Method for producing olefin-containing composition and catalyst for production of olefin-containing composition

Abstract

Disclosed is a method for producing an olefin-containing composition, the method being characterized by including a step for decomposing a plastic in the presence of zeolite so as to produce an olefin-containing composition that contains an olefin having 2 to 5 carbon atoms. This method for producing an olefin-containing composition is also characterized in that the zeolite is at least one selected from the group consisting of a beta type zeolite containing Rb+ and a mordenite type zeolite containing Rb+.

Description

Method for producing olefin-containing composition and catalyst for producing olefin-containing composition

[0001] The present disclosure relates to a method for producing an olefin-containing composition and a catalyst for producing an olefin-containing composition.

[0002] Conventionally, waste plastics have been disposed of by landfilling, dumping in the ocean, or incineration, but it is becoming increasingly difficult to secure landfill sites, and ocean dumping poses environmental problems because plastics do not decompose. Furthermore, while incineration can be used to generate heat, the carbon dioxide emissions contribute to global warming.

[0003] Therefore, in recent years, with the growing awareness of environmental issues, there has been a need for recycling, such as reusing and regenerating waste plastics, and research and development into this area has been actively carried out. Furthermore, since most plastics are produced using fossil fuels, there is a strong demand for the development of recycling methods from the perspective of effective resource utilization.

[0004] Among plastic materials, hydrocarbon-based plastic materials such as polyethylene (PE), polypropylene (PP), and polystyrene (PS) are widely used in beverage and food containers, packaging materials, molded products, films, and other applications due to their excellent properties, including heat resistance, weather resistance, mechanical strength, transparency, chemical resistance, and gas barrier properties. Therefore, these hydrocarbon-based plastic materials account for the majority of waste plastic materials. Chemical recycling through oil-gasification is one method for recycling these plastic materials. In the oil-gasification process, waste plastics are converted into low-molecular-weight hydrocarbons by thermal decomposition. Many methods using solid catalysts have been investigated to improve reactivity and product selectivity.

[0005] For example, in a method for inductively heating a plastic material, a catalyst, and a magnetic susceptor using a radio frequency (RF) field, it has been disclosed that nickel-doped beta zeolite (Ni-BEA) as the catalyst has a slower reaction rate than hydrogen-containing beta zeolite (H-BEA) (see Patent Document 1). It has also been disclosed that in a tire pyrolysis method, the yield of ethylene and propylene is higher with a beta zeolite supporting 1% palladium (1% PD / HBeta) than with a beta zeolite without a catalyst or a metal, and even higher with a beta zeolite supporting 10% nickel (10% Ni / HBeta). It has also been disclosed that the yield of monocyclic aromatic compounds in the liquid phase is higher with 1% PD / HBeta than with a beta zeolite without a metal, and is also somewhat higher with 5% Ni / HBeta and 10% Ni / HBeta (see Non-Patent Document 1).

[0006] International Publication No. 2023 / 064741

[0007] Z Wang et al. , International Journal of Metallurgical and Materials Engineering, 2021, Vol. 6, No. 4, pp. 260-264

[0008] However, even when the catalysts disclosed in the prior art documents are used, the yield of useful components such as lower olefins is not fully satisfactory.

[0009] An object of the present disclosure is to provide a method for producing an olefin-containing composition with a high yield of useful components.

[0010] A method for producing an olefin-containing composition according to one embodiment of the present disclosure includes a step of decomposing a plastic in the presence of a zeolite to produce an olefin-containing composition containing olefins having 2 to 5 carbon atoms, wherein the zeolite is selected from the group consisting of Rb ＋ Beta type zeolite containing Rb ＋ The mordenite-type zeolite is at least one selected from the group consisting of mordenite-type zeolites containing

[0011] The means for solving the above problems are as follows: <1> A method comprising the steps of decomposing a plastic in the presence of a zeolite to produce an olefin-containing composition containing an olefin having 2 to 5 carbon atoms, wherein the zeolite is selected from the group consisting of Rb ＋ Beta type zeolite containing Rb ＋ <2> The method for producing an olefin-containing composition according to <1>, wherein the plastic is a polyolefin. <3> The method for producing an olefin-containing composition according to <1>, wherein the plastic contains at least one selected from the group consisting of polyethylene, polypropylene, and polystyrene. <4> The method for producing an olefin-containing composition according to any one of <1> to <3>, wherein the temperature at which the plastic is decomposed is 300°C or higher and 1,100°C or lower. <5> The method for producing an olefin-containing composition according to any one of <1> to <3>, wherein the temperature at which the plastic is decomposed is 300°C or higher and 1,100°C or lower. ＋ Beta zeolite containing Rb ＋ Al of mordenite-type zeolite containing ２ O ３ SiO ２ The molar ratio of [SiO ２ / Al ２ O ３ <6> The method for producing an olefin-containing composition according to any one of <1> to <4>, wherein Rb ＋ The BET specific surface area of ​​the beta zeolite containing ２ / g or more 500m ２ / g or less, and the Rb ＋ The BET specific surface area of ​​the mordenite-type zeolite containing ２ / g or more 400m ２<7> The method for producing an olefin-containing composition according to any one of <1> to <5>, wherein the olefin-containing composition has a zeolite content of 0.01% or less, and the zeolite content is 0.01% or less. <8> A method for producing an olefin-containing composition according to any one of <1> to <5>, wherein the zeolite content is 0.01% or less, and the zeolite content is 0.01% or less. <9> A method for producing an olefin-containing composition according to any one of <1> to <5>, wherein the zeolite content is 0.01% or less, and the zeolite content is 0.01% or less. <10> A method for producing an olefin-containing composition according to any one of <1> to <5>, ＋ Beta zeolite containing Rb ＋ <8> The method for producing an olefin-containing composition according to any one of <1> to <6>, further comprising a calcination step of obtaining at least one selected from the group consisting of mordenite-type zeolites containing Rb ＋ Beta zeolite containing Rb ＋ The mass of at least one selected from the group consisting of mordenite-type zeolites containing Rb is defined as x (g), ＋ Beta zeolite containing Rb ＋ At least one Al selected from the group consisting of mordenite-type zeolites containing ２ O ３ SiO ２ The molar ratio of [SiO ２ / Al ２ O ３ ] is y, and the number of moles of the rubidium compound is z (mmol), the ratio of yz / x satisfies 1≦yz≦5,000. ＋ The mordenite zeolite is a beta zeolite containing H ＋ <10> A catalyst for use in producing an olefin-containing composition containing an olefin having 2 to 5 carbon atoms, comprising: a mordenite-type zeolite containing Rb ＋ Beta type zeolite containing Rb ＋<11> A catalyst for producing an olefin-containing composition, characterized by containing at least one selected from the group consisting of mordenite-type zeolites containing Rb ＋ Beta type zeolite containing Rb ＋ The present invention relates to a method for using at least one catalyst selected from the group consisting of mordenite-type zeolites containing

[0012] According to an embodiment of the present disclosure, a method for producing an olefin-containing composition with a high yield of useful components can be provided.

[0013] The present disclosure will be described in detail below. Note that the embodiments of the present disclosure are not limited by the following description and can be modified as appropriate within the scope of the gist of the present disclosure. Furthermore, in this specification, unless otherwise specified, the term "to" indicating a range of numerical values ​​means that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0014] (Method for producing olefin-containing composition) A method for producing an olefin-containing composition according to one embodiment includes a step of decomposing a plastic in the presence of a zeolite to produce an olefin-containing composition containing olefins having 2 to 5 carbon atoms (hereinafter, this step may be referred to as a "decomposition step"), and may further include other steps as necessary.

[0015] <Cracking Step> The cracking step is a step of cracking a plastic in the presence of a zeolite to produce an olefin-containing composition containing an olefin having 2 to 5 carbon atoms.

[0016] The zeolite is Rb ＋ Beta type zeolite containing Rb ＋ The mordenite-type zeolite containing Rb is at least one selected from the group consisting of mordenite-type zeolites containing Rb. ＋As compared with conventional beta-type zeolites and mordenite-type zeolites that do not contain olefins, it is possible to produce an olefin-containing composition that has an excellent yield of useful components such as olefins having 2 to 5 carbon atoms, benzene, toluene, ethylbenzene, xylene, styrene, and cumene.

[0017] The amount of zeolite used relative to the plastic in the decomposition step is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100 parts by mass or less, more preferably 1 part by mass or more and 100 parts by mass or less, even more preferably 10 parts by mass or more and 100 parts by mass or less, even more preferably 20 parts by mass or more and 100 parts by mass or less, and particularly preferably 1 part by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the plastic. When the amount of zeolite used relative to the plastic is 10 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the plastic, the plastic can be decomposed favorably and the yield of useful components is good.

[0018] <<Olefin-Containing Composition>> The olefin-containing composition contains an olefin having 2 to 5 carbon atoms, and preferably further contains an aromatic compound, and further contains other components as necessary.

