Thermal decomposition oil, elastomer, rubber product, and resin product

Abstract

To provide a thermal decomposition oil which is easily used as a raw material of a chemical product.SOLUTION: A thermal decomposition oil obtained by thermally decomposing a waste material containing used tires, characterized in that an aromatic content measured by GC×GC-MS is 80 vol.% or less, and that the density measured at 40°C within 3 hours after production is 0.82 g / cm3 or more and less than 0.89 g / cm3. The thermal decomposition oil preferably has a volume ratio (olefin content / aromatic content) of the olefin content to the aromatic content measured by GC×GC-MS of 0.1 or more, a 90% distillation temperature of 400°C or less, a 10% distillation temperature of 100°C or more, and an iodine value of 180 gI2 / 100 g or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to pyrolysis oil, elastomers, rubber products, and resin products. [Background technology]

[0002] Recently, recycling of used rubber products, including used tires, has been promoted from the viewpoint of protecting the global environment. One such recycling method is a technology for pyrolyzing used rubber products and recovering pyrolysis products such as oil (pyrolysis oil) and carbon black (carbide). For example, Patent Document 1 listed below discloses a method for recovering carbon and hydrocarbon mixtures from waste tires or similar polymer materials by pyrolysis. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2002-523552 Summary of the Invention [Problem to be solved by the invention]

[0004] As described in Patent Document 1 and the like, various studies have been conducted on methods for pyrolyzing used tires, but no studies have been conducted on the components in the oil (pyrolysis oil) recovered by pyrolysis. On the other hand, in order to pyrolyze used tires and reuse them as raw materials for chemical products, it is preferable that the recovered pyrolysis oil has specific properties.

[0005] Therefore, an object of the present invention is to provide a pyrolysis oil that can be easily used as a raw material for chemical products. Another object of the present invention is to provide elastomers, rubber products, and resin products that use such pyrolysis oil. [Means for solving the problem]

[0006] The pyrolysis oil, elastomer, rubber product, and resin product of the present invention, which solve the above problems, are summarized as follows.

[0007] [1] Pyrolysis oil obtained by pyrolysis of waste materials including used tires, The aromatic content measured by GC×GC-MS is 80% by volume or less, and the density measured at 40°C is 0.82 g / cm within 3 hours after production. 3 More than 0.89g / cm 3 Pyrolysis oil characterized in that it is less than. The pyrolysis oil of the present invention described in [1] above is light and has a low aromatic content, and therefore can be easily used as a raw material for chemical products.

[0008] [2] After leaving it for 3 days after production, the density measured at 40°C is 0.84 to 0.97 g / cm 3 The pyrolysis oil according to [1], The pyrolysis oil described in [2] above can be more easily used as a raw material for chemical products.

[0009] [3] The pyrolysis oil according to [1] or [2], in which the volume ratio of olefin content to aromatic content (olefin content / aromatic content) measured by GC×GC-MS is 0.1 or more. The pyrolysis oil described in [3] above can be more easily used as a raw material for chemical products.

[0010] [4] The pyrolysis oil according to any one of [1] to [3], having an olefin content of 10% by volume or more as measured by GC×GC-MS. The pyrolysis oil described in [4] above can be more easily used as a raw material for chemical products.

[0011] [5] The pyrolysis oil according to any one of [1] to [4], having an olefin content of 30% by volume or more as measured by GC×GC-MS. The pyrolysis oil described in [5] above can be more easily used as a raw material for chemical products.

[0012] [6] The pyrolysis oil according to any one of [1] to [5], having a 90% distillation temperature of 400°C or less. The pyrolysis oil described in [6] above can be more easily used as a raw material for chemical products.

[0013] [7] The pyrolysis oil according to any one of [1] to [6], having a 10% distillation temperature of 100°C or higher. The pyrolysis oil described in [7] above can be more easily used as a raw material for chemical products.

[0014] [8] The pyrolysis oil according to any one of [1] to [7], having an iodine value of 180 g I2 / 100 g or more. The pyrolysis oil described in [8] above can be more easily used as a raw material for chemical products.

[0015] [9] An elastomer, characterized in that the pyrolysis oil according to any one of [1] to [8] is used as a raw material in whole or in part. The elastomer described in [9] above can contribute to promoting the recycling of waste materials including used tires.

[0016]

[10] The elastomer according to [9], wherein the elastomer is at least one selected from the group consisting of resins and synthetic rubbers. The elastomer described in

[10] above can further contribute to promoting the recycling of waste materials including used tires.

[0017]

[11] A rubber product, characterized in that the elastomer according to [9] or

[10] is used as a part or all of a raw material. The rubber product described in

[11] above can contribute to promoting the recycling of waste materials including used tires.

