A dimethylaminoethyl acrylate production system

Abstract

The present application relates to the technical field of dimethylaminoethyl acrylate production, and particularly relates to a dimethylaminoethyl acrylate production system. The production system provided in the present application embodiment comprises a reaction unit, a primary distillation unit, a product rectification unit and a methanol rectification unit. The reaction unit comprises a mixing kettle, a microreactor and a primary distillation buffer tank. The mixing kettle is used for preheating and stirring raw materials. The feed inlet of the microreactor is connected with the discharge outlet of the mixing kettle. The discharge outlet of the microreactor is connected with the feed inlet of the primary distillation buffer tank. Two discharge outlets of the primary distillation buffer tank are respectively connected with the mixing kettle and the primary distillation unit. When the discharge outlet of the primary distillation buffer tank is opened to the mixing kettle, the reaction liquid circulates among the mixing kettle, the microreactor and the primary distillation buffer tank. When the discharge outlet of the primary distillation buffer tank is opened to the primary distillation unit, the reaction liquid enters the primary distillation unit for distillation to separate product liquid and methanol liquid. The product liquid enters the product rectification unit for purification, and the methanol liquid enters the methanol rectification unit for purification.

Description

Technical Field

[0001] This invention relates to the field of dimethylaminoethyl acrylate production technology, and particularly to a dimethylaminoethyl acrylate production system. Background Technology

[0002] Dimethylaminoethyl acrylate (DME) is an important monomer for the production of cationic polymers, especially quaternary ammonium salts required for the production of cationic polyacrylamide. Due to the wide range of applications of polymers, the market demand for DME has been steadily increasing, making it an important raw material for industries such as water treatment, household and personal care, papermaking, oil extraction, as well as for the production of products such as dyes, adhesives, and coatings.

[0003] Currently, the production process of dimethylaminoethyl acrylate mainly involves a batch esterification reaction in a reactor using dimethylaminoethanol and methyl acrylate as raw materials and dibutyl oxide as the main catalyst. However, the existing production system has low product preparation efficiency. Summary of the Invention

[0004] This invention provides a dimethylaminoethyl acrylate production system that can efficiently produce dimethylaminoethyl acrylate.

[0005] This invention provides a dimethylaminoethyl acrylate production system, including a reaction unit, a primary distillation unit, a product distillation unit, and a methanol distillation unit;

[0006] The reaction unit includes a mixing vessel, a microreactor, and a primary distillation buffer tank. The mixing vessel is used for preheating and stirring the raw materials. The inlet of the microreactor is connected to the outlet of the mixing vessel, and the outlet of the microreactor is connected to the inlet of the primary distillation buffer tank. The two outlets of the primary distillation buffer tank are respectively connected to the mixing vessel and the primary distillation unit. When the primary distillation buffer tank is opened to the outlet of the mixing vessel, the reaction liquid circulates between the mixing vessel, the microreactor, and the primary distillation buffer tank. When the primary distillation buffer tank is opened to the outlet of the primary distillation unit, the reaction liquid enters the primary distillation unit for distillation to separate the product liquid and the methanol liquid. The product liquid enters the product rectification unit for purification, and the methanol liquid enters the methanol rectification unit for purification.

[0007] In one possible design, the methanol distillation unit includes a primary distillation column, a primary distillation condenser, and a product distillation buffer tank.

[0008] The feed inlet of the primary distillation column is connected to the primary distillation buffer tank. The gas phase at the top of the primary distillation column is liquefied by the condensation assembly and flows into the primary distillation condenser. The liquid phase at the bottom of the primary distillation column is connected to the product rectification buffer tank. An overflow tank is provided inside the primary distillation condenser, and an overflow hole is provided in the overflow tank. Part of the reaction liquid in the primary distillation condenser flows back to the primary distillation column, and part overflows into the overflow tank. A deionized water nozzle is provided in the overflow tank to spray deionized water into the overflow tank. The overflow tank is connected to a separatory tank, which is used to separate methanol and n-hexane.

