Method for producing hydrocarbon-containing compositions

Abstract

To provide a method for producing hydrocarbon-containing compositions that yields excellent yields of useful components such as lower olefins and useful aromatic compounds. [Solution] The method for producing the hydrocarbon-containing composition of this disclosure is Rb + The method involves heating the plastic decomposition product in the presence of a zeolite containing the hydrocarbon-containing composition, wherein the hydrocarbon-containing composition contains at least one selected from the group consisting of olefins having 2 to 5 carbon atoms, benzene, toluene, ethylbenzene, and xylene.

Description

[Technical Field]

[0001] This disclosure relates to a method for producing a hydrocarbon-containing composition. [Background technology]

[0002] Traditionally, waste plastics have been disposed of through landfill, ocean dumping, or incineration. However, securing landfill sites is becoming increasingly difficult, and ocean dumping poses environmental problems because plastics do not decompose. Furthermore, while incineration can be used to generate heat, the emission of carbon dioxide contributes to global warming.

[0003] Therefore, in recent years, with the growing awareness of environmental issues, the recycling of waste plastics, including reuse and regeneration, has become necessary, and research and development for this purpose is actively underway. Furthermore, since much of the plastic is produced using fossil fuels, there is a strong demand for the development of recycling methods from the perspective of efficient resource utilization.

[0004] Among plastic materials, hydrocarbon-based plastics such as polyethylene (PE), polypropylene (PP), and polystyrene (PS) are widely used in beverage and food containers, packaging materials, molded products, and films due to their excellent properties such as heat resistance, weather resistance, mechanical strength, transparency, chemical resistance, and gas barrier properties. Therefore, these hydrocarbon-based plastics constitute the majority of waste plastic materials. One method of recycling these plastics involves using thermal decomposition products, such as oil obtained from the thermal decomposition of plastics, as raw materials to produce lower olefins and chemicals such as benzene. In this process, methods using solid catalysts are frequently being investigated to improve reactivity and product selectivity.

[0005] For example, a method for producing olefins that yields excellent yields of olefins having 2 to 3 carbon atoms and also has an excellent ratio of olefins to paraffins in the catalytic decomposition product having 2 to 3 carbon atoms has been proposed, which includes a catalytic decomposition step in which a thermal decomposition product obtained by heating a polyolefin-based plastic is brought into contact with an MFI-type zeolite containing 0.10% to 0.30% by mass of sodium atoms to obtain a catalytic decomposition product containing olefins (see Patent Document 1). In addition, Ga-supported zeolite (HZSM-5 and HZSM-11) catalysts have been proposed as catalysts with high aromatic yields, and NaHZSM-5, which is obtained by exchanging Na ions with HZSM-5, has been proposed as a catalyst with high selectivity for lower olefins (see Non-Patent Document 1). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2021 / 166854 [Non-patent literature]

[0007] [Non-Patent Document 1] Yoshio Kamimichi, Yasuharu Kanda, "Hydrogen-Transfer Type Decomposition of Plastic Mixtures Using Zeolite-Based Catalysts," Catalysis, 2023, Vol. 65, No. 2, pp. 114-119. [Overview of the project] [Problems that the invention aims to solve]

[0008] The purpose of this disclosure is to provide a method for producing hydrocarbon-containing compositions that yields excellent yields of useful components such as lower olefins and useful aromatic compounds. [Means for solving the problem]

[0009] The means to solve the aforementioned problem are as follows: <1> A method for producing a hydrocarbon-containing composition, Rb+ This includes heating plastic decomposition products in the presence of a zeolite containing the following: The present invention relates to a method for producing a hydrocarbon-containing composition, characterized in that the hydrocarbon-containing composition contains at least one selected from the group consisting of olefins having 2 to 5 carbon atoms, benzene, toluene, ethylbenzene, and xylene. <2> The plastic decomposition product is a fluid obtained by heating the raw material plastic at a temperature of 400°C to 700°C under an inert gas atmosphere selected from the group consisting of nitrogen and water vapor. <1> This is a method for producing the hydrocarbon-containing composition described above. <3> The aforementioned plastic decomposition product is Rb + The fluid is obtained by heating the raw material plastic at a temperature of 400°C to 700°C in the presence or absence of a catalyst other than a zeolite containing the above, and in an inert gas atmosphere selected from the group consisting of nitrogen and water vapor. <1> or the above <2> This is a method for producing the hydrocarbon-containing composition described above. <4> The plastic that serves as the raw material for the plastic decomposition product contains polyolefin, <1> from the above <3> This is a method for producing a hydrocarbon-containing composition as described in any one of the items. <5> The plastic used as a raw material for the plastic decomposition product contains at least one selected from the group consisting of polyethylene, polypropylene, and polystyrene. <1> from the above <4> This is a method for producing a hydrocarbon-containing composition as described in any one of the items. <6> The temperature at which the plastic decomposition product is heated is 300°C or more and 600°C or less. <1> from the above <5> This is a method for producing a hydrocarbon-containing composition as described in any one of the items. <7> The aforementioned Rb + Zeolites containing beta-type Rb + Zeolite and mordenite-type Rb containing + At least one selected from the group consisting of zeolites containing the above <1> from the above <6> This is a method for producing a hydrocarbon-containing composition as described in any one of the items. <8> The aforementioned Rb + The molar ratio of SiO2 to Al2O3 [SiO2 / Al2O3] of the zeolite containing the above is 10 or more and 10,000 or less. <1> from the above <7> This is a method for producing a hydrocarbon-containing composition as described in any one of the items. [Effects of the Invention]

[0010] According to embodiments of this disclosure, it is possible to provide a method for producing a hydrocarbon-containing composition that yields excellent yields of useful components such as lower olefins and useful aromatic compounds. [Modes for carrying out the invention]

[0011] The present disclosure will be described in detail below. However, the embodiments of this disclosure are not limited to those described below and may be modified as appropriate without departing from the gist of this disclosure. Furthermore, in this specification, the "~" indicating a numerical range means that the numbers before and after it are included as the lower and upper limits, respectively, unless otherwise specified.

[0012] (Method for producing hydrocarbon-containing compositions) The method for producing the hydrocarbon-containing composition disclosed herein is Rb + The method for producing the hydrocarbon-containing composition of this disclosure may further include, if necessary, other treatments.

[0013] <To be heated> By heating, Rb + The plastic decomposition product is heated in the presence of a zeolite containing [a specific substance]. By heating, a hydrocarbon-containing composition is obtained that contains at least one selected from the group consisting of olefins having 2 to 5 carbon atoms, benzene, toluene, ethylbenzene, and xylene.

[0014] In this disclosure, olefins having 2 to 5 carbon atoms may be referred to as "lower olefins." In this disclosure, at least one selected from the group consisting of benzene, toluene, ethylbenzene, and xylene may be referred to as "useful aromatic compounds." In addition, in this disclosure, lower olefins and useful aromatics together may be referred to as "useful components."

[0015] The method for producing the hydrocarbon-containing composition described herein uses plastic decomposition products as raw materials and yields a higher yield of useful components compared to conventional methods using catalysts.

[0016] In the method for producing the hydrocarbon-containing composition of this disclosure, a gaseous product and a liquid product are obtained as the hydrocarbon-containing composition. The gaseous and liquid products obtained as hydrocarbon-containing compositions by heating are analyzed using a gas chromatograph (hereinafter sometimes abbreviated as "GC") equipped with a flame ionization detector under the conditions described in the examples, and each component can be quantified from the ratio of the peak area of ​​each component to that of the internal standard substance by the internal standard method.

[0017] In this disclosure, "useful component yield" is the ratio of the mass of the useful component quantified by the internal standard method to the mass of the plastic decomposition product used as the raw material, and is calculated by the following formula. Useful component yield (%) = Mass of useful components produced by GC analysis [g] / Total mass of plastic decomposition products [g] × 100

[0018] Furthermore, there are no particular restrictions on the internal standard substance used in GC analysis, as long as it is stable under the analytical conditions and easily separated from the analyte. For example, at least one of the group consisting of cyclopentane and t-butylbenzene can be used.

[0019] The total mass of plastic decomposition products used to determine the yield of useful components can be calculated from the amount used. Furthermore, if the method for producing the hydrocarbon-containing composition of this disclosure includes decomposing plastic as described later, the total mass of plastic decomposition products can be calculated by the following method. First, the mass X of the plastic used as raw material for decomposing the plastic is measured. Next, after decomposing the plastic, tetrahydrofuran (THF) is added to the obtained product, and the resulting insoluble matter is vacuum-dried at 25°C for 24 hours, and its mass Y is measured. The mass of plastic decomposition products can be determined by subtracting mass Y from mass X.

[0020] In the method for producing the hydrocarbon-containing composition of this disclosure, the yield of useful components is preferably 50% or more, and more preferably 55% or more. A higher yield of useful components is preferable, and there is no particular upper limit.

[0021] In the method for producing the hydrocarbon-containing composition of this disclosure, the yield of the lower olefin is preferably 40% or more, and more preferably 45% or more. A higher yield of the lower olefin is preferable, and there is no particular upper limit.

[0022] In the method for producing the hydrocarbon-containing composition of this disclosure, the yield of useful aromatics is preferably 5% or more, and more preferably 10% or more. A higher yield of useful aromatics is preferable, and there is no particular upper limit.

