Antioxidant for carbon capture composite amine absorbent and preparation method thereof

Abstract

The invention relates to the technical field of carbon capture, in particular to an antioxidant for a carbon capture composite amine absorbent and a preparation method of the antioxidant, and the antioxidant comprises the following raw materials in parts by weight: 30-60 parts of a sulfur-containing organic compound, 20-40 parts of a metal complex and 10-30 parts of a high-molecular polymer; wherein the sulfur-containing organic compound has a sulfur-carbon bonded conjugated system; the metal complex is a complex formed by transition metal ions and an organic ligand containing nitrogen and oxygen coordination atoms; the high-molecular polymer comprises any one or more of a polyethylene glycol derivative, polyvinylpyrrolidone, polyacrylic acid and polymethyl methacrylate. The antioxidant provided by the invention has excellent oxidation resistance and good stability in the carbon capture composite amine absorbent, does not influence the absorption performance of the composite amine absorbent on carbon dioxide, and can effectively ensure the efficient and stable operation of the carbon capture process.

Description

Technical Field

[0001] The invention relates to the technical field of carbon capture, in particular to an antioxidant for a carbon capture composite amine absorbent and a preparation method thereof. Background Art

[0002] In the field of carbon capture, composite amine absorbents are widely used because of their high efficiency in absorbing carbon dioxide when in contact with it. These absorbents are usually composed of a combination of various amines such as ethanolamine (MEA) and N-methyldiethanolamine (MDEA), and they perform well in capturing carbon dioxide. However, composite amine absorbents face a severe challenge in practical applications, namely, they are easily affected by oxidation.

[0003] The oxidation reaction mainly comes from the aerobic environment in the carbon capture process. Whether it is the oxygen carried in the raw gas or the oxygen introduced by the system leakage, it will trigger the oxidation reaction of the complex amine absorbent. This oxidation reaction will not only lead to the decline of the absorbent performance and shorten its service life, but also produce degradation products, further affecting the physical and chemical properties of the absorbent and reducing the absorption efficiency of carbon dioxide.

[0004] In order to solve the oxidation problem of complex amine absorbents, some studies and applications have tried to use antioxidants. Although traditional sulfite antioxidants can delay the oxidation of absorbents to a certain extent, their antioxidant effect is significantly reduced under complex operating conditions such as long-term operation or high temperature. In addition, although some organic antioxidants show certain antioxidant ability in the initial stage, they have poor stability in the absorbent system and may interact with the components in the complex amine absorbent, affecting the absorbent's absorption performance for carbon dioxide, or decompose and fail in the absorbent.

[0005] Therefore, the antioxidants in the prior art generally have the following problems:

[0006] 1. Limited antioxidant effect: It is impossible to effectively inhibit the oxidation of the complex amine absorbent under long-term and complex working conditions, resulting in a decrease in absorbent performance and shortening the service life of the absorbent. In addition, the degradation products produced by the oxidation reaction may further affect the physical and chemical properties of the absorbent and reduce the absorption efficiency of carbon dioxide.

[0007] 2. Negative impact on absorption performance: while inhibiting oxidation, some antioxidants change the chemical balance of the composite amine absorbent or react with amine components, thereby affecting the absorbent's key performance indicators such as carbon dioxide absorption capacity and absorption rate, which is not conducive to the efficient implementation of the carbon capture process.

[0008] 3. Insufficient stability: Many antioxidants have poor stability in the complex amine absorbent system and cannot continue to exert their antioxidant effects, so the oxidation problem cannot be fundamentally solved.

[0009] In view of this, the present invention proposes a new and efficient antioxidant, which can effectively improve the antioxidant properties of the complex amine absorbent and extend its service life while avoiding negative effects on the absorption performance of the absorbent. It also has good stability and can continue to exert an antioxidant effect under complex working conditions. Summary of the invention

[0010] The object of the present invention is to provide an antioxidant for a carbon capture composite amine absorbent and a preparation method thereof. The antioxidant of the present invention has excellent antioxidant performance and good stability in the carbon capture composite amine absorbent, and will not affect the absorption performance of the composite amine absorbent for carbon dioxide, and can effectively ensure the efficient and stable operation of the carbon capture process.

