JP2014151254A - Recycling method of used paper diaper, soil improvement material and recycling system of used paper diaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in a recycling system of a used paper diaper of a present state.SOLUTION: A recycling method of the used paper diaper comprises an agitation process S20 of agitating the cut-off used paper diaper T and wash water including a polymer decomposer in a polymer decomposition tank and a separation process S40 for separating an agitation object in the polymer decomposition tank into three of a mixture of a water-absorbing polymer and a pulp component dehydrated by the polymer decomposer, a packing material of the paper diaper and waste water.

Description

  The present invention relates to a method for recycling used paper diapers, a soil improvement material, and a system for recycling used paper diapers.

  In 2010, there were 29.8 million elderly people aged 65 and over, accounting for about 23% of the total population. In addition, with the advancement of medical technology and changes in the living environment, the proportion of elderly people in the total population is expected to reach 36% in 2040.

  And as of 2010, the production of disposable diapers for adults used by the elderly is 5.4 billion, but with the increase in the elderly, it is expected to exceed the usage fee for infant diapers within a few years Has been. On the other hand, pulp pulp, which is the main raw material for paper diapers, is mostly dependent on imports, and used paper diapers are incinerated.

  Under such circumstances, research aimed at de-incineration of disposable diapers and recycling of pulp, which is the main component of disposable diapers, has been promoted (see, for example, Patent Document 1). In 2011, a recycling system for disposable diapers was constructed and is in operation.

JP 2000-84533 A

  However, the present facility is the only recycling facility for disposable diapers at present, and the facility is not widespread. Various factors can be considered as the cause, but problems such as the operation cost of the pulp recovery facility, the demand for the pulp recovered at the resource recovery facility, and the treatment of sewage generated by the processing can be considered.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to solve problems in a resource recycling system for used disposable diapers.

  One aspect of the present invention is a first step in which a cut used paper diaper and a washing water containing a polymer decomposing agent are stirred in a polymer decomposing tank, and the agitated material in the polymer decomposing tank is used as the polymer decomposing agent. A second step of separating the mixture into a mixture of the water-absorbing polymer and pulp components dehydrated by the above, a packaging material for paper diapers, and sewage, and recycling of used paper diapers characterized by comprising Is the method.

  In another aspect of the present invention, the cut used paper diaper and the water containing the polymer decomposing agent are stirred in a polymer decomposing tank, and the agitated material in the polymer decomposing tank is stirred by the polymer decomposing agent. A first agitation device for separating and discharging into a first mixture of dehydrated water-absorbing polymer, pulp component and sewage, and a second mixture of vinyl and non-woven fabric; a first dehydration device for dehydrating the first mixture; A used paper diaper comprising: a second dehydrating device for dehydrating the second mixture; and a non-advanced processing type purifying device for purifying sewage discharged from at least one of the first mixture and the second mixture. It is a recycling system.

  The recycling method of the used paper diaper mentioned above includes various aspects, such as being implemented as a part of other methods. Further, the above-mentioned used paper diaper recycling system includes various aspects such as being realized as one apparatus (paper diaper recycling apparatus) as a whole.

  ADVANTAGE OF THE INVENTION According to this invention, at least one part of the problem in the resource recycling system of the present used paper diaper can be solved.

It is a flowchart explaining the recycling method of the used paper diaper which concerns on 1st Embodiment. It is the figure which showed an example of the recycling system of the used paper diaper which concerns on 1st Embodiment. It is a figure which shows the inside of a paper diaper. It is a flowchart explaining the recycling method of the used paper diaper which concerns on 2nd Embodiment.

Hereinafter, the present invention will be described in the following order.
(1) First embodiment:
(2) Second embodiment:
(3) Third embodiment:
(4) Summary:

(1) First embodiment:
FIG. 1 is a flowchart for explaining the flow of a used paper diaper recycling method according to the first embodiment, and FIG. 2 is an example of a used paper diaper recycling system S according to the first embodiment. FIG.

  The recycling method shown in FIG. 1 includes a recovery step S10, a cutting step S20, a stirring step S30, and a separation step S40.

  In the collection step S10, the used paper diaper T is collected, and a device for recycling the used paper diaper T by a conveying means such as a loading truck (the cutting machine 10, the polymer decomposition tank 20, the first shown in FIG. 2). 1 dehydrator 30, second dehydrator 40, septic tank 50, etc.) are carried into the facility.

