Multi-energy coupling submerged arc furnace tail gas carbon capture and efficient utilization system and method

Abstract

The invention discloses a multi-energy coupling submerged arc furnace tail gas carbon capture and efficient utilization system which comprises a tail gas purification and pretreatment subsystem used for conducting step-by-step purification treatment on tail gas of a high-temperature submerged arc furnace to remove dust, tar and sulfide; the power generation and waste heat recovery subsystem is used for receiving and storing the purified tail gas, generating power by using the tail gas and recovering waste heat of flue gas generated in the power generation process to generate steam; the alcohol amine method carbon capture subsystem is used for capturing CO2 in the flue gas discharged by the power generation and waste heat recovery subsystem, driving an amine liquid regeneration process by using steam generated by the power generation and waste heat recovery subsystem, and finally outputting purified liquid CO2; and the control system is based on a programmable logic controller or a distributed control system, realizes full-process parameter monitoring and dynamic optimization, and coordinates energy and material flow among the subsystems.

Description

Technical Field

[0001] This application relates to the field of industrial exhaust gas treatment and resource utilization technology, and more specifically, to a multi-energy coupled system and method for carbon capture and efficient utilization of exhaust gas from submerged arc furnaces. Background Technology

[0002] Ferroalloy submerged arc furnaces generate large amounts of high-temperature exhaust gas during production. The main components of this exhaust gas include carbon monoxide, hydrogen, carbon dioxide, and nitrogen, characterized by high temperature, high dust content, and tar content. Traditional treatment methods typically involve direct combustion, which not only wastes a significant amount of energy but also generates substantial greenhouse gas emissions and environmental pollution. Although some companies have begun using exhaust gas power generation technology, this simple power generation model suffers from low energy conversion efficiency, and the flue gas still contains a high concentration of carbon dioxide, meaning the waste heat and carbon resources are not fully recovered and utilized.

[0003] In the field of carbon capture technology, the amine method, as a relatively mature post-combustion carbon capture technology, is severely limited by its high energy consumption. In particular, the amine liquid regeneration process requires a large amount of thermal energy, resulting in high overall operating costs. Existing technologies lack efficient and coordinated recovery schemes for latent heat and chemical energy in submerged arc furnace tail gas, and have also failed to effectively solve the energy coupling problem between the carbon capture system and the tail gas treatment system.

[0004] Currently, the main technical shortcomings of ferroalloy furnace tail gas utilization technology are as follows: high energy consumption and low resource recovery rate in the tail gas purification stage; independent operation of the power generation system and carbon capture system, lacking an energy cascade utilization mechanism; high energy consumption and poor economic efficiency in the carbon capture process; and lack of intelligent coordination and control throughout the entire treatment process. These problems severely restrict the economic and environmental benefits of ferroalloy furnace tail gas resource utilization.

[0005] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-energy coupled system and method for carbon capture and efficient utilization of tail gas from submerged arc furnaces, in order to solve the problems existing in the prior art.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0008] A multi-energy coupled system for carbon capture and efficient utilization of tail gas from a submerged arc furnace, comprising:

[0009] The exhaust gas purification and pretreatment subsystem is used to purify the exhaust gas from the high-temperature submerged arc furnace in stages to remove dust, tar and sulfides.

[0010] The power generation and waste heat recovery subsystem is used to receive and store the purified exhaust gas, use the exhaust gas to generate electricity, and recover the waste heat generated in the flue gas during the power generation process to generate steam.

[0011] The amine-based carbon capture subsystem is used to capture CO2 in the flue gas emitted by the power generation and waste heat recovery subsystem, and uses the steam generated by the power generation and waste heat recovery subsystem to drive the amine liquid regeneration process, ultimately outputting purified liquid CO2.

[0012] Furthermore, the exhaust gas purification and pretreatment subsystem includes components arranged along the exhaust gas flow direction.

[0013] Water-cooled flue is used to forcibly cool the exhaust gas from high-temperature submerged arc furnaces, reducing the exhaust gas temperature to the tolerance range of subsequent equipment.

[0014] Gravity settling device separates large dust particles and liquid tar from exhaust gas through gravity.

[0015] A radiant waste heat boiler is used to recover the heat of the exhaust gas and convert it into usable thermal energy. The steam is then transported to the desorption tower of the amine process carbon capture subsystem for heating, achieving secondary cooling.

