An external heating type biomass double-bed integrated gasifier system using CO2 as a gasification agent

Abstract

The utility model discloses a kind of external heating type biomass double-bed integrated gasification furnace system with CO2 as gasification agent, it is related to chemical equipment technical field.The system includes biomass delivery unit, double-bed reaction unit, hot air supply system and CO2 supply system;The double-bed reaction unit includes pyrolysis furnace and gasification furnace;The top of pyrolysis furnace is provided with two exhaust pipes, one of which is connected with gasification furnace;The bottom of pyrolysis furnace is the discharge opening that can be unloaded to gasification furnace;The hot air supply system includes pyrolysis furnace jacket around the outside of pyrolysis furnace, and gasification furnace jacket around the outside of gasification furnace and being communicated with pyrolysis furnace jacket;The CO2 supply system is connected with high-temperature CO2 gas source and is connected with gasification furnace.The system provided by the utility model breaks through from energy utilization and carbon cycle double dimensions by constructing the fourfold heat cycle system of "CO2 chemical heat cycle+flue gas physical heat cycle+coal gas sensible heat direct use+carbon substance circulation".

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, specifically to an externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent. Background Technology

[0002] In the process of carbon emission reduction in the cement industry, the application of alternative fuels is one of the important technological directions. The "Technical Guidelines for Carbon Emission Reduction in the Cement Industry" clearly states that alternative fuels such as waste-derived fuel (RDF), biomass fuels, plastics, rubber, leather, and waste tires can be used to replace traditional fossil fuels, thereby reducing carbon emissions from fuel combustion. At the same time, the guidelines also clarify two major technical paths for the application of alternative fuels: co-processing technology for alternative fuels and pre-combustion equipment technology for alternative fuels.

[0003] However, the large-scale application of alternative fuels in the cement industry currently faces significant bottlenecks: On the one hand, high-quality alternative fuel resources are scarce, and the imbalance between market supply and demand has led to persistently high prices, even exceeding those of high-quality coal, significantly increasing the fuel procurement costs for cement companies; on the other hand, the characteristics of alternative fuels differ greatly from traditional fossil fuels, requiring specialized storage, transportation, and combustion equipment, resulting in high initial equipment investment costs, which deters many cement companies from adopting alternative fuel technology. More importantly, the complex composition and unstable combustion characteristics of alternative fuels, coupled with improper control of alternative fuel processing by some companies, have led to several production safety accidents, further hindering the promotion and implementation of alternative fuel technology.

[0004] Cement production lines generate a large amount of CO2 during the production process. If the applicant were to capture CO2 from the entire cement production process using its existing patented technologies (authorized patent CN 118754473B "A High-Concentration Carbon Dioxide Capture System Built on a Cement Kiln System and a Low-Carbon Emission Cement Clinker Production Line", application number 2024227539414 "A System for Calcium Carbonate Cyclic Decomposition and CO2 Capture", and application number 2025207845939 "A Cement Production Line and Industrial By-product Gypsum Decomposition System with Complete Process CO2 Capture"), the total CO2 output would be enormous. Therefore, how to achieve efficient consumption and resource utilization of this captured CO2 becomes a crucial issue that must be considered in advance.

[0005] In fact, CO2 is not simply a waste emission; it possesses significant value as a carbon-containing resource: calculations show that every 1 Nm³ of CO2... 3 Pure CO2 can replace 0.54 kg of pure carbon (equivalent to 0.64 kg of standard coal), and can also replace 1 Nm³ of carbon dioxide. 3 Pure oxygen (equivalent to 0.21 kg of standard coal), that is, per 1 Nm³ 3Pure CO2 can replace a total of 0.85 kg of standard coal, demonstrating significant energy substitution potential and urgently requiring technological means to achieve resource utilization.

[0006] Through in-depth research, the applicant discovered that to achieve low-cost, full CO2 capture in cement production, a fundamental overhaul of the cement production line's fuel system is necessary, transforming the traditional coal-fired mode into a gas-fired mode. Specifically, this requires converting coal into syngas through a gasification process and then classifying and burning the syngas. Furthermore, if the high-concentration, high-temperature CO2 captured by the cement production line itself is used as the primary gasification agent, combustible syngas with CO and H2 as its main components can be produced. This approach not only provides a stable gas source for the gas-fired mode but also enables the resource utilization of CO2, forming a "capture-utilization" linkage mechanism.

[0007] Currently, the CO2 capture and utilization efforts in the cement industry are not ideal, and many technical and economic challenges remain to be addressed. From the perspective of key industry development, if the two core issues of "significantly reducing CO2 capture costs" and "developing alternative fuel sources (i.e., achieving this through CO2 resource utilization)" can be organically combined and achieved simultaneously, it will directly determine whether CO2 capture and utilization technologies in industries such as cement can have the long-term viability for industrial application.

[0008] Therefore, considering the energy consumption characteristics of cement production lines, developing a highly adaptable integrated system is particularly necessary. This system must meet the following requirements: first, the technical solution should be simple and applicable, and the operation stable and reliable, requiring only a small investment to upgrade existing production lines; second, the upgrade should not affect the normal production of cement clinker, while efficiently capturing high concentrations of CO2; and third, it should have a "multi-use" function, producing usable "alternative fuels" through the synergistic effect of CO2 and biomass fuels (and even other combustible industrial solid wastes). The application of such a system can not only significantly reduce fuel costs in cement production but also enable cement companies to simultaneously produce multiple products such as cement, liquid carbon dioxide, and green methanol, and obtain additional revenue by selling carbon emission credits. This not only significantly improves the economic benefits of enterprises but also provides key technical support for environmental protection and the cement industry's goal of achieving "carbon neutrality," possessing significant industry value and social significance. Utility Model Content

[0009] The purpose of this invention is to overcome the shortcomings of the existing technology and provide an externally heated biomass dual-bed integrated gasifier system with CO2 as the gasifying agent. By constructing a four-fold thermal cycle system of "CO2 chemical thermal cycle + flue gas physical thermal cycle + direct use of sensible heat from coal gas + carbon material cycle", a breakthrough is achieved from the dual dimensions of energy utilization and carbon cycle.

[0010] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0011] An externally heated biomass dual-bed integrated gasifier system using CO2 as a gasifying agent includes a biomass conveying unit, a dual-bed reaction unit, a hot air supply system, and a CO2 supply system.

[0012] The dual-bed reaction unit includes a pyrolysis furnace and a gasification furnace; the top of the pyrolysis furnace is equipped with two exhaust pipes, one of which is connected to the gasification furnace; the bottom of the pyrolysis furnace is a discharge port for unloading into the gasification furnace.

