Continuous synthesis reactor for ethylene glycol diacetate
By designing three reactors in series and installing cleaning nozzles, the problems of slow reaction rate and inconvenient cleaning during the synthesis of ethylene glycol diacetate were solved, enabling continuous synthesis and efficient cleaning of ethylene glycol diacetate, thereby improving synthesis efficiency and equipment lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGXIA GANGXING NEW MATERIAL TECH CO LTD
- Filing Date
- 2025-05-19
- Publication Date
- 2026-05-05
AI Technical Summary
In the existing technology, the reaction rate in the synthesis of ethylene glycol diacetate is relatively slow, which makes it impossible to achieve continuous synthesis, and the reaction vessel is inconvenient to clean, affecting the service life of the equipment.
The reactor employs a three-reactor series design, controlling the reaction process through temperature and pressure gradients, and is equipped with cleaning nozzles to facilitate reactor cleaning, thereby achieving continuous synthesis and efficient cleaning of ethylene glycol diacetate.
The continuous synthesis of ethylene glycol diacetate was achieved, which improved the synthesis efficiency, reduced heat consumption, and extended the service life of the reaction apparatus.
Smart Images
Figure CN224194739U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical synthesis technology, and in particular to a continuous synthesis reactor for ethylene glycol diacetate. Background Technology
[0002] Ethylene glycol diacetate is a colorless, transparent liquid produced by the esterification of ethylene glycol and acetate. It has a slight ester odor, a boiling point of approximately 190–191°C, and is soluble in water and organic solvents, particularly cellulose derivatives and some resins. It is mainly used as a high-boiling-point solvent, such as in paints or inks, as a plasticizer, and as an intermediate in organic synthesis. It is low in toxicity, but contact with eyes and skin should be avoided. This compound is flammable and should be kept away from sources of ignition. It is easily hydrolyzed under acidic or alkaline conditions. Chemical safety regulations should be followed during use, and it should be stored properly in a cool, well-ventilated place, taking precautions to prevent spills and environmental pollution.
[0003] 1. In the existing technology, the synthesis of ethylene glycol diacetate is often carried out by the acetic acid method. In this process, the overall reaction rate is slow, which makes it inconvenient for operators to carry out continuous synthesis operations. That is, after the synthesis is completed, the next synthesis can only be carried out after the reaction vessel is cleaned. The overall efficiency is not high.
[0004] 2. In the existing technology, since the lid and body of the reactor are not easily removed, it is not easy for operators to clean the inside of the reactor after completing the continuous synthesis of ethylene glycol diacetate. Since the synthesized substances are corrosive, failure to clean the inside of the reactor in time will have a certain impact on the inside of the reactor and will not be conducive to the long-term use of the reaction device. Utility Model Content
[0005] The purpose of this invention is to provide a continuous synthesis reactor for ethylene glycol diacetate, which can realize the continuous synthesis of ethylene glycol diacetate and makes it easier to clean the inner wall of the reactor.
[0006] To achieve the above objectives, a continuous synthesis reactor for ethylene glycol diacetate is provided, comprising a first reactor, a first connecting pipe fixedly connected to the lower part of the first reactor, a first water pump fixedly connected to the other end of the first connecting pipe, a second connecting pipe fixedly connected to the output end of the first water pump, a second reactor fixedly connected to the other end of the second connecting pipe, a third connecting pipe fixedly connected to the lower part of the second reactor, a second water pump fixedly connected to the other end of the third connecting pipe, a fourth connecting pipe fixedly connected to the output end of the second water pump, and a third reactor fixedly connected to the other end of the fourth connecting pipe.
[0007] A fifth connecting pipe is fixedly connected to the bottom of the third reactor. A third water pump is fixedly connected to the other end of the fifth connecting pipe. A sixth connecting pipe is fixedly connected to the output end of the third water pump. A distillation column is fixedly connected to the other end of the sixth connecting pipe.
[0008] According to the continuous synthesis reactor for ethylene glycol diacetate, a condenser is provided at the top of the distillation column, a fourth water pump is provided on the right side of the condenser, and a water storage tank is fixedly connected to the output end of the fourth water pump.
