Carbon dioxide capture and absorbent purification system and method coupled with metal refining

Abstract

The invention provides a carbon dioxide capture and absorbent purification system and method coupled with metal refining. The system comprises an absorption module with an absorbent, a regeneration module with an electrolytic absorption unit and a gas-liquid separation unit, and a purification module, the absorption module is communicated with flue gas; the regeneration module and the purification module are selectively communicated with the absorption module so as to selectively regenerate and purify the absorbent; the electrolytic suction unit comprises a first anode chamber provided with a crude copper anode and a first cathode chamber provided with a refined copper cathode; a first outlet of the absorption module is communicated with an inlet of the first anode chamber, and a second outlet of the absorption module is communicated with a purified gas pipeline; an inlet of the gas-liquid separation unit is communicated with the first anode chamber, a first outlet of the gas-liquid separation unit is communicated with the first cathode chamber, and a second outlet of the gas-liquid separation unit is communicated with an exhaust pipeline; and the outlet of the first cathode chamber is communicated with the second inlet of the absorption module. The system is high in energy efficiency, low in energy consumption, low in cost and high in trapping efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas purification and separation, and in particular relates to a carbon dioxide capture and absorbent purification system and method coupled with metal refining. Background Art

[0002] Carbon dioxide (CO2) is the main greenhouse gas that causes global warming. The capture, utilization and storage of CO2 has become one of the hot topics of international concern. CO2 emissions from coal-fired power generation in my country account for about 50% of total industrial emissions. The capture and separation of CO2 in flue gas from coal-fired power plants is an important area for greenhouse gas emission reduction. In addition, there are also a large number of CO2 capture or separation processes in industrial fields such as steelmaking, cement, and chemical industry (such as synthetic ammonia, hydrogen production, and natural gas purification). The main methods for capturing CO2 include absorption, adsorption, membrane separation, and low-temperature separation. Among them, the absorption method is currently the most mature CO2 capture and separation technology that is expected to achieve large-scale commercial application.

[0003] The existing CO2 absorption capture and separation method only captures CO2, and has high energy consumption and operating costs during the application process. In particular, the steam heat consumed by the absorbent regeneration accounts for the vast majority of the energy consumption of the entire system, which is not in line with the concept of green environmental protection. In addition, in the electrolytic regeneration stage, the consumed electricity is only used for absorbent regeneration, and the energy utilization efficiency is low.

[0004] In view of the above problems, it is necessary to propose a carbon dioxide capture and absorbent purification system and method for coupled metal refining that is reasonably designed and effectively solves the above problems. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art and provide a carbon dioxide capture and absorbent purification system and method coupled with metal refining.

[0006] One aspect of the present invention provides a carbon dioxide capture and absorbent purification system coupled with metal refining, comprising an absorption module provided with an absorbent, a regeneration module having an electrodesorption unit and a gas-liquid separation unit, and a purification module;

[0007] The absorption module is used to communicate with flue gas containing carbon dioxide so as to absorb carbon dioxide in the flue gas through the absorbent;

[0008] The regeneration module and the purification module are selectively connected to the absorption module to selectively regenerate and purify the absorbent based on the effective concentration of the absorbent in the absorption module; wherein,

[0009] The electrolysis unit comprises a first anode chamber and a first cathode chamber which are separated from each other, wherein a crude copper anode is arranged in the first anode chamber, and a refined copper cathode is arranged in the first cathode chamber;

[0010] The first outlet of the absorption module is connected to the inlet of the first anode chamber through the first absorption liquid pipeline, and the second outlet of the absorption module is connected to the purified gas pipeline; the inlet of the gas-liquid separation unit is connected to the first anode chamber, the first outlet of the gas-liquid separation unit is connected to the first cathode chamber, and the second outlet of the gas-liquid separation unit is connected to the exhaust pipeline to discharge the separated carbon dioxide;

[0011] The outlet of the first cathode chamber is connected to the second inlet of the absorption module through a first absorbent pipeline to provide absorbent into the absorption module.

[0012] Optionally, a first control valve is provided on the first absorption liquid pipeline, and a second control valve is provided on the first absorbent pipeline.

[0013] Optionally, the purification module includes a liquid storage tank and an electrolytic purification tank;

[0014] The electrolytic purification tank is provided with a second anode chamber and a second cathode chamber which are arranged at intervals;

[0015] The inlet of the second cathode chamber is connected to the first outlet of the absorption module through a second absorption liquid pipeline, so as to transport the absorbent to be purified to the second cathode chamber, so as to cause the absorbent to be purified to undergo electrodeposition to precipitate metal ions in the absorbent to be purified, and obtain a purified absorbent;

[0016] The outlet of the second cathode chamber is connected to the second inlet of the absorption module through a second absorbent pipeline to transport the purified absorbent to the absorption module;

[0017] The outlet of the liquid storage tank is communicated with the inlet of the second anode chamber, and the outlet of the second anode chamber is communicated with the inlet of the liquid storage tank to provide an electrolyte solution to the electrolytic purification cell.

[0018] Optionally, a third control valve is provided on the second absorption liquid pipeline, and a fourth control valve is provided on the second absorbent pipeline.

[0019] Optionally, a rinsing module is also included;

[0020] The first inlet of the elution module is connected to the second outlet of the absorption module through the purified gas pipeline;

[0021] The second inlet of the rinsing module is used to communicate with the rinsing water source;

[0022] The first outlet of the elution module is connected to the gas exhaust pipeline.

