Ironmaking system and method for gas-based shaft furnace

Abstract

The invention discloses an iron-making system and method for a gas-based shaft furnace. The system comprises gas production equipment, hydrogen-carbon adjusting equipment, reducing gas temperature adjusting equipment, the gas-based shaft furnace, gas dust removing equipment, circulating gas purifying equipment and circulating gas pressurizing equipment. According to the scheme provided by the invention, the reducing gas of high-concentration carbon monoxide and hydrogen is generated by high-pressure gasification of the carbon-containing substance, and the hydrogen-carbon ratio can be further adjusted to obtain the gas required by the efficient gas-based shaft furnace, so that a set of reducing atmosphere-adjustable preparation process system for reducing ironmaking by the gas-based shaft furnace is obtained; the problem that in the prior art, a gas-based shaft furnace depends on scarce energy such as natural gas is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas-based shaft furnaces, and in particular to an ironmaking system and method for a gas-based shaft furnace. Background Art

[0002] With increasing global environmental and resource pressures, the drawbacks of traditional blast furnace ironmaking are becoming increasingly prominent. These include: heavy reliance on coking coal; an inability to process complex polymetallic ores; large-scale production plants with numerous process steps requiring substantial investment; the significant amount of flue gas, dust, and water pollution generated by the coking-sintering-blast furnace-converter system, which has an increasingly serious environmental impact; and the long and complex process flow of the coking-sintering-blast furnace-converter-casting and rolling ironmaking and steelmaking system, resulting in low thermal efficiency and significant energy waste. In recent years, as my country's steel production has steadily increased, coking coal resources are facing depletion, making traditional coking coal metallurgical processes unviable.

[0003] Direct reduction ironmaking can use a variety of fuels as energy to produce direct reduced iron with low impurity content. It is an ideal way to get rid of the dilemma of resource scarcity and solve environmental pollution.

[0004] Among them, gas-based direct reduction ironmaking technology, which uses reducing gas as a reducing agent, offers fast reaction rates, high production efficiency, and high energy utilization, making it superior to coal-based direct reduction. This process can directly produce solid sponge iron, with advantages such as a short process, the absence of coke ovens and sintering plants, and low pollution. Currently, two main technologies are MIDREX and HYL. However, their disadvantages are that they require large quantities of natural gas, and their reducing gas relies primarily on natural gas reforming. Therefore, the bottleneck is the need for cheap and abundant natural gas resources. To date, few industrial production facilities for gas-based vertical furnace direct reduction technology have been built in my country, with only two projects currently applying this technology. Summary of the Invention

[0005] An object of the present invention is to provide an ironmaking system and method for a gas-based shaft furnace to at least partially solve the above-mentioned problems of the prior art.

[0006] To achieve the above-mentioned object, one aspect of the present invention provides an ironmaking system for a gas-based vertical furnace, comprising: a gas production device, a hydrogen-carbon regulating device, a reducing gas temperature regulating device, a gas-based vertical furnace, a gas dust removal device, a circulating gas purification device, and a circulating gas pressurizing device; wherein

[0007] The gas production equipment is used to produce reducing gas including hydrogen and carbon monoxide by chemically reacting carbon-containing substances with oxygen at high temperature and high pressure;

[0008] The hydrogen-carbon regulating device is used to receive the reducing gas output by the gas production device and to regulate the ratio of hydrogen and carbon monoxide in the reducing gas by reacting water or water vapor with the reducing gas under the action of a catalyst;

[0009] The reducing gas temperature regulating device is used to receive and regulate the temperature of the reducing gas output by the hydrogen-carbon regulating device;

[0010] The gas-based vertical furnace is used to receive the reducing gas output by the reducing gas temperature control device and reduce the pellets with the reducing gas at high pressure and high temperature;

[0011] The gas dust removal equipment is used to receive the exhaust gas from the top of the gas-based vertical furnace and remove dust particles in the exhaust gas;

[0012] The circulating gas pressurizing device is used to receive the exhaust gas after dust removal by the gas dust removal device and pressurize the exhaust gas;

[0013] The circulating gas purification device is used to receive the exhaust gas pressurized by the circulating gas pressurizing device, perform desulfurization and / or decarbonization treatment on the exhaust gas, and output the treated reducing gas to the reducing gas temperature regulating device.

