Carbon black manufacturing method

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

[Technical Field]

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

[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 hydrocarbon feedstock 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 the carbon black into a rubber composition, a carbon black having characteristics suited to the intended use of the component 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 of 40 to 180 mL / 100 g and a nitrogen adsorption specific surface area (N2SA) of 40 to 300 m 2 / g and a toluene color transmittance (LT) of 90% or more have been proposed (Patent Document 3, etc.). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-43598 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-277443 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-026392 Summary of the Invention [Problem to be solved by the invention]

[0008] The carbon black to be compounded in the rubber composition for tire treads described above is preferably a carbon black having a dibutyl phthalate (DBP) absorption of 40 to 180 mL / 100 g and a nitrogen adsorption specific surface area (N2SA) of 40 to 190 m 2 / g, and 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 hydrocarbon feedstock in a fire-resistant furnace under oxygen-deficient conditions.

[0011] Meanwhile, with the recent increase in environmental awareness, manufacturing industries are now seeking methods for manufacturing various products that reduce carbon dioxide (CO2) emissions, and there is also a demand for manufacturing methods that reduce carbon dioxide (CO2) emissions in the furnace process, which uses the above-mentioned hydrocarbons as raw materials.

[0012] However, the inventors have found through their investigations that in the above-mentioned furnace method, if an attempt is made to reduce carbon dioxide (CO) emissions by limiting the amount of fuel supplied to the fuel combustion zone, the temperature of the resulting combustion gas flow cannot be raised to the desired level, and the desired carbon black cannot be produced in a high yield.

[0013] Under these circumstances, an object of the present invention is to provide a furnace method for producing carbon black having desired properties at a high yield while reducing carbon dioxide (CO) emissions, and a reactor for producing carbon black. [Means for solving the problem]

[0014] As a result of intensive research by the present inventors to solve the above technical problems, a reactor for producing carbon black, 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 a gas flow path; The present inventors have found that the above technical problems can be solved by a method for producing carbon black, which comprises introducing an oxygen-containing gas and a fuel into the fuel combustion zone, mixing and combusting them to generate a fuel combustion gas stream, introducing a hydrocarbon as a primary feedstock while introducing the fuel combustion gas stream into the primary feedstock introduction zone to generate a primary reactant-containing gas, electrically heating the primary reactant-containing gas in the heating zone, and then introducing a 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 is (1) 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 a gas flow path, An oxygen-containing gas and a fuel are introduced into the fuel combustion zone, mixed and combusted to generate a fuel combustion gas stream, a hydrocarbon as a primary feedstock is introduced into the primary feedstock introduction zone while the fuel combustion gas stream 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 In the secondary raw material introduction zone, a hydrocarbon as a secondary raw material is introduced while the electrically heated primary reactant-containing gas is introduced to carry out a secondary reaction. A method for producing carbon black, (2) Dibutyl phthalate (DBP) absorption capacity is 40-180 mL / 100 g, and nitrogen adsorption specific surface area (N2SA) is 40-190 m 2 the method for producing carbon black according to (1) above, which produces carbon black having a toluene color transmittance (LT) of 90% or more; (3) A reactor for producing carbon black, in which a fuel combustion zone, a primary raw material introduction zone, a heating zone, and a secondary raw material introduction zone are sequentially provided from the upstream to the downstream direction of a gas flow path, 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 stream; the primary feedstock introduction zone is a zone where a hydrocarbon serving as a primary feedstock is introduced while the fuel combustion gas stream is introduced to generate a primary reactant-containing gas; the heating zone is a region in which the primary reactant-containing gas is electrically heated; The secondary raw material introduction zone is a region where the electrically heated primary reactant-containing gas is introduced while a hydrocarbon serving as a secondary raw material is introduced to carry out a secondary reaction. The present invention provides a reactor for producing carbon black, characterized by: [Effects of the Invention]

