Preparation method of metal ion chelating NH3 removal resin

Abstract

The invention discloses a preparation method of metal ion chelated NH3 removal resin, which comprises the following steps: S1, synthesizing styrene resin; s2, sulfonation treatment; and S3, resin modification. Chelate metal ions are introduced to construct Lewis acid sites in the sulfonated styrene-divinyl benzene resin, the Lewis acid sites and lone pair electrons in ammonia gas can generate a strong coordination effect, and the adsorption performance of the resin on NH3 is remarkably enhanced; by adopting a high-crosslinking-degree resin structure, the distribution and the number of Lewis acid sites are further enhanced, a wider contact area and a stable structure are provided for the adsorption process, the performance of the material in the aspect of capturing alkaline gases such as ammonia gas is remarkably improved, and the mass adsorption ratio is increased to 2.82% from 0.83%.

Description

Technical Field

[0001] The present invention relates to the technical field of ammonia purification, and in particular to a method for removing NH 3 Method for preparing resin. Background Art

[0002] Ammonia (NH 3 ) is an alkaline gas widely used in industrial and agricultural fields, but its high volatility and toxicity pose a potential threat to the environment and human health. In industries such as semiconductor manufacturing, fertilizer production, and animal husbandry, ammonia emissions need to be strictly controlled to prevent air pollution and health hazards in the working environment. Therefore, the study of efficient adsorbent materials to capture and remove ammonia has become an important topic.

[0003] Traditionally, activated carbon filter media is usually used as NH 3 Activated carbon is a highly porous carbon-based material that can adsorb NH due to its large specific surface area and abundant pores. 3 However, the overall adsorption efficiency of activated carbon is poor and the adsorption capacity is limited. Usually, secondary modification is required to achieve better NH removal. 3 For example, CN101516497B and CN202311600311.7 both use acid-impregnated modified activated carbon. By injecting inorganic acid into the activated carbon matrix, the NH 3 The adsorption effect of activated carbon is good, but inorganic strong acid impregnation modified activated carbon is prone to secondary pollution and equipment corrosion, which poses a great safety hazard. Unlike activated carbon, ion exchange resin is a polymer material composed of a cross-linked polymer skeleton and active functional groups. Its surface contains a large number of exchangeable ion groups. Through ion exchange reactions, it can selectively remove NH4+ from the air. For example, patent CN202311600311.7 uses styrene resin as NH4+ after a simple drying process. 3 However, due to the limited specific surface area and functional groups of ion exchange resins, NH 4+ The selectivity during exchange is poor, which limits the low concentration NH 3 In view of this, it is necessary to develop a highly selective NH 3 Resin, to achieve NH 3 Efficient removal. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a metal ion chelating method for removing NH 3 Method for preparing resin.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme: a metal ion chelating agent for removing NH 3 The method for preparing the resin comprises the following steps:

[0006] S1: Synthesis of styrene resin, 1-10 g of dispersant is dissolved in 50-500 ml of deionized water, and heated at 40-100° C. for 0.5-6 h to obtain aqueous solution A; 2-12 g of initiator is added to a mixed solution of 30-120 ml of styrene and 30-120 ml of divinylbenzene, and magnetically stirred at 300-1500 rpm for 0.5-6 h to obtain oil phase solution B; solution A is added to solution B, and mechanically stirred at 40-120° C. at 100-1500 rpm for 0.5-24 h to obtain styrene-divinylbenzene resin;

[0007] S2: Sulfonation treatment, weigh 5-20g of styrene resin and add it into a 250ml three-necked flask, then add 5-50ml of sulfonating agent, and heat the reaction at 50-120°C for 0.5-12h under magnetic stirring at 200-800rpm; then wash the obtained sample repeatedly with pure water until the washing liquid is neutral to remove excess sulfonating agent; finally, dry in an oven at 60-120°C for 5-24h to obtain sulfonated styrene resin;

[0008] S3: Resin modification: prepare 50-200 ml of a metal salt solution with a concentration of 0.5-5 mol / L, weigh 5-20 g of sulfonated styrene resin and add it to the above solution, and immerse it at 25-100 °C for 0.5-5 h; then use pure water to wash the resulting reactant until the washing solution is neutral to remove the H + Finally, the reaction product was transferred to a 60-120°C oven and dried for 5-24 hours to obtain NH 3 Special styrene chelating resin.

[0009] As a further description of the above technical solution:

[0010] In the step S1, the dispersant is one of polyvinyl alcohol, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose and sodium dodecylbenzene sulfonate.

[0011] As a further description of the above technical solution:

[0012] In the step S1, the initiator is one of dibenzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, di-tert-butylcyclohexyl peroxydicarbonate, and dilauroyl peroxide.

[0013] As a further description of the above technical solution:

[0014] In the step S1, the ratio of styrene to divinylbenzene is 1:0.5-1.5.

[0015] As a further description of the above technical solution:

[0016] In step S2, the sulfonating agent is one of concentrated sulfuric acid, chlorosulfonic acid, sulfur trioxide and fuming sulfuric acid.

