A method for producing high-purity sodium methallyl sulfonate

Abstract

The application discloses a production method of high-purity sodium methallyl sulfonate and belongs to the technical field of sodium methallyl sulfonate preparation. The production method comprises the following steps: mixing sodium sulfite and recovered water to obtain a sodium sulfite solution; adding methyl chloroallyl into the sodium sulfite solution, initiating a reaction by increasing the temperature to 65-75 DEG C, controlling the temperature at 45-50 DEG C and reacting for 0.5-1.5 h, and condensing and recovering tail gas after standing and precipitation; sequentially performing coarse dehydration and refined dehydration on the reaction liquid, condensing and recovering water vapor generated, and performing first solid-liquid separation on the dehydrated material; after crystallization of mother liquor, second solid-liquid separation is performed, and the crystallized mother liquor is returned to the dehydration process; and sequentially performing water leaching and drying on the sodium methallyl sulfonate crude product to obtain sodium methallyl sulfonate. The production method realizes efficient recycling of water resources and materials, guarantees high purity of the sodium methallyl sulfonate, and takes into account energy saving, environmental protection and economy in the production process.

Description

Technical Field

[0001] This application relates to a method for producing high-purity sodium methylpropene sulfonate, belonging to the technical field of sodium methylpropene sulfonate preparation. Background Technology

[0002] Sodium methpropylene sulfonate or sodium methallyl sulfonate is mainly used as the third monomer in acrylic fibers to improve their dyeing properties, exhibiting advantages such as good thermal stability and excellent dyeability. Recently, sodium methpropylene sulfonate has also been used to prepare a new generation of polycarboxylate superplasticizers, offering advantages such as being pollution-free and highly efficient.

[0003] However, existing methods for synthesizing sodium methpropylene sulfonate have some problems. For example, Chinese patent application CN101492399A discloses a method for preparing sodium methpropylene sulfonate. This method involves placing the crude product obtained from crystallization in a washing vessel, adding methanol containing 5-15% water, stirring, dissolving, filtering, and repeating the washing process 2-3 times. The separated crystals are then dried to obtain the finished sodium methpropylene sulfonate. This method adds methanol during the washing process, reducing product dissolution loss and increasing the yield. However, methanol is highly toxic and poses safety hazards. Chinese patent application CN101805275A discloses a method for synthesizing sodium methallyl sulfonate. This method uses sodium metabisulfite and methylallyl chloride as raw materials to synthesize sodium methpropylene sulfonate. This method uses sodium metabisulfite, which has higher solubility, instead of sodium sulfite to react and obtain the product. However, sodium metabisulfite is prone to oxidation during use, leading to a darker color in the reaction solution and affecting the quality of the final product. Therefore, we propose a method for producing high-purity sodium methpropylene sulfonate to solve the above problems. Summary of the Invention

[0004] To address the aforementioned issues, a method for producing high-purity sodium methyl propylene sulfonate is provided, which achieves efficient recycling of water resources and materials. While ensuring the high purity of sodium methyl propylene sulfonate, it also considers energy conservation, environmental protection, and economic efficiency in the production process.

[0005] The technical solution adopted in this invention is as follows: A method for producing high-purity sodium methylpropene sulfonate includes the following steps: (1) Dissolution process: Sodium sulfite is mixed evenly with recycled water to obtain a sodium sulfite solution; (2) Reaction process: Methylchloropropene is added dropwise to sodium sulfite solution, the temperature is raised to 65-75℃ to initiate the reaction, and then the temperature is controlled at 45-50℃ for 0.5-1.5h. The mixture is allowed to stand and precipitate. The tail gas is condensed and recovered during the reaction. (3) Dehydration process: The reaction liquid obtained from the reaction process is subjected to coarse dehydration and fine dehydration in sequence to obtain dehydrated material, and the water vapor generated in the two dehydration processes is condensed and recovered; (4) Separation and crystallization process: The dehydrated material is subjected to a first solid-liquid separation to obtain sodium chloride solid and mother liquor; after the mother liquor is crystallized, a second solid-liquid separation is performed to obtain crude sodium methyl propylene sulfonate and crystallization mother liquor, and the crystallization mother liquor is returned to the dehydration process; (5) Drying process: The crude sodium methacrylate is sequentially subjected to water rinsing and drying to obtain sodium methacrylate.

[0006] Optionally, in step (2), the molar ratio of methylchloropropene to sodium sulfite is 1:(1.05-1.1).

