A method and system for preparing high-value carbon materials by electromagnetic heating of biomass pyrolysis based on superheated steam flash explosion

Abstract

The application provides a method and system for preparing high-value carbon materials by electromagnetic heating biomass pyrolysis based on superheated steam flash explosion, and relates to the technical field of high-value carbon materials.The system of the application comprises a superheated steam generator, a biomass pretreatment unit, a conveying unit, a Venturi mixing jet, an electromagnetic auxiliary heating SX static mixer, an electromagnetic heating pyrolysis coil reactor, a gas-solid separation device and a waste heat recovery system.The application solves the problems of high energy consumption, long cycle and unstable product quality of the traditional process, significantly improves the specific surface area and pore structure uniformity of the carbon materials, can prepare various high-value carbon materials such as superfine carbon powder, activated carbon, nano-porous carbon and hard carbon, and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of high-value carbon materials technology, and in particular to a method and system for preparing high-value carbon materials by electromagnetic heating pyrolysis of biomass based on superheated steam flash explosion. Background Technology

[0002] Currently, biomass carbonization technologies mainly include two categories: hydrothermal carbonization and dry distillation carbonization.

[0003] While traditional hydrothermal carbonization can process raw materials with high water content, it has the following problems: First, the reaction time is long, usually requiring several to more than ten hours to complete carbonization, resulting in low production efficiency; second, it requires high operating pressure, usually between 2 and 10 MPa, leading to large equipment investment and high safety risks; third, the high solid-liquid ratio results in low unit equipment throughput and high energy consumption; and fourth, the intermittent operation mode makes it difficult to achieve continuous production, thus limiting capacity.

[0004] The carbonization method has the following problems: the raw materials must be pre-dried, which increases energy consumption and process complexity; the carbonization cycle is long, ranging from a dozen hours to several days; more importantly, the temperature control precision is poor, the product quality fluctuates greatly, and it is difficult to stably prepare high-performance carbon materials.

[0005] In terms of heating methods, existing technologies mostly use gas combustion heating, with temperature fluctuations reaching 50°C. Furthermore, the combustion process requires the participation of oxygen, inevitably causing some carbon oxidation loss and generating large amounts of waste gases such as carbon dioxide and carbon monoxide, which does not meet the requirements of clean production.

[0006] In addition, existing equipment generally lacks efficient gas-liquid mixing devices and waste heat recovery systems. Uneven mixing of raw materials and carrier gas leads to incomplete carbonization, and a large amount of high-temperature exhaust gas is directly emitted, resulting in energy waste.

[0007] Therefore, developing a rapid pyrolysis and carbonization method for biomass that features fast reaction speed, high temperature control accuracy, low energy consumption, stable product quality, and environmental friendliness is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] In view of this, the present invention provides a method and system for preparing high-value carbon materials by electromagnetic heating biomass pyrolysis based on superheated steam flash explosion. This invention combines superheated steam flash explosion technology with precise electromagnetic heating, employs a Venturi mixing jet to achieve rapid gas-liquid mixing, utilizes an SX-type static mixer to enhance mass and heat transfer, and coordinates with an electromagnetically heated pyrolysis reactor to achieve precise temperature control. Furthermore, it improves energy utilization efficiency through a multi-stage gas-solid separation and waste heat recovery system, achieving rapid and continuous pyrolysis carbonization of biomass. This solves the technical problems of long reaction time, high energy consumption, poor temperature control accuracy, and unstable product quality associated with traditional processes. Complete carbonization and activation of biomass can be completed within 8-15 seconds, producing a variety of high-value carbon materials with controllable specific surface area and high pore structure, showing promising application prospects.

[0009] The first aspect of this invention is to provide a system for preparing high-value carbon materials by electromagnetic heating biomass pyrolysis based on superheated steam flash explosion, comprising:

[0010] A superheated steam generator is used to produce high-temperature, high-pressure superheated steam.

[0011] The biomass pretreatment unit includes a device for mixing and homogenizing biomass pulverized raw materials with pure water;

[0012] The conveying unit is used to transport the homogenized and emulsified biomass slurry to the mixing station;

[0013] The Venturi mixing jet has its inlet end connected to the outlet of the superheated steam generator and the outlet of the biomass slurry conveying unit, respectively, and is used to perform preliminary mixing of superheated steam and biomass slurry.

