Method and system for producing conductive carbon black

Abstract

The invention relates to a method and a system for producing conductive carbon black. According to the method, the conductive carbon black is directly produced from cracking raw materials by a one-step method. According to the method for producing the carbon black, the conductive carbon black can be simply, conveniently and efficiently prepared at the same time, and the yield of the carbon black is high. The carbon black obtained by the method has good conductive carbon black performance, and can be used for lithium electron conductive materials.

Description

Technical Field

[0001] The invention relates to the field of petrochemicals, and in particular to a method and system for producing conductive carbon black. Background Art

[0002] In my country, due to the reduction of crude oil reserves and the gradual strengthening of environmental awareness, the availability of inferior oil and the increase in processing profits have reduced the market share of low-quality gasoline and diesel. At the same time, the demand for high-quality gasoline has gradually increased. The slowdown in economic growth has led to a structural surplus of diesel, and the market share of diesel has gradually decreased. However, the vacancies of chemical raw materials such as low-carbon olefins and aromatics still need to be supplemented to achieve the transformation of refining and further development. Therefore, it is necessary to develop high-temperature cracking technology for producing chemical materials from inferior heavy oil, so as to achieve a successful transformation from oil to chemical.

[0003] Carbon black is an important chemical raw material. As a reinforcing filler in the rubber industry, a colorant or toner for rubber compounds, it is widely used in many fields such as inks, coatings, leather making, chemical fibers, metallurgy, electronics, photosensitive materials, black agricultural films and packaging materials. The existing technology for producing carbon black includes furnace black, channel black, pyrolytic black and lampblack. Chinese patent (ZL89104111) provides a method for producing carbon black using natural gas as fuel and oxygen-rich gas as a combustion aid. This method improves the stability of furnace temperature and ensures heat supply, but does not solve the problem of carbon black yield and quality.

[0004] Conductive carbon black is generally obtained by producing carbon black as a byproduct of acetylene from natural gas. The main reaction process is that the raw natural gas and oxygen are heated to a certain temperature in the gas preheater and then mixed into the reactor. A part of the natural gas is burned to provide heat energy for the reaction, and another part of the natural gas undergoes cracking reaction at about 1500℃ to produce acetylene. Acetylene is easily decomposed into carbon black and hydrogen at high temperature, so the optimal reaction time at high temperature is only a few thousandths of a second, and the reaction is terminated by quenching with water spray. Although the reaction time is extremely short, carbon black is still generated. Carbon black is a byproduct in this process.

[0005] CN110204930B A production method and feeding equipment for controlling the specific surface area of ​​conductive carbon black, belonging to the technical field of conductive carbon black preparation. The production method for controlling the specific surface area of ​​conductive carbon black comprises subjecting mixed acetylene and hydrocarbon raw materials to cracking reaction at 1300-1500°C; the hydrocarbon raw materials comprise a combination of one or more hydrocarbon compounds. The specific surface area of ​​the conductive carbon black obtained by introducing acetylene to cracking reaction at 1800°C is generally above 80m2 / g. CN112210233A The present invention relates to a method for preparing conductive carbon black, mainly to the problem of the lack of an effective regeneration method for carbon black produced as a by-product of acetylene production from natural gas. The present invention discloses a method for preparing conductive carbon black, which comprises the following steps: (a) acid treatment: the raw carbon black is treated with an acid solution to obtain a conductive carbon black intermediate product I; (b) alkali treatment: the conductive carbon black intermediate product I is treated with an alkali solution to obtain a conductive carbon black intermediate product II; (c) salt loading: the conductive carbon black intermediate product II is mixed with a salt-containing aqueous solution to obtain a conductive carbon black intermediate product III; (d) calcination: the conductive carbon black intermediate product III is calcined to obtain a conductive carbon black finished product. The technical solution solves the problem well and can be used in the recycling and utilization of carbon black produced as a byproduct of natural gas to acetylene in industrial devices. CN112210233A discloses a granular conductive carbon black and a method for preparing the same, which belongs to the field of conductive carbon black technology. The method for preparing the granular conductive carbon black comprises wetting the conductive carbon black raw material with water at a temperature of ≥80°C, wet granulation and drying in sequence. By using water with a temperature of ≥80°C to infiltrate the conductive carbon black raw material, the hydrophilicity of the conductive carbon black raw material is enhanced, and the water with a temperature of ≥80°C enters the microporous structure of the conductive carbon black raw material to achieve a good wetting effect. Further, granular conductive acetylene carbon black with uniform particle size distribution is obtained through wet granulation and drying. Summary of the invention