[0023] In addition, the method for producing the hydrocarbon-containing composition of the present disclosure has a high improvement rate of the useful component yield compared to the conventional decomposition method using zeolite. In the present disclosure, the "improvement rate of the useful component yield" means the ratio of the useful component yield when heating is performed using a zeolite of a specific crystal system (zeolite framework) as a reference zeolite (for example, the zeolite conventionally used for plastic decomposition) to the useful component yield when heating is performed under the same conditions using a comparative zeolite. Specifically, the improvement rate of the useful component yield is obtained by the following formula. However, the reference zeolite used is of the same crystal system as the comparative zeolite. Improvement rate of useful component yield (%) = Useful component yield of comparative zeolite [%] / Useful component yield of reference zeolite [%] × 100

[0024] For example, when the reference zeolite is an MFI-type zeolite containing H + and the comparative catalyst is an MFI-type zeolite containing Rb + in the case of an MFI-type zeolite containing H + and an MFI-type zeolite containing Rb + are each used to perform heating under the same conditions, and the useful component yields are calculated respectively. Based on this useful component yield, the improvement rate of the useful component yield is obtained by the following formula. Improvement rate of useful component yield (%) = Useful component yield of MFI-type zeolite containing Rb + [%] / Useful component yield of MFI-type zeolite containing H + [%] × 100

[0025] If the improvement rate of the useful component yield is 100% or more, it can be said that the improvement effect of the useful component yield is higher than that of the reference zeolite. However, as the improvement rate of the useful component yield in the method for producing the hydrocarbon-containing composition of the present disclosure, 115% or more is preferable, and 120% or more is more preferable.

[0026] In heating, Rb with respect to the plastic decomposition product +There are no particular restrictions on the amount of zeolite containing Rb used, and it can be appropriately selected according to the purpose, but it is preferably 100 parts by mass or less per 100 parts by mass of plastic degradation product, more preferably 1 to 100 parts by mass, even more preferably 10 to 100 parts by mass, even more preferably 20 to 100 parts by mass, and particularly preferably 1 to 30 parts by mass. + When the amount of zeolite containing is 10 parts by mass or more and 100 parts by mass or less per 100 parts by mass of plastic decomposition product, the yield of useful components is good.

[0027] There are no particular restrictions on the reaction method used in heating, and it can be appropriately selected depending on the purpose. Examples include batch reaction methods, fixed-bed reaction methods, and fluidized-bed reaction methods.

[0028] Heating can be carried out in a reactor appropriately selected according to the desired reaction method, such as a batch reactor, fixed-bed reactor, or fluidized-bed reactor.

[0029] In heating, there are no particular restrictions on the temperature at which the plastic decomposition material is heated (hereinafter sometimes referred to as the "heating temperature"), and it can be appropriately selected depending on the purpose, but 300°C to 600°C is preferred, and 350°C to 500°C is more preferred. When the heating temperature is 300°C to 600°C, Rb + Zeolites containing this substance are easily activated, and yields of useful components are good.

[0030] In terms of heating, there are no particular restrictions on the heating time of the plastic decomposition material (hereinafter sometimes referred to as "heating time"), and it can be appropriately selected depending on the reaction system, etc.

[0031] For example, when heating by a batch reaction method using a sealed batch reactor, the heating time is preferably 1 hour to 20 hours, and more preferably 5 hours to 10 hours. When the heating time by the batch reaction method is 1 hour or more, the plastic decomposition products can be suitably decomposed, and the yield of useful components is good. Furthermore, when the heating time by the batch reaction method is 20 hours or less, it is efficient.

[0032] In continuous reactors such as fixed-bed reactors and fluidized-bed reactors, the heating time is the time from when the plastic decomposition products reach the reactor inlet heated to a predetermined temperature, until they are converted within the reactor and discharged outside the reactor as a hydrocarbon-containing composition. Therefore, the heating time depends on the flow rate of the inert gas circulating in the reactor, the composition and yield of the hydrocarbon-containing composition, and the progress of the reaction within the reactor, making it difficult to measure accurately. However, as a guideline, if the gas space velocity (GHSV) calculated for the inert gas is 30h -1 ~100h -1 It is preferable that this is the case. The gas space velocity is the value obtained by dividing the volume of the target component, in this case the inert gas, flowing into the continuous reactor per unit time by the reactor volume. The volume of the inert gas flowing in is determined based on the ideal gas volume at standard conditions (0°C, 1 bar).

[0033] There are no particular restrictions on the atmosphere in which heating is performed, and it can be appropriately selected depending on the purpose, but it is preferable to perform the heating under an inert gas atmosphere. There are no particular restrictions on the inert gas, and it can be appropriately selected depending on the purpose, for example, nitrogen gas, water vapor, and argon gas. These may be used individually or in combination of two or more.

[0034] <<Plastic Decomposition Products>> The plastic decomposition products used as raw materials in the heating process are obtained by thermally decomposing plastics. At the heating temperature, the plastic decomposition products are fluid. In this disclosure, "fluid" means liquid or gas.

[0035] The plastic decomposition product is not particularly limited as long as it is obtained by thermally decomposing plastic, but it is preferable that the total amount of C (carbon) and H (hydrogen) determined by elemental analysis is 70% by mass or more, and more preferably 80% by mass or more. When the total amount of C (carbon) and H (hydrogen) determined by elemental analysis in the plastic decomposition product is 70% by mass or more, a hydrocarbon-containing composition with a high yield of useful components can be obtained using readily available plastic decomposition products. In the plastic decomposition product, the higher the total amount of C (carbon) and H (hydrogen) determined by elemental analysis, the better, and it may even be 100% by mass.

[0036] In heating, the plastic decomposition product may be the liquid or gas obtained by thermally decomposing the plastic as is, or it may be a product that has been processed to remove impurities such as ash, metals, halogens, nitrogen, sulfur, and oxygen-containing compounds derived from the plastic, or a product that has been processed to adjust the boiling point range and viscosity by methods such as distillation or membrane separation.

[0037] As the plastic decomposition product used as a raw material for heating, commercially available plastic decomposition products may be used, or those manufactured by known methods may be used.

[0038] One example of a commercially available product containing plastic biodegradables is the plastic biodegradable oil offered by Neste.

[0039] There are no particular restrictions on the method for producing plastic decomposition products, and examples include the method described in "<<Decomposing plastics>>" under "<Other treatments>" below. Among these, it is preferable that the plastic decomposition product is a fluid obtained by heating the raw material plastic at 400°C to 700°C under an inert gas atmosphere selected from at least one of the group consisting of nitrogen and water vapor.

[0040] < <Rb + Zeolite containing >> Rb +In a zeolite containing Rb as a percentage of the zeolite mass, + There are no particular restrictions on the content, and it can be appropriately selected depending on the purpose, but it is preferably 1% to 20% by mass, and more preferably 3% to 15% by mass. + In a zeolite containing Rb as a percentage of the zeolite mass, + When the content of Rb is 1% by mass or more, the improvement rate of the yield of useful components increases. + In a zeolite containing Rb as a percentage of the zeolite mass, + If the content is 20% by mass or less, excess Rb is produced during the manufacture of the hydrocarbon-containing composition. + Side effects are less likely to occur due to the inclusion of this ingredient.

[0041] Rb + In a zeolite containing Rb as a percentage of the zeolite mass, + The content is determined by weighing approximately 10 mg of the sample into a 50 mL poly container, adding 1 mL of ultrapure water, 1 mL of nitric acid, and 1 mL of hydrofluoric acid, shaking gently, letting it stand for 8 hours, then diluting it to 50 mL with ultrapure water, and performing quantitative analysis using a high-frequency inductively coupled plasma (ICP) emission spectrometer (e.g., PlasmaQuant PQ 9000, Analytik Jena AG).

[0042] -Crystal System- The crystalline framework structures of zeolites are compiled into a database by the International Zeolite Association (IZA), and their IUPAC structural codes (hereinafter sometimes abbreviated as "structural codes") are defined. In these structural codes, MFI-type zeolites are indicated as "MFI," beta-type zeolites as "BEA," and mordenite-type zeolites as "MOR."

[0043] In this disclosure, there are no particular restrictions on the zeolite skeleton structure, and it can be appropriately selected depending on the type of component whose yield you want to increase or the type of other component whose formation you want to suppress. However, from the viewpoint of increasing the yield of lower olefins as useful components, the MFI type is preferred, and from the viewpoint of increasing the yield of useful aromatic compounds as useful components, the MOR (mordenite) type and BEA (beta) type are preferred.

[0044] The crystalline system of zeolites can be identified by analyzing it using X-ray diffraction (XRD) under the analytical conditions described in the examples. Alternatively, it can be identified by comparing it with either the XRD pattern described in "Collection of simulated XRD powder patterns for zeolites, Fifth revised edition (2007)" or the XRD pattern described in "Zeolite Framework Types" on the IZA Structural Committee website (http: / / www.iza-struture.org / databases / ).

[0045] -Pore diameter- The pore size of MFI-type zeolites is generally around 0.50 nm to 0.60 nm. The pore size of Al2O3 in BEA-type zeolites is generally around 0.65 nm. The pore size of Al2O3 in MOR-type zeolites is generally around 0.7 nm.

[0046] The pore size of the zeolite is measured in accordance with ISO 15901-3:2007 "Pore size distribution and porosity of solid materials by mercury porosimetry and gas adsorption - Part 3: Analysis of micropores by gas adsorption".

[0047] -Molar ratio [SiO2 / Al2O3]- Rb+ There are no particular restrictions on the molar ratio of SiO2 to Al2O3 [SiO2 / Al2O3] of the zeolite containing Rb, and it can be appropriately selected depending on the purpose, but a value of 10 or more and 10,000 or less is preferred. + The molar ratio of SiO2 to Al2O3 [SiO2 / Al2O3] of the zeolite containing the above is preferably as follows, depending on the crystal system of the zeolite.

[0048] Rb + If the zeolite containing Rb is of the MFI type, + The molar ratio of SiO2 to Al2O3 [SiO2 / Al2O3] of the zeolite containing Rb is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 to 10,000, more preferably 20 to 10,000, even more preferably 20 to 5,000, and particularly preferably 500 to 2,000. + When the zeolite containing [the substance] is of the MFI type, a molar ratio [SiO2 / Al2O3] of 10 to 10,000 results in a good yield of olefins having 2 to 5 carbon atoms and a good O / P ratio of the olefin-containing composition.

