Blast furnace gas wet desulfurization and carbon reduction system

Abstract

This invention discloses a wet desulfurization and carbon reduction system for blast furnace gas, comprising: an absorption tower and a regeneration tower; a rich liquor pipeline and a lean liquor pipeline connected between the absorption tower and the regeneration tower; a first heat exchange reflux pipeline for supplying the sulfur-containing gas in the regeneration tower after heat exchange and reflux, and a second heat exchange reflux pipeline for supplying the distillate in the regeneration tower after heat exchange and reflux, both of which are connected to the regeneration tower; and a heat exchange medium pipeline, wherein a first heat exchanger, a second heat exchanger, and a third heat exchanger are respectively installed between the heat exchange medium pipeline and the lean liquor pipeline, the first heat exchange reflux pipeline, and the second heat exchange reflux pipeline, and the heat exchange medium in the heat exchange medium pipeline flows sequentially through the first heat exchanger, the second heat exchanger, and the third heat exchanger. This invention can solve the problems of high energy consumption, high desulfurization cost, and low heat exchange efficiency in the current gas fine desulfurization process, achieving high-efficiency desulfurization of blast furnace gas while reducing carbon emissions.

Description

Technical Field

[0001] This invention relates to the field of blast furnace technology, and in particular to a wet desulfurization and carbon reduction system for blast furnace gas. Background Technology

[0002] Blast furnace ironmaking, as the primary method of steel production, produces blast furnace gas as a byproduct in addition to molten iron. After passing through bag filters and TRT (Blast Furnace Top Gas Recovery Turbine Unit) for residual pressure power generation, the gas contains large amounts of pollutants such as hydrogen sulfide and carbonyl sulfide. Compared to end-of-pipe desulfurization technologies, centralized fine desulfurization at the gas source can reduce costs by 15% to 20%. Among these methods, wet gas desulfurization aims to remove sulfides from blast furnace gas using solvents, such as ammonia and methyl diethanolamine, which are widely used in fine desulfurization processes.

[0003] For wet desulfurization processes, after alkali absorption, a regeneration tower is installed in the subsequent process to achieve alkali recycling. However, due to the large demand from steel production, a large amount of blast furnace gas is generated during the process, resulting in significant energy consumption for gas desulfurization. Furthermore, the regeneration process of the desulfurization absorbent involves an endothermic reaction, and traditional distillation methods consume a large amount of steam. Calculations show that removing 1 kg of sulfur requires approximately 35.87 kg of standard coal and produces about 88.24 kg of carbon dioxide. Therefore, in addition to the carbon emissions generated by the process itself, the carbon emissions from consuming steam heat energy are still considerable. Moreover, existing gas desulfurization processes suffer from high energy consumption for the regeneration tower, high desulfurization costs, and low heat exchange efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a wet desulfurization and carbon reduction system for blast furnace gas, which solves the problems of high energy consumption, high desulfurization cost, and low heat exchange efficiency in the current fine desulfurization process of blast furnace gas, and achieves high-efficiency desulfurization of blast furnace gas while reducing carbon emissions.

[0005] The above-mentioned objectives of this invention are mainly achieved by the following technical solutions:

[0006] This invention provides a wet desulfurization and carbon reduction system for blast furnace gas, comprising:

[0007] Absorption tower and regeneration tower;

[0008] A rich liquid pipeline, which connects the absorption tower and the regeneration tower;

[0009] A lean liquor pipeline, which connects the regeneration tower and the absorption tower;

[0010] A first heat exchange return pipeline is used to supply the sulfur-containing gas in the regeneration tower for heat exchange and return, and the first heat exchange return pipeline is connected to the regeneration tower.

[0011] A second heat exchange reflux line is used to supply the distillate in the regeneration tower for heat exchange and reflux, and the second heat exchange reflux line is connected to the regeneration tower;

[0012] A heat exchange medium pipeline is provided, with a first heat exchanger, a second heat exchanger, and a third heat exchanger respectively between the heat exchange medium pipeline and the lean liquid pipeline, the first heat exchange reflux pipeline, and the second heat exchange reflux pipeline. The heat exchange medium in the heat exchange medium pipeline flows sequentially through the first heat exchanger, the second heat exchanger, and the third heat exchanger.

[0013] The wet desulfurization and carbon reduction system for blast furnace gas described in this invention, through the setting of heat exchange medium pipelines, allows the heat exchange medium in the heat exchange pipelines to exchange heat with the medium in the lean liquor pipeline, the first heat exchange return pipeline, and the second heat exchange return pipeline. By utilizing indirect heat pumps and thermal integration technology between different streams, the high and low grade heat sources in the material are rematched, which can reduce the energy consumption of the process and the heat load of the equipment.