[0007] Optionally, in step (3), the temperature for coarse dehydration and fine dehydration is 60-70℃ and the time is 0.5-1.5h.

[0008] Optionally, the methylchloropropene in the tail gas recovered by condensation in step (2) is returned to the reaction process, and the water and the water vapor recovered by condensation in step (3) are combined as recycled water, which is then treated with modified activated carbon and returned to the dissolution process.

[0009] Optionally, the method for preparing the modified activated carbon includes the following steps: S1. Wash the activated carbon with water and dry it thoroughly at 85-100℃ to obtain pretreated activated carbon; S2. Disperse the pretreated activated carbon in a mixture of toluene and water, stir at a constant speed at room temperature for 0.5-1.5 h, then add aminosilane, reflux for 5-7 h, filter, wash, and dry to obtain functionalized activated carbon. S3. Disperse the functionalized activated carbon in an aqueous solution of copper chloride, stir and react at room temperature for 0.5-1.5 h, filter, wash and dry, and reflux the crude product in toluene for 1.5-3 h, filter, wash and dry to obtain modified activated carbon.

[0010] Optionally, the amount of aminosilane added is 12-30 wt% of the pretreated activated carbon. And / or, the weight ratio of the aminosilane to copper chloride is (0.35-0.5):1.

[0011] Optionally, the aminosilane is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane or N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane.

[0012] Optionally, in step (4), the crystallization process is as follows: the mother liquor is stirred, and first cooled to 40-50℃ at a rate of 0.5-1℃ / min, and then cooled to 20-30℃ at a rate of 0.3-0.8℃ / min, and the crystals are grown at a constant temperature for 0.5-1.5h.

[0013] Optionally, in step (4), a first solid-liquid separation and a second solid-liquid separation are performed by centrifugation; The centrifugation speed is 1800-3000 rpm, and the time is 10-15 min.

[0014] Optionally, in step (5), the water spraying is performed 2-3 times; And / or, the drying temperature is 80-105℃, and the time is 2-4h.

[0015] In this application, "room temperature" refers to 20-30℃.

[0016] The beneficial effects of this application include, but are not limited to: 1. The method for producing high-purity sodium methacrylate sulfonate in this application adopts a temperature control strategy of high-temperature initiation and low-temperature reaction, combined with a specific molar ratio of methyl chloride and sodium sulfite. This not only ensures the reaction activity and effectively inhibits side reactions such as hydrolysis or polymerization of methyl chloride, but also improves the selectivity of the reaction, ensures the yield of sodium methacrylate sulfonate, and reduces the generation of impurities. It also avoids the difficulty of subsequent separation caused by excessive sodium sulfite. Through the dual treatment of crude dehydration and refined dehydration, combined with two solid-liquid separations (first separating sodium chloride, then separating crude sodium methacrylate sulfonate), the reaction by-products and unreacted impurities are effectively removed. In particular, the gradient cooling crystallization used in step (4) is conducive to the formation of crystals with complete crystal form and few impurities, thereby obtaining high-purity sodium methacrylate sulfonate.

[0017] 2. The method for producing high-purity sodium methpropylene sulfonate of this application involves condensing and recovering the reaction tail gas, and directly returning methylchloropropylene to the reaction process, which greatly improves the utilization rate of raw materials and effectively increases the yield of sodium methpropylene sulfonate. The condensate from the dehydration process is combined with the tail gas condensate and treated with modified activated carbon before being reused for dissolving sodium sulfite in step (1), thus realizing a closed-loop circulation of process water, greatly reducing the amount of fresh water replenishment, and avoiding the generation and discharge of high-concentration organic wastewater, thereby reducing the burden of wastewater treatment.

[0018] 3. The production method of high-purity sodium methyl allyl sulfonate in this application utilizes modified activated carbon, which exhibits excellent removal effects on anions, organic matter (such as trace amounts of methyl chloride and reaction byproducts), and color. Especially in the adsorption of anions, the recovered anions in water are mainly chloride ions, sulfate ions, and sulfite ions. On the one hand, Cu... 2+ Able to interact with Cl- SO4 2- SO3 2- On the one hand, anions such as sulfite, sulfate, and chloride can coordinate and bind with each other; on the other hand, anions such as sulfite, sulfate, and chloride can be adsorbed by electrostatic interaction with positively charged amine groups. The synergistic effect of both makes the quality of the recycled water close to the industrial pure water standard, effectively blocking the circulation and accumulation of impurities in the system, thereby ensuring the long-term stability of the purity of sodium methyl propylene sulfonate. Detailed Implementation

[0019] 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.