[0014] The SX-type static mixer with electromagnetic assistance heating has its inlet connected to the outlet of the Venturi mixing jet, which is used to further homogenize the collision mixture and the carrier gas and start preheating. The electromagnetic heating temperature control accuracy of the SX-type static mixer with electromagnetic assistance heating is ±2℃.

[0015] The electromagnetically heated thermal pyrolysis coil reactor has its inlet connected to the outlet of the SX-type static mixer, providing the main site for thermal pyrolysis, carbonization and activation reactions of the material. The electromagnetic heating temperature control accuracy of the electromagnetically heated thermal pyrolysis coil reactor is ±2℃.

[0016] A gas-solid separation device is used to separate solid carbon materials and gaseous products generated after pyrolysis.

[0017] A waste heat recovery system is used to recover the waste heat from the gas discharged from the gas-solid separation device.

[0018] Preferably, the biomass pretreatment unit includes a biomass pulverizer, a vertical drum disperser, and a high-speed homogenizer or a high-pressure homogenizer connected in sequence. More preferably, the high-speed homogenizer has a rotation speed of 1500-10000 rpm, and the high-pressure homogenizer has a pressure of 80-200 MPa.

[0019] Preferably, the conveying unit is a combination of a single screw pump or a screw feeder and an air conveyor.

[0020] Preferably, the gas-solid separation device includes a cyclone separator and a bag filter connected in sequence.

[0021] Preferably, the waste heat recovery system includes a flash tank, a condenser, a hot water tank, a hot water circulation pump, and a steam compressor.

[0022] Preferably, the system further includes a carrier gas supply unit for providing carrier gas, which is connected to the carrier gas inlet of the SX-type static mixer.

[0023] A second aspect of the present invention is to provide a method for preparing high-value carbon materials using the above-described system, comprising the following steps:

[0024] S1. Pretreatment: The biomass raw material is crushed, mixed with pure water, and then homogenized and emulsified to obtain a homogenized biomass emulsion slurry.

[0025] S2, Mixing and Flash Explosion: The biomass homogeneous emulsion slurry obtained in S1 is mixed with superheated steam from the superheated steam generator in a Venturi mixing jet, and then enters an electromagnetically assisted heated SX-type static mixer and a thermal cracking coil reactor, where flash heating is carried out within 8-15 s in an anaerobic environment coupled with multiple fields (thermal field, pressure field, fluid field).

[0026] S3. Thermal pyrolysis and carbonization: In the thermal pyrolysis coil reactor, the material is heated by electromagnetic heating to carry out thermal pyrolysis and dehydration carbonization activation reactions to generate a gas-solid mixture.

[0027] S4. Separation and recovery: The gas-solid mixture generated in step S3 is separated by a gas-solid separation device to obtain high-value carbon materials. The gaseous products enter the waste heat recovery system for heat recovery.

[0028] Preferably, in step S1, the biomass raw material includes at least one of the following: straw, sawdust, bamboo powder, sugarcane bagasse, cassava residue, tofu residue, distiller's grains, brewer's grains, fruit and vegetable residues, animal manure, molasses waste from sugar factories, and molasses alcohol waste liquid; the particle size of the biomass raw material after pulverization is 50-1500 mesh; and the pure water is hot water.

[0029] Preferably, in step S2, the temperature of the superheated steam is 230-600℃ and the pressure is 1.6-5 MPa.

[0030] Preferably, in step S3, the temperature of the thermal cracking and dehydration carbonization activation reaction is 550-950℃.

[0031] Preferably, the high-value carbon material includes at least one of ultrafine carbon powder, activated carbon, high specific surface area activated carbon, nanoporous carbon, biomass-based graphene, carbon nanotubes, hard carbon for sodium-ion / lithium-ion batteries, and carbon for supercapacitors. This invention obtains high-value-added carbon material products of different specifications by controlling the temperature and pressure parameters of superheated steam, the electromagnetic heating temperature, and the residence time of materials in the reactor, combined with the use of protective carrier gas and auxiliary additives.