[0049] Rb + If the zeolite containing Rb is of the BEA type, + The molar ratio of SiO2 to Al2O3 [SiO2 / Al2O3] of the zeolite containing Rb is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 to 10,000, more preferably 20 to 10,000, even more preferably 20 to 5,000, and particularly preferably 500 to 2,000. + When the zeolite containing [the substance] is of the BEA type, a molar ratio [SiO2 / Al2O3] of 10 to 10,000 yields a good yield of useful components.

[0050] Rb + If it is a MOR type containing Rb +The molar ratio [SiO2 / Al2O3] of SiO2 to Al2O3 in a zeolite containing Rb is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 to 10,000, more preferably 10 to 10,000, even more preferably 10 to 5,000, and particularly preferably 10 to 2,000. + When the MOR type contains [a specific compound], a molar ratio [SiO2 / Al2O3] of 10 to 10,000 results in a good yield of useful components.

[0051] Rb + The molar ratio [SiO2 / Al2O3] of the zeolite containing Rb is + Zeolite containing [the specified substance] is weighed accurately, completely dissolved using an aqueous solution containing nitric acid and hydrofluoric acid, and the Si and Al content of the sample, which has been brought to a fixed volume, is measured using an ICP emission spectrometer (e.g., PlasmaQuant PQ 9000, manufactured by Analytik Jena AG). The number of moles of Si and Al calculated from the content is then used to determine the following formula. Molar ratio [SiO2 / Al2O3] = 2 × (moles of Si) / (moles of Al)

[0052] -BET specific surface area- Rb + If the zeolite containing Rb is of the MFI type, + There are no particular restrictions on the BET specific surface area of ​​the MFI type zeolite containing this material, and it can be appropriately selected depending on the purpose, but 100m 2 / g or more 1,000m 2 Preferably less than / g, 100m 2 / g or more 250m 2 More preferably less than / g, 150m 2 / g or more 250m 2 More preferably less than / g, and 200m 2 / g or more 250m 2 Rb + If the zeolite containing this material is of the MFI type, the BET specific surface area is 100m². 2 / g or more 1,000m 2When the value is less than / g, the yield of useful components is good.

[0053] Rb + If the zeolite containing Rb is of the BEA type, + There are no particular restrictions on the BET specific surface area of ​​BEA-type zeolite containing this material, and it can be appropriately selected depending on the purpose, but 100m 2 / g or more 1,000m 2 Preferably less than / g, 100m 2 / g or more 600m 2 Less than / g is more preferable, 200m 2 / g or more 500m 2 More preferably less than / g, 300m 2 / g or more 500m 2 Rb + If the zeolite containing Rb is of the BEA type, + The BET specific surface area of ​​the BEA-type zeolite containing this material is 100m². 2 / g or more 1,000m 2 When the value is less than / g, the yield of useful components is good.

[0054] Rb + If it is a MOR type containing Rb + There are no particular restrictions on the BET specific surface area of ​​MOR-type zeolite containing this material, and it can be appropriately selected depending on the purpose, but 100m 2 / g or more 1,000m 2 Preferably less than / g, 100m 2 / g or more 600m 2 Less than / g is more preferable, 200m 2 / g or more 500m 2 More preferably less than / g, 300m 2 / g or more 400m 2 Rb + If it is a MOR type containing Rb + The BET specific surface area of ​​the MOR-type zeolite containing this material is 100m². 2 / g or more 1,000m 2 When the value is less than / g, the yield of useful components is good.

[0055] The aforesaid Rb + The BET specific surface area of the zeolite containing the aforesaid Rb can be measured in accordance with ISO 9277:2010 "Determination of the specific surface area of powders (solids) by gas adsorption".

[0056] -Particle size- When heating, as the zeolite containing Rb + when using powdered zeolite containing Rb + as the zeolite containing Rb, there is no particular limitation on its 50% particle size D50 (median diameter) (volume average), and it can be appropriately selected according to the purpose. However, from the viewpoints of BET specific surface area, handling property, etc., it is preferably 1 μm or more and 500 μm or less, more preferably 2 μm or more and 350 μm or less, and still more preferably 2 μm or more and 100 μm or less.

[0057] Rb + The 50% particle size D50 of the zeolite containing Rb means the median diameter measured by a laser diffraction particle size distribution measuring device (for example, laser diffraction particle size distribution measuring device SALD-7100, manufactured by Shimadzu Corporation, etc.).

[0058] Rb + There is no particular limitation on the particle shape of the zeolite containing Rb, and examples thereof include spherical, ellipsoidal, crushed, flat, and irregular shapes. These may be used alone or in combination of two or more.

[0059] Rb + For the zeolite containing Rb, commercially available products may be used, or those appropriately manufactured by known methods may be used.

[0060] Rb + There is no particular limitation on the method for producing the zeolite containing Rb, and examples thereof include the method described in <<Producing the zeolite containing Rb>> of <Other treatments> described later. + For <<Producing the zeolite containing Rb>>

[0061] <Other treatments> Other treatments in the method for producing hydrocarbon-containing compositions are not particularly limited and can be appropriately selected depending on the purpose. Examples include decomposing plastics, recovering useful components obtained by heating, and removing hydrogen chloride. Furthermore, the method for producing hydrocarbon-containing compositions includes Rb + This may include the production of a zeolite containing [the specified substance].

[0062] <<Breaking down plastic>> Decomposing plastic involves thermally decomposing it, which produces plastic decomposition products to be used as raw materials by heating.

[0063] There are no particular restrictions on the plastics used as raw materials for plastic decomposition products, and they can be appropriately selected depending on the purpose. However, from the viewpoint of reducing environmental impact, it is preferable that they contain waste plastics.

[0064] The plastic used as a raw material for decomposing plastics preferably has a total of 65% by mass or more and 100% by mass or less of C (carbon) and H (hydrogen) as determined by elemental analysis, and more preferably 68% by mass or more and 95% by mass or less. When the total of C (carbon) and H (hydrogen) as determined by elemental analysis in the plastic is 65% by mass or more and 100% by mass or less, it is possible to obtain plastic decomposition products suitable for the production of hydrocarbon-containing compositions using readily available plastics.

[0065] Examples of plastics in which the total amount of C (carbon) and H (hydrogen) determined by elemental analysis is 65% by mass or more and 100% by mass or less include those containing a large amount of at least one polyolefin selected from the group consisting of polyethylene (PE), polypropylene (PP), and polystyrene (PS). Specific examples of plastics in which the total amount of C (carbon) and H (hydrogen) determined by elemental analysis is 65% by mass or more and 100% by mass or less include waste plastics derived from containers and packaging, waste plastics derived from so-called product plastics that have been molded from plastic, as well as scraps and production losses from manufacturing facilities for plastic containers and packaging, product plastics, and the aforementioned polyolefin pellets and films. From the viewpoint of reducing environmental impact, waste plastics derived from containers and packaging or product plastics are preferred.

[0066] The plastics used as raw materials for decomposing plastics may include, in addition to polyolefins, other plastics such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycarbonate (PC), polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, polyamide, polyurethane, acrylonitrile-butadiene-styrene copolymer (ABS), and polymethyl methacrylate.

[0067] The plastic used as a raw material for decomposing plastic may also be a plastic composition containing materials other than plastic or additives. Examples of materials other than plastic include paper and metal when the plastic composition is a waste plastic composition. Examples of additives include low molecular weight organic compounds such as colorants, antioxidants, and lubricants, and inorganic fillers such as silica and talc.

[0068] There are no particular restrictions on the content of materials other than plastic or additives in the plastic composition.

[0069] There are no particular restrictions on the reaction method used to decompose plastics, and it can be appropriately selected depending on the purpose. Examples include batch reaction methods, fixed-bed reaction methods, and fluidized-bed reaction methods.

[0070] The decomposition of plastics can be carried out in a reactor appropriately selected according to the desired reaction method, such as a batch reactor, fixed-bed reactor, or fluidized-bed reactor.

[0071] Decomposing plastics by heating is preferable due to its high manufacturing efficiency. While there are no particular restrictions on the heating temperature for decomposing plastics, as long as the plastic is decomposed, it can be appropriately selected depending on the purpose. However, a temperature of 400°C to 700°C is preferable, and 400°C to 500°C is more preferable. When the heating temperature for decomposing plastics is between 400°C and 700°C, the plastic can be efficiently decomposed and caulking can be suppressed.

[0072] In the process of decomposing plastics, there are no particular restrictions on the heating time, as long as the plastic can be decomposed; it can be appropriately selected depending on the reaction system and other factors.

[0073] For example, when heating plastics by a batch reaction method using a sealed batch reactor, the heating time is preferably between 1 hour and 20 hours, and more preferably between 5 hours and 10 hours. When the heating time of the plastics by the batch reaction method is 1 hour or more, the plastics can be suitably decomposed, and suitable plastic decomposition products can be obtained. Furthermore, when the heating time of the plastics by the batch reaction method is 20 hours or less, it is efficient.

[0074] There are no particular restrictions on the atmosphere used for heating plastics, and it can be appropriately selected depending on the purpose, but it is preferable to use an inert gas atmosphere. There are no particular restrictions on the inert gas, and it can be appropriately selected depending on the purpose, for example, nitrogen gas, water vapor, and argon gas. These may be used individually or in combination of two or more.

[0075] Heating plastics can be done for purposes such as altering the composition of the plastic, and Rb + The procedure may be carried out in the presence of a catalyst other than a zeolite containing Rb, or in the absence of a catalyst. Examples of catalysts that can be used by heating plastics include hydroxides and oxides of alkali metals and alkaline earth metals, Rb + Examples include zeolites that do not contain [the substance], FCC (Fluid Catalytic Cracking) catalysts, and waste FCC catalysts. It is preferable to heat the plastic without using a catalyst such as a zeolite, i.e., without a catalyst.