[0016] According to the present invention, a reactor for producing carbon black is used, which is provided, in 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. The primary feedstock is introduced into the primary feedstock introduction zone, where a portion of the primary feedstock is pyrolyzed to produce a primary reactant (carbon black nuclei) that serves as a precursor. The resulting primary reactant-containing gas is then electrically heated in the heating zone. This effectively reduces carbon dioxide (CO2) emissions and pyrolyzes the remainder of the primary feedstock to produce a gas containing a sufficient amount of the primary reactant (carbon black nuclei). Then, in the secondary feedstock introduction zone, the hydrocarbon secondary feedstock is introduced while the primary reactant-containing gas is being introduced. This thermal decomposition of the secondary feedstock grows the primary reactant (carbon black nuclei) into primary particles, and a secondary reaction occurs in which the primary particles form chain-like aggregates, resulting in the simple, continuous production of carbon black with desired properties at a high yield.

[0017] Therefore, the present invention can provide a furnace method for producing carbon black having desired properties at a high yield while reducing carbon dioxide (CO) emissions, using a secondary raw material as raw material hydrocarbons together with a primary raw material, and a reactor for producing carbon black that can be suitably used in the method. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing a cross section of an example of a reactor for producing carbon black. [Figure 2] A schematic diagram showing a cross section of an example of a conventionally used reactor for producing carbon black. DETAILED DESCRIPTION OF THE INVENTION

[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 includes the steps of: a reactor for producing carbon black, 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 a gas flow path; An oxygen-containing gas and a fuel are introduced into the fuel combustion zone, mixed and combusted to generate a fuel combustion gas stream, a hydrocarbon as a primary feedstock is introduced into the primary feedstock introduction zone while the fuel combustion gas stream 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 In the secondary raw material introduction zone, a hydrocarbon as a secondary raw material is introduced while the electrically heated primary reactant-containing gas is being introduced, and a secondary reaction is carried out.

[0021] In the carbon black production method 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 reactor for producing carbon black 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] The oxygen-containing gas may be oxygen, air, or a gas consisting of a mixture thereof, and the fuel may be 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 Preferably, it is 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, the hydrocarbon used as the primary raw material can be a gaseous fuel (gaseous hydrocarbon) or a fuel with a large molecular weight (hydrocarbon with a large molecular weight). Here, the gaseous fuel refers to a fuel that is gaseous under standard conditions (25°C, 1 atm), and the fuel with a large molecular weight refers to a fuel with a molecular weight of 70 or more as measured by GC-TOF / MS described below.

[0032] (Method for measuring molecular weight) The molecular weight was measured by GC-TOF / MS under the following conditions and with the following equipment. Measuring equipment JEOL JMS-T200GC Measurement conditions Inlet temperature: 280℃ Carrier gas: Helium Column: BPX-5 Ionization method: EI method Ionization voltage: 70 eV Ionization current: 300 μA The gaseous fuel may be 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.

[0033] Examples of the high-molecular-weight fuel 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 used as the primary raw material preferably contains the fuel having a large molecular weight, which makes it possible to easily generate a gas containing the primary reactant (carbon black nuclei) that serves as a precursor during pyrolysis.

[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 With respect to the total weight, 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] The primary raw material introduction nozzle 4 may be, for example, a one-fluid nozzle. 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, whereby a portion of the hydrocarbons is thermally decomposed to produce a primary reactant-containing gas containing primary reactants (carbon black nuclei) that serve as precursors.

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

[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 adjusted as appropriate 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 primary raw material flow in heating zone 8) and the flow rate of the fuel combustion gas flow and 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 method for producing carbon black according to the present invention, a fuel combustion gas flow is generated in fuel combustion zone 3, and electrical heating is performed in heating zone 8. This allows for favorable thermal decomposition of the hydrocarbons serving as the primary raw material while reducing carbon dioxide (CO2) emissions, producing primary reaction products (carbon black nuclei) with an appropriate particle size, and also allows for easy production of the desired carbon black while controlling the structure in the secondary reaction described below.

[0047] In the method for producing carbon black 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 resulting carbon black will be microparticulated, making it difficult to obtain carbon black having the desired nitrogen adsorption specific surface area (N2SA).

