JP5883585B2 - Separation and recovery method for composite plastic waste and universal type separation and recovery device used therefor - Google Patents

Description

  The present invention relates to various composite plastic waste, composite electrical products of metal and plastic, medical waste, blended products of synthetic fibers and natural fibers, composite plastic wastes such as FRP (hereinafter referred to as composite plastic waste) The present invention relates to a separation / recovery method and a universal separation / recovery device used therefor.

  As types of waste plastics, there are thermoplastic resins and thermosetting resins, and a method for separating them by specific gravity has been performed for a long time. However, thermoplastic resins are widely recycled, but PVC discharges chlorine gas when subjected to thermal incineration, so it is necessary to recover this (Patent Document 1). Does not meet the purpose of resource conservation. On the other hand, the decomposition reaction with diethylene glycol is difficult if PET resin does not use caustic soda as a catalyst (Patent Document 2). However, if caustic soda is used, it is depolymerized to produce terephthalate, etc., and recycled by washing with water It is necessary and post-processing is troublesome. On the other hand, recycling of the thermosetting resin is difficult. For example, a cured epoxy resin is excellent in electrical characteristics, heat resistance, and adhesiveness, and thus is used in a wide range of fields such as insulating materials, adhesives, and paints. However, thermal decomposition is difficult and recycling is difficult. On the other hand, fiber reinforced plastics (hereinafter referred to as FRP) are generally widely used in automobiles, aircraft, sporting goods, and other fields because glass fibers are generally used as reinforcing fibers in terms of lightness and durability. However, recycling is difficult due to the reinforcing fiber. Therefore, FRP products using unsaturated polyester as the matrix resin and organic fibers other than glass fibers as the reinforcing fibers are decomposed using glycol, and the resulting decomposition products are condensed with dibasic acid and recycled. A method has been proposed (Patent Document 3). On the other hand, as a method for recycling FRP, an atmospheric pressure dissolution method using diethylene glycol monomethyl ether as a solvent and tripotassium phosphate hydrate as a catalyst has been proposed (Non-patent Documents 1 and 2).

  In addition, renal dialysis set and infusion set waste is highly infectious because it contains bodily fluids such as blood and injection needles, and the material contains a large amount of vinyl chloride resin and metal. , One of the most difficult waste to process. Therefore, the actual situation is that the waste from the renal dialysis set has been incinerated for the purpose of heat sterilization treatment, although there is a problem of generation of hydrogen chloride gas and dioxin. However, especially when infectious waste is processed in a large incinerator, there are dangers when it is transported to the incinerator or when the incinerator fails and a large amount of waste is contaminated by infectious waste. Considering the dangers, it is desirable to process on a small scale where infectious waste is generated. For this reason, attempts have been made to develop a small incinerator capable of neutralizing hydrogen chloride gas in the exhaust gas, but there is a difficulty in treating a large amount of exhaust gas. In particular, incinerators that operate in batches have a problem that a large amount of dioxin is generated when combustion becomes unstable. Therefore, methods for thermally decomposing waste after compression have already been attempted, but these methods are based on a carbonization method using a continuous extrusion apparatus or a tunnel furnace heating method, and the apparatus becomes large (Patent Document 4, 5). Also, infectious waste may contain incompressible metal products and gypsum products, so there are considerable limitations in practical application.