[0018]

[12] The rubber product according to

[11] , which is at least one selected from the group consisting of a rubber tire, a rubber crawler, a rubber hose, a conveyor belt, and a seismic isolation rubber. The rubber product described in

[12] above can further contribute to promoting the recycling of waste materials including used tires.

[0019]

[13] A resin product characterized in that the elastomer according to [9] or

[10] is used as a part or all of a raw material. The resin product described in

[13] above can contribute to promoting the recycling of waste materials including used tires.

[0020]

[14] The resin product according to

[13] , wherein the resin product is at least one selected from the group consisting of a resin tire and a resin hose. The resin product described in

[14] above can further contribute to promoting the recycling of waste materials including used tires. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a pyrolysis oil that can be easily used as a raw material for chemical products. Furthermore, according to the present invention, it is possible to provide elastomers, rubber products, and resin products using such pyrolysis oil. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram illustrating classification of compounds in the pyrolysis oil recovered in the examples and comparative examples according to their structures. DETAILED DESCRIPTION OF THE INVENTION

[0023] The pyrolysis oil, elastomer, rubber product, and resin product of the present invention will be described in detail below with reference to exemplary embodiments.

[0024] <Definition> The compounds described herein may be derived in part or in whole from fossil sources, biological sources such as plant sources, recycled sources such as used tires, or a mixture of two or more of fossil, biological, and recycled sources.

[0025] <Pyrolysis oil> The pyrolysis oil of this embodiment is obtained by pyrolyzing waste materials including used tires. The pyrolysis oil of this embodiment has an aromatic content of 80% by volume or less as measured by GC×GC-MS (two-dimensional gas chromatography mass spectrometry), and a density of 0.82 g / cm3 measured at 40°C within 3 hours after production. 3 More than 0.89g / cm 3 It is characterized in that it is less than

[0026] Generally, aromatic compounds are chemically stable and therefore difficult to convert into other compounds, making them difficult to use as chemical products. In contrast, the pyrolysis oil of this embodiment has an aromatic content (aromatic compound content) of 80% by volume or less as measured by GC×GC-MS, and contains many components that are easy to use as chemical products. Furthermore, the pyrolysis oil of this embodiment has a density of 0.89 g / cm 3 measured at 40°C within 3 hours after production. 3 Since the molecular weight is less than 1000 kJ / kg, it is light and contains many components with a moderately small molecular weight. Components with a moderately small molecular weight can be easily used as chemical products as they are, and can also be easily converted into other chemical products by performing additional treatments or reactions. Furthermore, when butadiene, isoprene, etc. are contained as components with a moderately small molecular weight, these components can be used as raw materials for rubber (particularly diene rubber). Furthermore, the pyrolysis oil of this embodiment has a density of 0.82 g / cm3 measured at 40°C within 3 hours after production. 3 For these reasons, there are few components with too small a molecular weight, and the polymer can be easily used as a raw material for chemical products. Therefore, the pyrolysis oil of this embodiment can be easily used as a raw material for chemical products.

[0027] (raw materials) The pyrolysis oil of this embodiment is obtained by pyrolyzing waste materials including used tires. By pyrolyzing waste materials including used tires to obtain pyrolysis oil that can be easily used as a raw material for chemical products, the waste materials including used tires can be effectively utilized as a resource. Therefore, the pyrolysis oil of this embodiment can contribute to the recycling of waste materials including used tires.

[0028] The waste materials used as raw materials for the pyrolysis include used tires, and may further include waste materials other than used tires, such as waste rubber products other than tires and waste plastics.

[0029] The waste rubbers from used tires and other rubber products (waste rubbers) typically contain diene rubber as a rubber component, as well as fillers such as carbon black, silica, and calcium carbonate, as well as compounding agents such as silane coupling agents, antioxidants, softeners, processing aids, resins, surfactants, organic acids (such as stearic acid), zinc oxide (zinc white), vulcanization accelerators, and crosslinking agents (such as sulfur and peroxides). Specific examples of diene rubbers include natural rubber (NR), synthetic isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), and chloroprene rubber (CR). The rubber components in the waste materials are primarily thermally decomposed to produce the light pyrolysis oil described above, which is easily usable as a raw material for chemical products.

[0030] (Aromatic content) The pyrolysis oil of this embodiment has an aromatic content (aromatic compound content) of 80% by volume or less, preferably 60% by volume or less, and more preferably 40% by volume or less, as measured by GC×GC-MS (two-dimensional gas chromatography mass spectrometry). Having an aromatic content of 80% by volume or less makes it easier to use the pyrolysis oil as a raw material for chemical products other than benzene, toluene, and xylene. The lower limit of the aromatic content of the pyrolysis oil is not particularly limited, but the aromatic content of the pyrolysis oil is typically 10% by volume or more. Pyrolysis oil with an aromatic content of 10% by volume or more can be easily obtained, for example, from the pyrolysis of waste materials including used tires, using the method described below. Here, in this specification, the aromatic content (aromatic compound content) of the pyrolysis oil is a value measured using a GC×GC-MS (two-dimensional gas chromatograph mass spectrometer) by the method described in the examples.

