An apparatus for continuous production of dual-terminated ethylene glycol ethers

Abstract

This invention belongs to the field of chemical equipment technology, specifically relating to an apparatus for the continuous production of dual-terminated ethylene glycol ethers. The apparatus includes a four-stage reaction unit and a distillation system. Each reaction unit consists of a mixer, a reactor, and a dynamic filter connected sequentially by pipelines. This apparatus utilizes a continuous process to prepare dual-terminated ethylene glycol ether compounds, achieving continuous conversion from single ethers to dual ethers. The reaction time is short, significantly improving production efficiency. It allows for highly automated control, reducing operator workload and increasing labor efficiency. Furthermore, the product quality is stable, achieving safe and environmentally friendly production. This invention uses a dynamic filter to continuously and effectively remove sodium chloride solids from the system, reducing the solid content of the material in the mixer, facilitating material transport, and ensuring thorough stirring during the reaction process. This ensures high-efficiency production, reduces equipment wear, and yields high-quality ultrafine sodium chloride byproducts, improving product yield.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, specifically relating to an apparatus for the continuous production of double-terminated ethylene glycol ethers. Background Technology

[0002] Dual-terminated ethylene glycol ethers (DGEs) lack active hydrogen, exhibit strong chemical stability, and possess excellent solubility, making them widely used solvents in industry and laboratories. They are also used as pharmaceutical extractants and organic intermediates, and have applications in the cosmetics, fragrance, pharmaceutical, and oilfield industries, among others. In the lithium-ion battery field, DGEs can be mixed with various lithium salts to prepare lithium-ion battery electrolyte solutions, reducing electrolyte viscosity and improving battery charge / discharge efficiency and cycle life. In recent years, with the rapid development of end-use applications such as energy storage, new energy vehicles, and consumer electronics in my country, the market demand for DGEs, as a basic raw material for producing novel sodium-ion battery electrolyte solvents, has grown accordingly. With increasing global environmental awareness and the growing demand for new materials, the market prospects for DGEs, as an environmentally friendly solvent and raw material for new materials, are expected to be even broader.

[0003] There are two main methods for industrial-scale production of double-terminated ethylene glycol ethers. Taking the synthesis of ethylene glycol dimethyl ether as an example: (1) Williamson synthesis method: Starting from ethylene glycol monomethyl ether, sodium alkoxide of ethylene glycol monomethyl ether is first prepared, and then ethylene glycol dimethyl ether is obtained by passing chloromethane gas through it; (2) ethylene oxide ring-opening method: ethylene oxide reacts with dimethyl ether under the catalysis of Lewis acid or heteropolyacid to obtain ethylene glycol dimethyl ether. Among them, the Williamson synthesis method using ethylene glycol monomethyl ether as raw material has received widespread attention due to its high safety and low operation difficulty. The equation is as follows:

[0004] (1)CH3OCH2CH2OH+NaOH→CH3OCH2CH2ONa+H2O

[0005] (2)CH3OCH2CH2ONa+CH3Cl→CH3OCH2CH2OCH3+NaCl

[0006] This two-step process for preparing ethylene glycol dimethyl ether (EDGDME) is problematic. In the first step, sodium ethylene glycol monomethyl ether readily undergoes a side reaction in the presence of water, turning the reaction system reddish-brown. This reduces product purity and stains the sodium chloride byproduct from the second step, increasing post-processing difficulty and production costs. Furthermore, due to the violently exothermic reaction and equipment limitations, the final amount of alkali added can only be up to 0.5 equivalents. The process also suffers from long reaction times, low efficiency, numerous side reactions, and difficulty in controlling the reaction temperature. Moreover, as the amount of alkali added increases, the solid content in the system increases, leading to reduced production efficiency, increased equipment wear and tear, and limiting capacity expansion. Utility Model Content

[0007] To address the problems of low safety factor, long reaction time, and low efficiency in existing devices and methods, this invention provides an apparatus suitable for the continuous production of double-terminated ethylene glycol ethers.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] An apparatus for continuous production of dual-terminated ethylene glycol ethers includes four-stage reaction units, comprising a first-stage reaction unit, a second-stage reaction unit, a third-stage reaction unit, and a fourth-stage reaction unit connected in sequence. Each stage of the reaction unit consists of a mixer, a reactor, and a dynamic filter connected in sequence via pipelines. The dynamic filter of the previous stage reaction unit is connected to the mixer of the next stage reaction unit, and the mixer of the first stage reaction unit is provided with a liquid inlet.

[0010] Preferably, a transfer pump is provided on the pipe connecting the mixer and the reactor.

[0011] Preferably, the mixer is provided with a solid feeder at the top.

