Separation and recovery device

Abstract

Provided is a separation and recovery device for continuously separating and recovering a hydrolysis component a of a hydrolyzable polymer A and a non-hydrolyzable polymer B from a resin mixture containing a resin containing the hydrolyzable polymer and a resin containing the non-hydrolyzable polymer, the separation and recovery device comprising: a crushing unit for crushing the resin mixture; a melting and ejecting unit for melting the crushed product obtained by the crushing unit to form a fluid and ejecting the fluid at high pressure; and a hydrothermal reaction treatment unit for continuously performing a hydrothermal reaction treatment on the fluid ejected from the melting and ejecting unit, in which the hydrolyzable polymer A is hydrolyzed to dissolve and transfer the hydrolysis component a thereof to water impregnated through a sintered alloy diaphragm, thereby separating the non-hydrolyzable polymer B.

Description

Technical Field

[0001] The present invention relates to an apparatus for continuously separating and recovering hydrolyzed component a of hydrolyzable polymer A and non-hydrolyzable polymer B from a resin mixture comprising at least a resin 1 containing a hydrolyzable polymer A and a resin 2 containing a non-hydrolyzable polymer B. Background Technology

[0002] The recycling of polymers or their hydrolyzed components mostly targets resin waste consisting of a single component. This is to ensure that the stability of the polymer's melting temperature, remolding conditions, etc., is not compromised when the polymer is recycled directly (also known as material recycling). On the other hand, when the polymer is recycled (also known as chemical recycling) within its feedstock compound, the decomposition conditions for recovering the feedstock compound at the maximum yield can be easily and simply determined.

[0003] In contrast, actual resin waste is a mixture of various resins (polymers), and further includes vapor-deposited layers, printed layers, etc., to ensure the functionality and decorative properties of the resin itself. Additionally, as it is waste, it is sometimes also contaminated with dirt. Such resin waste, with the exception of a portion of high-purity resin discharged from PET bottles and resin molding plants, is discharged as plastic waste from ordinary households and as industrial waste from businesses. It is difficult for ordinary users to identify the type of resin and dispose of these substances, which is the main reason why actual resin waste is a mixture of various resins. Therefore, there is an increasing trend of most resin waste being recycled using the heat from combustion.

[0004] In this context, Patent Document 1 proposes a method that involves collecting waste materials such as multilayer plastic molded products composed of condensation polymer films and addition polymer films, and treating them with water at high temperatures. This process decomposes the condensation polymers into monomers for recycling, and decomposes and oils the remaining addition polymer mixture. While this method has caused some controversy under the current circumstances, its feasibility and versatility in recycling actual resin waste, achieved through simple batch processing and limited application under specific conditions, remain low, requiring further research.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 11-323006 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] As mentioned above, if resin waste contains a single polymer component, various recycling methods exist; however, existing recycling methods are largely inapplicable to resin waste containing a mixture of multiple polymers. Therefore, most resin waste is either thermally recycled or reused in cascaded processes where a large amount of filler is incorporated into the mixture for applications where purity is not critical. Recycling methods for resin waste containing multiple polymers, particularly industrially advantageous continuous recycling methods, and recycling equipment capable of implementing these methods, have not yet been established.

[0010] For example, in the method described in Patent Document 1 above, addition polymers are also difficult to recycle and decompose into oil, thus having to be used as fuels equivalent to heavy oil. This is because addition polymers do not decompose due to hydrothermal reaction treatment; therefore, due to the residual monomers from the condensation polymer source and the residue (mixing) of incompletely decomposed condensation polymers, the purity for recycling cannot be guaranteed.

[0011] Furthermore, when combining multiple polymers to manufacture resin molded articles (e.g., resin parts, resin products), the following method is commonly used: polypropylene (PP) or polyethylene (PE) is used as an addition polymer in a substrate, and a resin containing multiple polymers used to impart functionality is laminated onto it. In this case, since more than half of the resin molded article is formed from addition polymers such as PP and PE, even if these resin molded articles are applied to the method described in Patent Document 1, more than half of the addition polymers in the recycled material will become oily and thus require heat recycling, making it unsuitable as a highly versatile recycling method.

[0012] The objective of this invention is to provide an apparatus capable of continuously separating and recovering, from a resin mixture comprising a resin containing a hydrolyzable polymer and a resin containing a non-hydrolyzable polymer, the hydrolyzable polymer being used as a raw material compound and the non-hydrolyzable polymer being used as a high-purity polymer with the incorporation of the hydrolyzable polymer suppressed.

[0013] Methods for solving problems

[0014] The objective of this invention is achieved through the following means.

[0015] <1> A separation and recovery apparatus is provided for continuously separating and recovering hydrolyzed component a of hydrolyzable polymer A and non-hydrolyzable polymer B from a resin mixture comprising at least resin 1, which is mainly composed of hydrolyzable polymer A, and resin 2, which is mainly composed of non-hydrolyzable polymer B.

[0016] The separation and recovery device has the following features:

[0017] A crushing unit that crushes the aforementioned resin mixture;

[0018] A melt ejection unit that melts the crushed material obtained from the aforementioned crushing unit to form a fluid and ejects it under high pressure; and

[0019] The hydrothermal reaction processing unit continuously performs hydrothermal reaction processing on the fluid ejected from the aforementioned melt ejection unit.

[0020] In the above-mentioned hydrothermal reaction processing unit, the hydrolyzable polymer A is hydrolyzed so that its hydrolyzed component a dissolves and is transferred to water that has been impregnated through a sintered metal membrane, thereby separating the non-hydrolyzable polymer B.

[0021] <2> like <1> In the aforementioned separation and recycling device, the melt ejection unit melts and ejects the crushed material.

[0022] <3> like <1> or <2> The separation and recovery apparatus includes a separation unit between the melt ejection unit and the hydrothermal reaction processing unit, wherein the separation unit removes insoluble components from the fluid ejected from the melt ejection unit.

[0023] The above separation unit has:

[0024] The inlet allows fluid ejected from the aforementioned melt ejection unit to flow in;

[0025] The first flow path is connected to the aforementioned inlet and uses high pressure to allow the fluid flowing in from the aforementioned inlet to circulate.

[0026] A separation membrane, which is arranged along the first flow path described above, separates the insoluble components in the fluid from the fluid.

[0027] The second flow path is located on the side opposite to the first flow path relative to the separation membrane, and is used for the flow of fluid that has had insoluble components removed by the separation membrane.

[0028] A fluid outlet, connected to the second flow path described above, allows the fluid from which the insoluble components have been removed to flow out; and

[0029] An insoluble component discharge port is provided extending from the first flow path to discharge the separated insoluble components.

[0030] <4> like <1> ~ <3> The separation and recovery apparatus according to any one of the following methods, wherein a concentration unit is provided upstream of the hydrothermal reaction processing unit, the concentration unit separating non-hydrolyzable polymer B and increasing the content of non-hydrolyzable polymer B in the fluid supplied to the hydrothermal reaction processing unit.

[0031] The concentration unit comprises: a cooling subunit, which cools the supplied fluid to cause a portion of the polymer to precipitate and solidify; and a removal subunit, connected to the cooling subunit, which removes the precipitated and solidified polymer component.

[0032] The above-mentioned removal subunit has:

[0033] The inlet allows fluid containing the precipitated and solidified polymer, which is supplied from the aforementioned cooling subunit, to flow in.

[0034] The first flow path is connected to the aforementioned inlet to allow fluid flowing in from the aforementioned inlet to circulate;

[0035] A separation membrane, which is arranged along the first flow path, separates the precipitated and solidified polymer contained in the fluid from the fluid;

[0036] The second flow path is located on the side opposite to the first flow path relative to the separation membrane, and is used for the flow of fluid through which the precipitated and solidified polymer has been removed by the separation membrane.

[0037] A fluid outlet, connected to the second flow path described above, provides an outlet for the fluid from which the precipitated and solidified polymer has been removed; and

[0038] The outlet extends from the first flow path described above and discharges the separated, precipitated, and solidified polymer.

[0039] <5> like <1> ~ <4> The separation and recovery device described in any one of the following statements, wherein,

[0040] The above-mentioned hydrothermal reaction processing unit has:

[0041] Inlet, into which fluid containing hydrolyzable polymer A flows;

[0042] The first flow path is connected to the aforementioned inlet to allow fluid flowing in from the aforementioned inlet to circulate;

[0043] The residual flow outlet extends from the first flow path mentioned above, allowing the residual flow of the fluid after hydrothermal reaction treatment to exit.

[0044] A diaphragm, which is disposed along the first flow path described above, is permeable to water and prevents the passage of molten polymer;

[0045] The second flow path is arranged adjacent to the first flow path on the side opposite to the diaphragm, separated by the diaphragm, to allow water to flow.

[0046] A water inlet, which is located in the second flow path described above, allows water to flow into the second flow path; and

[0047] The water mixture outlet is provided in the second flow path, so that the water mixture containing the hydrolyzed component a of the hydrolyzable polymer A, which flows in from the water inlet and passes through the diaphragm in the second flow path, flows out from the second flow path.

[0048] <6> like <1> ~ <5> The separation and recovery device described in any one of the above descriptions includes one or more of the above-described hydrothermal reaction processing units connected in series or in parallel.

[0049] <7> like <1> ~ <6> The separation and recovery apparatus described in any one of the above-mentioned methods, wherein a hydrolysis component recovery unit is provided downstream of the hydrothermal reaction processing unit, the hydrolysis component recovery unit recovering hydrolysis component a of the hydrolytic polymer A from the water mixture.

[0050] The above-mentioned hydrolysis component recovery unit has:

[0051] A cooling precipitation subunit has an inlet, a flow path A, and an outlet. The inlet receives an influent mixture containing the hydrolyzed component a. The flow path A is connected to the inlet to allow the influent mixture to flow through. The outlet is connected to the flow path A to allow the hydrolyzed component a to flow out along with the water.

[0052] A solid-liquid separation subunit, which is connected to the outlet of the cooling precipitation subunit, separates hydrolyzed component a from the water mixture.

[0053] <8> like <1> ~ <7> The separation and recovery apparatus described in any one of the above-mentioned methods, wherein a polymer B recovery unit is provided downstream of the hydrothermal reaction treatment unit, the polymer B recovery unit recovering non-hydrolyzable polymer B from the residue.

[0054] The above-mentioned polymer B recycling unit has:

[0055] The residual logistics inlet is for the aforementioned residual logistics to enter;

[0056] Flow path P, which is connected to the aforementioned residual material inlet, allows the residual material flowing in from the aforementioned residual material inlet to pass through;

[0057] The membrane, which is arranged along the aforementioned flow path P, allows water and hydrolyzed components a remaining in the aforementioned residues to pass through and be removed; and

[0058] The outlet is connected to the flow path P at a position further downstream than the membrane removal point, allowing polymer B separated from residual water and hydrolyzed component a to flow out.

[0059] The effects of the invention

[0060] The separation and recovery apparatus of the present invention can separate and recover the hydrolyzable polymer as a raw material compound (hydrolyzable component) and the non-hydrolyzable polymer as a high-purity polymer from a resin mixture containing a resin containing a hydrolyzable polymer and a resin containing a non-hydrolyzable polymer through a continuous process.

[0061] The above and other features and advantages of the present invention may be further understood with reference to the accompanying drawings and the following description. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the separation and recycling device 1, which is a preferred embodiment of the present invention.

[0063] Figure 2 This is a diagram illustrating a series of processing steps in the separation and recovery apparatus 1, which is a preferred embodiment of the present invention, and the processed material obtained in each unit.

[0064] Figure 3 This is a partial cross-sectional view showing the general layout of the separation unit 30 of the separation and recovery apparatus suitable for the present invention.

[0065] Figure 4 This is a partial cross-sectional view showing the general layout of the hydrothermal reaction processing unit 50A, which is suitable for the separation and recovery apparatus of the present invention.

[0066] Figure 5 This is a partial cross-sectional view showing the general layout of the hydrothermal reaction processing unit 50B, which is suitable for the separation and recovery apparatus of the present invention.

[0067] Figure 6 This is a partial cross-sectional view showing the general layout of the hydrothermal reaction processing unit 50C, which is suitable for the separation and recovery apparatus of the present invention.

[0068] Figure 7A This is a partial cross-sectional view showing an overview of the hydrolysis component recovery unit suitable for the separation and recovery apparatus of the present invention.