[0013] The hot air supply system includes a pyrolysis furnace jacket surrounding the outside of the pyrolysis furnace, and a gasifier jacket surrounding the outside of the gasifier and connected to the pyrolysis furnace jacket.

[0014] The CO2 supply system is connected to an external high-temperature CO2 gas source and is connected to a gasifier.

[0015] Furthermore, the biomass conveying unit includes a hopper and a feeder connected to the hopper.

[0016] Furthermore, a rotary unloader is provided at the bottom discharge port of the pyrolysis furnace, and a high-temperature roller crusher that can discharge material to the gasification furnace is provided at the lower end of the rotary unloader.

[0017] Furthermore, the top of the pyrolysis furnace is provided with two exhaust pipes, namely a first exhaust pipe connected to the external cement kiln decomposition furnace and a second exhaust pipe connected to the gasification furnace.

[0018] Furthermore, the gasifier is equipped with an air distribution plate, an air cap, a buried pipe, a CO2 spray gun, and a vortex generator from top to bottom inside; below the air distribution plate is the gasifying agent inlet chamber, and the two ends of the buried pipe extend out of the gasifier and are respectively the cooling water inlet and outlet; the vortex generator has guide vanes set at a 45° angle.

[0019] Furthermore, the CO2 supply system includes an ultra-high temperature fan, a steam ejector, a buffer tank, and a ceramic piston compressor; the outlet of the ultra-high temperature fan is divided into two paths, one of which is connected to the gasifying agent inlet chamber of the gasifier, and the other is connected in sequence to the steam ejector, the buffer tank, and the ceramic piston compressor; the outlet of the ceramic piston compressor is connected to the CO2 spray gun.

[0020] Furthermore, the top of the gasifier is connected to two exhaust pipes, namely the third exhaust pipe and the fourth exhaust pipe; the third exhaust pipe is connected to the cement kiln decomposition furnace, and the exhaust gas purification system is installed in connection with the fourth exhaust pipe.

[0021] Furthermore, the exhaust gas purification system includes a cyclone separator, a ceramic filter, a waste heat boiler, and a bag filter arranged in sequence.

[0022] Furthermore, the cyclone separator includes a primary cyclone separator and a secondary cyclone separator.

[0023] Furthermore, the surfaces of the shells of the pyrolysis furnace and the gasification furnace, as well as the first exhaust pipe, the second exhaust pipe, the third exhaust pipe, and the fourth exhaust pipe, are all covered with heat-insulating materials.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The system provided by this utility model achieves a breakthrough in both energy utilization and carbon cycle by constructing a four-fold thermal cycle system of "CO2 chemical thermal cycle + flue gas physical thermal cycle + direct use of sensible heat of coal gas + carbon material cycle":

[0026] Through the synergistic effect of four heat cycles, the standard coal consumption per ton of cement clinker has been reduced from 103 kg in the traditional process to 37 kg, resulting in a net saving of 66 kg of standard coal. Simultaneously, the overall energy efficiency has increased from the industry average to 71.5%, with 60% of the energy savings coming from the CO2 capture cycle (replacing 50% of fossil carbon with captured CO2; one part coal combined with one part recovered carbon produces two parts CO chemical energy, achieving a thermal efficiency of 101%), and 22% from the physical and thermal cascade utilization of flue gas (1100℃ hot air from the kiln head is sequentially supplied to the gasifier and pyrolysis furnace, and finally enters the AQC boiler). Losses were reduced by 70%, and 1% came from the thermodynamic gain of the reaction (carbon conversion rate reached 98.7%, and almost all carbon in biomass pellets was converted into combustible gas).

[0027] Relying on the "carbon material cycle" and "CO2 chemical thermal cycle" in the quadruple thermal cycle, the cement production line achieves full CO2 capture during the production process. The captured high-temperature CO2 at 850℃ and 95% purity can be directly used as a gasification agent, eliminating the energy consumption of traditional low-temperature CO2 heating (1.2MJ / kg CO2). Combined with full oxygen combustion, the CO2 concentration in the flue gas is increased to over 95% (reducing purification energy consumption). The carbon capture cost is reduced by 64% compared to conventional technologies. At the same time, the system replaces part of the fossil fuel with biomass fuel, achieving negative carbon emissions of 188kg CO2 per ton of clinker, and promoting the transformation of cement plants from "carbon emission terminals" to "biomass carbon sink hubs".

[0028] (2) According to the traditional process, 103 kg of standard coal is required per ton of clinker, while this system only requires 37 kg of standard coal + 75.3 kg of biomass (the purchase cost of biomass is lower than that of standard coal). Taking a cement plant with a capacity of 1 million tons / year as an example, the original annual purchase of 103,000 tons of standard coal is required, while after the transformation, only 37,000 tons of standard coal are required. Based on the current price of standard coal of 800 yuan / ton, the annual coal purchase cost is saved by 52.8 million yuan. In addition, the bio-carbon slag produced by the gasifier can be sold externally to further supplement the company's revenue.

[0029] (3) The system is equipped with the applicant’s existing mature technologies (CN118754473B, application number 2024227539414, application number 2025207845939, etc.). After achieving full capture of CO2 in cement production, in addition to 30% of the captured CO2 being used as fuel for the kiln system, the remaining 70% of CO2 can be processed into liquid CO2 products for sale, or combined with the green hydrogen produced by the system (pyrolysis gas is rich in hydrogen, H2>35%, and after purification it becomes green hydrogen) to synthesize green methanol, forming a diversified product structure of “cement + liquid CO2 + green hydrogen / green methanol”; at the same time, the enterprise can sell carbon emission quotas, generate new carbon trading revenue, and break the traditional cement enterprise’s revenue limitation of “single selling cement”.

[0030] (4) After the cement plant production line is converted to use the gas produced by this system, the size of the decomposition furnace can be reduced by 40-60% because the combustion reaction time of the gas is shorter than that of coal, and the heat loss is reduced by 35-45 MJ / t clinker (a decrease of 25%-30%). If the existing production line only modifies the fuel system without adjusting the size of the decomposition furnace, the output of the kiln system can be significantly increased, further improving the capacity utilization rate.

[0031] (5) This technology is not only applicable to the transformation of conventional cement production lines, but also to newly built phosphogypsum-to-sulfuric acid co-production cement lines, as well as industrial scenarios with high CO2 emissions and a large amount of high-temperature hot air (such as steel, chemical industry, etc.), with wide scenario adaptability; at the same time, when used in conjunction with the applicant's existing CO2 capture technology, it can achieve full-chain synergy of "all-oxygen calcination + gas conversion + CO2 full capture + green hydrogen / green methanol synthesis", helping users to say goodbye to fossil energy dependence and enter a virtuous development track of "green negative carbon". Attached Figure Description

[0032] Figure 1 Overall structural diagram of the externally heated biomass dual-bed integrated gasifier system provided by this utility model;

[0033] Figure 2 This is a plan view of the CO2 nozzle layout.