[0012] Preferably, the reactor is provided with a gas inlet in the middle and lower part for conveying chloromethane gas.

[0013] Preferably, the lower outlet of the dynamic filter is connected to a sodium chloride storage tank.

[0014] Preferably, both the mixer and the reactor are equipped with a stirring device and an insulation jacket.

[0015] Preferably, the device also includes a distillation system, and the dynamic filter of the fourth-stage reaction unit and the distillation system are connected by pipelines.

[0016] In a further preferred embodiment, a transfer pump is provided on the pipeline connecting the dynamic filter and the distillation system of the fourth-stage reaction unit.

[0017] Further preferably, the first-stage reaction unit includes a first mixer, a first Williamson ether synthesis reactor, and a first dynamic filter connected in sequence via pipelines; the second-stage reaction unit includes a second mixer, a second Williamson ether synthesis reactor, and a second dynamic filter connected in sequence via pipelines; the third-stage reaction unit includes a third mixer, a third Williamson ether synthesis reactor, and a third dynamic filter connected in sequence via pipelines; the fourth-stage reaction unit includes a fourth mixer, a fourth Williamson ether synthesis reactor, and a fourth dynamic filter connected in sequence via pipelines; the fourth dynamic filter and the distillation system are connected via pipelines.

[0018] Preferably, in the first-stage reaction unit, the bottom outlet of the first mixer is connected to the top liquid inlet of the first Williamson ether synthesis reactor via a pipe, and the bottom outlet of the first Williamson ether synthesis reactor is connected to the upper inlet of the first dynamic filter via a pipe; in the second-stage reaction unit, the bottom outlet of the second mixer is connected to the top liquid inlet of the second Williamson ether synthesis reactor via a pipe, and the bottom outlet of the second Williamson ether synthesis reactor is connected to the upper inlet of the second dynamic filter via a pipe; in the third-stage reaction unit, The bottom outlet of the third mixer is connected to the top liquid inlet of the third Williamson ether synthesis reactor via a pipe, and the bottom outlet of the third Williamson ether synthesis reactor is connected to the top inlet of the third dynamic filter via a pipe. In the fourth stage reaction unit, the bottom outlet of the fourth mixer is connected to the top liquid inlet of the fourth Williamson ether synthesis reactor via a pipe, and the bottom outlet of the fourth Williamson ether synthesis reactor is connected to the top inlet of the fourth dynamic filter via a pipe. The distillation system is connected to the side wall liquid outlet of the fourth dynamic filter via a pipe.

[0019] More preferably, the side wall liquid outlet of the first dynamic filter of the first stage reaction unit is connected to the top liquid inlet of the second mixer of the second stage reaction unit via a pipe; the side wall liquid outlet of the second dynamic filter of the second stage reaction unit is connected to the top liquid inlet of the third mixer of the third stage reaction unit via a pipe; and the side wall liquid outlet of the third dynamic filter of the third stage reaction unit is connected to the top left liquid inlet of the fourth mixer of the fourth stage reaction unit via a pipe.

[0020] More preferably, a fifth transfer pump is also provided on the pipeline connecting the side wall feed outlet of the fourth dynamic filter to the distillation system.

[0021] Further preferably, a first transfer pump is provided on the pipe connecting the bottom outlet of the first mixer and the top liquid inlet of the first Williamson ether synthesis reactor; a second transfer pump is provided on the pipe connecting the bottom outlet of the second mixer and the top liquid inlet of the second Williamson ether synthesis reactor; a third transfer pump is provided on the pipe connecting the bottom outlet of the third mixer and the top liquid inlet of the third Williamson ether synthesis reactor; and a fourth transfer pump is provided on the pipe connecting the bottom outlet of the fourth mixer and the top liquid inlet of the fourth Williamson ether synthesis reactor.

[0022] Preferably, the top of the first mixer is provided with a liquid inlet and a solid feeder, the top of the second mixer is also provided with a solid feeder, the top of the third mixer is also provided with a solid feeder, and the top of the fourth mixer is also provided with a solid feeder. Sodium hydroxide is fed from the solid feeder, and monoether is fed from the liquid inlet at the top of the first mixer.

[0023] More preferably, the lower outlet of the first dynamic filter is connected to a first sodium chloride storage tank, the lower outlet of the second dynamic filter is connected to a second sodium chloride storage tank, the lower outlet of the third dynamic filter is connected to a third sodium chloride storage tank, and the lower outlet of the fourth dynamic filter is connected to a fourth sodium chloride storage tank, wherein the sodium chloride storage tank is used to store the filtered sodium chloride.

