Carbon black and process for its production

Abstract

The present application relates to the technical field of carbon black production, in particular to a kind of carbon black and its production process.The present application solves the problems of large viscosity of ethylene tar, incomplete cracking, poor dispersibility and surface inertness of carbon black.First, the raw oil is treated by decalin / NMP complex solvent and ultrasonic wave, then a ferrocene / potassium borate composite catalyst is added, and the double-stage atomization technology is combined with gradient temperature field for combustion cracking;In the reaction quenching section, the modified quenching liquid containing KH-550 and urea is sprayed in the specific temperature zone for in-situ grafting, and finally the finished product is obtained by alternating speed granulation and microwave fluidized drying;The prepared carbon black has the characteristics of high structure, high yield, low impurity and high surface activity, and has high application value in the field of rubber reinforcement and high-performance composite materials.

Description

Technical Field

[0001] This invention relates to the field of carbon black production technology, specifically to a type of carbon black and its production process. Background Technology

[0002] Ethylene tar, a byproduct of hydrocarbon cracking to produce ethylene, contains abundant polycyclic aromatic hydrocarbons and gums, making it a high-quality raw material for carbon black production. However, existing carbon black production processes from ethylene tar face two main technical challenges in practical applications: First, incomplete atomization and pyrolysis of raw materials lead to low yield and high impurities. Ethylene tar has extremely high viscosity at room temperature and contains complex asphaltenes and heavy components. Traditional processes reduce viscosity solely through high-temperature heating, resulting in uneven atomization of droplets within the reactor. Large droplets cannot be completely vaporized and pyrolyzed in the combustion zone, which not only reduces the carbon black yield but also increases ash and coking content in the product, severely affecting the basic physicochemical properties of the carbon black.

[0003] Secondly, the inert surface of traditional carbon black makes it difficult to meet the demands of high-end modification. Existing ethylene tar-based carbon black has few functional groups on its surface, resulting in extremely poor dispersibility in rubber, plastics, or conductive polymer composites, and it is highly prone to secondary agglomeration. To improve its dispersibility, traditional methods often employ post-treatment modification (such as adding modifiers during mixing or using strong acid oxidation). This not only increases the complexity of the process steps, but also easily damages the original branched structure of the carbon black (reducing the oil absorption value) due to physical mixing or violent chemical reactions, making it difficult to achieve the preparation of high-end carbon black products that balance high structure and high surface activity.

[0004] Therefore, a carbon black and its production process are proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a carbon black and its production process.

[0006] To achieve the above objectives, the present invention provides the following technical solution: Unless otherwise specified, all parts in this invention are by weight.

[0007] This invention provides a carbon black production process, which includes the following steps: Ethylene tar, decahydronaphthalene, and N-methylpyrrolidone are homogenized and pretreated to obtain a homogenized feedstock oil; a composite catalyst is added to the homogenized feedstock oil and stirred at 400 rpm for 15 minutes at 65°C to obtain a catalytic feedstock oil; the catalytic feedstock oil is subjected to two-stage atomization and gradient combustion pyrolysis to generate high-temperature carbon black flue gas; the high-temperature carbon black flue gas is modified and rapidly cooled in situ to obtain carbon black powder; the carbon black powder is fed into a wet granulator, deionized water is added (water-to-powder ratio of 1:1), and wet carbon black particles are obtained using an alternating speed process; the wet carbon black particles are fed into a microwave fluidized bed dryer and dried for 45 minutes at a microwave frequency of 2.45 GHz and a fluidized bed temperature of 85°C to obtain carbon black.

[0008] Preferably, the homogenization pretreatment step is as follows: 100 parts of ethylene tar, 10-20 parts of decahydronaphthalene and 5 parts of N-methylpyrrolidone are added to a premixing tank. Under the conditions of reaction temperature of 60℃ and stirring speed of 300rpm, an ultrasonic generator is turned on and the mixture is co-treated at 40kHz and 800W for 20-45min to obtain homogenized feedstock oil. The ethylene tar used in this invention must meet the following indicators: density (20℃) 1.05-1.15g / cm³, initial boiling point >200℃, BMCI value ≥120, and asphaltenes content <5%.

