Methods and apparatus for manufacturing chemicals

Abstract

A method for manufacturing a chemical, comprising: feeding a mixture of at least one chemical selected from the group consisting of olefins having 2 to 5 carbon atoms and aromatic hydrocarbons; the method comprising: feeding a mixture of at least one plastic selected from the group consisting of aromatic plastics and chlorinated plastics, and a mixture containing polyolefins, into a fixed-bed reaction section having a filler layer filled with filler; and thermally decomposing the mixture in the presence of an inert gas at a temperature below 820°C.

Description

[Technical Field]

[0001] This disclosure relates to methods and apparatus for manufacturing chemicals. [Previous Technology]

[0002] Fixed-bed reactors are widely used due to their simple structure and ease of operation. They are also used in the process of chemical regeneration, which involves the thermal decomposition of plastics to extract basic chemicals such as monomers that make up the raw plastic material.

[0003] For example, Patent Document 1 discloses a waste plastic treatment method that recovers catalyst reaction products by thermally decomposing and vaporizing waste plastic, and then contacting the obtained thermally decomposed gas with a gallium-containing silicate catalyst. Specifically, it discloses a treatment apparatus using a fixed bed filled with a gallium-containing silicate catalyst. Specifically, it discloses using granular gallium silicate as a fixed bed, continuously feeding molten polyethylene separately, thermally decomposing and vaporizing it at 425-525°C, and contacting it with the gallium silicate to obtain benzene, toluene, and xylene.

[0004] Furthermore, Patent Document 2 discloses a method for manufacturing olefins, comprising: a step of heating a polyolefin plastic to obtain a decomposition product, and a step of contacting the obtained decomposition product with an MFI-type zeolite containing 0.10% to 0.30% by mass of sodium atoms to obtain a contact decomposition product containing olefins. Specifically, it discloses filling a downstream reaction tube with an MFI-type zeolite containing sodium atoms, allowing polyethylene, polypropylene, or a mixture thereof to flow from an upstream reaction tube to a downstream reaction tube, contacting the MFI-type zeolite containing sodium atoms, and simultaneously undergoing thermal decomposition at 525°C to obtain an olefin with 2 to 3 carbon atoms.

[0005] Furthermore, Patent Document 3 discloses that in a batch-type fixed-bed reactor filled with a catalyst, various plastics such as polyethylene, polypropylene, and polystyrene are thermally decomposed at 500°C to obtain gaseous products composed of C1~C3 olefins and alkanes, and liquid products (mainly C4+).

[0006] On the other hand, in continuous reaction apparatuses that use aromatic plastics such as polystyrene, chlorinated plastics such as polyvinyl chloride, and mixed plastics containing polyolefins as raw materials to obtain basic chemicals in one stage without intermediate products such as thermal decomposition oils, fluidized bed reactors are generally used. For example, Patent Document 4 discloses a method for producing olefins and aromatic compounds by introducing hydrocarbon feedstocks such as plastics and catalyst components into a reactor, using a packed bed reactor, i.e., a fixed bed reactor, but only an example of using a fluidized bed reactor is disclosed as a specific example. [Prior Art Documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2001-316517 [Patent Document 2] Japanese International Publication No. 2021 / 166854 [Patent Document 3] Japanese Patent Publication No. 2022-533116 [Patent Document 4] Japanese Patent Publication No. 2016-513147 [Summary of the Invention]

[0008] [Problem to be solved by the invention] However, the methods described in the prior art documents are unable to use mixed plastics as raw materials to obtain useful components such as lower olefins in high yield.

[0009] The purpose of this disclosure is to provide a method for manufacturing chemicals that can obtain useful components in high yield and with good efficiency. [Means for solving the problem]

[0010] As a means to solve the aforementioned problem, the following is provided. That is, <1> A method for manufacturing a chemical, which is a method for manufacturing at least one chemical selected from the group of olefins having 2 to 5 carbon atoms and aromatic hydrocarbons, comprising: feeding at least one of the group of aromatic plastics and chlorinated plastics, and a mixed plastic containing polyolefins, into a fixed-bed reaction section, wherein the fixed-bed reaction section has a filler layer filled with filler; and setting the temperature of the aforementioned filler layer to 820°C or below, and thermally decomposing the aforementioned mixed plastic in the presence of an inert gas. <2> In the method for manufacturing the chemical described in <1> above, when the volume of the aforementioned packing layer is set to V (cm3), the volume of the aforementioned packing material in the aforementioned packing layer is set to Vs (cm3), and the flow rate of the aforementioned inert gas is set to v (mL / min), the residence time of the aforementioned inert gas in the aforementioned fixed-bed reaction section is determined to be 2 seconds or less by the ratio [(V-Vs) / v]. <3> In the method for manufacturing the chemical described in <1> or <2> above, when the aforementioned thermal decomposition is carried out, the temperature of the aforementioned packing layer is set to 770°C or less. <4> In the method for manufacturing the chemical described in any one of <1> to <3> above, when the aforementioned thermal decomposition is carried out, the porosity of the aforementioned packing layer is 20% or more and 80% or less. <5> In the method for manufacturing the chemical described in any one of <1> to <4> above, the aforementioned polyolefin contains at least one selected from the group consisting of polyethylene and polypropylene. <6> A method for manufacturing a chemical as described in any one of <1> to <5> above, wherein the aforementioned aromatic plastic contains polystyrene. <7> A method for manufacturing a chemical as described in any one of <1> to <6> above, wherein the aforementioned chlorinated plastic contains at least one selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, and chlorinated polyethylene. <8> A method for manufacturing a chemical as described in any one of <1> to <7> above, wherein in the aforementioned thermal decomposition, when the volume of the aforementioned packing layer is set to V (cm3), the volume of the aforementioned packing material in the aforementioned packing layer is set to Vs (cm3), and the flow rate of the aforementioned inert gas is set to v (mL / min), the residence time of the aforementioned inert gas in the aforementioned fixed-bed reaction section is obtained by the ratio [(V-Vs) / v] for 0.1 seconds or more. <9> A method for manufacturing a chemical substance as described in any one of <1> to <8> above, wherein the temperature of the aforementioned filler layer is set to 500°C or higher during the aforementioned thermal decomposition. <10> A method for manufacturing a chemical substance as described in any one of <1> to <9> above, wherein the aforementioned aromatic hydrocarbon is selected from at least one of the group consisting of benzene, toluene, xylene, ethylbenzene, and styrene.<11> An apparatus for manufacturing a chemical, comprising at least one of a group consisting of olefins having 2 to 5 carbon atoms and aromatic hydrocarbons, wherein the apparatus comprises: a fixed-bed reaction section having a packing layer filled with packing material; a mixed plastic supply section for supplying a mixed plastic containing a polyolefin and at least one of a group consisting of aromatic plastics and chlorinated plastics to the fixed-bed reaction section; a gas supply section for supplying an inert gas to the fixed-bed reaction section; and a heating section for heating the temperature of the packing layer to below 820°C. <12> In the apparatus described in <11> above, where the volume of the aforementioned packing layer is V (cm3), the volume of the aforementioned packing material in the aforementioned packing layer is Vs (cm3), and the flow rate of the aforementioned inert gas is v (mL / min), the gas supply unit supplies the aforementioned inert gas in such a way that the residence time of the aforementioned inert gas in the aforementioned fixed-bed reaction unit is less than 2 seconds, as determined by the ratio [(V-Vs) / v]. <13> In the apparatus described in <11> or <12> above, the aforementioned heating unit heats the temperature of the aforementioned packing layer to below 770°C. <14> In the apparatus described in any one of <11> to <13> above, the porosity of the aforementioned packing layer is more than 20% and less than 80%. <15> In the apparatus described in any one of <11> to <14> above, the aforementioned polyolefin contains at least one selected from the group consisting of polyethylene and polypropylene. <16> The apparatus described in any one of <11> to <15> above, wherein the aromatic plastic contains polystyrene. <17> The apparatus described in any one of <11> to <16> above, wherein the chlorinated plastic contains at least one selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, and chlorinated polyethylene. <18> The apparatus described in any one of <11> to <17> above, wherein when the volume of the packing layer is set to V (cm3), the volume of the aforementioned packing material in the packing layer is set to Vs (cm3), and the flow rate of the aforementioned inert gas is set to v (mL / min), the gas supply unit supplies the aforementioned inert gas in such a way that the residence time of the aforementioned inert gas in the aforementioned fixed-bed reaction unit is 0.1 seconds or more, as obtained by the ratio [(V-Vs) / v]. <19> The apparatus described in any of <11> to <18> above, wherein the heating unit heats the temperature of the filler layer to 500°C or higher. [Effects of the invention].