[0020] Unless otherwise specified in the examples, the procedures shall be performed under standard conditions or conditions recommended by the manufacturer. Raw materials or instruments whose manufacturers are not specified are all commercially available products.

[0021] The activated carbon mentioned below is mesoporous activated carbon with a particle size of 80-100 mesh, purchased from Ningxia Huahui Environmental Protection Technology Co., Ltd.

[0022] Example 1 A method for producing high-purity sodium methylpropene sulfonate includes the following steps: (1) Dissolution process: Sodium sulfite is mixed evenly with recycled water to obtain a sodium sulfite solution; (2) Reaction process: Methylchloropropene is added dropwise to sodium sulfite solution. The molar ratio of methylchloropropene to sodium sulfite is 1:1.05. The temperature is raised to 65℃ to initiate the reaction. Then the temperature is controlled at 45℃ for 1.5h. The mixture is allowed to stand and precipitate. During the reaction, the tail gas is condensed and recovered. Methylchloropropene is returned to the reaction process. The water and the water vapor recovered in step (3) are combined as recycled water. After being treated with modified activated carbon, the water is returned to the dissolution process. (3) Dehydration process: The reaction liquid obtained from the reaction process is subjected to coarse dehydration and fine dehydration in sequence. The temperature of coarse dehydration is 60℃ and the time is 0.5h. The temperature of fine dehydration is 60℃ and the time is 1h. Dehydrated material is obtained, and the water vapor generated in the two dehydration processes is condensed and recovered. (4) Separation and crystallization process: The dehydrated material is centrifuged for the first time to obtain sodium chloride solid and mother liquor; the mother liquor is stirred and first cooled to 40℃ at a rate of 0.5℃ / min, then cooled to 20℃ at a rate of 0.3℃ / min, and kept at a constant temperature for crystal growth for 0.5h. The second centrifugation is carried out, with the centrifugation speed at 1800rpm and the time at 15min, to obtain crude sodium methyl propylene sulfonate and crystallization mother liquor, and the crystallization mother liquor is returned to the dehydration process; (5) Drying process: The crude sodium methyl propylene sulfonate is subjected to water rinsing and drying in sequence. The water rinsing is repeated twice, the drying temperature is 80℃, and the drying time is 4h to obtain sodium methyl propylene sulfonate. The preparation method of modified activated carbon includes the following steps: S1. Wash the activated carbon with water and dry it thoroughly at 85°C to obtain pretreated activated carbon; S2. Disperse the pretreated activated carbon in a mixture of toluene and water, stir at a constant speed for 1.5 h at room temperature, then add 12 wt% of N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane to the pretreated activated carbon, reflux for 5 h, filter, wash, and dry to obtain functionalized activated carbon. S3. Disperse the functionalized activated carbon in an aqueous solution of copper chloride. The weight ratio of N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane to copper chloride is 0.35:1. Stir the reaction at room temperature for 0.5 h, filter, wash, and dry. The crude product is then refluxed in toluene for 1.5 h, filtered, washed, and dried to obtain modified activated carbon.