[0031] (olefin content) The pyrolysis oil of this embodiment preferably has an olefin content (olefin content) of 10% by volume or more, more preferably 30% by volume or more, and even more preferably 35% by volume or more, as measured by GC×GC-MS (two-dimensional gas chromatography mass spectrometry). When the olefin content of the pyrolysis oil is 10% by volume or more, the pyrolysis oil contains a large amount of compounds having non-aromatic carbon-carbon double bonds. These compounds having non-aromatic carbon-carbon double bonds can be easily used as chemical products as they are, and can also be easily converted into other chemical products by additional processing or reaction, making the pyrolysis oil even more useful as a raw material for chemical products. The upper limit of the olefin content of the pyrolysis oil is not particularly limited, but the olefin content of the pyrolysis oil is typically 60% by volume or less. Pyrolysis oils having an olefin content of 60% by volume or less can be easily obtained, for example, from the pyrolysis of waste materials including used tires, using the method described below. In this specification, the term "olefin" refers to a hydrocarbon that has one or more carbon-carbon double bonds but does not contain heteroatoms, aromatic rings, or carbon-carbon triple bonds, and may be linear or cyclic. Examples of olefins include butadiene, isoprene, pentene, hexene, cyclopentene, cyclohexene, cyclopentadiene, dicyclopentadiene, and limonene. Among these, butadiene and isoprene can be used as raw materials for rubber (particularly diene rubber). In this specification, the olefin content (olefin content) of the pyrolysis oil is a value measured using a GC×GC-MS (two-dimensional gas chromatograph mass spectrometer) by the method described in the Examples.

[0032] (iodine value) The pyrolysis oil of this embodiment preferably has an iodine value of 180 gI2 / 100 g or more. Pyrolysis oil with an iodine value of 180 gI2 / 100 g or more contains a large amount of olefins, making it easier to use as a raw material for chemical products. From the viewpoint of ease of use as a raw material for chemical products, the iodine value of the pyrolysis oil is more preferably 200 gI2 / 100 g or more. Furthermore, the upper limit of the iodine value of the pyrolysis oil is not particularly limited, but the iodine value of the pyrolysis oil is usually 400 gI2 / 100 g or less. Pyrolysis oil with an iodine value of 400 gI2 / 100 g or less can be easily obtained, for example, from the pyrolysis of waste materials including used tires by the method described below. In this specification, the iodine value of the pyrolysis oil is a value measured in accordance with JIS K0070.

[0033] (olefin content / aromatic content) The pyrolysis oil of this embodiment preferably has a volume ratio of olefins to aromatics (olefins / aromatics) measured by GC×GC-MS (two-dimensional gas chromatography mass spectrometry) of 0.1 or more, more preferably 0.2 or more, and even more preferably 0.5 or more. Olefins are compounds having non-aromatic carbon-carbon double bonds and can be easily used as chemical products as they are, or can be easily converted into other chemical products by additional processing or reaction. On the other hand, as mentioned above, aromatic compounds are chemically stable and therefore difficult to convert into other compounds. Therefore, pyrolysis oil having a volume ratio of olefins to aromatics (olefins / aromatics) of 0.1 or more contains many compounds having non-aromatic carbon-carbon double bonds that can be easily used as chemical products, and few aromatic compounds that are difficult to use as chemical products, making it even easier to use as a raw material for chemical products. Furthermore, the upper limit of the volume ratio of the olefin content to the aromatic content (olefin content / aromatic content) is not particularly limited, but the volume ratio (olefin content / aromatic content) of pyrolysis oil is usually not more than 10. Pyrolysis oil having a volume ratio of the olefin content to the aromatic content (olefin content / aromatic content) of not more than 10 can be easily obtained, for example, from the pyrolysis of waste materials including used tires by the method described below.

[0034] (Other ingredients) In addition to the olefins and aromatic compounds described above, the pyrolysis oil of this embodiment may contain paraffins, alkynes, heterocyclic compounds, etc., and may also contain nitrogen, sulfur, chlorine, etc.

[0035] (density) The pyrolysis oil of this embodiment has a density of 0.82 g / cm measured at 40 ° C within 3 hours after production. 3 More than 0.89g / cm 3 Density is less than 0.82 g / cm 3 The pyrolysis oil described above contains few components with too small molecular weight, making it easy to use as a raw material for chemical products. In addition, the density is 0.89 g / cm 3 Pyrolysis oil with a density of less than 0.84 g / cm is light and contains many components with a moderately small molecular weight, making it easy to use as a raw material for chemical products. 3 It is preferable that this is equal to or greater than this. In this specification, the density of the pyrolysis oil is a value measured at 40°C in accordance with ASTM D4052 by sampling the oil immediately after pyrolysis.