  In the cutting step S20, the used paper diaper T is cut into small pieces of about 10 cm square, for example, using the cutting machine 10. As a result, the used paper diaper T is cut off from the exterior material and the inner surface material that enclose the polymer water-absorbing polymer, and the polymer water-absorbing polymer contained therein is exposed or overflows.

  FIG. 3 is a diagram showing the inside of the disposable diaper D. This figure is a cross-sectional view showing the vicinity of the portion that comes into contact with the user of the disposable diaper D in a short direction. In addition, the structure of the paper diaper D shown to the figure is an example.

  In the drawing, a paper diaper D includes an exterior material D1, an internal surface material D2, an absorbent paper D3, a cotton-like pulp D4, and a polymer water-absorbing polymer D5.

  The exterior material D1 and the inner surface material D2 are non-biodegradable materials such as polyethylene and nonwoven fabric. As the polymer water-absorbing polymer D5, various publicly known products and various water-absorbing polymers developed in the future can be used. In the present embodiment, the exterior material D1 and the inner surface material D2 are water-insoluble, and may be collectively referred to as a packaging material below.

  The polymer water-absorbing polymer D5 is dried before water absorption, for example, in the form of granules, but after water absorption, it is softened and gels. The used paper diaper T has different water absorption depending on the level of use, and all of the polymer water-absorbing polymer D5 is gelled, part of the polymer water-absorbing polymer D5 is gelled, polymer Some water-absorbing polymers D5 are not gelled at all.

  That is, the used paper diaper T is discarded after being soiled by filth (stool, urine, etc.), but is also discarded before being soiled by periodic replacement or the like. Therefore, the former is at least a polymer water-absorbing polymer D5. A part is gelled, but in the latter, the polymer water-absorbing polymer D5 is not gelled. For this reason, when the used paper diaper T is cut, the polymer water-absorbing polymer D5 before gelation overflows or flows out.

  Therefore, in this embodiment, the used paper diaper T after cutting is subjected to vibration, for example, by rolling on a mesh-like mesh material, so that the polymer water-absorbing polymer D5 before gelation is used from the used paper diaper T. Remove by sifting. Thus, by performing cutting process S20 as pretreatment of stirring process S30, the amount of polymer water-absorbing polymer D5 charged into the stirrer in stirring process S30 can be reduced.

  As a result, the load on the stirrer is reduced, and the amount of water used and the amount of separation aid for the dehydration reaction of the polymer water-absorbing polymer D5, which will be described later, can be reduced, and the operation maintenance cost can be reduced. Moreover, since the time required for the polymer dehydration reaction is reduced, the electricity cost of the stirrer can be saved. In addition, the amount of cleaning water used can be reduced.

[Stirring step]
In the stirring step S30, the cut used paper diaper T is put into the polymer decomposition tank 20 (pulper in FIG. 2) as a stirring device together with cleaning water, a separation aid as a polymer decomposing agent, and a sterilizing / disinfecting agent. And stir. Thereby, the used paper diaper T is sterilized and sterilized, and the filth is washed away.

  In addition, the polymerized water-absorbing polymer D5 that has been gelled is dehydrated into sand particles having a particle size of 2 mm or less. The polymer water-absorbing polymer D5 thus dehydrated and granulated easily settles in water, and is easily discharged together with pulp and the like from the outlet provided in the lower part of the polymer decomposition tank 20 in the separation step S40 described later. .

As the separation aid, a substance that generates water and generates polyvalent metal ions such as Ca, Na, Mg and the like can be used, and particularly low-cost CaCl ₂ is preferable. Hereinafter, taking the case of using CaCl ₂ as a separating aid on the example will be described.

  The washing water used in the stirring step S30 adjusts the concentration of Ca ions using a sensor or the like so as to contain a predetermined amount of Ca ions (concentration adjustment step). The washing water may be poured after adjusting the Ca ion content in advance, or the Ca ion content may be adjusted while pouring into the polymer decomposition tank 20, or the Ca ion content after pouring. May be adjusted. The Ca ion concentration may be 0.1 to 0.5%, particularly preferably 0.3 to 0.5%.

  As the washing water used in the stirring step S30, various kinds of water that can wash the used paper diaper T can be used. In this embodiment, high-hardness water such as recycled water (medium water) or leachate is used. And This is because reclaimed water and leachate contain at least Ca ions, and in particular, leachate contains a lot of Ca ions.

