Purification system and method for amine liquid electrically neutral product

Abstract

The invention relates to a purification system and method for amine liquid electro-neutral products, the system comprises a system body, the system body comprises a dissolved organic matter adding module, an electro-neutral product photolysis reaction module and an electrodialysis high-concentration waste liquid photocatalytic degradation module, and the system body can be coupled to an electrodialysis device process of a carbon capture system. According to the invention, the dissolvable organic matter adding module, the electrically neutral product photolysis reaction module and the electrodialysis high-concentration waste liquid photocatalytic degradation module are arranged, and through the process operation of each module, on one hand, the defect that non-ionic pollutants cannot be removed when the amine liquid is purified by the existing electrodialysis technology can be made up; and on the other hand, the problems of complicated operation, solid waste disposal and the like caused by adopting pretreatment methods such as activated carbon removal for adapting to an electrodialysis device can be avoided, the treatment flow is simplified, and a more effective removal effect can be achieved.

Description

Technical Field

[0001] This invention relates to the field of amine liquid purification and recovery technology, specifically to a purification system and method for electrically neutral products of amine liquid. Background Technology

[0002] In chemical absorption systems for CO2 capture, organic amine molecules undergo a reversible reaction with CO2 to generate carbamate and protonated amines. However, due to trace impurities in coal-fired flue gas, such as O2, SO2, and NO2, and the presence of some impurities in industrial absorbents, organic amine absorbents can undergo irreversible chemical reactions with these impurities. These irreversible reactions are collectively referred to as degradation reactions. Different degradation processes, including thermal degradation and oxidative degradation, often occur simultaneously, producing a series of degradation products. Amine degradation products are classified into neutral degradation products and thermally stable salts (HSS) based on their electroneutrality in solution. Neutral products include organic compounds such as amides, organic acids, imidazoles, piperazines, HEEDA, HEIA, and urea. HSS are salts formed by the reaction of amines and their acidic degradation products with impurities (such as organic acids and hydrochloric acid), mainly including formates, acetates, glycolates, oxalates, and sulfates, which cannot be regenerated in the desorption tower.

[0003] The degradation of organic amine absorbents, with the accumulation of degradation products, not only leads to the loss of organic amines in the absorbent but also causes a series of operational problems such as equipment corrosion and system performance degradation. Currently, the most effective method is to purify the organic amine absorbent. Heat recovery, ion exchange resin methods, and electrodialysis are the three most commonly used methods for removing heat-stable salts from amine solutions. However, each method has its advantages and disadvantages. Heat recovery methods have excessively high energy consumption, and the high temperature may further degrade the absorbent. Ion exchange and electrodialysis do not require high temperatures, but ion exchange is only suitable for purifying amine solutions with low concentrations of HSS (Hydrochloric Acid Sediment). In comparison, electrodialysis technology has greater application prospects in amine solution purification and recovery.

[0004] However, current electrodialysis technology is mainly used to remove electrolyte ions from water. It is not effective at removing electrically neutral products, i.e., non-ionic pollutants, uncharged particles such as silicon, boron, and organic particles in water. Some systems choose to add an activated carbon pretreatment stage before the electrodialysis unit, but this raises the question of how to treat and recover the activated carbon that has adsorbed electrically neutral products.

[0005] Therefore, there is an urgent need to develop a new system and method to purify the electrically neutral products of amine solutions. Summary of the Invention

[0006] The purpose of this invention is to provide a purification system and method for electrically neutral products of amine liquid, which can remove non-ionic contaminants and achieve amine liquid purification.

[0007] To achieve the above objectives, the first aspect of the present invention provides a purification system for electrically neutral products of amine liquid, the system comprising: a system body, the system body including a dissolved organic matter addition module, an electrically neutral product photolysis reaction module, and an electrodialysis high-concentration waste liquid photocatalytic degradation module; The dissolved organic matter addition module is provided with a waste amine liquid inlet pipe and a dissolved organic matter inlet pipe on one side, and an outlet pipe on the other side; the outlet pipe is connected to the photolysis reaction module of the electroneutrally neutral product. The photolysis reaction module for the electrically neutral product is equipped with a multi-channel diversion pipe, and a xenon lamp is installed on the upper part of the photolysis reaction module for the electrically neutral product; the multi-channel diversion pipe is connected to the liquid outlet pipe after the removal of the electrically neutral product, and the liquid outlet pipe after the removal of the electrically neutral product is connected to the electrodialysis device. The electrodialysis device is equipped with a highly concentrated waste liquid outlet pipe, which is connected to the electrodialysis highly concentrated waste liquid photocatalytic degradation module. The electrodialysis high-concentration waste liquid photocatalytic degradation module is equipped with a photolysis multi-channel diversion pipe inside, an ultraviolet mercury lamp is installed on the upper part of the electrodialysis high-concentration waste liquid photocatalytic degradation module, and an external discharge pipe is installed on one side of the electrodialysis high-concentration waste liquid photocatalytic degradation module.

