Preparation process of amine liquid purification resin for desulfurization system

Abstract

The invention belongs to the technical field of ion exchange resin, and particularly relates to a preparation process of amine liquid purification resin for a desulfurization system. The amine liquid purification resin for the desulfurization system is prepared through a suspension polymerization method, polar third monomers such as acrylic acid and methyl methacrylate are added into a polymerization system of styrene and a cross-linking agent, the structure of the resin is changed, and therefore the purpose of regulating and controlling the polarity, the pore size and the adsorption performance of the resin is achieved. Besides, acrylic acid and methyl acrylate are added into the polymer monomer of the amine liquid purification resin, so that the hydrophilic performance of the amine liquid purification resin is effectively improved, and the prepared polymer product has good anti-pollution performance. The amine liquid purification resin prepared by using the preparation process of the amine liquid purification resin provided by the invention has the characteristics of large exchange capacity, rich pore structures, high activity, good adsorption performance, high pollution resistance and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of ion exchange resins, and in particular relates to a preparation process of an amine liquid purification resin for a desulfurization system. Background Art

[0002] Natural gas, coking waste gas, gasoline, petroleum liquefaction, etc. usually use alcohol amine absorption devices to remove acid gases such as H2S and CO2 in the gas flow. The acid gases are dissolved in the amine solution to form soluble alcohol amine salts. Then water, slightly reacted alcohol amine and alcohol amine salt solution enter the stripping tower for heating. The alcohol amine salt decomposes to release acid gases such as H2S and CO2. The alcohol amine solution is circulated into the absorption tower again to achieve the recycling of the alcohol amine solution. However, in addition to acid gases such as H2S and CO2, the gas flow also includes acid gases such as SO2, CS2, and COS. The alkanolamine salts formed after these gases react with the alcohol amine solution cannot be removed by the stripping tower, but will be retained in the alcohol amine solution and continue to accumulate, causing the quality of the amine solution to decline. With the recycling of the alcohol amine solution, the desulfurization and decarbonization capacity of the alcohol amine solution is reduced.

[0003] The deep purification and regeneration technologies currently used for amine liquid include alkali distillation, electrodialysis and ion exchange. The alkali distillation method is to add liquid alkali to the amine liquid, replace the alkanolamine salt with free amine, and then recover the amine by distillation. The electrodialysis method uses direct current and selective ion permeation membrane to achieve the purpose of desalination, so that the amine liquid is purified. These two methods have high energy consumption. The ion exchange method has become the mainstream in the deep purification and regeneration technology of amine liquid due to its low energy consumption and high amine liquid recovery rate. However, the type, pore size and ion exchange capacity of the resin in the ion exchange resin have an impact on the purification effect of the amine liquid and the life of the resin. In addition, the strong alkaline anion exchange resin is easily contaminated and the resin life is short, resulting in a high cost for the treatment of the amine liquid.

[0004] The Chinese patent application document with publication number CN116984035A discloses a method for preparing an ion exchange resin for amine liquid purification equipment, specifically: using styrene, divinylbenzene, benzoyl peroxide, gelatin, methylene blue, sodium chloride, chloromethyl ether, methylal, polyethylene glycol and trimethylamine as main raw materials, the preparation path is: synthesizing cross-linked polymers by suspension polymerization of styrene and divinylbenzene, chloromethylation reaction of cross-linked polymers of styrene and divinylbenzene, and amination reaction of cross-linked polymers of chloromethylated styrene and divinylbenzene. The resin particles prepared by this method have smaller particle size and shorter preparation time, but its removal efficiency of heat-stable salts in alcohol amine solution needs to be verified.

[0005] The Chinese patent application document with publication number CN119281407A discloses a modified anion exchange resin for removing heat-stable salts of amine solution and a preparation method thereof, which specifically comprises: (1) washing the anion exchange resin with deionized water; (2) activating the resin washed in step (1) with an acid solution or an alkaline solution; (3) subjecting the resin activated in step (2) and a 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. Summary of the invention

[0006] In order to solve the technical problems existing in the related art such as the purification resin being easily contaminated, having low adsorption capacity and low removal efficiency, the object of the present invention is to provide a preparation process of amine liquid purification resin for desulfurization system.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows: A preparation process for amine liquid purification resin for desulfurization system comprises the following steps: S1: Styrene, crosslinking agent, acrylic acid and methyl methacrylate are mixed evenly, an initiator is added, porogen is added after stirring evenly, and the mixture is stirred evenly to obtain an oil phase; S2: Add deionized water, carboxymethyl cellulose and sodium dodecyl sulfate to the reaction kettle, heat to 50-60°C while stirring, add the oil phase obtained in step S1, introduce nitrogen, heat to 85-90°C, keep the temperature for reaction, continue to heat to 95-100°C, react until the resin is formed, cool, filter, wash, and obtain spherical resin; S3: The spherical resin obtained in step S2 is placed in a Soxhlet extractor for extraction, and then taken out, dried, and sieved to obtain an amine solution purification resin for a desulfurization system.

