Modified anion exchange resin for removing amine liquor heat stable salts and method of making same

Abstract

The present application relates to the technical field of carbon dioxide capture, and discloses a modified anion exchange resin for removing heat stable salts in amine solution and a preparation method thereof.The method comprises the following steps: (1) washing the anion exchange resin with deionized water; (2) activating the resin washed in step (1) with an acid solution or an alkali solution; (3) refluxing the resin activated in step (2) with a hydrophobic silane coupling agent in a water-free solvent, and then washing the reaction product with deionized water; (4) reacting the resin treated in step (3) with an organic acid, and then washing the reaction product with deionized water; and (5) reacting the resin treated in step (4) with a vinyl compound containing a sulfonic acid group in a solvent, and then washing the reaction product with deionized water.The modified anion exchange resin prepared according to the method can improve the purification efficiency of the decarbonated amine solution in the ion exchange purification process of the alcohol amine solution.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide capture technology, specifically to a modified anion exchange resin for removing thermally stable salts from amine solutions and its preparation method. Background Technology

[0002] The problem of global warming is becoming increasingly prominent. The massive emission of greenhouse gases is one of the main causes of global warming. Currently, industrial carbon emissions, with carbon dioxide as the main component, have attracted increasing attention, and governments and enterprises are striving to capture, store, and utilize carbon dioxide on a large scale. Chemical absorption is currently the most widely used carbon dioxide capture technology. Its principle is to use chemical solvents to react reversibly with carbon dioxide, separating it from the gas. Commonly used chemical solvents include alkanolamines, such as monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA). These alkanolamines have advantages such as strong absorption capacity and easy regeneration, but they also have disadvantages such as low absorption efficiency and high energy consumption. The technology of treating heat-stable anions in amine solutions using modified ion exchange resins involves using specific ion exchange resins to purify the amine solution and remove heat-stable salts (HSS). These heat-stable salts are formed by the reaction of amine solutions with acidic components, such as hydrochlorides, sulfates, formates, acetates, oxalates, thiocyanates, and thiosulfinates. These salts cannot be regenerated by heating and will accumulate in the system, leading to reduced amine decarbonization efficiency and equipment corrosion. Anion exchange resins can be classified into three categories based on the nature of their basic groups: strongly basic, weakly basic, and a mixture of strongly and weakly basic resins. Strongly basic anion exchange resins contain strongly basic groups, such as quaternary ammonium groups, which can dissociate OH- in water. － These resins are strongly alkaline. The positively charged groups of these resins can adsorb and bind with anions in the solution, thus producing anion exchange. Weakly basic anion exchange resins contain weakly basic groups, such as primary, secondary, or tertiary amine groups, which can dissociate into OH- ions in water. － It is weakly alkaline. Strongly alkaline and weakly alkaline anion exchange resins have different adsorption capacities for different types of anions. Summary of the Invention

[0003] The purpose of this invention is to overcome the problem in existing technologies where ion exchange resins, while removing heat-stable salts from amine solutions during ion exchange purification, also adsorb carbamates, resulting in amine loss. This invention provides a modified anion exchange resin for removing heat-stable salts from amine solutions and its preparation method. The modified anion exchange resin prepared according to the method of this invention can remove heat-stable salts from amine solutions during ion exchange purification while reducing the adsorption of carbamates, thereby reducing amine loss.

[0004] To achieve the above objectives, the present invention provides a modified anion exchange resin and a method for preparing the same, the method comprising the following steps:

[0005] (1) Clean the anion exchange resin with deionized water;

[0006] (2) Activate the resin after cleaning in step (1) using an acidic or alkaline solution;

[0007] (3) The resin activated in step (2) and the hydrophobic silane coupling agent are refluxed in anhydrous solvent and then washed with deionized water.

[0008] (4) React the resin treated in step (3) with organic acid, and then wash it with deionized water.

[0009] (5) The resin treated in step (4) is reacted with a vinyl compound containing sulfonic acid groups in a solvent, and then washed with deionized water.

