Method for producing carbon black and reaction furnace for producing carbon black

Abstract

In order to provide a method for producing carbon black having desired characteristics at a high yield while reducing the amount of carbon dioxide (CO2) discharged in a furnace method in which a secondary raw material is used as a raw material hydrocarbon, this method for producing carbon black is characterized in that, using a reaction furnace for carbon black production in which a fuel combustion zone, a primary raw material introduction zone, a heating zone, and a secondary raw material introduction zone are provided sequentially from the upstream side toward the downstream direction of a gas flow path: an oxygen-containing gas and fuel are introduced into the fuel combustion zone, mixed, and combusted to generate a fuel combustion gas flow; a hydrocarbon that serves as the primary raw material is introduced while the fuel combustion gas is introduced into the primary raw material introduction zone, and a primary-reactant-containing gas is generated; the primary-reactant-containing gas is then electrically heated in the heating zone; and a hydrocarbon that serves as the secondary raw material is then introduced while the electrically heated primary-reactant-containing gas is introduced into the secondary raw material introduction zone to carry out a secondary reaction.

Description

Carbon black manufacturing method and reactor for manufacturing carbon black

[0001] The present invention relates to a method for producing carbon black and a reactor for producing carbon black.

[0002] Generally, known methods for producing carbon black include the furnace method, the acetylene black method, and the channel method. Of these, the furnace method is known as an economical method that allows for mass production of carbon black.

[0003] The furnace method is known as a method for producing carbon black by thermally decomposing liquid feedstock oil such as heavy oil or natural gas as a feedstock hydrocarbon in a fire-resistant furnace under oxygen-deficient conditions.

[0004] Specifically, as described in Patent Documents 1 and 2, for example, methods for producing carbon black are known that typically use a reactor having therein a fuel combustion zone that generates a combustion gas flow, a reaction zone in which liquid feed oil or natural gas is introduced as a feed hydrocarbon into the combustion gas flow obtained in the fuel combustion zone and converted into carbon black by a thermal decomposition reaction, and a reaction terminating zone in which the reaction gas obtained in the reaction zone is quenched to terminate the reaction.

[0005] Furthermore, there are many varieties of carbon black for rubber reinforcement, each with its own unique characteristics. These characteristics are the main factors that determine the performance of the rubber. Therefore, when compounding a rubber composition, carbon black with properties suited to the intended use is selected.

[0006] For example, carbon black to be compounded in a rubber composition for a tire tread, which can further reduce rolling resistance while improving durability such as abrasion resistance, is a carbon black having a dibutyl phthalate (DBP) absorption capacity of 40 to 180 mL / 100 g and a nitrogen adsorption specific surface area (N ２ SA) is 40 to 300m ２ / g and a toluene color transmittance (LT) of 90% or more have been proposed (Patent Document 3, etc.).

[0007] JP 2004-43598 A JP 2004-277443 A JP 2011-026392 A

[0008] The carbon black to be compounded in the rubber composition for tire treads described above has a dibutyl phthalate (DBP) absorption capacity of 40 to 180 mL / 100 g and a nitrogen adsorption specific surface area (N ２ SA) is 40 to 190m ２ / g, and a toluene color transmittance (LT) of 90% or more are now required.

[0009] As described above, generally known methods for producing carbon black include the furnace method, the acetylene black method, and the channel method. Of these, the furnace method is known as an economical method that allows for mass production of carbon black.

[0010] The furnace method is known as a method for producing carbon black by thermally decomposing liquid feedstock oil such as heavy oil or natural gas as a feedstock hydrocarbon in a fire-resistant furnace under oxygen-deficient conditions.

[0011] On the other hand, with the recent increase in environmental awareness, carbon dioxide (CO ２ There is a demand for manufacturing methods for various products that reduce carbon dioxide (CO) emissions. ２ There was a demand for manufacturing methods that reduced emissions of CO₂.

[0012] However, the inventors have investigated the above furnace method, and have found that the amount of fuel supplied to the fuel combustion zone is limited to reduce the amount of carbon dioxide (CO ２ It has been found that when attempting to reduce the emissions of toluene, the resulting combustion gas stream cannot be raised to the desired temperature, and the desired carbon black cannot be produced in high yield.

[0013] Under these circumstances, the present invention provides a furnace method for producing carbon dioxide (CO ２The present invention aims to provide a method for producing carbon black having desired properties in high yield while reducing emissions of toluene, and a reactor for producing carbon black.

[0014] As a result of intensive research by the present inventors to solve the above technical problems, they have found that the above technical problems can be solved by a method for producing carbon black, which includes using a reactor for producing carbon black, which is provided in this order from upstream to downstream of a gas flow path, a fuel combustion zone, a primary feedstock introduction zone, a heating zone, and a secondary feedstock introduction zone, introducing an oxygen-containing gas and a fuel into the fuel combustion zone, mixing and combusting them to generate a fuel combustion gas flow, introducing a hydrocarbon as a primary feedstock while introducing the fuel combustion gas flow into the primary feedstock introduction zone to produce a primary reactant-containing gas, electrically heating the primary reactant-containing gas in the heating zone, and then introducing the hydrocarbon as a secondary feedstock while introducing the electrically heated primary reactant-containing gas into the secondary feedstock introduction zone to carry out a secondary reaction. Based on this finding, the present invention has been completed.