[0011] In a first aspect, the present invention provides an antioxidant for a carbon capture composite amine absorbent, comprising the following raw materials in parts by weight:

[0012] 30-60 parts of sulfur-containing organic compounds, 20-40 parts of metal complexes and 10-30 parts of high molecular polymers; wherein the sulfur-containing organic compounds have a sulfur-carbon bond conjugated system; the metal complexes are complexes formed by transition metal ions and organic ligands containing nitrogen and oxygen coordination atoms; the high molecular polymers include any one or more of polyethylene glycol derivatives, polyvinyl pyrrolidone, polyacrylic acid and polymethyl methacrylate, wherein the polyethylene glycol derivatives include tetrapolyethylene glycol monolauryl ether, polyethylene glycol monolaurate, polyethylene glycol dimethacrylate, polyethylene glycol monomethyl ether, dodecyl heptapolyethylene glycol ether, polyethylene glycol diacrylate, polyethylene glycol dimethyl ether and the like.

[0013] The antioxidant for the carbon capture complex amine absorbent of the present invention comprises a sulfur-containing organic compound, a metal complex and a high molecular polymer, wherein the sulfur-containing organic compound has a unique sulfur-carbon bond conjugated system, so that it can react quickly with oxygen in the complex amine absorbent system; the metal complex is a complex formed by a transition metal ion and an organic ligand containing nitrogen and oxygen coordination atoms, and the metal complex can synergistically act with the sulfur-containing organic compound to promote the antioxidant reaction and further improve the antioxidant efficiency; the high molecular polymer comprises any one or more of polyethylene glycol derivatives, polyvinyl pyrrolidone, polyacrylic acid and polymethyl methacrylate, which has good chemical stability and solubility, can effectively improve the stability of the antioxidant in the complex amine absorbent, and prevent the antioxidant from agglomerating, precipitating or decomposing in the complex amine absorbent. In addition, the presence of the high molecular polymer also helps to maintain the uniformity and fluidity of the complex amine absorbent, ensuring its efficient operation in the carbon capture process. Therefore, the antioxidant of the present invention has excellent antioxidant performance and good stability in the carbon capture composite amine absorbent, and will not affect the absorption performance of the composite amine absorbent for carbon dioxide, and can effectively ensure the efficient and stable operation of the carbon capture process.

[0014] The metal complex used in the present invention is formed by a transition metal ion and an organic ligand containing nitrogen and oxygen coordination atoms. Wherein, the transition metal ion has an unfilled d orbital and can accept or provide electrons, thereby reacting with oxygen or other oxidants. The organic ligand can form a stable complex structure with the transition metal ion through the nitrogen and oxygen coordination atoms thereon. This structure not only enhances the stability of the metal complex, but also enables it to have synergistic effects such as electron transfer and free radical capture with sulfur-containing organic compounds, jointly promoting the progress of the antioxidant reaction, thereby further improving the antioxidant efficiency.

[0015] Specifically, the transition metal ion used in the present invention is preferably any one of manganese ion and copper ion, and the organic ligand includes any one of ethylenediamine, 8-hydroxyquinoline and o-phenanthroline.

[0016] In a second aspect, the present invention also discloses a method for preparing the antioxidant for the carbon capture composite amine absorbent, comprising the following steps:

[0017] The sulfur-containing organic compound, the metal complex and the high molecular polymer are stirred and mixed uniformly at room temperature to obtain an antioxidant for a carbon capture composite amine absorbent.

[0018] The preparation method of the antioxidant for the carbon capture composite amine absorbent of the present invention is simple and convenient, and only requires stirring and mixing the sulfur-containing organic compound, the metal complex and the high molecular polymer at room temperature until they are uniformly mixed.

