A method for the continuous production of AMPS

Abstract

The application provides a method for continuously producing AMPS, and belongs to the technical field of sulfonic acid; the production method comprises a sulfonation reaction, an addition reaction and separation and refining; the method for the sulfonation reaction is that qualified acrylonitrile and oleum are continuously input into a pipeline mixer to obtain a mixture; 75-85% of the mixture is continuously input into a reaction kettle; the remaining mixture circulates in the pipeline mixer; meanwhile, acrylonitrile is continuously input into the reaction kettle; the liquid level in the reaction kettle continuously rises; the mixture overflows from an upper overflow port and is input into a reaction kettle 2; the method for continuously producing AMPS provided by the application can obtain AMPS with a purity of 99.22-99.37% and a yield of 89.91-91.27%.

Description

Technical Field

[0001] This invention belongs to the field of sulfonic acid technology, specifically relating to a method for continuous production of AMPS. Background Technology

[0002] AMPS (2-acrylamido-2-methylpropanesulfonic acid) is an indispensable high-performance functional monomer in the chemical industry. Its vinyl double bonds, amide groups, and strongly hydrophilic sulfonic acid groups in its molecular structure endow it with excellent chemical properties, making it a key material for solving technical challenges in harsh environments such as high temperature, high salt, and high hardness. AMPS's most significant advantages lie in its excellent temperature and salt resistance and high reactivity, thus it is widely used in various industrial fields. In the water treatment industry, it is a core component of highly efficient scale inhibitors and dispersants and fouling-resistant reverse osmosis membranes, effectively preventing scaling and extending membrane lifespan. In oil extraction, AMPS is used to prepare temperature and salt resistant polymer flooding agents and drilling fluid and fracturing fluid additives, greatly improving oilfield recovery and operational stability. Furthermore, in the daily chemical and textile industries, it serves as an antistatic agent, dyeing and finishing auxiliary agent, and thickener in personal care products, optimizing product performance and user experience. At a higher technological level, AMPS is also used in the synthesis of biomedical hydrogels, cement admixtures, and high-performance coatings and adhesives. In summary, AMPS, with its unique and powerful functions, plays a fundamental and crucial role in major industrial processes ranging from everyday consumer goods to energy extraction and environmental protection, and is an important pillar of modern fine chemicals and materials science.

[0003] Currently, the isobutylene method is the most mature and economical industrial route for synthesizing AMPS. Its process uses acrylonitrile, isobutylene, and fuming sulfuric acid as core raw materials and can be divided into three core stages: sulfonation, addition, and separation and purification. However, this process is mostly intermittent and has the following problems: 1. The product AMPS is a solid in the reaction system and is prone to depositing in pipes and overflow outlets, clogging the equipment; 2. The contact between gaseous isobutylene and liquid reactants is insufficient, resulting in low mass transfer efficiency; 3. The batch feeding, reaction, cooling, discharging, and cleaning steps are time-consuming; 4. It leads to interruptions in production continuity, frequent cleaning, and the generation of multiple batches of washing waste liquid, mother liquor, and waste gas, resulting in low equipment utilization. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for continuous production of AMPS, achieving the following objectives: improving production efficiency and equipment utilization, and increasing product purity and yield through continuous and stable flow of materials and energy.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for continuous production of AMPS includes the following steps: 1. Sulfonation reaction The prepared acrylonitrile and fuming sulfuric acid are continuously fed into the pipeline mixer to obtain a mixture. 75-85% of the mixture is continuously fed into the reactor, while the remaining mixture is circulated in the pipeline mixer. At the same time, acrylonitrile is continuously fed into the reactor, and the liquid level inside the reactor continues to rise until it overflows from the upper overflow port and is fed into reactor 2. The mass ratio of acrylonitrile to fuming sulfuric acid in the mixture is 0.8–1.2:1.7–2.3. The mass flow ratio of the continuously input mixture to the continuously input acrylonitrile in the reactor is 0.9–1.1:3.5–4.5; Inside the pipeline mixer, the internal mixing temperature is controlled to be -10 to -15°C, and the residence time of the mixture in the pipeline mixer is 25 to 35 minutes. The internal temperature of the reactor is controlled at -8 to -10°C, and the internal liquid level rise rate is 1.8 to 2.2 m / h.

[0006] 2. Addition reaction Isobutylene is introduced from the upper, middle and lower parts of reactor 2 at different rates. The material inside reactor 2 overflows to the bottom of temporary storage vessel through the overflow port, and then overflows to the cooling vessel through the overflow port at the top of the temporary storage vessel. The temperature is reduced to 15-20°C to obtain a mixture of AMPS crystal particles and acrylonitrile liquid slurry, which is continuously pumped into a filter press for solid-liquid separation. The ratio of the rate at which isobutylene is introduced from the upper, middle, and lower parts of reactor 2 is 3.1–3.3: 1.2–1.4: 0.4–0.6. The reaction temperature inside the reactor 2 is 50-60℃; The material inside the reactor 2 rises at a rate of 1.5 to 1.7 m / h.

