An emission reduction method for producing activated carbon using waste biomass
By employing adaptive conditioning pretreatment, staged pyrolysis gasification, catalytic reforming, and energy self-consistent control, the problems of high energy consumption, poor raw material adaptability, and high pollutant treatment costs in existing activated carbon production have been solved. This has enabled efficient emission reduction and cascaded energy utilization of waste biomass, resulting in the production of high-efficiency activated carbon.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 云南中试验证科技发展集团有限公司
- Filing Date
- 2025-09-27
- Publication Date
- 2026-06-19
AI Technical Summary
Existing activated carbon production methods are energy-intensive, have high carbon emissions, poor raw material adaptability, high tar content, and high pollutant treatment costs. Furthermore, traditional processes are difficult to apply universally.
By employing adaptive conditioning pretreatment, staged pyrolysis gasification and primary carbon-gas separation, online catalytic reforming of syngas, biochar self-activation and product generation, and energy self-consistency and synergistic control of pollutants, efficient emission reduction of waste biomass is achieved in the production of activated carbon.
It significantly reduces external energy input, lowers tar content, improves raw material adaptability, achieves cascaded energy utilization and synergistic removal of pollutants, and generates highly efficient activated carbon.
Smart Images
Figure CN122233375A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of environmental protection and comprehensive resource utilization technology, specifically to an emission reduction method for producing activated carbon from waste biomass. Background Technology
[0002] With the global push towards carbon neutrality, the resource utilization of waste biomass (such as agricultural straw, forestry waste, and food processing residues) has become a research hotspot. Activated carbon, as a highly efficient adsorption material, is widely used in environmental remediation and energy storage. Traditional activated carbon production methods mainly include physical activation (using carbon dioxide or water vapor as activating agents) and chemical activation (using phosphoric acid, potassium hydroxide, etc. as activating agents).
[0003] After searching, the following problems were found in the existing technology:
[0004] 1. Physical activation requires high temperatures of 800–1000℃, while chemical activation, although at lower temperatures (400–600℃), consumes large amounts of activating agents that are difficult to recover, resulting in high energy consumption and carbon emissions. For example, producing 1 ton of activated carbon requires 3.5–5 tons of high-quality raw coal, while burning waste activated carbon releases 0.128 tons of carbon dioxide per ton.
[0005] 2. The lignocellulose composition of different biomass raw materials (such as straw, sawdust, and fruit shells) varies significantly. For example, the high ash content (5–15%) of straw easily leads to coking and equipment corrosion, while the efficient utilization of fruit shell raw materials is concentrated in specific regions (such as the Ningxia fruit shell activated carbon project), and no universally applicable technology has been formed.
[0006] 3. In traditional gasification-activation processes, the tar content is as high as 300–500 mg / m³, the calorific value of the fuel gas is low (requiring additional combustion), and black water waste containing heavy metals is generated, resulting in high treatment costs. The activation furnace exhaust gas contains SO2 (200–500 mg / m³), NOx (150–400 mg / m³), and particulate matter (50–150 mg / m³), requiring multi-technology coupling for treatment. Summary of the Invention
[0007] (a) Technical problems to be solved
[0008] To address the shortcomings of existing technologies, this invention provides an xxxx that solves the aforementioned problems in the background technology.
[0009] (II) Technical Solution
[0010] To achieve the above objectives, the present invention provides the following technical solution: a method for reducing emissions by producing activated carbon from waste biomass, comprising the following steps:
[0011] S1. Adaptive conditioning and pretreatment of raw materials: Obtain waste biomass raw materials containing at least one of agricultural straw, forestry waste, and food processing residue. Perform online composition and physical property testing on the waste biomass raw materials to obtain data on moisture content, ash content, volatile matter, and fixed carbon content. Based on the data, automatically classify the waste biomass raw materials into one of at least three preset processing grades through a material classification matrix. Based on the processing grade, adaptively adjust the crushing particle size of the crushing module and the drying temperature and drying time of the drying module to process the waste biomass raw materials into standardized pretreated materials with a particle size of 5-50 mm and a moisture content of less than 15%.
