Modified anion exchange resin for removing amine liquid thermal stability salt and preparation method of modified anion exchange resin

Abstract

The invention relates to the technical field of carbon dioxide capture, and discloses modified anion exchange resin for removing amine liquid thermal stability salt and a preparation method thereof. The method comprises the following steps: (1) cleaning anion exchange resin by using deionized water; (2) activating the resin cleaned in the step (1) by using an acid solution or an alkali solution; (3) performing reflux reaction on the resin activated in the step (2) and a hydrophobic silane coupling agent in an anhydrous solvent, and cleaning with deionized water after the reaction; (4) reacting the resin treated in the step (3) with organic acid, and cleaning with deionized water after the reaction; and (5) reacting the resin treated in the step (4) with a vinyl compound containing a sulfonic acid group in a solvent, and cleaning with deionized water after the reaction. The modified anion exchange resin prepared by the method provided by the invention can improve the purification efficiency of decarburized amine solution in the process of ion exchange purification of alcohol amine solution.

Description

Technical Field

[0001] The invention relates to the technical field of carbon dioxide capture, and in particular to a modified anion exchange resin for removing heat-stable salts of amine liquid and a preparation method thereof. Background Art

[0002] The problem of global warming is becoming increasingly prominent. The large-scale emission of greenhouse gases is one of the main causes of global warming. At present, the problem of industrial carbon emissions with carbon dioxide as the main component has attracted more and more attention. Governments and enterprises are trying to capture, store and consume carbon dioxide on a large scale. Chemical absorption is the most widely used carbon dioxide capture technology. Its principle is to use chemical solvents to react reversibly with carbon dioxide to separate carbon dioxide from the gas. Commonly used chemical solvents include alcohol amine compounds, such as monoethanolamine (MEA), diethanolamine (DEA) and methyldiethanolamine (MDEA). These alcohol amines have the advantages of strong absorption capacity and easy regeneration, but also have disadvantages such as low absorption efficiency and high energy consumption. The technology of treating heat-stable salts of anionic acid radicals in amine solution with modified ion exchange resin involves using specific ion exchange resins to purify amine solution and remove heat-stable salts (HSS) therein. These heat-stable salts are generated by the reaction of amine solution and acidic components, such as hydrochloride, sulfate, formates, acetates, oxalates, thiocyanates and thiosulfinates. These salts cannot be regenerated by heating and will accumulate in the system, resulting in reduced amine decarbonization efficiency, equipment corrosion and other problems. Anion exchange resins can be divided into three categories according to the nature of their basic groups: strong basic, weak basic and mixed strong and weak basic. Strong basic anion exchange resins contain strong basic groups, such as quaternary ammonium groups, which can dissociate into OH in water. － The positively charged groups of this type of resin can adsorb and combine with anions in the solution, thereby 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 in water. － Strong base and weak base anion resins have different adsorption capacities for different types of anions. Summary of the invention

[0003] The purpose of the present invention is to overcome the problem that the ion exchange resin in the prior art removes the heat-stable salt in the amine solution and adsorbs carbamate, resulting in amine loss, and to provide a modified anion exchange resin for removing the heat-stable salt in the amine solution and a preparation method thereof. The modified anion exchange resin prepared according to the method of the present invention can reduce the adsorption of carbamate while removing the heat-stable salt in the amine solution during the ion exchange purification of the alcohol amine solution, thereby reducing amine loss.

[0004] In order to achieve the above object, the present invention provides a modified anion exchange resin and a preparation method thereof, which comprises the following steps: (1) Use deionized water to clean the anion exchange resin; (2) activating the resin after being cleaned in step (1) using an acidic solution or an alkaline solution; (3) subjecting the resin activated in step (2) and the hydrophobic silane coupling agent to a reflux reaction in an anhydrous solvent, and washing with deionized water after the reaction; (4) reacting the resin treated in step (3) with an organic acid, and washing with deionized water after the reaction; (5) reacting the resin treated in step (4) with a vinyl compound containing a sulfonic acid group in a solvent, and washing with deionized water after the reaction.

[0005] Preferably, in step (2), the mass fraction of the acidic solution is 2-8wt%, preferably 3-5wt%.