[0014] In a preferred embodiment of the present invention, a rich-lean heat exchanger is provided between the rich-lean pipeline and the lean-lean pipeline.

[0015] In this embodiment, the lean-rich heat exchanger can realize heat exchange between lean liquid and rich liquid in the pipeline. The lean liquid coming out of the regeneration tower is at a high temperature, while the rich liquid coming out of the absorption tower is at a lower temperature. The lean liquid has a better absorption effect in the absorption tower under low temperature conditions. Therefore, the lean-rich heat exchanger is set up to perform preliminary heat exchange to cool down the lean liquid, and at the same time, it can also reduce the cooling load of the absorption tower.

[0016] In a preferred embodiment of the present invention, the heat exchange medium flowing in the heat exchange medium pipeline is methanol, water or ethanol.

[0017] In this embodiment, the heat exchange medium can be ethanol, preferably water, and more preferably methanol, thereby enabling multiple heat exchange processes to be efficiently achieved within the heat exchange medium pipeline.

[0018] In a preferred embodiment of the present invention, a compressor for pressurizing and heating the vaporized heat exchange medium is provided on the heat exchange medium pipeline, and the compressor is located between the second heat exchanger and the third heat exchanger.

[0019] In this embodiment, a compressor is installed before the third heat exchanger. The compressor further compresses and heats the gaseous heat exchange medium after two heat exchange heating cycles to improve the heat exchange effect of the heat exchange medium in the third heat exchanger.

[0020] In a preferred embodiment of the present invention, the compressor is connected to a replenishment pipeline for replenishing the heat exchange medium into the heat exchange medium pipeline.

[0021] In this embodiment, an appropriate amount of liquid heat exchange medium is added to the compressor through a supplementary pipeline to prevent the heat exchange medium from overheating.

[0022] In a preferred embodiment of the present invention, a heat pump separator is provided downstream of the third heat exchanger along the flow direction of the heat exchange medium in the heat exchange medium pipeline. The heat pump separator is connected to a first return pipeline. The outlet end of the first return pipeline is connected to the heat exchange medium pipeline between the second heat exchanger and the compressor. The gaseous heat exchange medium separated by the heat pump separator can flow back into the heat exchange medium pipeline through the first return pipeline.

[0023] In this embodiment, the heat pump separator can perform gas-liquid separation on the heat exchange medium after passing through the third heat exchanger, returning the gaseous heat exchange medium to the compressor inlet through the first return pipeline, and recycling the liquid heat exchange medium.

[0024] In a preferred embodiment of the present invention, a reflux cooler and a reflux tank are provided on the first heat exchange reflux pipeline, and the reflux tank is connected to an exhaust pipeline.

[0025] In this embodiment, the reflux cooler can further cool and reduce the temperature of the medium in the first heat exchange reflux pipeline, and the reflux tank can play a certain buffering role to reduce the fluctuation of airflow in the pipeline.

[0026] In a preferred embodiment of the present invention, a wastewater pipeline is connected to the first heat exchange reflux pipeline, and a wastewater tank is provided on the wastewater pipeline.

[0027] In this embodiment, the wastewater tank can discharge the liquid condensed in the first heat exchange reflux pipeline through the wastewater pipeline, preventing the liquid from re-entering the upper part of the regeneration tower.

[0028] In a preferred embodiment of the present invention, a reboiler for heating the liquid in the second heat exchange reflux line is provided on the second heat exchange reflux line, and the reboiler is connected to a steam heat exchange line.

[0029] In this embodiment, the reboiler can reheat the liquid that has passed through the third heat exchanger, thereby increasing the temperature of the bottom distillate in the second heat exchange reflux line.

[0030] In a preferred embodiment of the present invention, a second reflux pipeline is connected between the lower and upper parts of the absorption tower, and the rich liquid generated in the lower part of the absorption tower can flow back into the upper part of the absorption tower through the second reflux pipeline.

[0031] In this embodiment, the second reflux line can return the rich liquid generated at the bottom of the absorption tower to the absorption tower. The acidic gas introduced into the absorption tower can first come into contact with the rich liquid and be partially absorbed, thereby reducing the amount of lean liquid used.

[0032] In a preferred embodiment of the present invention, a rich liquid branch pipeline is connected between the rich liquid pipeline and the upper part of the regeneration tower, and one end of the rich liquid branch pipeline is located upstream of the rich-lean heat exchanger along the flow direction of the rich liquid in the rich liquid pipeline.

[0033] In this embodiment, the rich liquid in the rich liquid branch pipeline connected to the regeneration tower before the rich-pollution heat exchanger does not undergo heat exchange, thus the temperature of the regeneration tower can be adjusted.

[0034] In a preferred embodiment of the present invention, a rich liquid addition pipeline is connected to the rich liquid pipeline upstream of the rich liquid exchanger along the flow direction of the rich liquid in the rich liquid pipeline.

