JP2012001698A - Manufacturing method of carbide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing apparatus of a carbide which can efficiently obtain a carbide in which quality does not deteriorate, interaction with a rubber can be fully expressed when blended with a rubber component, and which can demonstrate performance sufficient as an alternative of a carbon black for rubber reinforcement.SOLUTION: The manufacturing method of a carbide includes a process in which the thermal decomposition of a predetermined waste material is carried out, wherein the predetermined waste material includes a peeling rubber and/or a buff powder.

Description

  The present invention relates to a method for producing carbide, and in particular, the quality is not deteriorated, and when mixed with a rubber component, the interaction with rubber can be sufficiently expressed, and the performance sufficient as an alternative to carbon black for rubber reinforcement is provided. The present invention relates to a method for producing a carbide capable of efficiently obtaining a carbide that can be exhibited.

  Conventionally, for the purpose of developing functional materials, various polymer materials such as rubber materials and resin materials, reinforcing materials, and composite materials containing fillers have been industrialized. Industrial development has led to the mass production and consumption of general-purpose materials, and the treatment of polymer waste has become an important issue to be solved as soon as possible. In order to solve this problem, technological progress such as reuse and recycling of polymer materials is essential. For example, tires, which are typical compounded rubber products, have been mass-produced and consumed as a necessary component for automobiles with the development of motorization, and the number of used tires has become enormous. The research on making and effective use is advanced, and the recovery of useful materials is a big issue.

  For example, in Patent Document 1, after carbon fiber reinforced plastic (CFRP) is crushed into a scaly shape, it is carbonized in a temperature range of 300 to 1000 ° C. in a substantially non-acidic atmosphere, or after carbonizing, and then into a scaly shape. It is reported that a carbon fiber lump is obtained by crushing, and the carbon fiber lump can be used as a reinforcing material when producing a carbon fiber reinforced thermoplastic (CFRTP) product, a carbon fiber reinforced cement (CFRC) molded body, or the like. Has been.

  Further, in Patent Document 2, it can be used as a chemical raw material or the like by thermally decomposing vulcanized rubber using a hydrogen donating solvent such as tetrahydronaphthalene in the presence of an inert gas such as nitrogen. And high-purity liquid hydrocarbons and high-level carbon black that can be used as a reinforcing material for rubber products because it is close to the original higher-order aggregate structure is disclosed. Has been.

  On the other hand, various researches have also been made on heat treatment of waste material materials. For example, in Patent Document 3, an oil component is extracted from waste tires, and activated carbon is produced using the remaining waste tire dry distillation char as a raw material. Is disclosed.

  Patent Document 4 reports a method for producing diesel oil and carbon black by thermal decomposition or catalytic decomposition of waste rubber or the like. Further, in Patent Document 5, a waste tire is obtained by a pyrolysis process in which a material is heated in the reactor to a pyrolysis temperature and the pyrolysis gas thus obtained is condensed in a condenser connected to the reactor. Or a method for recovering a mixture of carbon and hydrocarbons from a similar polymeric material.

Japanese Patent Laid-Open No. 7-118440 JP 7-310076 A Japanese Patent Laid-Open No. 6-144819 Japanese Patent Laid-Open No. 11-504672 Special table 2002-523552 gazette

  However, when the present inventors examined, in the thermal decomposition treatment of the waste material disclosed in Patent Documents 1 to 5, the reaction efficiency of the thermal decomposition reaction and the antioxidant effect of the carbide obtained by the thermal decomposition reaction are obtained. It was found that the level could not be sufficiently satisfied and there was still room for improvement.

  Furthermore, in the thermal decomposition treatment of the waste material disclosed in Patent Documents 1 to 5, due to problems such as the shape of the waste material, it is not possible to efficiently use the thermal decomposition furnace, the productivity is reduced, In addition, development of a method for producing carbide with high productivity has been desired.

  Therefore, the object of the present invention is to optimize the waste material so that the quality does not deteriorate and the interaction with the rubber can be fully expressed when blended with the rubber component. An object of the present invention is to provide a method for producing carbide capable of efficiently obtaining a carbide capable of exhibiting sufficient performance as a product as compared with a conventional production method.

