Method and device for removing iron ions in carbon capture absorbent

Abstract

The present invention relates to the technical field of carbon capture, in particular to a method and device for removing iron ions in a carbon capture absorbent. The removal method comprises: transferring an absorption liquid to a removal container; on the basis of the concentration of trivalent iron ions in the absorption liquid and flow rate parameters of the absorption liquid, determining the addition rate of a reducing agent, some trivalent iron ions being reduced to divalent iron ions; when the concentration of the trivalent iron ions in the absorption liquid is reduced to a preset concentration, adding alkali liquor into the removal container, the trivalent iron ions and the divalent iron ions reacting with the alkali liquor to generate a precipitate; when the pH value of the absorption liquid is adjusted to be within a preset range, stopping addition of the alkali liquor into the absorption liquid; and discharging the precipitate. The method for removing iron ions in a carbon capture absorbent provided by the embodiments of the present invention can remove iron ions in absorbents, thereby improving the performance of absorbents.

Description

Method and device for removing iron ions from carbon capture absorbent Technical Field

[0001] The present invention relates to the technical field of carbon capture, and in particular to a method and device for removing iron ions from a carbon capture absorbent. Background Art

[0002] During the long-term operation of carbon capture systems, corrosion issues gradually emerge due to the interaction of complex factors such as the reaction between the capture absorbent and carbon dioxide in the flue gas, the high temperature conditions of the system, and the gradual degradation of the reaction products. This corrosion process gradually erodes the iron components of the equipment, resulting in the presence of a large amount of impure iron ions in the absorbent, affecting its performance. Relevant technologies often use adsorption and filtration to remove these impurities, but this method is less effective in removing trivalent iron ions from the solution, which in turn affects the performance of the absorbent. Summary of the Invention

[0003] The present invention aims to at least partially address one of the technical problems in the related art. To this end, embodiments of the present invention provide a method for removing iron ions from a carbon capture absorbent, which can remove iron ions from the absorbent and improve the performance of the absorbent.

[0004] The embodiment of the present invention further provides a device for removing iron ions from a carbon capture absorbent.

[0005] The method for removing iron ions from a carbon capture absorbent according to an embodiment of the present invention comprises:

[0006] transferring the absorption liquid to a removal vessel;

[0007] The rate of adding the reducing agent is determined according to the concentration of the ferric ions in the absorption liquid and the flow rate parameter of the absorption liquid, so that part of the ferric ions is reduced to ferrous ions;

[0008] When the concentration of the ferric iron ions in the absorption liquid is reduced to a preset concentration, an alkali solution is added to the removal container, and the ferric iron ions and the ferrous iron ions react with the alkali solution to generate a precipitate;

[0009] When the pH value of the absorption liquid is adjusted to a preset range, stopping adding alkali solution to the absorption liquid;

[0010] The precipitate was drained off.

[0011] The method for removing iron ions from a carbon capture absorbent according to an embodiment of the present invention can remove iron ions from the absorbent and improve the performance of the absorbent.

[0012] In some embodiments, determining the rate of adding the reducing agent according to the concentration of the trivalent iron ions in the absorption liquid and the flow rate parameter of the absorption liquid includes:

[0013] measuring the flow rate of the absorption liquid flowing to the removal container as V;

[0014] The area of ​​the pipe cross section at the flow velocity measurement location is calculated as A;

[0015] The concentration of the ferric iron ions in the absorption liquid is measured to be ;

[0016] Determine the number of electrons lost by a molecule of reducing agent during the reaction with ferric ion as N;

[0017] The rate of addition of the reducing agent is calculated as R, and .

[0018] In some embodiments, when the concentration of the ferric iron ions in the absorption liquid is reduced to a preset concentration, an alkaline solution is added to the removal container, and the ferric iron ions and the ferrous iron ions react with the alkaline solution to form a precipitate, comprising:

[0019] The real-time concentration of the ferric ions in the absorption liquid is measured as c;

[0020] At c=2 / 3× When adding alkali solution into the removal container by using an electric control valve;

[0021] The alkali solution reacts with the ferric ion and the ferrous ion simultaneously, and the reaction is: , the precipitate is ferrosoferric oxide.