[0006] Preferably, in step (2), the mass fraction of the alkaline solution is 2-8wt%, preferably 3-5wt%.

[0007] Preferably, the acidic solution is at least one of a hydrochloric acid solution, a sulfuric acid solution and a nitric acid solution.

[0008] Preferably, the alkaline solution is at least one of a potassium hydroxide solution, a sodium hydroxide solution and a sodium carbonate solution.

[0009] Preferably, in step (2), the activation conditions include: temperature of 10-35°C and time of 8-18h.

[0010] Preferably, in step (3), the mass ratio of the resin to the hydrophobic silane coupling agent is 1:(0.5-2), preferably 1:(0.8-1.5).

[0011] Preferably, the hydrophobic silane coupling agent is at least one of octadecyltrimethoxysilane, dodecyltrimethoxysilane and methyltrimethoxysilane.

[0012] Preferably, the anhydrous solvent is at least one of toluene, dichloromethane and xylene.

[0013] Preferably, in step (3), the conditions of the reflux reaction include: temperature of 50-120° C. and time of 4-12 h.

[0014] Preferably, in step (4), the mass ratio of the resin to the organic acid is 1:(1-5), preferably 1:(2-3).

[0015] Preferably, the organic acid is at least one of acrylic acid, methacrylic acid and benzoic acid.

[0016] Preferably, in step (4), the reaction conditions include: temperature of 100-150° C. and time of 4-12 h.

[0017] Preferably, in step (5), the mass ratio of the resin to the vinyl compound containing a sulfonic acid group is 1:(0.1-0.5), preferably 1:(0.2-0.3).

[0018] Preferably, the vinyl compound containing a sulfonic acid group is at least one of 2-acrylamide-2-methylpropanesulfonic acid (AMPS), styrenesulfonic acid (SSA) and vinylsulfonic acid (VS).

[0019] Preferably, in step (5), the reaction conditions include: temperature of 50-120° C. and time of 4-12 h.

[0020] The second aspect of the present invention provides a modified anion exchange resin for removing heat-stable salts of amine solutions prepared by the method described above.

[0021] The third aspect of the present invention provides a method for treating heat-stable salts in decarbonized amine solution, the method comprising: contacting the alcohol amine solution after capturing carbon dioxide with the modified anion exchange resin for removing heat-stable salts in amine solution as described above.

[0022] According to the preparation method of the modified anion exchange resin for removing heat-stable salts of amine solution described in the present invention, the ion exchange resin is first activated by using an acidic solution or an alkaline solution, and then the surface is hydrophobically modified by using a hydrophobic silane coupling agent, and then the anion exchange groups on the resin are neutralized by using an organic acid, and then a vinyl compound containing a sulfonic acid group is grafted onto the resin to prepare the modified anion exchange resin. The modified anion exchange resin prepared by the present invention can reduce the adsorption of carbamate while removing the heat-stable salts in the amine solution during the ion exchange purification process of the alcohol amine solution, thereby reducing the amine loss and improving the purification efficiency of the decarbonized amine solution. DETAILED DESCRIPTION

[0023] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0024] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0025] The preparation method of the modified anion exchange resin for removing heat-stable salts of amine solution according to the present invention comprises the following steps: (1) Use deionized water to clean the anion exchange resin; (2) activating the resin after being cleaned in step (1) using an acidic solution or an alkaline solution; (3) subjecting the resin activated in step (2) and the hydrophobic silane coupling agent to a reflux reaction in an anhydrous solvent, and washing with deionized water after the reaction; (4) reacting the resin treated in step (3) with an organic acid, and washing with deionized water after the reaction; (5) reacting the resin treated in step (4) with a vinyl compound containing a sulfonic acid group in a solvent, and washing with deionized water after the reaction.

[0026] In the method described in the present invention, the anion exchange resin used to remove the heat-stable salt of amine solution can be various anion exchange resins conventionally used in the art. In a more preferred embodiment, the anion exchange resin used to remove the heat-stable salt of amine solution is a weakly basic anion exchange resin. Specifically, the anion exchange resin used to remove the heat-stable salt of amine solution 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 the heat-stable salt of amine solution is a weakly basic anion exchange resin, such as the weakly basic anion exchange resin with product model D301 purchased from Langfang Aoguang Energy Saving Technology Co., Ltd.

