A porous carbon activation system with heat-carrying particle circulation

Abstract

This invention relates to the field of porous carbon activation technology, and more particularly to a porous carbon activation system with circulating heat-carrying particles, comprising: a fluidized bed reaction unit; a cooling and unloading unit; a feeding unit; a tail gas conveying unit for collecting the reaction tail gas formed after the activation reaction; an activation gas supply unit for transferring the heat of the reaction tail gas to the activation gas for preheating and mixing with the activation gas to output a mixed activation gas; a heat-carrying particle heating unit for heating the particles that have not yet entered the heat-carrying particles; and a conveying and separating unit for conveying the heated heat-carrying particles to the activation reaction zone in the fluidized bed reaction unit to provide the heat required for the activation reaction, including a riser, a cyclone separator, and a conveying fan for providing conveying pressure to the heat-carrying particles and reaction raw materials by introducing nitrogen gas into the fluidized bed reaction unit. This invention achieves an increase in the specific surface area and microporosity of porous carbon.

Description

Technical Field

[0001] This invention relates to the field of porous carbon activation technology, and more particularly to a porous carbon activation system with heat-carrying particle circulation. Background Technology

[0002] In existing technologies, lithium-ion batteries, as the core power carrier of new energy technologies, rely heavily on innovation in anode materials for breakthroughs in energy density and cycle life. Silicon-based anode materials, with their theoretical capacity ten times that of graphite, are considered key to the next generation of high-energy batteries. However, their volume expansion of up to 300% during charge and discharge leads to structural pulverization and failure, severely hindering their practical application. Constructing composite anode materials by uniformly loading nano-silicon into a porous carbon matrix can effectively disperse expansion stress and maintain electrode integrity. The industrialization of this technology urgently requires porous carbon host materials that possess high specific surface area, gradient pore size, and excellent structural stability. However, the inherent defects exposed by existing porous carbon preparation equipment during industrial scale-up have become a key bottleneck limiting the improvement of silicon-carbon anode performance and cost reduction.

[0003] As the core equipment for the large-scale production of porous carbon, the performance of fluidized bed reactors directly determines material quality and production costs. Current mainstream equipment, due to structural design limitations, struggles to balance temperature field uniformity, fluidization efficiency, and energy consumption control. For ultrafine carbon powder with a particle size less than 10μm, its strong agglomeration tendency leads to the formation of localized high-temperature zones within the bed (temperature differences exceeding ±80℃). The microporous structure is excessively ablated at high temperatures, while the activation reaction in the edge regions is insufficient due to delayed heat conduction. This results in product specific surface area fluctuations of ±250m² / g and pore distribution dispersion exceeding 30%. Simultaneously, traditional fluidized beds rely on static heat conduction via external heating modules. The sensible heat recovery rate from the high-temperature exhaust gas (above 800℃) is less than 20%, and the discarding of the heat transfer medium after a single use causes additional energy consumption. Combined with the strong endothermic characteristics of the activation reaction, the overall energy consumption is more than three times higher than the theoretical value. Even more serious is the high entrainment rate of ultrafine particles due to the crude gas distribution design, resulting in short continuous operating cycles and frequent maintenance, further increasing production costs.

[0004] Existing technological improvements mostly focus on local optimization and fail to overcome systemic defects at the equipment level. For example, while zoned electric heating can reduce axial temperature difference, it does not solve the radial temperature gradient problem; improvements to the gas pre-distributor, although enhancing fluidization uniformity, lead to a doubling of pressure drop and increased energy consumption; and traditional cyclone separation systems are prone to clogging and failure under high-temperature conditions, failing to achieve efficient separation of the heat transfer medium and products. Against this backdrop, developing a new equipment system integrating dynamic control of the thermal field, optimization of fluidization state, and closed-loop energy management has become the core breakthrough for overcoming the predicament of industrial production of porous carbon.