[0024] A method for continuous production of dual-terminated ethylene glycol ethers includes the following steps:

[0025] (1) In the first stage reaction unit, monoether and sodium hydroxide are continuously added to the mixer to react and obtain intermediate reaction liquid. Then, the intermediate reaction liquid and chloromethane are continuously fed into the reactor to react and obtain reaction liquid. The reaction liquid is filtered to obtain colorless liquid phase feed liquid.

[0026] (2) In the second stage reaction unit, sodium hydroxide and the colorless liquid phase material generated in step (1) are continuously added to the mixer to react and obtain intermediate reaction liquid. Then, the intermediate reaction liquid and chloromethane are continuously fed into the reactor to react and obtain reaction liquid. The reaction liquid is filtered to obtain colorless liquid phase material.

[0027] (3) In the third stage reaction unit, sodium hydroxide and the colorless liquid phase material generated in step (2) are continuously added to the mixer to react and obtain intermediate reaction liquid. Then, the intermediate reaction liquid and chloromethane are continuously fed into the reactor to react and obtain reaction liquid. The reaction liquid is filtered to obtain colorless liquid phase material.

[0028] (4) In the fourth stage reaction unit, sodium hydroxide and the colorless liquid phase material generated in step (3) are continuously added to the mixer to react and obtain intermediate reaction liquid. Then, the intermediate reaction liquid and chloromethane are continuously fed into the reactor to react and obtain reaction liquid. The reaction liquid is filtered to obtain colorless liquid phase material.

[0029] Preferably, step (1) specifically includes:

[0030] A single ether and sodium hydroxide are continuously introduced into the first mixer to obtain an intermediate reaction solution. The intermediate reaction solution is then introduced into the first Williamson ether synthesis reactor and mixed countercurrently with chloromethane introduced from the lower part of the first Williamson ether synthesis reactor to obtain a reaction solution. The reaction solution is then filtered to obtain a colorless liquid phase feed solution.

[0031] Step (2) is as follows:

[0032] The colorless liquid phase feed obtained in step (1) is fed into the second mixer, and sodium hydroxide is continuously fed in at the same time to obtain an intermediate reaction liquid. The intermediate reaction liquid is fed into the second Williamson ether synthesis reactor and mixed countercurrently with chloromethane fed from the middle and lower part of the second Williamson ether synthesis reactor to obtain a reaction liquid. The reaction liquid is filtered to obtain a colorless liquid phase feed.

[0033] Step (3) is as follows:

[0034] (3) The colorless liquid phase material obtained in step (2) is fed into the third mixer, and sodium hydroxide is continuously fed into it to obtain an intermediate reaction liquid. The intermediate reaction liquid is fed into the third Williamson ether synthesis reactor and mixed countercurrently with chloromethane fed into the middle and lower part of the third Williamson ether synthesis reactor to obtain a reaction liquid. The reaction liquid is filtered to obtain a colorless liquid phase material.

[0035] Step (4) is as follows:

[0036] (4) The colorless liquid phase obtained in step (3) is fed into the fourth mixer, and sodium hydroxide is continuously fed into it to obtain an intermediate reaction liquid. The intermediate reaction liquid is fed into the fourth Williamson ether synthesis reactor and mixed countercurrently with chloromethane fed into the lower part of the fourth Williamson ether synthesis reactor to obtain a reaction liquid. The reaction liquid is filtered to obtain a colorless liquid phase. The colorless liquid phase is distilled to obtain a double-terminated ethylene glycol ether.

[0037] Preferably, the monoether in step (1) is one or more of ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, and diethylene glycol monoethyl ether.

[0038] Preferably, the sodium hydroxide in step (1) is in the form of flakes or granules.

[0039] Preferably, the molar ratio of the monoether and sodium hydroxide in step (1) is 1:0.2~0.35.

[0040] Preferably, the rate at which sodium hydroxide is added in steps (1)-(4) is 25-65 g / min, the flow rate of the monoether introduced in step (1) is 450-550 g / min, the flow rate of the chloromethane introduced in steps (1)-(4) is 90-250 g / min, and the flow rate of the colorless liquid phase feed into the mixer in steps (2)-(4) is 525-635 g / min.

[0041] Preferably, the temperature of the mixer in step (1) is controlled at 5-10°C.

[0042] Preferably, the temperature of the reactor in step (1) is controlled at 80-180℃ and the reaction pressure is controlled at 3-5 bar.

[0043] Preferably, the total reaction time of the method is 100-140 minutes. Reaction time refers to the time from when the raw material enters the first-stage reaction unit after the system has stabilized, to when the reaction solution flows out of the fourth-stage reaction unit.

