Novel electrodialysis purification equipment for chemical absorbent in CCUS system

Abstract

The utility model relates to novel electrodialysis purification equipment for a chemical absorbent in a CCUS system, and belongs to the field of electrodialysis purification of environmental equipment. The device comprises a water tank I, a water tank II, a water tank III, a water tank IV, a water tank V, a control cabinet and a membrane stack, wherein an organic amine liquid inlet is connected with an outlet of the water tank I, a sodium hydroxide solution outlet is connected with an inlet of the water tank II, a catholyte inlet is connected with an outlet of the water tank III, and a catholyte outlet is connected with an inlet of the water tank III; the sodium hydroxide solution inlet is connected with the water tank II inlet, the organic amine solution outlet is connected with the water tank I inlet, and the anolyte inlet is connected with the water tank III outlet and the anolyte outlet is connected with the water tank III inlet; the electrode protection covers cover the electrode connection points on the two sides, and the electrode connection points are connected with the control cabinet. The device is reasonable in structural design, safe, reliable and capable of purifying the organic amine solution, removing thermostable salt in the organic amine solution, guaranteeing the high recovery rate of the organic amine solution and meeting the use requirements.

Description

Technical Field

[0001] The utility model relates to a purification device, in particular to a novel electrodialysis purification device for a chemical absorbent in a CCUS system, and belongs to the field of electrodialysis purification of environmental equipment. Background Art

[0002] According to the process sequence, carbon dioxide capture methods can be divided into pre-combustion capture, oxygen-enriched combustion technology and post-combustion capture. Among them, post-combustion capture is the most important way to reduce carbon dioxide emissions. Post-combustion capture can be achieved through adsorption, membrane separation, low-temperature separation, biological method, and absorption method.

[0003] Chemical absorption has become the most suitable large-scale carbon capture technology for various industries due to its high absorption efficiency and large processing capacity. The most common absorbent is amine chemical solvent. However, during the use of organic amine solution, due to the high temperature and high pressure environment and complex gas composition, it is easy to produce oxidative degradation and sulfur degradation; these two degradation processes will form heatstable salts; heatstable salts will not only cause bubbles in the organic amine solution but also damage the construction equipment, so the organic amine solution needs to be purified.

[0004] During the operation of the CCUS system, a large amount of heat-stable salts are formed, which affect the efficiency of the system in absorbing carbon dioxide and damage the system itself. When planning related projects, it is necessary to consider adding a purification step for organic amine solutions. This application aims to solve the problem of amine solution purification in the CCUS system.

[0005] At present, the main HSS removal technologies for organic amine solutions in CCUS systems include: alkali neutralization method, thermal distillation method, electrodialysis method, anion exchange resin method, electrosorption method, electromagnetic separation method, adsorption extraction method, etc.

[0006] The alkali neutralization method refers to neutralizing the acidic HSS in the alcoholamine solution by adding NaOH to the alcoholamine solution and regenerating the alcoholamine. The OH- in NaOH resolves the HSS- bound to the alcoholamine molecules into the alcoholamine solution, regenerating the alcoholamine and increasing the effective concentration of the alcoholamine molecules. However, the neutralization method does not fundamentally remove the HSS in the alcoholamine solution, and HSS still exists in the alcoholamine solution. After the alcoholamine solution is circulated for a long time, the HSS concentration will accumulate to a high level, affecting the operation of the system, and finally the alcoholamine solution can only be completely abandoned. However, at this time, there are still 10%-20% of the active ingredients of alcoholamine in the alcoholamine solution, and abandoning the alcoholamine solution will cause great economic losses.