[0034] The corresponding names of the attached figures are as follows: 1-Gasifier, 2-Pyrolysis Furnace, 3-Hopper, 4-Feeder, 5-Pyrolysis Furnace Jacket, 6-High Temperature Roller Crusher, 7-Hot Air Pipe, 8-Gasifier Jacket, 9-Ultra-High Temperature Fan, 10-Steam Ejector, 11-Buffer Tank, 12-Ceramic Piston Compressor, 13-CO2 Spray Gun, 14-Slag Cooler, 15-Secondary Cyclone Separator, 16-Ceramic Filter, 17-Waste Heat Boiler, 18-Bag Filter, 19-Fan, 20-Buried Pipe, 21-Vortex Generator, 22-Gas Burner Heating Device, 23-Primary Cyclone Separator, 24-First Exhaust Pipe, 25-Second Exhaust Pipe, 26-Third Exhaust Pipe, 27-Fourth Exhaust Pipe. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0036] like Figure 1 As shown in the figure, this embodiment provides an externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent, including a biomass conveying unit and a dual-bed reaction unit. The biomass conveying unit is used to transport biomass raw materials, including a silo 3 and a feeder 4 connected to the silo 3. The feeder 4 is a screw metering feeder. After the biomass material enters the plant, it passes through a drying system to meet the moisture requirements, and then enters the biomass pelleting system. The biomass pellets are temporarily stored in a dedicated warehouse, and then, together with the catalyst, enter the silo 3 and, via the feeder 4, enter the dual-bed reaction unit.

[0037] The dual-bed reaction unit is the core structure of the system, realizing the pyrolysis of biomass and the CO2 gasification of semi-coke. It includes a pyrolysis furnace 2 and a gasification furnace 1. The pyrolysis furnace 2 is a vertical cylindrical structure with a pyrolysis gas outlet at the top and a rotary unloader at the bottom. The lower end of the rotary unloader is connected to a high-temperature roller crusher 6 through a material pipe. A pyrolysis furnace jacket 5 is arranged around the outside of the pyrolysis furnace 2. Two exhaust pipes are provided at the pyrolysis gas outlet, namely the first exhaust pipe 24 and the second exhaust pipe 25, wherein the second exhaust pipe 25 is connected to the gasification furnace 1. Biomass material enters pyrolysis furnace 2 via feeder 4. The gas decomposed in pyrolysis furnace 2 is discharged through the top exhaust pipe and splits into two paths. One path sends high-temperature gas (temperature about 550°C) directly to the cement kiln decomposition furnace via the first exhaust pipe 24. The other path is injected into gasifier 1 via the second exhaust pipe 25 as a reducing agent for denitrification. The biomass coke after pyrolysis is discharged into the bottom feed pipe of the pyrolysis furnace by the bottom rotary unloader, crushed by the high-temperature roller crusher 6, and then enters gasifier 1 for gasification.

[0038] Specifically as follows:

[0039] The bottom of the gasifier 1 is equipped with an air distribution plate, on which air caps are installed. Below the air distribution plate is a gasifying agent inlet chamber (air chamber). During actual use, the gasifying agent is evenly sprayed from the air caps on the air distribution plate, fluidizing the biomass semi-coke particles above and forming a dense phase zone for the gasification reaction. Within this dense phase zone, a submerged pipe 20 is installed, completely embedded in the fluidized semi-coke particles, extending outwards from the outer shell of the gasifier 1 through its two end ports. The two ends of the submerged pipe 20 extending outwards from the outer shell of the gasifier 1 are respectively a cooling water inlet and a cooling water outlet. A CO2 spray gun 13 is installed above the dense phase zone, with the nozzle of the CO2 spray gun 13 pointing inwards towards the gasifier (e.g., ...). Figure 2As shown, the inlet end of the CO2 spray gun 13 is connected to the outlet pipe of the ceramic piston compressor 12 to receive the pressurized CO2 and steam mixture. This mixture is used to adjust the concentration of the gasifying agent in the upper and middle parts of the gasifier, promoting further reaction of the incompletely reacted semi-coke, and simultaneously adjusting the H2 ratio in the syngas. The upper part of the gasifier 1 is a dilute phase zone, where a vortex generator 21 with 45° angled guide vanes is installed. The vortex generator 21 has no external pipe connection and serves only as a structural component within the furnace. When the syngas and fine particles generated in the dense phase zone flow upwards, the 45° guide vanes force the airflow to form a rotating vortex, extending the residence time of the particles in the dilute phase zone to 25 seconds, thus improving the carbon conversion rate. Simultaneously, centrifugal force throws some heavier particles back into the dense phase zone, achieving internal circulation. The gasifier 1 has an outlet at the top, which connects to two exhaust pipes: a third exhaust pipe 26 and a fourth exhaust pipe 27. The combustible gas produced by the gasifier is supplied directly to the cement kiln's decomposition furnace via the third exhaust pipe 26 (at approximately 750°C), and then transported via the fourth exhaust pipe 27 to the waste heat boiler 17 for cooling, a bag filter 18 for filtration, and finally to the purification and storage system via a fan 19. A slag discharge port is located below the gasifier 1, connected to a slag cooler 14. The slag from the gasifier 1, mainly biochar, is cooled by the slag cooler 14 and then transported by belt conveyor to a storage facility for sale.

[0040] Additionally, a gasifier jacket 8 is installed around the outside of the gasifier 1 to receive the 1100°C high-temperature hot air from the cement kiln head, providing heat for the gasification reaction. The high-temperature hot air from the cement kiln head hood enters tangentially from the top of the gasifier jacket 8, with guide vanes inside to extend the residence time of the hot air. The hot air (approximately 600°C) cooled by heat exchange in the gasifier 1 is then transported via hot air duct 7, entering tangentially from the top of the pyrolysis furnace jacket 5, again with guide vanes inside to extend the residence time. The hot air (approximately 300°C) cooled by heat exchange in the pyrolysis furnace 2 is then transported via duct to the kiln head AQC boiler for power generation. Both the gasifier jacket 8 and the pyrolysis furnace jacket 5 are equipped with electric valves for mixing cold air and gas burner reheating devices 22, the opening of which is controlled by a DCS system to stabilize the jacket temperature.