[0044] Compared with the prior art, the beneficial effects of this utility model are:

[0045] (1) The apparatus and method of this invention can be used to prepare double-terminated glycol ether compounds with high yield, few side reactions, high product purity, short reaction time and high production efficiency.

[0046] (2) By using a continuous process to prepare double-terminated ethylene glycol ether compounds, the continuous conversion from monoether to diether is achieved. The reaction time is short, which significantly improves production efficiency. It can achieve highly automatic control, reduce the labor intensity of operators, improve labor efficiency, and ensure stable product quality, achieving safe and environmentally friendly production. Compared with adding sodium hydroxide in more batches, adding it in 4 batches can improve the purity of the product and save resources. It does not require additional investment or land area, and the operation is simple with low equipment requirements. It has a high safety factor and is suitable for continuous large-scale production. Compared with adding sodium hydroxide in fewer batches, adding it in 4 batches will not cause a large accumulation of sodium ethylene glycol monomethyl ether and side reactions, resulting in a higher product yield.

[0047] (3) By adding sodium hydroxide to the reaction system in four separate steps, it can be ensured that the added alkali is reacted in time, preventing the large accumulation of sodium monomethyl ether and the resulting side reaction. It will not cause solid sedimentation and blockage of the pipeline. This utility model uses a dynamic filtration process to continuously and effectively remove sodium chloride solids from the system through a high-level difference or transfer pump, thereby reducing the solid content of the material in the mixer, facilitating the material transport, and allowing for full stirring during the reaction process. This ensures efficient production, reduces equipment wear, and yields high-quality ultrafine sodium chloride byproducts.

[0048] (4) Introducing chloromethane in four batches can improve product yield and purity: On the one hand, introducing chloromethane in batches can ensure that sodium monoether reacts completely with chloromethane, avoid side reactions caused by the long-term presence of sodium alkoxide generated, and effectively inhibit the hydrolysis of chloromethane, significantly reducing the generation of methanol byproducts; on the other hand, introducing chloromethane in batches can enhance the gas-liquid mass transfer effect, make the reaction more uniform, and avoid local overheating caused by introducing chloromethane all at once, resulting in thermal runaway, incomplete reaction or concentrated side reactions.

[0049] (5) Normally, sodium chloride is contaminated with a red color because sodium ethylene glycol monomethyl ether salt is prone to side reactions and the formation of byproducts. The present invention controls the temperature of the mixer to make sodium monomethyl ether more stable; by reacting the monomethyl ether, sodium hydroxide, and chloromethane in batches and setting up a dynamic filter, sodium chloride is effectively removed in a timely manner, reducing the solid content of the material in the mixer, increasing the contact area between sodium ethylene glycol and chloromethane, promoting the reaction, greatly increasing the reaction rate, and making the rate of dimethyl ether formation much greater than the rate of side reactions of sodium monomethyl ether salt, thus avoiding the staining phenomenon of sodium chloride; the present invention introduces chloromethane in batches to ensure that chloromethane reacts with the intermediate sodium ether to form the corresponding diether in a very fast time, reducing the occurrence of side reactions, effectively avoiding the coloring of the reaction liquid and byproduct sodium chloride, and greatly reducing the amount of decolorizing agent used.

[0050] (6) This invention uses a batch reaction of monoether, sodium hydroxide and chloromethane, and sets up a dynamic filter to effectively remove sodium chloride in a timely manner. It also solves the technical problem of long reaction time in the preparation of double-terminated ethylene glycol ether in the prior art and improves the reaction rate. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the structure of the device of this utility model.

[0052] The reference numerals in the attached figures are as follows: 1. First solids feeder; 2. First mixer; 3. First transfer pump; 4. First Williamson ether synthesis reactor; 5. First dynamic filter; 6. First sodium chloride storage tank; 7. Second solids feeder; 8. Second mixer; 9. Second transfer pump; 10. Second Williamson ether synthesis reactor; 11. Second dynamic filter; 12. Second sodium chloride storage tank; 13. Third solids feeder; 14. Third mixer; 15. Third transfer pump; 16. Third Williamson ether synthesis reactor; 17. Third dynamic filter; 18. Third sodium chloride storage tank; 19. Fourth solids feeder; 20. Fourth mixer; 21. Fourth transfer pump; 22. Fourth Williamson ether synthesis reactor; 23. Fourth dynamic filter; 24. Fourth sodium chloride storage tank; 25. Fifth transfer pump. Detailed Implementation

[0053] The preferred embodiments of the present invention will be described below. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0054] The raw materials used in this embodiment of the utility model are all commercially available products.

[0055] The yield in the examples is molar yield.

