TWI893120B - Separation and recovery method and separation and recovery device - Google Patents

Abstract

Efficiently separate materials from composite materials. One embodiment of the separation and recovery method includes a stripping step in which a composite material comprising multiple layers of materials is heated and stirred with a treatment solution of an aqueous monoethanolamine solution to produce a stripped mixture in which the layers of the materials contained in the stripped material are stripped.

Description

Separation and recovery method and separation and recovery device

The present invention relates to a separation and recovery method and a separation and recovery device.

Conventionally, there is a known technique for separating a specific material from a composite material formed by laminating multiple types of materials.

For example, Patent Document 1 discloses a method for separating and recovering components from composite plastics, using triethylene glycol as a separation solvent. Various processed materials are heated to near their boiling point and stirred, thereby recovering the components separately. Furthermore, Patent Document 2 discloses a method for recycling the resins of recyclable materials in mixed waste plastics and recovering the decomposed oil by thermally decomposing the resins of non-recyclable materials. Furthermore, Patent Document 3 discloses a method for stripping organic films from substrates using a solvent primarily composed of a high-boiling-point alcohol. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2013-6948 [Patent Document 2] Japanese Patent Application Publication No. 2008-95024 [Patent Document 3] Japanese Patent Application Publication No. 2019-516004

[Identify the problem you want to solve]

However, the techniques disclosed in Patents 1 and 2 require high heating temperatures, consuming significant energy and raising safety concerns. Furthermore, the technique disclosed in Patent 3 uses a flammable, carbon-rich higher alcohol as the main solvent, leading to increased operating costs. Therefore, a technique for efficiently separating and recovering materials from composite materials is desired.

The present invention was developed in light of the above-mentioned situation. The problem to be solved is to provide a separation and recovery method and a separation and recovery device capable of efficiently separating materials from a composite material formed by layering multiple types of materials. [Technical Means for Solving the Problem]

One aspect of the separation and recovery method of the present invention includes a stripping step in which a composite material comprising multiple layers of materials is heated and stirred with a treatment solution of a monoethanolamine aqueous solution to obtain a crushed mixture in which the layers of the materials contained in the crushed material are stripped.

It also includes a separation and recovery process, in which the crushed mixture is separated and recovered into the aforementioned multiple types of materials by screening based on specific gravity differences.

The content of monoethanolamine in the monoethanolamine aqueous solution is 2% by weight or more and 100% by weight or less.

The monoethanolamine aqueous solution may also contain at least one of an alkaline earth metal and an alkaline metal.

In the peeling process, microbubbles are generated in the treatment liquid to stir the treatment liquid, thereby promoting the peeling of the layers of the material.

In the stripping process, ultrasonic waves are transmitted in the treatment liquid to generate the microbubbles.

The aforementioned separation and recovery process includes: a centrifugal separation process for centrifuging the aforementioned treatment liquid containing the aforementioned crushed mixture; a separation process for separating the aforementioned materials according to each type by specific gravity screening using a specific gravity screening liquid, wherein the specific gravity of the specific gravity screening liquid is different from that of the aforementioned multiple types of materials contained in the aforementioned crushed mixture in the aforementioned treatment liquid centrifuged by the aforementioned centrifugal separation process; and a drying process for drying each of the aforementioned materials separated by the aforementioned separation process.

In addition, one aspect of the separation and recovery device of the present invention comprises: a peeling part, which heats and stirs a crushed material containing a composite material formed by the accumulation of multiple types of materials and a treatment liquid of a monoethanolamine aqueous solution to obtain a crushed mixture formed by peeling the layers of the aforementioned materials contained in the aforementioned crushed material; a centrifugal separation part, which separates the aforementioned crushed mixture from the composite material. The processing liquid is centrifugally separated; a separation section utilizes a gravity screening liquid to separate the materials into their respective types by gravity screening, wherein the gravity screening liquid has a specific gravity different from that of the plurality of types of materials contained in the crushed mixture in the processing liquid centrifugally separated by the centrifugal separation section; and a drying section is used to dry each of the materials separated by the separation section. [Effects of the Invention]

According to one aspect of the present invention, materials can be efficiently separated from a composite material formed by laminating multiple types of materials.

The following is an explanation of an embodiment of a separation and recovery method and a separation and recovery device with reference to the drawings. In addition, in this specification, parts indicating the same components or the same functions are marked with the same symbols, and the explanation is sometimes omitted.

Fig. 1 is a schematic diagram showing an example of the structure of a separation and recovery device 1 according to this embodiment. The separation and recovery device 1 is a device for separating and recovering materials constituting the composite material CM1 from the composite material CM1.

Here, the composite material CM1 to be processed by the separation and recovery device 1 is defined as any material formed by laminating multiple types of materials with adhesives, and its shape or structure is not particularly concerned.

For example, the composite material CM1 may be a laminate of two or more film materials selected from various synthetic resin films, synthetic resin sheets, and metal foils, with an adhesive layer interposed therebetween. An example of such a composite material CM1 is a laminate film.

Alternatively, for example, the composite material CM1 may be formed by attaching the aforementioned film material to a structure formed of wood, metal, synthetic resin, or other materials via an adhesive. In this case, the film material is also referred to as a coating film. The film material's constituent materials, quantity, or combination are not particularly limited.

Representative examples of synthetic resins used in film materials include polyethylene resins (PE), polypropylene resins (PP), polyamide resins, polyethylene terephthalate resins (PET), polymethacrylate resins (PMMA), cellophane, polystyrene resins (PS), ethylene-vinyl acetate copolymer (EVA), and polyvinyl chloride resins (PVC). Metal foils used in film materials include aluminum foil (AL). Furthermore, various materials besides synthetic resin films and metal foils can be used for film materials. Examples of other materials include paper, thermosetting resin films, and coatings. In addition, examples of adhesives used for bonding thin film materials include ether adhesives, epoxy adhesives, and ester adhesives.

In this embodiment, the composite material CM1 is composed of a first material M1 and a second material M2 of different types, with the second material M2 having a greater specific gravity than the first material M1. For example, the first material M1 is PE (specific gravity 0.9-0.9 g/cm ³ ), and the second material M2 is PET (specific gravity 1.29-1.40 g/cm ³ ).

As shown in FIG1 , the separation and recovery device 1 includes a crushing section 10, a peeling section 20, a centrifugal separation and water washing section 30, and a drying section 40. The configuration of each section of the separation and recovery device 1 will be described below.

