Lean solution regeneration device, regeneration system and regeneration method

Abstract

The invention relates to the technical field of flue gas purification, in particular to a barren liquor regeneration device, regeneration system and regeneration method.The barren liquor regeneration device comprises a flash evaporation unit, a desorption unit and a gas outlet unit, the flash evaporation unit can receive rich liquor formed after gas is absorbed, then part of gas is separated out of the rich liquor through the flash evaporation effect, the rich liquor forms semi-barren liquor, and the semi-barren liquor is separated out from the desorption unit; the desorption unit is connected with the flash evaporation unit and receives semi-barren liquor formed by the flash evaporation unit, the desorption unit thoroughly separates out gas in the semi-barren liquor under the high-temperature condition, the semi-barren liquor finally forms barren liquor, and regeneration of the barren liquor is achieved. Therefore, only part of gas contained in the semi-barren liquor needs to be separated out, waste heat recovery and mass transfer desorption are achieved through high-temperature gas supplied to the flash evaporation unit through the gas outlet unit, and energy consumption needed by barren liquor regeneration can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas purification, and in particular to a lean liquid regeneration device, a regeneration system and a regeneration method. Background Art

[0002] As the global warming problem becomes increasingly serious, steel enterprises, as an important source of greenhouse gas emissions, have a vital task to reduce emissions. Blast furnace gas is carbon dioxide (CO 2 ) is the main carrier of emissions, which contains a higher concentration of CO 2 Therefore, the CO 2 The application research of CO capture technology is of great significance. 2 Capture is the key to reducing CO 2 Emissions are key.

[0003] Due to the removal of CO from blast furnace gas 2 In addition, it also contains a variety of impurities such as sulfide, dust, etc. These impurities have a great impact on CO 2 In order to reduce the impact of these impurities on the subsequent treatment process, the CO2 capture technology disclosed in CN113684068A is usually used for blast furnace gas. 2 Capture and utilization device, first, the coal gas passes through the cyclone dust collector and bag dust collector to remove the dust in it; then the desulfurization device uses the desulfurization process to remove the sulfide; finally, the lean liquid in the absorption tower and the CO 2 Reaction to CO in coal gas 2 The lean liquid in the absorption tower and CO 2 After the reaction, a rich solution is formed.

[0004] In order to realize the recycling of rich liquid and reduce CO 2 The capture cost is borne by the rich liquid, which is usually desorbed by the desorption tower under certain high temperature conditions. 2 Desorption to obtain pure CO 2 , the rich liquid after desorption will form lean liquid, which can be recycled by the absorption tower. Since the rich liquid needs to be continuously heated in the desorption tower, a large amount of heat energy is consumed during the process, resulting in high energy consumption for desorption in the desorption tower. Summary of the invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies, and to propose a lean liquid regeneration device, a regeneration system and a regeneration method, so as to solve the technical problem of high energy consumption required for lean liquid regeneration in the prior art.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a lean liquid regeneration device, comprising: A flash unit having a rich liquid inlet, a semi-lean liquid outlet and an air inlet, and for flashing the rich liquid to form a semi-lean liquid; A desorption unit has a gas outlet, the desorption unit is connected with the semi-lean liquid outlet of the flash unit, and is used for the semi-lean liquid to form a lean liquid through desorption; and

[0007] An air outlet unit, two ends of which are respectively connected to the air inlet and the air outlet, and is used to pass at least part of the gas formed by the desorption unit into the flash unit.

[0008] In some embodiments, the flash unit includes a flash tank and an atomization module, wherein a flash chamber is disposed inside the flash tank, and the atomization module is connected to the flash tank and extends to the flash chamber for spraying rich liquid to the flash tank.

[0009] In some embodiments, the atomization module includes a liquid delivery pipe and a plurality of atomization heads, one end of the liquid delivery pipe has the rich liquid inlet, the other end of the liquid delivery pipe is connected to the flash tank and extends to the flash chamber, and each atomization head is installed at one end of the liquid delivery pipe extending to the flash chamber.

[0010] The liquid delivery pipeline includes a liquid delivery main pipe, a plurality of liquid delivery branch pipes and a plurality of control valves. The liquid delivery main pipe has the rich liquid inlet. One end of each of the liquid delivery branch pipes is connected to the liquid delivery main pipe, and the other end of each of the liquid delivery branch pipes is connected to the flash tank and extends to the flash chamber. Each of the control valves is respectively connected to each of the liquid delivery branch pipes, and each of the atomizing heads is respectively installed at one end of each of the liquid delivery branch pipes extending to the flash chamber.