[0006] The purpose of the present invention is to provide a method and system for producing conductive carbon black. In order to overcome the defects of the prior art, the present invention designs a reaction system to directly produce conductive carbon black in one step by cracking raw materials, skipping the production link of acetylene.

[0007] A first aspect of the present invention provides a method for producing conductive carbon black, comprising:

[0008] (1) heating a cracking reactor to a reaction temperature under an inert oxygen-free atmosphere, introducing a cracking raw material and a carrier gas into the cracking reactor for a cracking reaction, and obtaining a cracking product comprising conductive carbon black and a gas product;

[0009] (2) After the cracking product is cooled by a quenching medium, it is separated by a gas-solid separator to obtain conductive carbon black, and the gas after the gas-solid separation is filtered and collected in a gas collector to obtain a gas product;

[0010] Wherein, the reaction temperature of the cracking reactor is 800-3000°C, preferably 1000-1500°C;

[0011] The reaction time is 20 milliseconds to 10 seconds, preferably 40 milliseconds to 2 seconds;

[0012] The rapid cooling rate of the pyrolysis product is 50-1000°C / millisecond, preferably 50-500°C / millisecond; and / or

[0013] The temperature of the pyrolysis product after cooling is 100-900°C, preferably 200-500°C.

[0014] According to the method of the first aspect, the cracking feedstock is low-quality oil and / or low-value catalytic cracking products; and / or

[0015] The carrier gas is selected from one or more of the following: nitrogen, helium, argon, methane and C2-C4 light hydrocarbons;

[0016] Preferably, the inferior oil is selected from one or more of vacuum residue, coal tar and solvent deasphalted oil; and / or the catalytic cracking low-value product is selected from one or more of catalytic cracking slurry, catalytic cracking diesel and catalytic cracking recycled oil.

[0017] According to the method of the first aspect, the feed ratio per unit time of the carrier gas to the cracking raw material is 0.1-20 liters / gram, preferably 0.5-10 liters / gram.

[0018] According to the method of the first aspect, the cracking feedstock and carrier gas enter the cracking reactor after being preheated;

[0019] Preferably, the preheating temperature of the cracking feedstock is 200-600°C, more preferably 200-500°C; and / or the preheating temperature of the carrier gas is 500-2500°C, more preferably 800-2000°C.

[0020] According to the method of the first aspect, the quenching medium is selected from one or more of the following: water, nitrogen, argon, preferably liquid nitrogen.

[0021] A second aspect of the present invention provides a system for producing conductive carbon black, comprising:

[0022] Feed unit, comprising:

[0023] A first preheating furnace, used for preheating the carrier gas;

[0024] The second preheating furnace is used to preheat the cracking raw materials;

[0025] A reaction unit comprising:

[0026] The cracking reactor is a tubular reactor horizontally arranged along the axial direction, and is provided with a raw material inlet and a cracking product outlet. The carrier gas preheated by the first preheating furnace of the reaction unit and the cracking raw material preheated by the second preheating furnace enter the cracking reactor through the raw material inlet for cracking reaction;

[0027] A high-frequency electric induction heating device, comprising an electromagnetic induction coil sleeved on the periphery of the cracking reactor, for heating the cracking reactor;

[0028] The product separation and collection unit comprises:

[0029] A gas-solid separator, which is provided with a cracking product inlet, a gas outlet and one or more quenching medium inlets, wherein the cracking product inlet is connected to the cracking product outlet of the cracking reactor of the reaction unit, and the quenching medium inlet is arranged upstream of the gas-solid reactor;

[0030] A filter, used for filtering the gas separated by the gas-solid separator;

[0031] A gas collector is used to collect the gas products filtered by the filter.

