JP2005270950A - Method for degrading fibrous mixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently perform the biological degradation of waste fibrous mixture, particularly, the fibrous mixture of natural fiber and polyester fiber. <P>SOLUTION: In a first degradation tank, natural fiber in the fibrous mixture is anaerobically digested by using anaerobically digested sludge produced in an organic waste disposal plant as it is and, in a second degradation tank, natural fiber in the fibrous mixture is anaerobically digested by using anaerobically digested sludge produced in the first degradation tank. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention is intended to efficiently carry out the biological degradation treatment of a discarded fiber mixture, particularly a fiber mixture composed of natural fibers and polyester fibers. Although fiber products and clothes that are no longer needed become waste fibers, most of the waste fibers are a fiber mixture composed of natural fibers and polyester fibers, and it is desired to reuse the natural fibers and polyester fibers of the fiber mixture.

In order to collect and reuse a fiber mixture composed of natural fibers and synthetic resin fibers, it is necessary to separate the fibers into individual fibers. Cellulose fibers in a fiber mixture composed of cellulosic fibers and synthetic polymers are hydrolyzed by microorganisms. There is something to do. (For example, refer to Patent Document 1). There is also a method of treating a fiber product in which polyester fiber and cotton fiber are mixed with an aqueous solution containing a cellulase enzyme. (For example, refer to Patent Document 2). Moreover, there exists what performs an methane fermentation by mixing a fiber containing organic substance by making anaerobic digestive sludge into seed sludge. (For example, refer to Patent Document 3).
Japanese Patent Application Laid-Open No. 07-195056 Japanese Patent Laid-Open No. 08-158265 JP 2002-045896 A

The fiber mixture which becomes unnecessary and is discarded is extremely large and diverse, but there are many fiber mixtures composed of natural fibers and polyester fibers. In particular, many cotton and polyester fibers and wool and polyester fibers are mixed and used in a mixed spinning configuration. If the fiber product is composed only of polyester fiber, it can be reused using appropriate polyester resin regeneration technology. However, if the polyester fiber and natural fiber are mixed and used, the polyester must be separated if the natural fiber is not separated. The fiber cannot be recycled.

Since natural fibers are derived from plants and animals, cellulose and proteins are the main components and biological degradation is possible, but natural fibers are less biodegradable than sewage sludge and food waste, and biological The chemical degradation process is time consuming. In order to efficiently decompose natural fibers during the decomposition and recovery treatment of the waste fiber mixture, microorganisms and enzymes for performing biological treatment must be secured for each type of natural fiber such as cotton and wool. In addition, some textile products such as clothing are water-repellent with a water repellent for waterproofing, making it difficult for moisture to penetrate inside the fibers, biological treatment, especially anaerobic digestion treatment in liquids, etc. In this case, it is difficult for microorganisms to penetrate into the inside of the fiber, and it takes a longer time to process than those not treated with water repellent.

The waste fiber mixture targeted by the present invention is a fiber mixture composed of natural fiber and polyester fiber, and the natural fiber is mainly composed of cellulose or protein, such as cotton or wool, and has a composition such as mixed spinning or mixed weaving. Or, it becomes a fiber mixture by using properly for each use site. The waste fiber mixture is generated as waste after being used as a textile product or clothes or from a sewing factory.

In the present invention, the use ratio of the natural fiber and the polyester fiber in the fiber mixture is not limited, but the same kind of natural fiber is treated in one treatment step.

The method for decomposing a fiber mixture of the present invention uses anaerobic digested sludge generated from an organic waste treatment plant, anaerobically digesting natural fibers, recovering them as useful gases such as methane, and reusing them. Since natural fibers are decomposed by this anaerobic digestion treatment, the fiber mixture becomes only polyester fibers. The polyester fibers are taken out from the decomposition tank and collected, and an appropriate polyester resin is reused.

Anaerobic digestion sludge generated from organic waste treatment plants is generated in the digestion equipment of organic waste and sewage sludge treatment processes. Digestion processes include carbohydrates and fats caused by a wide variety of anaerobic microorganisms. Anaerobic digestion, and these microbial groups differ in the species of bacteria that act on conditions such as the components and concentration of organic matter, and they act sequentially or simultaneously to decompose organic matter into smaller molecules step by step . The hard-to-decompose sludge that remains undecomposed during the digestion process is anaerobic digestive sludge and contains a wide variety of anaerobic microorganisms. Since microorganisms grow according to the components of the organic matter of the organic waste, the anaerobic digested sludge obtained by digesting various organic matters such as organic waste and sewage sludge contains various anaerobic microorganism groups.

