Process and apparatus for the production of activated coke

Abstract

The present application belongs to the technical field of active coke, and particularly relates to a preparation method and device of active coke. The preparation method of active coke provided in the present application embodiment comprises the following steps: (1) performing granulation treatment on coal powder and red mud to obtain solid particles; and (2) performing coke making on the solid particles prepared in step (1) to obtain active coke. The method not only realizes resource utilization of solid waste, but also reduces the preparation cost of active coke. The prepared active coke not only has the original physical adsorption capacity of hydrogen sulfide, but also has the chemical adsorption capacity of metal oxides. The physical adsorption and chemical adsorption are combined, so that the active coke has higher adsorption capacity.

Description

Technical Field

[0001] This invention belongs to the technical field of activated carbon, specifically relating to a method and apparatus for preparing activated carbon. Background Technology

[0002] Currently, most activated coke used in industrial applications is produced from coal. The sulfur in coal generates sulfur-containing gases such as hydrogen sulfide during carbonization and activation, which mix with the coke oven gas. Hydrogen sulfide is corrosive, adversely affecting the transportation of coke oven gas and posing a threat to human health. Furthermore, the combustion of coke oven gas produces gaseous pollutants such as sulfur dioxide, damaging the ecological environment.

[0003] Due to the continued increase in global demand for aluminum products, the production and stockpiling of red mud, an industrial solid waste generated during the extraction of Al2O3 in the aluminum industry, are constantly rising. Red mud is generally highly alkaline, with its leachate having a pH value above 10. Therefore, large-scale stockpiling can easily cause pollution of groundwater, rivers, and lakes, or lead to soil alkalization and soil contamination. Furthermore, the extremely small particle size of red mud can cause dust pollution when stored in the open. Summary of the Invention

[0004] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0005] Activated carbon, as an inexpensive, readily available, and reusable adsorbent material, is widely used in pollutant treatment, air purification, and water treatment. However, fresh activated carbon has poor adsorption and catalytic oxidation capabilities for hydrogen sulfide, necessitating alkali modification and metal oxide modification.

[0006] In existing activated coke preparation processes, activated coke modification mainly involves nitrate impregnation followed by high-temperature heating to modify metal oxides. This process has high production costs, and the heating decomposition process generates nitrogen oxides, which pollute the environment.

[0007] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a method for preparing activated carbon. This method not only utilizes solid waste resources but also reduces the preparation cost of activated carbon. The resulting activated carbon possesses not only the original ability to physically adsorb hydrogen sulfide but also the ability to chemically adsorb metal oxides, combining physical and chemical adsorption to give the activated carbon a higher adsorption capacity.

[0008] The method for preparing activated carbon according to an embodiment of the present invention includes the following steps:

[0009] (1) Powdered coal and red mud are granulated to obtain solid particles;

[0010] (2) The solid particles obtained in step (1) are coked to obtain activated coke.

[0011] The advantages and technical effects of the activated carbon preparation method of this invention are as follows: 1. The method of this invention uses industrial solid waste red mud as the source of metal oxides in the modification of activated carbon, which not only utilizes solid waste resources but also reduces the cost of modified activated carbon; 2. The method of this invention adds red mud during the activated carbon preparation process, which is beneficial to activated carbon formation and also enhances the particle strength of activated carbon; 3. The activated carbon prepared by the method of this invention not only has the original ability to physically adsorb hydrogen sulfide but also has the ability to chemically adsorb hydrogen sulfide by metal oxides, combining physical adsorption and chemical adsorption to give the prepared activated carbon a higher adsorption capacity.

[0012] In some embodiments, in step (1), the mass ratio of pulverized coal to red mud is 100:(1-20).

[0013] In some embodiments, in step (1), the pulverized coal includes at least one of anthracite, bituminous coal, and lignite.

[0014] In some embodiments, in step (2), the coking process is carried out at a temperature of 700–900°C for 2–8 hours.

[0015] In some embodiments, in step (2), the solid particles react with water vapor during the coking process.

[0016] In some embodiments, in step (2), the mass ratio of the water vapor to the solid particles is (2-6):1.

[0017] This invention also provides an apparatus for preparing activated coke, including a pulverized coal storage bin, a red mud storage bin, a forming device, and a coking oven;

[0018] The outlets of the pulverized coal storage silo and the red mud storage silo are respectively connected to the inlet of the molding device;

[0019] The forming device is used to granulate coal powder and red mud to obtain solid particles, and the outlet of the forming device is connected to the inlet of the coke oven.

[0020] The coking oven is used to produce coke from solid particles and water vapor.

[0021] In some embodiments, the coking oven includes an inner layer and an outer layer, the inner layer being used for coking with solid particles and water vapor, and the outer layer being used for introducing flue gas to provide heat for coking.