[0041] In addition, the system is equipped with an ultra-high temperature blower 9, which is used to transport high-temperature (about 850°C) CO2 gas with a self-capture of more than 95% purity from the cement kiln. The outlet of the ultra-high temperature blower 9 is divided into two paths. One path is connected to the bottom air chamber of the gasifier 1. The high-temperature CO2 passes through the air distribution plate and the air cap and enters the gasifier as a gasifying agent. The other path is connected to a steam ejector 10. The output end of the steam ejector 10 is connected to a buffer tank 11, and the input end is connected to steam (in this embodiment, the steam comes from the waste heat boiler 17). The ceramic piston compressor 12 is connected to the buffer tank 11. The high-temperature CO2 passes through the steam ejector 10, together with the water vapor, and enters the ceramic piston compressor 12 through the buffer tank 11 for pressurization. Finally, it is injected into the gasifier 1 through the CO2 spray gun 13.

[0042] A separator is installed on the fourth exhaust pipe 27 at the outlet of gasifier 1. This separator includes a two-stage cyclone separator (including a primary cyclone separator 23 and a secondary cyclone separator 15) and a ceramic filter 16 arranged in series. The two-stage cyclone separator is used to initially separate solid particles from the gas produced by the gasifier to reduce the load on subsequent filtration equipment. The ceramic filter 16 is used to receive the syngas from the outlet of the two-stage cyclone separator and deeply filter fine dust and unreacted small carbon particles. Through the action of the separator, the carbon capture efficiency is ensured to be >99.9%.

[0043] All equipment surfaces (including pipe surfaces) in this system are covered with thermal insulation material of appropriate thickness; the metal materials are configured according to process requirements.

[0044] This system is powered by artificial intelligence (AI), which can significantly improve system efficiency, stability, and economy, as detailed below:

[0045] (I) The core effects of AI empowerment

[0046] 1. Dynamic optimization of operating parameters

[0047] Fuel adaptability enhancement: The AI ​​system collects and analyzes the characteristics of biomass raw materials (such as moisture, ash content, and calorific value of super reed, corn stalks, and wood chips) in real time, and automatically adjusts the gasification agent (CO2 / steam) ratio and fluidization velocity to ensure that the calorific value of the fuel gas is stably maintained at 1500-2600 kcal / m³. 3 Compared to traditional control methods, the range reduces calorific value fluctuation by 40%, making it suitable for mixed use scenarios of different types of biomass.

[0048] Carbon conversion rate breaks through the limit: Based on deep learning algorithms, AI predicts the amount of coke residue in the gasifier in real time and dynamically adjusts the bed temperature and material circulation rate, increasing the carbon conversion rate from 98% in the traditional process to 99.5%, reducing carbon resource waste and improving raw material utilization.

[0049] 2. Precise inhibition of tar formation

[0050] The AI ​​employs a Long Short-Term Memory (LSTM) network model, combined with parameters such as pyrolysis temperature, gasifying agent composition, and material residence time, to accurately predict the critical point of tar cracking. It automatically controls the pyrolysis section temperature at 600-650℃ and the gasification section temperature at 850-900℃, providing the optimal thermodynamic environment for secondary tar cracking, ultimately ensuring that the tar content in the fuel gas is <50mg / Nm³. 3 This process reduces costs by 70% compared to traditional methods, avoids tar clogging pipes and corroding equipment, and reduces system maintenance costs.

[0051] 3. Early warning and prevention of alkali metal corrosion

[0052] By using a spectral sensor to monitor the concentration of alkali metal vapors such as potassium and sodium in flue gas online, the AI ​​system combines a historical ash melting point database to build a slagging risk prediction model: when an abnormal concentration of alkali metals is detected or approaches the ash melting point threshold, the bed temperature is adjusted in advance to 100°C below the ash melting point (e.g., when the ash melting point of biomass is 900°C, the bed temperature is automatically controlled at 800°C), effectively preventing coking of core equipment such as cyclone separators and ceramic filters, reducing the slagging risk by 90%, and extending the service life of the equipment.

[0053] 4. Both energy consumption and emissions decreased.

[0054] System energy efficiency improvement: AI intelligently optimizes the distribution of high-temperature hot air in the gasifier and pyrolysis furnace jacket (1100℃ kiln head hot air → 600℃ pyrolysis furnace hot air in stages), reducing the self-consumption energy of the gasifier by 15%, and promoting the thermal efficiency of the entire system to 95%, which is 8% higher than the traditional process.

[0055] Carbon emission reduction and recycling: Based on a system with a steam production capacity of 15 tons, AI optimizes the CO2 recycling rate (40% of captured CO2 is reused as a gasification agent) to achieve an annual CO2 reduction of 48,600 tons, helping the system achieve its carbon emission negative growth target.

[0056] (II) Specific Solutions for AI Empowerment

[0057] System Architecture: Four-Layer AI Integration Framework

[0058] A [Edge Sensing Layer] → B [Smart Sensor: Real-time Monitoring of Temperature / Pressure / Composition]

[0059] A→C [Machine Vision: Fuel Morphology Recognition]

[0060] B→D [Network Transport Layer: 5G + Industrial IoT]

[0061] D→E [Platform Layer: Digital Twin Model]

[0062] E→F [Application Layer: AI Optimization Module]

[0063] Core module functions

[0064] 1. Digital Twin Model

[0065] A multiphysics simulation model of the gasifier (covering fluid dynamics and reaction thermodynamics) is constructed. Input parameters include biomass particle size distribution and oxygen carrier circulation rate, and output predicted gas composition (H2 / CO ratio optimized to 1.8-2.2).

[0066] 2. Adaptive Control Algorithm

[0067] Reinforcement learning (RL) is used to dynamically adjust the operating parameters:

[0068] Secondary air ratio: Adjust the secondary air ratio according to the real-time changes in bed pressure to ensure uniform fluidization of materials in the furnace and avoid local dead zones;

[0069] Steam injection rate: Optimize the steam injection rate according to the target H2 production to reduce water consumption to 0.3 tons / ton of biomass and reduce water waste.

[0070] 3. Fault diagnosis and predictive maintenance

[0071] By integrating data from vibration sensors and thermal imagers, AI identifies abnormal features (such as localized temperature anomalies caused by the peeling of the refractory layer in a gasifier) ​​and issues early warnings of faults, reducing maintenance response time by 60%, increasing equipment availability to >98%, and reducing unplanned downtime losses.

[0072] 4. Intelligent fuel blending system

[0073] Input local biomass prices and characteristics data, and AI will generate the optimal blend formula (such as 60% wood chips + 40% straw) to reduce fuel costs by 30%.