[0008] Optionally, the liquid outlet pipe is connected to the multi-channel diversion pipe in the photolysis reaction module of the electrically neutral product.

[0009] Optionally, the multi-channel diversion pipe is made of transparent glass.

[0010] Optionally, the high-concentration waste liquid outlet pipe is connected to the photolysis multi-channel diversion pipe in the electrodialysis high-concentration waste liquid photocatalytic degradation module.

[0011] Optionally, the photolysis multi-channel diversion pipe is made of transparent glass, and the transparent glass is surface-treated with nano-titanium dioxide.

[0012] Optionally, the photolysis multi-channel diversion pipe is connected to the outflow pipe.

[0013] Optionally, the system body is coupled with a CO2 chemical absorption capture system, and the CO2 chemical absorption capture system is equipped with the electrodialysis device.

[0014] A second aspect of the present invention provides a method for purifying electrically neutral products of amine solutions. This method uses the purification system provided in the first aspect of the present invention and includes: The amine solution containing degradation products and the dissolved organic matter are transported to the dissolved organic matter addition module through the waste amine solution inlet pipe and the dissolved organic matter inlet pipe, respectively, for mixing to obtain a mixed solution. The mixed solution is transported through the outlet pipe to the multi-channel diversion pipe in the photolysis reaction module of the electrically neutral product, and photolysis reaction is carried out by a xenon lamp to remove the electrically neutral product. The solution after removing the electrically neutral products is transported to the electrodialysis unit through the after-effects pipeline for treatment of thermally stable salts, resulting in a highly concentrated waste liquid. The highly concentrated waste liquid is transported through the high-concentration waste liquid outlet pipe to the photocatalytic multi-channel diversion pipe in the electrodialysis high-concentration waste liquid photocatalytic degradation module, and undergoes photocatalytic degradation reaction through an ultraviolet mercury lamp. The products after the reaction are discharged through the discharge pipe.

[0015] Optionally, the concentration of the dissolved organic matter is not less than 20 mg / L.

[0016] Optionally, the wavelength of the ultraviolet light generated by the ultraviolet mercury lamp is 180-254nm.

[0017] Through the above technical solution, this invention introduces dissolved organic matter and establishes a photolysis reaction module for electrically neutral products and a photocatalytic degradation module for highly concentrated waste liquid from electrodialysis. This can be coupled to existing carbon capture systems and electrodialysis devices. On the one hand, it can make up for the shortcomings of existing electrodialysis technology in purifying amine liquids by not being able to remove non-ionic pollutants. On the other hand, it can avoid the problems of complex operation and solid waste disposal associated with pretreatment methods such as activated carbon removal for adapting to electrodialysis devices, simplifying the treatment process and achieving a more effective removal effect.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a purification system for electrically neutral products of amine liquid according to the present invention.

[0020] Explanation of reference numerals in the attached figures 1-System body; 2-Dissolved organic matter addition module; 3-Neutral product photolysis reaction module; 4-Photocatalytic degradation module for highly concentrated electrodialysis waste liquid; 5-Waste amine liquid inlet pipe; 6-Dissolved organic matter inlet pipe; 7-Multi-channel diversion pipe; 8-Xenon lamp; 9-Discharge pipe after removal of neutral products; 10-Electrodialysis device; 11-Highly concentrated waste liquid outlet pipe; 12-Photolysis multi-channel diversion pipe; 13-Ultraviolet mercury lamp; 14-External discharge pipe. Detailed Implementation