[0010] Preferably, in step (2), the mass fraction of the acidic solution is 2-8 wt%, more preferably 3-5 wt%.

[0011] Preferably, in step (2), the mass fraction of the alkaline solution is 2-8 wt%, more preferably 3-5 wt%.

[0012] Preferably, the acidic solution is at least one of hydrochloric acid solution, sulfuric acid solution and nitric acid solution.

[0013] Preferably, the alkaline solution is at least one of potassium hydroxide solution, sodium hydroxide solution, and sodium carbonate solution.

[0014] Preferably, in step (2), the activation conditions include: a temperature of 10-35°C and a time of 8-18h.

[0015] Preferably, in step (3), the mass ratio of the resin to the hydrophobic silane coupling agent is 1:(0.5-2), more preferably 1:(0.8-1.5).

[0016] Preferably, the hydrophobic silane coupling agent is at least one selected from octadecyltrimethoxysilane, dodecyltrimethoxysilane, and methyltrimethoxysilane.

[0017] Preferably, the anhydrous solvent is at least one of toluene, dichloromethane, and xylene.

[0018] Preferably, in step (3), the reflux reaction conditions include: a temperature of 50-120°C and a time of 4-12h.

[0019] Preferably, in step (4), the mass ratio of the resin to the organic acid is 1:(1-5), more preferably 1:(2-3).

[0020] Preferably, the organic acid is at least one selected from acrylic acid, methacrylic acid, and benzoic acid.

[0021] Preferably, in step (4), the reaction conditions include: a temperature of 100-150°C and a time of 4-12 hours.

[0022] Preferably, in step (5), the mass ratio of the resin to the vinyl compound containing sulfonic acid groups is 1:(0.1-0.5), more preferably 1:(0.2-0.3).

[0023] Preferably, the vinyl compound containing a sulfonic acid group is at least one of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), styrene sulfonic acid (SSA), and vinyl sulfonic acid (VS).

[0024] Preferably, in step (5), the reaction conditions include: a temperature of 50-120°C and a time of 4-12h.

[0025] A second aspect of the present invention provides a modified anion exchange resin for removing thermally stable salts from amine solutions, prepared by the method described above.

[0026] A third aspect of the present invention provides a method for treating thermally stable salts in decarbonized amine solutions, the method comprising: contacting an alcoholic amine solution after carbon dioxide capture with the modified anion exchange resin described above for removing thermally stable salts from amine solutions.

[0027] The method for preparing the modified anion exchange resin for removing heat-stable salts from amine solutions according to the present invention involves first activating the ion exchange resin with an acidic or alkaline solution, then modifying its surface hydrophobically with a hydrophobic silane coupling agent, neutralizing the anion exchange groups on the resin with an organic acid, and finally grafting a vinyl compound containing sulfonic acid groups onto the resin to prepare the modified anion exchange resin. The modified anion exchange resin prepared by the present invention can remove heat-stable salts from amine solutions during ion exchange purification of alcoholic amine solutions while reducing the adsorption of carbamates, thereby reducing amine loss and improving the purification efficiency of decarbonized amine solutions. Detailed Implementation

[0028] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0029] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0030] The preparation method of the modified anion exchange resin for removing thermally stable salts from amine solutions according to the present invention includes the following steps:

[0031] (1) Clean the anion exchange resin with deionized water;

[0032] (2) Activate the resin after cleaning in step (1) using an acidic or alkaline solution;

[0033] (3) The resin activated in step (2) and the hydrophobic silane coupling agent are refluxed in anhydrous solvent and then washed with deionized water.

[0034] (4) React the resin treated in step (3) with organic acid, and then wash it with deionized water.

[0035] (5) The resin treated in step (4) is reacted with a vinyl compound containing sulfonic acid groups in a solvent, and then washed with deionized water.