[0015] That is, the present invention provides: (1) a method for producing carbon black, using a reactor for producing carbon black, which is provided in this order from upstream to downstream of a gas flow path with a fuel combustion zone, a primary feedstock introduction zone, a heating zone, and a secondary feedstock introduction zone, wherein an oxygen-containing gas and a fuel are introduced into the fuel combustion zone, mixed and combusted to generate a fuel combustion gas flow, a hydrocarbon as a primary feedstock is introduced into the primary feedstock introduction zone while the fuel combustion gas flow is being introduced to generate a primary reactant-containing gas, and then the primary reactant-containing gas is electrically heated in the heating zone, and then the hydrocarbon as a secondary feedstock is introduced into the secondary feedstock introduction zone while the electrically heated primary reactant-containing gas is being introduced to carry out a secondary reaction; (2) a method for producing carbon black, which is characterized by having a dibutyl phthalate (DBP) absorption capacity of 40 to 180 mL / 100 g and a nitrogen adsorption specific surface area (N ２ SA) is 40 to 190m ２(3) A reactor for producing carbon black, comprising a fuel combustion zone, a primary feedstock introduction zone, a heating zone, and a secondary feedstock introduction zone, provided in this order from upstream to downstream of a gas flow path, wherein the fuel combustion zone is a zone into which an oxygen-containing gas and a fuel are introduced, mixed, and combusted to generate a fuel combustion gas flow; the primary feedstock introduction zone is a zone into which a hydrocarbon serving as a primary feedstock is introduced while introducing the fuel combustion gas flow, and which generates a primary reactant-containing gas; the heating zone is a zone into which the primary reactant-containing gas is electrically heated; and the secondary feedstock introduction zone is a zone into which a hydrocarbon serving as a secondary feedstock is introduced while introducing the electrically heated primary reactant-containing gas, and which performs a secondary reaction.

[0016] According to the present invention, a reactor for producing carbon black is used, which is provided with a fuel combustion zone, a primary raw material introduction zone, a heating zone, and a secondary raw material introduction zone in that order from upstream to downstream of a gas flow path. Hydrocarbons serving as primary raw materials are introduced into the primary raw material introduction zone, and a portion of the hydrocarbons is thermally decomposed to produce primary reactants (carbon black nuclei) that serve as precursors. The primary reactant-containing gas thus produced is then electrically heated in the heating zone, whereby carbon dioxide (CO ２ It is believed that this process can effectively produce a gas containing a sufficient amount of primary reactants (carbon black nuclei), which serve as precursors, by pyrolyzing the remainder of the primary raw material while reducing emissions of other gases. Furthermore, by introducing a hydrocarbon secondary raw material into the secondary raw material introduction zone while simultaneously introducing the primary reactant-containing gas, the pyrolysis product of the secondary raw material grows the particle size of the primary reactants (carbon black nuclei) to form primary particles, and a secondary reaction occurs in which these primary particles form a chain-like aggregate in which a plurality of these primary particles are linked together like beads, thereby enabling simple, continuous production of carbon black with desired properties at a high yield.

[0017] Therefore, according to the present invention, in the furnace method using a secondary raw material as a raw material hydrocarbon together with the primary raw material, carbon dioxide (CO ２The present invention provides a method for producing carbon black having desired properties at a high yield while reducing emissions of toluene, toluene-containing toluene, and a reactor for producing carbon black that can be suitably used in the method.

[0018] Schematic diagram showing a cross section of an example of a reactor for producing carbon black. Schematic diagram showing a cross section of an example of a conventional reactor for producing carbon black.

[0019] First, the method for producing carbon black according to the present invention will be described.

[0020] The method for producing carbon black according to the present invention uses a reactor for producing carbon black, which is provided in this order from upstream to downstream of a gas flow path with a fuel combustion zone, a primary feedstock introduction zone, a heating zone, and a secondary feedstock introduction zone; an oxygen-containing gas and a fuel are introduced into the fuel combustion zone, mixed and combusted to generate a fuel combustion gas flow; a hydrocarbon serving as a primary feedstock is introduced into the primary feedstock introduction zone while the fuel combustion gas flow is being introduced to generate a primary reactant-containing gas; the primary reactant-containing gas is then electrically heated in the heating zone; and the hydrocarbon serving as a secondary feedstock is then introduced into the secondary feedstock introduction zone while the electrically heated primary reactant-containing gas is being introduced to carry out a secondary reaction.

[0021] In the method for producing carbon black according to the present invention, a reactor for producing carbon black is used which is provided with a fuel combustion zone, a primary raw material introduction zone, a heating zone, and a secondary raw material introduction zone in this order from upstream to downstream of the gas flow (gas flow path) inside the furnace.

[0022] In the reactor for producing carbon black, the gas flow path is preferably one in which the gas flows in a substantially unidirectional direction from the upstream side to the downstream side.

[0023] An example of such a reactor for producing carbon black is one whose cross-sectional shape is schematically shown in FIG. 1 . In the figure, a reactor 1 for producing carbon black is provided with a fuel combustion zone 3, a primary material introduction zone 5, a heating zone 8, and a secondary material introduction zone 9, which are connected in this order from upstream to downstream of a gas flow path 20 formed in the furnace.