[0009] In one possible design, the bottom of the primary distillation column is connected to a circulating liquid intermediate tank, which is connected to the mixing vessel.

[0010] In one possible design, the product distillation unit includes a product distillation column, a spent catalyst collection tank, and a finished product collection tank;

[0011] The product distillation buffer tank is connected to the product distillation column, and the product distillation column is connected to the waste catalyst collection tank and the finished product collection tank.

[0012] In one possible design, the separator is provided with a packing layer to increase the liquid diffusion area, and the separator is connected to a hexane intermediate tank and a methanol intermediate tank respectively.

[0013] In one possible design, the methanol distillation unit includes a methanol distillation column, a methanol product tank, and a distilled water buffer tank.

[0014] The methanol distillation column is used to receive the reaction liquid in the methanol intermediate tank, the methanol product tank is used to receive the methanol distilled from the methanol distillation column, and the distillation water buffer tank is used to receive the residual distillation water in the methanol distillation column.

[0015] In one possible design, the molar mass of methyl acrylate in the raw materials is greater than the molar mass of dimethylaminoethanol, and the catalyst is a titanate compound.

[0016] The amount of catalyst added is 1.2 to 1.6% of the mass of the methyl acrylate.

[0017] In one possible design, the mass of the inhibitor in the production feedstock is 8 to 10% of the mass of the catalyst.

[0018] In one possible design, the reaction liquid in the primary distillation column enters the mixing vessel through the intermediate circulating liquid tank, and then enters the primary distillation column from the mixing vessel through the microreactor and the primary distillation buffer tank to complete the reaction cycle, with the reaction cycle time being 3 to 5 hours.

[0019] In one possible design, the bottom temperature of the methanol distillation column is 70–90°C.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] In this embodiment, using a microreactor as the main container for the reaction increases the reaction rate. Circulating the reaction solution between the mixing vessel, the microreactor, and the initial distillation buffer tank allows for more uniform mixing of the reactants and a more consistent temperature. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a production system provided in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of a microreactor provided in an embodiment of the present invention.

[0025] Figure 1 middle:

[0026] 1. Mixing vessel; 11. Mixing vessel A; 12. Mixing vessel B; 13. Dimethylethanolamine; 14. Methyl acrylic acid; 15. Catalyst injection pipe; 2. Microreactor assembly; 21. First reactor; 22. Second reactor; 23. Third reactor; 24. Feed pump A; 25. Feed pump B; 26. Feed pump C; 27. Initial distillation buffer vessel feed pump; 28. Initial distillation buffer vessel A; 29. ​​Initial distillation buffer vessel B; 3. Initial distillation column; 31. Initial distillation feed pump; 32. Initial distillation circulation pump; 33. n-Hexane spray 34. Deionized water spray; 35. Primary distillation column discharge pump; 36. Primary distillation column stripping pump; 37. Primary distillation condenser assembly; 38. Primary distillation condensate pump; 39. Primary distillation condensate tank; 310. Primary distillation column reflux pump; 311. Primary distillation column condensate external pump; 312. Hexane and methanol separatory tank; 313. Hexane pump; 314. Hexane intermediate tank; 315. Methanol solution pump; 316. Methanol solution intermediate tank; 317. Primary distillation circulating liquid intermediate tank; 318. Primary distillation circulating liquid feed pump; 319. Primary distillation column charging... 4. Nitrogen line; 41. Product distillation column; 42. Product distillation buffer tank; 43. Product distillation feed pump; 44. Product distillation condenser assembly; 45. Product distillation condenser tank; 46. Product distillation vacuum pump assembly; 47. Product vacuum pump assembly outlet buffer tank; 48. Product vacuum exhaust condenser assembly; 49. Product vacuum exhaust condensate recovery pump; 410. Product reflux pump; 411. Product tank; 412. Catalyst concentrate external pump; 413. Nitrogen purging line for distillation column; 5. Waste catalyst 51. Catalyst recovery buffer vessel; 52. Waste catalyst recovery pump; 6. Waste catalyst collection tank; 7. Methanol distillation column; 8. Methanol solution feed pump; 9. Methanol distillation condenser assembly; 10. Methanol distillation vacuum pump assembly; 11. Methanol vacuum buffer tank; 2. Methanol vacuum exhaust condenser assembly; 3. Methanol vacuum exhaust condensate recovery pump; 4. Methanol vacuum buffer tank; 55. Methanol vacuum exhaust condensate recovery pump; 66. Methanol vacuum condensate recovery pump; 7. Methanol condensate tank; 8. Methanol distillation reflux pump; 9. Methanol product pump; 10. Methanol product tank; 11. Distilled water external pump; 12. Distilled water buffer tank. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] In the description of the embodiments of the present invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or stated, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0029] In this specification, it should be understood that the directional terms such as "upper" and "lower" used in the description of the embodiments of the present invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. Furthermore, in the context, it should also be understood that when it is mentioned that one element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0030] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a dimethylaminoethyl acrylate production system, including a reaction unit, a primary distillation unit, a product distillation unit, and a methanol distillation unit;

