Amino acid-based carbon capture agent, absorbent, device, capture system, and applications

Abstract

The application provides an amino acid-based carbon capture agent, an absorption liquid, a device, a capture system and an application, the carbon capture agent being used for absorption and / or capture of carbon dioxide; the carbon capture agent comprising amino acids and a basic additive; or, the carbon capture agent comprising a product obtained by mixing the amino acids and the basic additive; in this way, the carbon capture agent comprises deprotonated carboxyl and deprotonated amino, the deprotonated amino comprising one or more of -NH2, -NH and -N. The application can improve the cycle stability of carbon dioxide capture and reduce the energy consumption of carbon dioxide capture.

Description

Technical Field

[0001] This invention relates to the treatment of carbon dioxide, and more particularly to an amino acid-based carbon capture agent, absorbent, apparatus, capture system, and application. Background Technology

[0002] In recent years, global warming caused by greenhouse gases, especially carbon dioxide, has become a matter of great concern worldwide. However, the environmental problems caused by carbon dioxide remain very prominent. Therefore, how to effectively capture carbon dioxide from flue gas is an urgent problem to be solved.

[0003] Chinese invention patent CN113578025B (previous research by the inventor of this application) discloses a method and system for capturing carbon dioxide in flue gas. The method includes the following steps: conveying carbon dioxide-containing flue gas to an absorption device for carbon dioxide absorption, obtaining an absorbent liquid and purified gas; conveying the absorbent liquid to the anode chamber of an electrolytic desorption device for desorption, obtaining a gas-liquid mixture containing a metal / ammonia coordination compound and carbon dioxide; performing gas-liquid separation treatment on the gas-liquid mixture to obtain carbon dioxide gas and a separated liquid; conveying the separated liquid to the cathode chamber of the electrolytic desorption device, causing electrodeposition of the separated liquid in the cathode chamber, obtaining deposited metal and an ammonia-containing solution; and conveying the ammonia-containing solution to the absorption device for further carbon dioxide absorption. While this patent can achieve the absorption and desorption of carbon dioxide in flue gas, its cycle stability is poor, and the energy consumption of electrolysis increases significantly after repeated operation.

[0004] In view of this, it is necessary to provide an amino acid-based carbon capture agent, absorbent, device, capture system and application to solve or at least alleviate the above-mentioned technical defects of poor cycle stability and significantly increased energy consumption. Summary of the Invention

[0005] The main objective of this invention is to provide an amino acid-based carbon capture agent, absorbent, device, capture system, and application, aiming to solve the aforementioned technical problems of poor cycle stability and significantly increased energy consumption.

[0006] To achieve the above objectives, the present invention provides a carbon trapping agent for the absorption and / or capture of carbon dioxide; the carbon trapping agent comprises a deprotonated carboxyl group and a deprotonated amino group, wherein the deprotonated amino group comprises one or more of -NH2, -NH, and -N.

[0007] The present invention also provides an amino acid-based carbon capture agent for the absorption and / or capture of carbon dioxide;

[0008] The carbon capture agent includes amino acids and alkaline additives; or, the carbon capture agent includes a product obtained by mixing the amino acids and the alkaline additives.

[0009] Furthermore, the vapor pressure of the amino acid at room temperature is not higher than 1.31 kPa.

[0010] Further, the amino acid includes one or more of alanine, sarcosine, glycine, lysine, proline, glutamic acid, arginine, tryptophan, serine, threonine, lysine, histidine, valine, leucine, tyrosine, phenylalanine, and glutamine.

[0011] And / or, the alkaline additive includes one or more of alkaline hydroxides and alkaline carbonates.

[0012] Furthermore, the molar ratio of the amino acid to the alkaline additive is 0.2-8:1;

[0013] And / or, the concentration of the amino acid is 0.2-8 mol / L.

[0014] Furthermore, the carbon trapping agent also includes piperazine; the molar ratio of the amino acid to the piperazine is 0.2-8:1.

[0015] Furthermore, the carbon trapping agent also includes a supporting electrolyte.

[0016] The present invention also provides a method for preparing a carbon capture agent, the carbon capture agent being used for the absorption and / or capture of carbon dioxide; the preparation method comprising: mixing the amino acid and the alkaline additive to obtain the carbon capture agent.

[0017] The present invention also provides the application of the carbon capture agent as described above, or the carbon capture agent prepared by any of the preparation methods described above, in carbon dioxide absorption and / or carbon dioxide capture.

[0018] Furthermore, the carbon dioxide absorption step includes: contacting the carbon scavenger with the carbon dioxide-containing gas to be treated and absorbing it to obtain a carbon dioxide absorption liquid;

[0019] The carbon dioxide capture steps include:

[0020] The carbon capture agent is contacted with and absorbed by the gas to be treated containing carbon dioxide to obtain a carbon dioxide absorbent liquid.

[0021] The carbon dioxide absorbent is electrolyzed to desorb the carbon dioxide in the absorbent, resulting in a desorbed solution and desorbed carbon dioxide.

[0022] Furthermore, the carbon dioxide capture step further includes: electrolyzing the desorption solution to cause the metal ions bound to the carbon capture agent to undergo electrodeposition, thereby obtaining the carbon capture agent separated from the metal ions;

[0023] The desorption solution contains the carbon trapping agent, which is bound to metal ions originating from the electrode.

