Regeneration system of (METH)acrylic polymer, regeneration method of (METH)acrylic polymer, and production method of monomer having (METH)acrylic group

Abstract

To provide: a regeneration system of a (meth)acrylic polymer with which contamination by impurity gas in thermal decomposition gas obtained from the (meth)acrylic polymer can be suppressed and which is excellent in working efficiency; a regeneration method of the (meth)acrylic polymer; and a production method of a monomer having a (meth)acrylic group.SOLUTION: Provided is a regeneration system of a (meth)acrylic polymer which includes a thermal decomposition part 10 to thermally decompose the (meth)acrylic polymer, a thermally decomposed gas treatment part 20 to treat thermal decomposition gas generated in the thermal decomposition part 10, and a connection part 30 to connect the thermal decomposition part 10 and the thermally decomposed gas treatment part 20, in which the thermal decomposition part 10 includes a thermal decomposer including a raw material charging port to charge raw materials including the (meth)acrylic polymer and a gas discharging port to discharge the thermally decomposed gas, and the connection part 30 includes a removal part 30A to remove impurity contained in the thermally decomposed gas discharged from the gas discharging port of the thermal decomposer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a system for recycling a (meth)acrylic polymer, a method for recycling a (meth)acrylic polymer, and a method for producing a monomer having a (meth)acrylic group. [Background technology]

[0002] (Meth)acrylic polymers obtained by polymerizing monomers having (meth)acrylic groups have excellent transparency and weather resistance, and are therefore widely used as materials for components constituting automobile parts, signboards, display devices, etc.

[0003] In recent years, with the rise in resource prices and increasing awareness of environmental issues, there has been a growing trend to collect and recycle products (molded articles) containing (meth)acrylic polymers that have been used for various applications as described above.

[0004] Methods for recycling molded articles containing a (meth)acrylic polymer include, for example, material recycling in which recovered molded articles are subjected to a molding process again to produce new molded articles, chemical recycling in which recovered molded articles are thermally decomposed (depolymerized) to recover a pyrolyzed monomer, and this monomer is used to produce a new molded article, and thermal recycling in which recovered molded articles are combusted and the combustion energy obtained is used as a direct heat source or as converted electricity by a generator.

[0005] The (meth)acrylic polymer can be heated at a relatively low temperature of about 300° C. to 500° C. to recover the pyrolyzed monomer in high yield. Therefore, the (meth)acrylic polymer is suitable for chemical recycling.

[0006] Molded articles containing (meth)acrylic polymers may be accompanied by components (such as gaskets) made of chlorine-containing resins such as polyvinyl chloride, or may have moisture attached thereto. When a molded article in such a state is subjected to pyrolysis, impurity gases such as chlorine gas and water vapor may be generated together with pyrolysis gases containing monomers having (meth)acryloyl groups. If impurity gases are mixed into the pyrolysis gas, the quality of products obtained by recycling the pyrolysis gas may be reduced. Furthermore, hydrochloric acid produced by the reaction of chlorine gas with water vapor may cause corrosion of the recycling treatment equipment.

[0007] Patent Document 1 describes an apparatus that generates chlorine-containing gas in advance by maintaining a pyrolysis furnace at a temperature lower than the temperature at which the pyrolysis of the material to be treated is promoted for a certain period of time before carrying out the pyrolysis of the material to be treated. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2012-11299 A Summary of the Invention [Problem to be solved by the invention]

[0009] In the apparatus described in Patent Document 1, the step of thermally decomposing the material to be treated is interrupted by the step of generating a chlorine-containing gas, so there is room for improvement in the work efficiency. An object of the present disclosure is to provide a (meth)acrylic polymer regeneration system, a (meth)acrylic polymer regeneration method, and a method for producing a monomer having a (meth)acrylic group, which can suppress the inclusion of impurity gases in the pyrolysis gas obtained from the (meth)acrylic polymer and have excellent work efficiency. [Means for solving the problem]