[0007] The distillation method is usually carried out in the side stream of the distillation tower, and is extracted from the reboiler of the stripping tower in a semi-continuous manner. For DEA and MDEA, distillation needs to be carried out under vacuum conditions to ensure that its temperature is lower than its thermal degradation temperature, and the alcoholamine solution is recovered by condensing the evaporated gas; while the degradation products and HSS accumulate at the bottom of the recovery kettle. The distillation method for recovering alcoholamines is mainly limited by three aspects: first, the temperature of the reactor needs to be kept lower than the thermal degradation temperature of the alcoholamines; second, this method has a phase change process, which consumes a lot of heat energy, and the cost is still higher than other technologies; third, the crystallization of solid salts left by evaporation has complex composition and is difficult to recover, so it may cause new pollution.

[0008] Electrosorption is a new water treatment technology that uses the phenomenon of charged electrode surface adsorbing ions and charged particles in water, so that dissolved salts and other charged substances in water are enriched and concentrated on the surface of the electrode to achieve water purification. Electrosorption has a high water recovery rate (>90%) and can remove almost all ionic pollutants, making it popular in industrial wastewater desalination. However, due to the strong corrosiveness of industrial wastewater, even inert electrodes will still corrode severely after long-term operation.

[0009] A Chinese patent with publication date of May 4, 2021 and publication number CN112742177A discloses an invention patent entitled "A method and device for purifying and removing heat-stable salts in amine solution"; this method removes part of the HSS in the organic amine solution and maintains a certain recovery rate, but the main unit electrosorption in this method requires electrodialysis equipment to cooperate with cleaning, and the amine solution recovery rate is only 96%, resulting in a large economic loss.

[0010] In summary, conventional treatment processes cannot ensure the reuse of amine solution while removing most of the heat-stable salts; the present application proposes a new electrodialysis system for HSS removal of organic amine solution in CCUS system, which has high HSS removal rate and high amine solution recovery rate while ensuring the reuse of amine solution. Utility Model Content

[0011] The purpose of the utility model is to overcome the above-mentioned deficiencies in the prior art and to provide a new electrodialysis purification device for chemical absorbents in CCUS systems which has a reasonable structural design, is safe and reliable, can purify organic amine solutions, remove heat-stable salts therein and ensure a high recovery rate of organic amine solutions.

[0012] The technical solution adopted by the utility model to solve the above problems is: a new type of electrodialysis purification equipment for chemical absorbent in the CCUS system, including water tank one, water tank two, water tank three, water tank four, water tank five and a control cabinet, characterized in that: it also includes a membrane stack, the water tank one, water tank two, water tank three are connected to the core component membrane stack of the electrodialysis purification equipment through pipelines, and water tank four and water tank five are connected to water tank one and water tank two through pipelines; the membrane stack includes a membrane group body, a cathode side, an anode side, an electrode protection cover, an electrode connection point, a fixed foot support and a fixing bolt, and an organic amine liquid inlet and a sodium hydroxide solution inlet are arranged on the cathode side. outlet, cathode liquid inlet and cathode liquid outlet; the anode side is provided with a sodium hydroxide solution inlet, an organic amine liquid outlet, an anode liquid inlet and an anode liquid outlet; the organic amine liquid inlet is connected to the first outlet of the water tank, the sodium hydroxide solution outlet is connected to the second inlet of the water tank, the cathode liquid inlet is connected to the third outlet of the water tank, and the cathode liquid outlet is connected to the third inlet of the water tank; the sodium hydroxide solution inlet is connected to the second inlet of the water tank, the organic amine liquid outlet is connected to the first inlet of the water tank, the anode liquid inlet is connected to the third outlet of the water tank, and the anode liquid outlet is connected to the third inlet of the water tank; the electrode protection cover covers the electrode connection points on both sides, and the electrode connection points are connected to the control cabinet.

[0013] Preferably, the membrane stack of the utility model further includes fixing bolts, and the electrode protection cover is covered on the electrode connection points on both sides by the bolts.

[0014] Preferably, the electrode connection point of the utility model is connected to the DC power supply of the control cabinet via a cable.

