Recycling system and method for blast furnace gas

Abstract

The invention discloses a blast furnace gas recycling system and method.The recycling system comprises a blast furnace, alcohol amine decarburization device absorption equipment and alcohol amine decarburization device desorption equipment, and a gas inlet of the alcohol amine decarburization device absorption equipment is connected with a gas outlet of the blast furnace; a gas outlet of the alcohol amine decarburization device absorption equipment is connected with a gas inlet of a blast furnace, a liquid outlet of the alcohol amine decarburization device absorption equipment is connected with a liquid inlet of the alcohol amine decarburization device desorption equipment, and a liquid outlet of the alcohol amine decarburization device desorption equipment is connected with a liquid inlet of the alcohol amine decarburization device absorption equipment. And a gas outlet of the alcohol amine decarbonization device desorption equipment is connected with an oxidation gas inlet of the blast furnace. Therefore, carbon dioxide in the blast furnace gas is removed through the recycling system and regenerated into carbon monoxide through gasification treatment, recycling of the carbon dioxide is effectively achieved, the carbon utilization rate is effectively increased, and the emission rate of the carbon dioxide is effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of blast furnace smelting, and in particular to a system and method for recycling blast furnace gas. Background Art

[0002] Iron and steel smelting, especially iron-making blast furnaces, is the main source of carbon emissions. Blast furnaces produce a large amount of blast furnace gas during the iron-making process, which is rich in carbon monoxide. If the utilization rate of carbon resources can be improved, it can not only reduce carbon dioxide emissions, but also reduce environmental pollution. However, the high carbon dioxide content in blast furnace gas makes it difficult to reuse. Therefore, removing and reusing carbon dioxide is the key to the reuse of blast furnace gas, and it is also a problem that needs to be solved urgently. Summary of the invention

[0003] Based on the above-mentioned deficiencies of the prior art, the present application provides a system and method for recycling blast furnace gas to solve the problem of removing and recycling carbon dioxide.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] In a first aspect, the present application provides a blast furnace gas recycling system, the recycling system comprising a blast furnace, an alcohol amine decarbonization device absorption device and an alcohol amine decarbonization device desorption device;

[0006] The air inlet of the alcoholamine decarbonization device absorption equipment is connected to the air outlet of the blast furnace, the air outlet of the alcoholamine decarbonization device absorption equipment is connected to the gas inlet of the blast furnace, and the liquid outlet of the alcoholamine decarbonization device absorption equipment is connected to the liquid inlet of the alcoholamine decarbonization device desorption device; wherein the alcoholamine decarbonization device absorption equipment is used to hold the alcoholamine lean liquid, and react the blast furnace gas generated by the blast furnace with the alcoholamine lean liquid to obtain purified gas and alcoholamine rich liquid; the alcoholamine decarbonization device absorption equipment is also used to transmit the purified gas to the blast furnace, and transmit the alcoholamine rich liquid to the alcoholamine decarbonization device desorption device;

[0007] The liquid outlet of the desorption device of the alcoholamine decarbonization device is connected to the liquid inlet of the absorption device of the alcoholamine decarbonization device, and the gas outlet of the desorption device of the alcoholamine decarbonization device is connected to the oxidation gas inlet of the blast furnace. The desorption device of the alcoholamine decarbonization device is used to desorb the alcoholamine rich liquid to obtain desorption gas with a high content of carbon dioxide, and transmit the desorption gas to the blast furnace.

[0008] Optionally, in the above-mentioned blast furnace gas recycling system, the recycling system further comprises an oxygen supply system;

[0009] The oxygen supply system is respectively connected to the oxidation gas inlet of the blast furnace and the gas outlet of the desorption equipment of the alcohol amine decarbonization device.

[0010] Optionally, in the above-mentioned blast furnace gas recycling system, the recycling system further includes an iron ore system;

[0011] The iron ore system is connected to the iron ore inlet of the blast furnace.

[0012] Optionally, in the above-mentioned blast furnace gas recycling system, the recycling system further comprises a fuel supply system;

[0013] The fuel supply system is connected to the coal inlet of the blast furnace.

[0014] Optionally, in the above-mentioned blast furnace gas recycling system, the recycling system further comprises a use system;

[0015] The use system is connected to the gas outlet of the alcohol amine decarbonization device absorption equipment and the coal gas outlet of the blast furnace.

