Preparation device and method for increasing micropore proportion of activated carbon through segmented activation

Abstract

The invention belongs to the technical field of activated carbon preparation, and particularly discloses a preparation device and method for increasing the micropore proportion of activated carbon through segmented activation. A steam activation section and a carbon dioxide activation section are arranged in an activation furnace of the device, and a material channel penetrates through the steam activation section and the carbon dioxide activation section; and a through hole penetrating through the wall thickness is formed in the side wall of the material channel. Materials are subjected to primary activation through the steam activation section, so that more mesopores and macropores are quickly formed in the materials, and then the materials are subjected to secondary activation through the carbon dioxide activation section, so that micropores are further formed in the materials, the number and proportion of the micropores are increased, and the desulfurization performance of activated carbon is improved. According to the technical scheme, the pore structure of the activated carbon is regulated and controlled in a segmented activation mode, the micropore proportion is increased, and therefore the desulfurization performance of the activated carbon is improved, the technological process is simple, meanwhile, waste heat of flue gas obtained after incineration and purification can be recycled, energy is saved, efficiency is high, and industrial application is easy.

Description

Technical Field

[0001] This invention relates to the field of activated carbon preparation technology, specifically to a preparation apparatus and method for increasing the micropore ratio of activated carbon through segmented activation. Background Technology

[0002] Activated carbon for desulfurization and denitrification, as a key component in the activated carbon method for purifying sintering flue gas, has seen rapid development in recent years. Current production methods primarily use raw coal, binders, asphalt, and water as raw materials. The production process involves coal blending, grinding, mixing, molding, drying, carbonization, activation, screening, and packaging. The activation step in the preparation of desulfurization and denitrification activated carbon typically employs physical activation methods, with steam activation being the primary method in current industrial production due to its convenient, stable, and cost-effective source as a byproduct. However, because the reaction rate between steam and activated carbon is relatively fast, prolonged reaction times, while promoting extensive pore formation and improving adsorption performance, can reduce the carbon's wear resistance. Furthermore, steam activation tends to generate more macropores and mesopores. Experiments and analysis have revealed that the micropore content in activated carbon is more closely related to its desulfurization performance and contributes more significantly to desulfurization; that is, a higher proportion of micropores in the total pore size results in a greater increase in desulfurization value. Therefore, researching methods to specifically improve the pore distribution of activated carbon, especially increasing the number and proportion of micropores, is key to improving the desulfurization performance of activated carbon.

[0003] Existing Chinese patent CN102491323B discloses a method for preparing high-desulfurization activated coke. The method involves crushing coal raw materials to a size of 15-20 mm or less, then mixing and grinding the crushed material with a catalyst at a mass ratio of 60-80:1-2. The composite coal powder is then mixed with water at a mass ratio of 66-107:8-25 and extruded to obtain a shaped material. This material is then subjected to carbonization at 300-750℃ and activation at 800-1000℃ to obtain the final product. This method has a relatively common and traditional process flow. Using a single activation gas results in imprecise control of the pore structure, making it difficult to directionally control the pore composition of the activated carbon, and the desulfurization value improvement of the prepared activated carbon is limited. Another Chinese patent, CN104261405B, discloses a method for preparing activated coke with polarly oriented surface functional groups. This method involves crushing weakly caking coal to a particle size of 3–5 mm and sieving it. First, it undergoes pre-oxidation in air at 180–280°C for 4–10 hours, followed by carbonization at 700–800°C for 0.5–2 hours under air-isolated conditions. Next, it is activated at 700–850°C using a combination of steam and oxygen, followed by deep activation with carbon dioxide at 800–900°C. Finally, it is cooled to 200–300°C and subjected to surface oxidation with an air stream for 2–4 hours, resulting in irregularly shaped activated coke particles with microporous surfaces rich in alkaline functional groups and mesopores and macropores with a suitable distribution of polar functional groups. This method is relatively complex, has high production costs, and is not easily applicable to industrial production. In general, existing processes for improving the desulfurization value of activated carbon or for improving the pore structure of activated carbon by adjusting the activation atmosphere have the following disadvantages: (1) limited improvement in desulfurization performance; (2) complex processes and high costs; and (3) not easy to apply industrially. Summary of the Invention

[0004] The main objective of this invention is to provide a preparation apparatus and method for increasing the micropore ratio of activated carbon through segmented activation, so as to further improve the desulfurization performance of the prepared activated carbon.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0006] A preparation apparatus for increasing the micropore ratio of activated carbon through segmented activation includes an activation furnace. The activation furnace includes an inlet at the top, an outlet at the bottom, and a material channel connecting the inlet and the outlet at both ends. A discharge valve for controlling the material's descent is provided at the outlet. The activation furnace also includes a steam activation section and a carbon dioxide activation section located below the steam activation section. An activation section partition is provided between the steam activation section and the carbon dioxide activation section, and the material channel is sealed through the activation section partition. The material channel sections within the steam and carbon dioxide activation sections each have through holes penetrating the wall thickness to allow activation gas to pass through the material channel. The diameter of the through holes is smaller than the diameter of the material. A steam flow channel is provided within the steam activation section, through which steam passes into the material channel for primary activation of the material. A carbon dioxide flow channel is provided within the carbon dioxide activation section, through which carbon dioxide passes into the material channel for secondary activation of the material.

[0007] Preferably, the steam activation section is provided with multiple first air passage partitions, and the material channel is sealed through the first air passage partitions. A first flow port is provided at one end of each first air passage partition. The first flow ports of two adjacent first air passage partitions are located on opposite sides of the material channel. A steam injection inlet is provided at the bottom of the steam activation section, and a steam outlet is provided at the top of the steam activation section. The steam injection inlet and the first flow port of the first air passage partition closest to the steam injection inlet are located on opposite sides of the material channel. The steam outlet and the first flow port of the first air passage partition closest to the steam outlet are located on opposite sides of the material channel. Steam passes sequentially through the steam injection inlet, each of the first flow ports, and the steam outlet to form the steam flow passage. A first flow port valve for opening and closing the first flow port is provided on each first flow port.