[0015] Preferably, the water tank 1 described in the utility model is a raw water tank for storing an organic amine solution containing HSS; the water tank 2 is a sodium hydroxide water tank, the chamber of which contains a sodium hydroxide solution; the water tank 3 is an extreme liquid water tank, which is used to store a 1% sodium hydroxide solution serving as an extreme liquid; the water tank 4 is a pretreatment water tank, which is provided with a first-level 10um precision filtration, a second-level activated carbon filtration, and a third-level 5um precision filtration element; the water tank 5 is a dissolution water tank, which is used to prepare the sodium hydroxide solution in chamber B.

[0016] Preferably, the circuit connecting the water tank 1 and the membrane stack of the utility model is equipped with a magnetic pump, a pressure gauge and a flow meter.

[0017] Compared with the prior art, the utility model has the following advantages and effects: the overall structural design is reasonable, the heat-stable salt in the organic amine solution is removed to 0.5%, and the organic amine recovery rate is guaranteed to be above 99%, which not only purifies the organic amine solution, but also reduces the loss of the organic amine solution in the purification process, and the economic value and environmental value are linked together. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of the core membrane group of an embodiment of the utility model.

[0019] Figure 2 It is a schematic diagram of the cathode side structure of the core membrane group of an embodiment of the utility model.

[0020] Figure 3 It is a schematic diagram of the anode side structure of the core membrane group of an embodiment of the utility model.

[0021] Figure 4 It is the front view of the embodiment of the utility model.

[0022] Figure 5 It is a side view of an embodiment of the utility model.

[0023] Figure 6 This is a schematic diagram of the principle of removing HSS by electrodialysis in an embodiment of the utility model.

[0024] Figure 7 This is a purification system diagram of the utility model.

[0025] In the figure: water tank 1A, water tank 2B, water tank 3C, water tank 4D, water tank 5E, membrane stack 1, control cabinet 2;

[0026] Membrane stack 1: membrane group body 11, cathode side 12, anode side 13, electrode protection cover 14, electrode connection point 15, fixed foot support 16, fixing bolt 17;

[0027] Cathode side 12: amine solution inlet N-1, sodium hydroxide solution outlet N-2, cathode solution inlet N-3, cathode solution outlet N-4;

[0028] Anode side 13: sodium hydroxide solution inlet N-5, organic amine solution outlet N-6, anode solution inlet N-7, anode solution outlet N-8;

[0029] Figure 7 Chinese symbols: carbon dioxide Y1, amine solution A1, amine solution containing heat-stable salt H1, heat-stable salt solution H2, sodium hydroxide solution T1, new electrodialysis D1. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are provided to explain the present invention, but the present invention is not limited to the following examples.

[0031] Example

[0032] See also Figures 1 to 7 The novel electrodialysis purification equipment for chemical absorbent in the CCUS system of this embodiment includes a water tank 1 A, a water tank 2 B, a water tank 3 C, a water tank 4 D, a water tank 5 E, a control cabinet 2 and a membrane stack 1.

[0033] The novel electrodialysis purification equipment of this embodiment has a total of five water tanks, among which water tank 1 A is a raw water tank for storing HSS organic amine solution; water tank 2 B is a sodium hydroxide water tank, and the chamber thereof contains sodium hydroxide solution; water tank 3 C is an extreme liquid water tank, and is used to store 1% sodium hydroxide solution serving as the extreme liquid; water tank 4 D is a pretreatment water tank, and is provided with a first-level 10um precision filter, a second-level activated carbon filter, and a third-level 5um precision filter element; water tank 5 E is a dissolution water tank, and is used to prepare the sodium hydroxide solution in chamber B.

