Carbon dioxide trapping absorbent and trapping absorption method

Abstract

The invention provides a carbon dioxide trapping absorbent and a trapping absorption method. The carbon dioxide trapping absorbent has high main absorbent concentration, the formula of the main absorbent and the viscosity of the carbon dioxide trapping absorbent are limited to be smaller than or equal to 20 cp, the mass transfer and trapping absorption capacity of carbon dioxide is improved, meanwhile, the trapping absorption capacity of carbon dioxide is further improved by limiting the formula of the accelerant, and the carbon dioxide trapping absorption capacity is improved. And more importantly, the regeneration effect of the absorbent can be improved, and the regeneration energy consumption can be obviously reduced. In addition, the absorbent is friendly to equipment, a protective film is formed on the surface of the equipment, and equipment corrosion is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of carbon dioxide capture absorbent, especially to a kind of carbon dioxide capture absorbent and capture absorption method, belong to carbon dioxide recovery field. BACKGROUND

[0002] CO2 capture and storage technology (CCUS) refers to the separation of carbon dioxide from the emission source or direct utilization or storage, to achieve carbon dioxide emission reduction industrial process, including dry method and wet method, wherein, wet method includes chemical absorption method and physical absorption method.

[0003] Chemical absorption method is to contact the emission source including carbon dioxide with absorbent and carry out chemical reaction, so that carbon dioxide is absorbed into solution, then carbon dioxide is desorbed by heating, and the absorbent can be regenerated and recycled process. The commonly used absorbent generally contains 60-70% water, this part of water will be largely vaporized in the absorbent regeneration process, resulting in high regeneration energy consumption. In the existing research, by increasing the concentration of absorbent, the water content can be reduced, thereby reducing the water evaporation amount and regeneration energy consumption, but this poor water absorbent with high absorbent concentration still has the following problems: (1) the regeneration effect of the absorbent becomes poor after increasing the absorbent concentration; (2) the water evaporation amount is still large, resulting in still high regeneration energy consumption.

[0004] A kind of carbon dioxide absorbent with high carbon dioxide absorption capacity, good regeneration effect and low regeneration energy consumption is relatively lacking. SUMMARY

[0005] The present application provides a kind of carbon dioxide capture absorbent, the carbon dioxide capture absorbent has higher carbon dioxide absorption processing capacity, and good regeneration effect, low regeneration energy consumption.

[0006] The present application also provides a kind of carbon dioxide capture absorption method, which uses the above-mentioned carbon dioxide capture absorbent to capture and absorb carbon dioxide, with large processing capacity, and the regeneration effect of the above-mentioned carbon dioxide capture absorbent is better, with lower regeneration energy consumption, and has the advantages of environmental friendliness and resource saving.

[0007] The first aspect of the present application provides a kind of carbon dioxide capture absorbent, wherein the carbon dioxide capture absorbent includes main absorbent 40-70%, promoter 1-20%, corrosion inhibitor 0.05-1%, antioxidant 0.1-1% by mass percentage, and the balance is water.

[0008] The main absorbent includes at least one of primary amine, secondary amine, tertiary amine and polyamine, and the alcohol amine includes at least one of monohydroxy, dihydroxy and trihydroxy.

[0009] The accelerator comprises at least one of a salt, a steric amine and a sulfur-containing organic compound comprising S=O, the salt comprises at least one of a quaternary amine salt, an amino acid salt, a citric acid salt, the steric amine comprises at least one of 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, t-butylaminoethoxyethanol, the sulfur-containing organic compound comprises at least one of dimethyl sulfone, sulfolane, dimethyl sulfoxide, the mass ratio of the salt, the steric amine and the sulfur-containing organic compound is 0-2:0-4:0-6;

[0010] The viscosity of the carbon dioxide capture absorbent is ≤20 cp.

[0011] The carbon dioxide capture absorbent as described above, wherein the number of nitrogen atoms in the fatty amine is ≤3, and the number of carbon atoms is ≤6.

[0012] The carbon dioxide capture absorbent as described above, wherein the number of nitrogen atoms in the alcohol amine is ≤3, and the number of carbon atoms is ≤6.

[0013] The carbon dioxide capture absorbent as described above, wherein the salt comprises an amino acid salt, the steric amine comprises 2-amino-2-methyl-1-propanol, and the sulfur-containing organic compound comprises dimethyl sulfone, and the mass ratio of the salt, the steric amine and the sulfur-containing organic compound is 1:2:3.