[0008] Preferably, the carbon dioxide activation section is provided with multiple second air passage partitions, and the material channel is sealed through the second air passage partitions. A second flow port is provided at one end of each second air passage partition. The second flow ports of two adjacent second air passage partitions are located on opposite sides of the material channel. A carbon dioxide injection inlet is provided at the bottom of the carbon dioxide activation section, and a carbon dioxide outlet is provided at the top of the carbon dioxide activation section. The carbon dioxide injection inlet and the second flow port of the second air passage partition closest to the carbon dioxide injection inlet are located on opposite sides of the material channel. The carbon dioxide outlet and the second flow port of the second air passage partition closest to the carbon dioxide outlet are located on opposite sides of the material channel. Carbon dioxide passes sequentially through the carbon dioxide injection inlet, each of the second flow ports, and the carbon dioxide outlet to form the carbon dioxide flow passage. A second flow port valve is provided on each second flow port for opening and closing the second flow port.

[0009] Preferably, the device further includes a steam downstream flue and a carbon dioxide downstream flue. One end of the steam downstream flue is connected to a steam source, and the other end is connected to the steam injection inlet. A first flow meter is installed at the steam injection inlet. One end of the carbon dioxide downstream flue is connected to a carbon dioxide gas source, and the other end is connected to the carbon dioxide injection inlet. A second flow meter is installed at the carbon dioxide injection inlet. The device also includes a first pressure monitoring port and a first temperature monitoring port installed in the steam activation section, and a second pressure monitoring port and a second temperature monitoring port installed in the carbon dioxide activation section.

[0010] Preferably, the activation furnace further includes a cooling section located below the carbon dioxide activation section. A cooling section partition is provided between the cooling section and the carbon dioxide activation section. A cooling cylinder containing coolant is provided within the cooling section, and the material channel is sealed through the cooling section partition and the cooling cylinder, with the outer wall of the material channel in close contact with the cylinder wall of the cooling cylinder.

[0011] Preferably, the activation furnace further includes a supplementary carbonization section located above the steam activation section. A supplementary carbonization section partition is provided between the supplementary carbonization section and the steam activation section, and the material channel is sealed through the supplementary carbonization section partition. A first air inlet is provided at the bottom of the supplementary carbonization section, and a first air outlet is provided at the top of the supplementary carbonization section. The first air inlet is connected to both the carbon dioxide outlet and the steam outlet.

[0012] Preferably, the activation furnace also includes a preheating section located above the supplementary carbonization section. A preheating section partition is provided between the preheating section and the supplementary carbonization section, and the material channel is sealed through the preheating section partition. A second air inlet is provided at the bottom of the preheating section, and a second air outlet is provided at the top of the preheating section. The second air inlet is connected to the first air outlet.

[0013] Preferably, the upper part of the activation furnace is provided with a conical distributor, a feed transition hopper, and a feed valve. The upper part of the conical distributor is connected to the feed inlet, the lower part of the conical distributor is connected to the upper part of the feed transition hopper, and the lower part of the feed transition hopper is connected to the material channel. The feed valve is located between the feed transition hopper and the material channel. The lower part of the activation furnace is provided with a discharge transition hopper and a discharge buffer chamber. The upper part of the discharge transition hopper is connected to the material channel, and the lower part of the discharge transition hopper is connected to the discharge buffer chamber. The discharge valve is located between the discharge transition hopper and the discharge buffer chamber.

[0014] A method for preparing activated carbon with increased micropore content through segmented activation, applied to the aforementioned apparatus for preparing activated carbon with increased micropore content, comprising the following steps:

[0015] 1) Grind raw coal and carbon powder with asphalt to form a mixture in which more than 90% can pass through a 200-mesh sieve or more than 70% can pass through a 325-mesh sieve.

[0016] 2) Add binder and water to the mixture and stir and knead it. Then, extrude it through a molding equipment to form particles with a diameter of 3-12 mm and dry them. The binder is one or a combination of several of the following: coal tar, carboxymethyl cellulose, polyvinyl alcohol, guar gum powder and biomass starch.

[0017] 3) The dried material is fed into the carbonization furnace and carbonized at 200~850℃ for 20~50 minutes.

[0018] 4) The carbonized material is added to the activation furnace and activated in the steam activation section with steam at 800-950℃ for 2-6 hours. Then the material is activated in the carbon dioxide activation section with carbon dioxide at 850-1000℃ for 2-6 hours. The ratio of the time the material spends in the steam activation section to the time it spends in the carbon dioxide activation section is 1:1.1 to 1:1.5.

[0019] 5) The activated material is discharged from the activation furnace, cooled and sieved to obtain large-particle activated carbon. The small-particle powdered activated carbon obtained by sieving is used as raw material for grinding and reuse.

[0020] Preferably, the binder in step 2) is one or a combination of several of the following: coal tar, carboxymethyl cellulose, polyvinyl alcohol, guar gum powder, and biomass starch.

[0021] In the technical solution of this invention, the material channel is installed in the steam activation section and the carbon dioxide activation section of the activation furnace, and the side wall of the material channel is provided with through holes that penetrate the wall thickness. In the steam activation section, water vapor fully contacts the material along the steam flow channel, performing initial activation on the material and forming more mesopores and macropores. In the carbon dioxide activation section, carbon dioxide fully contacts the material along the carbon dioxide flow channel, performing secondary activation on the material and further forming micropores. By controlling the pore structure of activated carbon through segmented activation, and by designing the steam and carbon dioxide flow channels to fully activate the material, the number and proportion of micropores are increased, thereby improving the desulfurization performance of activated carbon.

[0022] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0023] (1) The present invention adopts a segmented activation method of first activating with steam and then activating with carbon dioxide, which is conducive to forming activated carbon with a richer micropore content, which helps to improve the desulfurization performance of activated carbon. At the same time, the activation effect is further guaranteed by optimizing the gas path design.

[0024] (2) This invention can make full use of the incineration exhaust gas and the residual heat in the exhaust gas, improve the utilization value of the residual heat and atmosphere of the exhaust gas, and has the effect of energy saving and emission reduction. It is low in cost and easy to apply in industrial applications. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the preparation device for increasing the micropore ratio of activated carbon through segmented activation according to the present invention.

