.
(6) The method for producing a bast fiber according to any one of (1) to (3), wherein a grinding treatment and a chemical treatment are sequentially or simultaneously performed before the saccharification treatment.

  According to the present invention, a large amount of bast fibers can be produced at a low cost in parallel with the production of sugars and fermented products using the bark of a woody plant as a raw material.

Hereinafter, the present invention will be described in more detail.
The raw material of the bast fiber of the present invention is a bark of a woody plant.
A woody plant is divided into an inner xylem and an outer bark with a formation layer where cell division is active as a boundary. In addition, the bark is divided into an outer bark of dead tissue and an inner bark of living tissue.
The outer bark mainly consists of pericytes or cork layers, which protects the wood tissue from mechanical damage and reduces fluctuations in temperature and humidity.
The inner bark is composed of mentor elements, parenchyma cells and thick wall cells.The mentor elements have a function of transporting liquids and nutrients, and the parenchyma cells have a function of storing nutrients such as starch. Intervene. Thick wall cells function as a supporting tissue, are observed in layers like the xylem rings, and are differentiated into bast fibers and scleroids by shape. Bast fibers are characterized by a long fiber length, thick walls and high tensile strength compared to other cells.

Bark is not used for timber applications, and when pulping in the papermaking process, it can be returned to the soil as fertilizer in the plantation with the branches and roots to reduce the quality of the pulp even if mixed slightly. Although it is peeled and incinerated at factories or chip factories and is not effectively used as woody biomass, it is suitable as a raw material for bast fibers because it is available in large quantities at a lumber factory and chip factories. It is particularly preferable.
For example, the bark of a tree species such as Eucalyptus or Acacia, which is commonly used for papermaking raw materials, can be obtained in large quantities from a sawmill or chip factory for papermaking raw materials. Preferably used.

Said bark raw material can obtain saccharide | sugar by performing a saccharification process by saccharification enzyme.
Further, it is possible to obtain a fermented product such as ethanol by subsequent fermentation with yeast. Alternatively, saccharification and fermentation can be performed simultaneously. In this specification, these treatments are collectively referred to as saccharification and fermentation.
The above bast fibers can be obtained from the residue recovered by solid-liquid separation of the saccharification product and the saccharification and fermentation product. Producing bast fibers in parallel with the production of saccharides and fermented products is an excellent production method in terms of cost because raw materials can be used effectively.

In the present invention, the bark raw material is first crushed. Here, the crushing means cutting or crushing into a form that can be enzymatically treated with a saccharifying enzyme. As a device for crushing, a cutter, a chipper, a uniaxial crusher, a biaxial crusher, a hammer crusher, or the like can be used.
Next, the saccharification treatment is performed, and the yield of the saccharification treatment or the saccharification and fermentation treatment may be improved by pretreating the bark raw material.

The pretreatment can be mechanical treatment, chemical treatment, or any other treatment depending on the type and state of bark used as a raw material.
The mechanical treatment improves the yield of the saccharification treatment or fermentation treatment in the next step by any mechanical means such as crushing and grinding. The means and the mechanical device to be used are not particularly limited. For example, a grinding device such as a kneader, a refiner, a mill, or a grinder can be suitably used.

The chemical treatment is to immerse in an aqueous solution of a chemical such as acid or alkali, hot water or the like to make it suitable for the saccharification or fermentation treatment in the next step.
The chemicals used for the chemical treatment are not particularly limited, but for example, one or more selected from alkali metal or alkaline earth metal hydroxides, sulfides, carbonates or sulfites, An alkali treatment or the like that is immersed in an aqueous solution of one or more kinds of chemicals selected from sodium, calcium hydroxide, sodium sulfide, sodium carbonate, sodium sulfite and the like is suitable as the chemical treatment.

In addition, although the chemical addition amount used for chemical treatment can be arbitrarily adjusted according to the situation, it is 50% or less with respect to the absolute dry mass of the woody biomass used from the aspect of chemical cost reduction. In addition, it is further desirable from the viewpoint of preventing yield reduction due to elution / overdecomposition of cellulose.
Any one of the mechanical treatment and the chemical treatment, which are pretreatments of these barks, may be performed either sequentially or simultaneously as necessary. In the present invention, it is particularly preferable to perform chemical treatment before the mechanical treatment step.

  In the chemical treatment step in the pretreatment of the present invention, the immersion time and treatment temperature of the chemical in the aqueous solution can be arbitrarily set depending on the raw materials and chemicals used, but the treatment time is 30 minutes to 1 hour. 80-130 degreeC is preferable. By tightening the treatment conditions, cellulose in the bark may be eluted to the liquid side, and the yield of bast fibers may decrease, so the treatment time is 1 hour or less and the treatment temperature is 130 ° C. or less. Preferably there is.