[0019] —Olefins Having 2 to 5 Carbon atoms— The olefins having 2 to 5 carbon atoms preferably have a main component of at least one selected from the group consisting of alkenes and dienes, more preferably at least one selected from the group consisting of alkenes having 2 to 5 carbon atoms and dienes having 3 to 5 carbon atoms, and even more preferably alkenes having 2 to 5 carbon atoms.

[0020] An example of the olefin having two carbon atoms is ethylene.

[0021] An example of the olefin having 3 carbon atoms is propylene.

[0022] Examples of the olefin having 4 carbon atoms include 1-butene, cis-2-butene, trans-2-butene, and 2-methylpropene.

[0023] Examples of the olefin having 5 carbon atoms include 1-pentene, cis-2-pentene, trans-2-pentene, 2-methyl-1-butene, and 2-methyl-2-butene.

[0024] In the present disclosure, olefins having 2 to 5 carbon atoms may be referred to as "lower olefins."

[0025] The lower olefins are used as raw materials for polyolefins, and the polyolefins can be suitably used as raw materials in various fields such as plastic bags, plastic wrap, straws, medical devices, housings for home appliances, erasers, hoses, tires, tubes, CD cases, food trays, food containers, PET bottles, and fibers.

[0026] The content of the lower olefin in the olefin-containing composition is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 30% by mass or more and 100% by mass or less, and more preferably 35% by mass or more and 60% by mass or less.

[0027] -Aromatic Compound- The aromatic compound is not particularly limited and can be appropriately selected depending on the purpose, but preferably contains at least one selected from the group consisting of benzene, toluene, ethylbenzene, three positional isomers of xylene (p-xylene, m-xylene, and o-xylene), styrene, and cumene.

[0028] In the present disclosure, the aromatic compounds may be referred to as "useful aromatic compounds."

[0029] The useful aromatic compounds can be used as raw materials for resins, and the resins can be suitably used as raw materials in various fields such as CD cases, food trays, food containers, PET bottles, and fibers.

[0030] The content of the useful aromatics in the olefin-containing composition is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0% by mass or more and 50% by mass or less, more preferably 0.1% by mass or more and 30% by mass or less, and even more preferably 1% by mass or more and 20% by mass or less.

[0031] In the present disclosure, the lower olefins and the useful aromatics may be collectively referred to as "useful components."

[0032] --Yield of Useful Components--In the present disclosure, the yield of useful components is determined by analyzing the olefin-containing composition obtained in the cracking step, specifically, the products soluble in tetrahydrofuran (hereinafter sometimes abbreviated as "THF") (hereinafter sometimes referred to as "THF-soluble products") from the gaseous products and residues using a gas chromatograph (hereinafter sometimes abbreviated as "GC") equipped with a flame ionization detector under the analytical conditions described below, and quantifying each component using an internal standard method based on the ratio of the peak area of ​​each component to that of an internal standard. The internal standard may be any substance that is stable under the analytical conditions and easily separable from the components to be analyzed; for example, at least one selected from the group consisting of cyclopentane and t-butylbenzene is used. GC analysis of the gaseous products and THF-soluble products is performed under the analytical conditions described in the Examples.

[0033] When the decomposition step is carried out in a closed reaction vessel, the THF-soluble product is obtained by adding THF to the residue in the reaction vessel. When the decomposition step is carried out in a continuous or open reaction vessel, the gaseous product and the residue are recovered not only in the reaction vessel but also in a trap outside the reaction vessel, and therefore the THF-soluble product is obtained by adding THF to the residue in the reaction vessel, and by adding THF to the trap and the connecting member between the reaction vessel and the trap.

[0034] The yield of useful components is preferably 35% or more, more preferably 40% or more.

[0035] The yield of useful components is calculated as the ratio of the number of moles of carbon atoms in the useful components to the number of moles of carbon atoms in the plastic using the following formula: Yield of useful components (%) = mass [g] of the useful components produced calculated by GC analysis / total mass [g] of plastic sample × 100

[0036] --O / P Ratio-- In the present disclosure, in addition to a high yield of useful components, it is preferable that the amount of paraffin, a minor component, is low. A low amount of paraffin, a minor component, and an 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"). In the present disclosure, "paraffin" refers to aliphatic saturated hydrocarbons having 2 to 5 carbon atoms, and preferably refers to chain aliphatic saturated hydrocarbons having 2 to 5 carbon atoms.

[0037] The O / P ratio is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.75 or more, more preferably 0.8 or more. Since a higher O / P ratio is more preferable, the upper limit is not particularly limited, but is preferably 50 or less, more preferably 20 or less.

[0038] The O / P ratio can be determined from the content of each component obtained by measuring the yield of useful components.

[0039] -Other Components- Examples of the other components in the olefin-containing composition include the zeolite, decomposition products of the plastics other than the useful components, undecomposed plastics, and materials or additives other than plastics contained in the raw materials.

[0040] The other components in the olefin-containing composition may be removed by a conventionally known method as appropriate when recycling the useful components.

[0041] <<Zeolite>> The skeletal structures of zeolites are compiled into a database by the International Zeolite Association (hereinafter sometimes abbreviated as "IZA"), and their IUPAC structure codes (hereinafter sometimes abbreviated as "structure codes") are defined. In this structure code, beta zeolite is represented as "BEA" and mordenite zeolite is represented as "MOR".

[0042] The crystal systems of the BEA-type zeolite and the MOR-type zeolite can be analyzed and identified by X-ray diffraction (XRD) under the analytical conditions described in the Examples. They can also be identified by comparing the XRD patterns with those described in "Collection of Simulated XRD Powder Patterns for Zeolites, Fifth Revised Edition (2007)" or the XRD patterns described in "Zeolite Framework Types" on the IZA Structure Committee website (http: / / www.iza-structure.org / databases / ).

[0043] -Pore diameter- Rb ＋ Al of BEA-type zeolite containing ２ O ３ The pore diameter of the porous silica is generally around 0.65 nm.

[0044] The Rb ＋ Al of MOR type zeolite containing ２ O ３ The pore diameter is generally around 0.7 nm.

[0045] The Rb ＋ BEA-type zeolite containing Rb ＋The pore size of the MOR-type zeolite containing can be 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".

[0046] - Molar ratio [SiO ２ / Al ２ O ３ ] - the Rb ＋ Al of BEA-type zeolite containing ２ O ３ SiO relative to the number of moles ２ The molar ratio of the number of moles of [SiO ２ / Al ２ O ３ ] is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 or more and 10,000 or less, more preferably 20 or more and 10,000 or less, even more preferably 20 or more and 5,000 or less, and particularly preferably 500 or more and 2,000 or less. ＋ The molar ratio of the BEA type zeolite containing [SiO ２ / Al ２ O ３ When the value of [Ratio of the % of the total mass of the polymer] is 10 or more and 10,000 or less, the yield of useful components is good.

[0047] The Rb ＋ Al of MOR type zeolite containing ２ O ３ SiO relative to the number of moles ２ The molar ratio of the number of moles of [SiO ２ / Al ２ O ３ ] is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 or more and 10,000 or less, more preferably 10 or more and 10,000 or less, even more preferably 10 or more and 5,000 or less, and particularly preferably 10 or more and 2,000 or less. ＋The molar ratio of the MOR type zeolite containing [SiO ２ / Al ２ O ３ When the value of [Ratio of the % of the total mass of the polymer] is 10 or more and 10,000 or less, the yield of useful components is good.

[0048] The molar ratio [SiO ２ / Al ２ O ３ ] is, for example, the Rb ＋ BEA-type zeolite containing Rb ＋ The MOR-type zeolite containing the compound (II) is precisely weighed, completely dissolved in an aqueous solution containing nitric acid and hydrofluoric acid, and the volume of the sample is measured to determine the Si and Al contents using an ICP optical emission spectrometer (e.g., PlasmaQuant PQ 9000, manufactured by Analytik Jena AG). The molar ratio [SiO ２ / Al ２ O ３ ] = 2 × (number of moles of Si) / (number of moles of Al)

[0049] -BET specific surface area- Rb ＋ The BET specific surface area of ​​the BEA-type zeolite containing ２ / g or more 1,000m ２ / g or less is preferable, and 100m ２ / g or more 600m ２ / g or less is more preferable, and 200m ２ / g or more 500m ２ / g or less is more preferable, and 300m ２ / g or more 500m ２ / g or less is particularly preferable. ＋ The BET specific surface area of ​​the BEA type zeolite containing ２ / g or more 1,000m ２ When the amount is 1 / g or less, the yield of useful components is good.

[0050] The Rb ＋ The BET specific surface area of ​​the MOR type zeolite containing２ / g or more 1,000m ２ / g or less is preferable, and 100m ２ / g or more 600m ２ / g or less is more preferable, and 200m ２ / g or more 500m ２ / g or less is more preferable, and 300m ２ / g or more 400m ２ / g or less is particularly preferable. ＋ The BET specific surface area of ​​the MOR type zeolite containing ２ / g or more 1,000m ２ When the amount is 1 / g or less, the yield of useful components is good.

[0051] The Rb ＋ BEA-type zeolite containing Rb ＋ The BET specific surface area of ​​the MOR-type zeolite containing can be measured in accordance with ISO 9277:2010 "Determination of the specific surface area of ​​powders (solids) by gas adsorption."