[0021] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0022] In the description of this invention, it should be noted that the terms "upper," "inner," "one side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] The first aspect of this invention provides a purification system for electrically neutral products of amine solutions, see below. Figure 1 The system includes: a system body 1, which includes a dissolved organic matter addition module 2, an electrically neutral product photolysis reaction module 3, and an electrodialysis high-concentration waste liquid photocatalytic degradation module 4; The dissolved organic matter addition module 2 is provided with a waste amine liquid inlet pipe 5 and a dissolved organic matter inlet pipe 6 on one side, and an outlet pipe on the other side; the outlet pipe is connected to the photolysis reaction module 3 of the electrically neutral product. The photolysis reaction module 3 for electrically neutral products is equipped with a multi-channel diversion pipe 7, and a xenon lamp 8 is installed on the upper part of the photolysis reaction module 3 for electrically neutral products; the multi-channel diversion pipe 7 is connected to the liquid outlet pipe 9 after the removal of electrically neutral products, and the liquid outlet pipe 9 after the removal of electrically neutral products is connected to the electrodialysis device 10. The electrodialysis device 10 is equipped with a highly concentrated waste liquid outlet pipe 11, which is connected to the electrodialysis highly concentrated waste liquid photocatalytic degradation module 4. The electrodialysis high-concentration waste liquid photocatalytic degradation module 4 is equipped with a photolysis multi-channel diversion pipe 12 inside, an ultraviolet mercury lamp 13 is provided on the upper part of the electrodialysis high-concentration waste liquid photocatalytic degradation module 4, and an external discharge pipe 14 is provided on one side of the electrodialysis high-concentration waste liquid photocatalytic degradation module 4.

[0024] According to the present invention, optionally, the waste amine liquid inlet pipe 5 is used to transport the amine liquid to be treated containing degradation products after cooling from the lean liquid cooler of the carbon capture system, and the dissolved organic matter inlet pipe 6 is used to transport dissolved organic matter (DOM) (such as humic acid or tannic acid).

[0025] According to the present invention, optionally, the liquid outlet pipe is connected to the multi-channel diversion pipe 7; used to transport the solution after mixing by the dissolved organic matter addition module 2 to the multi-channel diversion pipe 7 of the photolysis reaction module 3 of the electrically neutral product.

[0026] Optionally, according to the present invention, the multi-channel diversion pipe 7 is used to divide the amine solution to be treated, which has been mixed with dissolved organic matter, into multiple branches. The multi-channel diversion pipe 7 is made of transparent glass, which allows the solution inside the multi-channel diversion pipe 7 to be exposed to the maximum extent within the irradiation range of the xenon lamp 8 above the photolysis reaction module 3 for the neutral product. The xenon lamp 8 can provide light with a full spectrum of wavelengths simulating sunlight, meeting the specific wavelength range of light conditions required for the photolysis of neutral products by dissolved organic matter. The solution after the neutral products have been treated is finally collected into a single neutral product removal outlet pipe 9 through the outlet of the multi-channel diversion pipe 7, and transported to the electrodialysis device 10 coupled to the system for HSS treatment.

[0027] According to the present invention, optionally, the high-concentration waste liquid outlet pipe 11 is connected to the photolysis multi-channel diversion pipe 12; used to transport the high-concentration waste liquid to the photolysis multi-channel diversion pipe 12 of the electrodialysis high-concentration waste liquid photocatalytic degradation module 4.

[0028] According to the present invention, optionally, the photolysis multi-channel diversion pipe 12 is made of transparent glass, and the transparent glass is surface-treated with nano-titanium dioxide. After the highly concentrated waste liquid is diverted, it undergoes photolysis treatment under the catalysis of nano-titanium dioxide.

[0029] According to the present invention, optionally, the ultraviolet mercury lamp 13 is used to generate 254nm ultraviolet light, which can provide light in a specific wavelength range required for photocatalytic degradation reaction on the one hand, and can also generate ozone to deeply oxidize pollutants in highly concentrated waste liquid on the other hand.

[0030] According to the present invention, optionally, the photocatalytic multi-channel diversion pipe 12 is connected to the discharge pipe 14 for discharging the products of the photocatalytic degradation reaction from the discharge pipe 14.

[0031] According to the present invention, optionally, the system body 1 is coupled with a CO2 chemical absorption capture system, and the CO2 chemical absorption capture system is provided with the electrodialysis device 10.