[0024] The carbon black production method of the present invention will be explained below by taking the carbon black production reactor shown in FIG. 1 as an example.

[0025] In the method for producing carbon black according to the present invention, an oxygen-containing gas and a fuel are introduced into the fuel combustion zone 3, mixed and combusted to generate a fuel combustion gas stream.

[0026] Examples of the oxygen-containing gas include oxygen, air, and a gas consisting of a mixture thereof. Examples of the fuel include one or more selected from hydrogen, carbon monoxide, petroleum-based liquid fuels such as FCC residual oil and heavy oil, coal-based liquid fuels such as creosote oil, hydrocarbon gases such as methane, ethane, propane, natural gas, petroleum gas, ethylene, and acetylene, mixed gases of these, and gases generated by the thermal decomposition of rubber or plastic.

[0027] In the carbon black production method according to the present invention, when air is used as the oxygen-containing gas, the air supply rate is 5 to 20 Nm per 1 kg of the total supply amount of the primary raw material and the secondary raw material described below. ３ is preferably 6 to 18 Nm ３ More preferably, it is 7 to 15 Nm ３ It is more preferable that:

[0028] In the fuel combustion zone 3, for example, by supplying fuel while supplying oxygen-containing gas preheated to 400° C. to 600° C., the two can be mixed and burned to generate a high-temperature combustion gas flow.

[0029] In the reactor 1 for producing carbon black shown in the embodiment of FIG. 1 , the fuel combustion zone 3 is equipped with an oxygen-containing gas inlet 31 for introducing an oxygen-containing gas such as air, and a combustion burner 32 for supplying fuel. The oxygen-containing gas and the fuel are introduced into the fuel combustion zone 3, mixed, and combusted to generate a fuel combustion gas flow.

[0030] In the method for producing carbon black according to the present invention, hydrocarbons as the primary raw material are introduced into the primary raw material introduction zone 5 while the fuel combustion gas stream generated in the fuel combustion zone 3 is being introduced.

[0031] In the method for producing carbon black according to the present invention, examples of hydrocarbons used as a primary raw material include gaseous fuels (gaseous hydrocarbons) and fuels with large molecular weights (hydrocarbons with large molecular weights). Here, the term "gaseous fuel" refers to a fuel that is gaseous under standard conditions (25°C, 1 atm), and the term "fuel with large molecular weight" refers to a fuel that has a molecular weight of 70 or more as measured by GC-TOF / MS described below.

[0032] (Method for Measuring Molecular Weight) The molecular weight is a value measured by GC-TOF / MS using the following apparatus and conditions: Measuring apparatus: JEOL Ltd., JMS-T200GC Measuring conditions: Inlet temperature: 280°C Carrier gas: Helium Column: BPX-5 Ionization method: EI method Ionization voltage: 70 eV Ionization current: 300 μA Examples of the gaseous fuel include one or more selected from hydrocarbon gases such as methane, ethane, propane, natural gas, petroleum gas, ethylene, and acetylene, mixed gases of these, and gases generated by the thermal decomposition of rubber or plastic.

[0033] Examples of the fuel having a large molecular weight include one or more selected from aromatic hydrocarbons such as benzene, toluene, xylene, naphthalene, and anthracene; coal-based hydrocarbons such as creosote oil, tar oil, and carboxylic acid oil; petroleum heavy oils such as ethylene heavy end oil and FCC residual oil; acetylenic unsaturated hydrocarbons; ethylenic hydrocarbons; aliphatic saturated hydrocarbons such as pentane and hexane; vegetable oils such as rapeseed oil and soybean oil; and oils generated by the thermal decomposition of rubber or plastic. From the viewpoint of appropriately adjusting the properties of the resulting carbon black, benzene, toluene, xylene, naphthalene, anthracene, creosote oil, carboxylic acid oil, ethylene heavy end oil, FCC residual oil, and the like are preferred.

[0034] In the present invention, the primary raw material may be a mixture of two or more of the above hydrocarbons. In the present invention, the hydrocarbon serving as the primary raw material preferably contains the above fuel having a large molecular weight. When the hydrocarbon serving as the primary raw material contains a fuel having a large molecular weight, a gas containing a primary reactant (carbon black nuclei) that serves as a precursor during pyrolysis can be easily produced.

[0035] In the carbon black production method according to the present invention, when air is used as the oxygen-containing gas, the amount of the primary raw material introduced into the primary raw material introduction zone 5 is set to 1 Nm of air under standard conditions (25°C, 1 atm). ３ The weight is preferably 0.01 to 5.00 kg, more preferably 0.02 to 4.90 kg, and even more preferably 0.03 to 4.80 kg.

[0036] In the reactor 1 for producing carbon black shown in the embodiment of FIG. 1 , a primary raw material introduction zone 5 is provided in communication with the fuel combustion zone 3, and the primary raw material is introduced through a primary raw material introduction nozzle 4 that supplies the primary raw material in the axial direction of the furnace.

[0037] A one-fluid nozzle can be used as the primary raw material introduction nozzle 4. If the primary raw material is solid at room temperature, it is desirable to heat it appropriately to make it liquid or gaseous before introducing the primary raw material through the primary raw material introduction nozzle 4.