[0036] In addition, the pyrolysis oil of this embodiment has a density of 0.84 to 0.97 g / cm 3 measured at 40°C after being left for 3 days after production. 3 This is because if pyrolysis oil is left for a long time, low boiling point components will volatilize and the density will change. After being left for 3 days after production, the density measured at 40°C is preferably 0.84 to 0.97 g / cm 3 The pyrolysis oil can also be easily used as a raw material for chemical products.

[0037] (T90) The pyrolysis oil of this embodiment preferably has a 90% (mass) distillation temperature (T90) of 400°C or less, more preferably 350°C or less. Pyrolysis oil with a 90% distillation temperature of 400°C or less is light and contains many components with relatively small molecular weights. Components with relatively small molecular weights can be easily used as chemical products as they are, and can also be easily converted into other chemical products by additional processing or reaction. Therefore, pyrolysis oil with a 90% distillation temperature of 400°C or less is even more easily usable as a raw material for chemical products. Furthermore, when the 90% distillation temperature of the pyrolysis oil is 350°C or less, the pyrolysis oil can be even more easily used as a raw material for chemical products. Furthermore, the lower limit of the 90% distillation temperature is not particularly limited, but the 90% distillation temperature of pyrolysis oil is usually 250°C or higher. Pyrolysis oil having a 90% distillation temperature of 250°C or higher can be easily obtained, for example, from the pyrolysis of waste materials including used tires by the method described below. In this specification, the 90% distillation temperature of the pyrolysis oil is a value measured using a distillation gas chromatograph (GC) in accordance with ASTM D7169.

[0038] (T10) The pyrolysis oil of this embodiment preferably has a 10% (mass) distillation temperature (T10) of 100°C or higher, and more preferably 110°C or higher. Pyrolysis oils with a 10% distillation temperature of 100°C or higher contain fewer components with too small a molecular weight, making them more suitable for use as raw materials for chemical products. The upper limit of the 10% distillation temperature is not particularly limited, but the 10% distillation temperature of pyrolysis oils is typically 200°C or lower. Pyrolysis oils with a 10% distillation temperature of 200°C or lower can be easily obtained, for example, from the pyrolysis of waste materials including used tires, using the method described below. In this specification, the 10% distillation temperature of the pyrolysis oil is a value measured using a distillation gas chromatograph (GC) in accordance with ASTM D7169.

[0039] <Method of producing pyrolysis oil> The method for producing pyrolysis oil according to the present embodiment is not particularly limited. For example, the pyrolysis oil according to the present embodiment can be produced by pyrolyzing waste materials including used tires in a pyrolysis furnace to obtain pyrolysis gas, and then cooling the pyrolysis gas to obtain pyrolysis oil. Preferred embodiments of the method for producing pyrolysis oil are described below.

[0040] A preferred embodiment of the method for producing pyrolysis oil includes a step of pyrolyzing waste materials including used tires in a pyrolysis furnace to obtain a solid material including pyrolysis gas and char (pyrolysis step), and a step of cooling the pyrolysis gas to obtain pyrolysis oil (cooling step), wherein the pyrolysis temperature is preferably 300°C to 500°C and the pyrolysis reaction time is 0.6 minutes or longer. Here, the pyrolysis reaction time refers to the time from when the temperature inside the furnace reaches the reaction temperature until the gas inside the furnace is released in the case of a closed pyrolysis furnace, and refers to a value calculated based on the following formula in the case of an open or continuous pyrolysis furnace.

number

[0041] (pyrolysis process) In the pyrolysis process, waste materials including used tires are pyrolyzed in a pyrolysis furnace to obtain solid materials including pyrolysis gas and char. By pyrolyzing waste materials including used tires to obtain pyrolysis gas, and then cooling this to obtain light pyrolysis oil with low aromatic content, the waste materials including used tires can be effectively utilized as a resource. In the pyrolysis process, parts and components of the raw material waste that do not become pyrolysis gas remain in the pyrolysis furnace as residue. Examples of residues include char, such as carbon black.

[0042] -raw materials- The waste materials used as raw materials for the pyrolysis include used tires. The used tires may be grouped in advance by tire type (e.g., for passenger cars, trucks, buses, large vehicles such as off-road vehicles, aircraft, agricultural vehicles, etc.), and then pyrolysis may be performed for each group. Alternatively, the used tires may be grouped in advance by tire component (e.g., tread rubber, sidewall rubber, bead rubber, steel cord-coated rubber, organic fiber-coated rubber, pad rubber, cushion rubber, etc.), and then pyrolysis may be performed for each group. Furthermore, the used tires may be grouped both by tire type and by tire component, and then pyrolysis may be performed for each group. When pyrolysis is performed for each group in this way, pyrolysis oil with more uniform physical properties can be obtained.