[0011] In some embodiments, the lean liquid regeneration device further includes a heat preservation unit, which encloses the flash evaporation unit to keep the flash evaporation unit warm.

[0012] In some embodiments, one end of the gas outlet unit is connected to the desorption unit, and the other end of the gas outlet unit is respectively connected to the flash evaporation unit and the insulation unit, so that the gas formed by the desorption unit is respectively passed into the flash evaporation unit and the insulation unit.

[0013] In some embodiments, the gas outlet unit includes a gas outlet main pipe, a diverter, a first gas outlet branch pipe and a second gas outlet branch pipe, the gas outlet main pipe is connected to the gas outlet of the desorption unit, the diverter is installed on the gas outlet main pipe, one end of the first gas outlet branch pipe and the second gas outlet branch pipe is connected to the diverter, and the other end of the first gas outlet branch pipe and the second gas outlet branch pipe is respectively connected to the flash unit and the insulation unit.

[0014] In a second aspect, the present invention provides a lean liquid regeneration system, comprising: Absorption tower; and The lean liquid regeneration device, the flash unit is connected to the absorption tower and is used to receive the rich liquid from the absorption tower.

[0015] In a third aspect, the present invention provides a lean liquid regeneration method, which is performed by the lean liquid regeneration device, comprising the following steps: The absorber passes the rich liquid into the flash unit; The flash unit converts the rich liquid into semi-lean liquid through flash evaporation; The desorption unit receives the semi-lean liquid formed by the flash unit, and converts the semi-lean liquid into lean liquid through desorption.

[0016] In some embodiments, the high-temperature gas formed by desorbing the semi-lean liquid in the desorption unit is transported to the insulation unit and the flash unit in a constant ratio through the gas outlet unit.

[0017] Compared with the prior art, the lean liquid regeneration device provided by the present invention is provided with a flash unit, a desorption unit and a gas outlet unit. The flash unit can receive the rich liquid formed after absorbing the gas, and then the rich liquid is subjected to flash evaporation, and part of the gas is precipitated from the rich liquid, so that the rich liquid forms a semi-lean liquid. The desorption unit is connected to the flash unit, and receives the semi-lean liquid formed by the flash unit. The desorption unit completely precipitates the gas in the semi-lean liquid under high temperature conditions, and the semi-lean liquid finally forms a lean liquid, thereby realizing the regeneration of the lean liquid. Since the rich liquid is flashed in the flash unit to form the semi-lean liquid before being desorbed by the desorption unit, it is only necessary to precipitate part of the gas contained in the semi-lean liquid, and the high-temperature gas supplied to the flash unit by the gas outlet unit can realize waste heat recovery and mass transfer desorption, thereby effectively reducing the energy consumption required for the regeneration of the lean liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a lean liquid regeneration device provided in an embodiment of the present invention; Figure 2 is a schematic structural diagram of a flash unit provided in an embodiment of the present invention; Figure 3 It is a flow chart of the lean liquid regeneration method provided in an embodiment of the present invention.

[0019] Reference numerals in the figures: 10—Flash unit 11—Flash tank 12—Atomization module 13—Liquid discharge pipe 14—Gear pump 20—Desorption unit 21—desorption tower 30—insulation unit 31—steam conduit 40—air outlet unit 41—air outlet main pipe 42—flow divider 43 - first outlet branch pipe 44 - second outlet branch pipe 45 - dehydrator 111—glass window 112—liquid level gauge 121—liquid delivery pipeline 122—atomizing head 211—heater 1211—liquid delivery main pipe 1222—liquid delivery branch pipe 1223—control valve. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] In order to solve the technical problem of high energy consumption required for lean liquid regeneration in the prior art, the present invention provides a lean liquid regeneration device, a regeneration system and a regeneration method, by flashing the rich liquid before desorption in the desorption tower, thereby reducing the heat required for the rich liquid in the desorption process of the desorption tower and reducing the energy consumption required for lean liquid regeneration.