[Stripping Unit Configuration] The crushing unit 10 breaks the composite material CM1 into small pieces. Specifically, the crushing unit 10 includes a crusher 11, a blower 12, and a hopper 13.

Crusher 11, such as a roller mill, crushes composite material CM1 into a plurality of small pieces. Specifically, crusher 11 crushes composite material CM1 into small pieces ranging from 1 to 60 mm, more preferably from 5 to 10 mm. By crushing composite material CM1 in this way, the surface area of the end portions is increased, thereby facilitating the separation of the layers of material contained in the small pieces in the peeling section 20 (peeling process) described later. Hereinafter, the small pieces of composite material CM1 crushed by crushing section 10 will also be referred to as "crushed material CM2."

In addition, when the crusher 11 crushes the composite material CM1, a plurality of cuts or small holes can be provided on the small pieces. By providing the cuts or small holes on the small pieces, the contact area of the peripheral edge of the small piece with the peeling liquid 21a described later can be increased.

Crushed material CM2, crushed by the crushing unit 10, is conveyed to a hopper 13 by a blower 12. A valve V1 is mounted at the discharge port of the hopper 13, which is opened and closed to regulate the discharge of crushed material CM2. When valve V1 is opened, crushed material CM2 stored in the hopper 13 is discharged into a stripping chute 21, described later.

The crushing unit 10 is not limited to the above-mentioned configuration. For example, the crushing unit 10 may be configured without the blower 12 and the hopper 13. Furthermore, a conveying device such as a conveyor belt may be used in place of the blower 12.

[Structure of the Peeling Section] The peeling section 20 is an example of a peeling section. It is a device used to heat and stir a peeling liquid 21a, into which the crushed material CM2 is introduced, to produce a crushed mixture by peeling the interlayers of the material contained in the crushed material CM2. The peeling liquid 21a is an example of a processing liquid.

Specifically, the peeling section 20 includes a peeling tank 21 , a heating section 22 , and a stirring section 23 .

The stripping tank 21 is a container for holding the stripping liquid 21a supplied from the stripping liquid tank 51 described later. The stripping liquid 21a contains an aqueous solution of monoethanolamine (MEA). The MEA content in the stripping liquid 21a is, for example, from 2% by weight to 100% by weight, preferably from 5% by weight to 80% by weight. Furthermore, the MEA content in the stripping liquid 21a is particularly preferably from 10% by weight to 20% by weight. The water used as the solvent does not need to be of a particularly high purity; ordinary industrial water, tap water, well water, etc. can be used as is.

Furthermore, the peeling liquid 21a may contain either or both an alkaline earth metal and an alkaline metal as additives. Examples of such additives include sodium hydroxide, calcium hydroxide, and potassium hydroxide. These additives act as surfactants (surfactants) and promote the separation of the interlayers of the material contained in the crushed material CM2. The content of the additives in the peeling liquid 21a is preferably set to 5% by weight or less. Furthermore, the pH (hydrogen ion concentration index) of the peeling liquid 21a is preferably set to within a range of 8 to 13.

When crushed material CM2 is introduced into the peeling liquid 21a, the MEA aqueous solution acts to peel away the layers of material contained within it, effectively stripping away the adhesive. This separates the first and second materials M1, M2, which were previously bonded together by the adhesive, leaving a mixture of the first and second materials M1, M2. Hereinafter, this mixture of the first and second materials M1, M2 will also be referred to as the "crushed mixture."

Thus, using a stripping liquid 21a containing relatively inexpensive MEA in the stripping unit 20 can reduce operating costs. Furthermore, by setting the MEA content in the stripping liquid 21a to between 10% and 20% by weight and using water as the main component, the hazards and toxicity of MEA can be reduced, thereby improving safety.

Furthermore, the stripping fluid 21a within the stripping tank 21 acts as a specific gravity screening fluid, separating the first material M1 and the second material M2 contained in the crushed mixture by screening them based on their specific gravity difference. Specifically, due to the difference in specific gravity between the first material M1 and the second material M2 relative to 21a, the first material M1 and the second material M2 are retained at different positions (heights) within the stripping tank 21.

For example, MEA has a specific gravity of ^{approximately} 1.02 g/cm³ and dissolves in water at any ratio. Therefore, the stripping liquid 21a can be used as a specific gravity screening liquid with a specific gravity between 1.0 and 1.02 g/ ^cm³ . Within the stripping liquid 21a, the stripped materials are retained at positions (heights) corresponding to their specific gravities. For example, if the first material M1 is PE and the second material M2 is PET, as shown in Figure 1, the first material M1 is retained above the stripping tank 21 (stripping liquid 21a), while the second material M2 is retained below the stripping tank 21 (stripping liquid 21a).

The stripping tank 21 is provided with drain outlets (not shown) at various height locations. Each outlet is connected to the centrifugal separation and washing section 30 (the first centrifugal separation section 31 and the second centrifugal separation section 32 described later) via piping. Figure 1 illustrates an example of two drain outlets located above and below the stripping tank 21, each connected to a pipe T1 and a pipe T2. The drain outlets are positioned to correspond to the locations where the first and second materials M1, being stripped (separated), are retained. In other words, the stripping liquid 21a containing a large portion of the first material M1 is discharged through pipe T1. Furthermore, the peeling liquid 21a containing a large amount of the second material M2 is discharged from the pipe T2.

Pipes T1 and T2 are each equipped with valves V2 and V3, which are opened and closed to adjust the flow rate of the liquid flowing through the pipes. Furthermore, pipes T1 and T2 are each equipped with pumps P1 and P2, which deliver the liquid flowing through the pipes to the first centrifugal separation section 31 and the second centrifugal separation section 32, described below.

The exfoliation tank 21 is connected to the exfoliation liquid tank 51 via piping T3. A valve V4 is installed in piping T3 to adjust the flow rate of the liquid flowing through the piping. Furthermore, a pump P3 is installed in piping T3 to deliver the liquid flowing through the piping to the exfoliation tank 21.

The heating unit 22, which includes a heat source such as a boiler or electricity, heats the exfoliating liquid 21a stored in the exfoliating tank 21. The temperature of the exfoliating liquid 21a is, for example, between 25°C and 95°C, more preferably between 60°C and 95°C. Thus, in the exfoliating unit 20, the exfoliating liquid 21a is heated to a relatively low temperature range of between 25°C and 95°C, thereby improving safety and reducing energy consumption.