[0024] The present invention also provides a carbon dioxide absorption device, wherein the carbon dioxide absorption device comprises a carbon trapping agent as described above or prepared by any of the preparation methods described above.

[0025] The present invention also provides a carbon dioxide capture system, which includes a carbon dioxide absorption device and a carbon dioxide desorption device;

[0026] The carbon dioxide absorption device contains a carbon trapping agent as described above or a carbon trapping agent prepared by any of the preparation methods described above;

[0027] The carbon dioxide absorption device and the carbon dioxide desorption device are connected to each other so as to continuously or intermittently transport the carbon dioxide absorbent generated in the carbon dioxide absorption device to the carbon dioxide desorption device, and the carbon dioxide desorption device has an electrolysis mechanism.

[0028] The present invention also provides a carbon dioxide absorbent liquid, which is used for the desorption and / or capture of carbon dioxide;

[0029] The carbon dioxide absorbent contains any of the carbon traps described above or the carbon traps prepared by any of the preparation methods described above, wherein the carbon traps are bound to carbon dioxide.

[0030] The present invention also provides an application of the carbon dioxide absorbent as described above in carbon dioxide desorption and / or carbon dioxide capture.

[0031] Furthermore, the carbon dioxide desorption step includes: electrolyzing the carbon dioxide absorbent to desorb carbon dioxide from the carbon dioxide absorbent;

[0032] The carbon dioxide capture process includes:

[0033] Obtain the carbon dioxide absorbent as described;

[0034] The carbon dioxide absorbent is electrolyzed to desorb the carbon dioxide from the absorbent.

[0035] The present invention also provides a carbon dioxide desorption device, wherein the anode chamber of the carbon dioxide desorption device contains a carbon dioxide absorbent as described above.

[0036] The present invention also provides a carbon dioxide capture system, which includes a carbon dioxide absorption device and a carbon dioxide desorption device;

[0037] The anode chamber of the carbon dioxide desorption device contains any of the carbon dioxide absorption liquids described above.

[0038] The anode chamber of the carbon dioxide desorption device is connected to the carbon dioxide absorption device to continuously or intermittently receive the carbon dioxide absorbent from the carbon dioxide absorption device.

[0039] Compared with the prior art, the present invention has at least the following advantages:

[0040] This patent proposes an amino acid-based carbon capture agent. By using this agent to absorb carbon dioxide and then electrolyzing it during carbon dioxide desorption, the cycle stability of carbon dioxide capture can be improved, and the energy consumption of electrolysis can be reduced. In this invention, amino acids can also be flexibly compounded with other amino acids and alkaline additives to enhance the applicability of amino acids in carbon dioxide capture. This results in a carbon dioxide capture process with characteristics such as low loss, stable operation, excellent cycle performance, low energy consumption, low maintenance costs, green and non-toxic properties, and environmental friendliness. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0043] It should be noted that existing technologies typically use inorganic ammonia (NH3) as the CO2 capture solvent and transition metals (zinc, nickel, copper, etc.) as the dielectric for efficient and low-consumption CO2 capture.

[0044] The existing technology mainly includes the following four steps (see Figure 1 in Chinese Invention with Authorization Announcement No. CN113578025B for details):

[0045] 1. Desulfurization and deammoniation pretreatment

[0046] The ammonia released from the absorber after the scrubbing water is recovered is used for flue gas desulfurization, achieving the dual functions of desulfurization and ammonia removal. Previous studies have shown that this process has a high ammonia recovery rate (>99%), a low ammonia emission concentration (<25 ppmv), and a high SO2 removal rate (>99%).

[0047] 2. CO2 ammonia absorption (absorption tower)

[0048] The pretreated flue gas enters the CO2 absorption tower and is coupled with the metal ions (Me) after ammonia regeneration by electrodeposition. 2+ )-Lean load / CO2-lean load ammonia solution contact decarbonization (reaction formula as follows), after collection Me 2+ -The lean / CO2-rich solution is sent to the anode chamber of the electrolytic cell.

[0049]

[0050] 3. Electrolytically coupled CO2 desorption (anode)

[0051] Metal ions have a significantly stronger coordination ability with ammonia than with CO2. In the anolyte chamber, electrochemically dissolved metal ions compete with CO2 for coordination with the amino group, thereby breaking the NH3-CO2 bond and releasing CO2 (reaction formula below). The desorbed Me... 2+ -The enriched / CO2-lean solution is sent to the cathode chamber of the electrolytic cell.

[0052]

[0053] Me (s) Transition metals such as zinc, copper, and nickel

[0054] 4. Ammonia regeneration coupled by electrodeposition (cathode)

[0055] In the cathode chamber, Me(NH3) n 2+ Electrodeposition is Me (s) (The reaction formula is as follows), which promotes ammonia regeneration. At this time, the solution becomes Me. 2 + -Low-load / CO2-Low-load solution.

[0056]

[0057] After ammonia regeneration, the catholyte returns to the CO2 absorber for the next carbon capture cycle. An anion exchange membrane exists between the catholyte and anolyte; a heat exchanger exists between the absorber and the electrolytic cell; and a flash tank exists in the path from the anolyte to the catholyte for gas-liquid separation. After a certain number of cycles, the anode and cathode exchange fluids, or the flow directions of the anolyte and catholyte alternate periodically, to prevent complete dissolution of the anode metal.