[0032] Preferably, the auxiliary additive is at least one selected from activator, dopant, oxidant, template agent, and catalyst.

[0033] Preferably, the activator is at least one of potassium hydroxide, sodium hydroxide, baking soda, and potassium oxalate, and its dosage is 10%-50% of the toner; the dopant is at least one of melamine, urea, ammonium bicarbonate, and ammonia, and its dosage is 1-15% of the toner; the oxidant is at least one of hydrogen peroxide, ozone, potassium permanganate, sulfuric acid, and nitric acid, and its dosage is 5-10% of the toner; the template agent is at least one of minerals in ash, nano-alumina, nano-magnesium oxide, and nano-silica, and its dosage is 0.5-1.5% of the toner; the catalyst is a transition metal and its compound, preferably iron, cobalt, nickel, and their compounds, more preferably iron(III) oxide or ferrocene, and its dosage is 0.5-1.5% of the toner.

[0034] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0035] This invention achieves rapid and continuous production by combining superheated steam flash explosion with precise electromagnetic heating, enabling biomass to be converted from slurry to carbon materials within 8-15 seconds.

[0036] This invention employs electromagnetic heating technology, achieving a temperature control accuracy of ±2℃, which ensures the uniformity of the microstructure of carbon materials and the consistency of quality between batches, thus providing a guarantee for the preparation of high-performance carbon materials.

[0037] The system of this invention eliminates the need for pre-drying of raw materials, allowing direct processing of biomass slurry. Furthermore, this invention is equipped with a comprehensive waste heat recovery system to recover the sensible and latent heat of high-temperature exhaust gases, significantly improving overall energy utilization efficiency.

[0038] This invention enables the targeted preparation of various high-value carbon materials by controlling the temperature and pressure of superheated steam and electromagnetic heating temperature, combined with different residence times and the addition of different types of additives, to meet the needs of different application fields.

[0039] This invention utilizes electromagnetic heating throughout the entire process in an oxygen-free or protective atmosphere, avoiding carbon oxidation losses and harmful gas emissions caused by the participation of oxygen in traditional gas heating methods, thus meeting clean production requirements.

[0040] This invention can process a variety of agricultural and forestry wastes and industrial organic wastes, such as straw, sawdust, bamboo powder, sugarcane bagasse, cassava residue, tofu residue, distiller's grains, brewer's grains, fruit and vegetable residues, animal manure, molasses waste from sugar factories, and molasses alcohol waste liquid. It can process both dry-processed crushed materials and wet-processed slurries, providing an effective method for the comprehensive utilization of biomass resources and the resource utilization of waste.

[0041] This invention achieves efficient gas-liquid mixing through a Venturi mixing jet, enhances mass and heat transfer and uniform dispersion using an SX-type static mixer, and combines two-stage gas-solid separation with a cyclone separator and a bag filter to ensure high product collection efficiency and uniform particle size distribution. The entire system achieves full-process optimization from raw material pretreatment, mixing and flash explosion, thermal pyrolysis and carbonization, gas-solid separation to waste heat recovery, laying a technical foundation for industrial continuous production. Attached Figure Description

[0042] The present invention will be further described below with reference to the accompanying drawings.

[0043] Figure 1 This is a schematic diagram of the process flow of the system of the present invention;

[0044] Figure 2 This is a schematic diagram of the Venturi mixing jet structure of the present invention;

[0045] Figure 3 This is a schematic diagram of the SX-type static mixer structure of the present invention;

[0046] In the figure, 1-superheated steam inlet flange, 2-slurry inlet flange, 3-mixing section, 4-throat compression section, 5-diffusion section, 6-gas-solid mixture outlet flange, 7-mixture inlet flange, 8-carrier gas inlet flange, 9-internal structure of SX type static mixer, 10-mixture outlet flange, 11-electromagnetic heating coil. Detailed Implementation

[0047] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0048] Unless otherwise specified, all experiments were repeated three times, and the results are expressed as averages.