[0014] Preferably, the hydrogen-carbon regulating device is further used to be connected to a hydrogen source to adjust the ratio of hydrogen and carbon monoxide in the reducing gas by inputting hydrogen.

[0015] Preferably, the circulating gas purification device is connected to the reducing gas temperature regulating device through the hydrogen-carbon regulating device, and outputs the reducing gas to the hydrogen-carbon regulating device;

[0016] The hydrogen-carbon regulating device mixes the reducing gas output by the gas production device and the reducing gas input by the circulating gas purification device, adjusts the ratio of hydrogen and carbon monoxide in the reducing gas, and outputs the reducing gas with adjusted ratio to the reducing gas temperature regulating device.

[0017] Preferably, the circulating gas purification device is further used to receive the reducing gas output by the hydrogen-carbon regulating device, perform desulfurization and / or decarbonization treatment on the reducing gas, and then output it to the reducing gas temperature regulating device.

[0018] Preferably, the gas production equipment comprises a gasifier.

[0019] Preferably, the gas production equipment further comprises:

[0020] a cyclone dust collector, used to remove dust particles in the reducing gas;

[0021] A cooler is used to reduce the temperature of the reducing gas.

[0022] Preferably, the reducing gas temperature regulating device comprises a plurality of heaters, each of which is connected to the hydrogen-carbon regulating device and is used to receive the reducing gas outputted from multiple channels of the hydrogen-carbon regulating device;

[0023] The plurality of heaters are respectively connected to the gas-based vertical furnace and are used for heating the reducing gas to different temperatures and then outputting the reducing gas of different temperatures to the gas-based vertical furnace.

[0024] Another aspect of the present invention provides an ironmaking method for a gas-based vertical furnace, which is applied to the above-mentioned system and includes:

[0025] The carbon-containing substance and oxygen are introduced into the gas production equipment to undergo a chemical reaction under high temperature and high pressure to produce a reducing gas including hydrogen and carbon monoxide;

[0026] The reducing gas is fed into the hydrogen-carbon regulating device, and water or water vapor reacts with the reducing gas under the action of a catalyst to adjust the ratio of hydrogen and carbon monoxide in the reducing gas;

[0027] regulating the temperature of the reducing gas by the reducing gas temperature regulating device;

[0028] Outputting the temperature-adjusted reducing gas to the gas-based vertical furnace, and reducing the pellets by the reducing gas at high pressure and high temperature;

[0029] receiving exhaust gas from the top of the gas-based vertical furnace through the gas dust removal equipment and removing dust particles in the exhaust gas;

[0030] receiving the exhaust gas after dust removal by the gas dust removal device through the circulating gas pressurizing device and pressurizing the exhaust gas;

[0031] The exhaust gas pressurized by the circulating gas pressurizing device is received by the circulating gas purification device, desulfurization and / or decarbonization treatment is performed on the exhaust gas, and the treated reducing gas is output to the reducing gas temperature regulating device.

[0032] Preferably, it also includes:

[0033] The ratio of hydrogen to carbon monoxide in the reducing gas is adjusted by receiving hydrogen input from the hydrogen source.

[0034] Preferably, receiving the exhaust gas pressurized by the circulating gas pressurizing device through the circulating gas purification device, performing desulfurization and / or decarbonization treatment on the exhaust gas, and outputting the treated reducing gas to the reducing gas temperature regulating device includes:

[0035] receiving the exhaust gas pressurized by the circulating gas pressurizing device through the circulating gas purification device, and performing desulfurization and / or decarbonization treatment on the exhaust gas;

[0036] Mixing the exhaust gas after the desulfurization and / or decarbonization treatment with the reducing gas produced by the gas production equipment, and adjusting the ratio of hydrogen and carbon monoxide in the mixed reducing gas by the hydrogen-carbon adjustment equipment;

[0037] The mixed and proportion-adjusted reducing gas is output to the reducing gas temperature control device.