[0023] Example 2 A method for producing high-purity sodium methylpropene sulfonate includes the following steps: (1) Dissolution process: Sodium sulfite is mixed evenly with recycled water to obtain a sodium sulfite solution; (2) Reaction process: Methylchloropropene is added dropwise to sodium sulfite solution. The molar ratio of methylchloropropene to sodium sulfite is 1:1.08. The temperature is raised to 70°C to initiate the reaction. Then the temperature is controlled at 48°C for 1 hour. The mixture is allowed to stand and precipitate. During the reaction, the tail gas is condensed and recovered. Methylchloropropene is returned to the reaction process. The water and the water vapor recovered in step (3) are combined as recycled water. After being treated with modified activated carbon, the water is returned to the dissolution process. (3) Dehydration process: The reaction liquid obtained from the reaction process is subjected to coarse dehydration and fine dehydration in sequence. The temperature of coarse dehydration is 65℃ and the time is 0.5h. The temperature of fine dehydration is 65℃ and the time is 1h. Dehydrated material is obtained, and the water vapor generated in the two dehydration processes is condensed and recovered. (4) Separation and crystallization process: The dehydrated material is centrifuged for the first time to obtain sodium chloride solid and mother liquor; the mother liquor is stirred and first cooled to 48℃ at a rate of 0.8℃ / min, then cooled to 25℃ at a rate of 0.5℃ / min, and kept at a constant temperature for crystal growth for 1 hour. The second centrifugation is carried out, with the centrifugation speed at 2500 rpm and the time at 12 min to obtain crude sodium methyl propylene sulfonate and crystallization mother liquor. The crystallization mother liquor is then returned to the dehydration process. (5) Drying process: The crude sodium methyl propylene sulfonate is subjected to water rinsing and drying in sequence. The water rinsing is repeated 3 times, the drying temperature is 90℃, and the time is 3h to obtain sodium methyl propylene sulfonate. The preparation method of modified activated carbon includes the following steps: S1. Wash the activated carbon with water and dry it thoroughly at 90°C to obtain pretreated activated carbon; S2. Disperse the pretreated activated carbon in a mixture of toluene and water, stir at a constant speed for 1 hour at room temperature, then add 20 wt% of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane to the pretreated activated carbon, reflux for 6 hours, filter, wash, and dry to obtain functionalized activated carbon. S3. Disperse the functionalized activated carbon in an aqueous solution of copper chloride. The weight ratio of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane to copper chloride is 0.42:1. Stir the reaction at room temperature for 1 hour, filter, wash, and dry. The crude product is then refluxed in toluene for 2 hours, filtered, washed, and dried to obtain modified activated carbon.

[0024] Example 3 A method for producing high-purity sodium methylpropene sulfonate includes the following steps: (1) Dissolution process: Sodium sulfite is mixed evenly with recycled water to obtain a sodium sulfite solution; (2) Reaction process: Methylchloropropene is added dropwise to sodium sulfite solution. The molar ratio of methylchloropropene to sodium sulfite is 1:1.1. The temperature is raised to 75°C to initiate the reaction. Then the temperature is controlled at 50°C for 0.5 hours. The mixture is allowed to stand and precipitate. During the reaction, the tail gas is condensed and recovered. Methylchloropropene is returned to the reaction process. The water and the water vapor recovered in step (3) are combined as recycled water. After being treated with modified activated carbon, the water is returned to the dissolution process. (3) Dehydration process: The reaction liquid obtained from the reaction process is subjected to coarse dehydration and fine dehydration in sequence. The temperature of coarse dehydration is 70℃ and the time is 1h. The temperature of fine dehydration is 70℃ and the time is 1.5h to obtain dehydrated material. The water vapor generated in the two dehydration processes is condensed and recovered. (4) Separation and crystallization process: The dehydrated material is centrifuged for the first time to obtain sodium chloride solid and mother liquor; the mother liquor is stirred and first cooled to 50℃ at a rate of 1℃ / min, and then cooled to 30℃ at a rate of 0.8℃ / min. The crystals are kept at a constant temperature for 1.5h and then centrifuged for the second time. The centrifugation speed is 3000rpm and the time is 10min to obtain crude sodium methyl propylene sulfonate and crystallization mother liquor. The crystallization mother liquor is returned to the dehydration process. (5) Drying process: The crude sodium methyl propylene sulfonate is subjected to water rinsing and drying in sequence. The water rinsing is repeated 3 times, the drying temperature is 105℃, and the drying time is 2h to obtain sodium methyl propylene sulfonate. The preparation method of modified activated carbon includes the following steps: S1. Wash the activated carbon with water and dry it thoroughly at 100°C to obtain pretreated activated carbon; S2. Disperse the pretreated activated carbon in a mixture of toluene and water, stir at a constant speed for 0.5 h at room temperature, then add 30 wt% N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane to the pretreated activated carbon, reflux for 7 h, filter, wash, and dry to obtain functionalized activated carbon. S3. Disperse the functionalized activated carbon in an aqueous solution of copper chloride. The weight ratio of N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane to copper chloride is 0.5:1. Stir the reaction at room temperature for 1.5 h, filter, wash, and dry. The crude product is then refluxed in toluene for 3 h, filtered, washed, and dried to obtain modified activated carbon.

[0025] Comparative Example 1 The difference from Example 2 is that the exhaust gas during the reaction process was not condensed and recovered.

[0026] Comparative Example 2 The difference from Example 2 is that the recycled water is not treated with activated carbon and is directly returned to the dissolution process.