[0016] Optionally, in the above-mentioned blast furnace gas recycling system, the fuel contained in the fuel supply system is coal or coke.

[0017] Optionally, in the above-mentioned blast furnace gas recycling system, the alcoholamine lean solution is composed of alcoholamine, water and carbon dioxide.

[0018] Optionally, in the above-mentioned blast furnace gas recycling system, the volume range of the blast furnace is 450m 3 Up to 5000m 3 .

[0019] Optionally, in the above-mentioned blast furnace gas recycling system, an iron ore layer is provided in the blast furnace, and the iron ore layer contains iron ore, and the iron ore is used for smelting with purified gas to obtain iron.

[0020] The second aspect of the present application provides a method for recycling blast furnace gas, which is applied to a system for recycling blast furnace gas provided in the first aspect of the embodiment of the present application, and the method comprises:

[0021] Obtain blast furnace gas produced by blast furnaces;

[0022] The alcoholamine lean liquid in the alcoholamine decarbonization device absorption equipment is used to chemically react with the blast furnace gas to obtain purified gas and alcoholamine rich liquid rich in carbon dioxide;

[0023] Using the desorption equipment of the alcoholamine decarbonization device to carry out a desorption reaction on the alcoholamine rich liquid to obtain a desorbed gas with a high content of carbon dioxide;

[0024] The desorbed gas is mixed with oxygen to obtain an oxidizing gas, and the oxidizing gas and the cleaned gas are transmitted back to the blast furnace.

[0025] A blast furnace gas recycling system provided by the present application, the recycling system includes a blast furnace, an alcoholamine decarbonization device absorption device and an alcoholamine decarbonization device desorption device, the air inlet of the alcoholamine decarbonization device absorption device is connected to the air outlet of the blast furnace, the air outlet of the alcoholamine decarbonization device absorption device is connected to the gas inlet of the blast furnace, the liquid outlet of the alcoholamine decarbonization device absorption device is connected to the liquid inlet of the alcoholamine decarbonization device desorption device, the liquid outlet of the alcoholamine decarbonization device desorption device is connected to the liquid inlet of the alcoholamine decarbonization device absorption device, the air outlet of the alcoholamine decarbonization device desorption device is connected to the oxygen inlet of the blast furnace, and the alcoholamine decarbonization device desorption device is used to desorb the alcoholamine rich liquid, obtain the desorbed gas with a high content of carbon dioxide, and transmit the desorbed gas to the blast furnace. Thus, the carbon dioxide in the blast furnace gas is removed by the recycling system, and it is regenerated into carbon monoxide by gasification treatment, effectively realizing the recycling of carbon dioxide, thereby effectively improving the carbon utilization rate and reducing the emission rate of carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0027] Figure 1 A first structural schematic diagram of a blast furnace gas recycling system provided in an embodiment of the present application;

[0028] Figure 2 A second structural schematic diagram of a blast furnace gas recycling system provided in an embodiment of the present application;

[0029] Figure 3 A third structural schematic diagram of a blast furnace gas recycling system provided in an embodiment of the present application;

[0030] Figure 4 A fourth structural schematic diagram of a blast furnace gas recycling system provided in an embodiment of the present application;

[0031] Figure 5 A fifth structural schematic diagram of a blast furnace gas recycling system provided in an embodiment of the present application;

[0032] Figure 6 A complete schematic diagram of a blast furnace gas recycling system provided in another embodiment of the present application;

[0033] Figure 7 A schematic flow chart of a method for recycling blast furnace gas provided in another embodiment of the present application. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] In this application, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0036] As can be seen from the background technology, a large amount of blast furnace gas is produced during steel smelting in the blast furnace. The blast furnace gas is rich in carbon monoxide and carbon dioxide. Therefore, if the utilization rate of carbon resources can be improved, it can not only reduce carbon dioxide emissions but also achieve the effect of reducing pollution. Therefore, removing and reusing carbon dioxide is the key to the reuse of blast furnace gas.