[0038] In the method for producing carbon black according to the present invention, hydrocarbons serving as primary raw materials are introduced into primary raw material introduction zone 5 while the fuel combustion gas stream generated in fuel combustion zone 3 is being introduced, thereby producing a primary reactant-containing gas containing primary reactants (carbon black nuclei) that become precursors through thermal decomposition of a portion of the hydrocarbons.

[0039] The primary reactant-containing gas thus produced is electrically heated in heating zone 8. In the method for producing carbon black according to the present invention, examples of the electrical heating include resistance heating, induction heating, and dielectric heating. Specific examples include one or more types selected from heating using an electric heater, electromagnetic induction heating, microwave heating, and the like.

[0040] In the method for producing carbon black according to the present invention, the heating temperature in heating zone 8 is preferably 1000 to 2000°C, more preferably 1100 to 1900°C, and even more preferably 1200 to 1800°C.

[0041] In the method for producing carbon black according to the present invention, the heating time in heating zone 8 may be appropriately adjusted so that the primary raw material introduced into heating zone 8 is thermally decomposed to suitably generate a gas containing primary reactants (carbon black nuclei).

[0042] The heating time in heating zone 8 can be controlled by adjusting the flow path length of heating zone 8 (the length of the path through which the fuel combustion gas flow and the primary raw material flow in heating zone 8) and the flow speed of the fuel combustion gas flow and the primary raw material in heating zone 8.

[0043] In the reactor 1 for producing carbon black shown in the embodiment of FIG. 1 , among the furnace walls 2, the furnace wall 21 of the heating zone 8 is formed of a component material having higher thermal conductivity than the furnace walls of the other zones, and the inside of the furnace can be heated by heating the outer surface of the furnace wall 21 and conducting heat to the inner surface of the furnace wall 21.

[0044] The furnace wall 21 can be heated by an electric heater, electromagnetic induction heating, microwave heating, or the like.

[0045] Alternatively, the primary reactant itself introduced into the heating zone 8 can be heated by dielectric heating. Examples of the dielectric heating method include microwave heating.

[0046] In the carbon black production method according to the present invention, a fuel combustion gas flow is generated in the fuel combustion zone 3, and at the same time, carbon dioxide (CO ２ This method can favorably pyrolyze the hydrocarbons that serve as the primary raw material while reducing emissions of carbon black nuclei, thereby producing primary reaction products (carbon black nuclei) with appropriate particle sizes, and can easily produce the desired carbon black while controlling the structure in the secondary reaction described below.

[0047] In the carbon black production method according to the present invention, if carbon black is produced by heating only with the fuel combustion gas flow generated in the fuel combustion zone 3 (using high-temperature fuel combustion gas) without performing electrical heating in the heating zone 8, the carbon black obtained will be microparticulated and will not have the desired nitrogen adsorption specific surface area (N ２ It becomes difficult to obtain carbon black having a high molecular weight (SA).

[0048] Furthermore, in the method for producing carbon black according to the present invention, if carbon black is produced only by electrical heating in heating zone 8 without generating a fuel combustion gas flow in fuel combustion zone 3, it becomes difficult to produce carbon black.

[0049] According to the carbon black production method of the present invention, a reactor for producing carbon black 1 is used, which is provided with a fuel combustion zone 3, a primary raw material introduction zone 5, a heating zone 8, and a secondary raw material introduction zone 9 in this order from upstream to downstream of a gas flow path. The primary raw material is introduced into the primary raw material introduction zone 5, and the generated primary reactant-containing gas is heated by electrical heating in the heating zone 8, thereby producing carbon dioxide (CO ２ It is possible to suitably generate a gas containing the primary reactant (carbon black nuclei) while reducing the amount of discharged primary reactant (carbon black nuclei).

[0050] In the method for producing carbon black according to the present invention, a hydrocarbon serving as a secondary raw material is introduced into the secondary raw material introduction zone 9 while the gas containing the primary reactants produced in the heating zone 8 is being introduced, thereby carrying out a secondary reaction.

[0051] In the method for producing carbon black according to the present invention, examples of the hydrocarbon used as the secondary raw material include gaseous fuel (gaseous hydrocarbons) and large-molecular-weight fuel (hydrocarbons with large molecular weights). Here, the gaseous fuel refers to a fuel that is gaseous under standard conditions (25°C, 1 atm), and the large-molecular-weight fuel refers to a fuel with a molecular weight of 70 or more as measured by GC-TOF / MS.

[0052] Examples of the gaseous fuel include one or more selected from hydrocarbon gases such as methane, ethane, propane, natural gas, petroleum gas, ethylene, and acetylene, mixed gases thereof, and gases generated by thermal decomposition of rubber or plastic.

[0053] Examples of the fuel having a large molecular weight include one or more selected from aromatic hydrocarbons such as benzene, toluene, xylene, naphthalene, anthracene, etc.; coal-based hydrocarbons such as creosote oil, tar oil, carboxylic acid oil, etc.; petroleum heavy oils such as FCC residual oil and ethylene heavy end oil, hydrocarbons such as acetylenic unsaturated hydrocarbons, ethylenic hydrocarbons, and aliphatic hydrocarbons such as pentane and hexane; vegetable oils such as rapeseed oil and soybean oil; and oils generated by the thermal decomposition of rubber or plastic.