The present invention uses anaerobic digested sludge generated from an organic waste treatment plant as an anaerobic microorganism group. Natural fiber is anaerobically digested with anaerobic digestion sludge generated from an organic waste treatment plant in a fiber mixture composed of natural fiber and polyester fiber in the first decomposition tank. As a result, the natural fiber becomes a useful gas such as methane, and the polyester fiber that is not subjected to digestive decomposition remains as it is. Although anaerobic digestion sludge is newly generated in this first decomposition tank, microorganisms grow according to the type of natural fiber during the anaerobic digestion of natural fiber, so this anaerobic digestion sludge is acclimated according to the type of natural fiber. Therefore, the efficiency of anaerobic digestion of the same type of natural fiber is improved.

The present invention uses the anaerobic digested sludge generated in the first decomposition tank and anaerobically digests and decomposes the same fiber mixture in the second decomposition tank. The anaerobic digested sludge used in this case is a kind of natural fiber. Since the microorganisms grow and acclimatize according to the conditions, and are optimized according to the type of natural fiber, the fiber mixture that is anaerobically digested in the second decomposition tank can be decomposed more efficiently than in the first decomposition tank. .

Moreover, the fiber mixture which consists of a natural fiber and polyester fiber decomposed | disassembled in a 1st decomposition tank is made into the fiber mixture which carried out water-repellent processing, and the same kind of fiber mixture decomposed | disassembled in a 2nd decomposition tank is a fiber mixture which has not been water-repellent processed And The non-water-repellent fiber mixture that is decomposed in the second decomposition tank has good moisture permeability, so when natural fibers are anaerobically digested, the microorganisms in the decomposition tank easily penetrate into the fibers and are efficiently anaerobic. Can be digested.

The present invention uses anaerobic digested sludge generated from an organic waste treatment plant as an anaerobic microorganism source when a fiber mixture comprising natural fibers and polyester fibers is digested and decomposed under anaerobic conditions in a first decomposition tank. Therefore, the anaerobically digested sludge is composed of a wide variety of anaerobic microorganisms, so the anaerobic microorganisms become acclimatized according to the type of natural fiber to be anaerobically digested, and as time passes The anaerobic microorganism group in the first decomposition tank is suitable for anaerobic digestion of the natural fiber.

In the fiber mixture decomposition treatment method of the present invention, the anaerobic digestion sludge used in the first decomposition tank uses anaerobic digestion sludge composed of a wide variety of anaerobic microorganisms generated from the organic waste treatment plant. It can also be applied to other natural fibers such as silk and hemp, and there is no need to prepare various microorganisms and enzymes for each type of natural fiber.

In the present invention, the anaerobic digested sludge generated in the first decomposition tank is decomposed under the anaerobic condition in the second decomposition tank, but the anaerobic digested sludge generated in the first decomposition tank is natural. Acclimatized according to the type of fiber. That is, if the natural fiber of the fiber mixture is cotton, the most organic substance in the first decomposition tank is cotton, and the species that digest cotton grows during anaerobic digestion, and anaerobic digestion occurs in the first decomposition tank. Sludge is suitable for decomposing cotton. Since the fiber mixture cotton is anaerobically digested in the second decomposition tank using this anaerobic digestion sludge, it can be decomposed more efficiently than in the first decomposition tank.

Since natural fibers have low microbial degradability, it is better to acclimatize the anaerobic microorganisms of the anaerobic digestion sludge used for anaerobic digestion according to the type of natural fiber. The decomposition tank used is composed of two tanks, and in the first decomposition tank, anaerobic digestion is performed using the anaerobic digestion sludge generated from the organic waste treatment plant as it is, but in the second decomposition tank, the anaerobic digestion generated in the first decomposition tank. Since sludge is used, the anaerobic microorganisms in this anaerobic digestion sludge are acclimatized according to the natural fiber, and the same kind of natural fiber is anaerobically digested in the first decomposition tank and the second decomposition tank. The efficiency of anaerobic digestion in the tank is improved.

In the first decomposition tank, anaerobic microorganisms suitable for natural fibers to be anaerobically digested are created, so it is easy to change the type of natural fibers and just prepare anaerobic digested sludge generated from an organic waste treatment plant. There is no need to prepare specific microorganisms or enzymes.

Since the waste fiber mixture is soiled or surface-treated, the reaction of decomposition treatment under anaerobic conditions is not uniform, especially in the case of water-repellent fiber mixture, anaerobic digested sludge inside the natural fiber Is difficult to penetrate and prompt anaerobic digestion cannot be expected. When the water-repellent processed fiber mixture and the fiber mixture that is relatively easy to digest are decomposed at the same time, only the polyester fiber is removed unless all the fiber mixture in the decomposition tank is separated into only the polyester fiber. Since it cannot be removed, it must wait for the time-consuming anaerobic digestion of the water-repellent fiber mixture.

The water-repellent finish is a wax-type, silicon-type, or fluorine-type water-repellent that forms a film on the fiber surface, and normal water-repellent agents are not subject to anaerobic digestion by microorganisms. When the mixture is anaerobically digested simultaneously with other fiber mixtures, it is better to remove the water-repellent coating, but if physically crushed, the polyester fibers in the fiber mixture will also be crushed, making it difficult to recover the polyester fibers. When the water repellent wax is washed with an alkali, the polyester fiber is hydrolyzed and the polyester fiber cannot be recovered as it is.