[0043] The used tires may contain metal reinforcing materials such as steel cords and bead cores. When the used tires contain metal reinforcing materials, the metal reinforcing materials may or may not be removed from the used tires in advance. If the metal reinforcing materials are not removed from the used tires, the metal reinforcing materials remain as residue in the pyrolysis furnace. The used tires may also be cut and crushed in advance. The method for removing metal reinforcing materials and the like from used tires or crushed tires is not particularly limited, and examples thereof include methods using magnets, sieves, and the like. The used tires may contain organic fiber reinforcing materials such as organic fiber cords. When the used tires contain organic fiber reinforcing materials, the organic fiber reinforcing materials may or may not be removed from the used tires in advance. If the organic fiber reinforcing materials are not removed from the used tires, the organic fiber reinforcing materials remain as residue in the pyrolysis furnace or are vaporized and discharged as gas. The used tires may also be cut and crushed in advance. The method for removing the organic fiber reinforcing material and the like from used tires or crushed tires is not particularly limited, and examples thereof include methods using centrifugal force, sieving, and the like. The method for crushing used tires is not particularly limited, and examples thereof include mechanical crushing using a single-axis crusher or a twin-axis crusher, crushing using a water jet, freeze crushing, and laser crushing.

[0044] The waste material may include waste materials other than used tires. Examples of the waste materials other than used tires include waste materials of rubber products other than tires, waste plastics, etc. As described above, the used tires and waste materials of rubber products other than tires (waste rubbers) usually contain diene rubber as a rubber component, and the rubber component is mainly subjected to thermal decomposition to obtain the above-mentioned light pyrolysis oil having a low aromatic content.

[0045] -Thermal decomposition temperature- The pyrolysis temperature is preferably 300°C to 500°C. By setting the pyrolysis temperature to 300°C or higher, the pyrolysis of waste materials including used tires can be accelerated. Furthermore, by setting the pyrolysis temperature to 500°C or lower, aromatization of the generated pyrolysis gas can be suppressed, making it possible to obtain a light pyrolysis oil with a low aromatic content. From the viewpoint of accelerating the pyrolysis of waste materials, the pyrolysis temperature is preferably 350°C or higher, and from the viewpoint of suppressing aromatization of the generated pyrolysis gas, the pyrolysis temperature is preferably 450°C or lower.

[0046] The method for controlling the pyrolysis temperature is not particularly limited, and may be, for example, a method in which a heating means is attached to the pyrolysis furnace and the temperature of the pyrolysis furnace is increased by the heating means, a method in which the pyrolysis furnace is introduced into an electric furnace heated to a predetermined temperature, a method in which high-temperature gas heated to a predetermined temperature is introduced into the pyrolysis furnace, or other methods.

[0047] -Pyrolysis furnace- The pyrolysis furnace is not particularly limited, and examples thereof include a batch pyrolysis furnace, a fluidized bed pyrolysis furnace, and a kiln pyrolysis furnace. In one embodiment, the pyrolysis furnace comprises an inlet flow path for introducing an inert gas and an outlet flow path for discharging the inert gas and the generated pyrolysis gas. The inlet flow path is preferably equipped with a flow rate control device, which can adjust the amount of inert gas introduced. The flow rate control device provided in the inlet flow path is not particularly limited, and examples thereof include a mass flow controller. The outlet flow path is also preferably equipped with a flow rate control device, and the flow rate control device can adjust the discharge rate of a mixed gas of the inert gas and the generated pyrolysis gas. The flow rate control device provided in the outlet flow path is not particularly limited, and examples thereof include an exhaust valve. The flow rate control device provided in the inlet flow path makes it easier to control the residence time of the pyrolysis gas in the pyrolysis furnace and the pyrolysis reaction time than the flow rate control device provided in the outlet flow path.

[0048] -Reaction time- The thermal decomposition reaction time is preferably 0.6 minutes or more, and more preferably 1.0 minute or more. When the thermal decomposition reaction time is 0.6 minutes or more, the thermal decomposition of the waste material including used tires proceeds sufficiently, and when it is 1.0 minute or more, the thermal decomposition of the waste material proceeds further. The thermal cracking reaction time is preferably 10.0 minutes or less. If the thermal cracking reaction time exceeds 10.0 minutes, the thermal cracking gas will be turned into off-gas, the yield of the thermal cracking oil will be reduced, and the thermal cracking gas will be aromaticized, resulting in a reduced yield of the light, olefin-rich thermal cracking oil.