[0038] Compared with the prior art, the present invention has at least the following advantages:

[0039] The solution provided by the present invention utilizes high-pressure gasification of carbon-containing materials to generate reducing gas composed of carbon monoxide and hydrogen. The hydrogen-carbon ratio can be adjusted to achieve the gas required for efficient gas-based shaft furnace operation. This results in a gas-based shaft furnace reduction ironmaking process system with adjustable reducing atmosphere, overcoming the prior art's reliance on natural gas for gas-based shaft furnaces. Furthermore, the process system provided by the present invention is simple, technologically sound, and cost-effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic structural diagram of an ironmaking system for a gas-based vertical furnace provided in an embodiment of the present invention.

[0041] Figure 2 A schematic flow chart of an ironmaking method for a gas-based vertical furnace provided in an embodiment of the present invention.

[0042] Figure 3 An exemplary flow chart of an ironmaking method for a gas-based vertical furnace is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to facilitate understanding of the embodiments of the present invention described herein. In addition, the terms "including," "comprising," and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a product or device comprising a series of elements is not necessarily limited to those elements explicitly listed, but may include other elements not explicitly listed or inherent to the product or device.

[0045] In the present invention, terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "center," "vertical," "horizontal," "transverse," and "longitudinal" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are primarily intended to better describe the present invention and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0046] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0047] Furthermore, the terms "installed," "disposed," "provided with," "connected," "connected," and "socketed" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integral structures; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; or internal communication between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0048] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] Example 1

[0050] Embodiment 1 of the present invention provides an ironmaking system for a gas-based vertical furnace. Figure 1 The structural diagram of the system is shown in FIG. Figure 1As shown, the system includes: gas production equipment 10, hydrogen-carbon adjustment equipment 20, reducing gas temperature adjustment equipment 30, gas-based vertical furnace 40, gas dust removal equipment 50, circulating gas pressurizing equipment 60, and circulating gas purification equipment 70.

[0051] The gas production equipment 10 is used to produce reducing gas including hydrogen and carbon monoxide by chemically reacting carbon-containing substances with oxygen at high temperature and high pressure. The gas production equipment 10 is, for example, a gasifier in coal gasification technology. The carbon-containing substances include coal, coke, biomass, urban garbage and other substances, which react chemically with oxygen / air and steam at high temperature and high pressure in different forms. The higher the concentration of hydrogen and carbon monoxide produced, the more beneficial it is to the downstream gas-based vertical furnace system, and the lower the energy consumption of the device. The gas production equipment 10 can be equipped with a cyclone dust collector and a cooler. The cyclone dust collector is used to remove dust particles in the reducing gas; the cooler is used to reduce the temperature of the reducing gas. It is also possible to obtain reducing gas that meets the needs by removing dust and cooling through a full waste boiler / semi-waste boiler method.

[0052] In one embodiment, carbonaceous materials such as coal, biomass, and municipal waste from a material yard are crushed and dried before being transported via high-pressure dense phase transport to a gas production device 10, where they undergo a gasification reaction with high-pressure oxygen / steam at a pressure of 2.0 to 6.5 MPaG and a temperature of 1200 to 1500°C. After heat recovery, the reduced gas is cooled to 180 to 230°C and fed to a hydrogen-carbon conditioning device 20.

[0053] The hydrogen-carbon regulating device 20 is configured to receive the reducing gas output by the gas production device 10 and react water or water vapor with the reducing gas in the presence of a catalyst to adjust the ratio of hydrogen to carbon monoxide in the reducing gas. In a preferred embodiment, the hydrogen-carbon regulating device is also configured to be connected to a hydrogen source to adjust the ratio of hydrogen to carbon monoxide in the reducing gas by inputting hydrogen.

[0054] The main function of the hydrogen-carbon regulating device 20 is to convert the reducing gas produced by the gasification furnace system into hydrogen and carbon dioxide by adding water or water vapor. By adjusting the amount of water and water vapor added and designing a quantitative catalyst, the conversion rate of carbon monoxide to hydrogen can be achieved, thereby adjusting the ratio of hydrogen and carbon monoxide in the reducing gas; or the hydrogen-carbon monoxide ratio can be adjusted by adding other hydrogen sources. If the proportion of hydrogen is large, the reaction of hydrogen and carbon dioxide can also be adjusted to increase the proportion of carbon monoxide. Therefore, the hydrogen-carbon regulating device 20 can provide the gas components required by the downstream system, thereby helping to maximize the comprehensive utilization rate of the gas in the gas-based vertical furnace. The carbon monoxide and hydrogen in the reducing gas after purification from the gas purification tower (C2) can preferably reach 90-98%, and the hydrogen-carbon monoxide ratio can be adjusted from 8 to 0.5 as needed.