[0058] However, the existing technologies mentioned above use inorganic ammonia as the carbon capture agent, which results in high volatility, large losses, unstable operation, poor circulation performance, high operation and maintenance costs, and increased energy consumption in the electrolysis process. Furthermore, inorganic ammonia is toxic and pollutes the environment, while the volatilization recovery system for inorganic ammonia is relatively complex, has a long process, and high investment costs.

[0059] Based on this, the present invention provides an amino acid-based carbon capture agent, which is used for the absorption and / or capture of carbon dioxide; that is, the carbon capture agent can absorb carbon dioxide and release carbon dioxide under electrolytic conditions.

[0060] In this invention, the raw materials of the carbon scavenger include amino acids and alkaline additives. Therefore, it can be understood that the carbon scavenger includes amino acids and alkaline additives. Of course, since the carbon scavenger is liquid, it may also include a solvent, and the amino acids are soluble in the solvent. The solvent may include or be one or more of water, cyclohexane, hexane, and carbon tetrachloride.

[0061] Since the amino acid and the basic additive react to deprotonate and activate the amino group, the carbon scavenger can also be understood as a product obtained by mixing the amino acid and the basic additive; the mixing can be carried out in the solvent. That is, the carbon scavenger can also be understood as a product obtained by mixing the amino acid and the basic additive in the solvent.

[0062] As a preferred embodiment of the present invention, the vapor pressure of the amino acid at room temperature (25°C) may not exceed 1.31 kPa, that is, it may be 0-1.31 kPa; more specifically, it may be 0.00001 Pa-0.4 kPa (at 25°C).

[0063] For example, the amino acid may include or be one or more of alanine, sarcosine, glycine, lysine, proline, glutamic acid, arginine, tryptophan, serine, threonine, lysine, histidine, valine, leucine, tyrosine, phenylalanine, and glutamine. The alkaline additive may include or be one or more of alkaline hydroxides, alkaline carbonates, organic amines, and inorganic ammonia; further, the alkaline additive may include or be one or more of alkaline hydroxides and alkaline carbonates. The alkaline hydroxide may include one or more of sodium hydroxide and potassium hydroxide; the alkaline carbonate may specifically include or be an alkaline bicarbonate, and the alkaline carbonate may include or be one or more of sodium bicarbonate and potassium bicarbonate; the organic amine refers to a class of nitrogen-containing compounds with an amino group (-NH2, -NH, -N) generated by the chemical reaction of organic substances with ammonia. The organic amine in this invention typically has a pH greater than 7 and does not contain the amino acid. For example, the organic amine may include or be one or more of ethylenediamine and ethanolamine; the inorganic ammonia has the chemical formula NH3, and the inorganic ammonia may exist in the carbon capture agent in the form of ammonia water.

[0064] It should be noted that the inorganic ammonia can also be used as the alkaline additive in this invention; and when the alkaline additive includes inorganic ammonia, the volatility of inorganic ammonia and the energy consumption of electrolytic adsorption can be significantly reduced. Therefore, the amino acid-based carbon scavenger provided by this invention can also be used to reduce the volatility and operating energy consumption of inorganic ammonia in the carbon dioxide capture process. That is, compounding the carbon scavenger provided by this invention with an inorganic ammonia-based carbon scavenger is also one of the industrial applications of this invention.

[0065] To fully achieve the deprotonation and activation of the amino group of the amino acid, the molar ratio of the amino acid to the basic additive can be 0.2-8:1; further, it can be 0.5-5:1.

[0066] Since the carbon scavenger is typically in liquid form, the amino acid can be present in the solvent; the concentration of the amino acid can be 0.2-8 mol / L; further, it can be 0.5-5 mol / L. The concentration of the amino acid can be understood as the concentration of the amino acid in the carbon scavenger (the concentration of the amino acid after dissolving in the solvent), or as the initial concentration of the amino acid in the carbon scavenger (the concentration before reaction); for example, an amino acid solution with the above concentration can be obtained first, and then other substances (such as alkaline additives) can be added to the amino acid solution for mixing to obtain the carbon scavenger.

[0067] To improve CO2 capture capacity and reduce carbon capture energy consumption, the carbon capture agent may further include piperazine; the molar ratio of the amino acid to the piperazine may be 0.2-8:1; further, it may be 0.5-5:1.

[0068] Since the carbon dioxide capture in this invention involves carbon dioxide absorption and electrolytic desorption, in order to ensure the electrolytic desorption process, the carbon capture agent may also include a supporting electrolyte, such as potassium chloride.

[0069] Research has shown that the present invention, in applying carbon capture agents to carbon dioxide capture, possesses at least the following technical mechanisms:

[0070] First, amino acids need to be added to a basic substance (such as MEA, KOH, or NaOH) to deprotonate and activate the amino group. The chemical reaction is as follows:

[0071]

[0072] Then, when CO2 is absorbed in the carbon dioxide absorption device, the following reaction occurs:

[0073]

[0074] Subsequently, during the electrolytically coupled desorption of CO2 in the anode chamber of the carbon dioxide desorption unit, the following reaction occurs:

[0075] Me (s) →Me 2+ +2e -

[0076] Me 2+ +n - OOCRNH2-CO2→( - OOCRNH2) n -Me 2+ +nCO2↑

[0077] Me represents transition metals such as Zn, Cu, and Ni.