[0005] Chinese Patent Publication No. CN119240698A discloses a system and method for preparing porous electrode carbon, comprising a carbonization fluidized bed, an activation fluidized bed, and a heat carrier removal reactor connected in series. A porous distribution plate is provided within the reaction zone of the carbonization fluidized bed, dividing the reaction zone into a first reaction zone and a second reaction zone. The first reaction zone has a fluidizing gas inlet and a composite carbonization material outlet, while the second reaction zone has a mixed raw material inlet and a fluidization tail gas outlet. An overflow pipe is provided outside the carbonization fluidized bed, with one end connected to the first reaction zone and the other end connected to the second reaction zone. An activation gas inlet and an activation material outlet are provided at the bottom of the activation fluidized bed. A composite carbonization material inlet and an activation tail gas outlet are provided above the activation fluidized bed. The heat carrier removal reactor contains acid or water. Therefore, the porous electrode carbon preparation system and method have problems such as small specific surface area and low microporosity of porous carbon due to the uneven temperature field, unstable fluidization of ultrafine particles, excessive energy consumption and short continuous operation cycle of existing fluidized bed activation equipment during the preparation of porous carbon. Summary of the Invention

[0006] Therefore, the present invention provides a porous carbon activation system with heat-carrying particle circulation to overcome the problems of small specific surface area and low microporosity of porous carbon caused by the uneven temperature field, unstable fluidization of ultrafine particles, excessive energy consumption and short continuous operation cycle of existing fluidized bed activation equipment in the process of preparing porous carbon.

[0007] To achieve the above objectives, the present invention provides a porous carbon activation system with circulating heat-carrying particles, comprising:

[0008] Fluidized bed reaction unit is used to activate the reactants through activating gas and heat-carrying particles to convert them into porous carbon;

[0009] A cooling and unloading unit, which is connected to the fluidized bed reaction unit, is used to cool the output porous carbon.

[0010] A feeding unit, which is located above the cooling and unloading unit, is used to transport the reaction raw materials, including a raw material tank for loading the reaction raw materials and a discharge valve connected to the raw material tank for controlling whether the raw materials are transported.

[0011] The exhaust gas conveying unit is connected to the fluidized bed reaction unit and is used to collect the reaction exhaust gas formed after the activation reaction.

[0012] An activation gas supply unit, which is connected to the tail gas delivery unit, is used to transfer the heat of the reaction tail gas to the activation gas for preheating and mixing with the activation gas to output a mixed activation gas.

[0013] A conveying and separating unit, connected to the fluidized bed reaction unit, is used to convey the heated heat-carrying particles to the activation reaction zone in the fluidized bed reaction unit to provide the heat required for the activation reaction. It includes a riser pipe vertically installed outside the raw material tank to provide conveying pressure for the heat-carrying particles by introducing nitrogen into the fluidized bed reaction unit, a cyclone separator connected to the riser pipe to separate the heat-carrying particles from the porous carbon, and a conveying fan connected to the cyclone separator to provide conveying power for the separated heat-carrying particles.

[0014] A heat-carrying particle heating unit, which is connected to the conveying and separating unit, is used to heat the heat-carrying particles that have not entered the fluidized bed reaction unit. It includes a heating buffer tank connected to the riser to reduce the pressure of the input nitrogen and to heat the heat-carrying particles, and a heating furnace connected to the heating buffer tank to heat the heating buffer tank.

[0015] Furthermore, the heat-carrying particles include at least one of alumina, silicon dioxide, zirconium oxide, and silicon carbide.

[0016] Furthermore, the fluidized bed reaction unit includes:

[0017] A reaction vessel is used to provide a reaction site for activation reactions;

[0018] A particle pre-distributor, which is disposed inside the reaction vessel, is used to reduce the entry velocity of the heat-carrying particles;

[0019] A gradient gas distributor is disposed at the top of the reaction vessel to form a gradient gas flow of the activation gas to mix the reactants and the heat-carrying particles;

[0020] A metal filter, disposed below the gradient gas distributor, is used to filter carbon powder in the reaction tail gas.

[0021] Furthermore, the unloading method of the cooling unloading unit is a pressure-feed pneumatic conveying unloading method.

[0022] Furthermore, the activation gas supply unit includes:

[0023] A gas mixing vessel is used to mix the reaction tail gas and the activation gas to form a mixed activation gas;

[0024] Several flow meters are connected to the gas mixing tank to detect the flow rates of the activation gas, the reaction tail gas, and the mixed activation gas, respectively.

[0025] A gas preheating furnace, connected to the gas mixing tank, is used to heat the mixed activation gas.

