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

Abstract

A carbon dioxide capture and absorbent purification system and method coupled with metal refining. The system comprises an absorption module (A) having an absorbent, a regeneration module (B) having an electro-desorption unit (2) and a gas-liquid separation unit (3), and a purification module (C), wherein the absorption module (A) is in communication with flue gas; the regeneration module (B) and the purification module (C) are selectively in communication with the absorption module (A) so as to selectively regenerate and purify the absorbent; the electro-desorption unit (2) comprises a first anode chamber (21) with a crude copper anode, and a first cathode chamber (22) with a refined copper cathode, the first anode chamber being separated from the first cathode chamber; a first outlet of the absorption module (A) is in communication with an inlet of the first anode chamber (21), and a second outlet of the absorption module (A) is in communication with a purified-gas pipe (42); an inlet of the gas-liquid separation unit (3) is in communication with the first anode chamber (21), a first outlet of the gas-liquid separation unit (3) is in communication with the first cathode chamber (22), and a second outlet of the gas-liquid separation unit (3) is in communication with a gas discharge pipe; and an outlet of the first cathode chamber (22) is in communication with the second inlet of the absorption module (A). The method comprises: conveying flue gas containing carbon dioxide to the absorption module (A) to absorb the carbon dioxide from the flue gas, so as to obtain an absorption liquid and a purified gas; conveying the absorption liquid into the first anode chamber (21) of the electro-desorption unit (2), and desorbing the absorption liquid to obtain a gas-liquid mixture; performing a gas-liquid separation treatment on the gas-liquid mixture by means of the gas-liquid separation unit (3) to obtain carbon dioxide gas and a separated liquid; conveying the separated liquid into the first cathode chamber (22) of the electro-desorption unit (2) to obtain refined copper and an absorbent; and conveying the absorbent from the first cathode chamber (22) into the absorption module (A).

Description

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

[0001] This application claims priority to the Chinese patent application No. 202411302314.7, filed on September 18, 2024, and entitled "Carbon dioxide capture and absorbent purification system and method coupled with metal refining", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application belongs to the field of gas purification and separation technology, and specifically relates to a carbon dioxide capture and absorbent purification system and method coupled with metal refining. BACKGROUND

[0003] Carbon dioxide (CO2) is the main greenhouse gas causing global warming, and the capture, utilization and storage of CO2 have become one of the hot topics of international concern. The CO2 emissions from coal-fired power generation in China account for about 50% of the total industrial emissions, and the capture and separation of CO2 from flue gas in coal-fired power plants is an important field of greenhouse gas emission reduction. In addition, there are also a large number of CO2 capture or separation processes in the fields of steelmaking, cement, chemical industry (such as synthetic ammonia, hydrogen production, natural gas purification) and the like. The methods for capturing CO2 mainly include absorption method, adsorption method, membrane separation, low-temperature separation and the like, among which the absorption method is the most mature and promising CO2 capture and separation technology for large-scale commercial application.

[0004] The existing CO2 absorption method for capture and separation only captures CO2, and the energy consumption and operating cost in the application process are high, especially the steam heat energy consumed for absorbent regeneration accounts for a large proportion of the entire system energy consumption, which does not conform to the concept of green environmental protection. In addition, in the electrolytic regeneration link, the consumed electric energy is only used for absorbent regeneration, and the energy utilization efficiency is low.

[0005] In view of the above problems, it is necessary to provide a carbon dioxide capture and absorbent purification system and method which is reasonable in design and effectively solves the above problems. SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a carbon dioxide capture and absorbent purification system and method coupled with metal refining.

[0007] One aspect of the present application 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 electrolytic desorption unit and a gas-liquid separation unit, and a purification module.

[0008] The absorption module is used to communicate with flue gas containing carbon dioxide, so as to absorb carbon dioxide in the flue gas by the absorbent;

[0009] The regeneration module and the purification module are selectively connected with the absorption module to selectively regenerate and purify the absorbent based on the effective concentration of the absorbent in the absorption module; wherein,

[0010] The electrolytic desorption unit comprises a first anode chamber and a first cathode chamber arranged separately, wherein a crude copper anode is arranged in the first anode chamber and a refined copper cathode is arranged in the first cathode chamber;

[0011] The first outlet of the absorption module is connected with the inlet of the first anode chamber through a first absorption liquid pipeline, and the second outlet of the absorption module is connected with a purified gas pipeline; the inlet of the gas-liquid separation unit is connected with the first anode chamber, the first outlet of the gas-liquid separation unit is connected with the first cathode chamber, and the second outlet of the gas-liquid separation unit is connected with an exhaust pipeline to exhaust the separated carbon dioxide;

[0012] The outlet of the first cathode chamber is connected with the second inlet of the absorption module through a first absorbent pipeline to provide absorbent into the absorption module.

[0013] Optionally, the first absorption liquid pipeline is provided with a first control valve, and the first absorbent pipeline is provided with a second control valve.