[0056] The first Williamson ether synthesis reactor 4, the second Williamson ether synthesis reactor 10, the third Williamson ether synthesis reactor 16, and the fourth Williamson ether synthesis reactor 22 of this utility model are self-named and are all ordinary reactors.

[0057] In each embodiment, the amount of sodium hydroxide fed into the first, second, third, and fourth mixers is 25% of the total amount. The molar ratio of the amount of sodium hydroxide fed into each mixer to the amount of monochloromethane fed into each Williamson ether synthesis reactor is 1:3. The total molar ratio of monoether, sodium hydroxide, and monochloromethane is 1:1:3.

[0058] Example 1

[0059] An apparatus for the continuous production of dual-terminated glycol ethers, such as Figure 1 As shown, the system includes a four-stage reaction unit and a distillation system connected by pipelines. The four-stage reaction unit includes a first-stage reaction unit, a second-stage reaction unit, a third-stage reaction unit, and a fourth-stage reaction unit connected in sequence by pipelines. The first-stage reaction unit includes a first mixer 2, a first Williamson ether synthesis reactor 4, and a first dynamic filter 5 connected in sequence by pipelines. The second-stage reaction unit includes a second mixer 8, a second Williamson ether synthesis reactor 10, and a second dynamic filter 11 connected in sequence by pipelines. The third-stage reaction unit includes a third mixer 14, a third Williamson ether synthesis reactor 16, and a third dynamic filter 17 connected in sequence by pipelines. The fourth-stage reaction unit includes a fourth mixer 20, a fourth Williamson ether synthesis reactor 22, and a fourth dynamic filter 23 connected in sequence by pipelines. The fourth dynamic filter 23 and the distillation system are connected by pipelines.

[0060] Specifically, in the first-stage reaction unit, the bottom outlet of the first mixer 2 is connected to the top liquid inlet of the first Williamson ether synthesis reactor 4 via a pipe, and a first transfer pump 3 is installed on the pipe. The bottom outlet of the first Williamson ether synthesis reactor 4 is connected to the upper inlet of the first dynamic filter 5 via a pipe. In the second-stage reaction unit, the bottom outlet of the second mixer 8 is connected to the top liquid inlet of the second Williamson ether synthesis reactor 10 via a pipe, and a second transfer pump 9 is installed on the pipe. The bottom outlet of the second Williamson ether synthesis reactor 10 is connected to the upper inlet of the second dynamic filter 11 via a pipe. In the third-stage reaction unit, the bottom outlet of the third mixer 14... The feed inlet is connected to the top liquid inlet of the third Williamson ether synthesis reactor 16 via a pipeline, and a third transfer pump 15 is installed on the pipeline. The bottom outlet of the third Williamson ether synthesis reactor 16 is connected to the upper inlet of the third dynamic filter 17 via a pipeline. In the fourth stage reaction unit, the bottom outlet of the fourth mixer 20 is connected to the top liquid inlet of the fourth Williamson ether synthesis reactor 22 via a pipeline, and a fourth transfer pump 21 is installed on the pipeline. The bottom outlet of the fourth Williamson ether synthesis reactor 22 is connected to the upper inlet of the fourth dynamic filter 23 via a pipeline. The distillation system is connected to the side wall liquid outlet of the fourth dynamic filter 23 via a pipeline, and a fifth transfer pump 25 is installed on the pipeline.

[0061] Specifically, the side wall liquid outlet of the first dynamic filter 5 of the first stage reaction unit is connected to the top liquid inlet of the second mixer 8 of the second stage reaction unit via a pipe; the side wall liquid outlet of the second dynamic filter 11 of the second stage reaction unit is connected to the top liquid inlet of the third mixer 14 of the third stage reaction unit via a pipe; and the side wall liquid outlet of the third dynamic filter 17 of the third stage reaction unit is connected to the top left liquid inlet of the fourth mixer 20 of the fourth stage reaction unit via a pipe.

[0062] Specifically, the top of the first mixer 2 is provided with a liquid inlet and a solid feeder 1, the top of the second mixer 8 is also provided with a solid feeder 7, the top of the third mixer 14 is also provided with a solid feeder 13, and the top of the fourth mixer 20 is also provided with a solid feeder 19. Sodium hydroxide is fed from the solid feeder, and monoether is fed from the liquid inlet at the top of the first mixer 2.

[0063] Specifically, the lower middle part of the first Williamson ether synthesis reactor 4, the second Williamson ether synthesis reactor 10, the third Williamson ether synthesis reactor 16, and the fourth Williamson ether synthesis reactor 22 are all provided with gas inlets for conveying monochloromethane gas.