[0023] Optionally, a desulfurization module is also included;

[0024] The first inlet of the desulfurization module is used to communicate with the flue gas containing carbon dioxide, and the first outlet of the desulfurization module is connected to the first inlet of the absorption module;

[0025] The second inlet of the desulfurization module is connected to the second outlet of the elution module;

[0026] The reflux outlet of the desulfurization module is communicated with the reflux inlet of the elution module.

[0027] Optionally, a recycling module is also included;

[0028] The inlet of the recovery module is connected to the reflux outlet of the desulfurization module, so that when the desulfurization liquid in the desulfurization module reaches saturation, the liquid material in the desulfurization module is transported to the recovery module for processing.

[0029] Optionally, it further includes a first heat exchange module and a second heat exchange module;

[0030] The first heat exchange module is respectively connected to the elution module and the desulfurization module, and is used for heat exchange between the elution module and the desulfurization module;

[0031] The second heat exchange module is respectively connected to the absorption module and the electric desorption unit, and is used for heat exchange between the absorption module and the electric desorption unit.

[0032] Optionally, the gas-liquid separation unit includes a flash tank and a condenser;

[0033] The gas-liquid mixture inlet of the flash tank is connected to the outlet of the first anode chamber, the gas inlet to be condensed of the condenser is connected to the gas outlet to be condensed of the flash tank, the condensate inlet of the flash tank is connected to the condensate outlet of the condenser, and the inlet of the first cathode chamber is connected to the separated liquid outlet of the flash tank;

[0034] The top of the condenser is connected to the exhaust pipe for discharging the separated carbon dioxide.

[0035] Another aspect of the present invention provides a method for carbon dioxide capture and absorbent purification coupled with metal refining, using the carbon dioxide capture and absorbent purification system coupled with metal refining as described above, the method comprising:

[0036] Step S1, transporting flue gas containing carbon dioxide to the absorption module, and absorbing carbon dioxide in the flue gas through the absorbent in the absorption module to obtain absorption liquid and purified gas;

[0037] Step S2, transporting the absorption liquid to the first anode chamber of the electrodesorption unit, desorbing the absorption liquid under the action of the crude copper anode, wherein elements in the crude copper anode that are more active than metallic copper are dissolved into the absorption liquid to obtain a gas-liquid mixture containing a copper / ammonia coordination compound and carbon dioxide;

[0038] Step S3, performing gas-liquid separation on the gas-liquid mixture by the gas-liquid separation unit to obtain carbon dioxide gas and separation liquid;

[0039] Step S4, transporting the separated liquid to the first cathode chamber of the electrolytic desorption unit, so that the copper ions in the separated liquid are electro-deposited under the action of the refined copper cathode to obtain refined copper and absorbent;

[0040] Step S5, transporting the absorbent in the first cathode chamber to the absorption module to continue absorbing carbon dioxide in the flue gas and realize regeneration of the absorbent; wherein, when the effective concentration of the absorbent is lower than a preset concentration, the regeneration module is disconnected from the absorption module, and the purification module is connected to the absorption module to purify the absorbent; when the effective concentration of the absorbent reaches a preset concentration, the purification module is disconnected from the absorption module, and the regeneration module is connected to the absorption module.

[0041] The carbon dioxide capture and absorbent purification system and method coupled with metal refining of the present invention, the system of the present invention adopts the method of electric cycle carbon capture, and couples the capture of carbon dioxide, the metal copper refining process and the absorbent purification process, which has higher energy efficiency, lower energy consumption and lower operating cost; the carbon dioxide rich liquid enters the first anode chamber and the first cathode chamber in turn, and the regeneration efficiency of the carbon dioxide rich liquid is improved; the absorbent produced by the electrodeposition of the first cathode chamber enters the absorption module again to absorb carbon dioxide, and the recycling of ammonia and the recovery of deposited metals are realized, which has low energy consumption requirements and low operating costs, and improves the cycle efficiency of the whole system; the carbon dioxide capture rate / decarbonization rate is high, and the purity of the discharged carbon dioxide product is high; while absorbing carbon dioxide, the refining of metal copper can also be realized to obtain refined copper with higher purity, which is in line with the concept of green environmental protection. In addition, the purification module is selectively connected with the absorption module to play the role of absorbent purification, so that the absorbent concentration reaches the corresponding requirements and the carbon dioxide capture efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1It is a structural schematic diagram of a carbon dioxide capture and absorbent purification system and method coupled with metal refining according to an embodiment of the present invention;

[0043] Figure 2 It is a structural schematic diagram of an absorption module according to another embodiment of the present invention;

[0044] Figure 3 It is a schematic flow diagram of a method for carbon dioxide capture and absorbent purification coupled with metal refining in another embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0046] like Figure 1 As shown, one aspect of the present invention provides a carbon dioxide capture and absorbent purification system and method coupled with metal refining, comprising an absorption module A provided with an absorbent, a regeneration module B having an electrodesorption unit 2 and a gas-liquid separation unit 3, and a purification module C. The absorption module A is used to communicate with flue gas containing carbon dioxide so as to absorb carbon dioxide in the flue gas through the absorbent.

[0047] It should be noted that the absorbent may be an ammonia solution, but the absorbent is not limited to ammonia, and may also be organic amines, amino acids, etc., which may be selected according to actual needs. In this embodiment, the absorbent is an ammonia solution as an example for description.

[0048] The flue gas containing carbon dioxide enters the absorption module A through the first inlet of the absorption module A, and the ammonia solution absorbent in the absorption module A absorbs the carbon dioxide to obtain an absorption liquid and a purified gas. The absorption liquid is a liquid with a high carbon dioxide load obtained after the absorbent absorbs the carbon dioxide, and the purified gas refers to the gas obtained after the flue gas is freed of carbon dioxide.