[0014] Optionally, the purification module comprises a liquid storage tank and an electrolytic purification tank;

[0015] The electrolytic purification tank is provided with a second anode chamber and a second cathode chamber arranged separately;

[0016] The inlet of the second cathode chamber is connected with the first outlet of the absorption module through a second absorption liquid pipeline to transport the absorbent to be purified to the second cathode chamber, so that the absorbent to be purified is subjected to electrodeposition to precipitate metal ions in the absorbent to be purified to obtain purified absorbent;

[0017] The outlet of the second cathode chamber is connected with the second inlet of the absorption module through a second absorbent pipeline to transport the purified absorbent to the absorption module;

[0018] The outlet of the liquid storage tank is connected with the inlet of the second anode chamber, and the outlet of the second anode chamber is connected with the inlet of the liquid storage tank to provide electrolyte solution into the electrolytic purification tank.

[0019] Optionally, the second absorption liquid pipeline is provided with a third control valve, and the second absorbent pipeline is provided with a fourth control valve.

[0020] Optionally, it further comprises a elution module;

[0021] The first inlet of the rinsing module is connected with the second outlet of the absorption module through the purified gas pipeline;

[0022] The second inlet of the rinsing module is connected with a rinsing water source;

[0023] The first outlet of the rinsing module is connected with a gas discharge pipeline.

[0024] Optionally, a desulfurization module is further included;

[0025] The first inlet of the desulfurization module is connected with flue gas containing carbon dioxide, and the first outlet of the desulfurization module is connected with the first inlet of the absorption module;

[0026] The second inlet of the desulfurization module is connected with the second outlet of the rinsing module;

[0027] The backflow outlet of the desulfurization module is connected with the backflow inlet of the rinsing module.

[0028] Optionally, a recovery module is further included;

[0029] The inlet of the recovery module is connected with the backflow outlet of the desulfurization module, so that when the desulfurization liquid in the desulfurization module reaches saturation, the liquid substance in the desulfurization module is transported into the recovery module for treatment.

[0030] Optionally, a first heat exchange module and a second heat exchange module are further included;

[0031] The first heat exchange module is connected with the rinsing module and the desulfurization module respectively, and is used for heat exchange between the rinsing module and the desulfurization module;

[0032] The second heat exchange module is connected with the absorption module and the electrolysis unit respectively, and is used for heat exchange between the absorption module and the electrolysis unit.

[0033] Optionally, the gas-liquid separation unit includes a flash tank and a condenser;

[0034] The gas-liquid mixture inlet of the flash tank is connected with the outlet of the first anode chamber, the condensate gas inlet of the condenser is connected with the condensate gas outlet of the flash tank, the condensate liquid inlet of the flash tank is connected with the condensate liquid outlet of the condenser, and the inlet of the first cathode chamber is connected with the separation liquid outlet of the flash tank;

[0035] The top of the condenser is connected with the exhaust pipeline, and is used for discharging separated carbon dioxide.

[0036] Another aspect of the present application provides a method for coupling carbon dioxide capture and absorbent purification of metal refining, using the carbon dioxide capture and absorbent purification system of metal refining coupling as described above, the method comprising:

[0037] Step S1, delivering flue gas containing carbon dioxide to the absorption module, absorbing carbon dioxide in the flue gas by the absorbent in the absorption module, to obtain absorption liquid and purified gas;

[0038] Step S2, delivering the absorption liquid to the first anode chamber of the electrolytic desorption unit, desorbing the absorption liquid under the action of the crude copper anode, wherein the elements more active than copper in the crude copper anode dissolve into the absorption liquid, to obtain a gas-liquid mixture containing copper / ammonia coordination compounds and carbon dioxide;

[0039] Step S3, gas-liquid separation treatment of the gas-liquid mixture by the gas-liquid separation unit, to obtain carbon dioxide gas and separation liquid;

[0040] Step S4, delivering the separation liquid to the first cathode chamber of the electrolytic desorption unit, so that the copper ions in the separation liquid are subjected to electrodeposition under the action of the refined copper cathode, to obtain refined copper and absorbent;

[0041] Step S5, delivering the absorbent of the first cathode chamber to the absorption module to continue the absorption of carbon dioxide in the flue gas, to realize the regeneration of the absorbent; wherein when the effective concentration of the absorbent is lower than the 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 the preset concentration, the purification module is disconnected from the absorption module, and the regeneration module is connected to the absorption module.

[0042] The carbon dioxide capture and absorbent purification system and method coupled with metal refining of the present application adopts the mode of electric cycle carbon capture, and couples the carbon dioxide capture, copper metal refining process and absorbent purification process, so that the energy efficiency is higher, the energy consumption is lower, and the operation cost is lower; the carbon dioxide rich liquid enters the first anode chamber and the first cathode chamber in sequence, so as to improve the regeneration efficiency of the carbon dioxide rich liquid; the absorbent produced by the electrodeposition effect of the first cathode chamber enters the absorption module again to absorb carbon dioxide, so as to realize the cyclic use of ammonia and the recovery of deposited metal, and the energy consumption requirement and operation cost are low, and the cycle efficiency of the whole system is improved; the carbon dioxide capture rate / decarbonization rate is higher, and the purity of the discharged carbon dioxide product is higher; while absorbing carbon dioxide, copper metal refining can also be realized, and high-purity refined copper is obtained, which meets the concept of green environmental protection. In addition, the purification module is selectively connected with the absorption module, so as to play the role of absorbent purification, so that the absorbent concentration meets the corresponding requirements, and the carbon dioxide capture efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0043] Fig. 1 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 application;

[0044] Fig. 2 is a structural schematic diagram of an absorption module according to another embodiment of the present application;

[0045] Fig. 3 is a flow schematic diagram of a carbon dioxide capture and absorbent purification method coupled with metal refining according to another embodiment of the present application. DETAILED DESCRIPTION

[0046] In order for those skilled in the art to better understand the technical solutions of the present application, the present application will be described in further detail below in combination with the drawings and specific embodiments.