[0078] During the regeneration of amino acids via electrodeposition coupling in the cathode chamber of the carbon dioxide desorption apparatus, the following reaction occurs:

[0079] ( - OOCRNH2) n -Me 2+ +2e - →Me (s) +-OOCRNH2

[0080] In summary, this invention proposes a new formulation for electrochemical carbon capture technology, which uses low-volatility and environmentally friendly amino acids as the core, and flexibly combines them with hydroxides (including potassium hydroxide, sodium hydroxide, etc.), carbonates (including sodium bicarbonate, potassium bicarbonate, etc.), other amino acids, inorganic ammonia, organic amines, etc. to construct a CO2 carbon capture agent formulation.

[0081] Based on the effect of the alkaline additive on the amino acid, the present invention also provides a carbon trapping agent for the absorption and / or capture of carbon dioxide; the carbon trapping agent includes a deprotonated carboxyl group and a deprotonated amino group, wherein the deprotonated amino group includes one or more of -NH2, -NH, and -N.

[0082] Furthermore, the carbon trap may also include alkyl groups; that is, the carbon trap may be composed of the deprotonated carboxyl group, the deprotonated amino group, and the alkyl group.

[0083] For example, the chemical formula (form of existence) of the carbon capture agent can be:

[0084] - OOCRNH2

[0085] R may include or be an alkyl group.

[0086] It should be noted that in this invention, deprotonation refers to the removal of hydrogen ions, which is a result of the pH increase introduced by alkaline additives.

[0087] To obtain the carbon capture agent, the present invention also provides a method for preparing any of the above-mentioned carbon capture agents, wherein the carbon capture agent is used for the absorption and / or capture of carbon dioxide; the preparation method includes: mixing the amino acid and the alkaline additive to obtain the carbon capture agent; the mixing can be carried out in the solvent.

[0088] Furthermore, the amino acid may exist in the form of an amino acid solution, thereby providing a solvent for the reaction of the amino acid and the basic additive. The solvent in the preparation method may include or be one or more of water, cyclohexane, hexane, and carbon tetrachloride. The solvent used in the embodiments and comparative examples of the present invention is water. The carbon capture agent may be liquid.

[0089] The present invention also provides the application of the carbon capture agent as described in any of the above claims in carbon dioxide absorption and / or carbon dioxide capture.

[0090] It should be noted that the carbon dioxide absorption refers to the use of a carbon capture agent to absorb carbon dioxide gas into a carbon dioxide absorption liquid, thereby separating the carbon dioxide gas from other gases or substances in the gas to be treated.

[0091] The carbon dioxide capture refers to the following steps: first, carbon dioxide gas is absorbed into a carbon dioxide absorbent using a carbon capture agent; then, carbon dioxide is released by carbon dioxide desorption (e.g., electrodesorption), thereby completing the capture and recovery of carbon dioxide and obtaining carbon dioxide products.

[0092] For example, the carbon dioxide absorption step may include:

[0093] The carbon capture agent is contacted with the gas to be treated containing carbon dioxide (e.g., flue gas containing carbon dioxide) and absorbed to obtain a carbon dioxide absorbent liquid after carbon dioxide absorption.

[0094] Specifically, the process of contacting the carbon capture agent with the carbon dioxide-containing gas to be treated can be carried out in a carbon dioxide absorption device, specifically in a carbon absorption tower.

[0095] The carbon dioxide capture steps may include:

[0096] The carbon scavenger is contacted with and absorbed by the carbon dioxide-containing gas to obtain a carbon dioxide absorbent; then, the carbon dioxide absorbent is electrolyzed to desorb the carbon dioxide in the absorbent, resulting in an desorbed liquid and desorbed carbon dioxide; wherein the desorbed liquid contains the carbon scavenger, and the carbon scavenger in the desorbed liquid is bound with metal ions originating from the electrode.

[0097] Specifically, the process of contacting the carbon capture agent with the carbon dioxide-containing gas to be treated can be carried out in a carbon dioxide absorption device to generate a carbon dioxide absorbent liquid after absorbing carbon dioxide; then, the carbon dioxide absorbent liquid is transported to a carbon dioxide desorption device to release the carbon dioxide bound to the carbon capture agent by electrolysis, thereby realizing the capture and recovery of carbon dioxide.

[0098] As a further explanation of the carbon dioxide capture, the carbon dioxide capture step may further include: electrolyzing the desorption solution to cause the metal ions bound to the carbon capture agent to undergo electrodeposition, thereby obtaining the carbon capture agent separated from the metal ions.

[0099] It is important to understand that carbon dioxide release typically occurs in the anode chamber of a carbon dioxide desorption device. That is, the electrodes in the anode chamber undergo electrodissolution, then combine with the carbon scavenging agent in the carbon dioxide absorbent, thereby separating the carbon dioxide from the carbon scavenging agent, completing the release of carbon dioxide, and obtaining the desorbed liquid. This can be accomplished using an external gas-liquid separation device, or the gas-liquid separation of carbon dioxide and the desorbed liquid can be completed directly in the anode chamber.

[0100] Electrolysis of the desorption solution is usually carried out in the cathode chamber of a carbon dioxide desorption device; that is, electrodeposition of the desorption solution occurs in the cathode chamber, thereby depositing metal ions in the desorption solution onto the electrodes of the cathode chamber, completing the separation of the carbon scavenger and the metal ions; the separated carbon scavenger can be reused for carbon dioxide absorption, thereby reforming the carbon dioxide absorbent.