[0049] The regeneration module B and the purification module C are selectively connected to the absorption module A to selectively regenerate and purify the absorbent based on the effective concentration of the absorbent in the absorption module A.

[0050] Specifically, when the effective concentration of the absorbent is lower than a preset concentration, the regeneration module B is disconnected from the absorption module A, and the purification module C is connected to the absorption module A to purify the absorbent, and when the effective concentration of the absorbent reaches a preset concentration, the purification module C is disconnected from the absorption module A, and the regeneration module B is connected to the absorption module A. The effective concentration of the absorbent is always kept at the preset concentration to increase the carbon dioxide capture efficiency.

[0051] like Figure 1 As shown, the electrolysis unit 2 includes a first anode chamber 21 and a first cathode chamber 22 which are separated, wherein a crude copper anode is arranged in the first anode chamber 21, and a refined copper cathode is arranged in the first cathode chamber 22. That is, the electrode in the first anode chamber 21 is a crude copper metal plate, and the electrode in the first cathode chamber 22 is a refined copper metal plate. The first anode chamber 21 and the first cathode chamber 22 are separated by an anion exchange membrane 23.

[0052] A crude copper anode is arranged in the first anode chamber 21, and a refined copper cathode is arranged in the first cathode chamber 22, wherein there are relatively high impurities in the crude copper, such as lead, antimony, etc. During the electrolysis process, these impurity metals will dissolve into ions together with copper. Since the activity of metals such as gold, platinum, and silver is not as good as that of copper, they will directly precipitate under the anode to form anode mud, thereby realizing the separation of impurities and copper and improving the purity of copper. Crude copper also contains a large amount of chemical substances such as copper oxide. In the electrolyte solution, these copper oxides will be reduced to pure copper, increasing the amount of reduction reaction in the refining process, thereby improving the refining effect of copper. Through the above process, the crude copper on the anode is gradually dissolved, and the impurities are removed or precipitated, and finally the copper ions with higher purity are obtained, which can be formed into refined copper with higher purity through electrodeposition at the cathode, providing high-quality raw materials for the refined copper of the cathode. While absorbing carbon dioxide, the system can also realize the refining of metallic copper, and obtain refined copper with higher purity, which is in line with the concept of green environmental protection.

[0053] It should be noted that in addition to crude copper and refined copper as electrodes in this embodiment, crude nickel and refined nickel can also be used as electrodes, as long as the metal refining process can be achieved during the carbon dioxide capture process. The electrode types in the anode chamber and the cathode chamber can be selected according to actual needs.

[0054] The electrolysis unit 2 utilizes the electrochemical principle and adopts an electrochemical cycle with high energy utilization rate. By supplying power to the electrolysis unit 2, the desorption of carbon dioxide and the regeneration of ammonia can be achieved. The desorption of carbon dioxide is specifically as follows: since the electrode of the first anode chamber 21 contains copper elements that can coordinate with ammonia, the electrode of the first anode chamber 21 can produce corresponding metal copper ions. Through the coordination of metal copper ions and ammonia, carbon dioxide in the absorption liquid can be desorbed, thereby reducing energy consumption while ensuring the desorption of carbon dioxide. At the same time, during the electrolysis process, elements in the crude copper anode that are more active than metallic copper dissolve into the absorption liquid, realizing the separation of impurities in the crude copper anode, and obtaining copper ions with higher purity.

[0055] The first outlet of the absorption module A is connected to the inlet of the first anode chamber 21 through the first absorption liquid pipeline 41, so that the absorption liquid is transported to the first anode chamber 21 through the first absorption liquid pipeline 41. The absorption liquid is desorbed under the action of the crude copper anode, wherein the desorption process of carbon dioxide in the first anode chamber 21 is specifically as follows: Cu-2e - =Cu 2+ ;Cu 2+ +nNH3-CO2=Cu(NH3) n 2+ +CO2↑.

[0056] Elements in the crude copper anode that are more active than metallic copper dissolve into the absorption liquid to obtain a gas-liquid mixture containing a copper / ammonia coordination compound and carbon dioxide. The liquid component in the gas-liquid mixture has a low carbon dioxide load and a high metal load, mainly because most of the carbon dioxide is in the form of gas.

[0057] The electrolysis unit 2 utilizes the electrochemical principle and adopts an electrochemical cycle with high energy utilization rate. By supplying power to the electrolysis unit 2, the desorption of carbon dioxide and the regeneration of ammonia can be achieved. The desorption of carbon dioxide is specifically as follows: since the electrode of the first anode chamber 21 contains copper elements that can coordinate with ammonia, the electrode of the first anode chamber 21 can produce corresponding metal copper ions. Through the coordination of metal copper ions and ammonia, carbon dioxide in the absorption liquid can be desorbed, thereby reducing energy consumption while ensuring the desorption of carbon dioxide. At the same time, during the electrolysis process, elements in the crude copper anode that are more active than metallic copper dissolve into the absorption liquid, realizing the separation of impurities in the crude copper anode, and obtaining copper ions with higher purity.

[0058] The second outlet of the absorption module A is connected to the purified gas pipeline 42 to discharge the purified gas. In other words, the purified gas obtained after removing carbon dioxide from the flue gas can be discharged through the purified gas pipeline 42.

[0059] The inlet of the gas-liquid separation unit 3 is connected to the first anode chamber 21, the first outlet of the gas-liquid separation unit 3 is connected to the first cathode chamber 2, and the second outlet of the gas-liquid separation unit 3 is connected to the exhaust pipe to discharge the separated carbon dioxide.