[0047] As shown in Fig. 1, one aspect of the present application provides a carbon dioxide capture and absorbent purification system and method coupled with metal refining, which comprises an absorption module A provided with absorbent, a regeneration module B provided with an electrolytic desorption unit 2 and a gas-liquid separation unit 3, and a purification module C. The absorption module A is used to be connected with flue gas containing carbon dioxide, so as to absorb carbon dioxide in the flue gas by the absorbent.

[0048] It should be noted that the absorbent can be an ammonia-containing solution, but the type of absorbent is not limited to ammonia, and can also be organic amine, amino acid, etc., which can be selected according to actual needs. In the present embodiment, the absorbent is taken as an ammonia-containing solution as an example for description.

[0049] The flue gas containing carbon dioxide enters the absorption module A through the first inlet of the absorption module A, and the ammonia-containing 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 high-carbon-dioxide-loaded liquid obtained after the absorbent absorbs the carbon dioxide, and the purified gas is the gas obtained after the flue gas is removed of carbon dioxide.

[0050] The regeneration module B and the purification module C are selectively connected with the absorption module A to selectively regenerate and purify the absorbent based on the effective concentration of the absorbent in the absorption module A.

[0051] Specifically, when the effective concentration of the absorbent is lower than the preset concentration, the regeneration module B is disconnected from the absorption module A, and the purification module C is connected with the absorption module A to purify the absorbent. When the effective concentration of the absorbent reaches the preset concentration, the purification module C is disconnected from the absorption module A, and the regeneration module B is connected with the absorption module A. The effective concentration of the absorbent is always maintained at the preset concentration, and the carbon dioxide capture efficiency is increased.

[0052] As shown in FIG. 1, the electrolytic absorption unit 2 includes a first anode chamber 21 and a first cathode chamber 22 arranged separately, 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 arranged separately by an anion exchange membrane 23.

[0053] The first anode chamber 21 is provided with a crude copper anode, and the first cathode chamber 22 is provided with a refined copper cathode. The crude copper contains a high content of impurities such as lead and antimony. During the electrolysis process, these impurity metals will be dissolved into ions together with copper. Since the activity of metals such as gold, platinum and silver is not as high as that of copper, they will directly precipitate below the anode to form anode mud, thereby separating the impurities from the copper and improving the purity of the copper. The crude copper also contains a large amount of copper oxide and other chemical substances. In the electrolyte solution, these copper oxides will be reduced to pure copper, increasing the amount of reduction reaction in the refining process and thus improving the refining effect of the copper. Through the above process, the crude copper on the anode is gradually dissolved, and the impurities are removed or precipitated, and finally a high-purity copper ion is obtained, which can form a high-purity refined copper through electrodeposition at the cathode, providing high-quality raw materials for the refined copper at the cathode. The system can not only absorb carbon dioxide but also refine copper to obtain high-purity refined copper, which conforms to the concept of green environmental protection.

[0054] It should be noted that in addition to the crude copper and refined copper as electrodes in the embodiment, crude nickel and refined nickel can also be used as electrodes, as long as the metal refining process can be realized in the process of carbon dioxide capture.

[0055] The electrolytic absorption unit 2 utilizes the electrochemical principle and adopts the electrochemical cycle with high energy utilization rate. By supplying power to the electrolytic absorption unit 2, the desorption of carbon dioxide and the regeneration of ammonia can be realized. Specifically, the desorption of carbon dioxide is as follows: since the electrode of the first anode chamber 21 contains copper elements capable of being coordinated with ammonia, the electrode of the first anode chamber 21 can generate corresponding metal copper ions. Through the coordination of metal copper ions and ammonia, the carbon dioxide in the absorption liquid can be desorbed, thereby reducing the energy consumption while ensuring the desorption of carbon dioxide. At the same time, in the electrolytic absorption process, the elements in the crude copper anode that are more active than metal copper dissolve into the absorption liquid, thereby realizing the separation of impurities in the crude copper anode and obtaining copper ions with high purity.

[0056] 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 as to transport the absorption liquid into 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. Specifically, the desorption of carbon dioxide in the first anode chamber 21 is as follows: Cu-2e - = Cu 2+ Cu 2+ + nNH3-CO2 = Cu(NH3) n 2+ + CO2↑

[0057] The elements in the crude copper anode that are more active than metal copper dissolve into the absorption liquid, thereby obtaining a gas-liquid mixture containing copper / ammonia coordination compounds and carbon dioxide. The liquid component in the gas-liquid mixture is low in carbon dioxide load and high in metal load, mainly because most of the carbon dioxide is in gaseous form.