[0026] Figure 2 This is a top view of an embodiment of the preparation apparatus for segmented activation to increase the micropore ratio of activated carbon according to the present invention, when the material channel is circular (the conical feeder, feed transition hopper, and feed valve are not shown).

[0027] Figure 3 This is a top view of one of the first air passage partitions in an embodiment of the preparation apparatus for segmented activation to increase the proportion of micropores in activated carbon according to the present invention, when the material channel is circular.

[0028] Figure 4 This is a top view of an embodiment of the preparation apparatus for segmented activation to increase the micropore ratio of activated carbon according to the present invention, when the material channel is square (the conical feeder, feed transition hopper, and feed valve are not shown).

[0029] Figure 5This is a top view of one of the first air passage partitions in an embodiment of the preparation apparatus for segmented activation to increase the proportion of micropores in activated carbon according to the present invention, when the material channel is square.

[0030] Figure 6 This is a front cross-sectional view of the preheating section and the supplementary carbonization section of the preparation apparatus for segmented activation to increase the micropore ratio of activated carbon according to the present invention.

[0031] Figure 7 This is a front cross-sectional view of the cooling section of the apparatus for preparing activated carbon with segmented activation to increase the proportion of micropores according to the present invention.

[0032] Figure 8 This is a schematic flowchart of the preparation method for increasing the micropore ratio of activated carbon through segmented activation according to the present invention.

[0033] Attached reference numerals: 1-Feed inlet; 2-Conical distributor; 3-Feed transition hopper; 4-Feed valve; 5-Preheating section; 6-Supplementary carbonization section; 7-Steam flow duct; 8-Steam activation section; 9-Steam lower flue; 10-Steam injection inlet; 11-Activation section partition; 12-Carbon dioxide activation section; 13-Carbon dioxide lower flue; 14-Carbon dioxide injection inlet; 15-Cooling section; 16-Discharge transition hopper; 17-Discharge valve; 18-Discharge buffer bin; 19-Carbon dioxide flow duct 20-Second pressure monitoring port; 21-Second temperature monitoring port; 22-Carbon dioxide outlet; 23-First pressure monitoring port; 24-First temperature monitoring port; 25-First gas passage partition; 26-Steam outlet; 27-Material passage; 28-Activation furnace; 29-First flow port valve; 30-Cooling cylinder; 31-Coolant; 32-Preheating section partition; 33-Supplemental carbonization section partition; 34-First air inlet; 35-First air outlet; 36-Second air inlet; 37-Second air outlet. Detailed Implementation

[0034] The technical solution of the present invention will be illustrated below with examples. The scope of protection sought by the present invention includes, but is not limited to, the following embodiments.

[0035] Reference Figures 1 to 8A preparation apparatus for increasing the micropore ratio of activated carbon through segmented activation includes an activation furnace 28. The activation furnace 28 includes a feed inlet 1 at the top, a discharge outlet at the bottom, and a material channel 27 connecting the feed inlet 1 and the discharge outlet at both ends. A discharge valve 17 is provided at the discharge outlet to control the material's descent. The activation furnace 28 also includes a steam activation section 8 and a carbon dioxide activation section 12 located below the steam activation section 8. An activation section partition 11 is provided between the steam activation section 8 and the carbon dioxide activation section 12, and the material channel 27 is sealed through the activation section partition 11. The sections of the material channel 27 located within the steam activation section 8 and the carbon dioxide activation section 12 are provided with through holes that penetrate the wall thickness to allow activation gas to pass through the material channel 27. The diameter of the through holes is smaller than the diameter of the material. A steam flow passage 7 is provided within the steam activation section 8, and steam passes through the material channel 27 along the steam flow passage 7 to perform initial activation on the material. The carbon dioxide activation section 12 is equipped with a carbon dioxide flow channel 19. Carbon dioxide passes through the material channel 27 along the carbon dioxide flow channel 19 to perform secondary activation on the material.

[0036] In the technical solution of this invention, the material channel 27 passes through the steam activation section 8 and the carbon dioxide activation section 12 within the activation furnace 28, and the sidewall of the material channel 27 is provided with through holes that penetrate the wall thickness. In the steam activation section 8, water vapor fully contacts the material along the steam flow channel 7, performing initial activation on the material and causing it to form more mesopores and macropores. In the carbon dioxide activation section 12, carbon dioxide fully contacts the material along the carbon dioxide flow channel 19, performing secondary activation on the material and causing it to further form micropores. By controlling the pore structure of activated carbon through segmented activation, and by designing the steam flow channel 7 and the carbon dioxide flow channel 12, the material is fully activated, thereby increasing the number and proportion of micropores and improving the desulfurization performance of activated carbon.

[0037] Specifically, this invention uses high-temperature steam to first activate amorphous carbon, which can increase the volume of mesopores (2~50nm) by 40~60%. The open pores formed by steam activation provide diffusion channels for carbon dioxide activation, which can increase the specific surface area of ​​micropores (<2nm) by 25~35%. That is, the first half of the steam activates the carbonized material by expanding the pores, and the second half of the carbon dioxide in the flue gas activates the micropores by refining them. The desulfurization value of the final activated carbon can be increased by 20~30% compared with ordinary activated carbon.

[0038] Specifically, the activation section partition 11 is horizontally arranged, and the material channel 27 is perpendicular to the activation section partition 11. The cross-section of the material channel 27 is circular or square. The through holes are one or more combinations of circular, elliptical, square, or polygonal shapes, and are evenly arranged along the circumference of the material channel 27 so that the activating gas can enter the material channel 27 from all directions to carry out the activation reaction with the material. The activation section partition 11 is used to seal and isolate the steam activation section 8 and the carbon dioxide activation section 12. Optionally, the activation section partition is a ceramic fiber board.

[0039] Preferably, the steam activation section 8 is provided with multiple first air passage partitions 25, and the material passage 27 is sealed through the first air passage partitions 25. A first flow port is provided at one end of each first air passage partition 25. The first flow ports of two adjacent first air passage partitions 25 are located on opposite sides of the material passage 27. A steam injection inlet 10 is provided at the bottom of the steam activation section 8, and a steam outlet 26 is provided at the top of the steam activation section 8. The steam injection inlet 10 and the first flow port of the first air passage partition 25 closest to the steam injection inlet 10 are located on opposite sides of the material passage 27. The steam outlet 26 and the first flow port of the first air passage partition 25 closest to the steam outlet 26 are located on opposite sides of the material passage 27. Steam passes sequentially through the steam injection inlet 10, each first flow port, and the steam outlet 26 to form a steam flow passage 7. A first flow port valve 29 is provided on each first flow port for opening and closing the first flow port.