[0054] In the method for producing carbon black according to the present invention, the secondary raw material is preferably a gaseous fuel, particularly one or more hydrocarbon gases selected from methane, ethane, propane, natural gas, petroleum gas, ethylene, acetylene, etc., in order to appropriately adjust the properties of the carbon black to be produced.

[0055] In the method for producing carbon black according to the present invention, the amount of the secondary raw material introduced in secondary raw material introduction zone 9 is preferably 0.10 to 5.00 times by mass, more preferably 0.15 to 4.95 times by mass, and even more preferably 0.20 to 4.90 times by mass, the amount of the primary raw material introduced in primary raw material introduction zone 5.

[0056] In the method for producing carbon black according to the present invention, when the amount of secondary raw material introduced in secondary raw material introduction zone 9 relative to the amount of primary raw material introduced in primary raw material introduction zone 5 is within the above-described range, carbon black having the desired properties can be easily produced.

[0057] In the method for producing carbon black according to the present invention, the secondary raw material is introduced into the secondary raw material introduction zone 9 while the primary reactant-containing gas produced in the heating zone 8 is being introduced, and the secondary raw material is pyrolyzed while both are circulating in the furnace to carry out the secondary reaction.

[0058] In the reactor 1 for producing carbon black shown in the embodiment of FIG. 1 , a secondary material introduction zone 9 is provided coaxially in communication with the primary material introduction zone 5, and the secondary material is supplied to the secondary material introduction zone 9 from a secondary material introduction nozzle 6 that supplies the secondary material from a direction perpendicular to the furnace axial direction.

[0059] A one-fluid nozzle can be used as the secondary material introduction nozzle 6. If the secondary material is solid at room temperature, it is heated appropriately to a liquid or gaseous state and introduced through the secondary material introduction nozzle 6.

[0060] In the reactor 1 for producing carbon black shown in the embodiment of FIG. 1 , the secondary raw material introduced into the secondary raw material introduction zone 9 is pyrolyzed in the reaction zone 10 while flowing in the axial direction of the furnace, thereby causing a secondary reaction.

[0061] According to the method for producing carbon black of the present invention, a reactor for producing carbon black is used, which is provided in this order from upstream to downstream of a gas flow path with a fuel combustion zone 3, a primary material introduction zone 5, a heating zone 8, and a secondary material introduction zone 9. While introducing the gas containing the primary reactant (carbon black nuclei) obtained in heating zone 8 into secondary material introduction zone 9, a hydrocarbon serving as the secondary material is introduced. This causes the pyrolysis of the secondary material to grow the particle size of the primary reactant (carbon black nuclei) particles, forming primary particles. This then causes a secondary reaction in which a plurality of these primary particles are linked together in a beaded pattern to form aggregates with a chain structure, thereby easily producing carbon black having desired properties at a high yield.

[0062] In the method for producing carbon black according to the present invention, the reaction is stopped appropriately after the desired carbon black is produced.

[0063] In the reactor 1 for producing carbon black shown in the embodiment of FIG. 1 , a reaction termination zone 11 is provided coaxially in communication with the reaction zone 10, and a cooling liquid introduction nozzle 7 is provided in the reaction termination zone 11 in a direction perpendicular to the furnace axial direction. The reaction can be terminated by spraying a cooling liquid from the cooling liquid introduction nozzle 7.

[0064] The cooling liquid may be water or the like, and the carbon black particles suspended in the high-temperature combustion gas are cooled by spraying the cooling liquid.

[0065] The cooled carbon black particles are passed through a flue or the like and separated and collected by a collection system (separation and collection device) such as a cyclone or a bag filter, whereby the target carbon black can be recovered.

[0066] In the method for producing carbon black according to the present invention, the reactor for producing carbon black is not limited to the configuration shown in FIG. 1 and may have various other shapes.

[0067] The carbon black obtained by the production method according to the present invention preferably has a dibutyl phthalate (DBP) absorption of 40 to 180 mL / 100 g, more preferably 55 to 175 mL / 100 g, and even more preferably 70 to 170 mL / 100 g.

[0068] The DBP absorption amount is an index showing the degree of structure development, that is, the degree of complexity of the aggregate structure.

[0069] The carbon black obtained by the production method according to the present invention has a dibutyl phthalate (DBP) absorption amount within the above range, and therefore can suitably exhibit desired tensile stress and elongation when blended into, for example, a rubber composition for a tire tread.

[0070] In the present application, the DBP absorption amount means a value measured by the method specified in JIS K6217-4 "Carbon black for rubber - Fundamental properties - Part 4, Determination of DBP absorption amount".

[0071] The carbon black obtained by the production method according to the present invention has a nitrogen adsorption specific surface area (N ２ SA) is 40 to 190m 2 / g, and 55 to 180m 2 / g is more preferable, and 70 to 170m 2 / g is more preferred.

[0072] The carbon black obtained by the production method according to the present invention is ２ When the SA is within the above range, the desired tensile strength and abrasion resistance can be suitably exhibited when compounded in a rubber composition for a tire tread.