[0012] S2. Staged pyrolysis gasification and primary biochar separation: The standardized pretreated material is continuously fed into a multi-stage gasifier, which is configured from top to bottom as a drying section, a low-temperature pyrolysis section, a high-temperature gasification section, and a burnout section. In the low-temperature pyrolysis section, the temperature is set at 300-500℃ to cause the standardized pretreated material to undergo a pyrolysis reaction, generating primary syngas rich in tar and solid biochar. In the high-temperature gasification section, the temperature is set at 700-900℃, and a limited amount of oxidant is introduced to cause some of the solid biochar to undergo a gasification and combustion reaction with some combustible components in the primary syngas, providing heat for the low-temperature pyrolysis section. The primary syngas and the solid biochar are then separated by a solid-gas separation device to obtain syngas to be treated and primary biochar.
[0013] S3. Online catalytic reforming and upgrading of syngas: The syngas to be treated is introduced into a catalytic reforming reactor, which is filled with a nickel-based or dolomite-based catalyst. Under the conditions of a temperature of 650-850℃ and a pressure of 0.1-0.5 MPa, the tar macromolecules in the syngas to be treated undergo cracking and reforming reactions under the action of the catalyst, and are converted into small molecule combustible gases such as hydrogen, carbon monoxide, and methane, to obtain high-calorific-value upgraded syngas with a tar content of less than 50 mg / m³.
[0014] S4. Biochar self-activation and product generation: The primary biochar is transported to an activation furnace, and a portion of the high-calorific-value upgrading syngas is introduced into the activation furnace as an activator and heat source. Under a temperature of 800-950℃, the primary biochar is activated by etching the pore structure using water vapor and carbon dioxide components in the upgrading syngas to generate activated carbon products.
[0015] S5. Energy self-sufficiency and synergistic control of pollutants: Another portion of the high-calorific-value upgraded syngas is transported to the combustion chamber for combustion. The resulting high-temperature flue gas is supplied with the required heat for the staged pyrolysis gasification step, the online catalytic reforming step of the syngas, and the biochar self-activation step through a heat exchange system, forming a closed-loop energy system. The flue gas discharged from the combustion chamber is cooled and then sequentially passes through a selective catalytic reduction denitrification unit, a dry desulfurization unit, and a deep purification unit using the activated carbon product as an adsorbent to achieve synergistic removal of nitrogen oxides, sulfur oxides, and particulate matter, ensuring that the final exhaust gas meets the standards.
[0016] Preferably, the online component and property detection in step S1 specifically includes the following steps:
[0017] S101. Near-infrared spectroscopy analysis technology is used to scan the waste biomass raw materials on the conveyor belt in real time without contact and obtain their spectral data.
[0018] S102. The spectral data is input into a prediction model established in advance using chemometrics, wherein the prediction model establishes a quantitative relationship between spectral characteristics and biomass moisture content, ash content, volatile matter and fixed carbon content.
[0019] S103. The prediction model outputs the physical property data of the waste biomass raw material in real time and transmits the data to the central control system to trigger subsequent processing grade classification and adaptive adjustment of process parameters.
[0020] Preferably, the multi-stage gasifier in step S2 is a fluidized bed or fixed bed reactor, and the solid-gas separation is specifically achieved by an integrated high-temperature cyclone separator located at the outlet of the high-temperature gasification section. The limited oxidant is air, oxygen-enriched air, or water vapor, and its supply is precisely controlled by the central control system in a closed loop based on the real-time temperature feedback of the high-temperature gasification section to ensure that the temperature of the high-temperature gasification section remains stable within the set range.
[0021] Preferably, the solid biochar generated in step S2 further includes a sieving and magnetic separation step before entering step S4. The sieving step is used to remove carbon powder and carbon blocks that are too small or too large in particle size to ensure the uniformity of the subsequent activation reaction. The magnetic separation step is used to remove ferromagnetic impurities mixed into the solid biochar due to raw material entrainment or equipment wear, to prevent them from causing catalyst poisoning or equipment damage during subsequent catalysis or activation.
[0022] Preferably, the catalytic reforming reactor in step S3 is a fixed-bed reactor, and the catalyst bed inside adopts a layered packing structure. The layered packing structure includes a gas inlet end, an intermediate core layer, and a gas outlet end. The gas inlet end is provided with a gas distribution and preheating layer composed of high-temperature resistant ceramic balls. The intermediate core layer is the nickel-based or dolomite-based catalyst. The nickel-based catalyst has a nickel loading of 5% to 20%, and the support is alumina or zirconium oxide. The dolomite-based catalyst is calcined, and its calcium oxide to magnesium oxide mass ratio is 1.2-1.8. The gas outlet end is provided with a support and filter layer composed of inert packing to prevent catalyst powder loss.
