Blast furnace gas desulfurization and decarbonization process system

Abstract

The utility model relates to a blast furnace gas desulfurization and decarburization process system which comprises a spray tower, a desulfurization and decarburization module, a barren liquor regeneration tower, a desulfurization module and a storage tank, the spray tower is used for spraying blast furnace gas, and the desulfurization and decarburization module is used for carrying out wet desulfurization and decarburization on the blast furnace gas through barren liquor; barren liquor of the desulfurization and decarburization module is subjected to desulfurization and decarburization to form rich liquor, the barren liquor regeneration tower is connected with the desulfurization and decarburization module, the rich liquor is regenerated into the barren liquor, the barren liquor is introduced into the desulfurization and decarburization module again, the wet desulfurization and decarburization efficiency can be guaranteed, and mixed gas of H2S and CO2 is formed in the barren liquor regeneration process; the desulfurization module can perform dry desulfurization treatment on mixed gas formed by the barren liquor regeneration tower and tail gas which is not completely removed by the desulfurization and decarbonization module so as to remove sulfur in the coal gas, and after the sulfur in the coal gas is removed, the storage tank is connected with the desulfurization module so as to store carbon contained in the coal gas, so that the carbon and sulfur in the coal gas are removed; the desulfurization and decarbonization efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to metallurgical environmental protection technical field especially is concerned with a blast furnace gas desulfurization and decarburization process system. BACKGROUND

[0002] The coal accounts for 90% in the energy structure of the steel industry in China, resulting in high carbon emission intensity of the steel industry, and the carbon emission of the steel industry accounts for more than 60% of the total carbon emission of the global steel industry and about 15%-18% of the total carbon emission of China, ranking first among the 31 manufacturing industries. The CO2 emission of the blast furnace ironmaking link accounts for 73% of the total emission of the whole long process, and is the main contributor to the carbon emission of the manufacturing industry. The blast furnace gas is one of the main carriers of CO2 emission in the steelmaking process, and the CO2 capture technology directly recovers CO2 in the blast furnace gas, has direct carbon reduction capacity, is a key link to help the steel industry achieve the carbon neutralization target, and has important significance for realizing the double carbon target of China. The chemical absorption method is a relatively mature carbon capture technology at present, has high capture efficiency, small occupied area, and obvious cost advantage in large-scale treatment of gas sources.

[0003] The blast furnace gas, as the main by-product gas of ironmaking, mainly contains CO2, CO, N2, H2, CH4, H2S and COS, and can be widely applied to the process of hot blast furnace, heating furnace and power plant. With the gradual improvement of environmental protection requirements, the harmful substances such as sulfur and chlorine contained in the blast furnace gas limit its function. The total sulfur content in the blast furnace gas is 50-200 mg / m3, mainly COS and H2S, wherein COS accounts for about 60%-70%, and H2S accounts for about 30%-40%. After combustion, the SO2 content in the flue gas is 63-250 mg / Nm3, which exceeds the flue gas emission standard (35 mg / Nm3) of the steel industry. The five ministries and commissions including the Ministry of Ecological Environment clearly put forward to strengthen the source control, and the blast furnace gas should implement the fine desulfurization. The policy of the state on the source treatment of the blast furnace gas is also increasingly clear.

[0004] The existing desulfurization and decarburization process system mainly sets the decarburization tower and the desulfurization tower, and the blast furnace gas is reacted with the lean liquid in the decarburization tower and the desulfurization tower to remove H2S and COS in the gas. However, the content of CO2 in the gas is much higher than that of H2S and COS, and only the absorption of the decarburization tower and the desulfurization tower can remove H2S and COS in the gas, but it is difficult to effectively remove CO2 in the gas, resulting in low desulfurization and decarburization efficiency of the desulfurization and decarburization process system. UTILITY MODEL CONTENT

[0005] The utility model aims at overcoming the above technical defects, and provides a blast furnace gas desulfurization and decarburization process system, which solves the technical problem of low desulfurization and decarburization efficiency of the blast furnace gas desulfurization and decarburization process system in the prior art.

[0006] To achieve the above technical purpose, the technical scheme of the utility model provides a kind of blast furnace gas desulfurization and decarburization process system, comprising:

[0007] Spray tower, for spraying blast furnace gas;

[0008] Desulfurization and decarburization module is connected with the spray tower, for the blast furnace gas after spraying by lean liquid desulfurization and decarburization;

[0009] Lean liquid regeneration tower is connected with the desulfurization and decarburization module, for receiving the rich liquid formed by the desulfurization and decarburization module desulfurization and decarburization, and forming the lean liquid for the desulfurization and decarburization module;

[0010] Desulfurization module is connected with the lean liquid regeneration tower and the desulfurization and decarburization module, for receiving the tail gas of the desulfurization and decarburization module and the lean liquid regeneration tower, and carrying out dry desulfurization to tail gas;And

[0011] Storage tank is connected with the desulfurization module.