[0032] The system according to the second aspect, wherein the material of the cracking reactor is selected from one or more of the following: tungsten, molybdenum, tantalum, niobium, vanadium, chromium, titanium, zirconium, rare earth metal borides, rare earth metal carbides, rare earth metal nitrides, rare earth metal silicides, rare earth metal phosphides and rare earth metal sulfides;

[0033] The rare earth metal is selected from one or more of lanthanum, cerium, praseodymium and neodymium.

[0034] According to the system of the second aspect, the cracking reactor comprises a first diameter expansion section, a reaction section and a second diameter expansion section, the inner diameters of the first diameter expansion section and the second diameter expansion section are larger than the inner diameter of the reaction section, and the electromagnetic induction coil is sleeved on the outer circumference of the reaction section.

[0035] Through the above technical solution, the advantages of the present invention are:

[0036] (1) The electromagnetic induction coil heats the cracking reactor, which can achieve rapid temperature rise of the cracking reactor, and the reaction temperature control is simple and the operation is stable;

[0037] (2) It can provide ultra-high temperature and extremely short reaction time to achieve direct cracking of inferior oil and / or low-value catalytic cracking reaction products;

[0038] (3) The method for producing carbon black of the present invention can prepare conductive carbon black simultaneously in a simple and efficient manner, and the yield of carbon black is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0040] Figure 1 The present invention shows a process flow and structural schematic diagram of a specific implementation method of the method for producing acetylene and conductive carbon black.

[0041] Figure 2 The TEM analysis diagram of the conductive carbon black prepared in Example 1 of the present invention is shown.

[0042] Figure 3 The test results of the battery capacity of the conductive carbon black prepared in Example 1 of the present invention as a conductive agent for lithium batteries are shown.

[0043] Figure 4 The stability test results of the charge and discharge voltage platform of the conductive carbon black prepared in Example 1 of the present invention as a conductive agent for lithium batteries are shown.

[0044] Figure 5 The test results of the battery capacity of the carbon black prepared in Comparative Example 1 of the present invention as a lithium battery conductive agent are shown.

[0045] Figure 6 The stability test results of the charge and discharge voltage platform of the carbon black prepared in Comparative Example 1 of the present invention as a lithium battery conductive agent are shown.

[0046] Description of reference numerals:

[0047] 1. Pipeline; 2. Second preheating furnace; 3. First preheating furnace; 4. Cracking reactor; 5. High-frequency electric induction heating equipment; 6-7. Rapid cooling medium inlet; 8. Gas-solid separator; 9. Filter; 10. Gas collector; 11-14. Pipeline; 15. Electromagnetic induction coil. DETAILED DESCRIPTION

[0048] The present application is further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present application will become clearer and more specific.

[0049] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0050] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0051] In the present application, the terms "upstream" and "downstream" are based on the flow direction of the reactants. For example, when the reactants flow from bottom to top, "upstream" means the position below, while "downstream" means the position above.

[0052] The present invention provides a method for producing conductive carbon black, comprising:

[0053] (1) heating a cracking reactor to a reaction temperature under an inert oxygen-free atmosphere, introducing a cracking raw material and a carrier gas into the cracking reactor for a cracking reaction, and obtaining a cracking product comprising conductive carbon black and a gas product;

[0054] (2) After the cracking product is cooled by a quenching medium, it is separated by a gas-solid separator to obtain conductive carbon black, and the gas after the gas-solid separation is filtered and collected in a gas collector to obtain a gas product;

[0055] Wherein, the reaction temperature of the cracking reactor is 800-3000°C, preferably 1000-1500°C;

[0056] The reaction time is 20 milliseconds to 10 seconds, preferably 40 milliseconds to 2 seconds; the rapid cooling rate of the pyrolysis product is 50-1000°C / millisecond, preferably 50-500°C / millisecond; and / or

[0057] The temperature of the pyrolysis product after cooling is 100-900°C, preferably 200-500°C.