[0010] <1> The apparatus includes a pyrolysis unit that performs pyrolysis of a (meth)acrylic polymer, a pyrolysis gas treatment unit that treats a pyrolysis gas generated in the pyrolysis unit, and a connection unit that connects the pyrolysis unit and the pyrolysis gas treatment unit, The thermal decomposition section includes a thermal decomposition machine having a raw material inlet for introducing a raw material containing a (meth)acrylic polymer and a gas outlet for extracting a thermal decomposition gas, The system for regenerating a (meth)acrylic polymer, wherein the connecting section includes a removal section for removing impurities contained in the pyrolysis gas extracted from a gas extraction port of the pyrolyzer. <2> The portion of the connecting section from the gas outlet of the pyrolyzer to the removal section is made of a material selected from the group consisting of Ti, Zr, Ta and Hastelloy. <1> The reproducing system according to claim 1 . <3> The removal unit includes a pipe through which the pyrolysis gas flows, and an adsorbent or absorbent disposed inside the pipe to adsorb or absorb impurities. <1> or <2> The reproducing system according to claim 1 . <4> Further comprising a pressure gauge disposed between the pyrolysis unit and the removal unit, or between the removal unit and the pyrolysis gas treatment unit. <1> ~ <3> 13. The reproducing system according to claim 12 . <5> The connecting unit further includes a cooling unit disposed between the removing unit and the pyrolysis gas treating unit to cool the pyrolysis gas. <1> ~ <4> 13. The reproducing system according to claim 12 . <6> <1> ~ <5> A step of feeding a raw material containing a (meth)acrylic polymer to a thermal decomposition section in the regeneration system according to any one of the above items; removing impurities contained in the pyrolysis gas generated in the pyrolysis section in the removal section; and treating, in the pyrolysis gas treatment section, the pyrolysis gas from which impurities have been removed in the removal section. <6> <1> ~ <5> A step of feeding a raw material containing a (meth)acrylic polymer to a thermal decomposition section in the regeneration system according to any one of the above items; removing impurities contained in the pyrolysis gas generated in the pyrolysis section in the removal section; and treating, in the pyrolysis gas treatment section, the pyrolysis gas from which impurities have been removed in the removal section. Effect of the Invention

[0011] According to the present disclosure, there are provided a (meth)acrylic polymer regeneration system, a (meth)acrylic polymer regeneration method, and a method for producing a monomer having a (meth)acrylic group, which can suppress the inclusion of impurity gases in the pyrolysis gas obtained from the (meth)acrylic polymer and have excellent work efficiency. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a playback system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the present disclosure, "(meth)acrylic" includes acrylic, methacrylic, and combinations thereof.

[0014] In the present disclosure, a "(meth)acrylic polymer" refers to a polymer having a structural unit derived from a monomer having a (meth)acrylic group. Examples of the (meth)acrylic polymer include a (meth)acrylic homopolymer containing only monomer units derived from an alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms; and a (meth)acrylic copolymer having 85% by mass or more and less than 100% by mass of monomer units derived from an alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms, and more than 0% by mass and 15% by mass or less of monomer units derived from other vinyl monomers copolymerizable with the monomer units derived from an alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms.

[0015] The "alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms" refers to a compound represented by, for example, CH2=C(CH3)COOR (wherein R is an alkyl group having 1 to 4 carbon atoms).

[0016] The vinyl monomer copolymerizable with an alkyl (meth)acrylate having an alkyl group with 1 to 4 carbon atoms is a monomer which is copolymerizable with an alkyl methacrylate having an alkyl group with 1 to 4 carbon atoms and has a vinyl group.

[0017] Examples of alkyl (meth)acrylates having an alkyl group with 1 to 4 carbon atoms include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, sec-butyl methacrylate, and isobutyl methacrylate. The alkyl methacrylate having an alkyl group with 1 to 4 carbon atoms is preferably methyl methacrylate.

[0018] Examples of vinyl monomers copolymerizable with alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms include methacrylate esters such as cyclohexyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, and monoglycerol methacrylate (excluding alkyl methacrylates having an alkyl group having 1 to 4 carbon atoms); methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, Examples of suitable monomers include acrylic esters such as 2-hydroxypropyl acrylate and monoglycerol acrylate; unsaturated carboxylic acids or anhydrides thereof such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, maleic anhydride and itaconic anhydride; nitrogen-containing monomers such as acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, diacetone acrylamide and dimethylaminoethyl methacrylate; epoxy group-containing monomers such as allyl glycidyl ether, glycidyl acrylate and glycidyl methacrylate; and styrene-based monomers such as styrene and α-methylstyrene.