[0019] As a preferred embodiment of the present technical solution, during the stirring, the stirring speed is controlled to be 100-300 rpm / min and the time is 30-60 min.

[0020] The sulfur-carbon bond conjugated system in the sulfur-containing organic compound used in the present invention can enable the sulfur-containing organic compound to react quickly with oxygen, thereby effectively capturing and neutralizing free radicals, delaying or preventing the occurrence of oxidation reactions. In addition, sulfur atoms have high activity in chemical reactions and can form stable chemical bonds with oxygen, thereby further protecting other components in the composite amine absorbent from oxidation corrosion.

[0021] Specifically, the method for preparing the sulfur-containing organic compound of the present invention comprises the following steps:

[0022] The thiol compound and the organic raw material containing unsaturated bonds are dissolved in a mixed organic solvent, and an acidic catalyst is added to react at 50-100° C. for 6-12 hours. After the reaction is completed, the sulfur-containing organic compound is separated and purified by distillation, extraction and drying in sequence to obtain the sulfur-containing organic compound.

[0023] The thiol compound includes any one or more of ethyl mercaptan, methyl mercaptan and benzene mercaptan. The sulfur-hydrogen bonds in ethyl mercaptan, methyl mercaptan and benzene mercaptan have high reactivity under the action of an acidic catalyst and are easy to undergo addition or substitution reaction with an organic raw material containing an unsaturated bond. The organic raw material containing an unsaturated bond includes any one or more of methyl acrylate, styrene and butadiene. Methyl acrylate, styrene and butadiene all contain one or more unsaturated carbon-carbon double bonds or triple bonds. These unsaturated bonds are easy to react with thiol compounds under the action of an acidic catalyst. The sulfur-hydrogen bonds of the compound undergo addition reaction to generate sulfur-containing organic compounds; the acidic catalyst includes any one or more of p-toluenesulfonic acid, benzenesulfonic acid and naphthalenesulfonic acid, which are all organic sulfonic acid compounds with strong acidity and catalytic activity, and can effectively reduce the activation energy of the reaction and accelerate the reaction rate between the thiol compound and the organic raw material containing unsaturated bonds; the mixed organic solvent is a mixed solvent of toluene and ethanol to improve the solubility of the thiol compound and the organic raw material containing unsaturated bonds, and ensure that the reactants are completely dissolved;

[0024] The mass ratio of the thiol compound, the organic raw material containing unsaturated bonds and the acidic catalyst is (1-5): (1-3): (0.01-0.1). For example, the mass ratio of the thiol compound to the organic raw material containing unsaturated bonds is 1:1, 1.2:1, 1.5:1 or 2:1, and the amount of the acidic catalyst is preferably adjusted to adjust the pH value of the reaction system to about 3-5.

[0025] As a preferred embodiment of the present technical solution, during the distillation, the distillation temperature is controlled to be 120-200°C;

[0026] During the extraction, a non-polar extractant is used, and the volume ratio of the non-polar extractant to the solution to be extracted is 1:(1-3);

[0027] During the drying, the sample was placed in an oven and dried at 50-70° C. for 6-12 hours.

[0028] Specifically, the preparation method of the inventive metal complex comprises the following steps:

[0029] dissolving a transition metal salt in water to obtain a metal ion solution;

[0030] dissolving an organic ligand in an organic solvent to obtain an organic ligand solution;

[0031] Under stirring conditions, the metal ion solution is slowly added dropwise to the organic ligand solution, and the reaction is carried out at 20-40° C. for 3-12 hours. After the reaction is completed, the solution is filtered, washed and dried in sequence to obtain a metal complex.

[0032] As a preferred embodiment of the present technical solution, the mass ratio of the transition metal salt to the organic ligand is 1:(1-2), wherein the concentration of the transition metal salt in the metal ion solution is 0.1-5 mol / L, the concentration of the organic ligand in the organic ligand solution is 1-10 mol / L, and the organic solvents used include acetone, dimethylformamide, etc.