[0049] Example 1: A method for preparing nanoporous carbon using wood chips as raw material, comprising the following steps:

[0050] The process flow of this embodiment is as follows: Figure 1 As shown, the schematic diagrams of the Venturi mixing jet and the SX-type static mixer are as follows: Figure 2 , Figure 3 As shown;

[0051] After the wood chips are pulverized (500 mesh powder) by a pulverizer, they are mixed with urea to obtain a biomass nitrogen-doped mixture. A superheated steam generator is started to produce superheated steam at 400℃ and 1.6 MPa. The wood chip mixture is then fed through a screw feeder and pneumatic conveyor via the steam inlet flange 1 and the slurry inlet flange 2 to a Venturi mixing jet. The two streams converge in the mixing section 3, are accelerated and instantly mixed in the throat compression section 4, and then enter the diffusion section 5 for deceleration and pressurization. Finally, the mixture is discharged through the gas-solid mixture outlet flange 6, completing the initial mixing of the superheated steam and the wood chip mixture. The mixture then enters an electromagnetically assisted heated SX-type static mixer through the mixture inlet flange 7, while carbon dioxide activator carrier gas is introduced through the carrier gas inlet flange 8. The gas-solid mixture is fully dispersed and uniformly dispersed within the internal structure 9 of the SX-type static mixer, and is precisely preheated by the electromagnetic heating coil 11. The premixed mixture then enters an electromagnetically heated thermal decomposition coil reactor through the mixture outlet flange 10, where it is held at 850℃ for 10 minutes. The gas undergoes thermal cracking and carbonization activation; the gas-solid mixture after the reaction enters a cyclone separator and a bag filter to collect ultrafine carbon powder products; the high-temperature gas discharged from the bag filter enters the waste heat recovery system, the flash tank generates low-pressure steam, which is recovered and reused by a steam compressor or the hot water is recovered by a condenser and sent to a hot water tank for storage, and the exhaust gas is discharged by an induced draft fan after cooling.

[0052] Testing revealed that the obtained nanoporous carbon particles had a uniform size distribution. 50 It has a wavelength of 500 nm and a relatively large specific surface area of ​​850 m². 2 / g, suitable for supercapacitor carbon.

[0053] Example 2: A method for preparing hard carbon for lithium-ion / sodium-ion batteries using sugarcane bagasse as raw material, the steps of which are as follows:

[0054] The process flow of this embodiment is as follows: Figure 1 As shown, the schematic diagrams of the Venturi mixing jet and the SX-type static mixer are as follows: Figure 2 , Figure 3 As shown;

[0055] Sugarcane bagasse was pulverized (300 mesh) and then mixed with melamine and phosphorus to obtain a biomass nitrogen-phosphorus co-mixture. A superheated steam generator was then started to produce steam at 550℃ and 2.0℃. Superheated steam at MPa is fed through a screw feeder and pneumatic conveyor to transport the bagasse mixture through steam inlet flange 1 and slurry inlet flange 2 to a Venturi mixing jet. The two materials converge in mixing section 3, accelerate and collide in throat compression section 4, and are instantaneously mixed before entering diffusion section 5 for deceleration and pressurization. Finally, the mixture is discharged through gas-solid mixture outlet flange 6, completing the initial mixing of superheated steam and bagasse mixture. The mixture then enters an electromagnetically assisted heated SX-type static mixer through mixture inlet flange 7, while carbon dioxide activator carrier gas is introduced through carrier gas inlet flange 8. The gas-solid mixture is fully dispersed and uniformly dispersed in the internal structure 9 of the SX-type static mixer, and is precisely preheated by electromagnetic heating coil 11. The premixed mixture enters an electromagnetically heated thermal decomposition coil reactor through mixture outlet flange 10, where it is held at 950°C for 15 minutes. The gas undergoes thermal cracking and carbonization activation; the gas-solid mixture after the reaction enters a cyclone separator and a bag filter to collect ultrafine carbon powder products; the high-temperature gas discharged from the bag filter enters the waste heat recovery system, the flash tank generates low-pressure steam, which is recovered and reused by a steam compressor or the hot water is recovered by a condenser and sent to a hot water tank for storage, and the exhaust gas is discharged by an induced draft fan after cooling.