[0036] In the method described in this invention, the anion exchange resin used to remove thermally stable salts from amine solutions can be any type of anion exchange resin conventionally used in the art. In a preferred embodiment, the anion exchange resin used to remove thermally stable salts from amine solutions is a weakly basic anion exchange resin. Specifically, the anion exchange resin used to remove thermally stable salts from amine solutions can be a strongly basic anion exchange resin, a weakly basic anion exchange resin, or a quaternary ammonium base anion exchange resin. In the most preferred embodiment, the anion exchange resin used to remove thermally stable salts from amine solutions is a weakly basic anion exchange resin, such as the weakly basic anion exchange resin model D301 purchased from Langfang Aoguang Energy Saving Technology Co., Ltd.

[0037] In step (1), the cleaning process can be performed once or multiple times, preferably multiple times. The purpose of the cleaning is to remove impurities.

[0038] In step (2), the mass fraction of the acidic solution can be 2-8 wt%, preferably 3-5 wt%, and more preferably 3.5-4.5 wt%.

[0039] In step (2), the mass fraction of the alkaline solution can be 2-8 wt%, preferably 3-5 wt%, and more preferably 3.5-4.5 wt%.

[0040] In step (2), the acidic solution can be at least one of hydrochloric acid solution, sulfuric acid solution, and nitric acid solution. In the most preferred embodiment, the acidic solution is hydrochloric acid solution.

[0041] In step (2), the alkaline solution can be at least one of potassium hydroxide solution, sodium hydroxide solution, and sodium carbonate solution. In the most preferred embodiment, the alkaline solution is sodium hydroxide solution.

[0042] In step (2), the activation conditions may include a temperature of 10-35°C and a time of 8-18 hours. More preferably, the activation conditions include a temperature of 15-30°C and a time of 10-15 hours. The activation process can be carried out in various conventional reaction apparatuses.

[0043] In step (3), the mass ratio of the resin to the hydrophobic silane coupling agent can be 1:(0.5-2), preferably 1:(0.8-1.5), and more preferably 1:(1-1.2).

[0044] In this invention, the hydrophobic silane coupling agent can be at least one selected from octadecyltrimethoxysilane, dodecyltrimethoxysilane, and methyltrimethoxysilane. In the most preferred embodiment, the hydrophobic silane coupling agent is octadecyltrimethoxysilane.

[0045] In this invention, the anhydrous solvent can be at least one of toluene, dichloromethane, and xylene. Specifically, the xylene can be p-xylene, m-xylene, or o-xylene. In the most preferred embodiment, the anhydrous solvent is toluene.

[0046] In step (3), the conditions for the reflux reaction may include: a temperature of 50-120°C and a time of 4-12 hours. More preferably, the conditions for the reflux reaction include: a temperature of 60-100°C and a time of 5-10 hours. The reflux reaction process can be carried out in various conventional reflux reaction apparatuses.

[0047] In step (3), the cleaning process can be performed once or multiple times, preferably multiple times. The purpose of the cleaning is to remove unreacted hydrophobic silane coupling agent.

[0048] In step (4), the mass ratio of the resin to the organic acid can be 1:(1-5), preferably 1:(2-3), and more preferably 1:(2.2-2.8).

[0049] In this invention, the organic acid can be at least one selected from acrylic acid, methacrylic acid, and benzoic acid. In the most preferred embodiment, the organic acid is acrylic acid.

[0050] In step (4), the reaction conditions may include a temperature of 100-150°C and a time of 4-12 hours. More preferably, the reaction conditions include a temperature of 120-140°C and a time of 5-10 hours. The reaction process can be carried out in various conventional reaction apparatuses.

[0051] In step (4), the cleaning can be performed once or multiple times, preferably multiple times. The purpose of the cleaning is to remove excess organic acid.

[0052] In step (5), the mass ratio of the resin to the vinyl compound containing sulfonic acid groups can be 1:(0.1-0.5), preferably 1:(0.2-0.3), and more preferably 1:(0.22-0.28).

