A method for preparing high-purity nano carbon black

Abstract

The invention discloses a method for preparing high-purity nano carbon black, comprising: installing a high-purity nano carbon black preparation reaction device, evacuating the reaction device, introducing an inert gas to normal pressure, and evacuating the reaction device again; starting and operating a plasma generator to a rated operating power condition, operating the plasma generator to allow a high-temperature cracking reactor to reach a rated temperature; n H m The gaseous substance is introduced into the high-temperature cracking reactor; the gas-solid mixture generated in the high-temperature cracking reactor is transported to the heat exchanger through a pipeline for cooling; the cooled gas-solid mixture is introduced into the gas-solid separation device, and the tail gas enters the gas separation device after passing through the gas-solid separation device; the tail gas enters the gas separation device to separate hydrogen from other gases, recovers and collects the hydrogen, and recycles the inert gas. The present invention realizes the automated, continuous, and large-scale preparation of high-purity nano carbon black with uniform particle size, and has the advantages of continuous control and automated mass production.

Description

Technical Field

[0001] The invention belongs to the technical field of nano material preparation, and in particular relates to a method for preparing high-purity nano-grade carbon black. Background Art

[0002] Carbon black, also known as carbon black, is a light, loose and extremely fine black powder with a very large specific surface area. It is the product of incomplete combustion or thermal decomposition of carbon-containing substances (coal, natural gas, fuel oil, etc.) under insufficient air conditions. The main component of carbon black is carbon. It is the earliest nanomaterial developed and applied by humans.

[0003] Carbon black can be divided into pigment carbon black, rubber carbon black and conductive carbon black according to its use. They are widely used in many industrial fields such as rubber, ink, coating, plastic, electronic components, etc., and are one of the most important industrial raw materials in people's life and production today. They are widely used in rubber, especially the tire industry, anti-aging and antistatic of plastic products, lithium battery negative electrode materials, catalyst carriers, printing and dyeing, and biosensors. At present, the carbon black production processes in the world mainly include incomplete combustion and thermal cracking. These traditional chemical processes, while preparing carbon black, also cause a large amount of solid, liquid and gas "three wastes" emissions, waste of resources and unnecessary consumption of energy, which undoubtedly brings more burdens to the increasingly severe environmental problems, resource problems and energy problems.

[0004] At present, the demand for carbon black in my country is growing steadily year by year. As a major producer of carbon black, the traditional carbon black production process has low thermal efficiency and contains a large amount of NO x The carbon black yield is low. Therefore, it is urgent to actively explore new, green, efficient and environmentally friendly carbon black production and preparation processes, so as to contribute to the country's energy conservation and environmental protection, carbon reduction and nitrogen reduction. The plasma method for producing nano carbon black is environmentally friendly, can effectively utilize raw materials, has a high yield of hydrocarbons converted into carbon black, and the carbon utilization rate is close to 100%. The generated carbon black has the characteristics of high purity and uniform particle size, and eliminates CO2 and NO generated by combustion. x emission. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide a method for preparing high-purity nano-scale carbon black, to realize a pollution-free material preparation process, and to efficiently and quickly improve the reaction process, to realize large-scale preparation of high-purity, uniformly sized high-purity nano-carbon black, and to have the advantages of continuous control and automated mass production.

[0006] The technical solution adopted by the present invention is: a method for preparing high-purity nano carbon black, characterized by comprising:

[0007] Installing a high-purity nano-carbon black preparation reaction device, evacuating the high-purity nano-carbon black preparation reaction device, introducing an inert gas to normal pressure, and evacuating the device again;

[0008] Starting and operating the plasma generator to a rated operating power condition, and operating the plasma generator to make the high-temperature cracking reactor reach a rated temperature;

[0009] C n H m Gas substances are used as raw materials to convert C n H m The gaseous substance is introduced into the plasma core region formed in the high-temperature cracking reactor, and the gas phase substance undergoes cracking reaction in the core region to generate a gas-solid mixture; wherein the gas-solid mixture includes carbon vapor, carbon particles and hydrogen;

[0010] The gas-solid mixture generated in the high-temperature cracking reactor is transported to a heat exchanger through a pipeline for cooling, and the temperature is reduced to below a set temperature value;

[0011] The gas-solid mixture after cooling is passed into the gas-solid separation device, in which the nano carbon black particles are captured, and the tail gas passes through the gas-solid separation device and then enters the gas separation device;

[0012] The tail gas enters the gas separation device to separate hydrogen from other gases, recover and collect the hydrogen, and circulate the inert gas into the high-temperature cracking reactor and the plasma generator.