The stirring section 23 stirs the exfoliating liquid 21a into which the crushed material CM2 is added. The method for stirring the exfoliating liquid 21a is not particularly important, and various methods can be used. For example, the stirring section 23 can also be a stirring device that stirs the exfoliating liquid 21a using ultrasound. In this case, the stirring section 23 transmits ultrasound waves of 25 kHz or higher to the exfoliating liquid 21a via the exfoliating tank 21, etc., thereby stirring the exfoliating liquid 21a through microbubbles or acoustic flow generated in the exfoliating liquid 21a, promoting the exfoliation of the layers of material contained in the crushed material CM2.

Alternatively, for example, the stirring section 23 may be a stirring device that releases air into the exfoliating liquid 21a to generate microbubbles. In this case, the stirring section 23 releases air from below the exfoliating tank 21, thereby agitating the exfoliating liquid 21a through the microbubbles generated therein, thereby promoting the exfoliation of the layers of material contained in the crushed material CM2. Alternatively, for example, the stirring section 23 may be a stirring device that physically rotates an agitator such as a screw to stir the material. In this case, the stirring section 23 stirs the material by rotating the agitator disposed within the exfoliating liquid 21a. In addition, the stirring part 23 may also be a combination of the above stirring methods.

Here, the heating of the exfoliating liquid 21a by the heating unit 22 and the stirring of the exfoliating liquid 21a by the stirring unit 23 are intended to promote the exfoliation of the layers of materials contained in the crushed material CM2. Specifically, heating the exfoliating liquid 21a activates it, making it easier for it to penetrate the crushed material CM2, thereby promoting the exfoliation of the materials. Furthermore, stirring the exfoliating liquid 21a allows for the efficient exfoliation of the materials that have been loosened by the exfoliating liquid 21a.

Furthermore, when microbubbles are generated within the exfoliating liquid 21a by ultrasound or bubbling, the microbubbles adhere to the peripheral edges of the crushed object CM2, promoting the separation of the first material M1 from the second material M2, or from the adhesive, through buoyancy or oscillation. Therefore, by generating microbubbles within the exfoliating liquid 21a, the exfoliation (separation) of the first material M1 from the second material M2 can be efficiently performed. Furthermore, by employing a configuration that utilizes ultrasound to generate microbubbles, the temperature of the exfoliating liquid 21a can be raised, thereby reducing the amount of heat applied by the heating unit 22 and enabling the exfoliating liquid 21a to be heated with less energy.

In addition, the stripping section 20 is not limited to the above-mentioned structure. For example, the stripping section 20 may also be configured to include a stripping liquid tank 51. In addition, the stripping section 20 may also be configured to include the above-mentioned hopper 13 and the like.

[Centrifugal Separation and Washing Section Configuration] The centrifugal separation and washing section 30 cleans the first material M1 and second material M2 separated by the stripping section 20 while further performing separation and recovery based on specific gravity differences (specific gravity differential screening).

Specifically, the centrifugal separation and water washing section 30 includes a first centrifugal separation section 31, a second centrifugal separation section 32, a first water washing tank 33, and a second water washing tank 34. Here, the first centrifugal separation section 31 and the second centrifugal separation section 32 are examples of centrifugal separation sections. The first water washing tank 33 and the second water washing tank 34 are examples of separation sections.

The first centrifugal separation section 31 is connected to the pipe T1. Liquid flowing through the pipe T1 is supplied to the first centrifugal separation section 31 by pump P1. Furthermore, the second centrifugal separation section 32 is connected to the pipe T2. Liquid flowing through the pipe T2 is supplied to the second centrifugal separation section 32 by pump P2.

For example, when valve V2 is open and valve V14 (described later) is closed, the first centrifugal separation section 31 is supplied with the peeling liquid 21a discharged from the peeling tank 21. Furthermore, for example, when valve V2 is closed and valve V14 (described later) is open, the first centrifugal separation section 31 is supplied with the cleaning water discharged from the first and second water washing tanks 33 and 34.

For example, when valve V3 is open and valve V15 (described later) is closed, the second centrifugal separation section 32 is supplied with the peeling liquid 21a discharged from the peeling tank 21. Furthermore, for example, when valve V3 is closed and valve V15 (described later) is open, the second centrifugal separation section 32 is supplied with the washing water discharged from the first and second washing tanks 33 and 34.

The first centrifuge 31 is a centrifuge equipped with a motor 31a. Using motor 31a as a driving source, the first centrifuge 31 centrifuges liquid supplied via pipe T1, thereby extracting the crushed mixture contained in the liquid. Similarly, the second centrifuge 32 is a centrifuge equipped with a motor 32a, similar to the first centrifuge 31. Using motor 32a as a driving source, the second centrifuge 32 centrifuges liquid supplied via pipe T2, thereby extracting the crushed mixture contained in the liquid.

Furthermore, due to the gravity difference screening performed by the aforementioned peeling section 20 and the gravity difference screening in the centrifugal separation and water washing section 30 (described later), the liquid supplied to the first centrifugal separation section 31 contains a majority of the first material M1. Furthermore, due to the similar gravity difference screening, the liquid supplied to the second centrifugal separation section 32 contains a majority of the second material M2. Therefore, hereinafter, the crushed mixture processed in the first centrifugal separation section 31 (and the first water washing tank 33) will also be referred to as the first material M1, and the crushed mixture processed in the second centrifugal separation section 32 (and the second water washing tank 34) will be referred to as the second material M2.

Furthermore, each of the first centrifugal separation section 31 and the second centrifugal separation section 32 is connected to the exfoliation liquid tank 51 via piping T4. A valve V5 is provided on piping T4. When valve V5 is open, the liquid (exfoliation liquid 21a) centrifugally separated by the first centrifugal separation section 31 and the second centrifugal separation section 32 is discharged into the exfoliation liquid tank 51 via piping T4.

The peeling liquid tank 51 is a container for storing the peeling liquid 21a. The peeling liquid 21a stored in the peeling liquid tank 51 can be supplied to the peeling tank 21 via the pipe T3.