  Reclaimed water is water obtained by filtering and sterilizing (regenerating) sewage, rainwater, etc., and Ca ions derived from urine and the like are dissolved therein. The leachate is sewage that is decomposed and leached by sludge and waste disposed in rainwater that has permeated in waste disposal sites and landfills, and is derived from Ca added to remove dioxins in incineration waste Ca ions are dissolved.

  For this reason, when reclaimed water or leachate is used as washing water, the amount of separation aid newly added in the stirring step S30 can be reduced. In addition, at present, recycled water and leachate containing Ca are discharged into nature, but in this embodiment where Ca is consumed for dehydration of the polymer water-absorbing polymer D5, the regenerated water and leachate are improved and drained. Can do.

  Stirring in the stirring step S30 is performed until the polymer water-absorbing polymer D5 is sufficiently dehydrated by the separation aid. Further, the polymer water-absorbing polymer D5 and the separation aid are stopped when sufficiently reacted. That is, the polymer water-absorbing polymer D5 is finely divided into sand particles, and the finely divided polymer water-absorbing polymer 15 stops before being crushed by the rotating blade for stirring. Thereby, the polymer water-absorbing polymer D5 after dehydration is adjusted to have a particle size of about 1 to 2 mm.

[Separation process]
In the separation step S40, the content of the polymer decomposition tank 20 after the completion of stirring (hereinafter referred to as a stirred product) is separated into a first mixture and a second mixture. The first mixture is a mixture of a water-absorbing polymer dehydrated with a polymer decomposing agent, a pulp component, and sewage. The second mixture is a water-insoluble packaging material (a mixture of a shredded exterior material D1 and an internal surface material D2).

  The first mixture is discharged from an outlet provided in the lower part of the polymer decomposition tank 20. A filter is provided at the discharge port, and the filter is formed with a plurality of holes through which the above-described polymer water-absorbing polymer D5 after dehydration can pass. For this reason, the first mixture is discharged from the discharge port, and the second mixture is not discharged.

  The discharged first mixture is sent to the first dehydrating device 30 and dehydrated, so that the first mixture is separated into solid content and sewage as the third mixture. The third mixture thus separated includes high-quality pulp, low-quality pulp, and dehydrated polymer water-absorbing polymer D5.

  Since the 3rd mixture also contains nitrogen and phosphorus contained in large and small urine, it is suitable to reduce to a green farmland as a soil conditioner.

  On the other hand, the second mixture is discharged from the polymer decomposition tank 20 by at least one of scraping and overflow. Thereby, the 2nd mixture of vinyl and a nonwoven fabric is separated from a stirring thing. The second mixture is sent to the second dehydrator 40 and dehydrated, so that the second mixture is separated into a solid material and a liquid component as the fourth mixture. The fourth mixture is waste plastic and can be converted into oil to form RPF (solid fuel) or a raw material for thermal recycling. It is also possible to make a packaging material such as the outer packaging material D1 and the inner surface material D2 of the paper diaper T using a biodegradable material. In this case, a 4th mixture can also be used as a soil improvement material.

  The liquid components separated by the first dehydrator 30 and the second dehydrator 40 are sent to the septic tank 50. The septic tank is a so-called septic tank for home use, and is a non-advanced processing septic tank. For purification, the cost of recycling can be reduced by using a non-advanced treatment septic tank for the purification of sewage by the action of microorganisms. It is preferable that the sludge stored in the septic tank is returned to the green farmland as a soil conditioner, like the first solid content.

  The non-advanced processing septic tank is more compact than the advanced processing septic tank, and can be profitable even if the amount of used disposable diapers is smaller than that of the advanced processing septic tank. For this reason, for example, the septic tank 50 can be installed in a facility unit such as a community unit or a nursing facility, and the used disposable diaper T can be very easily recycled.

  According to the recycling method (recycling system) of the used paper diaper according to the first embodiment described above, the amount of cleaning water to be used as compared with the conventional recycling method (recycling system) And the amount of the separation aid for the polymer water-absorbing polymer can be reduced. In addition, the initial cost is low, the number of steps is small, and it is easy to implement. Therefore, it becomes easier to adopt recycling as an alternative to incineration, and used paper diapers that have flowed to incineration will be used for recycling, preventing damage to incineration facilities and the greenhouse effect generated by incineration. Gas (GHGs) can also be reduced, contributing to the prevention of global warming and the protection of forests.