[0035] In this embodiment, rich solution can be added to the rich solution pipeline through the rich solution addition pipeline, avoiding low absorption efficiency due to low flow rate or low concentration of rich solution.

[0036] In a preferred embodiment of the present invention, a first additive pipeline is connected to the rich liquid pipeline downstream of the rich liquid exchanger along the flow direction of the rich liquid in the rich liquid pipeline.

[0037] In this embodiment, a certain amount of additive can be added to the rich liquid flowing to the regeneration tower through the first additive pipeline, thereby removing the foam in the regeneration tower.

[0038] In a preferred embodiment of the present invention, a lean liquid cooler is provided on the lean liquid pipeline downstream of the first heat exchanger along the flow direction of the lean liquid in the lean liquid pipeline.

[0039] In this embodiment, the lean liquor cooler can further cool the lean liquor after heat exchange in the first heat exchanger, further reducing the temperature of the lean liquor and improving the absorption effect of the lean liquor in the absorption tower.

[0040] In a preferred embodiment of the present invention, a filter is provided on the lean liquid pipeline downstream of the first heat exchanger along the flow direction of the lean liquid in the lean liquid pipeline.

[0041] In this embodiment, the filter can filter the lean liquid in the lean liquid pipeline to prevent impurities from entering the absorption tower.

[0042] In a preferred embodiment of the present invention, a lean solution addition pipeline is connected to the lean solution pipeline downstream of the first heat exchanger along the flow direction of the lean solution in the lean solution pipeline.

[0043] In this embodiment, lean solution can be added to the lean solution pipeline through the lean solution addition pipeline, avoiding low absorption efficiency or poor absorption effect due to low flow rate or low concentration of lean solution.

[0044] In a preferred embodiment of the present invention, a second additive pipeline is connected to the lean liquid pipeline downstream of the first heat exchanger along the flow direction of the lean liquid in the lean liquid pipeline.

[0045] In this embodiment, a certain amount of additive can be added to the lean liquid flowing into the absorption tower through the second additive pipeline, thereby removing the foam in the absorption tower. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0047] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0048] Figure 1 This is a schematic diagram of the structure of the wet desulfurization and carbon reduction system for blast furnace gas described in this invention;

[0049] Figure 2 This is a schematic diagram of the heat exchange medium pipeline described in this invention;

[0050] Figure 3 This is a schematic diagram of the structure of the first heat exchange reflux pipeline of the present invention;

[0051] Figure 4 This is a schematic diagram of the structure of the second heat exchange reflux switching line of the present invention.

[0052] Explanation of reference numerals in the attached figures:

[0053] 10. Absorption tower; 11. Regeneration tower; 12. Second reflux pipeline;

[0054] 20. Rich solution pipeline; 21. Rich solution branch pipeline; 22. Rich solution addition pipeline; 23. First additive pipeline;

[0055] 30. Lean liquor line; 31. Lean liquor cooler; 32. Filter; 33. Lean liquor addition line; 34. Second additive line; 35. Lean liquor outlet line;

[0056] 40. First heat exchange reflux pipeline; 41. Reflux cooler; 42. Reflux tank; 421. Exhaust pipeline; 43. Wastewater pipeline; 431. Wastewater tank;

[0057] 50. Second heat exchange reflux line; 51. Reboiler; 52. Steam heat exchange line;

[0058] 60. Heat exchange medium pipeline; 61. Compressor; 611. Make-up pipeline; 62. Heat pump separator; 621. First return pipeline;

[0059] 70. First heat exchanger; 71. Second heat exchanger; 72. Third heat exchanger; 73. Rich and poor heat exchanger;

[0060] 80. Liquid pump. Detailed Implementation

[0061] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0062] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0064] like Figures 1 to 4As shown, the present invention provides a wet desulfurization and carbon reduction system for blast furnace gas, comprising: an absorption tower 10 and a regeneration tower 11; a rich liquor pipeline 20 connected between the absorption tower 10 and the regeneration tower 11; a lean liquor pipeline 30 connected between the regeneration tower 11 and the absorption tower 10; a first heat exchange reflux pipeline 40 for supplying the sulfur-containing gas in the regeneration tower 11 after heat exchange, the first heat exchange reflux pipeline 40 being connected to the regeneration tower 11; and a system for supplying the sulfur-containing gas in the regeneration tower 11 after heat exchange. The distillate is refluxed through a second heat exchange reflux line 50, which is connected to the regeneration tower 11. A heat exchange medium line 60 is provided between the heat exchange medium line 60 and the lean liquid line 30, the first heat exchange reflux line 40 and the second heat exchange reflux line 50, respectively equipped with a first heat exchanger 70, a second heat exchanger 71 and a third heat exchanger 72. The heat exchange medium in the heat exchange medium line 60 flows through the first heat exchanger 70, the second heat exchanger 71 and the third heat exchanger 72 in sequence.