  As a result of intensive investigations for achieving the above object, a method for producing a carbide comprising a step of thermally decomposing a predetermined waste material, the present inventors have found that the predetermined waste material includes a peeling rubber and / or It was found that by using buff powder, in particular containing 25% by mass or more in total, the oxidation efficiency of the generated carbide can be significantly suppressed while improving the reaction efficiency of the thermal decomposition reaction, and the present invention has been completed. It was.

  “Carbide” in the present application refers to a solid that is produced and left after a substance containing an organic substance is used as a raw material, and the raw material is released from a gas body and a liquid component by a thermal decomposition reaction by heating. It may contain an inorganic substance.

The present invention has been made based on such findings, and the gist thereof is as follows.
(1) A method for producing carbide comprising a step of thermally decomposing predetermined waste material, wherein the predetermined waste material contains peeling rubber and / or buff powder. .

(2) The method for producing carbide according to (1) above, wherein the waste rubber and / or the buff powder are contained in a total of 25% by mass or more in the waste material.

(3) The pyrolysis of the waste material is performed by storing the waste material in a pyrolysis furnace, continuously supplying heated oxygen-free gas into the pyrolysis furnace, and supplying the waste material to the pyrolysis furnace. The method for producing carbide according to (1) above, wherein pyrolysis is generated by direct contact with oxygen gas to generate pyrolysis gas.

(4) Furthermore, the step of heating the oxygen-free gas with a heat exchanger, the step of cooling the pyrolysis gas and recovering the condensed oil, and the dust contained in the residual gas after recovering the oil And a step of recovering carbide remaining in the pyrolysis furnace after thermal decomposition of the waste material, and the oil component is circulated and supplied to the pyrolysis furnace (1) ).

  According to the present invention, a carbide that does not deteriorate in quality, can sufficiently exhibit interaction with rubber when blended with a rubber component, and can exhibit sufficient performance as a substitute for carbon black for rubber reinforcement. It is possible to provide a method for producing carbide that can be obtained efficiently.

It is the schematic about one embodiment of the thermal decomposition apparatus suitable for implementing the manufacturing method of this invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view of a waste material pyrolysis apparatus suitable for the practice of the present invention. The pyrolysis apparatus shown in FIG. 1 includes a heat exchanger 1 for heating oxygen-free gas, a pyrolysis furnace 2 containing waste material 5 therein, and external heating means for heating the pyrolysis furnace 2 from the outside. A decomposition apparatus 6 for generating pyrolysis gas by thermally decomposing the waste material 5 by direct contact with the oxygen-free gas heated by the heat exchanger 1, The generated pyrolysis gas is cooled to recover the condensed oil component, and the residual gas after the oil component is recovered by the oil component recovery device 11 is returned to the heat exchanger 1 as an oxygen-free gas. A circulation path 4 for supplying, a gas generator 3 for generating oxygen-free gas introduced into the pyrolysis furnace 2, and an oxygen concentration detector 8 for detecting the oxygen concentration in the pyrolysis system. With.

  In the pyrolysis method used in the method for producing carbide according to the present invention, the oxygen-free gas heated by the heat exchanger 1 is supplied to the pyrolysis furnace 2 so that the waste material 5 in the pyrolysis furnace 2 is pyrolyzed. Is done. Here, the oxygen-free gas is a gas body other than oxygen and oxide, and examples thereof include inert gases such as nitrogen, argon and helium, and combustible gases such as hydrogen, methane and propane. By using oxygen gas, the oxidation of the carbide residue remaining in the pyrolysis furnace 2 after the pyrolysis of the waste material 5 can be prevented. In the pyrolysis method used in the carbide production method according to the present invention, the heat exchanger 1 is not particularly limited, but a spiral heat exchanger, a plate heat exchanger, a spiral heat exchanger, and the like. A liquid-liquid heat exchanger, an air-cooled heat exchanger, or the like can be used. Further, in order to supply the oxygen-free gas to the heat exchanger 1, for example, the residual gas after the oil content is recovered by the oil content recovery device 11 is supplied to the heat exchanger 1 as an oxygen-free gas via the circulation path 4 described later. Circulate.