[0011] According to the embodiments of this disclosure, a method for manufacturing a chemical product can be provided, which can obtain useful components with high yield and good efficiency.

Implementation Method

[0013] Hereinafter, embodiments of this disclosure will be described in detail. Furthermore, the embodiments are not limited to the following description, and can be appropriately modified without departing from the spirit of this disclosure. Also, the "~" used in this specification to indicate a numerical range, unless otherwise specified, means that the values ​​recorded before and after it are included as the lower and upper limits.

[0014] (Method for Manufacturing Chemicals) The method for manufacturing chemicals disclosed herein is a method for manufacturing at least one chemical selected from the group consisting of olefins having 2 to 5 carbon atoms and aromatic hydrocarbons, comprising: feeding at least one selected from the group consisting of aromatic plastics and chlorinated plastics, and a mixed plastic containing polyolefins, to a fixed-bed reaction section having a filler layer filled with filler; and, setting the temperature of the aforementioned filler layer to below 820°C, and thermally decomposing the aforementioned mixed plastic in the presence of an inert gas. The method for manufacturing chemicals disclosed herein may also include other processing as necessary.

[0015] The methods disclosed in Patent Documents 1 to 3 only disclose methods for thermally decomposing polyolefins alone, but do not disclose methods for efficiently thermally decomposing at least one of a group of aromatic plastics and chlorinated plastics, and a mixed plastic containing polyolefins, thereby producing useful components in high yield.

[0016] Generally, aromatic plastics and chlorinated plastics have lower decomposition temperatures compared to polyolefins. Therefore, if a mixture of these plastics is heated to the decomposition temperature of polyolefins, the aromatic and chlorinated plastics will carbonize. As a result, useful components cannot be obtained from the aromatic and chlorinated plastics. In addition to the problem of reduced yield of useful components, there is also the concern of blockage of the feed and decomposition product channels when using a fixed-bed reactor.

[0017] On the other hand, the fixed-bed reactor is simple in structure and easy to operate. Therefore, as long as a one-stage reaction can be carried out without generating a large amount of carbides from the mixed plastics, and useful components can be obtained in high yield, the fixed-bed reactor is ideal. Although Patent Document 4 discloses that the decomposition of mixed plastics can be carried out using a fixed-bed reactor, it does not describe the specific reaction conditions when using a fixed-bed reactor.

[0018] The inventors, through careful examination, have discovered a method for manufacturing a chemical that can obtain at least one chemical selected from the group consisting of olefins with 2 to 5 carbon atoms and aromatic hydrocarbons from a mixed plastic containing at least one of the group consisting of aromatic plastics and chlorinated plastics and polyolefins with high yield and good efficiency.

[0019] <Chemicals> The chemical manufactured by the method of manufacturing the chemical disclosed herein is at least one of the groups selected from olefins having 2 to 5 carbon atoms and aromatic hydrocarbons. Therefore, in this disclosure, "useful ingredient" means at least one of the groups selected from olefins having 2 to 5 carbon atoms and aromatic hydrocarbons.

[0020] Furthermore, in this disclosure, there are instances where alkenes having 2 to 5 carbon atoms are referred to as "lower alkenes". Also, in this disclosure, there are instances where aromatic hydrocarbons are referred to as "useful aromatic hydrocarbons".

[0021] <<Alkenes with 2 to 5 carbons>> As an alkene with 2 to 5 carbons, it is preferred to select at least one of the groups of alkenes with 2 to 5 carbons and dienes with 2 to 5 carbons, with alkenes with 2 to 5 carbons being more preferred.

[0022] As an olefin with two carbon atoms, ethylene can be cited as an example.

[0023] Propylene is an example of a 3-carbon olefin.

[0024] Examples of olefins with four carbon atoms include trans-2-butene, 1-butene, 2-methylpropene, cis-2-butene, 1,3-butadiene, isobutene, etc.

[0025] Examples of 5-carbon olefins include trans-2-pentene, 2-methyl-2-butene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, cis-2-pentene, 2-methyl-1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, and 1,3-cyclopentadiene.

[0026] Among these, the method for manufacturing the chemicals disclosed herein has the advantage of high yields of ethylene and propylene. There is no particular limitation on the total content (Cmol%) of ethylene and propylene in the chemicals, and it can be appropriately selected according to the purpose. It is preferable to have a content of 35 mol% to 70 mol% relative to the total carbon mol number (Cmol) of the chemicals, and even more preferably 36 mol% to 45 mol%.

[0027] Furthermore, in this disclosure, the content based on carbon mole number will be expressed as "Cmol%".

[0028] There is no particular limitation on the total content (Cmol%) of olefins with 2 to 5 carbons in the chemical product, and it can be appropriately selected according to the purpose. It is preferred to be 40 mol% to 90 mol% relative to the total carbon mol% (Cmol) of the hydrocarbon-containing composition, more preferably 42 mol% to 70 mol%, and even more preferably 45 mol% to 60 mol%.

[0029] Olefins with 2 to 5 carbon atoms can be used as basic chemicals suitable for chemical regeneration and can serve as raw materials for polyolefins. Polyolefins can be used in various fields such as plastic bags, cling film, straws, medical devices, appliance housings, erasers, hoses, tires, tubes, CD cases, food trays, food containers, plastic bottles, and fibers.

[0030] <<Aromatic Hydrocarbons>> There are no particular restrictions on aromatic hydrocarbons, but the three positional isomers of benzene, toluene, ethylbenzene, and xylene (p-xylene, m-xylene, and o-xylene), as well as styrene, are preferred, with the three positional isomers of benzene, toluene, and xylene being more preferred.

[0031] There is no particular limitation on the total content (Cmol%) of aromatic hydrocarbons in the chemical product, and it can be appropriately selected according to the purpose. It is preferable to be 20 mol% to 50 mol% relative to the total carbon mol number (Cmol) of the hydrocarbon-containing composition, and it is even more preferable to be 22 mol% to 30 mol%.

[0032] Furthermore, in this disclosure, there are instances where benzene, toluene, ethylbenzene, the three positional isomers of xylene (p-xylene, m-xylene, and o-xylene), and styrene are referred to as "useful aromatic hydrocarbons".

[0033] <<Byproducts>> Chemicals obtained by the manufacturing method of the chemicals disclosed herein may contain byproducts. Examples of byproducts include alkanes, carbon, and hydrogen.

[0034] As an alkane, there are no particular limitations, and examples include aliphatic saturated hydrocarbons having 1 to 5 carbon atoms, with aliphatic saturated hydrocarbons having 2 to 5 carbon atoms being preferred. Examples of aliphatic saturated hydrocarbons having 1 to 5 carbon atoms include chain aliphatic saturated hydrocarbons having 1 to 5 carbon atoms.

[0035] Specific examples of alkanes include methane, ethane, propane, isobutane, n-butane, and n-pentane. Among these, the method for manufacturing the chemicals disclosed herein has a low selectivity for methane.

[0036] The lower the methane content (Cmol%) in the chemical, the better. Relative to the total carbon mol number (Cmol) of the chemical, 12 mol% or less is preferred, 10 mol% or less is even better, and 9 mol% or less is especially preferred. The lower limit for the methane content in the chemical, relative to the total carbon mol number (Cmol) of the chemical, is preferably 0.1 mol% or more.