[0074] (III) Prediction of the effects of AI empowerment

[0075] 1. Technological Effects: AI-enabled biomass gasification systems achieve "three highs and one low"—high carbon conversion rate (99.5%), high gas calorific value (2600 kcal / m³), and high efficiency. 3 High system energy efficiency (95%), low tar content (<50mg / Nm³) 3 );

[0076] 2. Economic Returns: The initial investment increases by 25%, but through energy conservation and consumption reduction (such as a 30% reduction in fuel costs and a reduction in maintenance costs) and capacity optimization (such as an increase in equipment availability), the annual revenue of the system is significantly improved, and the investment payback period is only 1.1 years. In the long term, the dynamic optimization capabilities of AI can continuously reduce energy consumption and operation and maintenance costs, bringing stable economic benefits to enterprises.

[0077] This embodiment provides an externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent. This system deeply couples the existing cement production line system with the gasification furnace system. The design concept is as follows:

[0078] I. Design Concept

[0079] 1. Construct an externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent: including a biomass drying system, a biomass pellet manufacturing system, a silo, a tubular metering feeder, a pyrolysis furnace, a semi-coke crusher, a gasification furnace, a slag cooler, a cyclone separator, a ceramic filter, a waste heat boiler, a bag filter, and gas purification and storage, etc.

[0080] 2. High-temperature hot air extraction from the cement kiln hood: A hole is drilled in the cement kiln hood, and a pipe is installed to draw high-temperature hot air at approximately 1100℃ to the gasifier. The high-temperature hot air enters tangentially from the top of the gasifier jacket, providing heat to the gasifier; the hot air (approximately 600℃) after heat exchange and cooling in the gasifier enters tangentially from the top of the pyrolysis furnace jacket, providing heat to the pyrolysis furnace; finally, the hot air after heat exchange and cooling again in the pyrolysis furnace enters the AQC boiler.

[0081] 3. Install CO2 capture equipment: Modify the decomposition furnace, add a CO2 cyclone separator, a dedicated ultra-high temperature CO2 fan, ceramic filters, etc. High-temperature CO2 gas with a concentration of over 95% at 850℃ directly enters the gasification furnace as a gasifying agent, bringing in a large amount of heat. The remaining high-temperature CO2 gas is cooled by the boiler and enters the low-temperature purification system to be processed into CO2 products for sale.

[0082] 4. Add a green electricity water electrolysis hydrogen production unit: The main purpose is to utilize the oxygen produced as a byproduct in the water electrolysis hydrogen production process as an auxiliary combustion agent for the all-oxygen combustion in the cement kiln. The hydrogen is then used as fuel for combustion at the kiln head.

[0083] 5. Replace all pulverized coal injection pipes with oxygen-fired gas burners: Replace all pulverized coal injection pipes with oxygen-fired gas burners, which will significantly reduce the primary air volume.

[0084] 6. Direct combustion of hot coal gas at ~750℃: The combustible gas (containing tar) produced by the pyrolysis furnace is directly supplied to the decomposition furnace for combustion; the combustible gas produced by the gasification furnace is partially separated (pressure swing adsorption, separating hydrogen), and the hot hydrogen is directly supplied to the kiln head for combustion, while the remaining high-temperature gas is supplied to the decomposition furnace for combustion.

[0085] 7. Achieve full CO2 capture: After the upgrade, all CO2 generated during the cement production process will be captured.

[0086] 8. Processing and selling surplus gas: Utilizing the surplus capacity of the gasification furnace system, the surplus gas is further processed to output high-value products: Taking advantage of the surplus capacity of the gasification furnace system, the hydrogen-rich characteristics of pyrolysis gas (H2>35%) can be used to purify and produce hydrogen to replace coal-based hydrogen production, and green hydrogen / green methanol can be sold in reverse.

[0087] II. The core thermodynamic logic of the gasification reaction in this embodiment

[0088] 1. Carbon Cycle

[0089] The fundamental reason for the reduction in coal consumption is:

[0090] (1) Main reason for energy saving: CO2 gasification reaction replaces traditional combustion

[0091] Traditional process (traditional cement kiln): A [Direct combustion of coal (chemical reaction: C + O2 → CO2)] → releases heat → used for B [clinker calcination]. In this process, carbon is converted into CO2 (C → CO2) during coal combustion. Although all chemical energy is released, the carbon is depleted in one go and cannot be recycled.

[0092] New process (in this embodiment): C [CO2 gasification (chemical reaction: C + CO2 → 2CO)] → D [CO combustion (chemical reaction: 2CO + O2 → 2CO2)] → releases heat → used for B [clinker calcination]. The specific energy changes are as follows:

[0093] Step 1: CO2 vaporization, which is an endothermic reaction, absorbing 172 kJ / mol of heat;

[0094] Step 2: CO combustion, which is an exothermic reaction, releasing 566 kJ / mol of heat;

[0095] Net heat release calculation: 566kJ / mol - 172kJ / mol = 394kJ / mol. This net heat release is equivalent to 100.3% of the heat release from direct coal combustion in traditional processes (393kJ / mol), thus achieving carbon cycle while ensuring heat supply.

[0096] (2) Carbon atom utilization efficiency doubled

[0097] <![CDATA[Direct combustion C → CO2]]> 1 mol carbon → 393 kJ 100％ <![CDATA[CO2 gasification: C + CO2 → 2CO]]> 1 mol carbon → 2 mol CO 101％

[0098] Note: The total heat released by the combustion of 2 mol CO is 566 kJ (283 kJ / mol), and 566 kJ / 393 kJ≈144%. However, due to the heat absorption during gasification, the final net efficiency is approximately 101%.

[0099] (3) Supplementing the thermodynamic truth of carbon (CO2 + C = 2CO)

[0100] Core reaction: C + CO2 → 2CO (ΔG) 0 = +172kJ / mol, which is an endothermic reaction)

[0101] Where carbon goes (no carbon loss):

[0102] 1 mol of coal is converted into 1 part of carbon in 2 mol of CO.

[0103] The carbon in 1 mol of CO2 gasifying agent is converted into another 1 part of carbon in 2 mol of CO.

[0104] The system recycles CO2 captured in the cement kiln, allowing one part of coal and one part of recovered carbon (from the captured CO2) to react together and ultimately produce syngas (CO), thus achieving a closed-loop carbon cycle.

[0105] 2. Quantitative decomposition of the reduction in coal consumption per ton of clinker

[0106] Based on the benchmark of 3,000 MJ (equivalent to 718 kcal) of heat required to produce 1 ton of clinker, the coal consumption comparison and energy-saving mechanism between the traditional process and this system are as follows:

[0107] (1) Carbon cycle gain:

[0108] 51.5 kg of carbon, after being vaporized by CO2, produces 103 kg of CO (including 51.5 kg of recovered carbon);

[0109] The heat released by the complete combustion of 103 kg of CO is roughly equivalent to the heat released by the direct combustion of 103 kg of coal.