[0056] Testing revealed that the obtained hard carbon particles had a uniform size distribution. 50 The diameter is 8 μm, and the tap density is 0.8 g / cm³. 3 Its specific capacity reaches 450 mAh / g, and its charging cycle stability is excellent, making it suitable for hard carbon materials as anodes in lithium-ion / sodium batteries.

[0057] Example 3: A method for preparing organic carbon fertilizer using chicken manure as raw material, comprising the following steps:

[0058] The process flow of this embodiment is as follows: Figure 1 As shown, the schematic diagrams of the Venturi mixing jet and the SX-type static mixer are as follows: Figure 2 , Figure 3 As shown;

[0059] Chicken manure is pulverized in a pulverizer and then mixed with pure water (hot water) at a solids content to pure water ratio of 35% in a vertical drum disperser. The mixture is then homogenized and emulsified using a high-speed, high-pressure homogenizer to obtain a uniform biomass slurry. A superheated steam generator is then activated to produce steam at a temperature of 500℃ and a pressure of 3.0... Superheated steam at MPa is pumped via a single screw pump to transport chicken manure slurry through steam inlet flange 1 and slurry inlet flange 2 to a Venturi mixing jet. The two materials converge in mixing section 3, accelerate and collide in throat compression section 4, and are instantaneously mixed before entering diffusion section 5 for deceleration and pressurization. Finally, the mixture is discharged through gas-solid mixture outlet flange 6, completing the initial mixing of superheated steam and chicken manure slurry. The mixture then enters an electromagnetically assisted heated SX-type static mixer through mixture inlet flange 7, while nitrogen protective carrier gas is introduced through carrier gas inlet flange 8. The gas-solid mixture is fully dispersed and uniformly dispersed within the internal structure 9 of the SX-type static mixer, and is precisely preheated by electromagnetic heating coil 11. The premixed mixture then enters an electromagnetically heated thermal decomposition coil reactor through mixture outlet flange 10, where it is held at 650°C for 8 hours. The gas undergoes thermal cracking and carbonization; the gas-solid mixture after the reaction enters a cyclone separator and a bag filter to collect ultrafine carbon powder products; the high-temperature gas discharged from the bag filter enters the waste heat recovery system, the flash tank generates low-pressure steam, which is recovered and reused by a steam compressor or the hot water is recovered by a condenser and sent to a hot water tank for storage, and the exhaust gas is discharged by an induced draft fan after cooling.

[0060] The obtained organic carbon content was found to be 80%, and the carbon particle size distribution was uniform. 50 ≤1 μm, carbon products are suitable for preparing organic carbon raw materials, adaptable to soil improvement solid organic fertilizers, and can be applied directly or mixed with organic fertilizers.

[0061] Example 4 A method for preparing water-soluble carbon fertilizer using molasses / alcohol waste liquid as raw material, the steps of which are as follows:

[0062] The process flow of this embodiment is as follows: Figure 1 As shown, the schematic diagrams of the Venturi mixing jet and the SX-type static mixer are as follows: Figure 2 , Figure 3 As shown;

[0063] Molasses / alcohol waste liquid contains high moisture content and rich trace elements of organic matter. The molasses / alcohol waste liquid (mixture, 1:1) is directly added to a vertical tank disperser. A single screw pump transports the molasses / alcohol waste liquid through the hot steam inlet flange 1 and the slurry inlet flange 2 to a Venturi mixing jet. The two materials converge in the mixing section 3, are accelerated and collided in the throat compression section 4, and then enter the diffusion section 5 for deceleration and pressurization. Finally, the mixture is discharged through the gas-solid mixture outlet flange 6, completing the initial mixing of high-temperature (500℃, 2 MPa) high-pressure superheated steam with the molasses / alcohol waste liquid. The mixture then enters an electromagnetically assisted heated SX-type static mixer through the mixture inlet flange 7, while nitrogen protective carrier gas is introduced through the carrier gas inlet flange 8. The gas-solid mixture is fully dispersed and uniformly dispersed within the internal structure 9 of the SX-type static mixer, and is precisely preheated by the electromagnetic heating coil 11. The premixed mixture then enters an electromagnetically heated thermal decomposition coil reactor through the mixture outlet flange 10, where it is held at 750℃ for 12 minutes. The gas undergoes thermal cracking and carbonization; the gas-solid mixture after the reaction enters a cyclone separator and a bag filter to collect porous carbon powder products; the high-temperature gas discharged from the bag filter enters the waste heat recovery system, the flash tank generates low-pressure steam, which is recovered and reused by a steam compressor or the hot water is recovered by a condenser and sent to a hot water tank for storage, and the exhaust gas is discharged by an induced draft fan after cooling.