[0008] The present invention prepares an amine liquid purification resin for a desulfurization system by a suspension polymerization method, and changes the structure of the resin by adding a polar third monomer such as acrylic acid and methyl methacrylate to a polymerization system of styrene and a cross-linking agent, thereby achieving the purpose of regulating the polarity, pore size and adsorption performance of the resin. In addition, the present invention adds acrylic acid and methyl acrylate to the polymer monomers of the amine liquid purification resin, effectively improving the hydrophilicity of the amine liquid purification resin, so that the obtained polymer product has good anti-pollution performance. The present invention adds a cross-linking agent during the polymerization process, so that the obtained polymer product is cross-linked into a spherical shape, effectively increasing the pore structure of the polymer product and improving the adsorption capacity. The addition of a porogen can form a rich porous structure in the polymer product, effectively solving the technical problem of low adsorption capacity of existing purification resins.

[0009] Furthermore, in step S1, the mass proportions of styrene and methyl methacrylate are: 20-30 parts of styrene, 7-10 parts of acrylic acid, and 15-20 parts of methyl methacrylate.

[0010] Furthermore, in step S1, the cross-linking agent is composed of acryloyl triazine and divinyl pyridine in a mass ratio of 3-5:7-9, and the mass fraction of the cross-linking agent is 5-8 parts.

[0011] The present invention selects acryloyl triazine and divinyl pyridine to jointly form a crosslinking agent, which can form crosslinks between polymer chains, make the polymer product spherical, and improve the strength of the polymer. The crosslinking degree of the polymer product is controlled by controlling the mass ratio of acryloyl triazine and divinyl pyridine, thereby controlling the adsorption capacity of the polymer product.

[0012] Furthermore, in step S1, the cross-linking agent is composed of acryloyl triazine and divinyl pyridine in a mass ratio of 3:8, and the mass fraction of the cross-linking agent is 7 parts.

[0013] Furthermore, in step S1, the initiator is benzoyl peroxide, and the mass fraction of the initiator is 2-4 parts.

[0014] Furthermore, the porogen in step S1 is composed of polyethylene glycol, n-octanol and undecanol in a mass ratio of 12-15:7-11:4-8, and the mass fraction of the porogen is 9-13 parts.

[0015] In the present invention, a porogen is added to the oil phase so that a pore structure is formed in the polymer product through physical or chemical action during the polymerization process. The pore size and specific surface area in the polymer product are accurately controlled by selecting and using the porogen, the adsorption capacity of the amine liquid purification resin is increased, and the removal efficiency of the amine liquid purification resin is effectively improved. Polyethylene glycol can adsorb surrounding solvent molecules during the polymerization process to form a stable micelle structure, and a porous structure is formed in the polymer product as the solvent is removed; n-octanol can promote the formation of pores and improve the mechanical strength of the material; and undecanol can further regulate the pore size and improve the adsorption capacity of the polymer product.

[0016] Furthermore, the porogen in step S1 is composed of polyethylene glycol, n-octanol and undecanol in a mass ratio of 13:9:6, and the mass fraction of the porogen is 10 parts.

[0017] Furthermore, in step S2, the mass proportions of deionized water, carboxymethyl cellulose and sodium dodecyl sulfate are: 100-120 parts of deionized water, 0.5-1 parts of sodium carboxymethyl cellulose, and 5-7 parts of sodium dodecyl sulfate.

[0018] Furthermore, in step S2, the stirring speed of the stirring state is 250-300 rpm, the insulation reaction time is 2.2-2.5 h, and the heating rate of the continued heating is 5-7° C. / h.

[0019] Furthermore, the extraction time in step S3 is 8-10 hours, and the screening is through a 60-mesh sieve.