[0022] In some embodiments, when the pH value of the absorption liquid is adjusted to a preset range, stopping adding the alkali solution to the absorption liquid comprises:

[0023] Measuring the real-time pH value of the absorption liquid in the removal container as P;

[0024] When 10≤P≤12, the electric control valve is closed.

[0025] In some embodiments, the absorption liquid is a circulating absorption liquid, and the removal container is provided with an inlet pipe and a liquid outlet pipe arranged opposite to each other, the inlet pipe is suitable for connecting to the analysis tower, and the outlet pipe is suitable for connecting to the absorption tower.

[0026] In some embodiments, a plurality of magnetic rods arranged in a matrix are provided in the removal container, and the magnetic rods are detachably connected to the removal container, and the magnetic rods can absorb the precipitate.

[0027] The device for removing iron ions from a carbon capture absorbent according to an embodiment of the present invention comprises:

[0028] Remove container;

[0029] a liquid inlet pipe and a liquid outlet pipe, the liquid inlet pipe and the liquid outlet pipe being arranged opposite to each other in the radial direction of the removal container, the liquid inlet pipe being adapted to be connected to the desorption tower to transfer the absorption liquid into the removal container, and the liquid outlet pipe being adapted to be connected to the absorption tower to discharge the absorption liquid in the removal container;

[0030] an electrically controlled valve, the electrically controlled valve being provided on the removal container, the electrically controlled valve having a first state and a second state. In the first state, the electrically controlled valve is used to add a reducing agent to the removal container so that part of the trivalent iron ions in the absorption liquid is reduced to divalent iron ions. In the second state, the electrically controlled valve is used to add an alkaline solution to the removal container, and the alkaline solution reacts with the trivalent iron ions and the divalent iron ions in the absorption liquid to generate a precipitate.

[0031] A magnetic rod is located in the removal container and is used to absorb the precipitate.

[0032] The device for removing iron ions from a carbon capture absorbent according to an embodiment of the present invention can improve the performance of the absorbent.

[0033] In some embodiments, the removal device further includes a cover, the top of the removal container is open, and the cover is covered on the removal container.

[0034] In some embodiments, the cover body is provided with an addition port, and one end of the electric control valve is connected to the cover body and communicates with the removal container through the addition port.

[0035] In some embodiments, there are multiple magnetic rods, which are distributed in a matrix, and the magnetic rods are detachably connected to the cover or the bottom of the removal container. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a schematic flow diagram of a method for removing iron ions from a carbon capture absorbent according to an embodiment of the present invention.

[0037] FIG2 is a schematic diagram of a device for removing iron ions from a carbon capture absorbent according to an embodiment of the present invention.

[0038] FIG3 is a schematic diagram of a device for removing iron ions from a carbon capture absorbent according to an embodiment of the present invention from another perspective.

[0039] Reference numerals:

[0040] Remove the container 1 , the liquid inlet pipe 2 , the liquid outlet pipe 3 , the magnetic rod 4 , the cover 5 , and the addition port 51 . Modes for Carrying Out the Invention

[0041] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0042] An embodiment of the present invention proposes a method for removing iron ions in a carbon capture absorbent, comprising transferring an absorption liquid to a removal container; determining a rate of adding a reducing agent based on the concentration of trivalent iron ions in the absorption liquid and a flow rate parameter of the absorption liquid, wherein some trivalent iron ions are reduced to divalent iron ions; when the concentration of trivalent iron ions in the absorption liquid is reduced to a preset concentration, adding an alkaline solution to the removal container, and the trivalent iron ions and divalent iron ions react with the alkaline solution to form a precipitate; when the pH value of the absorption liquid is adjusted to a preset range, stopping adding the alkaline solution to the absorption liquid; and discharging the precipitate.

[0043] It should be noted that carbon dioxide is an acidic gas. When carbon dioxide reacts chemically with organic amine compounds, it forms a weakly acidic solution system. The carbon dioxide capture system captures and absorbs carbon dioxide through organic amines. During the carbon capture process, a large amount of impure iron ions will be present in the absorbent. On the one hand, the impure iron ions will hinder the effective reaction between the absorbent and carbon dioxide. On the other hand, the impure iron ions will accelerate the degradation process of the organic amine absorbent, not only reducing the effectiveness of the absorbent, but also may produce more corrosive substances, aggravating the corrosion of the equipment, and generating more iron ion impurities. This embodiment is a method for removing iron ions from the absorbent of the carbon dioxide capture system to reduce the iron ion content in the absorbent, thereby ensuring the efficient, safe and stable operation of the carbon capture system.