The stripping liquid tank 51 is equipped with a component concentration meter 51a for measuring the component concentration of the stripping liquid 21a. Furthermore, a pipe T6 is connected to the stripping liquid tank 51, through which cleaning water flows, via a valve V6. In the separation and recovery device 1, the stripping liquid 21a stored in the stripping liquid tank 51 can be adjusted to a desired component concentration by controlling the opening and closing of valve V6 based on the component concentration measured by the component concentration meter 51a.

The first centrifugal separation section 31 and the second centrifugal separation section 32 are each connected to the second cleaning water tank 62 via piping T5. A valve V7 is provided in piping T5. When valve V7 is open, the liquid (cleaning water) centrifugally separated by the first centrifugal separation section 31 and the second centrifugal separation section 32 is discharged into the second cleaning water tank 62 via piping T5.

The first centrifugal separation section 31 is connected to the first water washing tank 33 via valve V8. Furthermore, the second centrifugal separation section 32 is connected to the second water washing tank 34 via valve V9. When valves V8 and V9 are open, the crushed mixture separated by the first centrifugal separation section 31 and the second centrifugal separation section 32 is discharged into the corresponding first water washing tank 33 and second water washing tank 34.

The first and second water washing tanks 33 and 34 are connected to the first and second cleaning water tanks 61 and 62 via pipe T6. A valve V10 is installed on the path connecting the first water washing tank 33 and pipe T6. Furthermore, a valve V11 is installed on the path connecting the second water washing tank 34 and pipe T6.

Here, the first and second cleaning water tanks 61 and 62 are containers for storing cleaning water used to clean the centrifuged materials. Specifically, the first cleaning water tank 61 stores cleaning water 61a supplied from an external water supply (not shown). Cleaning water 61a does not need to be of a particularly high purity; ordinary industrial water, tap water, well water, etc. can be used directly.

The second cleaning water tank 62 stores the used cleaning water 61a as cleaning water 62a. Furthermore, a component concentration meter 62b is provided in the second cleaning water tank 62 for measuring the component concentrations of the cleaning water 62a. Hereinafter, when the distinction between cleaning water 61a and cleaning water 62a is not made, they will be referred to simply as cleaning water.

A valve V12 is installed on the path connecting the first washing water tank 61 and the pipe T6. A valve V13 is installed on the path connecting the second washing water tank 62 and the pipe T6. Furthermore, a pump P4 is installed on the path of the pipe T6 to supply the washing water stored in the first and second washing water tanks 61 and 62 to the first and second washing tanks 33 and 34.

When valve V12 is open and valve V13 is closed, pump P4 supplies the wash water 61a stored in the first wash water tank 61 to the first and second wash water tanks 33 and 34. Furthermore, when valve V12 is closed and valve V13 is open, pump P4 supplies the wash water 62a stored in the second wash water tank 62 to the first and second wash water tanks 33 and 34.

The first water washing tank 33 uses washing water supplied via pipe T6 to wash the first material M1 centrifugally separated by the first centrifuge 31. Furthermore, the second water washing tank 34 uses washing water supplied via pipe T6 to wash the second material M2 centrifugally separated by the second centrifuge 32. The washing method is not particularly limited, and various washing methods can be used.

For example, as shown in Figure 1, the first washing tank 33 may be configured to include a motor 33a, which serves as a driving source to rotate an agitator 33b, such as a screw, placed in the washing water, thereby performing a cleaning (stirring) operation. Similarly, the second washing tank 34 may be configured to include a motor 34a, which serves as a driving source to rotate an agitator 34b placed in the washing water, thereby performing a cleaning (stirring) operation. Furthermore, the first washing tank 33 and the second washing tank 34 may use different cleaning methods. Furthermore, the first washing tank 33 and the second washing tank 34 may be configured to utilize ultrasonic cleaning, for example.

Furthermore, the cleaning water in the first and second washing tanks 33 and 34 acts as a specific gravity screening liquid, similar to the stripping liquid 21a described above, separating the first material M1 and the second material M2 by screening based on their specific gravity difference. Specifically, due to the difference in specific gravity of the first and second materials M1, M2 relative to the cleaning water, the first and second materials M1, M2 are retained at different positions (heights) within the first and second washing tanks 33 and 34. For example, when water is used as the cleaning water, as in the case of the MEA aqueous solution described above, the first material M1 is retained above the cleaning water, while the second material M2 is retained below the cleaning water.

Each of the first and second water washing tanks 33 and 34 is equipped with a drain port (not shown) for returning the rinse water to the first and second centrifugal separation sections 31 and 32. This drain port is located at a position (height) corresponding to the retention point of the first and second materials M1 and M2, respectively. Specifically, the upper drain port of each of the first and second water washing tanks 33 and 34, corresponding to the retention point of the first material M1, is connected to pipe T7, which is connected to pipe T1. Furthermore, the lower drain port of each of the first and second water washing tanks 33 and 34, corresponding to the retention point of the second material M2, is connected to pipe T8, which is connected to pipe T2. As a result, the washing water containing a large amount of the first material M1 is discharged from the pipe T7, and the washing water containing a large amount of the second material M2 is discharged from the pipe T8.

Pipe T7 is connected between valve V2 and pump P1 on the path of pipe T1. Valve V14 is also installed near the connection between pipe T7 and pipe T1. Pipe T8 is connected between valve V3 and pump P2 on the path of pipe T2. Valve V15 is also installed near the connection between pipe T8 and pipe T2.

Here, in each set of valves V2 and V14, and valves V3 and V15, exclusive control is performed in such a way that one of the valves becomes open, thereby switching the liquid supplied to the first centrifugal separation section 31 and the second centrifugal separation section 32 to the stripping liquid 21a or the cleaning water.

As will be described later, the first material M1 and second material M2 separated from the washing water in the first centrifugal separation section 31 and the second centrifugal separation section 32 are then fed back into the first water washing tank 33 and the second water washing tank 34, thereby repeating centrifugal separation and washing (specific gravity difference screening). The first material M1 is collected in the first water washing tank 33, and the second material M2 is collected in the second water washing tank 34.

The first washing tank 33 also has a discharge port (not shown) for discharging the first material M1, which has been cleaned and screened for specific gravity differences, to the drying section 40. This discharge port is connected to piping T9, which connects to the drying section 40. Valve V16 and pump P5 are installed on the path of piping T9. When valve V16 is open, pump P5 draws washing water containing the first material M1 from the first washing tank 33 and supplies it to the drying section 40 (first drying section 41).