[0076] When the method for producing a hydrocarbon-containing composition includes decomposing plastic, the plastic decomposition products used as raw materials in the heating process can be supplied as raw materials after the plastic decomposition process, following the recovery of the plastic decomposition products obtained from the decomposition of the plastic. Alternatively, when the method for producing a hydrocarbon-containing composition includes decomposing plastic, the plastic decomposition products obtained from the decomposition of plastic may be supplied continuously or intermittently from the reactor used for decomposing the plastic to the reactor used for heating without recovering the plastic decomposition products obtained from the decomposition of the plastic.

[0077] <<Recovering useful components>> In recovering the useful components, the hydrocarbon-containing composition obtained by heating is recovered. The method for recovering the hydrocarbon-containing composition is not particularly limited, and it can be appropriately selected from known methods according to the type and physical properties of the obtained hydrocarbon-containing composition. For example, the gaseous product as the hydrocarbon-containing composition can be separated by atmospheric pressure or pressurized distillation. Also, the liquid product as the hydrocarbon-containing composition can be separated by atmospheric pressure or vacuum distillation.

[0078] <<Removing hydrogen chloride>> In removing hydrogen chloride, when the plastic decomposition product contains chlorinated hydrocarbons or when the method for producing the hydrocarbon-containing composition of the present disclosure includes decomposing plastic, the hydrogen chloride derived from salts etc. (hereinafter referred to as "chlorinated hydrocarbons etc.") adhering to the plastic used as a raw material is removed by decomposing the plastic.

[0079] When the plastic decomposition product contains chlorinated hydrocarbons etc., upon heating, hydrogen chloride is generated when heating the chlorinated hydrocarbons etc. In removing hydrogen chloride, this hydrogen chloride is vaporized and removed.

[0080] Also, in addition to heating, the plastic decomposition product may be heated at a low temperature in advance to vaporize hydrogen chloride for removing hydrogen chloride. The temperature when heating the plastic decomposition product at a low temperature in advance is preferably 100°C or higher and lower than 300°C. Thereby, the chlorine content in the plastic decomposition product can be reduced.

[0081] <<Producing zeolite containing Rb + >> Rb + In producing zeolite containing Rb, zeolite containing Rb used is produced by heating. +

[0082] Rb + ​There are no particular limitations on the method for producing zeolite containing Rb, and a suitable method can be selected from among those known in the art, for example, beforehand + A method for producing zeolite by incorporating (hereinafter referred to as "Rb according to the first embodiment") + (Sometimes referred to as "a method for producing zeolite containing Rb"), + Zeolite that does not contain Rb + Method of processing at the source (hereinafter referred to as "Rb according to the second embodiment") + Examples include methods sometimes referred to as "methods for producing zeolite containing [the specified substance]".

[0083] -Rb according to the first embodiment + Method for producing zeolite containing - Rb according to the first embodiment + A method for producing zeolite containing [the substance] preferably includes hydrothermal synthesis, further including solid-liquid separation, washing with water, drying, and calcination, and may further include other treatments as needed.

[0084] --Hydrothermal synthesis-- Hydrothermal synthesis involves silica source, alumina source, organic structure directing agent, hydroxide-containing compound, fluoride ion-containing compound, water, Rb + From a mixture (raw material composition) containing sources such as Rb + Zeolites containing [the specified substance] are synthesized hydrothermally.

[0085] There are no particular restrictions on the silica source, but precipitated silica, colloidal silica, fumed silica, silica gel, sodium silicate (e.g., sodium metasilicate, sodium orthosilicate, sodium silicate No. 1, sodium silicate No. 2, sodium silicate No. 3, sodium silicate No. 4, etc.), and alkoxysilane (e.g., tetraethoxysilane (TEOS) and trimethylethoxysilane (TMEOS), etc.) are preferred, more preferably tetraethoxysilane (TEOS) and trimethylethoxysilane (TMEOS), and even more preferably tetraethoxysilane (TEOS). These may be used individually or in combination of two or more.

[0086] There are no particular restrictions on the alumina source, but aluminum chloride, aluminum nitrate, aluminum sulfate, sodium aluminate, aluminum alkoxides such as aluminum isopropoxide, and aluminum hydroxide such as boehmite are preferred, and aluminum nitrate is more preferred. These may be used individually or in combination of two or more.

[0087] There are no particular restrictions on the organic structure directing agent; for example, quaternary ammonium compounds can be used. Specifically, when producing MFI-type zeolite, tetrapropylammonium compounds such as tetrapropylammonium hydroxide or tetraethylammonium compounds such as tetraethylammonium hydroxide are used. When producing BEA-type zeolite, tetraethylammonium compounds are used. When producing MOR-type zeolite, at least one selected from the group consisting of tetraethylammonium compounds and benzyltrimethylammonium compounds is used.

[0088] Hydroxide-containing compounds or fluoride ion-containing compounds are added to promote the crystallization of zeolites, and hydroxide-containing compounds are widely used because they are inexpensive and easy to handle. There are no particular restrictions on the hydroxide-containing compound, as long as it exhibits alkalinity in aqueous solution.

[0089] For example, an organic structure-directing agent can also function as a hydroxide-containing compound, in which case a hydroxide is used as the aforementioned quaternary ammonium compound. This method allows for the production of proton-type zeolites without alkali metals being incorporated into the zeolite.

[0090] On the other hand, alkali metal ions may be present in the zeolite. Alternatively, if alkali metal ions are to be actively introduced into the zeolite, an alkali metal or alkaline earth metal hydroxide, preferably an alkali metal hydroxide, is added as a hydroxide-containing compound, in addition to the organic structure-directing agent. Examples of organic structure-directing agents used in this case include tetrapropylammonium bromide and tetraethylammonium bromide. Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide.

[0091] Rb + There are no particular restrictions on the source, and any rubidium compound can be used depending on the purpose. For example, if rubidium hydroxide is used as the hydroxide, Rb + It can also serve as a source. + As a method for introducing alkali metal ions such as hydroxides, alkali metal compounds other than hydroxides can also be added, but in that case, hydroxide or fluoride ion-containing compounds should be added separately to promote the crystallization of zeolite. Also, during zeolite production, Rb + When using alkali metal compounds from sources or other sources to incorporate alkali metal ions, excess alkali metal compounds are often present. Therefore, after hydrothermal synthesis, washing with water should be performed to wash away the excess alkali metal ions. These Rb + It is preferable to add the source before hydrothermal synthesis.

[0092] There are no particular restrictions on the water used during hydrothermal synthesis. Examples include industrial water, tap water, distilled water, deionized water, pure water, RO water (reverse osmosis treated water), and ultrapure water. These may be used individually or in combination of two or more types.

[0093] Hydrothermal synthesis is usually carried out in a reaction vessel. Any known sealed pressure vessel suitable for hydrothermal synthesis can be used as the reaction vessel, and there are no particular limitations on its type. For example, a sealed heat-resistant and pressure-resistant vessel such as an autoclave equipped with a stirring device, heat source, pressure gauge, and safety valve is preferably used. The crystallization of the zeolite may be carried out by letting the mixture of zeolite raw materials stand still, but from the viewpoint of improving the uniformity of the resulting zeolite, the crystallization may be carried out by stirring the mixture.

[0094] There are no particular restrictions on the processing temperature (reaction temperature) for hydrothermal synthesis, and it can be appropriately selected from viewpoints such as the crystallinity of the obtained zeolite and economic feasibility, but 100°C to 200°C is preferred, 120°C to 190°C is more preferred, and 150°C to 180°C is even more preferred.

[0095] The processing time (reaction time) for hydrothermal synthesis is not particularly limited as long as crystallization can be achieved, and can be appropriately selected from viewpoints such as the crystallinity of the obtained zeolite and economic feasibility. However, a period of 1 hour to 20 days is preferred, 4 hours to 15 days is more preferred, and 12 hours to 11 days is even more preferred.

[0096] There are no particular restrictions on the processing pressure for hydrothermal synthesis; the spontaneous pressure generated when the mixture introduced into the reaction vessel is heated to the above temperature range is sufficient. If necessary, an inert gas such as nitrogen or argon may be introduced into the vessel.

[0097] Zeolite contains ammonium ions (NH4 + ) and protons (H + ) may contain nonmetallic cations such as Rb. + Source Rb + There are no particular restrictions on the method of ion exchange with the substance; it can be carried out by conventional methods.

[0098] --Solid-liquid separation-- By solid-liquid separation, Rb obtained by hydrothermal synthesis...+ Zeolite containing [the specified substance] is subjected to solid-liquid separation using a known filter or the like.

[0099] --Wash with water-- Washing involves washing the solid obtained through solid-liquid separation. The water used here can be the same water used in hydrothermal synthesis.

[0100] --Drying-- Drying involves hydrothermal synthesis, solid-liquid separation, or washing with water, followed by Rb + Dry the zeolite containing [the substance].

[0101] Rb + The zeolite containing this substance is dried, for example, at a temperature of approximately 50°C to 150°C in the atmosphere. This removes the moisture.

[0102] --Firing-- Calcination involves hydrothermal synthesis, solid-liquid separation, washing with water, or drying, followed by Rb + The zeolite containing [the substance] is calcined. By calcining, the organic structure-directing agent can be removed.

[0103] Rb + The temperature at which the zeolite containing is fired is preferably such that the zeolite skeleton collapses, and more preferably 500°C to 600°C.

[0104] -Rb according to the second embodiment + Method for producing zeolite containing - Rb according to the second embodiment + A method for producing zeolite containing the above may include mixing and calcination, preferably further including stirring and evaporation drying, and may also include other treatments as needed.

[0105] --Mixing-- The mixing process yields a mixture of zeolite (hereinafter sometimes referred to as "raw material zeolite") and a liquid containing a rubidium compound. By performing this mixing, for example, cations (Rb) contained in the rubidium compound are introduced to the acid sites of the raw material zeolite. + ) can be ionically bonded.