[0044] Specifically, as shown in Figure 1, in this embodiment, the absorbent containing trivalent iron ions is transferred to the removal container, and a reducing agent is added to the removal container. It can be understood that the iron ions dissolved in the solution are generally trivalent iron ions, and the trivalent iron ions are reduced to divalent iron ions under the action of the reducing agent. The concentration of trivalent iron ions in the absorption liquid is detected in real time. When the concentration of trivalent iron ions and the concentration of divalent iron ions in the absorption liquid reach the required concentration, alkali solution is added to the removal container to create an alkaline environment. The trivalent iron ions and divalent iron ions in the absorption liquid react with the alkali solution to generate a precipitate, thereby removing the iron ions in the absorption liquid.

[0045] Optionally, the removal device of this embodiment is arranged between the absorption tower and the decomposition tower, that is, the lean liquid flows out of the decomposition tower and flows into the pipeline between the absorption tower. The content of carbon dioxide in the lean liquid absorbent before entering the absorption tower is small, so as to prevent the reducing agent and alkali solution from affecting the carbon dioxide. Moreover, after the lean liquid is heat exchanged with the rich liquid, the temperature of the lean liquid is not high, and the reaction of iron ions with the reducing agent and alkali solution is not so violent, which is relatively safer, has a better effect on removing iron ions, and has less impact on the absorbent.

[0046] For example, the reducing agent is sodium thiosulfate or sodium sulfite.

[0047] For example, the flow rate parameters include the flow rate of the absorption liquid flowing to the removal container, the cross-sectional area of ​​the pipe where the flow rate is measured, and the number of electrons lost by one molecule of the reducing agent during the reaction with the ferric ion.

[0048] The method for removing iron ions from the carbon capture absorbent in an embodiment of the present invention reduces the valence of the iron ions dissolved in the absorbent by adding a reducing agent to the absorbent, and then adds an alkali solution to the absorbent. By adjusting the chemical ratio of the reducing agent and the alkali solution, the iron ions in the absorbent are co-precipitated with the alkali solution and converted into solid iron particles. This not only removes the iron ions in the absorbent, but also prevents the iron ions from participating in the degradation process of the absorbent, thereby slowing down the aging rate of the absorbent and improving the performance of the absorbent.

[0049] Furthermore, this embodiment discharges the solid iron particles produced by co-precipitation of iron ions and alkali solution to the outside of the removal container by filtering or magnetic attraction, thereby removing the iron ions in the absorption liquid and the iron particles generated by the reaction. Combining chemical and physical methods not only improves the removal efficiency, but also makes the operation simple and cost-effective. Moreover, by reducing the iron ion content in the absorbent, the long-term operation performance of the absorbent can be significantly improved, while reducing the corrosion risk of the equipment, thereby improving the capture efficiency, operation safety and stability of the carbon capture system.

[0050] In some embodiments, the rate of adding the reducing agent is determined based on the concentration of the ferric iron ions in the absorption liquid and the flow rate parameter of the absorption liquid, including: measuring the flow rate of the absorption liquid flowing to the removal container as V; calculating the area of ​​the pipe cross section at the flow rate measurement position as A; measuring the concentration of the ferric iron ions in the absorption liquid as ; Determine the number of electrons lost by a molecule of reducing agent during the reaction with trivalent iron ions as N; calculate the rate of addition of reducing agent as R, and .

[0051] Specifically, this embodiment calculates the rate of addition of the reducing agent by the flow rate of the absorption liquid entering the removal container, the area of ​​the pipe cross-section at the flow rate measurement position, the concentration of trivalent iron ions in the absorption liquid, and the number of electrons lost by one molecule of the reducing agent, and associates the rate of addition of the reducing agent with the iron ions in the absorbent, thereby facilitating the reaction between the reducing agent and the trivalent iron ions and improving the reaction efficiency of the reducing agent and the trivalent iron ions.