[0058] The electrolytic absorption unit 2 utilizes the electrochemical principle and adopts the electrochemical cycle with high energy utilization rate. By supplying power to the electrolytic absorption unit 2, the desorption of carbon dioxide and the regeneration of ammonia can be realized. Specifically, the desorption of carbon dioxide is as follows: since the electrode of the first anode chamber 21 contains copper elements capable of being coordinated with ammonia, the electrode of the first anode chamber 21 can generate corresponding metal copper ions. Through the coordination of metal copper ions and ammonia, the carbon dioxide in the absorption liquid can be desorbed, thereby reducing the energy consumption while ensuring the desorption of carbon dioxide. At the same time, in the electrolytic absorption process, the elements in the crude copper anode that are more active than metal copper dissolve into the absorption liquid, thereby realizing the separation of impurities in the crude copper anode and obtaining copper ions with high purity.

[0059] The second outlet of the absorption module A is communicated with the purified gas pipeline 42 to discharge the purified gas. That is, the purified gas obtained after removing the carbon dioxide from the flue gas can be discharged through the purified gas pipeline 42.

[0060] The inlet of the gas-liquid separation unit 3 is communicated with the first anode chamber 21, the first outlet of the gas-liquid separation unit 3 is communicated with the first cathode chamber 2, and the second outlet of the gas-liquid separation unit 3 is communicated with the exhaust pipeline to discharge the separated carbon dioxide.

[0061] Specifically, the gas-liquid mixture generated 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 mixture is separated by the gas-liquid separation unit 3 to obtain carbon dioxide gas and a separation liquid. Since ammonia has been coordinated with copper ions, gaseous carbon dioxide can be more easily separated from the gas-liquid mixture solution. The separated carbon dioxide gas is discharged through the first outlet of the gas-liquid separation unit 3.

[0062] The second outlet of the gas-liquid separation unit 3 is communicated with the inlet of the first cathode chamber 22 through the separation liquid pipeline 44 to transport the separation liquid to the first cathode chamber 22 of the electrolytic absorption unit 2. The copper ions in the separation liquid are subjected to electrodeposition under the action of the refined copper cathode to obtain refined copper and an ammonia-containing solution. The process of electrodeposition is as follows: Cu(NH3) n 2+ + 2e - = Cu + nNH3

[0063] The ammonia-containing solution in the first cathode chamber 22 has low carbon dioxide load and low copper load. Through the electrodeposition of the separation liquid in the first cathode chamber 22, the regeneration of ammonia and the recovery of refined copper are realized, resources are saved, and the concept of green environmental protection is met.

[0064] The outlet of the first cathode chamber 22 is communicated with the second inlet of the absorption module A through the first absorbent pipeline 45 to transport the ammonia-containing solution generated in the first cathode chamber 22 to the absorption module A through the first absorbent pipeline 45 to provide the ammonia-containing solution to the absorption module A, continue to realize the absorption of carbon dioxide in the flue gas, realize the cyclic use of ammonia, and further realize the complete carbon dioxide capture cycle.

[0065] Specifically, in the whole system of the present application, carbon dioxide is absorbed in the absorption module by an ammonia-containing solution; the absorption solution is desorbed by using a rough copper metal plate combined with ammonia coordination as the electrode of the first anode chamber under the action of the rough copper anode, wherein the elements more active than copper in the rough copper anode are dissolved into the absorption solution in the first anode chamber, copper ions can be released into the carbon dioxide-loaded absorption solution in the first anode chamber by electrochemical dissolution, and carbon dioxide is desorbed by coordination with ammonia to obtain a gas-liquid mixture containing copper / ammonia coordination compounds and carbon dioxide; the gas-liquid mixture is separated by a gas-liquid separation unit to obtain carbon dioxide gas and a separation solution; the separation solution is subjected to 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 the ammonia-containing solution, thereby ensuring the supply of the absorbent in the subsequent carbon dioxide capture process.

[0066] When the effective concentration of the absorbent is lower than the preset concentration, the regeneration module is disconnected from the absorption module, and the purification module is connected in communication with the absorption module to purify the absorbent; when the effective concentration of the absorbent reaches the preset concentration, the purification module is disconnected from the absorption module, and the regeneration module is connected in communication with the absorption module, so that the effective concentration of the absorbent always reaches the preset concentration, thereby increasing the carbon dioxide capture efficiency.

[0067] The carbon dioxide capture and absorbent purification system coupled with metal refining of the present application uses an electric cycle carbon capture method to couple the carbon dioxide capture, copper refining process and absorbent purification process, thereby having higher energy efficiency, lower energy consumption and lower operating cost; the carbon dioxide-rich solution enters the first anode chamber and the first cathode chamber in sequence, thereby improving the regeneration efficiency of the carbon dioxide-rich solution; the absorbent produced by the electrodeposition in the first cathode chamber enters the absorption module again to absorb carbon dioxide, thereby realizing the cyclic use of ammonia and the recovery of deposited metals, having low energy consumption and low operating cost, and improving the cycle efficiency of the whole system; the carbon dioxide capture rate and decarbonization rate are relatively high, and the purity of the discharged carbon dioxide product is relatively high; carbon dioxide is absorbed while copper is refined, thereby obtaining refined copper with high purity, which conforms to the concept of green environmental protection. In addition, the purification module is selectively connected in communication with the absorption module to purify the absorbent, so that the concentration of the absorbent meets the corresponding requirements, thereby improving the carbon dioxide capture efficiency.