[0031] The reaction unit includes a mixing vessel 1, a microreactor 2, and a primary distillation buffer vessel. The mixing vessel 1 is used for preheating and stirring the raw materials. The inlet of the microreactor 2 is connected to the outlet of the mixing vessel 1, and the outlet of the microreactor 2 is connected to the inlet of the primary distillation buffer vessel. The two outlets of the primary distillation buffer vessel are connected to the mixing vessel 1 and the primary distillation unit, respectively. When the primary distillation buffer vessel is opened and connected to the outlet of the mixing vessel 1, the reaction liquid circulates between the mixing vessel 1, the microreactor 2, and the primary distillation buffer vessel. When the primary distillation buffer vessel is opened and connected to the outlet of the primary distillation unit, the reaction liquid enters the primary distillation unit for distillation to separate the product liquid and the methanol liquid. The product liquid enters the product rectification unit for purification, and the methanol liquid enters the methanol rectification unit for purification.

[0032] In this embodiment, using the microreactor 2 as the main container for the reaction can increase the reaction rate. The circulation of the reaction solution between the mixing vessel 1, the microreactor 2, and the initial distillation buffer vessel allows for more uniform mixing of the reactants and a more consistent temperature.

[0033] The initial distillation buffer vessel may include initial distillation buffer vessel A28 and initial distillation buffer vessel B29.

[0034] In some embodiments of the present invention, the methanol distillation unit includes a primary distillation column 3, a primary distillation condenser 39, and a product distillation buffer tank 41;

[0035] The feed inlet of the primary distillation column 3 is connected to the primary distillation buffer vessel. The gas phase at the top of the primary distillation column 3 is liquefied by the condensation component and flows into the primary distillation condenser 39. The liquid phase at the bottom of the primary distillation column 3 is connected to the product distillation buffer vessel 41. The primary distillation condenser 39 is equipped with an overflow tank and an overflow hole. Part of the reaction liquid in the primary distillation condenser 39 flows back to the primary distillation column 3, and part overflows to the overflow tank. The overflow tank is equipped with a deionized water nozzle to spray deionized water into the overflow tank. The overflow tank is connected to a hexane and methanol separator 312, which is used to separate methanol and hexane.

[0036] In this embodiment, the reaction liquid in the primary distillation condenser 39 enters the overflow tank through the holes in the overflow tank. Deionized water is only sprayed into the overflow tank. After the reaction liquid in the overflow tank mixes with the deionized water, it enters the hexane and methanol separator 312 for separation. The reaction liquid inside the primary distillation condenser 39 and outside the overflow tank will not be mixed with deionized water and can continue to enter the primary distillation column 3.