[0058] The method of the present invention first heats the electromagnetic induction heating cracking reactor under inert atmosphere conditions, and when the temperature reaches the preset reaction temperature, introduces cracking raw materials to make the cracking raw materials undergo high-temperature cracking reaction under oxygen-free conditions, and obtains conductive carbon black products and gas products by controlling the reaction time, product cooling and gas-solid separation. The obtained reaction product is rapidly cooled and gas-solid separated by a quenching medium to obtain a gas product and a conductive carbon black product;

[0059] The present invention adopts electromagnetic induction heating pyrolysis reactor, which can realize rapid temperature rise of pyrolysis reactor and stable temperature. Compared with plasma reactor, the equipment is simpler, smaller in size, easy to implement and operate, and the pyrolysis process is easy to control with low energy consumption. The present invention combines the technical scheme of electromagnetic induction heating pyrolysis reactor for pyrolysis reaction with controlling the temperature drop rate of rapid cooling within a specific range, so as to produce more high-quality conductive carbon black.

[0060] According to the present invention, inferior oil and catalytic cracking reaction products are well known to those skilled in the art, and inferior oil and catalytic cracking reaction products are of low value. Those skilled in the art may also adopt or mix other cracking raw materials, which will not be described in detail in the present invention. The carrier gas is used to control the reaction time on the one hand, so that the cracking raw materials pass through the cracking reactor quickly, and on the other hand, to provide a high-temperature reaction gas environment for the cracking of the raw materials.

[0061] The method of the present invention is further described below in conjunction with the accompanying drawings. Figure 1 As shown, the cracking raw material preheated in the first preheating furnace 3 and the carrier gas preheated in the second preheating furnace 2 enter the cracking reactor 4 through pipelines 11 and 12 respectively. The cracking reactor 4 provides a high-temperature heat source through the electromagnetic induction coil 15 of the high-frequency electric induction heating device 5 so that the temperature of the cracking reactor reaches the reaction temperature. The cracking raw material entering the cracking reactor 4 passes through the cracking reactor 4 quickly from left to right under the drive of the carrier gas and undergoes a cracking reaction. The product enters the gas-solid separator 8 containing a quenching medium, and the product is rapidly cooled to 200-500°C. Among them, the gas product containing acetylene enters the filter 9 from the gas outlet of the gas-solid separator 8, and the gas product is further cooled and separated from the gas and solid. The obtained product gas enters the gas collector 10 through pipeline 14.

[0062] In one embodiment, the cracking feedstock is low-quality oil and / or catalytic cracking low-value products; and / or

[0063] The carrier gas is selected from one or more of the following: nitrogen, helium, argon, methane and C2-C4 light hydrocarbons;

[0064] Preferably, the inferior oil is selected from one or more of vacuum residue, coal tar and solvent deasphalted oil; and / or the catalytic cracking low-value product is selected from one or more of catalytic cracking slurry, catalytic cracking diesel and catalytic cracking recycled oil.

[0065] In one embodiment, the feed ratio per unit time of the carrier gas to the cracking raw material is -0.1-20 liters / gram, preferably 0.5-10 liters / gram.

[0066] The method of the present invention may further include: preheating the cracking raw material and the carrier gas before feeding them into the cracking reactor, so that the cracking raw material and the carrier gas quickly reach the reaction temperature in the cracking reactor. The temperature of the preheated cracking raw material and the carrier gas can vary within a large range.

[0067] In one embodiment, the cracking feedstock and carrier gas are preheated before entering the cracking reactor;

[0068] Preferably, the preheating temperature of the cracking raw material is 200-600°C, preferably 200-500°C; and / or the preheating temperature of the carrier gas is 500-2500°C, preferably 800-2000°C.

[0069] According to the present invention, rapid cooling is used to rapidly cool the reaction product to terminate the reaction and generate a product with a specific composition. The rapid cooling medium used for rapid cooling is well known to those skilled in the art.

[0070] In one embodiment, the quenching medium is selected from one or more of the following: water, nitrogen, argon, preferably liquid nitrogen.