[0037] The total content (Cmol%) of alkanes having 1 to 5 carbons in the hydrocarbon-containing composition is preferably 35 mol% or less, more preferably 30 mol% or less, and even more preferably 10 mol% or less, relative to the total carbon mol% of the hydrocarbon-containing composition. The lower limit of the total content (Cmol%) of alkanes having 1 to 5 carbons in the hydrocarbon-containing composition is preferably 0.1 mol% or more, relative to the total carbon mol% of the hydrocarbon-containing composition.

[0038] -O / P Ratio- In this disclosure, the fact that the by-product alkane is less can be evaluated by calculating the ratio of the total content of olefins (Cmol%) to the total content of alkanes (Cmol%) in the chemical, that is, the ratio [total content of olefins (Cmol%) / total content of alkanes (Cmol%)] (hereinafter referred to as "O / P ratio"). In the manufacturing method of the chemical disclosed in this disclosure, the ratio [total content of olefins (Cmol%) / total content of alkanes (Cmol%)] is evaluated as the ratio [total content of olefins with 2 to 5 carbon atoms (Cmol%) / total content of alkanes with 2 to 5 carbon atoms (Cmol%)].

[0039] There are no particular restrictions on the O / P ratio for carbon numbers 2 to 5, and it can be appropriately selected according to the purpose. A ratio of 5 or higher is preferred, and a ratio of 10 or higher is even better. Since the higher the O / P ratio, the better, there are no particular restrictions on the upper limit of the O / P ratio for carbon numbers 2 to 5, but a ratio of 50 or lower is preferred, and a ratio of 20 or lower is even better.

[0040] The content of useful components contained in the chemical and the O / P ratio of carbon 2 to carbon 5 can be determined by analyzing the gaseous and liquid products obtained by the manufacturing method of the chemical disclosed herein using a gas chromatography (GC) apparatus equipped with a flame ionization detector.

[0041] When analyzing the gaseous products that are the products, analysis can be performed by gas chromatography (GC) equipped with a flame ionization detector under the analytical conditions described in the examples. The internal standard method is used, and each component is quantified by the ratio of the peak area of ​​each component to that of the internal standard. Furthermore, there are no particular limitations on the aforementioned internal standard, as long as it is stable under the analytical conditions and does not easily separate from the analyte component; examples include cyclopentane.

[0042] Furthermore, in the case of analyzing liquid substances as products, analysis can be performed by gas chromatography (GC) equipped with a flame ionization detector under the analytical conditions described in the examples. An internal standard method is used, and each component is quantified by the ratio of its peak area to that of the internal standard. Moreover, the aforementioned internal standard is not particularly limited as long as it is stable under analytical conditions and does not easily separate from the analyte; examples include cyclopentane.

[0043] Furthermore, the content of by-products, such as coking residues, contained in the product can be calculated by air combustion of the packing layer inside the fixed bed reaction section, or by extracting the packing material constituting the packing layer from the fixed bed reaction section and air combustion, based on the weight change before and after air combustion.

[0044] (Supply to fixed bed reaction section) The supply to fixed bed reaction section is to supply at least one of a group of aromatic plastics and chlorinated plastics, and a mixed plastic containing polyolefins to a fixed bed reaction section having a filler layer filled with fillers.

[0045] There are no particular limitations on the method of supplying the mixed plastic to the fixed-bed reaction section; the supply can be performed intermittently or continuously. Among these methods, intermittent supply is preferable in terms of reducing temperature changes in the filler layer.

[0046] When the mixed plastic is intermittently supplied to the fixed bed reaction section, there are no particular restrictions on the supply time, non-supply time, and interval between the supply and non-supply times of the mixed plastic.

[0047] When the mixed plastic is intermittently supplied to the fixed-bed reaction section, there is no particular limitation on the amount of mixed plastic supplied each time. When the mass of the filler filling the filler layer is defined as "Wf" (g) and the amount of mixed plastic supplied each time is defined as "Ws" (g), the ratio of Ws to Wf [Ws / Wf] is preferably 0.001 to 0.05, more preferably 0.002 to 0.02, and even more preferably 0.005 to 0.015. If the ratio [Ws / Wf] is in the range of 0.001 to 0.05, the temperature change during the supply of the mixed plastic to the filler layer is small, and the useful components can be obtained efficiently with a high yield.

[0048] In the case of intermittently supplying the mixed plastic to the fixed bed reaction section, from the viewpoint of preventing the temperature of the filler layer from dropping too low, it is preferable that the addition of the mixed plastic after the second addition should be done after the temperature of the filler layer, which has been reduced by the previous addition, has recovered to 680°C or higher.

[0049] When the mixed plastic is continuously supplied to the fixed-bed reaction section, there is no particular limitation on the amount of mixed plastic supplied. When the mass of the filler in the filler layer is defined as "Wf" (g), and the amount of mixed plastic supplied per unit volume is defined as "Wsc" (g / min), the ratio of Wsc to Wf [Wsc / Wf·min] is preferably 0.00025 to 0.0125, more preferably 0.0005 to 0.005, and even more preferably 0.00125 to 0.00375. If the ratio [Wsc / Wf·min] is within the range of 0.00025 to 0.0125, the temperature change during the supply of the mixed plastic to the filler layer is small, and the useful component can be obtained efficiently with a high yield.

[0050] <Mixed Plastics> The mixed plastics contain at least one selected from the group consisting of aromatic plastics and chlorinated plastics, and a polyolefin. The mixed plastics may also contain other components as necessary.

[0051] <<Aromatic Plastics>> Aromatic plastics refer to plastics with an aromatic backbone. There are no particular limitations on aromatic plastics; they can be selected appropriately from those widely used in beverage and food containers, packaging materials, molded articles, films, etc., depending on the purpose. Examples include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), acrylonitrile-butadiene-styrene copolymer, polycarbonate (PC), and polystyrene (PS). These can contain one type or two or more types. Among these, aromatic plastics containing polystyrene (PS) are preferred.

[0052] <<Chlorinated Plastics>> There are no particular restrictions on chlorinated plastics. They can be appropriately selected according to the purpose. It is preferable to contain at least one of the group consisting of polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and chlorinated polyethylene (CPE), which are widely used in beverage and food containers, packaging materials, molded articles, films, etc.

[0053] There is no particular limitation on the content of at least one of the groups of aromatic plastics and chlorinated plastics in the mixed plastics, and it can be appropriately selected according to the purpose. It is preferable to be 10% to 50% by mass relative to the total mass of the mixed plastics, and even more preferable to be 15% to 40% by mass. If the content of at least one of the groups of aromatic plastics and chlorinated plastics in the mixed plastics is 10% to 50% by mass, at least one chemical selected from the group of olefins with carbon 2 to carbon 5 and aromatic hydrocarbons can be obtained with high yield and good efficiency.

[0054] <<Polyolefin>> There are no particular restrictions on the polyolefin, and it can be appropriately selected according to the purpose. It is preferable to contain at least one of the groups of polyethylene (PE) and polypropylene (PP), which are widely used in beverage and food containers, packaging materials, molded articles, films, etc.

[0055] There are no particular restrictions on the content of polyolefins in the blended plastics, and it can be appropriately selected according to the purpose. It is preferable to be 50% to 90% by mass relative to the total mass of the blended plastics, and even better to be 60% to 85% by mass. If the content of polyolefins in the blended plastics is 50% to 90% by mass, in addition to the fact that it is not necessary to use readily available blended plastics separately, at least one chemical selected from the group of olefins with 2 to 5 carbon atoms and aromatic hydrocarbons can be obtained with high yield and good efficiency.

[0056] <<Other Components>> There are no particular restrictions on other components contained in the mixed plastics, and they can be appropriately selected according to the purpose. Examples include at least one of the groups of aromatic plastics and chlorinated plastics, as well as other plastics other than polyolefins; materials commonly contained in waste plastics such as paper and metals, etc. These may be contained individually or in two or more forms.

[0057] There are no particular restrictions on other plastics, and appropriate ones can be selected according to the purpose. Examples include polyamide, polyurethane, polymethyl methacrylate, etc.