The saccharification treatment step of the present invention is a step of saccharifying bark with a saccharifying enzyme. The saccharification and fermentation treatment step is a step in which an enzyme saccharification treatment for saccharifying a raw material with an enzyme and a fermentation treatment for further fermenting the obtained saccharide with ethanol or the like are performed.
In the saccharification and fermentation treatment, the enzyme saccharification treatment and the ethanol fermentation treatment may be performed continuously in separate steps, or the enzyme saccharification treatment and the ethanol fermentation treatment may be performed simultaneously.

The saccharifying enzyme used in the saccharification treatment or the saccharification and fermentation treatment is a cellulolytic enzyme, and is an enzyme collectively referred to as so-called cellulase having cellobiohydrolase activity, endoglucanase activity, and betaglucosidase activity.
Each cellulolytic enzyme may be added with an appropriate amount of an enzyme having each activity. However, commercially available cellulase preparations have various cellulase activities as described above, and also have hemicellulase activity. Many commercially available cellulase preparations may be used.

Commercial cellulase preparations include Trichoderma, Acremonium, Aspergillus, Phanerocheet, Trametes, Humicola, and Humicola. There are cellulase preparations derived from the above. Commercially available products of such cellulase preparations are all trade names, for example, cellulosin T2 (manufactured by HIPI), mecerase (manufactured by Meiji Seika Co., Ltd.), Novozyme 188 (manufactured by Novozyme), multifect CX10L (manufactured by Genencor) ) And the like.
0.5-100 mass parts is preferable and, as for the usage-amount of the cellulase formulation with respect to 100 mass parts of raw material solid content, 1-50 mass parts is especially preferable.

  The treatment conditions are preferably pH 4-7. The temperature is preferably 25 to 50 ° C, more preferably 30 to 40 ° C. The saccharification and fermentation reaction is preferably a continuous type, but may be a batch type. The saccharification and fermentation reaction time varies depending on the enzyme concentration, but in the case of a batch type, it is 10 to 240 hours, more preferably 15 to 160 hours. Also in the case of a continuous type, the average residence time is 10 to 150 hours, more preferably 15 to 100 hours.

Next, fermentation will be described.
As the microorganism used for fermentation, yeast or the like is used, and a medium or the like may be added simultaneously. Known yeasts such as Saccharomyces cerevisiae can be used as the yeast.
Moreover, the microorganisms may be immobilized. By immobilizing microorganisms, it is possible to omit the process of sending the microorganisms together with the liquid and recovering them again in the next process, or at least reduce the burden on the recovery process and reduce the risk of losing microorganisms. You can also In addition, although there is no merit as to immobilize the microorganism, it is possible to facilitate the recovery of the microorganism by selecting an aggregating microorganism.

The fiber is recovered by solid-liquid separation from the saccharified solution obtained from the saccharification step or the fermentation solution obtained from the saccharification and fermentation treatment step. The obtained fiber can be washed to remove the enzyme and yeast remaining in the fiber to obtain a bast fiber.
It should be noted that the degree of saccharification treatment or saccharification and fermentation treatment of the bark can be appropriately changed according to the kind of tree to be used and the strength of the bast fiber to be obtained. If the saccharification treatment or saccharification and fermentation treatment is not sufficient, components other than bast fibers may remain in the treated fiber, but the obtained fiber is returned to the saccharification step or saccharification and fermentation treatment step and reprocessed and removed. It is also possible to do.

EXAMPLES Next, an Example is shown and this invention is demonstrated further in detail. Moreover, in each Example shown below,% is based on mass unless there is particular notice. The yield of bast fiber was calculated by the following formula.
Yield = dry fiber (g) / dry bark (g) x 100 (%)

The commercially available cellulase used in the examples is GC220 (cellobiohydrolase activity 100 U / mL, beta glucosidase activity 200 U / mL) manufactured by Genencor.
The yeast used was Saccharomyces cerevisiae, which was cultured in a liquid medium having the following composition at 30 ° C. for 24 hours, and the yeast cells were collected by centrifugation.
<Pre-culture liquid medium composition>
Glucose 30g / L
Polypeptone 5g / L
Yeast extract 3g / L
Malt extract 3g / L
pH 5.6