[0052] -Particle size- The above Rb ＋ As a BEA type zeolite containing Rb, powdered Rb ＋ When a BEA-type zeolite containing the above is used, its 50% particle diameter D50 (median diameter) (volume average) is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoints of the BET specific surface area, handleability, 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 even more preferably 2 μm or more and 100 μm or less.

[0053] The Rb ＋ As the MOR type zeolite containing Rb, powdered Rb ＋ When an MOR-type zeolite containing the above is used, its 50% particle size D50 (volume average) is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoints of the BET specific surface area, handleability, 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 even more preferably 2 μm or more and 100 μm or less.

[0054] Here, in the present disclosure, "powder-like" means at least one selected from the group consisting of primary particles, aggregates of primary particles (secondary particles), granules formed by granulating primary particles, and granules formed by granulating secondary particles.

[0055] The Rb ＋ BEA-type zeolite containing Rb ＋ The 50% particle size D50 of the MOR-type zeolite containing the above-mentioned compound means the median size measured with a laser diffraction particle size distribution analyzer (for example, a laser diffraction particle size distribution analyzer SALD-7100 manufactured by Shimadzu Corporation).

[0056] The Rb ＋ BEA-type zeolite containing Rb ＋ The particle shape of the MOR-type zeolite containing is not particularly limited, and examples thereof include spherical, ellipsoidal, crushed, flat, and irregular shapes. These may be used alone or in combination of two or more.

[0057] -Rb ＋ BEA-type zeolite containing Rb ＋ Method for producing MOR type zeolite containing Rb ＋ BEA-type zeolite containing Rb ＋ The method for producing an MOR-type zeolite containing Rb is not particularly limited and can be appropriately selected from methods known in the art. ＋ A BEA-type or MOR-type zeolite that does not contain Rb ＋ By treating with a source of Rb ＋ In another embodiment, for example, Rb ＋ It is also possible to produce a BEA-type or MOR-type zeolite by incorporating

[0058] --Method for Producing BEA-Type or MOR-Type Zeolite-- A typical method for producing a BEA-type or MOR-type zeolite involves, for example, mixing a mixture (raw material composition) containing a silica source, an alumina source, an organic structure-directing agent, a hydroxide-containing compound, a fluoride ion-containing compound, water, etc., with a mixture (raw material composition) containing Rb ＋When Rb is contained, ＋ Examples of suitable methods include hydrothermal synthesis from a source of zeolite. After the hydrothermal synthesis, if necessary, solid-liquid separation, water washing, drying in the atmosphere at a temperature of about 50°C to 150°C, or the like may be carried out according to conventional methods. Furthermore, the organic structure-directing agent may be removed by calcination within a range that does not cause the zeolite framework to collapse. In this case, the calcination temperature is preferably 500°C to 600°C.

[0059] The silica source is not particularly limited, but preferred are 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.), alkoxysilane (e.g., tetraethoxysilane (TEOS) and trimethylethoxysilane (TMEOS)), etc., more preferably tetraethoxysilane (TEOS) and trimethylethoxysilane (TMEOS), and even more preferably tetraethoxysilane (TEOS). These may be used alone or in combination of two or more.

[0060] The alumina source is not particularly limited, but is preferably aluminum chloride, aluminum nitrate, aluminum sulfate, sodium aluminate, aluminum alkoxides such as aluminum isopropoxide, aluminum hydroxides such as boehmite, and more preferably aluminum nitrate. These may be used alone or in combination of two or more.

[0061] The organic structure-directing agent is not particularly limited, and for example, a tetraethylammonium compound is used when producing a BEA-type zeolite, and at least one selected from the group consisting of a tetraethylammonium compound and a benzyltrimethylammonium compound is used when producing an MOR-type zeolite.

[0062] The hydroxide-containing compound or fluoride ion-containing compound is added to promote the crystallization of zeolite, and the hydroxide-containing compound is widely used because it is inexpensive and easy to handle. There are no particular restrictions on the hydroxide-containing compound as long as it is alkaline in aqueous solution.

[0063] For example, the organic structure-directing agent can also serve as the hydroxide-containing compound, in which case hydroxide is used as the tetrapropylammonium compound or tetraethylammonium compound described above. This method allows for the production of proton-type zeolite without incorporating alkali metals into the zeolite.

[0064] 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 the 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.

[0065] Rb in advance ＋ The Rb is used when producing a BEA-type zeolite or an MOR-type zeolite by incorporating ＋ The source is not particularly limited, and examples thereof include rubidium compounds. Specifically, rubidium hydroxide is used as the hydroxide to produce Rb ＋ It can also serve as a source of Rb ＋ As a method for introducing alkali metal ions such as Rb, an alkali metal compound other than hydroxide can be added. In this case, a hydroxide or fluoride ion-containing compound is added separately to promote the crystallization of the zeolite. ＋When alkali metal ions are incorporated using a source or other alkali metal compound, the alkali metal compound is often in excess, so after hydrothermal synthesis, washing with water is carried out to remove the excess alkali metal ions. ＋ The source is preferably added before the hydrothermal synthesis.

[0066] The water used in the hydrothermal synthesis is not particularly limited, and examples thereof include industrial water, tap water, distilled water, deionized water, pure water, RO water (water treated with a reverse osmosis membrane), and ultrapure water. These may be used alone or in combination of two or more.

[0067] The hydrothermal synthesis is usually carried out in a reaction vessel. The reaction vessel used in this hydrothermal synthesis can be any known sealed pressure-resistant vessel that can be used for hydrothermal synthesis, and the type is not particularly limited. For example, a sealed heat-resistant and pressure-resistant vessel such as an autoclave equipped with a stirrer, a heat source, a pressure gauge, and a safety valve is preferably used. Note that, although the crystallization of the zeolite may be carried out while the mixture is left standing, it is preferable to carry out the crystallization while the mixture is stirred and mixed in order to improve the uniformity of the resulting zeolite.

[0068] The treatment temperature (reaction temperature) of the hydrothermal synthesis is not particularly limited and can be appropriately selected from the viewpoints of the crystallinity of the zeolite to be obtained, economic efficiency, etc., but is preferably 100°C or higher and 200°C or lower, more preferably 120°C or higher and 190°C or lower, and even more preferably 150°C or higher and 180°C or lower.

[0069] The treatment time (reaction time) for the hydrothermal synthesis is not particularly limited as long as it can crystallize, and can be appropriately selected from the viewpoints of the crystallinity of the resulting zeolite, economic efficiency, etc., but is preferably from 1 hour to 20 days, more preferably from 4 hours to 15 days, and even more preferably from 12 hours to 11 days.

[0070] The treatment pressure for the hydrothermal synthesis is not particularly limited, and the autogenous pressure generated when the mixture introduced into the reaction vessel is heated to the above-mentioned temperature range is sufficient. At this time, an inert gas such as nitrogen gas or argon gas may be introduced into the vessel, if necessary.

[0071] The zeolite contains ammonium ions (NH ４ ＋ ) and protons (H ＋ ) and the nonmetallic cations. ＋ Source Rb ＋ The method for carrying out the ion exchange with the cation exchange agent is not particularly limited, and can be carried out by a conventional method.

[0072] --Rb derived from BEA type zeolite ＋ Method for producing Rb-containing BEA-type zeolite and method for producing Rb-containing BEA-type zeolite using MOR-type zeolite as raw material ＋ Method for producing MOR-type zeolite containing Rb of the present disclosure ＋ Method for producing BEA-type zeolite containing Rb ＋ The method for producing the MOR-type zeolite-containing material includes a mixing step and a calcination step, and preferably further includes a stirring step and an evaporation / drying step, and further includes other steps as necessary.

[0073] ---Mixing Step--- The mixing step is a step of obtaining a mixed liquid by mixing at least one selected from the group consisting of BEA-type zeolite and MOR-type zeolite (hereinafter, sometimes referred to as "raw material zeolite") with a liquid containing a rubidium compound.

[0074] By carrying out the mixing step, for example, the cation (Rb ＋ ) can be ionically bonded.

[0075] The rubidium compound is not particularly limited, and examples thereof include rubidium hydroxide, rubidium nitrate, rubidium chloride, and rubidium carbonate. These may be used alone or in combination of two or more. Among these, rubidium nitrate is preferred as the rubidium compound because of its excellent solubility.

[0076] The raw material zeolite in the mixing step may be an acidic zeolite or a basic zeolite, and among these, it is preferable to use an acidic zeolite having Bronsted acid sites as the raw material zeolite, since exchange with cations proceeds well when a liquid containing a rubidium compound is used.

[0077] The raw material zeolite used in the mixing step is not particularly limited, and may be suitably synthesized or a commercially available product.

[0078] The cation contained in the raw material zeolite is not particularly limited, but may be H ＋ BEA type zeolite containing H ＋ At least one selected from the group consisting of MOR type zeolites containing Rb ＋ This is preferred in terms of the efficiency of substitution.