[0019] <(Meth)acrylic polymer recycling system> One embodiment of the present disclosure comprises: The apparatus includes a pyrolysis unit that performs pyrolysis of a (meth)acrylic polymer, a pyrolysis gas treatment unit that treats a pyrolysis gas generated in the pyrolysis unit, and a connection unit that connects the pyrolysis unit and the pyrolysis gas treatment unit, The thermal decomposition section includes a thermal decomposition machine having a raw material inlet for introducing a raw material containing a (meth)acrylic polymer and a gas outlet for extracting a thermal decomposition gas, The connecting section is a (meth)acrylic polymer regeneration system including a removal section that removes impurities contained in the pyrolysis gas extracted from the gas extraction port of the pyrolyzer.

[0020] The regeneration system of the present disclosure performs a regeneration process of a (meth)acrylic polymer by thermally decomposing the (meth)acrylic polymer. That is, according to the regeneration system of the present disclosure, a monomer having a (meth)acrylic group can be obtained as a thermal decomposition product of the (meth)acrylic polymer. The regeneration system of the present disclosure has excellent operational efficiency since it can remove impurities from pyrolysis gas without interrupting the pyrolysis process of the raw material.

[0021] (pyrolysis section) The regeneration system of the present disclosure includes a pyrolysis section that performs pyrolysis of a (meth)acrylic polymer. The thermal decomposition section includes a thermal decomposition machine equipped with a raw material inlet for feeding a raw material containing a (meth)acrylic polymer, and a gas outlet for withdrawing a thermal decomposition gas.

[0022] In the present disclosure, the pyrolysis section includes a pyrolyzer. Examples of pyrolyzers include an extruder, a kneader, and a fluidized bed heater. In an embodiment of the present disclosure, the pyrolyzer preferably includes an extruder. The extruder means a device equipped with a mechanism for rotating a screw disposed inside a cylindrical member (cylinder) to melt raw materials introduced from the upstream side of the cylinder and transport them to the downstream side. In an embodiment of the present disclosure, an example of a kneader that can be suitably applied as a pyrolyzer includes, for example, the device described in U.S. Pat. No. 10,301,235. In an embodiment of the present disclosure, an example of a fluidized bed heater that can be suitably applied as a pyrolyzer includes, for example, the device described in JP-A-2009-112902. In the present disclosure, it is preferable to use an extruder as the pyrolyzer. By using an extruder as a device (pyrolyzer) for pyrolyzing the (meth)acrylic polymer, the pyrolysis process can be carried out efficiently.

[0023] The type of extruder included in the pyrolysis section is not particularly limited, and a known twin-screw extruder or single-screw extruder can be used. From the viewpoint of efficiently pyrolyzing the raw material containing the (meth)acrylic polymer, the extruder is preferably a twin-screw extruder such as a twin-screw co-rotating extruder or a twin-screw counter-rotating extruder. As components constituting the extruder, such as a cylinder and a screw, known configurations can be adopted without particular limitation.

[0024] The pyrolysis machine has a raw material inlet and a gas outlet in this order (i.e., from the upstream side in the flow direction of the raw material). The configurations of the raw material inlet and the gas outlet are not particularly limited, and known configurations can be used without any particular limitation.

[0025] When the thermal cracker is an extruder, the raw material inlet is not particularly limited as long as it is in a state suitable for feeding the raw material containing the (meth)acrylic polymer into the cylinder of the extruder. From the viewpoint of the efficiency of recovering the pyrolysis gas, the raw material inlet is preferably disposed near the upstream end of the pyrolyzer, and the raw material inlet is preferably oriented upward in the direction of gravity.

[0026] The gas outlet of the pyrolyzer is not particularly limited as long as it has a structure suitable for extracting the pyrolysis gas of the (meth)acrylic polymer from the pyrolyzer. From the viewpoint of the efficiency of recovering the pyrolysis gas, the gas outlet is preferably disposed near the downstream end of the pyrolyzer, and is preferably oriented upward in the direction of gravity.