[0033] As a preferred embodiment of the present technical solution, the stirring speed is 150-250 rpm / min;

[0034] During the reaction, an acid-base regulator such as ammonia water or hydrochloric acid is used to adjust the pH of the reaction system to 7-8, which can further promote the formation of the metal complex.

[0035] The antioxidant for carbon capture composite amine absorbent of the present invention has at least the following beneficial effects:

[0036] 1. The antioxidant for carbon capture composite amine absorbent of the present invention comprises sulfur-containing organic compounds, metal complexes and high molecular polymers, wherein the sulfur-containing organic compounds have a unique sulfur-carbon bond conjugated system, so that they can react quickly with oxygen in the composite amine absorbent system; the metal complex is a complex formed by transition metal ions and organic ligands containing nitrogen and oxygen coordination atoms, and the metal complex can synergize with the sulfur-containing organic compound to promote the antioxidant reaction and further improve the antioxidant efficiency; the high molecular polymer comprises any one or more of polyethylene glycol derivatives, polyvinyl pyrrolidone, polyacrylic acid and polymethyl methacrylate, which has good chemical stability and solubility, and is mainly used to improve the stability of the antioxidant in the composite amine absorbent, prevent the antioxidant from agglomerating, precipitating or decomposing in the composite amine absorbent, and in addition, the presence of the high molecular polymer also helps to maintain the uniformity and fluidity of the composite amine absorbent, ensuring its efficient operation in the carbon capture process;

[0037] 2. The antioxidant of the present invention exhibits excellent antioxidant effect in carbon capture composite amine absorbent. In the experiment simulating carbon capture working conditions, compared with the existing antioxidant, the oxidation degree of the composite amine absorbent using the antioxidant can be reduced to 60% of the prior art in the same time, and even under harsh conditions such as high temperature (such as 100-120°C) and high oxygen content (such as oxygen content reaching 10%-20%), it can still effectively inhibit the oxidation of the absorbent and significantly extend the service life of the absorbent;

[0038] 3. The antioxidant of the present invention will not affect the absorption performance of the composite amine absorbent for carbon dioxide. Through the carbon dioxide absorption experiment, it was found that the composite amine absorbent with the antioxidant added was basically consistent with the original absorbent without the antioxidant added in terms of carbon dioxide absorption capacity and absorption rate. For example, under standard test conditions, the deviation of carbon dioxide absorption capacity was within ±5%, and the change of absorption rate did not exceed ±10%, ensuring the efficient and stable operation of the carbon capture process;

[0039] 4. The antioxidant of the present invention has good stability. Studies have shown that during long-term storage and use, the antioxidant will not precipitate or decompose, and can continuously and stably exert its antioxidant effect, thus ensuring the durability of the antioxidant effect. DETAILED DESCRIPTION

[0040] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0041] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this description, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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.

[0043] Example 1

[0044] The method for preparing the sulfur-containing organic compound comprises the following steps:

[0045] Take 100g of ethanethiol and 150g of methyl acrylate, add them to 500ml of an organic solvent mixed with toluene and ethanol in a volume ratio of 3:2, then add 5g of an acidic catalyst, react at 80°C for 8h, and after the reaction is completed, separate and purify by distillation, extraction and drying in sequence, wherein during distillation, the distillation temperature is controlled to be 160°C; during extraction, petroleum ether is used as a non-polar extractant, and the volume ratio of petroleum ether to the solution to be extracted is 1:2, the standing time of the separatory funnel during extraction is about 10-30min, and extraction is performed 2-3 times; during drying, the sample is placed in an oven at 60°C for 12h to obtain about 120g of sulfur-containing organic compounds.

[0046] The preparation method of the metal complex comprises the following steps:

[0047] Dissolve 50 g of manganese nitrate in 200 ml of water to obtain a metal ion solution;

[0048] Dissolve 80 g of ethylenediamine in 300 ml of acetone to obtain an organic ligand solution;

[0049] Under the conditions of stirring speed of 200 rpm and temperature of 30°C, the metal ion solution was slowly added dropwise to the organic ligand solution, and the pH value was adjusted to 7-8 with aqueous ammonia. After the reaction was completed, it was filtered, washed and dried in sequence to obtain about 90g of metal complex.