[0009] The ultrasonic cavitation bubble closes instantly, generating extremely high temperatures and pressures in a microscopic local environment. This "microreactor" can induce dehydronaphthalene dehydrogenation and generate active hydrogen radicals H·, thereby achieving chemical viscosity reduction under a macroscopic environment of 60℃.

[0010] Preferably, the composite catalyst is prepared as follows: 0.5 parts of ferrocene and 0.2 parts of nano-sized potassium borate (prepared according to the method in Example 1 of CN105154172B) are added to 5 parts of N-methylpyrrolidone and ultrasonically dispersed at 50 kHz for 30 min to obtain a suspended composite catalyst.

[0011] Preferably, the two-stage atomization and gradient combustion pyrolysis steps are as follows: The catalytic feedstock oil is preheated to 150°C and fed into the carbon black reactor via a high-pressure diaphragm pump. First, it undergoes first-stage acoustic pre-atomization through an ultrasonic nozzle with a frequency of 60-100kHz. Then, it immediately enters a swirling high-pressure spray gun with a pressure of 2.0-4.5MPa for second-stage mechanical atomization and is sprayed into the reactor. The temperature of the pre-combustion section of the reactor is controlled at 1200°C, and the temperature of the reaction section is controlled at 1450-1750°C (the axial temperature field inside the reactor is controlled: from the outlet of the pre-combustion section to the center of the reaction zone, the temperature rises linearly from the pre-combustion section temperature to the reaction section temperature within 0.2s). The residence time of the atomized feedstock in the furnace is 0.8s, undergoing incomplete combustion and thermal pyrolysis to generate high-temperature carbon black flue gas.

[0012] Preferably, the in-situ modification quenching step is as follows: When the high-temperature carbon black flue gas enters the quenching section of the reactor and the temperature drops to 650℃, the modified quenching liquid is atomized and sprayed into the flue gas through a high-pressure nozzle (1.5MPa) (the average Sotter diameter of the atomized quenching liquid is controlled at 30-50μm), instantly reducing the flue gas temperature to below 400℃ within 0.1s, terminating the pyrolysis reaction and completing the in-situ chemical grafting modification to obtain carbon black powder; the injection volume of the modified quenching liquid is 1.2-1.8 times the weight of the homogenized feedstock oil, and the cross-sectional flow density is 20kg / (m³). 2 During a brief contact at 650°C (0.1 s), the latent heat of vaporization of the acetic acid aqueous solution in the modified quenching liquid is utilized to form a protective vapor film with an instantaneous temperature below 250°C around the droplet. Under this localized low-temperature microenvironment, the silanol functional groups of KH-550 covalently bond with the free radicals that have not disappeared on the carbon black surface before decomposition.

[0013] In addition, the carbon black at this time is in a newly formed "new ecology" with a large number of unsaturated dangling bonds and high-density free radicals on its surface. The chemical activity of this high-energy surface is far greater than that of finished carbon black, and its collision with the modifier is almost an instant reaction. Furthermore, the ammonia and isocyanate released by the decomposition of urea at high temperature act as surface activators, further inducing the rapid anchoring of the silane coupling agent.

[0014] Preferably, the modified quenching fluid is prepared as follows: 1 part of silane coupling agent KH-550 is added dropwise to 5 parts of acetic acid aqueous solution with pH 4, and stirred at 500 rpm for 20 min at 40°C to allow it to be fully hydrolyzed; 1-4 parts of urea and 10 parts of deionized water are added, and stirring is continued for 10 min to obtain the modified quenching fluid.

[0015] Preferably, the alternating speed process steps are as follows: first, shearing and granulation are carried out at a speed of 1000-1500 rpm for 1 minute, and the temperature of the granulator cylinder is controlled at 50℃. Then, the speed is seamlessly switched to 800 rpm for rounding and shaping for 2 minutes. The process is repeated twice to obtain wet carbon black particles.