  In addition, plastic products with metal materials, such as OA equipment, mobile terminals, mobile phones, TVs, vacuum cleaners, refrigerators and other electrical products, especially printed wiring boards used in these control units, and melting It is formed integrally with a metal material such as a pipe joint, a resin-coated electric wire, an optical cable, or a fiber reinforced plastic. In these metal-containing plastic products, it is required to cleanly and efficiently separate the metal material and the plastic material in the disposal process or the recycling process of the product that has become defective in the manufacturing process. Therefore, various treatment methods have been proposed as treatment methods in which a plastic material of a metal-containing plastic product is dissolved by heating and separated from the metal material or the like. For example, in Patent Document 6, edible waste oil is heated to 170 to 175 ° C., a metal-containing plastic product is introduced into the edible waste oil, and the edible waste oil is stirred to dissolve the plastic, and the metal material is exposed. By the way, the metal material selection method of the plastic waste which stops the heating of edible waste oil, naturally cools, and takes out a metal material from edible waste oil after that is proposed. Patent Document 7 discloses that waste of electrical products such as OA equipment and home appliances is introduced into vegetable oil such as tempura oil heated to a temperature at which the plastic material is softened and melted, and then softened and melted to produce vegetable matter. The disposal method of the waste of the electrical product which takes out the melted plastic material which floated on the upper part of oil, and takes out the metal material which remains in an oil tank after that is proposed. However, when a metal-containing plastic product, such as a mobile phone, is introduced into oil as a heating medium, the plastic material is heated and dissolved as if the food is fried in oil and floats on the oil, while other metal materials However, if a plastic material is poured into the oil, it may ignite when the plastic material melts, which is dangerous. Therefore, in the treatment of metal-containing plastic products, a method for treating metal-containing plastic products that can heat and dissolve the plastic material in the oil layer safely and efficiently has been proposed (Patent Document 8). However, in recent years, electrical components such as a semiconductor circuit are often formed on a thermosetting resin substrate such as an epoxy resin in an electrical component, but in the case of such a thermosetting resin, an oil heating treatment is applied. However, it is difficult to separate and collect the metal material and the resin material effectively, and there is a problem that it cannot be applied to many electric products using a thermosetting resin such as an epoxy resin.

  In addition, various composite plastic wastes are currently appearing as waste that is difficult to recycle, but as products, aluminum / PP / PET three-layer sheets, PE / PET carpets, silver layer / PET sheet laminated X-ray films , Nylon / PET bottles, PET / cotton / nylon / acrylic blended garments, FRP boats and bathtubs, carbon fiber piping and parts, electric wires, PVC paper, etc. Although there are many materials that need to be separated and recovered so that they can be reused, they are currently incinerated because separation and recovery are difficult.

JP 2001-55583 A JP 2006-110531 A Japanese Patent No. 4096000 JP-A-2-229588 Japanese Patent Laid-Open No. 11-218313 Japanese Patent Laid-Open No. 5-17041 JP-A-10-137734 JP 2008-213480 A

Hitachi Chemical Technical Report No. 42 (2004.4.1) Epoxy CFRP recycling by atmospheric pressure dissolution method

Intensive research to provide methods and devices that can separate and recover active components such as plastics and metals that can be recovered and reused without incineration of such composite plastic waste, including medical waste and FRP. As a result, since composite plastic wastes vary widely, if a method and an apparatus adapted to each composite waste are configured, the equipment cost and running cost increase. Therefore, an object of the present invention is to provide a universal separation and recovery method and apparatus widely applicable to composite plastic waste.

  In the present invention, when triethylene glycol is used as a solvent and heated to the vicinity of the boiling point, sufficient temperature treatment is possible for sterilization and melting of the thermoplastic resin necessary for medical waste, while Since it functions as a reaction solvent for polymerization, etc., when various processed materials are added and stirred as a separation solvent, the various processed materials are divided into a melt and a non-melt, and the non-melt is reacted with a residual solid. Since it is separated into a product or a dissociated product, each component can be separated and recovered according to its physical properties by using such various plastic separation modes, while the solvent can be regenerated and reused by evaporating it in vacuum. It has been found that the universal separation and recovery method and apparatus can be applied to a wide variety of complex wastes with low running costs.

That is, the present invention is a method for treating and separating and recovering each component of a composite plastic waste obtained by combining various thermoplastics, thermosetting plastics and non-plastic components, and using triethylene as a separation solvent. using glycol, the alkali metal hydroxide as a catalyst was added as a catalyst, heating the triethylene glycol in 200 ° C. above the boiling point near rather 2 50-280 ° C., to melt process the meltable component P1 in triethylene glycol A step, a step of dissolving or depolymerizing the component P2, which is difficult to be thermally melted, with stirring in triethylene glycol heated to 250 to 280 ° C., and discharging it together with the solvent; The step of recovering F or the metal component M, the non-molten component P2 and the separation solvent are recovered, and the separation solvent is evaporated under reduced pressure. It is a method for separating and recovering plastic composite waste, comprising a step of separating and separating from non-molten component P2 and purifying and reusing.

In the present invention, particularly, when waste plastics are FRP such as an epoxy resin and unsaturated polyester resin, pressure or in the presence of an alkali metal hydroxide in 2 from 50 to 280 ° C. under normal pressure 200 ° C. above the boiling point close rather It is good to isolate | separate from a reinforced fiber by the depolymerization process by the heated triethylene glycol.