[0055] The reducing gas temperature control device 30 is used to receive and control the temperature of the reducing gas output by the hydrogen-carbon control device. For example, the reducing gas temperature control device 30 can be a heating furnace that uses electrical or chemical energy to heat the reducing gas delivered by the hydrogen-carbon control device to the required temperature for the reduction reaction in the gas-based vertical furnace. If the temperature is high, the reducing gas temperature control device 30 can also include a cooler to lower the temperature of the reducing gas output by the hydrogen-carbon control device 20 to meet the needs of the gas-based vertical furnace.

[0056] In one embodiment, the reducing gas temperature control device 30 includes multiple heaters, each connected to the hydrogen-carbon control device, for receiving the reducing gas output from the hydrogen-carbon control device. The multiple heaters are each connected to the gas-based vertical furnace, for heating the reducing gas to different temperatures (adjustable between 800°C and 1050°C based on reaction efficiency) and then outputting the reducing gas at different temperatures to the gas-based vertical furnace. The reducing gas at different temperatures can be fed into different reaction zones of the gas-based vertical furnace 40.

[0057] The gas-based vertical furnace 40 is configured to receive the reducing gas output from the reducing gas temperature control device 30 and reduce the pellets using the reducing gas at high pressure and high temperature. The gas-based vertical furnace can be an existing gas-based vertical furnace, but it does not require natural gas as its gas source. Instead, it receives reducing gas from the reducing gas temperature control device 30. In a preferred embodiment, the gas-based vertical furnace 40 receives reducing gas at a specific ratio through multiple channels and reduces the pellets introduced from the top at high pressure and high temperature. The reducing gas flow rate and composition are adjusted to maximize the conversion efficiency of pellet reduction ironmaking, thereby minimizing the reduction gas consumption and maximizing the vertical furnace output. In one embodiment, reducing gas is fed into the high-pressure gas-based vertical furnace 40 to react with the pre-loaded iron ore within the furnace for reduction. The vertical furnace is divided into several zones according to the operating conditions of the reducing gas. The gas that has undergone the reduction reaction with the iron ore is ultimately discharged from the top pipe outlet of the high-pressure gas-based vertical furnace at a temperature of approximately 450-600°C.

[0058] The high-pressure gas-based vertical furnace 40 is fed and discharged via a variable-pressure lock hopper, achieving low-pressure collection and high-pressure delivery to meet the furnace's production capacity requirements. The feed station is equipped with a low-pressure chamber, a variable-pressure chamber, and a high-pressure chamber. The variable-pressure chamber completes a cycle of four steps: collection, gas pressurization, connection to the high-pressure chamber for delivery, and exhaust pressure reduction. This ensures a continuous flow of pellets into the high-pressure gas-based vertical furnace 40. A cooling system and a rotary discharge device are located beneath the high-pressure gas-based vertical furnace 40. The cooling system cools the pellets using circulating cooling gas. The rotary discharge device continuously delivers high-temperature direct reduced iron to the discharge system below. The discharge system, through a high-temperature variable-pressure lock hopper, achieves a four-step cycle of high-pressure collection, pressure relief, low-pressure discharge, and gas pressurization, ensuring continuous product discharge from the high-pressure gas-based vertical furnace while ensuring product integrity. The high-pressure variable-pressure lock hopper is pressurized with high-pressure nitrogen. During pressure relief, the gas is scrubbed and dust-removed before discharge.

[0059] The gas dust removal equipment 50 is used to receive the exhaust gas from the top of the gas-based shaft furnace and remove dust particles from the exhaust gas. In a preferred embodiment, this equipment may include gas heat recovery and heat exchange equipment, gas scrubbing equipment, and gas-liquid separation equipment. The exhaust gas from the top of the gas-based shaft furnace passes through the gas heat recovery and heat exchange equipment (e.g., a gas dust removal waste heat boiler) to reduce its temperature to 150-200°C. The gas is then cooled in a scrubbing tower using cooling water, which has both dust removal and cooling effects. The gas is then fed into a cooler for further cooling to 40°C.