[0016] In another aspect, the present invention provides a carbon black produced by any of the above-described production processes.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention addresses the challenges of high viscosity and complex composition in ethylene tar at the microscopic level by combining a decahydronaphthalene and NMP composite system with ultrasonic synergistic treatment. NMP, as a highly polar solvent, rapidly penetrates and expands the tightly packed structure of asphaltenes micelles in the tar. Meanwhile, decahydronaphthalene exhibits excellent hydrogen-donating activity under the localized, instantaneous high temperature and pressure environment generated by ultrasound, effectively inducing long-chain shearing and free radical stabilization of heavy components. This deep synergy between the material and the process not only achieves perfect homogenization of the feedstock at extremely low temperatures, significantly reducing production energy consumption, but more importantly, it eliminates the risk of nozzle coking caused by uneven feedstock atomization in subsequent processes. This ensures the continuity of carbon black production and the consistency of product particle size from the source, laying a solid foundation for the stable production of high-quality carbon black.

[0018] 2. This invention achieves precise control of the pyrolysis process through the dual superposition of acoustic pre-atomization and mechanical high-pressure atomization, combined with a gradient-temperature reactor environment. Ultrasonic waves first break the oil film into micron-sized droplets, followed by high-pressure swirling to further refine them into nano-sized aerosols, allowing the raw material to achieve a larger specific surface area upon entering the pre-combustion section. Guided by the gradient temperature field, the raw material undergoes a transition from gentle gasification to vigorous pyrolysis, avoiding the sudden explosion of carbon nuclei and the generation of coke particles caused by excessive temperature differences. This synergistic effect between processes results in a uniform spatial distribution of carbon black particles, significantly improving raw material utilization and carbon black yield, and giving the finished carbon black a narrow-distribution primary particle diameter, greatly enhancing its optical and reinforcing properties in applications.

[0019] 3. The composite introduction of ferrocene and potassium borate in this invention constructs a highly efficient catalytic synergistic system in the pyrolysis microenvironment. The metallic iron particles generated by the pyrolysis of ferrocene act as active centers, significantly reducing the nucleation barrier of gaseous carbon atoms and inducing the ordered arrangement of carbon layers. Meanwhile, potassium borate controls the branching growth of aggregates through the electrostatic repulsion of potassium ions and utilizes the special affinity of boron to inhibit the deposition of impurities such as sulfur and ash in the carbon lattice. This synergistic interaction between substances overcomes the bottleneck of precisely controlling the structure of traditional carbon black. While improving the conductivity and enhancing the physical framework structure of carbon black, it effectively reduces the content of chemical impurities in the product, enabling the transformation of ethylene tar, a low-end byproduct, into a high-structure, high-purity carbon black product.

[0020] 4. This invention utilizes the high-energy activation state of carbon black during its formation, introducing a modifying component within a specific rapid cooling temperature range to achieve the transformation of the carbon black surface from inert to active. During the rapid temperature drop from 800℃ to 500℃, the hydrolysis products of the silane coupling agent and the active groups generated by the decomposition of urea, with the help of the free radicals that have not yet disappeared on the carbon black surface, complete in-situ grafting through covalent bonds. This synergy between the material and the thermodynamic process eliminates the extremely cumbersome post-processing physical coating or chemical oxidation steps in traditional processes. The modified carbon black surface is rich in polar groups such as silanol and amino groups, which can form strong chemical bonds with rubber or plastic matrices, solving the problem of carbon black's easy agglomeration and difficulty in dispersion in composite materials.

[0021] 5. The synergistic application of alternating rotation speed granulation and microwave drying technology in this invention provides a reliable guarantee for the final morphology and activity retention of carbon black products. The cyclical switching between high and low rotation speeds, utilizing the alternating effects of mechanical shear force and centrifugal force, results in a dense internal structure and rounded surface of the carbon black particles, effectively controlling dust contamination. The subsequent microwave fluidized bed drying utilizes the selective heating characteristics of microwaves on polar molecules, enabling rapid moisture migration from the inside out, avoiding the risk of high-temperature surface oxidation associated with traditional hot air drying. This precise integration of processes not only significantly shortens the production cycle and improves granulation strength, but more importantly, it preserves the modified active groups on the carbon black surface in a low-energy environment, ensuring the physicochemical stability of the product during storage and transportation. Attached Figure Description

[0022] Figure 1 The graph shows the test results of carbon black yield and iodine uptake value in Examples 1-4 of this invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figure 1 This invention provides a carbon black and its production process, the technical solution of which is as follows: Example

[0025] 0.5 parts of ferrocene and 0.2 parts of nano-sized potassium borate were added to 5 parts of N-methylpyrrolidone and ultrasonically dispersed at 50 kHz for 30 min to obtain a suspended composite catalyst.