[0009] According to the continuous synthesis reactor for ethylene glycol diacetate, a fifth water pump is provided at the lower end of the distillation column, a seventh connecting pipe is fixedly connected to the output end of the fifth water pump, and a storage tank is fixedly connected to the other end of the seventh connecting pipe.
[0010] According to the aforementioned continuous synthesis reactor for ethylene glycol diacetate, the first reactor includes a reactor body, with support rods fixedly connected to the four lower corners of the reactor body, a discharge port fixedly connected to the lower center of the reactor body, and a cover provided on the top of the reactor body.
[0011] According to the aforementioned continuous synthesis reactor for ethylene glycol diacetate, a drive motor is fixedly connected to the top of the cover, a stirring rod is fixedly connected to the output end of the drive motor, a condenser is fixedly connected to the upper right side of the cover, a thermometer is fixedly connected to the upper right side of the cover, a cleaning nozzle is fixedly connected to the upper periphery of the cover, and a sealing cap is threadedly connected to the top of the cleaning nozzle.
[0012] According to the aforementioned continuous synthesis reactor for ethylene glycol diacetate, a heating tube is fixedly connected inside the reactor body, a support frame is fixedly connected to the upper part of the reactor body, and a feed pipe is fixedly connected to the upper right side of the cover.
[0013] According to the aforementioned continuous synthesis reactor for ethylene glycol diacetate, the stirring rod is located inside the reactor body, and the stirring rod is rotatably connected to the support frame.
[0014] According to the continuous synthesis reactor for ethylene glycol diacetate, the lower end of the thermometer is located inside the reactor body, and the lower end of the thermometer is not in contact with the stirring rod.
[0015] This utility model has the following beneficial effects:
[0016] 1. Compared with existing technologies, the method involves first adding raw materials to the first reactor according to a specified ratio. After reacting for a designated time, the first water pump is turned on, transferring the solution from the first reactor to the second reactor. Ten minutes later, the operator adds solution back to the first reactor. After the second reactor has reacted for a specified time, the second water pump is turned on, transferring the solution from the second reactor to the third reactor. After the reaction in the third reactor is complete, the solution from the third reactor is pumped into a distillation column by the third water pump. Then, the second water pump is turned on again, transferring the solution from the second reactor to the third reactor. Ten minutes later, the first water pump is turned on, transferring the solution from the first reactor to the second reactor. Twenty minutes later, solution is added back to the first reactor. This cycle is repeated to intermittently add raw materials to the first reactor, thus achieving continuous addition and synthesis of ethylene glycol diacetate.
[0017] 2. Compared with the existing technology, by setting up a cleaning nozzle with a sealing cap threaded on the top of the cleaning nozzle, after unscrewing the sealing cap, the operator can flush the cleaning liquid into the reactor body through the external pressurized water pipe, and then disconnect the pipe to discharge the cleaning liquid from the outlet, thus completing the cleaning of the reactor body. Attached Figure Description
[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments;
[0019] Figure 1 This is a perspective view of a continuous synthesis reactor for ethylene glycol diacetate according to the present invention;
[0020] Figure 2 This is a perspective view of the first reaction vessel of a continuous synthesis reactor for ethylene glycol diacetate according to the present invention;
[0021] Figure 3 This is a cross-sectional view of the reactor body of a continuous synthesis reactor for ethylene glycol diacetate according to this utility model;
[0022] Figure 4 This is a perspective view of the support frame of a continuous synthesis reactor for ethylene glycol diacetate according to the present invention.
[0023] Legend:
[0024] 1. First reactor; 2. First connecting pipe; 3. First water pump; 4. Second connecting pipe; 5. Second reactor; 6. Third connecting pipe; 7. Second water pump; 8. Fourth connecting pipe; 9. Third reactor; 10. Fifth connecting pipe; 11. Third water pump; 12. Sixth connecting pipe; 13. Distillation column; 14. Condenser; 15. Fourth water pump; 16. Water storage tank; 17. Fifth water pump; 18. Seventh connecting pipe; 19. Material storage tank;
[0025] 101. Reactor body; 102. Support rod; 103. Discharge port; 104. Cover; 105. Drive motor; 106. Stirring rod; 107. Condenser; 108. Thermometer; 109. Cleaning nozzle; 110. Sealing cover; 111. Heating tube; 112. Support frame; 113. Feed pipe. Detailed Implementation
[0026] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.