[0060] Specifically, the gas-liquid mixture produced by the first anode chamber 21 is transported to the gas-liquid separation unit 3 through the gas-liquid mixture pipeline 43. The gas-liquid separation unit 3 separates the gas-liquid mixture to obtain carbon dioxide gas and separation liquid. Since ammonia has been coordinated with the metal copper ions, gaseous carbon dioxide can be easily separated from the gas-liquid mixed solution. The separated carbon dioxide gas is discharged through the second outlet of the gas-liquid separation unit 3.

[0061] The second outlet of the gas-liquid separation unit 3 is connected to the inlet of the first cathode chamber 22 through the separation liquid pipeline 44, and the separation liquid is transported to the first cathode chamber 22 of the electrolysis unit 2. The copper ions in the separation liquid are electro-deposited under the action of the refined copper cathode to obtain refined copper and ammonia-containing solution, wherein the process of the electro-deposition is: Cu(NH3) n 2+ +2e - =Cu+nNH 3。 The ammonia-containing solution in the first cathode chamber 22 has a low carbon dioxide load and a low metallic copper load. Through the electrodeposition of the separation liquid in the first cathode chamber 22, ammonia regeneration and refined copper recovery are achieved, which saves resources and conforms to the concept of green environmental protection.

[0062] The outlet of the first cathode chamber 22 is connected to the second inlet of the absorption module A through the first absorbent pipeline 45, and the ammonia-containing solution produced in the first cathode chamber 22 is transported to the absorption module A through the first absorbent pipeline 45 to provide the ammonia-containing solution to the absorption module A, continue to absorb the carbon dioxide in the flue gas, realize the recycling of ammonia, and further realize the complete carbon dioxide capture cycle.

[0063] Specifically, in the whole system of the present invention, carbon dioxide is absorbed in the absorption module by an ammonia-containing solution; by using a blister copper metal plate coordinated with ammonia as the electrode of the first anode chamber, the absorption liquid is desorbed under the action of the blister copper anode, wherein in the first anode chamber, elements in the blister copper anode that are more active than metallic copper are dissolved into the absorption liquid, and copper ions can be released into the carbon dioxide-loaded absorption liquid in the first anode chamber by electrochemical dissolution, and carbon dioxide is desorbed by coordination with ammonia to obtain a gas-liquid mixture containing a copper / ammonia coordination compound and carbon dioxide; the gas-liquid mixture is separated by a gas-liquid separation unit to obtain carbon dioxide gas and a separation liquid; the separation liquid undergoes electrodeposition under the action of a refined copper cathode in the first cathode chamber, and copper ions are deposited on the cathode to obtain refined copper and an ammonia-containing solution, thereby realizing ammonia regeneration; finally, the ammonia-containing solution enters the absorption module again to provide the absorption module with an ammonia-containing solution, thereby ensuring the supply of absorbent in the subsequent carbon dioxide capture process in the absorption unit.

[0064] When the effective concentration of the absorbent is lower than a preset concentration, the regeneration module is disconnected from the absorption module, and the purification module is connected to the absorption module to purify the absorbent. When the effective concentration of the absorbent reaches a preset concentration, the purification module is disconnected from the absorption module, and the regeneration module is connected to the absorption module, so as to always maintain the effective concentration of the absorbent at the preset concentration and increase the carbon dioxide capture efficiency.

[0065] The carbon dioxide capture and absorbent purification system coupled with metal refining of the present invention adopts the method of electric cycle carbon capture to couple the capture of carbon dioxide, the metal copper refining process and the absorbent purification process, which has higher energy efficiency, lower energy consumption and lower operating cost; the carbon dioxide rich liquid enters the first anode chamber and the first cathode chamber in turn, thereby improving the regeneration efficiency of the carbon dioxide rich liquid; the absorbent produced by the electrodeposition of the first cathode chamber enters the absorption module again to absorb carbon dioxide, thereby realizing the recycling of ammonia and the recovery of deposited metals, having low energy consumption requirements and low operating costs, and improving the cycle efficiency of the entire system; the carbon dioxide capture rate / decarbonization rate is high, and the purity of the discharged carbon dioxide product is high; while absorbing carbon dioxide, the refining of metal copper can also be achieved to obtain refined copper with higher purity, which is in line with the concept of green environmental protection. In addition, the purification module is selectively connected to the absorption module to play the role of purifying the absorbent, so that the absorbent concentration reaches the corresponding requirements and improves the carbon dioxide capture efficiency.

[0066] For example, Figure 1 As shown, a first control valve 41a is provided on the first absorption liquid pipeline 41, and a second control valve 45a is provided on the first absorbent pipeline 45. The first control valve 41a controls the opening and closing of the first absorption liquid pipeline 41, and the second control valve 45a controls the opening and closing of the first absorbent pipeline 45, thereby controlling whether the absorbent is regenerated.

[0067] For example, Figure 1 As shown, the purification module C includes a liquid storage tank 51 and an electrolytic purification tank. The electrolytic purification tank is provided with a second anode chamber 52 and a second cathode chamber 53 arranged at intervals. A metal electrode plate is used in the second cathode chamber 53, and the metal ions in the absorbent can be electrodeposited at the metal electrode plate of the second cathode chamber 53.

[0068] The inlet of the second cathode chamber 53 is connected to the first outlet of the absorption module A through the second absorption liquid pipeline 54, so that the absorbent to be purified is transported to the second cathode chamber 53, so that the absorbent to be purified undergoes electrodeposition to precipitate the metal ions in the absorbent to be purified, and obtain the purified absorbent.