[0027] The material of the thermal cracker is not particularly limited, and any known material can be used without particular limitation. However, when the raw material supplied to the thermal cracker contains chlorine and water, there is a risk that hydrochloric acid will be generated by the reaction between the chlorine and the water.

[0028] An impurity gas outlet for discharging impurity gas may be provided between the raw material inlet and the gas outlet of the pyrolysis machine. This makes it possible to prevent impurities contained in the raw material fed from the raw material inlet from being mixed into the pyrolysis gas. As a result, the removal of impurities in the removal section described below can be performed more reliably.

[0029] From the viewpoint of suppressing the mixing of the impurity gas and the pyrolysis gas, the pyrolyzer may be capable of independently adjusting the temperature of the region between the raw material inlet and the impurity gas outlet and the temperature of the region between the impurity gas outlet and the gas outlet. That is, the temperature of the region between the raw material inlet and the impurity gas outlet and the temperature of the region between the impurity gas outlet and the gas outlet can be set to different temperatures. It is preferable that the temperature of the region between the impurity gas outlet and the gas outlet is set to a temperature higher than the temperature of the region between the raw material inlet and the impurity gas outlet.

[0030] For example, the temperature of the region between the raw material inlet and the impurity gas outlet may be adjusted to be equal to or higher than the temperature at which the impurity gas is generated and lower than the thermal decomposition onset temperature of the (meth)acrylic polymer, and the temperature of the region between the impurity gas outlet and the gas withdrawal port may be adjusted to be equal to the thermal decomposition onset temperature of the (meth)acrylic polymer.

[0031] By adjusting the temperature of the region between the raw material inlet and the impurity gas outlet so that it is equal to or higher than the temperature at which the impurity gas is generated and lower than the thermal decomposition starting temperature of the (meth)acrylic polymer, the impurity gas can be selectively generated from the raw material in the region and removed. As a result, it is possible to effectively prevent the impurity gas generated from the raw material being transported inside the thermal decomposition device from being mixed into the pyrolysis gas. As a means for adjusting the temperature of the pyrolyzer, any known means can be used without any particular limitation.

[0032] In order to prevent impurity gas from being mixed into the pyrolysis gas, the pyrolyzer may have a seal member disposed between the impurity gas discharge port and the gas extraction port. When the pyrolyzer is an extruder, the sealing member is provided around the axis of the screw of the extruder. The sealing member can, for example, prevent the impurity gas remaining in the cylinder without being discharged from the impurity gas discharge port from moving to the gas extraction port. The sealing member may be a screw element. Examples of the screw element include a seal ring, an element having a reverse flight structure, and an element having a reverse kneading structure. These elements form a resin pool by retaining or reversing the flow of the resin, which makes it easier to discharge the impurity gas from the impurity gas discharge port. As the sealing member, an appropriate commercially available product may be used in consideration of the size and material.

[0033] The pyrolyzer may include components other than those mentioned above. For example, the pyrolyzer may further include a residue discharge port through which residue containing undecomposed components generated during the pyrolysis of the raw material containing the (meth)acrylic polymer is discharged to the outside of the pyrolyzer. The residue discharge port is preferably provided near the downstream end of the pyrolyzer, and is preferably oriented downward in the direction of gravity.

[0034] The raw material containing a (meth)acrylic polymer to be fed into the pyrolyzer includes a molded product of a (meth)acrylic polymer. The type of the molded product is not particularly limited and can be selected from known molded products such as cast molded products and extrusion molded products. From the viewpoint of the cost-effectiveness of the thermal decomposition treatment, the molded article of the (meth)acrylic polymer is preferably a cast molded article.

[0035] The raw material containing a (meth)acrylic polymer may consist of only a (meth)acrylic polymer, or may contain a (meth)acrylic polymer and a component other than the (meth)acrylic polymer. Examples of the component different from the (meth)acrylic polymer include polymers different from the (meth)acrylic polymer, such as polyvinyl chloride, polyolefin, and polyester, and additives. Examples of the additives include fillers, colorants, ultraviolet protection agents, and mold release agents.

[0036] The (meth)acrylic polymer contained in the raw material may be polymethyl(meth)acrylate (PMMA or PMA), which is a polymer of methyl(meth)acrylate (MMA or MA).