[0037] Therefore, an embodiment of the present application provides a recycling system for blast furnace gas, which includes a blast furnace, an alcohol amine decarbonization device absorption device and an alcohol amine decarbonization device desorption device, so as to remove carbon dioxide from the blast furnace gas, and convert the carbon dioxide into carbon monoxide through a gasification process, so that the blast furnace gas is converted into high-quality gas with a high carbon monoxide content that can meet the needs of the blast furnace, and return it to the blast furnace for recycling, thereby realizing the high-value utilization of the blast furnace gas, and thus solving the problem of removing and reusing carbon dioxide for the reuse of blast furnace gas.

[0038] So see Figure 1 , showing a first structural schematic diagram of a blast furnace gas recycling system provided in an embodiment of the present application, the recycling system comprising a blast furnace 1, an alcohol amine decarbonization device absorption device 2 and an alcohol amine decarbonization device desorption device 3;

[0039] The air inlet 2-1 of the alcoholamine decarbonization device absorption device 2 is connected to the air outlet 1-1 of the blast furnace 1, the air outlet 2-3 of the alcoholamine decarbonization device absorption device 2 is connected to the coal gas inlet 1-5 of the blast furnace 1, and the liquid outlet 2-4 of the alcoholamine decarbonization device absorption device 2 is connected to the liquid inlet 3-1 of the alcoholamine decarbonization device desorption device 3;

[0040] Among them, the alcoholamine decarbonization device absorption equipment 2 is used to hold the alcoholamine lean liquid, and react the blast furnace gas generated by the blast furnace 1 with the alcoholamine lean liquid to obtain purified gas and alcoholamine rich liquid. The alcoholamine decarbonization device absorption equipment 2 is also used to transmit the purified gas to the blast furnace 1, and transmit the alcoholamine rich liquid to the alcoholamine decarbonization device desorption equipment 3.

[0041] It should be noted that the alcohol amine decarbonization device absorption equipment 2 is mainly used to absorb and remove carbon dioxide in blast furnace gas through absorption reaction using alcohol amine lean liquid.

[0042] In some embodiments, the alkanolamine lean solution is composed of alkanolamine, water, and carbon dioxide.

[0043] In some embodiments, the volume range of blast furnace 1 is 450m 3 Up to 5000m 3 Of course, the volume range of the blast furnace 1 can also be other thresholds, and the casting can be carried out according to specific needs.

[0044] The liquid outlet 3-3 of the desorption device 3 of the alcoholamine decarbonization device is connected to the liquid inlet 2-2 of the absorption device 2 of the alcoholamine decarbonization device, and the gas outlet 3-2 of the desorption device 3 of the alcoholamine decarbonization device is connected to the oxidation gas inlet 1-2 of the blast furnace 1. The desorption device 3 of the alcoholamine decarbonization device is used to desorb the alcoholamine rich liquid to obtain the desorption gas with high carbon dioxide content, and transmit the desorption gas to the blast furnace 1.

[0045] It should be noted that the desorption device 3 of the alcoholamine decarbonation device is mainly used to remove the carbon dioxide absorbed in the alcoholamine rich liquid through a desorption reaction and restore the ability to absorb carbon dioxide, thereby realizing the recycling of carbon dioxide.

[0046] It can be understood that the blast furnace gas (A) discharged from the blast furnace 1 is added to the alcoholamine decarbonization device absorption equipment 2 to first undergo a chemical absorption reaction with the alcoholamine lean solution (B), and the carbon dioxide in the blast furnace gas (A) is absorbed by the alcoholamine lean solution (B), thereby generating a purified gas (C) with a low carbon dioxide content and a high carbon monoxide content and an alcoholamine rich solution (D) rich in carbon dioxide, and then the purified gas (C) from which the carbon dioxide has been removed is returned to the blast furnace as a reducing gas for recycling, and the excess purified gas (D) is used as a gas with a high carbon monoxide content for use by other gas users.

[0047] In some embodiments, an iron ore layer is provided in the blast furnace, and the iron ore layer contains iron ore, and the iron ore is used for smelting with the purified gas to obtain iron, thereby effectively improving the efficiency of steel smelting.

[0048] In addition, the rich alcoholamine liquid (D) rich in carbon dioxide enters the desorption device 3 of the alcoholamine decarbonization unit to undergo a desorption reaction to desorb the carbon dioxide it has absorbed and become an alcoholamine lean liquid (B) with a low carbon dioxide content. The removed carbon dioxide is discharged in the form of desorption gas (E) with a high carbon dioxide content. The finally generated alcoholamine lean liquid (B) is returned to the absorption device 2 of the alcoholamine decarbonization unit for recycling.