[0026] Furthermore, the exhaust gas delivery unit includes:

[0027] An exhaust gas delivery pipeline, which is connected to the gas mixing tank;

[0028] A circulating fan, connected to the exhaust gas delivery pipeline, is used to deliver the reaction exhaust gas to the gas mixing tank.

[0029] Furthermore, the volume ratio of the reaction tail gas to the activation gas in the gas mixing tank is 3:7 to 5:5.

[0030] Furthermore, the types of activating gases include water vapor and carbon dioxide.

[0031] Furthermore, the fluidized bed reaction unit also includes a conveying port assembly, which is positioned from top to bottom in the reaction vessel as the reaction tail gas outlet, the heat-carrying particle inlet, the heat-carrying particle outlet, and the gas inlet.

[0032] Furthermore, the inlet of the heat-carrying particles is equipped with a high-temperature valve for regulating the flow rate of the heat-carrying particles.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows: The system of the present invention, by setting up a fluidized bed reaction unit, a cooling and unloading unit, a feeding unit, a tail gas conveying unit, an activation gas supply unit, a heat-carrying particle heating unit, and a conveying and separation unit, addresses the issue that traditional fluidized bed activation equipment, due to its single heat transfer method, results in uneven temperature distribution in the activation reaction zone, affecting the development of the microstructure of porous carbon. Micron- or nano-sized raw material particles are prone to non-ideal fluidization phenomena such as channeling and surging, leading to a decrease in reaction efficiency. Traditional processes also suffer from low thermal energy utilization and high energy consumption during heating, resulting in energy waste. Furthermore, unreasonable equipment design or poor operational stability leads to frequent system shutdowns for maintenance, further reducing production efficiency. All of these factors combined result in the final porous carbon having a small specific surface area and low microporosity. The heat-carrying particles are circulated through a heat-carrying particle circulation unit, replacing static wall heating with heat transfer to ensure uniform development of the microporous structure of porous carbon and reduce fluctuations in specific surface area. High-temperature exhaust gas is transported to a gas mixing tank via an exhaust gas conveying unit in the porous carbon processing unit. After mixing with fresh activation gas, it is heated in a preheating furnace, directly recovering the sensible heat of the exhaust gas, thereby improving the utilization rate of residual heat. This heat recovery reduces the energy consumption of the preheated gas and minimizes the disruption of fluidization caused by cold material entering the bed. This achieves increased specific surface area and microporosity during porous carbon production, as well as improved product uniformity and performance stability. By reconstructing the heat utilization mechanism, optimizing the porous carbon activation and heat-carrying particle separation process, and constructing an energy closed-loop network through exhaust gas circulation, efficient, stable, and low-consumption continuous production of porous carbon materials is achieved.

[0034] Furthermore, the system of the present invention preheats the heat-carrying particles to raise their temperature to the high-temperature range required for the activation reaction before they participate in the activation reaction. The preheated heat-carrying particles are then transported to the fluidized bed reaction unit via a riser using nitrogen as the transport medium. During this process, a heating buffer tank is used to reduce the airflow velocity, preventing the heat-carrying particles from breaking due to high-speed collisions. The particles are then uniformly dispersed into a fine beam by a particle pre-distributor before entering the activation reaction area, ensuring sufficient contact with the reaction raw materials and transferring heat. This improves the uniformity of temperature distribution in the reaction area and avoids problems such as excessive micropore ablation caused by local high temperatures or insufficient activation in low-temperature areas. The preheated heat-carrying particles provide a continuous and stable heat source for the activation reaction, improving the uniformity of the porous carbon microporous structure.

[0035] Furthermore, the system of the present invention introduces high-temperature alumina, silicon dioxide, and metal particles into the fluidized bed reaction unit through a heat-carrying particle circulation unit. Utilizing their high heat capacity and good heat transfer performance, the temperature uniformity of the activation reaction zone is significantly improved, thereby increasing the specific surface area and microporosity of the porous carbon. The recycling of heat-carrying particles not only improves the thermal energy utilization rate and reduces the overall energy consumption, but also enhances the continuous operation capability of the system and extends the operating cycle.