[0022] In some embodiments, the apparatus further includes a hydrogen sulfide removal chamber, a combustion chamber, and a steam generator;

[0023] The gas inlet of the hydrogen sulfide removal chamber is connected to the gas outlet of the coking oven, and is used to remove hydrogen sulfide from the pyrolysis gas generated in the coking oven; the gas outlet of the hydrogen sulfide removal chamber is connected to the gas inlet of the combustion chamber, so that the pyrolysis gas treated with hydrogen sulfide removal enters the combustion chamber and is burned to obtain flue gas.

[0024] The gas outlet of the combustion chamber is connected to the outer inlet of the coking oven and the heat source inlet of the steam generator, respectively, so that part of the flue gas enters the outer layer of the coking oven to provide heat for coking, and part of the flue gas enters the steam generator to generate steam.

[0025] The steam generator's steam outlet is connected to the inner steam inlet of the coking oven, allowing steam to enter the coking oven and react with solid particles to form coke.

[0026] In some embodiments, the apparatus further includes a cooling chamber connected to the activated coke outlet of the coking oven for cooling the activated coke, and the cooling water outlet of the cooling chamber is connected to the water inlet of the steam generator. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the device used in the embodiment;

[0028] Attached reference numerals: 1-Powdered coal storage bin, 2-Red mud storage bin, 3-Agitator, 4-Forming device, 5-Coking oven, 6-Cooling chamber, 7-Activated coke storage bin, 8-Hydrogen sulfide removal chamber, 9-Combustion chamber, 10-Steam generator. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] The method for preparing activated carbon according to an embodiment of the present invention includes the following steps:

[0031] (1) Powdered coal and red mud are granulated to obtain solid particles;

[0032] (2) The solid particles obtained in step (1) are coked to obtain activated coke.

[0033] The activated carbon preparation method of this invention uses industrial solid waste red mud as the source of metal oxides in the modification of activated carbon, which not only makes use of solid waste resources, but also reduces the cost of modified activated carbon. Adding red mud during the preparation of activated carbon is beneficial to the molding of activated carbon and also enhances the particle strength of activated carbon. The obtained activated carbon not only has the original ability to physically adsorb hydrogen sulfide, but also has the ability to chemically adsorb hydrogen sulfide by metal oxides. By combining physical adsorption and chemical adsorption, the obtained activated carbon has a higher adsorption capacity.

[0034] In some embodiments, preferably, in step (1), the mass ratio of coal powder to red mud is 100:(1-20). More preferably, in step (1), the coal powder includes at least one of anthracite, bituminous coal, and lignite. Even more preferably, before the granulation process, the coal powder and red mud are thoroughly mixed and ground.

[0035] In this embodiment of the invention, the preferred mass ratio of pulverized coal to red mud is selected. A suitable ratio can adjust the content of metal oxides in activated coke, which not only enables the activated coke to have better hydrogen sulfide adsorption performance, but also has a moderate strength.

[0036] In some embodiments, preferably, in step (2), the coking process is carried out at a temperature of 700–900°C for 2–8 hours.

[0037] In some embodiments, preferably, in step (2), the solid particles react with water vapor during the coking process. More preferably, in step (2), the mass ratio of water vapor to solid particles is (2-6):1. Even more preferably, the flow rate of the water vapor is 20-60 L / min.

[0038] In some embodiments, preferably, in step (2), the coking process is followed by cooling. More preferably, the cooling is carried out under a nitrogen atmosphere with a nitrogen flow rate of 20–60 L / min.

[0039] This invention also provides an apparatus for preparing activated coke, including a pulverized coal storage silo 1, a red mud storage silo 2, a molding device 4, and a coking oven 5;

[0040] The outlets of the pulverized coal storage silo 1 and the red mud storage silo 2 are respectively connected to the inlet of the forming device 4.

[0041] The forming device 4 is used to granulate coal powder and red mud to obtain solid particles. The outlet of the forming device 4 is connected to the inlet of the coke oven 5.

[0042] The coking oven 5 is used to produce coke from solid particles and water vapor.

[0043] In some embodiments, preferably, the coking oven 5 includes an inner layer and an outer layer, the inner layer being used for coking with solid particles and water vapor, and the outer layer being used for introducing flue gas to provide heat for coking.

[0044] In some embodiments, preferably, the apparatus further includes a hydrogen sulfide removal chamber 8, a combustion chamber 9, and a steam generator 10;

[0045] The gas inlet of the hydrogen sulfide removal chamber 8 is connected to the gas outlet of the coking oven 5, and is used to remove hydrogen sulfide from the pyrolysis gas generated in the coking oven 5; the gas outlet of the hydrogen sulfide removal chamber 8 is connected to the gas inlet of the combustion chamber 9, so that the pyrolysis gas treated with hydrogen sulfide removal enters the combustion chamber 9 and is burned to obtain flue gas.