[0012] In some embodiments, the process system further comprises rich-lean liquid heat exchanger, the rich-lean liquid heat exchanger is connected with the desulfurization and decarburization module and the lean liquid regeneration tower, for the rich liquid of the desulfurization and decarburization module and the lean liquid regeneration tower of the lean liquid regeneration tower heat exchange, and the rich liquid after heat exchange is supplied to the lean liquid regeneration tower, and the lean liquid after heat exchange is supplied to the desulfurization and decarburization module.

[0013] In some embodiments, the process system further comprises rich liquid heat exchanger, the rich liquid heat exchanger is connected with the desulfurization and decarburization module, the rich-lean liquid heat exchanger, the lean liquid regeneration tower and the desulfurization module, for the tail gas of the lean liquid regeneration tower and the rich liquid of the desulfurization and decarburization module heat exchange, and the rich liquid after heat exchange is supplied to the desulfurization and decarburization module, and the tail gas after heat exchange is supplied to the desulfurization module.

[0014] In some embodiments, the process system further comprises heater, the heater is connected with the rich liquid heat exchanger and the lean liquid regeneration tower, for heating the rich liquid of the rich liquid heat exchanger supplied to the lean liquid regeneration tower.

[0015] In some embodiments, the process system further comprises burner, the fuel inlet of the burner is connected with the desulfurization and decarburization module, and the heat supply port of the burner is connected with the desulfurization module, for supplying heat to the desulfurization module by burning the tail gas of the desulfurization and decarburization module.

[0016] In some embodiments, the process system further comprises waste heat boiler, the waste heat boiler is connected with the burner and the desulfurization and decarburization module, for receiving the tail gas of the burner, and the formed flue gas is introduced into the desulfurization and decarburization module.

[0017] In some embodiments, the desulfurization and decarbonization module comprises a wet desulfurization tower, a wet decarbonization tower and a water washing tower, the wet desulfurization tower is connected with the spray tower for desulfurization by lean liquid, the wet decarbonization tower is connected with the wet desulfurization tower for decarbonization by lean liquid, and the water washing tower is connected with the wet decarbonization tower and the lean liquid regeneration tower for removing liquid droplets carried in the tail gas of the wet decarbonization tower.

[0018] In some embodiments, the desulfurization module comprises a dry desulfurization tower and a dry regeneration tower, the dry desulfurization tower is connected with the lean liquid regeneration tower and the desulfurization and decarbonization module for desulfurization by desulfurization agent, and the dry regeneration tower is connected with the dry desulfurization tower for regeneration of the desulfurization agent.

[0019] In some embodiments, the desulfurization module further comprises a gas-liquid separator and a dryer, the gas-liquid separator is connected with the lean liquid regeneration tower, and the dryer is connected with the gas-liquid separator and the dry desulfurization tower.

[0020] In some embodiments, the desulfurization module further comprises a filter, the filter is connected with the dry regeneration tower and the storage tank.

[0021] Compared with the prior art, the blast furnace gas desulfurization and decarbonization process system provided by the utility model has the advantages that the spray tower, the desulfurization and decarbonization module, the lean liquid regeneration tower, the desulfurization module and the storage tank are arranged, the spray tower receives the blast furnace gas and sprays the blast furnace gas, the desulfurization and decarbonization module is connected with the spray tower, receives the blast furnace gas after spraying, carries out wet desulfurization and decarbonization of the blast furnace gas by lean liquid, the lean liquid of the desulfurization and decarbonization module forms rich liquid after desulfurization and decarbonization, the lean liquid regeneration tower is connected with the desulfurization and decarbonization module, can receive the rich liquid formed by the desulfurization and decarbonization module, and regenerates the rich liquid into lean liquid, the lean liquid can ensure the efficiency of wet desulfurization and decarbonization by being introduced into the desulfurization and decarbonization module again, the mixed gas of H2S and CO2 is formed in the process of regenerating the lean liquid, the desulfurization module is connected with the lean liquid regeneration tower and the desulfurization and decarbonization module, can carry out dry desulfurization treatment on the mixed gas formed by the lean liquid regeneration tower and the tail gas not removed by the desulfurization and decarbonization module, and thus the sulfur in the blast furnace gas can be effectively removed, after the sulfur in the blast furnace gas is removed, the storage tank can store the carbon contained in the blast furnace gas by being connected with the desulfurization module, and thus the carbon and sulfur in the blast furnace gas can be effectively removed, and the efficiency of desulfurization and decarbonization is improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The blast furnace gas desulfurization and decarbonization process system provided by the utility model embodiment is shown in the structural schematic view.