[0079] The Rb ＋ As a raw material for BEA-type zeolite containing H ＋ When a BEA type zeolite containing ＋ The acid amount of the BEA-type zeolite containing H is not particularly limited and can be appropriately selected depending on the purpose, but 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. ＋ When the acid amount of the BEA-type zeolite containing Rb is 0.05 mmol / g or more and 2.5 mmol / g or less, the useful component yield is good. ＋ A BEA type zeolite containing

[0080] The Rb ＋ As a raw material for MOR type zeolite containing H ＋ When using a MOR type zeolite containing ＋The acid amount of the BEA-type zeolite containing H is not particularly limited and can be appropriately selected depending on the purpose, but 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. ＋ When the acid amount of the MOR type zeolite containing Rb is 0.5 mmol / g or more and 2.5 mmol / g or less, the useful component yield is good. ＋ A zeolite of MOR type containing

[0081] The H ＋ BEA-type zeolite containing the H ＋ The acid amount of the MOR-type zeolite containing the above can be measured by the ammonia temperature programmed desorption method (hereinafter sometimes abbreviated as "TPD").

[0082] The method for synthesizing the raw material zeolite is not particularly limited and can be appropriately selected from known methods. For example, there is a method in which an aqueous aluminum nitrate solution is added to tetraalkoxysilane to hydrolyze the zeolite, and the resulting alcohol is then distilled off, followed by hydrothermal synthesis and calcination.

[0083] The solvent for the liquid containing the rubidium compound is not particularly limited, but is preferably one that can dissolve the rubidium compound, is relatively easily removable in the baking step described below, and does not decompose, and a highly polar solvent is more preferred. Examples of such solvents include water, methanol, ethanol, acetonitrile, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and hexamethylphosphoric triamide. These may be used alone 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 of its low cost.

[0084] The concentration of the rubidium compound contained in the liquid containing the rubidium compound is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of reducing solvent costs, it is preferably from 0.01 mol / L to 10 mol / L, and more preferably from 0.05 mol / L to 2.5 mol / L. When the concentration of the rubidium compound is from 0.01 mol / L to 10 mol / L, a uniform mixture of the raw zeolite and a solution in which the rubidium compound is dissolved in the solvent can be obtained, and this is also advantageous in terms of cost.

[0085] The amount of rubidium compound used in the liquid containing the rubidium compound is determined based on the acidity of the raw zeolite (i.e., the cation (Rb ＋ cation (Rb) in the rubidium compound relative to the amount of substance at which the ＋ ) and the valence of the cation (Rb ＋ ) and the amount of substance [Rb in the rubidium compound contained in the liquid containing rubidium compound] ＋ When two or more rubidium compounds are used, the amount of the cation (Rb ＋ The valence of the cation (Rb ＋ ) in the rubidium compound, and ＋ The amount of substance of the cation (Rb ＋ ) is the sum of the amounts of substance.

[0086] The ratio [Rb ＋ The ratio [(valence × amount of substance) / acid amount of raw zeolite] is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.6 to 50, more preferably 0.6 to 20, and even more preferably 1.0 to 20. ＋When the ratio of (valence × amount of substance) / acid amount of raw zeolite is 0.6 or more, the cations (Rb ＋ ) can be sufficiently provided. ＋ If the ratio (valence number x amount of substance) / acid amount of raw zeolite) is 50 or less, it is advantageous in terms of cost.

[0087] The amount of acid in the raw zeolite can be determined, for example, by measuring the amount of base adsorbed on the raw zeolite by temperature programmed desorption (TPD) using an appropriate base (e.g., ammonia).

[0088] The method for mixing the raw material zeolite with a liquid containing a rubidium compound to prepare a mixed liquid is not particularly limited and can be appropriately selected depending on the purpose. For example, a method of immersing the raw material zeolite in a solution in which a rubidium compound is dissolved in a solvent can be mentioned.

[0089] In the mixing step, the mass of at least one selected from the group consisting of the BEA-type zeolite and the MOR-type zeolite is defined as x (g), and the Rb ＋ BEA-type zeolite containing Rb ＋ At least one Al selected from the group consisting of MOR type zeolites containing ２ O ３ SiO ２ The molar ratio of [SiO ２ / Al ２ O ３] is defined as y, and the number of moles of the rubidium compound is defined as z (mmol), the range obtained by dividing the value obtained by multiplying y and z by x (the range of yz / x (mmol / g)) is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1≦yz / x≦5,000. Furthermore, in the BEA-type zeolite, it is more preferable that 50≦yz / x≦5,000 is satisfied, even more preferable that 200≦yz / x≦1,000 is satisfied, even more preferable that 300≦yz / x≦1,000 is satisfied, and particularly preferable that 400≦yz / x≦800 is satisfied. Furthermore, in the MOR-type zeolite, it is more preferable that 1≦yz / x≦100 is satisfied, and even more preferable that 8≦yz / x≦20 is satisfied. By satisfying these ranges, at least one selected from the group consisting of the BEA-type zeolite and the MOR-type zeolite contains Rb ＋ By containing the compound, the effect of improving the yield of useful components can be sufficiently obtained, and it is advantageous in terms of the labor required for preparing the zeolite and the cost of raw materials.

[0090] ---Stirring Step--- The stirring step is a step of stirring the mixture of the raw zeolite and the liquid containing the rubidium compound to obtain a solution-treated zeolite.

[0091] The method for stirring the mixture is not particularly limited, and any known method can be used.

[0092] The stirring time for the mixed solution is not particularly limited and can be determined appropriately depending on the concentration of the rubidium compound contained in the rubidium compound-containing liquid, but is preferably 0.5 to 48 hours, more preferably 1 to 24 hours, and even more preferably 6 to 15 hours at room temperature under an atmospheric atmosphere. A stirring time of 0.5 hours or more allows the cations contained in the rubidium compound to be sufficiently added to the raw zeolite. Furthermore, a stirring time of 48 hours or less prevents contamination by substances contained in the air and non-uniform addition of cations due to changes in the concentration of the mixed solution.

[0093] The solution-treated zeolite obtained by carrying out the stirring step is preferably filtered and washed, for example, by gravity filtration, suction filtration, etc. The solution-treated zeolite can be washed, for example, by passing the filtered solution-treated zeolite through the solvent used in the solution obtained by dissolving a rubidium compound in a solvent.

[0094] ---Evaporation and Drying Step--- The evaporation and drying step is a step in which the zeolite after the solution treatment is evaporated to dryness without being filtered. By including the evaporation and drying step, cation exchange can be further promoted.

[0095] The evaporation-to-dryness method is not particularly limited and can be appropriately selected depending on the type of solvent contained in the mixed solution. When the solvent is water, for example, the method includes leaving the mixture at room temperature in an atmospheric environment for an appropriate period of time. In this case, the leaving time is not particularly limited as long as the solvent can be removed, but is preferably 2 to 14 days, more preferably 3 to 12 days, and even more preferably 4 to 6 days.

[0096] The evaporation-drying step may be carried out by heating for an appropriate time in an air atmosphere using an oven set at a temperature above room temperature and below the boiling point of the solvent, where the temperature does not cause bumping of the solvent. By using this method, the time required for the evaporation-drying step to be completed can be shortened. The heating time using the oven may be adjusted appropriately depending on the heating temperature. For example, when the solvent is water, the step may be carried out 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.

[0097] Furthermore, the solution-treated zeolite collected by evaporation to dryness is preferably washed with the solvent used in preparing the liquid containing the rubidium compound in order to remove excess rubidium compound that is thought to have precipitated on the surface, before proceeding to the calcination step.

[0098] --- Calcination Step --- The calcination step is a step of calcining the zeolite obtained after the mixing step, the stirring step, or the evaporation drying step.

[0099] When an acidic zeolite is used as the raw material zeolite, the calcination step volatilizes protons on acid sites remaining on the raw material zeolite even after the mixing step and the stirring step, and nitrate ions derived from the rubidium compound, as water and nitrogen dioxide, thereby further promoting the addition of cations. Furthermore, the solvent remaining even after the filtration and evaporation drying steps can be almost completely removed.

[0100] The conditions and temperature for calcining the solution-treated zeolite in the calcination step are not particularly limited, but are preferably 300°C to 600°C in an air atmosphere, more preferably 450°C to 550°C in an air atmosphere.

[0101] The calcination time of the zeolite after the solution treatment in the calcination step is not particularly limited, but is preferably 1 hour to 20 hours, more preferably 6 hours to 15 hours.

[0102] In addition, the Rb ＋ BEA-type zeolite containing Rb ＋ The pore size of the MOR-type zeolite containing Rb can be controlled by changing the conditions of the mixing step and the stirring step. It is estimated that the pore size of the produced zeolite is smaller as the BET specific surface area is smaller. The ratio of the product of the valence of the cation in the rubidium compound contained in the solution and the amount of the cation in the rubidium compound to the amount of substance in the raw zeolite at which cations can be donated (the amount of acid in the raw zeolite) [Rb in the rubidium compound contained in the liquid containing the rubidium compound] is ＋ By varying at least one condition selected from the group consisting of (valence × amount of substance) / acid amount of raw zeolite), the concentration of the rubidium compound contained in a solution obtained by dissolving the rubidium compound in a solvent, and the stirring time of the mixed solution, solid catalysts with different BET specific surface areas can be produced.