[0027] Reference Figure 1-4 This utility model discloses a continuous synthesis reactor for ethylene glycol diacetate, comprising a first reactor 1, a first connecting pipe 2 fixedly connected to the lower part of the first reactor 1, a first water pump 3 fixedly connected to the other end of the first connecting pipe 2, a second connecting pipe 4 fixedly connected to the output end of the first water pump 3, a second reactor 5 fixedly connected to the other end of the second connecting pipe 4, a third connecting pipe 6 fixedly connected to the lower part of the second reactor 5, a second water pump 7 fixedly connected to the other end of the third connecting pipe 6, a fourth connecting pipe 8 fixedly connected to the output end of the second water pump 7, and a third reactor 9 fixedly connected to the other end of the fourth connecting pipe 8. A fifth connecting pipe 10 is fixedly connected to the bottom of the reactor 9. A third water pump 11 is fixedly connected to the other end of the fifth connecting pipe 10. A sixth connecting pipe 12 is fixedly connected to the output end of the third water pump 11. A distillation column 13 is fixedly connected to the other end of the sixth connecting pipe 12. A condenser 14 is installed at the top of the distillation column 13. A fourth water pump 15 is installed to the right of the condenser 14. A water storage tank 16 is fixedly connected to the output end of the fourth water pump 15. A fifth water pump 17 is installed at the bottom of the distillation column 13. A seventh connecting pipe 18 is fixedly connected to the output end of the fifth water pump 17. A storage tank 19 is fixedly connected to the other end of the seventh connecting pipe 18.
[0028] The above structure includes a first reactor 1, a second reactor 5, and a third reactor 9, with the second reactor 5 and the third reactor 9 having the same overall structure as the first reactor 1.
[0029] The presence of a first reaction vessel 1 allows operators to add raw materials or preheated raw materials into the first reaction vessel 1. The specific raw materials are ethylene glycol and acetic anhydride.
[0030] The specific ratio is:
[0031] The molar ratio of ethylene glycol to acetic anhydride is 1:2.1.
[0032] The specific formula is as follows:
[0033] HOCH2CH2OH+(CH3CO)2O→CH3COOCH2CH2OOCCH3+H2O;
[0034] The specific Chinese expression is:
[0035] Ethylene glycol + acetic anhydride → ethylene glycol diacetate + water.
[0036] The first reaction vessel 1 is provided, and the specific data inside the first reaction vessel 1 are as follows: temperature: 120-130℃, pressure: 0.2-0.3MPa, residence time: 40 minutes, stirring speed: 80-100rpm.
[0037] The second reactor 5 is provided, and the specific data inside the second reactor 5 are as follows: temperature: 130-140℃, pressure: 0.1-0.2MPa, residence time: 50 minutes, stirring speed: 60-80rpm.
[0038] The third reaction vessel 9 is provided, and the specific data inside the third reaction vessel 9 are as follows: temperature: 140-150℃, pressure: atmospheric pressure, residence time: 60 minutes, stirring speed: 40-60 rpm.
[0039] In the catalyst-free continuous synthesis process of ethylene glycol diacetate via the acetic anhydride method, a series reactor design is the core solution for achieving efficient conversion and stable production by setting up a first reactor (1), a second reactor (5), and a third reactor (9) connected in series. By setting temperature gradients (120℃→150℃) and pressure gradients (0.3MPa→atmospheric pressure), the system achieves three key functions: staged control of the reaction process, suppression of diethylene glycol byproduct formation (≤0.5%), and optimized heat energy utilization (steam consumption reduced by 30%). In a typical three-reactor series configuration, the material sequentially passes through the reaction environments of the first reactor (120-130℃), the second reactor (130-140℃), and the final reactor (140-150℃), with a total residence time of 2.5 hours, achieving a final conversion rate of over 99% and a product purity of ≥99.5%. This serves as the specific scheme for this reaction.
[0040] The system includes a distillation column 13 and a condenser 14, which are connected by a connecting pipe. The condenser 14 and a fourth water pump 15 are also connected by a connecting pipe. The fourth water pump 15 is also connected to a water storage tank 16 via a connecting pipe.