[0073] In this application, N ２ SA means a value measured by the amount of nitrogen adsorption according to the method specified in JIS K6217-2 2001 "Testing methods for basic performance of carbon black for rubber".

[0074] The carbon black obtained by the production method according to the present invention preferably has a toluene color transmittance (LT) of 90% or more, more preferably 93% or more, and even more preferably 95% or more.

[0075] The carbon black obtained by the production method according to the present invention has a toluene color transmittance (LT) within the above range, and therefore the tar content, particularly aromatic content, on the surface of the carbon black can be suppressed, and when blended into a rubber composition for a tire tread, the carbon black can suitably exhibit the desired abrasion resistance.

[0076] In the present application, the toluene color transmission (LT) refers to a value measured in accordance with JIS K6218 "Testing methods for additional properties of carbon black for rubber, 8. Toluene color transmission, Method A."

[0077] In the carbon black production method according to the present invention, in the furnace process using a secondary raw material as a raw hydrocarbon, carbon dioxide (CO ２ The present invention provides a method for producing carbon black having desired properties in high yield while reducing emissions of toluene, toluene-containing toluene, and toluene-containing toluene.

[0078] Next, the reactor for producing carbon black according to the present invention will be described.

[0079] The reactor for producing carbon black according to the present invention is a reactor for producing carbon black in which a fuel combustion zone, a primary feedstock introduction zone, a heating zone, and a secondary feedstock introduction zone are provided in this order from upstream to downstream of a gas flow path, wherein the fuel combustion zone is a region where an oxygen-containing gas and a fuel are introduced, mixed, and combusted to generate a fuel combustion gas flow; the primary feedstock introduction zone is a region where a hydrocarbon serving as a primary feedstock is introduced while introducing the fuel combustion gas flow, and a primary reactant-containing gas is produced; the heating zone is a region where the primary reactant-containing gas is electrically heated; and the secondary feedstock introduction zone is a region where a hydrocarbon serving as a secondary feedstock is introduced while introducing the electrically heated primary reactant-containing gas, and a secondary reaction is carried out.

[0080] Details of the reactor for producing carbon black according to the present invention are as described in the description of the method for producing carbon black according to the present invention, and a specific example thereof can be the reactor for producing carbon black 1 described above.

[0081] The reactor for producing carbon black according to the present invention can be suitably used in the method for producing carbon black according to the present invention.

[0082] According to the present invention, a method for producing a hydrocarbon-containing gas by a furnace process using a secondary raw material as a raw material is provided. ２ The present invention provides a reactor for producing carbon black that can produce carbon black having desired properties at a high yield while reducing emissions of toluene, toluene-containing toluene, and toluene-containing toluene.

[0083] Next, the present invention will be explained in more detail by way of examples, but these are merely illustrative and do not limit the present invention.

[0084] Examples 1 to 9 Carbon black was produced using a reactor 1 for producing carbon black having a generally cylindrical shape as shown in the cross section of FIG.

[0085] The reactor shown in FIG. 1 is provided with a fuel combustion zone 3, a primary material introduction zone 5, a heating zone 8, a secondary material introduction zone 9, a reaction zone 10, and a reaction terminating zone 11, which are connected in this order from upstream to downstream along a gas flow path 20 formed within the reactor.

[0086] In the reactor 1 for producing carbon black shown in FIG. 1, the fuel combustion zone 3 is provided with an oxygen-containing gas inlet 31 for introducing an oxygen-containing gas such as air, and a combustion burner 32 for supplying fuel.

[0087] The primary raw material introduction zone 5 is provided with a single-fluid nozzle, which is a primary raw material introduction nozzle 4 for supplying the primary raw material in the axial direction of the furnace, and is provided in communication with the fuel combustion zone 3 .

[0088] The heating zone 8 has a furnace wall 21 formed of a material having higher thermal conductivity than the furnace wall 2 of other parts, and is configured to heat the inside of the furnace by electrically heating the outer surface of this furnace wall 21 and conducting heat to the inner surface of the furnace wall 21.

[0089] The secondary material introduction zone 9 is equipped with a single-fluid nozzle, which is a secondary material introduction nozzle 6, which is introduced from a direction perpendicular to the furnace axis direction, and is provided coaxially in communication with the heating zone 8. Furthermore, the reaction zone 10 is provided coaxially in communication with the secondary material introduction zone 9. The reaction terminating zone 11 is equipped with a coolant introduction nozzle 7 (water-cooled quench) which supplies a coolant from a direction perpendicular to the furnace axis direction and whose position can be changed vertically in the drawing, and is provided coaxially in communication with the reaction zone 10.

[0090] In Examples 1 to 9, each carbon black was produced using the carbon black production reactor 1 as follows.

[0091] First, in the fuel combustion zone 3, air (oxygen content: 21% by volume) preheated to 500°C was supplied from the oxygen-containing gas inlet 31 in the amounts shown in Table 1, and city gas (gas type 13A) was injected as fuel from the combustion burner 32 in the amounts shown in Table 1, and the two were mixed and burned to form a high-temperature combustion gas flow that circulated within the furnace.