  In the pyrolysis method used in the method for producing carbide according to the present invention, the cracking device 6 includes a pyrolysis furnace 2 containing the waste material 5 therein and an external heating means 7 for heating the pyrolysis furnace 2 from the outside. . Here, the oxygen-free gas heated by the heat exchanger 1 is introduced into the pyrolysis furnace 2 containing the waste material 5, the waste material 5 is brought into direct contact with the oxygen-free gas, and the pyrolysis gas is supplied. generate. By bringing the waste material 2 into direct contact with oxygen-free gas, thermal decomposition in an oxygen-free state is possible. The pyrolysis furnace 2 is not particularly limited, but a normal kettle type pyrolysis furnace, fluidized bed type pyrolysis furnace, kiln type pyrolysis furnace or the like is used. Moreover, the waste material 5 mainly refers to organic waste, and specifically, tire waste (for example, spew, buff powder, 4-32 divided tires, peeling rubber), rubber hoses, tubes, conveyor belts. And the like, and resin material wastes such as polyethylene, polyethylene terephthalate, polyvinyl chloride, and nylon. In the present invention, as the predetermined waste material, the peeling rubber and / or the buff It contains 25% by mass or more of the powder in total.

  Furthermore, since the decomposition apparatus 6 includes the external heating means 7, the waste material 5 in the pyrolysis furnace 2 can be indirectly heated from the outside of the pyrolysis furnace 2. Can be reduced. This suppresses the generation of solid dust (fine suspended matter of waste material) that is swollen from the pyrolysis furnace 2 and mixed in the gas and circulates in the apparatus together with the gas, thereby reducing the generation of nitrogen oxides, etc. Can also be suppressed. The external heating means 7 is not particularly limited, but for example, an external heating furnace disposed around the pyrolysis furnace 2 is preferable. Moreover, since the heat medium used for the external heating means 7 indirectly heats the waste material 5 from the outside of the pyrolysis furnace 2, it is not limited to oxygen-free gas, and various substances can be used. .

In the thermal decomposition method used in the method for producing carbide according to the present invention, one or more oil content recovery devices 11 are provided for cooling the pyrolysis gas generated in the decomposition device 6 and recovering the condensed oil content. Is preferred. As shown in FIG. 1, if a plurality of oil component recovery devices 11 are used, the pyrolysis gas generated in the decomposition device 6 can be divided into oil components recovered according to the boiling point.
Specifically, the first oil recovery unit 11a on the upstream side of the gas flow path and the second oil recovery unit 11b on the downstream side have the same configuration, but the second oil recovery unit 11b The first oil component recovery device 11a recovers an oil component having a lower boiling point than the target oil component. In this way, by installing a plurality of oil component recovery devices 11, oil components having a constant composition and stable quality can be recovered with a high recovery rate. Moreover, each oil content collection | recovery apparatus 11 is connected to the collection | recovery tank 12 through piping, for example in the lower part, and can store the collect | recovered oil content. Furthermore, a condensing device or the like can be provided on the downstream side of the oil content recovery device, and the oil content condensed in the condensing device can be recovered.

  In the thermal decomposition method used in the method for producing carbide according to the present invention, the circulation path 4 supplies the residual gas after the oil is recovered by the oil recovery device 11 to the heat exchanger 1 as an oxygen-free gas. The oil content recovery device 11 and the heat exchanger 1 are connected by piping. The residual gas supplied to the heat exchanger 1 through the circulation path 4 can be supplied directly to the heat exchanger 1, or even if heated in a hot stove (not shown) and then supplied to the heat exchanger 1. Good. In FIG. 1, the circulation path 6 is connected only to the second oil recovery unit 11b. However, the present invention is not limited to this, and the circulation path 6 is connected to the first oil recovery unit 11a. May be. Moreover, in the thermal decomposition method used in the method for producing carbide according to the present invention, surplus gas can be discharged into the atmosphere after being treated by the exhaust gas treatment device 14 via the exhaust fan 13.