[0041] Driven by the third water pump 11, the reacted ethylene glycol diacetate and water enter the distillation column 13. Under the action of the distillation column 13, the finished ethylene glycol diacetate flows downwards, while the water moves upwards in the form of vapor. At this point, the ethylene glycol diacetate flows to the bottom of the distillation column 13 and, driven by the fifth water pump 17, enters the storage tank 19. The water vapor above enters the condenser 14, where it is converted from vapor to liquid. This liquid water is then driven by the fourth water pump 15 into the water storage tank 16. During this process, the operator can indirectly add raw materials to the first reaction vessel 1, thereby achieving continuous synthesis of ethylene glycol diacetate.
[0042] The first reaction vessel 1 includes a reaction vessel body 101. Support rods 102 are fixedly connected to the four lower corners of the reaction vessel body 101. A discharge port 103 is fixedly connected to the lower center of the reaction vessel body 101. A cover 104 is provided on top of the reaction vessel body 101. A drive motor 105 is fixedly connected to the top of the cover 104. A stirring rod 106 is fixedly connected to the output end of the drive motor 105. The stirring rod 106 is located inside the reaction vessel body 101 and is rotatably connected to a support frame 112. A [missing information - likely a component or component] is fixedly connected to the upper right side of the cover 104. A thermometer 108 is fixedly connected to the upper right side of the condenser tube 107 and the cover 104. The lower end of the thermometer 108 is located inside the reactor body 101 and does not contact the stirring rod 106. A cleaning nozzle 109 is fixedly connected to the upper periphery of the cover 104. A sealing cap 110 is threadedly connected to the upper part of the cleaning nozzle 109. A heating tube 111 is fixedly connected inside the reactor body 101. A support frame 112 is fixedly connected to the upper part of the reactor body 101. A feed pipe 113 is fixedly connected to the upper right side of the cover 104.
[0043] The above structure includes a cleaning nozzle 109 with a sealing cap 110 threadedly connected to its upper part. A sealing gasket is provided inside the sealing cap 110. When the cleaning nozzle 109 and the sealing cap 110 are tightly fitted together, the gas will not leak out from the connection point due to the sealing gasket. After unscrewing the sealing cap 110, the operator can flush the cleaning solution into the reactor body 101 through an external pressurized water pipe to complete the cleaning of the reactor body 101.
[0044] By providing a condenser 107, substances that evaporate during the reaction process can be re-entered into the interior of the reactor body 101.
[0045] Driven by the drive motor 105, the stirring rod 106 rotates inside the reactor body 101. The rotation of the stirring rod 106 allows the raw materials inside the reactor body 101 to react better.
[0046] By installing heating tube 111, the interior of the reactor body 101 can be heated, thereby heating the raw materials inside.
[0047] The reactor body 101 and the lid 104 are provided and connected by bolts and nuts.
[0048] The aforementioned structure and the continuous synthesis reactor for ethylene glycol diacetate are suitable for a pilot-scale operating environment. Pilot-scale testing, short for "intermediate-scale experiment," refers to a stage of testing conducted after successful small-scale laboratory experiments but before formal industrial production. It is a crucial link in the transition of research results from the laboratory to industrial application, aiming to verify technical feasibility, optimize process parameters, evaluate economic efficiency, and identify potential problems.
[0049] Working Principle: This continuous synthesis reactor for ethylene glycol diacetate uses the acetic anhydride method to synthesize ethylene glycol diacetate. In operation, the raw materials are first added to the first reactor 1 according to a specified ratio. After the reaction time in the first reactor 1, the first water pump 3 is turned on, transferring the solution from the first reactor 1 to the second reactor 5. The operator adds solution to the first reactor 1 again after ten minutes. After the solution has reacted sufficiently in the second reactor 5, the second water pump 7 is turned on, transferring the solution from the second reactor 5 to the third reactor 9. After ten minutes, the first water pump 3 is turned on again, transferring the solution from the first reactor 1 to the second reactor 5. Solution is added to the first reactor 1 again after twenty minutes. After the reaction in the third reactor 9 is complete, the solution in the third reactor 9 is driven by the third water pump 11 to enter the distillation column 13. Then, the second water pump 7 is turned on, allowing the solution inside the second reactor 5 to be introduced into the third reactor 9. Ten minutes later, the first water pump 3 is turned on, introducing the solution inside the first reactor 1 into the second reactor 5. Twenty minutes later, solution is added back into the first reactor 1. This cycle is repeated to intermittently add raw materials to the first reactor 1, thus achieving the continuous synthesis of ethylene glycol diacetate. Under the action of the distillation column 13, ethylene glycol diacetate enters the storage tank 19 from below the distillation column 13, driven by the fifth water pump 17. Water vapor, through the condenser 14 and the fourth water pump 15, enters the water storage tank 16, thus completing the continuous synthesis of ethylene glycol diacetate.