[0023] Preferably, in step S3, in order to maintain the long-term activity of the catalyst, an online catalyst regeneration sub-step is also included. When the tar content at the outlet of the catalytic reforming reactor exceeds a preset threshold or the pressure drop of the catalyst bed increases significantly, the central control system automatically performs the following operations: temporarily cuts off the supply of the syngas to be treated, introduces air containing water vapor into the catalytic reforming reactor, and performs coke burn-off regeneration of the coked catalyst at a temperature of 500-700°C until the carbon dioxide concentration in the outlet gas drops to a stable baseline, and then resumes normal operation.
[0024] Preferably, the activation furnace in step S4 is a rotary kiln activation furnace or a multi-layer activation furnace. The high-calorific-value upgrading syngas introduced as an activator and heat source has a water vapor to carbon dioxide volume ratio controlled between 0.5 and 2.0. The flow rate is dynamically adjusted according to the temperature inside the activation furnace and the iodine adsorption value of the discharged activated carbon, so as to achieve precise control of the specific surface area and pore size distribution of the activated carbon product.
[0025] Preferably, the energy self-consistency and pollutant synergistic control step in step S5 further includes:
[0026] S501. The heat exchange system is a multi-stage heat exchange network, which sequentially exchanges heat between the 1000-1200℃ high-temperature flue gas discharged from the combustion chamber and the activation furnace, the catalytic reforming reactor, the multi-stage gasification furnace and the drying module to achieve cascade energy utilization.
[0027] S502. The deep purification unit is a moving bed adsorption tower. The adsorbent filled inside is part of the qualified activated carbon product produced in step S4 of this method after cooling and sieving. The activated carbon after adsorption saturation is returned to the combustion section of the multi-stage gasifier in step S2 for incineration treatment, so as to realize the recycling and harmless disposal of the adsorbent.
[0028] (III) Beneficial Effects
[0029] This invention provides a method for emission reduction by producing activated carbon from waste biomass. It has the following beneficial effects:
[0030] (1) This invention utilizes a multi-stage heat exchange system to utilize the high-temperature flue gas (1000-1200℃) generated in the combustion chamber in stages, supplying energy to the activation furnace, catalytic reforming reactor, multi-stage gasification furnace, and drying module in sequence, thereby significantly reducing external energy input. At the same time, a portion of the high-calorific-value upgraded syngas is introduced into the activation furnace as an activator and heat source, replacing the energy consumed separately in the traditional physical activation method, such as raw coal. Furthermore, the saturated activated carbon can be returned to the combustion section of the gasification furnace for incineration and reuse, avoiding carbon emissions from waste activated carbon.
[0031] (2) This invention uses near-infrared spectroscopy to detect the moisture content, ash content, volatile matter, and fixed carbon content of different raw materials such as agricultural straw, forestry waste, and food processing residues in real time. Based on the material classification matrix, it automatically classifies them into at least three processing levels and adjusts the crushing particle size, drying temperature, and time parameters accordingly, so that the raw materials are finally processed into standardized pre-treated materials, solving the problems of high ash content straw easily coking and corroding equipment. At the same time, the subsequent screening and magnetic separation further optimize the state of the raw materials, ensuring that biomass raw materials with different lignocellulose compositions can stably enter the pyrolysis gasification and activation process, breaking the limitation of existing technologies that are limited to raw materials in specific regions, and improving the universality of the technology.
[0032] (3) The catalytic reforming reactor of the present invention uses a layered nickel-based or dolomite-based catalyst to crack and reform tar in syngas to a content of less than 50 mg / m³ at 650-850℃ and 0.1-0.5 MPa. Combined with the catalyst coking and regeneration mechanism, the purification efficiency is guaranteed, avoiding the problem of low calorific value of gas gas due to high tar content in traditional processes, which requires additional combustion. Attached Figure Description
[0033] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation
[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.
[0035] Please see Figure 1 This invention provides a method for reducing emissions by producing activated carbon from waste biomass, comprising the following steps:
[0036] First, waste biomass raw materials containing at least one of agricultural straw, forestry waste, or food processing residue are acquired and subjected to online composition and physical property testing. Near-infrared spectroscopy analysis is used during the testing process to acquire spectral data of the waste biomass raw materials on the conveyor belt through real-time non-contact scanning. This spectral data is input into a pre-established predictive model using chemometric methods, which establishes quantitative relationships between spectral characteristics and biomass moisture content, ash content, volatile matter, and fixed carbon content. The predictive model outputs the physical property data of the waste biomass raw materials in real time and transmits the data to the central control system to trigger subsequent processing grade classification and adaptive adjustment of process parameters.