[0058] There are no particular restrictions on the content of other components in the mixed plastic. It can be appropriately selected according to the type of mixed plastic used. From the viewpoint of the yield of at least one chemical group consisting of olefins with 2 to 5 carbon atoms and aromatic hydrocarbons, it is preferable to be less than 30% by mass relative to the total mass of the mixed plastic, preferably less than 25% by mass, and even more preferably less than 20% by mass.

[0059] From the perspective of reducing environmental impact, it is preferable for blended plastics to contain waste plastics. When blended plastics are made from waste plastics, there are no particular restrictions on the composition and composition ratio, and they can be appropriately selected according to the purpose. It is preferable to have PE of 20% to 40% by mass, PP of 20% to 40% by mass and PS of 10% to 30% by mass.

[0060] The structure and content of each component contained in the mixed plastic can be determined by analysis, for example, gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), liquid chromatography-mass spectrometry (LC-MS), thermal decomposition gas chromatography-mass spectrometry (PyGC-MS), matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOFMS).

[0061] The state of the mixed plastic supplied to the fixed-bed reactor is not particularly limited, and examples include crystalline, glassy, ​​rubbery, liquid, and undecomposed forms. The mixed plastic may also be in the form of decomposed products. Among these, from the viewpoint of easy control of the supply amount or obtaining hydrocarbon components from waste plastic in fewer steps, rubbery or liquid mixed plastics are preferred, and undecomposed plastics are even more preferred.

[0062] When the mixed plastic is crystalline or glassy, ​​there are no particular limitations on its form. Examples include crushed mixed plastic, granules of crushed mixed plastic, and chips of crushed mixed plastic.

[0063] There are no particular restrictions on the pulverized material used for mixing plastics. It can be selected appropriately according to the purpose. For example, it can be in powder form or flake form.

[0064] Rubber-like or liquid mixed plastics refer to plastics that are fluid at a temperature above the melting point of the mixed plastics but below the thermal decomposition temperature of the mixed plastics. Rubber-like or liquid mixed plastics are also referred to as "molten mixed plastics".

[0065] Decompositions of mixed plastics Materials that allow the mixed plastic to undergo hypomolecularization, but chemicals with a molecular weight greater than the final product, are typically obtained by heating the mixed plastic at a temperature above 300°C and less than 500°C.

[0066] The molecular weight of a rubbery or liquid hybrid plastic does not produce a change from the molecular weight of a crystalline or glassy hybrid plastic of the same composition. Therefore, the decompositions of hybrid and hybrid plastics cannot be distinguished by molecular weight. When the molecular weight changes due to decomposition, since the melting point will decrease, in practice it can be judged by the melting temperature. The melting temperature was measured by the method prescribed by JIS K7121-2012.

[0067] As the melting point of hybrid plastics, there are no special restrictions and can be appropriately selected according to the raw materials used, with 80°C~200°C preferably and 90°C~190°C.

[0068] The various forms of hybrid plastics may be used separately from the manufacturing method of an embodiment of the chemical and other treatments have been performed as described later.

[0069] <Fixed bed reaction portion> The fixed bed reaction portion has a filler layer filled with filler, and may more have other layers as necessary.

[0070] <<Filler Layer>> The filler layer is formed by filling the reaction portion with filler. The filler layer forms a fixed bed in the reactive portion of the fixed bed.

[0071] During the thermal decomposition of the filler layer, it is preferable to have a certain void in order to ensure the flow path of the mixed plastic and inert gas. As the filler layer, the void ratio ϕ, there is no special limitation, can be appropriately set according to the property state of the mixed plastic used, the conditions for thermal decomposition, etc. From the point of view of fully ensuring the flow path of the mixed plastic and inert gas, and the contact between the filler and the mixed plastic,

[0072] In this disclosure, "porosity ϕ" is the proportion of voids in the packing layer, calculated based on Equation 1 and Equation 2 below. [Equation 1] Porosity ϕ (%) = (1 - Vs / V) × 100 (In Equation 1, "Vs" represents the volume of the packing obtained by Equation 2 below (cm3), and "V" represents the volume of the packing layer (cm3). Furthermore, the volume of the packing layer is the volume of the packing filling section in the fixed bed reaction section.) [Equation 2] Vs = Wf / TD (In Equation 2, "Wf" represents the mass of the packing filling the packing layer (g), and "TD" represents the true density of the packing (g / cm3).)

[0073] There are no particular restrictions on the shape and structure of the filler layer, and it can be appropriately selected according to the purpose. From the viewpoint of enabling the mixed plastic and the generated chemicals to flow smoothly and ensuring sufficient contact time between the mixed plastic and the filler, it is preferable that the flow direction of the mixed plastic is perpendicular to the aforementioned flow direction, that is, longer than the inner diameter of the fixed bed reaction section.

[0074] - Packing - Packing is used to maintain the temperature of a reaction system undergoing thermal decomposition at a fixed temperature.

[0075] As a filler, there are no particular restrictions. It can be appropriately selected according to the purpose. It is preferable to be a material that is stable in the thermal decomposition temperature range where thermal decomposition occurs, is not affected by reduction caused by byproducts such as carbon and hydrogen generated during the thermal decomposition of the mixed plastic, and does not react with inert gases.

[0076] Specific examples of fillers include zirconium oxide, yttrium-stabilized zirconium oxide, calcium oxide-stabilized zirconium oxide, magnesium oxide, calcium oxide, silicon carbide, silicon nitride, silicon oxide, aluminum oxide, tantalum oxide, niobium oxide, beryllium oxide, lanthanum oxide, manganese oxide (II), chromium oxide (III), gallium oxide, magnesium silicate, cordierite, etc. Furthermore, fillers that have undergone surface treatment can also be used for purposes such as surface inertization and improving the flowability of mixed plastics. One type of these materials can be used alone, or two or more types can be used in combination. Among these, it is preferable to use one or more types of silicon carbide, aluminum oxide, silicon oxide, or surface-treated silicon carbide as fillers. It is also preferable to use one or more types selected from silicon carbide and aluminum oxide that have an inert surface that does not catalyze the oxidative decomposition reaction of water vapor and hydrocarbons and the carbon precipitation reaction, and have good thermal conductivity.

[0077] There are no particular limitations on the surface-treated filler, and it can be appropriately selected according to the purpose. Examples include fillers with an oxide film on the surface and fillers with a carbon film on the surface. Among these, from the viewpoint that surface-treated fillers are less likely to generate active sites due to surface treatment and can prevent side reactions, fillers with a carbon film on the surface are preferred.

[0078] There are no particular limitations on the method of surface treatment of the filler, and a suitable method can be selected from known methods.

[0079] For example, in the case of manufacturing fillers with an oxide film on the surface, a method can be given as forming an oxide film on the surface of the filler by oxidation.

[0080] Furthermore, in the case of manufacturing fillers with a carbon film on their surface, an example can be given: after attaching an organic compound to the surface of the filler, a carbon film is formed by firing it in the presence of an inert gas. From the viewpoint of easily forming a uniform and homogeneous carbon film, hydroxycarboxylic acids are preferred as the organic compound in the case of manufacturing fillers with a carbon film on their surface.

[0081] There are no particular limitations on the hydroxycarboxylic acid used; it can be selected appropriately according to the purpose. Examples include malic acid, citric acid, tartaric acid, gallic acid, salicylic acid, etc. One of these acids can be used alone, or two or more can be used in combination.

[0082] The structure of the surface-treated filler can be confirmed by, for example, observation using a scanning electron microscope (SEM), observation using a transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), micro Raman spectroscopy, etc.

[0083] The coverage rate of the filler formed by the carbon film on the filler with a carbon film on its surface is not particularly limited and can be appropriately selected according to the purpose. The mass ratio of carbon to filler in forming the carbon film [carbon / filler] is preferably 0.0001 to 0.5, more preferably 0.001 to 0.1, even more preferably 0.001 to 0.1, and particularly preferably 0.002 to 0.08. If the mass ratio [carbon / filler] is 0.0001 to 0.5, it can effectively assist the contact between fillers and efficiently enable the mixed plastic to undergo thermal decomposition in the thermal decomposition temperature range. Furthermore, the mass ratio [carbon / filler] is a mass ratio calculated from the mass of the organic compound that serves as the carbon source in the filler with a carbon film on its surface to the mass of the filler. Therefore, the coverage of the filler formed by the carbon film can be complete or partial. Therefore, carbon films are not only layered, but can also include those that appear to be island-like when observed on the surface.