[0053] In this invention, the vinyl compound containing a sulfonic acid group can be at least one of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), styrene sulfonic acid (SSA), and vinyl sulfonic acid (VS). In the most preferred embodiment, the vinyl compound containing a sulfonic acid group is 2-acrylamido-2-methylpropanesulfonic acid (AMPS).

[0054] In step (5), the reaction conditions may include a temperature of 50-120°C and a time of 4-12 hours. In the most preferred embodiment, the reaction includes a temperature of 60-100°C and a time of 5-10 hours. The reaction process can be carried out in various conventional reaction apparatuses.

[0055] In step (5), the washing can be performed once or multiple times, preferably multiple times. The purpose of the washing is to remove unreacted monomers and / or byproducts.

[0056] The present invention also provides a modified anion exchange resin prepared by the above method for removing thermally stable salts from amine solutions. This modified anion exchange resin for removing thermally stable salts from amine solutions can reduce the adsorption of carbamates during the ion exchange purification process of alcoholic amine solutions, thereby avoiding excessive amine loss.

[0057] The present invention also provides a method for treating thermally stable salts in decarbonized amine solutions, the method comprising: contacting an alcoholic amine solution after carbon dioxide capture with the modified anion exchange resin used to remove thermally stable salts from the amine solution.

[0058] In the method described in this invention, the amine solution may include at least one of monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA). The product of the reaction between monoethanolamine (MEA) and carbon dioxide may be MEA carbamate, protonated amine MEA H, etc. + HCO3 - and CO3 2- At least one of the following. The product of the reaction between the diethanolamine (DEA) and carbon dioxide can be a carbamate. The product of the reaction between the triethanolamine (TEA) and carbon dioxide can be a bicarbonate.

[0059] The following examples further illustrate the application of the anion exchange resin for removing thermally stable salts from amine solutions according to the present invention in the ion exchange process. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0060] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0061] In the following examples and comparative examples, the methods for testing the concentrations of the thermally stable salts and amines in the test samples were as follows:

[0062] Thermal stability salt concentration test: Take 50 mL of the test sample and heat it under reflux for 5 min to remove residual CO2 and H2S. After heating, cover the sample with a quartz glass lid and cool it in the dark. Use deionized water to compensate for the difference to ensure that the final sample volume is consistent with the initial volume. Weigh 2-3 g of the test sample into a 100 mL plastic cup, and record the sample weight as . W Pour the sample into the resin column and rinse the plastic cup several times with deionized water. Pour the washings into the resin column as well, and then rinse with deionized water. Collect the effluent from the resin column in a 250 mL beaker. Test the effluent from the resin column with pH paper until it is neutral (pH=7) or equal to the pH of the washing water. Add 2-3 drops of 5 g / L phenolphthalein indicator to the beaker and titrate with 0.1 mol / L sodium hydroxide solution until it turns pink. Record the amount of sodium hydroxide solution consumed (V). The formula for calculating the mass concentration Wt% of the thermally stable salt is as follows:

[0063] Wt%=

[0064] Amine concentration test: The amine concentration of the sample was tested using GC-MS. The chromatograph was preheated for 30 min, and 20 μL of sample was diluted in 50 g of deionized water. After injection, the amine concentration of the sample was determined by baseline correction, peak identification, and quantitative analysis of the chromatogram.

[0065] Example 1

[0066] (1) Weigh 100g of weakly basic anion exchange resin (purchased from Langfang Aoguang Energy Saving Technology Co., Ltd., product model D301), wash it 5 times with deionized water, and let it air dry naturally.

[0067] (2) The resin after cleaning in step (1) is placed in a hydrochloric acid solution with a mass fraction of 4wt% for activation treatment at a temperature of 25℃ for 10h.

[0068] (3) Add 100g of the activated resin from step (2), 100g of octadecyltrimethoxysilane and 200mL of toluene to a reflux reactor for reaction at 80℃ for 8h. After the reaction is complete, wash the reaction product with deionized water 4 times.

[0069] (4) Add 80g of the resin treated in step (3) and 200g of acrylic acid to the reaction apparatus for reaction at 120℃ for 8 hours. After the reaction is completed, wash with deionized water 5 times.