[0069] The outlet of the second cathode chamber 53 is connected to the second inlet of the absorption module A through the second absorbent pipe 55 to transport the purified absorbent to the absorption module A, provide the absorption module A with the purified absorbent, continue to absorb the carbon dioxide in the flue gas, realize the recycling of ammonia, and further realize the complete carbon dioxide capture cycle, thereby increasing the carbon dioxide capture efficiency.

[0070] The outlet of the liquid storage tank 51 is connected to the inlet of the second anode chamber 52, and the outlet of the second anode chamber 52 is connected to the inlet of the liquid storage tank 51 to provide an electrolyte solution to the electrolytic purification tank. The electrolyte solution may be Na2SO4, NaCl, NaNO3, K2SO4, etc., and may be selected according to actual needs.

[0071] In this embodiment, by providing a purification module selectively connected to the absorption module, by increasing the voltage, the active impurity elements of the absorbent in the absorption module can be deposited in the second cathode chamber, which plays a role in purifying the absorbent and increasing the carbon dioxide capture efficiency.

[0072] For example, Figure 1 As shown, a third control valve 54a is provided on the second absorption liquid pipeline 54, and a fourth control valve 55a is provided on the second absorbent pipeline 55. The third control valve 54a controls the opening and closing of the second absorption liquid pipeline 54, and the fourth control valve 55a controls the opening and closing of the second absorbent pipeline 55, thereby controlling whether the absorbent is purified.

[0073] Specifically, when the absorbent needs to be regenerated, the first control valve and the second control valve are opened, and the third control valve and the fourth control valve are closed, so that the absorbent in the absorption module enters the electrodesorption unit for regeneration. When the absorbent needs to be purified, the first control valve and the second control valve are closed, and the third control valve and the fourth control valve are opened, so that the absorbent in the absorption module enters the purification module for purification.

[0074] For example, Figure 1 As shown, the carbon dioxide capture and absorbent purification system coupled with metal refining of the present invention further includes a leaching module 5. The first inlet of the leaching module 5 is connected to the second outlet of the absorption module A through the purified gas pipeline 42. The second inlet of the leaching module 5 is used to be connected to the leaching water source. The first outlet of the leaching module 5 is connected to the gas exhaust pipeline 46.

[0075] Specifically, the purified gas generated in the absorption module A will contain residual ammonia. The purified gas containing ammonia is transmitted to the elution module 5 through the purified gas pipeline 42. The elution water source enters the elution module 5 through the second inlet to elute the purified gas containing ammonia, so as to separate and recover the residual ammonia. The separated ammonia exists in the form of ammonia-containing eluent, and an ammonia-containing solution and the gas to be discharged are obtained. The gas to be discharged is discharged through the gas discharge pipeline 46.

[0076] For example, Figure 1As shown, the carbon dioxide capture and absorbent purification system coupled with metal refining of the present invention further comprises a desulfurization module 6. The first inlet of the desulfurization module 6 is used to communicate with the flue gas containing carbon dioxide, and the flue gas containing carbon dioxide first enters the desulfurization module 6 for pretreatment of flue gas desulfurization to obtain a desulfurized liquid.

[0077] The first outlet of the desulfurization module 6 is connected to the first inlet of the absorption unit 1. The flue gas after desulfurization treatment enters the absorption unit 1 to absorb and capture carbon dioxide.

[0078] The second inlet of the desulfurization module 6 is connected to the second outlet of the elution unit 5. The ammonia separated in the elution unit 5 is transported from the elution unit 5 to the desulfurization module 6 in the form of an ammonia-containing eluent.

[0079] The reflux outlet of the desulfurization module 6 is connected to the reflux inlet of the elution unit 5. The height of the reflux inlet is lower than the height of the second inlet.

[0080] Specifically, the separated ammonia exists in the form of desulfurization liquid after combining with sulfur dioxide in the flue gas. The desulfurization liquid that has not reached the saturated state flows back from the desulfurization module 6 to the elution unit 5 to elute the purified gas, and is transported from the elution unit 5 to the desulfurization device 6 along with the separated ammonia-containing eluent, forming a circulation loop.

[0081] It should be noted that the purified gas can be eluted with a circulating desulfurization liquid or with externally supplemented water. Of course, the purified gas can also be eluted with both desulfurization liquid and externally supplemented water. The choice can be made according to actual needs.

[0082] For example, Figure 1 As shown, the carbon dioxide capture and absorbent purification system coupled with metal refining of the present invention also includes a recovery module 7, the inlet of the recovery module 7 is connected to the reflux outlet of the desulfurization module 6, so that when the desulfurization liquid in the desulfurization module reaches saturation, the liquid material in the desulfurization module 6 is transported to the recovery module 7 for processing.

[0083] Specifically, when the desulfurized liquid reaches saturation, the liquid substance in the desulfurization module 6 can be transported to the recovery module 7 for processing to obtain the utilized sulfur dioxide, such as ammonium sulfate fertilizer product. The desulfurized liquid can be recycled and reused through the recovery module 7, saving resources.

[0084] For example, Figure 1 As shown, the carbon dioxide capture and absorbent purification system coupled with metal refining of the present invention also includes a first heat exchange module 8, which is respectively connected to the elution unit 5 and the desulfurization module 6 and is used for heat exchange between the elution unit 5 and the desulfurization module 6.