[0037] The raw material containing the (meth)acrylic polymer may be in a scrap state. In this disclosure, "scrap" refers to waste products collected after being used for a specific purpose, defective products and scraps generated during the manufacturing process of a product, and the like, whose shape and size have been adjusted so that they can be used as raw materials for pyrolysis processing.

[0038] The conditions for carrying out the thermal decomposition of the raw material using a thermal decomposer are not particularly limited, and can be set taking into consideration the properties, composition, etc. of the raw material to be treated.

[0039] The pressure in the thermal decomposition step is preferably 0.005 MPa to 1.5 MPa, and more preferably 0.01 MPa to 0.3 MPa, from the viewpoint of preventing air from leaking into the system and preventing decomposition gas from leaking out of the system.

[0040] From the viewpoint of pyrolysis efficiency, the temperature of the pyrolysis section in the pyrolysis step (for example, the cylinder temperature of the extruder) can usually be set to 400° C. to 500° C. When the raw material is a pure (meth)acrylic polymer, the temperature is preferably 450° C. to 470° C.

[0041] From the viewpoint of stable operation of the extruder, the screw rotation speed of the extruder in the thermal decomposition step can usually be set to 500 rpm to 1500 rpm, and when the raw material is a pure (meth)acrylic polymer, it is preferably 500 rpm to 1000 rpm.

[0042] The supply amount of the raw material in the pyrolysis step varies depending on the scale of the pyrolysis section (e.g., the diameter of the cylinder of the extruder), and can usually be 10 kg / hour to 5000 kg / hour. For example, when the cylinder diameter is 47 mm, the supply amount is preferably 40 kg / hour to 90 kg / hour.

[0043] (Pyrolysis gas treatment section) The pyrolysis gas treatment section treats the pyrolysis gas generated in the pyrolysis section. The method for treating the pyrolysis gas is not particularly limited and can be selected from known methods. As a means for treating the pyrolysis gas, known means such as a cooler for cooling and liquefying the pyrolysis gas, a purifier for increasing the purity of the monomer having a (meth)acrylic group contained in the pyrolysis gas, and a tank for storing the monomer having a (meth)acrylic group liquefied by cooling can be used without any particular limitation, and any combination thereof can be used as necessary.

[0044] (Connection part) The connecting part connects the pyrolysis part and the pyrolysis gas treatment part, more specifically, the connecting part connects a gas outlet of a pyrolyzer included in the pyrolysis part and the pyrolysis gas treatment part. The form of the connecting portion is not particularly limited, and any known connecting means such as piping can be used without particular limitation.

[0045] The connecting section includes a removal section that removes impurities contained in the pyrolysis gas discharged from the gas discharge port of the pyrolysis machine. The impurities removed by the removal section include chlorine, water, and hydrogen chloride produced by the reaction of chlorine with water.

[0046] The removal unit includes, for example, a pipe through which the pyrolysis gas flows, and an adsorbent or absorbent that is disposed inside the pipe and adsorbs or absorbs impurities. By configuring the removal section as described above, impurities can be removed while the transfer of the pyrolysis gas from the pyrolysis section to the pyrolysis gas treatment section is continued.

[0047] The type of adsorbent contained in the removal section is not particularly limited, and can be selected depending on the type, concentration, etc. of the impurities to be removed. Specific examples of the adsorbent include alumina, calcium oxide, calcium carbonate, iron oxide, iron hydroxide, carbon, zeolite, a complex of iron oxide and / or metallic iron and carbon, a complex of calcium oxide and carbon, a complex of iron oxide and / or metallic iron and calcium carbonate and / or calcium oxide and carbon, and the like. A specific example of the absorbent is an aqueous solution containing a reducing agent and a base. By contacting this aqueous solution with the pyrolysis gas, impurities in the pyrolysis gas can be absorbed. The base is preferably selected from the group consisting of sodium hydroxide, sodium carbonate, and sodium hydrogen carbonate (NaHCO3). The reducing agent is preferably selected from the group consisting of sodium sulfite, hydrogen peroxide, sodium thiosulfate, and sodium bisulfite (or hydrogen sulfite) (NaHSO3). The adsorbent or absorbent contained in the removal section may be of one type or of two or more types.