[0026] One part of silane coupling agent KH-550 was added dropwise to five parts of acetic acid aqueous solution with a pH of 4, and stirred at 500 rpm for 20 min at 40 °C to allow for complete hydrolysis; one part of urea and ten parts of deionized water were added, and stirring was continued for 10 min to obtain the modified quenching solution.

[0027] 100 parts of ethylene tar, 10 parts of decahydronaphthalene, and 5 parts of N-methylpyrrolidone were added to a premixing tank. Under conditions of a reaction temperature of 60℃ and a stirring speed of 300 rpm, an ultrasonic generator was turned on, and the mixture was synergistically treated at 40 kHz and 800 W for 20 minutes to obtain homogenized feedstock oil. A composite catalyst was added to the homogenized feedstock oil, and the mixture was stirred at 65℃ and 400 rpm for 15 minutes to obtain catalytic feedstock oil. The catalytic feedstock oil was preheated to 150℃ and pumped into a carbon black reactor at an output pressure of 3.0 MPa using a high-pressure diaphragm pump. It first underwent first-stage acoustic pre-atomization through an ultrasonic nozzle at a frequency of 60 kHz, and then immediately entered a swirling high-pressure spray gun at a pressure of 2.0 MPa for second-stage mechanical atomization before being sprayed into the reactor. The temperature of the pre-combustion section of the reactor was controlled at 1200℃, and the temperature of the reaction section was controlled at... The temperature is 1450℃ (the axial temperature field inside the reactor is controlled: from the outlet of the pre-combustion section to the center of the reaction zone, the temperature linearly increases from the pre-combustion section temperature to the reaction section temperature within 0.2s). The residence time of the atomized raw material in the furnace is 0.8s, undergoing incomplete combustion and thermal pyrolysis to generate high-temperature carbon black flue gas. When the high-temperature carbon black flue gas enters the quenching section of the reactor and the temperature drops to 650℃, the modified quenching liquid (prepared according to the above proportions, and in actual operation, prepared and sprayed proportionally according to the weight multiple of the homogenized raw material oil) is atomized and sprayed into the flue gas through a high-pressure nozzle (1.5MPa). This instantly reduces the flue gas temperature to below 400℃ within 0.1s, terminating the pyrolysis reaction and completing the in-situ chemical grafting modification to obtain carbon black powder. The injection volume of the modified quenching liquid is 1.2 times the weight of the homogenized raw material oil, and the cross-sectional flow density is 20kg / (m³). 2 •s); Carbon black powder is fed into a wet granulator, pure water is added (water-to-powder ratio is 1:1), and the powder is first sheared and granulated at 1000 rpm for 1 min, with the temperature of the granulator cylinder controlled at 50℃. Then, the powder is seamlessly switched to 800 rpm for rounding and shaping for 2 min. This process is repeated twice to obtain wet carbon black particles. The wet carbon black particles are then fed into a microwave fluidized bed dryer and dried for 45 min at a microwave frequency of 2.45 GHz and a fluidized bed temperature of 85℃ to obtain carbon black.

[0028] Example 2 Referring to the preparation method and parameters of Example 1, the difference is that when preparing homogenized feedstock oil, 13 parts of decahydronaphthalene were used, and ultrasonic treatment was performed at 40 kHz and 800 W for 28 min; during the two-stage atomization and gradient combustion pyrolysis, the first stage frequency was 75 kHz, the second stage pressure was 2.8 MPa, and the reaction temperature was 1550 °C; during in-situ modification and quenching, 2 parts of urea were added after KH-550 hydrolysis, and the amount of quenching liquid injected was 1.4 times the weight of the oil; during granulation and drying, granulation was performed at 1150 rpm for 1 min.

[0029] Example 3 Referring to the preparation method and parameters of Example 1, the difference is that when preparing homogenized feedstock oil, 17 parts of decahydronaphthalene were used, and ultrasonic treatment was performed at 40 kHz and 800 W for 36 min; during two-stage atomization and gradient combustion pyrolysis, the first stage frequency was 85 kHz, the second stage pressure was 3.6 MPa, and the reaction temperature was 1650 °C; during in-situ modification and quenching, 3 parts of urea were added after KH-550 hydrolysis, and the amount of quenching liquid injected was 1.6 times the weight of the oil; during granulation and drying, granulation was performed at 1300 rpm for 1 min.