[0065] The wet desulfurization and carbon reduction system for blast furnace gas described in this invention utilizes indirect heat pumps and thermal integration technology between different streams to re-match high- and low-grade heat sources in the material flow, thereby reducing the energy consumption of the process and the heat load of the equipment. Through the setting of the heat exchange medium pipeline 60, the heat exchange medium in the heat exchange medium pipeline 60 is successively exchanged with the medium in the lean liquor pipeline 30, the first heat exchange return pipeline 40, and the second heat exchange return pipeline 50, thereby reducing the heat load of the corresponding pipelines.

[0066] The following section will provide a detailed description of the specific structure of each part of the wet desulfurization and carbon reduction system for blast furnace gas described in this invention, as well as the pipeline connection relationships between each part.

[0067] The wet desulfurization and carbon reduction system for blast furnace gas described in this invention includes an absorption tower 10 and a regeneration tower 11 arranged adjacent to each other. Both the absorption tower 10 and the regeneration tower 11 are mature absorption and regeneration structures in existing wet desulfurization processes. Their specific internal structures, absorption principles, and regeneration principles are all existing technologies. Therefore, the internal structures of the absorption tower 10 and the regeneration tower 11 will not be described in detail here.

[0068] A rich liquid pipeline 20 and a lean liquid pipeline 30 are connected between the absorption tower 10 and the regeneration tower 11. One end of the rich liquid pipeline 20 is connected to the bottom of the absorption tower 10, and the other end is connected to the top of the regeneration tower 11. The rich liquid generated in the absorption tower 10 can flow to the regeneration tower 11 through the rich liquid pipeline 20. One end of the lean liquid pipeline 30 is connected to the bottom of the regeneration tower 11, and the other end is connected to the top of the absorption tower 10. The lean liquid generated by the regeneration process of the rich liquid entering the regeneration tower 11 can flow to the absorption tower 10 through the lean liquid pipeline 30.

[0069] The lower side wall of the absorption tower 10 is provided with a gas inlet, and the upper side wall of the absorption tower 10 is provided with a gas outlet. The raw material gas entering the absorption tower 10 through the gas inlet can contact the lean liquid entering the absorption tower 10 to remove the acidic gas in the raw material gas. The pure gas obtained flows out through the gas outlet. The rich liquid produced after the lean liquid absorbs the acidic gas enters the rich liquid pipeline 20 through the bottom of the absorption tower 10.

[0070] Specifically, absorption tower 10 employs a method of direct contact between an alkaline solvent (lean solution) and acidic gases (the feed gas contains acidic gases such as H2S and COS) within the tower for absorption. The lean solution can use alkaline solvents such as methyl diethanolamine or ammonia as absorbents. Since the absorbed solvent (rich solution) contains a large amount of acidic gas, to further recover the solvent, the rich solution is fed into regeneration tower 11. Using the principle of distillation separation, the acidic gases are desorbed from the solvent at high temperatures under heating conditions, thereby achieving the separation of the solvent and acidic gases, obtaining lean solution, and thus realizing the recycling of the absorbent.

[0071] Furthermore, such as Figure 1 As shown, both the rich liquid pipeline 20 and the lean liquid pipeline 30 are equipped with liquid pumps 80, which can drive the flow of liquid in the corresponding pipelines.

[0072] like Figure 1 and Figure 3 As shown, the regeneration tower 11 of the present invention is provided with a first heat exchange reflux pipeline 40 at its upper part. The first heat exchange reflux pipeline 40 is used for cooling and reflux of the acid gas (top steam) generated at the upper part of the regeneration tower 11. The high temperature acid gas generated at the upper part of the regeneration tower 11 enters the first heat exchange reflux pipeline 40 for heat exchange and cooling. After the temperature is reduced, it is returned to the regeneration tower 11.

[0073] Furthermore, such as Figure 3 As shown, a liquid pump 80 is installed on the first heat exchange reflux pipeline 40, which can drive the flow of acidic gas in the pipeline.

[0074] like Figure 1 and Figure 4 As shown, the regeneration tower 11 of the present invention is provided with a second heat exchange reflux pipeline 50 at its lower part. The second heat exchange reflux pipeline 50 is used for heating and reflux of the bottom distillate generated at the lower part of the regeneration tower 11. The bottom distillate (usually liquid) generated at the lower part of the regeneration tower 11 enters the second heat exchange reflux pipeline 50 for heat exchange and temperature rise. After the temperature rises, it is returned to the regeneration tower 11.