[0110] Net coal savings: 103kg - 51.5kg = 51.5kg.

[0111] (2) Sensible heat recovery gain:

[0112] The sensible heat carried by CO2 (as a gasifying agent) at a high temperature of 850℃ can save 8 kg of coal consumption;

[0113] The cascade utilization of waste heat from the gasifier and pyrolysis furnace jackets can save 12 kg of coal.

[0114] 3. System carbon flow balance verification (based on ton clinker production)

[0115] A [Input 80kg of coal - C] → B [Gasifier]

[0116] C [Input CO2 220kg] → B

[0117] B→D [Production of syngas 300kg - CO containing approximately 129kg carbon]

[0118] D→E [Cement kiln combustion]

[0119] E→F [CO2 emissions 300kg]

[0120] F→G[CO2 capture 220kg]→C

[0121] Note: 220kg CO2 = 80kg (generated from coal combustion) + 140kg (generated from carbonate decomposition)

[0122] Carbon conservation: 80kg (coal) + 220kg (kiln capture) = 300kg (syngas carbon) → Zero fossil carbon emissions for the entire system

[0123] Summary: The essence of disruptive breakthroughs

[0124] a. High carbon conversion efficiency: The carbon conversion rate reaches 98.7%, and almost all the carbon in coal is converted into carbon in syngas (CO), with no significant carbon loss;

[0125] b. The core logic of reducing coal consumption per ton of clinker: Through CO2 recycling gasification, one part of coal can produce two parts of CO chemical energy through gasification (thermal efficiency reaches 101%). At the same time, the captured CO2 replaces 50% of fossil carbon (coal), and is further supplemented by extreme waste heat recovery (such as high-temperature CO2 sensible heat and jacket waste heat cascade utilization), ultimately achieving comprehensive energy saving.

[0126] c. Restructuring of carbon utilization rules: In this system, coal is no longer a single energy source, but an "energy carrier"; CO2 is no longer an emission waste, but a "carbon cycle medium". The two work together to achieve near-zero carbon emissions in clinker production.

[0127] III. The Scientific Principles of Energy Saving in this Embodiment

[0128] The core of energy saving in this embodiment lies in the revolutionary reconstruction of the energy flow in the cement kiln, based on the first law of thermodynamics (conservation of energy) and the second law of thermodynamics (…). Based on efficiency improvement, the two are optimized synergistically to minimize energy loss and improve energy utilization efficiency.

[0129] 1. The four pillars of energy conservation and their scientific principles

[0130] (1) Deep cascade utilization of high-temperature waste heat (contributing 40-45% energy saving)

[0131] Traditional process defects: The 1100℃ high-temperature exhaust gas generated at the kiln head of cement kiln is usually directly discharged, and the high-grade heat energy is not effectively utilized, resulting in serious energy waste.

[0132] This embodiment constructs a tiered utilization process of "high-temperature hot air - multi-stage heat exchange - waste heat recovery", and the specific path is as follows:

[0133] A [1100℃ kiln head hot air] → B [gasifier jacket]

[0134] B→C[600℃ hot air]→D[pyrolysis furnace jacket]

[0135] D→E[300℃ hot air]→F[AQC boiler]

[0136] Scientific principles:

[0137] Temperature matching principle: Heat energy is supplied in stages according to the temperature requirements of different equipment to maximize the efficiency of the Carnot cycle: the gasifier requires ≥900℃ and is directly matched with 1100℃ high-temperature hot air to meet the heat requirements of the core reaction; the pyrolysis furnace reaction requires 600-800℃ and is precisely matched with 600℃ hot air after heat exchange in the gasifier to avoid excess or insufficient heat energy; finally, the 300℃ low-temperature hot air is sent to the AQC boiler for power generation or other low-grade heat demand scenarios, realizing "on-demand distribution" of heat energy;

[0138] Minimizing losses: During the cooling process of hot air from 1100℃ to 300℃, the huge direct emission of high-temperature heat is avoided through stepped heat exchange. Losses compared to traditional processes Losses were reduced by 70%.

[0139] (2) The capture of CO2 utilizes both physical heat and chemical energy (contributing 25-30% energy savings).

[0140] Physical heat utilization (sensible heat recovery):

[0141] The captured 850℃ high-temperature CO2 is directly fed into the gasifier as a gasification agent, saving heating energy consumption.

[0142] Q = CO2 from 25℃ to 850℃, Cp dT≈1.2MJ / kg CO2.

[0143] Chemical energy utilization (Budouar reaction):

[0144] CO2 participates in the carbon reduction reaction as a gasifying agent, with the reaction equation being CO2 + C → 2CO (ΔH). 0 = +172kJ / mol (endothermic reaction);

[0145] The essence of energy conversion: utilizing the waste heat from the gasifier jacket to drive this endothermic reaction, converting high-temperature heat... Chemical conversion into coal gas (Conversion efficiency > 90%), while the direct emission of CO2 in traditional processes leads to chemical... Reset to zero.

[0146] (3) Pyrolysis-gasification-combustion energy self-closed loop (contributing 15-20% energy saving)

[0147] Semi-coke internal circulation mechanism: Constructing a closed-loop process of "biomass pretreatment - reaction - energy recovery", the specific path is as follows:

[0148] A [biomass pellets] → B [pyrolysis furnace]

[0149] B→C [Volatile matter + Tar]→D [Mixed combustion]

[0150] B→E [Semi-coke]→F [Gasifier]→G [CO+H2]→D

[0151] Scientific advantages:

[0152] a. Avoid energy degradation: The semi-coke produced by the pyrolysis furnace carries 600℃ of physical heat and is directly sent to the gasifier to participate in the reaction. Unlike traditional processes, it does not need to be cooled and then reheated, which can save 18% of energy.

[0153] b. Complete capture of tar energy: The tar produced by pyrolysis enters the combustion system along with 750℃ hot coal gas, and is decomposed into small molecule combustible gases such as CH4 and H2 at high temperature. The energy utilization rate is increased from 50% in the traditional process to 95%, avoiding energy loss caused by tar condensation.

[0154] (4) Direct combustion of hot coal gas (contributes 8-10% energy saving)

[0155] The drawbacks of traditional processes: Traditional gas utilization requires a process of "cooling (dropping to 50℃, resulting in significant loss of sensible heat) → purification → reheating → combustion". Efficiency <40%, resulting in significant energy waste;

[0156] This system achieves a breakthrough: the 750℃ high-temperature coal gas generated by the gasifier and pyrolysis furnace is directly fed into the cement kiln's decomposition furnace for combustion, utilizing the sensible heat of the coal gas itself to increase the combustion temperature.