[0007] 3. Separation and Refining After solid-liquid separation of AMPS crystal particles and acrylonitrile liquid slurry, the solid material is continuously fed into a thin-film steam dryer. The dried material is then continuously fed into an automatic packaging system via a nitrogen pneumatic conveying system for automatic metering and packaging to obtain AMPS. The liquid is distilled, and the main component of the top product is acrylonitrile. The top product is fed into an acrylonitrile preparation kettle, and the concentrated liquid at the bottom of the column is discharged. The continuous feed film steam dryer uses steam heating and Roots blower to induce air flow. It continuously feeds material from the top of one end, and the material is distributed in a thin layer around the inner wall under the stirring of the stirring shaft and stirring blades inside the dryer. It evaporates instantly when it encounters the high temperature jacket, and the finally dried AMPS is continuously discharged from the bottom of the other end. The temperature of the high-temperature jacket is 150–170°C.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: By adopting continuous production, the continuous and stable flow of materials and energy systematically solves the efficiency and quality bottlenecks of traditional intermittent processes, significantly improves production efficiency and equipment utilization, achieves uniform and stable product quality, and significantly reduces energy consumption and increases the absorption rate of raw materials (such as isobutylene) through precise temperature control (such as the critical low-temperature sulfonation stage) and enhanced gas-liquid mass transfer. At the same time, it reduces the emission of waste gas, wastewater, and solid waste from the source and improves the inherent safety of production. Specifically, the system employs a dual-vessel linkage between reactor 1 and reactor 2, with continuous material feeding and discharging. This significantly reduces clogging, improves reaction uniformity, and enhances isobutylene absorption rate. Acrylonitrile and fuming sulfuric acid are continuously output from the pipeline mixer while being partially circulated, ensuring thorough contact between the acrylonitrile and fuming sulfuric acid and a complete sulfonation reaction. Isobutylene is introduced from the upper, middle, and lower parts of reactor 2 at different rates, increasing the contact area between isobutylene and the material, thereby improving the isobutylene absorption rate.

[0009] The continuous production method of AMPS of the present invention yields AMPS with a purity of 99.22-99.37% and a yield of 89.91-91.27%. Detailed Implementation

[0010] Example 1 A method for continuous production of AMPS includes the following steps: 1. Sulfonation reaction The prepared acrylonitrile and fuming sulfuric acid are continuously fed into the pipeline mixer to obtain a mixture. 80% of the mixture is continuously fed into the reactor, while the remaining mixture is circulated in the pipeline mixer. At the same time, acrylonitrile is continuously fed into the reactor, and the liquid level inside the reactor continues to rise until it overflows from the upper overflow port and is fed into reactor 2. The mass ratio of acrylonitrile to fuming sulfuric acid in the mixture is 1:2. The mass flow ratio of the continuously input mixture to the continuously input acrylonitrile in the reactor is 1:4. Inside the pipeline mixer, the internal mixing temperature is controlled at -13℃, and the residence time of the mixture in the pipeline mixer is 30 minutes. The internal temperature of the reactor is controlled at -9℃, and the internal liquid level rise rate is 2m / h.

[0011] 2. Addition reaction Isobutylene is introduced from the upper, middle and lower parts of reactor 2 at different rates. The material inside reactor 2 overflows to the bottom of the temporary storage vessel through the overflow port, and then overflows to the cooling vessel through the overflow port at the top of the temporary storage vessel. The temperature is reduced to 17°C to obtain a mixture of AMPS crystal particles and acrylonitrile liquid slurry, which is continuously pumped into a filter press for solid-liquid separation. The rate ratio of isobutylene introduced from the upper, middle, and lower parts of reactor 2 is 3.2:1.3:0.5. The reaction temperature inside the reactor 2 is 55°C; The material inside the reactor 2 rises at a rate of 1.6 m / h.

[0012] 3. Separation and Refining After solid-liquid separation of AMPS crystal particles and acrylonitrile liquid slurry, the solid material is continuously fed into a thin-film steam dryer. The dried material is then continuously fed into an automatic packaging system via a nitrogen pneumatic conveying system for automatic metering and packaging to obtain AMPS. The liquid is distilled, and the main component of the top product is acrylonitrile. The top product is fed into an acrylonitrile preparation kettle, and the concentrated liquid at the bottom of the column is discharged. The continuous feed film steam dryer uses steam heating and Roots blower to induce air flow. It continuously feeds material from the top of one end, and the material is distributed in a thin layer around the inner wall under the stirring of the stirring shaft and stirring blades inside the dryer. It evaporates instantly when it encounters the high temperature jacket, and the finally dried AMPS is continuously discharged from the bottom of the other end. The temperature of the high-temperature jacket is 160°C.