[0022] It should be noted that the lean liquid regeneration device described in the present invention is used for but not limited to the regeneration of carbon dioxide (CO2) capture lean liquid, etc. For the convenience of explanation, in the present invention, only the application of the lean liquid regeneration device to the regeneration of carbon dioxide capture lean liquid is taken as an example for explanation, and the principle of the application of the lean liquid regeneration device in other types of equipment is substantially the same as the principle applied to the regeneration of carbon dioxide CO2 capture lean liquid, which will not be described in detail here.

[0023] An embodiment of the present invention provides a lean liquid regeneration device, such as Figure 1 As shown, it includes a flash unit 10 and a desorption unit 20. The flash unit 10 has a rich liquid inlet, a semi-lean liquid outlet and an air inlet, and is used to form a semi-lean liquid through flash evaporation of the rich liquid; the desorption unit 20 has a gas outlet, and the desorption unit 20 is connected to the flash unit 10, and is used to receive the semi-lean liquid formed by the flash unit 10, and is used to form a lean liquid through desorption of the semi-lean liquid.

[0024] Specifically, the lean liquid regeneration device is provided with a flash unit 10 and a desorption unit 20. The flash unit 10 can receive rich liquid formed after absorbing gas, and then flash the rich liquid to separate part of the gas from the rich liquid, so that the rich liquid becomes semi-lean liquid. The desorption unit 20 is connected to the flash unit 10, and receives the semi-lean liquid formed by the flash unit 10. The desorption unit 20 completely separates the gas in the semi-lean liquid under high temperature conditions, and the semi-lean liquid finally forms lean liquid, thereby realizing the regeneration of the lean liquid. Since the rich liquid is flashed by the flash unit 10 to form the semi-lean liquid before being desorbed by the desorption unit 20, it is only necessary to separate part of the gas contained in the semi-lean liquid, thereby effectively reducing the energy consumption required for the regeneration of the lean liquid.

[0025] In this embodiment, the lean liquid is an organic solution that absorbs CO2 in blast furnace gas, the rich liquid is a solution formed after absorbing CO2 in blast furnace gas, and the semi-lean liquid is a solution formed after desorbing part of CO2.

[0026] It can be understood that the rich liquid can be introduced into the flash unit 10 through any rich liquid storage module for flash evaporation.

[0027] Flash evaporation is mainly based on the difference between the saturated vapor pressure of a substance and the ambient pressure. When a saturated liquid at high pressure enters a low-pressure container, the boiling point of the liquid decreases due to the sudden decrease in pressure. At this time, the temperature of the liquid is higher than the boiling point at the low pressure, causing the liquid to vaporize rapidly and form a gas-liquid two-phase.

[0028] In one embodiment, if Figure 1 As shown, the lean liquid regeneration device further includes a gas outlet unit 40, and both ends of the gas outlet unit 40 are respectively connected to the flash unit 10 and the desorption unit 20, and are used to pass at least part of the gas formed by the desorption unit 20 into the flash unit 10. Specifically, after the semi-lean liquid is passed into the desorption unit 20, the carbon dioxide contained in the semi-lean liquid is fully desorbed by high temperature to form high-temperature carbon dioxide, and the high-temperature carbon dioxide is passed into the flash unit 10 through the gas outlet unit 40 to assist the flash reaction of the flash unit 10, thereby accelerating the flash efficiency and promoting the formation of the semi-lean liquid in the flash unit 10. Therefore, the gas formed by the regeneration of the lean liquid itself can be used to assist the regeneration of the lean liquid, and the energy consumption required for the regeneration of the lean liquid can be effectively reduced.

[0029] In this embodiment, the rich liquid of the flash evaporation unit 10 is supplied from the absorption tower. Since the rich liquid in the absorption tower has a pressure of 0.8-1.0 MPa, by directly supplying the rich liquid of the absorption tower into the flash evaporation unit 10, the pressure of the rich liquid in the absorption tower itself can be used to provide a driving force for the flash evaporation of the rich liquid, thereby accelerating the flash evaporation of the rich liquid and reducing the energy consumption required for the flash evaporation of the rich liquid.

[0030] In one embodiment, if Figure 2 As shown, the flash unit 10 includes a flash tank 11 and an atomizing module 12. The flash tank 11 is provided with a flash chamber inside. The atomizing module 12 is connected to the flash tank 11 and extends to the flash chamber, and is used to spray rich liquid to the flash tank 11. Specifically, the saturated rich liquid is sprayed to the flash chamber in the form of atomization through the atomizing module 12. The pressure of the atomized rich liquid is instantly reduced. The rich liquid is flashed under the state of the instantaneous pressure drop, so that the saturated rich liquid instantly releases a large amount of carbon dioxide and forms a semi-lean liquid. The spraying liquid of the atomizing module 12 is used to achieve efficient flash evaporation of the saturated rich liquid.