[0037] Based on the test results, the material classification matrix automatically categorizes the raw materials into one of at least three preset processing levels. Different processing levels correspond to different crushing particle sizes and drying temperature and time parameters. For example, when the raw material is agricultural straw with high moisture content, the system classifies it into the first processing level and sets the crushing particle size of the crushing module to 50 mm, while the drying temperature of the drying module is set to 120℃ and the drying time to 3 hours. For forestry waste with low moisture content, it is classified into the third processing level, with a crushing particle size set to 5 mm, a drying temperature set to 80℃, and a drying time to 1 hour. Finally, the raw material is processed into standardized pre-treated material with a particle size of 5–50 mm and a moisture content of less than 15%.
[0038] The standardized pretreated feedstock is then continuously fed into a multi-stage gasifier for staged pyrolysis and gasification. The multi-stage gasifier is configured from top to bottom as a drying section, a low-temperature pyrolysis section, a high-temperature gasification section, and a burnout section. In the drying section, the feedstock is heated by waste heat from the heat exchange system to further reduce its moisture content. In the low-temperature pyrolysis section, a temperature range of 300-500℃ is set to allow the standardized pretreated feedstock to undergo a pyrolysis reaction, generating tar-rich primary syngas and solid biochar. In the high-temperature gasification section, a temperature range of 700-900℃ is set, and a limited amount of oxidant, such as oxygen-enriched air or water vapor, is introduced to cause some of the solid biochar to gasify and combust with the combustible components in the primary syngas, providing heat for the low-temperature pyrolysis section. The temperature of the high-temperature gasification section is precisely controlled in a closed-loop manner by a central control system based on real-time temperature feedback to ensure that the temperature remains stable within the set range.
[0039] Furthermore, a solid-gas separation device, using an integrated high-temperature cyclone separator at the outlet of the high-temperature gasification section, separates the primary syngas from the solid biochar to obtain syngas to be treated and primary biochar. The syngas to be treated is then introduced into a catalytic reforming reactor for upgrading and purification. The catalytic reforming reactor is a fixed-bed reactor with a layered catalyst bed structure. A gas distribution and preheating layer composed of high-temperature resistant ceramic balls is installed at the gas inlet, with a nickel-based or dolomite-based catalyst in the middle core layer. A support and filtration layer composed of inert packing is installed at the gas outlet. The nickel-based catalyst has a nickel loading of 5%–20%, and the support is alumina or zirconium oxide. The dolomite-based catalyst undergoes calcination treatment, with a calcium oxide to magnesium oxide mass ratio of 1.2–1.8.
[0040] Furthermore, under conditions of 650-850℃ and 0.1-0.5 MPa pressure, the large tar molecules in the syngas to be treated undergo cracking and reforming reactions under the action of a catalyst, transforming them into small-molecule combustible gases such as hydrogen, carbon monoxide, and methane, resulting in high-calorific-value upgraded syngas with a tar content of less than 50 mg / m³. When the tar content at the outlet of the catalytic reforming reactor exceeds a preset threshold or the catalyst bed pressure drop increases significantly, the central control system executes a catalyst coking and regeneration operation, temporarily cutting off the supply of the syngas to be treated and introducing air containing water vapor into the catalytic reforming reactor to regenerate the coked catalyst at a temperature of 500-700℃ until the carbon dioxide concentration in the outlet gas drops to a stable baseline, and then resumes normal operation.
[0041] Furthermore, the primary biochar undergoes screening and magnetic separation before entering the activation furnace. Screening removes excessively small or large particles of biochar powder and lumps to ensure uniformity in the subsequent activation reaction. Magnetic separation removes ferromagnetic impurities mixed into the solid biochar due to raw material entrainment or equipment wear, preventing catalyst poisoning or equipment damage during subsequent catalysis or activation. The treated primary biochar is then transported to the activation furnace for self-activation. The activation furnace is either a rotary kiln or a multi-layer furnace, introducing a portion of the high-calorific-value upgrading syngas as an activator and heat source. At a temperature of 800-950℃, the water vapor and carbon dioxide components in the upgrading syngas are used to etch and activate the pore structure of the primary biochar, generating activated carbon. The volume ratio of water vapor to carbon dioxide in the introduced high-calorific-value upgrading syngas is controlled between 0.5 and 2.0, and the flow rate is dynamically adjusted based on the temperature inside the activation furnace and the iodine adsorption value of the discharged activated carbon to achieve precise control over the specific surface area and pore size distribution of the activated carbon product.