[0064] The obtained organic carbon content was found to be 80%, and the carbon particle size distribution was uniform. 50 With a particle size of ≤10 μm, the carbon product is suitable for deep processing to prepare 100 nm organic water-soluble carbon fertilizer, which is suitable for foliar spraying of plants.

[0065] Example 5: A method for preparing water-soluble carbon fertilizer using tofu residue as raw material, comprising the following steps:

[0066] The process flow of this embodiment is as follows: Figure 1 As shown, the schematic diagrams of the Venturi mixing jet and the SX-type static mixer are as follows: Figure 2 , Figure 3 As shown;

[0067] The tofu dregs are pulverized using a wet grinder and then mixed with pure water (hot water) at a solids-to-water ratio of 50% in a vertical tank disperser. The mixture is then homogenized and emulsified using a high-speed, high-pressure homogenizer to obtain a uniform tofu dregs protein slurry. A superheated steam generator is then activated to produce steam at a temperature of 550℃ and a pressure of 2.5... Superheated steam at MPa is pumped via a single screw pump to deliver tofu residue slurry through steam inlet flange 1 and slurry inlet flange 2 to a Venturi mixing jet. The two materials converge in mixing section 3, accelerate and collide in throat compression section 4, and are instantaneously mixed before entering diffusion section 5 for deceleration and pressurization. Finally, the mixture is discharged through gas-solid mixture outlet flange 6, completing the initial mixing of superheated steam and tofu residue slurry. The mixture then enters an electromagnetically assisted heated SX-type static mixer through mixture inlet flange 7, while nitrogen protective carrier gas is introduced through carrier gas inlet flange 8. The gas-solid mixture is fully dispersed and uniformly dispersed within the internal structure 9 of the SX-type static mixer, and is precisely preheated by electromagnetic heating coil 11. The premixed mixture then enters an electromagnetically heated thermal decomposition coil reactor through mixture outlet flange 10, where it is held at 650°C for 10 minutes. The gas undergoes thermal cracking and carbonization; the gas-solid mixture after the reaction enters a cyclone separator and a bag filter to collect ultrafine carbon powder products; the high-temperature gas discharged from the bag filter enters the waste heat recovery system, the flash tank generates low-pressure steam, which is recovered and reused by a steam compressor or the hot water is recovered by a condenser and sent to a hot water tank for storage, and the exhaust gas is discharged by an induced draft fan after cooling.

[0068] The obtained organic carbon content was found to be 70%, and the carbon particle size distribution was uniform. 50 With a particle size of ≤5 μm, the carbon product is suitable for deep processing to prepare 200 nm organic water-soluble carbon fertilizer, and is suitable for drip application of liquid fertilizer to plant roots.

[0069] Example 6

[0070] The difference from Example 1 is that the hot steam temperature and pyrolysis temperature are changed. The parameter settings and test results are shown in Table 1.

[0071] Table 1

[0072]

[0073] As the temperature and steam temperature increase, the specific surface area and total pore volume of pyrolysis carbon materials increase, but the carbonization efficiency gradually decreases with increasing temperature. This is because high temperatures cause more organic matter to be converted into gaseous products, reducing the amount of solid carbon products. Therefore, if high carbonization efficiency is desired, low-temperature carbonization groups 1 and 2 are used for organic carbon fertilizers used in agricultural soil improvement; if a balance between carbon yield and pore structure is desired for electrode materials, medium-temperature carbonization group 3 is selected; and if high specific surface area is desired for adsorption materials and activated carbon, high-temperature carbonization groups 4 and 5 are selected.

[0074] Comparative Example 1

[0075] The difference from Example 1 is that there is no superheated steam flash explosion.