[0075] The first heat exchange reflux line 40 and the second heat exchange reflux line 50 mentioned above are basic distillation settings on the distillation column (regeneration column 11). Through the heat exchange reflux process of the first heat exchange reflux line 40 and the second heat exchange reflux line 50, in conjunction with the corresponding reaction process in the regeneration column 11, the regeneration of lean liquor is achieved.

[0076] like Figure 1 and Figure 2 As shown, the wet desulfurization and carbon reduction system for blast furnace gas of the present invention also includes a heat exchange medium pipeline 60. The heat exchange medium pipeline 60 is filled with a heat exchange medium that can exchange heat with various pipelines on the absorption tower 10 and the regeneration tower 11. Along the flow direction of the heat exchange medium inside the heat exchange medium pipeline 60, a first heat exchanger 70 is provided between the heat exchange medium pipeline 60 and the lean liquid pipeline 30, a second heat exchanger 71 is provided between the heat exchange medium pipeline 60 and the first heat exchange return pipeline 40, and a third heat exchanger 72 is provided between the heat exchange medium pipeline 60 and the second heat exchange return pipeline 50.

[0077] The heat exchange medium in the heat exchange medium pipeline 60 first exchanges heat with the lean liquid in the lean liquid pipeline 30 in the first heat exchanger 70 to raise its temperature. Some of the heat in the lean liquid is transferred to the heat exchange medium, which can partially vaporize. Then, it enters the second heat exchanger 71 to exchange heat with the top steam of the regeneration tower in the first heat exchange reflux pipeline 40 to raise its temperature. Some of the heat in the top steam is transferred to the heat exchange medium, which allows the top steam to be initially cooled and the heat exchange medium to be completely vaporized. Finally, it enters the third heat exchanger 72 to exchange heat with the bottom distillate of the regeneration tower in the second heat exchange reflux pipeline 50 to lower its temperature, which allows the bottom distillate to be initially heated and the heat exchange medium to be liquefied.

[0078] The wet desulfurization and carbon reduction system for blast furnace gas described in this invention re-matches high and low grade heat sources in the material through a separately installed heat exchange medium pipeline 60. That is, through the heat exchange effect of the heat exchange medium, part of the heat in the lean liquor, which originally required a separate cooling device for cooling, and part of the heat in the top steam of the regeneration tower are used for the heat exchange and heating process of the distillate at the bottom of the regeneration tower, realizing the recycling of heat. At the same time, it can reduce the heat exchange cooling load (or heat exchange heating load) of each pipeline, that is, reduce the heat load of the original cooling device on the lean liquor pipeline 30, thereby reducing carbon emissions.

[0079] According to one embodiment of the present invention, such as Figure 1 As shown, a lean-rich heat exchanger 73 is provided between the rich liquid pipeline 20 and the lean liquid pipeline 30. The lean-rich heat exchanger 73 can realize heat exchange between the lean liquid and the rich liquid in the pipeline. The lean liquid coming out of the regeneration tower 11 is at a high temperature, while the rich liquid coming out of the absorption tower 10 is at a lower temperature. The lean liquid has a better absorption effect in the absorption tower 10 under low temperature conditions. Therefore, the lean-rich heat exchanger 73 is set up to perform preliminary heat exchange to cool down the lean liquid, and at the same time, it can also reduce the cooling load in front of the absorption tower 10.

[0080] According to one embodiment of the present invention, the heat exchange medium flowing in the heat exchange medium pipeline 60 is methanol, water, or ethanol. Ethanol can be selected as the heat exchange medium, water is preferred, and methanol is more preferred, thereby enabling efficient multiple heat exchange processes within the heat exchange medium pipeline 60. For ease of explanation of the working principle of the heat exchange medium pipeline 60 in this invention, methanol will be used as an example for the following description.

[0081] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, a compressor 61 for pressurizing and heating the vaporized heat exchange medium is installed on the heat exchange medium pipeline 60. The compressor 61 is located between the second heat exchanger 71 and the third heat exchanger 72. The compressor 61 is installed before the third heat exchanger 72 to further compress and heat the gaseous heat exchange medium after two heat exchange heating processes, thereby improving the heat exchange effect of the heat exchange medium (methanol) in the third heat exchanger 72.

[0082] The methanol in the heat exchange medium pipeline 60 is completely vaporized into methanol vapor after heat exchange with the first heat exchanger 70 and the second heat exchanger 71. Before entering the third heat exchanger 72, the methanol vapor enters the compressor 61 and is compressed to an outlet pressure of 3-8 bar, which further increases the temperature of the methanol vapor.

[0083] Preferably, the compressor 61 is connected to a replenishment pipeline 611 for replenishing the heat exchange medium into the heat exchange medium pipeline 60; during the process of pressurizing and heating the methanol vapor, an appropriate amount of liquid methanol is replenished into the compressor 61 through the replenishment pipeline 611 to avoid overheating of the methanol vapor.