[0157] T_flame = T_gas + H_combustion C_p (200-300℃ higher than room temperature gas), where H_combustion is the heat released by gas combustion, and Cp is the specific heat capacity of the combustion products. Compared to room temperature gas, 750℃ hot gas can increase the flame temperature by 200-300℃.

[0158] Gain: Sensible heat of coal gas High temperature directly converted into flame No additional heating step is required, which improves the heat exchange efficiency of cement kiln boilers by 12%.

[0159] 2. Kinetic and thermodynamic optimization of the core reaction

[0160] (1) Enhancement of CO2 reduction reaction in gasifier

[0161] Mechanisms for increasing reaction rate:

[0162] The gasifier jacket provides a temperature gradient from 1100℃ to 900℃, which increases the reaction rate constant k by a factor of 3 (Arrhenius equation). The captured CO2 has a purity of 95%. According to Le Chatelier's principle, high concentrations of CO2 drive the reaction (CO2 + C → 2CO) to the right, increasing CO production and reaction efficiency.

[0163] (2) Minimizing energy loss in tar cracking

[0164] Secondary cleavage pathway:

[0165] A [heavy tar] -- pyrolysis at 600℃ → B [light tar]

[0166] B--750℃ mixed gas → C[CH4+H2+CO]

[0167] Dynamic control:

[0168] Effect of temperature on cracking rate: The tar cracking rate reaches 10 at 750℃. -2 s -1 Compared to 500℃ (pyrolysis rate 10), -4 s -1 It is 100 times faster and can complete the full cracking of gas before it enters the combustion system, avoiding energy loss and blockage risks caused by tar condensation and adhesion to pipelines or equipment.

[0169] (3) Fluidized bed gasification Transmitting Advantages

[0170] The gasifier employs a fluidized bed design, where fluidized particles reduce the gas-solid heat transfer coefficient h from 50 W / (m³) in traditional fixed beds. 2 ·K) increased to 500W / (m 2 (K); The high heat transfer coefficient ensures that the high-temperature waste heat from the jacket quickly penetrates to the core reaction area, reducing heat loss during the transfer process. Losses are minimized, ensuring the efficient execution of the gasification reaction.

[0171] IV. Energy-saving effect evaluation of this embodiment

[0172] Based on energy conservation and Analysis and quantitative evaluation:

[0173] 1. The impact of key points on the system

[0174] (1) Change of use of high-temperature gas at the kiln head (tertiary air → jacket heat source)

[0175] Traditional process: The 1100℃ high-temperature exhaust gas generated at the cement kiln head is traditionally sent directly to the decomposition furnace as tertiary air for combustion support. However, its energy utilization is significantly limited. The specific energy destination is as follows:

[0176] Effective utilization: Only 35%-40% of the heat is used to heat the raw materials and provide heat for the carbonate decomposition reaction (decomposition furnace thermal efficiency is about 35-40%).

[0177] Energy loss: 60%-65% of the heat is directly emitted with the 600-700℃ exhaust gas, and the high-grade heat energy is not fully utilized, resulting in serious waste.

[0178] This system restructures the use of high-temperature exhaust gas from the kiln head, converting it into a heat source for the gasifier jacket, thereby achieving cascaded energy utilization and added value. The specific energy destinations are as follows:

[0179] First, energy is supplied to the gasifier jacket to drive the core gasification reaction (CO2 + C → 2CO), converting the high-temperature heat... Chemical conversion to syngas (CO) Achieve energy value-added;

[0180] The exhaust gas (approximately 600°C) cooled after heat exchange continues to power the pyrolysis furnace jacket, meeting the requirements of the pyrolysis reaction.

[0181] The exhaust gas, which eventually drops to a low temperature of 300°C, enters the kiln head AQC boiler for power generation or other waste heat recovery scenarios, achieving energy utilization with zero waste throughout the entire process.

[0182] (2) Oxygen-based combustion replaces air-assisted combustion

[0183] Traditional process (air-assisted combustion): 78% of the N2 in the flue gas carries away a large amount of sensible heat (accounting for 15-20% of the fuel energy); flame temperature is limited (approximately 2000℃).

[0184] This system (all-oxygen combustion) eliminates nitrogen dilution, reducing flue gas emissions by 70% and sensible heat loss by 12%-15% compared to traditional processes. The flame temperature can reach 2500℃, significantly improving radiative heat transfer efficiency and directly achieving coal savings of 5%-8%. However, the oxygen production process consumes electricity, with an energy consumption of approximately 0.05-0.06 kWh / Nm³. 3 O2 needs to be offset by the energy-saving benefits of combustion.

[0185] 2. Decomposition of Energy Saving Contribution

[0186] (1) Calculation of net energy saving of jacketed heat source

[0187] Using the total heat of the high-temperature exhaust gas at the kiln head as a benchmark (denoted as Qh), the energy-saving contribution of the jacket heat source is quantified by comparing the energy utilization efficiency of traditional processes with that of this system:

[0188] Effective utilization of tertiary air in traditional processes: Qeffective = 0.38Qh (thermal efficiency of the precalciner)

[0189] The jacket gain of this system is: Q_jacket = 85% vaporization / Qh - Q_effective = 0.85Qh - 0.38Qh = 0.47Qh

[0190] Conclusion: Compared with the traditional tertiary air utilization method, the jacketed heat source scheme of this system achieves an additional 47% Qh energy saving, which greatly improves the energy utilization efficiency of kiln head exhaust gas.

[0191] (2) Energy saving from full oxygen combustion offsets the energy consumption of oxygen production.

[0192] Energy saving in the combustion process (compared to air-assisted combustion):

[0193] Reducing sensible heat loss from flue gas contributes 0.15Qc, improving heat transfer efficiency contributes 0.07Qc, and the total combustion energy saving is:

[0194] Qcombustion = 0.15Qc + 0.07Qc = 0.22Qc;

[0195] Oxygen production energy consumption converted to standard coal consumption: The oxygen production energy consumption is converted to standard coal consumption (0.3 kg standard coal / Nm³). 3 O2), the energy consumption for oxygen production accounts for approximately 12% of the total fuel energy consumption, i.e.: QO2 = 0.12Qc

[0196] Net energy saving: Q_net combustion = 0.22Qc - 0.12Qc = 0.10Qc

[0197] Conclusion: Even after deducting the energy consumption for oxygen production, oxy-fuel combustion can still achieve a net energy saving of 10% Qc, thus possessing both energy-saving and environmental protection value.