The second washing tank 34 also has an outlet (not shown) for discharging the second material M2, which has been cleaned and screened for specific gravity differences. This outlet is connected to the pipe T10 that connects to the drying section 40. Valve V17 and pump P6 are installed on the path of pipe T10. When valve V17 is open, pump P6 draws washing water containing the second material M2 from the second washing tank 34 and supplies it to the drying section 40 (second drying section 42).

In addition, the centrifugal separation water washing section 30 is not limited to the above-mentioned structure. For example, the centrifugal separation water washing section 30 can also be set to include a structure such as a stripping liquid tank 51, a first cleaning water tank 61, and a second cleaning water tank 62.

While the configuration shown in FIG1 illustrates a configuration in which the material cleaned and selected by specific gravity difference in the centrifugal separation washing section 30 is supplied from the first and second washing tanks 33 and 34 to the drying section 40, the present invention is not limited thereto. For example, the material separated in the first and second centrifugal separation sections 31 and 32 may be supplied to the drying section 40 using a conveyor belt or other transport device.

1 , the first centrifugal separation section 31 and the second centrifugal separation section 32 are connected to the second cleaning water tank 62. However, the first water washing tank 33 and the second water washing tank 34 may also be connected to the second cleaning water tank 62. In this way, the used cleaning water in the first water washing tank 33 and the second water washing tank 34 can be supplied to the second cleaning water tank 62.

[Drying Section Configuration] Drying section 40 is an example of a drying section. Drying section 40 dries the first material M1 and the second material M2, which have been cleaned and gravity-screened in the centrifugal separation and water-washing section 30.

Specifically, the drying section 40 includes a first drying section 41 and a second drying section 42 .

The first drying section 41 dries the first material M1 supplied from the centrifugal separation and water washing section 30 (first centrifugal separation section 31) via pipe T9. Furthermore, the second drying section 42 dries the second material M2 supplied from the centrifugal separation and water washing section 30 (second centrifugal separation section 32) via pipe T10. The first and second materials M1, M2 dried in the drying section 40, are recovered according to their respective material types.

The drying method used in the first drying section 41 and the second drying section 42 is not particularly important, and various drying methods can be used. For example, the first drying section 41 and the second drying section 42 can also be drying devices that dry by blowing warm air at approximately 90°C. Furthermore, the first drying section 41 and the second drying section 42 can also be drying devices that perform reduced-pressure drying by depressurizing and exhausting a sealed container containing the first material M1 or the second material M2.

Next, the separation and recovery method performed by the separation and recovery device 1 of this embodiment will be described.

Figure 2 is a schematic flow chart illustrating an example of the separation and recovery process. As shown in Figure 2, the separation and recovery process includes crushing step S1, stripping step S2, centrifugal separation step S3, water washing step S4, and drying step S5. Here, stripping step S2 is an example of a stripping process. Furthermore, centrifugal separation step S3, water washing step S4, and drying step S5 are examples of a separation and recovery process. Furthermore, the gravity difference screening process performed in stripping step S2 can also be considered part of the separation and recovery process.

Each step of the separation and recovery method described above is executed, for example, by a control device (not shown) comprised of a computer. The control device comprises a computer including a processor, a main memory device, an auxiliary memory device, and the like, and executes each step of the separation and recovery method described above by cooperating with programs stored in the auxiliary memory device. In this case, the control device controls the operation of the separation and recovery device 1 based on, for example, the opening and closing control of valves installed in various components of the separation and recovery device 1, the drive control of the pump, and the sensing results of a sensor device (not shown).

The control device may be a single unit that controls the operation of the separation and recovery device 1 as a whole, or may be a plurality of units that individually control the operation of each of the crushing section 10, the peeling section 20, the centrifugal separation and water washing section 30, and the drying section 40. Furthermore, although the present embodiment describes the separation and recovery method as being executed under the control of the control device, the present invention is not limited thereto and each process may also be executed manually.

The following describes each process in FIG2 with reference to FIG1 and FIG3 to FIG5.

Crushing Process Crushing process S1 is primarily performed by crushing unit 10. In crushing process S1, composite material CM1, the target material, is crushed into small pieces, or crushed material CM2, by crusher 11. Crushed material CM2 is then transported to hopper 13 using transport means such as blower 12.

[Stripping Process] Stripping process S2 is primarily performed by the stripping unit 20. In stripping process S2, the control device first closes valves V2 and V3, opens valve V4, and activates pump P3, thereby supplying the stripping fluid 21a stored in the stripping fluid tank 51 to the stripping tank 21. Once the stripping fluid 21a supplied to the stripping tank 21 reaches a specified amount, the control device stops pump P3 and closes valve V4. Next, the control device activates the heating unit 22, heating the stripping fluid 21a in the stripping tank 21 to a specified temperature.

Next, the control device opens valve V1, allowing the crushed material CM2 contained in hopper 13 to be fed into the exfoliating liquid 21a in exfoliating tank 21. In this embodiment, the exfoliating liquid 21a is supplied before the crushed material CM2 is fed, but this is not limiting. For example, the exfoliating liquid 21a may be supplied after the crushed material CM2 is fed.

Once the crushed material CM2 is added to the exfoliating liquid 21a, the control device activates the stirring unit 23, thereby stirring the exfoliating liquid 21a. This stirring of the exfoliating liquid 21a increases the frequency and area of contact between the adhesive layer contained in the crushed material CM2 and the exfoliating liquid 21a. Furthermore, the heating of the exfoliating liquid 21a by the heating unit 22 facilitates its penetration into the adhesive layer contained in the crushed material CM2.

Thus, in the stripping section 20 (stripping step S2), the adhesive can be efficiently stripped from the crushed material CM2, thereby efficiently separating the first material M1 and the second material M2. Furthermore, since the adhesive can be removed from the crushed material CM2, the quality of the separated and recovered first material M1 and second material M2 can be improved.

Next, the control device stops the heating section 22 and the stirring section 23, allowing the exfoliating liquid 21a to rest for a predetermined time. As the exfoliating liquid 21a rests, the exfoliated first material M1 and second material M2 separate to positions (heights) corresponding to their specific gravities. Specifically, the first material M1, with its lower specific gravity, remains at the upper portion of the exfoliating tank 21, while the second material M2, with its higher specific gravity, remains at the lower portion of the exfoliating tank 21. The resting time for the exfoliating liquid 21a is not specifically defined. For example, the control device may adjust the resting time based on the size of the crushed material CM2 or the viscosity of the exfoliating liquid 21a.