[0064] Specifically, the device also includes a first sodium chloride storage tank 6 connected to the lower outlet of the first dynamic filter 5, a second sodium chloride storage tank 12 connected to the lower outlet of the second dynamic filter 11, a third sodium chloride storage tank 18 connected to the lower outlet of the third dynamic filter 17, and a fourth sodium chloride storage tank 24 connected to the lower outlet of the fourth dynamic filter 23. The sodium chloride storage tanks are used to store the filtered sodium chloride.

[0065] Specifically, the first mixer 2, the second mixer 8, the third mixer 14, and the fourth mixer 20 are all equipped with stirring devices and heat insulation jackets.

[0066] Specifically, the first Williamson ether synthesis reactor 4, the second Williamson ether synthesis reactor 10, the third Williamson ether synthesis reactor 16, and the fourth Williamson ether synthesis reactor are all equipped with a stirring device and a heat insulation jacket.

[0067] Example 2

[0068] A method for the continuous production of ethylene glycol dimethyl ether includes the following steps:

[0069] (1) The first mixer 2 is cooled to 5°C and ethylene glycol monomethyl ether is introduced at a flow rate of 482.5 g / min. At the same time, sodium hydroxide is fed from the solid feeder 1 at a rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the first Williamson ether synthesis reactor 4 through the first transfer pump 3 at a flow rate of 545.9 g / min. In the first Williamson ether synthesis reactor 4, monochloromethane gas is introduced from the lower part of the reactor at a flow rate of 240.1 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 80°C and the reaction pressure is 3 bar. After 10 min, the reaction liquid is transferred into the first dynamic filter 5 through the differential pressure and the by-product white sodium chloride solid is separated at a rate of 95.1 g / min. Then it is transferred to the first sodium chloride storage tank 6 for collection. The colorless liquid phase flows into the second mixer 8 at a flow rate of 530.8 g / min.

[0070] (2) The temperature of the second mixer 8 is 5℃. The colorless liquid phase generated in step (1) flows into the second mixer 8 at a flow rate of 530.8 g / min. At the same time, sodium hydroxide is fed from the solid feeder 7 at a flow rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the second Williamson ether synthesis reactor 10 through the second transfer pump 9 at a flow rate of 594.2 g / min. In the second Williamson ether synthesis reactor 10, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 240.1 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 80℃ and the reaction pressure is 3 bar. After 10 min, the reaction liquid is transferred into the second dynamic filter 11 through the differential pressure. The by-product white sodium chloride solid is separated at a flow rate of 95.1 g / min and then transferred to the second sodium chloride storage tank 12 for collection. The colorless liquid phase flows into the third mixer 14 at a flow rate of 579.1 g / min.

[0071] (3) The temperature of the third mixer 14 is 5°C. The colorless liquid phase generated in step (2) flows into the third mixer 14 at a flow rate of 579.1 g / min. At the same time, sodium hydroxide is fed from the solid feeder 13 at a flow rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the third Williamson ether synthesis reactor 16 through the third transfer pump 15 at a flow rate of 642.5 g / min. In the third Williamson ether synthesis reactor 16, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 240.1 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 80°C and the reaction pressure is 3 bar. After 10 min, the reaction liquid is transferred into the third dynamic filter 17 through the differential pressure. The by-product white sodium chloride solid is separated at a flow rate of 95.1 g / min and then transferred to the third sodium chloride storage tank 18 for collection. The colorless liquid phase flows into the fourth mixer 20 at a flow rate of 627.4 g / min.

[0072] (4) The temperature of the fourth mixer 20 is 5°C. The colorless liquid phase generated in step (3) flows into the fourth mixer 20 at a flow rate of 627.4 g / min. At the same time, sodium hydroxide is fed from the solid feeder 19 at a rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the fourth Williamson ether synthesis reactor 22 through the fourth transfer pump 21 at a flow rate of 690.8 g / min. In the fourth Williamson ether synthesis reactor 22, chloromethane gas was introduced from the lower part of the reactor at a flow rate of 240.1 g / min, and mixed countercurrently with the intermediate reaction liquid. The reaction temperature was controlled at 80℃ and the reaction pressure at 3 bar. After 10 min, the reaction liquid began to enter the fourth dynamic filter 23 via differential transfer, where the by-product white sodium chloride solid was separated at a rate of 95.1 g / min. It was then transferred to the fourth sodium chloride storage tank 24 for collection. The colorless liquid phase was fed into the distillation process via the fifth transfer pump 25 at a flow rate of 671.7 g / min. GC analysis showed that the purity of the target product, ethylene glycol dimethyl ether, was 99.6%. The yield of the target product was 97.5%.