[0076] When there is no superheated steam flash explosion in the system, the dry-crushed powder or biomass slurry cannot be instantly dispersed, propelled, and heated at high temperature. As a result, the mixture is prone to agglomeration and caking, which can easily block the reaction pipeline, making carbonization and activation difficult, and further hindering the separation and collection of gas-solid powders.

[0077] Comparative Example 2

[0078] The difference from Example 1 is that conventional 170°C saturated steam is used.

[0079] Since saturated steam temperature is directly proportional to pressure, when the saturated steam temperature is low, the slurry cannot form flash heating characteristics when it collides with the steam. The slurry cannot undergo dehydration, pyrolysis, and condensation reactions. The low-pressure driving force and fluidity are insufficient, and the gas-solid carbonization instantaneous carbonization mechanism cannot be formed.

[0080] Comparative Example 3

[0081] The difference from Example 1 is that gas combustion heating is used instead of electromagnetic heating.

[0082] Electromagnetic heating indirectly heats powders or slurries in an oxygen-free environment, allowing for precise temperature control within ±2℃. In contrast, natural gas combustion requires oxygen. If natural gas is directly mixed with powders or slurries for heating, a large amount of oxygen participates in the combustion process, leading to significant temperature fluctuations and making precise temperature control difficult (comparison of combustion temperature differences: natural gas temperature control ±50℃ vs. electromagnetic heating temperature control ±2℃, a difference of approximately 25 times). This results in aerobic combustion of biomass, failing to achieve oxygen-free carbonization. Instead, the carbonization process generates a large amount of impurities, ash, and harmful combustion gases, hindering biomass carbonization. Therefore, the importance and necessity of high-temperature electromagnetic heating in accelerating the dry or wet carbonization activation of biomass are highlighted.

[0083] Comparative Example 4

[0084] The difference from Example 1 is that there is no static mixer.

[0085] In the dry or wet pyrolysis process of biomass powder, when the powder or slurry flashes and explodes with superheated steam in a Venturi mixing jet tube, the temperature of the mixture decreases and agglomerates during gas-liquid mixing. When the gas-liquid mixture enters the electromagnetically assisted heating SX-type static mixer, it is thoroughly mixed and dispersed, and instantly heated to a high temperature, enhancing the heating, mixing, and flow, thus accelerating the carbonization and activation reaction of the next stage of electromagnetic heating coil pyrolysis. Therefore, the gas-liquid mixture is premixed and preheated with nitrogen or carbon dioxide carrier gas in the static mixer, illustrating the necessity of premixing and preheating in the electromagnetically assisted heating static mixer.

[0086] Comparative Example 5

[0087] Traditional hydrothermal carbonization processes typically involve a solid-liquid ratio of 1:5 to 1:10 in high-moisture wet hydrothermal carbonization, with relatively low reaction temperatures (usually 180-250℃) and high pressures (2-10MPa). This process suffers from intermittent operation, lack of waste heat recovery, slow reaction speed (usually requiring several to over ten hours), long reaction time, high energy consumption, and low efficiency. The carbon products obtained from carbonization have low recovery rates and poor quality. Therefore, the importance of using superheated steam flash explosion electromagnetic heating pyrolysis carbonization technology for biomass powder dry or wet slurry is highlighted.

[0088] Comparative Example 6

[0089] Traditional dry distillation carbonization processes cannot use biomass raw materials with high moisture content. Carbonization requires drying, dehydration, and a long carbonization process of several hours to several days. The slow pyrolysis cycle is long and the carbonization efficiency is low. Therefore, the superheated steam flash explosion electromagnetic heating pyrolysis carbonization process of biomass powder dry or wet slurry is of great importance.