In the pyrolysis method used in the method for producing carbide according to the present invention, the gas generator 3 for generating an inert gas to be introduced into the pyrolysis furnace 3 is used to control the oxygen concentration in the apparatus system to a certain value or less. And an oxygen concentration detector 8 for detecting the oxygen concentration in the thermal decomposition apparatus system. Here, by using the gas generator 3 and the oxygen concentration detector 8 together, the oxygen concentration in the pyrolysis apparatus system is monitored, and an inert gas is introduced into the pyrolysis furnace 2 according to the detection result. It becomes possible to suppress oxidation of carbides remaining in the pyrolysis furnace 2 after pyrolysis, and to recover carbides suitable as a rubber compound.
Here, the relationship between the oxygen concentration in the thermal decomposition apparatus system and the total acidity will be described. There is “total acidity” as an index for evaluating the degree of oxidation of the recovered carbide. If this value is large, it means that the surface of the carbide is oxidized, and the carbide is not suitable as a compounding agent for rubber. Means. As a result of investigations by the present inventors, when the total acidity of the recovered carbide is 0.1 meq / g or less, the physical properties of the rubber composition are reduced when the recovered carbide is mixed with pure carbon black (100% carbon black). It was found that it was possible to keep it within 5%, and that the recovered carbide could be reused as a rubber reinforcing filler. And as shown in FIG. 2, in order to suppress total acidity to 0.1 meq / g or less, it is preferable to control the oxygen concentration in a thermal decomposition apparatus system to 1.0 volume% or less. Therefore, in the thermal decomposition method used in the method for producing carbide according to the present invention, a signal is further sent to the inert gas flow rate control means 9 based on the oxygen concentration in the thermal decomposition system detected by the oxygen concentration detector 8. The gas generator 3 is activated by this signal to generate an inert gas, and this inert gas is introduced into the thermal decomposition system through the flow rate control means 9 whose opening degree is changed by the signal. The

  In addition, the measuring method of the said total acidity is as follows. First, 1 g of carbon black is precisely weighed, transferred to a flat bottom flask, added with 50 ml of 0.002N NaOH aqueous solution, and dispersed with ultrasonic waves. Then, a condenser tube is attached to the flat bottom flask and boiled for 2 hours while refluxing. The dispersion was cooled and solubilized, and a portion thereof was titrated with 0.002N NaOH aqueous solution, and the amount of NaOH used in the neutralization reaction per 1 g of carbon black was determined from the remaining amount of NaOH left unreacted. Ask. The unit is expressed in milliequivalents (meq / g) per unit mass.

  When the oxygen concentration detector 8 detects an oxygen concentration exceeding a preset reference value, the gas generator 7 for supplying an inert gas operates in conjunction with the detection result, and at the same time the flow rate Inert gas is introduced into the circulation path 6 by adjusting the opening of the control means 13. By introducing the inert gas, the oxygen concentration detected by the oxygen concentration detector 8 is lowered, and the oxygen concentration in the thermal decomposition apparatus system can be controlled to a reference value or less. Specifically, the gas generator 9 operates when the oxygen concentration in the thermal decomposition system detected by the oxygen concentration detector 8 exceeds 1.0 vol%, and at the same time, in the circulation path 6 via the flow rate control means 13. An inert gas is supplied to the gas, and the oxygen concentration in the thermal decomposition apparatus system is lowered. Next, when the oxygen concentration in the circulation path 6 is reduced to 0.2% by volume, a stop signal is issued to each device (the gas generator 7 and the flow rate control means 13), and the supply of the inert gas is stopped. Thereby, the oxygen concentration in the thermal decomposition apparatus system can be controlled to a reference value or less. When supplying an inert gas into the pyrolysis furnace 3, it is ideal to reduce the oxygen concentration to 0% by volume. However, from the viewpoint of the cost of supplying the inert gas, When the oxygen concentration is lowered to 0.2% by volume, it is preferable to stop the supply of the inert gas to the pyrolysis furnace 3. As the oxygen concentration detector 8, for example, a zirconia oxygen sensor using a solid electrolyte zirconia-based oxygen concentration cell is used. As the gas generator 7, for example, P.I. S. A nitrogen gas generator using the A (Pressure Swing Adsorption) method is used.