[0071] In one specific embodiment, the quenching medium can be pre-injected into the gas-solid separator; in another specific embodiment, the quenching medium is argon, and a quenching medium inlet can be provided on the upper portion of the gas-solid separator, and the quenching medium is continuously introduced into the gas-solid separator through the quenching medium inlet.

[0072] The present invention also provides a system for producing conductive carbon black, comprising:

[0073] Feed unit, comprising:

[0074] A first preheating furnace, used for preheating the carrier gas;

[0075] The second preheating furnace is used to preheat the cracking raw materials;

[0076] A reaction unit comprising:

[0077] The cracking reactor is a tubular reactor horizontally arranged along the axial direction, and is provided with a raw material inlet and a cracking product outlet. The carrier gas preheated by the first preheating furnace of the reaction unit and the cracking raw material preheated by the second preheating furnace enter the cracking reactor through the raw material inlet for cracking reaction;

[0078] A high-frequency electric induction heating device, comprising an electromagnetic induction coil sleeved on the periphery of the cracking reactor, for heating the cracking reactor;

[0079] The product separation and collection unit comprises:

[0080] A gas-solid separator, which is provided with a cracking product inlet, a gas outlet and one or more quenching medium inlets, wherein the cracking product inlet is connected to the cracking product outlet of the cracking reactor of the reaction unit, and the quenching medium inlet is arranged upstream of the gas-solid reactor;

[0081] A filter, used for filtering the gas separated by the gas-solid separator;

[0082] A gas collector is used to collect the gas products filtered by the filter.

[0083] According to the present invention, the cracking reactor of the present invention is a reactor that can be heated by electromagnetic induction, for example, it can be a metal tubular reactor arranged horizontally. There is no specific restriction on the way of introducing the cracking raw material and the carrier gas into the metal tubular reactor. The outer periphery of the metal tubular reactor is provided with an electromagnetic induction coil to heat the reactor by the alternating magnetic field generated by the electromagnetic induction coil. High-frequency electric induction heating equipment is well known to those skilled in the art. On the one hand, it can power the electromagnetic induction coil, and on the other hand, it can be provided with an electromagnetic heating controller to control the frequency of the alternating current input into the electromagnetic induction coil. The electromagnetic heating controller is well known to those skilled in the art, and the present invention will not be repeated.

[0084] like Figure 1 As shown, the system of the present invention includes: a cracking reactor 4, an electromagnetic induction coil 15, a high-frequency electric induction heating device 5, and a gas-solid separator 8; the cracking reactor 4 is provided with a raw material inlet and a product outlet; the gas-solid separator 8 is provided with a material inlet, a gas outlet and a solid outlet; the electromagnetic induction coil 15 is wound around the outer periphery of the cracking reactor 4, and the high-frequency electric induction heating device 5 is connected to the electromagnetic induction coil 15; the product outlet of the cracking reactor 4 is connected to the material inlet of the gas-solid separator 8.

[0085] In order to further purify and collect the gaseous products, the system may further include a filter 9 and a gas collector 10. The gas outlet of the gas-solid separator 8 may be connected to the gas collector 10 through the filter 9. Two quenching medium inlets 6 and 7 are provided upstream of the gas-solid separator 8. The filter 9 is used to further separate the gaseous products to separate a small amount of carbon black carried in the gas to obtain a pure gas without solids. The filter 9 may be well known to those skilled in the art, for example, it may be a filter bottle. The filter 9 may be provided with a quenching medium inlet, and the quenching medium enters the filter through the cooling medium inlet to further cool and separate the gaseous products separated by the gas-solid separator 8. The gas collector may be a container such as a gas tank or an air bag.

[0086] According to the present invention, in order to enable the cracking raw material and the carrier gas to quickly reach the reaction temperature in the cracking reactor, the system of the present invention may further include a first preheating furnace 3 and a second preheating furnace 2. The first preheating furnace 3 may be provided with a cracking raw material inlet and a preheating material outlet, and the second preheating furnace 2 may be provided with a carrier gas inlet and a preheating material outlet. The preheating material outlet of the first preheating furnace 3 and the preheating material outlet of the second preheating furnace 2 may be connected to the raw material inlet of the cracking reactor 4.