[0060] The circulating gas pressurizing device 60 receives the exhaust gas after dust removal from the gas dust removal device 50 and pressurizes the exhaust gas. This device pressurizes the circulating gas after dust removal and feeds it into the gas-based vertical furnace for recycling, helping to maintain the reducing gas composition in the vertical furnace.

[0061] The circulating gas purification equipment 70 is configured to receive the pressurized exhaust gas from the circulating gas pressurizing equipment 60, perform desulfurization and / or decarbonization on the exhaust gas, and output the treated reducing gas to the reducing gas temperature control equipment 30. The circulating gas purification equipment 70 may include a gas purification tower. The pressurized gas from the circulating gas pressurizing equipment is fed into the gas purification tower, where it is mixed with fresh gas to remove acidic gases such as carbon dioxide and hydrogen sulfide. The purified gas is continuously circulated and ultimately fed into the high-pressure gas-based vertical furnace. The removed high-concentration carbon dioxide can be recycled and reused after passing through a carbon capture and recovery system to achieve carbon emission reduction.

[0062] In one embodiment, the circulating gas purification device 70 directly outputs the treated reducing gas to the reducing gas temperature control device 30 , and the reducing gas temperature control device 30 only needs to supplement a small amount of reducing gas from the hydrogen-carbon adjustment device 20 .

[0063] In another embodiment, the circulating gas purification equipment 70 is connected to the reducing gas temperature control equipment 30 through the hydrogen-carbon regulating equipment 20, and outputs the reducing gas to the hydrogen-carbon regulating equipment 20; the hydrogen-carbon regulating equipment 20 mixes the reducing gas output by the gas production equipment and the reducing gas input by the circulating gas purification equipment, adjusts the ratio of hydrogen and carbon monoxide in the reducing gas, and outputs the reducing gas with adjusted ratio to the reducing gas temperature control equipment 30.

[0064] In another embodiment, the circulating gas purification device 70 may also directly send the purified reducing gas into the high-pressure gas-based vertical furnace 40 to accelerate the circulation.

[0065] By adopting the ironmaking system for the fusion of a gasifier and a gas-based vertical furnace provided in this embodiment, the reducing gas generator provides the required high-pressure, high-temperature, high-concentration reducing gas for the vertical furnace. The reducing gas can be adjusted to a hydrogen-carbon ratio through a conversion device, and can also be mixed with green hydrogen produced by electrolysis of water. The high-pressure gasification raw materials can be coal, coke, or biomass, urban garbage and other green recyclable carbon-containing materials, which can meet the resource conditions of the construction site in a variety of ways, solving the problem of gas-based vertical furnaces' dependence on natural gas in the prior art. The gas dust removal system is a process technology that utilizes waste heat boiler cooling, cyclone dust removal or water washing dust removal. It has a short process and excellent energy efficiency, is suitable for large-scale modern low-carbon ironmaking plants, can produce high-quality sponge iron, and is a low-carbon alternative to blast furnace ironmaking.

[0066] Example 2

[0067] Based on the same technical concept as the above system embodiment, an embodiment of the present invention further provides an ironmaking method for a gas-based vertical furnace. Figure 2 The flow chart of the method is shown in FIG. Figure 2 As shown, the method includes:

[0068] In step 201 , a carbon-containing substance and oxygen are introduced into the gas production equipment to undergo a chemical reaction under high temperature and high pressure to obtain a reducing gas including hydrogen and carbon monoxide.

[0069] In step 202, the reducing gas is fed into the hydrogen-carbon regulating device, and water or water vapor reacts with the reducing gas under the action of a catalyst to regulate the ratio of hydrogen to carbon monoxide in the reducing gas.

[0070] Step 203: regulating the temperature of the reducing gas by the reducing gas temperature regulating device.

[0071] Step 204 : Output the temperature-adjusted reducing gas to the gas-based vertical furnace, and reduce the pellets by the reducing gas at high pressure and high temperature.

[0072] Step 205 : receiving the exhaust gas from the top of the gas-based vertical furnace through the gas dust removal equipment, and removing dust particles in the exhaust gas.

[0073] Step 206: receiving the exhaust gas after dust removal by the gas dust removal device through the circulating gas pressurizing device and pressurizing the exhaust gas;

[0074] Step 207 : receiving the exhaust gas pressurized by the circulating gas pressurizing device through the circulating gas purification device, performing desulfurization and / or decarbonization treatment on the exhaust gas, and outputting the treated reducing gas to the reducing gas temperature regulating device.