  In the method for producing carbide according to the present invention, it is preferable that a total of 25 mass% or more of peeling rubber and / or buff powder is contained in the waste material 5. The peeling rubber and buff powder have the advantage that the time required for thermal decomposition is shortened because the volume of the particles is small compared to the waste material used in the production of conventional carbides. Since it can be made smaller, the oxidation opportunity of the generated carbide can be reduced, the total acidity of the carbide can be further reduced, and characteristics closer to the performance of carbon black can be obtained. Further, the total content of peeling rubber and / or buff powder in the waste material 5 is 25% or more. When the content is less than 25%, the time required for thermal decomposition is shortened and the pyrolysis furnace 2 This is because an improvement in the filling rate in the furnace cannot be expected and the effects of the present invention cannot be fully exhibited. In particular, when the total amount in the waste material 5 is peeling rubber and / or buff powder, no component other than rubber is contained in the waste material 5, so that the metal component from the conventional generated carbide is not included. There is an advantage that a separation process with the above can be omitted, and a factory with a large work efficiency can be achieved.

  In addition, the said peeling rubber means a kind of waste rubber which consists of a tread scraped off from the tire tread part. According to the standards of the American Recycled Rubber Association, No.1 peeling: No cloth, No.2 peeling: Carcass cloth with no more than one ply, No.3 peeling: Part of tread is missing Other than that, it is the same as No. 2 peeling.

  The buff powder refers to rubber powder obtained by rubbing with a grinding wheel rotating at high speed or an equivalent thereof. Some are manufactured for use as compounding agents or dusting powders, while others are obtained as by-products during processing. In the present invention, the latter buff powder is mainly targeted, and in particular, tread powder obtained at the time of tire rehabilitation is targeted.

  Here, both the peeling rubber and the buff powder are rubbers scraped off or rubbed off from the tread portion during the manufacture of a retread tire that is vulcanized with the tread portion pasted again. In the case of using a carcass member that is a side surface of a tire constituent member, sufficient hardness cannot be maintained when the recovered carbide is blended, and sufficient performance as a substitute for rubber reinforcing carbon black may not be exhibited. Because.

  Furthermore, the carbon black content in the peeling rubber and the buff powder is more preferably 25% by mass or more in total. If the amount is less than 25% by mass, the carbon black content is too low, so that sufficient hardness cannot be maintained and sufficient performance as a substitute for carbon black for rubber reinforcement may not be exhibited. Because.

In the present invention, it is preferable to control the gas flow rate of oxygen-free gas to be introduced into the pyrolysis furnace 2 in the range of ^{0.0015m 3 /s[ntp]~0.0095m 3 / s [ntp} ] . This is because it is suitable for suppressing the oxidation of the carbide remaining in the pyrolysis furnace 2 after the thermal decomposition and recovering a carbide suitable as a rubber compound.

  In the step of generating pyrolysis gas from the waste material 5 and oxygen-free gas, the temperature during pyrolysis is preferably controlled to 300 to 600 ° C. If the temperature at the time of thermal decomposition is within the above specified range, the waste material can be subjected to stable and continuous thermal decomposition without undergoing a melting step. If the waste material is melted, the rate of contact with the oxygen-free gas is limited to the melt surface, so the thermal decomposition rate is reduced. If the temperature during the pyrolysis is less than 300 ° C., the pyrolysis reaction does not proceed sufficiently, and this is not preferable because there is a possibility of generating a carbide in which the components to be decomposed are not completely removed. Exceeding the above, there is a possibility of occurrence of the above-described melting phenomenon, and an undesirable reforming reaction or activation reaction occurs between the generated carbide and a component (for example, oxide) that can be contained in the gas, There is a possibility that the total acidity in the carbide is increased, or a carbide which is porous and may adversely affect the reinforcing effect on the rubber may be generated. Here, in order to control the temperature at the time of thermal decomposition, oxygen-free gas heated in the heat exchanger 1 or external heating means 7 for heating the thermal decomposition furnace 4 from the outside may be used.

  Furthermore, the method for producing carbide according to the present invention further includes a step of heating the oxygen-free gas with a heat exchanger, a step of cooling the pyrolysis gas, and recovering the condensed oil, and after recovering the oil Recovering dust contained in the residual gas, cleaning the residual gas after recovering the dust, and recovering carbide remaining in the pyrolysis furnace after thermal decomposition of the waste material It is preferable to circulate and supply the oil component into the pyrolysis furnace. This is because the oil content recovered by the oil content recovery means 11 is circulated and supplied to the thermal cracking furnace 2 so that the oil content serves as a catalyst, and as a result, the thermal decomposition efficiency can be further improved.

