Carbon black preparation system and method

Abstract

The invention relates to the technical field of carbon black preparation, in particular to a carbon black preparation system and method.The carbon black preparation system comprises a reaction furnace with a product outlet; the plasma generator is arranged on the reaction furnace, and the plasma generator is provided with a bearing gas inlet; the carbon black collecting device is connected to the product outlet and is used for carrying out gas-solid separation on the product and collecting carbon black in the product, and the carbon black collecting device is provided with a gas outlet for discharging gas subjected to gas-solid separation; the hydrogen collecting device is connected to the gas outlet and used for separating the gas into hydrogen and tail gas, and the hydrogen collecting device is provided with a first tail gas outlet; the gas-solid separation assembly is connected to the first tail gas outlet and used for conducting gas-solid separation on the tail gas to form regenerated tail gas, the gas-solid separation assembly is provided with a second tail gas outlet, the second tail gas outlet is connected with the bearing gas inlet, and the regenerated tail gas serves as the bearing gas of the plasma generator. Tail gas is recycled and used as bearing gas, and the using amount of the bearing gas is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon black preparation, in particular to a carbon black preparation system and method. Background Art

[0002] Carbon black is a widely used functional material. At present, the main method for producing carbon black is the furnace method (including the oil furnace method and the gas furnace method). Due to the quality of the raw gas (oil) and the structure and materials of the reactor under high temperature conditions, the yield of carbon black prepared by the furnace method is relatively low. Generally speaking, only 40-60% of the carbon element in the raw gas (oil) is converted into carbon black, and the remaining carbon exists in the flue gas in the form of CO / CO2, causing great energy waste and increasing carbon emissions. In addition, for every ton of furnace carbon black produced, 8,000 to 10,000 Nm 3 Carbon black flue gas, because the furnace carbon black is heated by combustion, the carbon black flue gas inevitably contains pollutants SO2 and NO x , these pollutants have a great impact on the environment.

[0003] In order to avoid the generation of the above-mentioned pollutants, in recent years, the plasma method has begun to be used to heat the reactor. The plasma method uses hydrogen, CH gas (such as natural gas) or inert gases including helium, nitrogen, argon, etc. as carrier gases. The carrier gas is ionized into an electronic state by a plasma generator, and generates heat to heat the reactor to reach the temperature required for the cracking of the raw gas (oil). The raw hydrocarbon (including gaseous hydrocarbon, liquid hydrocarbon or solid hydrocarbon) is introduced into the reactor, thereby cracking to generate carbon black and hydrogen (if the cracking is incomplete, it will contain some CH gas). After rapid cooling, the carbon black and hydrogen are separated and recovered, and the excess gas is directly discharged.

[0004] Theoretically, by using the plasma method to prepare carbon black, all the carbon elements in the raw hydrocarbon can be converted into carbon black, and because the cracking occurs in an anaerobic state (there is no oxygen element in the carrier gas), no harmful gases such as CO, CO2, SO2, NO and NO2 will be produced, which indirectly improves the quality of carbon black and the purity of hydrogen.

[0005] However, on the one hand, the plasma method requires a large amount of carrier gas to maintain the temperature in the reactor; on the other hand, the plasma method still produces a large amount of tail gas, which is usually discharged directly into the atmosphere through a venting chimney, which is not conducive to environmental protection. Summary of the invention

[0006] The purpose of the present invention is to provide a carbon black preparation system and method, to recycle tail gas, so that the recovered tail gas can be used as a carrier gas, thereby reducing the amount of the original carrier gas.