[0036] Furthermore, the system of the present invention achieves gradient distribution of activation gas in the fluidized bed by setting up a particle pre-distributor, a gradient gas distributor, and a metal filter, thereby improving gas-solid contact efficiency. By setting up a circulating fan and a tail gas delivery pipeline, the tail gas is recycled and reused, allowing unreacted components in the reaction tail gas to participate in the reaction again, which not only improves the utilization rate of raw materials but also reduces environmental pollution caused by reaction tail gas emissions. Further heating by the waste heat of the tail gas reduces energy consumption and increases the temperature uniformity of the mixed gas.

[0037] Furthermore, the system described in this invention avoids the blockages and wear caused by traditional mechanical conveying by adopting pressurized pneumatic conveying, and improves the continuity and stability of the feeding and discharging process. The metal filter reduces the escape of fine particles with the exhaust gas, and improves the stability of normal operation of the equipment. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the porous carbon activation system of the heat-carrying particle circulation system according to an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the activation reaction process of the porous carbon activation system with circulating heat-carrying particles according to an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the fluidized bed reaction unit structure of the porous carbon activation system with circulating heat-carrying particles according to an embodiment of the present invention.

[0041] Explanation of reference numerals: 1-Heating buffer tank, 2-Raw material tank, 3-Lifting pipe, 4-Discharge valve, 5-Reaction tank, 6-Circuit pipe, 7-Gradient gas distributor, 8-Discharge valve, 9-Receiving tank, 10-Circulating fan, 11-Flow meter, 12-Gas preheating furnace, 13-Nitrogen pulse backflushing filter column, 14-Particle predistributor, 15-Reaction tail gas outlet, 16-Heat-carrying particle inlet, 17-Gas inlet, 18-Heat-carrying particle outlet, 19-Cyclone separator, 20-Tail gas conveying pipeline, 21-Gas mixing tank. Detailed Implementation

[0042] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0043] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0044] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0045] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] Please see Figure 1 , Figure 2 , Figure 3 The figures shown are schematic diagrams of the porous carbon activation system, the activation reaction flow diagram, and the fluidized bed reaction unit structure of the porous carbon activation system with heat-carrying particle circulation according to an embodiment of the present invention. The present invention provides a porous carbon activation system with heat-carrying particle circulation, comprising:

[0047] Fluidized bed reaction unit is used to activate the reactants through activating gas and heat-carrying particles to convert them into porous carbon;

[0048] A cooling and unloading unit, which is connected to the fluidized bed reaction unit, is used to cool the output porous carbon.

[0049] A feeding unit, which is located above the cooling and unloading unit, is used to transport the reaction raw materials, including a raw material tank for loading the reaction raw materials and a discharge valve connected to the raw material tank for controlling whether the raw materials are transported.

[0050] The exhaust gas conveying unit is connected to the fluidized bed reaction unit and is used to collect the reaction exhaust gas formed after the activation reaction.

[0051] An activation gas supply unit, which is connected to the tail gas delivery unit, is used to transfer the heat of the reaction tail gas to the activation gas for preheating and mixing with the activation gas to output a mixed activation gas.

[0052] A conveying and separating unit, connected to the fluidized bed reaction unit, is used to convey the heated heat-carrying particles to the activation reaction zone in the fluidized bed reaction unit to provide the heat required for the activation reaction. It includes a riser pipe vertically installed outside the raw material tank to provide conveying pressure for the heat-carrying particles by introducing nitrogen into the fluidized bed reaction unit, a cyclone separator connected to the riser pipe to separate the heat-carrying particles from the porous carbon, and a conveying fan connected to the cyclone separator to provide conveying power for the separated heat-carrying particles.

[0053] A heat-carrying particle heating unit, which is connected to the conveying and separating unit, is used to heat the heat-carrying particles that have not entered the fluidized bed reaction unit. It includes a heating buffer tank connected to the riser to reduce the pressure of the input nitrogen and to heat the heat-carrying particles, and a heating furnace connected to the heating buffer tank to heat the heating buffer tank.

[0054] Specifically, the cooling unloading unit includes:

[0055] The discharge valve 8 is connected to the reaction vessel 5 and is used to control whether porous carbon is output from the reaction vessel 5;

[0056] The receiving tank 9 is connected to the discharge valve 8 and is used to collect porous carbon;

[0057] The heat exchange tubes are installed on the wall of the receiving tank 9 to cool the receiving tank 9.

[0058] The condenser is connected to heat exchange tubes, which can also be replaced by water-cooled walls.