[0037] In some embodiments of the present invention, the bottom of the primary distillation column 3 is connected to a primary distillation circulating liquid intermediate tank 317, and the primary distillation circulating liquid intermediate tank 317 is connected to the mixing tank 1.

[0038] In this embodiment, the reaction liquid in the primary distillation column 3 can be returned to the mixing vessel 1 for recycling reaction through the intermediate tank 317 of the primary distillation circulating liquid, thereby improving the reaction efficiency.

[0039] In some embodiments of the present invention, the product distillation unit includes a product distillation column 4, a waste catalyst collection tank 52, and a product tank 411;

[0040] The product distillation buffer tank 41 is connected to the product distillation column 4, and the product distillation column 4 is connected to the waste catalyst collection tank 52 and the product tank 411.

[0041] In some embodiments of the present invention, a packing layer is provided inside the hexane and methanol separator 312. The packing layer is used to increase the liquid diffusion area. The hexane and methanol separator 312 is respectively connected to an intermediate hexane tank and an intermediate methanol tank.

[0042] In some embodiments of the present invention, the methanol distillation unit includes a methanol distillation column 6, a methanol product tank 610, and a distillation water buffer tank 612.

[0043] The methanol distillation column 6 is used to receive the reaction liquid in the methanol intermediate tank, the methanol product tank 610 is used to receive the methanol distilled from the methanol distillation column 6, and the distillation water buffer tank 612 is used to receive the residual distillation water in the methanol distillation column 6.

[0044] In some embodiments of the present invention, the molar mass of methyl acrylate in the raw materials is greater than the molar mass of dimethylaminoethanol, and the catalyst is a titanate compound.

[0045] The amount of catalyst added is 1.2 to 1.6% of the mass of methyl acrylate.

[0046] In some embodiments of the present invention, the mass of the inhibitor in the production raw materials is 8 to 10% of the mass of the catalyst.

[0047] In some embodiments of the present invention, the reaction liquid in the primary distillation column 3 enters the mixing vessel 1 through the primary distillation circulating liquid intermediate tank 317, and then enters the primary distillation column 3 from the mixing vessel 1 through the microreactor 2 and the primary distillation buffer vessel to complete the reaction cycle. The reaction cycle time is 3 to 5 hours.

[0048] In some embodiments of the present invention, the bottom temperature of the methanol distillation column 6 is 70–90°C.

[0049] In some specific embodiments, the production steps of the entire production system are as follows:

[0050] I. Premixing and heating of reaction raw materials

[0051] Preheated to 50°C and dehydrated via molecular sieve, dimethyl ethanolamine 13 and methyl acrylic acid 14 are pumped into mixing tank A11 / mixing tank B12 at a molar ratio of 1:1 to 1.15 (the two tanks in mixing tank group 1 are used alternately to maintain production continuity), preferably 1:1.05. Stirring is started after the feed rate reaches the stirring start-up level, and the feed is simultaneously fed while stirring at 25 to 50 rpm, preferably 40 rpm. Temperature is increased during stirring, and the mixture is fed through a process at 1% to 2.5% of the mass of methyl acrylic acid per tank. The catalyst is added through the catalyst filling tube 15. The catalyst can be a titanate compound, an alkali metal phosphate, an organotin compound, or a carbonate, preferably tetrabutyl titanate, with a preferred proportion of 1.4%. An inhibitor is added at 1 / 12 to 1 / 8 of the catalyst mass. The inhibitor can be phenothiazine, hydroquinone, or p-methoxyphenol, preferably p-methoxyphenol, with a preferred proportion of 1 / 10 of the catalyst mass. After the inhibitor is added, the mixture is stirred for another 0.5 hours, and the temperature is raised to 85-90°C through the jacket of the mixing vessel.