[0087] In one embodiment, the material of the cracking reactor is selected from one or more of the following: tungsten, molybdenum, tantalum, niobium, vanadium, chromium, titanium, zirconium, rare earth metal borides, rare earth metal carbides, rare earth metal nitrides, rare earth metal silicides, rare earth metal phosphides and rare earth metal sulfides;

[0088] The rare earth metal is selected from one or more of lanthanum, cerium, praseodymium and neodymium.

[0089] According to the present invention, in order to facilitate feeding and discharging, the cracking reactor 4 may include a first diameter expansion section, a reaction section, and a second diameter expansion section from left to right, the inner diameters of the first diameter expansion section and the second diameter expansion section may be larger than the inner diameter of the reaction section, and the electromagnetic induction coil 15 may be wound around the outer periphery of the reaction section. The first diameter expansion section and the second diameter expansion section may be in the shape of a trumpet tube or a straight cylinder, if the first diameter expansion section is a trumpet tube, the tube diameter decreases from left to right, if the second diameter expansion section is a trumpet tube, the tube diameter increases gradually from left to right.

[0090] In one embodiment, the cracking reactor includes a first expansion section, a reaction section and a second expansion section, the inner diameters of the first expansion section and the second expansion section are larger than the inner diameter of the reaction section, and the electromagnetic induction coil is sleeved on the outer circumference of the reaction section.

[0091] The present invention is further illustrated by the following examples, but the present invention is not limited thereto.

[0092] like Figure 1 As shown, the cracking raw material heated to 200-500°C in the first preheating furnace 3 and the carrier gas preheated to 500-2000°C in the second preheating furnace 2 enter the cracking reactor 4 through pipelines 11 and 12 respectively. The cracking reactor 4 provides a high-temperature heat source through a high-frequency electric induction heating device 5 and an electromagnetic induction coil 15 to make the temperature of the cracking reactor reach the reaction temperature. The cracking raw material entering the cracking reactor 4 passes through the cracking reactor 4 quickly from left to right under the drive of the carrier gas and undergoes a cracking reaction. The product enters the gas-solid separator 8 containing a quenching medium (liquid nitrogen), and the product is rapidly cooled (the cooling rate of the reaction product during rapid cooling is 100°C / millisecond) to 200-500°C. Among them, the gas product containing acetylene enters the filter 9 from the gas outlet of the gas-solid separator 8, and the quenching medium from pipeline 6 and pipeline 7 is sprayed into the gas-solid separator 8 through the two quenching medium inlets of the gas-solid separator 8 to further cool the gas product and perform gas-solid separation. The obtained product gas enters the gas collector 10 through pipeline 14.

[0093] Example 1

[0094] This embodiment Figure 1In the system shown, catalytic cracking diesel with properties as described in Table 1 is used as cracking raw material, and the preheating temperature is 230°C; the carrier gas is nitrogen, and the preheating temperature is 1500°C. The molybdenum tube is used as a reactor, and the molybdenum tube is horizontally arranged along the length direction, with an inner diameter of 10mm and a length of 38mm. The outer periphery of the molybdenum tube is sheathed with an electromagnetic induction coil. Liquid nitrogen is introduced into the gas-solid separator 8 from the quenching medium inlet 6 and 7 at the top, as a quenching medium, and the liquid nitrogen flow rate is 4 liters / minute. The cooling rate of the reaction product is controlled to be 100°C / millisecond, so that its temperature is reduced to about 250°C. The generated gas product enters the filter 9 from the gas outlet of the gas-solid separator 8. The generated gas product mainly includes hydrogen, acetylene, methane and a very small amount of other low-carbon gas hydrocarbons. The product gas obtained enters the gas collector 10 through the pipeline 14. The carbon black product is separated and dried to obtain a conductive carbon black product. The gas-solid separator 8 is a carbon black filter bottle, the filter is a cooling bottle, and the gas collector is a gas collection bag.