[0020] Compared with the prior art, the preparation process of the amine liquid purification resin for a desulfurization system provided by the present invention has the following technical advantages: (1) The amine liquid purification resin prepared by the preparation process of the amine liquid purification resin provided by the present invention has the characteristics of large exchange capacity, strong activity, strong anti-pollution ability, etc.; (2) The amine liquid purification resin prepared by the preparation process of the amine liquid purification resin provided by the present invention has good adsorption performance, rich multi-level porous structure, and large specific surface area; (3) The preparation process of the amine liquid purification resin for the desulfurization system provided by the present invention is simple, and the raw materials are available, which is conducive to industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a scanning electron microscope image of the amine solution purification resin for the desulfurization system prepared in Example 3 at 100 μm; Figure 2 This is a scanning electron microscope image of the amine liquid purification resin for the desulfurization system prepared in Example 3 at 1 μm. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments. Those skilled in the art can make various modifications based on the basic idea of ​​the present invention, but as long as they do not deviate from the basic idea of ​​the present invention, they are all within the scope of the present invention.

[0023] Example 1 A preparation process for amine liquid purification resin for desulfurization system comprises the following steps: S1: 20g styrene, 5g cross-linking agent, 7g acrylic acid and 15g methyl methacrylate are mixed evenly, 2g benzoyl peroxide is added, 9g porogen is added after stirring evenly, and stirring evenly to obtain an oil phase; the cross-linking agent is composed of acryloyl triazine and divinyl pyridine in a mass ratio of 3:7; the porogen is composed of polyethylene glycol, n-octanol and undecanol in a mass ratio of 12:7:4; S2: Add 120g of deionized water, 0.5g of carboxymethyl cellulose and 5g of sodium dodecyl sulfate to the reactor, heat to 50°C with stirring at a speed of 250rpm, add the oil phase prepared in step S1, introduce nitrogen, heat to 85°C, keep the temperature for reaction for 2.2h, continue to heat to 95°C at a rate of 5°C / h, react until the resin is formed, cool, filter, wash, and obtain spherical resin; S3: The spherical resin obtained in step S2 is placed in a Soxhlet extractor for extraction for 8 hours, then taken out, dried, and passed through a 60-mesh sieve to obtain an amine solution purification resin for a desulfurization system.

[0024] Example 2 A preparation process for amine liquid purification resin for desulfurization system comprises the following steps: S1: 30g styrene, 8g cross-linking agent, 10g acrylic acid and 20g methyl methacrylate are mixed evenly, 4g benzoyl peroxide is added, 13g porogen is added after stirring evenly, and stirring evenly to obtain an oil phase; the cross-linking agent is composed of acryloyl triazine and divinyl pyridine in a mass ratio of 5:9; the porogen is composed of polyethylene glycol, n-octanol and undecanol in a mass ratio of 15:11:8; S2: Add 100 g of deionized water, 1 g of carboxymethyl cellulose and 7 g of sodium dodecyl sulfate to a reactor, heat to 60° C. under stirring at a speed of 300 rpm, add the oil phase obtained in step S1, introduce nitrogen, heat to 90° C., keep warm for 2.5 h, continue to heat to 100° C. at a rate of 7° C. / h, react until the resin is formed, cool, filter, and wash to obtain a spherical resin; S3: The spherical resin obtained in step S2 is placed in a Soxhlet extractor for extraction for 10 hours, then taken out, dried, and passed through a 60-mesh sieve to obtain an amine solution purification resin for a desulfurization system.

[0025] Example 3 A preparation process for amine liquid purification resin for desulfurization system comprises the following steps: S1: 26g styrene, 7g cross-linking agent, 9g acrylic acid and 17g methyl methacrylate are mixed evenly, 3g benzoyl peroxide is added, 10g porogen is added after stirring evenly, and stirring evenly to obtain an oil phase; the cross-linking agent is composed of acryloyl triazine and divinyl pyridine in a mass ratio of 3:8; the porogen is composed of polyethylene glycol, n-octanol and undecanol in a mass ratio of 13:9:6; S2: Add 115 g of deionized water, 0.7 g of carboxymethyl cellulose and 8 g of sodium dodecyl sulfate to a reactor, heat to 57° C. under stirring at a speed of 280 rpm, add the oil phase obtained in step S1, introduce nitrogen, heat to 88° C., keep warm for 2.4 h, continue to heat to 98° C. at a rate of 6° C. / h, react until the resin is formed, cool, filter, and wash to obtain a spherical resin; S3: The spherical resin obtained in step S2 is placed in a Soxhlet extractor for extraction for 9 hours, then taken out, dried, and passed through a 60-mesh sieve to obtain an amine solution purification resin for a desulfurization system.