[0069] Figure 7B This is a partial cross-sectional view showing an overview of another hydrolysis component recovery unit suitable for the separation and recovery apparatus of the present invention.

[0070] Figure 8 This is a partial cross-sectional view showing an overview of the polymer B recovery unit 80 suitable for the separation and recovery apparatus of the present invention.

[0071] Figure 9 This is a schematic diagram of the separation and recycling device 2, which is another preferred embodiment of the present invention.

[0072] Figure 10 This is a diagram illustrating a series of processing steps in the separation and recovery apparatus 2, which is another preferred embodiment of the present invention, and the processed material obtained in each unit.

[0073] Figure 11 This is a partial cross-sectional view showing the general layout of the concentration unit 40 of the separation and recovery apparatus suitable for the present invention.

[0074] Figure 12This is a schematic diagram of the separation and recovery device 3, which is another preferred embodiment of the present invention.

[0075] Figure 13 This is a diagram illustrating a series of processing steps in the separation and recovery apparatus 3, which is another preferred embodiment of the present invention, and the processed material obtained in each unit.

[0076] Figure 14 This is a schematic diagram of the separation and recycling device 4, which is another preferred embodiment of the present invention.

[0077] Figure 15 This is a diagram illustrating a series of processing steps in the separation and recovery apparatus 4, which is another preferred embodiment of the present invention, and the processed material obtained in each unit. Detailed Implementation

[0078] In this invention, a hydrolyzable polymer refers to a polymer in which the bonds of the constituent compounds are hydrolyzable (the polymer backbone is hydrolyzable). In the hydrothermal reaction processing unit of the separation and recovery apparatus of this invention (for example, under the specific hydrothermal reaction processing conditions described later), the polymer refers to a polymer that is hydrolyzed due to the chemical properties of its constituent compounds. On the other hand, a non-hydrolyzable polymer refers to a polymer in which the bonds of the constituent compounds are not hydrolyzed or are not easily hydrolyzed. In the hydrothermal reaction processing unit of the separation and recovery apparatus of this invention (for example, under the specific hydrothermal reaction processing conditions described later), the polymer refers to a polymer that is not hydrolyzed or is not easily hydrolyzed into its constituent compounds. As a specific example, it refers to a polymer in which the chemical structure of the polymer backbone (linking chain) is substantially composed only of carbon atoms.

[0079] In this invention, a resin with a specific polymer as its main component refers to a resin containing a specific polymer as its most abundant component.

[0080] In this invention, the numerical range represented by “~” refers to the range that includes the values ​​recorded before and after “~” as the lower limit and upper limit.

[0081] First, the resin mixture used as the processing object in the separation and recovery apparatus of the present invention will be described.

[0082] [Resin Mixture]

[0083] The processing object used in the separation and recovery apparatus of the present invention is a mixture comprising at least resin 1, which is mainly composed of hydrolyzable polymer A, and resin 2, which is mainly composed of non-hydrolyzable polymer B. Resin 1 and resin 2 can, for example, constitute part of the mixture as a molding body or a film-forming body, and can be formed into the mixture in the form of a molding substrate, a resin layer (resin film), etc. Since this mixture comprises at least resin 1 containing hydrolyzable polymer A and resin 2 containing non-hydrolyzable polymer B, it is also referred to as a resin mixture or a mixture of dissimilar resins.

[0084] The mixture can be any mixture containing resin 1 and resin 2. Examples include simple mixtures of resin 1 and resin 2 that are not laminated together, laminates of resin 1 and resin 2, and mixtures of simple mixtures and laminates. Laminated materials (laminated films) can be used as the mixture. In this case, plastic molded products consisting of multiple layers (also called multilayer plastic films) that are discarded in large quantities as waste plastics, and especially substances composed of dissimilar materials (also called dissimilar multilayer films), can be used. The shape of the mixture is not particularly limited; the above-mentioned mixtures and laminates can be used directly. The resin layers of resin 1 and resin 2 in the mixture, especially the laminate, can be single layers or two or more layers.

[0085] The mixing ratio (mass ratio) of resin 1 and resin 2 in the mixture is not particularly limited and can be appropriately set considering the amount of decomposition products generated by hydrolyzable polymer A, the amount of non-hydrolyzable polymer B, and the operating cost of the equipment. For example, it can be set to resin 1: resin 2 = 1:0.1 to 1:10 (mass ratio).

[0086] The resin 1 in the mixture contains one or more hydrolyzable polymers A as its main component. Examples of hydrolyzable polymers include condensation polymers. Condensation polymers are polymers generated through the condensation polymerization of low molecular weight molecules such as water molecules and alcohol molecules from monomers that serve as raw materials for polymerization. Examples include polyesters, polycarbonates, polyamides (sometimes abbreviated as PA in this invention) (in this invention, for convenience, this includes ring-opening polymerized polyamides such as nylon 6 generated by the ring-opening polymerization of ε-caprolactam rather than condensation polymerization), polyacetals, and polyethers. It should be noted that in this invention, even when generated by a non-condensation polymerization reaction (e.g., ring-opening polymerization), any polymers exemplified above are included for convenience. More specific examples are given below.

[0087] Polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), and polycarbonate (PC) with bisphenol A as the main raw material are polymers with ester bonds (-COO-) in the repeating units of the polymer backbone; Nylon 6 (PA6), Nylon 66 (PA66), Nylon 6 / 66 (PA6 / 66), Nylon 12 (PA12), and aliphatic dimethylamine and other polymers are also mentioned. Polyamides are made primarily from aromatic dicarboxylic acids such as amines and phthalates (terephthalic acid, isophthalic acid), and polyamides made primarily from aromatic diamines such as isophthalic acid (MXD) and aliphatic dicarboxylic acids such as adipic acid (e.g., PAMXD6). This invention also includes polyoxymethylene polymers (POM, also known as polyacetal polymers), polyphenylene ether polymers (PPE), and their polymer alloy modified products (modified PPE; e.g., polymer alloys of PPE and polystyrene). Among these, PET and PA6 are important as constituent polymers of multilayer films in terms of versatility and industrial use. PC, PBT, POM, PPE, and various PAs, as the five major general-purpose engineering plastics, are important in automotive parts, electrical equipment (e.g., home appliances, personal computers), and plastic parts for portable communication terminals due to their heat resistance and mechanical strength. Therefore, this invention is suitable for application to thermoplastic resin molded bodies using these polymers.

[0088] Resin 2 in the mixture contains one or more non-hydrolyzable polymers B as its main component. Examples of non-hydrolyzable polymers B include non-condensation polymers. Non-condensation polymers refer to polymers synthesized through addition polymerization, coordination polymerization, metathesis polymerization, etc., whose main molecular backbone consists only of carbon atoms, including substances known as vinyl polymers and cycloolefin polymers. Examples include: polyolefin polymers (PO) such as polyethylene (PE) and polypropylene (PP); styrene polymers such as polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), and acrylonitrile-styrene copolymer (AS or SAN); (meth)acrylic polymers such as polymethyl methacrylate (PMMA); and acrylic polymers such as copolymers of common acrylic monomers (e.g., methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, etc., which are (meth)acrylic compounds) with any free radical polymerizable monomer. Among them, PE, PP and PS are important as constituent polymers of multilayer films, ABS and AS are important structural materials between general polyolefins and engineering plastics, and PMMA is widely used in industry as a transparent polymer. Therefore, the present invention is suitable for thermoplastic resin molded articles using these polymers.

[0089] The combination of hydrolyzable polymer A and non-hydrolyzable polymer B contained in the mixture can be exemplified by suitable combinations of the aforementioned polymers, preferably combinations of preferred polymers, and particularly preferably combinations of polyamide or polyester with polyethylene or polypropylene.

[0090] In this invention, the occurrence of the hydrolysis reaction of the hydrolytic polymer A can be adjusted by changing the hydrothermal reaction treatment conditions. Therefore, a resin mixture having a resin 1 containing two or more hydrolytic polymers A can be used. For example, in the case where a resin 1 formed by laminating polyethylene terephthalate (PET) and nylon 6 (PA6) is used as a resin mixture containing hydrolytic polymer A, and PET and PA6 are independently mixed (in a non-laminated state), by selecting hydrothermal reaction treatment conditions suitable for the overlap of the hydrolysis conditions of PET and PA6, their hydrolysis products can be recovered together without the effort of separating them in advance.

[0091] Resin 1 and Resin 2 may each contain components other than the aforementioned polymer. Examples of components other than the polymer include: glass, carbon fiber, carbon black, silicon dioxide, titanium dioxide, calcium carbonate, magnesium carbonate, magnesium silicate (talc), kaolin, mica, particles and fibers of pigments composed of organic or inorganic materials, plasticizers such as phthalates, adipates, phosphates, and stearates (long-chain fatty acid esters), hindered phenolic heat stabilizers, amines (ultraviolet absorbers), lubricants such as long-chain fatty acid esters of polyols such as glycerol, sodium benzoate, sodium phthalate, sodium salicylate, and 4-hydroxyl groups. Nucleating agents such as sodium benzoate and sodium stearate carboxylates, sodium benzenesulfonate, sodium toluenesulfonate, and sodium 4-hydroxybenzenesulfonate organic sulfonates, fluoropolymers containing fluorine atoms in the repeating units of the polymer's chemical structure (imparting slip properties), elastomers (imparting softness and toughness), and other polymers intended to impart special functions, such as heat stabilizers, UV absorbers, lubricants, colorants, flame retardants, and reinforcing materials (e.g., glass fibers, glass flakes). The content of components other than polymers in each resin is not particularly limited and can be appropriately set within a range that allows for fluidization through heating and melting, and can be ejected through a melt-spraying unit.

[0092] In addition to hydrolyzable polymer A, resin 1 may also contain non-hydrolyzable polymer B as a polymer component. Similarly, in addition to non-hydrolyzable polymer B, resin 2 may also contain hydrolyzable polymer A as a polymer component, but it usually does not contain hydrolyzable polymer A.

[0093] In addition to resin 1 and resin 2, the mixture, especially the laminate, may also include a coating layer C covering resin 1 or resin 2, an adhesive layer D that bonds the resin layers together, etc. Examples of coating layer C and adhesive layer D include inorganic films (including metal films) made of inorganic compounds and organic films (including resin films) made of organic compounds. The materials forming them may be one type or two or more types.

[0094] Examples of the aforementioned materials include, for instance, metals (vacuum processes such as sputtering or evaporation, inorganic materials such as plating (e.g., transition metals such as aluminum, silicon, copper-nickel-chromium combinations, gold, palladium, tin, ruthenium, black trivalent chromium, tin-cobalt alloys, oxides and / or nitrides of these metals; see, for example, the homepage of Tsukada-riken Industries, Ltd., "https: / / www.tukada-riken.co.jp / products / index.html#wc_anc00001")), ceramics primarily composed of metal oxides such as alumina, silica, zirconium oxide, and titanium dioxide (used to impart scratch resistance, and further including UV-absorbing coatings composed of transition metal oxides, anti-reflective coatings, etc.), and inks (e.g., organic pigments, inorganic pigments, dyes, vinyl chloride resins, vinyl acetate resins). The coating layer C and the adhesive layer D can be used in various combinations and lamination structures.

[0095] The combination of polymer A or B with the material forming the coating layer C or adhesive layer D can be exemplified by appropriate combinations of the above-mentioned polymers and materials. It is preferred to apply the present invention to substances that are used in large quantities in industry, for example, (1) as a heterogeneous multilayer film, on a film formed by laminating polymer A (representative examples are PET and PA6) on polymer B such as PE, PP or PS as a substrate, a printing layer, a barrier layer (aluminum layer or silicon dioxide layer, alumina layer, vinylidene chloride layer, etc.), an antistatic layer, an adhesive layer for bonding heterogeneous films, an anti-adhesion layer, etc. are laminated as coating layer C and adhesive layer D; (2) the above-mentioned metal and ceramic coatings are applied to the molded articles of the above five general-purpose engineering plastics (PC, PBT, POM, PPE and various PAs) (preferably manufactured by injection molding or extrusion molding); (3) the above-mentioned ink and ceramic coatings are applied to large molded articles of polymer B such as PP, ABS (e.g., automotive parts, appliance housings).