[0084] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, a heat pump separator 62 is located downstream of the third heat exchanger 72. The heat pump separator 62 is connected to a first return line 621. The outlet end of the first return line 621 is connected to the heat exchange medium line 60 between the second heat exchanger 71 and the compressor 61. The gaseous heat exchange medium separated by the heat pump separator 62 can flow back into the heat exchange medium line 60 through the first return line 621. The heat pump separator 62 can perform gas-liquid separation on the heat exchange medium after passing through the third heat exchanger 72, returning the gaseous heat exchange medium to the inlet of the compressor 61 through the first return line 621, and recycling the liquid heat exchange medium.

[0085] After being pressurized and heated, the methanol vapor enters the third heat exchanger 72 and exchanges heat with the bottom distillate in the second heat exchange reflux line 50. The heat in the methanol vapor is transferred to the bottom distillate, and the methanol vapor is liquefied into methanol liquid. Then, it enters the heat pump separator 62 for gas-liquid separation. The separated gaseous methanol flows back into the heat exchange medium line 60 through the first reflux line 621 and before reaching the inlet of the compressor 61, the separated liquid methanol can be used as the heat exchange medium in the heat exchange medium line 60 and be circulated back into its inlet.

[0086] According to one embodiment of the present invention, such as Figure 1 and Figure 3 As shown, the first heat exchange reflux pipeline 40 is equipped with a reflux cooler 41 and a reflux tank 42, and the reflux tank 42 is connected to an exhaust pipeline 421. The reflux cooler 41 can further cool down the medium (top steam) in the first heat exchange reflux pipeline 40, and the reflux tank 42 can play a certain buffering role to reduce the fluctuation of airflow in the pipeline.

[0087] Specifically, such as Figure 3 As shown, along the flow direction of the overhead steam within the first heat exchange reflux pipeline 40, both the reflux cooler 41 and the reflux tank 42 are located downstream of the second heat exchanger 71. This means the overhead steam first undergoes initial cooling via the second heat exchanger 71, and then further cooling via the reflux cooler 41 to reach the required temperature. Due to the placement of the second heat exchanger 71 between the heat exchange medium pipeline 60 and the first heat exchange reflux pipeline 40, the overhead steam can undergo heat exchange and cooling beforehand, thereby reducing the heat load on the reflux cooler 41, which in turn reduces the energy consumption of the reflux cooler 41 and consequently reduces carbon emissions.

[0088] Furthermore, such as Figure 1 and Figure 3 As shown, a wastewater pipeline 43 is connected to the first heat exchange reflux pipeline 40, and a wastewater tank 431 is installed on the wastewater pipeline 43. The wastewater pipeline 43 is connected downstream of the reflux tank 42, and the wastewater tank 431 on the wastewater pipeline 43 can discharge the liquid condensed in the first heat exchange reflux pipeline 40 through the wastewater pipeline 43, preventing the liquid from re-entering the upper part of the regeneration tower 11.

[0089] Preferably, a liquid pump 80 is installed on the wastewater pipeline 43, which can drive the flow of wastewater in the pipeline.

[0090] According to one embodiment of the present invention, such as Figure 1 and Figure 4As shown, a reboiler 51 for heating the liquid in the second heat exchange reflux line 50 is provided on the second heat exchange reflux line 50, and the reboiler 51 is connected to a steam heat exchange line 52. The reboiler 51 can reheat the liquid after it has been heated by the third heat exchanger 72, thereby increasing the temperature of the bottom distillate in the second heat exchange reflux line 50.

[0091] Specifically, such as Figure 4 As shown, along the flow direction of the bottom distillate within the second heat exchange reflux line 50, the reboiler 51 is located downstream of the third heat exchanger 72. The steam heat exchange line 52 connected to the reboiler 51 includes a steam inlet line and a condensate outlet line. The bottom distillate entering the reboiler 51 exchanges heat with the steam. The condensate generated after the steam cools and liquefies is discharged through the condensate outlet line. The bottom distillate partially vaporizes after heat exchange and heating, and the generated gas and the heated liquid flow back into the regeneration tower 11 through the two lines respectively. Due to the placement of the third heat exchanger 72 between the heat exchange medium line 60 and the second heat exchange reflux line 50, the bottom distillate can undergo heat exchange and heating first, thereby reducing the heat load of the reboiler 51, which in turn reduces the energy consumption of the reboiler 51 and thus reduces carbon emissions.