In the present invention, when waste plastic is PVC, the pressure or in the presence of sodium hydroxide is melted while desalted in triethylene glycol heated to 2 50 to 280 ° C. under normal pressure 200 ° C. above the boiling point close rather It is good.

In the present invention, product waste plastic products containing a metal component (e.g., a substrate) if a, pressure or heat melting in triethylene glycol was heated to rather boiling near or under normal pressure 200 ° C. 2 fifty to two hundred eighty ° C., The metal component and the resin component are preferably separated by thermal decomposition and depolymerization treatment.

In the present invention, when waste plastics are medical waste, pressure or in the presence of an alkali metal hydroxide heat treatment in triethylene glycol was heated to rather boiling near or under normal pressure 200 ° C. 2 50-280 ° C. It is preferable to separate from the metal component by heat melting, thermal decomposition and / or depolymerization treatment together with sterilization treatment.

In the present invention it, if the waste plastic is PET resin component, pressure or without catalyst addition to depolymerization by dissolving treatment with triethylene glycol was heated to rather boiling near or under normal pressure 200 ° C. 2 fifty to two hundred eighty ° C. It is better to dissolve the resin component and recover the resin component.

  In the present invention, as a device for carrying out the above method, a rotating mesh 11 of a mesh mesh mesh is supported by a rotating shaft 12 that is driven to rotate by a motor. Means 13 is provided so that a heated separation solvent can be supplied into the reaction tank 10. The reaction tank 10 treats an object to be treated with the separation solvent under stirring in the rotating drum, and the bottom of the reaction tank 10. The first solvent receiving tank 20 for recovering the separation solvent S together with the molten plastic P1 and the non-molten plastic P2, and the separation solvent S from the first solvent receiving tank 20, and heating the solvent to the boiling point or higher under reduced pressure. A solvent evaporation tank 30 for separating reactants such as a catalyst contained in the solvent while recovering, a water evaporation tank 40 for receiving the washing water W in the dissolution reaction tank 10 and evaporating water to recover the solvent; The solvent vapor Connected to the tank 30, the solvent to be evaporated is exhausted from the non-aggregated gas and the solvent is condensed and recovered under reduced pressure, and connected to the waste water evaporation tank 40 to condense and recover the evaporated water. A solvent regeneration and circulation type universal separation and recovery device comprising a waste water receiving tank 60, wherein the solvent recovered in the waste water evaporation tank 40 and the second solvent receiving tank 50 is supplied to the reaction tank 10 and reused. It is also something to offer.

  In the present invention, it is preferable that the mesh size of the mesh of the rotating drum is set to a size in which the roughly crushed and melted plastic P1 piece charged into the reaction tank remains without melting and leaching. Is preferably adjusted in two stages, a low speed for stirring the solvent during the reaction and a high speed for water centrifugation after washing.

According to the present invention, PE in the waste plastics, pressure or pressure PP and PS component is solidified after melted in triethylene glycol heated to 2 50 to 280 ° C. under normal pressure 200 ° C. above the boiling point near rather, formed in a wire mesh It can remain in the rotating drum and be collected separately.

Further, the present invention is pressurized or a PVC in the waste plastics in the presence of sodium hydroxide is melted together with the desalted in triethylene glycol heated to 2 fifty to two hundred and eighty ° C. under normal pressure 200 ° C. above the boiling point near rather, a wire mesh It can remain in the formed rotating drum.

Furthermore, the present invention is a FRP such as an epoxy resin and unsaturated polyester resin in the waste plastics, pressure or in the presence of an alkali metal hydroxide was heated to rather boiling near or under normal pressure 200 ° C. 2 fifty to two hundred and eighty ° C. While separating from the reinforcing fiber by the depolymerization treatment with triethylene glycol, the epoxy resin and the polyester resin can be separated.

Furthermore, the present invention is an electrical product waste plastic products comprising a metal component, for example when a substrate, pressure or heat melting in triethylene glycol was heated to rather boiling near or under normal pressure 200 ° C. 2 50 to 280 ° C. In addition, the metal component and the resin component can be separated by the depolymerization treatment.

The invention also relates to a waste plastic products medical waste, pressure or sterilization and hot-melt and / or by heat treatment at triethylene glycol heated to 2 50-280 ° C. under normal pressure 200 ° C. above the boiling point close rather The metal component can be separated by depolymerization treatment.

