A separation and purification system for 2-methyl-4-isothiazolin-3-one
By designing a separation and purification system, and utilizing equipment such as a neutralization vessel, extraction tower, and adsorption device, the MIT feed solution is neutralized, extracted, adsorbed, and condensed, thus solving the problem of impurity removal in MIT and achieving the production of high-purity MIT.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG YUBIN NEW MATERIALS CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-07-03
AI Technical Summary
In the existing technology, the synthesis of 2-methyl-4-isothiazolin-3-one (MIT) has the problem of unreacted raw materials, by-products and impurities being difficult to remove effectively, resulting in low product purity.
A separation and purification system was designed, including equipment such as a neutralization vessel, an extraction tower, an adsorption device, a vacuum condenser, and a crystallization tower. Through steps such as neutralization, extraction, adsorption, condensation, and crystallization, the system achieves effective separation and purification of MIT (Mixed Oxygenated Protein) feed liquid.
It significantly improved the purity of MIT products, effectively removed impurities, and enhanced product quality.
Smart Images
Figure CN224443008U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of 2-methyl-4-isothiazolin-3-one production technology, and in particular to a separation and purification system for 2-methyl-4-isothiazolin-3-one. Background Technology
[0002] 2-Methyl-4-isothiazolin-3-one (MIT) is a highly effective bactericide and preservative, exhibiting strong inhibitory and bactericidal effects against bacteria, fungi, molds, and algae. It is widely used in industrial cooling water, circulating water, papermaking, coatings, paints, rubber, leather, textiles, and oilfield water injection. In cosmetics and personal care products such as bath liquids, shampoos, detergents, and conditioners, it is used as a preservative to maintain product stability and safety, ensuring product quality. The synthesis of MIT typically uses acrolein, methylamine, and carbon disulfide as main raw materials, first synthesizing intermediates, then undergoing an oxidation reaction, followed by separation and purification to obtain the MIT product. However, the synthesis of MIT may generate unreacted raw materials (such as excess methylamine or carbon disulfide), byproducts (such as polysulfide compounds or polymers), or impurities (such as inorganic salts or heavy metal ions). Therefore, to address these issues, it is necessary to develop a separation and purification system for 2-methyl-4-isothiazolin-3-one. Utility Model Content
[0003] The technical problem to be solved by this invention is to provide a separation and purification system for 2-methyl-4-isothiazolin-3-one, which can effectively remove impurities from MIT and greatly improve the purity of MIT products, in order to address the shortcomings of the existing technology.
[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:
[0005] A separation and purification system for 2-methyl-4-isothiazolin-3-one includes a neutralization vessel connected to a feed liquid delivery pipeline and a hydrochloric acid delivery pipeline. The outlet of the neutralization vessel and the extractant delivery pipeline are respectively connected to an extraction tower. The organic phase outlet of the extraction tower is connected to an adsorption device. The outlet of the adsorption device is connected to a distillation vessel. The vent of the distillation vessel is connected to a vacuum condenser. The condensate outlet of the vacuum condenser is connected to a solvent storage tank. The concentrate outlet of the distillation vessel is connected to a crystallization tower. The crystal outlet of the crystallization tower is connected to a centrifuge. The outlet of the centrifuge is connected to a drying device. The outlet of the drying device is connected to a product storage tank.
[0006] As an improved technical solution, the neutralization vessel includes a vessel body, with a feed inlet and a hydrochloric acid inlet at the top of the vessel body, and a discharge outlet at the bottom of the vessel body. Inside the vessel body, there is a stirring shaft and a pH sensor. One end of the stirring shaft is connected to a motor, and a spiral plate is provided on the stirring shaft. Multiple stirring rods are provided on the outer edge of the spiral plate, and the pH sensor is electrically connected to a controller.
[0007] As an improved technical solution, the extraction tower includes a tower body, with a feed pipe and an aqueous phase outlet respectively on both sides of the bottom of the tower body, and an extractant inlet pipe and an organic phase outlet respectively on the top of the tower body; a liquid distributor connected to the extractant inlet pipe is provided at the top of the interior of the tower body, a liquid disperser connected to the feed pipe is provided at the bottom of the tower body, a multi-layer hollow structure flow divider is provided below the liquid distributor, a multi-layer packing layer is provided below the flow divider, and a multi-layer hollow structure baffle is provided below the packing layer.