[0042] Furthermore, another portion of the high-calorific-value upgraded syngas is transported to the combustion chamber for combustion. The resulting high-temperature flue gas is then supplied with the necessary heat through a heat exchange system for the staged pyrolysis gasification step, the syngas catalytic reforming step, and the biochar self-activation step, forming a closed-loop energy system. The heat exchange system is a multi-stage heat exchange network that sequentially exchanges heat between the 1000-1200℃ high-temperature flue gas discharged from the combustion chamber and the activation furnace, catalytic reforming reactor, multi-stage gasifier, and drying module to achieve tiered energy utilization. After cooling, the flue gas discharged from the combustion chamber sequentially passes through a selective catalytic reduction denitrification unit, a dry desulfurization unit, and a deep purification unit using activated carbon as an adsorbent to achieve the synergistic removal of nitrogen oxides, sulfur oxides, and particulate matter. The deep purification unit is a moving bed adsorption tower filled with a portion of qualified activated carbon product after cooling and sieving. The saturated activated carbon is then returned to the burnout section of the multi-stage gasifier for incineration.
[0043] Example:
[0044] Agricultural straw is fed into a conveyor belt as waste biomass, and its surface is scanned in real time using near-infrared spectroscopy to obtain spectral data. This spectral data is input into a pre-established predictive model, which uses chemometrics to construct a quantitative relationship between spectral characteristics and moisture content, ash content, volatile matter, and fixed carbon content. Based on the physical property data output by the predictive model, the central control system automatically determines that the batch of straw belongs to the first processing grade with high moisture content, and sets the crushing particle size of the crushing module to 50 mm, the drying module temperature to 120℃, and the drying time to 3 hours. After processing, the raw material is transformed into standardized pre-treated material with a particle size of 5–50 mm and a moisture content of less than 15%.
[0045] Furthermore, the standardized pretreated material is continuously fed into a multi-stage gasifier. In the drying section, waste heat from the heat exchange system further reduces the moisture content of the raw material. Subsequently, in the low-temperature pyrolysis section, the raw material undergoes a pyrolysis reaction within a temperature range of 300-500℃, generating tar-rich primary syngas and solid biochar. The temperature range of the high-temperature gasification section is set at 700-900℃, and a limited amount of oxidant, such as air or water vapor, is introduced to cause some of the biochar to undergo gasification and combustion reactions with the combustible components in the primary syngas, providing heat for the low-temperature pyrolysis section. The central control system regulates the supply of limited oxidant through a real-time temperature feedback closed-loop to ensure that the temperature of the high-temperature gasification section remains stable within the set range. An integrated high-temperature cyclone separator is located at the outlet of the high-temperature gasification section to separate the primary syngas and solid biochar.
[0046] Furthermore, the syngas to be treated is then introduced into a catalytic reforming reactor. The reactor employs a layered packing structure, with a distribution and preheating layer composed of high-temperature resistant ceramic balls at the gas inlet, and a core layer filled with a nickel-based catalyst with a nickel loading of 10%, supported by alumina. Under conditions of 650-850℃ and 0.3 MPa pressure, the large tar molecules in the syngas undergo cracking and reforming reactions under the action of the catalyst, converting into small-molecule combustible gases such as hydrogen, carbon monoxide, and methane, resulting in high-calorific-value upgraded syngas with a tar content of less than 50 mg / m³. When the tar content at the outlet of the catalytic reforming reactor exceeds a preset threshold, the central control system temporarily cuts off the supply of syngas to be treated and introduces air containing water vapor into the reactor to regenerate the coked catalyst at 600℃ until the carbon dioxide concentration in the outlet gas drops to a stable baseline, after which normal operation resumes.