[0059] In implementation, the system of this invention comprises a fluidized bed reaction unit, a cooling and unloading unit, a feeding unit, a tail gas conveying unit, an activation gas supply unit, a heat-carrying particle heating unit, and a conveying and separation unit. Traditional fluidized bed activation equipment suffers from uneven temperature distribution in the activation reaction zone due to its singular heat transfer method, affecting the microstructure development of porous carbon. Micron- or nano-sized raw material particles are prone to channeling, surging, and other non-ideal fluidization phenomena, leading to decreased reaction efficiency. Traditional processes also exhibit low thermal energy utilization and high energy consumption during heating, resulting in energy waste. Furthermore, unreasonable equipment design or poor operational stability leads to frequent system shutdowns for maintenance, further reducing production efficiency. All these factors contribute to the final porous carbon having a small specific surface area and low microporosity. The system utilizes heat-carrying particles... The circulation unit circulates the heat-carrying particles, replacing static wall heating with heat transfer to ensure uniform development of the porous carbon micropore structure and reduce specific surface area fluctuations. The high-temperature exhaust gas is transported to a gas mixing tank via the exhaust gas conveying unit in the porous carbon processing unit. After mixing with fresh activation gas, it is heated in a preheating furnace, directly recovering the sensible heat of the exhaust gas, thereby improving the utilization rate of residual heat. This heat recovery reduces the energy consumption of the preheated gas and minimizes the disruption of fluidization caused by cold material entering the bed. This achieves increased specific surface area and microporosity during porous carbon production, as well as improved product uniformity and performance stability. By reconstructing the heat utilization mechanism, optimizing the porous carbon activation and heat-carrying particle separation process, and constructing an energy closed-loop network through exhaust gas circulation, efficient, stable, and low-consumption continuous production of porous carbon materials is achieved.

[0060] Specifically, the heat-carrying particles include at least one of alumina, silicon dioxide, zirconium oxide, and silicon carbide.

[0061] Specifically, the particle size of the heat-carrying particles does not exceed 300 μm, with a preferred particle size range of 80~120 μm, and the preferred shape of the heat-carrying particles is spherical.

[0062] Specifically, the heat-carrying particle heating unit includes a heating buffer tank and a heating furnace.

[0063] The heating buffer tank can be any one of fluidized bed, moving bed, rotary kiln, or fixed bed, with a preferred embodiment being a fluidized bed; the heating furnace can be any one of resistance heating, electromagnetic induction heating, or natural gas combustion heating.

[0064] In practice, the system of this invention preheats the heat-carrying particles to raise their temperature to the high-temperature range required for the activation reaction before they participate in the activation reaction. The preheated heat-carrying particles are then transported to the fluidized bed reaction unit via a riser using nitrogen as the transport medium. During this process, a heating buffer tank is used to reduce the airflow velocity, preventing the heat-carrying particles from breaking due to high-speed collisions. The particles are then uniformly dispersed into a fine beam by a particle pre-distributor before entering the activation reaction area. This ensures sufficient contact with the reaction raw materials and the transfer of heat, thereby improving the uniformity of temperature distribution in the reaction area and avoiding problems such as excessive micropore ablation caused by localized high temperatures or insufficient activation in low-temperature areas. The preheated heat-carrying particles provide a continuous and stable heat source for the activation reaction, improving the uniformity of the porous carbon microporous structure.

[0065] Specifically, the fluidized bed reaction unit includes:

[0066] A reaction vessel is used to provide a reaction site for activation reactions;

[0067] A particle pre-distributor 14 is disposed inside the reaction vessel to reduce the entry velocity of the heat-carrying particles;

[0068] A gradient gas distributor 7 is disposed below the particle pre-distributor to form a gradient gas flow of the activation gas to mix the reactants and the heat-carrying particles.

[0069] A metal filter, located at the top of the reaction vessel, is used to filter carbon powder in the reaction exhaust gas.

[0070] Specifically, the metal filter is equipped with a pulse gas backflushing device, which includes four nitrogen pulse backflushing filter columns 13.

[0071] Specifically, the heat-carrying particle inlet 16 is provided with a high-temperature valve for regulating the flow rate of the heat-carrying particles.