(2) Second embodiment:
Next, a method for recycling used paper diapers according to the second embodiment will be described. The recycling method for used paper diapers according to the present embodiment is the first implementation described above in that it sorts according to the dirtyness of the used paper diaper T and optimizes the subsequent steps according to the sorting result. Different from form.

  FIG. 4 is a flowchart for explaining an example of a method for recycling used paper diapers according to the second embodiment. In addition, the process after the 1st stirring process and 2nd stirring process which are abbreviate | omitted in the same figure is the same as the process after the stirring process of the recycling method of the used paper diaper which concerns on 1st Embodiment, respectively. is there.

  In the collection / sorting step S110, sorting according to the degree of contamination of the used paper diaper T is performed before or after the collection of the used paper diaper. For example, as shown in FIG. 4, the used paper diaper T is classified into three types: a high-stained used paper diaper T1, a medium-stained used paper diaper T2, and a low-stained used paper diaper T3.

  For example, the used paper diaper T1 has stool (and urine) attached, the used paper diaper T2 has a polymer water-absorbing polymer D5 absorbed stool (moisture), and the used paper diaper T3 has stool attached. The polymer water-absorbing polymer D5 does not absorb urine (water).

  In addition, when sorting, for example, if a recycling box with a number of storage units according to the number of separation is installed in a facility where used paper diapers come out, and the used paper diapers are separated in advance by the employees of the facility, they can be separated smoothly. It becomes possible.

  Then, the subsequent steps are performed according to the level of contamination, and the processing content is appropriately adjusted according to the level of contamination.

  For example, the high-contaminated used paper diaper T1 is incinerated without being washed (cutting step S20, stirring step S30, separation step S40, etc.) (incineration step), and the medium-contaminated used paper diaper T2 is used. For the above, the cutting step S20, the stirring step S30, the separation step S40, and the like similar to those in the first embodiment described above are sequentially performed.

  On the other hand, for the used disposable diaper T3 having a low degree of contamination, the same cutting step S20 as in the first embodiment is performed. At this time, since the polymer water-absorbing polymer D5 of the used paper diaper T3 does not absorb moisture, almost all the polymer water-absorbing polymer D5 can be removed by sieving.

  And in the stirring process S130 performed about the used paper diaper T3 next, the quantity of the washing water put into the polymer decomposition tank 20, a separation adjuvant, another chemical | medical agent, etc. is decreased compared with the case of the used paper diaper T2. Thereby, the quantity of the washing water used for recycling of a disposable diaper, a separation aid, and other chemical | medical agents can be reduced, an environmental load can be reduced, and recycling cost can be suppressed.

  Moreover, you may adjust the rotational speed and operating time of the rotary blade which stirs the polymer decomposition tank 20 according to the dirtyness of a used paper diaper. For example, compared with the stirring step S30 of the used paper diaper T2 having a large amount of the polymer water-absorbing polymer D5, in the stirring step S130 of the used paper diaper T3 having a small amount of the polymer water-absorbing polymer D5, the rotational speed and operating time of the rotary blade are shortened. Thereby, the cost of recycling can be suppressed by suppressing the power consumption, and the maintenance cost of the apparatus can also be suppressed.

  As described above, according to the present embodiment, it is possible to further reduce the cost of recycling compared to the above-described first embodiment, and it becomes easier to adopt recycling as an alternative to incineration.

(3) Third embodiment:
Next, a recycling system for used paper diapers according to the third embodiment will be described. The used paper diaper recycling system according to the present embodiment is different from the first embodiment and the second embodiment in that the facility is arranged in parallel with a water treatment facility for middle water or leachate. .

  According to the recycling system of the used paper diaper according to the present embodiment, it is easy to receive the supply of middle water or leachate, and the piping can be shortened. Since middle water and leachate contain Ca, the piping is easily clogged. Therefore, if the piping is short, maintenance is easy.

  In particular, landfills contain incineration waste and heavy metals, so leachate water treatment facilities have been in operation for 20 to 30 years after landfill completion. There are no residential areas and the location is good.