[0027] In step (1), the cleaning process may be performed once or multiple times, preferably multiple times. The purpose of the cleaning is to remove impurities.

[0028] In step (2), the mass fraction of the acidic solution may be 2-8 wt %, preferably 3-5 wt %, and more preferably 3.5-4.5 wt %.

[0029] In step (2), the mass fraction of the alkaline solution may be 2-8 wt %, preferably 3-5 wt %, and more preferably 3.5-4.5 wt %.

[0030] In step (2), the acidic solution may be at least one of a hydrochloric acid solution, a sulfuric acid solution and a nitric acid solution. In the most preferred embodiment, the acidic solution is a hydrochloric acid solution.

[0031] In step (2), the alkaline solution may be at least one of a potassium hydroxide solution, a sodium hydroxide solution and a sodium carbonate solution. In the most preferred embodiment, the alkaline solution is a sodium hydroxide solution.

[0032] In step (2), the activation conditions may include: temperature of 10-35°C, time of 8-18h. In a more preferred case, the activation conditions include: temperature of 15-30°C, time of 10-15h. The activation process may be implemented in various conventional reaction devices.

[0033] In step (3), the mass ratio of the resin to the hydrophobic silane coupling agent may be 1:(0.5-2), preferably 1:(0.8-1.5), and more preferably 1:(1-1.2).

[0034] In the present invention, the hydrophobic silane coupling agent may be at least one of octadecyltrimethoxysilane, dodecyltrimethoxysilane and methyltrimethoxysilane. In the most preferred embodiment, the hydrophobic silane coupling agent is octadecyltrimethoxysilane.

[0035] In the present invention, the anhydrous solvent may be at least one of toluene, dichloromethane and xylene, and specifically, the xylene may be p-xylene, m-xylene or o-xylene. In the most preferred embodiment, the anhydrous solvent is toluene.

[0036] In step (3), the conditions of the reflux reaction may include: a temperature of 50-120° C. and a time of 4-12 h. In a more preferred case, the conditions of the reflux reaction include: a temperature of 60-100° C. and a time of 5-10 h. The reflux reaction process may be implemented in various conventional reflux reaction devices.

[0037] In step (3), the cleaning process may be performed once or multiple times, preferably multiple times. The purpose of the cleaning is to remove the unreacted hydrophobic silane coupling agent.

[0038] In step (4), the mass ratio of the resin to the organic acid may be 1:(1-5), preferably 1:(2-3), and more preferably 1:(2.2-2.8).

[0039] In the present invention, the organic acid may be at least one of acrylic acid, methacrylic acid and benzoic acid. In the most preferred embodiment, the organic acid is acrylic acid.

[0040] In step (4), the reaction conditions may include: temperature of 100-150°C, time of 4-12 hours. In a more preferred case, the reaction conditions include: temperature of 120-140°C, time of 5-10 hours. The reaction process may be implemented in various conventional reaction devices.

[0041] In step (4), the cleaning may be performed once or multiple times, preferably multiple times. The purpose of the cleaning is to remove excess organic acid.

[0042] In step (5), the mass ratio of the resin to the vinyl compound containing a sulfonic acid group may be 1:(0.1-0.5), preferably 1:(0.2-0.3), and more preferably 1:(0.22-0.28).

[0043] In the present invention, the vinyl compound containing a sulfonic acid group may be at least one of 2-acrylamide-2-methylpropanesulfonic acid (AMPS), styrenesulfonic acid (SSA) and vinylsulfonic acid (VS). In the most preferred embodiment, the vinyl compound containing a sulfonic acid group is 2-acrylamide-2-methylpropanesulfonic acid (AMPS).

[0044] In step (5), the reaction conditions may include: temperature of 50-120°C, time of 4-12 hours. In the most preferred embodiment, the reaction conditions include: temperature of 60-100°C, time of 5-10 hours. The reaction process may be implemented in various conventional reaction devices.

[0045] In step (5), the cleaning may be performed once or multiple times, preferably multiple times. The purpose of the cleaning is to remove unreacted monomers and / or by-products.