[0026] Comparative Example 1 The preparation process of the amine liquid purification resin in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that an equal amount of styrene is used instead of methyl acrylate in this comparative example.

[0027] Comparative Example 2 The preparation process of the amine liquid purification resin in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that the cross-linking agent used in this comparative example is divinylbenzene.

[0028] Comparative Example 3 The preparation process of the amine liquid purification resin in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that the cross-linking agent used in this comparative example is all divinylpyridine.

[0029] Comparative Example 4 The preparation process of the amine liquid purification resin in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that the cross-linking agent used in this comparative example is composed of acryloyl triazine and divinyl pyridine in a mass ratio of 10:3.

[0030] Comparative Example 5 The preparation process of the amine liquid purification resin in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that the porogens used in this comparative example are all polyethylene glycol.

[0031] Comparative Example 6 The preparation process of the amine liquid purification resin in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that the porogens used in this comparative example are all n-octanol.

[0032] Comparative Example 7 The preparation process of the amine liquid purification resin in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that the porogen used in this comparative example is composed of polyethylene glycol, n-octanol and undecanol in a mass ratio of 2:5:11.

[0033] Test example After the amine liquid purification resins prepared in Examples 1 to 3 and Comparative Examples 2 to 7 were fully dried in a vacuum drying oven, the pore volume, pore diameter and specific surface area of ​​the resins were determined by a nitrogen adsorption-desorption method using a Tristar 3000 fully automatic specific surface area and porosity analyzer. The relative pressure during the measurement was 0.0-1.0 (P / P0). The test results are shown in Table 1.

[0034] The microscopic morphology of the amine solution purification resin prepared in Example 3 was observed using a scanning electron microscope (SEM; ZEISS Sigma 300). The test results are shown in Figure 1 and Figure 2 .

[0035] The desulfurization amine liquid (light yellow and transparent in appearance, with a heat-stable salt content of about 3.5%) from a catalytic unit of a certain refinery was selected to test the anti-pollution ability of the amine liquid purification resins prepared in Example 3 and Comparative Example 1. Specifically, 10 mL of the test resin was taken to purify the amine liquid, and the amount of amine liquid used was 30 L. The attenuation of the working exchange capacity of the two resins was observed. The test results are shown in Table 2.

[0036] Table 1 Test results of pore volume, pore diameter and specific surface area

[0037] As shown in Table 1, the pore volume of the amine liquid purification resin prepared by the production process of the amine liquid purification resin for the desulfurization system provided by the present invention is 1.28-1.75cm 3 / g, pore size of 11.85-12.64nm, specific surface area of ​​350.33-367.89m 2 / g, which fully demonstrates that the amine liquid purification resin provided by the present invention has good adsorption capacity and can improve the removal efficiency of amine liquid. Among them, the amine liquid purification resin prepared in Example 3 has the best performance and is the best embodiment of the present invention.

[0038] Compared with Example 3, the crosslinking agent used in Comparative Example 2 is divinylbenzene, but the pore volume of the prepared amine liquid purification resin is reduced, the pore diameter is increased, and the specific surface area is reduced. This shows that although divinylbenzene can be copolymerized with monomers such as styrene and methyl methacrylate as a crosslinking agent to make the polymer chain into a mutually crosslinked network structure, its crosslinking density and crosslinking uniformity are poor, resulting in a decrease in the pore volume of the amine liquid purification resin and an increase in the pore diameter and specific surface area; Comparative Examples 3 and Comparative Examples 4 respectively changed the type and amount ratio of the crosslinking agent, but the pore volume, pore diameter and specific surface area of ​​the amine liquid purification resin were affected to varying degrees, which shows that the component and amount of the crosslinking agent in the present invention have achieved the best Optimization, changing the cross-linking agent component or mass ratio will lead to poor cross-linking of the polymer and reduced adsorption capacity; Comparative Examples 5-7 respectively changed the type and dosage ratio of the porogen, but had different degrees of influence on the pore volume, pore diameter and specific surface area of ​​the amine liquid purification resin, which shows that the porogen has a key influence on the amine liquid purification resin. The use of the porogen within the scope of the present invention is conducive to the generation of macropores that act as diffusion channels inside the resin, and the pore structure is uniform, which effectively improves the pore volume, pore diameter and specific surface area of ​​the amine liquid purification resin. Among them, the pore diameter of the amine liquid purification resin obtained in Example 5 is significantly reduced, which shows that polyethylene glycol is more conducive to the formation of micropores and increases the number of pore structures.