[0092] While the high-temperature combustion gas stream was being introduced into primary raw material introduction zone 5, naphthalene (molecular weight 128) was supplied as a primary raw material from the single-fluid nozzle serving as primary raw material introduction nozzle 4 in the amounts shown in Table 1, and then the high-temperature combustion gas stream and the primary raw materials were introduced into heating zone 8.

[0093] In the heating zone 8, the outer surface of the furnace wall 21 was electrically heated to 1200 to 1400°C by an electric heater, and the inside of the furnace was heated to the electric heating temperatures shown in Table 1, thereby sufficiently generating a gas containing the primary reactant.

[0094] Next, while the primary reactant-containing gas was being introduced into secondary raw material introduction zone 9, city gas (gas type 13A) was supplied as a secondary raw material from secondary raw material introduction nozzle 6 in the amounts shown in Table 1, and after sufficient secondary reaction was carried out in reaction zone 10, the resulting mixture was introduced into reaction termination zone 11, where cooling water was sprayed from coolant introduction nozzle 7. The cooled carbon black particles were passed through a flue or the like and collected by a separation and collection device (not shown), and the target carbon black was recovered.

[0095] From the partial pressure of the gas in the furnace at the rear of the reaction zone 10 (the point immediately before the reaction cessation zone 11), the H ２ Gas, CO ２ The content (vol %) of each of the carbon monoxide gas and the carbon dioxide gas was calculated. The results are shown in Table 1.

[0096] In addition, the nitrogen adsorption specific surface area N ２ SA (m ２ The absorbance (mL / 100 g) of the toluene-based coating was measured, and the absorbance (mL / 100 g) of the dibutyl phthalate (DBP) was measured. The results are shown in Table 2.

[0097] Furthermore, the production amount (kg) of each carbon black (CB) and CO ２ Amount generated (m ３ ) and each CO ２ Amount generated / CB generation amount (m ３ The results are shown in Table 2.

[0098] Comparative Examples 1 to 10 Carbon black was produced using a reactor 1A for producing carbon black, which had a generally cylindrical shape as shown in the cross section of FIG.

[0099] The reactor 1A for producing carbon black shown in FIG. 2 does not have the furnace wall 21 made of a structural material with high thermal conductivity and is not provided with the heating zone 8, but the structure, furnace size, etc. are the same as those of the reactor 1 for producing carbon black shown in FIG. 1 .

[0100] In each part of the reactor 1A for producing carbon black shown in FIG. 2, the zones or members common to those of the reactor 1 for producing carbon black shown in FIG. 1 are assigned the same reference numerals as those of the reactor 1 for producing carbon black shown in FIG. 1.

[0101] In Comparative Examples 1 to 10, each carbon black was produced using the carbon black production reactor 1A as follows.

[0102] First, in the fuel combustion zone 3, air (oxygen content: 21% by volume) preheated to 500°C was supplied from the oxygen-containing gas inlet 31 in the amounts shown in Table 3, and city gas (gas type 13A) was injected as fuel from the combustion burner 32 in the amounts shown in Table 3. The two gases were mixed and burned to form a high-temperature combustion gas flow that circulated within the furnace.

[0103] While the above-mentioned high-temperature combustion gas stream was being introduced into the primary raw material introduction zone 5, naphthalene (molecular weight 128) was fed as a primary raw material from the single-fluid nozzle serving as the primary raw material introduction nozzle 4 in the amounts shown in Table 3.

[0104] In Comparative Example 1, the supply rate of the primary raw material was set to 0 kg / h (the primary raw material was not supplied).

[0105] Next, while the primary reactant-containing gas was being introduced into secondary raw material introduction zone 9, city gas (gas type 13A) was supplied as a secondary raw material from secondary raw material introduction nozzle 6 in the amounts shown in Table 3, and after sufficient secondary reaction was carried out in reaction zone 10, the resulting mixture was introduced into reaction termination zone 11, where cooling water was sprayed from cooling liquid introduction nozzle 7. The cooled carbon black particles were passed through a flue or the like and collected by a separation and collection device (not shown), and the target carbon black was recovered.

[0106] In Comparative Example 1, no carbon black was obtained.

[0107] From the partial pressure of the gas in the furnace at the rear of the reaction zone 10 (the point immediately before the reaction cessation zone 11), the H ２ Gas, CO ２ The content (vol %) of the CO gas and the HCl gas was calculated. The results are shown in Table 3.

[0108] In addition, the nitrogen adsorption specific surface area N ２ SA (m ２ The absorbance (mL / 100 g) of the toluene-based coating was measured, and the absorbance (mL / 100 g) of the dibutyl phthalate (DBP) was measured. The results are shown in Table 4.

[0109] Furthermore, the production amount (kg) of each carbon black (CB) and CO２ Amount generated (m ３ ) and each CO ２ Amount generated / CB generation amount (m ３ / kg) was calculated.

[0110] The results are shown in Table 4.