[0103] <<Plastic>> The plastic is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint of reducing the environmental load, it preferably contains waste plastic, more preferably contains polyolefin, and even more preferably contains at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), and polystyrene (PS), which are widely used in beverage and food containers, packaging materials, molded products, films, etc.

[0104] In addition to the above-mentioned plastics, the plastic may include 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.

[0105] When the plastic is waste plastic, the composition ratio is preferably 20% to 40% by mass of PE, 20% to 40% by mass of PP, and 10% to 30% by mass of PS.

[0106] The content of the other plastics in the plastics is not particularly limited and can be selected appropriately depending on the type of waste plastic, etc., but from the viewpoint of the yield of olefins having 2 to 5 carbon atoms, the content is preferably 50 mass% or less of the total mass of the plastics, more preferably 45 mass% or less, and even more preferably 40 mass% or less.

[0107] The plastic may be a plastic composition further containing a material other than plastic or an additive. When the plastic composition is a waste plastic composition, examples of the material other than plastic include paper and metal.

[0108] There are no particular restrictions on the content of materials other than the plastics or additives in the plastic composition.

[0109] The decomposition step is preferably carried out under heating, since this improves the decomposition efficiency.

[0110] The reactor in which the decomposition step is carried out is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a batch reactor, a fixed bed reactor, and a fluidized bed reactor.

[0111] The temperature at which the decomposition step is carried out (hereinafter may be referred to as "decomposition temperature") is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 300° C. or higher and 1,100° C. or lower, and more preferably 300° C. or higher and 600° C. or lower. When the decomposition temperature is 300° C. or higher and 1,100° C. or lower, the catalyst is easily activated, and the yield of olefins having 2 to 5 carbon atoms is good.

[0112] The time for which decomposition is carried out at the decomposition temperature (hereinafter sometimes referred to as "decomposition time") is not particularly limited and can be appropriately selected depending on the reaction system, etc. For example, when the decomposition is carried out using a sealed batch reactor, the decomposition time is preferably 1 hour or more and 20 hours or less, and more preferably 5 hours or more and 10 hours or less. When the decomposition time is 1 hour or more, the plastic can be decomposed suitably, and the yield of olefins having 2 to 5 carbon atoms is good. Furthermore, when the decomposition time is 20 hours or less, it is efficient.

[0113] The atmosphere in which the decomposition is carried out is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable to carry out the decomposition in the presence of an inert gas.

[0114] The inert gas is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include nitrogen gas and argon gas. These may be used alone or in combination of two or more.

[0115] In order to completely fluidize the plastics, some of the plastics may be vaporized in the decomposition process. Furthermore, in the case of industrial waste, relatively homogeneous waste plastic materials consisting of specific plastic components and having a molecular weight distribution within a certain range may be obtained. In such cases, it is preferable to set the treatment conditions for the decomposition process according to the type and molecular weight of the plastic components that make up the waste plastic material. Separating inorganic substances from waste plastic materials, which are general waste, may be done using a laboratory-scale separation device, but it can also be carried out on an industrial level in various plants, such as oil refineries.

[0116] <Other Steps> The other steps in the production method of the olefin-containing composition are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a pretreatment step for the plastic and a recovery step of the volatile components obtained in the decomposition step. ＋ A BEA-type zeolite containing Rb ＋ The method may include a mixing step, a stirring step, and a calcination step for producing at least one selected from the group consisting of MOR type zeolites containing:

[0117] <<Pretreatment Step>> The pretreatment step is a step of pretreating the plastic before subjecting it to the decomposition step. In the pretreatment step, the plastic is put into a form or state that is easy to decompose, thereby enabling the plastic to be decomposed more efficiently.

[0118] Examples of the pretreatment include crushing the plastic, pelletizing (chipping) the crushed plastic, and melting the plastic.

[0119] The melt processing of the plastic is preferably carried out in the absence of zeolite at a temperature below 300°C.

[0120] The pulverized plastic material is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include powder and flake forms.

[0121] The method for obtaining the pulverized plastic is not particularly limited and can be appropriately selected from conventionally known methods, such as a method in which the plastic is pulverized using a pulverizer to obtain powder or flakes.

[0122] Furthermore, the method for pelletizing the pulverized material (chips) is not particularly limited and can be appropriately selected from conventionally known methods, such as a method in which the pulverized material is melt-extruded and then the strand-like molten extruded material is cut to obtain chipped raw material.

[0123] The plastics can also be supplied to the decomposition step in a molten state. The method for melting the plastics is not particularly limited and can be appropriately selected from conventionally known methods, such as a method in which the plastics are continuously supplied to the decomposition step using a melt extruder.

[0124] <<Volatile Component Recovery Step>> The volatile component recovery step is a step of recovering the volatile components obtained in the decomposition step.

[0125] The inclusion of the volatile component recovery step is advantageous in that, if volatile components are generated in the decomposition step, they can be recovered or removed depending on their usefulness. For example, if the plastic contains polystyrene, the styrene monomer generated in the decomposition step can be vaporized and recovered. The recovered styrene monomer can be advantageously reused for the production of polystyrene, etc. Furthermore, if the plastic material contains chlorine-containing plastics such as polyvinyl chloride and polyvinylidene chloride, it is preferable to vaporize and remove hydrogen chloride generated when the chlorine-containing plastic is heated in the decomposition step. Furthermore, separately from the decomposition step, the plastic can be heated at a low temperature in advance to vaporize the hydrogen chloride before being subjected to the decomposition step. In this case, the low-temperature heating temperature is preferably 100°C or higher but lower than 300°C. This allows the chlorine content of the fluidized olefin-containing composition to be reduced after the plastic is fluidized.

[0126] The method for recovering the volatile components is not particularly limited, and can be appropriately selected from conventionally known methods.

[0127] By the above-mentioned method for producing an olefin-containing composition, a raw material suitable for chemical recycling can be obtained, which has an excellent yield of useful components. ＋ The use of a BEA-type zeolite containing Rb is particularly advantageous in that it provides an excellent yield of useful aromatic compounds. It is generally known that attempts to increase the aromatic components tend to result in residues (see, for example, paragraph

[0003] of JP-A No. 2023-504126). However, it is known that the use of a BEA-type zeolite containing Rb ＋ The BEA-type zeolite containing the above is advantageous in that it has a high yield of useful aromatics and does not produce residues.

[0128] (Catalyst for producing an olefin-containing composition) In one embodiment of the present disclosure, the catalyst for producing an olefin-containing composition is a catalyst used for producing an olefin-containing composition containing an olefin having 2 to 5 carbon atoms, and the catalyst comprises Rb ＋ BEA-type zeolite containing Rb ＋ The composition further contains other components as required.

[0129] The raw material of the olefin-containing composition can be plastic.

[0130] <Rb ＋ BEA-type zeolite containing Rb ＋ MOR-type zeolite containing Rb ＋ BEA-type zeolite containing Rb ＋ The MOR type zeolite containing the above is as described in the section (Method for producing an olefin-containing composition).

[0131] In the catalyst for producing an olefin-containing composition, ＋ BEA-type zeolite containing Rb ＋The content of at least one selected from the group consisting of MOR type zeolites containing Rb is not particularly limited as long as it does not impair the effects of the present embodiment, and can be appropriately selected depending on the purpose. ＋ BEA-type zeolite containing Rb ＋ At least one selected from the group consisting of MOR type zeolites containing Rb ＋ BEA-type zeolite containing Rb ＋ The content of at least one selected from the group consisting of MOR type zeolites containing

[0132] <Other Components> The other components in the catalyst for producing an olefin-containing composition are not particularly limited, and examples thereof include a pH adjuster, an antiseptic and antifungal agent, a binder, and a granulation aid.

[0133] The content of the other components in the catalyst for producing an olefin-containing composition is not particularly limited as long as it does not impair the effects of the embodiment of the present disclosure, and can be appropriately selected depending on the purpose.

[0134] The catalyst for producing the olefin-containing composition is a catalyst, namely, ＋ BEA-type zeolite containing Rb ＋ The present invention relates to a method for producing an olefin-containing composition containing an olefin having 2 to 5 carbon atoms, comprising the step of: ＋ Beta type zeolite containing Rb ＋ Also included within the scope of the present disclosure is a method for using a catalyst selected from the group consisting of mordenite-type zeolites containing:

[0135] Hereinafter, embodiments of the present disclosure will be specifically described with reference to Production Examples, Comparative Production Examples, Examples, and Comparative Examples, but the embodiments of the present disclosure are not limited to these Test Examples, Production Examples, Comparative Production Examples, Examples, and Comparative Examples. In the following description, "%" indicates "% by mass" unless otherwise specified.