[0008] As an improved technical solution, the liquid distributor includes a main spray pipe and multiple spray branch pipes connected to the main spray pipe, and the main spray pipe and the spray branch pipes are respectively provided with multiple spray holes.
[0009] As an improved technical solution, the liquid disperser includes a hollow conical body, with multiple liquid distribution pipes connected to the conical body at the bottom, and multiple distribution holes on the liquid distribution pipes.
[0010] As an improved technical solution, the adsorption device includes a body, with an inlet on the upper part of one side of the body and an outlet on the lower part of the other side of the body. The interior of the body is provided with a coconut shell activated carbon layer, a chelating resin layer and an ion exchange resin layer in sequence.
[0011] As an improved technical solution, the vacuum condensation device includes a first condenser, the uncondensed gas outlet of the first condenser is connected to a second condenser, the uncondensed gas outlet of the second condenser is connected to a buffer tank, and the vent of the buffer tank is connected to a vacuum pump; the condensate outlets of the first condenser and the second condenser are respectively connected to the solvent storage tank.
[0012] As an improved technical solution, the crystallization tower includes a tower body, a feed inlet on the upper side of the tower body, a crystal outlet at the bottom of the tower body, a jacket on the outside of the tower body, a rotating shaft and multiple interconnected cooling coils inside the tower body, a motor connected to one end of the rotating shaft, and multiple stirring plates on the rotating shaft.
[0013] After adopting the above technical solution, the beneficial effects of this utility model are:
[0014] The separation and purification system for 2-methyl-4-isothiazolin-3-one includes a neutralization vessel connected to a feed liquid delivery pipeline and a hydrochloric acid delivery pipeline. The outlet of the neutralization vessel and the extractant delivery pipeline are respectively connected to an extraction tower. The organic phase outlet of the extraction tower is connected to an adsorption device. The outlet of the adsorption device is connected to a distillation vessel. The vent of the distillation vessel is connected to a vacuum condenser. The condensate outlet of the vacuum condenser is connected to a solvent storage tank. The concentrate outlet of the distillation vessel is connected to a crystallization tower. The crystal outlet of the crystallization tower is connected to a centrifuge. The outlet of the centrifuge is connected to a drying device. The outlet of the drying device is connected to a product storage tank. The MIT-containing solution is pumped into the neutralization vessel via a feed pipe, while hydrochloric acid is simultaneously pumped into the neutralization vessel via a hydrochloric acid feed pipe. After neutralization, the MIT is converted from an ionic state to a molecular state (facilitating subsequent extraction and crystallization). Then, pumped again, the solution enters the extraction tower, along with the extraction solvent. After extraction with the extractant (separating water-soluble salts, unreacted methylamine, and MIT), the MIT-containing organic phase is pumped into an adsorption unit for further processing. The solution, after removing pigments and metal ions, is pumped into a distillation vessel. The distillate gaseous solvent is condensed using a vacuum condenser and stored in a solvent storage tank. The concentrated MIT-containing solution is pumped into a crystallization tower. After cooling and crystallization, the crystals and mother liquor are fed into a centrifuge. The crystals after centrifugation are dried using a drying unit. Finally, the MIT product is stored in a product storage tank. This separation and purification system is rationally designed and can effectively separate impurities from the MIT solution, significantly improving the purity of the MIT product.