[0095] Table 1 Properties of catalytic cracking diesel

[0096]

[0097]

[0098] The specific conditions of Example 1 are as follows: reaction temperature is 1400°C, nitrogen is used as carrier gas, carrier gas flow rate is 4L / min, feed rate is 1.0 g / min, oil feeding time is 4 minutes, reaction time is 44 milliseconds, cooling rate is 100°C / millisecond, product temperature is 200°C, the gas product yield is 14.91%, and the conductive carbon black yield is 85.09%. The conductive carbon black obtained in this example was tested for product morphology and electrochemistry, and the results are as follows: Figure 2-Figure 4 shown.

[0099] from Figure 2 From the TEM analysis diagram, it can be seen that the carbon black produced by the present invention is approximately spherical particles, a part of which is connected end to end to form a chain agglomerate, and the other part is overlapped; the particle size is generally less than 100nm; and the end to end is connected to form a chain aggregate.

[0100] Electrochemical performance test

[0101] The conductive carbon black prepared in Example 1 was assembled into a battery with lithium iron phosphate. The assembled battery was allowed to stand at 25°C for 5 hours before the electrochemical performance test was performed. In the experiment, the battery charge and discharge performance test was performed on a blue electric system with a test voltage of 2.0 to 3.9V. The test items were the battery's charge and discharge specific capacity, cycle performance, rate performance, etc. The battery's cyclic voltammetry test (CV) was performed on an electrochemical analyzer.

[0102] (1) Charge and discharge performance test

[0103] The test is mainly to obtain the battery's first charge and discharge, cycle stability and rate performance data. The test system used is the blue electric test system, the test conditions are 25℃, 2.0~3.9V, and the current density is 160mAh / g. Before the test, the assembled battery is left to stand at 25℃ for 5h before subsequent testing.

[0104] (2) Cyclic voltammetry (CV)

[0105] Cyclic voltammetry tests analyze the electrochemical performance of batteries by studying the redox process occurring on the electrodes. The test instrument used is Shanghai Chenhua CHI electrochemical analyzer, and the test conditions are: test temperature is room temperature, test voltage is 2.5~4V, and scan rate is 0.2mV / s.

[0106] from Figure 3 From the battery capacity test curve, when the rate increases from a small rate, the discharge capacity slightly decays, and when the rate returns to the initial rate from a large rate, the discharge capacity returns to the initial state, indicating that the battery capacity is good and relatively stable. Figure 3 Medium and commercial carbon black ( Figure 3 The carbon black prepared by the present invention ( Figure 3 The red curve in the middle) has a higher battery capacity.

[0107] from Figure 4 It can be seen that the charge and discharge voltage platform stability of the prepared conductive carbon black is very good. Therefore, the method and system of the present invention can be used to prepare conductive carbon black.

[0108] Comparative Example 1

[0109] This comparative example uses the same system, reactor, raw materials and reaction conditions as Example 1 to carry out the cracking reaction. The only difference from Example 1 is that: (1) the reaction time is 20 milliseconds; (2) the rapid cooling rate of the reaction product is 50°C / millisecond, and the temperature is reduced to about 450°C. The gas product yield is 22.35%, and the carbon black yield is 73.08%. The carbon black obtained by this comparative example is subjected to electrochemical testing. The results are as follows: Figure 5 shown.

[0110] Depend on Figure 5 It can be seen that when the rate increases from 0.1C to 2C, the discharge specific capacity has a significant decay. At a high rate of 2C, the capacity decay is large and the performance is poor. When the rate returns from 2C to 0.1C, the discharge specific capacity cannot return to the initial state, indicating that the carbon black prepared by this method has poor charge and discharge stability.

[0111] Figure 6The following is the charge and discharge specific capacity performance diagram at 0.1C, 0.5C, 1C, and 2C, and the test voltage is 2.0 to 3.9V. Figure 6 It can be obtained that the material has a high discharge capacity at a low rate of 0.1C, which can reach more than 150mAh / g. When the rate is gradually increased to 0.5C, 1C, and 2C, the discharge capacity is significantly attenuated, and the polarization degree of the material is large, which is not conducive to the long-term cycle of the battery. Therefore, it is not suitable for application in the preparation of battery materials. In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connected", and "connected" should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0112] The present application has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, various replacements and improvements may be made to the present application, all of which fall within the scope of protection of the present application.