[0031] In this embodiment, the flash unit 10 and the desorption unit 20 are connected via a discharge pipe 13 equipped with a gear pump 14 . The rich liquid becomes a semi-lean liquid after the flash reaction and is then pumped into the desorption unit 20 by the gear pump 14 .

[0032] In this embodiment, the flash unit 10 is mainly divided into an upper section and a lower section. The upper section is used to introduce rich liquid for flash evaporation reaction, and the lower section mainly stores semi-lean liquid formed after releasing carbon dioxide.

[0033] In this embodiment, the saturated rich liquid of the atomization module 12 is supplied by the absorption tower. Since the rich liquid in the absorption tower itself has a certain hydraulic pressure, the atomization module 12 can form atomization by itself under the liquid supply of the absorption tower, thereby fully utilizing the hydraulic pressure of the saturated rich liquid in the absorption tower, thereby eliminating the need to set up special atomization drive equipment for atomization, thereby reducing the regeneration cost of the lean liquid.

[0034] In one embodiment, if Figure 2 As shown, the atomization module 12 includes a liquid delivery pipe 121 and a plurality of atomization heads 122. One end of the liquid delivery pipe 121 is used to connect to the absorption tower, and the other end of the liquid delivery pipe 121 is connected to the flash tank 11 and extends to the flash chamber. Each atomization head 122 is installed at one end of the liquid delivery pipe 121 extending to the flash chamber. Specifically, the absorption tower delivers the formed saturated rich liquid to each atomization head 122 through the liquid delivery pipe 121. The saturated rich liquid delivered to the atomization head 122 is atomized under its own pressure and the porous structure of the atomization head 122. After atomization, the pressure is instantly reduced, thereby releasing a large amount of carbon dioxide.

[0035] In one embodiment, if Figure 2 As shown, the liquid delivery pipeline 121 includes a liquid delivery main pipe 1211, a plurality of liquid delivery branch pipes 1222 and a plurality of control valves 1223. The liquid delivery main pipe 1211 has a rich liquid inlet. The liquid delivery main pipe 1211 is used to connect the absorption tower through the rich liquid inlet. One end of each liquid delivery branch pipe 1222 is connected to the liquid delivery main pipe 1211, and the other end of each liquid delivery branch pipe 1222 is connected to the flash tank 11 and extends to the flash chamber. Each control valve 1223 is respectively connected to each liquid delivery branch pipe 1222, and each atomizing head 122 is respectively installed at one end of each liquid delivery branch pipe 1222 extending to the flash chamber. Specifically, the saturated rich liquid in the absorption tower first enters the liquid delivery main pipe 1211, then is distributed to each liquid delivery branch pipe 1222, and finally enters the atomizing head 122, and is atomized and sprayed to the flash evaporation chamber through the atomizing head 122. The control valve 1223 can control the liquid inlet flow rate of each liquid delivery branch pipe 1222 according to actual needs, so as to achieve the best flash evaporation effect.

[0036] In this embodiment, Figure 2 As shown, the flash tank 11 is provided with a plurality of glass windows 111 , through which the atomization flash evaporation effect of the high-pressure absorbent rich liquid can be observed in real time, so as to adjust the control valve 1223 .

[0037] In one embodiment, if Figure 2As shown, the flash tank 11 is also provided with a liquid level gauge 112, which is used to observe the liquid level in the flash tank 11. When in use, the progress of atomization flash evaporation and the gas-liquid separation effect can be observed through the glass window 111, and the volume of liquid in the flash tank 11 can be grasped through the liquid level gauge 112, so as to timely control the flow of each liquid delivery branch pipe 1222 and the power of the gear pump 14 by adjusting the control valve 1223, so that the equipment is in the most energy-saving working state and the energy consumption of lean liquid regeneration is reduced.

[0038] In this embodiment, Figure 1 As shown, the desorption unit 20 includes a desorption tower 21, which is provided with a heater 211. The desorption tower 21 desorbs the semi-lean liquid containing a small amount of carbon dioxide entering the interior and forms a lean liquid through pressure holding and high temperature conditions. The formed lean liquid is again introduced into the absorption tower through a conveying pipeline for the absorption tower to capture carbon dioxide.