[0048] From the viewpoint of increasing the efficiency of removing impurities from the pyrolysis gas passing through the removal section, it is preferable that the adsorbent has a large contact area with the pyrolysis gas. From this viewpoint, it is preferable that the adsorbent is in a particulate form.

[0049] When the raw material supplied to the pyrolysis section contains chlorine and water, hydrochloric acid may be generated by the reaction between the chlorine and water. Therefore, the portion of the connecting section from the gas outlet of the pyrolysis machine to the removal section is preferably made of a material having excellent corrosion resistance. Examples of the material having excellent corrosion resistance include Ti, Zr, Ta, and Hastelloy (registered trademark).

[0050] The connecting section may further include a pressure gauge disposed between the pyrolysis section and the removal section, or between the removal section and the pyrolysis gas treatment section. Since the pyrolysis gas transported through the connecting section contains polymerizable substances, there is a risk of the polymerizable substances causing blockage of the pipes. By providing a pressure gauge at the connecting section, blockage of the pipes due to polymerization of the polymerizable substances can be predicted by the generation of a pressure difference, and replacement of the pipes can be planned.

[0051] The connection may include a cooling section for cooling the pyrolysis gases. Since the connecting section is provided with the cooling section, ignition and explosion of the pyrolysis gas being transferred from the pyrolysis section to the pyrolysis gas treatment section can be effectively prevented.

[0052] When the connecting portion includes a cooling portion, the cooling portion is preferably provided between the impurity removal portion and the pyrolysis gas treatment portion.

[0053] The cooling section may be in a state where a refrigerant is in contact with the outer surface of a pipe through which the pyrolysis gas flows, or in a state where a refrigerant passes through the inside of the pipe to cool the pyrolysis gas. A specific example of the cooling section is a double-pipe heat exchanger through which a refrigerant can flow. The refrigerant may be at least one selected from the group consisting of water, air, oil, molten salt, and water vapor.

[0054] The pipe through which the pyrolysis gas flows may consist of one pipe section, or two or more pipe sections may be connected by a connection section, specifically, a flange connection section or a screw connection section. When the pipe through which the pyrolysis gas flows includes a connection part, it is preferable to provide a cooling part in at least a part (preferably the entire area) between the connection part located closest to the pyrolysis part and the pyrolysis part. From the viewpoint of effectively preventing ignition and explosion of pyrolysis gas while obtaining a sufficient cooling effect, the length of the region between the connection part located closest to the pyrolysis part and the pyrolysis part is preferably 5% to 50%, and more preferably 5% to 15%, of the total length of the pipe through which the pyrolysis gas flows, taken as 100%.

[0055] The cooling section is preferably capable of cooling the pyrolysis gas to a temperature equal to or higher than the boiling point and lower than the ignition point of the pyrolysis gas. Specifically, it is preferable to be able to cool the pyrolysis gas to a temperature that is equal to or higher than the boiling point (about 100°C) of the pyrolysis gas containing methyl (meth)acrylate and lower than the ignition point (about 421°C) of the pyrolysis gas containing methyl (meth)acrylate. The temperature of the pyrolysis gas after being cooled by the cooling section is, for example, preferably 200°C to 410°C, and more preferably 300°C to 400°C.

[0056] The regeneration system may include various components in addition to the pyrolysis section, the pyrolysis gas treatment section and the connection section. For example, the regeneration system may include a raw material supplying section that supplies raw material to the pyrolysis device, a residue storage section that stores the residue discharged from the pyrolysis device, and the like.

[0057] (Raw material supply department) The raw material supply unit supplies raw material to the pyrolysis device. The method for supplying the raw material to the thermal cracking device is not particularly limited and can be selected from known methods. The raw material supply unit may include a processing device for processing the raw materials, such as crushing the raw materials, a detector for detecting foreign matter contained in the raw materials, a measuring device for controlling the amount of raw materials fed in, and the like.

[0058] (Residue storage area) The residue storage tank stores the residue discharged from the thermal decomposition device. The method for storing the residue is not particularly limited and can be selected from known methods. The residue storage section may be equipped with a processor or the like for processing the residue into a disposable state.