[0111]

[0112]

[0113]

[0114]

[0115] In Examples 1 to 9, a reactor 1 for producing carbon black is used, which is provided with a fuel combustion zone 3, a primary raw material introduction zone 5, a heating zone 8, and a secondary raw material introduction zone 9 in that order from upstream to downstream of a gas flow path 20. An oxygen-containing gas and a fuel are introduced into the fuel combustion zone 3, mixed, and combusted to generate a fuel combustion gas flow. The primary raw materials are introduced into the primary raw material introduction zone 5 while the fuel combustion gas flow is being introduced to generate a primary reactant-containing gas. Thereafter, the primary reactant-containing gas is electrically heated in the heating zone 8. Next, the secondary raw materials are introduced into the secondary raw material introduction zone 9 while the primary reactant-containing gas is being introduced, thereby causing a secondary reaction and producing carbon black.

[0116] Therefore, from Tables 1 and 2, in Examples 1 to 9, in the furnace method using secondary raw materials as raw hydrocarbons, the CO per unit production amount of carbon black (CB) was ２ Amount of CO ２ Generation amount / CB production amount) is 0.76 to 1.43 m ３ / kg, and carbon dioxide (CO ２ It can be seen that carbon black can be produced while reducing emissions of carbon black.

[0117] Furthermore, from Table 1, in Examples 1 to 9, H after the secondary reaction ２ The generated amount was as high as 13.2 to 21.5 volume % (vol %), which indicates that the primary and secondary raw materials can be effectively pyrolyzed to produce carbon black in high yield.

[0118] Furthermore, from Table 2, in Examples 1 to 9, the nitrogen adsorption specific surface area N ２ SA is 41 to 190m ２ / g, dibutyl phthalate (DBP) absorption of 45 to 180 mL / 100 g, and toluene color transmittance LT of 96 to 99%.

[0119] On the other hand, Tables 3 and 4 show that in Comparative Example 1, in relation to Examples 1 to 9, no primary raw materials were supplied in primary raw material introduction zone 5 and no electrical heating was performed in heating zone 8, and therefore no carbon black was obtained.

[0120] Furthermore, from Table 4, in Comparative Examples 2 to 10, in relation to Examples 1 to 9, electric heating was not performed in the heating zone, and therefore the CO per unit production amount of carbon black (CB) was ２ Amount of CO ２ The amount of carbon dioxide (CO ２ ) during the production of carbon black. ２ ) emissions cannot be reduced.

[0121] Furthermore, as can be seen from Table 3, in Comparative Examples 2 to 10, in comparison with Examples 1 to 9, electrical heating was not performed in the heating zone, so the thermal decomposition properties of the primary raw material and the secondary raw material were low, and the H ２ It can be seen that the amount of carbon black produced is low, which results in a poor carbon black yield.

[0122] Furthermore, Table 4 shows that in Comparative Examples 2 to 10, in comparison with Examples 1 to 9, no electrical heating was performed in the heating zone, and therefore only carbon blacks with low toluene coloring transmittances LT of 1 to 43% were obtained.

[0123] According to the present invention, in a furnace process using a secondary raw material as a raw hydrocarbon, carbon dioxide (CO ２ The present invention provides a method for producing carbon black having desired properties at a high yield while reducing emissions of toluene, toluene-containing toluene, and a reactor for producing carbon black that can be suitably used in the method.

[0124] 1, 1A Reactor for producing carbon black 2 Furnace wall 21 Furnace wall of heating zone 3 Fuel combustion zone 31 Oxygen-containing gas inlet 32 ​​Combustion burner 4 Primary raw material introduction nozzle 5 Primary raw material introduction zone 6 Secondary raw material introduction nozzle 7 Cooling liquid introduction nozzle 8 Heating zone 9 Secondary raw material introduction zone 10 Reaction zone 11 Reaction termination zone 20 Gas flow path

Claims

1. A method for producing carbon black, comprising the steps of: using a reactor for producing carbon black, which is provided in this order from upstream to downstream of a gas flow path, a fuel combustion zone, a primary raw material introduction zone, a heating zone, and a secondary raw material introduction zone; introducing an oxygen-containing gas and a fuel into the fuel combustion zone, mixing and combusting them to generate a fuel combustion gas flow; introducing a hydrocarbon as a primary raw material while introducing the fuel combustion gas flow into the primary raw material introduction zone to generate a primary reactant-containing gas, electrically heating the primary reactant-containing gas in the heating zone; and then introducing the hydrocarbon as a secondary raw material while introducing the electrically heated primary reactant-containing gas into the secondary raw material introduction zone to carry out a secondary reaction.

2. Dibutyl phthalate (DBP) absorption capacity is 40-180mL / 100g, and nitrogen adsorption specific surface area (N ２ SA) is 40 to 190m ２ 2. The method for producing carbon black according to claim 1, which obtains carbon black having a toluene color transmittance (LT) of 90% or more.

3. A reactor for producing carbon black having a fuel combustion zone, a primary raw material introduction zone, a heating zone, and a secondary raw material introduction zone provided in that order from upstream to downstream of a gas flow path, wherein the fuel combustion zone is a region where an oxygen-containing gas and a fuel are introduced, mixed, and combusted to generate a fuel combustion gas flow, the primary raw material introduction zone is a region where a hydrocarbon that is a primary raw material is introduced while introducing the fuel combustion gas flow, and a primary reactant-containing gas is produced, the heating zone is a region where the primary reactant-containing gas is electrically heated, and the secondary raw material introduction zone is a region where a secondary reaction is carried out by introducing a hydrocarbon that is a secondary raw material while introducing the primary reactant-containing gas.

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