[0052] Furthermore, the removal container in this embodiment is arranged between the absorption tower and the analysis tower, that is, the removal container is embedded in the circulation process of the rich liquid and the lean liquid. Since the absorption liquid is continuously circulating, the addition rate of the reducing agent is limited to facilitate the reaction of the reducing agent with the trivalent iron ions, thereby improving the distribution uniformity of the divalent iron ions in the absorption liquid.

[0053] For example, the concentration of ferric ions is expressed in mol / m 3 The unit of the absorption liquid flow rate is m / min, and the area of ​​the pipe cross section at the flow rate measurement position is m 2 , the rate of adding reducing agent is mol / min.

[0054] For example, when the reducing agent is sodium thiosulfate, the number of electrons lost by one molecule of the reducing agent during the reaction with trivalent iron ions is 1. When the reducing agent is sodium sulfite, the number of electrons lost by one molecule of the reducing agent during the reaction with trivalent iron ions is 2. Sodium sulfite is used in this embodiment.

[0055] In some embodiments, when the concentration of the ferric iron ions in the absorption liquid is reduced to a preset concentration, an alkali solution is added to the removal container, and the ferric iron ions and the ferrous iron ions react with the alkali solution to form a precipitate, comprising: measuring the real-time concentration of the ferric iron ions in the absorption liquid as c; at c = 2 / 3× When adding alkali solution to the removal container by means of an electric control valve, the alkali solution reacts with the ferric ions and the ferrous ions simultaneously, and the reaction is:

[0056] , the precipitate is ferroferric oxide.

[0057] Specifically, under the action of the reducing agent, the trivalent iron ions in the absorption liquid are reduced to divalent iron ions. When 1 / 3 of the trivalent iron ions are converted into divalent iron ions, alkaline solution is added to the removal container. By limiting the concentrations of the trivalent iron ions and divalent iron ions in the absorption liquid, only when the trivalent iron ions and divalent iron ions participate in the reaction together will a precipitate of ferroferric oxide be generated, so that the alkaline solution can react with the trivalent iron ions and divalent iron ions at the same time, and the iron ions are co-precipitated in the form of ferromagnetic ore ferroferric oxide.

[0058] Optionally, the reaction of ferric ions under the action of a reducing agent is .

[0059] For example, the concentration of ferric ions can be detected by ion chromatography, and the preset concentration is 2 / 3 of the ferric ions in the original absorption solution.

[0060] In some embodiments, when the pH value of the absorption liquid is adjusted to a preset range, stopping adding the alkali solution to the absorption liquid comprises:

[0061] Measure the real-time pH value of the absorption liquid in the removal container as P;

[0062] When 10≤P≤12, close the electric control valve.

[0063] Specifically, alkali solution is added into the removal container. The alkaline environment facilitates the reaction of hydroxide in the alkali solution with trivalent iron ions and divalent iron ions. As the alkali solution is continuously added, the pH value of the absorption liquid continues to rise under the action of the alkali solution. When the pH value of the alkali solution is in the preset range of 10-12, the electric control valve is closed and the addition of alkali solution into the removal container is stopped. The amount of alkali solution added is limited by the pH value of the absorption liquid to facilitate the reaction of iron ions in the absorption liquid with the alkali solution.

[0064] For example, the amount of alkali solution added is 5-10 times the amount of reducing agent added.

[0065] In some embodiments, the absorption liquid is a circulating absorption liquid, and the removal container is provided with a liquid inlet pipe and a liquid outlet pipe arranged relatively to each other. The liquid inlet pipe is suitable for connecting to the analysis tower, and the liquid outlet pipe is suitable for connecting to the absorption tower.

[0066] Specifically, as shown in Figures 2 and 3, the liquid inlet pipe is located on the left side of the removal container, and the liquid outlet pipe is located on the right side of the removal container. One end of the liquid inlet pipe is connected to the decomposition tower, and the other end of the liquid inlet pipe is connected to the removal container to transfer the decomposed lean liquid into the removal container. One end of the liquid outlet pipe is connected to the removal container, and the other end of the liquid outlet pipe is connected to the absorption tower to transfer the lean liquid in the removal container into the absorption tower. The removal container is integrated into the carbon dioxide capture system by setting the liquid inlet pipe and the liquid outlet pipe.