[0016] Cyclone dust collectors and baghouse dust collectors remove fine particulate dust from exhaust gas through a combination of dust removal devices.

[0017] An electrostatic precipitator uses a high-voltage electric field to capture gaseous tar in exhaust gas.

[0018] Jacketed air coolers remove sulfides from exhaust gases through adsorption or catalytic reactions.

[0019] Furthermore, the power generation and waste heat recovery subsystem includes components arranged along the exhaust gas direction.

[0020] Precision filters are used to remove residual particulate matter from exhaust gases;

[0021] Dry gas holders are used to receive and buffer purified exhaust gas.

[0022] A booster fan is used to increase the pressure of exhaust gas delivery in order to meet the intake air requirements of a gas-fired internal combustion engine.

[0023] A gas-fired internal combustion engine is used to generate electricity by burning purified exhaust gas.

[0024] A condensing waste heat boiler is used to recover waste heat from the exhaust of an internal combustion engine and generate steam, which is then delivered to the desorption tower of the amine process carbon capture subsystem for heating.

[0025] Furthermore, the alkanolamine-based carbon capture subsystem includes a tail gas flow direction setting.

[0026] The flue gas cooling system is used to cool the exhaust gas from the power generation process.

[0027] The absorption tower is used to receive the cooled exhaust gas. The exhaust gas enters from the bottom of the absorption tower, and the lean amine liquid is sprayed from the top of the absorption tower to absorb CO2 in the exhaust gas to form rich amine liquid. The purified exhaust gas is discharged from the top of the absorption tower.

[0028] The stripping tower is used to receive the rich amine solution from the absorption tower, and decomposes the rich amine solution with steam heating to achieve the separation and regeneration of CO2 and lean amine solution;

[0029] Amine liquid purification device is used to treat degradation products and impurities in circulating amine liquid;

[0030] The CO2 compression and purification unit is used to purify the CO2 gas released from the stripping tower and output a high-purity product.

[0031] The heating steam for the analytical tower is supplied by a radiant waste heat boiler.

[0032] A method for carbon capture and efficient utilization of tail gas from a multi-energy coupled submerged arc furnace includes the following steps:

[0033] S1. Stage-by-stage exhaust gas purification treatment:

[0034] The exhaust gas from the high-temperature electric arc furnace is forcibly cooled by a water-cooled flue. Large dust particles and liquid tar are separated by a gravity settling device. The sensible heat of the exhaust gas is then recovered and cooled a second time using a radiant waste heat boiler. Finally, fine particles are removed by a combination of a cyclone dust collector and a bag filter. Gaseous tar is removed by an electrostatic precipitator and sulfides are removed by a jacketed air cooler.

[0035] S2. Purified exhaust gas power generation and waste heat recovery:

[0036] After the purified exhaust gas is filtered to remove residual particulate matter, it is fed into a dry gas holder for buffer storage. Then, the exhaust gas pressure is increased by a pressurizing fan and fed into a gas-fired internal combustion engine for combustion and power generation. A condensing waste heat boiler is used to recover the waste heat from the flue gas to generate steam.

[0037] S3. CO2 capture and amine solution regeneration:

[0038] The exhaust gas after power generation is cooled and then contacted with lean amine liquid in the absorption tower to absorb CO2 and generate rich amine liquid. The rich amine liquid is then transported to the desorption tower, where it is heated and decomposed using the heat energy recovered by the S1 radiant waste heat boiler and the steam generated by S2, releasing CO2 and regenerating the lean amine liquid. The regenerated lean amine liquid is returned to the absorption tower for recycling. The CO2 gas released from the desorption tower is compressed and purified to output liquid product.

[0039] In summary, the present invention has the following beneficial effects:

[0040] By coordinating the operation of the exhaust gas purification and pretreatment subsystem, the power generation and waste heat recovery subsystem, and the amine-based carbon capture subsystem, and combining the waste heat cascade utilization and steam-driven amine liquid regeneration technology, the system achieves efficient energy conversion and a significant reduction in carbon capture energy consumption. It has the advantages of realizing cascade energy utilization, reducing carbon capture energy consumption, and improving the comprehensive utilization rate of resources. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the multi-energy coupled submerged arc furnace tail gas carbon capture and efficient utilization system described in this invention. Detailed Implementation

[0042] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to the figures and specific embodiments.