[0050] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.
Claims
1. A continuous synthesis reactor for ethylene glycol diacetate, characterized in that, The reactor includes a first reactor (1), a first connecting pipe (2) is fixedly connected to the bottom of the first reactor (1), a first water pump (3) is fixedly connected to the other end of the first connecting pipe (2), a second connecting pipe (4) is fixedly connected to the output end of the first water pump (3), a second reactor (5) is fixedly connected to the other end of the second connecting pipe (4), a third connecting pipe (6) is fixedly connected to the bottom of the second reactor (5), a second water pump (7) is fixedly connected to the other end of the third connecting pipe (6), a fourth connecting pipe (8) is fixedly connected to the output end of the second water pump (7), and a third reactor (9) is fixedly connected to the other end of the fourth connecting pipe (8). A fifth connecting pipe (10) is fixedly connected to the bottom of the third reactor (9). A third water pump (11) is fixedly connected to the other end of the fifth connecting pipe (10). A sixth connecting pipe (12) is fixedly connected to the output end of the third water pump (11). A distillation column (13) is fixedly connected to the other end of the sixth connecting pipe (12).
2. The continuous synthesis reactor for ethylene glycol diacetate according to claim 1, characterized in that, A condenser (14) is provided at the top of the distillation column (13), and a fourth water pump (15) is provided on the right side of the condenser (14). A water storage tank (16) is fixedly connected to the output end of the fourth water pump (15).
3. The continuous synthesis reactor for ethylene glycol diacetate according to claim 1, characterized in that, The lower end of the distillation column (13) is provided with a fifth water pump (17), the output end of the fifth water pump (17) is fixedly connected to a seventh pipe (18), and the other end of the seventh pipe (18) is fixedly connected to a storage tank (19).
4. The continuous synthesis reactor for ethylene glycol diacetate according to claim 1, characterized in that, The first reactor (1) includes a reactor body (101), with support rods (102) fixedly connected to the four lower corners of the reactor body (101), a discharge port (103) fixedly connected to the lower center of the reactor body (101), and a cover (104) provided on the top of the reactor body (101).
5. The continuous synthesis reactor for ethylene glycol diacetate according to claim 4, characterized in that, A drive motor (105) is fixedly connected to the top of the cover (104), and a stirring rod (106) is fixedly connected to the output end of the drive motor (105). A condenser (107) is fixedly connected to the upper right side of the cover (104), and a thermometer (108) is fixedly connected to the upper right side of the cover (104). A cleaning nozzle (109) is fixedly connected to the upper periphery of the cover (104), and a sealing cap (110) is threadedly connected to the upper part of the cleaning nozzle (109).
6. The continuous synthesis reactor for ethylene glycol diacetate according to claim 5, characterized in that, A heating tube (111) is fixedly connected inside the reactor body (101), a support frame (112) is fixedly connected to the upper part of the reactor body (101), and a feed pipe (113) is fixedly connected to the upper right side of the cover (104).
7. The continuous synthesis reactor for ethylene glycol diacetate according to claim 6, characterized in that, The stirring rod (106) is located inside the reactor body (101), and the stirring rod (106) is rotatably connected to the support frame (112).
8. The continuous synthesis reactor for ethylene glycol diacetate according to claim 5, characterized in that, The lower end of the thermometer (108) is located inside the reactor body (101), and the lower end of the thermometer (108) does not contact the stirring rod (106).