[0023] In the drawings, various reference signs represent:

[0024] 10 - spray tower 20 - desulfurization and decarbonization module 21 - wet desulfurization tower

[0025] 22 - wet decarburization column 23 - water scrubbing column 30 - lean liquid regeneration column

[0026] 40 - desulfurization module 41 - dry desulfurization column 42 - dry regeneration column

[0027] 43 - gas-liquid separator 44 - dryer 45 - filter

[0028] 50 - storage tank 60 - rich lean liquid heat exchanger 61 - heater

[0029] 62 - cooler 70 - rich liquid heat exchanger 80 - burner

[0030] 90 - waste heat boiler 101 - reheater. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.

[0032] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.

[0033] In order to solve the technical problem of low desulfurization and decarburization efficiency of the blast furnace gas desulfurization and decarburization process system in the prior art, the utility model embodiment provides a blast furnace gas desulfurization and decarburization process system, the blast furnace gas mainly contains CO2, H2S and COS and the like, considering that the content of CO2 in the gas is much higher than H2S and COS, and COS is difficult to remove, so high selectivity desulfurization and decarburization absorbent is used in combination with sub-column to remove sulfide and CO2 integrally. Specifically, the gas is first passed through a desulfurization column and then a decarburization column, considering that the gas-liquid ratio difference between desulfurization and decarburization is huge, the lean liquid after regeneration is divided into two paths and respectively enters the desulfurization column and the decarburization column, the desorption gas from the regeneration column is separated from CO2 and sulfide through a dry desulfurization column, CO2 is purified and then enters a storage tank, and the sulfide is finally collected in the form of elemental sulfur. The high-value gas after desulfurization and decarburization is mainly returned to the pipe network for gas power generation or back blowing into the blast furnace, and a small part is extracted for combustion to increase the heat for the system regeneration process. The desulfurization and decarburization efficiency of the blast furnace gas can be effectively improved.

[0034] The blast furnace gas desulfurization and decarburization process system provided by the utility model embodiment has the advantages that Figure 1As shown, the system includes a spray tower 10, a desulfurization and decarburization module 20, a lean liquid regeneration tower 30, a desulfurization module 40, and a storage tank 50. The spray tower 10 is used for spraying the blast furnace gas. The desulfurization and decarburization module 20 is connected to the spray tower 10 and is used for desulfurization and decarburization of the sprayed blast furnace gas by using lean liquid. The lean liquid regeneration tower 30 is connected to the desulfurization and decarburization module 20 and is used for receiving the rich liquid formed by the desulfurization and decarburization module 20 and forming the lean liquid supplied to the desulfurization and decarburization module 20. The desulfurization module 40 is connected to the lean liquid regeneration tower 30 and the desulfurization and decarburization module 20 and is used for receiving the tail gas of the desulfurization and decarburization module 20 and the lean liquid regeneration tower 30 and performing dry desulfurization on the tail gas. The storage tank 50 is connected to the desulfurization module 40.

[0035] Specifically, the blast furnace gas desulfurization and decarburization process system is provided with the spray tower 10, the desulfurization and decarburization module 20, the lean liquid regeneration tower 30, the desulfurization module 40, and the storage tank 50. The blast furnace gas is supplied to the spray tower 10. The spray tower 10 receives the blast furnace gas and sprays the blast furnace gas. The desulfurization and decarburization module 20 is connected to the spray tower 10 and receives the sprayed blast furnace gas. The lean liquid is used to perform wet desulfurization and decarburization on the blast furnace gas. The lean liquid of the desulfurization and decarburization module 20 forms the rich liquid after desulfurization and decarburization. The lean liquid regeneration tower 30 is connected to the desulfurization and decarburization module 20 and can receive the rich liquid formed by the desulfurization and decarburization module 20 and regenerate the rich liquid into the lean liquid. The lean liquid is supplied to the desulfurization and decarburization module 20 again to ensure the efficiency of the wet desulfurization and decarburization. During the regeneration of the lean liquid, the mixed gas of H2S and CO2 is formed. The desulfurization module 40 is connected to the lean liquid regeneration tower 30 and the desulfurization and decarburization module 20 and can perform dry desulfurization on the mixed gas formed by the lean liquid regeneration tower 30 and the tail gas not removed by the desulfurization and decarburization module 20, thereby effectively removing the sulfur in the blast furnace gas. After the sulfur in the blast furnace gas is removed, the storage tank 50 is connected to the desulfurization module 40 and can store the carbon in the blast furnace gas, thereby effectively removing the carbon and sulfur in the blast furnace gas and improving the efficiency of the desulfurization and decarburization.