[0059] <Method for Regenerating (Meth)acrylic Polymer> One embodiment of the present disclosure comprises: A step of feeding a raw material containing a (meth)acrylic polymer into a pyrolysis section in the regeneration system of the present disclosure described above; removing impurities contained in the pyrolysis gas generated in the pyrolysis section in the removal section; and treating, in the pyrolysis gas treatment section, the pyrolysis gas from which impurities have been removed in the removal section.

[0060] According to the recycling method of the present disclosure, it is possible to efficiently carry out recycling treatment of a (meth)acrylic polymer while suppressing the inclusion of impurities in the pyrolysis gas obtained by pyrolyzing the (meth)acrylic polymer.

[0061] From the viewpoint of work efficiency, it is preferable to carry out the steps of feeding the raw material into the pyrolysis section, removing impurities contained in the pyrolysis gas generated in the pyrolysis section, and processing the pyrolysis gas from which the impurities have been removed, in parallel.

[0062] According to the recycling method of the present disclosure, the (meth)acrylic polymer contained in the raw material is recycled by thermal decomposition into a monomer having a (meth)acrylic group. The regenerated monomer having a (meth)acrylic group is used, for example, as a raw material monomer for a (meth)acrylic polymer.

[0063] The monomer having a (meth)acrylic group obtained by the recycling method of the present disclosure may include methyl (meth)acrylate. The monomer having a (meth)acrylic group obtained by the regeneration method of the present disclosure may be a mixture of methyl (meth)acrylate and monomers other than methyl (meth)acrylate that may be inevitably contained (methyl isobutyrate, methyl propionate, methyl acrylate, etc.). In this case, the monomers other than methyl (meth)acrylate in the mixture may or may not be removed.

[0064] <Method of producing monomer having (meth)acrylic group> One embodiment of the present disclosure comprises: A step of feeding a raw material containing a (meth)acrylic polymer into a pyrolysis section in the regeneration system of the present disclosure described above; removing impurities contained in the pyrolysis gas generated in the pyrolysis section in the removal section; and treating, in the pyrolysis gas treatment section, the pyrolysis gas from which impurities have been removed in the removal section.

[0065] According to the production method of the present disclosure, it is possible to efficiently produce a monomer having a (meth)acrylic group while suppressing the inclusion of impurities in the pyrolysis gas obtained by pyrolyzing a (meth)acrylic polymer.

[0066] From the viewpoint of work efficiency, it is preferable to carry out the steps of feeding the raw material into the pyrolysis section, removing impurities contained in the pyrolysis gas generated in the pyrolysis section, and processing the pyrolysis gas from which the impurities have been removed, in parallel.

[0067] The step of removing impurities may be a step of removing chlorine and impurities derived therefrom (hereinafter also referred to as a chlorine removal step), a step of removing water and impurities derived therefrom (hereinafter also referred to as a water removal step), or a step that includes both of these steps. When the step of removing impurities includes both a chlorine removal step and a water removal step, the order of the chlorine removal step and the water removal step is not particularly limited and can be appropriately determined in consideration of the properties of the adsorbent or absorbent to be used, but it is preferable to perform the chlorine removal step first. When removing both chlorine and water as impurities, it is preferable to perform the steps while maintaining the pyrolysis gas at a high temperature from the viewpoint of suppressing deterioration such as corrosion of the device.

[0068] According to the production method of the present disclosure, a monomer having a (meth)acrylic group is obtained as a thermal decomposition product of a (meth)acrylic polymer contained in a raw material. The monomer having a (meth)acrylic group obtained as a pyrolyzate is used, for example, as a raw material monomer for a (meth)acrylic polymer.

[0069] The monomer having a (meth)acrylic group obtained by the production method of the present disclosure is used, for example, as a raw material monomer for a (meth)acrylic polymer.

[0070] The monomer having a (meth)acrylic group obtained by the production method of the present disclosure may include methyl (meth)acrylate. The monomer having a (meth)acrylic group obtained by the production method of the present disclosure may be a mixture of methyl (meth)acrylate and monomers other than methyl (meth)acrylate that may be inevitably contained (methyl isobutyrate, methyl propionate, methyl acrylate, etc.). In this case, the monomers other than methyl (meth)acrylate in the mixture may or may not be removed.