[0048] Furthermore, in the method for producing carbon black according to the present invention, if carbon black is produced using only 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 method for producing carbon black 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 that 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 gas containing the primary reactant is heated by electrical heating in the heating zone 8, thereby making it possible to suitably produce a gas containing the primary reactant (carbon black nuclei) while reducing carbon dioxide (CO2) emissions.

[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 hydrocarbons used as secondary raw materials include gaseous fuels (gaseous hydrocarbons) and large-molecular-weight fuels (hydrocarbons with large molecular weights). Here, gaseous fuels refer to fuels that are gaseous under standard conditions (25°C, 1 atm), and large-molecular-weight fuels refer to fuels with a molecular weight of 70 or more as measured by GC-TOF / MS.

[0052] The gaseous fuel may be 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-based 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 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 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] The secondary material introduction nozzle 6 may be, for example, a one-fluid nozzle. If the secondary raw material is solid at room temperature, it is heated appropriately to a liquid or gaseous state, and the secondary raw material is introduced from the secondary raw 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 carbon black production method of the present invention, a reactor for producing carbon black is used, which 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, in that order from upstream to downstream of the gas flow path. A hydrocarbon serving as a secondary material is introduced into the secondary material introduction zone 9 while introducing a gas containing primary reactants (carbon black nuclei) obtained in heating zone 8 into the secondary material introduction zone 9. 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 with 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 bag filter, thereby allowing the target carbon black to 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 various other configurations can be used.

[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 amount of DBP absorbed is an index of 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 - Basic 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 (N2SA) of 40 to 190 m 2 / g is preferred, 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 has an N2SA within the above range, and therefore can suitably exhibit desired tensile strength and abrasion resistance when blended into a rubber composition for a tire tread.

[0073] In the present application, N2SA refers to 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 desired abrasion resistance can be suitably exhibited.

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

[0077] The method for producing carbon black according to the present invention can provide a furnace method using a secondary raw material as a raw hydrocarbon, which produces carbon black having desired properties in high yield while reducing carbon dioxide (CO) emissions.

[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, 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 a gas flow path, 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 stream; the primary feedstock introduction zone is a zone where a hydrocarbon serving as a primary feedstock is introduced while the fuel combustion gas stream is introduced to generate a primary reactant-containing gas; the heating zone is a region in which the primary reactant-containing gas is electrically heated; The secondary raw material introduction zone is a region where the electrically heated primary reactant-containing gas is introduced while a hydrocarbon serving as a secondary raw material is introduced to carry out a secondary reaction. It is characterized by the following.

[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] The present invention provides a reactor for producing carbon black, which is used in a furnace process using a secondary raw material as a raw hydrocarbon, and which can produce carbon black having desired properties at a high yield while reducing carbon dioxide (CO) emissions.

[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. [Example]

[0084] (Examples 1 to 9) Carbon black was produced using a reactor 1 for producing carbon black having a roughly cylindrical shape as shown in the cross-sectional view 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 in 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 furnace axial direction, 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 with 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 in the vertical direction 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 reactor 1 for producing carbon black 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 mixture was 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 the primary raw material introduction zone 5, naphthalene (molecular weight 128) was supplied 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 1, and then the high-temperature combustion gas stream and the primary raw material were introduced into the 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 to sufficiently generate a gas containing the primary reactant.

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

[0095] The contents (vol %) of H gas, CO gas, and CO gas in the furnace after the secondary reaction were calculated from the partial pressure of the gas in the furnace downstream of the reaction zone 10 (just before the reaction termination zone 11). The results are shown in Table 1.

[0096] In addition, the nitrogen adsorption specific surface area N2SA (m 2 The absorbance (mL / 100g), dibutyl phthalate (DBP) absorption (mL / 100g), and toluene color transmittance (LT) (%) were measured. The results are shown in Table 2.

[0097] Furthermore, the amount of carbon black (CB) produced (kg) and the amount of CO2 generated (m 3 ) and calculate the CO2 generation / CB generation amount (m 3 / kg) was calculated. 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 has a roughly cylindrical shape and is shown in cross section in FIG.