[0015] The neutralization vessel comprises a vessel body with an inlet and a hydrochloric acid inlet at the top and an outlet at the bottom. Inside the vessel body are a stirring shaft and a pH sensor. One end of the stirring shaft is connected to a motor, and a spiral plate is mounted on the shaft. Multiple stirring rods are located on the outer edge of the spiral plate. The pH sensor is electrically connected to a controller. The MIT-containing solution and hydrochloric acid enter the vessel body separately. After the motor starts, it drives the stirring shaft, spiral plate, and multiple stirring rods to rotate, ensuring thorough contact and mixing between the hydrochloric acid and the MIT-containing solution, thus achieving effective neutralization. The pH sensor detects the pH of the solution, thereby controlling the amount of hydrochloric acid added. This neutralization vessel design is reasonable, effectively neutralizing the MIT solution and promoting the conversion of MIT from an ionic state to a molecular state, facilitating subsequent extraction and crystallization.
[0016] The extraction tower comprises a tower body with feed pipes and aqueous phase outlets on both sides of the bottom, and extractant inlet pipe and organic phase outlet on the top. Inside the tower, a distributor connected to the extractant inlet pipe is located at the top, and a feed disperser connected to the feed pipe is located at the bottom. Below the distributor is a multi-layer perforated flow divider, below which are multiple layers of packing, and below that, multiple layers of perforated baffles. The MIT feed solution, driven by a pump, flows from the feed pipe into the feed distributor. The extractant, driven by a pump, flows from the extractant inlet pipe into the distributor. The fully dispersed MIT feed solution flows upwards through the baffles, while the fully dispersed extractant flows downwards, first passing through the flow divider. Then, the MIT feed solution and extractant come into full contact as they pass through the packing layer, allowing the MIT to enter the extractant. The upper organic phase containing MIT is discharged from the organic phase outlet to the next processing unit, while the lower aqueous phase is discharged from the bottom aqueous phase outlet. This extraction tower design is efficient and significantly improves the extraction efficiency of MIT.
[0017] The distributor comprises a main spray pipe and multiple branch spray pipes connected to it, each with multiple spray holes. Under the action of a delivery pump, the extractant enters the main spray pipe and branch spray pipes from the extractant inlet pipe via the extractant delivery pipeline, and then disperses evenly through the spray holes. This distributor design is reasonable, achieving sufficient dispersion of the extractant and facilitating effective extraction of MIT.
[0018] The feed disperser comprises a hollow conical body with multiple feed distribution pipes connected to it at the bottom. These distribution pipes have multiple distribution holes. The feed liquid containing MIT (methyl methacrylate) enters the conical body through the feed pipe under the action of a delivery pump, then flows into the feed distribution pipes, passes through the distribution holes, and is uniformly dispersed before making full contact with the extractant. This feed disperser design is reasonable, achieving thorough dispersion of the MIT feed liquid and promoting sufficient contact with the extractant.
[0019] The adsorption device comprises a main body with an inlet on the upper part of one side and an outlet on the lower part of the other side. Inside the main body, there are sequentially arranged layers of coconut shell activated carbon, chelating resin, and ion exchange resin. The liquid containing MIT enters the main body under the action of a pump. It first undergoes adsorption by the coconut shell activated carbon layer, effectively removing impurity ions such as pigments. Then, it undergoes adsorption by the chelating resin and ion exchange resin, effectively removing metal ions and further improving the purity of the MIT product.
[0020] The vacuum condensation device includes a first condenser, whose uncondensed gas outlet is connected to a second condenser, whose uncondensed gas outlet is connected to a buffer tank, and whose vent is connected to a vacuum pump. The condensate outlets of the first and second condensers are respectively connected to solvent storage tanks. Solvent vapors discharged during distillation enter the first condenser, while uncondensed gas enters the second condenser. Finally, the remaining uncondensed gas is extracted using a vacuum pump. The solvent condensed by the first and second condensers is stored in the solvent storage tanks. This vacuum condensation device is rationally designed, effectively recycling the extraction process and avoiding resource waste.