[0049] Therefore, in the embodiment of the present application, through the alcohol amine decarbonization device absorption equipment and the alcohol amine decarbonization device desorption equipment, it is possible to convert all the useless carbon dioxide in the blast furnace gas produced by the blast furnace into carbon monoxide with a reducing effect, so that the blast furnace gas is converted into high-quality gas with a high carbon monoxide content that can meet the needs of the blast furnace, and is returned to the blast furnace for recycling, thereby realizing the high-value utilization of the blast furnace gas, and no longer discharges the blast furnace gas of low-calorific value fuel as a by-product of the blast furnace, and the excess carbon source is discharged in the form of excess purified gas with a very high carbon monoxide content and is used as a high carbon monoxide content, high calorific value gas for other gas customers, thereby improving carbon utilization, reducing carbon emissions, and realizing low-carbon and low-emission production of steel smelting.

[0050] In some embodiments, in combination Figure 1 , see Figure 2 , showing a second structural schematic diagram of a plasma heating circulation device for furnace top gas, the recycling system also includes an oxygen supply system 21;

[0051] The oxygen supply system 21 is connected to the oxidation gas inlet 1-2 of the blast furnace 1 and the gas outlet 3-2 of the desorption device 3 of the alcohol amine decarbonization device.

[0052] Specifically, the oxygen supply system is used to deliver oxygen to the blast furnace 1 and the desorption device 3 of the alcohol amine decarbonization device, so that the oxygen and carbon dioxide generate a mixed gas, so that the carbon dioxide can be recycled later by means of the mixed gas.

[0053] In an embodiment of the present application, the oxygen supply system is connected to the blast furnace and the desorption equipment of the amine decarbonization device to provide the required oxygen to the furnace and the desorption equipment of the amine decarbonization device, which can improve combustion efficiency, reduce energy consumption, and help control the furnace temperature. Furthermore, through precise oxygen supply regulation, the smelting process can be optimized and the quality of steel can be improved.

[0054] In some embodiments, in combination Figure 1 and Figure 2 , see Figure 3, showing a third structural schematic diagram of a plasma heating circulation device for top gas, the recycling system also includes an iron ore system 31;

[0055] The iron ore system 31 is connected to the iron ore inlets 1 - 4 of the blast furnace 1 .

[0056] Specifically, the iron ore system 31 is used to provide iron ore to the blast furnace 1 so that the blast furnace 1 smelts the iron ore into iron.

[0057] In the embodiment of the present application, the iron ore system helps to smoothly operate the blast furnace and optimize steel production.

[0058] In some embodiments, in combination Figure 1 , Figure 2 and Figure 3 , see Figure 4 , showing a fourth structural schematic diagram of a plasma heating circulation device for furnace top gas, the recycling system also includes a fuel supply system 41;

[0059] The fuel supply system 41 is connected to the coal inlet 1 - 3 of the blast furnace 1 .

[0060] Specifically, the fuel supply system 41 is used to provide fuel to the blast furnace 1 so that the blast furnace 1 operates based on the fuel.

[0061] In some embodiments, the fuel contained in the fuel supply system is coal or coke, but is not limited to these two fuels. Specifically, the fuel can be stored in the fuel supply system according to demand.

[0062] In some embodiments, in combination Figure 1 , Figure 2 , Figure 3 as well as Figure 4 , see Figure 5 , showing a fifth structural schematic diagram of a plasma heating circulation device for furnace top gas, the recycling system also includes a use system 51;

[0063] The use system 51 is connected to the gas outlet 2 - 3 of the alcohol amine decarbonization device absorption equipment 2 and the coal gas outlet 1 - 1 of the blast furnace 1 .

[0064] Specifically, the system 51 is used to reduce carbon dioxide (CO2) and other pollutants therein by capturing and treating the coal gas emitted by the blast furnace 1, thereby improving the environmental friendliness and energy efficiency of the entire smelting process.