[0017] As a further description of the above technical solution:

[0018] The metal salt in step S3 is one or more of aluminum salt, iron salt, cobalt salt, nickel salt, manganese salt, titanium salt, zinc salt, copper salt, cerium salt, vanadium salt and molybdenum salt.

[0019] The present invention has the following beneficial effects:

[0020] 1. Compared with the prior art, the present invention introduces chelated metal ions to construct Lewis acid sites in sulfonated styrene-divinylbenzene resin, which can have a strong coordination effect with the lone pair electrons in ammonia, significantly enhancing the resin's NH 3 adsorption performance.

[0021] 2. Compared with the prior art, the present invention further enhances the distribution and quantity of Lewis acid sites by adopting a highly cross-linked resin structure, providing a wider contact area and a stable structure for the adsorption process, so that the material shows significant performance improvement in capturing alkaline gases such as ammonia, and the mass adsorption ratio is increased from 0.83% to 2.82%. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the infrared spectra of Examples 1-3 of the present invention. DETAILED DESCRIPTION

[0023] Embodiment 1

[0024] S1: Styrene resin synthesis

[0025] Take 5g of sodium dodecylbenzene sulfonate and dissolve it in 100ml of deionized water, heat it at 40°C for 5h to obtain aqueous solution A; take 5g of azobisisoheptanenitrile and add it to a mixed solution prepared by 40ml of styrene and 20ml of divinylbenzene, and magnetically stir it at 600rpm for 5h to obtain oil phase solution B; add solution A to solution B, mechanically stir it at 60°C at 800rpm for 8h to obtain styrene-divinylbenzene resin.

[0026] S2: Sulfonation

[0027] Weigh 10g of styrene resin and add it into a 250ml three-necked flask, then add 8ml of fuming sulfuric acid, and heat the reaction at 120°C for 8h under magnetic stirring at 800rpm; then wash the obtained sample repeatedly with pure water until the washing liquid is neutral to remove excess sulfonation reagent; finally, dry it in an oven at 60°C for 24h to obtain sulfonated styrene resin.

[0028] S3: Resin modification

[0029] Prepare 50 ml of 5 mol / L cobalt nitrate solution, weigh 10 g of sulfonated styrene resin and add it to the solution, immerse at 80 °C for 2 h; then use pure water to wash the resulting reactant until the washing solution is neutral to remove the H + Finally, the reaction product was transferred to a 60°C oven and dried for 24 h to obtain NH 3 Special styrene chelating resin.

[0030] Embodiment 2

[0031] S1: Styrene resin synthesis

[0032] Take 5g of sodium dodecylbenzene sulfonate and dissolve it in 100ml of deionized water, heat it at 40°C for 5h to obtain aqueous solution A; take 5g of azobisisoheptanenitrile and add it to a mixed solution prepared by 40ml of styrene and 30ml of divinylbenzene, and magnetically stir it at 600rpm for 5h to obtain oil phase solution B; add solution A to solution B, mechanically stir it at 60°C at 800rpm for 8h to obtain styrene-divinylbenzene resin.

[0033] S2: Sulfonation

[0034] Weigh 10g of styrene resin and add it into a 250ml three-necked flask, then add 8ml of fuming sulfuric acid, and heat the reaction at 120°C for 8h under magnetic stirring at 800rpm; then wash the obtained sample repeatedly with pure water until the washing liquid is neutral to remove excess sulfonation reagent; finally, dry it in an oven at 60°C for 24h to obtain sulfonated styrene resin.

[0035] S3: Resin modification

[0036] Prepare 50 ml of 5 mol / L cobalt nitrate solution, weigh 10 g of sulfonated styrene resin and add it to the solution, immerse at 80 °C for 2 h; then use pure water to wash the resulting reactant until the washing solution is neutral to remove the H + Finally, the reaction product was transferred to a 60°C oven and dried for 24 h to obtain NH 3 Special styrene chelating resin.

[0037] Embodiment 3

[0038] S1: Styrene resin synthesis

[0039] Take 5g of sodium dodecylbenzene sulfonate and dissolve it in 100ml of deionized water, heat it at 40°C for 5h to obtain aqueous solution A; take 5g of azobisisoheptanenitrile and add it to a mixed solution prepared by 40ml of styrene and 40ml of divinylbenzene, and magnetically stir it at 600rpm for 5h to obtain oil phase solution B; add solution A to solution B, mechanically stir it at 60°C at 800rpm for 8h to obtain styrene-divinylbenzene resin.

[0040] S2: Sulfonation

[0041] Weigh 10g of styrene resin and add it into a 250ml three-necked flask, then add 8ml of fuming sulfuric acid, and heat the reaction at 120°C for 8h under magnetic stirring at 800rpm; then wash the obtained sample repeatedly with pure water until the washing liquid is neutral to remove excess sulfonation reagent; finally, dry it in an oven at 60°C for 24h to obtain sulfonated styrene resin.

[0042] S3: Resin modification

[0043] Prepare 50 ml of 5 mol / L cobalt nitrate solution, weigh 10 g of sulfonated styrene resin and add it to the solution, immerse at 80 °C for 2 h; then use pure water to wash the resulting reactant until the washing solution is neutral to remove the H + Finally, the reaction product was transferred to a 60°C oven and dried for 24 h to obtain NH 3 Special styrene chelating resin.