[0096] There are no particular restrictions on the ratio (mass ratio) of polymer to coating layer C and adhesive layer D. It can be set appropriately, and typically, for example, it can be set to polymer:coating layer C and adhesive layer D = 100:10 to 100:0.001 (mass ratio).

[0097] As a resin mixture, in addition to unused resin mixtures, it can also use waste plastics (used molded products, defective molded products or molding residues and other waste or recyclables). In particular, the use of waste plastics helps to achieve carbon resource recycling and the protection of the Earth's environment. As for waste plastics, there are no particular limitations. Examples include plastic automotive parts (chassis, interior, exterior, window glass, headlight covers, reflectors and other lighting parts, rearview mirrors, displays, safety mechanisms such as seat belts / airbags / airbag covers, fuel system mechanisms such as tanks / piping / pumps, electrical wiring mechanisms such as connectors, gears and other mechanical mechanisms), electrical equipment (such as home appliances, personal computers), plastic parts of portable communication terminals (shells, display parts, circuit boards, antennas, etc.), various optical discs, plastic parts of medical / health devices (artificial dialysis, infusion bags, disposable syringes, physical training equipment, etc.), containers, packaging trays, stationery, toys, furniture, daily necessities, various molded products such as home appliance shells, and packaging films (including packaging for tablets / powders / liquids), plastic shopping bags, etc. If this invention is preferably applied to waste from large quantities of automotive parts, electrical equipment, portable communication terminals, various optical discs, packaging films, etc., it can promote the recycling of large quantities of waste multilayer plastic films (multilayer plastic laminates).

[0098] The resin mixture used in the separation and recycling apparatus of the present invention can contain molded bodies made of resins containing thermoplastic polymers and molded bodies made of resins containing non-thermoplastic polymers. In particular, when using a resin mixture derived from waste plastics, it is suitable to mix molded bodies other than the aforementioned resin mixture from the perspective of not needing to pre-separate the waste plastics. Furthermore, when using a resin mixture derived from waste plastics, for example, a resin mixture containing paper or plastic labels, inner caps, etc., can also be used.

[0099] [The separation and recovery device of the present invention]

[0100] The separation and recovery apparatus of the present invention comprises: a crushing unit that crushes a resin mixture; a melt ejection unit that melts the crushed material obtained from the crushing unit to form a fluid and ejects it under high pressure; and a hydrothermal reaction treatment unit that continuously performs hydrothermal reaction treatment on the fluid (molten material) ejected from the melt ejection unit.

[0101] Each unit is configured to transport the processed material from one unit to the next unit via a conveying pipe that connects adjacent units. In the separation and recovery apparatus of the present invention, the units located upstream (typically melt-blowing units) to the downstream units are integrally connected by conveying pipes, and the pressure is set to gradually decrease from the upstream units to the downstream units. Therefore, it is possible to operate without the need for a separate unit to pressurize the fluid during transport. It should be noted that, depending on the pressure resistance limit of the units, pressure amplification mechanisms such as high-temperature pumps can be used in the apparatus design. The conveying pipes can include conventional cooling and heating units, or valves that can adjust the flow rate and transport duration.

[0102] The separation and recovery apparatus of the present invention, comprising the aforementioned units in the above order, performs hydrothermal reaction treatment on the fluid (processed material) obtained from the treatment of each unit of the resin mixture in a hydrothermal reaction treatment unit. The hydrolyzable polymer A contained in resin 1 of the resin mixture is hydrolyzed to form hydrolyzable component a. This hydrolyzable component a is dissolved and transferred to water impregnated by a sintered alloy membrane. This allows for the continuous separation and recovery of non-hydrolyzable polymer B contained in resin 2 of the resin mixture, which does not impregnate (pass through) the membrane. Furthermore, the separation and recovery apparatus of the present invention can continuously recover the hydrolyzable component of hydrolyzable polymer A and the non-hydrolyzable polymer regardless of the type or combination of the hydrolyzable and non-hydrolyzable polymers. Therefore, the separation and recovery apparatus of the present invention enables continuous and industrial-scale mixed recycling of resin waste, simultaneously performing chemical recycling of hydrolyzable polymer A and high-purity material recycling of the non-hydrolyzable polymer, which are universally applicable. In this invention, "simultaneously" means that the hydrolyzable polymer (hydrolyzable component) and the non-hydrolyzable polymer B are separated and recovered (able to be mixed and recycled) by performing hydrothermal reaction treatment in the separation and recovery device (a series of treatments carried out in each unit from the crushing unit to the hydrothermal reaction treatment unit, and in units that may be appropriately equipped as described later), and does not mean that both are adopted at the same time.

[0103] In addition to the crushing unit, the melting and spraying unit, and the hydrothermal reaction treatment unit, the separation and recovery device of the present invention may also appropriately include at least one or more of the following units, such as the separation unit, the concentration unit, the hydrolyzed component recovery unit, the polymer B recovery unit, and the circulating water reheating unit, as arbitrary units. When multiple arbitrary units are provided, each arbitrary unit can be arranged simultaneously in any combination.

[0104] The detailed description of the separation and recovery device and the function of each unit of the present invention is as follows. The preferred embodiment of the separation and recovery device of the present invention will be described with reference to the accompanying drawings.

[0105] <Preferred Separation and Recovery Device of the Invention>

[0106] like Figure 1 As shown, the separation and recovery apparatus 1, a preferred embodiment of the present invention, includes a crushing unit 10, a melt spraying unit 20, a separation unit 30, a hydrothermal reaction processing unit 50A, a cooling precipitation subunit 60A, a solid-liquid separation subunit 60B, a circulating water reheating unit 60C, and a polymer B recovery unit 80. In the separation and recovery apparatus 1, the crushing unit 10, the melt spraying unit 20, the separation unit 30, and the hydrothermal reaction processing unit 50A are arranged in series, and the melt spraying unit 20 to the hydrothermal reaction processing unit 50A are connected via a conveying pipe. The cooling precipitation subunit 60A and the polymer B recovery unit 80 are connected in parallel with respect to the hydrothermal reaction processing unit 50A (each branching off from the hydrothermal reaction processing unit 50A). A solid-liquid separation subunit 60B is connected downstream of the cooling precipitation subunit 60A, and the circulating water reheating unit 60C is connected to the inlet 52 of the hydrothermal reaction processing unit 50A. In the separation and recovery device 1, the hydrolysis component recovery unit 60 has an upstream cooling precipitation subunit 60A and a downstream solid-liquid separation subunit 60B.

[0107] In the separation and recovery device 1, each unit after the melt ejection unit 20 is connected by a conveying pipe that maintains the ejection pressure of the melt ejection unit 20 and the molten state of the fluid (molten component) while conveying it. The pressure is set to slowly decrease from the melt ejection unit 20 to the solid-liquid separation subunit 60B and the polymer B recovery unit 80.

[0108] In the separation and recovery device 1, on / off valves are provided on the conveying pipes connecting the cooling precipitation subunit 60A and the solid-liquid separation subunit 60B, the conveying pipes extending from the solid-liquid separation subunit 60B, and the outlets of each unit. Additionally, pumps are provided on the conveying pipes connecting the separation unit 30 and the hydrothermal reaction processing unit 50A, the conveying pipes connecting the cooling precipitation subunit 60A and the circulating water reheating unit 60C, and the inlets of each unit.

[0109] The separation and recovery device 1 includes a solid-liquid separation subunit 60B, but if Figure 1 As shown by the dashed line, multiple units can also be configured to be connected in parallel (in... Figure 1 (3 units in the middle).

[0110] The separation and recovery device 1 is capable of performing... Figure 2The series of processing steps shown can yield the processed product obtained from each unit as shown in the figure. The hydrothermal reaction processing unit 50 includes a diaphragm that is permeable to water and prevents the passage of molten polymer. In the hydrothermal reaction processing unit 50, specifically the partition-contact type hydrothermal reaction processing unit 50A, by dissolving and transferring the hydrolyzed component a, generated from the hydrolysis of the hydrolyzable polymer A contained in the fluid transported from the separation unit 30 (the fluid in which insoluble components are removed or separated in the separation unit 30), into water permeated by the sintered alloy diaphragm, the non-hydrolyzable polymer B contained in the aforementioned fluid can be separated from the fluid (hydrolyzed component a) in a molten state with high purity, and the hydrolyzed component a of the hydrolyzable polymer A and the non-hydrolyzable polymer B can be continuously recovered. In this way, the resin mixture can be continuously mixed and reused.

[0111] The resin mixture used in the separation and recovery device 1 is as described above. For example, it preferably contains one hydrolyzable polymer A and one non-hydrolyzable polymer B, respectively, wherein the melting point MTA of the hydrolyzable polymer A is higher than the melting point MTB of the non-hydrolyzable polymer B.

[0112] The following is a detailed explanation of each unit.

[0113] It should be noted that the crushing unit side, which is the first to be processed in the processing sequence (conveying direction) of the object being processed (resin mixture), is called the upstream side or the front section, and the recycling unit side is called the downstream side or the rear section.

[0114] (Fragmentation Unit)

[0115] The crushing unit 10 is located at the upstream side of the separation and recovery device 1 and is a unit for crushing the resin mixture. The mechanical structure of the crushing unit is not particularly limited as long as it can crush the resin mixture; a unit that performs physical crushing is preferred.

[0116] The crushing unit only needs to be able to crush the resin mixture, preferably to a size that can be applied to the melt ejection unit 20 (e.g., a size that can be rapidly melted). There are no particular limitations on the size and shape of the crushed material obtained by the crushing unit 10.

[0117] Specifically, the crushing unit 10 that can be applied to the separation and recycling apparatus 1 of the present invention can include crushers such as jaw crushers, ball mills, shredders, shears, and grinders. In addition, sometimes the resin mixture softens due to heat generated during the crushing process, making crushing difficult. In this case, cryogenic pulverization using liquid nitrogen or the like can also be used.

[0118] Furthermore, when a resin mixture with a surface treated with plating, coating, etc., is broken up, the plating or coating layer may sometimes peel off during the breaking process. Utilizing this, the absolute amount of insoluble components flowing into the melt ejection unit 20 and the separation unit 30 can be reduced. As a result, in the separation unit 30, when discharging the insoluble components, the amount of fluid (e.g., non-hydrolyzable polymer B) mixed into the insoluble components and used as a whole can be minimized, thereby improving the recycling rate.

[0119] (Melting and ejection unit)

[0120] The melt ejection unit 20 is disposed directly or indirectly (via other processing units, such as belt conveyors) downstream of the aforementioned crushing unit (e.g., the crushed material discharge port of the crushing unit 10). This melt ejection unit 20 is a unit that imparts fluidity to the crushed material by heating and melting it, and then ejects it under high pressure; preferably, it melts and ejects the crushed material. Here, "melting the crushed material" means heating the crushed material conveyed to the melt ejection unit 20, causing the polymer contained in the crushed material to melt and mix, thereby changing the phase to a molten state (fluid state).

[0121] The melt ejection unit 20 heats and melts the broken material, making it flowable before ejecting it. Therefore, unlike conventional methods, it does not require the use of water or other solvents to achieve a flowable state during ejection, resulting in a significant reduction in energy compared to conventional methods. In other words, the melt ejection unit 20 can eject the broken resin mixture itself in a molten state even without mixing with solvents such as water. Conventional methods, for example, in hydrothermal reaction treatment, typically involve mixing the broken material with water to form a slurry, ejecting it using a high-pressure slurry pump, and then heating it externally to achieve the hydrothermal reaction treatment state. However, this method ultimately requires the formation of a slurry, so the limit for the ratio of broken material (solid component) to water is approximately 1:9, leading to a waste of energy during melting due to the excessive amount of water or other solvents used for heating the mixture.

[0122] The ejected material from the molten ejection unit 20 is transported under high pressure to the next unit, in this case, the separation unit 30, while maintaining a molten state (as a fluid).

[0123] There are no particular limitations on the melt ejection unit 20; it can be applied to extruders with single or multiple screws, gear pumps, etc.

[0124] The ejection pressure (transport pressure to the next unit, etc.) of the ejected material (fluid) melted and ejected in the melt ejection unit 20 is preferably a pressure that can ensure the differential pressure between the two sides of the separation membrane 35 in the separation unit 30, for example, a high pressure exceeding 101 kPa (1 atm). It should be noted that if the melt ejection unit 20 cannot eject the fluid at a pressure that can ensure the above-mentioned differential pressure, the pressure can also be increased to a pressure that can ensure the above-mentioned differential pressure by installing a pressurizing device such as a gear pump in the delivery pipe connecting the melt ejection unit and the separation unit.