  In the present invention, although not shown, in order to control the gas flow rate, a flow meter for measuring the gas flow rate, a valve for adjusting the gas flow rate at the opening degree, and a blower for keeping the gas flow rate constant (FIG. (Not shown) can be installed. In the carbide production apparatus, the oxygen concentration in the apparatus is preferably controlled to 1% by volume or less. If the oxygen concentration in the production apparatus is 1% by volume or less, oxidation of carbides remaining in the pyrolysis furnace after pyrolysis can be more reliably suppressed, quality does not deteriorate, and even if blended with a rubber component, rubber Carbide that can sufficiently maintain the characteristics can be obtained more reliably. The oxygen concentration in the production apparatus can be measured by, for example, a zirconia oxygen sensor using a solid electrolyte zirconia-based oxygen concentration cell.

  The above description is merely an example of the embodiment of the present invention, and various modifications can be made within the scope of the claims.

Example 1
Using the thermal decomposition apparatus shown in FIG. 1, carbides were recovered by thermal decomposition using a retreading truck tire as a material. As shown in FIG. 1, the pyrolysis apparatus includes a heat exchanger 1, a pyrolysis furnace 2, a gas generator 3, a circulation path 4, a waste material 5, an external heating means 7, an oxygen concentration detector 8, An active gas flow rate control means 9, a first oil content recovery device 11a, a second oil content recovery device 11b, a recovery tank 12, an exhaust fan 13 and an exhaust gas treatment device 14 are provided.
Specifically, about 15 kg of scraping rubber (peeling rubber) (waste material 5) of the tire tread for rehabilitation trucks is put into the pyrolysis furnace 2 (with a capacity of 0.5 m ³ ), and nitrogen gas is put into the pyrolysis furnace 2 After the replacement, the gas temperature was raised to about 500 ° C. by the heat exchanger 1 while circulating the nitrogen gas in the thermal decomposition apparatus system, and this temperature was maintained. The gas flow rate of nitrogen gas introduced into the pyrolysis furnace 2 is set to 0.005m ³ / s [ntp], controlled in the range of ^{0.0045m 3 /s[ntp]~0.0055m 3 / s [ntp} ] However, the oxygen concentration in the pyrolyzer system was controlled within a range of 1% by volume or less. Here, a zirconia oxygen sensor or the like was used for measuring the oxygen concentration in the thermal decomposition apparatus.
30 minutes after the start of heating by the heat exchanger 1, the pyrolysis gas started to be accumulated in the oil recovery unit 11a, and the distillation stopped about 2 hours after the start of the heating by the heat exchanger 1. Stopping the distillation showed that the thermal decomposition reaction was completed, and the heat exchanger 1 was stopped and the system was left to cool for about 12 hours. Thereafter, the carbide was taken out from the pyrolysis furnace 2.
Since the carbide includes a steel cord as a tire material, excess tire material was removed with a magnetic separator. Carbide from which excess tire material has been removed is pulverized into fine powder with a particle size of 1 mm or less with a hammer-type pulverizer, and this pulverized product is classified with an air classifier having rotating blades, resulting in a particle size of 50 μm. The above coarse powder was removed, and fine carbide for rubber compounding was recovered.
Next, when the total acidity of the recovered fine carbide for rubber compounding was measured by the above method, it was 0.0918 meq / g.