Furthermore, powdery PET resin without the present invention is to depolymerization by dissolving treatment with triethylene glycol pressure or pressure to the PET resin component in the waste plastics by heating to rather boiling near or under normal pressure 200 ° C. 2 50-280 ° C. Can be recovered.

  Therefore, the present invention is useful as a method for separating and recovering composite waste plastic products composed of various thermoplastic and thermosetting resins into respective components. That is, the waste plastic product can be separated into a molten component composed of PE, PP, PS, ABS and the like and a non-melted component composed of PVC, PET, FRP component and the like in triethylene glycol. Furthermore, PE, PP, PS, ABS, and the like in the molten component of triethylene glycol can be separated without fusing the resins together. On the other hand, the PET composite system of non-molten components can be separated and recovered by dissolution reaction with triethylene glycol without catalyst, and PVC is heated in the presence of caustic soda near the boiling point under pressure or normal pressure. This is because it can be separated by being melted together with the desalting treatment. FRP epoxy resin and unsaturated polyethylene resin can only be depolymerized by contacting with triethylene glycol heated near the boiling point under pressure or normal pressure in the presence of alkali metal hydroxide, especially caustic soda as a catalyst. If the difference between the depolymerization times is used, the depolymerization component can be separated. In particular, PVC is desalted without separation, and when triethylene glycol is used, the desalination rate is higher than when ethylene glycol is used, and the salt is almost completely desalted. preferable. On the other hand, epoxy resins and unsaturated polyester resins that are matrix resins in FRP have a difference in depolymerization time, and these can be collected separately. After the depolymerization treatment, triethylene glycol can be heated to the boiling point or higher to separate and recover the catalyst and the like. The depolymerized non-floating component may be reused as it is, but may be recovered by thermal decomposition in the presence of an alkaline compound such as slaked lime.

  In addition, when a metal component and a thermosetting resin are combined in an electrical product, a depolymerization treatment is effective for separating the resin and the metal component, and triethylene glycol in the glycol solvent has a high boiling point and is alkaline. When heating near the boiling point under pressure or normal pressure in the presence of metal hydroxide, particularly caustic soda, not only unsaturated polyester but also epoxy resin can be depolymerized simultaneously. Therefore, in the present invention, the thermoplastic resin melts and separates by heating triethylene glycol near the boiling point under pressure or normal pressure without separating various plastic products including metal materials, while the thermosetting resin is alkaline. The metal material can be separated by dissolution or depolymerization in the presence of a metal hydroxide. That is, according to the present invention, since triethylene glycol is used, there is no ignition accident, and the thermoplastic resin and the thermosetting resin are separated in advance or without being separated, and then added to triethylene glycol. While the thermoplastic resin is melted and separated, the thermosetting resin can be dissolved or depolymerized, and the metal material can be separated and recovered together with the plastic. Therefore, it is excellent in the separation and collection of various metal-containing plastic products. In particular, when PVC is included, as described above, by adding caustic soda to triethylene glycol, desalting can be performed at the same time, and depolymerization in the thermosetting resin can be improved. .

  Furthermore, according to the present invention, medical waste is not a thermal incineration method, and can be sterilized without any problem of exhaust gas treatment by high-temperature heat treatment in a solvent. Can be separated and collected. That is, according to the present invention, medical waste containing chlorine-containing and metal-containing plastics can be sterilized (detoxified) and plastics can be collected separately.

  Furthermore, according to the present invention, in the mixed waste FRP, when triethylene glycol is used as a common solvent and an alkali metal hydroxide, particularly caustic soda is used as a catalyst and is brought into contact at a boiling point or lower, it can be depolymerized with ethylene glycol. The missing epoxy resin is depolymerized. In disassembling the FRP product using the thermosetting resin as the matrix resin, the waste FRP product was heated to the boiling point under pressure or normal pressure in the presence of an alkali metal hydroxide as it was or after grinding without separation. The matrix resin and the reinforcing fiber can be separated by depolymerization treatment by contacting with triethylene glycol. On the other hand, since epoxy resins and unsaturated polyester resins that are thermosetting resins have a difference in depolymerization time, they can be collected separately in order.

It is a left side schematic diagram of a batch type fraction collection system to which the method of the present invention is applied. It is a right side schematic diagram of a batch type fraction collection system to which the method of the present invention is applied.

  Embodiments of the present invention will be described below based on examples.