[0007] To achieve the above objectives, in a first aspect, a carbon black preparation system is provided, comprising:

[0008] A reaction furnace having a raw material inlet and a product outlet;

[0009] A plasma generator, arranged on the reaction furnace, used to make the reaction furnace generate a temperature required for raw material reaction, and the plasma generator has a carrier gas inlet for carrier gas to enter;

[0010] A carbon black collecting device, connected to the product outlet, for performing gas-solid separation on the product and collecting carbon black in the product, the carbon black collecting device having a gas outlet for discharging gas after gas-solid separation;

[0011] A hydrogen collecting device, connected to the gas outlet, for separating the gas into hydrogen and tail gas, wherein the hydrogen collecting device has a first tail gas outlet;

[0012] The carbon black preparation system also includes:

[0013] A gas-solid separation component is connected to the first exhaust gas outlet, and is used to perform gas-solid separation on the exhaust gas to form regenerated exhaust gas. The gas-solid separation component has a second exhaust gas outlet for discharging the regenerated exhaust gas. The second exhaust gas outlet is connected to the carrier gas inlet, so that the regenerated exhaust gas serves as at least part of the carrier gas of the plasma generator.

[0014] In certain embodiments, the carbon black preparation system further comprises:

[0015] A buffer tank comprises a storage chamber and a regeneration exhaust gas inlet and a carrier gas outlet which are connected to the storage chamber. The regeneration exhaust gas inlet is connected to the second exhaust gas outlet to allow the regeneration exhaust gas to enter the storage chamber. The carrier gas outlet is connected to the carrier gas inlet to transport the carrier gas in the storage chamber to the carrier gas inlet.

[0016] In some embodiments, the gas pressure of the storage chamber of the buffer tank is 0.3-0.4 MPa.

[0017] In some embodiments, a pressurizing component is provided between the second exhaust gas outlet and the carrier gas inlet for pressurizing the regenerated exhaust gas so that the pressure of the regenerated exhaust gas is adapted to the pressure of the storage chamber of the buffer tank.

[0018] In some embodiments, the buffer tank also has an original carrier gas inlet connected to the storage cavity, and the original carrier gas inlet is used to allow the original carrier gas to enter the storage cavity. The carrier gas in the storage cavity is the original carrier gas, or the regenerated tail gas, or a mixture of the original carrier gas and the regenerated tail gas.

[0019] In some embodiments, a fourth connecting pipe is provided on the second exhaust gas outlet, and a first valve for controlling the opening and closing of the fourth connecting pipe is provided on the fourth connecting pipe. The purpose of providing the fourth connecting pipe and the first valve is to adjust the gas balance of the system.

[0020] In certain embodiments, a fifth connecting pipe is provided between the gas outlet of the carbon black collection device and the gas-solid separation component, and a second valve for controlling the opening and closing of the fifth connecting pipe is provided on the fifth connecting pipe.

[0021] In a second aspect, a method for preparing carbon black is provided, comprising the steps of:

[0022] The plasma generator generates the temperature required for the raw material reaction in the reactor;

[0023] The raw material enters the reactor from the raw material inlet of the reactor and is cracked to form a product, which is then discharged from the product outlet of the reactor;

[0024] The carbon black collecting device performs gas-solid separation on the product and collects the carbon black in the product, and the gas after gas-solid separation is discharged from the gas outlet of the carbon black collecting device;

[0025] The hydrogen collecting device separates hydrogen from the gas discharged from the gas outlet, and discharges the tail gas from the first tail gas outlet of the hydrogen collecting device;

[0026] The carbon black preparation method also includes:

[0027] The gas-solid separation component performs gas-solid separation on the tail gas discharged from the first tail gas outlet to obtain regenerated tail gas, and transports the regenerated tail gas to the carrier gas inlet of the plasma generator.

[0028] In some embodiments, the regenerated tail gas first enters the storage chamber of the buffer tank and then enters the carrier gas inlet.

[0029] In some embodiments, the regenerated tail gas is mixed with the original carrier gas in the storage chamber of the buffer tank and then enters the carrier gas inlet, or the regenerated tail gas directly passes through the storage chamber of the buffer tank and enters the carrier gas inlet.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: the reactor is heated by a plasma generator so that the raw materials are cracked in an oxygen-free state, ensuring that the main component of the tail gas is a mixture of H2 and CH. After the tail gas is treated by the tail gas treatment device, it can be mixed with the original carrier gas in a buffer tank and used as the carrier gas of the plasma generator, which not only reduces the amount of the original carrier gas, but also allows the tail gas to be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1A schematic diagram of a carbon black preparation system provided in an embodiment of the present invention.