[0050] The method for preparing an antioxidant for a carbon capture composite amine absorbent comprises the following steps:

[0051] 45 g of a sulfur-containing organic compound, 30 g of a metal complex and 25 g of polyethylene glycol monolaurate were mixed, and stirred at a stirring speed of 200 rpm / min at room temperature for 45 min to obtain an antioxidant for a carbon capture composite amine absorbent.

[0052] Example 2

[0053] The method for preparing the sulfur-containing organic compound comprises the following steps:

[0054] Take 72g of methyl mercaptan and 156g of styrene, add them to 500ml of an organic solvent mixed with toluene and ethanol in a volume ratio of 3:2, then add 5g of an acidic catalyst, react at 80°C for 8h, and after the reaction is completed, separate and purify by distillation, extraction and drying in sequence, wherein during distillation, the distillation temperature is controlled to be 180°C; during extraction, petroleum ether is used as a non-polar extractant, and the volume ratio of petroleum ether to the solution to be extracted is 1:2, the standing time of the separatory funnel during extraction is about 10-30min, and extraction is performed 2-3 times; during drying, the sample is placed in an oven at 60°C for 12h to obtain about 100g of sulfur-containing organic compounds.

[0055] The preparation method of the metal complex comprises the following steps:

[0056] Dissolve 94 g of copper nitrate in 200 ml of water to obtain a metal ion solution;

[0057] Dissolve 218 g of 8-hydroxyquinoline in 300 ml of acetone to obtain an organic ligand solution;

[0058] Under the conditions of stirring speed of 200 rpm and temperature of 30°C, the metal ion solution was slowly added dropwise to the organic ligand solution, and the pH value was adjusted to 7-8 with aqueous ammonia. After the reaction was completed, it was filtered, washed and dried in sequence to obtain about 150g of metal complex.

[0059] The method for preparing an antioxidant for a carbon capture composite amine absorbent comprises the following steps:

[0060] 30 g of a sulfur-containing organic compound, 40 g of a metal complex and 20 g of a polyethylene glycol derivative were mixed, and stirred at a stirring speed of 200 rpm / min for 45 min at room temperature to obtain an antioxidant for a carbon capture composite amine absorbent.

[0061] Example 3

[0062] The method for preparing the sulfur-containing organic compound comprises the following steps:

[0063] Take 165g of benzenethiol and 81g of butadiene, add them to 500ml of an organic solvent mixed with toluene and ethanol in a volume ratio of 3:2, then add 5g of an acidic catalyst, react at a temperature of 80°C for 8h, and after the reaction is completed, separate and purify by distillation, extraction and drying in sequence, wherein during distillation, the distillation temperature is controlled to be 180°C; during extraction, petroleum ether is used as a non-polar extractant, and the volume ratio of petroleum ether to the solution to be extracted is 1:2, the standing time of the separatory funnel during extraction is about 10-30min, and extraction is performed 2-3 times; during drying, the sample is placed in an oven at 60°C for 12h to obtain about 120g of sulfur-containing organic compounds.

[0064] The preparation method of the metal complex comprises the following steps:

[0065] Dissolve 90 g of manganese nitrate in 200 ml of water to obtain a metal ion solution;

[0066] Dissolve 297 g of o-phenanthroline in 300 ml of acetone to obtain an organic ligand solution;

[0067] Under the conditions of stirring speed of 200 rpm and temperature of 30°C, the metal ion solution was slowly added dropwise to the organic ligand solution, and the pH value was adjusted to 7-8 with aqueous ammonia. After the reaction was completed, 280 g of metal complex was obtained by filtering, washing and drying in sequence.