Next, the control device opens valve V2 (closes valve V14) and activates pump P1, thereby supplying the exfoliation liquid 21a above the exfoliation tank 21 to the first centrifugal separation section 31. Furthermore, the control device opens valve V3 (closes valve V15) and activates pump P2, thereby supplying the exfoliation liquid 21a below the exfoliation tank 21 to the second centrifugal separation section 32. Specifically, the peeling liquid 21 a mainly containing the first material M1 is supplied to the first centrifugal separation section 31, and the peeling liquid 21 a mainly containing the second material M2 is supplied to the second centrifugal separation section 32.

In the stripping step S2, the stripping liquid 21a may be mixed with the other material and supplied to the first centrifugal separation section 31 and the second centrifugal separation section 32. Therefore, in the separation and recovery method of this embodiment, the first material M1 and the second material M2 are further separated in the centrifugal separation step and the water washing step described below.

[Centrifugal Separation Process and Water Washing Process] Centrifugal separation process S3 and water washing process S4 are primarily performed by the centrifugal separation and water washing section 30. The following describes centrifugal separation process S3 and water washing process S4 with reference to Figures 3 to 5.

Figures 3 through 5 illustrate the centrifugal separation process S3 and the water washing process S4. The solid arrows indicate the movement of the first and second materials M1, which are being recovered. Furthermore, the dashed arrows indicate the movement of the stripping liquid 21a. Furthermore, the dotted arrows indicate the movement of the washing water. In Figures 3 through 5, open piping is indicated by solid lines, while closed piping is indicated by dashed lines.

First, in centrifugal separation step S3, as shown in Figure 3, valves V2 and V3 are set to the open state, and valves V14 and V15 are set to the closed state. Then, the control device drives pumps P1 and P2 to supply the stripping fluid 21a to the first centrifugal separation section 31 and the second centrifugal separation section 32.

In the first centrifugal separation section 31 and the second centrifugal separation section 32, motors 31a and 32a are driven, centrifugally separating the supplied exfoliating liquid 21a into a liquid (exfoliating liquid 21a) and a solid (crushed mixture). At this point, the control device opens valve V5, thereby controlling the exfoliating liquid 21a separated by the first centrifugal separation section 31 and the second centrifugal separation section 32 to be discharged into the exfoliating liquid tank 51. Thus, the peeling liquid 21a used in the first centrifugal separation section 31 and the second centrifugal separation section 32 can be reused, thereby reducing the operating cost.

Once the centrifugal separation by the first centrifugal separation section 31 and the second centrifugal separation section 32 is completed, the control device sets valves V8 and V9 to the open state, thereby discharging the separated crushed mixture into the first water washing tank 33 and the second water washing tank 34.

In the following washing step S4, the control device, as shown in Figures 4 or 5, uses the wash water supplied from the first washing tank 61 or the second washing tank 62 to wash the crushed mixture in the first washing tank 33 and the second washing tank 34. The control device then allows the wash water in the first washing tank 33 and the second washing tank 34 to settle, thereby separating the first material M1 and the second material M2 based on their specific gravity difference, similar to the stripping section 20 described above.

Next, the control device closes valve V2 and opens valve V14, thereby supplying washing water containing the first material M1 from each of the first and second washing tanks 33 and 34 to the first centrifugal separation section 31. Furthermore, the control device closes valve V3 and opens valve V15, thereby supplying washing water containing the second material M2 from each of the first and second washing tanks 33 and 34 to the second centrifugal separation section 32. The control device then executes the centrifugal separation process S3 and the water washing process S4 using washing water a specified number of times, thereby repeatedly separating the first material M1 and the second material M2.

Furthermore, when using wash water for centrifugal separation step S3, the control device sets valve V5 to a closed state and valve V7 to an open state, thereby controlling the discharge of the centrifugally separated wash water into the second wash water tank 62. This allows the wash water used in the first centrifugal separation section 31 and the second centrifugal separation section 32 to be reused as wash water 62a, thereby reducing the amount of water used for washing and lowering operating costs.

It is also preferred that the initial (or first few) washing steps S4 be performed using the washing water 62a stored in the second washing tank 62, while the final washing step S4 be performed using the washing water 61a stored in the first washing tank 61. In this case, the control device may also execute the centrifugal separation step S3 and the washing step S4, for example, by the following procedure.

First, as shown in Figure 4, valves V10, V11, and V13 are opened, and valve V12 is closed. This causes the wash water 62a stored in the second wash water tank 62 to be supplied to the first and second wash water tanks 33 and 34 via pump P4. Meanwhile, valves V14 and V15 are closed at this time.

Once the supply of cleaning water 62a reaches the specified amount, the control device sets valves V10, V11, and V13 to the closed state, stopping pump P4. Next, the control device activates the first and second water washing tanks 33 and 34, and starts washing using the supplied cleaning water 62a.

Once the washing is completed for a predetermined time, the control device stops the operation of the first washing tank 33 and the second washing tank 34, and allows the washing water 62a to remain still for a predetermined time.

Next, the control device opens valve V14 and drives pump P1, thereby supplying the cleaning water 62a above the first and second water washing tanks 33 and 34 to the first centrifugal separation section 31. Furthermore, the control device opens valve V15 and drives pump P2, thereby supplying the cleaning water 62a below the first and second water washing tanks 33 and 34 to the second centrifugal separation section 32.

Next, in the first and second centrifugal separation sections 31 and 32, as described above, centrifugal separation step S3 is performed to separate the liquid (washing water 62a) and solids (first material M1 and second material M2). The centrifugally separated washing water 62a can be discarded or discharged to the second washing water tank 62. Furthermore, the centrifugally separated solids are returned to the first and second washing tanks 33 and 34. Furthermore, the washing step S4 using the washing water 62a can be performed one or more times.

Then, once the washing process S4 using the washing water 62a is performed a predetermined number of times, the washing process S4 using the washing water 61a of the first washing water tank 61 is performed one or more times as the final washing.

Specifically, as shown in Figure 5, valves V10, V11, and V12 are opened, and valve V13 is closed. As a result, the wash water 61a stored in the first wash water tank 61 is supplied to the first and second wash tanks 33 and 34 via pump P4. At this time, valves V14 and V15 are closed.