[0032] In the figure: 1. Reactor; 2. Plasma generator; 3. Cooling device; 4. Carbon black collecting device; 41. First connecting pipe; 42. Second connecting pipe; 43. Fifth connecting pipe; 44. Second valve; 5. Hydrogen collecting device; 6. Tail gas treatment device; 61. Gas-solid separation component; 62. Pressurizing component; 63. Third connecting pipe; 64. Fourth connecting pipe; 65. First valve; 7. Buffer tank. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It is also necessary to explain that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all.

[0034] Some directional words are defined in the present invention. Unless otherwise specified, the directional words used, such as "up", "down", "left", "right", "inside" and "outside", are used to facilitate understanding and therefore do not constitute a limitation on the scope of protection of the present invention.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Figure 1 Schematic diagram of a carbon black preparation system provided by an embodiment of the present invention is shown. Figure 1The carbon black preparation system includes a reactor 1 having a reaction chamber, and a plasma generator 2 disposed in the reactor 1 for heating the reaction chamber. The reactor 1 is also provided with a raw material inlet connected to the reaction chamber for raw materials to enter the reaction chamber, and a product outlet connected to the reaction chamber for products to be discharged. A cooling component for cooling the plasma generator 2 is disposed on the periphery of the plasma generator 2, and the cooling medium used by the cooling component is preferably soft water.

[0038] It should be noted that the raw material can be raw gas or raw oil. If it is raw oil, it is best to atomize it before the reaction so that it can be cracked completely. Whether it is raw gas or raw oil, the main components are hydrocarbon substances composed of carbon and hydrogen elements. Hydrocarbon substances will crack at high temperatures to form carbon black and hydrogen. Taking methane as an example, the cracking reaction is as follows:

[0039]

[0040] Of course, in reality the cracking cannot be complete, so the cracking products include, in addition to carbon black and hydrogen, a small amount of uncracked hydrocarbons and a small amount of impurities (depending on the purity of the hydrocarbons).

[0041] When preparing carbon black, first, the plasma generator 2 is powered on so that the plasma generator 2 forms a plasma torch in the reaction chamber of the reactor 1, and the reaction chamber is heated to a temperature at which the raw materials can be cracked; then, the raw materials enter the reaction chamber from the raw material inlet of the reactor 1, and are cracked in a high temperature environment to form products; finally, the products are discharged from the product outlet of the reactor 1.

[0042] like Figure 1 As shown, since the product discharged from the product outlet is high-temperature flue gas mixed with carbon black, in order to collect the carbon black in the product, the high-temperature flue gas needs to be cooled first, so a cooling device 3 is connected to the product outlet, and the cooling device 3 is used to cool the product. Preferably, the temperature of the product after cooling by the cooling device 3 is 200-280°C. The cooling device 3 can be a cooling screw conveyor.

[0043] like Figure 1 As shown, the outlet of the cooling device 3 is connected to a blower, and a carbon black collecting device 4 is arranged in the air supply direction of the blower. The carbon black collecting device 4 is used to perform gas-solid separation on the product, thereby separating the carbon black in the product, and transporting the carbon black to the carbon black storage tank by mechanical transportation. The carbon black transporting device also has a gas outlet for discharging the gas after gas-solid separation. As an example, the carbon black collecting device 4 can be a cyclone separator or a bag dust collector.

[0044] As mentioned above, there are a small amount of uncracked hydrocarbons in the product. Therefore, after gas-solid separation, the gas can be sent back to the reactor 1 to crack the uncracked hydrocarbons. At the same time, the gas sent back to the reaction chamber can also balance the pressure of the entire carbon black preparation system.

[0045] Specifically, Figure 1 As shown, a first connecting pipe 41 is connected to the gas outlet of the carbon black collecting device 4 , and the other end of the first connecting pipe 41 is connected to the reaction chamber, so that the gas discharged from the gas outlet can flow back into the reaction chamber along the first connecting pipe 41 .