[0040] Specifically, the first air passage partition 25 is horizontally arranged. The distance between each first air passage partition 25 can be set according to requirements. In one embodiment, each first air passage partition is equally spaced. The first air passage partition 25 divides the steam activation section 8 into multiple compartments, which are connected only through the first flow port. The first flow port valve 29 can finely control the steam flow rate of each compartment to adapt to different working conditions. The steam injection inlet 10, each first flow port, and the steam outlet 26 are staggered on both sides of the material channel 27 and located at opposite ends of the steam activation section 8, thus forming a zigzag steam flow channel 7, which allows the material in the material channel 27 to fully contact the water vapor and improve the activation efficiency. Optionally, the first air passage partition 25 is a ceramic fiber board.

[0041] Preferably, the carbon dioxide activation section 12 is provided with multiple second air passage partitions, and the material passage 27 is sealed through the second air passage partitions. A second flow port is provided at one end of each second air passage partition. The second flow ports of two adjacent second air passage partitions are located on opposite sides of the material passage 27. A carbon dioxide injection inlet 14 is provided at the bottom of the carbon dioxide activation section 12, and a carbon dioxide outlet 22 is provided at the top of the carbon dioxide activation section 12. The carbon dioxide injection inlet 14 and the second flow port of the second air passage partition closest to the carbon dioxide injection inlet 14 are located on opposite sides of the material passage 27. The carbon dioxide outlet 22 and the second flow port of the second air passage partition closest to the carbon dioxide outlet 22 are located on opposite sides of the material passage 27. Carbon dioxide passes sequentially through the carbon dioxide injection inlet 14, each of the second flow ports, and the carbon dioxide outlet 22 to form a carbon dioxide flow passage 19. A second flow port valve is provided on each second flow port for opening and closing the second flow port.

[0042] Specifically, the second air duct partitions are horizontally arranged. The distance between each second air duct partition can be set according to requirements. In one embodiment, the second air duct partitions are equally spaced. The second air duct partitions divide the carbon dioxide activation section 12 into multiple compartments, which are connected only through second flow ports. The valves at the second flow ports allow for precise control of the carbon dioxide flow rate in each compartment to adapt to different operating conditions. The carbon dioxide injection inlet 14, each second flow port, and the carbon dioxide outlet 22 are staggered on both sides of the material channel 27 and located at opposite ends of the steam activation section 12, thus forming a zigzag carbon dioxide flow channel 19. This allows the material in the material channel 27 to fully contact and activate with the carbon dioxide, improving activation efficiency. Optionally, the second air duct partition is a ceramic fiber board.

[0043] Furthermore, the activation section partition 11, the first air passage partition, and the second air passage partition can all be dynamically adjusted to allow for real-time adjustment of the process parameters in the two zones by adjusting the distance of segmented activation, thereby achieving synergistic optimization. Specifically, taking the activation section partition 11 as an example, a rack is fixedly connected to the side wall of the activation section partition 11, and a vertically extending slide groove is provided on the inner wall of the activation furnace 28. The rack is slidably embedded in the slide groove, and a rotating motor is provided outside the activation furnace 28. The rotating shaft of the rotating motor is sealed and passes through the side wall of the activation furnace 28, and a gear that meshes with the rack is coaxially connected to the rotating shaft. When the rotating motor is started, the gear drives the rack to move up and down along the slide groove, thereby driving the activation section partition 11 to move up and down. To improve high-temperature resistance, the rack, gear, and rotating shaft are all made of ceramic material. In one embodiment, there are two racks, which are symmetrically arranged on opposite sides of the activation section partition 11. There are also two rotating motors, and each rotating motor corresponds to a rack. The two rotating motors synchronously drive the corresponding rack to rise or fall.

[0044] To further improve activation efficiency, the material channel 27 located within the steam activation section 8 and the carbon dioxide activation section 12 is equipped with a spiral section. To avoid the spiral tube affecting material descent, the spiral angle of the material channel 27 should not be too small; specifically, the spiral angle of the material channel 27 should be ≥60°. To prevent material blockage within the material channel 27, the device also includes a vibration device. The vibration device includes a vibrator and a transmission rod. The vibrator (such as an electric vibrator or a pneumatic vibrator) is connected to one end of the transmission rod (such as a ceramic composite rod) via a connector (such as a coupling or flange). The other end of the transmission rod is sealed and passes through the side wall of the activation furnace 28 and is fixedly connected to the bend of the material channel 27. When the vibrator is started, it transmits vibration to the bend of the material channel 27 via the transmission rod, thereby preventing material blockage. Preferably, the material channel 27 located within the steam activation section 8 and the carbon dioxide activation section 12 are both spiral sections.

[0045] When the activation section partition 11, the first air passage partition, and the second air passage partition are all dynamically adjustable, and the material channel 27 located within the steam activation section 8 and the carbon dioxide activation section 12 is equipped with a spiral section, the material channel 27 passing through the activation section partition 11, the first air passage partition, and the second air passage partition is set as a vertical section, and the length of the vertical section is the dynamically adjustable range of the partition. The other channel sections of the material channel 27 located within the steam activation section 8 and the carbon dioxide activation section 12 are equipped with spiral sections. Preferably, the other channel sections of the material channel 27 located within the steam activation section 8 and the carbon dioxide activation section 12 are all spiral sections.

[0046] Preferably, the device further includes a steam downstream flue 9 and a carbon dioxide downstream flue 13. One end of the steam downstream flue 9 is connected to a steam source, and the other end is connected to a steam injection inlet 10. A first flow meter is installed at the steam injection inlet 10. One end of the carbon dioxide downstream flue 13 is connected to a carbon dioxide gas source, and the other end is connected to a carbon dioxide injection inlet 14. A second flow meter is installed at the carbon dioxide injection inlet 14. The device also includes a first pressure monitoring port 23 and a first temperature monitoring port 24 installed in the steam activation section 8, and a second pressure monitoring port 20 and a second temperature monitoring port 21 installed in the carbon dioxide activation section 12.