[0021] The crystallization tower consists of a tower body with a feed inlet on one side of the upper part and a crystal outlet at the bottom. The tower body is equipped with a jacket, and inside is a rotating shaft and multiple interconnected cooling coils. One end of the rotating shaft is connected to a motor, and multiple stirring plates are mounted on the shaft. The MIT-containing liquid feed enters the tower body through the feed inlet under the action of a delivery pump. The refrigerant in the jacket and cooling coils cools and crystallizes the MIT liquid feed. After the motor starts, it drives the rotating shaft and multiple stirring plates to rotate, promoting uniform cooling of the MIT liquid and greatly improving crystallization efficiency. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the separation and purification system for 2-methyl-4-isothiazolin-3-one according to the present invention;
[0023] Among them, 1-liquid conveying pipe, 2-hydrochloric acid conveying pipe, 3-neutralization vessel, 30-stirring shaft, 31-pH sensor, 32-motor, 33-spiral plate, 34-stirring rod, 35-controller, 4-extractant conveying pipe, 5-extraction tower, 50-distributor, 500-main spray pipe, 501-branch spray pipe, 51-liquid disperser, 510-conical body, 511-liquid distribution pipe, 52-diverter plate, 53-packing layer, 54- 6-Break plate, 6-Adsorption device, 60-Coconut shell activated carbon layer, 61-Chlorination resin layer, 62-Ion exchange resin layer, 7-Distillation kettle, 8-Vacuum condensation device, 80-First condenser, 82-Second condenser, 83-Buffer tank, 84-Vacuum pump, 9-Solvent storage tank, 10-Crystallization tower, 100-Jacket, 101-Rotating shaft, 102-Cooling coil, 103-Stirring plate, 11-Centrifuge, 12-Drying device, 13-Product storage tank. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0025] A separation and purification system for 2-methyl-4-isothiazolin-3-one, such as Figure 1 As shown, the system includes a neutralization vessel 3 connected to a feed liquid conveying pipe 1 and a hydrochloric acid conveying pipe 2. The outlet of the neutralization vessel 3 and the extractant conveying pipe 4 are respectively connected to an extraction tower 5. The organic phase outlet of the extraction tower 5 is connected to an adsorption device 6. The outlet of the adsorption device 6 is connected to a distillation vessel 7. The vent of the distillation vessel 7 is connected to a vacuum condenser 8. The condensate outlet of the vacuum condenser 8 is connected to a solvent storage tank 9. The concentrate outlet of the distillation vessel 7 is connected to a crystallization tower 10. The crystal outlet of the crystallization tower 10 is connected to a centrifuge 11. The outlet of the centrifuge 11 is connected to a drying device 12 (drying box). The outlet of the drying device 12 is connected to a product storage tank 13.
[0026] The MIT-containing solution is pumped into the neutralization vessel via a feed pipe, while hydrochloric acid is simultaneously pumped into the neutralization vessel via a hydrochloric acid feed pipe. After neutralization, the MIT is converted from an ionic state to a molecular state (facilitating subsequent extraction and crystallization). Then, pumped again, the solution enters the extraction tower, along with the extraction solvent. After extraction with the extractant (separating water-soluble salts, unreacted methylamine, and MIT), the MIT-containing organic phase is pumped into an adsorption unit for further processing. The solution, after removing pigments and metal ions, is pumped into a distillation vessel. The distillate gaseous solvent is condensed using a vacuum condenser and stored in a solvent storage tank. The concentrated MIT-containing solution is pumped into a crystallization tower. After cooling and crystallization, the crystals and mother liquor are fed into a centrifuge. The crystals after centrifugation are dried using a drying unit. Finally, the MIT product is stored in a product storage tank. This separation and purification system is rationally designed and can effectively separate impurities from the MIT solution, significantly improving the purity of the MIT product.
[0027] The neutralization vessel 3 includes a vessel body with an inlet and a hydrochloric acid inlet at the top and an outlet at the bottom. Inside the vessel body are a stirring shaft 30 and a pH sensor 31. One end of the stirring shaft 30 is connected to a motor 32, and a spiral plate 33 is mounted on the shaft. Multiple stirring rods 34 are located on the outer edge of the spiral plate 33. The pH sensor 31 is electrically connected to a controller 35. The MIT-containing liquid and hydrochloric acid enter the vessel body. After the motor starts, it drives the stirring shaft, spiral plate, and multiple stirring rods to rotate, promoting thorough contact and mixing between the hydrochloric acid and the MIT-containing liquid, achieving effective neutralization. The pH sensor detects the pH of the liquid, thereby controlling the amount of hydrochloric acid added. This neutralization vessel design is reasonable, achieving effective neutralization of the MIT liquid and promoting the conversion of MIT from an ionic state to a molecular state, facilitating subsequent extraction and crystallization.