<Example 1>
A bark raw material was obtained by crushing a chip-shaped Eucalyptus globulus bark by attaching a 20 mm round hole screen to a uniaxial crusher (SC-15, manufactured by Saiho Kiko Co., Ltd.).
100 g of the bark raw material absolutely dried was mixed with 250 mL of 10% sodium carbonate solution, water was added so that the total volume became 1 L, and then heat treatment was performed at 100 ° C. for 30 minutes for alkali treatment.
After alkali treatment, solid-liquid separation is performed on a 40 mesh screen, and the treated product is ground with a refiner (KRK High Density Disc Refiner, manufactured by Kumagai Riki Kogyo Co., Ltd.) with a clearance of 0.5 mm. After adding water and stirring for 10 minutes, a pre-processed product was obtained by solid-liquid separation on a 40 mesh screen and washing.
After adjusting the pretreated product to a concentration of 2%, 40 mL of commercially available cellulase was added, and enzymatic saccharification was performed at 50 ° C. for 24 hours. The solid-liquid separated residue was washed with 5 L of water and dehydrated, and the water content was 77 8%, 176 g of bast fibers were obtained. The yield was 39.1%.

<Example 2>
A bark raw material was obtained by crushing a chip-shaped Eucalyptus globulus bark by attaching a 20 mm round hole screen to a uniaxial crusher (SC-15, manufactured by Saiho Kiko Co., Ltd.).
100 g of the bark raw material absolutely dried was mixed with 250 mL of 10% sodium carbonate solution, water was added so that the total volume became 1 L, and then heat treatment was performed at 100 ° C. for 30 minutes for alkali treatment.
After alkali treatment, solid-liquid separation is performed on a 40 mesh screen, and the treated product is ground with a refiner (KRK High Density Disc Refiner, manufactured by Kumagai Riki Kogyo Co., Ltd.) with a clearance of 0.5 mm. After adding water and stirring for 10 minutes, a pre-processed product was obtained by solid-liquid separation on a 40 mesh screen and washing.
After adjusting the pretreatment product to a concentration of 8%, polypeptone 3 g / L, yeast extract 2 g / L, malt extract 2 g / L are added, and yeast cells after pre-culture with 200 mL of the liquid medium are added. 40 mL of commercially available cellulase was added, and saccharification and fermentation treatment was performed at 37 ° C. for 48 hours. The solid-liquid separated residue was washed with 5 L of water and dehydrated to obtain a bast fiber having a moisture content of 73.5% and 136 g. . The yield was 36.0%.

<Example 3>
A bark raw material was obtained by crushing a chip-shaped Eucalyptus globulus bark by attaching a 20 mm round hole screen to a uniaxial crusher (SC-15, manufactured by Saiho Kiko Co., Ltd.).
100 g of the bark raw material absolutely dried was mixed with 250 mL of 10% sodium carbonate solution, water was added so that the total volume became 1 L, and then heat treatment was performed at 100 ° C. for 30 minutes for alkali treatment.
After alkali treatment, solid-liquid separation was performed on a 40-mesh screen, 5 L of pure water was added, and the mixture was stirred for 10 minutes. .
After adjusting the pretreatment product to a concentration of 8%, polypeptone 3 g / L, yeast extract 2 g / L, malt extract 2 g / L are added, and yeast cells after pre-culture with 200 mL of the liquid medium are added. 40 mL of commercially available cellulase was added, saccharification and fermentation treatment was performed at 37 ° C. for 48 hours, and the solid-liquid separated residue was washed with 5 L of water and dehydrated to obtain a bast fiber with a moisture content of 69.9% and 134 g. . The yield was 40.3%.

Claims (7)

The bark of a woody plant is crushed and dispersed in water, saccharified with a saccharifying enzyme, and then subjected to a solid-liquid separation process to separate the liquid component containing sugar and the solid residue, and the bast fiber is removed from the residue. A method for producing a bast fiber, characterized in that it is obtained. The method for producing a bast fiber according to claim 1, wherein after the saccharification treatment, a fermentation treatment with yeast is performed, followed by a solid-liquid separation treatment. The method for producing a bast fiber according to claim 1, wherein the saccharification treatment is a treatment in which fermentation with yeast is performed simultaneously. The method for producing a bast fiber according to any one of claims 1 to 3, wherein a mechanical treatment is performed before the saccharification treatment. The method for producing a bast fiber according to any one of claims 1 to 3, wherein a chemical treatment is performed before the saccharification treatment. The method for producing bast fibers according to any one of claims 1 to 3, wherein mechanical treatment and chemical treatment are sequentially or simultaneously performed before the saccharification treatment. A bast fiber obtained by the production method according to claim 1.