[0092] According to one embodiment of the present invention, such as Figure 1 As shown, a second reflux line 12 connects the lower and upper parts of the absorption tower 10. The rich liquid produced in the lower part of the absorption tower 10 can flow back into the upper part of the absorption tower 10 through the second reflux line 12. The second reflux line 12 can return the rich liquid produced in the lower part of the absorption tower 10 into the absorption tower 10, so that the acidic gas (raw material gas) introduced into the absorption tower 10 can first contact with the rich liquid and be partially absorbed, thereby reducing the amount of lean liquid used.

[0093] According to one embodiment of the present invention, such as Figure 1 As shown, a rich liquid branch line 21 connects the rich liquid line 20 and the upper part of the regeneration tower 11. Along the flow direction of the rich liquid in the rich liquid line 20, one end of the rich liquid branch line 21 is located upstream of the lean-rich heat exchanger 73. The rich liquid in the rich liquid branch line 21, which runs directly to the regeneration tower 11 before the lean-rich heat exchanger 73, does not undergo heat exchange. This portion of low-temperature rich liquid can regulate the temperature inside the regeneration tower 11.

[0094] According to one embodiment of the present invention, such as Figure 1 As shown, along the flow direction of the rich liquid in the rich liquid pipeline 20, a rich liquid addition pipeline 22 is connected to the upstream rich liquid pipeline 20 of the lean-rich heat exchanger 73. Rich liquid is added to the rich liquid pipeline 20 through the rich liquid addition pipeline 22 to avoid the problem of reduced absorption efficiency due to low flow rate or low concentration of the rich liquid.

[0095] According to one embodiment of the present invention, such as Figure 1As shown, along the flow direction of the rich liquid in the rich liquid pipeline 20, a first additive pipeline 23 is connected to the rich liquid pipeline 20 downstream of the lean-rich heat exchanger 73; a certain amount of additive is added to the rich liquid flowing to the regeneration tower 11 through the first additive pipeline 23, thereby removing the foam in the regeneration tower 11.

[0096] According to one embodiment of the present invention, such as Figure 1 As shown, a lean liquid cooler 31 is provided on the lean liquid pipeline 30 downstream of the first heat exchanger 70, along the flow direction of the lean liquid in the lean liquid pipeline 30. The lean liquid cooler 31 can further cool the lean liquid after heat exchange in the first heat exchanger 70, further reduce the temperature of the lean liquid, and improve the absorption effect of the lean liquid in the absorption tower 10.

[0097] The first heat exchanger 70, which is installed between the heat exchange medium pipeline 60 and the lean liquid pipeline 30, is located upstream of the lean liquid heat exchanger. The lean liquid in the lean liquid pipeline 30 can first pass through the first heat exchanger 70 for heat exchange and cooling, thereby reducing the heat load of the lean liquid cooler 31, which in turn reduces the energy consumption of the lean liquid cooler 31 and thus reduces carbon emissions.

[0098] According to one embodiment of the present invention, such as Figure 1 As shown, a filter 32 is provided on the lean liquid pipeline 30 downstream of the first heat exchanger 70 along the flow direction of the lean liquid in the lean liquid pipeline 30; the filter 32 can filter the lean liquid in the lean liquid pipeline 30 to prevent impurities in it from entering the absorption tower 10.

[0099] Specifically, such as Figure 1 As shown, the lean liquid after passing through the lean liquid cooler 31 enters the first mechanical filter 3, the activated carbon filter and the second mechanical filter at a temperature of 20℃-50℃, and then enters the absorption tower 10 for recycling.

[0100] According to one embodiment of the present invention, such as Figure 1 As shown, along the flow direction of the lean liquid in the lean liquid pipeline 30, a lean liquid addition pipeline 33 is connected to the lean liquid pipeline 30 downstream of the first heat exchanger 70; lean liquid is added to the lean liquid pipeline 30 through the lean liquid addition pipeline 33 to avoid low absorption efficiency or poor absorption effect due to low lean liquid flow rate or low concentration.

[0101] According to one embodiment of the present invention, such as Figure 1 As shown, along the flow direction of the lean liquid in the lean liquid pipeline 30, a second additive pipeline 34 is connected to the lean liquid pipeline 30 downstream of the first heat exchanger 70; a certain amount of additive is added to the lean liquid flowing into the absorption tower 10 through the second additive pipeline 34, thereby removing the foam in the absorption tower 10.

[0102] According to one embodiment of the present invention, such as Figure 1 As shown, along the flow direction of the lean liquid in the lean liquid line 30, two lean liquid outlet lines 35 are connected to the lean liquid line 30 downstream of the first heat exchanger 70. One of the lean liquid outlet lines 35 is connected to a solvent storage tank outside the system, and the other lean liquid outlet line 35 can be connected to... Figure 1 Another absorption tower not shown in the image is connected to...