[0072] Optionally, the high-temperature valve can be implemented using any one of a slide valve, gate valve, or ball valve, and the valve core of the high-temperature valve can be a water-cooled jacketed valve core.

[0073] In practice, the system of the present invention introduces high-temperature alumina, silica, and metal particles into the fluidized bed reaction unit through a heat-carrying particle circulation unit. Utilizing their high heat capacity and good heat transfer performance, the temperature uniformity of the activation reaction zone is significantly improved, thereby increasing the specific surface area and microporosity of the porous carbon. The recycling of heat-carrying particles not only improves the thermal energy utilization rate and reduces the overall energy consumption, but also enhances the continuous operation capability of the system and extends the operating cycle.

[0074] Specifically, the unloading method of the cooling unloading unit is the pressure-feeding pneumatic conveying unloading method. In this embodiment, the conveying can be carried out by a Venturi feeder.

[0075] Specifically, a gas ring pipe 6 is provided at the bottom of the cyclone separator 19, and the gas introduced into the gas ring pipe 6 is nitrogen.

[0076] Specifically, the conveying and separating unit can convey gas via a conveying fan and / or transport heat-carrying particles via a conveyor belt.

[0077] Specifically, the activation gas supply unit includes:

[0078] Gas mixing tank 21 is used to mix the reaction tail gas and the activation gas to form a mixed activation gas;

[0079] A plurality of flow meters 11 are connected to the gas mixing tank to detect the flow rates of the activation gas, the reaction tail gas and the mixed activation gas, respectively.

[0080] A gas preheating furnace 12 is connected to the gas mixing tank and is used to heat the mixed activation gas.

[0081] Specifically, the gas preheating furnace 12 adopts any one or a combination of tail gas residual heat heating, resistance heating, and natural gas combustion heating.

[0082] Specifically, the exhaust gas delivery unit includes:

[0083] The exhaust gas delivery pipeline 20 is connected to the gas mixing tank;

[0084] A circulating fan 10 is connected to the exhaust gas conveying pipeline 20 to convey the reaction exhaust gas to the gas mixing tank.

[0085] Specifically, the volume ratio of the reaction tail gas to the activation gas in the gas mixing tank is 3:7 to 5:5.

[0086] Specifically, the types of activating gases include water vapor and carbon dioxide.

[0087] In practice, the system described in this invention achieves gradient distribution of activation gas in the fluidized bed by setting up a particle pre-distributor, a gradient gas distributor, and a metal filter, thereby improving gas-solid contact efficiency. By setting up a circulating fan and a tail gas delivery pipeline, the tail gas is recycled and reused, allowing unreacted components in the reaction tail gas to participate in the reaction again. This not only improves the utilization rate of raw materials but also reduces environmental pollution caused by reaction tail gas emissions. Further heating by the waste heat of the tail gas reduces energy consumption and increases the temperature uniformity of the mixed gas.

[0088] Specifically, the fluidized bed reaction unit also includes a conveying port assembly, which is located at the following positions from top to bottom on the reaction tank 5: reaction tail gas outlet 15, heat-carrying particle inlet 16, heat-carrying particle outlet 18, and gas inlet 17.

[0089] In practice, the system described in this invention avoids the blockages and wear caused by traditional mechanical conveying by adopting pressurized pneumatic conveying, and improves the continuity and stability of the feeding and discharging process. The metal filter reduces the escape of fine particles with the exhaust gas, and improves the stability of normal operation of the equipment.

[0090] Example 1: Preparation of petroleum coke-based high specific surface area porous carbon by a porous carbon activation system with circulating heat-carrying particles.

[0091] This embodiment uses a Φ800mm×6000mm reaction vessel, equipped with a four-stage precision temperature-controlled heating buffer tank. The bottom temperature is 950℃, the middle temperature is 900℃, the upper temperature is 850℃, and the separation zone temperature is 800℃. A high-temperature slide valve is used, with a valve core water cooling flow rate of 15L / min and a cooling medium temperature of 20℃. The heat-carrying particle circulation flow rate is controlled at 15kg / min to achieve self-equilibrium of the bed temperature field, i.e., the bed temperature difference is controlled within ±5℃. The heat-carrying particle circulation unit uses spherical Al2O3 particles with a particle size of 100±5μm and a bulk density of 1.32g / cm³. 3 The fluidized bed exhibits a 99.5% recovery rate with an entrainment rate of no more than 0.5%.