[0014] The carbon dioxide capture absorbent as described above, wherein the boiling point of the steric amine is >160℃.

[0015] The carbon dioxide capture absorbent as described above, wherein the corrosion inhibitor comprises sodium metavanadate, and the mass percentage of the sodium metavanadate in the carbon dioxide capture absorbent is 0.05-0.2%.

[0016] The carbon dioxide capture absorbent as described above, wherein the antioxidant comprises potassium sodium tartrate, and the mass percentage of the potassium sodium tartrate in the carbon dioxide capture absorbent is 0.1-0.3%.

[0017] The carbon dioxide capture absorbent as described above, wherein the carbon dioxide removal rate of the carbon dioxide capture absorbent is 60-90%, the regeneration rate of the carbon dioxide capture absorbent is 50-85%, and the energy consumption for regenerating the carbon dioxide capture absorbent is 2.2-3.2 GJ / t.

[0018] The second aspect of the present application provides a carbon dioxide capture and absorption method, comprising the following steps:

[0019] 1) contacting a gas source comprising carbon dioxide with the carbon dioxide capture absorbent according to any one of claims 1-7, so that the carbon dioxide is captured and absorbed by the carbon dioxide capture absorbent to obtain a carbon dioxide-rich liquid;

[0020] The flow ratio of the carbon dioxide capture absorbent and the gas source comprising the carbon dioxide is 1.5-4:1;

[0021] 2) heating the carbon dioxide-rich liquid to desorb the carbon dioxide from the carbon dioxide-rich liquid to obtain a hot solution and the carbon dioxide.

[0022] The method as described above, wherein the volume fraction of the carbon dioxide in the gas source comprising the carbon dioxide is 5-30%.

[0023] The method as described above, wherein the heating comprises preheating the carbon dioxide-rich liquid with the hot solution obtained in step 2).

[0024] The mass percentage of the main absorbent in the carbon dioxide capture absorbent of the present application is high, reaching 40-70%, and the carbon dioxide capture absorbent comprises a promoter, a corrosion inhibitor and an antioxidant, so that the mass percentage of water is lower than that of conventional carbon dioxide absorbents, and the carbon dioxide capture absorbent belongs to a lean water absorbent with a high main absorbent concentration. The carbon dioxide capture absorbent not only helps to improve the absorption capacity of the carbon dioxide capture absorbent for carbon dioxide, but also helps to reduce the amount of water evaporation in the carbon dioxide desorption process, thereby helping to reduce the regeneration energy consumption. The present application limits the formula of the main absorbent and the promoter in the carbon dioxide capture absorbent and the viscosity of the carbon dioxide capture absorbent, which helps to improve the mass transfer performance of the carbon dioxide in the aforementioned lean water absorbent, thereby improving the ability of the carbon dioxide capture absorbent to capture and absorb carbon dioxide. More importantly, through the synergistic cooperation of the main absorbent, the promoter, the corrosion inhibitor and the antioxidant, the regeneration effect of the carbon dioxide capture absorbent is improved and the regeneration energy consumption is reduced, thereby helping to reduce the cost of carbon dioxide capture and absorption. DETAILED DESCRIPTION

[0025] To make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0026] The first aspect of the present application provides a carbon dioxide capture absorbent, which comprises, in terms of mass percentage, 40-70% of a main absorbent, 1-20% of a promoter, 0.05-1% of a corrosion inhibitor and 0.1-1% of an antioxidant; and the balance is water.

[0027] The main absorbent comprises 0-40% of fatty amine, 60-100% of alcohol amine by mass percentage, the fatty amine comprises at least one of primary amine, secondary amine, tertiary amine and polyamine, and the alcohol amine comprises at least one of monohydroxy, dihydroxy and trihydroxy;

[0028] The promoter comprises at least one of salt, steric amine and sulfur-containing organic compound comprising S=O, the salt comprises at least one of quaternary amine salt, amino acid salt and citric acid salt, the steric amine comprises at least one of 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol and tert-butyl amino ethoxy ethanol, and the sulfur-containing organic compound comprises at least one of dimethyl sulfone, sulfolane and dimethyl sulfoxide, and the mass ratio of the salt, the steric amine and the sulfur-containing organic compound is 0-2:0-4:0-6;

[0029] The viscosity of the carbon dioxide capture absorbent is less than or equal to 20 cp.

[0030] The carbon dioxide capture absorbent of the present application can capture carbon dioxide by chemical reaction with carbon dioxide, and then desorb carbon dioxide by heating, so that the carbon dioxide capture absorbent can be regenerated and recycled.