[0043] Current technologies for treating flue gas from ferroalloy submerged arc furnaces present the dual problems of energy waste and environmental pollution. Traditional methods, such as direct combustion or simple power generation, fail to effectively recover the sensible heat from the high-temperature flue gas, leaving the generated flue gas still containing a large amount of untreated carbon dioxide. While existing carbon capture technologies can separate carbon dioxide, the regeneration process relies on an external steam supply, resulting in high energy consumption. The independent operation of each stage leads to low energy utilization and makes it difficult to achieve overall optimization of flue gas resources.

[0044] To address the aforementioned issues, the inventors discovered the potential for energy coupling between exhaust gas purification, power generation, waste heat recovery, and carbon capture. Analysis of the exhaust gas treatment process revealed that waste heat generated during power generation can serve as a heat source for amine regeneration in the carbon capture subsystem, thereby reducing regeneration energy consumption. Further consideration was given to integrating and controlling each subsystem, forming a closed-loop treatment system through synergistic optimization of material and energy flows. This integrated design approach overcomes the limitations of traditional segmented treatment, achieving synergistic benefits in energy cascade utilization and carbon emission reduction.

[0045] See Figure 1 This application proposes a multi-energy coupled carbon capture and efficient utilization system for submerged arc furnace tail gas, including a tail gas purification and pretreatment subsystem, a power generation and waste heat recovery subsystem, an alkanolamine carbon capture subsystem, and a control system. The tail gas purification and pretreatment subsystem performs step-by-step purification treatment on the high-temperature tail gas. The power generation and waste heat recovery subsystem uses the purified tail gas to generate electricity and recover waste heat. The alkanolamine carbon capture subsystem captures carbon dioxide in the power generation tail gas and uses waste heat steam to drive regeneration. The control system realizes full-process monitoring and optimization.

[0046] The exhaust gas purification and pretreatment subsystem refers to a combination of devices that remove solid particles, tar, and sulfides from exhaust gas using physical and chemical methods. Specifically, it can be implemented by connecting water-cooled flues, dust collectors, and desulfurization devices in series. Its function is to ensure the safe operation of subsequent power generation equipment and the stability of the carbon capture system. The power generation and waste heat recovery subsystem refers to an energy conversion system that uses purified exhaust gas as fuel to generate electricity and recover waste heat. Specifically, it can be a combination of a gas-fired internal combustion engine and a waste heat boiler. Its function is to convert chemical energy into electrical energy and provide a heat source for carbon capture. The amine-based carbon capture subsystem refers to a device that uses amine liquid absorption-regeneration cycle to capture carbon dioxide. Specifically, it includes an absorption tower, a stripping tower, and supporting equipment. Its function is to achieve continuous capture and purification of carbon dioxide. The control system refers to an automated management platform that coordinates the operation of each subsystem. Specifically, it can use a programmable logic controller (PLC) or a distributed control system. Its function is to optimize energy and material allocation and maintain the system's efficient and stable operation.

[0047] Specifically, the high-temperature exhaust gas first undergoes multi-stage purification to remove dust, tar, and sulfides, forming clean fuel gas that meets power generation requirements. After purification and buffering, the exhaust gas is sent to the power generation equipment. The electricity generated from combustion powers a radiant waste heat boiler, while simultaneously recovering waste heat from the high-temperature flue gas to generate steam. The exhaust gas after power generation enters the carbon capture stage, where, after cooling, it comes into contact with lean amine solution in an absorption tower. Carbon dioxide is selectively absorbed to form rich amine solution. The rich amine solution is then transported to the desorption tower, where it is regenerated using steam recovered from the power generation stage. The released carbon dioxide is compressed and purified to form a liquid product, and the regenerated lean amine solution is returned to the absorption tower for recycling. Throughout the process, a control system monitors parameters such as temperature, pressure, and flow rate in real time, dynamically adjusting equipment operation to ensure efficient matching of energy and materials.

[0048] Compared to existing technologies, traditional treatment methods operate exhaust gas purification, power generation, and carbon capture as independent processes, resulting in underutilization of waste heat resources and the need for additional energy supply for carbon capture. This solution, through energy coupling design between subsystems, directly utilizes waste heat from power generation for amine liquid regeneration, forming an internal heat source cycle. Simultaneously, the integrated control system overcomes the limitations of independent operation of each stage, achieving globally optimized allocation of energy and materials, thus reducing overall system energy consumption for the same treatment scale.