[0032] A second aspect of the present invention provides a method for purifying electrically neutral products of amine solutions. This method uses the purification system provided in the first aspect of the present invention and includes: The amine solution containing degradation products and the dissolved organic matter are transported to the dissolved organic matter addition module 2 through the waste amine solution inlet pipe 5 and the dissolved organic matter inlet pipe 6 respectively for mixing to obtain a mixed solution. The mixed solution is transported through the outlet pipe to the multi-channel diversion pipe 7 in the photolysis reaction module 3 for electrically neutral products, and photolysis reaction is carried out by the xenon lamp 8 to remove electrically neutral products. The solution after removing the neutral products is transported to the electrodialysis unit 10 through the neutral product removal outlet pipe 9 for treatment of thermally stable salts, resulting in highly concentrated waste liquid. The highly concentrated waste liquid is transported through the highly concentrated waste liquid outlet pipe 11 to the photolysis multi-channel diversion pipe 12 in the electrodialysis highly concentrated waste liquid photocatalytic degradation module 4, and undergoes photocatalytic degradation reaction through the ultraviolet mercury lamp 13. The products after the reaction are discharged through the discharge pipe 14.

[0033] In a specific embodiment of the present invention, the system body 1 can be coupled to a CO2 chemical absorption capture system equipped with electrodialysis purification of amine solution, and connected through corresponding pipelines. The amine solution to be treated, containing degradation products, after being cooled by the lean solution cooler of the capture system, is transported to the dissolved organic matter (DOM) addition module 2 through the waste amine solution inlet pipeline 5 on one side of the module. The DOM inlet pipeline 6 on the same side is used to transport DOM (such as humic acid or tannic acid) to the module, ensuring that the DOM concentration entering the module is not less than 20 mg / L. The amine solution to be treated and DOM are mixed in the dissolved organic matter (DOM) addition module 2 and then transported to the photolysis reaction module 3 of the electrically neutral product.

[0034] In the photolysis reaction module 3 of the neutral product of this invention, the mixed amine solution and dissolved organic matter (DOM) are divided into multiple branches through the multi-channel diversion pipe 7 inside the module. The transparent glass material of the pipe allows sufficient light emitted by the xenon lamp 8 at the top of the module to pass through. The xenon lamp 8 can simulate sunlight irradiation conditions. The numerous chromophores in the DOM molecules can directly absorb photons and form unstable singlet states (…). 1 DOM * )or 3 DOM * On the one hand, it undergoes reactions such as cracking, rearrangement, or dissociation; on the other hand, it can react with O2 and H2O to generate hydroxyl radicals (HO·) and singlet oxygen (…). 1 O2), superoxide ions (O2· - The active substances, such as hydrogen peroxide (H2O2), react with the electrically neutral products through a photolysis reaction. The solution containing the neutral products is then collected through a multi-channel branch pipe and finally converged into a single outlet pipe 9, which is then transported to the system-coupled electrodialysis unit 10 for HSS treatment.

[0035] The highly concentrated waste liquid generated in the electrodialysis device 10 is transported to the electrodialysis highly concentrated waste liquid photocatalytic degradation module 4 of this invention through the highly concentrated waste liquid outlet pipe 11, where it is diverted within the photolysis multi-channel diversion pipe 12 inside the module. The ultraviolet mercury lamp 13 at the top of the module generates 254nm ultraviolet light, providing light within the specific wavelength range required for the photolysis catalytic degradation reaction. Under the action of ultraviolet light, the nano-titanium dioxide on the surface of the photolysis multi-channel diversion pipe 12 catalyzes the photocatalytic degradation reaction of the highly concentrated waste liquid inside the pipe, and also promotes the reaction of oxygen to generate ozone, thereby generating active substances such as H2O2, deeply oxidizing the pollutants in the highly concentrated waste liquid. HSS substances, represented by formate, can ultimately be degraded into CO2 and H2O in this module, and discharged through the external discharge pipe 14 on one side of the module.

[0036] Through the above implementation method, the dissolved organic matter (DOM) addition module 2 of the system body 1 introduces DOM into the amine solution to be treated. In the photolysis reaction module 3 of the electrically neutral products, simulated sunlight provided by the xenon lamp 8 promotes the activation of DOM, thereby triggering the photolysis reaction of the electrically neutral products in the amine solution to be treated, which compensates for the inability of the electrodialysis device to remove non-ionized pollutants. At the same time, the photolysis reaction products of the electrically neutral products are mostly small molecules, which can be processed in the electrodialysis device 10. The resulting highly concentrated waste liquid is transported to the electrodialysis highly concentrated waste liquid photocatalytic degradation module 4. Under the ultraviolet light provided by the ultraviolet mercury lamp 13, a photocatalytic degradation reaction occurs in the photolysis multi-channel diversion pipe 12, ultimately generating CO2 and H2O for discharge. The products are relatively simple, and the problem of difficult solid waste treatment that exists with pretreatment methods such as activated carbon is avoided. The system has better adaptability, a relatively simple treatment process, and better removal effect.