[0068] The method for preparing an antioxidant for a carbon capture composite amine absorbent comprises the following steps:

[0069] 50 g of a sulfur-containing organic compound, 30 g of a metal complex and 20 g of a polyethylene glycol derivative were mixed, and stirred at room temperature at a stirring speed of 200 rpm / min for 45 min to obtain an antioxidant for a carbon capture composite amine absorbent.

[0070] Example 4

[0071] The method for preparing the sulfur-containing organic compound comprises the following steps:

[0072] Take 93g of ethanethiol and 156g of styrene, add them to 500ml of an organic solvent mixed with toluene and ethanol in a volume ratio of 3:2, then add 5g of an acidic catalyst, react at a temperature of 80°C for 8h, and after the reaction is completed, separate and purify by distillation, extraction and drying in sequence, wherein during distillation, the distillation temperature is controlled to be 180°C; during extraction, petroleum ether is used as a non-polar extractant, and the volume ratio of petroleum ether to the solution to be extracted is 1:2, the standing time of the separatory funnel during extraction is about 10-30min, and extraction is performed 2-3 times; during drying, the sample is placed in an oven at 60°C for 12h to obtain about 140g of sulfur-containing organic compounds.

[0073] The preparation method of the metal complex comprises the following steps:

[0074] Dissolve 80g of copper sulfate in 200ml of water to obtain a metal ion solution;

[0075] Dissolve 90 g of ethylenediamine in 300 ml of acetone to obtain an organic ligand solution;

[0076] Under the conditions of stirring speed of 200 rpm and temperature of 30°C, the metal ion solution was slowly added dropwise to the organic ligand solution, and the pH value was adjusted to 7-8 with aqueous ammonia. After the reaction was completed, it was filtered, washed and dried in sequence to obtain about 120g of metal complex.

[0077] The method for preparing an antioxidant for a carbon capture composite amine absorbent comprises the following steps:

[0078] 60 g of a sulfur-containing organic compound, 20 g of a metal complex and 20 g of a polyethylene glycol derivative were mixed, and stirred at a stirring speed of 200 rpm / min for 45 min at room temperature to obtain an antioxidant for a carbon capture composite amine absorbent.

[0079] Comparative Example 1

[0080] Using thioether to replace the sulfur-containing organic compound in Example 1;

[0081] The preparation method of the antioxidant for carbon capture composite amine absorbent in this comparative example comprises the following steps:

[0082] 45 g of thioether, 30 g of the metal complex and 25 g of polyethylene glycol monolaurate were mixed, and stirred at a stirring speed of 200 rpm / min at room temperature for 45 minutes to obtain an antioxidant.

[0083] Comparative Example 2

[0084] Use copper sulfate to replace the metal complex in Example 1;

[0085] The preparation method of the antioxidant for carbon capture composite amine absorbent in this comparative example comprises the following steps:

[0086] 45 g of a sulfur-containing organic compound, 30 g of copper sulfate and 25 g of polyethylene glycol monolaurate were mixed, and stirred at a stirring speed of 200 rpm / min for 45 min at room temperature to obtain an antioxidant for a carbon capture composite amine absorbent.

[0087] Comparative Example 3

[0088] Polyvinyl chloride was used to replace the polyethylene glycol monolaurate in Example 1;

[0089] The preparation method of the antioxidant for carbon capture composite amine absorbent in this comparative example comprises the following steps:

[0090] 45 g of a sulfur-containing organic compound, 30 g of a metal complex and 25 g of polyvinyl chloride were mixed, and stirred at a stirring speed of 200 rpm / min for 45 min at room temperature to obtain an antioxidant for a carbon capture composite amine absorbent.

[0091] Comparative Example 4

[0092] Sodium nitrite in the prior art is used as an antioxidant.

[0093] Test Example 1

[0094] Antioxidant performance test

[0095] The antioxidants in Example 1 of the present invention and Comparative Examples 1-4 were added to a certain amount of a typical composite amine absorbent (such as MEA-MDEA composite amine absorbent) to make the concentration of the antioxidant 0.5%. At the same time, the same composite amine absorbent without adding the antioxidant was prepared as a blank control group. The composite amine absorbent was placed in an environment containing 8% oxygen at a temperature of 110°C for the same time, and then the oxidation degree was evaluated by detecting the content of oxidation products in the composite amine absorbent. The results are shown in Table 1.