[0070] (5) Add 80g of the resin treated in step (4), 20g of 2-acrylamide-2-methylpropanesulfonic acid and 200mL of ethanol to the reaction apparatus for reaction at 80℃ for 8h. After the reaction, wash with deionized water 5 times to obtain the modified anion exchange resin A1 of the present invention.

[0071] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin A1, sample Y1 was obtained. The thermal stability salt concentration and amine concentration of samples X1 and Y1 were tested, and the test results are as follows:

[0072] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0073] The thermal stability of sample Y1 is 0.50 wt% salt concentration and 28 wt% amine concentration.

[0074] Example 2

[0075] (1) Weigh 100g of weakly basic anion exchange resin (purchased from Langfang Aoguang Energy Saving Technology Co., Ltd., product model D301), wash it 4 times with deionized water, and let it air dry naturally.

[0076] (2) The resin after cleaning in step (1) is placed in a hydrochloric acid solution with a mass fraction of 4.5 wt% for activation treatment at a temperature of 30°C for 15 h.

[0077] (3) Add 100g of the activated resin from step (2), 110g of octadecyltrimethoxysilane and 200mL of toluene to a reflux reactor for reaction at 60℃ for 10h. After the reaction is complete, wash the reaction product with deionized water four times.

[0078] (4) Add 80g of the resin treated in step (3) and 176g of acrylic acid to the reaction apparatus for reaction at 140℃ for 5 hours. After the reaction is completed, wash with deionized water 5 times.

[0079] (5) Add 80g of the resin treated in step (4), 17.6g of 2-acrylamide-2-methylpropanesulfonic acid and 200mL of ethanol to the reaction apparatus for reaction at 60℃ for 10h. After the reaction, wash with deionized water 5 times to obtain the modified anion exchange resin A2 of the present invention.

[0080] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin A2, sample Y2 was obtained. The thermal stability salt concentration and amine concentration of samples X1 and Y2 were tested, and the test results are as follows:

[0081] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0082] The thermal stability of sample Y2 is 0.45 wt% salt concentration and 27 wt% amine concentration.

[0083] Example 3

[0084] (1) Weigh 100g of weakly basic anion exchange resin (purchased from Langfang Aoguang Energy Saving Technology Co., Ltd., product model D301), wash it 5 times with deionized water, and let it air dry naturally.

[0085] (2) The resin after cleaning in step (1) is placed in a 3.5 wt% hydrochloric acid solution for activation treatment at 15°C for 12 hours.

[0086] (3) Add 100g of the activated resin from step (2), 120g of octadecyltrimethoxysilane and 200mL of toluene to a reflux reactor for reaction at 100℃ for 5h. After the reaction is complete, wash the reaction product with deionized water 4 times.

[0087] (4) Add 80g of the resin treated in step (3) and 224g of acrylic acid to the reaction apparatus for reaction at 130℃ for 10h. After the reaction is completed, wash with deionized water 5 times.

[0088] (5) Add 80g of the resin treated in step (4), 22.4g of 2-acrylamide-2-methylpropanesulfonic acid and 200mL of ethanol to the reaction apparatus for reaction at 100℃ for 5h. After the reaction, wash with deionized water 5 times to obtain the modified anion exchange resin A3 of the present invention.

[0089] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin A3, sample Y3 was obtained. The thermal stability salt concentration and amine concentration of samples X1 and Y3 were tested, and the test results are as follows:

[0090] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0091] The thermal stability of sample Y3 is 0.48 wt% salt concentration and 27 wt% amine concentration.

[0092] Example 4

[0093] The modified anion exchange resin was prepared according to the method of Example 1, except that in step (3), the mass ratio of the activated resin to octadecyltrimethoxysilane was adjusted to 1:0.7, and the modified anion exchange resin A4 was finally prepared.