[0046] The present invention also provides a modified anion exchange resin for removing heat-stable salts of amine solution prepared by the above method. The modified anion exchange resin for removing heat-stable salts of amine solution can reduce the adsorption of carbamate in the ion exchange purification process of alcohol amine solution, thereby avoiding excessive amine loss.

[0047] The invention also provides a method for treating heat-stable salts of decarbonized amine solution, which comprises: contacting the alcohol amine solution after capturing carbon dioxide with the modified anion exchange resin for removing heat-stable salts of amine solution.

[0048] In the method of the present invention, the alcohol amine solution may include at least one of monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA). The product of the reaction of monoethanolamine (MEA) with carbon dioxide may be MEA carbamate, proton amine MEA H+ 、HCO3 - and CO3 2- At least one of the following. The product of the reaction of diethanolamine (DEA) and carbon dioxide may be carbamate. The product of the reaction of triethanolamine (TEA) and carbon dioxide may be bicarbonate.

[0049] The following examples further illustrate the application of the anion exchange resin for removing heat-stable salts of amine solution in the ion exchange process of the present invention. The examples are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following examples.

[0050] The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, are all commercially available.

[0051] In the following examples and comparative examples, the test method for the concentration of the thermal stability salt and the amine concentration of the test samples was carried out in the following manner: Thermal stability salt concentration test: Take 50mL of the test sample, heat it, and reflux it with bubbling for 5 minutes to remove the residual CO2 and H2S. After heating, cover the sample with a quartz glass cover and cool it in a dark place. Use deionized water to compensate the difference to ensure that the final sample volume is consistent with the initial volume. Weigh 2-3g of the test sample and place it in a 100mL plastic cup. The sample weight is recorded as W . Pour the sample into the resin column and rinse the plastic cup with deionized water several times. The washing solution is also poured into the resin column and then rinsed with deionized water. Use a 250mL beaker to collect the solution flowing out of the resin column. Use pH test paper to test the effluent from the resin column until it is neutral (pH=7) or equal to the pH value of the rinse water. Add 2-3 drops of phenolphthalein indicator with a concentration of 5g / L to the beaker, titrate with 0.1mol / L sodium hydroxide solution to pink, and record the consumption of sodium hydroxide solution (V). The calculation formula for the mass concentration Wt% of thermally stable salt is as follows: Wt%=

[0052] Amine concentration test: Use GC-MS to test the amine concentration of the sample. Preheat the chromatograph for 30 minutes, take 20 μL of sample and dilute it into 50 g of deionized water. After injection, perform baseline correction, peak identification and quantitative analysis on the chromatogram to determine the amine concentration of the sample.

[0053] Example 1 (1) Weigh 100 g of weakly alkaline anion exchange resin (purchased from Langfang Aoguang Energy Saving Technology Co., Ltd., product model D301), wash it with deionized water for 5 times, and dry it naturally.

[0054] (2) The resin cleaned in step (1) was placed in a 4 wt% hydrochloric acid solution for activation at 25°C for 10 h.

[0055] (3) 100 g of the resin activated in step (2), 100 g of octadecyltrimethoxysilane and 200 mL of toluene were added to a reflux reaction apparatus for reaction at 80° C. for 8 h. After the reaction was completed, the reaction product was washed 4 times with deionized water.

[0056] (4) 80 g of the resin treated in step (3) and 200 g of acrylic acid were added to a reaction apparatus for reaction at 120° C. for 8 h. After the reaction was completed, the mixture was washed with deionized water for 5 times.

[0057] (5) 80 g of the resin treated in step (4), 20 g of 2-acrylamide-2-methylpropanesulfonic acid and 200 mL of ethanol were added to a reaction apparatus for reaction at 80° C. for 8 h. After the reaction, the resin was washed with deionized water for 5 times to obtain the modified anion exchange resin A1 of the present invention.

[0058] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y1 was obtained after adsorption by modified anion exchange resin A1. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y1. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0059] The thermally stable salt concentration of sample Y1 is 0.50 wt % and the amine concentration is 28 wt %.