[0096] Table 1 Antioxidant performance test results

[0097] Serial number Oxidation degree % Example 1 15 Comparative Example 1 33 Comparative Example 2 45 Comparative Example 3 28 Comparative Example 4 40 Blank control group 70

[0098] It can be seen from Table 1 that after being placed for 200 hours, the oxidation degree of the complex amine absorbent using the antioxidant of the present invention is only 15%, while the oxidation degree of the complex amine absorbent without adding the antioxidant can reach 70%. The oxidation degrees of the complex amine absorbents of Control Examples 1-4 are 33%, 45%, 28% and 40%, respectively.

[0099] Test Example 2

[0100] Carbon dioxide absorption performance test

[0101] The carbon dioxide absorption performance of the composite amine absorbents containing antioxidants prepared in Example 1 of the present invention and Comparative Examples 1-4 was tested using a laboratory-scale carbon dioxide absorption device, and the original composite amine absorbent without adding antioxidants was used as a blank control group. The carbon dioxide absorption capacity and absorption rate of the composite amine absorbent were measured at a temperature of 40°C and a carbon dioxide partial pressure of 0.5 MPa, and the results are shown in Table 2.

[0102] Table 2 Absorption performance test results

[0103] Serial number Absorption capacity mol / mol Absorption rate mol / (mol·h) Example 1 0.52 0.48 Comparative Example 1 0.49 0.47 Comparative Example 2 0.45 0.43 Comparative Example 3 0.49 0.48 Comparative Example 4 0.46 0.44 Blank control group 0.50 0.49

[0104] As can be seen from Table 2, the absorption capacity of the composite amine absorbent to which the antioxidant prepared in Example 1 of the present invention is added is 0.52 mol / mol, the absorption capacity of the composite amine absorbent to which the antioxidant is not added is 0.5 mol / mol, and the absorption capacity of the composite amine absorbent to which the antioxidant is not added is 0.49 mol / mol, 0.45 mol / mol, 0.49 mol / mol and 0.46 mol / mol, respectively; in terms of absorption rate, the absorption rate of the composite amine absorbent to which the antioxidant is added in Example 1 of the present invention is 0.48 mol / (mol·h), and the absorption rate of the composite amine absorbent to which the antioxidant is not added is 0.49 mol / (mol·h), which are basically the same, while the absorption capacity of the composite amine absorbent to which the antioxidant is not added is 0.47 mol / (mol·h), 0.43 mol / (mol·h), 0.48 mol / (mol·h) and 0.44 mol / (mol·h), respectively.

[0105] Test Example 3

[0106] Stability test

[0107] The composite amine absorbent to which the antioxidant prepared in Example 1 of the present invention was added was stored at room temperature for different periods of time, and then the content of the active ingredient in the antioxidant was determined by a chemical analysis method.

[0108] The results show that after 6 months of storage, the content of the active ingredient in the antioxidant in Example 1 of the present invention still remains above 90% of the initial content.

[0109] The present invention further adds the antioxidants in Example 1 and Comparative Examples 1-4 after storage at room temperature for 6 months to the complex amine absorbent, and tests the antioxidant performance of the complex amine absorbent. The test method is the same as that of Test Example 1. The test results are shown in Table 3.

[0110] Table 3 Antioxidant performance test results

[0111] Serial number Oxidation degree % Example 1 20 Comparative Example 1 40 Comparative Example 2 55 Comparative Example 3 36 Comparative Example 4 50

[0112] It can be seen from Table 3 that the antioxidant prepared by the present invention has good stability. After being stored at room temperature for 6 months, the oxidation degree of the corresponding complex amine absorbent can still be maintained at more than 20%, while the oxidation degree of the complex amine absorbent in Control Examples 1-4 increases to varying degrees.