[0031] The carbon dioxide capture absorbent of the present application can capture carbon dioxide by chemical reaction with carbon dioxide, and then desorb carbon dioxide by heating, so that the carbon dioxide capture absorbent can be regenerated and recycled.

[0032] The carbon dioxide capture absorbent of the present application can capture carbon dioxide by chemical reaction with carbon dioxide, and then desorb carbon dioxide by heating, so that the carbon dioxide capture absorbent can be regenerated and recycled.

[0033]

[0034]

[0035] Formula 1 represents the reaction of primary amine, secondary amine and CO2, and formula 2 represents the reaction of tertiary amine, hindered amine and CO2. The reaction of alcohol amine and CO2 is similar to the above reaction.

[0036] Meanwhile, the present application also solves the problem of difficult mass transfer of carbon dioxide existing in the lean water absorbent with high concentration of main absorbent by optimizing the formula of main absorbent and promoter and limiting the viscosity of the capture absorbent, i.e. the viscosity of the absorbent is less than or equal to 20 cp, and the high concentration of main absorbent, the specific formula of the promoter and the like are synergistically matched, thereby ensuring that the above carbon dioxide capture absorbent has high carbon dioxide absorption capacity.

[0037] The promoter of the present application includes salts, hindered amines and sulfur-containing organic matter, the salts include at least one of quaternary ammonium salt, amino acid salt and citrate, the hindered amines include at least one of 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol and tert-butyl amino ethoxy ethanol, and the sulfur-containing organic matter includes at least one of dimethyl sulfone, sulfolane and dimethyl sulfoxide, and the mass ratio of the salts, the hindered amines and the sulfur-containing organic matter is 0-2:0-4:0-6; in addition to the functions of assisting carbon dioxide absorption and improving carbon dioxide absorption capacity, the above-mentioned promoter is more important in that, on the basis of limiting the viscosity of the absorbent, the above-mentioned formula of the promoter can reduce the pH value of the solution and the hydrogen bond strength of the solution, thereby improving the regeneration effect of the carbon dioxide capture absorbent of the present application, avoiding the poor regeneration effect problem existing in the lean water absorbent with high concentration of main absorbent, being conducive to the recycling of the carbon dioxide capture absorbent, further reducing the regeneration energy consumption in the carbon dioxide desorption process, and having the advantages of cost saving and environmental friendliness.

[0038] The function of the corrosion inhibitor is to slow down the corrosion speed of the carbon dioxide capture absorbent on the equipment and prolong the service life of the equipment. The type of the above-mentioned corrosion inhibitor is not particularly limited in the present application, and the corrosion inhibitor commonly used in the art can be used, for example, an oxidizing corrosion inhibitor and / or a surface adsorption type corrosion inhibitor. The above-mentioned oxidizing corrosion inhibitor forms an oxidation protective film on the equipment by oxidation, thereby slowing down the corrosion speed on the equipment, and the oxidizing corrosion inhibitor can include at least one of sodium molybdate, sodium metavanadate, sodium thiosulfate, zinc acetate, copper carbonate, sodium tungstate, sodium tetraborate, sodium vanadate and manganate; the above-mentioned surface adsorption type corrosion inhibitor forms a protective film on the surface of the equipment by adsorption, thereby achieving the purpose of protecting the equipment, and the surface adsorption type corrosion inhibitor can include a straight-chain alkane containing one amino group and having a carbon atom number of 1-20.

[0039] The antioxidant can slow down the oxidation degradation rate of the carbon dioxide capture absorbent. The present application maximizes the carbon dioxide absorption capacity and regeneration capacity of the carbon dioxide capture absorbent while minimizing the regeneration energy consumption by using a specific main absorbent, a promoter and an antioxidant at specific concentrations, which cooperate with each other. The present application does not particularly limit the type of the antioxidant, and any antioxidant commonly used in the art can be used, such as at least one of acetaldoxime, acetone oxime, hydroxyethylidene diphosphonic acid, ethylenediaminetetraacetic acid, ascorbic acid, sodium sulfite, potassium sulfite, ammonium sulfite, ammonium nitrite, and potassium sodium tartrate.

[0040] The carbon dioxide capture absorbent of the present application has high carbon dioxide absorption capacity, good regeneration effect, low regeneration energy consumption, and the advantages of cost saving and environmental friendliness, and has a wide application prospect.