[0125] The “fluid” prepared by the melt ejection unit 20 refers to a melt formed by simply melting the broken parts of the resin mixture, excluding substances that contain a large amount of solid components as impurities and do not have fluidity even when heated and melted.

[0126] In the melt ejection unit 20, the conditions for melting the broken material cannot be uniquely determined based on the type of hydrolyzable polymer A and non-hydrolyzable polymer B, and can be appropriately set. For example, the heating temperature is not particularly limited and is usually set to a temperature above the highest melting point of the polymer contained in the resin mixture and below the lowest decomposition temperature, with a temperature range generally from 100°C to 350°C. Preferably, the temperature is above the melting point of the polymer with the highest melting point and below the melting point +50°C, more preferably above the melting point +10°C and below the melting point +30°C. Specifically, when the polymer with the highest melting point is PA6, the temperature is preferably 230°C to 280°C, more preferably 240°C to 260°C; when the polymer with the highest melting point is PA6 / 66, the temperature is preferably 200°C to 250°C, more preferably 210°C to 230°C; and when the polymer with the highest melting point is PA66 or PET, the temperature is preferably 250°C to 300°C, more preferably 260°C to 280°C. Furthermore, there are no particular limitations on the heating time (processing time), but extending the heating time increases the likelihood of thermal decomposition of the polymer. Therefore, it is preferable to keep the time as short as possible within the range achievable in the apparatus.

[0127] (Separation Unit)

[0128] The separation and recovery apparatus 1 of the present invention includes a separation unit 30 between the melt ejection unit 20 and the hydrothermal reaction processing unit 50A. The separation unit 30 removes insoluble components such as inclusions from the ejected material (fluid) from the melt ejection unit 20. This separation unit is appropriately applied to the separation and recovery apparatus of the present invention. Without the separation unit, insoluble components remain in the separation and recovery apparatus 1 along with the non-hydrolyzable polymer B to the final outlet. During this period, the concentration of insoluble components relatively increases due to the removal of the hydrolyzable polymer A, resulting in reduced flowability and blockages in the unit / transport pipe, etc. Therefore, it is preferable to remove them as much as possible upstream, which contributes to the stable operation of the apparatus.

[0129] As described above, actual resin waste contains a large amount of insoluble components such as plating, coatings, and labels. These components only become impurities in the recycled material, and therefore it is preferable to remove them before recycling from the resin mixture. Insoluble components are those that do not melt in the melt ejection unit 20 but are mixed in the ejection material in solid form. Examples include paper such as labels, and various inorganic materials that form plating and coatings. In the separation unit, there is no particular limitation on the method for removing insoluble components, and the following methods can be appropriately cited. For example, solid-liquid separation such as heating to a temperature at which all the polymer contained in the resin mixture melts, or filtering the fluid that makes all the polymer flowable, can remove insoluble components. However, if insoluble components accumulate in the separation unit 30, the ejection material loses its fluidity and remains in the separation unit. Therefore, it is preferable to adjust the amount of molten polymer to a level that maintains the fluidity of the ejection material so that it can be transported (separated and processed) in the separation unit. As a separation unit, there are no particular limitations on the application of equipment capable of removing or separating the aforementioned insoluble components. Examples include continuous solid-liquid separators that can use sintered alloy filters with excellent heat and pressure resistance to perform filtration at a large differential pressure. In this case, the "differential pressure" simply refers to the pressure difference across the separation membrane (sintered alloy filter) that removes insoluble components from the ejecta. It can be appropriately set considering factors such as the type or content of components in the ejecta and the viscosity of the ejecta.

[0130] A preferred separation unit 30 applicable to the separation and recovery device 1 is a solid-liquid separator having the following structure. For example... Figure 3As shown, the separation unit 30 has a tubular body 31 with a generally circular cross-section. At one end of the tubular body 31 are: an inlet 32 ​​that allows fluid (ejected material) ejected from the melt ejection unit 20 to flow into the tubular body 31; a first flow path 33 connected to the inlet 32 ​​and extending along the length of the tubular body 31, which uses high pressure to circulate the fluid flowing in from the inlet 32; and an insoluble component outlet 34 extending from the downstream end of the first flow path 33 (connected to the other end of the tubular body 31), which discharges the insoluble components separated from the fluid. That is, the inlet 32 ​​and the insoluble component outlet 34 are respectively connected to the ends of the tubular body 31 (first flow path 33).

[0131] The separation unit 30 further comprises: a tubular separation membrane 35 disposed inside the tubular body 31 along the first flow path 33, surrounding the outer peripheral surface of the first flow path 33, for separating insoluble components mixed in the fluid flowing within the first flow path 33; a second flow path 36, which is divided (distributed) on the outer peripheral side of the separation membrane 35 (the side opposite to the first flow path 33 relative to the separation membrane 35) and extends along the length direction of the tubular body 31, for removing insoluble components through the separation membrane 35 and allowing the separated fluid to flow; and a fluid outlet 37 connected to the second flow path 36 for allowing the fluid from which the insoluble components have been removed to flow out. That is, the tubular body 31 has a sleeve structure, which has a first flow path (inner flow path) 33 whose internal space is divided by the separation membrane 35 inside the separation membrane 35 and a second flow path (outer flow path) 36 divided outside the separation membrane 35.

[0132] The separation unit 30 is a sleeve structure with the first flow path 33 as the inner flow path and the second flow path 36 as the outer flow path. However, in this invention, it can also be a sleeve structure with the first flow path 33 as the outer flow path and the second flow path 36 as the inner flow path. That is, in the separation and recovery device of this invention, the separation membrane of the separation unit can be configured (connected) along the inside or outside of the first flow path. It should be noted that when the first flow path 33 is used as the outer flow path, the inlet, the fluid outlet, and the insoluble component outlet are positioned to perform their respective functions.

[0133] The separation membrane 35 is a membrane that separates molten components, such as polymers, in the fluid flowing in the first flow path 33 through the second flow path 36. For example, porous sintered alloy tubes, ceramic tubes, etc. can be used.

[0134] The separation unit 30 may also have a heating mechanism on the outer periphery of the tubular body 31 for maintaining the molten state of the ejected material. The heating temperature of the tubular body 31 is not particularly limited and can be set to the heating temperature in the molten ejection unit 20. In addition, the separation unit 30 may also be equipped with a mixer (static mixer) or the like that capable of stirring the fluid in the first flow path 33.

[0135] The function of the separation unit 30 described above will be explained.

[0136] While maintaining a molten state, the fluid (ejectories) flowing in from the inlet 32 ​​at high pressure maintains the molten state and ejection pressure in the molten ejection unit 20, and flows towards the insoluble component discharge outlet 34 within the first flow path 33. At this time, the aforementioned ejection pressure acts within the first flow path 33, while the fluid outlet 37 is controlled by a valve located at the outlet 37 to maintain a pressure lower than that of the first flow path. This creates a pressure difference between the first flow path 33 and the second flow path 36. Due to this pressure difference, the molten components constituting the ejectories flow into the second flow path 36 through the separation membrane 35, while the insoluble components, unable to pass through the separation membrane 35, remain in the first flow path 33 and flow towards the insoluble component discharge outlet 34. The molten components flowing into the second flow path 36 are discharged from the fluid outlet 37 and transported to the next unit, in this embodiment, the hydrothermal reaction processing unit 50. Meanwhile, the insoluble components flowing within the first flow path 33 are discharged from the insoluble component discharge outlet 34. Here, the insoluble component typically exists in a solid state within the first flow path 33, making rapid movement difficult. Therefore, it is preferable to leave a portion of the molten component within the first flow path 33 without passing through the separation membrane 35, and to transport the insoluble component along with this molten component and discharge it from the insoluble component outlet 34. To ensure that a portion of the molten component remains, it can be appropriately set, for example, based on the differential pressure between the first flow path 33 and the second flow path 36, the pore size or thickness of the separation membrane 35, and, if valves are installed at the insoluble component outlet 34 and the fluid outlet 37, the valve opening balance. It should be noted that, from the perspective of suppressing a significant decrease in recycling efficiency, the amount of residual molten component is preferably the minimum amount required to transport the insoluble component to the insoluble component outlet 34.

[0137] In this way, the molten components containing polymers A and B in the fluid fed to the separation unit 30 can be separated from the insoluble components, and the molten components with the insoluble components removed can be transported to the next unit. As a result, high-purity hydrolyzed component a and non-hydrolyzed polymer B, free from impurities from the insoluble components, can be separated and recovered with higher recycling efficiency.

[0138] (Hydrothermal reaction processing unit)

[0139] In the separation and recovery device 1, the hydrothermal reaction processing unit 50 is a unit that performs hydrothermal reaction processing on the molten component obtained in the separation unit 30 after separating the fluid ejected from the melt ejection unit 20, i.e., after removing the insoluble components. By supplying the fluid as the molten component to the hydrothermal reaction processing unit 50, the hydrolysis reaction of the hydrolyzable polymer A can be carried out, and then the non-hydrolyzable polymer B can be rapidly separated from the reaction system (hydrolyzable component a), thereby achieving high recycling efficiency.

[0140] The hydrothermal reaction processing unit 50 separates the non-hydrolyzable polymer B contained in the molten component by contacting the hydrolyzable polymer A in the polymer contained in the molten component transported from the separation unit 30 with water under high temperature and high pressure conditions, thereby hydrolyzing the hydrolyzable polymer A and dissolving its hydrolyzable component a, which is then transferred to the water that permeates the diaphragm 55.

[0141] The hydrothermal reaction processing unit 50 can be any unit capable of performing hydrothermal reaction processing on the aforementioned fluid (molten component) under the conditions described later. Appropriate processing equipment, such as an autoclave, a reaction tube, or other closed reaction vessel, can be selected. In this invention, an apparatus capable of continuous hydrothermal reaction processing is preferred. Specifically, a unit equipped with a diaphragm (such as a porous membrane) that is permeable to water and prevents the passage of molten polymer is preferred. The diaphragm can be selected as a suitable medium that is impermeable to high-viscosity resins but easily permeable to water. This allows for separate control of the flow rate of the molten component (polymer) and the flow rate of water, thus preventing the decrease in purity caused by prolonged exposure of the hydrolyzed component a through the diaphragm to high temperatures. Examples of such preferred hydrothermal reaction processing units include diaphragm-contact type hydrothermal reaction processing units (units with a sleeve structure, units with a double-wall structure, etc.) and countercurrent-contact type hydrothermal reaction processing units.

[0142] Since the hydrothermal reaction processing unit 50 hydrolyzes the hydrolyzable polymer, the fluid flowing into the hydrothermal reaction processing unit 50 is a fluid with a high content of hydrolyzable polymer A, obtained from the unit located upstream. For example, when the concentration unit 40 described later is located upstream, the fluid is not mainly composed of non-hydrolyzable polymer B, but rather of hydrolyzable polymer A.

[0143] As one of the preferred embodiments of a hydrothermal reaction processing unit applicable to the separation and recovery device 1, a partition-type hydrothermal reaction processing unit 50A with a sleeve structure can be cited. For example... Figure 4As shown, the unit 50A has a tubular body 51 with a generally circular cross-section. At one end of the tubular body 51 are: an inlet 52, which allows fluid (molten component) ejected from the separation unit 30, i.e., a fluid containing hydrolyzable polymer A (preferably a fluid in a molten state), to flow into the tubular body 51; a first flow path 53, connected to the inlet 52, extending along the length of the tubular body 51 and allowing the fluid flowing in from the inlet 52 to circulate; and a residual stream outlet 54, extending from the downstream end of the first flow path 53 (connected to the other end of the tubular body 51), allowing the residual fluid after the hydrothermal reaction treatment to exit. That is, the inlet 52 and the residual stream outlet 54 are respectively connected to the end of the tubular body 51 (first flow path 53).