[0049] -atmosphere- The pyrolysis is preferably carried out in an atmosphere of the gas generated by pyrolysis or in an atmosphere of a mixture of the gas generated by pyrolysis and an inert gas. By carrying out the pyrolysis in an atmosphere of the gas generated by pyrolysis or in an atmosphere of a mixture of the gas generated by pyrolysis and an inert gas, oxidation of the waste raw material and the generated pyrolysis gas is suppressed, and a pyrolysis gas containing a higher olefin content can be obtained. After the cooling step described below, a pyrolysis oil containing a higher olefin content can be obtained. Examples of inert gases include nitrogen, carbon dioxide, argon, and helium. Furthermore, the atmosphere of the gas generated by pyrolysis or the atmosphere of the mixture of the gas generated by pyrolysis and an inert gas may contain 1% by volume or less of oxygen.

[0050] The pyrolysis is preferably carried out while circulating the gas generated by pyrolysis or a mixture of the gas generated by pyrolysis and an inert gas through the pyrolysis furnace. By circulating the gas generated by pyrolysis or a mixture of the gas generated by pyrolysis and an inert gas through the pyrolysis furnace, oxidation of the raw material waste and the generated pyrolysis gas is suppressed, and a pyrolysis gas containing a higher olefin content is obtained. Furthermore, by adjusting the flow rate of the inert gas, it is easy to accurately control the residence time of the pyrolysis gas in the pyrolysis furnace, i.e., the pyrolysis reaction time. By passing through the cooling step described below, a light pyrolysis oil containing a lower aromatic content and a higher olefin content can be obtained.

[0051] -others- The thermal decomposition step can be carried out at any pressure, and can be carried out under reduced pressure, normal pressure, or increased pressure. By carrying out thermal decomposition under reduced pressure or normal pressure, polymerization (repolymerization) of olefins in the thermal decomposition gas can be suppressed. The pressure in the thermal decomposition furnace is preferably 0.1 kPaG or less, and more preferably 0 kPaG or less, in gauge pressure. When the pressure in the thermal decomposition furnace is 0.1 kPaG or less, polymerization (repolymerization) of olefins in the thermal decomposition gas can be further suppressed, and when the pressure in the thermal decomposition furnace is 0 kPaG or less, polymerization (repolymerization) of olefins in the thermal decomposition gas can be further suppressed. When the pressure in the thermal decomposition furnace is 0 kPaG or less, a reduced pressure state is also included.

[0052] The thermal decomposition step may or may not use a catalyst, but it is preferable not to use a catalyst. Not using a catalyst in the thermal decomposition step can reduce the cost of the thermal decomposition step. When a catalyst is used, any catalyst that has the effect of accelerating the thermal decomposition reaction of waste materials including used tires can be used, and examples of such catalysts include acidic catalysts such as zeolite, activated clay, acid clay, and bentonite, and basic catalysts such as sodium carbonate.

[0053] (cooling process) In the cooling step, the pyrolysis gas is cooled to obtain a pyrolysis oil, which is separated into a gaseous off-gas and a liquefied pyrolysis oil, thereby obtaining a light pyrolysis oil with a low aromatic content. The components of the off-gas depend on the cooling temperature, but examples include gaseous components at normal pressure and 20°C, such as hydrogen and hydrocarbons having 1 to 4 carbon atoms. The off-gas can be used as a raw material for chemical products, or as a fuel for a heat source in a pyrolysis furnace.

[0054] The method for cooling the pyrolysis gas is not particularly limited, and the pyrolysis gas may be actively cooled using a condenser, a cooling tower, or the like, or may be naturally cooled by standing. The cooling temperature of the pyrolysis gas is also not particularly limited, and is preferably, for example, -20°C to 100°C, and more preferably 0°C to 50°C. When the pyrolysis gas is cooled using a medium, the medium is not particularly limited, and examples thereof include water.

[0055] The yield of the pyrolysis oil is preferably 30% or more, more preferably 35% or more, based on the mass of the waste material. When the yield of the pyrolysis oil is 30% or more, based on the mass of the waste material, a light pyrolysis oil with a low aromatic content can be obtained efficiently in large quantities, improving economic efficiency and further contributing to the recycling of waste materials including used tires.

[0056] In one embodiment, it is preferable that 55% by mass or more of the pyrolysis gas is recovered as pyrolysis oil. By recovering 55% by mass or more of the pyrolysis gas as pyrolysis oil, a large amount of light pyrolysis oil rich in olefins can be efficiently obtained, which improves economic efficiency and further contributes to the recycling of waste materials including used tires.

[0057] (Other processes) The above-described method for producing pyrolysis oil may include other steps in addition to the pyrolysis step and cooling step, such as a pretreatment step for raw material waste, a carbonization step for treating carbonized material to obtain carbon black, and a purification step for the produced pyrolysis oil. The carbide treatment step may include a step of removing substances other than carbon black, a pulverization step, a carbon black granulation step, etc. The method for the carbide treatment step is not particularly limited, and a generally known treatment method can be used. However, it is preferable that the method for producing pyrolysis oil does not include a step of further fractionating the pyrolysis oil obtained in the cooling step. By not including a step of fractionating the pyrolysis oil obtained after cooling the pyrolysis gas, the yield of pyrolysis oil based on the mass of the rubber component in the waste raw material is improved, and the process as a whole is simplified and more economical.