[0136] (Production Example 1) <Treatment Step> Rubidium nitrate (RbNO ３ 0.39 g (mass) (2.6 mmol) of rubidium nitrate (product name: HSZ-980HOA, product of Tosoh Corporation, purity: 95.0% or higher, manufactured by Kanto Chemical Co., Inc.) was added to pure water and completely dissolved to prepare a 0.26 mol / L aqueous solution of rubidium nitrate. In a glass container, beta (BEA) type zeolite (product name: HSZ-980HOA, product of Tosoh Corporation, molar ratio [SiO ２ / Al ２ O ３ ]: 40, BET specific surface area: 500m ２ 3.0 g of the aqueous solution of rubidium nitrate (1 / g) was mixed with the entire amount of the aqueous rubidium nitrate solution, and the mixture was stirred in an air atmosphere at room temperature (20°C ± 5°C) for 12 hours to obtain a reaction product.

[0137] <Caking Step> After the treatment step, the reaction product was left to stand at room temperature in an air atmosphere for 5 days, and evaporated to dryness to obtain a solidified product. The obtained solidified product was washed with water, transferred to a porcelain crucible, and calcined in an electric furnace set at 500°C in an air atmosphere for 8 hours to obtain a solid catalyst of Production Example 1.

[0138] (Production Example 2) In Production Example 1, 0.39 g (by mass) (2.6 mmol) of rubidium nitrate was added to pure water to completely dissolve it, thereby preparing a 0.26 mol / L rubidium nitrate aqueous solution. However, 0.34 g (by mass) (2.3 mmol) of rubidium nitrate was added to pure water to completely dissolve it, thereby preparing a 0.23 mol / L rubidium nitrate aqueous solution. 3.0 g of beta-type zeolite was replaced with mordenite (MOR)-type zeolite (product name: HSZ-640HOA, manufactured by Tosoh Corporation, molar ratio [SiO ２ / Al ２ O ３ ]: 18, BET specific surface area: 380m ２ A solid catalyst of Production Example 2 was obtained in the same manner as in Production Example 1, except that the amount of the catalyst (wt. / g) was changed to 3.0 g.

[0139] (Production Example 3) A solid catalyst of Production Example 3 was obtained in the same manner as in Production Example 1, except that in Production Example 1, pure water was added to 0.39 g (mass) (2.6 mmol) of rubidium nitrate to completely dissolve it and prepare a 0.26 mol / L aqueous rubidium nitrate solution, but instead pure water was added to 0.18 g (mass) (1.2 mmol) of rubidium nitrate to completely dissolve it and prepare a 0.12 mol / L aqueous rubidium nitrate solution.

[0140] (Production Example 4) A solid catalyst of Production Example 4 was obtained in the same manner as in Production Example 1, except that in Production Example 1, pure water was added to 0.39 g (by mass) (2.6 mmol) of rubidium nitrate to completely dissolve it and prepare a 0.26 mol / L aqueous rubidium nitrate solution, but instead pure water was added to 0.52 g (by mass) (3.5 mmol) of rubidium nitrate to completely dissolve it and prepare a 0.35 mol / L aqueous rubidium nitrate solution.

[0141] (Production Example 5) A solid catalyst of Production Example 5 was obtained in the same manner as in Production Example 1, except that in Production Example 1, pure water was added to 0.39 g (by mass) (2.6 mmol) of rubidium nitrate to completely dissolve it and prepare a 0.26 mol / L aqueous rubidium nitrate solution, but instead pure water was added to 0.69 g (by mass) (4.7 mmol) of rubidium nitrate to completely dissolve it and prepare a 0.47 mol / L aqueous rubidium nitrate solution.

[0142] Comparative Production Example 1 In Production Example 1, 0.39 g (mass) (2.6 mmol) of rubidium nitrate was added to pure water to completely dissolve the rubidium nitrate, and a 0.26 mol / L aqueous solution of rubidium nitrate was prepared. ３ A solid catalyst of Comparative Production Example 1 was obtained in the same manner as in Production Example 1, except that 0.22 g (by mass) (2.6 mmol) of sodium nitrate (purity: 95.0% or more, manufactured by Kanto Chemical Co., Inc.) was added to pure water to completely dissolve it, thereby preparing a 0.26 mol / L aqueous sodium nitrate solution.

[0143] Comparative Production Example 2 In Production Example 2, 0.34 g (mass) (2.3 mmol) of rubidium nitrate was added to pure water to completely dissolve the nitrate, and a 0.23 mol / L aqueous solution of rubidium nitrate was prepared. ３ A solid catalyst of Comparative Production Example 2 was obtained in the same manner as in Production Example 2, except that 0.45 g (by mass) (2.3 mmol) of cesium nitrate (product of Kanto Chemical Co., Inc., purity: 95.0% or more) was added to pure water to completely dissolve it, thereby preparing a 0.23 mol / L aqueous cesium nitrate solution.

[0144] Comparative Production Example 3 In Production Example 1, 0.39 g (by mass) (2.6 mmol) of rubidium nitrate was added to pure water to completely dissolve it, thereby preparing a 0.26 mol / L aqueous rubidium nitrate solution. Instead, 0.54 g (by mass) (3.7 mmol) of rubidium nitrate was added to pure water to completely dissolve it, thereby preparing a 0.37 mol / L aqueous rubidium nitrate solution. 3.0 g of beta-type zeolite was added to faujasite (FAU)-type zeolite (product name: HSZ-350HUA, manufactured by Tosoh Corporation, molar ratio [SiO ２ / Al ２ O ３ ]:10, BET specific surface area: 650m ２ A solid catalyst of Production Example 2 was obtained in the same manner as in Production Example 1, except that the amount of the catalyst (wt. / g) was changed to 3.0 g.

[0145] <Measurement of Acid Amount of Solid Catalyst (Zeolite)> The acid amounts of the BEA-type zeolite (trade name: HSZ-980HOA), MOR-type zeolite (trade name: HSZ-640HOA), and FAU-type zeolite (trade name: HSZ-350HUA) (hereinafter, these may be collectively referred to as "raw material zeolites") used as raw materials in the production of the solid catalysts of Production Examples 1 to 5 and Comparative Production Examples 1 to 3 were analyzed by ammonia temperature-programmed desorption (TPD) under the following measurement conditions. [Acid amount measurement conditions] Apparatus: BEL-CAT-BASIC (manufactured by Microtrac-Bell Corporation) Detector: quadrupole mass spectrometer BEL-Mass (manufactured by Microtrac-Bell Corporation) Species to be measured: NH ３(m / z = 16) Pretreatment conditions: Pretreatment was performed in the order of steps 1 to 9 shown in Table 1 below under the conditions shown in Table 1 below. Temperature increase conditions: The temperature was increased 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 the temperature increase was 30 mL / min.

[0146]

[0147] The acid amount of the BEA-type zeolite (trade name: HSZ-980HOA) was 0.079 mmol / g, the acid amount of the MOR-type zeolite (trade name: HSZ-640HOA) was 1.0 mmol / g, and the acid amount of the FAU-type zeolite (trade name: HSZ-350HUA) was 1.7 mmol / g.

[0148] <Calculation of the ratio [(valence × substance amount) of cation in nitrate contained in nitrate aqueous solution / acid amount of starting zeolite]> The measured acid amount of the starting zeolite used in the production of the solid catalysts of Production Examples 1 to 5 and Comparative Production Examples 1 to 3 corresponds to the substance amount at which the starting zeolite can provide a cation. In addition, the cation (Rb ＋ , Na ＋ , or Cs ＋ The product of the valence of the cation in the nitrate in the nitric acid aqueous solution and the amount of substance of the cation in the nitrate in the nitric acid aqueous solution was calculated. Next, the ratio of the (valence × amount of substance) of the cation in the nitrate in the nitrate aqueous solution to the acid amount of the raw zeolite [(valence × amount of substance) of the cation in the nitrate in the nitrate aqueous solution / acid amount of the raw zeolite] was calculated. The results are shown in Tables 2-1 and 2-2 below.

[0149] [Evaluation of Physical Properties of Solid Catalysts] The crystal systems, BET specific surface areas, molar ratios [SiO ] of the solid catalysts (zeolites) obtained in Production Examples 1 to 5 and Comparative Production Examples 1 to 3, and the BEA-type zeolite (trade name: HSZ-980HOA), MOR-type zeolite (trade name: HSZ-640HOA), and FAU-type zeolite (trade name: HSZ-350HUA) used as raw materials in the production of the solid catalysts of Production Examples 1 to 5 and Comparative Production Examples 1 to 3 were evaluated. ２ / Al ２ O ３ The results are shown in Tables 2-1 and 2-2 below.

[0150] In addition, in the following Tables 2-1 and 2-2, the cation ion crystal radius of the ions contained in each of the solid catalysts (zeolites) obtained in Production Examples 1 to 5 and Comparative Production Examples 1 to 3, and the BEA-type zeolite (trade name: HSZ-980HOA), MOR-type zeolite (trade name: HSZ-640HOA), and FAU-type zeolite (trade name: HSZ-350HUA) used as raw materials in the production of the solid catalysts of Production Examples 1 to 5 and Comparative Production Examples 1 to 3, shows the value of the crystal radius determined by R. D. Shannon and C. T. Prewitt et al., and the cation element electronegativity shows the value of Pauling's electronegativity.