[0144] The partition-contact type hydrothermal reaction processing unit 50A further includes: a tubular diaphragm 55 disposed inside the tubular body 51 along the first flow path 53 in a manner surrounding the outer peripheral surface of the first flow path 53, capable of being permeated with water and preventing the passage of molten polymer; a second flow path 56, which is a tubular structure extending along the length direction of the tubular body 51 on the outer peripheral side of the diaphragm 55 (the side opposite to the first flow path 53 relative to the diaphragm 55) and disposed adjacent to the first flow path 53 across the diaphragm 55, allowing water or a water mixture (aqueous phase) containing hydrolyzed component a that has passed through the diaphragm 55 to flow through; a water inlet 57 disposed in the second flow path 56, allowing water to flow into the second flow path; and a water mixture outlet 58 disposed in the second flow path 56, allowing the water mixture containing hydrolyzed component a of hydrolyzed polymer A that flows in from the water inlet 57 and passes through the diaphragm 55 while flowing through the second flow path 56 to flow out from the second flow path 56 (towards its exterior). That is, the tubular body 51 has a sleeve structure, which has a first flow path (inner flow path) 53 with its internal space divided by a diaphragm 55 on the inner side of the diaphragm 55 and a second flow path (outer flow path) 56 on the outer side of the diaphragm 55. The diaphragm 55 separates the hydrolyzed component a from the molten component flowing in the first flow path 53 and transfers it to the second flow path 56. The diaphragm 55 is configured to maintain the hydrothermal reaction processing conditions in the second flow path 56, particularly the pressure. For example, in the case of a porous membrane, the pressure can be appropriately set according to the opening diameter, porosity, etc. The water pressure is set to be lower than the fluid pressure. Specifically, the water pressure is set to be higher than the saturated vapor pressure of water at the temperature of the highest temperature part of the entire device and lower than the lowest pressure when the fluid pressure changes for some reason. Regarding the pressure difference between the fluid and water, since it is necessary to retain the fluid within the diaphragm 55, a preliminary study was conducted using a diaphragm made of the same material to ensure that the fluid does not leak directly into the second flow path 56 through the diaphragm 55. The water pressure can be adjusted, for example, by installing a high-pressure pump for water supply and a back pressure valve for pressure control before and after the second flow path 56. Although there are no particular limitations, it is preferable that the water inlet 57 is located on the downstream side of the tubular body 51 and the water mixture outlet 58 is located on the upstream side of the tubular body 51.

[0145] The partition-contact type hydrothermal reaction processing unit 50A is a sleeve structure with the first flow path 53 as the inner flow path and the second flow path 56 as the outer flow path. However, in this invention, it can also be a sleeve structure with the first flow path 53 as the outer flow path and the second flow path 56 as the inner flow path. That is, in the separation and recovery device of this invention, the diaphragm of the hydrothermal reaction processing unit can be configured (connected) along the inside or outside of the first flow path. It should be noted that when the first flow path 53 is used as the outer flow path, the inlet, the residual stream outlet, the water inlet, and the water mixture outlet are located at positions where they perform their respective functions.

[0146] In the adjacent contact-type hydrothermal reaction treatment unit 50A, the state of the water supplied from the water inlet 57 to the second flow path 56 is not particularly limited; it can be water that does not meet the hydrothermal reaction treatment conditions, but it is preferred to use water that does meet the hydrothermal reaction treatment conditions. In this case, it is preferable to install a known pressurized heating device upstream of the water inlet 57. In the separation and recovery device 1, such as Figure 1 As shown, a circulating water reheating unit 60C is provided. It should be noted that when water that does not meet the hydrothermal reaction treatment conditions is supplied to the second flow path 56, the water flowing in the second flow path 56 can be heated to meet the hydrothermal reaction treatment conditions by means of a heating mechanism (described later) provided on the outer periphery of the tubular body 51. At this time, it is necessary to prevent the fluid in the first flow path 53 from cooling / freezing due to the temperature of the incoming water.

[0147] The diaphragm 55 is a membrane that allows water flowing in the second flow path 56 to pass through the first flow path 53 and prevents molten components from passing through due to the high viscosity of the fluid. For example, porous sintered alloy tubes, ceramic tubes, etc. can be used.

[0148] The partition-contact type hydrothermal reaction processing unit 50A may have a heating mechanism on the outer periphery of the tubular body 51 for maintaining the hydrothermal reaction processing temperature. The heating temperature of the tubular body 51 is not particularly limited and is set to the hydrothermal reaction processing temperature described later.

[0149] In the separation and recovery device 1, although not shown, the fluid flowing through each unit is gradually transported from the melt ejection unit to the downstream unit while the pressure is gradually reduced, for example, by installing a pressure-maintaining valve at the downstream outlet. On the other hand, the water flowing into the partition-contact type hydrothermal reaction processing unit 50A can be supplied with a pump and a back pressure valve (not shown) separately from the fluid supply line to ensure pressure. Furthermore, a heater (not shown) for heating the water can be installed outside the partition-contact type hydrothermal reaction processing unit 50A to adjust the temperature. In this way, the hydrothermal reaction processing conditions (especially pressure and temperature) described later in the partition-contact type hydrothermal reaction processing unit 50A can be achieved.

[0150] The function of the aforementioned partition-contact type hydrothermal reaction treatment unit 50A will be explained.

[0151] The fluid flowing in from inlet 52 maintains a molten state while flowing through the first flow path 53 toward the residual stream outlet 54. At this time, the first flow path 53 is under hydrothermal reaction processing conditions described later, with the fluid in contact with water permeating the diaphragm 55, thus placing it in a hydrothermal reaction processing environment. The hydrolyzable polymer A contained in the fluid undergoes a hydrolysis reaction to produce its hydrolyzed component a, which dissolves and transfers to the water permeating the diaphragm 55 (aqueous phase). Furthermore, due to the concentration gradient of the hydrolyzed component a, the hydrolyzed component a dissolved in the water permeating the diaphragm 55 transfers to the water flowing through the second flow path 56. On the other hand, the non-hydrolyzable polymer B contained in the fluid does not undergo a hydrolysis reaction and maintains a high viscosity, therefore it cannot pass through the diaphragm 55, remains in a molten state within the first flow path 53, and flows toward the residual stream outlet 54.

[0152] In this way, the hydrolyzed component a in the molten composition delivered to the adjacent contact-type hydrothermal reaction treatment unit 50A mixes with the water flowing in the second flow path 56 and is discharged from the water mixture outlet 58, while the non-hydrolyzed polymer B is discharged from the residual stream outlet 54. Thus, the hydrolyzed polymer A (its hydrolyzed component a) and the non-hydrolyzed polymer B can be separated and recovered (mixed and recycled).

[0153] As another preferred embodiment of the hydrothermal reaction processing unit that can be applied to the separation and recovery apparatus of the present invention, which includes the separation and recovery device 1, a partitioned contact type hydrothermal reaction processing unit 50B with a double-wall structure can be cited.

[0154] like Figure 5 As shown, the unit 50B has a tubular body 51 with a generally circular cross-section. At one end of the tubular body 51 are: an inlet 52, which allows fluid (molten component) ejected from the separation unit 30, i.e., a fluid containing the hydrolyzable polymer A (preferably a fluid in a molten state), to flow into the tubular body 51; a first flow path 53, connected to the inlet 52, extending along the length of the tubular body 51 and allowing the fluid flowing in from the inlet 52 to circulate; and a residual stream outlet 54, extending from the downstream end of the first flow path 53 (connected to the other end of the tubular body 51), allowing the residual fluid after the hydrothermal reaction treatment to exit. That is, the inlet 52 and the residual stream outlet 54 are respectively connected to the end of the tubular body 51 (the first flow path 53).

[0155] The diaphragm-contact type hydrothermal reaction processing unit 50B further includes: a tubular diaphragm 55 disposed inside the tubular body 51 in contact with the inner circumferential surface of the tubular body 51, surrounding the outer circumferential surface of the first flow path 53; a water inlet 57 disposed in contact with the diaphragm 55 to allow water to flow into the diaphragm; and a water mixture outlet 58 disposed in contact with the diaphragm 55 to allow a water mixture containing hydrolyzed component a of the hydrolyzable polymer A that has passed through the diaphragm 55 to flow out of the diaphragm 55 (towards its exterior). The diaphragm 55 is a porous membrane that allows water to permeate its interior while preventing the passage of molten polymer, allowing the water mixture (aqueous phase) containing hydrolyzed component a that has penetrated the diaphragm 55 to circulate within it. The water flowing within the diaphragm 55 forms the hydrothermal reaction processing conditions, which, like those in the diaphragm-contact type hydrothermal reaction processing unit 50A, are maintained by externally located pumps, back pressure valves, heaters, etc. Although there are no particular restrictions, it is preferable that the water inlet 57 is located on the downstream side of the tubular body 51 and the water mixture outlet 58 is located on the upstream side of the tubular body 51.

[0156] Apart from the above structure, it is the same as the partition contact type hydrothermal reaction treatment unit 50A.

[0157] Regarding the function of the aforementioned partition-contact type hydrothermal reaction treatment unit 50B, it is basically the same as that of the partition-contact type hydrothermal reaction treatment unit 50A, except that the water (water mixture) dissolving the hydrolyzed components flows within the diaphragm 55 instead of in the second flow path.

[0158] Furthermore, as another preferred embodiment of the hydrothermal reaction processing unit applicable to the separation and recovery apparatus of the present invention, which includes the separation and recovery device 1, a countercurrent contact type hydrothermal reaction processing unit 50C with the following configuration can be cited.

[0159] like Figure 6 As shown, the unit 50C has a tubular body 51 with a generally circular cross-section, which is vertically arranged. The upper end of the tubular body 51 has: an inlet 52 for allowing fluid (molten component) ejected from the separation unit 30, i.e., a fluid containing hydrolyzable polymer A (preferably a fluid in a molten state), to flow into the tubular body 51; a water mixture outlet 58 located at the upper part of the tubular body 51; a residue outlet 54 located at the lower part of the tubular body 51; and a water inlet 57 located at the lower end of the tubular body 51. The inlet 52, residue outlet 54, water inlet 57, and water mixture outlet 58 are connected to the internal space of the tubular body 51. The internal space of the tubular body 51 is filled with a filler 55A, on which fluid flows down and water flows, thereby ensuring a large contact area.

[0160] Unit 50C performs a hydrothermal reaction while allowing fluid ejected from separation unit 30 to flow in through inlet 52 and water to flow in through water inlet 57. This causes the hydrolyzed component a to permeate into filler 55A and separate from the non-hydrolyzed polymer B. Thus, the hydrolyzed polymer A (its hydrolyzed component a) and the non-hydrolyzed polymer B can be separated and recovered (mixed and recycled).

[0161] The fluid after hydrothermal reaction treatment is discharged from the residue outlet 54, and the water mixture is discharged from the water mixture outlet 58. Regarding the operation method of unit 50C, it can be applied to situations where the specific gravity of the fluid is greater than that of water under hydrothermal treatment conditions. When the specific gravity of water is greater than that of the fluid, the same effect can be obtained by reversing the configuration of their respective inlets, outlets, etc.

[0162] The filler 55A used in unit 50C is formed of the same material as the diaphragm 55, which allows water to permeate through the interior but not the molten components.

[0163] Appropriately set the hydrothermal reaction processing conditions in the hydrothermal reaction processing unit 50.

[0164] Hydrothermal reaction processing can continue (continuously) while fluid is being transported (continuous hydrothermal reaction processing). For example, in the partition contact type hydrothermal reaction processing unit 50A, the process can continue while fluid is being transported to the first flow path 53.

[0165] In this invention, the hydrothermal reaction processing unit can be a single unit, or it can be two or more units. Two or more hydrothermal reaction processing units can be units that perform hydrothermal reaction processing under the same conditions, or units that perform hydrothermal reaction processing under different but identical conditions. Furthermore, multiple hydrothermal processing units can be connected in series to perform continuous hydrothermal reaction processing, or they can be connected in parallel to perform hydrothermal reaction processing simultaneously.

[0166] In particular, when the fluid ejected from the separation unit 30 and supplied to the hydrothermal reaction processing unit 50 contains multiple polymers (hydrolytic polymer A), by connecting the same number of hydrothermal reaction processing units in series as the number of types of polymer A, hydrothermal reaction processing in multiple stages from low temperature to high temperature can be carried out, and hydrolytic component a can be recovered from multiple polymers A at the same time.