[0046] The gas outlet of the combustion chamber 9 is connected to the outer layer inlet of the coking oven 5 and the heat source inlet of the steam generator 10, respectively, so that part of the flue gas enters the outer layer of the coking oven 5 to provide heat for coking, and part of the flue gas enters the steam generator 10 to generate steam.

[0047] The steam outlet of the steam generator 10 is connected to the inner steam inlet of the coking oven 5, so that the steam enters the coking oven 5 and reacts with the solid particles to form coke.

[0048] In some embodiments, preferably, the device further includes a cooling chamber 6 connected to the activated coke outlet of the coking oven 5 for cooling the activated coke, and the cooling water outlet of the cooling chamber 6 is connected to the water inlet of the steam generator 10.

[0049] Cooling water enters the cooling chamber 6 and undergoes heat exchange, reducing the temperature of the high-temperature activated coke before entering the steam generator 10 to generate steam. The steam then enters the coking oven 5 to react with the solid particles in the coking process.

[0050] The technical solution of the present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0051] Example 1

[0052] (1) First, grind the lignite and red mud to below 200 mesh. Then, feed the bituminous coal and red mud with a mass ratio of 100:10 (total amount of 100kg) into the mixer 3 through the feeder. After being fully mixed in the mixer 3, feed it into the molding device 4 for granulation to obtain columnar particles with a diameter of 0.5cm and a height of 1cm.

[0053] (2) The columnar particles are fed into the coking oven 5 by the feeder and reacted with water vapor at 800°C for 5 hours. The heating is stopped and then cooled to room temperature under nitrogen atmosphere. The activated coke is then sent to the activated coke storage silo 7 for storage. The flow rate of water vapor and nitrogen is 40 L / min, and both enter the oven body from below the coking oven 5. The mass ratio of water vapor to columnar particles is 5:1.

[0054] Example 2

[0055] (1) First, the bituminous coal and red mud are ground to less than 200 mesh. The bituminous coal and red mud with a mass ratio of 100:10 (total amount of 100kg) are fed into the mixer 3 by the feeder. After being fully mixed in the mixer 3, they are fed into the molding device 4 for granulation to obtain columnar particles with a diameter of 0.5cm and a height of 1cm.

[0056] (2) The columnar particles are fed into the coking oven 5 by the feeder and reacted with water vapor at 800°C for 5 hours. The heating is stopped and then cooled to room temperature under nitrogen atmosphere. The activated coke is then sent to the activated coke storage silo 7 for storage. The flow rate of water vapor and nitrogen is 40 L / min, and both enter the oven body from below the coking oven 5. The mass ratio of water vapor to columnar particles is 5:1.

[0057] Example 3

[0058] (1) First, the anthracite and red mud are ground to less than 200 mesh. The anthracite and red mud with a mass ratio of 100:10 (total amount of 100kg) are fed into the mixer 3 by the feeder. After being fully mixed in the mixer 3, they are fed into the molding device 4 for granulation to obtain columnar particles with a diameter of 0.5cm and a height of 1cm.

[0059] (2) The columnar particles are fed into the coking oven 5 by the feeder and reacted with water vapor at 800°C for 5 hours. The heating is stopped and then cooled to room temperature under nitrogen atmosphere. The activated coke is then sent to the activated coke storage silo 7 for storage. The flow rate of water vapor and nitrogen is 40 L / min, and both enter the oven body from below the coking oven 5. The mass ratio of water vapor to columnar particles is 5:1.

[0060] Example 4

[0061] (1) First, grind the lignite and red mud to below 200 mesh. Then, feed the bituminous coal and red mud with a mass ratio of 100:5 (total amount of 100kg) into the mixer 3 through the feeder. After being fully mixed in the mixer 3, feed it into the molding device 4 for granulation to obtain columnar particles with a diameter of 0.5cm and a height of 1cm.

[0062] (2) The columnar particles are fed into the coking oven 5 by the feeder and reacted with water vapor at 800°C for 5 hours. The heating is stopped and then cooled to room temperature under nitrogen atmosphere. The activated coke is then sent to the activated coke storage silo 7 for storage. The water vapor and nitrogen flow rates are 40L / min, and both enter the oven body from below the coking oven 5. The mass ratio of water vapor to columnar particles is 2:1.

[0063] Example 5

[0064] (1) First, grind the lignite and red mud to below 200 mesh. Then, feed the bituminous coal and red mud with a mass ratio of 100:20 (total amount of 100kg) into the mixer 3 through the feeder. After being fully mixed in the mixer 3, feed it into the molding device 4 for granulation to obtain columnar particles with a diameter of 0.5cm and a height of 1cm.