[0037] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0038] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0039] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A purification system for electrically neutral products of amine solutions, characterized in that, The system includes: a system body (1), which includes a dissolved organic matter addition module (2), an electrically neutral product photolysis reaction module (3), and an electrodialysis high-concentration waste liquid photocatalytic degradation module (4). The dissolved organic matter addition module (2) is provided with a waste amine liquid inlet pipe (5) and a dissolved organic matter inlet pipe (6) on one side, and an outlet pipe on the other side; the outlet pipe is connected to the photolysis reaction module (3) of the electrically neutral product; The photolysis reaction module (3) for the neutral products is equipped with a multi-channel diversion pipe (7), and a xenon lamp (8) is installed on the upper part of the photolysis reaction module (3); the multi-channel diversion pipe (7) is connected to the liquid outlet pipe (9) after the removal of the neutral products, and the liquid outlet pipe (9) after the removal of the neutral products is connected to the electrodialysis device (10). The electrodialysis device (10) is equipped with a high-concentration waste liquid outlet pipe (11), which is connected to the electrodialysis high-concentration waste liquid photocatalytic degradation module (4). The electrodialysis high-concentration waste liquid photocatalytic degradation module (4) is equipped with a photolysis multi-channel diversion pipe (12) inside, an ultraviolet mercury lamp (13) is provided on the upper part of the electrodialysis high-concentration waste liquid photocatalytic degradation module (4), and an external discharge pipe (14) is provided on one side of the electrodialysis high-concentration waste liquid photocatalytic degradation module (4).

2. The purification system according to claim 1, wherein, The liquid outlet pipe is connected to the multi-channel diversion pipe (7) in the photolysis reaction module (3) of the electrically neutral product.

3. The purification system according to claim 1, wherein, The multi-channel diversion pipe (7) is made of transparent glass.

4. The purification system according to claim 1, wherein, The high-concentration waste liquid outlet pipe (11) is connected to the photolysis multi-channel diversion pipe (12) in the electrodialysis high-concentration waste liquid photocatalytic degradation module (4).

5. The purification system according to claim 1, wherein, The photolysis multichannel diversion pipe (12) is made of transparent glass, and the transparent glass is surface treated with nano titanium dioxide.

6. The purification system according to claim 1, wherein, The photolysis multichannel diversion pipe (12) is connected to the outflow pipe (14).

7. The purification system according to claim 1, wherein, The system body (1) is coupled with a CO2 chemical absorption capture system, and the CO2 chemical absorption capture system is equipped with the electrodialysis device (10).

8. A method for purifying the electrically neutral products of amine solutions, characterized in that, This method uses the purification system of any one of claims 1-7, and the method comprises: The amine solution containing degradation products and the dissolved organic matter are transported to the dissolved organic matter addition module (2) through the waste amine solution inlet pipe (5) and the dissolved organic matter inlet pipe (6) respectively for mixing to obtain a mixed solution; The mixed solution is transported through the outlet pipe to the multi-channel diversion pipe (7) in the photolysis reaction module (3) for neutral products, and photolysis reaction is carried out by the xenon lamp (8) to remove neutral products; The solution after removing the neutral products is transported to the electrodialysis unit (10) through the neutral product removal outlet pipe (9) for treatment of thermally stable salts to obtain highly concentrated waste liquid. The highly concentrated waste liquid is transported through the highly concentrated waste liquid outlet pipe (11) to the photolysis multi-channel diversion pipe (12) in the electrodialysis highly concentrated waste liquid photocatalytic degradation module (4), and photocatalytic degradation reaction is carried out through the ultraviolet mercury lamp (13). The reaction product is discharged through the discharge pipe (14).

9. The purification method according to claim 8, wherein, The concentration of the dissolved organic matter is not less than 20 mg / L.

10. The purification method according to claim 8, wherein, The ultraviolet light produced by the ultraviolet mercury lamp (13) has a wavelength of 180-254nm.

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