Example 1
The universal separation and recovery apparatus according to the present invention is a reaction tank 10 provided with a rotating drum 11 and a first solvent that is connected to the bottom of the reaction tank 10 and recovers the separation solvent S together with the molten plastic P1 and the precipitated depolymerized plastic P2. Receiving the separation solvent S from the receiving tank 20 and the solvent receiving tank 20, receiving the solvent evaporating tank 30 for recovering by heating the solvent to the boiling point or higher under reduced pressure, and the washing water W in the dissolution reaction tank 10 to evaporate the water. A waste water evaporation tank 40 for recovering the solvent, a second solvent receiving tank 50 that is connected to the solvent evaporation tank 30 and exhausts the non-aggregated gas to condense and recover the solvent under reduced pressure, and the water evaporation tank 40. And a water receiving tank 60 for condensing and recovering the evaporated water, and a vacuum pump 70.

  The reaction tank 10 is a tank that treats an object to be treated with stirring in a heated separation solvent, and a rotating mesh 11 of a metal mesh mesh is supported on a rotating shaft 12 that is driven to rotate by a motor and placed horizontally. The electric motor M can be rotated in two stages, low speed and high speed. The mesh size of the metal mesh is designed so that the molten plastic is roughly crushed (10 cm square) and melted, but the molten plastic does not leach out of the drum system when the drum rotates at a low speed. When plastic is processed, it is rotated at a low speed, water is radiated at the time of washing after the reaction, and waste water is discharged outside the drum by centrifugal force due to high speed rotation. On the other hand, the upper part is opened so that the raw material can be supplied into the tank, and the lower part is provided with a solvent heating means 13 so that the heated separation solvent can be supplied into the reaction tank 10 via the three-way valve 14. It has become. In addition, a first solvent receiving tank 20 is connected to the bottom of the reaction tank 10 via a three-way valve 14, and the separation solvent S is recovered together with the plastic P2 that is separated from the molten plastic P1 and dissolved or depolymerized. An overflow valve 15 keeps the liquid level in the reaction tank 10 and can be received and recovered by the first solvent receiving tank 20. In the solvent receiving tank 20, the separation solvent S is received together with the melted or depolymerized product of the non-molten plastic P2, and the plastic P2 and the solvent S are separated. In the solvent receiving tank 20, the upper layer solvent is collected by the circulation pump 21 through the valve 22, sent to the heater 13, heated and retransmitted to the reaction tank 10, while the lower layer solvent S is passed through the valve 23 by the circulation pump 21. The solvent is sent to the solvent evaporation tank 30 and is recovered by heating the solvent to the boiling point or higher under reduced pressure. The separation solvent S includes a catalyst and the like contained in the solvent, but is separated from the solvent S in the solvent evaporation tank 30 and recovered.

  The solvent evaporation tank 30 is connected to a second solvent receiving tank 50, and the solvent evaporation tank 30 is depressurized by sucking the second solvent receiving tank 50 by a vacuum pump 70, and the separated solvent S is evaporated under reduced pressure. ing. When the solvent evaporates, the reactants and catalyst in the solvent remain at the bottom and are separated. On the other hand, the evaporated solvent S is sent to the second solvent receiving tank 50 and is aggregated by the capacitor 51 located at the top. On the other hand, the unaggregated gas is exhausted and the solvent is recovered under reduced pressure. Since the recovered solvent S is in a purified state, it is reused after adding about 5% of a new solvent.

  Since the plastic component heated and melted or depolymerized in the reaction tank 10 is collected in the first solvent receiving tank 20 together with the solvent, plastic particles and depolymerized in the rotating drum 11 of the reaction tank 10 are solidified by heat melting. In mixed garments, natural fibers other than synthetic fibers remain, such as FRP reinforcing fibers that do not react, etc., metal components of electrical products, injection needles for medical waste, etc., and these are collected after washing with water. The waste water evaporation tank 40 receives the washing water W from the reaction tank 10 and evaporates the water to recover the solvent. Since the boiling point of water is lower than that of the present solvent triethylene glycol, the solvent remains in the waste water evaporation tank 40 and the evaporated water is sent to the waste water receiving tank 60 and condensed and recovered by the upper condenser 61. The solvent recovered in the water evaporation tank 40 and the second solvent receiving tank 50 is supplied to the reaction tank 10 and reused. In addition, cooling water is circulated through the condensers 51 and 61 to perform cooling.