[0013] Example 2 A method for continuous production of AMPS includes the following steps: 1. Sulfonation reaction The prepared acrylonitrile and fuming sulfuric acid are continuously fed into the pipeline mixer to obtain a mixture. 75% of the mixture is continuously fed into the reactor, while the remaining mixture is circulated in the pipeline mixer. At the same time, acrylonitrile is continuously fed into the reactor, and the liquid level inside the reactor continues to rise until it overflows from the upper overflow port and is fed into reactor 2. The mass ratio of acrylonitrile to fuming sulfuric acid in the mixture is 0.8:1.7. The mass flow ratio of the continuously input mixture to the continuously input acrylonitrile in the reactor is 0.9:3.5. Inside the pipeline mixer, the internal mixing temperature is controlled at -10℃, and the residence time of the mixture in the pipeline mixer is 25 minutes. The internal temperature of the reactor is controlled at -8℃, and the internal liquid level rise rate is 1.8m / h.

[0014] 2. Addition reaction Isobutylene is introduced from the upper, middle and lower parts of reactor 2 at different rates. The material inside reactor 2 overflows to the bottom of temporary storage vessel through the overflow port, and then overflows to the cooling vessel through the overflow port at the top of the temporary storage vessel. The temperature is reduced to 15°C to obtain a mixture of AMPS crystal particles and acrylonitrile liquid slurry, which is continuously pumped into a filter press for solid-liquid separation. The rate ratio of isobutylene introduced from the upper, middle, and lower parts of reactor 2 is 3.1:1.2:0.4. The reaction temperature inside the reactor 2 is 50°C; The liquid level inside the reactor 2 rises at a rate of 1.5 m / h.

[0015] 3. Separation and Refining After solid-liquid separation of AMPS crystal particles and acrylonitrile liquid slurry, the solid material continuously enters a thin-film steam dryer. The dried material is then continuously fed into an automatic packaging system via a nitrogen pneumatic conveying system for automatic metering and packaging to obtain AMPS. The liquid is then distilled, and the top product is mainly composed of acrylonitrile. The top product is fed into an acrylonitrile preparation kettle, and the bottom concentrate is discharged. The continuous feed film steam dryer uses steam heating and Roots blower to induce air flow. It continuously feeds material from the top of one end, and the material is distributed in a thin layer around the inner wall under the stirring of the stirring shaft and stirring blades inside the dryer. It evaporates instantly when it encounters the high temperature jacket, and the finally dried AMPS is continuously discharged from the bottom of the other end. The temperature of the high-temperature jacket is 150°C.

[0016] Example 3 A method for continuous production of AMPS includes the following steps: 1. Sulfonation reaction The qualified acrylonitrile and fuming sulfuric acid are continuously fed into the pipeline mixer to obtain a mixture. 85% of the mixture is continuously fed into the reactor, while the remaining mixture is circulated in the pipeline mixer. At the same time, acrylonitrile is continuously fed into the reactor, and the liquid level inside the reactor continues to rise until it overflows from the upper overflow port and is fed into reactor 2. The mass ratio of acrylonitrile to fuming sulfuric acid in the mixture is 1.2:2.3. The mass flow ratio of the continuously input mixture to the continuously input acrylonitrile in the reactor is 1.1:4.5; Inside the pipeline mixer, the internal mixing temperature is controlled at -15℃, and the residence time of the mixture in the pipeline mixer is 35 minutes. The internal temperature of the reactor is controlled at -10℃, and the internal liquid level rise rate is 2.2m / h.

[0017] 2. Addition reaction Isobutylene is introduced from the upper, middle and lower parts of reactor 2 at different rates. The material inside reactor 2 overflows to the bottom of temporary storage vessel through the overflow port, and then overflows to the cooling vessel through the overflow port at the top of the temporary storage vessel. The temperature is reduced to 20°C to obtain a mixture of AMPS crystal particles and acrylonitrile liquid slurry, which is continuously pumped into a filter press for solid-liquid separation. The rate ratio of isobutylene introduced from the upper, middle, and lower parts of reactor 2 is 3.3:1.4:0.6. The reaction temperature inside the reactor 2 is 60°C; The liquid level inside the reactor 2 rises at a rate of 1.7 m / h.

