Working method of carbon dioxide composite absorption liquid

Abstract

The invention belongs to the technical field of gas absorption liquid preparation, and discloses a working method of a carbon dioxide composite absorption liquid, the working method comprises a composite absorption liquid body, absorption liquid preparation, an absorption process, a regeneration process and discharge treatment, the main raw materials of the composite absorption liquid body comprise a main absorbent, an auxiliary absorbent, a catalyst and an auxiliary additive, through the arranged composite absorption liquid body, absorption liquid preparation, absorption process and pH value detection device, the main raw materials are added into a reaction container according to a certain proportion and uniformly stirred, all the components can be fully mixed and dissolved, waste gas containing carbon dioxide is introduced into the bottom of an absorption tower, the waste gas is fully contacted with the absorption liquid, and the absorption process is completed. Carbon dioxide in the waste gas reacts with amine compounds in the absorption liquid and is absorbed into the absorption liquid, a pH value detection device is arranged in the absorption process, the pH value of the absorption liquid is detected regularly, and a buffering agent is added to adjust the pH value when necessary so as to keep the pH value within the optimal absorption range.

Description

Technical Field

[0001] The invention relates to the technical field of gas absorption liquid preparation, in particular to a working method of a carbon dioxide composite absorption liquid. Background Art

[0002] Carbon dioxide composite absorption liquid is a liquid containing multiple chemical components that can efficiently absorb and fix carbon dioxide. Its working principle is mainly based on chemical reactions. When carbon dioxide gas comes into contact with the absorption liquid, a chemical reaction will occur between them to generate unstable salts (such as amino acid salts or carbonates). These salts can decompose under specific temperature and pressure conditions, thereby releasing carbon dioxide and restoring the absorbent, realizing the regeneration and recycling of the absorbent. With the intensification of global climate change, reducing greenhouse gas emissions, especially carbon dioxide emissions, has become a hot topic of global concern. However, traditional absorption liquids have problems such as low absorption efficiency, high regeneration energy consumption, and complex emission treatment. Therefore, the development of a high-efficiency, low-energy-consumption, easy-to-regenerate and emission-treatment carbon dioxide composite absorption liquid and its treatment method is of great significance for achieving green treatment of industrial waste gas.

[0003] However, there are still some problems in the use of the existing working method of carbon dioxide composite absorption liquid: There is a CO2 composite absorption liquid body and its preparation method and application, such as the Chinese patent application number 202010476388.8. The absorption liquid includes ethyleneamine and sterically hindered amine; the sterically hindered amine includes menthane diamine and / or 2-piperidine ethanol. The CO2 composite absorption liquid body has a high absorption rate, a large absorption amount, a fast regeneration speed, and high reusability; this is because the carbon source connected to the sterically hindered amine and the amino group is a branched substituent, which can produce an obvious steric hindrance effect. After absorbing carbon dioxide, compared with other substances that absorb carbon dioxide, the CO2 composite absorption liquid body provided by the present invention has a weaker force with carbon dioxide, which helps to desorb carbon dioxide from the absorption liquid, so that the carbon dioxide absorption liquid has good regeneration efficiency, reusability and easy desorption, which helps to reduce the desorption energy consumption of the CO2 composite absorption liquid and accelerate the desorption of the CO2 composite absorption liquid. The composite absorption liquid uses ethyleneamine and sterically hindered amine. Although the absorption liquid has a high absorption rate and regeneration speed, its stability may be affected by various factors, such as temperature, pressure, pH value, etc., and some chemical components may corrode equipment or pipelines, and additional anti-corrosion measures need to be taken. In addition, no exhaust gas monitoring device is set during emission treatment. If the exhaust gas is discharged without meeting the standards, it is easy to cause a certain impact on the environment.

[0004] In view of the above problems, an innovative design is carried out on the basis of the original working method of the carbon dioxide composite absorption liquid. Summary of the invention

[0005] The object of the present invention is to provide a working method of a carbon dioxide composite absorption liquid to solve the problem that the existing composite absorption liquid proposed in the above background technology uses ethyleneamine and sterically hindered amine, but the absorption liquid has a high absorption rate and regeneration speed, but its stability may be affected by various factors, such as temperature, pressure, pH value, etc., and some chemical components may corrode equipment or pipelines, and additional anti-corrosion measures need to be taken. In addition, during emission treatment, no exhaust gas monitoring device is set. If the exhaust gas is discharged without meeting the standards, it is easy to cause a certain impact on the environment.