[0106] There are no particular restrictions on the rubidium compound, and examples include rubidium hydroxide, rubidium nitrate, rubidium chloride, and rubidium carbonate. These may be used individually or in combination of two or more. Among these, rubidium nitrate is preferred due to its excellent solubility.

[0107] The raw material zeolite used in the mixing process may be either an acidic zeolite or a basic zeolite. Among these, it is preferable to use an acidic zeolite having Brønsted acid sites, as this allows for good exchange with cations when a liquid containing a rubidium compound is used.

[0108] There are no particular restrictions on the cations contained in the raw material zeolite, but H + The zeolite contains Rb + It is preferable because it has good substitution efficiency.

[0109] Rb + As a raw material for zeolite containing H + When using a zeolite containing H + There are no particular restrictions on the acid content of the MFI-type zeolite containing the above, and it can be appropriately selected depending on the purpose, but it is preferably 0.01 mmol / g or more and 2.5 mmol / g or less, more preferably 0.01 mmol / g or more and 2.0 mmol / g or less, and even more preferably 0.01 mmol / g or more and 0.1 mmol / g or less.

[0110] Rb + As a raw material for zeolite containing H + When using a zeolite containing H+ There are no particular restrictions on the acid content of the BEA-type zeolite containing the above, and it can be appropriately selected depending on the purpose, but it is preferably 0.05 mmol / g or more and 2.5 mmol / g or less, more preferably 0.05 mmol / g or more and 2.0 mmol / g or less, and even more preferably 0.05 mmol / g or more and 0.1 mmol / g or less.

[0111] Rb + As a raw material for zeolite containing H + When using a zeolite containing H + There are no particular restrictions on the acid content of the MOR-type zeolite containing the above, and it can be appropriately selected depending on the purpose, but it is preferably 0.5 mmol / g or more and 2.5 mmol / g or less, more preferably 1.0 mmol / g or more and 2.5 mmol / g or less, and even more preferably 1.0 mmol / g or more and 2.0 mmol / g or less.

[0112] H + The acid content of zeolite containing [the specified substance] can be measured by the ammonia temperature desorption method (hereinafter sometimes abbreviated as "TPD").

[0113] There are no particular restrictions on the method for synthesizing the raw material zeolite, and any known method can be appropriately selected. For example, one method involves adding an aqueous aluminum nitrate solution to tetraalkoxysilane and hydrolyzing it, then distilling off the resulting alcohol, followed by hydrothermal synthesis and calcination.

[0114] There are no particular restrictions on the solvent in the liquid containing the rubidium compound, but it is preferable that the solvent can dissolve the rubidium compound, can be removed relatively easily by calcination as described later, and does not decompose, with highly polar solvents being more preferable. Examples of such solvents include water, methanol, ethanol, acetonitrile, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and hexamethylphosphate triamide. These may be used individually or in combination of two or more. Among these solvents, at least one selected from the group consisting of water, methanol, and ethanol is preferred because it has a relatively low boiling point and can be easily removed, and water is particularly preferred because it is low-cost.

[0115] There are no particular restrictions on the concentration of the rubidium compound in the liquid containing the rubidium compound, and it can be appropriately selected depending on the purpose. However, from the viewpoint of reducing solvent costs, a concentration of 0.01 mol / L to 10 mol / L is preferred, and a concentration of 0.05 mol / L to 2.5 mol / L is more preferred. When the concentration of the rubidium compound is 0.01 mol / L to 10 mol / L, a homogeneous mixture of the raw material zeolite and the solution in which the rubidium compound is dissolved in the solvent can be obtained, and it is also advantageous in terms of cost.

[0116] The amount of rubidium compound used in a liquid containing rubidium compounds depends on the acidity of the raw material zeolite (i.e., the cations of the raw material zeolite (Rb + The amount of substance at which cations (Rb) in the rubidium compound can be imparted + The valence of ) and the cation (Rb) in rubidium compounds + The ratio of the product of the amount of substance of ) and [Rb in the rubidium compound contained in a liquid containing rubidium compounds] + The (valence × amount of substance) / acid content of the raw material zeolite can be appropriately determined. Furthermore, when using two or more rubidium compounds, the cation (Rb) in the rubidium compound can be appropriately determined. + The valency of the cation (Rb) in two or more rubidium compounds is determined by the cation (Rb) +The sum of the valencies of cations (Rb) in rubidium compounds. + The amount of substance of ) is the amount of cation (Rb) in two or more rubidium compounds. + This is the sum of the amounts of substance of the substances.

[0117] Ratio [Rb in rubidium compounds contained in a liquid containing rubidium compounds] + The ratio of (valence × amount of substance) / acid content of raw material zeolite is not particularly limited and can be appropriately selected depending on the purpose, but 0.6 to 120 is preferred, 0.6 to 100 is more preferred, and 1.0 to 80 is even more preferred. Ratio [Rb in rubidium compound contained in liquid containing rubidium compound] + If the ratio of (valence × amount of substance) / acidity of raw material zeolite is 0.6 or higher, the cation-adding points of the raw material zeolite will be cation-added to the rubidium nitrate (Rb + ) can be sufficiently imparted. Ratio [Rb in rubidium compound contained in a liquid containing rubidium compound] + It is cost-effective if the ratio of (valence × amount of substance) / acidity of the raw material zeolite is 120 or less.

[0118] The amount of acid in the raw material zeolite can be determined, for example, by measuring the amount of base adsorbed onto the raw material zeolite using a temperature-controlled desorption method (TPD method) with an appropriate base (e.g., ammonia).

[0119] There are no particular limitations on the method for mixing the raw material zeolite with a liquid containing a rubidium compound to form a mixed solution, and any method can be appropriately selected depending on the purpose. For example, one method is to immerse the raw material zeolite in a solution in which the rubidium compound is dissolved in a solvent.

[0120] --Stirring-- By stirring, a mixture of raw material zeolite and a liquid containing a rubidium compound is stirred, and the resulting solution is treated to obtain zeolite.

[0121] There are no particular restrictions on the method of stirring the mixture; known methods can be used.

[0122] There are no particular restrictions on the stirring time of the mixture, and it can be appropriately determined depending on the concentration of the rubidium compound contained in the liquid containing the rubidium compound. However, 0.5 to 48 hours at room temperature under an atmospheric environment is preferred, 1 to 24 hours is more preferred, and 6 to 15 hours is even more preferred. If the stirring time is 0.5 hours or more, the cations contained in the rubidium compound can be sufficiently imparted to the raw material zeolite. If the stirring time is 48 hours or less, contamination by substances in the air and uneven cation impartment due to changes in the concentration of the mixture can be prevented.

[0123] The zeolite obtained after solution treatment by stirring is preferably filtered and washed, for example, by natural filtration or suction filtration. Washing of the zeolite after solution treatment can be carried out, for example, by passing the filtered solution-treated zeolite through a solvent used in a solution in which a rubidium compound is dissolved.

[0124] --Dry by evaporation-- In evaporative drying, the zeolite after solution treatment is evaporated to dryness without filtration. Including evaporative drying allows for further cation exchange.

[0125] There are no particular restrictions on the method of evaporation to dryness, and it can be appropriately selected depending on the type of solvent contained in the mixture. When the solvent is water, for example, it can be carried out by letting it stand for an appropriate amount of time in a room temperature environment under an atmospheric atmosphere. In this case, there are no particular restrictions on the standing time as long as the solvent can be removed, but 2 to 14 days is preferred, 3 to 12 days is more preferred, and 4 to 6 days is even more preferred.

[0126] Evaporative drying may also be carried out by heating in an air atmosphere for an appropriate amount of time using an oven set to a temperature above room temperature and below the boiling point of the solvent, so as not to cause the solvent to bump. This method can shorten the time required to complete evaporation to dryness. The heating time using the oven can be adjusted as appropriate depending on the heating temperature. For example, if the solvent is water, it may be done at a temperature of about 80°C for 5 to 10 hours, or at a temperature of about 50°C for 40 to 60 hours.

[0127] Furthermore, it is preferable to proceed with calcination after washing the zeolite, which has been collected by evaporation to dryness and treated with the solution, with the solvent used to prepare the liquid containing the rubidium compound in order to remove any excess rubidium compound that is thought to have precipitated on the surface.

[0128] --Firing-- In the calcination process, the zeolite obtained after mixing, stirring, or evaporation drying is calcined.

[0129] When acidic zeolite is used as the raw material zeolite, calcination can further promote cation addition by volatilizing the protons on the acid sites remaining on the raw material zeolite even after mixing and stirring, as well as nitrate ions derived from rubidium compounds, into water and nitrogen dioxide. Furthermore, any remaining solvent after filtration or evaporation can be almost completely removed.

[0130] There are no particular restrictions on the conditions and temperature for calcining the zeolite after solution treatment, but 300°C to 600°C in an atmospheric atmosphere is preferred, and 450°C to 550°C in an atmospheric atmosphere is more preferred.

[0131] Furthermore, there are no particular restrictions on the calcination time of the zeolite after solution treatment, but 1 to 20 hours is preferred, and 6 to 15 hours is more preferred.

[0132] The above method for producing a hydrocarbon-containing composition yields a hydrocarbon-containing composition containing at least one selected from the group consisting of olefins having 2 to 5 carbon atoms, benzene, toluene, ethylbenzene, and xylene.

[0133] <<Hydroxide-containing composition>> The hydrocarbon-containing composition contains at least one selected from the group consisting of olefins having 2 to 5 carbon atoms, benzene, toluene, ethylbenzene, and xylene, and optionally contains other components. The xylene contains at least one selected from three positional isomers: p-xylene, m-xylene, and o-xylene.

[0134] -Olefins with 2 to 5 carbon atoms- The hydrocarbon-containing composition preferably contains at least one carbon-2 to carbon-5 olefin selected from the group consisting of alkenes and dienes, more preferably at least one carbon-2 to carbon-5 alkene and carbon-3 to carbon-5 dienes, and even more preferably carbon-2 to carbon-5 alkene.