[0046] like Figure 1 As shown, although part of the gas flows back into the reaction chamber through the first connecting pipe 41, most of the gas does not need to flow back, but goes to the hydrogen collecting device 5. Specifically, a second connecting pipe 42 is also provided on the gas outlet of the carbon black collecting device 4, and the other end of the second connecting pipe 42 is connected to the hydrogen collecting device 5. The hydrogen collecting device 5 is used to separate the hydrogen in the gas to obtain high-purity hydrogen. The hydrogen collecting device 5 can be a pressure swing adsorption device.

[0047] However, as mentioned above, not all of the gas is hydrogen. Therefore, after the hydrogen is separated, some gas will remain. In addition, the carbon black collection device 4 cannot guarantee that all of the carbon black is collected. Carbon black with smaller particles will be discharged from the gas outlet of the carbon black collection device 4. In this embodiment, the gas remaining after the hydrogen is separated is called tail gas.

[0048] like Figure 1 As shown, the hydrogen collecting device 5 has a first exhaust gas outlet for discharging the exhaust gas. The first exhaust gas outlet is connected to an exhaust gas treatment device 6. The exhaust gas treatment device 6 is used to perform gas-solid separation on the exhaust gas, remove solid particles in the exhaust gas, and obtain pure exhaust gas containing only gas. The exhaust gas treatment device 6 has a second exhaust gas outlet for discharging the treated exhaust gas. In this embodiment, the exhaust gas treated by the exhaust gas treatment device 6 is referred to as regenerated exhaust gas.

[0049] like Figure 1 As shown, after the regenerated tail gas comes out from the second tail gas outlet, it enters the buffer tank 7, which is used to store the carrier gas required by the plasma generator 2. The carrier gas can be hydrogen, hydrocarbon substances or inert gases, preferably hydrogen and hydrocarbon substances. The regenerated tail gas can be mixed with the original carrier gas (a gas used to make the plasma generator 2 work in addition to the regenerated tail gas) to form a mixed gas, thereby reducing the amount of the original carrier gas. Therefore, in this embodiment, when the carbon black preparation system is just started, the original carrier gas needs to be used. Once a sufficient amount of regenerated tail gas enters the buffer tank 7, the amount of the original carrier gas can be gradually reduced, or even the original carrier gas can be stopped.

[0050] like Figure 1 As shown, the buffer tank 7 includes a storage chamber and an original carrier gas inlet, a regenerated tail gas inlet and a carrier gas outlet connected to the storage chamber. The original carrier gas inlet is used for the original carrier gas to enter the storage chamber, the regenerated tail gas inlet is used for the regenerated tail gas to enter the storage chamber, and the carrier gas outlet is connected to the plasma generator 2 to transport the carrier gas to the plasma generator 2. The gas pressure of the storage chamber is 0.3-0.4 MPa. In order to connect the tail gas treatment device 6 with the buffer tank 7, a third connecting pipe 63 is provided on the second tail gas outlet.

[0051] like Figure 1 As shown, the tail gas treatment device 6 includes a gas-solid separation component 61 and a pressurizing component 62. The gas-solid separation component 61 is used to separate the solid and gas in the tail gas and transport the gas to the pressurizing component 62. The pressurizing component 62 is used to pressurize the gas. Since the pressure of the tail gas is about 1000-1500 Pa, it needs to be pressurized to 0.3-0.4 MPa of the buffer tank 7. At the same time, when the gas passes through the gas-solid separation component 61, the temperature will also drop accordingly, usually to 20-35°C.

[0052] The gas-solid separation component 61 may be a liquid filter, the liquid being water, for example, and the solids in the tail gas are separated by passing the tail gas into the water.

[0053] The pressurizing component 62 can be a fluid mechanical structure such as a pump or a compressor that converts a low-pressure fluid into a high-pressure fluid. Specifically, a hydrogen compressor can be used.