[0065] In the embodiment of the present application, the use of the system not only helps to reduce greenhouse gas emissions, but also improves the utilization efficiency of coal gas to a certain extent, thereby enhancing the sustainability of the smelting process of the blast furnace 1.

[0066] It should be noted that, based on the above description, this embodiment is described in detail by taking the operation of the blast furnace 1 with amine decarbonization and carbon dioxide recycling as an example.

[0067] The fuel provided by the fuel supply system to the blast furnace 1 is coke, and its element analysis is shown in Table 1.

[0068] Table 1

[0069] Carbon H Hydrogen Oxygen N S-sulfur 92.2 2.30 2.51 1.81 1.48

[0070] The contents of various elements are merely examples.

[0071] Specifically, the blast furnace 1 gas generation system of the present application embodiment is shown in Figure 6 The system mainly includes a blast furnace 1, an alcohol amine decarbonization device absorption device 2 and an alcohol amine decarbonization device desorption device 3, as follows:

[0072] Coke as fuel (sin) is added into blast furnace 1 from carbon inlet 1-3 of blast furnace 1 at a feeding rate of 1 t / h. At the same time, mixed gas (sin) composed of desorption gas mainly composed of carbon dioxide and oxygen desorbed by desorption device 3 of amine decarbonization device is supplied to blast furnace 1 from oxidation gas inlet 1-2 of blast furnace 1 at a rate of 500 Nm3 / h. The volume ratio of carbon dioxide to oxygen in the mixed gas is 4:6. Coke (sin) reacts with oxygen in the mixed gas at 900°C to generate carbon dioxide and release a large amount of heat. Under the action of heat, the generated carbon dioxide gas and the original carbon dioxide gas in the mixed gas (sin) are A part of the carbon dioxide reacts with coke again to generate 1000Nm3 / h synthesis gas (a) mainly composed of carbon monoxide. The synthesis gas (a) is mixed with the purified gas (c) from the alcohol amine decarbonization device desorption equipment 2 to form a reducing gas and introduced into the iron ore layer to reduce the iron ore to iron at 1200°C. Not only is the carbon monoxide in the blast furnace gas (a) produced by the blast furnace 1 recovered and recycled, but the carbon dioxide in the blast furnace gas is also separated after being treated by the alcohol amine decarbonization device desorption equipment 2 and the alcohol amine decarbonization device desorption equipment 3, and is reduced to generate carbon monoxide, thereby realizing the recycling of carbon dioxide in the blast furnace gas.

[0073] After the reduction of the iron ore, the reducing gas is converted into blast furnace gas (A) rich in carbon dioxide, and its composition is basically the same as the properties of the blast furnace gas produced in Table 2.

[0074] Table 2 Physical properties of blast furnace gas

[0075] Element CO CO2 H2 H2O N2 other Content / vol.% 33.5 51.2 5.0 2.8 7.0 0.5

[0076] It should be noted that the contents shown in Table 2 are only for illustration.

[0077] The generated blast furnace gas (A) enters the alcoholamine decarbonization device absorption device 2 from the air inlet 2-1 of the alcoholamine decarbonization device absorption device 2, and is mixed with the alcoholamine lean liquid (B) from the liquid inlet 2-2 of the alcoholamine decarbonization device absorption device 2. The carbon dioxide in the blast furnace gas (A) is absorbed and removed by the alcoholamine lean liquid (B) to become a purified gas (C) with a flow rate of about 1000Nm3 / h and is discharged from the alcoholamine decarbonization device absorption device 2. The physical properties of the purified gas (C) are shown in Table 1. At the same time, the alcoholamine lean liquid (D) absorbs carbon dioxide and becomes an alcoholamine rich liquid (D).

[0078] The produced purified gas (C) is recycled as reducing gas to blast furnace 1 for recycling. Among them, the excess purified gas (D) is used as high carbon monoxide emission and high calorific value gas (physical properties see Table 4) for use by other gas customers.

[0079] Table 3 Composition and calorific value of blast furnace gas

[0080] Components CO CO2 H2 H2O NOx SO2 N2 other Content / vol.% 98.56 0.2 0.51 0.51 0.17 0.05 0 0

[0081] It should be noted that the contents shown in Table 3 are only for illustration.