[0006] To achieve the above object, the present invention provides the following technical solution: a working method of a carbon dioxide composite absorption liquid, comprising a composite absorption liquid body, preparation of the absorption liquid, an absorption process, a regeneration process and a discharge treatment, characterized in that it comprises the following steps: S1. Composite absorption liquid body: the main raw materials include main absorbent, auxiliary absorbent, catalyst and auxiliary additives; S2. Preparation of absorption liquid: The above main raw materials need to be mixed evenly in a certain proportion to form a carbon dioxide composite absorption liquid body; S3, absorption process: the waste gas containing carbon dioxide is passed into the absorption tower filled with the absorption liquid obtained in step S1, and the carbon dioxide in the waste gas reacts with the absorption liquid and is absorbed into the absorption liquid; S4, regeneration process: heating or reducing the pressure of the absorption liquid obtained in step S2 and the saturated carbon dioxide obtained in step S3, and desorbing the carbon dioxide from the absorption liquid; S5. Emission treatment: The carbon dioxide obtained in step S4 can be further treated and utilized.

[0007] The above main raw materials are added into the reaction container in a certain proportion, stirred evenly, and then stirred, mixed and dissolved by adding water. The stirring time and speed need to be adjusted according to the specific situation to ensure that the components can be fully mixed and dissolved. The waste gas containing carbon dioxide is introduced into the bottom of the absorption tower. The waste gas passes through the filler or spray device from bottom to top and is fully in contact with the absorption liquid. The carbon dioxide in the waste gas reacts with the amine compounds in the absorption liquid and is absorbed into the absorption liquid. During the absorption process, a pH value detection device is provided to regularly detect the pH value of the absorption liquid. If necessary, a buffer is added to adjust the pH value to keep it in the optimal absorption range.

[0008] Preferably, in the step S1, the main absorbent comprises sodium hydroxide (NaOH), potassium hydroxide (KOH), etc., as the main CO2 absorbent, and the auxiliary absorbent adopts sterically hindered amines, and the sterically hindered amines comprise menthanediamine and / or 2-piperidineethanol.

[0009] As a preferred technical solution of the present invention, the carbon source connected to the amine group in the sterically hindered amine has a branched substituent, which can produce a significant steric hindrance effect and help desorb carbon dioxide from the absorption liquid.

[0010] Preferably, the catalyst in step S1 uses copper ions (Cu²⁺) and iron ions (Fe³⁺) to ensure the acceleration of the reaction between carbon dioxide and the composite absorption liquid.

[0011] As the preferred technical solution of the present invention, the reaction rate and absorption efficiency of carbon dioxide and the composite absorption liquid body are significantly improved. At the same time, by optimizing the absorption liquid composition and process design, the regeneration and recycling of the absorption liquid are realized, reducing energy consumption and costs.

[0012] Preferably, in step S1, the auxiliary additives are surfactants and stabilizers, and the surface additive is dodecyl sulfuric acid (SDS).

[0013] As a preferred technical solution of the present invention, the surface additive can improve the surface tension of the absorbing liquid and promote gas-liquid contact.

[0014] Preferably, in step S1, the stabilizer is a buffer sodium bicarbonate (NaHCO3) and an inhibitor benzotriazole (BTA).

[0015] As a preferred technical solution of the present invention, sodium bicarbonate (NaHCO3) in the buffer can maintain the pH value of the absorption liquid stable, and benzotriazole (BTA) in the inhibitor can prevent metal corrosion during the absorption process.

[0016] Preferably, the prepared absorption liquid in step S2 needs to be added into the reaction container in a certain proportion and stirred evenly, and then stirred, mixed and dissolved by adding water.