[0101] The present invention also provides a carbon dioxide absorption device, wherein the carbon dioxide absorption device includes a carbon scavenger as described in any of the above claims. The carbon scavenger may be pre-placed in the absorption chamber of the carbon dioxide absorption device; alternatively, the carbon scavenger may be supplied to the carbon dioxide absorption device from the outside during the carbon dioxide absorption process.

[0102] The present invention also provides a carbon dioxide capture system, which includes a carbon dioxide absorption device and a carbon dioxide desorption device.

[0103] The carbon dioxide absorption device includes a carbon capture agent as described in any of the above descriptions; the carbon dioxide absorption device and the carbon dioxide desorption device are connected to each other so as to continuously or intermittently transport the carbon dioxide absorbent generated in the carbon dioxide absorption device to the carbon dioxide desorption device, and the carbon dioxide desorption device has an electrolysis mechanism.

[0104] It should be noted that, since the carbon dioxide desorption device is an electrodesorption device, the anode chamber and cathode chamber contained therein can be interchanged due to the influence of electrical properties. Therefore, the carbon dioxide absorption device can be connected to the anode chamber of the carbon dioxide desorption device, or it can be connected to the cathode chamber of the carbon dioxide desorption device at the same time, in order to adapt to the electrodesorption of carbon dioxide after the electrical properties are converted.

[0105] It should also be noted that, since the desorbed liquid needs to be electrolyzed in the cathode chamber after being generated in the anode chamber of the carbon dioxide desorption device, the anode chamber and cathode chamber of the carbon dioxide desorption device can be connected to each other to facilitate the transport of the desorbed liquid.

[0106] The present invention also provides a carbon dioxide absorbent for desorption and / or capture of carbon dioxide; the carbon dioxide absorbent contains a carbon capture agent as described in any of the above claims, the carbon capture agent in the carbon dioxide absorbent is bound to carbon dioxide, and is typically obtained by the carbon capture agent absorbing carbon dioxide.

[0107] The present invention also provides an application of the carbon dioxide absorbent as described in any one of the above claims in carbon dioxide desorption and / or carbon dioxide capture. It should be understood that, during the desorption process of the carbon dioxide absorbent, the volatilization rate of the carbon capture agent can be significantly reduced, and the electrolysis energy consumption during the desorption process can be reduced.

[0108] For example, the carbon dioxide desorption step may include:

[0109] Electrolysis is performed on the carbon dioxide absorbent as described in any of the above claims to desorb carbon dioxide from the absorbent, thereby obtaining carbon dioxide gas and a desorbent, wherein the carbon scavenger in the desorbent contains metal ions.

[0110] During the electrolysis process, the carbon dioxide absorbent can be placed in the anode chamber of the carbon dioxide desorption device, and the previously desorbed solution can be placed in the cathode chamber of the same device. This allows for simultaneous desorption of carbon dioxide in the anode chamber and electrodeposition of metal ions in the cathode chamber, while also enabling the re-acquisition of the carbon capture agent. The electrolysis current density can be 1 A / m³. 2 -500A / m 2 .

[0111] The carbon dioxide capture process may include:

[0112] Obtain the carbon dioxide absorbent as described in any of the above; the carbon dioxide absorbent may be derived from a carbon dioxide absorption device.

[0113] The carbon dioxide absorbent is subjected to any of the electrolysis methods described above to desorb the carbon dioxide from the absorbent.

[0114] The present invention also provides a carbon dioxide desorption device, wherein the anode chamber of the carbon dioxide desorption device contains the carbon dioxide absorbent as described. The carbon dioxide absorbent in the anode chamber can be supplied continuously from an external source or intermittently from an external source. When the carbon dioxide absorbent is continuously supplied to the anode chamber, the supply of the carbon dioxide absorbent and the electrolysis of the carbon dioxide absorbent can be performed simultaneously; when the carbon dioxide absorbent is intermittently supplied to the anode chamber, the carbon dioxide absorbent can be supplied to the anode chamber first, and then the carbon dioxide absorbent can be electrolyzed.

[0115] As a further description of the carbon dioxide desorption device, the carbon dioxide desorption device is typically an electrodesorption device, having an anode chamber and a cathode chamber separated by an anion exchange membrane. The electrodes in the anode chamber and the cathode chamber may contain transition metals (such as Zn, Cu, Ni, etc.). The electrodes in the anode chamber and the cathode chamber are electrically electrolyzed with an external power source. A cover may also be provided above the anode chamber and the cathode chamber to prevent gas escape. The anode chamber and the cathode chamber may also have channels for liquid and / or gas transport, as well as corresponding valves.

[0116] The present invention also provides a carbon dioxide capture system, comprising a carbon dioxide absorption device and a carbon dioxide desorption device; the anode chamber of the carbon dioxide desorption device contains a carbon dioxide absorbent as described above; the anode chamber of the carbon dioxide desorption device and the carbon absorbent outlet of the carbon dioxide absorption device are connected to each other to continuously or intermittently receive the carbon dioxide absorbent from the carbon dioxide absorption device. Wherein, when the anode chamber of the carbon dioxide desorption device is adjusted, the adjusted anode chamber can also be directly connected to the carbon absorbent outlet of the carbon dioxide absorption device.