[0151] <Analysis of Crystal System of Solid Catalyst (Zeolite)> The crystal systems of the solid catalysts (zeolites) obtained in Production Examples 1 to 5 and Comparative Production Examples 1 to 3, and the BEA-type zeolite (trade name: HSZ-980HOA), MOR-type zeolite (trade name: HSZ-640HOA), and FAU-type zeolite (trade name: HSZ-350HUA) used as raw materials in the production of the solid catalysts of Production Examples 1 to 5 and Comparative Production Examples 1 to 3, were analyzed by X-ray diffraction (XRD) under the following measurement conditions. [X-ray diffraction measurement conditions] ・ Apparatus: X'Pert Pro MPD (manufactured by Pnalytical) ・ X-ray source: CuKα radiation ・ Incident X-ray side filter: 10 mm brass mask ・ Detector side filter: Ni filter ・ Incident side slit: Sollerslit 0.04 rad ASS 1 / 8° ・ Detector side slit: ASS 5.0 mm Sollerslit 0.04 rad ・ Detector: PIXel1D ・ Measurement method: Reflection method ・ Operation range (measurement range): 2θ = 5° to 120° ・ Step width: 0.006565° ・ Counting time: 78.795 sec / step

[0152] <Measurement of BET Specific Surface Area of ​​Solid Catalyst (Zeolite)> The BET specific surface areas of the solid catalysts (zeolites) obtained in Production Examples 1 to 5 and Comparative Production Examples 1 to 3, and the BEA-type zeolite (trade name: HSZ-980HOA), MOR-type zeolite (trade name: HSZ-640HOA), and FAU-type zeolite (trade name: HSZ-350HUA) used as raw materials in the production of the solid catalysts of Production Examples 1 to 5 and Comparative Production Examples 1 to 3, were measured in accordance with ISO 9277:2010 "Determination of the specific surface area of ​​powders (solids) by gas adsorption."

[0153] Specifically, the specific surface area was determined by measurement in accordance with ISO 9277:2010 using a specific surface area measuring device (BELSORP (registered trademark) MAX II, manufactured by Microtrac-Bell Corporation) at liquid nitrogen temperature using nitrogen molecules as a probe, and analysis by the BET method.

[0154] <Mole ratio of solid catalyst (zeolite) [SiO ２ / Al ２ O ３ Measurement of] > Each of the solid catalysts (zeolites) obtained in Production Examples 1 to 5 and Comparative Production Examples 1 to 3, and the BEA-type zeolite (trade name: HSZ-980HOA), MOR-type zeolite (trade name: HSZ-640HOA), and FAU-type zeolite (trade name: HSZ-350HUA) used as raw materials in the production of the solid catalysts in Production Examples 1 to 5 and Comparative Production Examples 1 to 3 were each precisely weighed, and the resulting solution was diluted with nitric acid (EL nitric acid 1.38 for electronics industry, purity 60.0% to 61.0%, manufactured by Kanto Chemical Co., Ltd.) and hydrofluoric acid (ultrapur ultra-high purity reagent, manufactured by Kanto Chemical Co., Ltd.) ＴＭ The measurement sample was completely dissolved in an aqueous solution containing SiO 2 -100 (purity 46.0% to 51.0%) and adjusted to a constant volume. The Si and Al contents of this measurement sample were measured using an ICP emission spectrometer (PlasmaQuant PQ 9000, manufactured by Analytik Jena AG). The molar ratio [SiO 2 ] was calculated from the number of moles of Si and Al based on the following formula: ２ / Al ２ O ３ The molar ratio [SiO ２ / Al ２ O ３ ] = 2 × (number of moles of Si) / (number of moles of Al)

[0155] <Measurement of Nitrate Concentration in Liquid> The nitrate concentration in each of the aqueous nitrate solutions used in the treatment steps of Production Examples 1 to 5 and Comparative Production Examples 1 to 3 was determined by molar calculation, assuming that there was no change in the liquid volume due to mixing.

[0156]

[0157]

[0158] (Example 1) The solid catalyst obtained in Production Example 1 (hereinafter referred to as "Rb ＋ In the presence of substituted BEA-type zeolite, the decomposition of mixed plastics was carried out by the following method.

[0159] A mixture of 0.3 g of polyethylene (Sigma-Aldrich, number average molecular weight 1,700, weight average molecular weight 4,000), 0.3 g of polypropylene (Sigma-Aldrich, number average molecular weight 5,000, weight average molecular weight 12,000), 0.3 g of polystyrene (Sigma-Aldrich, weight average molecular weight 35,000), and 0.2 g of the solid catalyst of Production Example 1 was placed in a quartz inner cylinder. The inner cylinder was placed in a high-temperature, high-pressure reaction vessel (Model 4790, made of SUS-316, capacity 100 mL, manufactured by Parr) together with nitrogen gas at atmospheric pressure and sealed, and then heated to an internal temperature of 450°C and maintained for 8 hours. After cooling, the gaseous product was recovered, and 10 mL of tetrahydrofuran (THF) (manufactured by Kanto Chemical Co., Inc., high-performance liquid chromatography reagent, stabilizer-free) was added to the residue and mixed well at room temperature. The solid content was filtered off and washed twice with a small amount of THF. In this way, a product soluble in THF (THF-soluble product) was extracted into a THF solution consisting of the combined filtrate and washings.

[0160] (Example 2) In Example 1, the solid catalyst of Production Example 1 was replaced with the solid catalyst of Production Example 2 (hereinafter, "Rb ＋ The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the zeolite used in Example 1 was changed to a substituted MOR-type zeolite (sometimes referred to as "substituted MOR-type zeolite").

[0161] Example 3 In Example 1, the solid catalyst of Production Example 1 was replaced with the solid catalyst of Production Example 3 (hereinafter, "Rb ＋ The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the zeolite used in Example 1 was changed to a substituted BEA-type zeolite (sometimes referred to as "substituted BEA-type zeolite").

[0162] Example 4 In Example 1, the solid catalyst of Production Example 1 was replaced with the solid catalyst of Production Example 4 (hereinafter, "Rb ＋ The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the zeolite used in Example 1 was changed to a substituted BEA-type zeolite (sometimes referred to as "substituted BEA-type zeolite").

[0163] (Example 5) In Example 1, the solid catalyst of Production Example 1 was replaced with the solid catalyst of Production Example 5 (hereinafter, "Rb ＋The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the zeolite used in Example 1 was changed to a substituted BEA-type zeolite (sometimes referred to as "substituted BEA-type zeolite").

[0164] Comparative Example 1 In Example 1, the solid catalyst of Production Example 1 was replaced with the solid catalyst of Comparative Production Example 1 (hereinafter, "Na ＋ The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the zeolite used in Example 1 was changed to a substituted BEA-type zeolite (sometimes referred to as "substituted BEA-type zeolite").

[0165] Comparative Example 2 The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the solid catalyst in Production Example 1 was changed to a BEA-type zeolite (HSZ-980HOA).

[0166] Comparative Example 3 In Example 1, the solid catalyst of Production Example 1 was replaced with the solid catalyst of Comparative Production Example 2 (hereinafter, "Cs ＋ The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the zeolite used in Example 1 was changed to a substituted MOR-type zeolite (sometimes referred to as "substituted MOR-type zeolite").

[0167] Comparative Example 4 The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the solid catalyst in Production Example 1 was changed to MOR-type zeolite (product name: HSZ-640HOA).

[0168] Comparative Example 5 In Example 1, the solid catalyst of Production Example 1 was replaced with the solid catalyst of Comparative Production Example 3 (hereinafter, "Ra ＋ The gaseous products and the THF-soluble products were extracted in the same manner as in Example 1, except that the zeolite used in Example 1 was changed to a substituted FAU-type zeolite (sometimes referred to as "substituted FAU-type zeolite").

[0169] Comparative Example 6 The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the solid catalyst in Production Example 1 was changed to FAU-type zeolite (product name: HSZ-350HUA).

[0170] [Evaluation of Plastic Degradability] 38 mg of cyclopentane (manufactured by Tokyo Chemical Industry Co., Ltd., reagent, purity: 98.0% or higher) was added as an internal standard to each of the gaseous products recovered in Examples 1 to 5 and Comparative Examples 1 to 6 to prepare analytical samples. In addition, 0.12 g of t-butylbenzene (manufactured by Tokyo Chemical Industry Co., Ltd., reagent, purity: 98.0% or higher) was added as an internal standard to each of the THF-soluble products recovered in Examples 1 to 5 and Comparative Examples 1 to 6 to prepare analytical samples.

[0171] These analytical samples were analyzed using a gas chromatograph (GC) equipped with a flame ionization detector under the following analytical conditions, and each component was quantified from the ratio of the peak area of ​​each component to that of the internal standard. The results are shown in Tables 3-1 and 3-2 below.