[0013] Furthermore, the high-purity nano-carbon black preparation reaction device includes a raw material tank, an inert gas supply system, a high-temperature cracking reactor, a plasma generator, a heat exchanger, a gas-solid separation device and a gas separation device, a vacuum pump and a pipeline;

[0014] Fill the raw material tank with C n H m The raw material tank is connected to the high-temperature cracking reactor; the inert gas supply system is respectively connected to the plasma generator and the high-temperature cracking reactor, the plasma generator is connected to the high-temperature cracking reactor, the high-temperature cracking reactor is connected to the heat exchanger, the heat exchanger is connected to the gas-solid separation device, the gas-solid separation device is respectively connected to the gas separation device and the vacuum pump, and the gas outlet of the gas separation device is connected back to the plasma generator through a pipeline.

[0015] Furthermore, the inert gas is any single inert gas selected from He, Ne, and Ar, or a mixture thereof.

[0016] Furthermore, after the high-purity nano-carbon black preparation reaction device is evacuated, an inert gas is introduced to normal pressure, and the process of evacuating again is repeated three times or more, wherein the high-purity nano-carbon black preparation reaction device is evacuated to ≤0.001Pa, an inert gas is introduced to normal pressure, and then evacuated to ≤0.001Pa.

[0017] Furthermore, the high temperature cracking reactor uses an electrode-free non-contact radio frequency plasma generator or a DC or AC arc plasma generator with a pure graphite electrode structure as a heating source.

[0018] Furthermore, the plasma generator uses any single inert gas among He, Ne, Ar or a mixture thereof as the working medium gas, and does not use N2 or a mixed gas doped with N2 as the working medium gas.

[0019] Furthermore, the starting and operating the plasma generator to a preset rated operating power condition includes:

[0020] Start the plasma generator and adjust the operating power to less than 50% of the rated operating power for a running time of t1;

[0021] Adjust the operating power of the plasma generator to the rated operating power.

[0022] Furthermore, the C n H m The purity of the gas-like substance is greater than 99.9% by mass.

[0023] Furthermore, the gas-solid separation device includes a cyclone separation device with a water cooling kit and a bag-type separation device; the cyclone separation device is installed after the heat exchanger, and the bag-type separation device is installed after the cyclone separation device.

[0024] Furthermore, the gas separation device adopts a pressure swing adsorption device.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention uses an electrodeless non-contact radio frequency plasma generator or a DC or AC arc plasma generator with a pure graphite electrode structure as a reactor heating source, which can effectively control the reaction atmosphere, and the C in the reaction gas during the preparation of nano carbon black n H mThe material undergoes an extremely fast heating process, so the reaction gas molecules are quickly decomposed into single atoms by the high energy density plasma energy, and finally re-bonded to form nano carbon black. In the whole process, except for the generation of carbon element, hydrogen and the inert gas of the plasma working medium, no other substances are generated, so the prepared nano silicon has a very high purity, which can reach more than 99.999%;

[0027] (2) The present invention realizes a pollution-free material preparation process, and can efficiently and quickly improve the reaction process, realize large-scale preparation of high-purity, uniform-sized, high-purity nano-carbon black, and has the advantages of continuous control and automated mass production;

[0028] (3) The present invention realizes the recycling of inert gas. Compared with the traditional furnace method for preparing carbon black, it not only saves energy in the system, but also reduces NO x And CO2 and other emissions, the carbon conversion rate is very high. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0030] Figure 1 It is a flow chart of a method for preparing high-purity nano carbon black provided in an embodiment of the present invention.