[0198] 3. Overall Energy Saving Model

[0199] System input total energy baseline: Total energy consumption of conventional processes Q0

[0200]

[0201] 4. The scientific significance and industrial value of the system

[0202] (1) The core principle for achieving 64% energy saving

[0203] A leap in quality: In traditional processes, the 600℃ low-temperature waste gas can only be utilized for power generation through waste heat. (Efficiency only 35%); This system converts low-temperature waste heat into high efficiency through a jacket-driven gasification reaction. The syngas (CO + H2) has a high syngas content. With an efficiency of over 85%, it achieves a fundamental improvement in the "quality" of energy and breaks through the limitations of traditional waste heat utilization.

[0204] Enhanced carbon cycle: All-oxygen combustion increases the CO2 concentration in flue gas to over 95%, significantly reducing the difficulty and cost of capture; the captured CO2 is recycled as a gasification agent, with a CO2 recycling rate (CO2 consumed by gasification ÷ captured CO2) of 30%-40%, forming a closed loop of "carbon emission-capture-reuse" and reducing dependence on fossil carbon.

[0205] (2) Economic verification

[0206] Energy consumption per ton of clinker reduced:

[0207] Traditional process: approximately 103 kg of standard coal is consumed per ton of clinker;

[0208] This system consumes approximately 103 × (1 - 0.64) = 37 kg of standard coal per ton of clinker;

[0209] Coal savings: 103kg - 37kg = 66kg / ton of clinker, significantly reducing fuel procurement costs.

[0210] The energy consumption for oxygen production per ton of clinker is approximately 18 kg of standard coal, far lower than the coal saving of 66 kg. The net coal saving is 48 kg / ton of clinker. The energy saving benefits can fully cover the cost of oxygen production, and there is still a significant surplus.

[0211] In summary, the system achieves a scientific energy-saving rate of 64%, and its core breakthrough lies in:

[0212] Upgrading waste gas energy: Converting 600℃ waste gas, which is inefficiently utilized in traditional processes, into high-grade syngas fuel, thus reconstructing the energy utilization path;

[0213] Oxygen-fueled combustion gain: While achieving 10% net energy savings, it reduces CO2 capture costs by 50%, providing a low-cost solution for carbon capture and utilization (CCUS);

[0214] Carbon-energy synergy: Transforming CO2 from "emission waste" into "gasification feedstock" to achieve synergy between carbon atom recycling and efficient energy utilization, and promoting the cement industry's transformation from "high carbon emissions" to "near-zero carbon".

[0215] Industrial value: This system can reduce the coal consumption per ton of clinker in cement production lines from 103 kg of standard coal (the industry average) to 37 kg of standard coal. While significantly reducing the energy consumption costs of enterprises, it creates low-cost conditions for carbon capture and helps the cement industry achieve the goal of "carbon neutrality". In addition, the system can also generate high value-added products such as green hydrogen and green methanol, expand the revenue channels of cement enterprises, and promote the green transformation of the industry.

[0216] The above embodiments are merely one of the preferred embodiments of this utility model and should not be used to limit the scope of protection of this utility model. Any modifications or refinements made to the main design concept and spirit of this utility model that are not of substantial significance, but solve the same technical problem as this utility model, should be included within the scope of protection of this utility model.

Claims

1. An externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent, characterized in that, It includes a biomass delivery unit, a dual-bed reaction unit, a hot air supply system, and a CO2 supply system; The dual-bed reaction unit includes a pyrolysis furnace (2) and a gasification furnace (1); the top of the pyrolysis furnace (2) is provided with two exhaust pipes, one of which is connected to the gasification furnace (1); the bottom of the pyrolysis furnace (2) is a discharge port that can discharge material to the gasification furnace (1); The hot air supply system includes a pyrolysis furnace jacket (5) surrounding the outside of the pyrolysis furnace (2) and a gasifier jacket (8) surrounding the outside of the gasifier (1) and connected to the pyrolysis furnace jacket (5). The CO2 supply system is connected to an external high-temperature CO2 gas source and is connected to the gasifier (1).

2. The externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent according to claim 1, characterized in that, The biomass conveying unit includes a hopper (3) and a feeder (4) connected to the hopper (3).

3. The externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent according to claim 2, characterized in that, A rotary unloader is provided at the bottom outlet of the pyrolysis furnace (2), and a high-temperature roller crusher (6) is provided at the lower end of the rotary unloader to unload material into the gasifier (1).

4. The externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent according to claim 3, characterized in that, The top of the pyrolysis furnace (2) is provided with two exhaust pipes, namely the first exhaust pipe (24) connected to the external cement kiln decomposition furnace and the second exhaust pipe (25) connected to the gasification furnace (1).

5. A dual-bed integrated biomass gasification furnace system with CO2 as the gasifying agent according to any one of claims 1 to 4, characterized in that, The gasifier (1) is provided with an air distribution plate, an air cap, a buried pipe (20), a CO2 spray gun (13) and a vortex generator (21) from top to bottom inside; the air distribution plate is located below the gasifying agent inlet chamber, and the two ends of the buried pipe (20) extend out of the gasifier (1) and are respectively the cooling water inlet and outlet; the vortex generator (21) has guide vanes set at a 45° angle.

6. The externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent according to claim 5, characterized in that, The CO2 supply system includes an ultra-high temperature fan (9), a steam injector (10), a buffer tank (11), and a ceramic piston compressor (12). The outlet of the ultra-high temperature fan (9) is divided into two paths, one of which is connected to the gasifying agent inlet chamber of the gasifier (1), and the other path is connected in sequence to the steam injector (10), the buffer tank (11), and the ceramic piston compressor (12). The outlet of the ceramic piston compressor (12) is connected to the CO2 spray gun (13).

7. The externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent according to claim 6, characterized in that, The top of the gasifier (1) is connected to two exhaust pipes, namely the third exhaust pipe (26) and the fourth exhaust pipe (27); the third exhaust pipe (26) is connected to the cement kiln decomposition furnace and is connected to the fourth exhaust pipe (27) and is equipped with a tail gas purification system.

8. The externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent according to claim 7, characterized in that, The exhaust gas purification system includes a cyclone separator, a ceramic filter (16), a waste heat boiler (17), and a bag filter (18) arranged in sequence.

9. The externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent according to claim 8, characterized in that, The cyclone separator includes a primary cyclone separator (23) and a secondary cyclone separator (15).

10. The externally heated biomass dual-bed integrated gasification furnace system using CO2 as the gasifying agent according to claim 9, characterized in that, The shells of the pyrolysis furnace (2) and the gasification furnace (1), as well as the surfaces of the first exhaust pipe (24), the second exhaust pipe (25), the third exhaust pipe (26), and the fourth exhaust pipe (27), are all covered with heat-insulating materials.

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