[0036] In this embodiment, the lean liquid is an organic amine solution used to absorb the sulfur and carbon in the blast furnace gas, and the rich liquid is the solution after the absorption of the sulfur and carbon in the blast furnace gas.

[0037] In this embodiment, the spray tower 10 mainly sprays the alkali solution. The spraying of the alkali solution in the spray tower 10 can remove chlorine, impurities, and moisture, reduce the poisoning of the absorbent and the desulfurizer, and promote the absorption of the amine solution to the sulfides and CO2.

[0038] It can be understood that the desulfurization and decarburization module 20 can be a single tower structure sprayed with an organic amine absorbent. When the wet blast furnace tail gas flows through the inside of the tower sprayed with the organic amine absorbent, the carbon dioxide and sulfides in the tail gas are absorbed by the organic amine absorbent, thereby achieving decarburization and desulfurization of the blast furnace tail gas. Alternatively, the desulfurization and decarburization module 20 can be a decarburization and desulfurization tank provided with an organic amine solution. The carbon dioxide and sulfides in the tail gas are absorbed by the organic amine solution, thereby achieving decarburization and desulfurization of the blast furnace tail gas.

[0039] In one embodiment, to improve the decarburization and desulfurization efficiency of the tail gas, the desulfurization and decarburization module 20 includes a wet desulfurization tower 21, a wet decarburization tower 22, and a water washing tower 23. The wet desulfurization tower 21 is connected to the spray tower 10 for desulfurization by lean liquid. The wet decarburization tower 22 is connected to the wet desulfurization tower 21 for decarburization by lean liquid. The water washing tower 23 is connected to the wet decarburization tower 22 and the lean liquid regeneration tower 30 for removing liquid droplets carried in the tail gas of the wet decarburization tower 22. Specifically, the coal gas discharged from the spray tower 10 flows from the bottom to the top of the wet desulfurization tower 21. The wet coal gas reacts with the organic amine solution sprayed in the upper part of the wet desulfurization tower 21 in countercurrent to complete the main desulfurization. The wet coal gas is discharged from the top of the wet desulfurization tower 21 and enters the wet decarburization tower 22 from the bottom. The wet coal gas reacts with the organic amine absorbent sprayed in the wet decarburization tower 22 in countercurrent to remove CO2. The inter-stage cooler 62 on the side of the wet desulfurization tower 21 and the wet decarburization tower 22 can extract the high-temperature amine liquid in the upper part to the middle and lower part after cooling, so as to maintain the overall temperature of the wet desulfurization tower 21 and the wet decarburization tower 22 at about 40°C, and ensure the desulfurization and decarburization efficiency.

[0040] In this embodiment, the wet desulfurization tower 21 and the wet decarburization tower 22 are both packed towers, and the fixed packing is Westitaring packing.

[0041] In this embodiment, the blast furnace gas process system is provided with two separate towers, i.e., the wet desulfurization tower 21 and the wet decarburization tower 22, for desulfurization and decarburization, respectively. The different internal components and tower body sizes of the wet desulfurization tower and the wet decarburization tower are used to achieve efficient integrated desulfurization or decarburization. The tower body of the wet desulfurization tower 21 is higher than that of the wet decarburization tower 22, and the inner diameter of the tower body of the wet desulfurization tower 21 is smaller than that of the wet decarburization tower 22. The tower body structure of the wet desulfurization tower 21 is more conducive to desulfurization in cooperation with the desulfurization and decarburization absorbent, and the tower body structure of the wet decarburization tower 21 is more conducive to decarburization in cooperation with the desulfurization and decarburization absorbent. Therefore, the use of high-selectivity desulfurization and decarburization absorbent in combination with the two separate towers, i.e., the wet desulfurization tower 21 and the wet decarburization tower 22, for integrated removal of sulfides and CO2 can effectively improve the decarburization and desulfurization efficiency of the desulfurization and decarburization module 20.

[0042] In this embodiment, the wet desulfurization tower 21 and the wet decarbonization tower 22 are provided with self-circulation pumps. The self-circulation pumps at the lower part of the wet desulfurization tower 21 and the wet decarbonization tower 22 can circulate the amine liquid inside the wet desulfurization tower 21 and the wet decarbonization tower 22, shorten the time to reach the absorption saturation, and improve the desulfurization and decarbonization efficiency.