[0017] As a preferred technical solution of the present invention, the absorption efficiency and regeneration performance need to be balanced through the selection of the ratio. A certain ratio can ensure that there will be no negative impact on the performance of the composite absorption liquid body. The stirring time and speed also need to be adjusted according to the specific situation to ensure that the various components can be fully mixed and dissolved.

[0018] Preferably, the absorption process in step S3 uses an absorption tower filled with absorption liquid, and a pH value detection device is provided during the absorption process.

[0019] As a preferred technical solution of the present invention, waste gas containing carbon dioxide is introduced into the bottom of the absorption tower, and the gas passes through the filler or spray device from bottom to top, fully contacts with the absorption liquid, and reacts with the amine compounds in the absorption liquid. The pH value detection device can regularly detect the pH value of the absorption liquid, and add a buffer to adjust it when necessary to keep it in the optimal absorption range.

[0020] Preferably, a desorption tower is provided in the regeneration process in step S4, and carbon dioxide is desorbed from the absorption liquid by heating or reducing pressure, and the absorption liquid enriched with carbon dioxide is pumped into the desorption tower, and a flow control device and a temperature control device are provided in the regeneration process.

[0021] As a preferred technical solution of the present invention, heating or other physical methods are used to promote the desorption of carbon dioxide from the absorption liquid, and the absorption liquid after absorption is treated by a regeneration device to restore its absorption capacity.

[0022] Preferably, the emission treatment in step S5 can recycle the desorbed carbon dioxide, and a monitoring device is provided in the emission treatment.

[0023] As a preferred technical solution of the present invention, the carbon dioxide desorbed from the carbon dioxide is concentrated and purified, and then the carbon dioxide concentration and other pollutant content in the exhaust gas are monitored in real time by a monitoring device during discharge to ensure that the emission meets the standards, establish a recycling system, and reintroduce the purified carbon dioxide into the production process or use it for other industrial purposes to maximize resource utilization.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: the working method of the carbon dioxide composite absorption liquid comprises the following steps: adding the above main raw materials into a reaction container in a certain proportion through the provision of a composite absorption liquid body, preparing the absorption liquid, absorbing process and a pH value detection device, stirring and mixing and dissolving the above main raw materials in a uniform manner, adding water for stirring, mixing and dissolving, and adjusting the stirring time and speed according to the specific situation to ensure that the various components can be fully mixed and dissolved, introducing the waste gas containing carbon dioxide into the bottom of the absorption tower, passing the waste gas from bottom to top through the filler or the spraying device to fully contact with the absorption liquid, reacting the carbon dioxide in the waste gas with the amine compound in the absorption liquid and being absorbed into the absorption liquid, and providing a pH value detection device during the absorption process to regularly detect the pH value of the absorption liquid, and adding a buffer (such as sodium bicarbonate) to adjust the pH value when necessary to keep it within the optimal absorption range.

[0025] 1. Through the regeneration process, desorption tower, flow control device and temperature control device, the absorption liquid enriched with carbon dioxide is pumped into the desorption tower, and the carbon dioxide is desorbed from the absorption liquid by heating or decompression. The flow rate of the absorption liquid entering the desorption tower is controlled by the flow control device, and then the temperature in the desorption process is controlled by the temperature control device to ensure the desorption efficiency; 2. Through the emission treatment and monitoring devices set up, the carbon dioxide desorbed is concentrated and purified, and the monitoring device monitors the carbon dioxide concentration and other pollutant content in the exhaust gas in real time during emission to ensure that the emission meets the standards. A recycling system is established to reintroduce the purified carbon dioxide into the production process or use it for other industrial purposes to maximize resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the present invention.