[0068] Exemplarily, as shown in FIG. 1, the first absorption liquid pipeline 41 is provided with a first control valve 41a, and the first absorbent pipeline 45 is provided with a second control valve 45a. 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.

[0069] Exemplarily, as shown in FIG. 1, 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. The second cathode chamber 53 is provided with a metal electrode plate, and the metal ions in the absorbent can be deposited on the metal electrode plate in the second cathode chamber 53.

[0070] The inlet of the second cathode chamber 53 is connected to the first outlet of the absorption module A through a second absorption liquid pipeline 54, so as to transport the absorbent to be purified to the second cathode chamber 53, so that the absorbent to be purified is deposited to precipitate the metal ions in the absorbent to be purified, thereby obtaining the purified absorbent.

[0071] The outlet of the second cathode chamber 53 is connected to the second inlet of the absorption module A through a second absorbent pipeline 55, so as to transport the purified absorbent to the absorption module A, to provide the purified absorbent for the absorption module A, to continue to absorb the carbon dioxide in the flue gas, to recycle the ammonia, to realize the complete carbon dioxide capture cycle, and to increase the carbon dioxide capture efficiency.

[0072] 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, so as to provide an electrolyte solution in the electrolytic purification tank. The electrolyte solution can be Na2SO4, NaCl, NaNO3, K2SO4, etc., which can be selected according to actual needs.

[0073] In this embodiment, by providing the purification module selectively connected to the absorption module, and by increasing the voltage, the active impurity elements in the absorbent in the absorption module can be deposited in the second cathode chamber, thereby playing a role in purifying the absorbent, and increasing the carbon dioxide capture efficiency.

[0074] Exemplarily, as shown in FIG. 1, the second absorption liquid pipeline 54 is provided with a third control valve 54a, and the second absorbent pipeline 55 is provided with a fourth control valve 55a. 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.

[0075] 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 electrolytic desorption 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.

[0076] As shown in FIG. 1, the carbon dioxide capture and absorbent purification system coupled with metal refining of the present application further comprises a rinsing module 5. The first inlet of the rinsing module 5 is connected with the second outlet of the absorption module A through the purified gas pipeline 42. The second inlet of the rinsing module 5 is connected with a rinsing water source. The first outlet of the rinsing module 5 is connected with a gas discharge pipeline 46.

[0077] Specifically, the purified gas generated in the absorption module A still contains ammonia. The purified gas containing ammonia is transported to the rinsing module 5 through the purified gas pipeline 42, and the rinsing water source enters the rinsing module 5 through the second inlet to rinse the purified gas containing ammonia, so as to separate and recover the residual ammonia. The separated ammonia exists in the form of ammonia-containing rinsing liquid, and the ammonia-containing solution and the gas to be discharged are obtained. The gas to be discharged is discharged through the gas discharge pipeline 46.

[0078] As shown in FIG. 1, the carbon dioxide capture and absorbent purification system coupled with metal refining of the present application further comprises a desulfurization module 6. The first inlet of the desulfurization module 6 is connected with the flue gas containing carbon dioxide. The flue gas containing carbon dioxide first enters the desulfurization module 6 for flue gas desulfurization pretreatment, and a desulfurization liquid is obtained.

[0079] The first outlet of the desulfurization module 6 is connected with the first inlet of the absorption unit 1. The flue gas after desulfurization treatment enters the absorption unit 1 for carbon dioxide absorption and capture.

[0080] The second inlet of the desulfurization module 6 is connected with the second outlet of the rinsing unit 5. The separated ammonia in the rinsing unit 5 is transported to the desulfurization module 6 in the form of ammonia-containing rinsing liquid.

[0081] The backflow outlet of the desulfurization module 6 is connected with the backflow inlet of the rinsing unit 5. The height of the backflow inlet is lower than the height of the second inlet of the rinsing unit 5.

[0082] Specifically, the separated ammonia combines with sulfur dioxide in the flue gas to exist in the form of desulfurization liquid. The desulfurization liquid that does not reach the saturated state flows back from the desulfurization module 6 to the rinsing unit 5 to rinse the purified gas, and is transported from the rinsing unit 5 to the desulfurization device 6 in the form of ammonia-containing rinsing liquid, forming a circulating loop.

[0083] It should be noted that the purified gas can be washed by circulating desulfurization liquid, or can be washed by externally supplemented water, of course, the purified gas can also be washed by the desulfurization liquid and the externally supplemented water together, which can be selected according to actual needs.

[0084] Exemplarily, as shown in FIG. 1, the coupled metal refining carbon dioxide capture and absorbent purification system further comprises a recovery module 7, an inlet of the recovery module 7 being in communication with a reflux outlet of the desulfurization module 6, so that when the desulfurization liquid in the desulfurization module reaches saturation, the liquid substance in the desulfurization module 6 is transported into the recovery module 7 for treatment.