[0094] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin A4, sample Y4 was obtained. The thermally stable salt concentration and amine concentration of samples X1 and Y4 were tested, and the test results are as follows:

[0095] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0096] The thermal stability of sample Y4 is 0.71 wt% salt concentration and 24 wt% amine concentration.

[0097] Example 5

[0098] The modified anion exchange resin was prepared according to the method of Example 1, except that in step (3), the mass ratio of the activated resin to octadecyltrimethoxysilane was adjusted to 1:1.6, and the modified anion exchange resin A5 was finally prepared.

[0099] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin A5, sample Y5 was obtained. The thermally stable salt concentration and amine concentration of samples X1 and Y5 were tested, and the test results are as follows:

[0100] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0101] The thermal stability of sample Y5 is 0.75 wt% salt concentration and 23 wt% amine concentration.

[0102] Example 6

[0103] The modified anion exchange resin was prepared according to the method of Example 1, except that in step (4), the mass ratio of the resin treated in step (3) to acrylic acid was adjusted to 1:1.5, and the modified anion exchange resin A6 was finally prepared.

[0104] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin A6, sample Y6 was obtained. The thermal stability salt concentration and amine concentration of samples X1 and Y6 were tested, and the test results are as follows:

[0105] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0106] The thermal stability of sample Y6 is 0.74 wt% salt concentration and 25 wt% amine concentration.

[0107] Example 7

[0108] The modified anion exchange resin was prepared according to the method of Example 1, except that in step (4), the mass ratio of the resin treated in step (3) to acrylic acid was adjusted to 1:3.5, and the modified anion exchange resin A7 was finally prepared.

[0109] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin A7, sample Y7 was obtained. The thermally stable salt concentration and amine concentration of samples X1 and Y7 were tested, and the results are as follows:

[0110] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0111] The thermal stability of sample Y7 is 0.79 wt% salt concentration and 24 wt% amine concentration.

[0112] Example 8

[0113] The modified anion exchange resin was prepared according to the method of Example 1, except that in step (5), the mass ratio of the resin treated in step (4) to 2-acrylamide-2-methylpropanesulfonic acid was adjusted to 1:0.1, and the modified anion exchange resin A8 was finally prepared.

[0114] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin A8, sample Y8 was obtained. The thermally stable salt concentration and amine concentration of samples X1 and Y8 were tested, and the test results are as follows:

[0115] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0116] The thermal stability of sample Y8 is 0.75 wt% salt concentration and 23 wt% amine concentration.

[0117] Example 9

[0118] The modified anion exchange resin was prepared according to the method of Example 1, except that in step (5), the mass ratio of the resin treated in step (4) to 2-acrylamide-2-methylpropanesulfonic acid was adjusted to 1:0.5, and the modified anion exchange resin A9 was finally prepared.

[0119] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin A9, sample Y9 was obtained. The thermal stability salt concentration and amine concentration of samples X1 and Y9 were tested, and the test results are as follows:

[0120] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0121] The thermal stability of sample Y9 is 0.74 wt% salt concentration and 24 wt% amine concentration.

[0122] Comparative Example 1

[0123] The modified anion exchange resin was prepared according to the method of Example 1, except that the weakly basic anion exchange resin was only treated in steps (1) and (2) to finally obtain the modified anion exchange resin D1.

[0124] A solution containing a high concentration of thermally stable amine salts, which had been in long-term operation at a certain field engineering site, was used as sample X1. After adsorption by modified anion exchange resin D1, sample Y10 was obtained. The thermally stable salt concentration and amine concentration of samples X1 and Y10 were tested, and the test results are as follows:

[0125] The thermal stability of sample X1 is 2.9 wt% salt concentration and 30 wt% amine concentration.

[0126] The thermal stability of sample Y10 is 1.51 wt% salt concentration and 19 wt% amine concentration.

[0127] The relevant parameters of the above embodiments and comparative examples, as well as the test results of the modified anion exchange resin, are shown in Table 1 below.