[0041] In some embodiments, the number of nitrogen atoms in the above-mentioned fatty amines is ≤3, and the number of carbon atoms is ≤6, which is conducive to improving the carbon dioxide absorption capacity of the carbon dioxide capture absorbent, reducing the viscosity of the carbon dioxide capture absorbent, improving the mass transfer effect of carbon dioxide, thereby improving the absorption capacity of the carbon dioxide capture absorbent for carbon dioxide, and improving the regeneration effect of the carbon dioxide capture absorbent and reducing the regeneration energy consumption.

[0042] In some embodiments, the number of nitrogen atoms in the above-mentioned alcohol amines is ≤3, and the number of carbon atoms is ≤6, which is conducive to improving the carbon dioxide absorption capacity of the carbon dioxide capture absorbent, increasing the water solubility of the absorbent, reducing the volatility, reducing the viscosity of the carbon dioxide capture absorbent, improving the mass transfer effect of carbon dioxide, thereby improving the absorption capacity of the carbon dioxide capture absorbent for carbon dioxide, and reducing the regeneration energy consumption.

[0043] Further, the quaternary ammonium salt in the above-mentioned promoter includes at least one of benzoic acid triethyl ammonium salt or benzoic acid methyl benzyl quaternary ammonium salt, amino acid salt includes α-amino acetic acid salt, 2-amino propionic acid salt, 3-amino propionic acid salt, 2-amino-3-methyl butyric acid salt, α-amino isohexanoic acid salt, α-amino-β-methyl valeric acid salt, 2-amino phenyl propionic acid salt, α-imino acid salt, β-indole propionic acid salt, L-2-amino-3-hydroxy propionic acid salt, 2-amino-3-p-hydroxy phenyl propionic acid salt, L-2-amino-3-mercapto propionic acid salt, glutamic acid salt, methylthio butyric acid salt, β-hydroxy-α-amino butyric acid salt, aspartic acid salt, α-amino glutaric acid salt, 2,6-diamino hexanoic acid salt, 2-amino-5-guanidino valeric acid salt, α-amino β-imidazole propionic acid salt, and benzoic acid triethyl ammonium salt, which is conducive to enhancing the regeneration effect of the carbon dioxide capture absorbent and greatly reducing the regeneration energy consumption.

[0044] Further, when the salt comprises an amino acid salt, the sterically hindered amine comprises 2-amino-2-methyl-1-propanol, the sulfur-containing organic compound comprises dimethyl sulfone, and the mass ratio of the salt, the sterically hindered amine, and the sulfur-containing organic compound is 1:2:3, the accelerator composed of the salt, the sterically hindered amine, and the sulfur-containing organic compound can better enhance the regeneration effect of the carbon dioxide capture absorbent and greatly reduce the regeneration energy consumption.

[0045] Since the carbon dioxide desorption process is an endothermic process, in order to avoid the components in the carbon dioxide capture absorbent from being degraded or volatilized by heat, the present application further limits the boiling point of the sterically hindered amine in the above-mentioned accelerator to be > 160 ℃, which is beneficial to avoid the volatilization of the sterically hindered amine by heat, improve the stability of the carbon dioxide capture absorbent in the desorption process, improve the regeneration effect of the carbon dioxide capture absorbent, and also beneficial to reduce the regeneration energy consumption and save costs.

[0046] The inventors have found through a large number of studies that when the corrosion inhibitor comprises sodium metavanadate, and the mass percentage of sodium metavanadate in the above-mentioned carbon dioxide capture absorbent is 0.05-0.2%, preferably 0.1%, it helps to further reduce the corrosion rate of the equipment.

[0047] When the antioxidant comprises potassium sodium tartrate, and the mass percentage of potassium sodium tartrate in the above-mentioned carbon dioxide capture absorbent is 0.1-0.3%, preferably 0.2%, it can more obviously reduce the oxidative degradation rate of the carbon dioxide capture absorbent, and cooperate with the main absorbent, the accelerator, etc., to make the regeneration effect of the carbon dioxide capture absorbent better.

[0048] In some embodiments, the carbon dioxide removal rate of the above-mentioned carbon dioxide capture absorbent is 60-90%, the regeneration rate of the carbon dioxide capture absorbent is 50-85%, and the regeneration energy consumption of the carbon dioxide capture absorbent is 2.2-3.2 GJ / t. It can be seen that the carbon dioxide capture absorbent of the present application has a high carbon dioxide absorption capacity, and has a good regeneration effect and low regeneration energy consumption.