[0099] The reactor 1A for producing carbon black shown in FIG. 2 does not have a furnace wall 21 made of a highly thermally conductive material and is not provided with a 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, and the two 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 supplied 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 amount of the primary raw material was set to 0 kg / h (the primary raw material was not supplied).

[0105] Next, while introducing the primary reactant-containing gas into secondary raw material introduction zone 9, city gas (gas type 13A) was supplied as the secondary raw material from secondary raw material introduction nozzle 6 in the amounts shown in Table 3, and after sufficient secondary reaction in reaction zone 10, the mixture was introduced into reaction termination zone 11, where cooling water was sprayed from cooling liquid introduction nozzle 7. The cooled carbon black particles passed through a flue or the like and were 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] The contents (vol %) of H gas, CO gas, and CO gas in the furnace after the secondary reaction were calculated from the partial pressure of the gas in the furnace downstream of the reaction zone 10 (just before the reaction terminating zone 11). The results are shown in Table 3.

[0108] In addition, the nitrogen adsorption specific surface area N2SA (m 2 The absorbance (mL / 100g), dibutyl phthalate (DBP) absorption (mL / 100g), and toluene color transmittance (LT) (%) were measured. The results are shown in Table 4.

[0109] Furthermore, the amount of carbon black (CB) produced (kg) and the amount of CO2 generated (m 3 ) and calculate the CO2 generation / CB generation amount (m 3 / kg) was calculated.

[0110] The results are shown in Table 4.

[0111] [Table 1]

[0112] [Table 2]

[0113] [Table 3]

[0114] [Table 4]

[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, arranged in this 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. The primary reactant-containing gas is then 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 amount of CO2 generated per unit production amount of carbon black (CB) (CO2 generation amount / CB production amount) was 0.76 to 1.43 m 3 / kg, which shows that carbon black can be produced while reducing carbon dioxide (CO2) emissions.

[0117] Furthermore, Table 1 shows that in Examples 1 to 9, the amount of H generated after the secondary reaction was as high as 13.2 to 21.5 volume % (vol%), indicating that the primary and secondary raw materials were effectively pyrolyzed and carbon black could be produced in high yield.

[0118] Furthermore, from Table 2, in Examples 1 to 9, the nitrogen adsorption specific surface area N2SA was 41 to 190 m 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 material was 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, Table 4 shows that, in comparison with Examples 1 to 9, Comparative Examples 2 to 10 do not employ electrical heating in the heating zone, and therefore the amount of CO2 generated per unit production of carbon black (CB) (CO2 generation amount / CB production amount) is high, and it is not possible to reduce the amount of carbon dioxide (CO2) emitted during the production of carbon black.

[0121] Furthermore, Table 3 shows that in Comparative Examples 2 to 10, compared to Examples 1 to 9, electrical heating was not performed in the heating zone, which resulted in a lower thermal decomposition rate of the primary and secondary raw materials and a lower amount of H generated after the secondary reaction, resulting in a lower 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 black with a low toluene coloring transmittance LT of 1 to 43% was obtained. [Industrial Applicability]

[0123] The present invention provides a furnace method using a secondary raw material as a raw hydrocarbon, which produces carbon black having desired properties at a high yield while reducing carbon dioxide (CO) emissions, and a reactor for producing carbon black that can be suitably used in the method. [Explanation of symbols]

[0124] 1. 1A Carbon black production reactor 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 material introduction nozzle 7 Coolant introduction nozzle 8 Heating Zone 9 Secondary raw material introduction zone 10 Reaction Zone 11. Termination Zone 20 Gas flow path

Claims

1. a reactor for producing carbon black, 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 a gas flow path; 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 at a heating temperature of 1000°C to 2000°C, and then In the secondary raw material introduction zone, a hydrocarbon as a secondary raw material is introduced while the electrically heated primary reactant-containing gas is being introduced to carry out a secondary reaction; the amount of hydrocarbons introduced as the secondary feedstock is 0.10 to 5.00 times by mass the amount of hydrocarbons introduced as the primary feedstock; Reduce the amount of carbon dioxide generated relative to the amount of carbon black produced to 1.43 m 3 / kg or less A method for producing carbon black, comprising:

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

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