[0054] like Figure 1 As shown, a fourth connecting pipe 64 is also provided on the second tail gas outlet, the outer end of the fourth connecting pipe 64 is connected to the atmosphere, and a first valve 65 for controlling the opening and closing of the fourth connecting pipe 64 is provided on the fourth connecting pipe 64. When the amount of regenerated tail gas is too much, the first valve 65 can be opened to discharge the regenerated tail gas outward. The purpose of setting the fourth connecting pipe 64 and the first valve 65 is to adjust the gas balance of the system.

[0055] like Figure 1 As shown, a fifth connecting pipe 43 is also provided on the gas outlet of the carbon black collecting device 4, and the other end of the fifth connecting pipe 43 is connected to the exhaust gas treatment device 6. The fifth connecting pipe 43 is provided with a second valve 44 for controlling the opening and closing of the fifth connecting pipe 43. When the amount of regenerated exhaust gas is too small, the second valve 44 can be opened so that the gas directly enters the exhaust gas treatment device 6, avoiding the hydrogen collecting device 5 from collecting hydrogen in the gas, thereby greatly increasing the amount of regenerated exhaust gas.

[0056] like Figure 1 As shown, the method for preparing carbon black using a carbon black preparation system comprises the following steps:

[0057] The plasma generator 2 generates the temperature required for the raw material reaction in the reaction furnace 1;

[0058] The raw material enters the reactor 1 from the raw material inlet of the reactor 1 and is cracked to form a product, which is then discharged from the product outlet of the reactor 1;

[0059] The product is cooled by cooling device 3, and the temperature drops to 200-280°C;

[0060] The carbon black collecting device 4 performs gas-solid separation on the cooled product and collects the carbon black in the product. The gas after gas-solid separation is discharged from the gas outlet of the carbon black collecting device 4. A part of the gas flows back into the reaction furnace 1, and a part of the gas flows into the hydrogen collecting device 5.

[0061] The hydrogen collecting device 5 separates the hydrogen in the gas and discharges the remaining tail gas from the first tail gas outlet of the hydrogen collecting device 5;

[0062] The tail gas treatment device 6 performs gas-solid separation on the tail gas discharged from the first tail gas outlet, and at the same time reduces the temperature of the tail gas to 20-35°C. The pressurizing component 62 pressurizes the tail gas to 0.3-0.4MPa to form regenerated tail gas, and the regenerated tail gas is first transported to the buffer tank 7, and finally enters the carrier gas inlet of the plasma generator 2;

[0063] As the amount of regenerated tail gas gradually increases, the amount of original carrier gas can be gradually reduced, or even stopped.

[0064] It can be seen that the carbon black preparation system of the present invention heats the reaction furnace 1 through the plasma generator 2, so that the raw material is cracked in an oxygen-free state, ensuring that the main component of the tail gas is a mixture of H2 and CH. After the tail gas is treated by the tail gas treatment device 6, it can be mixed with the original carrier gas in the buffer tank 7 and used as the carrier gas of the plasma generator 2, which not only reduces the amount of the original carrier gas, but also can reuse the tail gas. In addition, the amount of regenerated tail gas entering the buffer tank 7 can be controlled by the first valve 65 and the second valve 44.

[0065] The above is a description of the embodiments of the present invention. Through the above description of the disclosed embodiments, professionals and technicians in the field can implement or use the present invention. Various modifications to these embodiments will be apparent to professionals and technicians in the field. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will comply with the widest range consistent with the principles and novelties disclosed herein.