[0039] In this embodiment, the desorption tower 21 is also provided with a back pressure valve. Due to the sudden pressure reduction of the high-pressure absorbent rich liquid, the temperature of the absorbent will be reduced. The back pressure valve is used to hold the pressure of the desorption tower 21. The purpose of the back pressure valve is to compensate for the lowered absorption liquid temperature due to the flash evaporation of the flash unit 10, and at the same time improve the desorption tower 21 desorption problem to better realize waste heat recovery. Therefore, by installing a back pressure valve on the top of the desorption tower 21, the desorption tower 21 is pressed at 10-40 KPa, thereby raising the temperature of the desorption tower 21 to 120°C, and the absorbent is temperature compensated.

[0040] In one embodiment, if Figure 2 As shown, the lean liquid regeneration device further includes a heat preservation unit 30, which surrounds the flash evaporation unit 10 and keeps the flash evaporation unit 10 warm. Specifically, the heat preservation unit 30 keeps the flash evaporation unit 10 warm, thereby effectively preventing the flash evaporation unit 10 from losing heat and improving the flash evaporation efficiency.

[0041] In one embodiment, if Figure 1As shown, one end of the gas outlet unit 40 is connected to the desorption unit 20, and the other end of the gas outlet unit 40 is respectively connected to the flash unit 10 and the insulation unit 30, so that the gas formed by the desorption unit 20 is respectively passed into the flash unit 10 and the insulation unit 30. Specifically, after the high-temperature carbon dioxide is output from the desorption unit 20, it will be passed into the flash unit 10 and the insulation unit 30 in two directions through the gas outlet unit 40. The carbon dioxide entering the flash unit 10 will enhance the mass transfer effect of the flash reaction, thereby promoting flash evaporation. The carbon dioxide entering the insulation unit 30 increases the temperature of the flash tank 11 through its high temperature and the greenhouse effect of the body, thereby promoting flash evaporation. Through the above structure, a large amount of carbon dioxide can be further precipitated without inputting additional heat, so that the carbon dioxide content of the semi-lean liquid is further reduced, effectively alleviating the heat demand of the desorption unit, and the overall energy saving effect is better.

[0042] In this embodiment, a small amount of carbon dioxide (10-30%) is injected into the bottom of the flash tank 11 for mass transfer desorption, and most of the carbon dioxide (70-90%) is injected into the insulation unit 30 through the steam conduit to heat and insulate the flash tank 11.

[0043] In one embodiment, if Figure 1-2 As shown, the gas outlet unit 40 includes a gas outlet main pipe 41, a flow divider 42, a first gas outlet branch pipe 43 and a second gas outlet branch pipe 44. The gas outlet main pipe 41 is connected to the gas outlet of the desorption unit 20. The flow divider 42 is installed on the gas outlet main pipe 41. One end of the first gas outlet branch pipe 43 and the second gas outlet branch pipe 44 is connected to the flow divider 42. The other ends of the first gas outlet branch pipe 43 and the second gas outlet branch pipe 44 are respectively connected to the flash unit 10 and the insulation unit 30. Specifically, after being output from the desorption unit 20, the high-temperature carbon dioxide will enter the gas outlet main pipe 41, and then be distributed to the first gas outlet branch pipe 43 and the second gas outlet branch pipe 44 in a certain proportion through the flow divider 42. Finally, the first gas outlet branch pipe 43 and the second gas outlet branch pipe 44 are proportionally distributed to the flash unit 10 and the insulation unit 30, so as to realize the proportional transportation of the high-temperature carbon dioxide to the flash unit 10 and the insulation unit 30.

[0044] In this embodiment, Figure 1 As shown, the gas outlet unit 40 further includes a dehydrator 45 , which is installed on the gas outlet main pipe 41 to remove water vapor contained in the carbon dioxide flowing through the gas outlet main pipe 41 .

[0045] In one embodiment, if Figure 1 As shown, a continuously curved steam conduit 31 is provided inside the heat preservation unit 30, and the steam conduit 31 is connected to the gas outlet unit 40 to receive the gas from the gas outlet unit 40 to enter the heat preservation unit 30. Specifically, the high-temperature carbon dioxide output by the second gas outlet branch 44 will enter the steam conduit 31, and finally be output by the steam conduit 31.