[0049] Through the above technical solution, this application achieves the synergistic control of energy utilization efficiency and carbon emissions during the treatment of tail gas from an electric arc furnace. The sensible heat and chemical energy of the tail gas are converted into electricity and steam through cascade utilization, and the waste heat from power generation is directly supplied to the carbon capture stage, reducing external energy consumption. Multi-stage purification treatment ensures the safe operation of the power generation equipment and the stability of the carbon capture system, while the closed-loop control system ensures efficient coordination among all subsystems. Ultimately, while completing tail gas treatment, efficient carbon dioxide capture and resource utilization are achieved.

[0050] This application further proposes a tail gas purification and pretreatment subsystem including a water-cooled flue, gravity settling device, radiant waste heat boiler, cyclone dust collector and bag filter, electrostatic precipitator and jacketed air cooler arranged along the tail gas flow direction.

[0051] Among them, water-cooled flue gas ducts refer to pipes with circulating cooling water pipes, which rapidly reduce the exhaust gas temperature through forced convection heat exchange to prevent deformation and failure of subsequent equipment due to high temperatures. Gravity settling chambers refer to settling chambers with enlarged cross-sectional areas, specifically implemented using a multi-stage baffle structure, utilizing the gravity settling effect generated by reduced airflow velocity to separate large-diameter particles. Radiant waste heat boilers refer to heat exchange devices using membrane water-cooled wall structures, recovering sensible heat from exhaust gas and generating saturated steam through radiative heat exchange. A combination of cyclone dust collectors and bag filters refers to centrifugal separation and filtration devices, specifically implemented using a combination of multi-tube cyclone separators and pulse-jet filter bags, for graded collection of fine particulate dust. Electrostatic precipitators are honeycomb reactors with high-voltage electrodes, ionizing gaseous tar particles through a high-voltage electric field to charge and deposit them. Jacketed air coolers are desulfurization reactors with cooling jackets, specifically implemented using a combination of activated carbon adsorption beds and circulating cooling water jackets, used for the adsorption and removal of sulfides.

[0052] Specifically, the high-temperature exhaust gas first enters a water-cooled flue for cooling, preventing damage to downstream equipment and preventing tar from forming aerosols due to slow cooling. The cooled exhaust gas then enters a gravity settling chamber, where large dust particles and liquid tar naturally settle and separate under gravity. The exhaust gas then flows through a radiant waste heat boiler, where the temperature is further reduced to approximately 200°C, and the recovered heat is converted into steam for system heating. After secondary cooling, the exhaust gas passes through a cyclone dust collector and a bag filter to remove fine dust particles. The purified exhaust gas then enters an electrostatic precipitator to remove tar droplets under a high-voltage electric field, and finally passes through an adsorbent bed in a jacketed air cooler to remove sulfides. The various units are arranged according to temperature and pollutant particle size gradients, forming a staged purification process.

[0053] Compared to existing technologies, traditional processes often employ single-stage water film dust removal or electrostatic precipitators, which cannot simultaneously treat multiple forms of pollutants and have low waste heat recovery rates. This solution improves heat recovery efficiency through a synergistic design of a radiant waste heat boiler and forced cooling, while the combination of multi-stage dust removal devices enhances dust removal efficiency. Compared to conventional wet desulfurization processes, the jacketed air cooler uses dry adsorption and operates at low temperatures, avoiding wastewater generation and equipment corrosion problems.

[0054] Through the above technical solutions, this application achieves rapid cooling and efficient recovery of sensible heat from high-temperature exhaust gas, solving the energy waste problem caused by low waste heat utilization rate in traditional processes; by combining gravity sedimentation and electrostatic precipitator for tar, different physical tar pollutants are effectively separated, overcoming the technical obstacle that single physical dust removal cannot handle aerosol tar; by adopting an integrated design of staged dust removal and dry desulfurization, while ensuring that pollutants are discharged in compliance with standards, water consumption and secondary pollution from wet processes are avoided, ensuring the long-term stable operation of subsequent power generation equipment.

[0055] This application further proposes a power generation and waste heat recovery subsystem including a precision filter installed along the exhaust gas flow direction to remove residual particulate matter from the exhaust gas; a dry gas holder to receive and buffer the purified exhaust gas; a pressurizing fan to increase the exhaust gas delivery pressure to meet the intake requirements of the gas-fired internal combustion engine; a gas-fired internal combustion engine to burn the purified exhaust gas for power generation; and a condensing waste heat boiler to recover the waste heat from the internal combustion engine exhaust and generate steam, which is then transported to the analysis tower of the amine carbon capture subsystem.