[0135] Examples of olefins with 2 carbon atoms include ethylene. Examples of olefins with 3 carbon atoms include propylene. Examples of olefins with 4 carbon atoms include 1-butene, cis-2-butene, trans-2-butene, and 2-methylpropene. Examples of olefins with 5 carbon atoms include 1-pentene, cis-2-pentene, trans-2-pentene, 2-methyl-1-butene, and 2-methyl-2-butene.

[0136] Olefins having 2 to 5 carbon atoms can be used as raw materials for polyolefins, which can be suitably used as raw materials in various fields such as shopping bags, plastic wrap, straws, medical devices, home appliance casings, erasers, hoses, tires, tubes, CD cases, food trays, food containers, PET bottles, and textiles.

[0137] There are no particular restrictions on the content of olefins having 2 to 5 carbon atoms in the hydrocarbon-containing composition, and it can be appropriately selected depending on the purpose, but it is preferably 50% by mass or more and 90% by mass or less, and more preferably 55% by mass or more and 80% by mass or less.

[0138] -Useful aromatic compounds- The hydrocarbon-containing composition contains at least one of the following useful aromatic compounds selected from the group consisting of benzene, toluene, ethylbenzene, and three positional isomers of xylene (p-xylene, m-xylene, and o-xylene).

[0139] Useful aromatic compounds can be used as raw materials for resins, and these resins can be suitably used as raw materials in various fields such as CD cases, food trays, food containers, PET bottles, and textiles.

[0140] There are no particular restrictions on the content of useful aromatics in the hydrocarbon-containing composition, and it can be appropriately selected depending on the purpose, but it is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 30% by mass or less.

[0141] --O / P ratio-- The hydrocarbon-containing compounds obtained by the method for producing hydrocarbon-containing compositions have the advantage of having a high yield of useful components as well as a low amount of paraffin as a by-component. The low amount of paraffin as a by-component and the excellent yield of olefins having 2 to 5 carbon atoms can be evaluated by determining the ratio of the total yield (%) of olefin products having 2 to 5 carbon atoms to the total yield (%) of paraffin products having 2 to 5 carbon atoms, i.e., the ratio [total yield (%) of olefin products having 2 to 5 carbon atoms (%) / total yield (%) of paraffin products having 2 to 5 carbon atoms (%)] (hereinafter sometimes referred to as the "O / P ratio").

[0142] In this disclosure, "paraffin" refers to an aliphatic saturated hydrocarbon having 2 to 5 carbon atoms, preferably a chain-like aliphatic saturated hydrocarbon having 2 to 5 carbon atoms.

[0143] There are no particular restrictions on the O / P ratio, and it can be appropriately selected according to the purpose, but a value of 1.5 or higher is preferred, and a value of 1.9 or higher is more preferred. Since a higher O / P ratio is preferable, there are no particular restrictions on its upper limit, but a value of 50 or less is preferred, and a value of 20 or less is more preferred.

[0144] The O / P ratio can be determined from the content of each component obtained by measuring the yield of useful components.

[0145] -Other ingredients- Other components in hydrocarbon-containing compositions include, for example, Rb + Examples include zeolites containing [the specified substance], hydrocarbons other than the useful components, undegraded plastic decomposition products, and materials or additives other than plastic decomposition products contained in the raw materials.

[0146] Other components in the hydrocarbon-containing composition may be removed as appropriate by conventionally known methods when recycling the useful components. [Examples]

[0147] The embodiments of this disclosure will be specifically described below with reference to a reference catalyst manufacturing example, a catalyst manufacturing example, a comparative catalyst manufacturing example, an example, and a comparative example. However, the embodiments of this disclosure are not limited in any way to these reference catalyst manufacturing examples, catalyst manufacturing examples, comparative catalyst manufacturing examples, examples, and comparative examples. In the following description, unless otherwise specified, "%" refers to "mass%".

[0148] (Reference catalyst production example 1) <Synthesis process of zeolite a> 55 g (0.26 mol) of tetraethoxysilane was weighed into a 200 mL three-necked flask equipped with a stirrer, condenser, and dropping funnel. Separately, an aqueous aluminum nitrate solution was prepared by dissolving 0.132 g of aluminum nitrate nonahydrate in 10 g of pure water. The tetraethoxysilane in the three-necked flask was stirred at room temperature (20 °C ± 5 °C) and the entire amount of the aqueous aluminum nitrate solution was added and mixed to prepare a mixture. Subsequently, while stirring the mixture at room temperature, 85.06 g (0.085 mol) of a 1 mol / L tetrapropylammonium hydroxide aqueous solution was added dropwise from the dropping funnel over 1 hour. Then, the reactor was heated in an oil bath set to 100 °C and stirred for 1 hour to hydrolyze the tetraethoxysilane. Subsequently, the condenser in the three-necked flask was replaced with a distillation apparatus, and the reactor was heated in an oil bath set to 130 °C, and the ethanol produced by the hydrolysis was removed by distillation over 1.5 hours. During the distillation and removal of ethanol, 5 mL of pure water was added twice, and finally, approximately 70 mL of mixed slurry was obtained. The entire amount of the obtained mixed slurry was placed in an autoclave equipped with a Teflon® inner cylinder and hydrothermally synthesized at 180°C for 11 days. After cooling to room temperature, the slurry was centrifuged to separate the solid and liquid components. The obtained solid was washed twice by adding pure water, stirring, and centrifuging. The obtained solid was dried at 80°C for 1 day. The obtained dried solid was calcined in air at 550°C for 6 hours to decompose and remove organic matter, and an MFI-type zeolite (hereinafter sometimes referred to as "zeolite a") with a molar ratio of [SiO2 / Al2O3] of 2,000 was obtained.

[0149] (Catalyst manufacturing example 1) <Mixing and stirring> 1.51 g (mass) (10.2 mmol) of rubidium nitrate (RbNO3, purity: 95.0% or higher, manufactured by Kanto Chemical Co., Ltd.) was completely dissolved in pure water to prepare a 0.20 mol / L aqueous solution of rubidium nitrate. In a glass container, 5 g of zeolite a obtained in Reference Catalyst Production Example 1 and the entire amount of the aforementioned aqueous solution of rubidium nitrate were mixed and stirred at room temperature under an atmospheric environment for 12 hours to obtain the reaction product.

[0150] <Evaporation drying and firing> The resulting reaction product was left to stand at room temperature in an atmospheric environment for 5 days, and a solidified product was obtained by evaporation to dryness. After washing the obtained solidified product with water, it was transferred to a magnetic crucible and calcined in an electric furnace set to 500°C in an atmospheric environment for 8 hours to obtain the solid catalyst of Catalyst Production Example 1.

[0151] (Comparative catalyst manufacturing example 1) The solid catalyst for Comparative Catalyst Production Example 1 was obtained using the same method as in Catalyst Production Example 1, except that the mixing and stirring were modified as follows.

[0152] <Mixing and stirring> 0.87 g (by mass) (10.2 mmol) of sodium nitrate (NaNO3, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was completely dissolved in pure water to prepare a 0.20 mol / L aqueous sodium nitrate solution. In a glass container, 5 g of zeolite a obtained in Reference Catalyst Production Example 1 and the entire amount of the aforementioned aqueous sodium nitrate solution were mixed and stirred at room temperature under an atmospheric environment for 12 hours to obtain the reaction product.

[0153] (Comparative catalyst manufacturing example 2) The solid catalyst for Comparative Catalyst Production Example 2 was obtained using the same method as in Catalyst Production Example 1, except that the mixing and stirring were modified as follows.

[0154] <Mixing and stirring> 1.31 g (mass) (5.1 mmol) of magnesium nitrate hexahydrate (Mg(NO3)2·6H2O, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was completely dissolved in pure water to prepare a 0.10 mol / L magnesium nitrate aqueous solution. In a glass container, 5 g of zeolite a obtained in Reference Catalyst Production Example 1 and the entire amount of the magnesium nitrate aqueous solution were mixed and stirred at room temperature under an atmospheric environment for 12 hours to obtain the reaction product.

[0155] (Catalyst manufacturing example 2) <Mixing and stirring> 0.39 g (mass) (2.6 mmol) of rubidium nitrate (RbNO3, purity: 95.0% or higher, manufactured by Kanto Chemical Co., Ltd.) was completely dissolved in pure water to prepare a 0.26 mol / L aqueous solution of rubidium nitrate. In a glass container, 3.0 g of beta (BEA) type zeolite (product name: HSZ-980HOA, manufactured by Tosoh Corporation, molar ratio [SiO2 / Al2O3]: 500) was mixed with the entire amount of the aforementioned aqueous solution of rubidium nitrate, and the mixture was stirred at room temperature (20℃±5℃) under an atmospheric environment for 12 hours to obtain the reaction product.

[0156] <Evaporation drying and firing> The resulting reaction product was left to stand at room temperature in an atmospheric environment for 5 days, and a solidified product was obtained by evaporation to dryness. After washing the obtained solidified product with water, it was transferred to a magnetic crucible and calcined in an electric furnace set to 500°C in an atmospheric environment for 8 hours to obtain the solid catalyst of catalyst production example 2.

[0157] (Catalyst manufacturing example 3) <Mixing and stirring> 0.34 g (mass) (2.3 mmol) of rubidium nitrate (RbNO3, purity: 95.0% or higher, manufactured by Kanto Chemical Co., Ltd.) was completely dissolved in pure water to prepare a 0.23 mol / L rubidium nitrate aqueous solution. In a glass container, mordenite (MOR) type zeolite (product name: HSZ-640HOA, manufactured by Tosoh Corporation, molar ratio [SiO2 / Al2O3]: 18, BET specific surface area: 380 m²) was used to prepare the solution. 2 3.0 g of ( / g) was mixed with the entire amount of the rubidium nitrate aqueous solution, and the mixture was stirred at room temperature (20°C ± 5°C) under an atmospheric environment for 12 hours to obtain the reaction product.