[0034] In the process route of this embodiment, water tank 1A is connected to the core component membrane stack 1 of the new electrodialysis equipment through a pipeline. A series of supporting instruments such as a magnetic pump, a pressure gauge, and a flow meter are also provided on the connection loop; the magnetic pump provides circulation power for conveying the feed liquid, the pressure gauge is used to display the membrane inlet pressure, and the flow meter is used to display the circulation flow; water tank 1A, water tank 2B, water tank 3C are connected to the membrane stack in the same way, water tank 4D and water tank 5E are connected to water tank 1A and water tank 2B through a pipeline, and a magnetic pump is provided on the loop as a power transportation system. Water tank 1A and water tank 2B form a circulation loop with membrane stack 1 through a series of accessories. The organic amine solution containing HSS heat-stable salt produced in the CCUS system is transported to water tank 4D via a magnetic pump. After primary, secondary and tertiary filtration, the pretreated HSS organic amine solution enters water tank 1A (raw water tank) and is transported to membrane stack 1 via a magnetic pump. Sodium hydroxide reagent is added to water tank 5E to dissolve and prepare sodium hydroxide solution and transport it to water tank 2B. The solution is finally sent to membrane stack 1 in water tank 2B. Driven by the magnetic pump, the two circulations of water tank 1A and water tank 2B continuously enter and flow out of the membrane stack. When the solutions of water tank 1A and water tank 2B enter the membrane stack, under the action of the external DC electric field, the anions (HSS) in the HSS organic amine solution of water tank 1A rush to the anode under the selection of the anion exchange membrane and enter the water tank 2B circulation. The anions (hydroxyl) in the water tank 2B circulation are also replenished back to the water tank 1A circulation; while the cations (organic amines) in the organic amine solution are intercepted in the circulating solution of water tank 1A; with the continuous operation of the equipment, the HSS in the organic amine solution containing HSS is continuously removed to achieve the amine solution purification effect (for the specific principle, see Figure 6 , X: HSS-aggregate); the organic amine solution purified by the equipment is transported back to the CCUS system process for continued use.

[0035] The membrane stack 1 in this embodiment includes a membrane group body 11, a cathode side 12, an anode side 13, an electrode protection cover 14, an electrode connection point 15, a fixed foot support 16 and a fixing bolt 17. The cathode side 12 is provided with an organic amine liquid inlet N-1, a sodium hydroxide solution outlet N-2, a cathode liquid inlet N-3 and a cathode liquid outlet N-4; the anode side 13 is provided with a sodium hydroxide solution inlet N-5, an organic amine liquid outlet N-6, an anode liquid inlet N-7 and an anode liquid outlet N-8; the organic amine liquid inlet N-1 is connected to the water tank outlet A, and the sodium hydroxide solution outlet N-2 is provided with a cathode liquid inlet N-3 and a cathode liquid outlet N-4; the anode side 13 is provided with a sodium hydroxide solution inlet N-5, an organic amine liquid outlet N-6, an anode liquid inlet N-7 and an anode liquid outlet N-8; the organic amine liquid inlet N-1 is connected to the water tank outlet A, and the sodium hydroxide solution outlet N-2 is provided with a cathode liquid inlet N-3 and an anode liquid outlet N-4 ... The liquid outlet N-2 is connected to the B inlet of water tank 2, the cathode liquid inlet N-3 is connected to the C outlet of water tank 3, and the cathode liquid outlet N-4 is connected to the C inlet of water tank 3; the sodium hydroxide solution inlet N-5 is connected to the B inlet of water tank 2, the organic amine liquid outlet N-6 is connected to the A inlet of water tank 1, the anode liquid inlet N-7 is connected to the C outlet of water tank 3, and the anode liquid outlet N-8 is connected to the C inlet of water tank 3; the electrode protection cover 14 is covered on the electrode connection points 15 on both sides by bolts 17, and the electrode connection points 15 are connected to the DC power supply of the control cabinet 2 through cables.

[0036] The main principle of this embodiment is to use a new type of electrodialysis equipment to purify the organic amine solution, and then reuse the organic amine solution in the process, thereby reducing the amount of waste amine solution in the system and reducing system investment.

[0037] The process route of this embodiment is to use a new type of electrodialysis equipment to treat an organic amine solution containing HSS; under the action of the electric field, the heat-stable salt in the organic amine solution migrates to the positive electrode through the anion exchange membrane and enters the adjacent chamber. At the same time, the amine is blocked by the anion exchange membrane and remains in the original chamber, thereby achieving the effect of removing HSS from the amine solution.