[0056] Among them, a precision filter refers to a device that uses multi-stage filter media to intercept residual particulate matter in exhaust gas. Specifically, it can be implemented using ceramic fiber filter elements or sintered metal filter elements, and a differential pressure monitoring device can be installed to provide early warning of filter element blockage. This device is used to prevent cylinder wear in gas-fired internal combustion engines caused by the intake of particulate matter. A dry gas holder is a storage device that buffers gas volume, maintaining stable system pressure by adjusting the height of the holder. A pressurized blower is a gas conveying device that uses a variable frequency motor to drive an impeller to pressurize the gas. By adjusting the speed to match the intake pressure requirements of the gas-fired internal combustion engine, this device is used to optimize combustion efficiency. A gas-fired internal combustion engine is a piston generator set that uses combustible gas as fuel, improving fuel utilization through direct injection technology. This device is used to convert the chemical energy of exhaust gas into electrical energy. A condensing waste heat boiler is a steam generating device equipped with a tail-end condensing heat exchange section, specifically implemented using a combination structure of finned tube bundles and stainless steel condensers, improving thermal efficiency by recovering the latent heat of water vapor in the flue gas. This device is used to convert exhaust waste heat into high-grade steam.

[0057] Specifically, the purified exhaust gas first passes through a precision filter, where a gradient pore structure traps residual particulate matter, preventing erosion damage to the gas-fired internal combustion engine. The filtered exhaust gas then enters a dry gas holder, where the volumetric regulation capability of the rubber diaphragm seal buffers gas supply fluctuations, maintaining stable operation of the power generation system. The pressurized exhaust gas is then boosted by a pressure blower, and a pressure sensor forms a closed-loop control system with the gas-fired internal combustion engine, ensuring the combustion chamber reaches the optimal air-fuel ratio. After the chemical energy is converted into electrical energy within the internal combustion engine, the high-temperature exhaust gas enters a condensing waste heat boiler. The flue gas flows sequentially through an evaporation section and a condensation section. Steam is generated in the evaporation section, and latent heat is recovered in the condensation section by reducing the exhaust gas temperature. The generated steam is directly delivered to the carbon capture subsystem for amine regeneration. This process couples power generation and carbon capture, achieving cascaded utilization of waste heat.

[0058] Through the above technical solutions, this application solves the problems of low energy conversion efficiency and high carbon emissions in traditional power generation systems, achieving efficient conversion of tail gas chemical energy and deep recovery of waste heat resources. The application of precision filters ensures long-term stable operation of the gas-fired internal combustion engine, the synergistic effect of the dry gas holder and the pressurized blower optimizes combustion conditions, and the condensing waste heat boiler reduces the regeneration energy consumption of the carbon capture process through a combined steam supply mechanism. Each device forms a pressure and temperature gradient along the tail gas flow direction, constructing an energy coupling network for power generation and carbon capture, thereby improving the overall energy utilization rate of the system while reducing the need for external energy supply.

[0059] This application further proposes an amine-based carbon capture subsystem including a flue gas cooling system positioned along the exhaust gas flow direction to cool the input exhaust gas after power generation; an absorption tower to receive the cooled exhaust gas, which enters from the bottom of the absorption tower, while lean amine solution is sprayed from the top of the absorption tower and absorbs CO2 from the exhaust gas to form rich amine solution, with the purified exhaust gas discharged from the top of the absorption tower; a desorption tower to receive the rich amine solution from the absorption tower, and decomposes the rich amine solution with steam heating to achieve separation and regeneration of CO2 and lean amine solution; an amine solution purification device to treat degradation products and impurities in the circulating amine solution; and a CO2 compression and purification device to purify the CO2 gas released from the desorption tower and output a high-purity product; the heating steam for the desorption tower is supplied by a radiant waste heat boiler.

[0060] The flue gas cooling system refers to the equipment that reduces the temperature of the exhaust gas after power generation to a suitable range for amine absorption through heat exchange devices, preventing amine loss due to high-temperature flue gas volatilization. The absorption tower is a device that achieves gas-liquid mass transfer using a counter-current contact method, specifically employing a packed tower or plate tower structure. The exhaust gas flows upwards and forms counter-current contact with the lean amine liquid sprayed from the top, enhancing CO2 absorption efficiency. The desorption tower is a regeneration device that decomposes rich amine liquid through heat energy input, specifically employing a combination structure of a steam reboiler and the tower body, utilizing waste heat boiler steam to replace traditional external heat sources and reduce energy consumption. The amine liquid purification device is a treatment unit used to remove thermally stable salts and oxidation products from the amine liquid, specifically employing ion exchange resins or electrodialysis equipment to maintain the chemical stability of the amine liquid circulation system. The CO2 compression and purification device is equipment that converts the desorbed gas into liquid products, specifically employing a combination of multi-stage compression and cryogenic distillation processes to ensure that the CO2 product meets industrial-grade purity standards.