[0092] The operating parameters of the porous carbon activation system with circulating heat-carrying particles in this embodiment are as follows: ultrafine petroleum coke powder with a particle size of 5-8 μm is fed at a feed rate of 12 kg / h via pressurized pneumatic conveying, and mixed with the reaction tail gas preheated to 200°C, resulting in a 25% reduction in raw material preheating energy consumption; a mixed activation gas with a volume ratio of 7:3 water vapor and reaction tail gas is introduced into the gas mixing tank, and activation is carried out at 900°C for 7 hours; the gradient gas distributor forms an apparent gas velocity of 0.10 m / s for the gradient flow of activation gas; and the dynamic heat transfer of the heat-carrying particles is utilized. The process improves the temperature uniformity of the reaction zone by 90%, reducing micropore ablation caused by localized high temperatures in traditional processes. The process also involves switching to an activation gas mixture of CO2 and N2 at a volume ratio of 6:4, activating at 850℃ for 5 hours, reducing the apparent gas velocity to 0.08 m / s. A metal filter, combined with a pulsed nitrogen backflushing device at a pressure of 0.5 MPa and a frequency of 1 Hz, ensures zero-clogging separation of the ultrafine carbon powder. 40% of the reaction tail gas is combusted in a combustion jacket at 850℃ to produce fuel for raw material preheating, achieving a waste heat recovery rate of 65%.

[0093] Example 2: Preparation of phenolic resin-based narrow mesoporous carbon by a porous carbon activation system with heat-carrying particle circulation.

[0094] In this embodiment, a Φ600mm reaction vessel is used to crush phenolic resin carbonized material agglomerates with a particle size of 2-3μm to a dispersion of not less than 95%, and the radial temperature difference of the bed is reduced from ±50℃ in the traditional process to ±8℃; the heat-carrying particle circulation unit uses spherical SiO2 particles with a particle size of 80μm.

[0095] The operating parameters of the porous carbon activation system with circulating heat-carrying particles in this embodiment are as follows: The waste heat from the exhaust gas is used for heating; a circulating fan transports the 800°C reaction exhaust gas to a gas mixing tank, where it is mixed with the activation gas to preheat the raw materials from 25°C to 550°C, reducing energy consumption by 40% compared to electric heating; CO2 is activated at 920°C for 3 hours with an apparent gas velocity of 0.15 m / s; the mass ratio of heat-carrying particles to reaction raw materials is 8:1, and uniform mixing is achieved through a particle pre-distributor; a mixed activation gas of water vapor and reaction exhaust gas with a volume ratio of 5:5 is switched, and activation is performed at 780°C for 4 hours with an apparent gas velocity of 0.12 m / s; the stirring paddle speed is 15 rpm to suppress particle agglomeration; a 0.3μm pore size stainless steel 310s metal filter is used, combined with 0.5MPa nitrogen backflushing, achieving a 99.9% recovery rate of ultrafine carbon powder; 90% of the porous carbon has a pore size concentrated in the 3-5nm range, and the tap density is 0.75 g / cm³.

[0096] Example 3: Preparation of hierarchical porous structure of coconut shell biochar by a porous carbon activation system with heat-carrying particle circulation.

[0097] In this embodiment, the heat-carrying particle circulation unit uses γ-Al2O3 with a particle size of 90μm and a surface coated with a 2nm carbon layer, which isolates alkali metals through the carbon layer.

[0098] The operating parameters of the porous carbon activation system with heat-carrying particle circulation in this embodiment are as follows: In the first stage, a gradient gas distributor introduces a mixed activation gas of water vapor and reaction tail gas with a volume ratio of 7:3 and activates at 880°C for 5 hours, with a micropore formation rate of 200 m² / g•h; In the second stage, a mixed activation gas of CO2 and N2 with a volume ratio of 6:4 is introduced into the gradient gas distributor and activates at 820°C for 3 hours, with an apparent gas velocity of 0.07 m / s. Heat is supplied and the porous carbon particles are dispersed through heat-carrying particle circulation, connecting adjacent micropores into 2-50 nm mesopores, with a mesopore ratio of 30%.

[0099] In summary, the three embodiments verify that this embodiment is suitable for various raw materials such as petroleum coke, phenolic resin, and coconut shell, and achieves efficient activation through the selection of heat-carrying particles and process adjustments.