[0067] This embodiment can be effectively integrated by directly embedding it into the carbon capture system without modifying the carbon capture system, thereby achieving the effect of significantly removing iron ions. This embodiment does not limit the embedding position and can be set after the analysis tower and before the absorption tower. As long as the reduction precipitation method and the ferromagnetic adsorption method are used to remove the iron ions in the absorbent, they are within the protection scope of the embodiment.

[0068] In some embodiments, a plurality of magnetic rods arranged in a matrix are provided in the removal container, and the magnetic rods are detachably connected to the removal container, and the magnetic rods can absorb the precipitate.

[0069] Specifically, as shown in Figures 2 and 3, the outer contour of the magnetic rod on the projection surface perpendicular to the left-right direction and the front-back direction is a rectangle. Since the precipitate in this embodiment is ferroferric oxide, and ferroferric oxide is magnetic, the ferroferric oxide can be adsorbed on the outside of the magnetic rod by the magnetic rod. By introducing the setting of the magnetic rod in this embodiment, the reaction precipitate in the absorbent can be adsorbed and separated, thereby improving the removal efficiency.

[0070] Furthermore, the provision of multiple magnetic bars can also form a barrier to the absorption liquid, reduce the flow rate of the absorption liquid in the removal container, increase the contact time between the reducing agent and the alkaline solution and the absorption liquid, and improve the removal efficiency of iron ions.

[0071] For example, the outer contour of the magnetic bar on a projection plane perpendicular to the left-right direction and the front-back direction is a circle.

[0072] For example, the magnetic rod is a neodymium iron boron magnet rod or an electromagnet rod.

[0073] The device for removing iron ions from a carbon capture absorbent according to an embodiment of the present invention comprises a removal vessel 1, a liquid inlet pipe 2, a liquid outlet pipe 3, an electrically controlled valve (not shown), and a magnetic rod 4. The liquid inlet pipe 2 and the liquid outlet pipe 3 are arranged relative to each other in the radial direction of the removal vessel 1. The liquid inlet pipe 2 is adapted to be connected to a desorption tower to transfer absorbent into the removal vessel 1, while the liquid outlet pipe 3 is adapted to be connected to an absorption tower to discharge the absorbent from the removal vessel 1. The electrically controlled valve is provided on the removal vessel 1 and has a first state and a second state. In the first state, the electrically controlled valve is used to add a reducing agent to the removal vessel 1 to reduce some of the trivalent iron ions in the absorbent to divalent iron ions. In the second state, the electrically controlled valve is used to add an alkaline solution to the removal vessel 1. The alkaline solution reacts with the trivalent iron ions and divalent iron ions in the absorbent to form a precipitate. The magnetic rod 4 is located within the removal vessel 1 and is used to adsorb the precipitate.

[0074] Specifically, as shown in Figure 1, Figure 2 and Figure 3, the outer contour of the removal container 1 on the projection surface perpendicular to the left-right direction and the front-back direction is circular. After the absorption liquid enters the removal container 1 from the liquid inlet pipe 2, the flow rate of the absorption liquid will slow down, which facilitates the absorption liquid to react with the reducing agent and alkaline solution in the removal container 1.

[0075] The liquid inlet pipe 2 is located on the left side of the removal container 1, and the liquid outlet pipe 3 is located on the right side of the removal container 1. One end of the liquid inlet pipe 2 is connected to the desorption tower, and the other end of the liquid inlet pipe 2 is connected to the removal container 1 to transfer the desorbed lean liquid to the removal container 1. One end of the liquid outlet pipe 3 is connected to the removal container 1, and the other end of the liquid outlet pipe 3 is connected to the absorption tower to transfer the lean liquid in the removal container 1 to the absorption tower. The removal container 1 is integrated into the carbon dioxide capture system by setting the liquid inlet pipe 2 and the liquid outlet pipe 3.