[0090] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A system for preparing high-value carbon materials by electromagnetic heating biomass pyrolysis based on superheated steam flash explosion, characterized in that, include: A superheated steam generator is used to produce high-temperature, high-pressure superheated steam. The biomass pretreatment unit includes a device for mixing and homogenizing biomass pulverized raw materials with pure water; The biomass slurry conveying unit is used to convey homogenized and emulsified biomass slurry to the mixing station; The Venturi mixing jet has its inlet end connected to the outlet of the superheated steam generator and the outlet of the biomass slurry conveying unit, respectively, and is used to perform preliminary mixing of superheated steam and biomass slurry. An electromagnetically assisted heating SX-type static mixer, with its inlet connected to the outlet of the Venturi mixing jet, is used to further homogenize the collision mixture and carrier gas and initiate preheating. The electromagnetic heating temperature control accuracy of the electromagnetically assisted heating SX-type static mixer is ±2℃. An electromagnetically heated pyrolysis coil reactor, with its inlet connected to the outlet of the SX-type static mixer, provides the main pyrolysis, carbonization, and activation reaction sites for the material. The electromagnetic heating temperature control accuracy of the electromagnetically heated pyrolysis coil reactor is ±2℃. A gas-solid separation device is used to separate solid carbon materials and gaseous products generated after pyrolysis. A waste heat recovery system is used to recover the waste heat from the gas discharged from the gas-solid separation device.

2. The system for preparing high-value carbon materials by electromagnetic heating biomass pyrolysis based on superheated steam flash explosion according to claim 1, characterized in that... The biomass pretreatment unit includes a biomass pulverizer, a vertical drum disperser, and a high-speed homogenizer or a high-pressure homogenizer connected in sequence.

3. The system for preparing high-value carbon materials by electromagnetic heating biomass pyrolysis based on superheated steam flash explosion according to claim 1, characterized in that, The biomass slurry conveying unit is a combination of a single screw pump or a screw feeder and an air conveyor.

4. The system for preparing high-value carbon materials by electromagnetic heating biomass pyrolysis based on superheated steam flash explosion according to claim 1, characterized in that, The gas-solid separation device includes a cyclone separator and a bag filter connected in sequence.

5. The system for preparing high-value carbon materials by electromagnetic heating biomass pyrolysis based on superheated steam flash explosion according to claim 1, characterized in that, The waste heat recovery system includes a flash tank, a condenser, a hot water tank, a hot water circulation pump, and a steam compressor.

6. A method for preparing high-value carbon materials, characterized in that, The preparation method, carried out using the system according to any one of claims 1-5, comprises the following steps: S1. Pretreatment: The biomass raw material is crushed, mixed with pure water, and then homogenized and emulsified to obtain a homogenized biomass emulsion slurry. S2, Mixing and Flash Explosion: The biomass homogeneous emulsion slurry obtained in S1 is mixed with superheated steam from the superheated steam generator in a Venturi mixing jet, and then enters an electromagnetically assisted heated SX-type static mixer and a thermal cracking coil reactor, where flash heating is carried out within 8-15s in a multi-field coupled anaerobic environment. S3. Thermal pyrolysis and carbonization: In the thermal pyrolysis coil reactor, the material is heated by electromagnetic heating to carry out thermal pyrolysis and dehydration carbonization activation reactions to generate a gas-solid mixture. S4. Separation and recovery: The gas-solid mixture generated in step S3 is separated by a gas-solid separation device to obtain high-value carbon materials. The gaseous products enter the waste heat recovery system for heat recovery.

7. The preparation method according to claim 6, characterized in that, In step S1, the biomass raw material includes at least one of the following: straw, sawdust, bamboo powder, sugarcane bagasse, cassava residue, tofu residue, distiller's grains, brewer's grains, fruit and vegetable residues, animal manure, molasses waste from sugar factories, and molasses alcohol waste liquid; the particle size of the biomass raw material after pulverization is 50-1500 mesh; and the pure water is hot water.

8. The preparation method according to claim 6, characterized in that, In step S2, the temperature of the superheated steam is 230-600℃ and the pressure is 1.6-5MPa.

9. The preparation method according to claim 6, characterized in that, In step S3, the temperature of the thermal cracking and dehydration carbonization activation reaction is 550-950℃.

10. The preparation method according to claim 6, characterized in that, The high-value carbon materials include at least one of ultrafine carbon powder, activated carbon, nanoporous carbon, biomass-based graphene, carbon nanotubes, hard carbon for sodium-ion / lithium-ion batteries, and carbon for supercapacitors.

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