[0167] (Hydrolysis component recovery unit)

[0168] The separation and recovery device 1 includes a hydrolysis component recovery unit 60 downstream of the hydrothermal reaction processing unit 50, which recovers hydrolyzed component a of the hydrolyzable polymer A from the water mixture. This hydrolysis component recovery unit 60 is suitable for components whose solubility changes significantly with temperature, allowing the hydrolyzed components to be separated with minimal cooling and recovered through solid-liquid separation. Furthermore, as... Figure 1 As shown, if a hydrothermal treatment unit and circulation path are constructed, the water itself can also be reused, which is preferable from this perspective. In the preferred method of water reuse, both water consumption and the energy required for reheating can be reduced.

[0169] The hydrolysis component recovery unit includes: a cooling precipitation subunit 60A for cooling a water mixture to hydrolyze it into precipitated components; and a solid-liquid separation subunit 60B for separating the precipitated hydrolyzed components from the water. The cooling precipitation subunit 60A can be any commonly used cooling precipitation subunit without particular limitations, as long as it can cool the water mixture. Examples include units that have a flow path or container for accommodating the water mixture and air-cool the flow path or container, or units that also have a cooler (e.g., a water-cooled jacket) around the flow path or container. Figure 1 The diagram shows a unit having a tubular flow path and a cooler surrounding the flow path.

[0170] Furthermore, the solid-liquid separation subunit can use commonly used units without particular restrictions, such as filters. In the hydrolysis component recovery unit, the cooling precipitation subunit and the solid-liquid separation subunit can be integrated or configured separately.

[0171] like Figure 1 and Figure 7A As shown, the hydrolysis component recovery unit 60 in the separation and recovery device 1 includes a tubular cooling precipitation subunit 60A and a tubular solid-liquid separation subunit 60B connected to the downstream side of the cooling precipitation subunit 60A.

[0172] The cooling precipitation subunit 60A includes: an inlet 62 connected to a delivery pipe 61a extending from the water mixture outlet 58 of the hydrothermal reaction processing unit 50, for which a water mixture containing hydrolyzed component a flows in; a flow path 63 (also called flow path A) connected to the inlet 62, allowing the water mixture flowing in from the inlet 62 to circulate; and an outlet 64 connected to the flow path 63, allowing the (precipitated) hydrolyzed component a to flow out along with water. Furthermore, it includes a cooling jacket 65 surrounding the outer periphery of the flow path 63, having: a cooling water inlet 65a connected to the outlet 64 side of the cooling jacket 65 and allowing cooling water to flow into the cooling jacket 65; a cooling water outlet 65b connected to the inlet 62 side of the cooling jacket 65 and discharging cooling water from the cooling jacket 65; and a cooling water delivery section (cooling water storage tank and pump for delivering cooling water, etc., not shown). Thus, the water mixture flowing in the flow path 63 can be cooled, causing the hydrolyzed component to precipitate.

[0173] It should be noted that the conveying pipe 61a may also have a heating mechanism on its outer circumference to maintain the temperature of the water mixture.

[0174] The solid-liquid separation subunit 60B is composed of a separator connected to the cooling precipitation subunit 60A (specifically, the outlet 64). Specifically, it includes: a tubular body 66; a connection port 67 located at the upstream end of the body 66 and connected to the outlet 64; and an outlet 68 located at the downstream end of the body 66 for the outflow of water after solid-liquid separation. Furthermore, inside the body 66 are: a disc-shaped filter membrane 69; a conveying pipe 61c extending from the outlet 68 and connected to the reheating subunit 60C (described later); and a conveying pipe 61b connecting the reheating subunit 60C to the inlet 57 of the hydrothermal reaction processing unit 50. Figure 1 and Figure 7A As shown, the solid-liquid separation subunit 60B, together with the partitioned-wall contact type hydrothermal reaction processing unit 50A and the cooling precipitation subunit 60A located on the upstream side, and the reheating subunit 60C located on the downstream side, are connected by conveying pipes 61a, 61c and 61b to form a water circulation path. This allows for the recycling of water separated from hydrolyzed component a.

[0175] The specific gravity of the circulating water heated by the reheating subunit 60°C decreases, thus generating upward (in) Figure 1 and Figure 7A The flow is located at the inlet 57 side of the partition-contact type hydrothermal reaction treatment unit 50A. Additionally, the circulating water cooled by the cooling precipitation subunit 60A flows downwards (towards the inlet 57 side). Figure 1 and Figure 7A The flow is at the inlet 67 side of the solid-liquid separation subunit 60B. As a result, water can be circulated in the above-mentioned circulation path as a whole without the need for pumps or other mechanisms.

[0176] In the above-mentioned circulation path, in order to suppress the water consumed due to hydrolysis, the density changes caused by cooling and heating, and the pressure changes in the circulation path caused thereby, it is preferable to provide a constant pressure pump 70 for adding water and a back pressure valve 71 for discharging excess water.

[0177] The outer edge of the filter membrane 69 contacts the inner surface of the main body 66, dividing the internal space of the main body 66 in two along its axial direction. A discharge section 66a for discharging the precipitated hydrolyzed components is provided in the upstream internal space, while a backwash water inlet section 66b for introducing water for backwashing the filter membrane 69 is connected to the downstream internal space. The filter membrane 69 can be made of metal, a porous membrane made of heat-resistant resin, a sintered alloy filter, or the like. In the solid-liquid separation subunit 60B, the hydrolyzed components precipitated in the cooling precipitation subunit 60A and water (water mixture) flow into the main body 66 from the connection port 67. The water passes through the filter membrane 69, while the hydrolyzed components a accumulate on the filter membrane 69. In this way, the hydrolyzed components a can be separated (filtered) from the water and taken out and recovered from section 66a together with the backwash water introduced from the backwash water inlet section 66b.

[0178] In this invention, the hydrolysis component recovery unit 60 can be a single unit, or two or more units can be provided. When there are two or more hydrolysis component recovery units 60, the multiple units can be connected in series or in parallel.

[0179] In addition, when the separation and recovery device 1 has multiple hydrothermal reaction processing units 50, it is preferable to simultaneously install one hydrolysis component recovery unit 60 in each hydrothermal reaction processing unit 50.

[0180] The hydrolysis component recovery unit 60 preferably has at least one cooling precipitation subunit 60A and one solid-liquid separation subunit 60B, but may also have at least one of two or more cooling precipitation subunits 60A and solid-liquid separation subunits 60B. Figure 1 and Figure 7A As shown by the dashed line, the separation and recovery device 1 has three solid-liquid separation sub-units 60B connected in parallel with one cooling precipitation sub-unit 60A. All three units are assembled into the circulation path, and by using them alternately, a state in which solid-liquid separation can be continuously performed is achieved.

[0181] Furthermore, in situations where it is desired to further increase the flow rate of circulating water utilizing the aforementioned density difference, such as... Figure 7B As shown, a circulation pump 72 can also be installed in the middle of the conveying path 61c to force water to circulate.

[0182] (Circulating water reheating unit)

[0183] The separation and recovery device 1 includes a circulating water reheating unit 60C, which is assembled in the aforementioned circulation path to heat the circulating water supplied to the hydrothermal reaction processing unit 50A. This circulating water reheating unit 60C only needs to be capable of heating water; conventional circulating water reheating units can be used without particular limitations. For example, it can have the same configuration as the aforementioned cooling and precipitation subunit 60A, except that it includes a heater instead of a cooler. Here, the circulating water reheating unit 60C is described as a separate unit, but... Figure 1 As shown, in the separation and recovery device 1, the circulating water reheating unit 60C constitutes the hydrolysis component recovery unit (the same in separation and recovery devices 2 to 4).

[0184] (Polymer B Recycling Unit)

[0185] The separation and recovery device 1 has a polymer B recovery unit 80 configured in parallel with the hydrolysis component recovery unit 60 at the downstream end of the hydrothermal reaction processing unit 50 to recover the non-hydrolyzable polymer B separated from the aqueous phase.

[0186] The fluid extracted from water via the hydrothermal reaction processing unit 50A, where hydrolyzable polymer A is extracted as hydrolyzable component a, is a fluid whose main component is non-hydrolyzable polymer B. This fluid solidifies upon cooling; therefore, it is preferable to discharge it directly under reduced pressure at a high temperature. Specifically, a structure is employed that provides back pressure via a back pressure valve, needle valve, or similar means corresponding to the high temperature. Furthermore, by passing it through a sintered metal pipe or similar means open to the atmosphere, it is possible to evaporate and remove any small amounts of water and unextracted decomposition products a that may be mixed in.

[0187] like Figure 8 As shown, the polymer B recovery unit 80 includes: a tubular body 81 forming both ends of the tubular polymer B recovery unit 80; a residual stream inlet 82 disposed on the upstream side of the tubular body 81 for the inflow of residue (fluid containing non-hydrolyzable polymer B) obtained from the hydrothermal reaction treatment unit 50A; a flow path P connected to the residual stream inlet 82 for the flow of the residual stream flowing in from the residual stream inlet 82; a removal membrane 84 disposed along the flow path P for removing residual water and hydrolyzable component a from the residue; and an outlet 83 connected to the downstream side of the tubular body 81 (downstream of the removal membrane 84 in the flow path P) for the outflow of non-hydrolyzable polymer B from which residual water and hydrolyzable component a have been removed. The removal membrane 84 is a tubular tube formed of sintered metal that surrounds its outer periphery along the flow path P.

[0188] The polymer B recovery unit 80 can recover hydrolyzable polymer A and thus remove hydrolyzable component a, resulting in high-purity non-hydrolyzable polymer B.

[0189] As described above, the separation and recycling apparatus 1 having the above configuration can use resin waste and other resin mixtures as raw materials, the hydrolyzable polymer A constituting it as its raw material compound, i.e., hydrolyzable component a, and the non-hydrolyzable polymer B as a high-purity polymer that suppresses the mixing of the hydrolyzable polymer and its hydrolyzable component, and can recover them separately and continuously.

[0190] The separation and recovery device 1 can install the separation unit 30 between the hydrothermal reaction treatment unit 50A and the polymer B recovery unit 80, thereby also being able to remove insoluble components remaining in the non-hydrolyzable polymer B to a high degree.

[0191] <Another preferred separation and recovery device of the present invention>

[0192] like Figure 9 As shown, the separation and recovery apparatus 2, as another preferred embodiment of the present invention, includes a crushing unit 10, a melt ejection unit 20, a separation unit 30, a concentration unit 40, a hydrothermal reaction processing unit 50A, a hydrolysis component recovery unit 60, and a polymer B recovery unit 80. The concentration unit 40 is connected to the hydrothermal reaction processing unit 50A via a conveying pipe that maintains the molten state while conveying the fluid flowing out of the concentration unit 30. The separation and recovery apparatus 2 has the same configuration as the separation and recovery apparatus 1, except that the concentration unit 40 is located in the section before the hydrothermal reaction processing unit 50A and in the section after the separation unit 30.

[0193] The separation and recovery device 2 is capable of performing... Figure 10 The series of processing steps shown can yield the processed products obtained from each unit as shown in the figure. Non-hydrolyzable polymer B can be separated and recovered in the concentration unit 40, and further in the polymer B recovery unit 80, while the hydrolyzed component a of hydrolyzable polymer A can be recovered in the hydrolyzed component recovery unit 60. Thus, the hydrolyzed component a of hydrolyzable polymer A and non-hydrolyzable polymer B can be continuously recovered, allowing for continuous mixing and recycling.

[0194] The resin mixture used in the separation and recovery device 2 is as described above. For example, it preferably contains one hydrolyzable polymer A and one non-hydrolyzable polymer B, respectively, with the melting point MTA of the hydrolyzable polymer A being higher than the melting point MTB of the non-hydrolyzable polymer B.

[0195] The units in the separation and recovery unit 2, except for the concentration unit, are the same as those in the separation and recovery unit 1, so their descriptions are omitted.

[0196] (Concentrated Unit)

[0197] A concentration unit 40 is disposed between a separation unit 30 and a hydrothermal reaction processing unit 50A to separate non-hydrolyzable polymer B and increase the content of hydrolyzable polymer A in the fluid supplied to the hydrothermal reaction processing unit 50A. This concentration unit 40 cools the fluid (ejectories) from which insoluble components have been removed in the separation unit 30, causing the high-melting-point component (preferably hydrolyzable polymer A) to solidify preferentially. By performing solid-liquid separation, such as filtration, the high-melting-point component and the low-melting-point component (preferably non-hydrolyzable polymer B) can be separated based on the difference in melting points of the polymers, thereby increasing the concentration of the high-melting-point component (concentrating the high-melting-point component).