[0047] Specifically, the steam source in the steam downstream flue 9 comes from the boiler, and the carbon dioxide source in the carbon dioxide downstream flue 13 comes from the flue gas containing a large amount of carbon dioxide after combustion in the carbonization furnace and incinerator. The flue gas is purified before being introduced into the carbon dioxide downstream flue 13. Both the steam inlet 10 and the carbon dioxide inlet 14 are equipped with flow valves, and the steam outlet 26 and the carbon dioxide outlet 22 are also equipped with flow meters and flow valves to control the flow rates of steam and carbon dioxide.

[0048] During operation of the activation furnace, the steam pressure in the steam activation section 8 is 0.1~0.5MPa, the steam flow rate is 80~200L / min / kg, and the water-to-carbon ratio (H2O / C) is 3:1~8:1. In the carbon dioxide activation section 12, the carbon dioxide concentration is ≥80%, the gas flow rate is 50~180L / min / kg, and the carbon-to-carbon ratio (CO2 / C) is 1.2:1~3.5:1.

[0049] Preferably, the activation furnace 28 is further provided with a cooling section 15 located below the carbon dioxide activation section 12. A cooling section partition is provided between the cooling section 15 and the carbon dioxide activation section 12. A cooling cylinder 30 containing coolant 31 is provided in the cooling section 15, and a material channel 27 is sealed through the cooling section partition and the cooling cylinder 30, with the outer wall of the material channel 27 in close contact with the cylinder wall of the cooling cylinder 30.

[0050] Specifically, the cooling section partition is horizontally arranged. To insulate against temperature, the cooling section partition can be made of ceramic fiber board. Furthermore, the cooling cylinder 30 is connected to a water pump via pipes, and the water pump is used to drive the coolant 31 (such as water or glycol-based coolant) to circulate, thereby enhancing the cooling effect. Even further, a refrigerator (such as an air-cooled refrigerator or a water-cooled refrigerator) is also connected to the pipes.

[0051] Preferably, the activation furnace 28 also includes a supplementary carbonization section 6 located above the steam activation section 8. A supplementary carbonization section partition 33 is provided between the supplementary carbonization section 6 and the steam activation section 8, and the material channel 27 is sealed and passes through the supplementary carbonization section partition 33. A first air inlet 34 is provided at the bottom of the supplementary carbonization section 6, and a first air outlet 35 is provided at the top of the supplementary carbonization section 6. The first air inlet 34 is connected to both the carbon dioxide outlet 22 and the steam outlet 26.

[0052] Preferably, the activation furnace 28 also includes a preheating section 5 located above the supplementary carbonization section 6. A preheating section partition 32 is provided between the preheating section 5 and the supplementary carbonization section 6, and the material channel 27 is sealed through the preheating section partition 32. A second air inlet 36 is provided at the bottom of the preheating section 5, and a second air outlet 37 is provided at the top of the preheating section 5. The second air inlet 36 is connected to the first air outlet 35.

[0053] Specifically, the supplementary carbonization section partition 33 and the preheating section partition 32 are both horizontally arranged, and the supplementary carbonization section partition 33 and the preheating section partition 32 can be ceramic fiber boards. The first air inlet 34, the first air outlet 35, the second air inlet 36 and the second air outlet 37 are all equipped with flow meters and flow valves.

[0054] Since the exhaust gas emitted after activation in steam activation section 8 and carbon dioxide activation section 12 still has a high temperature, and the temperature required for supplementary carbonization section 6 is usually higher than that required for preheating section 5, the first air inlet 34 of supplementary carbonization section 6 is connected to carbon dioxide outlet 22 and steam outlet 26 respectively. This allows the activated exhaust gas to be introduced into supplementary carbonization section 6 to supplement the carbonization of the material. Then, the second air inlet 36 of preheating section 5 is connected to the first air outlet 35 of supplementary carbonization section 6, allowing the carbonized exhaust gas to be introduced into preheating section 5 to preheat the material. This significantly improves the utilization rate of the exhaust gas and reduces production costs. Of course, the exhaust gas from the carbonization furnace and incinerator can also be used in supplementary carbonization section 6 and preheating section 5. In supplementary carbonization section 6 and preheating section 5, the high-temperature exhaust gas can be indirectly heated through the channel wall of material channel 27 or directly heated in contact with the material. When the high-temperature exhaust gas needs to directly contact the material for heat transfer, the material channel 27 located in the supplementary carbonization section 6 and the preheating section 5 is provided with through holes that penetrate the wall thickness. The diameter of the through holes is smaller than the particle size of the material to ensure that the gas can pass through the material channel 27 without the material falling out. Furthermore, the first air inlet 34 and the first air outlet 35 are located on opposite sides of the material channel 27, and the second air inlet 36 and the second air outlet 37 are located on opposite sides of the material channel 27 to ensure sufficient contact between the high-temperature gas and the material.

[0055] Preferably, the upper part of the activation furnace 28 is provided with a conical distributor 2, a feed transition hopper 3, and a feed valve 4. The upper part of the conical distributor 2 is connected to the feed inlet 1, the lower part of the conical distributor 2 is connected to the upper part of the feed transition hopper 3, and the lower part of the feed transition hopper 3 is connected to the material channel 27. The feed valve 4 is located between the feed transition hopper 3 and the material channel 27. The lower part of the activation furnace 28 is provided with a discharge transition hopper 16 and a discharge buffer chamber 18. The upper part of the discharge transition hopper 16 is connected to the material channel 27, and the lower part of the discharge transition hopper 16 is connected to the discharge buffer chamber 18. The discharge valve 17 is located between the discharge transition hopper 16 and the discharge buffer chamber 18.

[0056] This invention also provides a method for preparing activated carbon with increased micropore content through segmented activation, comprising the following steps:

[0057] Step 1: Grind raw coal and charcoal powder with asphalt to form a mixture in which more than 90% can pass through a 200-mesh sieve or more than 70% can pass through a 325-mesh sieve.