[0085] Specifically, the ammonia-containing eluent and the desulfurization liquid can be heat exchanged through the first heat exchange module 8, and the heat exchange between the ammonia-containing eluent and the desulfurization liquid is performed through the first heat exchange module 8, which is used to transfer the heat of the desulfurization liquid to the ammonia-containing eluent. In addition, after the heat exchange, the ammonia-containing eluent can be further heated by the heating component during the process of being transported to the desulfurization device 6 to promote the desulfurization treatment in the desulfurization device 6; after the heat exchange, the desulfurization liquid can be further cooled by the cooling component during the process of being transported to the elution device 5.

[0086] In this embodiment, the heat utilization rate of the entire system is improved by the first heat exchange module, thereby saving energy consumption.

[0087] For example, Figure 1 As shown, the carbon dioxide capture and absorbent purification system coupled with metal refining of the present invention further includes a second heat exchange module 9, which is respectively connected to the absorption unit 1 and the electrolysis unit 2 and is used for heat exchange between the absorption unit 1 and the electrolysis unit 2.

[0088] Specifically, the second heat exchange module 9 includes a cold end inlet, a cold end outlet, a hot end inlet and a hot end outlet. The cold end inlet of the second heat exchange module 9 is connected to the second outlet of the absorption unit 1, the hot end outlet of the second heat exchange module 9 is connected to the inlet of the first anode chamber 21, the hot end inlet of the second heat exchange module 9 is connected to the outlet of the first cathode chamber 22, and the cold end outlet of the second heat exchange module 9 is connected to the second inlet of the absorption unit 1.

[0089] In this embodiment, the ammonia-containing solution and the absorption liquid are heat-exchanged only through the second heat exchange module 9, and the heat of the ammonia-containing solution is transferred to the absorption liquid. The ammonia-containing solution and the absorption liquid are isolated from each other in the second heat exchange module 9. The delivery channel between the cold end outlet of the second heat exchange module 9 and the ammonia-containing solution inlet of the absorption unit 1 is used to deliver the ammonia-containing solution to the absorption unit 1, and a cooling component can be installed on the delivery channel; the delivery channel between the hot end outlet of the second heat exchange module 9 and the inlet of the first anode chamber 21 is used to deliver the absorption liquid to the first anode chamber 21, and a heating component can be installed on the delivery channel.

[0090] For example, Figure 1 As shown, the gas-liquid separation unit 3 includes a flash tank 31 and a condenser 32 .

[0091] The gas-liquid mixture inlet of the flash tank 31 is connected to the outlet of the first anode chamber 21, the gas inlet to be condensed of the condenser 32 is connected to the gas outlet to be condensed of the flash tank 31, the condensate inlet of the flash tank 31 is connected to the condensate outlet of the condenser 32, and the inlet of the first cathode chamber 22 is connected to the separated liquid outlet of the flash tank 31. The top of the condenser 32 also includes a carbon dioxide outlet for discharging the separated carbon dioxide.

[0092] The separation liquid is a mixture of the initial separation liquid and the condensate, the initial separation liquid level is the liquid substance obtained by flash evaporation in the flash tank 31 , and the condensate is the liquid substance obtained by condensation in the condenser 32 .

[0093] For example, Figure 2 As shown, the absorption module A includes an absorption part 11 , a condensation part 12 , and an isolation plate 13 for isolating the absorption part 11 from the condensation part 12 .

[0094] The absorption part 11 is located at the bottom of the absorption module A, and the condensation part 12 is located at the top of the absorption module A. The isolation plate 12 allows gas to pass through and blocks liquid substances from passing through. The material of the isolation plate 12 can be a PTFE film, and preferably, the material of the isolation plate 12 can be a PTFE film of Teflon.

[0095] The flue gas inlet of the absorption part 11 is used to communicate with the flue gas containing carbon dioxide, and the absorbent inlet of the absorption part 11 is used to communicate with the outlet of the first cathode chamber 22 .

[0096] The absorption liquid outlet of the condensation section 12 is connected to the first absorption liquid pipeline 41 , and the gas outlet of the condensation section 12 is connected to the purified gas pipeline 42 .

[0097] Specifically, the absorption part 11 and the condensation part 12 are connected through a conveying pipeline, one end of the conveying pipeline is connected to the bottom of the absorption part 11, and the other end of the conveying pipeline is connected to the upper part of the condensation part 12. A cooling component is installed on the conveying pipeline. Specifically, the connection point between the absorption part 11 and the pipeline can be located at the bottom of the absorption part 11, and the connection point between the condensation part 12 and the pipeline can be located at the upper part of the condensation part 12, and lower than the height position of the purified gas.

[0098] Specifically, flue gas containing carbon dioxide enters the absorption part 11 through the flue gas inlet, and the absorbent enters the absorption part 11 through the absorbent inlet, and absorbs carbon dioxide in the absorption part 11. After the absorbent absorbs carbon dioxide, it is transported to the condensation part 12 through the pipeline, and the purified gas obtained after absorption is discharged from the gas outlet, and the absorption liquid obtained after absorbing carbon dioxide is discharged to the first anode chamber 21. It should be noted that since a cooling component is installed on the pipeline, ammonia can be present in the solution, thereby avoiding the volatilization of ammonia and ensuring the recycling of ammonia.

[0099] In this embodiment, the gas-liquid separation unit 3 includes a flash tank 31 and a condenser 32. The flash tank 31 and the condenser 32 can separate the gas-liquid mixture, thereby reducing the loss of ammonia and the energy consumption of the entire system.

[0100] like Figure 3 As shown, another aspect of the present invention provides a method for carbon dioxide capture and absorbent purification coupled with metal refining, using the carbon dioxide capture and absorbent purification system coupled with metal refining as described above. The specific structure of the carbon dioxide capture and absorbent purification system coupled with metal refining has been described in detail above and will not be repeated here. The method includes:

[0101] Step S1, transporting flue gas containing carbon dioxide to the absorption module, and absorbing carbon dioxide in the flue gas through the absorbent in the absorption module to obtain absorption liquid and purified gas.