[0027] Comparative Example 3 The difference from Example 2 is that the modified activated carbon is replaced with activated carbon.

[0028] Comparative Example 4 The difference from Example 2 is that the crystallization process is as follows: The mother liquor was stirred and crystallized, then cooled to 25°C and kept at a constant temperature for 1 hour.

[0029] Comparative Example 5 The difference from Example 2 is that step S3 is not disclosed.

[0030] Comparative Example 6 The difference from Example 2 is that N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is replaced with γ-glycidoxypropyltrimethoxysilane.

[0031] Comparative Example 7 The difference from Example 2 is that the copper chloride aqueous solution in step S3 is replaced with an iron chloride aqueous solution.

[0032] Effect evaluation Sodium methyl methacrylate obtained by the production methods of Examples 1-3 and Comparative Examples 1-7 was subjected to quality testing. The yield was calculated based on the ratio of actual yield to theoretical yield, and the results are shown in Table 1 below.

[0033] Table 1

[0034] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for producing high-purity sodium methylpropene sulfonate, characterized in that, Includes the following steps: (1) Dissolution process: Sodium sulfite is mixed evenly with recycled water to obtain a sodium sulfite solution; (2) Reaction process: Methylchloropropene is added dropwise to sodium sulfite solution, the molar ratio of methylchloropropene to sodium sulfite is 1:(1.05-1.1), the temperature is raised to 65-75℃ to initiate the reaction, and then the temperature is controlled at 45-50℃ for 0.5-1.5h. The mixture is allowed to stand and precipitate. The tail gas is condensed and recovered during the reaction. (3) Dehydration process: The reaction liquid obtained from the reaction process is subjected to coarse dehydration and fine dehydration in sequence to obtain dehydrated material, and the water vapor generated in the two dehydration processes is condensed and recovered; (4) Separation and crystallization process: The dehydrated material is subjected to a first solid-liquid separation to obtain sodium chloride solid and mother liquor; the mother liquor is stirred and first cooled to 40-50℃ at a rate of 0.5-1℃ / min, then cooled to 20-30℃ at a rate of 0.3-0.8℃ / min, and kept at a constant temperature for crystal growth for 0.5-1.5h, and then subjected to a second solid-liquid separation to obtain crude sodium methyl propylene sulfonate and crystallization mother liquor, and the crystallization mother liquor is returned to the dehydration process; (5) Drying process: The crude sodium methacrylate is subjected to water rinsing and drying in sequence to obtain sodium methacrylate; In this process, methylchloropropene in the tail gas recovered by condensation in step (2) is returned to the reaction process, and water and water vapor recovered by condensation in step (3) are combined as recycled water, which is then treated with modified activated carbon and returned to the dissolution process. The method for preparing the modified activated carbon includes the following steps: S1. Wash the activated carbon with water and dry it thoroughly at 85-100℃ to obtain pretreated activated carbon; S2. Disperse the pretreated activated carbon in a mixture of toluene and water, stir at a constant speed at room temperature for 0.5-1.5 h, then add aminosilane, reflux for 5-7 h, filter, wash, and dry to obtain functionalized activated carbon. S3. Disperse the functionalized activated carbon in an aqueous solution of copper chloride, stir and react at room temperature for 0.5-1.5 h, filter, wash and dry, and reflux the crude product in toluene for 1.5-3 h, filter, wash and dry to obtain modified activated carbon.

2. The method for producing high-purity sodium methylpropene sulfonate according to claim 1, characterized in that, In step (3), the temperature for coarse dehydration and fine dehydration is 60-70℃ and the time is 0.5-1.5h.

3. The method for producing high-purity sodium methylpropene sulfonate according to claim 1, characterized in that, The amount of aminosilane added is 12-30 wt% of the pretreated activated carbon; And / or, the weight ratio of the aminosilane to copper chloride is (0.35-0.5):

1.

4. The method for producing high-purity sodium methylpropene sulfonate according to claim 1, characterized in that, The aminosilane is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane or N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane.

5. The method for producing high-purity sodium methylpropene sulfonate according to claim 1, characterized in that, In step (4), the first solid-liquid separation and the second solid-liquid separation are performed by centrifugation; The centrifugation speed is 1800-3000 rpm, and the time is 10-15 min.

6. The method for producing high-purity sodium methylpropene sulfonate according to claim 1, characterized in that, In step (5), the water is sprayed 2-3 times; And / or, the drying temperature is 80-105℃, and the time is 2-4h.

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