[0117] The following are specific examples of the present invention:

[0118] Comparative Example 1: Inorganic Ammonia (NH3) System

[0119] 1. Simulation device for carbon dioxide desorption:

[0120] The simulation device includes a first electrolysis chamber and a second electrolysis chamber. The first electrolysis chamber contains a first electrode, and the second electrolysis chamber contains a second electrode. Both the first electrode and the second electrode are 7 cm long. 2 The zinc plate has an electrode spacing of 2cm. Both the first and second electrodes are electrically connected to an external power source. When one electrolysis chamber is used as the anode chamber, the other electrolysis chamber is used as the cathode chamber. The first and second electrolysis chambers are separated by an anion exchange membrane, and the upper openings of both the first and second electrolysis chambers are sealed with the cover. Both the first and second electrolysis chambers are provided with carbon dioxide exhaust channels and electrolyte delivery channels.

[0121] 2. Preparation of anolyte and catholyte (M represents mol / L):

[0122] The anolyte in the anode chamber is a CO2-rich and zinc-poor solution (17.5 mL);

[0123] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 2M ammonia + 2M potassium chloride.

[0124] The catholy solution located in the cathode chamber is a CO2-poor, zinc-rich solution (17.5 mL);

[0125] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 + 2M ammonia + 2M potassium chloride.

[0126] 3. Simulation of electrolytic adsorption:

[0127] The prepared anolyte was used as the first electrolyte, and the prepared catholyte was used as the second electrolyte. Using the aforementioned simulation apparatus, the electrolyte was tested at 60°C and 100 A / m. 2 Constant current cyclic electrolysis is performed at a current density; the cyclic electrolysis is measured by the completion of the electrolysis of the first electrolyte in the cathode chamber.

[0128] The specific process of one cycle of electrolysis is as follows:

[0129] The first electrolyte was placed in the anode chamber, and the second electrolyte was placed in the cathode chamber. The mixture was subjected to an atmosphere of 60°C and 100 A / m. 2 The first electrolysis is carried out at a certain current density, thereby releasing carbon dioxide from the first electrolyte and causing zinc ions in the second electrolyte to electrodeposit. When the amount of CO2 discharged from the anode chamber reaches about 90% (at this time the carbon content of the solution is about 10% of the initial amount), the first electrolysis ends. After the first electrolysis is completed, the second electrolyte is used to absorb carbon dioxide until the carbon dioxide concentration reaches saturation (based on pH stability).

[0130] The second electrolyte was placed in the anode chamber, and the first electrolyte was placed in the cathode chamber, at 60°C and 100 A / m. 2 The second electrolysis is carried out at a certain current density, thereby releasing carbon dioxide from the second electrolyte and causing zinc ions in the first electrolyte to electrodeposit. When the amount of CO2 discharged from the anode chamber reaches about 90% (at this time the carbon content of the solution is about 10% of the initial amount), the second electrolysis is ended. The first electrolyte is then subjected to carbon dioxide absorption until the carbon dioxide concentration reaches saturation (based on pH stability).

[0131] Then, subsequent cycles of electrolysis are performed.

[0132] The experimental results of this comparative example are as follows:

[0133] First cycle electrolysis: ammonia loss 5%, energy consumption 26kJ / molCO2;

[0134] Fifth cycle electrolysis: ammonia loss 28%, energy consumption 78kJ / molCO2;

[0135] The tenth cycle of electrolysis resulted in a 48% loss of ammonia and an energy consumption of 113 kJ / mol CO2.

[0136] Note: "Loss" refers to the amount of a corresponding component in the first electrolyte that is lost after electrolysis in the cathode chamber during this cycle of electrolysis, compared to its initial formulation (before the cycle of electrolysis).

[0137] "Energy consumption" refers to the power consumption generated by the first electrolyte in a single electrolysis in the cathode chamber during this electrolysis cycle.

[0138] Example 1: Alanine + NaOH

[0139] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 2M alanine + 2M sodium hydroxide; and replaces the 2M ammonia in the catholyte with 2M alanine + 2M sodium hydroxide, while keeping other conditions unchanged.

[0140] Right now:

[0141] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 2M alanine + 2M sodium hydroxide + 2M potassium chloride;

[0142] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 + 2M alanine + 2M sodium hydroxide + 2M potassium chloride.

[0143] The experimental results of this embodiment are as follows:

[0144] First cycle electrolysis: alanine loss 0.01%, energy consumption 45 kJ / mol CO2;

[0145] Fifth cycle electrolysis: alanine loss 0.04%, energy consumption 44 kJ / mol CO2;

[0146] The tenth cycle of electrolysis resulted in a 0.11% loss of alanine and an energy consumption of 48 kJ / mol CO2.

[0147] Example 2: Alanine + Creatine + NaOH

[0148] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 1M alanine + 1M sarcosine + 2M sodium hydroxide; and replaces the 2M ammonia in the catholyte with 1M alanine + 1M sarcosine + 2M sodium hydroxide, while keeping other conditions unchanged.

[0149] Right now:

[0150] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 1M alanine + 1M sarcosine + 2M sodium hydroxide + 2M potassium chloride;

[0151] Cathodic solution composition: 0.7M Zn2+ +0.5M CO2 +1M alanine +1M sarcosine +2M sodium hydroxide +2M potassium chloride.