[0052] II. Reactions within the microreactor assembly

[0053] After being premixed and heated to the reaction temperature in mixing tank group 1, the reactants enter microreactor group 2. The reactants are then circulated through mixing tank A11 / mixing tank B12, feed pump A24, first reactor 21, feed pump B25, second reactor 22, feed pump C26, third reactor 23, initial distillation buffer tank feed pump 27, initial distillation buffer tank A28 / initial distillation buffer tank B29, initial distillation feed pump 31, and mixing tank A11 / mixing tank B12 for 1 to 1.5 hours of temperature increase (if the reactor temperature is unstable during shutdown and startup, the circulation reaction time can be increased by 0.5 hours), preferably 1 hour. The flow rate of the reactants is not higher than 3 m / s, and the reaction temperature of 90°C under normal pressure is reached in the microreactor group.

[0054] The diameter of the channels inside the reactor gradually decreases from 5 mm to 3 mm in the first third, and the diameter of the insulated fluid pipes also gradually decreases from 5 mm to 3 mm in the first third; the reaction pipes and the insulated fluid pipes are arranged alternately and in reverse order. The reaction channel of a single microreactor is 9 meters long, and the number of reaction channels is determined according to the designed reaction flow rate. Multiple sets can be configured in parallel to increase the reaction volume.

[0055] III. Tower preheating

[0056] Preheat the primary distillation column 3 to 60°C with n-hexane in advance; prepare 3.5% to 5% of the mass of methyl acrylate for spraying n-hexane in each reactor, preferably 4%; leave 1 / 20 of the n-hexane in the bottom of the primary distillation column 3, and return the rest to the preheating and insulation tank for spraying when the primary distillation column 3 is fed.

[0057] IV. Product, initial methanol distillation separation and recycling reaction

[0058] After the reaction liquid reaches the set temperature and reaches the set liquid level in the primary distillation buffer tank A28 / B29, the discharge valve of the buffer tank is opened, and the reaction liquid enters the primary distillation column 3 through the primary distillation feed pump 31; hexane, preheated to 55℃~60℃, is sprayed into the column through the hexane sprayer 33; high-purity nitrogen is introduced into the column through the nitrogen purging line 319, and the inlet flow rate is maintained at 0.05~0.15Nm. 3 / h, with a preferred intake flow rate of 0.1Nm 3 For speeds above 90°C, the reboiler maintains the bottom temperature of the distillation column at no less than 90°C. When the liquid level in the column reaches the set stripping line, the primary distillation column stripping pump 36 is started to re-strip the bottom liquid. After the vapor phase at the top of the column is condensed by the primary distillation condenser group 37, the liquid phase enters the primary distillation condenser tank 39 via the primary distillation condenser pump 38. The primary distillation condenser tank 39 is equipped with overflow troughs with perforations on the sides and bottom (the bottom of the trough is slightly higher than the tank wall for venting during shutdown). The flow rate of the perforations is less than the feed flow rate of the condensate (to facilitate maintaining the liquid level in the overflow trough). When liquid overflows from the overflow trough of the primary distillation condenser tank 39, the ambient temperature deionized water spray 34 and the primary distillation column reflux pump 310 are started simultaneously. The primary distillation column reflux pump 310 controls the top temperature of the column to be between 50°C and 52°C. The preferred temperature at the top of the column is 51℃. The feed inlet of the primary distillation column reflux pump 310 is located at the bottom of the overflow tank. The reboiler of the primary distillation column 3 is equipped with a start-up level line and a stop level line for the primary distillation circulation pump 32. As the distillation rate reaches the normal value, the reboiler level of the primary distillation column 3 continues to rise. After reaching the start-up level line of the primary distillation circulation pump 32, the primary distillation circulation pump 32 is started, and the primary distillation circulation liquid enters the primary distillation circulation liquid intermediate tank 317 through the primary distillation circulation pump 32. After reaching the discharge level of the primary distillation circulation liquid intermediate tank 317, the primary distillation circulation liquid feed pump 318 is started to circulate the reaction liquid back to the mixing tank A11 / mixing tank B12. At this point, the circulation reaction process is established, and the circulation reaction lasts for 3 to 5 hours, preferably 4 hours.