[0082] The generated alcoholamine rich liquid (D) enters the alcoholamine decarbonization device desorption device 3 through the liquid inlet 3-1 of the alcoholamine decarbonization device desorption device 3 to desorb and remove the absorbed carbon dioxide and form a desorption gas (E) with a flow rate of 200Nm3 / h and a carbon dioxide content of about 99.8vol.%, and the alcoholamine rich liquid (D) becomes alcoholamine lean liquid (B) again, and the desorbed gas.

[0083] The generated amine lean solution (B) is returned to the amine decarbonization device absorption equipment 2 for recycling, and the desorbed gas (E) and about 300Nm3 / h of oxygen (H) form a mixed gas and return to the blast furnace 1 as an oxidizing gas (H) for recycling.

[0084] A blast furnace gas recycling system provided by the present application, the recycling system includes a blast furnace, an alcoholamine decarbonization device absorption device and an alcoholamine decarbonization device desorption device, the air inlet of the alcoholamine decarbonization device absorption device is connected to the air outlet of the blast furnace, the air outlet of the alcoholamine decarbonization device absorption device is connected to the gas inlet of the blast furnace, the liquid outlet of the alcoholamine decarbonization device absorption device is connected to the liquid inlet of the alcoholamine decarbonization device desorption device, the liquid outlet of the alcoholamine decarbonization device desorption device is connected to the liquid inlet of the alcoholamine decarbonization device absorption device, the air outlet of the alcoholamine decarbonization device desorption device is connected to the oxygen inlet of the blast furnace, and the alcoholamine decarbonization device desorption device is used to desorb the alcoholamine rich liquid, obtain the desorbed gas with a high content of carbon dioxide, and transmit the desorbed gas to the blast furnace. Thus, the carbon dioxide in the blast furnace gas is removed by the recycling system, and it is regenerated into carbon monoxide by gasification treatment, effectively realizing the recycling of carbon dioxide, thereby effectively improving the carbon utilization rate and reducing the emission rate of carbon dioxide.

[0085] A blast furnace gas recycling system provided in the above-mentioned embodiment of the present application, see Figure 7 , shows a flow chart of a method for recycling blast furnace gas provided in an embodiment of the present application, the method comprising:

[0086] S701, obtaining blast furnace gas generated by a blast furnace;

[0087] S702, using the alcoholamine lean liquid in the alcoholamine decarbonization device absorption equipment to chemically react with blast furnace gas to obtain purified gas and alcoholamine rich liquid rich in carbon dioxide;

[0088] Specifically, the blast furnace gas undergoes a chemical absorption reaction with the alcoholamine lean liquid in the alcoholamine decarbonization device absorption equipment, so that the alcoholamine lean liquid absorbs the carbon dioxide in the blast furnace gas, thereby generating purified gas with low carbon dioxide content and high carbon monoxide content and alcoholamine rich liquid rich in carbon dioxide.

[0089] Optionally, the alcohol amine decarbonation unit absorption device can also produce excess purified gas, which can be used as coal gas with high carbon monoxide content for other coal gas users.

[0090] S703, using the desorption equipment of the alcoholamine decarbonization device to perform a desorption reaction on the alcoholamine rich liquid to obtain a desorbed gas with a high content of carbon dioxide;

[0091] Specifically, the carbon dioxide absorbed by the alcoholamine rich liquid is desorbed to become an alcoholamine lean liquid with a low carbon dioxide content, and the removed carbon dioxide is discharged in the form of desorbed gas with a high carbon dioxide content.

[0092] Optionally, the lean alcoholamine solution with low carbon dioxide content is returned to the alcoholamine decarbonation unit absorption device for recycling.

[0093] S704, mixing the desorbed gas with oxygen to obtain oxidizing gas, and transmitting the oxidizing gas and the purified gas back to the blast furnace.

[0094] Specifically, when the desorbed gas with a high carbon dioxide content is mixed with oxygen, high-concentration oxygen and carbon dioxide gases will be formed, and then the high-concentration oxygen and carbon dioxide gases will be combined to obtain oxidizing gas, which is returned to the blast furnace and reacts with the fuel in the blast furnace to generate synthetic coal gas with a high carbon monoxide content. The purified gas and the synthetic coal gas are mixed and used as reducing gas through the iron ore layer for ironmaking.