[0039] Depend on Figure 1 and Figure 2 It can be seen that the amine liquid purification resin prepared by the production process of the amine liquid purification resin for the desulfurization system provided by the present invention has a spherical structure and a complex porous structure, which can effectively improve the adsorption capacity and removal efficiency.

[0040] Table 2 Anti-pollution performance test results

[0041] As shown in Table 2, the initial working exchange capacity of the amine liquid purification resin prepared in Example 3 is 0.75 mol / L, and the working exchange capacity after 200 purification cycles is 0.61 mol / L, which fully demonstrates that it has good anti-pollution performance. In Comparative Example 1, an equal amount of styrene is used to replace methyl acrylate, but the working exchange capacity of the prepared amine liquid purification resin after work is significantly reduced, which shows that the present invention adds acrylic acid and methyl acrylate to the polymer monomer of the amine liquid purification resin, effectively improving the hydrophilicity of the amine liquid purification resin, so that the prepared polymer product has good anti-pollution performance.

[0042] The above embodiments are merely illustrative of the preparation method of the present invention, and are not intended to limit the present invention. Any person skilled in the art may not modify the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the technical concept provided by the present invention are still covered by the claims of the present invention.

Claims

1. A process for preparing an amine solution purification resin for a desulfurization system, characterized in that: The following steps are involved: S1: Styrene, crosslinking agent, acrylic acid and methyl methacrylate are mixed evenly, an initiator is added, porogen is added after stirring evenly, and the mixture is stirred evenly to obtain an oil phase; S2: Add deionized water, carboxymethyl cellulose and sodium dodecyl sulfate to the reaction kettle, heat to 50-60°C while stirring, add the oil phase obtained in step S1, introduce nitrogen, heat to 85-90°C, keep the temperature for reaction, continue to heat to 95-100°C, react until the resin is formed, cool, filter, wash, and obtain spherical resin; S3: putting the spherical resin obtained in step S2 into a Soxhlet extractor for extraction, then taking it out, drying it, and sieving it to obtain an amine solution purification resin for a desulfurization system; The cross-linking agent in step S1 is composed of acryloyl triazine and divinyl pyridine in a mass ratio of 3-5:7-9; the porogen is composed of polyethylene glycol, n-octanol and undecanol in a mass ratio of 12-15:7-11:4-8; the mass proportions of styrene and methyl methacrylate in step S1 are: 20-30 parts of styrene, 7-10 parts of acrylic acid, and 15-20 parts of methyl methacrylate.

2. The preparation process of the amine liquid purification resin for desulfurization system according to claim 1, characterized in that: The mass fraction of the cross-linking agent in step S1 is 5-8 parts.

3. The preparation process of the amine liquid purification resin for desulfurization system according to claim 1, characterized in that: In step S1, the cross-linking agent is composed of acryloyl triazine and divinyl pyridine in a mass ratio of 3:8, and the mass fraction of the cross-linking agent is 7 parts.

4. The preparation process of the amine liquid purification resin for desulfurization system according to claim 1, characterized in that: The initiator in step S1 is benzoyl peroxide, and the mass fraction of the initiator is 2-4 parts.

5. The preparation process of the amine liquid purification resin for desulfurization system according to claim 1, characterized in that: The mass fraction of the porogen in step S1 is 9-13 parts.

6. The preparation process of the amine liquid purification resin for desulfurization system according to claim 1, characterized in that: The porogen in step S1 is composed of polyethylene glycol, n-octanol and undecanol in a mass ratio of 13:9:6, and the mass fraction of the porogen is 10 parts.

7. The process for preparing the amine solution purification resin for desulfurization system according to claim 1, characterized in that: The mass proportions of the deionized water, carboxymethyl cellulose and sodium dodecyl sulfate in step S2 are: 100-120 parts of deionized water, 0.5-1 parts of sodium carboxymethyl cellulose, and 5-7 parts of sodium dodecyl sulfate.

8. The process for preparing the amine solution purification resin for desulfurization system according to claim 1, characterized in that: The stirring speed of the stirring state in step S2 is 250-300 rpm, the insulation reaction time is 2.2-2.5 h, and the heating rate of the continued heating is 5-7° C. / h.

9. The process for preparing the amine liquid purification resin for desulfurization system according to claim 1, characterized in that: The extraction time in step S3 is 8-10 hours, and the sieving is through a 60-mesh sieve.

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