Once the supply of cleaning water 61a reaches the specified amount, the control device closes valves V10, V11, and V12, stopping pump P4. Next, the control device activates the first and second water washing tanks 33 and 34, starting washing using the supplied cleaning water 61a.

Here, the control device may also be configured to return the first material M1 and the second material M2, which have undergone gravity separation and selection as described above, to the first centrifugal separation section 31 and the second centrifugal separation section 32 after a predetermined cleaning period. In this case, the control device closes valve V5 and opens valve V7 in the centrifugal separation step S3, thereby discharging the centrifugally separated cleaning water 61a into the second cleaning water tank as cleaning water 62a.

Alternatively, the control device can transfer the first material M1 and second material M2, which have been cleaned and gravity-separated, to the drying process S5. In this case, the control device opens valve V16 and activates pump P5, thereby supplying the first material M1 accumulated in the first washing tank 33 along with the washing water 61a to the first drying section 41. Similarly, the control device opens valve V17 and activates pump P6, thereby supplying the second material M2 accumulated in the second washing tank 34 along with the washing water 61a to the second drying section 42.

In this manner, the separation and recovery method of this embodiment repeatedly performs the centrifugal separation step S3 and the water washing step S4 multiple times to repeatedly clean the first material M1 and the second material M2 and screen them based on their specific gravity difference. This improves the degree of cleaning of the first material M1 and the second material M2 and the accuracy of their separation. Consequently, the separation and recovery method of this embodiment efficiently separates and recovers the first material M1 and the second material M2, and improves the quality of the separated and recovered first material M1 and second material M2.

Furthermore, in the separation and recovery method of this embodiment, the stripping liquid 21a used for material stripping can be reused, and the washing water 61a used for material washing can be reused as washing water 62a. Therefore, in the separation and recovery method of this embodiment, the amount of stripping liquid 21a used for material stripping or the amount of water used for material washing can be reduced, enabling efficient material separation and recovery.

[Drying Process] Drying process S5 is primarily performed by drying section 40. Drying process S5 dries the first material M1 and second material M2, which have been cleaned and screened by specific gravity difference in washing process S4. Drying process S5 is described below with reference to Figure 5.

The control device drives the first drying section 41 to dry the first material M1 supplied from the centrifugal separation and water washing section 30, thereby recovering the first material M1. Furthermore, the control device drives the second drying section 42 to dry the second material M2 supplied from the centrifugal separation and water washing section 30, thereby recovering the second material M2.

As described above, the separation and recovery apparatus 1 of this embodiment performs a stripping process, specifically heating and stirring a crushed product CM2 (a composite material containing multiple types of materials layered with a bonding agent) and a stripping liquid 21a (an aqueous MEA solution) to obtain a crushed mixture in which the bonding agent has been stripped from the crushed product. This facilitates stripping of the bonding agent from the crushed product CM2, enabling efficient separation of multiple types of materials.

Furthermore, in the separation and recovery apparatus 1 of this embodiment, the crushed mixture is separated into a plurality of types of materials by screening based on specific gravity differences during the stripping process or the washing process. Thus, the separation and recovery apparatus 1 can separate the plurality of types of materials dispersed by the stripping of the adhesive based on their specific gravity.

Furthermore, in the separation and recovery apparatus 1 of this embodiment, an MEA aqueous solution (stripping liquid 21a) containing MEA at a content of 2% by weight to 100% by weight is used to strip the adhesive from the crushed material CM2. This reduces the hazards and toxicity of MEA in the separation and recovery apparatus 1, thereby improving safety.

Furthermore, the separation and recovery apparatus 1 of this embodiment utilizes an aqueous MEA solution (stripping liquid 21a) containing at least one of an alkaline earth metal and an alkaline metal to strip the adhesive from the crushed material CM2. This facilitates stripping of the adhesive from the crushed material CM2 in the separation and recovery apparatus 1, enabling efficient separation of multiple types of materials.

Furthermore, in the separation and recovery apparatus 1 of this embodiment, microbubbles are generated in the peeling liquid 21a to stir the peeling liquid 21a. This facilitates the peeling of the adhesive from the crushed material CM2 in the separation and recovery apparatus 1, thereby enabling efficient separation of multiple types of materials.

(Variation 1) In the above embodiment, the materials to be recovered are divided into two types (first material M1 and second material M2), and thus a configuration is provided consisting of two centrifugal separation and water washing sections. However, this is not limiting, and the configuration of the separation and recovery apparatus 1 can be modified to suit the number of materials to be recovered.

For example, if there are three types of materials to be recycled (each with a different specific gravity), three sets of centrifuges and washing sections are provided. Furthermore, in the stripping tank 21, outlets are provided at positions (heights) corresponding to the specific gravity of each material, and piping is provided to connect these outlets to the centrifuges of each set. Furthermore, in each washing section, outlets are provided at positions (heights) corresponding to the specific gravity of each material, and piping is provided to connect these outlets to the centrifuges of the set responsible for gravity difference screening of that specific gravity. This allows the materials stripped (separated) by the stripping tank 21 to be separated and recycled in the drying section 40 connected to each set of centrifuges.

(Variant 2) The above embodiment describes a separation and recovery device 1 (separation and recovery method) including a crushing unit 10 (crushing step S1). However, if, for example, pre-crushed composite material CM1 is prepared, a configuration can be employed that eliminates the crushing unit 10 (crushing step S1). In this case, the pre-crushed composite material CM1 (crushed material CM2) is processed in the stripping unit 20 (stripping step S2), thereby achieving the same effects as the above embodiment.

(Variant 3) In the above embodiment, the stripping liquid 21a is configured to contain at least one of an alkaline earth metal and an alkaline metal as an additive. However, it can also be configured to contain neither alkaline earth metal nor alkaline metal. In this case, while lacking the functionality of an additive (activator) compared to the above embodiment, the advantages listed below can be achieved.

First, when stripping liquid 21a contains alkali earth metals or alkaline metals, there is a possibility of damaging the synthetic resin (PET, etc.) or metal (AL, etc.) being recycled. Specifically, alkali earth metals or alkaline metals have the effect of decomposing synthetic resins, and therefore have the potential to degrade the synthetic resin during stripping step S2. Furthermore, alkali earth metals or alkaline metals react with AL, converting the AL into aluminum hydroxide or aluminum oxide, and generating hydrogen gas, which increases the risk of explosion. Therefore, by adopting a composition that does not contain alkali earth metals or alkaline metals, the quality and safety of the recycled materials can be improved.