[0058] Step 2: Add binder and water to the mixture and stir and knead it. Then, extrude it through a molding device to form particles with a diameter of 3-12 mm and dry them.

[0059] Specifically, the activated carbon granules can be spherical, cylindrical, or rectangular. Cylindrical shape is preferred. The drying process ensures the material's moisture content is below 8%.

[0060] Step 3: Send the dried material into the carbonization furnace and carbonize it at 200~850℃ for 20~50 minutes.

[0061] Specifically, the carbonization process controls the final carbonization temperature to be 600~850℃, preferably 650~850℃, and more preferably 650~800℃.

[0062] Step 4: Add the carbonized material to the activation furnace and activate it in the steam activation section (8) with steam at a temperature of 800-950℃ for 2-6 hours. Then, put the material into the carbon dioxide activation section (12) and activate it with carbon dioxide at a temperature of 850-1000℃ for 2-6 hours. The ratio of the time the material spends in the steam activation section (8) to the time it spends in the carbon dioxide activation section (12) is 1:1.1 to 1:1.5.

[0063] Step 5: Discharge the activated material from the activation furnace, cool and sieve it to obtain large-particle activated carbon. The small-particle powdered activated carbon obtained by sieving is used as raw material for grinding and reuse.

[0064] Preferably, the binder in step 2 is one or a combination of several of the following: coal tar, carboxymethyl cellulose, polyvinyl alcohol, guar gum powder, and biomass starch.

[0065] Example 1

[0066] like Figure 1-8 As shown, a preparation apparatus for increasing the micropore ratio of activated carbon through segmented activation includes an activation furnace 28. The activation furnace 28 includes a feed inlet 1 located at the top, a discharge outlet located at the bottom, and a material channel 27 connecting the feed inlet 1 and the discharge outlet at both ends. A discharge valve 17 is provided at the discharge outlet to control the material's descent. The activation furnace 28 also includes a steam activation section 8 and a carbon dioxide activation section 12 located below the steam activation section 8. An activation section partition 11 is horizontally arranged between the steam activation section 8 and the carbon dioxide activation section 12, and the material channel 27 is vertically and sealed through the activation section partition 11. The channel sections of the material channel 27 located within the steam activation section 8 and the carbon dioxide activation section 12 are provided with through holes that penetrate the wall thickness, allowing activation gas to pass through the material channel 27. The diameter of the through holes is smaller than the diameter of the material. A steam flow passage 7 is provided within the steam activation section 8, and steam passes through the material channel 27 along the steam flow passage 7 to perform initial activation on the material. The carbon dioxide activation section 12 is equipped with a carbon dioxide flow channel 19. Carbon dioxide passes through the material channel 27 along the carbon dioxide flow channel 19 to perform secondary activation on the material.

[0067] Example 2

[0068] The embodiment 1 is repeated, except that two first air passage partitions 25 are horizontally arranged within the steam activation section 8, and the material channel 27 is vertically and sealed through the first air passage partitions 25. The two first air passage partitions 25 are equally spaced. A first flow port is opened at one end of each first air passage partition 25. The first flow ports of two adjacent first air passage partitions 25 are located on both sides of the material channel 27. A steam injection inlet 10 is provided at the bottom of the steam activation section 8, and a steam outlet 26 is provided at the top of the steam activation section 8. The steam injection inlet 10 and the first flow port of the first air passage partition 25 closest to the steam injection inlet 10 are located on both sides of the material channel 27. The steam outlet 26 and the first flow port of the first air passage partition 25 closest to the steam outlet 26 are located on both sides of the material channel 27. Steam passes sequentially through the steam injection inlet 10, the two first flow ports, and the steam outlet 26 to form a steam flow passage 7. A first flow port valve 29 for opening and closing the first flow port is provided on the first flow port.

[0069] Example 3

[0070] The embodiment 2 is repeated, except that two second air passage partitions are horizontally arranged within the carbon dioxide activation section 12, and the material channel 27 is vertically and sealed through the second air passage partitions. The two second air passage partitions are equally spaced. A second flow port is opened at one end of each second air passage partition. The second flow ports of two adjacent second air passage partitions are located on both sides of the material channel 27. A carbon dioxide injection inlet 14 is provided at the bottom of the carbon dioxide activation section 12, and a carbon dioxide outlet 22 is provided at the top of the carbon dioxide activation section 12. The carbon dioxide injection inlet 14 and the second flow port of the second air passage partition closest to the carbon dioxide injection inlet 14 are located on both sides of the material channel 27. The carbon dioxide outlet 22 and the second flow port of the second air passage partition closest to the carbon dioxide outlet 22 are located on both sides of the material channel 27. Carbon dioxide passes sequentially through the carbon dioxide injection inlet 14, the two second flow ports, and the carbon dioxide outlet 22 to form a carbon dioxide flow passage 19. A second flow port valve for opening and closing the second flow port is provided on the second flow port.

[0071] Example 4

[0072] The device repeats Embodiment 3, except that it further includes a steam downstream flue 9 and a carbon dioxide downstream flue 13. One end of the steam downstream flue 9 is connected to a steam source, and the other end is connected to a steam injection inlet 10. A first flow meter is installed at the steam injection inlet 10. One end of the carbon dioxide downstream flue 13 is connected to a carbon dioxide gas source, and the other end is connected to a carbon dioxide injection inlet 14. A second flow meter is installed at the carbon dioxide injection inlet 14. The device also includes a first pressure monitoring port 23 and a first temperature monitoring port 24 installed in the steam activation section 8, and a second pressure monitoring port 20 and a second temperature monitoring port 21 installed in the carbon dioxide activation section 12. The steam source comes from the boiler, and the carbon dioxide gas source comes from the flue gas after combustion in the carbonization furnace and the incinerator.

[0073] Example 5

[0074] Example 4 is repeated, except that a cooling section 15 is also provided in the activation furnace 28, located below the carbon dioxide activation section 12. A cooling section partition is horizontally provided between the cooling section 15 and the carbon dioxide activation section 12. A cooling cylinder 30 containing coolant 31 is provided in the cooling section 15. A material channel 27 is vertically and sealed through the cooling section partition and the cooling cylinder 30, and the outer wall of the material channel 27 is in close contact with the cylinder wall of the cooling cylinder 30.