[0043] It can be understood that the desulfurization module 40 can be a mixer provided with a desulfurizing agent, the mixer mixes the desulfurizing agent with the flue gas to promote the chemical reaction, realizes the dry desulfurization, or is a desulfurization tower provided with a spray pipe, the spray pipe sprays the desulfurizing agent slurry into the tower through a circulating pump to fully contact with the tail gas, realizes the dry desulfurization, or is a stirring tank provided with a desulfurizing agent, the stirring tank stirs the desulfurizing agent to fully mix the tail gas with the desulfurizing agent, realizes the dry desulfurization.

[0044] In one of the embodiments, the desulfurization module 40 includes a dry desulfurization tower 41 and a dry regeneration tower 42. The dry desulfurization tower 41 is connected with the lean liquid regeneration tower 30 and the desulfurization and decarbonization module 20, and is used for desulfurization by the desulfurizing agent. The dry regeneration tower 42 is connected with the dry desulfurization tower 41, and is used for regenerating the desulfurizing agent. Specifically, the mixed gas of COS, H2S and CO2 which is not absorbed by the desulfurization and decarbonization module 20 and the mixed gas of H2S and CO2 formed by the lean liquid regeneration tower 30 enter the dry desulfurization tower 41, and are subjected to dry desulfurization by the desulfurizing agent in the dry desulfurization tower 41. The gas after desulfurization is only CO2, and the CO2 is finally stored in a storage tank. The dry regeneration tower 42 can regenerate the desulfurizing agent, thereby ensuring the continuity of the desulfurization process.

[0045] In this embodiment, the dry desulfurization tower 41 is a packed tower, and the tower is filled with iron oxide desulfurizing agent. The desulfurizing agent includes composite iron oxide, a binder, an activator and a pore-forming agent, which can ensure that the COS and H2S in the desorption gas are completely absorbed, and high-purity CO2 product is obtained.

[0046] In this embodiment, the dry desulfurization tower 41 and the dry regeneration tower 42 are used intermittently. The regeneration tower can be regenerated synchronously while the absorption tower is working, thereby ensuring the continuous desulfurization process.

[0047] In one of the embodiments, the desulfurization module 40 further includes a gas-liquid separator 43 and a dryer 44. The gas-liquid separator 43 is connected with the lean liquid regeneration tower 30, and the dryer 44 is connected with the gas-liquid separator 43 and the dry desulfurization tower 41. Specifically, the gas-liquid separator 43 can separate the gas and liquid in the mixed gas generated by the lean liquid regeneration tower 30, and the dryer 44 can further dry the separated gas, thereby facilitating the dry desulfurization of the mixed gas.

[0048] In this embodiment, the liquid at the bottom of the gas-liquid separator 43 is periodically pumped back to the lean liquid regeneration tower 30 to supplement the water in the entire circulation system, thereby avoiding the amine-water imbalance of the lean liquid regeneration tower 30.

[0049] In one of the embodiments, the desulfurization module 40 further comprises a filter 45 connected with the dry regeneration tower 42 and the storage tank 50. Specifically, the gas discharged from the top of the lean liquid regeneration tower 30 can be stored in the storage tank after removing the dust carried by the filter 45, and can be subsequently combined with the steel production process to produce high value-added chemical products.

[0050] In one of the embodiments, the process system further comprises a rich-lean liquid heat exchanger 60 connected with the desulfurization and decarbonization module 20 and the lean liquid regeneration tower 30, for heat exchange of the rich liquid of the desulfurization and decarbonization module 20 and the regenerated lean liquid of the lean liquid regeneration tower 30, and supplying the heat-exchanged rich liquid to the lean liquid regeneration tower 30 and supplying the heat-exchanged lean liquid to the desulfurization and decarbonization module 20. Specifically, since the temperature of the regenerated lean liquid of the lean liquid regeneration tower 30 is relatively high, and the temperature of the lean liquid required by the desulfurization and decarbonization module 20 is relatively low, and the temperature of the rich liquid discharged from the desulfurization and decarbonization module 20 is relatively low, and the temperature of the rich liquid required by the lean liquid regeneration tower 30 is relatively high, therefore, through the heat exchange of the rich-lean liquid heat exchanger 60, the temperature requirements of the desulfurization and decarbonization module 20 and the lean liquid regeneration tower 30 can be met respectively.

[0051] In the embodiment, the lean liquid is circulated and absorbed by the two wet desulfurization towers and the wet decarbonization tower under the driving of the pump body after heat exchange by the rich-lean liquid heat exchanger 60.