[0085] Specifically, when the desulfurization liquid reaches saturation, the liquid substance in the desulfurization module 6 can be transported into the recovery module 7 for treatment, to obtain a sulfur dioxide utilization product, for example, the sulfur dioxide utilization product can be an ammonium sulfate fertilizer product. The recovery module 7 realizes recycling of the desulfurization liquid, thereby saving resources.

[0086] Exemplarily, as shown in FIG. 1, the coupled metal refining carbon dioxide capture and absorbent purification system further comprises a first heat exchange module 8, the first heat exchange module 8 being in communication with the washing unit 5 and the desulfurization module 6 respectively, for heat exchange between the washing unit 5 and the desulfurization module 6.

[0087] Specifically, the ammonia-containing washing liquid and the desulfurization liquid can be heat exchanged through the first heat exchange module 8, the ammonia-containing washing liquid and the desulfurization liquid being heat exchanged through the first heat exchange module 8, for transferring heat of the desulfurization liquid to the ammonia-containing washing liquid. In addition, after heat exchange, the ammonia-containing washing liquid can be further heated by a heating assembly during transportation to the desulfurization device 6, to promote desulfurization treatment in the desulfurization device 6; after heat exchange, the desulfurization liquid can be further cooled by a cooling assembly during transportation to the washing device 5.

[0088] In this embodiment, the first heat exchange module improves the heat utilization rate of the entire system, thereby saving energy consumption.

[0089] Exemplarily, as shown in FIG. 1, the coupled metal refining carbon dioxide capture and absorbent purification system further comprises a second heat exchange module 9, the second heat exchange module 9 being in communication with the absorption unit 1 and the electrolysis unit 2 respectively, for heat exchange between the absorption unit 1 and the electrolysis unit 2.

[0090] Specifically, the second heat exchange module 9 comprises 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 in communication with the second outlet of the absorption unit 1, the hot end outlet of the second heat exchange module 9 is in communication with the inlet of the first anode chamber 21, the hot end inlet of the second heat exchange module 9 is in communication with the outlet of the first cathode chamber 22, and the cold end outlet of the second heat exchange module 9 is in communication with the second inlet of the absorption unit 1.

[0091] In the present embodiment, the ammonia-containing solution and the absorption solution exchange heat only through the second heat exchange module 9, and the heat of the ammonia-containing solution is transferred to the absorption solution. The ammonia-containing solution and the absorption solution are isolated from each other in the second heat exchange module 9. The conveying passage between the cold end outlet of the second heat exchange module 9 and the ammonia-containing solution inlet (second inlet) of the absorption unit 1 is used to convey the ammonia-containing solution to the absorption unit 1, and a cooling assembly can be installed on the conveying passage; the conveying passage between the hot end outlet of the second heat exchange module 9 and the inlet of the first anode chamber 21 is used to convey the absorption solution to the first anode chamber 21, and a heating assembly can be installed on the conveying passage.

[0092] For example, as shown in FIG. 1, the gas-liquid separation unit 3 comprises a flash tank 31 and a condenser 32.

[0093] The gas-liquid mixture inlet of the flash tank 31 is in communication with the outlet of the first anode chamber 21, the condensate gas inlet of the condenser 32 is in communication with the condensate gas outlet of the flash tank 31, the condensate liquid inlet of the flash tank 31 is in communication with the condensate liquid outlet of the condenser 32, and the inlet of the first cathode chamber 22 is in communication with the separation liquid outlet of the flash tank 31. The top of the condenser 32 further comprises a carbon dioxide outlet for discharging the separated carbon dioxide.

[0094] The separation liquid is a mixture of the initial separation liquid and the condensate liquid. The initial separation liquid is the liquid substance obtained by flashing in the flash tank 31, and the condensate liquid is the liquid substance obtained by condensing in the condenser 32.

[0095] For example, as shown in FIG. 2, the absorption module A comprises an absorption part 11, a condensation part 12 and a separation plate 13 separating the absorption part 11 and the condensation part 12.

[0096] 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 separation plate 13 allows gas to pass through and blocks liquid substances from passing through. The material of the separation plate 13 can be a PTFE film, preferably, the material of the separation plate 13 can be a PTFE film of (registered trademark).

[0097] 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.

[0098] The absorption liquid outlet of the condensing part 12 is connected with the first absorption liquid pipeline 41, and the gas outlet of the condensing part 12 is connected with the purified gas pipeline 42.

[0099] Specifically, the absorption part 11 and the condensing part 12 are connected by a conveying pipeline, one end of the conveying pipeline is connected with the bottom of the absorption part 11, the other end of the conveying pipeline is connected with the upper part of the condensing part 12, and a cooling assembly is installed on the conveying pipeline. Specifically, the connection between the absorption part 11 and the pipeline can be located at the bottom of the absorption part 11, the connection between the condensing part 12 and the pipeline can be located at the upper part of the condensing part 12, and the height position is lower than that of the purified gas outlet.

[0100] Specifically, the flue gas containing carbon dioxide enters the absorption part 11 through the flue gas inlet, the absorbent enters the absorption part 11 through the absorbent inlet, and the carbon dioxide is absorbed in the absorption part 11. After the absorbent absorbs the carbon dioxide, it is conveyed to the condensing 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 the carbon dioxide is discharged to the first anode chamber 21. It should be noted that since the pipeline is provided with a cooling assembly, ammonia can exist in the solution, thereby avoiding the volatilization of ammonia and ensuring the recycling of ammonia.