[0075] Example 6

[0076] Example 5 is repeated, except that the activation furnace 28 also includes a supplementary carbonization section 6 located above the steam activation section 8. A supplementary carbonization section partition 33 is horizontally disposed between the supplementary carbonization section 6 and the steam activation section 8, and the material channel 27 is vertically and sealed through the supplementary carbonization section partition 33. A first air inlet 34 is provided at the bottom of the supplementary carbonization section 6, and a first air outlet 35 is provided at the top of the supplementary carbonization section 6. The first air inlet 34 is connected to both the carbon dioxide outlet 22 and the steam outlet 26.

[0077] Example 7

[0078] The process repeats Example 6, except that the activation furnace 28 also includes a preheating section 5 located above the supplementary carbonization section 6. A preheating section partition 32 is horizontally disposed between the preheating section 5 and the supplementary carbonization section 6, and a material channel 27 is vertically and sealed through the preheating section partition 32. A second air inlet 36 is disposed at the bottom of the preheating section 5, and a second air outlet 37 is disposed at the top of the preheating section 5. The second air inlet 36 is connected to the first air outlet 35.

[0079] Example 8

[0080] Repeating Example 7, the upper part of the activation furnace 28 is provided with a conical distributor 2, a feed transition hopper 3, and a feed valve 4. The upper part of the conical distributor 2 is connected to the feed inlet 1, the lower part of the conical distributor 2 is connected to the upper part of the feed transition hopper 3, and the lower part of the feed transition hopper 3 is connected to the material channel 27. The feed valve 4 is located between the feed transition hopper 3 and the material channel 27. The lower part of the activation furnace 28 is provided with a discharge transition hopper 16 and a discharge buffer chamber 18. The upper part of the discharge transition hopper 16 is connected to the material channel 27, and the lower part of the discharge transition hopper 16 is connected to the discharge buffer chamber 18. The discharge valve 17 is located between the discharge transition hopper 16 and the discharge buffer chamber 18.

[0081] Example 9

[0082] Reread Example 8, except that the material channel 27 is a circular channel.

[0083] Example 10

[0084] Repeat Example 8, except that the material channel 27 is a square channel.

[0085] Application Example 1

[0086] Raw coal and charcoal powder are ground with asphalt to form a mixture with over 90% density that can pass through a 200-mesh sieve. Starch and water are added to the mixture and stirred and kneaded. The mixture is then extruded through a molding device to form cylindrical granules with a diameter of 10 mm, and dried until the moisture content is below 8%. The dried material is then fed into a carbonization furnace for carbonization. Specifically, the carbonization temperature rises gradually from 280°C to 800°C before exiting the furnace, a process that takes 35 minutes.

[0087] The carbonized material is added to an activation furnace and activated in a steam activation section with steam at 900°C for 3 hours. Then, the material is moved to a carbon dioxide activation section and activated with carbon dioxide at 900°C for 4 hours. The material is then removed from the activation furnace, cooled, and screened.

[0088] The micropore content of the finished activated carbon was found to be 75%, and the specific surface area was 575 m². 2 / g.

[0089] Comparative Example 1

[0090] Raw coal and charcoal powder are ground with asphalt to form a mixture with over 90% density that can pass through a 200-mesh sieve. Starch and water are added to the mixture and stirred and kneaded. The mixture is then extruded through a molding device to form cylindrical granules with a diameter of 10 mm, and dried until the moisture content is below 8%. The dried material is then fed into a carbonization furnace for carbonization. Specifically, the carbonization temperature rises gradually from 280°C to 800°C before exiting the furnace, a process that takes 35 minutes.

[0091] The carbonized material is added to an activation furnace and activated for 7 hours using steam at 900°C. The material is then discharged from the activation furnace and cooled and screened.

[0092] The micropore content of the finished activated carbon was found to be 55%, and the specific surface area was 325 m². 2 / g.

Claims

1. A preparation apparatus for increasing the micropore ratio of activated carbon through segmented activation, comprising an activation furnace (28), characterized in that: The activation furnace (28) includes a feed inlet (1) at the top, a discharge outlet at the bottom, and a material channel (27) connecting the feed inlet (1) and the discharge outlet at both ends respectively; a discharge valve (17) for controlling the material falling is provided at the discharge outlet; the activation furnace (28) also includes a steam activation section (8) and a carbon dioxide activation section (12) located below the steam activation section (8); an activation section partition (11) is provided between the steam activation section (8) and the carbon dioxide activation section (12), and the material channel (27) is sealed through the activation section partition (11); the material channel (27) The channel sections located in the steam activation section (8) and the carbon dioxide activation section (12) are provided with through holes that penetrate the wall thickness so that the activation gas can pass through the material channel (27); the diameter of the through hole is smaller than the diameter of the material; the steam activation section (8) is provided with a steam flow channel (7), and the steam passes through the material channel (27) along the steam flow channel (7) to perform the initial activation of the material; the carbon dioxide activation section (12) is provided with a carbon dioxide flow channel (19), and the carbon dioxide passes through the material channel (27) along the carbon dioxide flow channel (19) to perform the secondary activation of the material.

2. The apparatus for preparing activated carbon with segmented activation to increase the proportion of micropores according to claim 1, characterized in that: The steam activation section (8) is provided with multiple first air passage partitions (25), and the material channel (27) is sealed through the first air passage partitions (25); a first flow port is opened at one end of the first air passage partition (25); the first flow ports of two adjacent first air passage partitions (25) are respectively located on both sides of the material channel (27); a steam injection inlet (10) is provided at the bottom of the steam activation section (8), and a steam outlet (26) is provided at the top of the steam activation section (8); the steam injection inlet (10) is located at a distance from the steam injection inlet. The first flow port of the first air passage partition (25) closest to the mouth (10) is located on both sides of the material passage (27); the steam outlet (26) and the first flow port of the first air passage partition (25) closest to the steam outlet (26) are located on both sides of the material passage (27); steam passes through the steam injection port (10), each of the first flow ports and the steam outlet (26) in sequence to form the steam flow passage (7); a first flow port valve (29) for opening and closing the first flow port is provided on the first flow port.