[0027] In the figure: 100, composite absorption liquid body; 101, preparation of absorption liquid; 200, absorption process; 201, pH value detection device; 300, regeneration process; 301, desorption tower; 302, flow control device; 303, temperature control device; 400, emission treatment; 401, monitoring device. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1 The present invention provides a technical solution: a working method of a carbon dioxide composite absorption liquid, comprising a composite absorption liquid body 100, an absorption liquid preparation 101, an absorption process 200, a regeneration process 300 and a discharge treatment 400, characterized in that it comprises the following steps: S1, composite absorption liquid body 100: main raw materials include main absorbent, auxiliary absorbent, catalyst and auxiliary additives; S2, preparing the absorption liquid 101: the above main raw materials are mixed evenly according to a certain proportion to form a carbon dioxide composite absorption liquid body 100; S3, absorption process 200: the exhaust gas containing carbon dioxide is passed into an absorption tower filled with the absorption liquid obtained in step S1, and the carbon dioxide in the exhaust gas reacts with the absorption liquid and is absorbed into the absorption liquid; S4, regeneration process 300: heating or reducing the pressure of the absorption liquid obtained in step S2 and the saturated carbon dioxide obtained in step S3, and desorbing the carbon dioxide from the absorption liquid; S5. Emission treatment 400: The carbon dioxide obtained in step S4 can be further processed and utilized. The above main raw materials are added into a reaction container in a certain proportion, stirred evenly, and then stirred, mixed and dissolved by adding water. The stirring time and speed need to be adjusted according to the specific situation to ensure that the various components can be fully mixed and dissolved. The waste gas containing carbon dioxide is introduced into the bottom of the absorption tower. The waste gas passes through the filler or spray device from bottom to top and is fully in contact with the absorption liquid. The carbon dioxide in the waste gas reacts with the amine compounds in the absorption liquid and is absorbed into the absorption liquid. In the absorption process 200, a pH value detection device 201 is provided to regularly detect the pH value of the absorption liquid. If necessary, a buffer such as sodium bicarbonate is added to adjust the pH value to keep it in the optimal absorption range.

[0030] In step S1, the main absorbent includes sodium hydroxide NaOH, potassium hydroxide KOH, etc., as the main CO2 absorbent, and the auxiliary absorbent adopts sterically hindered amines, which include menthane diamine and / or 2-piperidine ethanol. The carbon source connected to the amine group in the sterically hindered amine has a branched substituent, which can produce a significant steric hindrance effect and help desorb carbon dioxide from the absorption liquid.

[0031] In step S1, the catalyst uses copper ions Cu²⁺ and iron ions Fe³⁺ to ensure the acceleration of the reaction between carbon dioxide and the composite absorption liquid body 100, which significantly improves the reaction rate and absorption efficiency of carbon dioxide and the composite absorption liquid body 100. At the same time, by optimizing the absorption liquid composition and process design, the regeneration and recycling of the absorption liquid are achieved, reducing energy consumption and costs.

[0032] In step S1, the auxiliary additives include surfactants and stabilizers, and the surface additive includes dodecyl sulfate (SDS). The surface additive can improve the surface tension of the absorption liquid and promote gas-liquid contact.

[0033] In step S1, the stabilizer is a buffer sodium bicarbonate NaHCO3 and an inhibitor benzotriazole BTA. The sodium bicarbonate NaHCO3 in the buffer can maintain the pH value of the absorption liquid stable, and the benzotriazole BTA in the inhibitor can prevent metal corrosion during the absorption process 200.

[0034] The prepared absorption liquid 101 in step S2 needs to be added to the reaction container in a certain proportion and stirred evenly, and then stirred, mixed and dissolved by adding water. The selection of the proportion needs to balance the absorption efficiency and regeneration performance. A certain proportion can ensure that there will be no negative impact on the performance of the composite absorption liquid body 100. The stirring time and speed also need to be adjusted according to the specific situation to ensure that the various components can be fully mixed and dissolved.

[0035] In step S3, the absorption process 200 uses an absorption tower filled with absorption liquid, and a pH value detection device 201 is provided in the absorption process 200. The waste gas containing carbon dioxide is introduced into the bottom of the absorption tower. The gas passes through the filler or the spray device from bottom to top, fully contacts with the absorption liquid, and reacts with the amine compounds in the absorption liquid. The pH value detection device 201 can regularly detect the pH value of the absorption liquid, and add a buffer to adjust it when necessary to keep it in the optimal absorption range.