[0052] In one of the embodiments, the process system further comprises a rich liquid heat exchanger 70 connected with the desulfurization and decarbonization module 20, the rich-lean liquid heat exchanger 60, the lean liquid regeneration tower 30 and the desulfurization module 40, for heat exchange of the tail gas of the lean liquid regeneration tower 30 and the rich liquid of the desulfurization and decarbonization module 20, and supplying the heat-exchanged rich liquid to the desulfurization and decarbonization module 20 and supplying the heat-exchanged tail gas to the desulfurization module 40. Specifically, since the mixed gas of H2S and CO2 formed by the lean liquid regeneration tower 30 contains certain heat, the rich liquid heat exchanger 70 can transfer the heat in the mixed gas to the rich liquid discharged from the desulfurization and decarbonization module 20, thereby increasing the temperature of the rich liquid and realizing the utilization of the heat.

[0053] In one of the embodiments, a heater 61 is arranged in the pipeline connecting the rich-lean liquid heat exchanger 60 and the lean liquid regeneration tower 30, and the heater 61 is used to heat the rich liquid supplied from the rich-lean liquid heat exchanger 60 to the lean liquid regeneration tower 30. Specifically, since the temperature of the rich liquid is still relatively low after being heated by the rich-lean liquid heat exchanger 60, it is still difficult to meet the regeneration requirements of the lean liquid, and the heater 61 further heats the rich liquid, thereby increasing the temperature of the rich liquid, so that the temperature of the rich liquid can meet the regeneration requirements of the lean liquid.

[0054] In one of the embodiments, the pipeline connecting the rich-lean liquid heat exchanger 60 and the decarbonization and desulfurization module 40 is provided with a cooler 62 for cooling the lean liquid supplied to the decarbonization and desulfurization module 40 by the rich-lean liquid heat exchanger 60. Specifically, since the lean liquid supplied by the lean liquid regeneration tower 30 is still difficult to meet the use requirements of the decarbonization and desulfurization module 40 after being cooled by the rich-lean liquid heat exchanger 60, the cooler 62 further cools the lean liquid, thereby reducing the temperature of the lean liquid, so that the temperature of the lean liquid can meet the use requirements of the decarbonization and desulfurization module 40.

[0055] In one of the embodiments, the process system further comprises a combustor 80, the fuel inlet of the combustor 80 is connected with the decarbonization and desulfurization module 20, and the heat supply port of the combustor 80 is connected with the desulfurization module 40, for supplying heat to the desulfurization module 40 by burning the tail gas of the decarbonization and desulfurization module 20. Specifically, the coal gas from which COS, H2S and CO2 are removed is returned to the coal gas pipeline network after removing the organic amine droplets carried in the coal gas by the water washing tower 23, and a small amount of bypass on the coal gas return pipeline is introduced into the combustor 80 for combustion to produce heat, and the heat is mainly used to supply heat to the desulfurization module 40, which can greatly reduce the supply of external heat sources.

[0056] In one of the embodiments, the process system further comprises a waste heat boiler 90, which is connected with the combustor 80 and the decarbonization and desulfurization module 20, for receiving the tail gas of the combustor 80 and passing the formed flue gas into the decarbonization and desulfurization module 20. Specifically, the flue gas generated by the waste heat boiler 90 is returned to the wet decarbonization tower to complete decarbonization, realizing zero carbon emission.

[0057] In the embodiment, the process system is further provided with a reheater 101, which can supply heat to the desulfurization module 40.

[0058] In combination Figure 1 As shown in the figure, the blast furnace gas desulfurization and decarbonization process system of the embodiment mainly comprises the following process steps:

[0059] Step 1: 100 Nm 3 / h, 50℃, 30kPa blast furnace gas enters the spray tower 10, and the gas is sprayed with lye to remove chlorine, impurities and moisture. The 30℃, 25kPa gas from the top of the spray tower 10 enters the bottom of the wet desulfurization tower and flows to the top of the tower. One of the 40℃ organic amine solutions flows at a rate of 125 L / h (control gas-liquid ratio of 800) in the upper part of the wet desulfurization tower and reacts with the wet gas in countercurrent to complete the main desulfurization. The inter-stage cooler 62 composed of the cooler 62 and the circulating pump on the side of the wet desulfurization tower can draw the high-temperature amine solution in the upper part to the middle and lower parts after cooling, maintaining the overall temperature of the wet desulfurization tower at about 40℃, and ensuring the desulfurization efficiency. The self-circulating pump in the middle and lower parts of the wet desulfurization tower circulates the amine solution at a rate of 40 L / h, shortens the time to reach the saturation of sulfide adsorption, and improves the desulfurization efficiency.