[0076] In an embodiment of the present invention, the absorption liquid is transferred to the removal container 1 through the liquid inlet pipe 2, and the absorption liquid in the removal container 1 is discharged through the liquid outlet pipe 3. The removal device is embedded in the carbon capture system, and the reducing agent is added to the removal container 1 by adjusting the electric control valve to the first state. The trivalent iron ions are partially converted into divalent iron ions under the action of the reducing agent, and when the concentration of the trivalent iron ions in the absorption liquid is a preset concentration, the electric control valve is adjusted to the second state to add alkaline solution to the removal container 1. The alkaline solution reacts with the trivalent iron ions and divalent iron ions to generate a precipitate. Finally, the precipitate is adsorbed by the magnetic rod 4, and the iron ions in the carbon capture absorbent are removed by coupling the chemical precipitant and the magnetic adsorption effect.

[0077] Furthermore, this embodiment effectively removes iron ions from the carbon dioxide capture absorbent through the coupling of chemical reduction precipitation and magnetic attraction. The dissolved iron ions are converted into a solid form that can be magnetically separated by a chemical reduction reaction, and then separated from the absorbent by magnetic attraction, thereby achieving the purpose of purifying the absorbent, extending its service life, and improving carbon capture efficiency.

[0078] Furthermore, the removal device of this embodiment is embedded in the circulation pipeline of the absorption liquid in the carbon capture system as a mobile removal device, so as to remove the iron ions in the absorption liquid without affecting the normal operation of the carbon capture system.

[0079] In some embodiments, the removal device further comprises a cover 5 , which is provided at the top opening of the removal container 1 , and the cover 5 covers the removal container 1 .

[0080] Specifically, the provision of the cover 5 realizes a closed provision of the removal device, thereby preventing dust in the air from entering the absorption liquid, and the provision of the cover 5 facilitates the cleaning of the removal container 1 .

[0081] In some embodiments, a feeding port 51 is provided on the cover body 5 , and one end of the electric control valve is connected to the cover body 5 and communicates with the removal container 1 through the feeding port 51 .

[0082] Specifically, as shown in Figures 2 and 3, the reducing agent and alkali solution are added to the removal container 1 through the addition port 51. By setting the electric control valve, it is convenient to control the capacity and addition of the reducing agent and alkali solution added to the removal container 1, thereby improving the reaction accuracy.

[0083] The removal device of the embodiment of the present invention introduces the carbon capture absorbent into the removal container 1, opens an opening on the cover plate above the removal container 1, and controls the amount and speed of the added reducing agent and alkali solution through an electric control valve. Under the action of the reducing agent, part of the trivalent iron ions are converted into divalent iron ions. Under the action of the alkali solution, the trivalent iron ions and the divalent iron ions react with the alkali solution to form a precipitate. The iron ions are co-precipitated in the form of ferromagnetic ferroferric oxide, and are thereby adsorbed by the high-strength magnetic rod 4. The magnetic rod 4 is used to adsorb the iron-containing precipitate in the carbon capture absorbent, thereby reducing the content of iron impurities in the carbon capture absorbent, achieving the purpose of reducing the degradation of the absorbent and increasing the stability of long-term operation.

[0084] In some embodiments, there are multiple magnetic rods 4 , which are distributed in a matrix. The magnetic rods 4 are detachably connected to the cover 5 or the bottom of the container 1 .

[0085] Specifically, the arrangement of multiple magnetic bars 4 can also form a barrier to the absorption liquid, reduce the flow rate of the absorption liquid in the removal container 1, increase the contact time between the reducing agent and the alkaline solution and the absorption liquid, and improve the removal efficiency of iron ions.

[0086] For example, the magnetic rod 4 and the cover 5 or the bottom of the removal container 1 can be detachably connected by a flange, a clamp, a bolt plate or other means that can quickly release the clip. After running for a period of time, the magnetic rod 4 can be removed, which is convenient for regular cleaning of the magnetic rod 4 and reuse.