[0046] The lean liquid regeneration system provided by the embodiment of the present invention includes an absorption tower and a lean liquid regeneration device, and the flash unit 10 is connected to the absorption tower for receiving the rich liquid of the absorption tower. Specifically, by setting the absorption tower and the lean liquid regeneration device, the lean liquid regeneration system can utilize the pressure and supersaturation characteristics of the absorbent rich liquid in the absorption tower as the driving force of the flash reaction, and efficiently recycle the high-temperature carbon dioxide waste heat resources. Compared with directly transporting the high-pressure absorbent rich liquid to the desorption tower for high-temperature regeneration, the energy consumption required for the lean liquid regeneration of carbon dioxide is significantly reduced, and the lean liquid regeneration cost is reduced.

[0047] In this embodiment, the gas-liquid separation effect in the flash tank 11 is crucial to the overall efficiency of the system. The separation efficiency of carbon dioxide gas and absorption liquid can be improved by designing a special separation plate inside the flash tank 11 or using a high-efficiency separation device to ensure that carbon dioxide can be efficiently released and recovered.

[0048] In this embodiment, the lean liquid regeneration system further includes a gas collecting device disposed on the top of the flash tank 11. The gas collecting device guides the generated carbon dioxide gas to a gas storage tank or other recovery device to avoid gas leakage and increase resource utilization.

[0049] In this embodiment, the lean liquid regeneration system also includes an operation human-machine interface. In addition to the liquid level meter 112 and the glass window 111, more operation panels can be added to provide real-time data, alarm systems and operation guides to help operators better monitor and adjust the equipment in daily operation; In this embodiment, the lean liquid regeneration system also includes a safety alarm device, which can be set with abnormal alarm functions such as over-temperature, over-pressure, and over-flow, and automatically remind the operator to take measures to ensure that the equipment operates within a safe range.

[0050] In this embodiment, the lean liquid regeneration system also includes a waste gas treatment unit. Although the purpose of the system is to regenerate the lean liquid, carbon dioxide containing by-products or other gases will be generated simultaneously. When recovering the carbon dioxide, a waste gas treatment unit can be added to the system, such as using a water washing tower or an adsorption tower to purify the carbon dioxide collected at the top of the flash tank 11 of the device to reduce the negative impact on the environment.

[0051] In this embodiment, the lean liquid regeneration system of the embodiment of the present invention utilizes the pressure of the absorbent rich liquid to make the sudden pressure reduction of the saturated rich liquid realize the flash evaporation of the absorbent rich liquid, thereby instantly releasing a large amount of carbon dioxide gas, reducing the amount of carbon dioxide in the absorbent semi-lean liquid to the desorption tower, reducing the load of the desorption tower during desorption, and reducing the energy input required for the desorption tower. At the same time, after the high-temperature carbon dioxide desorbed from the top of the desorption tower is dehydrated and diverted in turn, a small part of the carbon dioxide (10-30%) is injected into the bottom of the flash tank 11 for mass transfer desorption, and most of the carbon dioxide (70-90%) is injected into the insulation unit 30 through the steam conduit 31 for heating and insulation, realizing the efficient recovery and utilization of high-temperature carbon dioxide waste heat resources. The lean liquid regeneration system of the embodiment of the present invention utilizes the pressure and supersaturation characteristics of the absorbent rich liquid as the driving force of the flash reaction, and the efficient recovery and utilization of the high-temperature carbon dioxide waste heat resources. Compared with the high-pressure absorbent rich liquid directly transported to the desorption tower for high-temperature regeneration, it significantly reduces the energy consumption required for the lean liquid regeneration of carbon dioxide and reduces the lean liquid regeneration cost.

[0052] The lean liquid regeneration method provided in the embodiment of the present invention is performed by a lean liquid regeneration device, such as Figure 3 As shown, the following steps are included: The absorber passes the rich liquid into the flash unit 10; The flash unit 10 converts the rich liquid into a semi-lean liquid through flash evaporation; The desorption unit 20 receives the semi-lean liquid formed by the flash unit 10, and converts the semi-lean liquid into a lean liquid through desorption.

[0053] Specifically, the above lean solution regeneration scheme can significantly reduce the energy consumption required for the lean solution regeneration of carbon dioxide and reduce the lean solution regeneration cost.

[0054] In this embodiment, the lean liquid regeneration method further includes transporting the high-temperature gas generated during the desorption of the semi-lean liquid by the desorption unit 20 to the flash chamber and the heat preservation unit 30 through the gas outlet unit 40 .