[0044] Structural characterization and performance testing

[0045] Infrared spectrum test, please refer to the attached Figure 1 .

[0046] Figure 1 Display, at 1030-1080cm -1 and 1150–1180cm -1 There are characteristic absorption peaks at 3 H) S=O and SO vibrations; 3000–3500 cm -1 The broad absorption band at 1450-1600 cm represents the stretching vibration of OH, indicating the presence of sulfonic acid groups; the characteristic peak of the benzene ring structure is at 1450-1600 cm -1 area is shown, indicating that the styrene backbone of the resin is still retained.

[0047] BET and NH 3 Adsorption performance test

[0048] (1) Analysis and testing: BelsorpMAXⅡ analyzer, using N 2 Adsorption and desorption, BET surface area and pore structure of materials were tested at -195 °C. Gas adsorption tests were performed to determine the total surface area using the Brunauer-Emmett-Taylor (BET) equation.

[0049] (2) NH 3 Adsorption performance test: The material was subjected to gas (NH 3 ) Adsorption test. Initial efficiency: control the test air volume (12L / min), test resistance (100Pa), test concentration (600ppb); pollutant holding capacity: control the test air volume (15L / min), test resistance (100Pa), test concentration (10ppm).

[0050] Table 1 BET and NH of different resin samples 3 Adsorption performance

[0051] sample <![CDATA[BET(m 2 / g)]]> Initial efficiency (%) Mass adsorption ratio (mg / g) Pure resin 12 87.8 0.83％ Example 1 462 94.3 1.32％ Example 2 498 96.1 2.05％ Example 3 564 97.8 2.82％

[0052] It can be seen from Table 1 that the modified styrene resin has a strong resistance to alkaline gas (NH 3 ) significantly improved its adsorption performance, with the mass adsorption ratio increased from 0.83% to 2.82%. The adsorption performance of styrene resin is also closely related to the crosslinking degree of the resin itself. With the increase of the amount of crosslinking agent divinylbenzene, a styrene resin with a denser structure and a higher specific surface area can be obtained, thereby further increasing its mass adsorption ratio for alkaline gases from 1.32% to 2.82%.

[0053] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a metal ion chelating NH3-removing resin, characterized in that: The following steps are included: S1: Synthesis of styrene resin, 1-10 g of dispersant is dissolved in 50-500 ml of deionized water, and heated at 40-100° C. for 0.5-6 h to obtain aqueous solution A; 2-12 g of initiator is added to a mixed solution of 30-120 ml of styrene and 30-120 ml of divinylbenzene, and magnetically stirred at 300-1500 rpm for 0.5-6 h to obtain oil phase solution B; solution A is added to solution B, and mechanically stirred at 40-120° C. at 100-1500 rpm for 0.5-24 h to obtain styrene-divinylbenzene resin; S2: Sulfonation treatment, weigh 5-20g of styrene resin and add it into a 250ml three-necked flask, then add 5-50ml of sulfonating agent, and heat the reaction at 50-120°C for 0.5-12h under magnetic stirring at 200-800rpm; then wash the obtained sample repeatedly with pure water until the washing liquid is neutral to remove excess sulfonating agent; finally, dry in an oven at 60-120°C for 5-24h to obtain sulfonated styrene resin; S3: Resin modification: prepare 50-200 ml of a metal salt solution with a concentration of 0.5-5 mol / L, weigh 5-20 g of sulfonated styrene resin and add it to the above solution, and immerse it at 25-100 °C for 0.5-5 h; then use pure water to wash the resulting reactant until the washing solution is neutral to remove the H + Finally, the reaction product is transferred to a 60-120°C oven and dried for 5-24 hours to obtain a styrene chelating resin specifically for removing NH3.

2. The method for preparing a metal ion chelating NH3-removing resin according to claim 1, characterized in that: In the step S1, the dispersant is one of polyvinyl alcohol, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose and sodium dodecylbenzene sulfonate.

3. The method for preparing a metal ion chelating NH3-removing resin according to claim 1, characterized in that: In the step S1, the initiator is one of dibenzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, di-tert-butylcyclohexyl peroxydicarbonate, and dilauroyl peroxide.

4. The method for preparing a metal ion chelating NH3-removing resin according to claim 1, characterized in that: In the step S1, the ratio of styrene to divinylbenzene is 1:0.5-1.

5.

5. The method for preparing a metal ion chelating NH3-removing resin according to claim 1, characterized in that: In step S2, the sulfonating agent is one of concentrated sulfuric acid, chlorosulfonic acid, sulfur trioxide and fuming sulfuric acid.

6. The method for preparing a metal ion chelating NH3-removing resin according to claim 1, characterized in that: The metal salt in step S3 is one or more of aluminum salt, iron salt, cobalt salt, nickel salt, manganese salt, titanium salt, zinc salt, copper salt, cerium salt, vanadium salt and molybdenum salt.

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