[0038] In the process flow of CCUS, long-term use of organic amines will degrade and produce heat-stable salts, which not only affect the organic amines but also damage the equipment. This embodiment uses a new type of electrodialysis device to purify the organic amine solution, remove the heat-stable salts therein and ensure a high recovery rate of the organic amine solution, thereby ensuring the continuous and good operation of the entire CCUS system.

[0039] Through the above description, those skilled in the art can already implement it.

[0040] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the utility model. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the utility model are included in the protection scope of the utility model patent. Technicians in the technical field of the utility model can make various modifications or supplements to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should be protected by the utility model.

Claims

1. A novel electrodialysis purification device for chemical absorbent in a CCUS system, comprising a water tank 1 (A), a water tank 2 (B), a water tank 3 (C), a water tank 4 (D), a water tank 5 (E) and a control cabinet (2), characterized in that: It also includes a membrane stack (1), wherein the water tank 1 (A), water tank 2 (B), and water tank 3 (C) are all connected to the core element membrane stack (1) of the electrodialysis purification equipment through pipelines, and the water tank 4 (D) and water tank 5 (E) are connected to the water tank 1 (A) and water tank 2 (B) through pipelines; the membrane stack (1) includes a membrane group body (11), a cathode side (12), an anode side (13), an electrode protection cover (14), an electrode connection point (15), a fixed foot support (16), and a fixing bolt (17); the cathode side (12) is provided with an organic amine solution inlet (N-1), a sodium hydroxide solution outlet (N-2), a cathode liquid inlet (N-3), and a cathode liquid outlet (N-4); the anode side (13) is provided with a sodium hydroxide solution inlet (N-5), an organic amine solution outlet (N-6), and a cathode liquid outlet (N-7). 6), an anode liquid inlet (N-7) and an anode liquid outlet (N-8); the organic amine liquid inlet (N-1) is connected to the outlet of water tank one (A), the sodium hydroxide solution outlet (N-2) is connected to the inlet of water tank two (B), the cathode liquid inlet (N-3) is connected to the outlet of water tank three (C), and the cathode liquid outlet (N-4) is connected to the inlet of water tank three (C); the sodium hydroxide solution inlet (N-5) is connected to the inlet of water tank two (B), the organic amine liquid outlet (N-6) is connected to the inlet of water tank one (A), the anode liquid inlet (N-7) is connected to the outlet of water tank three (C), and the anode liquid outlet (N-8) is connected to the inlet of water tank three (C); the electrode protection cover (14) covers the electrode connection points (15) on both sides, and the electrode connection points (15) are connected to the control cabinet (2).

2. The novel electrodialysis purification equipment for chemical absorbent in CCUS system according to claim 1, characterized in that: The membrane stack (1) further comprises fixing bolts (17), and the electrode protection cover (14) is covered on the electrode connection points (15) on both sides via the bolts (17).

3. The novel electrodialysis purification equipment for chemical absorbent in CCUS system according to claim 1, characterized in that: The electrode connection point (15) is connected to a direct current power supply of the control cabinet (2) via a cable.

4. The novel electrodialysis purification equipment for chemical absorbent in CCUS system according to claim 1, characterized in that: The water tank one (A) is a raw water tank for storing HSS organic amine solution; the water tank two (B) is a sodium hydroxide water tank, the chamber of which contains sodium hydroxide solution; the water tank three (C) is a polar liquid water tank, for storing sodium hydroxide solution serving as polar liquid; the water tank four (D) is a pretreatment water tank, which is provided with a first-level 10um precision filter, a second-level activated carbon filter, and a third-level 5um precision filter element; the water tank five (E) is a dissolution water tank, for preparing the sodium hydroxide solution in the B chamber.

5. The novel electrodialysis purification equipment for chemical absorbent in CCUS system according to claim 1, characterized in that: The loop connecting the water tank 1 (A) and the membrane stack (1) is equipped with a magnetic pump, a pressure gauge and a flow meter.

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