[0049] The second aspect of the present application provides a carbon dioxide capture and absorption method, comprising the following steps:

[0050] 1) contacting a gas source comprising carbon dioxide with the carbon dioxide capture absorbent of the first aspect of the present application, so that the carbon dioxide is captured and absorbed by the carbon dioxide capture absorbent to obtain a carbon dioxide-rich liquid;

[0051] wherein the flow ratio of the above-mentioned carbon dioxide capture absorbent and the gas source comprising carbon dioxide is 1.5-4:1;

[0052] 2) heating the carbon dioxide-rich liquid to desorb the carbon dioxide from the carbon dioxide-rich liquid to obtain a hot solution and carbon dioxide.

[0053] The carbon dioxide capture and absorption method is a method for capturing and absorbing carbon dioxide using the carbon dioxide capture and absorption agent.

[0054] In the step 1), the gas source containing carbon dioxide is contacted with the carbon dioxide capture and absorption agent, so that the carbon dioxide is mass transfered and diffused in the carbon dioxide capture and absorption agent, chemically reacts with the carbon dioxide capture and absorption agent, and is captured and absorbed by the carbon dioxide capture and absorption agent, thereby obtaining the carbon dioxide enriched liquid.

[0055] In the above process, in order to improve the treatment efficiency of carbon dioxide, the gas source and the carbon dioxide capture and absorption agent should be fully contacted. The present application does not limit the specific contact method. For example, the gas source can be introduced into the bottom of the absorption tower, and the carbon dioxide capture and absorption agent can be introduced into the top of the absorption tower, so that the two are countercurrently contacted in the absorption tower. This countercurrent contact method has the advantages of large contact area and sufficient reaction, and can make the carbon dioxide be fully absorbed by the capture and absorption agent.

[0056] The present application does not limit the flow rate of the gas source and the carbon dioxide capture and absorption agent introduced into the absorption tower. The flow rate can be adjusted in combination with the carbon dioxide absorption capacity of the carbon dioxide capture and absorption agent and the carbon dioxide content in the gas source.

[0057] In some embodiments, the flow rate ratio of the carbon dioxide capture and absorption agent and the gas source containing carbon dioxide is 1.5-4:1 (L / h) / (Nm 3 / h), preferably 1.8-3.6:1 (L / h) / (Nm 3 / h), and the carbon dioxide capture and absorption agent can completely capture and absorb the carbon dioxide. This indicates that the carbon dioxide capture and absorption agent of the present application has high carbon dioxide absorption capacity.

[0058] In the step 2), the carbon dioxide enriched liquid is heated to a certain extent, and the carbon dioxide is desorbed therefrom, thereby obtaining a hot solution and carbon dioxide. The carbon dioxide can be directly used or sequestrated, thereby realizing the capture and absorption and utilization of carbon dioxide.

[0059] The carbon dioxide desorption process can be carried out in a regeneration tower. The regeneration tower is provided with a heating device and a gas collection device, which is beneficial to the desorption and collection of carbon dioxide.

[0060] Generally, the heating treatment of the carbon dioxide enriched liquid can be saturated steam heating, which is beneficial to rapid heating of the carbon dioxide enriched liquid and energy saving. For example, in some embodiments, water vapor with a pressure of 0.4 MPa is used for heating.

[0061] The carbon dioxide capture and absorption method provided by the application can efficiently capture and absorb carbon dioxide in a gas source containing carbon dioxide.

[0062] The carbon dioxide capture and absorption method can be used for capturing and absorbing carbon dioxide in flue gas discharged by a power plant.

[0063] When the volume fraction of carbon dioxide in the gas source containing carbon dioxide is 5-30%, the carbon dioxide in the gas source can be effectively captured and absorbed by the carbon dioxide capture and absorption method.

[0064] The carbon dioxide in the carbon dioxide-rich liquid is desorbed after being heated in step 2), and the hot solution and carbon dioxide are obtained, and the hot solution has a high heat. In order to avoid waste of the heat in the hot solution, the heating includes preheating the carbon dioxide-rich liquid by using the hot solution obtained in step 2), that is, the hot solution is used as a heat source for the next carbon dioxide desorption, and part of the heat in the hot solution is transferred to the carbon dioxide-rich liquid to be desorbed for carbon dioxide desorption, so that the heat in the hot solution is fully utilized, energy waste is avoided, and the regeneration energy consumption is further reduced.

[0065] The preheating process can be performed in a heat exchanger.