[0158] <Evaporation drying and firing> The resulting reaction product was left to stand at room temperature in an atmospheric environment for 5 days, and a solidified product was obtained by evaporation to dryness. After washing the obtained solidified product with water, it was transferred to a magnetic crucible and calcined in an electric furnace set to 500°C in an atmospheric environment for 8 hours to obtain the solid catalyst of catalyst production example 3.

[0159] (Comparative catalyst manufacturing example 3) In Catalyst Production Example 2, the process of preparing a 0.26 mol / L aqueous solution of rubidium nitrate was changed from completely dissolving 0.39 g (by mass) (2.6 mmol) of rubidium nitrate in pure water to preparing a 0.26 mol / L aqueous solution of rubidium nitrate to completely dissolving 0.22 g (by mass) (2.6 mmol) of sodium nitrate (NaNO3, purity: 95.0% or higher, manufactured by Kanto Chemical Co., Ltd.) in pure water to prepare a 0.26 mol / L aqueous solution of sodium nitrate. The solid catalyst for Comparative Catalyst Production Example 3 was obtained using the same method as in Catalyst Production Example 2.

[0160] (Comparative catalyst manufacturing example 4) In Catalyst Production Example 3, the process of preparing a 0.23 mol / L aqueous solution of rubidium nitrate was changed from completely dissolving 0.34 g (by mass) (2.3 mmol) of rubidium nitrate in pure water to preparing a 0.23 mol / L aqueous solution of rubidium nitrate to completely dissolving 0.45 g (by mass) (2.3 mmol) of cesium nitrate (CsNO3, purity: 95.0% or higher, manufactured by Kanto Chemical Co., Ltd.) in pure water to prepare a 0.23 mol / L aqueous solution of cesium nitrate. The solid catalyst of Comparative Catalyst Production Example 4 was obtained using the same method as in Catalyst Production Example 3.

[0161] <Measurement of acid content in solid catalyst (zeolite)> The acid content of the zeolite used as a raw material in the production of the solid catalysts in Catalyst Production Examples 1-3 and Comparative Catalyst Production Examples 1-4 (hereinafter sometimes referred to as "raw material zeolite") was analyzed by the ammonia thermal desorption (TPD) method under the following measurement conditions. [Acid content measurement conditions] • Device: BEL-CAT-BASIC (Microtrac, manufactured by Bell Co., Ltd.) • Detector: Quadrupole mass spectrometer BEL-Mass (manufactured by Microtrac-Bel Corporation) • Target species for measurement: NH3 (m / z=16) • Pretreatment conditions: Pretreatment was performed in the order of 1 to 9 as listed in Table 1, under the conditions listed in Table 1. • Heating conditions: The temperature was raised from 100°C to 850°C at a rate of 10°C / min, and held at 850°C for 30 minutes. The He gas flow rate during heating was 30 mL / min.

[0162] [Table 1]

[0163] The acid content of MFI-type zeolite (zeolite a) was 0.037 mmol / g, the acid content of BEA-type zeolite (product name: HSZ-980HOA) was 0.079 mmol / g, and the acid content of MOR-type zeolite (product name: HSZ-640HOA) was 1.0 mmol / g.

[0164] [Evaluation of the physical properties of solid catalysts] The crystalline structure, molar ratio [SiO2 / Al2O3], and nitrate concentration in aqueous solution of each solid catalyst (zeolite) obtained in Catalyst Production Examples 1-3 and Comparative Catalyst Production Examples 1-4, as well as the MFI-type zeolite (zeolite a), BEA-type zeolite (product name: HSZ-980HOA), and MOR-type zeolite (product name: HSZ-640HOA) used as raw materials in the production of the solid catalysts in Catalyst Production Examples 1-3 and Comparative Catalyst Production Examples 1-4, were analyzed by the following methods. The results are shown in Tables 2-1 and 2-2.

[0165] <Crystalline analysis of solid catalysts (zeolites)> The crystalline systems of each solid catalyst (zeolite) obtained in Catalyst Production Examples 1-3 and Comparative Catalyst Production Examples 1-4, as well as the MFI-type zeolite (zeolite a), BEA-type zeolite (product name: HSZ-980HOA), and MOR-type zeolite (product name: HSZ-640HOA) used as raw materials in the production of the solid catalysts in Catalyst Production Examples 1-3 and Comparative Catalyst Production Examples 1-4, were analyzed by X-ray diffraction (XRD) under the following measurement conditions. [X-ray diffraction measurement conditions] • Equipment: X'Pert Pro MPD (manufactured by Pnalytical) · X-ray source: CuKα ray • Incident X-ray filter: 10mm brass mask • Detector-side filter: Ni filter • Entrance slit: Sollerslit0.04rad ASS1 / 8° • Detector-side slit: ASS5.0mm Sollerslit0.04rad • Detector: PIXel1D · Measurement method: Reflection method • Operating range (measurement range): 2θ = 5° to 120° • Step width: 0.006565° • Counting time: 78.795 sec / step

[0166] <Measurement of the molar ratio [SiO2 / Al2O3] of solid catalyst (zeolite)> The crystalline systems of each solid catalyst (zeolite) obtained in Catalyst Production Examples 1-3 and Comparative Catalyst Production Examples 1-4, as well as the MFI-type zeolite (zeolite a), BEA-type zeolite (product name: HSZ-980HOA), and MOR-type zeolite (product name: HSZ-640HOA) used as raw materials in the production of the solid catalysts in Catalyst Production Examples 1-3 and Comparative Catalyst Production Examples 1-4, were accurately weighed. These were then completely dissolved in an aqueous solution containing nitric acid (manufactured by Kanto Chemical Co., Ltd., EL Nitric Acid 1.38 for the Electronics Industry, purity 60.0%-61.0%) and hydrofluoric acid (manufactured by Kanto Chemical Co., Ltd., Ultrapur-100, ultra-high purity reagent, purity 46.0%-51.0%), and measured samples were prepared in fixed volumes. For this sample, the Si and Al content was measured using an ICP emission spectrometer (PlasmaQuant PQ 9000, manufactured by Analytik Jena AG). From the number of moles of Si and Al calculated from the content, the molar ratio [SiO2 / Al2O3] was calculated based on the following formula. Molar ratio [SiO2 / Al2O3] = 2 × (moles of Si) / (moles of Al)

[0167] <Measurement of nitrate concentration in liquid> The nitrate concentrations in the nitrate aqueous solutions used in Catalyst Production Examples 1-3 and Comparative Catalyst Production Examples 1-4 were determined by molar calculation, assuming no change in liquid volume due to mixing.

[0168] [Table 2-1]

[0169] [Table 2-2]

[0170] (Manufacturing Example 1) <Preparation of plastic degradation products> 0.3 g each of polyethylene (Sigma-Aldrich, number average molecular weight 1,700, weight average molecular weight 4,000), polypropylene (Sigma-Aldrich, number average molecular weight 5,000, weight average molecular weight 12,000), and polystyrene (Sigma-Aldrich, weight average molecular weight 35,000) were accurately weighed and placed in a quartz inner cylinder. The inner cylinders were sealed in a reaction vessel (Type 4567, made of SUS-316, capacity 450 mL, manufactured by Parr) connected to a nitrogen gas introduction pipe and a product extraction pipe, along with nitrogen gas at atmospheric pressure, and the vessel was heated to an internal temperature of 450°C. After 8 hours of heating, heating was stopped and the reaction vessel was allowed to cool to 25°C. A gas bag was connected to the product extraction pipe to extract the gas from the reaction vessel. Furthermore, the reaction vessel was opened, 10 mL of tetrahydrofuran (THF) (manufactured by Kanto Chemical Co., Ltd., reagent for high-performance liquid chromatography, stabilizer-free) was added, and the mixture was thoroughly mixed at room temperature. The insoluble matter was filtered off and washed twice with a small amount of THF. The insoluble matter after washing was vacuum-dried at 25°C for 24 hours, and its mass was measured. This was subtracted from the total mass (g) of polyethylene, polypropylene, and polystyrene charged in the reaction vessel to determine the yield (g) of plastic decomposition products, which was 0.68 g.

[0171] (Example 1) The solid catalyst obtained in Catalyst Production Example 1 (hereinafter referred to as "Rb + In the presence of a substituted MFI-type zeolite (sometimes referred to as "substituted MFI-type zeolite"), the following methods were used to successively produce plastic decomposition products and hydrocarbon-containing compositions.

[0172] Except for loading 0.2 g of the solid catalyst obtained in Catalyst Production Example 1 into an adder capable of injecting solid catalyst under pressure and attaching it to the reaction vessel, the inner cylinders containing polyethylene, polypropylene, and polystyrene were sealed into the reaction vessel along with nitrogen gas at atmospheric pressure, in the same manner as in Production Example 1. The reactor was heated to an internal temperature of 450°C and heated for 8 hours to produce plastic decomposition products.

[0173] Next, nitrogen gas was introduced into the adder, and the solid catalyst was injected into the reaction vessel under pressure. The internal temperature of the reaction vessel was maintained at 450°C for 8 hours. After cooling, the gaseous product was collected, and 10 mL of tetrahydrofuran (THF) (manufactured by Kanto Chemical Co., Ltd., reagent for high-performance liquid chromatography, stabilizer-free) was added to the contents remaining in each of the two reaction vessels and mixed thoroughly at room temperature. The solid components were filtered off and washed twice with a small amount of THF. In this way, the THF-soluble products (THF-soluble products) were extracted into a THF solution combining the filtrate and washings.

[0174] (Comparative Example 1) In Example 1, the solid catalyst of Catalyst Production Example 1 was replaced with the solid catalyst of Comparative Catalyst Production Example 1 (hereinafter referred to as "Na"). + Except for changing to a substituted MFI-type zeolite (sometimes referred to as "substituted MFI-type zeolite"), the gaseous product and THF-soluble product were extracted in the same manner as in Example 1.