[0060] Step 2: The 36℃ desulfurized gas is discharged from the top of the wet desulfurization tower and enters the bottom of the wet decarbonization tower, and reacts with a 40℃ organic amine absorbent sprayed at a flow rate of 1000 L / h (control gas-liquid ratio of 100) in the wet decarbonization tower to remove CO2. The inter-stage cooler 62 composed of the cooler 62 and the circulating pump on the side of the wet decarbonization tower can draw the high-temperature amine solution in the upper part to the middle and lower parts after cooling, maintaining the overall temperature of the wet decarbonization tower at about 40℃, and ensuring the CO2 absorption efficiency. The self-circulating pump in the middle and lower parts of the wet decarbonization tower circulates the amine solution at a rate of 200 L / h, accelerates the reaction of CO2 and amine solution, and promotes CO2 absorption.

[0061] Step 3: The gas after removing COS, H2S and CO2 is about 80 Nm 3 / h, the temperature is 38℃, and after the water washing tower 23 removes the organic amine droplets carried in the gas, the temperature drops to 25℃, and the main part returns to the blast furnace gas pipe network. A small amount of bypass gas is introduced into the burner 80 to produce heat, and the heat is mainly used for the reheater 101, the dry desulfurization tower 41 and the dry regeneration tower 42, which can greatly reduce the supply of external heat sources. The flue gas generated by the waste heat boiler 90 returns to the wet decarbonization tower to complete decarbonization and achieve zero carbon emission.

[0062] Step 4: The temperature of the rich liquid absorbent after absorbing COS, H2S and CO2 is about 40℃, one stream of absorbent is pumped at a flow rate of 1000 L / h, and another stream of absorbent is combined at a flow rate of 125 L / h, then heated to 60℃ by the rich-lean liquid heat exchanger 70, and then heated to 95℃ by the rich-lean liquid heat exchanger 60 and the heater 61, and then sprayed from the upper part of the lean liquid regeneration tower 30. The saturated organic amine solution is continuously heated by the reheater 101 to maintain the amine solution in the tower at 105℃ and 10 kPa to complete the rich liquid regeneration. The lean liquid at 105℃ is first heated by the rich-lean liquid heat exchanger 60 to 60℃, then cooled to 40℃ by the subcooler 62, and then returned to the wet desulfurization tower and the wet decarbonization tower for cyclic absorption.

[0063] Step 5: The mixed gas of H2S and CO2 at the top of the lean liquid regeneration tower is about 85℃, which is heated by the rich-lean liquid heat exchanger 70, then removed by the gas-liquid separator 43 and the dryer 44 to obtain dry H2S and CO2 mixed gas at about 30℃. The liquid at the bottom of the gas-liquid separator 43 is periodically pumped back to the regeneration tower to supplement the water in the entire circulation system. The system is provided with a liquid supplement port, and amine-water is periodically supplemented according to the operation to avoid imbalance of amine-water in the system.

[0064] Step 6: The H2S and CO2 mixed gas at 30℃ enters the dry desulfurization tower 41 filled with desulfurizing agent from the bottom, and reacts with the desulfurizing agent. The reaction space velocity is set to 1000 h -1 , to achieve high-efficiency selective absorption of H2S. The dry desulfurization tower 41 and the dry regeneration tower 42 are used intermittently, and the working temperature of the regeneration tower is maintained at 60℃. The regeneration tower can be regenerated simultaneously while the absorption tower is working, to ensure the continuous desulfurization process. The gas discharged from the top of the regeneration tower 14 passes through the filter 45 to remove the carried dust impurities, and can be filled into the storage tank for storage. The desulfurizing agent reaches adsorption saturation and is regenerated at high temperature in an oxygen atmosphere in the dry regeneration tower 42, to obtain elemental sulfur product and complete the circulation of the absorbent. The desulfurizing agent can be added to the sintering process as a granulation raw material after multiple cycles, to realize resource recycling. The operation results show that the process system can achieve CO2 absorption rate of more than 95%, H2S absorption rate of more than 95%, and COS absorption rate of more than 90%.

[0065] The process system can effectively remove sulfides and carbon dioxide, and the heat value and reducing capacity of the purified coal gas are obviously improved. Through the designed absorption device and energy-saving process, the absorption efficiency of sulfides and carbon dioxide can be greatly improved, and the capture cost of sulfides and carbon dioxide can be reduced. At the same time, the captured high-purity carbon dioxide can be combined with steel production and oxygen-enriched blast furnace carbon cycle process to obtain high-value utilization; and the elemental sulfur obtained by regeneration can be used as raw material for producing sulfuric acid, rubber and other products. The desulfurization and decarburization integrated process system can effectively purify blast furnace gas, and help to realize efficient and collaborative emission reduction and efficiency increase and cost reduction in the steel industry.