[0065] (2) The columnar particles are fed into the coking oven 5 by the feeder and reacted with water vapor at 800°C for 5 hours. The heating is stopped and then cooled to room temperature under nitrogen atmosphere. The activated coke is then sent to the activated coke storage silo 7 for storage. The flow rate of water vapor and nitrogen is 40 L / min, and both enter the oven body from below the coking oven 5. The mass ratio of water vapor to columnar particles is 6:1.

[0066] Comparative Example 1

[0067] (1) First, grind the lignite to below 200 mesh. Then, feed the bituminous coal (total amount of 100 kg) into the mixer 3 through the feeder. After mixing thoroughly in the mixer 3, feed it into the molding device 4 for granulation to obtain columnar particles with a diameter of 0.5 cm and a height of 1 cm.

[0068] (2) The columnar particles are fed into the coking oven 5 by the feeder and reacted with water vapor at 800°C for 5 hours. The heating is stopped and then cooled to room temperature under nitrogen atmosphere. The activated coke is then sent to the activated coke storage silo 7 for storage. The flow rate of water vapor and nitrogen is 40 L / min, and both enter the oven body from below the coking oven 5. The mass ratio of water vapor to columnar particles is 5:1.

[0069] The activated coke samples prepared in Examples 1-5 and Comparative Example 1 were subjected to hydrogen sulfide removal experiments on a fixed bed. Their desulfurization performance was tested by a sulfur analyzer, and their specific surface area was measured. The results are shown in Table 1.

[0070] Table 1

[0071] <![CDATA[Specific surface area / (m 2 / g)]]> Hydrogen sulfide adsorption capacity (mmol / g) Example 1 530 5.5 Example 2 211 4.3 Example 3 158 4.2 Example 4 503 4.5 Example 5 550 6.3 Comparative Example 1 470 2.4

[0072] As can be seen from the data in Table 1, the activated coke prepared in Examples 1-5 has very good adsorption performance for hydrogen sulfide; while in Comparative Example 1, since no red mud was added, the activated coke prepared only has physical adsorption for hydrogen sulfide, resulting in an adsorption capacity of only 2.4 mmol / g for hydrogen sulfide, which cannot meet the requirements for use.

[0073] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0074] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A method for preparing activated coke, characterized in that, Includes the following steps: (1) The coal powder and red mud are granulated to obtain solid particles; the coal powder is lignite. (2) The solid particles obtained in step (1) are coked to obtain activated coke; during the coking process, the solid particles react with water vapor.

2. The method for preparing activated coke according to claim 1, characterized in that, In step (1), the mass ratio of pulverized coal to red mud is 100:(1-20).

3. The method for preparing activated coke according to claim 1, characterized in that, In step (2), the coking process is carried out at a temperature of 700-900°C for 2-8 hours.

4. The method for preparing activated carbon according to claim 1, characterized in that, In step (2), the mass ratio of water vapor to solid particles is (2-6):

1.

5. The method for preparing activated coke according to any one of claims 1 to 4, characterized in that, The preparation method uses a preparation apparatus including a pulverized coal storage silo, a red mud storage silo, a molding device, and a coking oven. The outlets of the pulverized coal storage silo and the red mud storage silo are respectively connected to the inlet of the molding device; The forming device is used to granulate coal powder and red mud to obtain solid particles, and the outlet of the forming device is connected to the inlet of the coke oven. The coking oven is used to produce coke from solid particles and water vapor.

6. The method for preparing activated coke according to claim 5, characterized in that, The coking oven includes an inner layer and an outer layer. The inner layer is used for coking with solid particles and water vapor, and the outer layer is used to introduce flue gas to provide heat for coking.

7. The method for preparing activated coke according to claim 6, characterized in that, The device also includes a hydrogen sulfide removal chamber, a combustion chamber, and a steam generator; The gas inlet of the hydrogen sulfide removal chamber is connected to the gas outlet of the coking oven, and is used to remove hydrogen sulfide from the pyrolysis gas generated in the coking oven; the gas outlet of the hydrogen sulfide removal chamber is connected to the gas inlet of the combustion chamber, so that the pyrolysis gas treated with hydrogen sulfide removal enters the combustion chamber and is burned to obtain flue gas. The gas outlet of the combustion chamber is connected to the outer inlet of the coking oven and the heat source inlet of the steam generator, respectively, so that part of the flue gas enters the outer layer of the coking oven to provide heat for coking, and part of the flue gas enters the steam generator to generate steam. The steam generator's steam outlet is connected to the inner steam inlet of the coking oven, allowing steam to enter the coking oven and react with solid particles to form coke.

8. The method for preparing activated coke according to claim 7, characterized in that, The device also includes a cooling chamber connected to the activated coke outlet of the coking oven for cooling the activated coke, and the cooling water outlet of the cooling chamber is connected to the water inlet of the steam generator.

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