3. The apparatus for preparing activated carbon by segmented activation to increase the proportion of micropores according to claim 2, characterized in that: The carbon dioxide activation section (12) is provided with multiple second air passage partitions, and the material channel (27) is sealed through the second air passage partitions; a second flow port is provided at one end of the second air passage partition; the second flow ports of two adjacent second air passage partitions are respectively located on both sides of the material channel (27); a carbon dioxide injection inlet (14) is provided at the bottom of the carbon dioxide activation section (12), and a carbon dioxide outlet (22) is provided at the top of the carbon dioxide activation section (12); the carbon dioxide injection inlet (14) and the second flow port of the second air passage partition closest to the carbon dioxide injection inlet (14) are respectively located on both sides of the material channel (27); the carbon dioxide outlet (22) and the second flow port of the second air passage partition closest to the carbon dioxide outlet (22) are respectively located on both sides of the material channel (27); carbon dioxide passes through the carbon dioxide injection inlet (14), each of the second flow ports and the carbon dioxide outlet (22) in sequence to form the carbon dioxide flow air passage (19); a second flow port valve for opening and closing the second flow port is provided on the second flow port.

4. The apparatus for preparing activated carbon with segmented activation to increase the proportion of micropores according to claim 3, characterized in that: The device also includes a steam downstream flue (9) and a carbon dioxide downstream flue (13); one end of the steam downstream flue (9) is connected to a steam source, and the other end is connected to the steam injection inlet (10); a first flow meter is provided at the steam injection inlet (10); one end of the carbon dioxide downstream flue (13) is connected to a carbon dioxide gas source, and the other end is connected to the carbon dioxide injection inlet (14); a second flow meter is provided at the carbon dioxide injection inlet (14); the device also includes a first pressure monitoring port (23) and a first temperature monitoring port (24) provided in the steam activation section (8), and a second pressure monitoring port (20) and a second temperature monitoring port (21) provided in the carbon dioxide activation section (12).

5. The apparatus for preparing activated carbon with segmented activation to increase the proportion of micropores according to any one of claims 1 to 4, characterized in that: The activation furnace (28) is also provided with a cooling section (15) located below the carbon dioxide activation section (12); a cooling section partition is provided between the cooling section (15) and the carbon dioxide activation section (12); a cooling cylinder (30) containing coolant (31) is provided in the cooling section (15); the material channel (27) is sealed through the cooling section partition and the cooling cylinder (30), and the outer wall of the material channel (27) is in close contact with the cylinder wall of the cooling cylinder (30).

6. The apparatus for preparing activated carbon by segmented activation to increase the proportion of micropores according to claim 3 or 4, characterized in that: The activation furnace (28) is also provided with a supplementary carbonization section (6) located above the steam activation section (8); a supplementary carbonization section partition (33) is provided between the supplementary carbonization section (6) and the steam activation section (8), and the material channel (27) is sealed through the supplementary carbonization section partition (33); a first air inlet (34) is provided at the bottom of the supplementary carbonization section (6), and a first air outlet (35) is provided at the top of the supplementary carbonization section (6); the first air inlet (34) is connected to the carbon dioxide outlet (22) and the steam outlet (26) respectively.

7. The apparatus for preparing activated carbon with segmented activation to increase the proportion of micropores according to claim 6, characterized in that: The activation furnace (28) is also provided with a preheating section (5) located above the supplementary carbonization section (6); a preheating section partition (32) is provided between the preheating section (5) and the supplementary carbonization section (6), and the material channel (27) is sealed through the preheating section partition (32); a second air inlet (36) is provided at the bottom of the preheating section (5), and a second air outlet (37) is provided at the top of the preheating section (5); the second air inlet (36) is connected to the first air outlet (35).

8. The apparatus for preparing activated carbon by segmented activation to increase the micropore ratio according to any one of claims 1 to 7, characterized in that: The upper part of the activation furnace (28) is provided with a conical distributor (2), a feed transition lock hopper (3) and a feed valve (4); the upper part of the conical distributor (2) is connected to the feed inlet (1), the lower part of the conical distributor (2) is connected to the upper part of the feed transition lock hopper (3), and the lower part of the feed transition lock hopper (3) is connected to the material channel (27); the feed valve (4) is located between the feed transition lock hopper (3) and the material channel (27); the lower part of the activation furnace (28) is provided with a discharge transition lock hopper (16) and a discharge buffer chamber (18); the upper part of the discharge transition lock hopper (16) is connected to the material channel (27), and the lower part of the discharge transition lock hopper (16) is connected to the discharge buffer chamber (18); the discharge valve (17) is located between the discharge transition lock hopper (16) and the discharge buffer chamber (18).

9. A method for preparing activated carbon with increased micropore content through segmented activation, applied to the apparatus for preparing activated carbon with increased micropore content as described in any one of claims 1 to 8, characterized in that: The method includes the following steps: 1) Grind raw coal and charcoal powder with asphalt to form a mixture in which more than 90% can pass through a 200-mesh sieve or more than 70% can pass through a 325-mesh sieve; 2) Add binder and water to the mixture and stir and knead it. Then, extrude it through a molding equipment to form particles with a diameter of 3-12 mm and dry them. 3) The dried material is fed into the carbonization furnace and carbonized at 200~850℃ for 20~50 minutes; 4) The carbonized material is added to the activation furnace and activated in the steam activation section (8) with steam at a temperature of 800-950°C for 2-6 hours. Then the material is put into the carbon dioxide activation section (12) and activated in the carbon dioxide at a temperature of 850-1000°C for 2-6 hours. The ratio of the time the material spends in the steam activation section (8) to the time it spends in the carbon dioxide activation section (12) is 1:1.1 to 1:1.

5. 5) The activated material is discharged from the activation furnace, cooled and sieved to obtain large-particle activated carbon. The small-particle powdered activated carbon obtained by sieving is used as raw material for grinding and reuse.

10. The method for preparing activated carbon with increased micropore content through segmented activation according to claim 9, characterized in that: The binder mentioned in step 2) is one or a combination of several of the following: coal tar, carboxymethyl cellulose, polyvinyl alcohol, guar gum powder, and biomass starch.

Images