[0030] Example 4 Referring to the preparation method and parameters of Example 1, the difference is that when preparing homogenized feedstock oil, 20 parts of decahydronaphthalene were used, and ultrasonic treatment was performed at 40 kHz and 800 W for 45 min; during the two-stage atomization and gradient combustion pyrolysis, the first stage frequency was 100 kHz, the second stage pressure was 4.5 MPa, and the reaction temperature was 1750 °C; during in-situ modification and quenching, 4 parts of urea were added after KH-550 hydrolysis, and the amount of quenching liquid injected was 1.8 times the weight of the oil; during granulation and drying, granulation was performed at 1500 rpm for 1 min.

[0031] Comparative Example 1 The preparation method and parameters of Example 1 are the same, except that decahydronaphthalene is not added in the premixing step.

[0032] Comparative Example 2 The preparation method and parameters of Example 1 are the same, except that N-methylpyrrolidone (NMP) is not added in the premixing step.

[0033] Comparative Example 3 The preparation method and parameters are the same as in Example 1, except that in the premixing step, the ultrasonic generator is turned off and mechanical stirring is used only.

[0034] Comparative Example 4 The preparation method and parameters of Example 1 are the same, except that only the second-stage mechanical atomization is performed in the pyrolysis step.

[0035] Comparative Example 5 The preparation method and parameters of Example 1 are the same, except that only the first stage of acoustic pre-atomization is performed in the pyrolysis step.

[0036] Comparative Example 6 The preparation method and parameters are the same as in Example 1, except that no composite catalyst is added.

[0037] Comparative Example 7 The preparation method and parameters of Example 1 are the same, except that potassium borate is not added to the composite catalyst.

[0038] Comparative Example 8 The preparation method and parameters are the same as in Example 1, except that in the modified quenching step, the quenching liquid sprayed in is only deionized water.

[0039] Comparative Example 9 The preparation method and parameters of Example 1 are the same, except that the temperature of the flue gas into which the modified quenching liquid is injected is changed from 650°C to 800°C in the quenching step.

[0040] Comparative Example 10 The preparation method and parameters of Example 1 are the same, except that the wet granulation process is changed to "granulation at a constant speed of 800 rpm for 3 min" and the drying process is changed to "drying at 120°C in a traditional hot air drying oven for 45 min".

[0041] Experimental Example 1 Carbon black yield = (total weight of finished carbon black / total weight of ethylene tar feedstock) × 100%; Iodine uptake value was determined according to standard GB / T 3778-2021. It characterizes the specific surface area of ​​carbon black. The higher the value, the smaller the primary particles and the better the reinforcing performance. The DBP absorbance value is determined according to the standard GB / T 3778-2021, which characterizes the structure degree (degree of branching) of carbon black. The higher the value, the higher the structure degree and the better the conductivity and dispersion network. Ash content was determined according to standard GB / T 3778-2021, which characterizes the content of inorganic impurities in carbon black; the lower the value, the better. The water contact angle was measured using a DSA100 optical contact angle meter after the carbon black tablets were compressed. Traditional carbon black is hydrophobic, but the contact angle decreases significantly after grafting polar groups. The lower the value, the better the surface polarity and the better the dispersion in the polar matrix. The results are shown in Table 1.

[0042] Table 1 Performance Tests of Examples 1-4 and Comparative Examples 1-10 Example 1 60.5 118.5 123.5 0.35 62.2 Example 2 62.4 122.4 126.8 0.30 58.6 Example 3 64.8 125.6 130.4 0.23 53.3 Example 4 63.2 126.3 129.2 0.26 55.5 Comparative Example 1 53.4 107.3 115.4 0.62 64.1 Comparative Example 2 55.2 111.5 117.6 0.55 63.8 Comparative Example 3 50.6 98.8 111.2 0.85 65.5 Comparative Example 4 52.1 104.2 121.5 0.48 63.4 Comparative Example 5 51.3 101.4 118.6 0.52 62.8 Comparative Example 6 59.8 116.6 88.4 0.68 65.2 Comparative Example 7 60.0 117.1 101.5 0.56 63.5 Comparative Example 8 61.0 119.0 124.2 0.34 129.5 Comparative Example 9 60.4 117.8 122.5 0.53 125.4 Comparative Example 10 60.2 118.0 117.8 0.36 122.5