[0198] The cooling temperature cannot be uniquely determined based on the type of polymer, but can be set between the melting point MTA of hydrolyzable polymer A and the melting point MTB of non-hydrolyzable polymer B.

[0199] The separation and recovery apparatus 2 includes multiple concentration units 40. By adjusting the cooling temperature in each concentration unit according to the melting point of each polymer, different non-hydrolyzable polymers can be separated and recovered in the concentration units. Therefore, when the resin mixture contains multiple non-hydrolyzable polymers B, by setting a number of concentration units equal to the number of types of polymer B, and setting the cooling temperature of each unit to adjust the solidification or melting temperature of each polymer with reference to the melting points of polymer B and hydrolyzable polymer A, different types of non-hydrolyzable polymer B can be recovered for each unit. The configuration of having multiple concentration units 40 will be specifically described in another preferred embodiment of the separation and recovery apparatus of the present invention.

[0200] As a concentration unit 40 suitable for separation and recovery device 2, such as Figure 9 and Figure 11 As shown, it includes: a cooling subunit 40A, which cools a portion of the polymer by cooling a fluid supplied from a unit (e.g., a melt ejection unit, a separation unit) disposed on the upstream side, thereby causing a portion of the polymer to precipitate and solidify; and a removal subunit 40B, which is connected to the cooling subunit 40A, and removes the precipitated and solidified polymer.

[0201] The cooling subunit 40A cools the incoming fluid, causing the polymer with a high melting point to precipitate and solidify, forming a fluid containing the precipitated and solidified polymer as an insoluble substance. The cooling subunit 40A can have any structure as long as it can achieve the above function; the aforementioned cooling precipitation subunit 60A is used in the separation and recovery device 2.

[0202] The removal subunit 40B removes the solidified polymer precipitated from the fluid transported by the cooling subunit 40A as an impurity, and then transports the fluid, from which the solidified polymer has been removed, to the next unit. The removal subunit 40B can have any structure as long as it can perform the above functions; the separation unit 30 described above is used in the separation and recovery device 2. Specifically, as... Figure 9 and Figure 11 As shown, the subunit 40B has a tubular body 41 with a generally circular cross-section. At one end of the tubular body 41 are: an inlet 42 that allows fluid supplied from the cooling subunit 40A to flow into the tubular body 41; a first flow path 43 connected to the inlet 42 and extending along the length of the tubular body 41 to allow fluid flowing in from the inlet 42 to circulate; and an outlet 44 extending from the downstream end of the first flow path 43 (connected to the other end of the tubular body 41) to discharge the polymer that has separated from the fluid and solidified.

[0203] In addition to subunit 40B, it also includes: a tubular separation membrane 45 disposed inside the tubular body 41 along a first flow path 43, which separates the precipitated and solidified polymer mixed in the fluid flowing within the first flow path 43 from the fluid; a second flow path 46, which is divided (distributed) on the outer periphery of the separation membrane 45 (the side opposite to the first flow path 43 relative to the separation membrane 45) and extends along the length of the tubular body 41, through which insoluble components are removed and the separated fluid flows; and a fluid outlet 47 connected to the second flow path 46 for the fluid from which the precipitated and solidified polymer has been removed to flow out. That is, the tubular body 41 has a sleeve structure, which has a first flow path (inner flow path) 43 whose internal space is divided by the separation membrane 45 inside the separation membrane 45 and a second flow path (outer flow path) 46 divided outside the separation membrane 45.

[0204] The subunit 40B can also be a sleeve structure with the first flow path 43 as the outer flow path and the second flow path 46 as the inner flow path, just like the separation unit 30.

[0205] In this invention, the concentration unit can be as follows: Figure 9 The unit shown is a single unit; alternatively, two or more units may be provided depending on the type of polymer contained in the fluid supplied to the concentration unit. Two or more concentration units may be connected in series or in parallel.

[0206] The series of processes in the separation and recovery device 2 are described.

[0207] In the separation and recovery device 2, the resin mixture is sequentially applied to the crushing unit 10, the melt ejection unit 20, and the separation unit 30, similar to that in the separation and recovery device 1. Thus, by conveying the fluid (molten component) flowing out of the fluid outlet 37 of the separation unit 30 to the cooling sub-unit 40A of the concentration unit 40 for cooling, the polymer, which is the high-melting-point component, can be discharged as a solid from the discharge outlet 44 and recovered. On the other hand, the polymer, which is the low-melting-point component, is transferred and flows through the separation membrane 45 in a molten state to the second flow path and flows out from the fluid outlet 47. The low-melting-point component flowing out of this fluid outlet 47 is supplied to the next unit, the hydrothermal reaction processing unit 50A, for hydrothermal reaction processing. It should be noted that the fluid conveyed to the cooling sub-unit 40A and the removal sub-unit 40B maintains fluidity while containing the precipitated and solidified polymer in a dispersed state. Subsequent processing is the same as in the separation and recovery device 1.

[0208] The separation and recovery device 2 can use resin waste and other resin mixtures as raw materials, the hydrolyzable polymer A constituting it as its raw material compound, namely hydrolyzable component a, and the non-hydrolyzable polymer B as a high-purity polymer that has suppressed the mixing of the hydrolyzable polymer and its hydrolyzable component, and recover them separately and continuously.

[0209] In particular, most of the non-hydrolyzable polymer B is separated and recovered from the hydrolyzable polymer A without undergoing hydrothermal reaction treatment in the concentration unit 40. Therefore, polymer B can avoid the thermal process caused by hydrothermal reaction treatment, and the degradation of polymer B's properties can be further suppressed. In addition, the amount of polymer supplied to the hydrothermal reaction treatment unit can be reduced, which also reduces the load and energy of the hydrothermal reaction treatment unit. Furthermore, polymer B can also be recovered in the hydrothermal reaction treatment unit 50A, and material recycling can be performed according to its properties.

[0210] <Another preferred separation and recovery device of the present invention>

[0211] like Figure 12 As shown, in another preferred embodiment of the present invention, the separation and recovery device 3 connects two hydrothermal reaction processing units 50A in series via a heater 5. Each hydrothermal reaction processing unit 50A is connected to a hydrolysis component recovery unit 60 (a cooling precipitation subunit 60A, a solid-liquid separation subunit 60B, and a circulating water reheating unit 60C), which is otherwise identical to the separation and recovery device 2. Since the units in the separation and recovery device 3 are the same as those in the separation and recovery device 2, their description is omitted.

[0212] Heater 5 is not particularly limited as long as it can reheat the fluid flowing out of the hydrothermal treatment unit 50A located on the upstream side; any suitable heater can be used. In the separation and recovery device 3, the same device as the circulating water reheating unit 60C is used.

[0213] The separation and recovery device 3 is capable of performing... Figure 13 The series of processing steps shown can yield the processed products obtained from each unit as shown in the figure. Non-hydrolyzable polymer B can be separated and recovered in the concentration unit 40, and hydrolyzable component a of hydrolyzable polymer A can be recovered in each hydrolyzable component recovery unit 60. Thus, hydrolyzable component a of hydrolyzable polymer A and non-hydrolyzable polymer B can be continuously recovered, allowing for continuous mixing and recycling.

[0214] The resin mixture used in the separation and recovery device 3, as described above, preferably contains, for example, two hydrolyzable polymers A (e.g., PET and nylon) and one non-hydrolyzable polymer B. The melting point of the hydrolyzable polymer A is higher than that of the non-hydrolyzable polymer B. Furthermore, the two hydrolyzable polymers A have different melting points (TMA1). <TMA2)。

[0215] The separation and recovery device 3 includes two hydrothermal reaction processing units 50A, capable of performing the same mixing and recycling as the separation and recovery device 2. Furthermore, by adjusting the hydrothermal temperature of each hydrothermal reaction processing unit 50A, a specified hydrolyzable polymer A can undergo a hydrolysis reaction in each unit. For example, the temperature of the hydrothermal processing unit 50A located upstream can be set above and below the temperature at which the hydrolyzable polymer A with a melting point of TMA1 undergoes a hydrolysis reaction, but not at the temperature at which the hydrolyzable polymer A with a melting point of TMA2 undergoes a hydrolysis reaction. On the other hand, the temperature of the hydrothermal processing unit 50A located downstream can be set above the temperature at which the hydrolyzable polymer A with a melting point of TMA2 undergoes a hydrolysis reaction. Therefore, through the hydrolysis component recovery unit 60 connected to each hydrothermal reaction processing unit 50A, the hydrolyzed components a of the hydrolyzable polymers A1 and A2 can be chemically recycled separately.

[0216] The series of processes in the separation and recovery device 3 are described.

[0217] In the separation and recovery unit 3, similarly to the separation and recovery unit 2, the high-melting-point component (hydrolyzable polymer A) flowing out of the insoluble component discharge port 34 of the concentration unit 40 is supplied to the first hydrothermal reaction processing unit 50A. The water mixture (containing hydrolyzable component a1 of hydrolyzable polymer A1) flowing out of the water mixture discharge port 58 of the hydrothermal reaction processing unit 50A is supplied to the hydrolyzable component recovery unit 60, whereby the hydrolyzable component a1 can be recovered. On the other hand, the fluid flowing out of the residual stream discharge port 54 of the hydrothermal reaction processing unit 50A is reheated by a heater and supplied to the second hydrothermal reaction processing unit 50A for hydrothermal reaction processing. The water mixture obtained from the second hydrothermal reaction processing unit 50A (containing hydrolyzable component a2 of hydrolyzable polymer A2) is supplied to the hydrolyzable component recovery unit 60, whereby the hydrolyzable component a2 can be recovered. Finally, the fluid flowing out of the residual stream discharge port 54 of the second hydrothermal reaction processing unit is supplied to the polymer B recovery unit 80, whereby the non-hydrolyzable polymer B can be recovered. On the other hand, the low-melting-point component (non-hydrolyzable polymer B) flowing out from the fluid outlet 37 of the concentration unit 40 is separately recovered for material recycling. In this method, by processing a fluid containing multiple hydrolyzable polymers together, multiple decomposition products a can be continuously obtained.

[0218] <Another preferred separation and recovery device of the present invention>

[0219] like Figure 14 As shown, in another preferred embodiment of the present invention, the separation and recovery apparatus 4 comprises two concentration units 40 connected in series, and includes a hydrothermal reaction processing unit 50A connected to the fluid outlet 37 of the downstream concentration unit 40, and a hydrothermal reaction processing unit 50A connected to the insoluble component outlet 34 of the downstream concentration unit 40. Furthermore, each hydrothermal reaction processing unit 50A is connected to a hydrolysis component recovery unit 60 (a cooling precipitation subunit 60A, a solid-liquid separation subunit 60B, and a circulating water reheating unit 60C). Additionally, the hydrothermal reaction processing unit 50A connected to the insoluble component outlet 34 of the downstream concentration unit 40 has a polymer B recovery unit 80 connected to its residual stream outlet 54. This configuration is otherwise identical to that of the separation and recovery apparatus 2. Since the units included in the separation and recovery apparatus 4 are the same as those in the separation and recovery apparatus 2, descriptions are omitted.

[0220] The resin mixture used in the separation and recovery device 4, as described above, preferably contains two hydrolyzable polymers A (e.g., PET and nylon) and one non-hydrolyzable polymer B. The melting point of the hydrolyzable polymer A is higher than that of the non-hydrolyzable polymer B. Furthermore, the two hydrolyzable polymers A have different melting points (TMA1). <TMA2)。

[0221] The separation and recovery device 4 is capable of performing... Figure 15 The series of processing steps shown can obtain the processed product obtained by each unit as shown in the figure. It is possible to separate the non-hydrolyzable polymer B while a small amount of hydrolyzable polymer A is mixed in the upstream concentration unit 40, and to separate and recover the non-hydrolyzable polymer B from the small amount of mixed hydrolyzable polymer A in the downstream concentration unit 40. Here, the cooling temperature in the upstream concentration unit 40 is set to a temperature higher than the melting point TMA2 of the hydrolyzable polymer A, and the cooling temperature in the downstream concentration unit 40 is set to a temperature higher than the melting point MTB of the non-hydrolyzable polymer and lower than the melting point TMA1 of the hydrolyzable polymer A. Furthermore, the hydrothermal reaction processing unit 50 connected to the fluid outlet 37 can set the hydrothermal reaction temperature to a temperature higher than the temperature at which the hydrolyzable polymer A with a melting point TMA2 can undergo a hydrolysis reaction. On the other hand, the hydrothermal reaction processing unit 50 connected to the insoluble component discharge port 34 can set the hydrothermal reaction temperature to a temperature above and below that which allows the hydrolyzable polymer A with a melting point of TMA1 to undergo a hydrolysis reaction, and does not allow the hydrolyzable polymer A with a melting point of TMA2 to undergo a hydrolysis reaction.