[0066] In some embodiments, in order to desorb carbon dioxide from the carbon dioxide desorption liquid with the lowest energy consumption, the carbon dioxide-rich liquid can be introduced from the bottom of the regeneration tower and heated by saturated water vapor in step 2) to generate a mixed gas of water vapor and carbon dioxide, the mixed gas flows from bottom to top, and the preheated carbon dioxide-rich liquid introduced from the top of the regeneration tower is countercurrently contacted to realize mass transfer and heat transfer, and the desorbed carbon dioxide is obtained from the top of the regeneration tower, and the hot solution is obtained from the bottom of the regeneration tower. The above process fully utilizes heat exchange, countercurrent contact and other methods to minimize the regeneration energy consumption.

[0067] Hereinafter, the carbon dioxide capture and absorption agent and the carbon dioxide capture and absorption method of the application will be described in more detail through specific examples and comparative examples.

[0068] Example 1

[0069] The carbon dioxide capture and absorption agent provided in this example includes, in terms of mass percentage, 40% of a main absorbent, 10% of a promoter, 1% of sodium molybdate, and 0.5% of sodium sulfite; and the balance is water.

[0070] The main absorbent includes, in terms of mass percentage, 12.5% of ethylenediamine and 87.5% of diethanolamine.

[0071] The accelerator includes a salt, a steric amine and a sulfur-containing organic substance, the salt is sodium citrate, the steric amine is 2-amino-2-methyl-1, 3-propanediol (AMP), the sulfur-containing organic substance is dimethyl sulfoxide, and the mass ratio of the salt and the steric amine is 1:2:3;

[0072] The viscosity of the carbon dioxide capture absorption agent is less than or equal to 20 cp.

[0073] The embodiment also provides a carbon dioxide capture absorption method, including the following steps:

[0074] 1) The flue gas containing carbon dioxide is introduced into the bottom of the absorption tower at a flow rate of 830 Nm 3 / h, and the carbon dioxide capture absorption agent is introduced into the top of the absorption tower at a flow rate of 1500 L / h, so that the carbon dioxide is captured and absorbed by the carbon dioxide capture absorption agent, and a carbon dioxide enrichment liquid is obtained;

[0075] The volume fraction of carbon dioxide in the flue gas is 12%, and the flow rate ratio of the carbon dioxide capture absorption agent to the flue gas containing carbon dioxide is 1.8:1 (L / h / (Nm 3 / h);

[0076] 2) The carbon dioxide enrichment liquid is introduced into the bottom of the regeneration tower at a flow rate of 1550 L / h, and is heated by saturated water vapor with a flow rate of 180 kg / h and a pressure of 0.4 MPa to obtain a water vapor and carbon dioxide mixed gas; the carbon dioxide enrichment liquid preheated to 85-95 DEG C is introduced into the top of the regeneration tower at a flow rate of 150 L / h, and is countercurrently contacted with the mixed gas, so that the carbon dioxide enrichment liquid is regenerated to obtain a hot solution from the bottom of the regeneration tower and carbon dioxide gas from the top of the regeneration tower;

[0077] The carbon dioxide enrichment liquid is preheated by the hot solution in the heat exchanger.

[0078] Example 2

[0079] The embodiment is basically the same as example 1, and the difference lies in that:

[0080] The mass percentage of the main absorption agent in the carbon dioxide capture absorption agent is 50%, and the other conditions remain unchanged.

[0081] Example 3

[0082] The embodiment is basically the same as example 1, and the difference lies in that:

[0083] The mass percentage of the main absorption agent in the carbon dioxide capture absorption agent is 60%, and the other conditions remain unchanged.

[0084] Example 4

[0085] The embodiment is basically the same as example 1, and the difference lies in that:

[0086] The mass percentage of the main absorbent in the carbon dioxide capture absorbent is 70%, and other conditions remain unchanged.

[0087] Example 5

[0088] This example is basically the same as Example 1, except that:

[0089] The mass percentage of the promoter in the carbon dioxide capture absorbent is 20%, and the mass percentage of sodium sulfite is 1%; other conditions remain unchanged.

[0090] Example 6

[0091] This example is basically the same as Example 1, except that:

[0092] The main absorbent includes 12.5% ethylenediamine and 87.5% monoethanolamine by mass percentage.

[0093] Example 7

[0094] This example is basically the same as Example 1, except that:

[0095] The main absorbent includes 12.5% diethylenetriamine and 87.5% diethanolamine by mass percentage.