[0172] <<GC analysis conditions for gaseous products>> 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 amount: 1 mL Split ratio: 1 / 200 Column temperature: The temperature rise program was set in the following order: 120°C (9 min) → temperature rise (10°C / min) → 200°C (30 min) Detector: Flame ionization detector (FID) Detector temperature: 200°C

[0173] <<GC analysis conditions for THF soluble products>> Apparatus: Nexis GC-2030 (Shimadzu Corporation) Column: DB-1 (diameter: 0.25 mm, length: 30 m, Agilent Technology) Carrier gas type: He Carrier gas flow rate: 97 mL / min Injection temperature: 350°C Sample injection amount: 1 μL Split ratio: 1 / 50 Column temperature: The temperature rise program was set in the following order: 35°C (10 min) → temperature rise (5°C / min) → 350°C (10 min) Detector: Flame ionization detector (FID) Detector temperature: 350°C

[0174] In Tables 3-1 and 3-2 below, the "yield of useful components" refers to the ratio of the total number of moles of carbon atoms contained in the olefins having 2 to 5 carbon atoms and useful aromatics in the product (useful components) to the number of moles of carbon atoms contained in the raw material. The "useful components" refer to ethylene, propylene, olefins having 4 carbon atoms (1-butene, cis-2-butene, trans-2-butene, and 2-methylpropene), olefins having 5 carbon atoms (1-pentene, cis-2-pentene, trans-2-pentene, 2-methyl-1-butene, and 2-methyl-2-butene), and useful aromatics (benzene, toluene, ethylbenzene, three positional isomers of xylene (p-xylene, m-xylene, and o-xylene), styrene, and cumene). The "yield of useful aromatics" refers to the ratio of the total number of moles of carbon atoms contained in the useful aromatics in the product (useful components) to the number of moles of carbon atoms contained in the raw material. "Useful aromatics" refers to benzene, toluene, ethylbenzene, the three positional isomers of xylene (p-xylene, m-xylene, and o-xylene), styrene, and cumene.

[0175] [Quantitative Determination of Reaction Residue] In Examples 1 to 5 and Comparative Examples 1 to 6, the solids remaining after extracting the THF-soluble product from the residue remaining in the reaction vessel were dried and weighed to determine mass A. Separately, mass B of the reaction vessel before the reaction and mass C of the reaction vessel emptied and dried after the reaction were weighed, and the difference between mass B and mass C (mass C - mass B) was calculated. The mass of the reaction residue was determined by adding mass A of the dried solids and the difference between the masses of the reaction vessel before and after the reaction (mass C - mass B) (mass A + (mass C - mass B)). The number of moles was calculated assuming that all of this was carbon, and the ratio to the number of moles of carbon atoms contained in the raw material [number of moles of carbon atoms in the reaction residue / number of moles of carbon atoms contained in the raw material] was taken as the yield of the reaction residue. The results are shown in Tables 3-1 and 3-2 below.

[0176]

[0177]

[0178] From the results of Tables 2-1 to 3-2, Rb ＋ BEA type containing Rb ＋The MOR type zeolite containing the above compound gave the best yield of useful components (35% or more).

[0179] Furthermore, Rb ＋ The BEA type containing Rb gave a better yield of useful aromatics and no residue. ＋ Although the FAU type containing β-methyl-2-pyrrolidone (β-methyl-2-pyrrolidone) produced a certain amount of useful aromatics, it also produced a large amount of residue. It is presumed that the FAU type has a large pore size, which makes it easier for benzene rings to grow, which leads to side reactions and an increase in residue.

[0180] Comparative Example 7 The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that the solid catalyst of Production Example 1 was not used.

[0181] Example 6 The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that 0.2 g of the solid catalyst of Production Example 1 was added to 0.3 g of polyethylene, 0.3 g of polypropylene, and 0.3 g of polystyrene in Example 1, but 0.0045 g of the solid catalyst of Production Example 1 was added to 0.3 g of polyethylene, 3 g of polypropylene, and 0.3 g of polystyrene.

[0182] Example 7 The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that 0.2 g of the solid catalyst of Production Example 1 was added to 0.3 g of polyethylene, 0.3 g of polypropylene, and 0.3 g of polystyrene in Example 1, but 0.018 g of the solid catalyst of Production Example 1 was added to 0.3 g of polyethylene, 3 g of polypropylene, and 0.3 g of polystyrene.

[0183] Example 8 The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that 0.2 g of the solid catalyst of Production Example 1 was added to 0.3 g of polyethylene, 0.3 g of polypropylene, and 0.3 g of polystyrene in Example 1, but 0.27 g of the solid catalyst of Production Example 1 was added to 0.3 g of polyethylene, 3 g of polypropylene, and 0.3 g of polystyrene.

[0184] Example 9 The gaseous product and the THF-soluble product were extracted in the same manner as in Example 1, except that 0.2 g of the solid catalyst of Production Example 1 was added to 0.3 g of polyethylene, 0.3 g of polypropylene, and 0.3 g of polystyrene in Example 1, but 0.45 g of the solid catalyst of Production Example 1 was added to 0.3 g of polyethylene, 3 g of polypropylene, and 0.3 g of polystyrene.

[0185] [Evaluation of Plastic Degradability] Analytical samples of the gaseous products and THF-soluble products recovered in Comparative Example 7 and Examples 6 to 9 were prepared in the same manner as in the evaluation of plastic degradability in Examples 1 to 5 and Comparative Examples 1 to 6. These samples were analyzed under the above-mentioned analytical conditions using a gas chromatograph (GC) equipped with a flame ionization detector, and the amount of each component was quantified from the ratio of the peak area of ​​each component to that of the internal standard. The results are shown in Table 4 below.

[0186] [Quantitative Determination of Reaction Residue] The yields of the reaction residues of Comparative Example 7 and Examples 6 to 9 were calculated in the same manner as in the quantitative determination of the reaction residues of Examples 1 to 5 and Comparative Examples 1 to 6. The results are shown in Table 4 below.

[0187] In Table 4 below, the "amount added [phr]" of the solid catalyst indicates the mass parts of the solid catalyst added when the total mass (0.9 g) of polyethylene, polypropylene, and polystyrene is taken as 100 mass parts.

[0188]

[0189] As described above, the present disclosure has been described based on specific embodiments, manufacturing examples, and examples. However, these embodiments, manufacturing examples, and examples are presented merely as examples, and the present disclosure is not limited to the above embodiments, manufacturing examples, and examples. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, additions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims.

[0190] This international application claims priority based on Japanese Patent Application No. 2023-131008, filed on August 10, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A method for producing an olefin-containing composition comprising decomposing a plastic in the presence of a zeolite to produce an olefin having 2 to 5 carbon atoms, the zeolite being selected from the group consisting of Rb ＋ Beta type zeolite containing Rb ＋ The present invention relates to a method for producing an olefin-containing composition, and more particularly to a mordenite-type zeolite containing at least one of the following:

2. The method for producing an olefin-containing composition according to claim 1, wherein the plastic is a polyolefin.

3. The method for producing an olefin-containing composition according to claim 1, wherein the plastic contains at least one selected from the group consisting of polyethylene, polypropylene, and polystyrene.

4. The method for producing an olefin-containing composition according to claim 1 or 2, wherein the temperature at which the plastic is decomposed is 300°C or higher and 1,100°C or lower.

5. The Rb ＋ A beta type zeolite containing Rb ＋ Al-containing mordenite-type zeolite ２ O ３ SiO ２ Molar ratio [SiO ２ / Al ２ O ３ 3. The method for producing an olefin-containing composition according to claim 1 or claim 2, wherein the value of n is 10 or more and 10,000 or less.

6. The Rb ＋ The BET specific surface area of ​​the beta zeolite containing ２ / g or more 500m ２ / g or less, and ＋ The BET specific surface area of ​​the mordenite-type zeolite containing ２ / g or more 400m ２ The method for producing an olefin-containing composition according to claim 1 or claim 2, wherein the olefin content is 1 / g or less.

7. A mixing step of mixing at least one selected from the group consisting of beta-type zeolite and mordenite-type zeolite with a liquid containing a rubidium compound to obtain a mixed liquid; and calcining the mixed liquid in air to obtain the Rb ＋ A beta type zeolite containing Rb ＋ The method for producing an olefin-containing composition according to claim 1, further comprising: a calcination step of obtaining at least one selected from the group consisting of mordenite-type zeolites containing 8. In the mixing step, ＋ A beta type zeolite containing Rb ＋ The mass of at least one selected from the group consisting of mordenite-type zeolites containing Rb is defined as x (g). ＋ A beta type zeolite containing Rb ＋ At least one selected from the group consisting of mordenite-type zeolites containing ２ O ３ SiO ２ Molar ratio [SiO ２ / Al ２ O ３ 8. The method for producing an olefin-containing composition according to claim 7, wherein 1≦yz / x≦5,000 is satisfied, where y is the molar ratio of the rubidium compound and z (mmol) is the number of moles of the rubidium compound.

9. The beta type zeolite is H ＋ The zeolite of the beta type contains H ＋ The method for producing an olefin-containing composition according to claim 7, wherein the zeolite is a mordenite type zeolite containing:

10. A catalyst for use in the production of an olefin-containing composition containing an olefin having 2 to 5 carbon atoms, comprising Rb ＋ Beta type zeolite containing Rb ＋ 1. A catalyst for producing an olefin-containing composition, comprising at least one selected from the group consisting of mordenite-type zeolites containing:

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