(Example 2)
Using the thermal decomposition apparatus shown in FIG. 1, carbides were recovered by thermal decomposition using a retreading truck tire as a material. As shown in FIG. 1, the pyrolysis apparatus includes a heat exchanger 1, a pyrolysis furnace 2, a gas generator 3, a circulation path 4, a waste material 5, an external heating means 7, an oxygen concentration detector 8, An active gas flow rate control means 9, a first oil content recovery device 11a, a second oil content recovery device 11b, a recovery tank 12, an exhaust fan 13 and an exhaust gas treatment device 14 are provided.
Specifically, about 15 kg of rubber powder (buff powder) (waste material 5) rubbed off from the tire tread for rehabilitation trucks is put into the pyrolysis furnace 2 (with a capacity of 0.5 m ³ ). After the gas was replaced with nitrogen gas, the gas temperature was raised to about 500 ° C. by the heat exchanger 1 while circulating the nitrogen gas in the thermal decomposition apparatus system, and this temperature was maintained. The gas flow rate of nitrogen gas introduced into the pyrolysis furnace 2 is set to ^{0.005 m 3 / s [ntp]} , controlled in the range of ^{0.0045 m 3 /s[ntp]~0.0055 m 3 / s} [ntp] However, the oxygen concentration in the pyrolyzer system was controlled within a range of 1% by volume or less. Here, a zirconia oxygen sensor or the like was used for measuring the oxygen concentration in the thermal decomposition apparatus.
Forty minutes after the start of heating by the heat exchanger 1, the pyrolysis gas started to be accumulated in the oil recovery device 11a, and the distillation stopped about 2 hours after the start of the heating by the heat exchanger 1. Stopping the distillation showed that the thermal decomposition reaction was completed, and the heat exchanger 1 was stopped and the system was left to cool for about 12 hours. Thereafter, the carbide was taken out from the pyrolysis furnace 2.
Since the carbide includes a steel cord as a tire material, excess tire material was removed with a magnetic separator. Carbide from which excess tire material has been removed is pulverized into fine powder with a particle size of 1 mm or less with a hammer-type pulverizer, and this pulverized product is classified with an air classifier having rotating blades, resulting in a particle size of 50 μm. The above coarse powder was removed, and fine carbide for rubber compounding was recovered.
Next, the total acidity of the collected fine carbide for rubber compounding was measured by the above method and found to be 0.0934 meq / g.

(Example 3)
Using the thermal decomposition apparatus shown in FIG. 1, carbides were recovered by thermal decomposition using a retreading truck tire as a material. As shown in FIG. 1, the pyrolysis apparatus includes a heat exchanger 1, a pyrolysis furnace 2, a gas generator 3, a circulation path 4, a waste material 5, an external heating means 7, an oxygen concentration detector 8, An active gas flow rate control means 9, a first oil content recovery device 11a, a second oil content recovery device 11b, a recovery tank 12, an exhaust fan 13 and an exhaust gas treatment device 14 are provided.
Specifically, about 8 kg each of scraping rubber (peeling rubber) and rubbed rubber powder (buffing powder) (waste material 5) in the tire tread portion for rehabilitation trucks in the pyrolysis furnace 2 (capacity 0.5 m ³ ) Then, after the inside of the pyrolysis furnace 2 was replaced with nitrogen gas, the gas temperature was raised to about 500 ° C. by the heat exchanger 1 while circulating the nitrogen gas in the pyrolysis apparatus system, and this temperature was maintained. The gas flow rate of nitrogen gas introduced into the pyrolysis furnace 2 is set to ^{0.005 m 3 / s [ntp]} , controlled in the range of ^{0.0045 m 3 /s[ntp]~0.0055 m 3 / s} [ntp] However, the oxygen concentration in the pyrolyzer system was controlled within a range of 1% by volume or less. Here, a zirconia oxygen sensor or the like was used for measuring the oxygen concentration in the thermal decomposition apparatus.
Forty minutes after the start of heating by the heat exchanger 1, the pyrolysis gas started to be accumulated in the oil recovery device 11a, and the distillation stopped about 2 hours after the start of the heating by the heat exchanger 1. Stopping the distillation showed that the thermal decomposition reaction was completed, and the heat exchanger 1 was stopped and the system was left to cool for about 12 hours. Thereafter, the carbide was taken out from the pyrolysis furnace 2.
Since the carbide includes a steel cord as a tire material, excess tire material was removed with a magnetic separator. Carbide from which excess tire material has been removed is pulverized into fine powder with a particle size of 1 mm or less with a hammer-type pulverizer, and this pulverized product is classified with an air classifier having rotating blades, resulting in a particle size of 50 μm. The above coarse powder was removed, and fine carbide for rubber compounding was recovered.
Next, when the total acidity of the recovered fine carbide for rubber compounding was measured by the above method, it was 0.0918 meq / g.