Claims

1. Carbon black preparation system, including: A reaction furnace (1) having a raw material inlet and a product outlet; A plasma generator (2) is arranged on the reaction furnace (1) and is used to make the reaction furnace (1) generate a temperature required for raw material reaction. The plasma generator (2) has a carrier gas inlet for the carrier gas to enter. A carbon black collecting device (4) connected to the product outlet, used for performing gas-solid separation on the product and collecting carbon black in the product, wherein the carbon black collecting device (4) has a gas outlet for discharging gas after gas-solid separation; A hydrogen collecting device (5), connected to the gas outlet, for separating the gas into hydrogen and tail gas, wherein the hydrogen collecting device (5) has a first tail gas outlet; Characterized in that the carbon black preparation system also includes: A gas-solid separation component (61) is connected to the first tail gas outlet and is used to perform gas-solid separation on the tail gas to form regenerated tail gas. The gas-solid separation component (61) has a second tail gas outlet for discharging the regenerated tail gas. The second tail gas outlet is connected to the carrier gas inlet so that the regenerated tail gas serves as at least part of the carrier gas of the plasma generator (2).

2. The carbon black preparation system according to claim 1, characterized in that: The carbon black preparation system also includes: A buffer tank (7) comprises a storage chamber and a regeneration exhaust gas inlet and a carrier gas outlet communicated with the storage chamber, wherein the regeneration exhaust gas inlet is connected to the second exhaust gas outlet for allowing the regeneration exhaust gas to enter the storage chamber, and the carrier gas outlet is connected to the carrier gas inlet for conveying the carrier gas in the storage chamber to the carrier gas inlet.

3. The carbon black preparation system according to claim 2, characterized in that: The gas pressure of the storage chamber of the buffer tank (7) is 0.3-0.4 MPa.

4. The carbon black preparation system according to claim 2 or 3, characterized in that: A pressurizing component (62) is provided between the second tail gas outlet and the carrier gas inlet, and is used to pressurize the regenerated tail gas so that the pressure of the regenerated tail gas is adapted to the pressure of the storage chamber of the buffer tank (7).

5. The carbon black preparation system according to claim 2 or 3, characterized in that: The buffer tank (7) also has an original carrier gas inlet connected to the storage chamber, and the original carrier gas inlet is used to allow the original carrier gas to enter the storage chamber. The carrier gas in the storage chamber is the original carrier gas, or the regenerated tail gas, or a mixture of the original carrier gas and the regenerated tail gas.

6. The carbon black preparation system according to claim 2, characterized in that: A fourth connecting pipe (64) is provided on the second exhaust gas outlet, and a first valve (65) for controlling the opening and closing of the fourth connecting pipe (64) is provided on the fourth connecting pipe (64).

7. The carbon black preparation system according to claim 1 or 6, characterized in that: A fifth connecting pipe (43) is provided between the gas outlet of the carbon black collection device (4) and the gas-solid separation component (61), and a second valve (44) for controlling the opening and closing of the fifth connecting pipe (43) is provided on the fifth connecting pipe (43).

8. A method for preparing carbon black, comprising the steps of: The plasma generator (2) generates the temperature required for the raw material reaction in the reaction furnace (1); The raw material enters the reaction furnace (1) from the raw material inlet of the reaction furnace (1), and is cracked to form a product, and the product is discharged from the product outlet of the reaction furnace (1); The carbon black collecting device (4) performs gas-solid separation on the product and collects the carbon black in the product, and the gas after the gas-solid separation is discharged from the gas outlet of the carbon black collecting device (4); The hydrogen collecting device (5) separates hydrogen from the gas discharged from the gas outlet, and discharges the tail gas from the first tail gas outlet of the hydrogen collecting device (5); Characterized in that the carbon black preparation method also includes: The gas-solid separation component (61) performs gas-solid separation on the tail gas discharged from the first tail gas outlet to obtain regenerated tail gas, and transports the regenerated tail gas to the carrier gas inlet of the plasma generator (2).

9. The method for preparing carbon black according to claim 8, characterized in that: The regenerated tail gas first enters the storage chamber of the buffer tank (7) and then enters the carrier gas inlet.

10. The method for preparing carbon black according to claim 9, characterized in that: The regenerated tail gas is mixed with the original carrier gas in the storage chamber of the buffer tank (7) and then enters the carrier gas inlet, or the regenerated tail gas directly passes through the storage chamber of the buffer tank (7) and enters the carrier gas inlet.

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