[0047] Furthermore, the primary biochar undergoes sieving and magnetic separation before entering the activation furnace. The sieving step removes excessively small or large particles and lumps of biochar to ensure the uniformity of the subsequent activation reaction. The magnetic separation step removes ferromagnetic impurities to prevent catalyst poisoning or equipment damage during later processes. The treated primary biochar is then conveyed to a rotary kiln activation furnace, where a portion of the high-calorific-value upgrading syngas is introduced as an activator and heat source. At 850°C, the water vapor and carbon dioxide components in the upgrading syngas are used to etch and activate the pore structure of the primary biochar, generating activated carbon. The volume ratio of water vapor to carbon dioxide in the introduced high-calorific-value upgrading syngas is controlled at 1.0, and the flow rate is dynamically adjusted based on the temperature inside the activation furnace and the iodine adsorption value of the discharged activated carbon to achieve precise control over the specific surface area and pore size distribution of the activated carbon product.
[0048] Furthermore, another portion of the high-calorific-value upgraded syngas is transported to the combustion chamber for combustion. The resulting 1100°C high-temperature flue gas undergoes heat exchange sequentially with the activation furnace, catalytic reforming reactor, multi-stage gasifier, and drying module through a multi-stage heat exchange network, achieving cascaded energy utilization. The cooled flue gas then passes through a selective catalytic reduction denitrification unit, a dry desulfurization unit, and a moving bed adsorption tower using activated carbon as an adsorbent, achieving synergistic removal of nitrogen oxides, sulfur oxides, and particulate matter. The activated carbon, after adsorption saturation, is returned to the burnout section of the multi-stage gasifier for incineration.
[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for reducing emissions by producing activated carbon from waste biomass, characterized in that, Includes the following steps: S1. Adaptive conditioning and pretreatment of raw materials: Obtain waste biomass raw materials containing at least one of agricultural straw, forestry waste, and food processing residue. Perform online composition and physical property testing on the waste biomass raw materials to obtain data on moisture content, ash content, volatile matter, and fixed carbon content. Based on the data, automatically classify the waste biomass raw materials into one of at least three preset processing grades through a material classification matrix. Based on the processing grade, adaptively adjust the crushing particle size of the crushing module and the drying temperature and drying time of the drying module to process the waste biomass raw materials into standardized pretreated materials with a particle size of 5-50 mm and a moisture content of less than 15%. S2. Staged pyrolysis gasification and primary biochar separation: The standardized pretreated material is continuously fed into a multi-stage gasifier, which is configured from top to bottom as a drying section, a low-temperature pyrolysis section, a high-temperature gasification section, and a burnout section. In the low-temperature pyrolysis section, the temperature is set at 300-500℃ to cause the standardized pretreated material to undergo a pyrolysis reaction, generating primary syngas rich in tar and solid biochar. In the high-temperature gasification section, the temperature is set at 700-900℃, and a limited amount of oxidant is introduced to cause some of the solid biochar to undergo a gasification and combustion reaction with some combustible components in the primary syngas, providing heat for the low-temperature pyrolysis section. The primary syngas and the solid biochar are then separated by a solid-gas separation device to obtain syngas to be treated and primary biochar. S3. Online catalytic reforming and upgrading of syngas: The syngas to be treated is introduced into a catalytic reforming reactor, which is filled with a nickel-based or dolomite-based catalyst. Under the conditions of a temperature of 650-850℃ and a pressure of 0.1-0.5 MPa, the tar macromolecules in the syngas to be treated undergo cracking and reforming reactions under the action of the catalyst, and are converted into small molecule combustible gases such as hydrogen, carbon monoxide, and methane, to obtain high-calorific-value upgraded syngas with a tar content of less than 50 mg / m³. S4. Biochar self-activation and product generation: The primary biochar is transported to an activation furnace, and a portion of the high-calorific-value upgrading syngas is introduced into the activation furnace as an activator and heat source. Under a temperature of 800-950℃, the primary biochar is activated by etching the pore structure using water vapor and carbon dioxide components in the upgrading syngas to generate activated carbon products. S5. Energy self-sufficiency and synergistic control of pollutants: Another portion of the high-calorific-value upgraded syngas is transported to the combustion chamber for combustion. The resulting high-temperature flue gas is supplied with the required heat for the staged pyrolysis gasification step, the online catalytic reforming step of the syngas, and the biochar self-activation step through a heat exchange system, forming a closed-loop energy system. The flue gas discharged from the combustion chamber is cooled and then sequentially passes through a selective catalytic reduction denitrification unit, a dry desulfurization unit, and a deep purification unit using the activated carbon product as an adsorbent to achieve synergistic removal of nitrogen oxides, sulfur oxides, and particulate matter, ensuring that the final exhaust gas meets the standards.