[0101] In this embodiment, the gas-liquid separation unit 3 includes a flash tank 31 and a condenser 32, which can separate the gas-liquid mixture, reduce the loss of ammonia, and reduce the energy consumption of the entire system.

[0102] As shown in FIG. 3, another aspect of the present application provides a method for coupling carbon dioxide capture and absorbent purification with metal refining, which uses the carbon dioxide capture and absorbent purification system with metal refining as described above. The specific structure of the carbon dioxide capture and absorbent purification system with metal refining has been described in detail above, and will not be described again here. The method includes the following steps:

[0103] In step S1, the flue gas containing carbon dioxide is conveyed to the absorption module, and the carbon dioxide in the flue gas is absorbed by the absorbent in the absorption module to obtain absorption liquid and purified gas.

[0104] Specifically, the ammonia-containing solution in the absorption module can contain a supporting electrolyte, which can be potassium chloride, sodium chloride, sodium sulfate, etc. In addition, some additives, such as tetraethylammonium chloride, tetrapropylammonium chloride, etc. can be added to the ammonia-containing solution in the absorption module.

[0105] The absorption liquid is a high-carbon dioxide-loaded liquid obtained after the ammonia-containing solution absorbs carbon dioxide, and the purified gas is the gas obtained after the flue gas is removed of carbon dioxide.

[0106] Step S2, delivering 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 the elements more active than copper in the crude copper anode dissolve into the absorption liquid to obtain a gas-liquid mixture containing copper / ammonia coordination compounds and carbon dioxide.

[0107] The liquid component in the gas-liquid mixture is low in carbon dioxide load and high in metal load, mainly because carbon dioxide is mostly in gaseous form. The desorption of carbon dioxide is specifically as follows: since the electrode of the first anode chamber 21 contains copper elements capable of coordination with ammonia, the electrode of the first anode chamber 21 can generate corresponding metal copper ions, and the coordination of the metal copper ions with ammonia can desorb carbon dioxide in the absorption liquid, thereby reducing energy consumption while ensuring carbon dioxide desorption. At the same time, in the electrolytic desorption process, the elements more active than copper in the crude copper anode dissolve into the absorption liquid, realizing the separation of impurities in the crude copper anode, and obtaining copper ions with high purity.

[0108] Step S3, performing gas-liquid separation treatment on the gas-liquid mixture by the gas-liquid separation unit to obtain carbon dioxide gas and a separated liquid.

[0109] Specifically, in the embodiment, the gas-liquid separation treatment specifically includes: sequentially performing flash evaporation and condensation on the gas-liquid mixture; wherein the initial separated liquid and the gas to be condensed are obtained after flash evaporation, and the carbon dioxide gas and the condensed liquid are obtained after condensation.

[0110] Step S4, delivering the separated liquid to the first cathode chamber of the electrolytic desorption unit, so that the copper ions in the separated liquid are subjected to electrodeposition under the action of the refined copper cathode to obtain refined copper and an absorbent.

[0111] Specifically, the copper ions in the separated liquid are subjected to electrodeposition 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 is low in carbon dioxide load and low in metal copper load. Through the electrodeposition of the separated liquid in the first cathode chamber 22, the regeneration of ammonia and the recovery of refined copper are realized, resources are saved, and the concept of green environmental protection is met.

[0112] Step S5, the absorbent in the first cathode chamber is transported into the absorption module to continue the absorption of carbon dioxide in the flue gas and to regenerate the absorbent; wherein, when the effective concentration of the absorbent is lower than the 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 the preset concentration, the purification module is disconnected from the absorption module and the regeneration module is connected to the absorption module.

[0113] Specifically, the ammonia-containing solution generated in the first cathode chamber 22 is transported into the absorption module A through the first ammonia-containing solution pipeline 45 to provide the ammonia-containing solution into the absorption module A, to continue the absorption of carbon dioxide in the flue gas, to realize the recycling of ammonia, and to realize the complete carbon dioxide capture cycle.

[0114] 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 electrolytic absorption 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.

[0115] The coupled metal refining carbon dioxide capture and absorbent purification method of the present application adopts the electric cycle carbon capture mode to couple the carbon dioxide capture, the metal copper refining process and the absorbent purification process, has higher energy efficiency, lower energy consumption and lower operation cost; the carbon dioxide rich solution enters the first anode chamber and the first cathode chamber in sequence, improving the regeneration efficiency of the carbon dioxide rich solution; the absorbent generated by the electrodeposition of the first cathode chamber reenters the absorption module for carbon dioxide absorption, realizing the recycling of ammonia and the recovery of the deposited metal, having low energy consumption demand and low operation cost, and improving the cycle efficiency of the whole system; the carbon dioxide capture rate / decarbonization rate is relatively high, and the purity of the discharged carbon dioxide product is relatively high; while absorbing carbon dioxide, the metal copper can also be refined to obtain refined copper with high purity, 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 absorbent purification, so that the concentration of the absorbent meets the corresponding requirements and the carbon dioxide capture efficiency is improved.

[0116] It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principles of the present application, but the present application is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present application, and these modifications and improvements are also considered within the protection scope of the present application.