[0036] In step S4, the regeneration process 300 is provided with a desorption tower 301, and the carbon dioxide is desorbed from the absorption liquid by heating or reducing pressure, and the absorption liquid enriched with carbon dioxide is pumped into the desorption tower 301. In addition, the regeneration process 300 is provided with a flow control device 302 and a temperature control device 303, and the carbon dioxide is desorbed from the absorption liquid by heating or other physical methods. The absorption liquid after absorption is treated by the regeneration device to restore its absorption capacity.

[0037] In step S5, the emission treatment 400 can recycle the desorbed carbon dioxide, and a monitoring device 401 is provided in the emission treatment 400. After the carbon dioxide desorbed is concentrated and purified, the monitoring device 401 monitors the carbon dioxide concentration and other pollutant contents in the exhaust gas in real time during emission to ensure that the emission meets the standards, establish a recycling system, and reintroduce the purified carbon dioxide into the production process or use it for other industrial purposes to maximize resource utilization.

[0038] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field. Although the embodiments of the present invention have been shown and described, it is understood by ordinary technicians in the field that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for operating a carbon dioxide composite absorption liquid, comprising a composite absorption liquid body (100), preparing an absorption liquid (101), an absorption process (200), a regeneration process (300) and a discharge treatment (400), characterized in that: The following steps are involved: S1, composite absorption liquid body (100): main raw materials include main absorbent, auxiliary absorbent, catalyst and auxiliary additives; S2, preparing an absorption liquid (101): the above main raw materials are mixed evenly according to a certain proportion to form a carbon dioxide composite absorption liquid body (100); S3, absorption process (200): the exhaust gas containing carbon dioxide is introduced into an absorption tower filled with the absorption liquid obtained in step S1, and the carbon dioxide in the exhaust gas reacts with the absorption liquid and is absorbed into the absorption liquid; S4, regeneration process (300): heating or reducing the pressure of the absorption liquid obtained in step S2 and the saturated carbon dioxide obtained in step S3, and desorbing the carbon dioxide from the absorption liquid; S5. Emission treatment (400): The carbon dioxide obtained in step S4 can be further treated and utilized.

2. The working method of a carbon dioxide composite absorption liquid according to claim 1, characterized in that: In the step S1, the main absorbent includes sodium hydroxide (NaOH), potassium hydroxide (KOH), etc., as the main CO2 absorbent, and the auxiliary absorbent uses sterically hindered amines, and the sterically hindered amines include menthane diamine and / or 2-piperidine ethanol.

3. The working method of a carbon dioxide composite absorption liquid according to claim 2, characterized in that: In the step S1, the catalyst uses copper ions (Cu²⁺) and iron ions (Fe³⁺) to ensure the acceleration of the reaction between carbon dioxide and the composite absorption liquid body (100).

4. The working method of a carbon dioxide composite absorption liquid according to claim 1, characterized in that: In the step S1, the auxiliary additives include surfactants and stabilizers, and the surface additive includes dodecyl sulfuric acid (SDS).

5. The working method of a carbon dioxide composite absorption liquid according to claim 1, characterized in that: The stabilizer is a buffer sodium bicarbonate (NaHCO3) and an inhibitor benzotriazole (BTA).

6. The working method of a carbon dioxide composite absorption liquid according to claim 1, characterized in that: The prepared absorption liquid (101) in step S2 needs to be added into the reaction container in a certain proportion and stirred evenly, and then water is added to stir, mix and dissolve.

7. The working method of a carbon dioxide composite absorption liquid according to claim 1, characterized in that: The absorption process (200) in step S3 uses an absorption tower filled with absorption liquid, and a pH value detection device (201) is provided in the absorption process (200).

8. The working method of a carbon dioxide composite absorption liquid according to claim 1, characterized in that: In the S4 step, the regeneration process (300) is provided with a desorption tower (301), and carbon dioxide is desorbed from the absorption liquid by heating or reducing pressure, and the absorption liquid enriched with carbon dioxide is pumped into the desorption tower (301), and the regeneration process (300) is provided with a flow control device (302) and a temperature control device (303).

9. The working method of a carbon dioxide composite absorption liquid according to claim 1, characterized in that: The emission treatment (400) in step S5 can recycle the desorbed carbon dioxide, and a monitoring device (401) is provided in the emission treatment (400).

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