[0128] Table 1

[0129]

[0130] As can be seen from the results in Table 1, the modified anion exchange resin for removing thermally stable salts from amine solutions prepared according to the method described in this invention can significantly reduce amine loss and improve the purification efficiency of decarbonized amine solutions while removing thermally stable salts from amine solutions during the ion exchange purification process.

[0131] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a modified anion exchange resin for removing thermally stable salts from amine solutions, characterized in that, The method includes: (1) Clean the anion exchange resin with deionized water; (2) Activate the resin after cleaning in step (1) using an acidic or alkaline solution; (3) The resin activated in step (2) and the hydrophobic silane coupling agent are refluxed in anhydrous solvent and then washed with deionized water. (4) React the resin treated in step (3) with organic acid, and then wash it with deionized water. (5) The resin treated in step (4) is reacted with a vinyl compound containing sulfonic acid groups in a solvent, and then washed with deionized water.

2. The method according to claim 1, characterized in that, In step (2), the acidic solution has a mass fraction of 2-8 wt%; and / or The alkaline solution has a mass fraction of 2-8 wt%.

3. The method according to claim 2, characterized in that, In step (2), the mass fraction of the acidic solution is 3-5 wt%.

4. The method according to claim 2, characterized in that, In step (2), the mass fraction of the alkaline solution is 3-5 wt%.

5. The method according to claim 1 or 2, characterized in that, The acidic solution is at least one of hydrochloric acid solution, sulfuric acid solution, and nitric acid solution; and / or The alkaline solution is at least one of potassium hydroxide solution, sodium hydroxide solution, and sodium carbonate solution.

6. The method according to claim 1 or 2, wherein in step (2), the activation conditions include: The temperature is 10-35℃, and the time is 8-18 hours.

7. The method according to claim 1, characterized in that, In step (3), the mass ratio of the resin to the hydrophobic silane coupling agent is 1:(0.5-2).

8. The method according to claim 7, characterized in that, In step (3), the mass ratio of the resin to the hydrophobic silane coupling agent is 1:(0.8-1.5).

9. The method according to claim 1, characterized in that, The hydrophobic silane coupling agent is at least one of octadecyltrimethoxysilane, dodecyltrimethoxysilane, and methyltrimethoxysilane.

10. The method according to claim 1, characterized in that, The anhydrous solvent is at least one of toluene, dichloromethane, and xylene.

11. The method according to claim 1, characterized in that, In step (3), the reflux reaction conditions include: a temperature of 50-120℃ and a time of 4-12h.

12. The method according to claim 1, characterized in that, In step (4), the mass ratio of the resin to the organic acid is 1:(1-5).

13. The method according to claim 12, characterized in that, In step (4), the mass ratio of the resin to the organic acid is 1:(2-3).

14. The method according to claim 1 or 12, characterized in that, The organic acid is at least one of acrylic acid, methacrylic acid, and benzoic acid.

15. The method according to claim 1 or 12, characterized in that, In step (4), the reaction conditions include: a temperature of 100-150℃ and a time of 4-12h.

16. The method according to claim 1, characterized in that, In step (5), the mass ratio of the resin to the vinyl compound containing sulfonic acid groups is 1:(0.1-0.5).

17. The method according to claim 16, characterized in that, In step (5), the mass ratio of the resin to the vinyl compound containing sulfonic acid groups is 1:(0.2-0.3).

18. The method according to claim 1, characterized in that, The vinyl compound containing a sulfonic acid group is at least one of 2-acrylamido-2-methylpropanesulfonic acid, styrene sulfonic acid, and vinyl sulfonic acid.

19. The method according to claim 1, characterized in that, In step (5), the reaction conditions include a temperature of 50-120°C and a time of 4-12 hours.

20. A modified anion exchange resin for removing thermally stable salts from amine solutions, prepared by the method of claim 1.

21. A method for treating thermally stable salts in decarbonized amine solution, characterized in that, The method includes contacting the amine solution after carbon dioxide capture with the modified anion exchange resin of claim 20 for removing thermally stable salts from amine solutions.

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