(Processing example 1)
1) PET / PE / aluminum composite system can be separated into PET resin, aluminum, and PE resin by contacting with T-EG (triethylene glycol) liquid at 250 ° C. for 10 minutes, cooling and washing.
In detail:
When the PET dissolution is completed, the PET resin powder is transferred to the solvent receiving tank together with the solvent. Undissolved aluminum and molten PE remain in the wire mesh of the rotating drum. Since the solvent adheres to them, water washing and cooling are performed with water. The aqueous solution containing the solvent is transferred to a waste water evaporation tank. Washed and separated aluminum and PE resin in the wire mesh are discharged out of the system. The two substances are not welded at all.
When the solution transferred to the solvent receiving tank is given time, the PET resin is precipitated due to a difference in specific gravity. The tank bottom liquid is heated and evaporated in a solvent evaporation tank, and T-EG (triethylene glycol) as a solvent is evaporated, condensed in a condenser, collected in a solvent receiving tank, and recirculated for use.
The aqueous solution containing T-EG is heated in a wastewater evaporation tank to evaporate and condense water, and is collected in a wastewater receiving tank and reused.
The melting temperature of T-EG is controlled by heating with a heater.

(Processing example 2)
"Mixed waste plastic containing composite material" = Separation and recovery of PE, PP, PS, PVC, substrate, FRP, PET mixture Caustic soda is added to T-EG solvent as a catalyst and heated to 280 ° C together to rotate the rotating drum at low speed After a certain period of time, each resin reacts with the solvent triethylene glycol in the order of melting ⇒ dissolution ⇒ depolymerization.
1) PE, PP, and PS resins are melted and solidified and remain in the wire mesh reaction tank, but the resins remain in a state where they can be separated without welding. This is based on the characteristics of triethylene glycol and is an advantage that it can be collected separately.
2) PVC undergoes a dechlorination reaction, and the generated HCL and NaOH are neutralized to become NaCL, which remains as a powder in the solvent. On the other hand, the dechlorinated resin remains in the wire mesh reaction vessel. Since a high desalting rate is obtained, it is not necessary to separate PVC in advance.
3) The bonded part of the substrate dissolves. The filler remains in the solvent, and the metal and glass fiber remain in the wire mesh and can be easily separated by hand.
4) FRP is mixed with glass fiber, filler, and FRP solution by adding a little NaOH to T-EG solvent and contacting at 280 ° C for 15 hours. The liquid passes through the wire mesh and exists in the solvent.
5) PET resin is dissolved in T-EG at 230 to 285 ° C. for 10 to 20 minutes and exists as a powder resin in the solvent. Since it does not undergo depolymerization in triethylene glycol, it is convenient for reuse.
Each substance present in the above solvent is transferred to a solvent receiving tank, and is separated by specific gravity difference over time. The solution containing the solid accumulated at the bottom is transferred to a solvent evaporation tank, and T-EG is evaporated by heating and vacuum evaporation. Since PET resin or the like accumulates at the bottom of the solvent evaporator, it is discharged out of the system with a screw. The aqueous solution containing T-EG is heated in a wastewater evaporation tank to evaporate and condense water, and is collected in a wastewater receiving tank and reused. Glass fiber, metal, and plastic remaining in the wire mesh tank are washed with water, removed at high speed, discharged to the outside of the system, and separated by hand separation.

  Table 1 shows examples of each waste material, upper discharge, and lower discharge.

In particular, the following two points can be cited as advantages when using the present invention.
1) Dechlorination effect of 100% PVC using T-EG / NaOH When 100% PVC resin is immersed in T-EG solution with NaOH and maintained at a temperature of 270-280 ° C for 20 minutes, a dechlorination rate of 94 wt% is obtained. Moreover, it was found that the pH of steam vaporized outside the system is 8, and that dechlorination can be performed without corrosion of the apparatus and without affecting the environment.
2) When conventional ethylene glycol is used and caustic soda is used as a catalyst, PET is depolymerized to produce terephthalate, but terephthalate can only be used back to PET resin. For this purpose, a large amount of sulfuric acid was used to make terephthalic acid, which had to be polymerized. In addition, a large amount of sodium nitrate was produced as a by-product, requiring many processes and costs.
On the other hand, according to the present invention, it can be recovered as a powdery PET resin or oligomer by contacting the PET resin near the boiling point of T-EG only with triethylene glycol (T-EG) instead of ethylene glycol / NaOH. This makes it possible to produce a PET resin product, which makes the recycling cost extremely low. By applying this technique, composite plastics (including metal) such as PET / aluminum / PE film can be separated and the process can be largely omitted because it is not depolymerized.