[0075] In a preferred embodiment, the method further comprises:

[0076] The ratio of hydrogen to carbon monoxide in the reducing gas is adjusted by receiving hydrogen input from the hydrogen source.

[0077] In one embodiment, receiving the exhaust gas pressurized by the circulating gas pressurizing device through the circulating gas purification device, performing desulfurization and / or decarbonization treatment on the exhaust gas, and outputting the treated reducing gas to the reducing gas temperature regulating device includes:

[0078] receiving the exhaust gas pressurized by the circulating gas pressurizing device through the circulating gas purification device, and performing desulfurization and / or decarbonization treatment on the exhaust gas;

[0079] Mixing the exhaust gas after the desulfurization and / or decarbonization treatment with the reducing gas produced by the gas production equipment, and adjusting the ratio of hydrogen and carbon monoxide in the mixed reducing gas by the hydrogen-carbon adjustment equipment;

[0080] The mixed and proportion-adjusted reducing gas is output to the reducing gas temperature control device.

[0081] In order to more clearly understand the solution of the present invention, the method provided in this embodiment is further described below through a preferred example process. Figure 3 A flowchart illustrating this example is shown below.

[0082] First, carbon-containing materials such as coal, biomass, and urban garbage from the material yard are crushed and dried, and then transported to the gas production equipment (F1) through high-pressure dense phase, where they undergo a gasification reaction with high-pressure oxygen / steam. The reaction pressure is 2.0 to 6.5 MPaG, and the temperature is 1200 to 1500°C. After heat recovery, the reducing gas (FG) is cooled to 180 to 230°C, and most of it is sent to the hydrogen-carbon regulating reactor (HC), and a small part is sent to (HT) for use as fuel gas. In one implementation, a distributor can be provided to distribute the ratio of gases fed into HC and HT. The ratio can be, for example, 1:9, and can be flexibly adjusted by the distributor according to actual needs.

[0083] The reducing gas passes through the hydrogen-carbon conditioning reactor (HC) to adjust the carbon monoxide to hydrogen ratio to the required gas ratio for downstream systems. It is then fed into the gas purification tower (C2) along with the recycle gas to remove acidic gases such as carbon dioxide, thereby increasing the reducing gas ratio. The purified reducing gas from the gas purification tower (C2) contains 90-98% carbon monoxide and hydrogen, and the hydrogen to carbon monoxide ratio can be adjusted from 8 to 0.5 as needed.

[0084] After being conditioned by the hydrogen-carbon conditioning equipment, the reducing gas first passes through a gas purification tower (C2) to remove dust and other particulate matter. The purified reducing gas is generally at room temperature. Based on the needs of the high-pressure gas-based vertical furnace (F2), the reducing gas temperature control equipment divides the reducing gas into two or more streams. These streams are heated to different temperatures (adjustable between 800°C and 1050°C depending on reaction efficiency) via different heaters (HT) before being fed into different reaction zones within the high-pressure gas-based vertical furnace (F2). The high-temperature flue gas at the heater (HT) outlet exchanges heat with the combustion-supporting air (Ar) through the heat exchange components above the heater (HT), further recovering the high-temperature flue gas heat. This, in turn, raises the combustion air temperature, reducing the amount of fuel gas used by the heater (HT).

[0085] The heated reducing gas is fed through a gas distribution system at various inlet heights into a high-pressure gas-based vertical furnace (F2). It reacts with pre-loaded iron ore pellets (ORE, iron ore concentrate or natural ore mixed with water and a pelletizing binder, formed into green pellets through high-temperature roasting and consolidation) to produce direct reduced iron (DRI). The vertical furnace is divided into several zones based on the operating conditions of the reducing gas. The resulting gas, which has reacted with the iron ore, is discharged from the top nozzle of the high-pressure gas-based vertical furnace (F2) at a temperature of approximately 450-600°C.

[0086] The high-pressure, high-temperature top gas is sent to the waste heat boiler (E1) to recover heat, then cooled to 150-200°C. The gas is then cooled in the scrubber (C1) using cooling water, which has both dust removal and cooling functions. The gas is then sent to the cooler (E2) for further cooling to 40°C.