[0071] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the components shown in each drawing can be modified without departing from the scope of the present disclosure.

[0072] FIG. 1 is a diagram illustrating an example of the configuration of a playback system according to the present disclosure. As shown in FIG. 1, the regeneration system 100 includes a pyrolysis section 10, a pyrolysis gas treatment section 20, a connection section 30, a raw material supply section 40, and a residue storage section 50. The connecting portion 30 includes a removing portion 30A that removes impurities contained in the pyrolysis gas, and a cooling portion 30B that cools the pyrolysis gas.

[0073] The pyrolysis section 10 includes a pyrolyzer (not shown). The pyrolysis gas treatment section 20 is connected to a gas outlet of the pyrolyzer included in the pyrolysis section 10 . The raw material supply unit 40 is connected to a raw material inlet of a pyrolyzer included in the pyrolysis unit 10 . The residue storage section 50 is connected to a residue discharge port of the pyrolyzer included in the pyrolyzer 10 .

[0074] The raw material containing a (meth)acrylic polymer is fed from the raw material inlet of the pyrolyzer included in the pyrolysis section 10, softens and becomes fluid inside the pyrolyzer (e.g., inside the cylinder of an extruder), and is transported toward the gas outlet of the pyrolyzer by means of, for example, a rotating screw inside the pyrolyzer. The pyrolysis gas discharged from the gas discharge port of the pyrolysis machine passes through a removal section 30A and a cooling section 30B provided in the connection section 30 when being transferred to the pyrolysis gas treatment section 20. The pyrolysis gas passes through the removal section 30A, whereby impurities contained in the pyrolysis gas are removed. The pyrolysis gas passes through the cooling section 30B, thereby preventing the pyrolysis gas from igniting and exploding. [Explanation of symbols]

[0075] 10: Pyrolysis section 20: Pyrolysis gas treatment section 30:Connection part 30A:Removal part 30B: Cooling section 40: Raw material supply department 50: Residue storage section 100: Playback System

Claims

1. The present invention comprises a pyrolysis section for pyrolyzing a (meth)acrylic polymer, a pyrolysis gas treatment section for treating a pyrolysis gas generated in the pyrolysis section, and a connection section for connecting the pyrolysis section and the pyrolysis gas treatment section, the thermal decomposition section includes a thermal decomposition machine having a raw material inlet for introducing a raw material containing a (meth)acrylic polymer and a gas outlet for extracting a thermal decomposition gas, The system for regenerating a (meth)acrylic polymer, wherein the connecting section includes a removal section for removing impurities contained in the pyrolysis gas extracted from a gas extraction port of the pyrolyzer.

2. 2. The regeneration system according to claim 1, wherein the portion of the connecting section from the gas outlet of the thermal decomposition machine to the removal section is made of a material selected from the group consisting of Ti, Zr, Ta and Hastelloy.

3. 2. The regeneration system according to claim 1, wherein the removal unit includes a pipe through which the pyrolysis gas flows, and an adsorbent or absorbent disposed inside the pipe for adsorbing or absorbing impurities.

4. The regeneration system according to claim 1 , further comprising a pressure gauge disposed between the pyrolysis section and the removal section, or between the removal section and the pyrolysis gas treatment section.

5. The regeneration system according to claim 1 , wherein the connecting unit further includes a cooling unit disposed between the removing unit and the pyrolysis gas treating unit to cool the pyrolysis gas.

6. A step of feeding a raw material containing a (meth)acrylic polymer into a thermal decomposition section of the regeneration system according to any one of claims 1 to 5; removing impurities contained in the pyrolysis gas generated in the pyrolysis section in the removal section; and treating, in the pyrolysis gas treatment section, the pyrolysis gas from which impurities have been removed in the removal section.

7. A step of feeding a raw material containing a (meth)acrylic polymer into a thermal decomposition section of the regeneration system according to any one of claims 1 to 5; removing impurities contained in the pyrolysis gas generated in the pyrolysis section in the removal section; and treating, in the pyrolysis gas treatment section, the pyrolysis gas from which impurities have been removed in the removal section.

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