[0222] Next, the hydrolysis component recovery unit 60, connected to each hydrothermal reaction processing unit 50, can separate and recover the hydrolysis component a from a specific polymer A. In this way, the hydrolysis component a of the hydrolytic polymer A and the non-hydrolytic polymer B can be continuously recovered, and continuous mixing and recycling can be carried out.

[0223] As described above, the separation and recovery device 4 includes two concentration units 40 and two hydrothermal reaction processing units 50A, and is capable of performing the same mixing and recycling as the separation and recovery device 2. Furthermore, by adjusting the hydrothermal temperature of each hydrothermal reaction processing unit 50A, the specified hydrolyzable polymer B can be hydrolyzed in each unit 50A in the same manner as the separation and recovery device 3, and the hydrolyzed components a of each hydrolyzable polymer B can be chemically recycled separately.

[0224] The series of processes in the separation and recovery device 4 are described.

[0225] In the separation and recovery device 4, similarly to the separation and recovery device 2, after recovering the low-melting-point component from the fluid outlet 37 of the first-stage concentration unit 40, the fluid containing multiple high-melting-point components (hydrolyzable polymer A) flowing out from the insoluble component outlet 34 is further separated by the second concentration unit. Thus, the low-melting-point hydrolyzable polymer A is obtained from the fluid outlet 37 of the second concentration unit 40, and the high-melting-point hydrolyzable polymer A is obtained from the insoluble component outlet 34. These are then fed to the hydrothermal reaction processing unit 50A for hydrothermal treatment, thereby enabling the recovery of hydrolyzable component a. Additionally, non-hydrolyzable polymer B remaining in the hydrolyzable polymer A mixes with the fluid discharged from the insoluble component outlet 34 of the second concentration unit. Therefore, the polymer B recovery unit 80 is connected only to the second hydrothermal reaction processing unit 50A, where polymer B is also recovered.

[0226] <Other Components>

[0227] The separation and recovery apparatus of the present invention may also include units other than those described above. Examples include a storage tank for storing raw materials (e.g., water used in hydrothermal reaction processing) used in the separation and recovery apparatus of the present invention, a delivery pipe and pump for conveying the raw materials stored in the storage tank to the unit, and a refining unit. Furthermore, a static mixer can be provided in the first flow path of the hydrothermal reaction processing unit. This stirs the molten material flowing within the flow path, promoting the hydrolysis reaction.

[0228] In the separation and recovery devices 1 to 4, the hydrolyzed component recovery unit includes a hydrolyzed component recovery unit 60, which is applicable to components whose solubility changes significantly with temperature. However, in the present invention, when recovering hydrolyzed components that do not precipitate even when the temperature is lowered, a conventional heat exchanger is provided, which can be used for cooling and recovery.

[0229] In addition, in the separation and recovery devices 1 to 4, the connecting pipes and conveying pipes that connect each unit can also be equipped with coolers or heaters on their outer circumferential surfaces.

[0230] Unless otherwise specified, the main body, inlet, and other components of each unit can be made of appropriate materials, such as various metals, ceramics, and heat-resistant resins.

[0231] As described above, the separation and recovery apparatus of the present invention can separate and recover the hydrolyzable polymer as a raw material compound (hydrolyzable component) and the non-hydrolyzable polymer as a high-purity polymer from a resin mixture containing a resin containing a hydrolyzable polymer and a resin containing a non-hydrolyzable polymer through a continuous process.

[0232] Explanation of reference numerals in the attached figures

[0233] The present invention has been described in conjunction with its embodiments; however, the applicant believes that, unless otherwise specified, the present invention is not limited in any detail described and should be interpreted broadly without departing from the spirit and scope of the invention as set forth in the appended claims.

[0234] This application claims priority based on Japanese Patent Application No. 2021-101555 filed on June 18, 2021, and Japanese Patent Application No. 2022-097670 filed on June 16, 2022, the contents of which are incorporated herein by reference and are incorporated as part of the description herein.

[0235] 1-4 Separation and Recovery Devices

[0236] 5 heaters

[0237] 10 Crushing Units

[0238] 20 Melt ejection units

[0239] 30 Separation Units

[0240] 31 Tubular body

[0241] 32 Inlet

[0242] 33 1st flow path

[0243] 34. Insoluble component discharge outlet

[0244] 35 Separation Membrane

[0245] 36 2nd flow path

[0246] 37 fluid outlet

[0247] 40 Concentration Units

[0248] 40A Cooling Subunit

[0249] 40B (removing sub-units)

[0250] 41 Tubular body

[0251] 42 Inlet

[0252] 43 1st flow path

[0253] 44 Discharge outlets

[0254] 45 Separation Membrane

[0255] 46 2nd flow path

[0256] 47 Fluid outlet

[0257] 50 Hydrothermal Reaction Processing Units

[0258] 50A and 50B partition-type hydrothermal reaction treatment units

[0259] 50C Countercurrent Contact Type Hydrothermal Reaction Treatment Unit

[0260] 51 Tubular body

[0261] 52 Inlet

[0262] 52A Inflow and Outflow

[0263] 53 1st flow path

[0264] 54. Residual logistics exports

[0265] 55 Diaphragm

[0266] 55A filler

[0267] 56 2nd flow path

[0268] 57 Water inlet

[0269] 58 Water mixture outlet

[0270] 60 Hydrolyzed Component Recovery Units

[0271] 60A Cooling Precipitation Subunit

[0272] 60B Solid-Liquid Separation Subunit

[0273] 60°C Circulating Water Reheating Unit

[0274] 61a, 61b, 61c conveying pipes

[0275] 62 Inlet

[0276] 63 flow path

[0277] 64 Outlets

[0278] 65 Cooling Jacket

[0279] 65a Cooling water inlet section

[0280] 65b Cooling water discharge section

[0281] 66 Main Body

[0282] 66a Discharge section

[0283] 66b Backwash water inlet section

[0284] 67 Connection Port

[0285] 68 Outlet

[0286] 69 Filter Membrane

[0287] 70 Constant pressure pump

[0288] 71 Back pressure valve

[0289] 72 circulating pump

[0290] 80 Polymer B Recycling Unit

[0291] 81 Tubular body

[0292] 82 Residual Logistics Entry Point

[0293] 83 Outlet

[0294] 84. Remove the membrane.

[0295] P flow path

Claims

1. A separation and recovery apparatus for continuously separating and recovering hydrolyzed component a of hydrolyzable polymer A and non-hydrolyzable polymer B from a resin mixture comprising at least resin 1, which is mainly composed of hydrolyzable polymer A, and resin 2, which is mainly composed of non-hydrolyzable polymer B, wherein, The separation and recovery device has the following features: A crushing unit that crushes the resin mixture; A melt ejection unit that melts the crushed material obtained from the crushing unit to form a fluid and ejects it under high pressure; and A hydrothermal reaction processing unit continuously performs hydrothermal reaction processing on the fluid ejected from the melt ejection unit. In the hydrothermal reaction processing unit, the hydrolyzable polymer A is hydrolyzed, causing its hydrolyzed component a to dissolve and transfer to water that has been permeated through a sintered gold membrane, thereby separating the non-hydrolyzable polymer B. A separation unit is provided between the melt ejection unit and the hydrothermal reaction processing unit, the separation unit removing insoluble components contained in the fluid ejected from the melt ejection unit. The separation unit has: An inlet is provided in which fluid ejected from the melt ejection unit flows in; The first flow path is connected to the inlet and uses high pressure to allow the fluid flowing in from the inlet to pass through; A separation membrane, disposed along the first flow path, separates insoluble components from the fluid. The second flow path, which is located on the side opposite to the first flow path relative to the separation membrane, allows the fluid that has had insoluble components removed by the separation membrane to flow through. A fluid outlet, connected to the second flow path, allows the fluid from which the insoluble components have been removed to flow out; and An insoluble component discharge port is provided extending from the first flow path to discharge the separated insoluble components.

2. The separation and recovery device as described in claim 1, wherein, The melt ejection unit melts and ejects the broken material.

3. The separation and recovery device as described in claim 1 or 2, wherein, The hydrothermal reaction processing unit includes a concentration unit upstream of the unit. This concentration unit separates non-hydrolyzable polymer B, thereby increasing the content of non-hydrolyzable polymer B in the fluid supplied to the hydrothermal reaction processing unit. The concentration unit includes: a cooling subunit that cools the supplied fluid to cause a portion of the polymer to precipitate and solidify; and a removal subunit connected to the cooling subunit to remove the precipitated and solidified polymer component. The removal subunit has: An inlet allows fluid containing the precipitated and solidified polymer, supplied from the cooling subunit, to flow in; The first flow path is connected to the inlet to allow fluid flowing in from the inlet to circulate; A separation membrane, configured along the first flow path, separates precipitated and solidified polymers contained in the fluid from the fluid; The second flow path, which is located on the side opposite to the first flow path relative to the separation membrane, allows fluid flow through which the precipitated and solidified polymer has been removed by the separation membrane; A fluid outlet, which is connected to the second flow path, allows the fluid from which the precipitated and solidified polymer has been removed to flow out; as well as An outlet, which extends from the first flow path, discharges the separated precipitated and solidified polymer.

4. The separation and recovery apparatus as described in claim 1 or 2, wherein, The hydrothermal reaction processing unit has: Inlet, into which fluid containing hydrolyzable polymer A flows; The first flow path is connected to the inlet to allow fluid flowing in from the inlet to circulate; A residual flow outlet is provided, which extends from the first flow path, to allow the residual flow of the fluid after hydrothermal reaction treatment to exit. A diaphragm, configured along the first flow path, is permeable to water and prevents the passage of molten polymer; The second flow path is arranged adjacent to the first flow path on the side opposite to the diaphragm and separated by the diaphragm, allowing water to flow. A water inlet is provided in the second flow path to allow water to flow into the second flow path; as well as A water mixture outlet is provided in the second flow path, so that the water mixture containing hydrolyzed component a of hydrolyzable polymer A, which flows in from the water inlet and passes through the diaphragm in the second flow path, flows out from the second flow path.

5. The separation and recovery apparatus as described in claim 1 or 2, comprising one or more of the hydrothermal reaction processing units connected in series or in parallel.

6. The separation and recovery apparatus as described in claim 1 or 2, wherein, The downstream section of the hydrothermal reaction processing unit includes a hydrolysis component recovery unit, which recovers hydrolysis component a of the hydrolyzable polymer A from the water mixture. The hydrolysis component recovery unit has the following features: The cooling precipitation subunit has an inlet, a flow path A, and an outlet. The inlet is for a water mixture containing the hydrolyzed component a to flow into it. The flow path A is connected to the inlet to allow the water mixture flowing in from the inlet to circulate. The outlet is connected to the flow path A to allow the hydrolyzed component a to flow out together with the water. as well as A solid-liquid separation subunit, connected to the outlet of the cooling precipitation subunit, separates hydrolyzed component a from the water mixture.

7. The separation and recovery apparatus as described in claim 1 or 2, wherein, The downstream section of the hydrothermal reaction treatment unit includes a polymer B recovery unit, which recovers non-hydrolyzable polymer B from the residue. The polymer B recycling unit has: The residual logistics inlet is for the entry of residual logistics. Flow path P, which is connected to the residual material inlet, allows the residual material flowing in from the residual material inlet to pass through; A membrane, disposed along the flow path P, is used to remove water and hydrolyzed components a remaining in the residue; and An outlet is connected to the flow path P at a position further downstream than the removal membrane, allowing polymer B separated from residual water and hydrolyzed component a to flow out.

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