[0055] Specifically, through the above process, the waste heat of high-temperature gas can be used to desorb carbon dioxide, so that the waste heat of high-temperature gas can be recovered, and the flash evaporation effect in the flash evaporation unit can be improved, thereby reducing the energy consumption required for the regeneration of the lean liquid.

[0056] In this embodiment, the gas flow rate allocated to the flash unit cannot be too low, otherwise the mass transfer and desorption effect cannot be achieved, and cannot be too high, otherwise it will cause flooding of the system.

[0057] In this embodiment, the high-temperature CO mixed with a small amount of water vapor released from the top outlet of the desorption tower 21 2 Through the dehydrator 45 (dehydrator 45 has a built-in high-purity CaCl 2 or SiO 2or activated carbon powder), to remove the moisture therein to avoid corrosion of the pipeline; at the same time, the diverter 44 2 The gas is diverted, and a small amount (10-30%) of high temperature CO 2 Enter the bottom of the flash tank 11 for mass transfer to promote internal flash desorption. The main reason is that the introduction of excessive steam will be counterproductive, and excessive gas disturbance will affect the flash desorption reaction; most (70-90%) high temperature CO 2 The vapor enters the surrounding steam conduit 31 to heat the flash tank 11, so as to maintain a relatively high temperature to ensure the atomization flash desorption effect.

[0058] The specific energy-saving effect of the lean liquid regeneration system of the present invention is studied and demonstrated as follows: 1) At 10 Nm 3 / h inlet blast furnace gas source environment, under the condition of liquid-gas ratio of 0.01, 30% MEA chemical absorbent reacts with blast furnace gas under 0.8 MPa environment, and the generated high-pressure absorbent rich liquid directly goes to desorption tower 21 for thermal desorption. The experiment shows that the energy consumption of carbon dioxide regeneration is 2.1 GJ / t carbon dioxide; 2) At 10 Nm 3 / h inlet blast furnace gas source environment, under the condition of liquid-gas ratio of 0.01, 30% MEA chemical absorbent and blast furnace gas undergo absorption reaction under 0.8 MPa environment, and the generated high-pressure absorbent rich liquid is firstly subjected to atomization flash desorption by the regeneration device, and then goes to the desorption tower 21 for thermal desorption under the condition of 30 KPa of back pressure valve, and the high-temperature carbon dioxide generated by thermal desorption is directly collected uniformly. The experiment shows that the energy consumption of carbon dioxide regeneration is 1.95 GJ / t carbon dioxide; 3) At 10 Nm 3 / h inlet blast furnace gas source environment, under the condition of liquid-gas ratio of 0.01, 30% MEA chemical absorbent and blast furnace gas react under 0.8 MPa environment, and the high-pressure absorbent rich liquid produced is first atomized flash desorbed by this regeneration device, and then sent to the desorption tower 21 for thermal desorption under the condition of 30 KPa of back pressure valve. The high-purity carbon dioxide produced by thermal desorption in the desorption tower 21 is dehydrated by the dehydrator 45 filled with CaCl2, and then all is introduced into the bottom of the flash tank 11 through the carbon dioxide outlet unit 40 for mass transfer drive. The experiment shows that the energy consumption of carbon dioxide regeneration is 2.05 GJ / t carbon dioxide; 4) At 10 Nm 3 / h inlet blast furnace gas source environment, under the condition of liquid-gas ratio of 0.01, 30% MEA chemical absorbent and blast furnace gas react with absorption under 0.8 MPa environment, and the high-pressure absorbent rich liquid produced is first atomized flash desorbed by the regeneration device, and then sent to the desorption tower 21 for thermal desorption under the condition of 30 KPa of back pressure valve. The high-purity carbon dioxide produced by thermal desorption in the desorption tower 21 is dehydrated by the dehydrator 45 filled with CaCl2 and then diverted. 20% of the carbon dioxide is introduced into the flash tank 11 through the gas outlet unit 40 for mass transfer drive, further enhancing the atomization flash effect, and 80% of the carbon dioxide is introduced into the insulation unit 30 through the carbon dioxide steam conduit 31 for heating and insulation, realizing the efficient recovery and utilization of the waste heat resources of the carbon dioxide desorption gas. The experiment shows that the energy consumption of carbon dioxide regeneration is 1.85 GJ / t carbon dioxide.