[0061] Specifically, the exhaust gas from power generation first enters the flue gas cooling system for cooling, ensuring its temperature matches the optimal operating conditions for the amine absorption reaction. The cooled exhaust gas enters from the bottom of the absorption tower, forming a counter-current contact with the lean amine solution sprayed from the top. CO2 is selectively absorbed by the amine solution, forming a rich amine solution, and the purified exhaust gas is discharged from the top of the tower. The rich amine solution is pumped into the desorption tower, where it is heated to the desorption temperature by steam provided by a radiant waste heat boiler. CO2 is released from the amine solution and discharged from the top of the tower, and the regenerated lean amine solution is returned to the absorption tower for recycling. During the circulation process, the amine purification device continuously removes impurities such as thermally stable salts to prevent a decrease in absorption efficiency due to amine degradation. The CO2 gas discharged from the desorption tower is compressed and purified into a liquid product, realizing the recovery and utilization of carbon resources.

[0062] Compared to existing technologies, traditional amine-based carbon capture systems require external steam for amine regeneration, resulting in excessive energy consumption and waste of waste heat. This solution directly connects waste heat boiler steam to the reboiler of the desorption tower, enabling targeted utilization of waste heat within the system and avoiding external energy input. Simultaneously, the synergistic effect of the flue gas cooling system and the amine purification device solves the problem of decreased circulation efficiency caused by high-temperature degradation and impurity accumulation in traditional processes, forming a complete closed-loop energy and material system.

[0063] Through the above technical solutions, this application achieves thermal energy coupling between waste heat from power generation and carbon capture process, reducing the external energy dependence of amine liquid regeneration process; through impurity removal and temperature control of amine liquid circulation system, the long-term stable operation of absorbent is maintained; through multi-stage compression and distillation process combination, the purity of CO2 capture product is ensured to meet the requirements of industrial application.

[0064] This application further proposes a method for carbon capture and efficient utilization of tail gas from a multi-energy coupled submerged arc furnace, comprising the following steps:

[0065] S1. Stage-by-stage exhaust gas purification treatment:

[0066] The exhaust gas from the high-temperature electric arc furnace is forcibly cooled by a water-cooled flue. Large dust particles and liquid tar are separated by a gravity settling device. The sensible heat of the exhaust gas is then recovered and cooled a second time using a radiant waste heat boiler. Finally, fine particles are removed by a combination of a cyclone dust collector and a bag filter. Gaseous tar is removed by an electrostatic precipitator and sulfides are removed by a jacketed air cooler.

[0067] S2. Purified exhaust gas power generation and waste heat recovery:

[0068] After the purified exhaust gas is filtered to remove residual particulate matter, it is fed into a dry gas holder for buffer storage. Then, the exhaust gas pressure is increased by a pressurizing fan and fed into a gas-fired internal combustion engine for combustion and power generation. A condensing waste heat boiler is used to recover the waste heat from the flue gas to generate steam.

[0069] S3. CO2 capture and amine solution regeneration:

[0070] The exhaust gas after power generation is cooled and then contacted with lean amine liquid in the absorption tower to absorb CO2 and generate rich amine liquid. The rich amine liquid is then transported to the desorption tower, where it is heated and decomposed using the heat energy recovered by the S1 radiant waste heat boiler and the steam generated by S2, releasing CO2 and regenerating the lean amine liquid. The regenerated lean amine liquid is returned to the absorption tower for recycling. The CO2 gas released from the desorption tower is compressed and purified to output liquid product.