Furthermore, during pressure reduction drying in drying step S5, inorganic alkali metals and alkaline metals do not volatilize but remain as residues, resulting in the inclusion of alkali metals and alkaline metals in the recycling material. Therefore, by designating a composition that does not use alkali metals and alkaline metals, it is possible to reduce residues other than the recycling material, thereby improving the quality of the recycled material.

Furthermore, if the stripping liquid 21a contains alkaline earth metals or alkali metals, the final disposal of the stripping liquid 21a becomes complicated. On the other hand, if the stripping liquid 21a does not contain alkaline earth metals or alkali metals, the MEA, which is the main component, is combustible, and can be mixed with other fuels for combustion. Therefore, by adopting a structure that does not use alkaline earth metals or alkali metals, the burden of stripping liquid 21a disposal can be reduced.

While the embodiments and variations of the present invention have been described above, these embodiments and variations are provided as examples and are not intended to limit the scope of the invention. These novel embodiments and variations may be implemented in various other forms and may be omitted, replaced, or modified without departing from the gist of the invention. These embodiments and variations are intended to be included within the scope and gist of the invention and are also intended to be included in the invention and its equivalents as set forth in the claims.

1: Separation and Recovery Unit 10: Crushing Unit 11: Crusher 12: Blower 13: Hopper 20: Peeling Unit 21: Peeling Tank 22: Heating Unit 23: Mixing Unit 30: Centrifugal Separation and Water Washing Unit 31: First Centrifugal Separation Unit 32: Second Centrifugal Separation Unit 33: First Water Washing Tank 34: Second Water Washing Tank 40: Drying Unit 41: First Drying Unit 42: Second Drying Unit 51: Peeling Liquid Tank 61: First Rinse Tank 62: Second Rinse Tank

[Figure 1] Figure 1 is a schematic diagram illustrating an example of the structure of a separation and recovery device according to an embodiment. [Figure 2] Figure 2 is a schematic flow chart illustrating an example of the procedures for a separation and recovery method according to an embodiment. [Figure 3] Figure 3 is a diagram illustrating the separation and recovery method according to an embodiment. [Figure 4] Figure 4 is a diagram illustrating the separation and recovery method according to an embodiment. [Figure 5] Figure 5 is a diagram illustrating the separation and recovery method according to an embodiment.

1: Separation and recovery device

10: Crushing Section

11: Crusher

12: Blower

13: Hopper

20: Peeling

21: Peeling groove

21a: Exfoliating fluid

22: Heating Section

23: Mixing Section

30: Centrifugal separation and water washing section

31: First centrifugal separation section

31a: Motor

32: Second centrifugal separation section

32a: Motor

33: 1st water washing tank

33a: Motor

33b: Blender

34: Second water washing tank

34a: Motor

34b: Blender

40: Drying Section

41: Drying Section 1

42: Second Drying Section

51: Peeling liquid tank

51a: Component Concentrator

61: First cleaning sink

61a: Clean water

62: Second cleaning sink

62a: Clean water

62b: Component Concentrator

CM1: Composite Materials

CM2: Broken Objects

M1: Material 1

M2: Material 2

P1~P6: Pumping

T1~T10: piping

V1~V17: Valve

Claims (8)

A separation and recovery method comprises: a stripping step, wherein a crushed material comprising a composite material formed by layering multiple types of materials with different specific gravities and a treatment solution of a monoethanolamine aqueous solution are placed into a stripping tank, heated, and stirred to obtain a crushed mixture in which the layers of the materials contained in the crushed material are stripped; and a first separation and recovery step, wherein the crushed mixture is separated and recovered by screening based on specific gravity differences. In the first separation and recovery step, after the stirring, the crushed mixture is separated and recovered at a retention point in the stripping tank corresponding to the specific gravities of the materials. The separation and recovery method of claim 1, further comprising: a second separation and recovery step for separating and recovering the crushed mixture separated and recovered in the first separation and recovery step into the plurality of materials by screening based on specific gravity differences; In the second separation and recovery step, the plurality of materials are separated and recovered from the crushed mixture separated and recovered at each of the retention locations in parallel. The separation and recovery method according to claim 1 or 2, wherein the monoethanolamine content in the monoethanolamine aqueous solution is not less than 2% by weight and not more than 100% by weight. The separation and recovery method according to claim 1 or 2, wherein: the monoethanolamine aqueous solution contains at least one of an alkaline earth metal and an alkaline metal. The separation and recovery method as described in claim 1, wherein: During the stripping process, microbubbles are generated in the treatment liquid to agitate the treatment liquid, thereby promoting the stripping of the layers of the material. The separation and recovery method as described in claim 5, wherein: During the stripping process, ultrasonic waves are transmitted through the treatment liquid to generate the microbubbles. The separation and recovery method as described in claim 2, wherein: the second separation and recovery step comprises: a centrifugal separation step for centrifuging the treated liquid containing the crushed mixture; a separation step for separating the materials into categories by gravity screening using a gravity screening liquid, wherein the gravity screening liquid has a specific gravity different from that of the plurality of categories of materials contained in the crushed mixture in the treated liquid centrifuged by the centrifugal separation step; and a drying step for drying each of the materials separated by the separation step. A separation and recovery device comprises: a stripping section for feeding a crushed material comprising a composite material formed by layering multiple types of materials having different specific gravities and a treatment liquid comprising an aqueous monoethanolamine solution into a stripping tank, where the mixture is heated and stirred to obtain a crushed mixture formed by peeling the layers of the materials contained in the crushed material; a centrifugal separation section for centrifuging the treatment liquid containing the crushed mixture; a separation section for separating the materials into their respective types by gravity screening using a specific gravity screening liquid, wherein the specific gravity of the specific gravity screening liquid is different from that of the multiple types of materials contained in the crushed mixture in the treatment liquid centrifuged in the centrifugal separation section; and The drying section dries each of the materials separated by the separation section. The stripping section separates and recovers the crushed mixture after agitation at retention points in the stripping tank corresponding to the specific gravities of the materials. The centrifugal separation section centrifuges the treated liquid containing the crushed mixture recovered in the stripping section.