[0031] Figure 2 This is a structural block diagram of the reaction device for preparing high-purity nano-carbon black in the present invention. DETAILED DESCRIPTION

[0032] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] Figure 1 Flow chart of the method for preparing high-purity nano carbon black provided by the embodiment of the present invention. Figure 1 As shown, the method comprises the following steps:

[0034] (1) The entire high-purity nano-carbon black preparation reaction device is evacuated to ≤0.001Pa, and then an inert gas is introduced to normal pressure and then evacuated to ≤0.001Pa. The whole process is repeated three times or more; the inert gas is a single inert gas such as He, Ne or Ar or a mixture thereof.

[0035] like Figure 2 As shown, the high-purity nano-carbon black preparation reaction device includes a raw material tank, an inert gas supply system, a high-temperature cracking reactor, a plasma generator, a heat exchanger, a gas-solid separation device and a gas separation device, a vacuum pump and a pipeline;

[0036] Fill the raw material tank with C n H m The raw material tank is connected to the high-temperature cracking reactor; the inert gas supply system is respectively connected to the plasma generator and the high-temperature cracking reactor, the plasma generator is connected to the high-temperature cracking reactor, the high-temperature cracking reactor is connected to the heat exchanger, the heat exchanger is connected to the gas-solid separation device, the gas-solid separation device is respectively connected to the gas separation device and the vacuum pump, and the gas outlet of the gas separation device is connected back to the plasma generator through a pipeline.

[0037] (2) starting and operating the plasma generator to a preset rated power condition, running it for a period of time and allowing the high-temperature cracking reactor to reach a preset rated temperature;

[0038] (3) C n H m The gaseous substances are used as raw materials and introduced into the plasma core area formed in the high-temperature cracking reactor. The gas phase substances undergo cracking reactions in the core area to generate a gas-solid mixture. The gas-solid mixture includes carbon vapor, carbon particles and hydrogen.

[0039] (4) transporting the gas-solid mixture generated in the high-temperature cracking reactor to a heat exchanger through gas ejection for forced cooling to below 150° C.;

[0040] (5) The gas-solid mixture after cooling enters the gas-solid separation device, in which the nano carbon black particles are captured, and the tail gas passes through the gas-solid separation device and enters the gas separation device;

[0041] (6) The tail gas enters the gas separation device to separate hydrogen from other gases, the hydrogen is recovered and collected, and the inert gas is circulated into the high-temperature cracking reactor and the plasma generator to participate in the operation of the entire reactor.

[0042] In step (2), the high temperature cracking reactor uses an electrodeless non-contact radio frequency plasma generator or a DC or AC arc plasma generator with a pure graphite electrode structure as a heating source.

[0043] In step (2), the plasma generator uses a single inert gas such as He, Ne or Ar or a mixture thereof as the working medium gas, and avoids using N2 or a mixed gas doped with N2 as the working medium gas.

[0044] Step (2) is divided into two stages in two sequential orders. First, the plasma generator is started and the operating power is adjusted to less than 50% of the rated operating power required for the system carbon black production process. It is operated at this power for a period of time, firstly, to further remove the impurities in the reactor, and secondly, to gradually increase the temperature in the high-temperature cracking reactor to the rated operating temperature; then, in the second step, the operating power of the plasma generator is adjusted to the rated operating power required for the system carbon black preparation process.

[0045] The C n H m The purity of the gaseous substance should be greater than 99.9% by mass, and after reaching the rated temperature in the high-temperature cracking reactor in step (2), it is transported to the core area where plasma is formed in the high-temperature cracking reactor.

[0046] The gas-solid separation device includes a cyclone separation device with a water cooling kit and a bag separation device. The cyclone separation device is installed after the heat exchanger, and the bag separation device is installed after the cyclone separation device. Among them, the cyclone diversion device can not only collect a part of the nano-scale carbon black, but also further cool the gas-solid mixture to below 50°C, which plays a further cooling role. The gas separation device adopts a pressure swing adsorption device.

[0047] The invention comprises three steps of collecting nano carbon black, namely: using the strong adsorption of nano carbon black to attach to the solid surface, gas-solid two-phase flow cyclone separation and physical interception such as cloth bags, and the powder collection rate reaches more than 99.9%.