[0102] Specifically, the ammonia-containing solution in the absorption module may contain a supporting electrolyte, which may be potassium chloride, sodium chloride, sodium sulfate and other substances; in addition, some additives may be added to the ammonia-containing solution in the absorption module, such as surfactants such as tetraethylammonium chloride and tetrapropylammonium chloride.

[0103] The absorption liquid is a liquid with a high carbon dioxide load obtained after the ammonia-containing solution absorbs carbon dioxide, and the purified gas refers to the gas obtained after the carbon dioxide is removed from the flue gas.

[0104] Step S2, transporting the absorption liquid to the first anode chamber of the electrolytic desorption unit, and desorbing the absorption liquid under the action of the crude copper anode, wherein elements in the crude copper anode that are more active than metallic copper are dissolved into the absorption liquid to obtain a gas-liquid mixture containing a copper / ammonia coordination compound and carbon dioxide.

[0105] Among them, the liquid component in the gas-liquid mixture is low carbon dioxide load and high metal load, mainly because most of the carbon dioxide is in the form of gas. Among them, the desorption of carbon dioxide is specifically: since the electrode of the first anode chamber 21 contains copper elements that can coordinate with ammonia, the electrode of the first anode chamber 21 can produce corresponding metal copper ions, and the carbon dioxide in the absorption liquid can be desorbed through the coordination of metal copper ions and ammonia, thereby reducing energy consumption while ensuring the desorption of carbon dioxide. At the same time, during the electrolysis process, elements in the crude copper anode that are more active than metallic copper dissolve into the absorption liquid, realizing the separation of impurities in the crude copper anode, and obtaining copper ions with higher purity.

[0106] Step S3, performing gas-liquid separation processing on the gas-liquid mixture by the gas-liquid separation unit to obtain carbon dioxide gas and separation liquid.

[0107] Specifically, in this embodiment, the gas-liquid separation process specifically includes: flashing and condensing the gas-liquid mixture in sequence; wherein, after flashing, an initial separation liquid and a gas to be condensed are obtained, and after condensation, carbon dioxide gas and a condensate are obtained.

[0108] Step S4, transporting the separation liquid to the first cathode chamber of the electrolytic desorption unit, so that the copper ions in the separation liquid are electro-deposited under the action of the refined copper cathode to obtain refined copper and absorbent.

[0109] Specifically, the copper ions in the separation liquid are electro-deposited under the action of the refined copper cathode to obtain refined copper and an ammonia-containing solution, wherein the ammonia-containing solution in the first cathode chamber 22 has a low carbon dioxide load and a low metallic copper load. Through the electro-deposition of the separation liquid in the first cathode chamber 22, ammonia regeneration and refined copper recovery are achieved, which saves resources and conforms to the concept of green environmental protection.

[0110] Step S5, transporting the absorbent in the first cathode chamber to the absorption module to continue absorbing carbon dioxide in the flue gas and realize regeneration of the absorbent; wherein, when the effective concentration of the absorbent is lower than a preset concentration, the regeneration module is disconnected from the absorption module, and the purification module is connected to the absorption module to purify the absorbent; when the effective concentration of the absorbent reaches a preset concentration, the purification module is disconnected from the absorption module, and the regeneration module is connected to the absorption module.

[0111] Specifically, the ammonia-containing solution produced in the first cathode chamber 22 is transported to the absorption module A through the first ammonia-containing solution pipeline 45 to provide the ammonia-containing solution to the absorption module A, continue to absorb the carbon dioxide in the flue gas, realize the recycling of ammonia, and further realize the complete carbon dioxide capture cycle.

[0112] When the absorbent needs to be regenerated, the first control valve and the second control valve are opened, and the third control valve and the fourth control valve are closed, so that the absorbent in the absorption module enters the electrodesorption unit for regeneration. When the absorbent needs to be purified, the first control valve and the second control valve are closed, and the third control valve and the fourth control valve are opened, so that the absorbent in the absorption module enters the purification module for purification.

[0113] The carbon dioxide capture and absorbent purification method coupled with metal refining of the present invention adopts the method of electric cycle carbon capture to couple the capture of carbon dioxide, the metal copper refining process and the absorbent purification process, which has higher energy efficiency, lower energy consumption and lower operating cost; the carbon dioxide rich liquid enters the first anode chamber and the first cathode chamber in turn, thereby improving the regeneration efficiency of the carbon dioxide rich liquid; the absorbent produced by the electrodeposition of the first cathode chamber enters the absorption module again to absorb carbon dioxide, thereby realizing the recycling of ammonia and the recovery of deposited metals, having low energy consumption requirements and low operating costs, and improving the cycle efficiency of the entire system; the carbon dioxide capture rate / decarbonization rate is high, and the purity of the discharged carbon dioxide product is high; while absorbing carbon dioxide, the refining of metal copper can also be achieved to obtain refined copper with higher purity, which is in line with the concept of green environmental protection. In addition, the purification module is selectively connected to the absorption module to play the role of purifying the absorbent, so that the absorbent concentration reaches the corresponding requirements and improves the carbon dioxide capture efficiency.