DESCRIPTION OF SYMBOLS 10 Dissolution reaction tank 11 Rotating drum 20 1st solvent receiving tank 30 Solvent evaporation tank 40 Water evaporation tank 50 2nd solvent receiving tank 60 Waste water receiving tank 70 Vacuum pump

Claims (8)

A method of treating and recovering each component by treating a composite plastic waste formed by combining various thermoplastics and / or thermosetting plastics and non-plastic components, using triethylene glycol as a separation solvent, An alkali metal hydroxide is added as a catalyst, triethylene glycol is heated to 230 ° C. or more and 285 ° C. or less, and the meltable component P1 in the composite plastic waste is melted in triethylene glycol. And a step of dissolving or depolymerizing the component P2, which is difficult to heat-melt in the composite plastic waste, with stirring in triethylene glycol heated to 230 ° C. or more and 285 ° C. or less and discharging it together with the solvent. A process of recovering the remaining meltable component P1 and reinforcing fiber F or metal component M, and non-melting The and minutes P2 and separated solvent is recovered, fractional recovery method for a plastic-based composite waste separation solvent, comprising the step of reusing purified with separating the non-melting component P2 by distillation under reduced pressure. The composite plastic waste is FRP such as an epoxy resin and an unsaturated polyester resin, which is made of triethylene glycol heated to 230 ° C. or higher and 285 ° C. or lower under pressure or normal pressure in the presence of an alkali metal hydroxide. The separation and recovery method according to claim 1, wherein the separation and separation are performed by depolymerization treatment. The composite plastic waste is PVC, which is desalted and melted in triethylene glycol heated to 230 ° C or higher and 285 ° C or lower under pressure or normal pressure in the presence of caustic soda. Separation collection method. Heat from triethylene glycol, where the composite plastic waste is an electrical product such as a substrate containing a metal component and heated to 230 ° C. or higher and 285 ° C. or lower under pressure or normal pressure in the presence of an alkali metal hydroxide. The fractional collection method according to claim 1, wherein the metal component and the resin component are separated by melting, thermal decomposition and depolymerization treatment. Composite plastic waste is medical waste, and it is melted together with sterilization by heat treatment with triethylene glycol heated to 230 ° C or higher and 285 ° C or lower under pressure or normal pressure in the presence of alkali metal hydroxide. The separation and recovery method according to claim 1, wherein the metal component is separated from the metal component by thermal decomposition and / or depolymerization.   Inside, a rotating mesh (11) made of wire mesh is supported by a rotating shaft (12) that is driven to rotate by a motor. The heated separation solvent can be supplied into the tank (10), the object to be treated is treated with the separation solvent with stirring in the rotating drum, and the molten plastic P1, the reinforcing fiber F, and the metal component are processed in the rotating drum. A reaction tank (10) for allowing M to remain and recover, a first solvent receiving tank (20) connected to the bottom of the reaction tank (10) and recovering the separation solvent S together with the reactant of the non-molten plastic P2, and A solvent evaporating tank (30) for receiving the separation solvent S from the first solvent receiving tank (20) and recovering the solvent by heating to a boiling point or higher under reduced pressure, while separating a reactant such as a catalyst contained in the solvent; In the dissolution reactor (10) The washing water W is connected to a waste water evaporation tank (40) for recovering the solvent by evaporating water and the solvent evaporation tank (30), and the solvent to be evaporated is exhausted from the non-aggregated gas to remove the solvent under reduced pressure. A second solvent receiving tank (50) for coagulating and collecting, and a waste water receiving tank (60) connected to the waste water evaporating tank (40) for condensing and recovering the evaporated water, and comprising the waste water evaporating tank (40) and the above A solvent regeneration / circulation type separation / recovery device, wherein the solvent recovered in the second solvent receiving tank (50) is supplied to the reaction tank (10) and reused.   7. The separation and recovery device according to claim 6, wherein the mesh size of the wire mesh of the rotating drum is set to a size in which the roughly crushed and melted plastic P1 piece charged into the reaction vessel remains melted and not leached.   7. The separation and recovery apparatus according to claim 6, wherein the rotation of the rotating drum is adjusted in two stages, a low speed for stirring the solvent during the reaction and a high speed for water centrifugation after washing.

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