[0100] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A porous carbon activation system with circulating heat-carrying particles, characterized in that, include: Fluidized bed reaction unit is used to activate the reactants through activating gas and heat-carrying particles to convert them into porous carbon; A cooling and unloading unit, which is connected to the fluidized bed reaction unit, is used to cool the output porous carbon. A feeding unit, which is located above the cooling and unloading unit, is used to transport the reaction raw materials, including a raw material tank for loading the reaction raw materials and a discharge valve connected to the raw material tank for controlling whether the raw materials are transported. The exhaust gas conveying unit is connected to the fluidized bed reaction unit and is used to collect the reaction exhaust gas formed after the activation reaction. An activation gas supply unit, which is connected to the tail gas delivery unit, is used to transfer the heat of the reaction tail gas to the activation gas for preheating and mixing with the activation gas to output a mixed activation gas. A conveying and separating unit, connected to the fluidized bed reaction unit, is used to convey the heated heat-carrying particles to the activation reaction zone in the fluidized bed reaction unit to provide the heat required for the activation reaction. It includes a riser pipe vertically installed outside the raw material tank to provide conveying pressure for the heat-carrying particles by introducing nitrogen into the fluidized bed reaction unit, a cyclone separator connected to the riser pipe to separate the heat-carrying particles from the porous carbon, and a conveying fan connected to the cyclone separator to provide conveying power for the separated heat-carrying particles. A heat-carrying particle heating unit, which is connected to the conveying and separating unit, is used to heat the heat-carrying particles that have not entered the fluidized bed reaction unit. It includes a heating buffer tank connected to the riser to reduce the pressure of the input nitrogen and to heat the heat-carrying particles, and a heating furnace connected to the heating buffer tank to heat the heating buffer tank. The activation gas supply unit includes: A gas mixing vessel is used to mix the reaction tail gas and the activation gas to form a mixed activation gas; Several flow meters are connected to the gas mixing tank to detect the flow rates of the activation gas, the reaction tail gas, and the mixed activation gas, respectively. A gas preheating furnace, connected to the gas mixing tank, is used to heat the mixed activation gas; The exhaust gas delivery unit includes: An exhaust gas delivery pipeline, which is connected to the gas mixing tank; A circulating fan, connected to the exhaust gas delivery pipeline, is used to deliver the reaction exhaust gas to the gas mixing tank.

2. The porous carbon activation system with circulating heat-carrying particles according to claim 1, characterized in that, The heat-carrying particles include at least one of alumina, silicon dioxide, zirconium oxide, and silicon carbide.

3. The porous carbon activation system with circulating heat-carrying particles according to claim 2, characterized in that, The fluidized bed reaction unit includes: A reaction vessel is used to provide a reaction site for activation reactions; A particle pre-distributor, which is disposed inside the reaction vessel, is used to reduce the entry velocity of the heat-carrying particles; A gradient gas distributor is disposed below the particle pre-distributor to form a gradient gas flow of the activation gas to mix the reactants and the heat-carrying particles; A metal filter, located at the top of the reaction vessel, is used to filter carbon powder in the reaction exhaust gas.

4. The porous carbon activation system with circulating heat-carrying particles according to claim 3, characterized in that, The unloading method of the cooling unloading unit is the pressure conveying pneumatic conveying unloading method.

5. The porous carbon activation system with circulating heat-carrying particles according to claim 4, characterized in that, The volume ratio of the reaction tail gas to the activation gas in the gas mixing tank is 3:7 to 5:

5.

6. The porous carbon activation system with circulating heat-carrying particles according to claim 5, characterized in that, The types of activated gases include water vapor and carbon dioxide.

7. The porous carbon activation system with circulating heat-carrying particles according to claim 6, characterized in that, The fluidized bed reaction unit also includes a conveying port assembly, which is positioned from top to bottom in the reaction vessel as the reaction tail gas outlet, the heat-carrying particle inlet, the heat-carrying particle outlet, and the gas inlet.

8. The porous carbon activation system with circulating heat-carrying particles according to claim 7, characterized in that, The inlet of the heat-carrying particles is equipped with a high-temperature valve for regulating the flow rate of the heat-carrying particles.

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