[0084] The coverage rate of the filler formed by the carbon film in the filler with the carbon film on the surface can be confirmed by methods such as calculating from the amount of input or analyzing the weight change of the carbon film based on the weight change obtained by thermogravimetric differential thermal analysis (TG-DTA).

[0085] There are no particular restrictions on the size of the packing material, and it can be selected appropriately according to the purpose. A nominal sieve aperture of 90μm to 125mm is preferred, and 125μm to 90mm is even better. Furthermore, the size of the packing material is measured according to JIS Z 8801-1:2019.

[0086] There are no particular restrictions on the shape and structure of the filler, and it can be selected appropriately according to the purpose. The shape of the filler is preferably one in which the molten plastic mixed on the filler does not easily stagnate, and spherical shape is preferred, with true spherical shape being even better.

[0087] (Temperature Decomposition) The temperature of the aforementioned filler layer is set below 820°C, and the aforementioned mixed plastic is thermally decomposed in the presence of an inert gas. By performing thermal decomposition, at least one chemical substance selected from the group consisting of olefins having 2 to 5 carbon atoms and aromatic hydrocarbons can be obtained.

[0088] During thermal decomposition, there are no particular restrictions on the temperature of the filler layer as long as it is below 820°C, with 770°C being preferred. If the temperature of the filler layer is below 820°C, the useful components can be obtained with high yield and good efficiency. Furthermore, if the temperature of the filler layer is below 770°C, the byproducts generated from the decomposition of the mixed plastics can be suppressed, making it difficult to generate methane, a basic chemical.

[0089] During thermal decomposition, there are no particular restrictions on the lower limit of the filler layer temperature, as long as it can decompose the mixed plastic. It can be appropriately selected according to the purpose, with 500°C or above being preferred, 580°C or above being even better, and 650°C or above being even better. During thermal decomposition, if the temperature of the filler layer is above 500°C, the useful components can be obtained with high yield and good efficiency.

[0090] During thermal decomposition, the upper and lower limits of the temperature of the packing layer can be appropriately combined, preferably between 500°C and 820°C, better between 580°C and 820°C, and even better between 650°C and 770°C.

[0091] <Inert Gas> There are no particular restrictions on the inert gas, but it is preferable to use one that is stable in the temperature range of thermal decomposition.

[0092] Specific examples of inert gases include nitrogen, water vapor, carbon dioxide, and rare gases. One of these can be used alone, or two or more can be used together. Among these, as an inert gas, it is preferable to select one or more from the group consisting of nitrogen and water vapor, with nitrogen being the most preferred, since they are inexpensive.

[0093] During thermal decomposition, the flow rate of the inert gas is not particularly limited and can be appropriately selected according to the purpose. When the volume of the packing layer is set as V (cm³), the volume of the packing material in the packing layer is set as Vs (cm³), and the flow rate of the inert gas is set as v (mL / min), the residence time t of the inert gas in the fixed-bed reaction section, calculated using the ratio [(V-Vs) / v], is preferably 2.5 seconds or less, and more preferably 2 seconds or less. If the inert gas flow rate results in a residence time t of 2.5 seconds or less, sufficient contact time between the mixed plastic and the packing material can be ensured, and side reactions can be suppressed, thus enabling the acquisition of useful components with high yield and efficiency. Vs is calculated using Equation 2.

[0094] There is no particular limitation on the lower limit of the inert gas flow rate. From the viewpoint that the contact time between the mixed plastic and the filler can be fully ensured and the useful components can be obtained with high yield and good efficiency, it is preferable that the residence time t of the inert gas in the fixed bed reaction section is 0.1 seconds or more, preferably 0.5 seconds or more, and even more preferably 1 second or more.

[0095] The upper and lower limits of the inert gas flow rate can be appropriately combined. The residence time t of the inert gas in the fixed bed reaction section is preferably a flow rate of 0.1 seconds to 4.0 seconds, preferably a flow rate of 0.5 seconds to 2.5 seconds, and even more preferably a flow rate of 1 second to 2 seconds.

[0096] (Other treatments) The manufacturing method of the chemicals disclosed herein may also include, as necessary, other treatments besides supplying to a fixed-bed reaction section and performing thermal decomposition.

[0097] As other treatments, there are no particular limitations, and appropriate options can be selected depending on the purpose. Examples include pretreatment of mixed plastics, recycling of chemicals obtained by thermal decomposition, and separation of chemicals.

[0098] <<Pretreatment>> Pretreatment is the process of pre-treating the mixed plastics before they are delivered to the supply. By performing pretreatment, the mixed plastics are made into a form or state that is easy to decompose, thereby enabling more efficient decomposition of the mixed plastics.

[0099] As a pretreatment, examples include, pulverizing the mixed plastic, granulating (shaving) the pulverized mixed plastic, and melting the mixed plastic.

[0100] The melt treatment of mixed plastics is preferably carried out at a temperature not exceeding 300°C.

[0101] There are no particular restrictions on the pulverized form of mixed plastics. The appropriate form can be selected according to the purpose. For example, powder or flakes are acceptable.

[0102] There are no particular limitations on the method for obtaining pulverized mixed plastics. A suitable method can be selected from conventionally known methods. For example, a method of obtaining powder or small pieces by pulverizing mixed plastics using a pulverizer.

[0103] Furthermore, there are no particular limitations on the method of granulating (fragmenting) the pulverized material. It is appropriate to choose from the methods known in the past. For example, a method of obtaining the pulverized material by cutting the melt extrusion into strands after melt extrusion is given.

[0104] The mixed plastic system can also be supplied in a molten state. There are no particular limitations on the method of molten mixing of plastics, and conventionally known methods can be appropriately selected. For example, a method of continuously supplying to the decomposition step using a melt extruder can be cited.

[0105] <<Recovery>> Recovery refers to the recovery of liquid and gaseous products, including chemicals obtained through thermal decomposition. There are no particular limitations on the recovery method; a suitable method can be selected from known methods depending on the type of product obtained. Examples include methods for separating gaseous products by atmospheric or pressurized distillation, and methods for separating liquid hydrocarbons by atmospheric or vacuum distillation.

[0106] <<Separation>> Separation is a process of separating useful components from liquid and gas substances that have been recovered through recycling, while removing unwanted components.

[0107] The substance produced by the chemical manufacturing method disclosed herein may include at least one of the groups of olefins and aromatic hydrocarbons having carbon 2 to carbon 5, and may also include alkanes having carbon 2 to carbon 5 as by-components.

[0108] In the separation process, there are no particular restrictions on the method for separating the useful components and by-products. The appropriate method can be selected from known methods depending on the type of product or by-product obtained.

[0109] By means of the above-described chemical manufacturing method, at least one chemical selected from the group consisting of olefins having 2 to 5 carbon atoms and aromatic hydrocarbons can be obtained with high yield and good efficiency. The manufactured chemical can be used as a basic chemical suitable for chemical regeneration.

[0110] (Apparatus) The apparatus disclosed herein is an apparatus for manufacturing at least one chemical selected from the group consisting of olefins having 2 to 5 carbon atoms and aromatic hydrocarbons, comprising: a storage section containing a polyolefin and a mixed plastic selected from the group consisting of at least one aromatic plastic and a chlorinated plastic; a fixed-bed reaction section having a filler layer filled with filler; a mixed plastic supply section for supplying the aforementioned mixed plastic from the storage section to the aforementioned fixed-bed reaction section; a gas supply section for supplying an inert gas to the aforementioned fixed-bed reaction section; and a heating section for heating the aforementioned filler layer to a temperature of 820°C or below. The apparatus disclosed herein may be further equipped with other components as necessary.

[0111] The apparatus disclosed herein is suitable for carrying out the manufacturing method of the chemicals disclosed herein.