[0058] <Elastomer> The elastomer of this embodiment is characterized in that it uses the above-mentioned pyrolysis oil as a part or all of the raw material. Because the elastomer of this embodiment uses the above-mentioned pyrolysis oil as a part or all of the raw material, it can contribute to promoting the recycling of waste materials including used tires.

[0059] The elastomer is preferably at least one selected from the group consisting of resins and synthetic rubbers. Elastomers selected from the group consisting of resins and synthetic rubbers are easy to use as rubber products or resin products and are in high demand, and can therefore further contribute to promoting the recycling of waste materials, including used tires. Here, examples of the resin include thermoplastic elastomers such as polyester thermoplastic elastomer (TPC), polyamide thermoplastic elastomer (TPA), polyolefin thermoplastic elastomer (TPO), polystyrene thermoplastic elastomer (TPS), etc. Examples of the synthetic rubber include diene rubbers such as synthetic isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), and chloroprene rubber (CR).

[0060] <Rubber products> The rubber product of this embodiment is characterized in that it contains the above-described elastomer as part or all of its raw materials. Because the rubber product of this embodiment contains the above-described elastomer as part or all of its raw materials, it can contribute to promoting the recycling of waste materials, including used tires. Here, the rubber product can be manufactured by, for example, preparing a rubber composition containing synthetic rubber and a vulcanizing agent such as sulfur in advance, molding the rubber composition into a desired shape, and then subjecting the composition to a vulcanization process by heating. The rubber composition may further contain compounding ingredients such as fillers such as carbon black, silica, and calcium carbonate, silane coupling agents, antioxidants, softeners, processing aids, resins, surfactants, organic acids (such as stearic acid), zinc oxide (zinc white), and vulcanization accelerators.

[0061] The rubber product is preferably at least one selected from the group consisting of rubber tires, rubber crawlers, rubber hoses, conveyor belts, and seismic isolation rubber. Rubber products selected from the group consisting of rubber tires, rubber crawlers, rubber hoses, conveyor belts, and seismic isolation rubber are widely used and produced in large quantities, and can therefore further contribute to promoting the recycling of waste materials including used tires.

[0062] <Resin products> The resin product of this embodiment is characterized in that it uses the above-mentioned elastomer as part or all of its raw materials. Because the resin product of this embodiment uses the above-mentioned elastomer as part or all of its raw materials, it can contribute to promoting the recycling of waste materials including used tires. Here, the resin product can be produced, for example, by molding a resin into a desired shape. Alternatively, a resin product can be produced by preparing a resin composition containing a resin and desired additives in advance and molding the resin composition into a desired shape. Examples of additives added to the resin composition include weather-resistant antioxidants, heat-resistant antioxidants, moist heat-resistant additives, antistatic agents, lubricants, crystal nucleating agents, tackifiers, antifogging agents, mold release agents, plasticizers, fillers, dyes, fragrances, and flame retardants.

[0063] The resin product is preferably at least one selected from the group consisting of resin tires and resin hoses. Resin products selected from the group consisting of resin tires and resin hoses have a high resin content, and can therefore further contribute to promoting the recycling of waste materials, including used tires. [Example]

[0064] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0065] <Sample preparation> As samples of used tires, tire chips made from actual used truck and bus (TBR) tires and used passenger car (PSR) tires were prepared.

[0066] <Production of pyrolysis oil> A pyrolysis furnace with a capacity of 34 L was prepared, equipped with an inlet flow path for introducing an inert gas and an outlet flow path for discharging the inert gas and the generated pyrolysis gas. A mass flow controller was attached to the inlet flow path, allowing the amount of inert gas introduced to be adjusted. A pressure exhaust valve was attached to the outlet flow path, allowing the amount of inert gas and the generated pyrolysis gas discharged to be adjusted.

[0067] The vulcanized rubber sample (tire chip) prepared as described above was placed in the pyrolysis furnace, and then the vulcanized rubber sample was placed together with the pyrolysis furnace in an electric heating furnace adjusted to the temperature shown in Table 1, and pyrolysis of the vulcanized rubber sample was initiated. At this time, for Comparative Examples 1 to 4, 6, and 8, nitrogen gas was introduced through the inlet flow path of the pyrolysis furnace, and a mixed gas of nitrogen gas and generated pyrolysis gas was extracted from the outlet flow path. The amount of nitrogen gas introduced and the amount of mixed gas of nitrogen gas and pyrolysis gas discharged were adjusted to control the pyrolysis reaction time to the time shown in Table 1. The pyrolysis reaction time was calculated from the amount of nitrogen gas introduced, the amount of pyrolysis gas generated, the average molecular weight of the pyrolysis gas, the temperature of the pyrolysis gas, and the volume of the pyrolysis furnace using the following formula:

number

[0068] Next, the gas obtained from the discharge passage was cooled to 0°C through a condenser, separated into pyrolysis oil and off-gas, and the pyrolysis oil was recovered. In addition, GC×GC-MS analysis was performed on the recovered pyrolysis oil by the following method to measure the content of each component. Also, the distillation properties, iodine value, and density of the recovered pyrolysis oil were measured by the following method.