[0018] 3. Separation and Refining After solid-liquid separation of AMPS crystal particles and acrylonitrile liquid slurry, the solid material is continuously fed into a thin-film steam dryer. The dried material is then continuously fed into an automatic packaging system via a nitrogen pneumatic conveying system for automatic metering and packaging to obtain AMPS. The liquid is distilled, and the main component of the top product is acrylonitrile. The top product is fed into an acrylonitrile preparation kettle, and the concentrated liquid at the bottom of the column is discharged. The continuous feed film steam dryer uses steam heating and Roots blower to induce air flow. It continuously feeds material from the top of one end, and the material is distributed in a thin layer around the inner wall under the stirring of the stirring shaft and stirring blades inside the dryer. It evaporates instantly when it encounters the high temperature jacket, and the finally dried AMPS is continuously discharged from the bottom of the other end. The temperature of the high-temperature jacket is 170°C.

[0019] Comparative Example 1 Add qualified acrylonitrile to the reactor and control the temperature inside the reactor at -13℃. Then add fuming sulfuric acid dropwise. After the addition is complete, raise the temperature to 55℃ and steadily introduce gasified isobutylene. After reacting at a constant temperature for 3 hours, lower the temperature to 17℃, centrifuge and dry to obtain AMPS. The mother liquor from the centrifugation is distilled under reduced pressure to recover propylene for recycling. The mass ratio of acrylonitrile, fuming sulfuric acid, and isobutylene is 40:7:4.

[0020] Test case The purity and yield of AMPS produced in Examples 1-3 and Comparative Example 1 were tested respectively, and the test results are shown in Table 1: Yield = Actual output / Theoretical output × 100%; Table 1

[0021] The results above show that Comparative Example 1 uses a single-reactor production method for AMPS, which requires batch sulfonation, addition, separation, and discharge of residual liquid, resulting in differences in purity and yield of each batch of AMPS and unstable quality.

Claims

1. A method for continuous production of AMPS, characterized in that: The production method includes sulfonation reaction, addition reaction, and separation and purification. The sulfonation reaction method is as follows: qualified acrylonitrile and fuming sulfuric acid are continuously fed into a pipeline mixer to obtain a mixture. 75-85% of the mixture is continuously fed into a reaction vessel, and the remaining mixture is circulated in the pipeline mixer. At the same time, acrylonitrile is continuously fed into the reaction vessel, and the liquid level inside the reaction vessel continues to rise until it overflows from the upper overflow port and is fed into reaction vessel 2.

2. The method for continuous production of AMPS according to claim 1, characterized in that: In the sulfonation reaction method, the mass ratio of acrylonitrile to fuming sulfuric acid in the mixture is 0.8–1.2:1.7–2.

3. Inside the reactor, the mass flow ratio of the continuously fed mixture to the continuously fed acrylonitrile is 0.9–1.1:3.5–4.5; Inside the pipeline mixer, the internal mixing temperature is controlled at -10 to -15℃, and the residence time of the mixture in the pipeline mixer is 25 to 35 minutes. The internal temperature of the reactor is controlled at -8 to -10℃, and the internal liquid level rise rate is 1.8 to 2.2 m / h.

3. The method for continuous production of AMPS according to claim 1, characterized in that: The addition reaction method is as follows: isobutylene is introduced into the upper, middle and lower parts of the reactor 2 at different rates. The material inside the reactor 2 overflows to the bottom of the temporary storage vessel through the overflow port, and then overflows to the cooling vessel through the overflow port at the top of the temporary storage vessel. The temperature is reduced to 15-20°C to obtain a mixture of AMPS crystal particles and acrylonitrile liquid slurry, which is then continuously pumped into a filter press for solid-liquid separation.

4. The method for continuous production of AMPS according to claim 3, characterized in that: In the addition reaction method, the ratio of the rates at which isobutylene is introduced from the upper, middle, and lower parts of the reactor 2 is 3.1–3.3: 1.2–1.4: 0.4–0.

6. The reaction temperature inside reactor 2 is 50–60°C; The material inside reactor 2 rises at a rate of 1.5–1.7 m / h.

5. A method for continuous production of AMPS according to claim 1, characterized in that: The separation and purification method is as follows: after solid-liquid separation of AMPS crystal particles and acrylonitrile liquid slurry, the solid material continuously enters a thin-film steam dryer. The dried material is then continuously fed into an automatic packaging system via a nitrogen pneumatic conveying system for automatic metering and packaging to obtain AMPS. The liquid is then distilled, and the main component of the product output from the top of the column is acrylonitrile. The product output from the top of the column is fed into an acrylonitrile preparation kettle, and the concentrated liquid at the bottom of the column is discharged.

6. A method for continuous production of AMPS according to claim 5, characterized in that: In the separation and refining method, a continuous feeding film steam dryer is used. The dryer is heated by steam and induced by a Roots blower. The material is continuously fed from the top of one end and distributed in a thin layer around the inner wall under the stirring of the stirring shaft and stirring blades inside the dryer. It evaporates instantly when it encounters the high temperature jacket. Finally, the dried AMPS is continuously discharged from the bottom of the other end. The temperature of the high-temperature jacket is 150-170℃.

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