[0112] (First Embodiment) Hereinafter, embodiments of the apparatus disclosed herein will be described with reference to the drawings. FIG1 is a schematic cross-sectional view showing an example of the apparatus disclosed herein. The embodiments shown below are examples of apparatuses that embody the technical concept of the present disclosure, but the present disclosure is not limited thereto. Furthermore, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the constituent parts described below are not intended to limit the scope of the present disclosure to its essential points, but are intended as examples. Also, the size or positional relationship of the components shown in the drawings may be exaggerated for clarity. In addition, to avoid the drawings becoming overly complex, the schematic cross-sectional views are schematic diagrams using simplified illustrations of some elements.

[0113] The apparatus 100 includes: a fixed bed reaction section 1 having a filler layer 2, a plastic mixing supply section 3, a gas supply section 4, and a heating section 5.

[0114] <Fixed Bed Reaction Section> The fixed bed reaction section 1 is a component having a packing layer 2 filled with packing material 2a. The structure, shape, material, and size of the fixed bed reaction section 1 are not particularly limited, as long as they allow the packing layer 2 to be configured and allow the flow of a raw material M containing a polyolefin and at least one of a group consisting of aromatic plastics and chlorinated plastics. The appropriate material can be selected according to the purpose; for example, a cylindrical tube can be used. To retain the packing material within the tube, a material that allows the flow of organic compounds such as glass wool can be used to hold the tube in place.

[0115] <Mixed Plastic Supply Unit> The mixed plastic supply unit 3 is a component that supplies raw material M containing mixed plastic to the fixed bed reaction unit 1. Examples of mixed plastic supply units 3 include a raw material conveying unit 3a that allows the raw material M containing mixed plastic to flow, and a raw material feeding unit 3b that feeds the raw material M containing mixed plastic into the fixed bed reaction unit 1. The mixed plastic supply unit 3 can also use a known pump or the like to supply the raw material M to the fixed bed reaction unit 1.

[0116] Furthermore, the plastic mixing supply unit 3 may also have a material supply stop unit, such as a brake, for stopping the supply of the raw material M containing the plastic mixing. With the material supply stop unit, the plastic mixing can be intermittently supplied to the fixed-bed reaction unit 1. The material supply stop unit may be located, for example, at the inlet of the material input unit 3b.

[0117] <Gas Supply Unit> The gas supply unit 4 is a component that supplies inert gas G to the fixed bed reaction unit 1. Examples of gas supply units 4 include a gas flow unit 4a that causes the inert gas G to flow, and a pump 4b that causes the inert gas G to flow at a fixed amount for a fixed time.

[0118] <Heating Unit> The heating unit 5 is a component that heats the temperature of the filler layer 2 to below 820°C. There are no particular limitations on the heating unit 5; it can be an external heating method that heats the filler layer by conducting heat from the outside, or an internal heating method that heats the filler layer itself. For an external heating method, a known electric furnace can be used. For an internal heating method, a resistance heating method can be used, for example, using a conductive material such as silicon carbide as filler, and attaching electrodes to both ends of the filler layer, applying a voltage between the electrodes to heat it.

[0119] The temperature of the packing layer 2 can be measured by inserting a thermocouple in the center of the packing layer 2.

[0120] <Other Components> There are no particular restrictions on other components. They can be selected appropriately according to the purpose. Examples include storage section 6, cooling section 7, gas product recovery section 8, and measuring section for measuring the yield of useful components.

[0121] <<Storage Section>> Storage Section 6 is a component for storing raw material M, which includes: a mixed plastic containing polyolefin and selected from aromatic plastics and chlorinated plastics, and other components as necessary.

[0122] The structure, shape, material and size of the storage section 6 are not particularly limited as long as they can store raw material M containing mixed plastics, and can be appropriately selected according to the purpose.

[0123] There is no particular limitation on the number of storage sections 6; there may be one or more. When the device 100 has a plurality of storage sections 6, it can be used, for example, to store mixed plastics with different compositions and contents of each component in a mixed plastic containing a polyolefin and at least one of a group consisting of aromatic plastics and chlorinated plastics.

[0124] <<Cooling Unit>> The cooling unit 7 is a component for cooling the products obtained through the fixed-bed reaction unit 1. The cooling unit 7 is preferably disposed between the fixed-bed reaction unit 1 and the gas product recovery unit 8.

[0125] Examples of cooling units 7 include traps 7a for cooling the product and cold-preserving units 7b for cooling traps 7a. The structure, shape, material, and size of traps 7a and cold-preserving units 7b are not particularly limited as long as they can cool the product, and can be appropriately selected according to the purpose.

[0126] Trap 7a may also contain organic solvent 7c for dissolving the product. The organic solvent 7c allows the useful components in the product, especially liquid useful components, to condense. A non-aqueous solvent is preferred as the organic solvent for dissolving the product. Examples of non-aqueous solvents include aromatic organic solvents such as monochlorobenzene, o-dichlorobenzene, and mesitylene.

[0127] Useful components that have dissolved in non-aqueous solvents can be appropriately separated by distillation under normal pressure.

[0128] The cold insulation section 7b is not particularly limited as long as it can cool the trap 7a, and can also store, for example, refrigerant 7d. Examples of refrigerant 7d include ice water.

[0129] <<Gas Product Recovery Unit>> The gas product recovery unit 8 is a component that generates gas products containing useful components in the recovery device 100. There may be only one gas product recovery unit 8, or there may be two or more.

[0130] There are no particular restrictions on the structure, shape, material and size of the gaseous product recovery unit 8. It can be appropriately selected according to the purpose and the type of product. For example, a known container can be used.

[0131] Furthermore, the gas product recovery unit 8 may also contain solvents that can separate useful components. There are no particular restrictions on the solvent, and it can be appropriately selected according to the type of useful component that can be recovered. For example, solvents used to extract useful components from liquid products include ethanol, hexane, dimethylformamide, cyclopentane, and water.

[0132] The useful components in the gaseous products can be appropriately separated by further pressurized distillation.

[0133] <<Measuring Section>> The measuring section is a component that measures the yield of useful components in a product containing useful components manufactured in the measuring device 100.

[0134] The measuring unit may be located inside the device 100 or it may be connected to the outside of the device 100.

[0135] The measuring unit is not particularly limited as long as it can measure the yield of the useful component in the product, and can use a known measuring device. Examples of known measuring devices include flame ionization detector (FID) and thermal conductivity detector (TCD).

[0136] There are no particular restrictions on the structure, shape, material and size of the measuring part, and it can be appropriately selected according to the purpose and the type of product.

[0137] The apparatus 100, for example, can supply raw material M, which includes at least one group of aromatic plastics and chlorinated plastics, and a polyolefin-containing mixed plastic, stored in the storage section 6, to the fixed-bed reaction section 1 via the mixed plastic supply section 3, thereby carrying out the supply in the method for manufacturing the compound disclosed herein. The fixed-bed reaction section 1 functions as a fixed-bed reactor in the method for manufacturing the compound disclosed herein.

[0138] Subsequently, inert gas G can be supplied to the fixed bed reaction section 1 from the gas supply section 4, and the fixed bed reaction section 1 can be heated by the heating section 5 in such a way that the temperature is below 820°C, so as to carry out the heating in the method for manufacturing the compound disclosed herein.

[0139] The product containing useful components obtained by heating is recovered and separated in the cooling section 7 and the gas product recovery section 8 in the method for manufacturing the compound disclosed herein.

[0140] The chemicals produced by the apparatus 100 disclosed herein are those described in the method for producing the compounds disclosed herein.

[0141] (Second Embodiment) Figure 2 is a schematic cross-sectional view showing another example of the device disclosed herein. Except for the different configuration of the cooling section 7, the device of the second embodiment is the same as that of the device of the first embodiment.

[0142] In the second embodiment of the apparatus, the outlet of the product from the pipe connected to the fixed-bed reaction unit 1, disposed within the trap 7a of the cooling unit 7, is placed in the organic solvent 9c, resulting in a state where the gaseous product system bubbles in the organic solvent 9c. [Example]

[0143] The following examples and comparative examples are used to illustrate the present disclosure in detail, but the present disclosure is not limited to these examples and comparative examples.