[0028] The extraction tower 5 includes a tower body, with a feed pipe and an aqueous phase outlet on both sides of the bottom of the tower body, and an extractant inlet pipe and an organic phase outlet on the top of the tower body. Inside the tower body, a liquid distributor 50 connected to the extractant inlet pipe is located at the top, and a liquid disperser 51 connected to the feed pipe is located at the bottom of the tower body. Below the liquid distributor 50, a multi-layer hollow structure flow divider 52 (specifically, a plate with multiple through holes) is located. Below the flow divider 52, a multi-layer packing layer 53 (Pall ring packing layer) is located. Below the packing layer 53, a multi-layer hollow structure baffle 54 (specifically, a plate with multiple through holes) is located. The MIT (Methyl MIT) feed solution, driven by a delivery pump, enters the feed distributor through the inlet pipe. The extractant, driven by a delivery pump, enters the distributor through the extractant inlet pipe. The fully dispersed MIT feed solution flows upward through multiple layers of baffles, while the fully dispersed extractant flows downward through a flow divider. Then, the MIT feed solution and extractant come into full contact as they pass through the packing layer. The MIT enters the extractant, and the upper organic phase containing MIT is discharged from the organic phase outlet to the next processing unit. The lower aqueous phase is discharged from the bottom aqueous phase outlet.
[0029] The distributor 50 includes a main spray pipe 500 and multiple branch spray pipes 501 connected to the main spray pipe 500. The main spray pipe 500 and the branch spray pipes 501 are each provided with multiple spray holes. Under the action of a delivery pump, the extractant enters the interior of the main spray pipe and branch spray pipes from the extractant inlet pipe along the extractant delivery pipeline, then passes through the spray holes and is evenly dispersed before extracting the MIT.
[0030] The feed disperser 51 includes a hollow conical body 510. Multiple feed distribution pipes 511, connected to the conical body, are located below the conical body. Each feed distribution pipe 511 has multiple distribution holes. The feed liquid containing MIT enters the interior of the conical body through the feed pipe under the action of a delivery pump, and then enters the interior of the feed distribution pipes. Passing through the multiple distribution holes, it is evenly dispersed and comes into full contact with the extractant.
[0031] The adsorption device 6 includes a main body with an inlet on the upper part of one side and an outlet on the lower part of the other side. Inside the main body, there are sequentially arranged coconut shell activated carbon layer 60, chelating resin layer 61 (D403 chelating resin), and ion exchange resin layer 62 (strong acid cation exchange resin – Amberlite IR-120). The MIT-containing liquid enters the main body under the action of a pump. It first undergoes adsorption by the coconut shell activated carbon layer, effectively removing impurity ions such as pigments. Then, it undergoes adsorption by the chelating resin and ion exchange resin, effectively removing metal ions and further improving the purity of the MIT product.
[0032] The vacuum condensation device 8 includes a first condenser 80, whose uncondensed gas outlet is connected to a second condenser 81, whose uncondensed gas outlet is connected to a buffer tank 82, and whose vent is connected to a vacuum pump 83. The condensate outlets of the first and second condensers are respectively connected to solvent storage tanks. Solvent vapors discharged during distillation in the distillation kettle enter the interior of the first condenser, and the uncondensed gas then enters the interior of the second condenser. Finally, the remaining uncondensed gas is extracted using a vacuum pump. The solvent condensed by the first and second condensers is stored in the solvent storage tank.
[0033] The crystallization tower 10 includes a tower body with a feed inlet on one side of the upper part and a crystal outlet at the bottom. The tower body is equipped with a jacket 100 on its exterior and a rotating shaft 101 and multiple interconnected cooling coils 102 inside. One end of the rotating shaft is connected to a motor, and multiple stirring plates 103 are mounted on the shaft. The MIT-containing liquid enters the tower body through the feed inlet via a delivery pump. The refrigerant in the jacket and cooling coils cools and crystallizes the MIT liquid. After the motor starts, it drives the rotating shaft and multiple stirring plates to rotate, promoting uniform cooling of the MIT liquid and greatly improving crystallization efficiency.