[0073] Example 3

[0074] (1) The first mixer 2 is cooled to 5°C and diethylene glycol monomethyl ether is introduced at a flow rate of 511.5 g / min. At the same time, sodium hydroxide is fed from the solid feeder 1 at a rate of 42.6 g / min. After 10 min, the intermediate reaction liquid is transported to the first Williamson ether synthesis reactor 4 through the first transfer pump 3 at a flow rate of 554.1 g / min. In the first Williamson ether synthesis reactor 4, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 161.2 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 130°C and the reaction pressure is 3.5 bar. After 10 min, the reaction liquid is transferred into the first dynamic filter 5 through the differential pressure and separated into by-product white sodium chloride solid at a rate of 65.2 g / min. Then it is transferred to the first sodium chloride storage tank 6 for collection. The colorless liquid phase flows into the second mixer 8 at a flow rate of 540.5 g / min.

[0075] (2) The temperature of the second mixer 8 is 5℃. The colorless liquid phase generated in step (1) flows into the second mixer 8 at a flow rate of 540.5 g / min. At the same time, sodium hydroxide is fed from the solid feeder 7 at a flow rate of 42.6 g / min. After 10 min, the intermediate reaction liquid is transported to the second Williamson ether synthesis reactor 10 through the second transfer pump 9 at a flow rate of 583.1 g / min. In the second Williamson ether synthesis reactor 10, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 161.2 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 130℃ and the reaction pressure is 3.5 bar. After 10 min, the reaction liquid is transferred into the second dynamic filter 11 through the differential pressure. The by-product white sodium chloride solid is separated at a flow rate of 65.2 g / min and then transferred to the second sodium chloride storage tank 12 for collection. The colorless liquid phase flows into the third mixer 14 at a flow rate of 562 g / min.

[0076] (3) The rest is the same as step (2), except that: the colorless liquid phase generated in step (2) flows into the third mixer 14 at a flow rate of 562 g / min; the intermediate reaction liquid is initially transported to the third Williamson ether synthesis reactor 16 by the third transfer pump 15 at a flow rate of 604.6 g / min; the colorless liquid phase after being filtered by the third dynamic filter 11 flows into the fourth mixer at a flow rate of 603.8 g / min.

[0077] (4) The rest is the same as step (3), except that: the colorless liquid phase generated in step (3) flows into the fourth mixer at a flow rate of 603.8 g / min; the intermediate reaction liquid is initially transported to the fourth Williamson ether synthesis reactor 22 by the fourth transfer pump 21 at a flow rate of 646.4 g / min; the liquid phase after filtration by the fourth dynamic filter 23 enters the distillation process by the fifth transfer pump 25 at a flow rate of 631.8 g / min, and the purity of the target product diethylene glycol dimethyl ether is 99.3% as determined by GC. The yield of the target product is 96.7%.

[0078] Example 4

[0079] (1) The first mixer 2 is cooled to 5°C and triethylene glycol monomethyl ether is introduced at a flow rate of 513.0 g / min. At the same time, sodium hydroxide is fed from the solid feeder 1 at a rate of 31.2 g / min. After 10 min, the intermediate reaction liquid is transported to the first Williamson ether synthesis reactor 4 through the first transfer pump 3 at a flow rate of 544.2 g / min. In the first Williamson ether synthesis reactor 4, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 118.3 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 130°C and the reaction pressure is 3.5 bar. After 10 min, the reaction liquid is transferred into the first dynamic filter 5 through the differential pressure. The by-product white sodium chloride solid is separated at a rate of 48.6 g / min and then transferred to the first sodium chloride storage tank 6 for collection. The colorless liquid phase flows into the second mixer at a flow rate of 535.7 g / min.

[0080] (2) The second mixer 8 is cooled to 5°C and the colorless liquid phase generated in step (1) is introduced at a flow rate of 535.7 g / min. At the same time, sodium hydroxide is fed from the solid feeder 7 at a rate of 31.2 g / min. After 10 min, the intermediate reaction liquid is transported to the second Williamson ether synthesis reactor through the second transfer pump at a flow rate of 566.9 g / min. In the second Williamson ether synthesis reactor, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 118.3 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 130°C and the reaction pressure is 3.5 bar. After 10 min, the reaction liquid is transferred through the differential transfer into the second dynamic filter 11, where the by-product white sodium chloride solid is separated at a rate of 48.6 g / min. Then it is transferred to the second sodium chloride storage tank 12 for collection. The colorless liquid phase flows into the third mixer at a flow rate of 560.4 g / min.