[0087] The cooled, recycled reducing gas is fed into a compressor (COM) for pressure increase and then into a gas purification tower (C2) where it is mixed with fresh gas (FG) to remove acidic gases such as carbon dioxide and hydrogen sulfide. The purified gas is then fed into a high-pressure gas-based vertical furnace (F2). The removed high-concentration carbon dioxide can then be recycled and reused in a carbon capture and recovery system to achieve carbon emission reduction goals.

[0088] The high-pressure gas-based vertical furnace (F2) is fed and discharged through a variable-pressure lock hopper (V1), achieving low-pressure collection and high-pressure delivery to meet the production capacity requirements of the high-pressure gas-based vertical furnace. A low-pressure chamber, a variable-pressure chamber, and a high-pressure chamber are configured. The variable-pressure chamber completes four cycles: collecting materials in the low-pressure chamber, pressurizing the gas, connecting to the high-pressure chamber for delivery, and then exhausting and reducing the pressure. This ensures a continuous flow of pellets into the high-pressure gas-based vertical furnace (F2).

[0089] A cooling system and a rotary unloading device are provided at the lower part of the high-pressure gas-based vertical furnace (F2). The cooling system cools the pellets by circulating cooling gas.

[0090] The rotary discharge device continuously feeds high-temperature direct reduced iron (DRI) into the discharge system below. This system, through a high-temperature variable-pressure lock hopper (V2), implements a four-step cycle: high-pressure collection, pressure relief, low-pressure discharge, and gas pressurization. This ensures continuous product discharge from the high-pressure gas-based vertical furnace while ensuring the product remains intact. The high-temperature variable-pressure lock hopper is pressurized with high-pressure nitrogen, and during pressure relief, the gas is scrubbed and dust-removed before being discharged.

[0091] By adopting the ironmaking method for gas-based vertical furnace fusion provided in this embodiment, the reducing gas generator provides the required high-pressure, high-temperature, high-concentration reducing gas for the vertical furnace. The reducing gas can be adjusted to a hydrogen-carbon ratio through a conversion device, and can also be mixed with green hydrogen produced by electrolysis of water. The high-pressure gasification raw materials can be coal, coke, or biomass, urban garbage and other green recyclable carbon-containing materials, which can meet the resource conditions of the construction site in a variety of ways, solving the problem of gas-based vertical furnace dependence on natural gas in the existing technology. The gas dust removal system is a process technology that combines waste heat boiler cooling, cyclone dust removal or water washing dust removal. It has a short process and excellent energy efficiency, is suitable for large-scale modern low-carbon ironmaking plants, can produce high-quality sponge iron, and is a low-carbon alternative to blast furnace ironmaking.

[0092] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit them. Those skilled in the art will appreciate that the technical solutions described in the aforementioned embodiments may be modified, or some of the technical features thereof may be replaced with equivalents; such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An ironmaking system for a gas-based vertical furnace, characterized in that: include: Gas production equipment, hydrogen-carbon regulating equipment, reducing gas temperature regulating equipment, gas-based vertical furnace, gas dust removal equipment, circulating gas purification equipment, and circulating gas pressurizing equipment; The gas production equipment is used to produce reducing gas including hydrogen and carbon monoxide by chemically reacting carbon-containing substances with oxygen at high temperature and high pressure; The hydrogen-carbon regulating device is used to receive the reducing gas output by the gas production device and to regulate the ratio of hydrogen and carbon monoxide in the reducing gas by reacting water or water vapor with the reducing gas under the action of a catalyst; The reducing gas temperature regulating device is used to receive and regulate the temperature of the reducing gas output by the hydrogen-carbon regulating device; The gas-based vertical furnace is used to receive the reducing gas output by the reducing gas temperature control device and reduce the pellets with the reducing gas at high pressure and high temperature; The gas dust removal equipment is used to receive the exhaust gas from the top of the gas-based vertical furnace and remove dust particles in the exhaust gas; The circulating gas pressurizing device is used to receive the exhaust gas after dust removal by the gas dust removal device and pressurize the exhaust gas; The circulating gas purification device is used to receive the exhaust gas pressurized by the circulating gas pressurizing device, perform desulfurization and / or decarbonization treatment on the exhaust gas, and output the treated reducing gas to the reducing gas temperature regulating device.