[0087] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0088] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0089] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0090] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0091] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0092] It is understood that the above embodiments are exemplary and are not to be construed as limiting the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for removing iron ions from a carbon capture absorbent, characterized in that: include: transferring the absorption liquid to a removal vessel; Determining the rate of adding the reducing agent according to the concentration of the ferric ions in the absorption liquid and the flow rate parameter of the absorption liquid, wherein a portion of the ferric ions are reduced to ferrous ions; When the concentration of the ferric iron ions in the absorption liquid is reduced to a preset concentration, an alkali solution is added to the removal container, and the ferric iron ions and the ferrous iron ions react with the alkali solution to generate a precipitate; When the pH value of the absorption liquid is adjusted to a preset range, stopping adding alkali solution to the absorption liquid; The precipitate was drained off.

2. The method for removing iron ions from a carbon capture absorbent according to claim 1, wherein: The step of determining the rate of adding the reducing agent according to the concentration of the trivalent iron ions in the absorption liquid and the flow rate parameter of the absorption liquid comprises: measuring the flow rate of the absorption liquid flowing to the removal container as V; The area of ​​the pipe cross section at the flow velocity measurement location is calculated as A; The concentration of the ferric iron ions in the absorption liquid is measured to be ； Determine the number of electrons lost by a molecule of reducing agent during the reaction with ferric ion as N; The rate of addition of the reducing agent is calculated as R, and 。 3. The method for removing iron ions from a carbon capture absorbent according to claim 2, wherein: When the concentration of the ferric iron ions in the absorption liquid is reduced to a preset concentration, an alkali solution is added to the removal container, and the ferric iron ions and the ferrous iron ions react with the alkali solution to generate a precipitate, comprising: The real-time concentration of the ferric ions in the absorption liquid is measured as c; At c=2 / 3× When adding alkali solution into the removal container by using an electric control valve; The alkali solution reacts with the ferric ion and the ferrous ion simultaneously, and the reaction is: , the precipitate is ferrosoferric oxide.

4. The method for removing iron ions from a carbon capture absorbent according to claim 3, wherein: When the pH value of the absorption liquid is adjusted to a preset range, the addition of alkali solution to the absorption liquid is stopped, comprising: Measuring the real-time pH value of the absorption liquid in the removal container as P; When 10≤P≤12, the electric control valve is closed.

5. The method for removing iron ions from a carbon capture absorbent according to claim 1, wherein: The absorption liquid is a circulating absorption liquid. The removal container is provided with an inlet pipe and a liquid outlet pipe arranged opposite to each other. The inlet pipe is suitable for connecting to the analysis tower, and the outlet pipe is suitable for connecting to the absorption tower.

6. The method for removing iron ions from a carbon capture absorbent according to claim 3, wherein: A plurality of magnetic rods arranged in a matrix are provided in the removal container. The magnetic rods are detachably connected to the removal container and can absorb the precipitate.

7. A device for removing iron ions from a carbon capture absorbent, characterized in that: include: Remove container; a liquid inlet pipe and a liquid outlet pipe, the liquid inlet pipe and the liquid outlet pipe being arranged opposite to each other in the radial direction of the removal container, the liquid inlet pipe being adapted to be connected to the desorption tower to transfer the absorption liquid into the removal container, and the liquid outlet pipe being adapted to be connected to the absorption tower to discharge the absorption liquid in the removal container; an electrically controlled valve, the electrically controlled valve being provided on the removal container, the electrically controlled valve having a first state and a second state. In the first state, the electrically controlled valve is used to add a reducing agent to the removal container so that part of the trivalent iron ions in the absorption liquid is reduced to divalent iron ions. In the second state, the electrically controlled valve is used to add an alkaline solution to the removal container, and the alkaline solution reacts with the trivalent iron ions and the divalent iron ions in the absorption liquid to generate a precipitate. A magnetic rod is located in the removal container and is used to absorb the precipitate.

8. The device for removing iron ions from carbon capture absorbent according to claim 7, characterized in that: The removal container further comprises a cover body, the top of the removal container is opened, and the cover body is covered on the removal container.

9. The device for removing iron ions from carbon capture absorbent according to claim 8, characterized in that: The cover body is provided with an addition port, and one end of the electric control valve is connected to the cover body and communicates with the removal container through the addition port.

10. The device for removing iron ions from carbon capture absorbent according to claim 8, characterized in that: There are multiple magnetic bars, which are distributed in a matrix. The magnetic bars are detachably connected to the cover or the bottom of the removal container.

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