[0096] Example 8

[0097] This example is basically the same as Example 1, except that:

[0098] The promoter includes salts, steric amines, and sulfur-containing organic matter, the salts are alpha amino acetate and 2 amino propionate, the steric amine is 2-amino-2-methyl-1-propanol, and the sulfur-containing organic matter is dimethyl sulfone, the mass ratio of the above-mentioned salts, steric amines, and sulfur-containing organic matter is 1:2:3; other conditions remain unchanged.

[0099] Example 9

[0100] This example is basically the same as Example 1, except that:

[0101] The steric ammonium is replaced by 2-amino-2-methyl-1-propanol (AMPD) instead of 2-amino-2-methyl-1,3-propanediol (AMP); other conditions remain unchanged.

[0102] Example 10

[0103] This example is basically the same as Example 1, except that:

[0104] The accelerator includes a salt, a steric amine and a sulfur-containing organic substance, the salt is sodium 2-aminopropanoate, the steric amine is 2-amino-2-methyl-1-propanol, and the sulfur-containing organic substance is dimethyl sulfone, and a mass ratio of the salt, the steric amine and the sulfur-containing organic substance is 1:2:3; other conditions remain unchanged.

[0105] Example 11

[0106] This example is basically identical with Example 1, except that:

[0107] Sodium molybdate 1% is replaced by sodium metavanadate 0.2%.

[0108] Example 12

[0109] This example is basically identical with Example 1, except that:

[0110] Sodium sulfite 0.5% is replaced by potassium sodium tartrate 0.3%.

[0111] Example 13

[0112] This example is basically identical with Example 1, except that:

[0113] The volume fraction of carbon dioxide in the flue gas is 20%.

[0114] Example 14

[0115] This example is basically identical with Example 1, except that:

[0116] The main absorbent includes, by mass percentage, 12.5% amino octane and 87.5% diethanolamine; other conditions remain unchanged.

[0117] Example 15

[0118] This example is basically identical with Example 1, except that:

[0119] The main absorbent includes, by mass percentage, 12.5% ethylenediamine and 87.5% N-methylcyclohexylamine; other conditions remain unchanged.

[0120] Comparative Example 1

[0121] This comparative example is basically identical with Example 1, except that:

[0122] The main absorbent includes, by mass percentage, 100% di-n-butylamine; other conditions remain unchanged.

[0123] Comparative Example 2

[0124] This comparative example is basically identical with Example 1, except that:

[0125] The accelerator is a sulfur-containing organic compound, and the sulfur-containing organic compound is dimercaprol.

[0126] Comparative Example 3

[0127] This comparative example is basically identical with Example 1, except that:

[0128] The main absorbent is 12.5% diethylene triamine, 87.5% triisopropanolamine,

[0129] The viscosity of the carbon dioxide capture absorbent in this comparative example is 35 cp.

[0130] Test Example

[0131] 1. The following parameters were detected for the above examples and comparative examples:

[0132] 1) Carbon dioxide removal rate: The concentration of carbon dioxide in the gas source was detected by infrared spectroscopy method, and the carbon dioxide removal rate = (the concentration of carbon dioxide in the gas source at the inlet of the absorption tower - the concentration of carbon dioxide in the gas source at the outlet of the absorption tower) / the concentration of carbon dioxide in the gas source at the inlet of the absorption tower, and the specific results are shown in Table 1;

[0133] 2) Regeneration rate of absorbent: Regeneration rate = the amount of carbon dioxide desorbed from the carbon dioxide-rich liquid / the amount of carbon dioxide in the carbon dioxide-rich liquid before desorption, wherein the amount of carbon dioxide desorbed from the carbon dioxide-rich liquid is detected by a wet gas flow meter, and the amount of carbon dioxide in the carbon dioxide-rich liquid before desorption is detected by acid-base titration, and the specific results of the regeneration rate are shown in Table 1;

[0134] 3) Regeneration energy consumption: calculated by the enthalpy value of the steam consumption per unit of carbon dioxide capture amount, the calculation formula is: regeneration energy consumption = steam consumption × (enthalpy value of steam at the inlet of the reboiler - enthalpy value of steam at the outlet of the reboiler) / the amount of carbon dioxide desorbed, and the specific results are shown in Table 1;

[0135] 4) Coupon corrosion rate: detected by the method specified in HGT2159-91, and the specific results are shown in Table 1.