[0059] The results of the above embodiments show that compared with the traditional blast furnace gas high-pressure absorption and normal-pressure desorption, the blast furnace gas carbon dioxide capture and regeneration device based on pressure change proposed in the present invention can effectively reduce the regeneration energy consumption and capture cost of carbon dioxide by making full use of the high-pressure power of the absorbent to drive the atomization flash evaporation, the desorption tower pressure holding to achieve temperature compensation, and the efficient distribution of high-temperature carbon dioxide vapor.

[0060] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A lean liquid regeneration device, characterized in that: include: A flash unit having a rich liquid inlet, a semi-lean liquid outlet and an air inlet, and for flashing the rich liquid to form a semi-lean liquid; A desorption unit having a gas outlet, the desorption unit being connected to the semi-lean liquid outlet of the flash unit and providing the semi-lean liquid with a desorption effect to form a lean liquid; and An air outlet unit, two ends of which are respectively connected to the air inlet and the air outlet, and is used to pass at least part of the gas formed by the desorption unit into the flash unit.

2. The lean liquid regeneration device according to claim 1, characterized in that: The flash evaporation unit comprises a flash evaporation tank and an atomization module. A flash evaporation chamber is arranged inside the flash evaporation tank. The atomization module is connected to the flash evaporation tank and extends to the flash evaporation chamber for spraying rich liquid to the flash evaporation tank.

3. The lean liquid regeneration device according to claim 2, characterized in that: The atomization module includes a liquid delivery pipeline and a plurality of atomization heads. One end of the liquid delivery pipeline has the rich liquid inlet. The other end of the liquid delivery pipeline is connected to the flash tank and extends to the flash chamber. Each atomization head is installed at one end of the liquid delivery pipeline extending to the flash chamber.

4. The lean liquid regeneration device according to claim 3, characterized in that: The liquid delivery pipeline includes a liquid delivery main pipe, a plurality of liquid delivery branch pipes and a plurality of control valves. The liquid delivery main pipe has the rich liquid inlet. One end of each of the liquid delivery branch pipes is connected to the liquid delivery main pipe, and the other end of each of the liquid delivery branch pipes is connected to the flash tank and extends to the flash chamber. Each of the control valves is respectively connected to each of the liquid delivery branch pipes, and each of the atomizing heads is respectively installed at one end of each of the liquid delivery branch pipes extending to the flash chamber.

5. The lean liquid regeneration device according to any one of claims 1 to 4, characterized in that: The lean liquid regeneration device further comprises a heat preservation unit, which surrounds the flash evaporation unit to keep the flash evaporation unit warm.

6. The lean liquid regeneration device according to claim 5, characterized in that: One end of the gas outlet unit is connected to the desorption unit, and the other end of the gas outlet unit is respectively connected to the flash evaporation unit and the heat preservation unit, so that the gas formed by the desorption unit is respectively passed into the flash evaporation unit and the heat preservation unit.

7. The lean liquid regeneration device according to claim 6, characterized in that: The gas outlet unit includes a gas outlet main pipe, a diverter, a first gas outlet branch pipe and a second gas outlet branch pipe, the gas outlet main pipe is connected to the gas outlet of the desorption unit, the diverter is installed on the gas outlet main pipe, one end of the first gas outlet branch pipe and the second gas outlet branch pipe is connected to the diverter, and the other ends of the first gas outlet branch pipe and the second gas outlet branch pipe are respectively connected to the flash unit and the insulation unit.

8. A lean liquid regeneration system, characterized in that: include: Absorption tower; and The lean liquid regeneration device according to any one of claims 1 to 8, wherein the rich liquid inlet of the flash unit is connected to the rich liquid outlet of the absorption tower.

9. A lean solution regeneration method, characterized in that: The method is performed by the lean liquid regeneration device according to any one of claims 1 to 8, comprising the following steps: The rich liquid is passed into a flash unit; The flash unit converts the rich liquid into semi-lean liquid through flash evaporation; The desorption unit receives the semi-lean liquid formed by the flash unit, and converts the semi-lean liquid into lean liquid through desorption.

10. The lean solution regeneration method according to claim 9, characterized in that: Also includes: The high-temperature gas formed by desorbing the semi-lean liquid in the desorption unit is transported to the insulation unit and the flash unit at a fixed ratio through the gas outlet unit.

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