[0066] The specific implementation manner of the utility model above does not constitute a limitation on the protection scope of the utility model. Any various other corresponding changes and modifications made according to the technical concept of the utility model should be included in the protection scope of the utility model claim.

Claims

1. A blast furnace gas desulfurization and decarbonization process system, characterized in that, include: Spray tower, used for spraying blast furnace gas; The desulfurization and decarbonization module is connected to the spray tower and is used to desulfurize and decarbonize the sprayed blast furnace gas through lean liquor. The lean liquor regeneration tower is connected to the desulfurization and decarbonization module and is used to receive the rich liquor formed by the desulfurization and decarbonization of the desulfurization and decarbonization module, and to form the lean liquor supplied to the desulfurization and decarbonization module. A desulfurization module, connected to the lean liquor regeneration tower and the desulfurization and decarbonization module, is used to receive the tail gas from the desulfurization and decarbonization module and the lean liquor regeneration tower, and to perform dry desulfurization on the tail gas. and The storage tank is connected to the desulfurization module.

2. The blast furnace gas desulfurization and decarbonization process system according to claim 1, characterized in that, The process system also includes a rich-lean liquor heat exchanger, which is connected to the desulfurization and decarbonization module and the lean liquor regeneration tower. It is used to exchange heat between the rich liquor of the desulfurization and decarbonization module and the lean liquor regenerated by the lean liquor regeneration tower, and to supply the rich liquor after heat exchange to the lean liquor regeneration tower and the lean liquor after heat exchange to the desulfurization and decarbonization module.

3. The blast furnace gas desulfurization and decarbonization process system according to claim 2, characterized in that, The process system also includes a rich liquid heat exchanger, which is connected to the desulfurization and decarbonization module, the rich-lean liquid heat exchanger, the lean liquid regeneration tower, and the desulfurization module. It is used to exchange heat between the tail gas of the lean liquid regeneration tower and the rich liquid of the desulfurization and decarbonization module, and to supply the rich liquid after heat exchange to the desulfurization and decarbonization module, and the tail gas after heat exchange to the desulfurization module.

4. The blast furnace gas desulfurization and decarbonization process system according to claim 2, characterized in that, The pipe connecting the rich-lean liquid heat exchanger and the lean liquid regeneration tower is equipped with a heater, which is used to heat the rich liquid supplied to the lean liquid regeneration tower from the rich-lean liquid heat exchanger.

5. The blast furnace gas desulfurization and decarbonization process system according to any one of claims 1-4, characterized in that, The process system also includes a burner, the fuel inlet of which is connected to the desulfurization and decarbonization module, and the heating port of which is connected to the desulfurization module, for supplying heat to the desulfurization module by burning the exhaust gas of the desulfurization and decarbonization module.

6. The blast furnace gas desulfurization and decarbonization process system according to claim 5, characterized in that, The process system also includes a waste heat boiler, which, together with the burner and the desulfurization and decarbonization module, is used to receive the exhaust gas from the burner and to introduce the resulting flue gas into the desulfurization and decarbonization module.

7. The blast furnace gas desulfurization and decarbonization process system according to any one of claims 1-4, characterized in that, The desulfurization and decarbonization module includes a wet desulfurization tower, a wet decarbonization tower, and a water washing tower. The wet desulfurization tower is connected to the spray tower and is used for desulfurization through lean liquor. The wet decarbonization tower is connected to the wet desulfurization tower and is used for decarbonization through lean liquor. The water washing tower is connected to the wet decarbonization tower and the lean liquor regeneration tower and is used to remove liquid droplets carried in the tail gas of the wet decarbonization tower.

8. The blast furnace gas desulfurization and decarbonization process system according to any one of claims 1-4, characterized in that, The desulfurization module includes a dry desulfurization tower and a dry regeneration tower. The dry desulfurization tower is connected to the lean liquor regeneration tower and the desulfurization and decarbonization module, and is used for desulfurization by a desulfurizing agent. The dry regeneration tower is connected to the dry desulfurization tower and is used for regenerating the desulfurizing agent.

9. The blast furnace gas desulfurization and decarbonization process system according to claim 8, characterized in that, The desulfurization module also includes a gas-liquid separator and a dryer. The gas-liquid separator is connected to the lean liquid regeneration tower, and the dryer is connected to both the gas-liquid separator and the dry desulfurization tower.

10. The blast furnace gas desulfurization and decarbonization process system according to claim 8, characterized in that, The desulfurization module also includes a filter, which is connected to the dry regeneration tower and the storage tank.

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