[0144] (Example 1) <Preparation of the Mixed Plastic> Polyethylene (HI-ZEX 1300J, manufactured by Prime Polypro Co., Ltd.), polypropylene (Prime Polypro J108M, manufactured by Prime Polypro Co., Ltd.), and polystyrene (PSJ-SGP10-K3900, manufactured by PS Japan Co., Ltd.) were mixed in a 1:1:1 (w / w) ratio to prepare a mixed plastic. The prepared mixed plastic is represented as "PE+PP+PS" in Tables 1 and 2.

[0145] <Preparation of the Apparatus> Silicon carbide (SiC) particles (trade name: Carborundum, 16-mesh sieve (particle size: 1.119mm), manufactured by Toko Pharmaceutical Co., Ltd.) were filled into a quartz tube with an inner diameter of 2.2cm, with a filling length of 6cm. 35g of silicon carbide particles were used. The quartz tube was installed in a vertically oriented tubular furnace (trade name: ARF-30MC, manufactured by ASAHI RIKEN). A manual powder feeding device for introducing mixed plastics (airless feed cock, manufactured by Asahi Manufacturing Co., Ltd.) and a gas inlet were connected to the upper part of the tubular furnace and to the inlet side of the quartz tube. A gas extraction pipe was connected to one end of the lower part of the tubular furnace. The other end of the gas extraction pipe was connected to the inlet side of a cooling trap containing 15mL of o-dichlorobenzene (reagent grade, manufactured by Kanto Chemical Co., Ltd.). The cooling trap was placed in an ice bath. Connect one end of another gas extraction pipe to the outlet side of the cooling trap, and connect the other end of the other gas extraction pipe to a gas bag (10L volume). Insert a thermocouple into the center of the silicon carbide filling the quartz tube. Purge nitrogen gas from the gas inlet at a flow rate of 400 mL / min, set the temperature of the tubular furnace to 700°C, and begin heating.

[0146] <Decomposition of the Mixed Plastic> After the furnace reaches the set temperature of 700°C and stabilizes, the mixed plastic is repeatedly fed into the quartz tube 6 times over 4 minutes using a manual powder feeding device under a nitrogen flow rate of 400 mL / min. Subsequent feedings of the mixed plastic are only performed after the furnace temperature has returned to a range of 680°C to 700°C. After the total feeding of 1.98 g of mixed plastic is completed, the generated gas is captured using a gas bag. The gas bag is then removed from the device 5 minutes after the complete feeding of the mixed plastic. The cooling trap is then removed from the device after approximately 3 minutes of returning to room temperature (25°C ± 5°C).

[0147] (Example 2) Except for changing the furnace setting temperature from 700°C to 750°C in Example 1, the decomposition of the mixed plastic was carried out in the same way as in Example 1.

[0148] (Example 3) Except for changing the furnace setting temperature from 700°C to 800°C in Example 1, the decomposition of the mixed plastic was carried out using the same method as in Example 1.

[0149] (Example 4) Except for changing the supply time of the mixed plastic from 4 minutes to 3 minutes in Example 1, the method of decomposing the mixed plastic is the same as in Example 1.

[0150] (Example 5) Except for changing the nitrogen flow rate from 400 mL / min to 200 mL / min in Example 1, the decomposition of the mixed plastic was carried out in the same way as in Example 1.

[0151] (Example 6) Except for changing the nitrogen flow rate from 400 mL / min to 500 mL / min in Example 1, the decomposition of the mixed plastic was carried out in the same way as in Example 1.

[0152] (Example 7) Except that in Example 1, the 35g of silicon carbide particles filled into the quartz tube was replaced with 36g of alumina particles (Al2O3) (trade name: alumina balls HD-3, diameter: 30mm, manufactured by Nikkato Co., Ltd.), the decomposition of the mixed plastic was carried out in the same way as in Example 1.

[0153] (Example 8) Except that in Example 1, the 35g of silicon carbide particles that were filled into the quartz tube were replaced with 55g of zirconium oxide / silicon oxide mixture particles (trade name: zirconium balls CZS 0160, diameter: 1.40mm~1.60mm, manufactured by AS ONE Co., Ltd., composition: ZrO2 / 55%~65%, SiO2 / 35%~45%), the decomposition of the mixed plastic was carried out in the same way as in Example 1.

[0154] (Example 9) Except for Example 1, except that the type of filler was changed from silicon carbide particles to carbon-coated silicon carbide particles manufactured by the following method (sometimes referred to as "surface-treated SiC"), the decomposition of the mixed plastic was carried out in the same way as in Example 1.

[0155] <Preparation of Carbon-Coated Silicon Carbide Particles> Measure 0.50 g of citric acid monohydrate (citric acid monohydrate, reagent grade, manufactured by Fujifilm and Hikari Pure Chemical Industries Co., Ltd.) and 10 g of ethanol (reagent grade, manufactured by Kanto Chemical Co., Ltd.) into a 250 mL covered container. Cover and stir until the citric acid is completely dissolved. Add 66 g of silicon carbide particles (trade name: Densilic C, particle size (JIS R 6001-1-2017) F10, manufactured by Resonac Co., Ltd.) to the container, stirring until the solution completely covers the silicon carbide particles. Remove the lid of the container and place it in a vacuum desiccator. Reduce the pressure to less than 20 kPa at room temperature and dry. Continue drying until completely dry, removing the container from the vacuum desiccator at intervals of several tens of minutes and stirring. The completely dried mixture was transferred to an alumina boat and calcined at 800°C for 1 hour in a nitrogen atmosphere to obtain carbon-coated silicon carbide particles.

[0156] (Example 10) Except for changing the nitrogen flow rate from 400 mL / min to 200 mL / min in Example 9, the decomposition of the mixed plastic was carried out in the same way as in Example 9.

[0157] (Comparative Example 1) Except for changing the furnace setting temperature from 700°C to 850°C in Example 1, the decomposition of the mixed plastic was carried out in the same way as in Example 1.

[0158] <<Analysis of contents of gas bags>> In Examples 1 to 10 and Comparative Example 1, the yields of useful components and byproducts in the thermally decomposed gas recovered in the gas bags were determined using the following method based on carbon mole number (Cmol%).

[0159] Add 40 μL of cyclopentane (>98.0%, manufactured by Tokyo Chemical Industry Co., Ltd.) to the gas bag. Heat the gas bag to 40°C to completely vaporize the contents, then gently knead the gas bag to mix the contents. Use the obtained contents as an analytical sample and analyze by gas chromatography (GC) under the following GC analytical conditions. Calculate the proportion (Cmol%) of each component in the gas bag from the ratio of the peak area of ​​cyclopentane to the peak area of ​​each component. The results are shown in Tables 1 and 2. [GC Analysis Conditions] • Apparatus: Nexis GC-2030 (Shimadzu Corporation) • Column: Rt-Alumina BOND (diameter: 0.32 mm, length: 30 m, Restek) • Carrier gas type: Ar • Carrier gas flow rate: 360 mL / min • Injection temperature: 200 °C • Sample injection volume: 1 mL • Split ratio: 1 / 200 • Column temperature: Hold at 120 °C for 9 minutes, then increase to 200 °C at 10 °C / min, and hold at 200 °C for 30 minutes. • Detector: Flame ionization detector (FID) • Detector temperature: 200 °C

[0160] <<Analysis of the contents of the cooling trap>> In Examples 1 to 10 and Comparative Example 1, the yields of useful components and byproducts in the thermally decomposed components recovered into the cooling trap were determined using the following method based on carbon mole number (Cmol%).