[0152] The experimental results of this embodiment are as follows:

[0153] First cycle electrolysis: alanine + sarcosine loss 0.02%, energy consumption 36kJ / molCO2;

[0154] Fifth cycle electrolysis: alanine + sarcosine loss 0.07%, energy consumption 39kJ / molCO2;

[0155] The tenth cycle of electrolysis resulted in a 0.13% loss of alanine and sarcosine, with an energy consumption of 38 kJ / mol CO2.

[0156] Example 3: Alanine + Ethylenediamine

[0157] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 1M alanine + 1M ethylenediamine; and replaces the 2M ammonia in the catholyte with 1M alanine + 1M ethylenediamine, while keeping other conditions unchanged.

[0158] Right now:

[0159] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 1M alanine + 1M ethylenediamine + 2M potassium chloride;

[0160] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 +1M alanine +1M ethylenediamine +2M potassium chloride.

[0161] The experimental results of this embodiment are as follows:

[0162] First cycle electrolysis: alanine + ethylenediamine loss 0.01%, energy consumption 64kJ / molCO2;

[0163] Fifth cycle electrolysis: alanine + ethylenediamine loss 0.03%, energy consumption 69kJ / molCO2;

[0164] The tenth cycle of electrolysis resulted in a 0.05% loss of alanine and ethylenediamine, with an energy consumption of 73 kJ / mol CO2.

[0165] Example 4: Alanine + Ethylenediamine

[0166] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 2M alanine + 2M ethylenediamine; and replaces the 2M ammonia in the catholyte with 2M alanine + 2M ethylenediamine, while keeping other conditions unchanged.

[0167] Right now:

[0168] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 2M alanine + 2M ethylenediamine + 2M potassium chloride;

[0169] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 + 2M alanine + 2M ethylenediamine + 2M potassium chloride.

[0170] The experimental results of this embodiment are as follows:

[0171] First cycle electrolysis: alanine + ethylenediamine loss 0.01%, energy consumption 52kJ / molCO2;

[0172] Fifth cycle electrolysis: alanine + ethylenediamine loss 0.04%, energy consumption 55kJ / molCO2;

[0173] The tenth cycle of electrolysis resulted in a 0.09% loss of alanine and ethylenediamine, with an energy consumption of 51 kJ / mol CO2.

[0174] Example 5: Alanine + Ethylenediamine + Piperazine

[0175] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 1M alanine + 1M ethylenediamine + 1M piperazine; and replaces the 2M ammonia in the catholyte with 1M alanine + 1M ethylenediamine + 1M piperazine, while keeping other conditions unchanged.

[0176] Right now:

[0177] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 1M alanine + 1M ethylenediamine + 1M piperazine + 2M potassium chloride;

[0178] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 +1M alanine +1M ethylenediamine +1M piperazine +2M potassium chloride.

[0179] The experimental results of this embodiment are as follows:

[0180] First cycle electrolysis: alanine + ethylenediamine + piperazine loss 0.002%, energy consumption 45kJ / molCO2;

[0181] Fifth cycle electrolysis: alanine + ethylenediamine + piperazine loss 0.007%, energy consumption 44kJ / molCO2;

[0182] The tenth cycle of electrolysis resulted in a loss of 0.011% in alanine + ethylenediamine + piperazine, with an energy consumption of 43 kJ / mol CO2.

[0183] Example 6: Creatine + NaOH

[0184] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 2M sarcosine + 2M sodium hydroxide; and replaces the 2M ammonia in the catholyte with 2M sarcosine + 2M sodium hydroxide, while keeping other conditions unchanged.

[0185] Right now:

[0186] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 2M sarcosine + 2M sodium hydroxide + 2M potassium chloride;

[0187] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 + 2M sarcosine + 2M sodium hydroxide + 2M potassium chloride.

[0188] The experimental results of this embodiment are as follows:

[0189] First cycle of electrolysis: sarcosine loss 0.03%, energy consumption 55 kJ / mol CO2;

[0190] Fifth cycle of electrolysis: sarcosine loss 0.07%, energy consumption 62kJ / molCO2;

[0191] The tenth cycle of electrolysis resulted in a 0.12% loss of sarcosine and an energy consumption of 70 kJ / mol CO2.

[0192] Example 7: Creatine + Inorganic Ammonia (NH3)

[0193] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 2M sarcosine + 2M inorganic ammonia; and replaces the 2M ammonia in the catholyte with 2M sarcosine + 2M inorganic ammonia, while keeping other conditions unchanged.

[0194] Right now:

[0195] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 2M sarcosine + 2M inorganic ammonia + 2M potassium chloride;

[0196] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 + 2M sarcosine + 2M inorganic ammonia + 2M potassium chloride.

[0197] The experimental results of this embodiment are as follows:

[0198] First cycle electrolysis: sarcosine + inorganic ammonia loss 0.1%, energy consumption 41kJ / molCO2;

[0199] Fifth cycle electrolysis: sarcosine + inorganic ammonia loss 0.4%, energy consumption 43kJ / molCO2;

[0200] The tenth cycle of electrolysis resulted in a 0.9% loss of sarcosine and inorganic ammonia, with an energy consumption of 44 kJ / mol CO2.