Claims

1. A method for producing conductive carbon black, comprising: (1) heating a cracking reactor to a reaction temperature under an inert oxygen-free atmosphere, introducing a cracking raw material and a carrier gas into the cracking reactor for a cracking reaction, and obtaining a cracking product comprising conductive carbon black and a gas product; (2) After the cracking product is cooled by a quenching medium, it is separated by a gas-solid separator to obtain conductive carbon black, and the gas after the gas-solid separation is filtered and collected in a gas collector to obtain a gas product; Wherein, the reaction temperature of the cracking reactor is 800-3000°C, preferably 1000-1500°C; The reaction time is 20 milliseconds to 10 seconds, preferably 40 milliseconds to 2 seconds; The rapid cooling rate of the pyrolysis product is 50-1000°C / millisecond, preferably 50-500°C / millisecond; and / or The temperature of the pyrolysis product after cooling is 100-900°C, preferably 200-500°C.

2. The method according to claim 1, characterized in that The cracking feedstock is low-quality oil and / or low-value catalytic cracking products; and / or The carrier gas is selected from one or more of the following: nitrogen, helium, argon, methane and C2-C4 light hydrocarbons; Preferably, the inferior oil is selected from one or more of vacuum residue, coal tar and solvent deasphalted oil; and / or the catalytic cracking low-value product is selected from one or more of catalytic cracking slurry, catalytic cracking diesel and catalytic cracking recycled oil.

3. The method according to claim 1, characterized in that The feed ratio per unit time of the carrier gas to the cracking raw material is 0.1-20 liters / gram, preferably 0.5-10 liters / gram.

4. The method according to claim 1, characterized in that: The cracking raw material and carrier gas enter the cracking reactor after being preheated; Preferably, the preheating temperature of the cracking feedstock is 200-600°C, more preferably 200-500°C; and / or the preheating temperature of the carrier gas is 500-2500°C, more preferably 800-2000°C.

5. The method according to claim 1, characterized in that The quenching medium is selected from one or more of the following: water, nitrogen, argon, preferably liquid nitrogen.

6. A system for producing conductive carbon black, comprising: Feed unit, comprising: A first preheating furnace, used for preheating the carrier gas; The second preheating furnace is used to preheat the cracking raw materials; A reaction unit comprising: The cracking reactor is a tubular reactor horizontally arranged along the axial direction, and is provided with a raw material inlet and a cracking product outlet. The carrier gas preheated by the first preheating furnace of the reaction unit and the cracking raw material preheated by the second preheating furnace enter the cracking reactor through the raw material inlet for cracking reaction; A high-frequency electric induction heating device, comprising an electromagnetic induction coil sleeved on the periphery of the cracking reactor, for heating the cracking reactor; The product separation and collection unit comprises: A gas-solid separator, which is provided with a cracking product inlet, a gas outlet and one or more quenching medium inlets, wherein the cracking product inlet is connected to the cracking product outlet of the cracking reactor of the reaction unit, and the quenching medium inlet is arranged upstream of the gas-solid reactor; A filter, used for filtering the gas separated by the gas-solid separator; A gas collector is used to collect the gas products filtered by the filter.

7. The system according to claim 6, characterized in that The material of the cracking reactor is selected from one or more of the following: tungsten, molybdenum, tantalum, niobium, vanadium, chromium, titanium, zirconium, rare earth metal borides, rare earth metal carbides, rare earth metal nitrides, rare earth metal silicides, rare earth metal phosphides and rare earth metal sulfides; The rare earth metal is selected from one or more of lanthanum, cerium, praseodymium and neodymium.

8. The system according to claim 6, characterized in that The cracking reactor comprises a first diameter expansion section, a reaction section and a second diameter expansion section. The inner diameters of the first diameter expansion section and the second diameter expansion section are larger than the inner diameter of the reaction section. The electromagnetic induction coil is sleeved on the outer circumference of the reaction section.

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