[0043] As shown in Table 1, in Comparative Example 1, the lack of decahydronaphthalene as a hydrogen-donating solvent in the premixing step prevented the ethylene tar from undergoing a microscopic hydrogen-donating reaction to cleave the macromolecular side chains under high-temperature ultrasonic conditions. This resulted in a failure to substantially reduce the tar viscosity, leading to larger droplets and easier coking upon entering the reactor, causing a significant decrease in yield. Furthermore, the incompletely pyrolyzed coking material increased the ash content. In Comparative Example 2, the absence of NMP as a strong polar solvent in the premixing step prevented the effective dispersing of the polar stacked layers of asphaltenes micelles in the ethylene tar. This resulted in poor homogeneity of the raw material system, extremely uneven subsequent atomization, and the inability of some heavy components to vaporize instantaneously, forming coke particles. This led to a decrease in carbon black yield and a reduction in specific surface area (iodine uptake value). In Comparative Example 3, during the premixing step, the ultrasonic generator was turned off, and mechanical stirring alone was insufficient to break down the network-like heavy component structure inside the tar. This resulted in extremely high viscosity of the feedstock entering the nozzle, forming huge oil droplets after spraying. These large droplets underwent incomplete combustion in the furnace, causing significant damage to the yield, iodine uptake value, and ash content. In Comparative Example 4, the lack of a first-stage acoustic pre-atomization in the pyrolysis step meant that single-stage mechanical high pressure was insufficient to completely pulverize the viscous polymer feedstock into nanoscale aerosols. The large oil droplets prevented them from fully undergoing the nucleation and growth stages within 0.8 seconds, reducing the feedstock conversion rate and resulting in larger initial particles. In Comparative Example 5, only a first-stage acoustic pre-atomization was performed in the pyrolysis step. Although ultrasound could break the oil film, the lack of kinetic energy and swirling shear provided by high-pressure mechanical jet resulted in insufficient penetration of the atomized droplets in the pre-combustion section, leading to overly concentrated distribution, localized oxygen-deficient combustion, and coking, causing a sharp drop in yield. In Comparative Example 6, without the addition of a composite catalyst, the lack of nucleation active centers provided by ferrocene and the structural guidance of potassium ions hindered the lateral bonding of free carbon atoms, leading to a sharp drop in carbon black structure. Simultaneously, the lack of boron's impurity removal and adsorption effects resulted in a significant increase in the ash content of the final product. In Comparative Example 7, without the addition of potassium borate in the composite catalyst, only ferrocene promoted nucleation, but the lack of electrostatic repulsion and guiding effects from potassium ions resulted in fewer branched carbon aggregates that were prone to agglomeration, with a DBP value of only 101.5. Furthermore, the lack of boron's inhibition of sulfur impurities led to a decrease in product purity. In Comparative Example 8, the quenching liquid sprayed in the modification quenching step was only deionized water. No polar functional groups were grafted onto the carbon black surface, resulting in a product exhibiting typical strong hydrophobicity, making it extremely difficult to disperse in subsequent polar polymer matrices. In Comparative Example 9, the flue gas temperature point into which the modified quenching liquid was injected was changed from 650℃ to 800℃ during the quenching step. KH-550 and urea were injected at a high temperature of 800℃. Although the free radicals on the carbon black surface were active, the extremely high temperature caused the modifier to undergo instantaneous thermal oxidation decomposition or carbonization, making it impossible to form effective grafting. This resulted in a rebound of the water contact angle, and the modification was essentially ineffective. Furthermore, the in-situ carbonization or decomposition of the modifier at ultra-high temperatures would leave more non-carbon solid impurities, leading to a decrease in product purity.In Comparative Example 10, the traditional hot air drying oven, due to prolonged baking at high external temperatures, oxidized and burned off a large number of fragile silicon- and nitrogen-containing organic functional groups that had just been grafted onto the surface of the carbon black in the oven, resulting in a decrease in the hydrophilicity of the product and an increase in the contact angle; and non-alternating granulation would cause the carbon black particle structure to be damaged or unevenly agglomerated during the drying process.