[0059] When the steam flow rate at the top of the initial distillation column 3 decreases, the initial distillation circulation pump 32 is stopped, and the liquid level in the bottom of the initial distillation column 3 continues to rise. The flow rate of the initial distillation column stripping pump 36 is increased to 1.5 to 3 times the original flow rate. The initial distillation circulation liquid feed pump 318 introduces the reaction liquid in the intermediate tank 317 into the mixing tank A11 / mixing tank B12 and then stops. After all the reaction liquid in the mixing tanks A11 / B12 is introduced into reactor group 2 for exchange, the circulation and heating reaction operation of the new batch of feed is started. After the initial distillation column is circulated and stripped for 1 to 1.5 hours, the liquid in the bottom of the column after initial distillation is pumped by the initial distillation column discharge pump 35 to the product rectification buffer tank 41, and the initial distillation column discharge pump 35 is shut down.

[0060] When the liquid level in the primary distillation condenser 39 reaches the set start position of the primary distillation column condensate delivery pump 311, the primary distillation column condensate delivery pump 311 starts, supplying liquid to the hexane and methanol separator 312. The combination of spraying and double-layer packing in the hexane and methanol separator 312 increases the liquid diffusion area and shortens the sedimentation and stratification time of the condensate. Due to the different densities of the hexane and methanol solutions, they naturally stratify. After the hexane and methanol separator 312 reaches the set liquid level, the hexane pump 313 starts, pumping hexane into the hexane intermediate tank 314 for further hexane spraying. At the same time as the hexane pump 313 starts, the methanol solution pump 315 starts, and the sum of the flow rates of the two pumps is equal to the flow rate of the primary distillation column condensate delivery pump 311. The methanol solution is stored in the methanol solution intermediate tank 316.

[0061] V. Product distillation and waste catalyst recovery

[0062] After the product distillation buffer tank 41 is fed, the agitator is started and an inhibitor is added at 1 / 12 to 1 / 8 of the catalyst mass, preferably p-methoxyphenol, and more preferably 1 / 10 of the catalyst mass. After the product distillation feed pump 42 is started, the reaction liquid is sprayed into the product distillation column 4. The bottom of the product distillation column 4 is maintained at 70°C to 90°C, preferably 80°C, by steam. When the liquid level in the bottom of the product distillation column 4 reaches the set level, the nitrogen purging line 413 of the distillation column is maintained at 0.05 to 0.15 Nm³. 3 / h, with a preferred intake flow rate of 0.1Nm 3 / h or higher; After the product distillation feed pump 42 pumps all the reaction liquid in the product distillation buffer tank 41 into the product distillation column 4, the feed valve is closed and the stripping valve of the product distillation column 4 is opened to strip and circulate the liquid in the bottom of the product distillation column 4 to improve the distillation rate and product purity; While the nitrogen charging line 413 of the distillation column is charging with nitrogen, the following components are started: product distillation condenser group 43, product distillation vacuum pump group 45, product distillation vacuum pump group outlet buffer tank 46, product vacuum exhaust condenser group 47, product vacuum exhaust condensate recovery pump 48, and product distillation condenser tank 44. The condensation, vacuum, and reflux system, consisting of the product distillation reflux pump 49, maintains the pressure at the top of the product distillation column 4 at 12 mmHg and the temperature at 64°C. When the liquid levels of the product distillation condenser group 43, the product distillation vacuum pump group outlet buffer tank 46, and the product vacuum exhaust condenser group 47 reach their respective set values, the condensate is pumped into the product distillation condenser tank 44. After the liquid level in the product distillation condenser tank 44 reaches the set value, the product delivery pump 410 is started, and the finished product is pumped into the product tank 411. The non-condensable gas from the product distillation condenser tank 44 and the product vacuum exhaust condenser group 47 is introduced into the tail gas treatment system.