[0060] Example 2 (1) Weigh 100 g of weakly alkaline anion exchange resin (purchased from Langfang Aoguang Energy Saving Technology Co., Ltd., product model D301), wash it with deionized water for 4 times, and dry it naturally.

[0061] (2) The resin cleaned in step (1) was placed in a 4.5 wt% hydrochloric acid solution for activation at 30°C for 15 h.

[0062] (3) 100 g of the resin activated in step (2), 110 g of octadecyltrimethoxysilane and 200 mL of toluene were added to a reflux reaction apparatus for reaction at 60° C. for 10 h. After the reaction was completed, the reaction product was washed with deionized water 4 times.

[0063] (4) 80 g of the resin treated in step (3) and 176 g of acrylic acid were added to a reaction apparatus for reaction at 140° C. for 5 h. After the reaction was completed, the mixture was washed with deionized water for 5 times.

[0064] (5) 80 g of the resin treated in step (4), 17.6 g of 2-acrylamide-2-methylpropanesulfonic acid and 200 mL of ethanol were added to a reaction apparatus for reaction at 60° C. for 10 h. After the reaction, the resin was washed with deionized water for 5 times to obtain the modified anion exchange resin A2 of the present invention.

[0065] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y2 was obtained after adsorption by modified anion exchange resin A2. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y2. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0066] The thermally stable salt concentration of sample Y2 is 0.45 wt % and the amine concentration is 27 wt %.

[0067] Example 3 (1) Weigh 100 g of weakly alkaline anion exchange resin (purchased from Langfang Aoguang Energy Saving Technology Co., Ltd., product model D301), wash it with deionized water for 5 times, and dry it naturally.

[0068] (2) The resin cleaned in step (1) was placed in a 3.5 wt% hydrochloric acid solution for activation at a temperature of 15°C for 12 h.

[0069] (3) 100 g of the resin activated in step (2), 120 g of octadecyltrimethoxysilane and 200 mL of toluene were added to a reflux reaction apparatus for reaction at a temperature of 100° C. for 5 h. After the reaction was completed, the reaction product was washed with deionized water 4 times.

[0070] (4) 80 g of the resin treated in step (3) and 224 g of acrylic acid were added to a reaction apparatus for reaction at 130° C. for 10 h. After the reaction was completed, the mixture was washed with deionized water for 5 times.

[0071] (5) 80 g of the resin treated in step (4), 22.4 g of 2-acrylamide-2-methylpropanesulfonic acid and 200 mL of ethanol were added to a reaction apparatus for reaction at 100° C. for 5 h. After the reaction, the resin was washed with deionized water for 5 times to obtain the modified anion exchange resin A3 of the present invention.

[0072] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y3 was obtained after adsorption by modified anion exchange resin A3. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y3. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0073] The thermally stable salt concentration of sample Y3 is 0.48 wt % and the amine concentration is 27 wt %.

[0074] Example 4 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 finally a modified anion exchange resin A4 was prepared.

[0075] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y4 was obtained after adsorption by modified anion exchange resin A4. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y4. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0076] The thermally stable salt concentration of sample Y4 is 0.71 wt % and the amine concentration is 24 wt %.

[0077] Example 5 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 finally the modified anion exchange resin A5 was prepared.

[0078] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y5 was obtained after adsorption by modified anion exchange resin A5. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y5. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0079] The thermally stable salt concentration of sample Y5 is 0.75 wt % and the amine concentration is 23 wt %.

[0080] Example 6 A 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 finally a modified anion exchange resin A6 was prepared.

[0081] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y6 was obtained after adsorption by modified anion exchange resin A6. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y6. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0082] The thermally stable salt concentration of sample Y6 is 0.74 wt % and the amine concentration is 25 wt %.

[0083] Example 7 A 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 finally a modified anion exchange resin A7 was prepared.

[0084] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y7 was obtained after adsorption by modified anion exchange resin A7. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y7. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0085] The thermally stable salt concentration of sample Y7 is 0.79 wt % and the amine concentration is 24 wt %.

[0086] Example 8 A 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 finally a modified anion exchange resin A8 was prepared.

[0087] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y8 was obtained after adsorption by modified anion exchange resin A8. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y8. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0088] The thermally stable salt concentration of sample Y8 is 0.75 wt % and the amine concentration is 23 wt %.