The present invention classifies a water-repellent processed fiber mixture and a non-water-repellent fiber mixture and performs anaerobic digestion. A fiber mixture composed of natural fibers and polyester fibers to be decomposed in a first decomposition tank is provided. A fiber mixture that has been subjected to water repellent treatment, and the same kind of fiber mixture that undergoes decomposition treatment in the second decomposition tank is a fiber mixture that has not been subjected to water repellent finish. That is, since the fiber mixture to be decomposed in the second decomposition tank is not water-repellent, it takes time-consuming water-repellent processing even when waiting for all the fiber mixture in the decomposition tank to decompose into polyester fibers only. There is no need to wait for the anaerobic digestion of the fiber mixture to end.

The fiber mixture composed of natural fibers and polyester fibers to be decomposed in the first decomposition tank is a water-repellent processed fiber mixture. In the first decomposition tank, anaerobic digestion sludge generated from the organic waste treatment plant is used. In the 1st decomposition tank, an anaerobic microorganism group suitable for natural fibers to be anaerobically digested is also produced, so the efficiency of the anaerobic digestion is lower than that in the 2nd decomposition tank, and the water-repellent processed fiber mixture takes more time. If the decomposition treatment is performed, the efficiency is further deteriorated, but the efficiency of the anaerobic digestion in the second decomposition tank is improved, so that improvement of the efficiency as a whole can be expected.

In the case of batch processing, an improvement in the efficiency of anaerobic digestion can be expected just by dividing and splitting the water-repellent processed fiber mixture. However, in the present invention, the decomposition tank has two tanks and one tank is water-repellent. Since it is for the processed fiber mixture, anaerobic digestion is not hindered by the water-repellent fiber mixture in other tanks.

The anaerobic digested sludge generated from the organic waste treatment plant in the first decomposition tank is used for anaerobic digestion of the natural fiber of the fiber mixture, and the second decomposition tank is used for the fiber using the anaerobic digested sludge generated in the first decomposition tank. Anaerobic digestion of the natural fibers of the mixture. The same kind of natural fiber is anaerobically digested in the first decomposition tank and the second decomposition tank. If the fiber mixture in the decomposition tank is separated into only polyester fibers, it is removed from the tank and collected, and the next fiber mixture is put into the tank. To do. Since the decomposition treatment efficiency of the fiber mixture in the second decomposition tank is good, the second decomposition tank can be decomposed at a faster cycle than the first decomposition tank.

FIG. 1 is a process diagram showing an embodiment of the present invention, in which a first decomposition tank 1 is a decomposition treatment reaction apparatus under anaerobic conditions, and is a water-repellent fiber mixture made of natural fibers and polyester fibers. The anaerobic digestion sludge generated from the organic waste treatment plant is injected to anaerobically digest the natural fibers of the fiber mixture. Natural fiber becomes useful gas by anaerobic digestion, but usually methane is fermented to generate methane, so methane is used as fuel. The separated polyester fiber is collected and reused using an appropriate polyester resin recycling technique.

The second decomposition tank 2 is a decomposition treatment reaction apparatus under anaerobic conditions, containing therein a fiber mixture composed of natural fibers and polyester fibers, injecting anaerobic digested sludge generated in the first decomposition tank, Anaerobic digestion of the natural fibers of the mixture. Natural fiber becomes useful gas by anaerobic digestion, but usually methane is fermented to generate methane, so methane is used as fuel. The separated polyester fiber is collected and reused using an appropriate polyester resin recycling technique. The same type of natural fiber is anaerobically digested in the first decomposition tank and the second decomposition tank, but the anaerobic digestion sludge used in the second decomposition tank is acclimated according to the type of natural fiber, and is also water repellent. Since only the unprocessed fiber mixture is anaerobically digested, it can be anaerobically digested more efficiently than the first decomposition tank.

It is process drawing which shows the Example of this invention.

Explanation of symbols

1 First decomposition tank 2 Second decomposition tank

Claims (2)

In the first decomposition tank, the fiber mixture comprising natural fibers and polyester fibers is anaerobically digested with sludge generated from the organic waste treatment plant to anaerobically digest natural fibers into useful gas, and the separated polyester fibers are recovered. The fiber mixture of the same type as described above in the second decomposition tank is anaerobically digested sludge generated in the first decomposition tank to anaerobically digest natural fibers into useful gas, and the separated polyester fibers are recovered. Method 2. The fiber mixture comprising natural fibers and polyester fibers to be decomposed in the first decomposition tank is a water-repellent processed fiber mixture, and the same kind of fiber mixture to be decomposed in the second decomposition tank is a water repellent. Method for decomposing fiber mixture, which is an unprocessed fiber mixture

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