(Comparative example)
Using the pyrolysis apparatus shown in FIG. 1, carbides were recovered by pyrolysis using a waste truck tire as a material. As shown in FIG. 1, the pyrolysis apparatus includes a heat exchanger 1, a pyrolysis furnace 2, a gas generator 3, a circulation path 4, a waste material 5, an external heating means 7, an oxygen concentration detector 8, An active gas flow rate control means 9, a first oil content recovery device 11a, a second oil content recovery device 11b, a recovery tank 12, an exhaust fan 13 and an exhaust gas treatment device 14 are provided.
Specifically, after putting about 15 kg of 32 truck cut waste products (waste material 5) into the pyrolysis furnace 2 (capacity 0.5 m ³ ) and replacing the pyrolysis furnace 2 with nitrogen gas, While circulating the nitrogen gas in the thermal decomposition apparatus system, the gas temperature was raised to about 500 ° C. by the heat exchanger 1, and this temperature was maintained. The gas flow rate of nitrogen gas introduced into the pyrolysis furnace 2 is set to ^{0.005 m 3 / s [ntp]} , controlled in the range of ^{0.0045 m 3 /s[ntp]~0.0055 m 3 / s} [ntp] However, the oxygen concentration in the pyrolyzer system was controlled within a range of 1% by volume or less. Here, a zirconia oxygen sensor or the like was used for measuring the oxygen concentration in the thermal decomposition apparatus.
Forty minutes after the start of heating by the heat exchanger 1, the pyrolysis gas started to be accumulated in the oil recovery device 11a, and the distillation stopped about 2 hours after the start of the heating by the heat exchanger 1. Stopping the distillation showed that the thermal decomposition reaction was completed, and the heat exchanger 1 was stopped and the system was left to cool for about 12 hours. Thereafter, the carbide was taken out from the pyrolysis furnace 2. Since the carbide includes a steel cord as a tire material, excess tire material was removed with a magnetic separator. Carbide from which excess tire material has been removed is pulverized into fine powder with a particle size of 1 mm or less with a hammer-type pulverizer, and this pulverized product is classified with an air classifier having rotating blades, resulting in a particle size of 50 μm. The above coarse powder was removed, and fine carbide for rubber compounding was recovered.
Next, the total acidity of the collected fine carbide for rubber compounding was measured by the above method and found to be 0.0989 meq / g.

  As can be seen from the above results, heat can be obtained by including at least scraping rubber (peeling rubber) and / or rubbing rubber powder (buff powder) of the tire tread portion for trucks as a material of the waste tire subjected to thermal decomposition. It has properties almost similar to those of carbon black obtained by decomposition, particularly carbon black, which is a carbon material for rubber compounding, and can be used as a carbon black substitute.

  According to the present invention, a carbide that does not deteriorate in quality, can sufficiently exhibit interaction with rubber when blended with a rubber component, and can exhibit sufficient performance as a substitute for carbon black for rubber reinforcement. Can be obtained efficiently. Moreover, it is also possible to manufacture the rubber composition for tires containing the carbide obtained by the manufacturing method by this invention.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Pyrolysis furnace 3 Gas generator 4 Circulation path 5 Waste material 6 Decomposition device 7 External heating means 8 Oxygen concentration detector 9 Inert gas flow control means 11 Oil content recovery device 12 Recovery tank 13 Exhaust machine 14 Exhaust gas Processing means

Claims (4)

A method for producing a carbide comprising a step of thermally decomposing a predetermined waste material,
The predetermined waste material contains peeling rubber and / or buff powder.   The said peeling rubber and / or the said buff powder | flour are included in the said waste material in total 25 mass% or more, The manufacturing method of the carbide | carbonized_material of Claim 1 characterized by the above-mentioned.   In the thermal decomposition of the waste material, the waste material is accommodated in a pyrolysis furnace, heated oxygen-free gas is continuously supplied into the pyrolysis furnace, and the waste material is combined with the oxygen-free gas. The method for producing carbide according to claim 1 or 2, wherein pyrolysis gas is generated by pyrolysis by direct contact. Furthermore, the step of heating the oxygen-free gas with a heat exchanger, the step of cooling the pyrolysis gas, collecting the condensed oil, and collecting the dust contained in the residual gas after collecting the oil The method according to claim 1, further comprising a step of recovering carbide remaining in the pyrolysis furnace after pyrolyzing the waste material, and circulating and supplying the oil into the pyrolysis furnace. The manufacturing method of the carbide | carbonized_material of any one.

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