[0071] Among them, water-cooled flue gas refers to a device that rapidly cools high-temperature exhaust gas using circulating cooling water. Specifically, it can be implemented using metal pipes with a jacketed structure, and internal guide vanes are installed to enhance heat exchange efficiency. Its function is to prevent damage to subsequent equipment due to high temperatures and to recover some sensible heat. Gravity settling tanks are containers that use the gravity of particles to achieve solid-liquid separation. Specifically, they can be implemented using a settling chamber structure with a gradually expanding cross-section. Their function is to initially remove large particles to reduce the subsequent dust removal load. Radiant waste heat boilers are devices that recover sensible heat from exhaust gas through radiant heat exchange. Specifically, they can be implemented using a membrane water-cooled wall structure. Their function is to convert high-temperature waste heat into steam and achieve secondary cooling of the flue gas. A combination of cyclone dust collectors and bag filters refers to a series arrangement of centrifugal separation and filtration dust removal equipment. Specifically, it can be implemented using a multi-tube cyclone dust collector combined with a pulse-jet bag filter. Its function is to remove particles of different sizes in stages to improve overall dust removal efficiency. An electrostatic precipitator is a device that uses a high-voltage electric field to capture gaseous tar, its function being to remove gasified tar and prevent blockage of downstream equipment. A jacketed air cooler is a gas processing device with a cooling jacket, specifically implemented using a shell-and-tube structure filled with desulfurization catalyst, its function being to remove sulfides through adsorption or catalytic reaction.

[0072] Specifically, the high-temperature exhaust gas is first rapidly cooled in a water-cooled flue to prevent damage to subsequent equipment due to high temperatures, while also recovering some sensible heat. A gravity settling device separates large particles from the initially cooled flue gas, reducing the processing load on subsequent dust removal devices. A radiant waste heat boiler further recovers waste heat and generates steam through radiant heat exchange, while simultaneously achieving a step-wise decrease in flue gas temperature. A combination of a cyclone dust collector and a bag filter removes fine particles in stages through centrifugal force and filtration. An electrostatic precipitator captures gaseous tar through a high-voltage electric field, and a jacketed air cooler desulfurizes through catalytic reaction, forming a complete purification process. The purified exhaust gas is buffered, stored, and then pressurized before being sent to a gas-fired internal combustion engine for power generation. The exhaust waste heat is recovered by a condensing waste heat boiler to generate steam, which serves as a heat source for subsequent carbon capture processes. After power generation, the flue gas is cooled and enters an absorption tower for carbon dioxide absorption. The amine-rich liquid is regenerated and recycled in a stripping tower using waste heat steam, ultimately yielding a high-purity liquid carbon dioxide product.

[0073] Compared to existing technologies, traditional processes involving direct combustion of exhaust gas for power generation result in insufficient waste heat utilization, and the carbon capture process requires additional energy consumption. This solution utilizes a series arrangement of radiant and condensing waste heat boilers to achieve cascaded recovery of sensible heat from flue gas and waste heat from exhaust gases. The generated steam is directly used for amine regeneration, reducing energy consumption for carbon capture. Existing technologies involve independent operation of dust removal and desulfurization equipment, leading to system complexity. This solution employs the synergistic effect of gravity setters and combined dust collectors to form a multi-stage pollutant control system, ensuring purification efficiency while reducing equipment footprint.

[0074] Through the above technical solutions, this application realizes the energy coupling of exhaust gas purification, power generation and carbon capture. It uses waste heat steam to drive the amine liquid regeneration process, which significantly reduces the energy consumption of carbon capture. Through a multi-stage waste heat recovery device, the sensible heat of the exhaust gas is converted into usable steam, which improves the overall energy utilization efficiency. A complete purification chain is formed by adopting a combined dust removal and directional removal device, which effectively reduces pollutant emissions. Through buffer storage and pressure regulation devices, the stable operation of the gas internal combustion engine is ensured, which improves the reliability of the power generation system.

[0075] In this document, the terms "upper," "lower," "front," "back," "left," "right," "top," "bottom," "inner," "outer," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used for the clarity of expressing the technical solution and for the convenience of description, and therefore should not be construed as limiting the present invention.

[0076] In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0077] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A multi-energy coupled system for carbon capture and efficient utilization of tail gas from a submerged arc furnace, characterized in that, include: The exhaust gas purification and pretreatment subsystem is used to purify the exhaust gas from the high-temperature submerged arc furnace in stages to remove dust, tar and sulfides. The power generation and waste heat recovery subsystem is used to receive and store the purified exhaust gas, use the exhaust gas to generate electricity, and recover the waste heat generated in the flue gas during the power generation process to generate steam. The amine-based carbon capture subsystem is used to capture CO2 in the flue gas emitted by the power generation and waste heat recovery subsystem, and uses the steam generated by the power generation and waste heat recovery subsystem to drive the amine liquid regeneration process, ultimately outputting purified liquid CO2.