[0161] Transfer the contents to a sample vial, and add 2 mL of o-dichlorobenzene (premium grade, manufactured by Kanto Chemical Co., Ltd.) to the nearly empty cooling trap to dissolve the contents, then transfer it to the previously prepared sample vial. Repeat three times to thoroughly clean the cooling trap. Add cyclopentane (>98.0%, manufactured by Tokyo Chemical Industry Co., Ltd.) as an internal standard to the sample vial as the analytical sample, and analyze by gas chromatography (GC) under the following GC analytical conditions. Calculate the proportion (Cmol%) of each component in the cooling trap from the ratio of the peak area of ​​cyclopentane to the peak area of ​​each component. The results are shown in Tables 1 and 2. [GC Analysis Conditions] • Apparatus: Nexis GC-2030 (Shimadzu Corporation) • Column: DB-1 (Diameter: 0.25 mm, Length: 30 m, Agilent Technologies) • Carrier Gas Type: He • Carrier Gas Flow Rate: 97 mL / min • Injection Temperature: 350℃ • Sample Injection Volume: 1 μL • Split Ratio: 1 / 50 • Column Temperature: Temperature program set in the sequence of 35℃ (10 min) → ramp (5℃ / min) → 350℃ (10 min) • Detector: Flame Ionization Detector (FID) • Detector Temperature: 350℃

[0162] <<Calculation of Firing Loss Rate>> In Examples 1-10 and Comparative Example 1, after the decomposition of the mixed plastic was completed, o-dichlorobenzene (reagent grade, manufactured by Kanto Chemical Co., Ltd.) and acetone (reagent grade, manufactured by Kanto Chemical Co., Ltd.) were fed into the manual powder feeding device to wash the filler layer. Then, the mixture was allowed to stand for 10 minutes under a nitrogen atmosphere at a flow rate of 1,600 NmL / min to remove o-dichlorobenzene and acetone from the filler layer. Subsequently, the quartz tube with the filler layer was fired at 200°C for 30 minutes under a nitrogen atmosphere at a flow rate of 1,600 NmL / min. The mass X after firing was measured under a nitrogen atmosphere. Next, the quartz tube with the filler layer was fired at 600°C for 30 minutes under an air atmosphere at a flow rate of 500 NmL / min. The mass Y after air firing was measured. The firing loss rate was calculated from the measured value based on the following formula. This value corresponds to the amount of coke. The firing loss rate in Examples 1-10 and Comparative Example 1 was 0% by mass. Firing loss rate (mass%) = (mass X - mass Y) / mass of raw material M input × 100

[0163] In Tables 1 and 2, “Yield of useful components” and “Yield of by-products” refer to the ratio of the total number of moles of carbon atoms in each product recorded in Tables 1 and 2 to the number of moles (Cmol) of carbon atoms contained in the mixed plastic.

[0164] In Tables 1 and 2, "total yield of useful components" refers to the ratio of the total number of moles of carbon atoms contained in the 2- to 5-carbon olefins and useful aromatic hydrocarbons in the product to the number of moles of carbon atoms contained in the mixed plastic. "Useful ingredients" refers to ethylene, propylene, 4-carbon olefins (trans-2-butene, 1-butene, 2-methylpropene, cis-2-butene, 1,3-butadiene, and isobutene), 5-carbon olefins (trans-2-pentene, 2-methyl-2-butene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, cis-2-pentene, 2-methyl-1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, and 1,3-cyclopentadiene), and useful aromatic hydrocarbons (benzene, toluene, ethylbenzene, the three positional isomers of xylene (p-xylene, m-xylene, and o-xylene), and styrene.

[0165] Furthermore, in Tables 1 and 2, the "O / P ratio of carbon 2 to carbon 5" is calculated based on the following Equation 3. [Equation 3] O / P ratio of carbon 2 to carbon 5 = [Total content of alkenes of carbon 2 to carbon 5 (Cmol%)] / [Total content of alkanes of carbon 2 to carbon 5 (Cmol%)]

[0166] Since the calcination loss rate of Examples 1-10 and Comparative Example 1 was 0% by mass, the "Yield of Useful Components" and "Yield of By-products" in Tables 1 and 2 are the same values ​​as the ratio of the total moles of carbon atoms in each product to the moles of carbon atoms (Cmol) contained in the total mass of the products in Examples 1-10 and Comparative Example 1. The "Total Yield of Useful Components" in Tables 1 and 2 is also the same, being the same value as the ratio of the total moles of carbon atoms contained in the olefins with 2 to 5 carbon atoms and the useful aromatic hydrocarbons in the products to the moles of carbon atoms (Cmol) contained in the total mass of the products in Examples 1-10 and Comparative Example 1.

[0167]

[0168]

[0169] As described above, this disclosure is based on specific embodiments and examples. However, these embodiments and examples are merely illustrative, and this disclosure is not limited to the aforementioned embodiments and examples. The aforementioned embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, additions, and modifications can be made without exceeding the scope of the invention's spirit. These embodiments or their variations are all included within the scope or spirit of the invention, and are included within the scope of the invention described in the patent application and its equivalents.

[0170] This international application claims priority based on Japanese Patent Application No. 2024-028236, filed on February 28, 2024, and incorporates by reference the entire contents of Japanese Patent Application No. 2024-028236 in this international application. [Simplified Explanation of the Diagram]

[0012] [Figure 1] Figure 1 is a schematic cross-sectional view showing one example of the device disclosed herein. [Figure 2] Figure 2 is a schematic cross-sectional view showing another example of the device disclosed herein.

Claims

1. A method for manufacturing a chemical, comprising: supplying a mixed plastic containing at least one of the groups selected from olefins having 2 to 5 carbon atoms and aromatic hydrocarbons, the mixed plastic comprising: feeding a mixed plastic containing at least one of the groups selected from aromatic plastics and chlorinated plastics, and a polyolefin, the mixed plastic comprising having a packing layer filled with a filler; and thermally decomposing the mixed plastic in the presence of an inert gas at a temperature of 820°C or below; wherein, during the thermal decomposition, when the volume of the packing layer is V (cm3), the volume of the filler in the packing layer is Vs (cm3), and the flow rate of the inert gas is v (mL / min), the residence time of the inert gas in the fixed-bed reaction section is determined by the ratio [(V-Vs) / v] to be 0.1 seconds or more and 2 seconds or less.

2. A method for manufacturing the chemical as claimed in claim 1, wherein during the aforementioned thermal decomposition, the temperature of the aforementioned filler layer is set to below 770°C.

3. A method for manufacturing a chemical as claimed in claim 1 or claim 2, wherein during the aforementioned thermal decomposition, the porosity of the aforementioned filler layer is 20% or more and 80% or less.

4. A method for manufacturing the chemical as claimed in claim 1 or claim 2, wherein the aforementioned polyolefin contains at least one selected from the group consisting of polyethylene and polypropylene.

5. A method for manufacturing the chemical as described in claim 1 or claim 2, wherein the aforementioned aromatic plastic contains polystyrene.

6. A method for manufacturing the chemical as claimed in claim 1 or claim 2, wherein the aforementioned chlorinated plastic contains at least one selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, and chlorinated polyethylene.

7. A method for manufacturing the chemical as claimed in claim 1 or claim 2, wherein the temperature of the aforementioned filler layer is set to 500°C or higher during the aforementioned thermal decomposition.

8. A method for manufacturing the chemical as claimed in claim 1 or claim 2, wherein the aforementioned aromatic hydrocarbon is selected from at least one of the group consisting of benzene, toluene, xylene, ethylbenzene, and styrene.

9. An apparatus for manufacturing a chemical, comprising at least one of an olefin selected from the group consisting of olefins having 2 to 5 carbon atoms and aromatic hydrocarbons, wherein the apparatus comprises: a fixed-bed reaction section having a packing layer filled with packing material; a mixed plastic supply section for supplying a mixed plastic containing a polyolefin and at least one of an aromatic plastic and a chlorinated plastic to the fixed-bed reaction section; a gas supply section for supplying an inert gas to the fixed-bed reaction section; and a heating section for heating the temperature of the packing layer to below 820°C; wherein... When the volume of the aforementioned packing layer is set as V (cm3), the volume of the aforementioned packing material in the aforementioned packing layer is set as Vs (cm3), and the flow rate of the aforementioned inert gas is set as v (mL / min), the residence time of the aforementioned inert gas in the aforementioned fixed bed reaction section is determined by the ratio [(V-Vs) / v] and is made to be more than 0.1 seconds and less than 2 seconds.

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