2. The ironmaking system for a gas-based vertical furnace according to claim 1, characterized in that: The hydrogen-carbon regulating device is also used to be connected to a hydrogen source and to adjust the ratio of hydrogen to carbon monoxide in the reducing gas by inputting hydrogen.

3. The ironmaking system for a gas-based vertical furnace according to claim 1 or 2, characterized in that: The circulating gas purification device is connected to the reducing gas temperature control device through the hydrogen-carbon regulating device, and outputs the reducing gas to the hydrogen-carbon regulating device; The hydrogen-carbon regulating device mixes the reducing gas output by the gas production device and the reducing gas input by the circulating gas purification device, adjusts the ratio of hydrogen and carbon monoxide in the reducing gas, and outputs the reducing gas with adjusted ratio to the reducing gas temperature regulating device.

4. The ironmaking system for a gas-based vertical furnace according to claim 1, characterized in that The circulating gas purification device is further used to receive the reducing gas output by the hydrogen-carbon regulating device, perform desulfurization and / or decarbonization treatment on the reducing gas, and then output it to the reducing gas temperature regulating device.

5. The ironmaking system for a gas-based vertical furnace according to claim 1, characterized in that: The gas production equipment includes a gasifier.

6. The ironmaking system for a gas-based vertical furnace according to claim 1 or 4, characterized in that: The gas production equipment also includes: a cyclone dust collector, used to remove dust particles in the reducing gas; A cooler is used to reduce the temperature of the reducing gas.

7. The ironmaking system for a gas-based vertical furnace according to claim 1, characterized in that The reducing gas temperature regulating device comprises a plurality of heaters, each of which is connected to the hydrogen-carbon regulating device and is used to receive the reducing gas outputted from multiple channels by the hydrogen-carbon regulating device; The plurality of heaters are respectively connected to the gas-based vertical furnace and are used for heating the reducing gas to different temperatures and then outputting the reducing gas of different temperatures to the gas-based vertical furnace.

8. An ironmaking method for a gas-based shaft furnace, applied to a system according to any one of claims 1 to 7, characterized in that: include: The carbon-containing substance and oxygen are introduced into the gas production equipment to undergo a chemical reaction under high temperature and high pressure to produce a reducing gas including hydrogen and carbon monoxide; The reducing gas is fed into the hydrogen-carbon regulating device, and water or water vapor reacts with the reducing gas under the action of a catalyst to adjust the ratio of hydrogen and carbon monoxide in the reducing gas; regulating the temperature of the reducing gas by the reducing gas temperature regulating device; Outputting the temperature-adjusted reducing gas to the gas-based vertical furnace, and reducing the pellets by the reducing gas at high pressure and high temperature; receiving exhaust gas from the top of the gas-based vertical furnace through the gas dust removal equipment and removing dust particles in the exhaust gas; receiving the exhaust gas after dust removal by the gas dust removal device through the circulating gas pressurizing device and pressurizing the exhaust gas; The exhaust gas pressurized by the circulating gas pressurizing device is received by the circulating gas purification device, desulfurization and / or decarbonization treatment is performed on the exhaust gas, and the treated reducing gas is output to the reducing gas temperature regulating device.

9. The ironmaking method for a gas-based shaft furnace according to claim 8, characterized in that: Also includes: The ratio of hydrogen to carbon monoxide in the reducing gas is adjusted by receiving hydrogen input from the hydrogen source.

10. The ironmaking method for a gas-based shaft furnace according to claim 8, characterized in that: The circulating gas purification device receives the exhaust gas pressurized by the circulating gas pressurizing device, performs desulfurization and / or decarbonization treatment on the exhaust gas, and outputs the treated reducing gas to the reducing gas temperature regulating device, which includes: receiving the exhaust gas pressurized by the circulating gas pressurizing device through the circulating gas purification device, and performing desulfurization and / or decarbonization treatment on the exhaust gas; Mixing the exhaust gas after the desulfurization and / or decarbonization treatment with the reducing gas produced by the gas production equipment, and adjusting the ratio of hydrogen and carbon monoxide in the mixed reducing gas by the hydrogen-carbon adjustment equipment; The mixed and proportion-adjusted reducing gas is output to the reducing gas temperature control device.

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