[0175] (Comparative Example 2) In Example 1, the solid catalyst of Catalyst Production Example 1 was replaced with the solid catalyst of Comparative Catalyst Production Example 2 (hereinafter referred to as "Mg + Except for changing to a substituted MFI-type zeolite (sometimes referred to as "substituted MFI-type zeolite"), the gaseous product and THF-soluble product were extracted in the same manner as in Example 1.

[0176] (Comparative Example 3) In Example 1, the gaseous product and THF-soluble product were extracted in the same manner as in Example 1, except that the solid catalyst of Catalyst Production Example 1 was replaced with the MFI-type zeolite (zeolite a) of Reference Catalyst Production Example 1.

[0177] (Example 2) In Example 1, the solid catalyst of Catalyst Production Example 1 was replaced with the solid catalyst of Catalyst Production Example 2 (hereinafter referred to as "Rb + Except for changing to a substituted BEA-type zeolite (sometimes referred to as "substituted BEA-type zeolite"), the gaseous product and THF-soluble product were extracted in the same manner as in Example 1.

[0178] (Comparative Example 4) In Example 1, the solid catalyst of Catalyst Production Example 1 was replaced with the solid catalyst of Comparative Catalyst Production Example 3 (hereinafter referred to as "Na"). + Except for changing to a substituted BEA-type zeolite (sometimes referred to as "substituted BEA-type zeolite"), the gaseous product and THF-soluble product were extracted in the same manner as in Example 1.

[0179] (Comparative Example 5) In Example 1, the gaseous product and THF-soluble product were extracted using the same method as in Example 1, except that the solid catalyst in Catalyst Production Example 1 was changed to a BEA-type zeolite (product name: HSZ-980HOA).

[0180] (Example 3) In Example 1, the solid catalyst of Catalyst Production Example 1 was replaced with the solid catalyst of Catalyst Production Example 3 (hereinafter referred to as "Rb + Except for changing to a substituted MOR-type zeolite (sometimes referred to as "substituted MOR-type zeolite"), the gaseous product and THF-soluble product were extracted in the same manner as in Example 1.

[0181] (Comparative Example 6) In Example 1, the solid catalyst of Catalyst Production Example 1 was replaced with the solid catalyst of Comparative Catalyst Production Example 4 (hereinafter referred to as "Cs + Except for changing to a substituted MOR-type zeolite (sometimes referred to as "substituted MOR-type zeolite"), the gaseous product and THF-soluble product were extracted in the same manner as in Example 1.

[0182] (Comparative Example 7) In Example 1, the gaseous product and THF-soluble product were extracted using the same method as in Example 1, except that the solid catalyst in Catalyst Production Example 1 was changed to a MOR-type zeolite (product name: HSZ-640HOA).

[0183] [Evaluation of Hydrocarbon-containing Composition] To the gas products recovered in Examples 1 to 3 and Comparative Examples 1 to 7, 38 mg of cyclopentane (manufactured by Tokyo Chemical Industry Co., Ltd., reagent, purity: 98.0% or more) was added as an internal standard substance to prepare analytical samples. Also, to the THF-soluble products recovered in Examples 1 to 3 and Comparative Examples 1 to 7, 0.24 g of t-butylbenzene (manufactured by Tokyo Chemical Industry Co., Ltd., reagent, purity: 98.0% or more) was added as an internal standard substance to prepare analytical samples. These analytical samples were analyzed under the following analytical conditions using a gas chromatograph (GC) apparatus equipped with a flame ionization detector, and each component was quantified from the ratio of the peak area of each component to the internal standard substance. The results are shown in Tables 3-1 to 3-3.

[0184] [[GC Analysis Conditions for Gas Products]] · Apparatus: Nexis GC-2030 (manufactured by Shimadzu Corporation) · Column: Rt-Alumina BOND (diameter: 0.32 mm, length: 30 m, manufactured by 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: Set a temperature program in the order of 120 °C (for 9 minutes) → temperature increase (10 °C / min) → 200 °C (for 30 minutes) ​​​​​​​​​​​​​​​​Injection temperature: 350℃ • Sample injection volume: 1 μL • Split ratio: 1 / 50 • Column temperature: Set the heating program in the following order: 35°C (10 minutes) → heating (5°C / minute) → 350°C (10 minutes). • Detector: Flame ionization detector (FID) • Detector temperature: 350℃

[0186] In Tables 3-1 to 3-3, "Yield of useful components" refers to the ratio (mass%) of the mass of useful components quantified by GC analysis to the mass of the plastic decomposition product used. "Useful components" refers to lower olefins and useful aromatics. "Lower olefins" refer to ethylene, propylene, olefins with 4 carbon atoms (1-butene, cis-2-butene, trans-2-butene, and 2-methylpropene), and olefins with 5 carbon atoms (1-pentene, cis-2-pentene, trans-2-pentene, 2-methyl-1-butene, and 2-methyl-2-butene). "Useful aromatics" refer to benzene, toluene, ethylbenzene, and three positional isomers of xylene (p-xylene, m-xylene, and o-xylene). Furthermore, "Yield of lower olefins" and "Yield of useful aromatics" refer to the ratio (mass%) of the mass of lower olefins and useful aromatics to the mass of the raw materials used, respectively.

[0187] Furthermore, in Tables 3-1 to 3-3, the improvement rate (%) of the yield of useful components was calculated using the following formula as an indicator of the improvement in the yield of useful components compared to the raw material zeolite by incorporating various cations into the solid catalyst. Improvement rate of useful component yield (%) = Useful component yield of the zeolite being compared [%] / Useful component yield of the base zeolite [%] × 100

[0188] Here, the "zeolite for comparison" is the zeolite used in Examples 1 to 3 and Comparative Examples 1 to 7. Also, the "reference zeolite" is the raw material zeolite of the zeolite used in Examples 1 to 3 and Comparative Examples 1 to 7. That is, Examples 1, Comparative Example 1, and Comparative Example 2 were based on the MFI-type zeolite (zeolite a) used in Comparative Example 3 (Table 3-1). Example 2 and Comparative Example 4 were based on the BEA-type zeolite (trade name: HSZ-980HOA) used in Comparative Example 5. Example 3 and Comparative Example 6 were based on the MOR-type zeolite (trade name: HSZ-640HOA) used in Comparative Example 7. [[ID=X]] [[ID=Y]]

[0189] [[ID=Z]] [Quantification of reaction residue] In Examples 1 to 3 and Comparative Examples 1 to 7, after extracting the THF-soluble product from the residue remaining in the reaction vessel, the solid content remaining was dried, and the mass A was measured. Separately, the mass B of the reaction vessel before the reaction and the mass C of the reaction vessel dried after being emptied after the reaction were measured, and the difference between the mass B and the mass C (mass C - mass B) was obtained. The sum of the mass A of the dried solid content and the difference in the mass of the reaction vessel before and after the reaction (mass C - mass B) {mass A + (mass C - mass B)} was taken as the mass of the reaction residue, and the ratio of the mass to the raw material used was taken as the yield (mass%) of the reaction residue. The results are shown in Tables 3-1 to 3-3.

[0190] [Table 3-1]

[0191] [Table 3-2]

[0192] [Table 3-3]

[0193] From the results in Tables 3-1 to 3-3, in all of the MFI-type zeolite, BEA-type zeolite, and MOR-type zeolite, Rb +Zeolites containing Rb yielded the best improvement in yield of useful components. + In the MFI type containing Rb, the yield of lower olefins and the O / P ratio of C2 to C5 olefins were better. + BEA-type zeolite and Rb containing + MOR-type zeolites containing [specific compound] showed better yields of useful aromatic compounds.

[0194] As described above, this disclosure has been explained based on specific embodiments and examples, but these embodiments and examples are merely presented as examples, and this disclosure is not limited to the above embodiments and examples. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, additions, modifications, etc., are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

Claims

1. A method for producing a hydrocarbon-containing composition, Rb ＋ This includes heating plastic decomposition products in the presence of a zeolite containing the following: A method for producing a hydrocarbon-containing composition, characterized in that the hydrocarbon-containing composition contains at least one selected from the group consisting of olefins having 2 to 5 carbon atoms, benzene, toluene, ethylbenzene, and xylene.

2. The method for producing a hydrocarbon-containing composition according to claim 1, wherein the plastic decomposition product is a fluid obtained by heating a raw material plastic at 400°C to 700°C in an inert gas atmosphere selected from at least one of nitrogen and water vapor.

3. The aforementioned plastic decomposition product is Rb ＋ A method for producing a hydrocarbon-containing composition according to claim 1, wherein the fluid is obtained by heating a raw material plastic at 400°C to 700°C in the presence or absence of a catalyst other than a zeolite containing the above, and in an inert gas atmosphere selected from the group consisting of nitrogen and water vapor.

4. A method for producing the hydrocarbon-containing composition according to claim 1 or claim 2, wherein the plastic used as a raw material for the plastic decomposition product contains a polyolefin.

5. A method for producing a hydrocarbon-containing composition according to claim 1 or claim 2, wherein the plastic used as a raw material for the plastic decomposition product contains at least one selected from the group consisting of polyethylene, polypropylene, and polystyrene.

6. A method for producing a hydrocarbon-containing composition according to claim 1 or claim 2, wherein the temperature at which the plastic decomposition product is heated is 300°C or more and 600°C or less.

7. The aforementioned Rb ＋ Zeolites containing beta-type Rb ＋ Zeolite and mordenite-type Rb containing ＋ A method for producing a hydrocarbon-containing composition according to claim 1 or claim 2, wherein the method is selected from at least one of the group consisting of zeolites containing the above.

8. The Rb ＋ -containing zeolite has an Al ２ O ３ to SiO ２ molar ratio [SiO ２ / Al ２ O ３ of 10 or more and 10,000 or less. The method for producing a hydrocarbon-containing composition according to claim 1 or claim 2.

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