Claims

1. A coupled metal refining carbon dioxide capture and sorbent purification system, characterized in that, The system comprises an absorption module provided with an absorbent, a regeneration module provided with an electrolytic 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 to absorb carbon dioxide in the flue gas by the absorbent; The regeneration module and the purification module are selectively communicated with the absorption module to selectively regenerate and purify the absorbent based on the effective concentration of the absorbent in the absorption module; wherein, The electrolytic desorption unit comprises a first anode chamber and a first cathode chamber arranged in separation, wherein a crude copper anode is arranged in the first anode chamber, and a refined copper cathode is arranged in the first cathode chamber; A first outlet of the absorption module is communicated with an inlet of the first anode chamber through a first absorption liquid pipeline, 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 to discharge separated carbon dioxide; An outlet of the first cathode chamber is communicated with a second inlet of the absorption module through a first absorbent pipeline to provide absorbent into the absorption module.

2. The system of claim 1, wherein, A first control valve is arranged on the first absorption liquid pipeline, and a second control valve is arranged on the first absorbent pipeline.

3. The system of claim 1, wherein, The purification module comprises 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 arranged in separation; An inlet of the second cathode chamber is communicated with the first outlet of the absorption module through a second absorption liquid pipeline to transport the absorbent to be purified to the second cathode chamber, so that the absorbent to be purified is subjected to electrodeposition to precipitate metal ions in the absorbent to be purified to obtain purified absorbent; An outlet of the second cathode chamber is communicated with the second inlet of the absorption module through a second absorbent pipeline to transport the purified absorbent to the absorption module; An outlet of the liquid storage tank is communicated with an inlet of the second anode chamber, and an outlet of the second anode chamber is communicated with an inlet of the liquid storage tank to provide electrolyte solution into the electrolytic purification tank.

4. The system of claim 3, wherein, A third control valve is arranged on the second absorption liquid pipeline, and a fourth control valve is arranged on the second absorbent pipeline.

5. The system of any one of claims 1 to 4, wherein, Further comprising a leaching module; A first inlet of the leaching module is communicated with the second outlet of the absorption module through the purified gas pipeline; A second inlet of the leaching module is used to communicate with a leaching water source; A first outlet of the leaching module is communicated with a gas discharge pipeline.

6. The system of claim 5, wherein, Further comprising a desulfurization module; A first inlet of the desulfurization module is used to communicate with flue gas containing carbon dioxide, and a first outlet of the desulfurization module is communicated with a first inlet of the absorption module; A second inlet of the desulfurization module is communicated with a second outlet of the leaching module; A reflux outlet of the desulfurization module is communicated with a reflux inlet of the leaching module.

7. The system of claim 6, wherein, Further comprising a recovery module; The inlet of the recovery module is communicated with the backflow outlet of the desulfurization module, so that when the desulfurization liquid in the desulfurization module reaches saturation, the liquid substance in the desulfurization module is transported into the recovery module for treatment.

8. The system of claim 6, wherein, The first heat exchange module and the second heat exchange module are further included; The first heat exchange module is respectively communicated with 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 communicated with the absorption module and the electrolytic desorption unit, and is used for heat exchange between the absorption module and the electrolytic desorption unit.

9. The system of any one of claims 1 to 4, wherein, The gas-liquid separation unit includes a flash tank and a condenser; The gas-liquid mixture inlet of the flash tank is communicated with the outlet of the first anode chamber, the condensate gas inlet of the condenser is communicated with the condensate gas outlet of the flash tank, the condensate liquid inlet of the flash tank is communicated with the condensate liquid outlet of the condenser, and the inlet of the first cathode chamber is communicated with the separation liquid outlet of the flash tank; The top of the condenser is communicated with the exhaust pipeline, and is used for exhausting the separated carbon dioxide.

10. A process for coupled metal refining, carbon dioxide capture and sorbent purification, characterized by, The carbon dioxide capture and absorbent purification system coupled with metal refining according to any one of claims 1 to 9, the method comprising: Step S1, delivering flue gas containing carbon dioxide to the absorption module, absorbing carbon dioxide in the flue gas by the absorbent in the absorption module, and obtaining absorption liquid and purified gas; Step S2, delivering 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 the elements more active than copper in the crude copper anode dissolve into the absorption liquid, and a gas-liquid mixture containing copper / ammonia coordination compounds and carbon dioxide is obtained; Step S3, performing gas-liquid separation treatment on the gas-liquid mixture by the gas-liquid separation unit, and obtaining carbon dioxide gas and separation liquid; Step S4, delivering the separation liquid to the first cathode chamber of the electrolytic desorption unit, so that copper ions in the separation liquid are deposited under the action of the refined copper cathode, and refined copper and absorbent are obtained; Step S5, delivering the absorbent in the first cathode chamber to the absorption module to continue absorbing carbon dioxide in the flue gas and regenerate the absorbent; wherein when the effective concentration of the absorbent is lower than the preset concentration, the regeneration module is disconnected from the absorption module, and the purification module is communicated with the absorption module to purify the absorbent; when the effective concentration of the absorbent reaches the preset concentration, the purification module is disconnected from the absorption module, and the regeneration module is communicated with the absorption module.

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