[0069] <GC×GC-MS Analysis> The component composition of the recovered pyrolysis oil was analyzed using a two-dimensional gas chromatograph mass spectrometer (GC×GC-MS, manufactured by JEOL, product name "JEOL JMS-T2000GC", equipped with "DB-1 (length 60 m, inner diameter 0.25 mm, film thickness 0.1 μm)" manufactured by Agilent Technology for the first dimension and "DB-17 (length 2 m, inner diameter 0.25 mm, film thickness 0.1 μm)" manufactured by Agilent Technology for the second dimension). Qualitative analysis of the detected peaks was carried out, and classification was performed according to the structure as shown in Figure 1. Specifically, first, classification was performed based on whether the compound has heteroatoms (S, N, O), and compounds with heteroatoms were defined as "heterocompounds". Next, for compounds without heteroatoms, classification was performed based on whether they have an aromatic ring. For compounds with an aromatic ring, compounds with one aromatic ring were defined as "monocyclic aromatics", compounds with two aromatic rings were defined as "dicyclic aromatics", and compounds with three or more aromatic rings were defined as "tricyclic or higher aromatics". Also, for compounds without an aromatic ring, compounds with only single bonds were defined as "paraffins", compounds with triple bonds were defined as "alkynes", and compounds with double bonds and without triple bonds were defined as "olefins".

[0070] <Distillation GC Analysis> In accordance with ASTM D7169, the distillation properties of the recovered pyrolysis oil were analyzed using a distillation gas chromatograph (GC).

[0071] <Measurement of Iodine Value> In accordance with JIS K0070, the iodine value of the recovered pyrolysis oil was measured.

[0072] <Measurement of Density> In accordance with ASTM D4052, the density of the pyrolysis oil at 40 °C was measured.

[0073] [Table 1]

[0074] From Table 1, it can be seen that the pyrolysis oils of the examples according to the present invention are light and have low aromatic content, and therefore can be easily used as raw materials for chemical products. [Industrial Applicability]

[0075] The pyrolysis oil of the present invention can be used as a raw material for chemical products, and also contributes to the recycling of waste materials including used tires. The elastomer of the present invention can also be used in rubber products such as rubber tires, rubber crawlers, rubber hoses, conveyor belts, and seismic isolation rubber, as well as in resin products such as resin tires and resin hoses.

Claims

1. Pyrolysis oil obtained by pyrolysis of waste materials including used tires, The aromatic content measured by GC×GC-MS is 80% by volume or less, and the density measured at 40°C is 0.82 g / cm within 3 hours after production. ３ 0.89g / cm or more ３ Pyrolysis oil characterized in that it is less than.

2. After being left for 3 days after production, the density measured at 40°C is 0.84 to 0.97 g / cm ３ 2. The pyrolysis oil of claim 1, wherein:

3. The pyrolysis oil according to claim 1, wherein the volume ratio of olefin content to aromatic content (olefin content / aromatic content) measured by GC×GC-MS is 0.1 or more.

4. The pyrolysis oil according to claim 1, wherein the olefin content measured by GC x GC-MS is 10% by volume or more.

5. The pyrolysis oil according to claim 1, wherein the olefin content measured by GC x GC-MS is 30% by volume or more.

6. The pyrolysis oil according to claim 1, wherein the 90% distillation temperature is 400°C or less.

7. The pyrolysis oil according to claim 1, having a 10% distillation temperature of 100°C or higher.

8. Iodine value is 180gI ２ 100g or more of pyrolysis oil according to claim 1.

9. An elastomer, characterized in that the pyrolysis oil according to claim 1 is used as a raw material in whole or in part.

10. The elastomer according to claim 9, wherein the elastomer is at least one selected from the group consisting of resins and synthetic rubbers.

11. A rubber product, characterized in that the elastomer according to claim 9 is used as a part or all of a raw material.

12. The rubber product according to claim 11, which is at least one selected from the group consisting of a rubber tire, a rubber crawler, a rubber hose, a conveyor belt, and a seismic isolation rubber.

13. A resin product, characterized in that the elastomer according to claim 9 is used as a part or all of a raw material.

14. The resin product according to claim 13, wherein the resin product is at least one selected from the group consisting of a resin tire and a resin hose.

Images