[0136] 2. Test results

[0137] Table 1: Related parameters of carbon dioxide capture absorbent

[0138]

[0139] The results of Table 1 show that:

[0140] 1) The carbon dioxide removal rate data of Examples 1-4 shows that increasing the concentration of the main absorbent helps to improve the carbon dioxide removal rate;

[0141] 2) Example 5 increases the concentration of the promoter, improves the carbon dioxide removal rate and reduces the energy consumption of the carbon dioxide capture absorbent regeneration;

[0142] 3) Compared with Examples 1, 14 and 15, Examples 6 and 7 adjust the formula of the main absorbent, which improves the performance of the carbon dioxide capture absorbent;

[0143] 4) Examples 8 and 10 optimize the formula of the promoter, which further improves the performance of the carbon dioxide capture absorbent based on Example 1.

[0144] 5) The carbon dioxide capture absorbent formula of Comparative Examples 1-3 is different from Example 1, which results in low carbon dioxide removal rate, low regeneration rate or high energy consumption of the regeneration.

[0145] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A carbon dioxide capture absorbent, characterized in that: The carbon dioxide capture absorbent comprises, by weight percentage, 40-70% of a main absorbent, 1-20% of a accelerator, 0.05-1% of a corrosion inhibitor, and 0.1-1% of an antioxidant; the balance being water; The main absorbent comprises 0-40% of aliphatic amine and 60-100% of alcohol amine in terms of mass percentage, wherein the aliphatic amine comprises at least one of primary amine, secondary amine, tertiary amine and polyamine, and the alcohol amine comprises at least one of monohydroxy, dihydroxy and trihydroxy; The accelerator includes at least one of salts, hindered amines, and sulfur-containing organic matter including S=O, the salt includes at least one of quaternary ammonium salts, amino acid salts, and citrates, the hindered amine includes at least one of 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, and tert-butylaminoethoxyethanol, the sulfur-containing organic matter includes at least one of dimethyl sulfone, sulfolane, and dimethyl sulfoxide, and the mass ratio of the salt, hindered amine, and sulfur-containing organic matter is 0-2:0-4:0-6; The viscosity of the carbon dioxide capture absorbent is ≤20cp.

2. The carbon dioxide capture absorbent according to claim 1, characterized in that The number of nitrogen atoms in the fatty amine is ≤3, and the number of carbon atoms is ≤6; And / or, the number of nitrogen atoms in the alcoholamine is ≤3, and the number of carbon atoms is ≤6.

3. The carbon dioxide capture absorbent according to claim 1 or 2, characterized in that The salts include amino acid salts, the hindered amines include 2-amino-2-methyl-1-propanol, the sulfur-containing organic matter includes dimethyl sulfone, and the mass ratio of the salts, the hindered amines and the sulfur-containing organic matter is 1:2:

3.

4. The carbon dioxide capture absorbent according to any one of claims 1 to 3, characterized in that The boiling point of the hindered amine is greater than 160°C.

5. The carbon dioxide capture absorbent according to any one of claims 1 to 4, characterized in that The corrosion inhibitor comprises sodium metavanadate, and the mass percentage of the sodium metavanadate in the carbon dioxide capture absorbent is 0.05-0.2%.

6. The carbon dioxide capture absorbent according to any one of claims 1 to 5, characterized in that: The antioxidant includes potassium sodium tartrate, and the mass percentage of the potassium sodium tartrate in the carbon dioxide capture absorbent is 0.1-0.3%.

7. The carbon dioxide capture absorbent according to any one of claims 1 to 6, characterized in that: The carbon dioxide removal rate of the carbon dioxide capture absorbent is 60-90%, the regeneration rate of the carbon dioxide capture absorbent is 50-85%, and the regeneration energy consumption of the carbon dioxide capture absorbent is 2.2-3.2 GJ / t.

8. A method for capturing and absorbing carbon dioxide, characterized in that: The following steps are involved: 1) contacting a gas source comprising the carbon dioxide with the carbon dioxide capture absorbent according to any one of claims 1 to 7, so that the carbon dioxide is captured and absorbed by the carbon dioxide capture absorbent to obtain a carbon dioxide-enriched liquid; Wherein, the flow ratio of the carbon dioxide capture absorbent and the gas source including the carbon dioxide is 1.5-4:1; 2) heating the carbon dioxide-enriched liquid to desorb carbon dioxide from the carbon dioxide-enriched liquid, thereby obtaining a hot solution and the carbon dioxide.

9. The method according to claim 8, characterized in that The volume fraction of the carbon dioxide in the gas source including carbon dioxide is 5-30%.

10. The method according to claim 8 or 9, characterized in that The heating includes preheating the carbon dioxide-enriched liquid using the hot solution obtained in step 2).

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