[0034] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A separation and purification system for 2-methyl-4-isothiazolin-3-one, characterized by, The system includes a neutralization vessel connected to a feed liquid conveying pipeline and a hydrochloric acid conveying pipeline. The outlet of the neutralization vessel and the extractant conveying pipeline are respectively connected to an extraction tower. The organic phase outlet of the extraction tower is connected to an adsorption device. The outlet of the adsorption device is connected to a distillation vessel. The vent of the distillation vessel is connected to a vacuum condenser. The condensate outlet of the vacuum condenser is connected to a solvent storage tank. The concentrate outlet of the distillation vessel is connected to a crystallization tower. The crystal outlet of the crystallization tower is connected to a centrifuge. The outlet of the centrifuge is connected to a drying device. The outlet of the drying device is connected to a product storage tank.
2. The separation and purification system for 2-methyl-4-isothiazolin-3-one according to claim 1, characterized in that, The neutralization vessel includes a vessel body, with a feed inlet and a hydrochloric acid inlet at the top and a discharge outlet at the bottom. Inside the vessel body, there is a stirring shaft and a pH sensor. One end of the stirring shaft is connected to a motor, and a spiral plate is provided on the stirring shaft. Multiple stirring rods are provided on the outer edge of the spiral plate. The pH sensor is electrically connected to a controller.
3. A separation and purification system for 2-methyl-4-isothiazolin-3-one according to claim 1, characterized in that, The extraction tower includes a tower body, with a feed pipe and an aqueous phase outlet on each side of the bottom of the tower body, and an extractant inlet and an organic phase outlet on the top of the tower body. Inside the tower body, at the top, there is a liquid distributor connected to the extractant inlet, and at the bottom of the tower body, there is a liquid disperser connected to the feed pipe. Below the liquid distributor, there is a multi-layer perforated flow divider, below the flow divider, there are multi-layer packing layers, and below the packing layers, there are multi-layer perforated baffles.
4. A separation and purification system for 2-methyl-4-isothiazolin-3-one according to claim 3, characterized in that, The liquid distributor includes a main spray pipe and multiple spray branch pipes connected to the main spray pipe, and multiple spray holes are provided on the main spray pipe and the spray branch pipes respectively.
5. A separation and purification system for 2-methyl-4-isothiazolin-3-one according to claim 4, characterized in that, The liquid disperser includes a hollow cone-shaped body, and a plurality of liquid distribution pipes connected to the cone-shaped body are provided below the cone-shaped body. The liquid distribution pipes are provided with a plurality of distribution holes.
6. The separation and purification system for 2-methyl-4-isothiazolin-3-one according to claim 1, characterized in that, The adsorption device includes a main body, with an inlet on the upper part of one side of the main body and an outlet on the lower part of the other side of the main body. The interior of the main body is provided with a coconut shell activated carbon layer, a chelating resin layer and an ion exchange resin layer in sequence.
7. A separation and purification system for 2-methyl-4-isothiazolin-3-one according to claim 1, characterized in that, The vacuum condensation device includes a first condenser, the uncondensed gas outlet of the first condenser is connected to a second condenser, the uncondensed gas outlet of the second condenser is connected to a buffer tank, and the vent of the buffer tank is connected to a vacuum pump; the condensate outlets of the first condenser and the second condenser are respectively connected to the solvent storage tank.
8. A separation and purification system for 2-methyl-4-isothiazolin-3-one according to claim 1, characterized in that, The crystallization tower includes a tower body, a feed inlet on one side of the upper part of the tower body, a crystal outlet at the bottom of the tower body, a jacket on the outside of the tower body, a rotating shaft and multiple interconnected cooling coils inside the tower body, a motor connected to one end of the rotating shaft, and multiple stirring plates on the rotating shaft.