[0063] When the reaction solution in one batch is distilled to the minimum liquid level set in the product distillation column 4, the product distillation feed pump 42 stops the distillation cycle. The catalyst concentrate in the bottom of the product distillation column 4 is pumped by the catalyst concentrate external pump 412 to the mixing vessel that has just finished feeding for re-mixing. Each batch of catalyst is recycled 3 to 5 times and then replaced, preferably 3 times, to ensure reaction efficiency and product purity.

[0064] The catalyst waste liquid that has been used 3 to 5 times is pumped to the waste catalyst recovery buffer tank 5 by the catalyst concentrate external pump 412; when the liquid level in the waste catalyst recovery buffer tank 5 reaches the set value, the cooling and stirring are started until the catalyst waste liquid drops to room temperature and the stirring is stopped; the waste catalyst is pumped into the waste catalyst collection tank 52 by the waste catalyst recovery pump 51.

[0065] V. Methanol distillation:

[0066] After the methanol solution level in the intermediate methanol solution tank 316 reaches the set value, the methanol solution feed pump 61 is started to spray the methanol distillation column 6; the bottom temperature of the methanol distillation column 6 is maintained at 70-90℃, preferably 80℃. After the minimum liquid level in the bottom of the methanol distillation column 6 is reached, the condensation, vacuum, and reflux system consisting of the methanol distillation condenser group 62, the methanol distillation vacuum pump group 63, the methanol vacuum buffer tank 64, the methanol vacuum exhaust condenser group 65, the methanol vacuum exhaust condensate recovery pump 66, the methanol condensate tank 67, and the methanol distillation reflux pump 68 is started to maintain the column top pressure at 420 mmHg and the column top temperature at 50-51℃, preferably 50.5℃. When the liquid level in the methanol condensate tank 67 reaches the minimum requirement, the methanol product pump 69 is started to introduce high-purity methanol into the methanol product tank 610. When the methanol content of the distillate decreases to the set value, the distillation is stopped, and the distillation water external pump 611 is started to introduce the bottom water of the methanol distillation column 6 into the distillation water buffer tank 612 for reuse.

[0067] VI. Replacing methyl acrylate with methyl methacrylate produces dimethylaminoethyl methacrylate.

[0068] VII. The conversion rate of dimethylaminoethanol in this invention can reach over 98.5%, and the purity of the dimethylaminoethyl acrylate (or dimethylaminoethyl methacrylate) product is over 99.5%.

[0069] Multiple production implementations were conducted using the production system provided in this application, resulting in data for multiple embodiments. The process parameters differed across these production embodiments, and the specific process parameters and product quality are shown in the table below:

[0070] Example 1: Process Parameter Table 1

[0071]

[0072]

[0073] Example 2: Process Parameter Table 2

[0074]

[0075]

[0076] Example 3: Process Parameter Table 3

[0077]

[0078]

[0079] Example 1: Comparison of Product Quality and Energy Consumption

[0080]

[0081] Comparing the molar ratio of reactants in Examples 1, 2, and 3, a slight excess of methyl acrylate is preferable; comparing the catalyst addition ratio in Examples 1, 4, and 5, a methyl acrylate mass of 1.4% is preferable.

[0082] Example 2: Comparison Table of Product Quality and Energy Consumption

[0083]

[0084]

[0085] For Examples 1, 6, and 7, the amount of reaction inhibitor added should be 1 / 10 of the amount of catalyst. For Examples 1, 8, and 9, the mixing time is compared, and the product quality is not significantly different. For Examples 1, 10, and 11, the cycle reaction time is compared, which has a greater impact on product quality. Considering both product quality and energy consumption, 4 hours is appropriate.