[0103] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wet desulfurization and carbon reduction system for blast furnace gas, characterized in that, include: Absorption tower and regeneration tower; Rich solution pipeline and lean solution pipeline connected between the absorption tower and the regeneration tower; A first heat exchange return pipeline is used to supply the sulfur-containing gas in the regeneration tower for heat exchange and return, and the first heat exchange return pipeline is connected to the regeneration tower. A second heat exchange reflux line is used to supply the distillate in the regeneration tower for heat exchange and reflux, and the second heat exchange reflux line is connected to the regeneration tower; A heat exchange medium pipeline is provided, with a first heat exchanger, a second heat exchanger, and a third heat exchanger respectively connected between the heat exchange medium pipeline and the lean liquid pipeline, the first heat exchange reflux pipeline, and the second heat exchange reflux pipeline. The heat exchange medium in the heat exchange medium pipeline flows sequentially through the first heat exchanger, the second heat exchanger, and the third heat exchanger. The heat exchange medium in the heat exchange medium pipeline first exchanges heat with the lean liquid in the lean liquid pipeline in the first heat exchanger, and some of the heat in the lean liquid is transferred to the heat exchange medium, allowing the heat exchange medium to partially vaporize. Then, it enters the second heat exchanger and exchanges heat with the top steam of the regeneration tower in the first heat exchange reflux pipeline, and exchanges heat with it, and some of the heat in the top steam is transferred to the heat exchange medium, allowing the top steam to be initially cooled and the heat exchange medium to be completely vaporized. Finally, it enters the third heat exchanger and exchanges heat with the bottom distillate of the regeneration tower in the second heat exchange reflux pipeline, and exchanges heat with it, allowing the bottom distillate to be initially heated and the heat exchange medium to liquefy.

2. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, A rich-pollution heat exchanger is provided between the rich-pollution pipeline and the lean-pollution pipeline.

3. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, The heat exchange medium flowing in the heat exchange medium pipeline is methanol, water, or ethanol.

4. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, The heat exchange medium pipeline is equipped with a compressor for pressurizing and heating the vaporized heat exchange medium, and the compressor is located between the second heat exchanger and the third heat exchanger.

5. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 4, characterized in that, The compressor is connected to a replenishment pipeline for supplying the heat exchange medium into the heat exchange medium pipeline.

6. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 4 or 5, characterized in that, Along the flow direction of the heat exchange medium in the heat exchange medium pipeline, a heat pump separator is provided downstream of the third heat exchanger. The heat pump separator is connected to a first return pipeline. The outlet end of the first return pipeline is connected to the heat exchange medium pipeline between the second heat exchanger and the compressor. The gaseous heat exchange medium separated by the heat pump separator can flow back into the heat exchange medium pipeline through the first return pipeline.

7. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, The first heat exchange reflux pipeline is equipped with a reflux cooler and a reflux tank, and the reflux tank is connected to an exhaust pipeline.

8. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1 or 7, characterized in that, A wastewater pipeline is connected to the first heat exchange reflux pipeline, and a wastewater tank is installed on the wastewater pipeline.

9. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, The second heat exchange reflux line is equipped with a reboiler for heating the liquid in the second heat exchange reflux line, and the reboiler is connected to a steam heat exchange line.

10. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, A second reflux pipeline connects the lower and upper parts of the absorption tower, allowing the rich liquid generated in the lower part of the absorption tower to flow back into the upper part of the absorption tower via the second reflux pipeline.

11. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 2, characterized in that, A rich liquid branch pipeline is connected between the rich liquid pipeline and the upper part of the regeneration tower. Along the flow direction of the rich liquid in the rich liquid pipeline, one end of the rich liquid branch pipeline is located upstream of the rich-lean heat exchanger.

12. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 2, characterized in that, Along the flow direction of the rich liquid in the rich liquid pipeline, a rich liquid addition pipeline is connected to the upstream rich liquid pipeline of the lean-rich heat exchanger.

13. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 2, characterized in that, Along the flow direction of the rich liquid in the rich liquid pipeline, a first additive pipeline is connected to the rich liquid pipeline downstream of the lean-rich heat exchanger.

14. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, Along the flow direction of the lean liquid in the lean liquid pipeline, a lean liquid cooler is provided on the lean liquid pipeline downstream of the first heat exchanger.

15. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, A filter is provided on the lean solution pipeline downstream of the first heat exchanger, along the flow direction of the lean solution in the lean solution pipeline.

16. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, Along the flow direction of the lean solution in the lean solution pipeline, a lean solution addition pipeline is connected to the lean solution pipeline downstream of the first heat exchanger.

17. The wet desulfurization and carbon reduction system for blast furnace gas according to claim 1, characterized in that, Along the flow direction of the lean solution in the lean solution pipeline, a second additive pipeline is connected to the lean solution pipeline downstream of the first heat exchanger.

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