(4) Summary:
As described above, according to the used paper diaper recycling method and the used paper diaper recycling system according to each embodiment described above, the used used paper diaper T and the washing water containing the polymer decomposing agent Is stirred in the polymer decomposition tank, and the mixture in the polymer decomposition tank 20 is mixed with the polymer water-absorbing polymer D5 dehydrated with the polymer decomposer and the pulp component (third mixture), and the packaging material for the paper diaper (fourth mixture). And sewage. As a result, it is possible to solve at least a part of problems in the resource recycling system for used paper diapers at present.

  Note that the present invention is not limited to the above-described embodiments, and the configurations disclosed in the above-described embodiments are interchanged with each other or the combinations thereof are changed, disclosed in the known technology, and in the above-described embodiments. A configuration in which each configuration is mutually replaced or a combination is changed is also included. Further, the technical scope of the present invention is not limited to the above-described embodiments, but extends to the matters described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Cutting machine, 20 ... Polymer decomposition tank, 30 ... 1st dehydration apparatus, 40 ... 2nd dehydration apparatus, 50 ... Septic tank, D1 ... Exterior material, D2 ... Internal surface material, D3 ... Absorption paper, D4 ... Cotton-like pulp , D5 ... polymer water-absorbing polymer, S ... used paper diaper recycling system, S10 ... recovery step, S20 ... cutting step, S30 ... stirring step, S40 ... separation step, S110 ... recovery / sorting step, S130 ... stirring step

Claims (13)

An agitation step of agitating the cut used paper diaper and the washing water containing the polymer decomposing agent in a polymer decomposing tank;
A separation step of separating the agitated material in the polymer decomposition tank into three: a mixture of a water-absorbing polymer dehydrated by the polymer decomposer and a pulp component, a packaging material for paper diapers, and sewage;
A method for recycling used paper diapers characterized by comprising: The recycling method of used paper diapers according to claim 1, wherein in the stirring step, middle water is used as water containing the polymer decomposing agent. The recycling method for used paper diapers according to claim 1 or 2, wherein in the stirring step, leachate is used as water containing the polymer decomposing agent. The method for recycling used paper diapers according to claim 2 or 3, further comprising a concentration adjusting step of adjusting the concentration of the polymer decomposing agent in the washing water to be a predetermined value. The cut paper diaper is obtained by cutting the used paper diaper and removing the non-gelling water-absorbing polymer from the cut used paper diaper by a cutting process executed as a pretreatment of the stirring process. The recycling method of the used paper diaper of any one of Claims 1-4. A separation step of separating the used paper diaper according to the degree of contamination;
The recycling method for used paper diapers according to any one of claims 1 to 5, wherein the stirring step is performed for each level of the degree of contamination. An incineration step of incinerating the used paper diaper, which has been separated to a certain degree of high contamination in the separation step, without going through the stirring step;
A recycling method for used paper diapers according to claim 6. In the stirring step, a sterilizing / disinfectant is added to the polymer decomposition tank,
The recycling method for used paper diapers according to any one of claims 1 to 7, wherein the sterilizing / sterilizing agent is added as the dirtyness of the used paper diapers increases. 9. The stirring process according to claim 1, wherein the stirring step comprises stirring with a rotating blade and stirring until the particle size of the water-absorbing polymer dehydrated by the polymer decomposing agent becomes 1 to 2 mm. Recycling method of used paper diapers described in 1. The recycling method of the used paper diaper of any one of Claims 1-9 provided with the purification | cleaning process of purifying the said waste water isolate | separated at the said separation | separation process in a non-high-processing type septic tank.   A mixture of a water-absorbing polymer dehydrated by the polymer decomposing agent and a pulp component separated by the recycling method of used paper diapers according to any one of claims 1 to 10. And soil improvement material. The cut used paper diaper and the washing water containing the polymer decomposing agent are agitated in a polymer decomposing tank, and the agitated product in the polymer decomposing tank is made up of the water-absorbing polymer dehydrated by the polymer decomposing agent, pulp components, and sewage. A stirrer for separating and discharging into a first mixture and a second mixture of vinyl and non-woven fabric;
A first dehydrator for dehydrating the first mixture;
A second dehydrator for dehydrating the second mixture;
A non-highly treated septic tank that purifies sewage from at least one of the first mixture and the second mixture;
A recycling system for used paper diapers characterized by comprising: The facility related to the recycling system for used paper diapers is installed in parallel with the water treatment facility for middle water or leachate, and the middle water or leachate treated at the water treatment facility is used as the washing water. The recycling system for used paper diapers according to claim 12.

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