[0113] In summary, the antioxidant of the present invention can show excellent antioxidant effect and good stability in the carbon capture composite amine absorbent, and will not affect the absorption performance of the composite amine absorbent for carbon dioxide, thereby ensuring the efficient and stable operation of the carbon capture process.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An antioxidant for a carbon capture composite amine absorbent, characterized in that: The invention comprises the following raw materials in parts by weight: 30-60 parts of sulfur-containing organic compound, 20-40 parts of metal complex and 10-30 parts of high molecular polymer; Wherein, the sulfur-containing organic compound has a sulfur-carbon bond conjugated system; The metal complex is a complex formed by a transition metal ion and an organic ligand containing nitrogen and oxygen coordination atoms; The high molecular polymer includes any one or more of polyethylene glycol derivatives, polyvinyl pyrrolidone, polyacrylic acid and polymethyl methacrylate.

2. The antioxidant for carbon capture composite amine absorbent according to claim 1, characterized in that: The transition metal ion includes any one of manganese ion and copper ion, and the organic ligand includes any one of ethylenediamine, 8-hydroxyquinoline and o-phenanthroline.

3. The method for preparing an antioxidant for carbon capture composite amine absorbent according to any one of claims 1 to 2, characterized in that: The following steps are involved: The sulfur-containing organic compound, the metal complex and the high molecular polymer are stirred and mixed uniformly at room temperature to obtain an antioxidant for a carbon capture composite amine absorbent.

4. The preparation method according to claim 3, characterized in that: During the stirring, the stirring speed is controlled to be 100-300 rpm / min and the time is 30-60 min.

5. The preparation method according to claim 3, characterized in that: The preparation method of the sulfur-containing organic compound comprises the following steps: The thiol compound and the organic raw material containing unsaturated bonds are dissolved in a mixed organic solvent, and an acidic catalyst is added to react at 50-100° C. for 6-12 hours. After the reaction is completed, the sulfur-containing organic compound is separated and purified by distillation, extraction and drying in sequence to obtain the sulfur-containing organic compound.

6. The preparation method according to claim 5, characterized in that: The thiol compound includes any one or more of ethyl mercaptan, methyl mercaptan and benzene mercaptan; The organic raw material containing unsaturated bonds includes any one or more of methyl acrylate, styrene and butadiene; The acidic catalyst includes any one or more of p-toluenesulfonic acid, benzenesulfonic acid and naphthalenesulfonic acid; The mixed organic solvent is a mixed solvent of toluene and ethanol; Wherein, the mass ratio of the thiol compound, the organic raw material containing unsaturated bonds and the acid catalyst is (1-5): (1-3): (0.01-0.1).

7. The preparation method according to claim 5, characterized in that: During the distillation, the distillation temperature is controlled to be 120-200° C.; During the extraction, a non-polar extractant is used, and the volume ratio of the non-polar extractant to the solution to be extracted is 1:(1-3); During the drying, the sample was placed in an oven and dried at 50-70° C. for 6-12 hours.

8. The preparation method according to claim 3, characterized in that: The preparation method of the metal complex comprises the following steps: dissolving a transition metal salt in water to obtain a metal ion solution; dissolving an organic ligand in an organic solvent to obtain an organic ligand solution; Under stirring conditions, the metal ion solution is slowly added dropwise to the organic ligand solution, and the reaction is carried out at 20-40° C. for 3-12 hours. After the reaction is completed, the solution is filtered, washed and dried in sequence to obtain a metal complex.

9. The preparation method according to claim 8, characterized in that: The mass ratio of the transition metal salt to the organic ligand is 1:(1-2), wherein the concentration of the transition metal salt in the metal ion solution is 0.1-5 mol / L, and the concentration of the organic ligand in the organic ligand solution is 1-10 mol / L.

10. The preparation method according to claim 8, characterized in that: The stirring speed is 150-250 rpm / min; During the reaction, an acid-base regulator is used to adjust the pH of the reaction system to 7-8.