[0048] The present invention realizes a pollution-free material preparation process, and can efficiently and quickly improve the reaction process, thereby realizing large-scale preparation of high-purity nano carbon black with uniform particle size, and has the advantages of continuous control and automated mass production.

[0049] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing high-purity nano carbon black, characterized in that: include: Installing a high-purity nano-carbon black preparation reaction device, evacuating the high-purity nano-carbon black preparation reaction device, introducing an inert gas to normal pressure, and evacuating the device again; Starting and operating the plasma generator to a rated operating power condition, and operating the plasma generator to make the high-temperature cracking reactor reach a rated temperature; C n H m Gas substances are used as raw materials to convert C n H m The gaseous substance is introduced into the plasma core region formed in the high-temperature cracking reactor, and the gas phase substance undergoes cracking reaction in the core region to generate a gas-solid mixture; wherein the gas-solid mixture includes carbon vapor, carbon particles and hydrogen; The gas-solid mixture generated in the high-temperature cracking reactor is transported to a heat exchanger through a pipeline for cooling, and the temperature is reduced to below a set temperature value; The gas-solid mixture after cooling is passed into a gas-solid separation device, in which the nano carbon black particles are captured, and the tail gas passes through the gas-solid separation device and then enters the gas separation device; The tail gas enters the gas separation device to separate hydrogen from other gases, recover and collect the hydrogen, and circulate the inert gas into the high-temperature cracking reactor and the plasma generator; The plasma generator uses any single inert gas among He, Ne, Ar or a mixture thereof as the working medium gas, and does not use N2 or a mixed gas doped with N2 as the working medium gas; The starting and operating of the plasma generator to a preset rated operating power condition comprises: Start the plasma generator and adjust the operating power to less than 50% of the rated operating power for a running time of t1; Adjust the operating power of the plasma generator to the rated operating power.

2. A method for preparing high-purity nano carbon black according to claim 1, characterized in that: The high-purity nano-carbon black preparation reaction device comprises a raw material tank, an inert gas supply system, a high-temperature cracking reactor, a plasma generator, a heat exchanger, a gas-solid separation device and a gas separation device, a vacuum pump and a pipeline; Fill the raw material tank with C n H m The raw material tank is connected to the high-temperature cracking reactor; the inert gas supply system is respectively connected to the plasma generator and the high-temperature cracking reactor, the plasma generator is connected to the high-temperature cracking reactor, the high-temperature cracking reactor is connected to the heat exchanger, the heat exchanger is connected to the gas-solid separation device, the gas-solid separation device is respectively connected to the gas separation device and the vacuum pump, and the gas outlet of the gas separation device is connected back to the plasma generator through a pipeline.

3. A method for preparing high-purity nano carbon black according to claim 1, characterized in that: The inert gas is any single inert gas of He, Ne, Ar or a mixture thereof.

4. A method for preparing high-purity nano carbon black according to claim 1, characterized in that: After the high-purity nano-carbon black preparation reaction device is evacuated, an inert gas is introduced to normal pressure, and the process of evacuating again is repeated three times or more, wherein the high-purity nano-carbon black preparation reaction device is evacuated to ≤0.001Pa, an inert gas is introduced to normal pressure, and then evacuated to ≤0.001Pa.

5. A method for preparing high-purity nano carbon black according to claim 1, characterized in that: The high temperature cracking reactor adopts an electrode-free non-contact radio frequency plasma generator or a DC or AC arc plasma generator with a pure graphite electrode structure as a heating source.

6. A method for preparing high-purity nano carbon black according to claim 1, characterized in that: The C n H m The purity of the gas-like substance is greater than 99.9% by mass.

7. A method for preparing high-purity nano carbon black according to claim 1, characterized in that: The gas-solid separation device comprises a cyclone separation device with a water cooling kit and a bag-type separation device; the cyclone separation device is installed after the heat exchanger, and the bag-type separation device is installed after the cyclone separation device.

8. A method for preparing high-purity nano carbon black according to claim 1, characterized in that: The gas separation device adopts a pressure swing adsorption device.

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