[0044] In summary, as shown in Comparative Examples 1-3, the "decahydronaphthalene + NMP + ultrasonic cavitation" system pioneered in the premixing stage of this application overcomes the limitations of single physical viscosity reduction and achieves the coupling of chemical hydrogen supply chain scission and polar depolymerization, laying the foundation for subsequent atomization. Comparative Examples 4-5 demonstrate that "two-stage atomization and gradient temperature field" are not optional additions; the combination of acoustic pre-crushing and mechanical swirling matches the ultra-short residence time cracking of high-viscosity heavy oil, which is unattainable by single-factor methods. Comparative Examples 6-7 highlight the synergy between ferrocene and potassium borate in high-temperature gas-phase nucleation, accurately targeting the stringent structural and low ash requirements of high-end carbon black. Furthermore, this application differs from the traditional "granulation followed by modification" approach. As demonstrated in Comparative Examples 8-10, the modifier is sprayed in during a specific high-energy residual heat "window" at 800°C in the rapid cooling section, instantly capturing the unsaturated dangling bonds of carbon atoms and completing in-situ covalent grafting. It also leverages the "internal heating cold dehydration" characteristic of microwave fluidized bed drying to preserve surface functional groups. Each step in this application is interconnected; the product state of the previous step is a prerequisite for the reaction in the next step, collectively constructing a synergistic chain from macroscopic processes to microscopic molecules.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A carbon black production process, characterized in that: The production process is as follows: ethylene tar, decahydronaphthalene, and N-methylpyrrolidone are homogenized and pretreated to obtain homogenized feedstock oil; a composite catalyst is added to the homogenized feedstock oil, and the mixture is heated and stirred to obtain catalytic feedstock oil; the catalytic feedstock oil is subjected to two-stage atomization and gradient combustion pyrolysis to generate high-temperature carbon black flue gas; the high-temperature carbon black flue gas is modified and rapidly cooled in situ to obtain carbon black powder; the carbon black powder is fed into a wet granulator, deionized water is added, and wet carbon black particles are obtained using an alternating speed process; the wet carbon black particles are fed into a microwave fluidized bed dryer and dried to obtain the carbon black.

2. The carbon black production process according to claim 1, characterized in that: The homogenization pretreatment steps are as follows: the ethylene tar, the decahydronaphthalene and the N-methylpyrrolidone are added to a premix tank, the temperature is raised and stirring is started, and an ultrasonic generator is used for synergistic processing to obtain the homogenized feedstock oil.

3. The carbon black production process according to claim 1, characterized in that: The composite catalyst is prepared as follows: ferrocene and potassium borate are added to the N-methylpyrrolidone and ultrasonically dispersed to obtain the composite catalyst.

4. The carbon black production process according to claim 1, characterized in that: The two-stage atomization and gradient combustion pyrolysis steps are as follows: the catalytic feedstock oil is preheated and fed into the carbon black reactor through a high-pressure diaphragm pump. First, it undergoes first-stage acoustic pre-atomization through an ultrasonic nozzle, and then enters a swirl high-pressure spray gun for second-stage mechanical atomization. It is then injected into the reactor for incomplete combustion and thermal pyrolysis to generate the high-temperature carbon black flue gas.

5. The carbon black production process according to claim 1, characterized in that: The in-situ modification and quenching step is as follows: when the high-temperature carbon black flue gas enters the quenching section of the reactor, the modified quenching liquid is atomized and sprayed into the high-temperature carbon black flue gas through a high-pressure nozzle, and the temperature of the high-temperature carbon black flue gas drops instantly to obtain the carbon black powder.

6. The carbon black production process according to claim 5, characterized in that: The modified quenching fluid is prepared as follows: silane coupling agent KH-550 is added dropwise to an aqueous acetic acid solution and stirred to hydrolyze; urea and deionized water are added and stirring is continued to obtain the modified quenching fluid.

7. The carbon black production process according to claim 1, characterized in that: The alternating rotation speed process steps are as follows: first, shearing and granulation are performed, then the rotation speed is reduced to perform rounding and shaping to obtain the wet carbon black particles.

8. A type of carbon black, characterized in that: The carbon black is produced by the production process described in any one of claims 1-7.

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