[0201] Example 8: Proline + NaOH

[0202] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 2M proline + 2M sodium hydroxide; and replaces the 2M ammonia in the catholyte with 2M proline + 2M sodium hydroxide, while keeping other conditions unchanged.

[0203] Right now:

[0204] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 2M proline + 2M sodium hydroxide + 2M potassium chloride;

[0205] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 + 2M proline + 2M sodium hydroxide + 2M potassium chloride.

[0206] The experimental results of this embodiment are as follows:

[0207] First cycle electrolysis: proline loss 0.04%, energy consumption 59 kJ / mol CO2;

[0208] Fifth cycle electrolysis: proline loss 0.08%, energy consumption 61kJ / molCO2;

[0209] The tenth cycle of electrolysis resulted in a 0.11% loss of proline and an energy consumption of 65 kJ / mol CO2.

[0210] Example 9: Lysine + NaOH

[0211] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 2M lysine + 2M sodium hydroxide; and replaces the 2M ammonia in the catholyte with 2M lysine + 2M sodium hydroxide, while keeping other conditions unchanged.

[0212] Right now:

[0213] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 2M lysine + 2M sodium hydroxide + 2M potassium chloride;

[0214] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 + 2M lysine + 2M sodium hydroxide + 2M potassium chloride.

[0215] The experimental results of this embodiment are as follows:

[0216] First cycle electrolysis: lysine loss 0.06%, energy consumption 63kJ / molCO2;

[0217] Fifth cycle electrolysis: lysine loss 0.11%, energy consumption 67 kJ / mol CO2;

[0218] The tenth cycle of electrolysis resulted in a 0.19% loss of lysine and an energy consumption of 69 kJ / mol CO2.

[0219] Example 10: Tyrosine + NaOH

[0220] Compared to Comparative Example 1, this embodiment only replaces the 2M ammonia in the anolyte with 2M tyrosine + 2M sodium hydroxide; and replaces the 2M ammonia in the catholyte with 2M tyrosine + 2M sodium hydroxide, while keeping other conditions unchanged.

[0221] Right now:

[0222] Anode solution composition: 0.2M Zn 2+ +1.2M CO2 + 2M tyrosine + 2M sodium hydroxide + 2M potassium chloride;

[0223] Cathodic solution composition: 0.7M Zn 2+ +0.5M CO2 + 2M tyrosine + 2M sodium hydroxide + 2M potassium chloride.

[0224] The experimental results of this embodiment are as follows:

[0225] First cycle electrolysis: tyrosine loss 0.09%, energy consumption 53 kJ / mol CO2;

[0226] Fifth cycle electrolysis: tyrosine loss 0.17%, energy consumption 58 kJ / mol CO2;

[0227] The tenth cycle of electrolysis resulted in a tyrosine loss of 0.21% and an energy consumption of 55 kJ / mol CO2.

[0228] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the present invention specification under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An application of a carbon capture agent in carbon dioxide capture, characterized in that, The carbon dioxide capture steps include: contacting the carbon capture agent with the gas to be treated containing carbon dioxide and absorbing it to obtain a carbon dioxide absorbent; electrolyzing the carbon dioxide absorbent to desorb the carbon dioxide in the carbon dioxide absorbent to obtain a desorbed liquid and desorbed carbon dioxide. The carbon dioxide capture step further includes: electrolyzing the desorption solution to cause the metal ions bound to the carbon capture agent to undergo electrodeposition, thereby obtaining the carbon capture agent separated from the metal ions; the desorption solution contains the carbon capture agent, and the carbon capture agent in the desorption solution is bound with metal ions originating from the electrode; The carbon capture agent comprises a product obtained by mixing amino acids and alkaline additives; the amino acids are alanine and sarcosine; and the alkaline additives are alkaline hydroxides.

2. The application according to claim 1, characterized in that, The molar ratio of the amino acid to the alkaline additive is 0.2-8:

1.

3. The application according to claim 1, characterized in that, The concentration of the amino acid is 0.2-8 mol / L.

4. The application according to any one of claims 1 to 3, characterized in that, The carbon capture agent also includes a supporting electrolyte.

5. The application of a carbon dioxide absorbent in carbon dioxide desorption, characterized in that, The carbon dioxide absorbent contains a carbon trapping agent, and the carbon trapping agent in the carbon dioxide absorbent is bound to carbon dioxide; the carbon trapping agent includes a product obtained by mixing amino acids and alkaline additives; The amino acids are alanine and sarcosine; The alkaline additive is an alkaline hydroxide; The carbon dioxide desorption step includes: electrolyzing the carbon dioxide absorbent to desorb the carbon dioxide in the carbon dioxide absorbent, to obtain a desorbed liquid and desorbed carbon dioxide; The desorption solution is electrolyzed to cause the metal ions bound to the carbon scavenger to undergo electrodeposition, thereby obtaining the carbon scavenger separated from the metal ions; the desorption solution contains the carbon scavenger, and the carbon scavenger in the desorption solution is bound to metal ions originating from the electrode.

6. The application according to claim 5, characterized in that, The molar ratio of the amino acid to the alkaline additive is 0.2-8:

1.

7. The application according to claim 5, characterized in that, The concentration of the amino acid is 0.2-8 mol / L.

8. The application according to any one of claims 5 to 7, characterized in that, The carbon capture agent also includes a supporting electrolyte.

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