2. The multi-energy coupled submerged arc furnace tail gas carbon capture and high-efficiency utilization system according to claim 1, characterized in that, The exhaust gas purification and pretreatment subsystem includes components arranged along the exhaust gas flow direction. Water-cooled flue is used to forcibly cool the exhaust gas from high-temperature submerged arc furnaces, reducing the exhaust gas temperature to the tolerance range of subsequent equipment. Gravity settling device separates large dust particles and liquid tar from exhaust gas through gravity. A radiant waste heat boiler is used to recover the heat of the exhaust gas and convert it into usable thermal energy. The steam is then transported to the desorption tower of the amine process carbon capture subsystem for heating, achieving secondary cooling. Cyclone dust collectors and baghouse dust collectors remove fine particulate dust from exhaust gas through a combination of dust removal devices. An electrostatic precipitator uses a high-voltage electric field to capture gaseous tar in exhaust gas. Jacketed air coolers remove sulfides from exhaust gases through adsorption or catalytic reactions.

3. The multi-energy coupled submerged arc furnace tail gas carbon capture and high-efficiency utilization system according to claim 1, characterized in that, The power generation and waste heat recovery subsystem includes components installed along the exhaust gas direction. Precision filters are used to remove residual particulate matter from exhaust gases; Dry gas holders are used to receive and buffer purified exhaust gas. A booster fan is used to increase the pressure of exhaust gas delivery in order to meet the intake air requirements of a gas-fired internal combustion engine. A gas-fired internal combustion engine is used to generate electricity by burning purified exhaust gas. A condensing waste heat boiler is used to recover waste heat from the exhaust of an internal combustion engine and generate steam, which is then delivered to the desorption tower of the amine process carbon capture subsystem for heating.

4. The multi-energy coupled submerged arc furnace tail gas carbon capture and high-efficiency utilization system according to claim 1, characterized in that, The alkanolamine-based carbon capture subsystem includes a tail gas flow direction setting. The flue gas cooling system is used to cool the exhaust gas from the power generation process. The absorption tower is used to receive the cooled exhaust gas. The exhaust gas enters from the bottom of the absorption tower, and the lean amine liquid is sprayed from the top of the absorption tower to absorb CO2 in the exhaust gas to form rich amine liquid. The purified exhaust gas is discharged from the top of the absorption tower. The stripping tower is used to receive the rich amine solution from the absorption tower, and decomposes the rich amine solution with steam heating to achieve the separation and regeneration of CO2 and lean amine solution; Amine liquid purification device is used to treat degradation products and impurities in circulating amine liquid; The CO2 compression and purification unit is used to purify the CO2 gas released from the stripping tower and output a high-purity product. The heating steam for the analytical tower is supplied by a radiant waste heat boiler.

5. A method for carbon capture and efficient utilization of tail gas from a multi-energy coupled submerged arc furnace, characterized in that, Includes the following steps: S1. Stage-by-stage exhaust gas purification treatment: The exhaust gas from the high-temperature electric arc furnace is forcibly cooled by a water-cooled flue. Large dust particles and liquid tar are separated by a gravity settling device. The sensible heat of the exhaust gas is then recovered and cooled a second time using a radiant waste heat boiler. Finally, fine particles are removed by a combination of a cyclone dust collector and a bag filter. Gaseous tar is removed by an electrostatic precipitator and sulfides are removed by a jacketed air cooler. S2. Purified exhaust gas power generation and waste heat recovery: After the purified exhaust gas is filtered to remove residual particulate matter, it is fed into a dry gas holder for buffer storage. Then, the exhaust gas pressure is increased by a pressurizing fan and fed into a gas internal combustion engine for combustion and power generation. Utilize a condensing waste heat boiler to recover waste heat from flue gas and generate steam; S3. CO2 capture and amine solution regeneration: The exhaust gas after power generation is cooled and then contacted with lean amine liquid in the absorption tower to absorb CO2 and generate rich amine liquid. The rich amine solution is transported to the desorption tower, where it is heated and decomposed using the heat energy recovered by the S1 radiant waste heat boiler and the steam generated by S2, releasing CO2 and regenerating the lean amine solution. The regenerated lean amine solution is returned to the absorption tower for recycling; the CO2 gas released from the stripping tower is compressed and purified to output liquid products.

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