[0089] Example 9 A 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 finally a modified anion exchange resin A9 was prepared.

[0090] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y9 was obtained after adsorption by modified anion exchange resin A9. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y9. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0091] The thermally stable salt concentration of sample Y9 is 0.74 wt % and the amine concentration is 24 wt %.

[0092] Comparative Example 1 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 by step (1) and step (2), and finally the modified anion exchange resin D1 was prepared.

[0093] The alcohol amine solution containing high concentration of heat-stable salt in a long-term operation of a field project was used as sample X1, and sample Y10 was obtained after adsorption by modified anion exchange resin D1. The heat-stable salt concentration test and amine concentration test were conducted on sample X1 and sample Y10. The test results are as follows: Sample X1 has a thermally stable salt concentration of 2.9 wt % and an amine concentration of 30 wt %.

[0094] The thermally stable salt concentration of sample Y10 is 1.51 wt % and the amine concentration is 19 wt %.

[0095] The relevant parameters of the above examples and comparative examples and the test results of the modified anion exchange resin are shown in Table 1 below.

[0096] Table 1

[0097] It can be seen from the results in Table 1 that the modified anion exchange resin for removing heat-stable salts in amine solution prepared according to the method described in the present invention can significantly reduce amine loss and improve the decarbonation amine solution purification efficiency while removing heat-stable salts in the amine solution during the ion exchange purification of the alcohol amine solution.

[0098] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a modified anion exchange resin for removing heat-stable salts of amine solutions, characterized in that: The method includes: (1) Use deionized water to clean the anion exchange resin; (2) activating the resin after being cleaned in step (1) using an acidic solution or an alkaline solution; (3) subjecting the resin activated in step (2) and the hydrophobic silane coupling agent to a reflux reaction in an anhydrous solvent, and washing with deionized water after the reaction; (4) reacting the resin treated in step (3) with an organic acid, and washing with deionized water after the reaction; (5) reacting the resin treated in step (4) with a vinyl compound containing a sulfonic acid group in a solvent, and washing with deionized water after the reaction.

2. The method according to claim 1, characterized in that In step (2), the mass fraction of the acidic solution is 2-8wt%, preferably 3-5wt%; and / or The mass fraction of the alkaline solution is 2-8wt%, preferably 3-5wt%.

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

4. The method according to any one of claims 1 to 3, wherein in step (2), the activation conditions include: The temperature is 10-35℃ and the time is 8-18h.

5. 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), preferably 1:(0.8-1.5).

6. The method according to claim 1 or 5, characterized in that: The hydrophobic silane coupling agent is at least one of octadecyltrimethoxysilane, dodecyltrimethoxysilane and methyltrimethoxysilane.

7. The method according to claim 1 or 5, characterized in that: The anhydrous solvent is at least one of toluene, dichloromethane and xylene.

8. The method according to any one of claims 1 and 5-7, characterized in that In step (3), the conditions of the reflux reaction include: temperature of 50-120° C. and time of 4-12 h.

9. 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), preferably 1:(2-3).

10. The method according to claim 1 or 9, characterized in that: The organic acid is at least one of acrylic acid, methacrylic acid and benzoic acid.

11. The method according to claim 1 or 9, characterized in that: In step (4), the reaction conditions include: temperature of 100-150° C. and time of 4-12 h.

12. The method according to claim 1, characterized in that In step (5), the mass ratio of the resin to the vinyl compound containing a sulfonic acid group is 1:(0.1-0.5), preferably 1:(0.2-0.3).

13. The method according to claim 1 or 12, characterized in that: The vinyl compound containing a sulfonic acid group is at least one of 2-acrylamide-2-methylpropanesulfonic acid, styrenesulfonic acid and vinylsulfonic acid.

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

15. A modified anion exchange resin for removing heat-stable salts of amine solutions prepared by the method according to any one of claims 1 to 14.

16. A method for treating heat-stable salt of decarbonized amine liquid, characterized in that: The method comprises: contacting the alcohol amine solution after capturing carbon dioxide with the modified anion exchange resin for removing heat-stable salts of amine solution as claimed in claim 15.

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