[0095] The present application provides a method for recycling blast furnace gas, which obtains blast furnace gas generated by a blast furnace, and then uses the alcoholamine lean liquid in the alcoholamine decarbonization device absorption device to chemically react with the blast furnace gas to obtain purified gas and alcoholamine rich liquid rich in carbon dioxide, and then uses the alcoholamine decarbonization device desorption device to desorb the alcoholamine rich liquid to obtain desorbed gas with a high content of carbon dioxide, and finally mixes the desorbed gas with oxygen to obtain oxidized gas, and transmits the oxidized gas and purified gas back to the blast furnace. Thus, the problem of removing and reusing carbon dioxide is solved by the alcoholamine decarbonization device absorption device and the alcoholamine decarbonization device desorption device.

[0096] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0097] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A blast furnace gas recycling system, characterized in that: The recycling system includes a blast furnace, an alcohol amine decarbonization device absorption device and an alcohol amine decarbonization device desorption device; The air inlet of the alcoholamine decarbonization device absorption equipment is connected to the air outlet of the blast furnace, the air outlet of the alcoholamine decarbonization device absorption equipment is connected to the gas inlet of the blast furnace, and the liquid outlet of the alcoholamine decarbonization device absorption equipment is connected to the liquid inlet of the alcoholamine decarbonization device desorption device; wherein the alcoholamine decarbonization device absorption equipment is used to hold the alcoholamine lean liquid, and react the blast furnace gas generated by the blast furnace with the alcoholamine lean liquid to obtain purified gas and alcoholamine rich liquid; the alcoholamine decarbonization device absorption equipment is also used to transmit the purified gas to the blast furnace, and transmit the alcoholamine rich liquid to the alcoholamine decarbonization device desorption device; The liquid outlet of the desorption device of the alcoholamine decarbonization device is connected to the liquid inlet of the absorption device of the alcoholamine decarbonization device, and the gas outlet of the desorption device of the alcoholamine decarbonization device is connected to the oxidation gas inlet of the blast furnace. The desorption device of the alcoholamine decarbonization device is used to desorb the alcoholamine rich liquid to obtain desorption gas with a high content of carbon dioxide, and transmit the desorption gas to the blast furnace.

2. The recycling system according to claim 1, characterized in that: The recycling system also includes an oxygen supply system; The oxygen supply system is respectively connected to the oxidation gas inlet of the blast furnace and the gas outlet of the desorption equipment of the alcohol amine decarbonization device.

3. The recycling system according to claim 1, characterized in that: The recycling system also includes an iron ore system; The iron ore system is connected to the iron ore inlet of the blast furnace.

4. The recycling system according to claim 1, characterized in that: The recycling system also includes a fuel supply system; The fuel supply system is connected to the coal inlet of the blast furnace.

5. The recycling system according to claim 1, characterized in that: The recycling system also includes a utilization system; The use system is connected to the gas outlet of the alcohol amine decarbonization device absorption equipment and the coal gas outlet of the blast furnace.

6. The recycling system according to claim 4, characterized in that: The fuel contained in the fuel supply system is coal or coke.

7. The recycling system according to claim 1, characterized in that: The alkanolamine lean solution is composed of alkanolamine, water and carbon dioxide.

8. The recycling system according to claim 1, characterized in that: The volume range of the blast furnace is 450m 3 Up to 5000m 3 .

9. The recycling system according to claim 1, characterized in that: An iron ore layer is arranged in the blast furnace. The iron ore layer contains iron ore. The iron ore is used for smelting with purified gas to obtain iron.

10. A method for recycling blast furnace gas, characterized in that: A blast furnace gas recycling system applied to any one of claims 1 to 9, the method comprising: Obtain blast furnace gas produced by blast furnaces; The alcoholamine lean liquid in the alcoholamine decarbonization device absorption equipment is used to chemically react with the blast furnace gas to obtain purified gas and alcoholamine rich liquid rich in carbon dioxide; Using the desorption equipment of the alcoholamine decarbonization device to carry out a desorption reaction on the alcoholamine rich liquid to obtain a desorbed gas with a high content of carbon dioxide; The desorbed gas is mixed with oxygen to obtain an oxidizing gas, and the oxidizing gas and the cleaned gas are transmitted back to the blast furnace.

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