2. The emission reduction method for producing activated carbon from waste biomass according to claim 1, characterized in that: The online component and property detection in step S1 specifically includes the following steps: S101. Near-infrared spectroscopy analysis technology is used to scan the waste biomass raw materials on the conveyor belt in real time without contact and obtain their spectral data. S102. The spectral data is input into a prediction model established in advance using chemometrics, wherein the prediction model establishes a quantitative relationship between spectral characteristics and biomass moisture content, ash content, volatile matter and fixed carbon content. S103. The prediction model outputs the physical property data of the waste biomass raw material in real time and transmits the data to the central control system to trigger subsequent processing grade classification and adaptive adjustment of process parameters.
3. The emission reduction method for producing activated carbon from waste biomass according to claim 1, characterized in that: The multi-stage gasifier in step S2 is a fluidized bed or fixed bed reactor, and the solid-gas separation is specifically achieved by an integrated high-temperature cyclone separator located at the outlet of the high-temperature gasification section. The limited oxidant is air, oxygen-enriched air, or water vapor, and its supply is precisely controlled by the central control system in a closed loop based on the real-time temperature feedback of the high-temperature gasification section to ensure that the temperature of the high-temperature gasification section remains stable within the set range.
4. The emission reduction method for producing activated carbon from waste biomass according to claim 1, characterized in that: The solid biochar generated in step S2 includes a sieving and magnetic separation step before entering step S4. The sieving step is used to remove carbon powder and carbon blocks that are too small or too large in size to ensure the uniformity of the subsequent activation reaction. The magnetic separation step is used to remove ferromagnetic impurities mixed into the solid biochar due to raw material entrainment or equipment wear, to prevent them from causing catalyst poisoning or equipment damage during subsequent catalysis or activation.
5. The emission reduction method for producing activated carbon from waste biomass according to claim 1, characterized in that: The catalytic reforming reactor in step S3 is a fixed-bed reactor. The catalyst bed inside adopts a layered packing structure, which includes a gas inlet end, an intermediate core layer, and a gas outlet end. The gas inlet end is provided with a gas distribution and preheating layer composed of high-temperature resistant ceramic balls. The intermediate core layer is the nickel-based or dolomite-based catalyst. The nickel-based catalyst has a nickel loading of 5% to 20%, and the support is alumina or zirconium oxide. The dolomite-based catalyst is calcined, and its calcium oxide to magnesium oxide mass ratio is 1.2-1.
8. The gas outlet end is provided with a support and filter layer composed of inert packing to prevent catalyst powder loss.
6. The emission reduction method for producing activated carbon from waste biomass according to claim 1, characterized in that: In step S3, in order to maintain the long-term activity of the catalyst, an online catalyst regeneration sub-step is also included. When the tar content at the outlet of the catalytic reforming reactor exceeds a preset threshold or the pressure drop of the catalyst bed increases significantly, the central control system automatically performs the following operations: temporarily cuts off the supply of the syngas to be treated, introduces air containing water vapor into the catalytic reforming reactor, and performs coking regeneration of the coked catalyst at a temperature of 500-700°C until the carbon dioxide concentration in the outlet gas drops to a stable baseline, and then resumes normal operation.
7. The emission reduction method for producing activated carbon from waste biomass according to claim 1, characterized in that: The activation furnace in step S4 is a rotary kiln activation furnace or a multi-layer activation furnace. The high-calorific-value upgrading syngas introduced as an activator and heat source has a water vapor to carbon dioxide volume ratio controlled between 0.5 and 2.
0. The flow rate is dynamically adjusted according to the temperature inside the activation furnace and the iodine adsorption value of the discharged activated carbon, so as to achieve precise control of the specific surface area and pore size distribution of the activated carbon product.
8. The emission reduction method for producing activated carbon from waste biomass according to claim 1, characterized in that: The energy self-consistency and pollutant synergistic control steps in step S5 further include: S501. The heat exchange system is a multi-stage heat exchange network, which sequentially exchanges heat between the 1000-1200℃ high-temperature flue gas discharged from the combustion chamber and the activation furnace, the catalytic reforming reactor, the multi-stage gasification furnace and the drying module to achieve cascade energy utilization. S502. The deep purification unit is a moving bed adsorption tower. The adsorbent filled inside is part of the qualified activated carbon product produced in step S4 of this method after cooling and sieving. The activated carbon after adsorption saturation is returned to the combustion section of the multi-stage gasifier in step S2 for incineration treatment, so as to realize the recycling and harmless disposal of the adsorbent.