[0114] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A carbon dioxide capture and absorbent purification system coupled with metal refining, characterized in that: It includes an absorption module provided with an absorbent, a regeneration module having an electric desorption unit and a gas-liquid separation unit, and a purification module; The absorption module is used to communicate with flue gas containing carbon dioxide so as to absorb carbon dioxide in the flue gas through the absorbent; The regeneration module and the purification module are selectively connected to the absorption module to selectively regenerate and purify the absorbent based on the effective concentration of the absorbent in the absorption module; wherein, The electrolysis unit comprises a first anode chamber and a first cathode chamber which are separated from each other, wherein a crude copper anode is arranged in the first anode chamber, and a refined copper cathode is arranged in the first cathode chamber; The first outlet of the absorption module is connected to the inlet of the first anode chamber through the first absorption liquid pipeline, and the second outlet of the absorption module is connected to the purified gas pipeline; the inlet of the gas-liquid separation unit is connected to the first anode chamber, the first outlet of the gas-liquid separation unit is connected to the first cathode chamber, and the second outlet of the gas-liquid separation unit is connected to the exhaust pipeline to discharge the separated carbon dioxide; The outlet of the first cathode chamber is connected to the second inlet of the absorption module through a first absorbent pipeline to provide absorbent into the absorption module.

2. The system according to claim 1, characterized in that The first absorption liquid pipeline is provided with a first control valve, and the first absorbent pipeline is provided with a second control valve.

3. The system according to claim 1, characterized in that The purification module includes a liquid storage tank and an electrolytic purification tank; The electrolytic purification tank is provided with a second anode chamber and a second cathode chamber which are arranged at intervals; The inlet of the second cathode chamber is connected to the first outlet of the absorption module through a second absorption liquid pipeline, so as to transport the absorbent to be purified to the second cathode chamber, so as to cause the absorbent to be purified to undergo electrodeposition to precipitate metal ions in the absorbent to be purified, and obtain a purified absorbent; The outlet of the second cathode chamber is connected to the second inlet of the absorption module through a second absorbent pipeline to transport the purified absorbent to the absorption module; The outlet of the liquid storage tank is communicated with the inlet of the second anode chamber, and the outlet of the second anode chamber is communicated with the inlet of the liquid storage tank to provide an electrolyte solution to the electrolytic purification cell.

4. The system according to claim 3, characterized in that The second absorption liquid pipeline is provided with a third control valve, and the second absorbent pipeline is provided with a fourth control valve.

5. The system according to any one of claims 1 to 4, characterized in that: Also includes a rinsing module; The first inlet of the elution module is connected to the second outlet of the absorption module through the purified gas pipeline; The second inlet of the rinsing module is used to communicate with the rinsing water source; The first outlet of the elution module is connected to the gas exhaust pipeline.

6. The system according to claim 5, characterized in that It also includes a desulfurization module; The first inlet of the desulfurization module is used to communicate with the flue gas containing carbon dioxide, and the first outlet of the desulfurization module is connected to the first inlet of the absorption module; The second inlet of the desulfurization module is connected to the second outlet of the elution module; The reflux outlet of the desulfurization module is communicated with the reflux inlet of the elution module.

7. The system according to claim 6, characterized in that Also includes recycling module; The inlet of the recovery module is connected to the reflux outlet of the desulfurization module, so that when the desulfurization liquid in the desulfurization module reaches saturation, the liquid material in the desulfurization module is transported to the recovery module for processing.

8. The system according to claim 6, characterized in that Also includes a first heat exchange module and a second heat exchange module; The first heat exchange module is respectively connected to the elution module and the desulfurization module, and is used for heat exchange between the elution module and the desulfurization module; The second heat exchange module is respectively connected to the absorption module and the electric desorption unit, and is used for heat exchange between the absorption module and the electric desorption unit.

9. The system according to any one of claims 1 to 4, characterized in that: The gas-liquid separation unit comprises a flash tank and a condenser; The gas-liquid mixture inlet of the flash tank is connected to the outlet of the first anode chamber, the gas inlet to be condensed of the condenser is connected to the gas outlet to be condensed of the flash tank, the condensate inlet of the flash tank is connected to the condensate outlet of the condenser, and the inlet of the first cathode chamber is connected to the separated liquid outlet of the flash tank; The top of the condenser is connected to the exhaust pipe for discharging the separated carbon dioxide.

10. A method for carbon dioxide capture and absorbent purification coupled with metal refining, characterized in that: The carbon dioxide capture and absorbent purification system coupled with metal refining according to any one of claims 1 to 9 is used, and the method comprises: Step S1, transporting flue gas containing carbon dioxide to the absorption module, and absorbing carbon dioxide in the flue gas through the absorbent in the absorption module to obtain absorption liquid and purified gas; Step S2, transporting the absorption liquid to the first anode chamber of the electrodesorption unit, desorbing the absorption liquid under the action of the crude copper anode, wherein elements in the crude copper anode that are more active than metallic copper are dissolved into the absorption liquid to obtain a gas-liquid mixture containing a copper / ammonia coordination compound and carbon dioxide; Step S3, performing gas-liquid separation on the gas-liquid mixture by the gas-liquid separation unit to obtain carbon dioxide gas and separation liquid; Step S4, transporting the separated liquid to the first cathode chamber of the electrolytic desorption unit, so that the copper ions in the separated liquid are electro-deposited under the action of the refined copper cathode to obtain refined copper and absorbent; Step S5, transporting the absorbent in the first cathode chamber to the absorption module to continue absorbing carbon dioxide in the flue gas and realize regeneration of the absorbent; wherein, when the effective concentration of the absorbent is lower than a preset concentration, the regeneration module is disconnected from the absorption module, and the purification module is connected to the absorption module to purify the absorbent; when the effective concentration of the absorbent reaches a preset concentration, the purification module is disconnected from the absorption module, and the regeneration module is connected to the absorption module.

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