[0086] Example 3: Comparison of Product Quality and Energy Consumption

[0087] purity,% 99.54 99.55 99.55 Moisture,% 0.098 0.098 0.098 Polymerization inhibitor (MEHQ), % 0.087 0.087 0.087 Methyl acrylate, % 0.127 0.126 0.126 Dimethylethanolamine, % 0.075 0.072 0.072 Other ingredients, % 0.073 0.067 0.067 Methanol purity, % 99.6 99.4

[0088] For Examples 1, 12, and 13, the distillation time in the primary distillation column 3 should be 1.5 hours. For Examples 1, 14, and 15, comparing the bottom temperature of the methanol distillation column 6, at 70℃ the product purity is high, the distillation time is long, and the production efficiency is lower; at 90℃, the production efficiency is high, but the product purity is slightly affected, so 80℃ is preferable.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dimethylaminoethyl acrylate production system, characterized in that, It includes a reaction unit, a primary distillation unit, a product distillation unit, and a methanol distillation unit; The reaction unit includes a mixing tank (1), a microreactor (2), and a primary distillation buffer tank. The mixing tank (1) is used to preheat and stir the raw materials. The inlet of the microreactor (2) is connected to the outlet of the mixing tank (1). The outlet of the microreactor (2) is connected to the inlet of the primary distillation buffer tank. The two outlets of the primary distillation buffer tank are respectively connected to the mixing tank (1) and the primary distillation unit. When the primary distillation buffer tank is opened to the outlet of the mixing tank (1), the reaction liquid circulates between the mixing tank (1), the microreactor (2), and the primary distillation buffer tank. When the primary distillation buffer tank is opened to the outlet of the primary distillation unit, the reaction liquid enters the primary distillation unit for distillation to separate the product liquid and the methanol liquid. The product liquid enters the product rectification unit for purification, and the methanol liquid enters the methanol rectification unit for purification.

2. The production system according to claim 1, characterized in that, The primary distillation unit includes a primary distillation column (3), a primary distillation condenser (39), and a product distillation buffer tank (41). The feed inlet of the primary distillation column (3) is connected to the primary distillation buffer vessel. The gas phase at the top of the primary distillation column (3) is liquefied by the condensation assembly and flows into the primary distillation condenser (39). The liquid phase at the bottom of the primary distillation column (3) is connected to the product distillation buffer vessel (41). An overflow tank is provided inside the primary distillation condenser (39). An overflow hole is provided in the overflow tank. Part of the reaction liquid in the primary distillation condenser (39) flows back to the primary distillation column (3), and part overflows to the overflow tank. A deionized water nozzle is provided in the overflow tank to spray deionized water into the overflow tank. The overflow tank is connected to a hexane and methanol separator (312). The hexane and methanol separator (312) is used to separate methanol and hexane.

3. The production system according to claim 2, characterized in that, The bottom of the primary distillation column (3) is connected to the intermediate tank (317) of the primary distillation circulating liquid, and the intermediate tank (317) of the primary distillation circulating liquid is connected to the mixing vessel (1).

4. The production system according to claim 2, characterized in that, The product distillation unit includes a product distillation column (4), a waste catalyst collection tank (52), and a product tank (411). The product distillation buffer tank (41) is connected to the product distillation column (4), and the product distillation column (4) is connected to the waste catalyst collection tank (52) and the product tank (411) respectively.

5. The production system according to claim 2, characterized in that, The hexane and methanol separator (312) is provided with a packing layer, which is used to increase the liquid diffusion area. The hexane and methanol separator (312) is connected to an intermediate hexane tank and an intermediate methanol tank respectively.

6. The production system according to claim 5, characterized in that, The methanol distillation unit includes a methanol distillation column (6), a methanol product tank (610), and a distillation water buffer tank (612). The methanol distillation column (6) is used to receive the reaction liquid in the methanol intermediate tank, the methanol product tank (610) is used to receive the methanol distilled from the methanol distillation column (6), and the distillation water buffer tank (612) is used to receive the residual distillation water in the methanol distillation column (6).

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