[0081] (3) The rest is the same as step (2), except that: the colorless liquid phase feed liquid generated in step (2) is introduced at a flow rate of 560.4 g / min; the intermediate reaction liquid is initially transported to the third Williamson ether synthesis reactor 16 by the third transfer pump 15 at a flow rate of 591.6 g / min; the colorless liquid phase feed liquid filtered by the third dynamic filter 11 flows into the fourth mixer at a flow rate of 582.9 g / min;

[0082] (4) The rest is the same as step (3), except that: the colorless liquid phase feed generated in step (3) is introduced at a flow rate of 582.9 g / min; the intermediate reaction liquid is initially transported to the fourth Williamson ether synthesis reactor 22 by the fourth transfer pump 21 at a flow rate of 614.1 g / min; the liquid phase feed after filtration by the fourth dynamic filter 23 enters the distillation process by the fifth transfer pump 25 at a flow rate of 599.2 g / min, and the purity of the target product triethylene glycol dimethyl ether is 99.2% as determined by GC. The yield of the target product is 96.5%.

[0083] Example 5

[0084] (1) The first mixer 2 is cooled to 5°C and tetraethylene glycol monomethyl ether is introduced at a flow rate of 522.5 g / min. At the same time, sodium hydroxide is fed from the solid feeder 1 at a rate of 25.1 g / min. After 10 min, the intermediate reaction liquid is transported to the first Williamson ether synthesis reactor 4 through the first transfer pump 3 at a flow rate of 547.6 g / min. In the first Williamson ether synthesis reactor 4, monochloromethane gas is introduced from the lower part of the reactor at a flow rate of 95.0 g / min and begins to mix countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 150°C and the reaction pressure is 4 bar. After 10 min, the reaction liquid begins to enter the first dynamic filter 5 through the differential transfer and the by-product white sodium chloride solid is separated at a rate of 38.7 g / min. Then it is transferred to the first sodium chloride storage tank 6 for collection. The colorless liquid phase flows into the second mixer at a flow rate of 537.1 g / min.

[0085] (2) The second mixer 8 is cooled to 5°C and the colorless liquid phase generated in step (1) is introduced at a flow rate of 537.1 g / min. At the same time, sodium hydroxide is fed from the solid feeder 7 at a rate of 25.1 g / min. After 10 min, the intermediate reaction liquid is transported to the second Williamson ether synthesis reactor 10 through the second transfer pump 9 at a flow rate of 562.2 g / min. In the second Williamson ether synthesis reactor 10, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 95.0 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 150°C and the reaction pressure is 4 bar. After 10 min, the reaction liquid is transferred into the second dynamic filter 11 through the differential pressure and the by-product white sodium chloride solid is separated at a rate of 38.7 g / min. Then it is transferred to the second sodium chloride storage tank 12 for collection. The colorless liquid phase flows into the third mixer 14 at a flow rate of 557.9 g / min.

[0086] (3) The rest is the same as step (2), except that: the colorless liquid phase generated in step (2) flows into the third mixer 14 at a flow rate of 557.9 g / min; the intermediate reaction liquid is initially transported to the third Williamson ether synthesis reactor 16 by the third transfer pump 15 at a flow rate of 583 g / min; the colorless liquid phase after being filtered by the third dynamic filter 11 flows into the fourth mixer at a flow rate of 576.4 g / min.

[0087] (4) The rest is the same as step (3), except that: the colorless liquid phase generated in step (3) flows into the fourth mixer at a flow rate of 576.4 g / min; the intermediate reaction liquid is initially transported to the fourth Williamson ether synthesis reactor 22 by the fourth transfer pump 21 at a flow rate of 601.5 g / min; the liquid phase after filtration by the fourth dynamic filter 23 enters the distillation process by the fifth transfer pump 25 at a flow rate of 582.9 g / min, and the purity of the target product tetraethylene glycol dimethyl ether is 99.0% as determined by GC. The yield of the target product is 95.7%.

[0088] Example 6

[0089] (1) The first mixer 2 is cooled to 10°C and diethylene glycol monoethyl ether is introduced at a flow rate of 499.5 g / min. At the same time, sodium hydroxide is fed from the solid feeder 1 at a rate of 37.2 g / min. After 10 min, the intermediate reaction liquid is transported to the first Williamson ether synthesis reactor 4 through the first transfer pump 3 at a flow rate of 536.7 g / min. In the first Williamson ether synthesis reactor 4, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 141.0 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 180°C and the reaction pressure is 5 bar. After 10 min, the reaction liquid is transferred to the first dynamic filter 5 through the differential pressure and separated into white sodium chloride solid by-product at a rate of 57.4 g / min. Then it is transferred to the sodium chloride storage tank 6 for collection. The colorless liquid phase flows into the second mixer 8 at a flow rate of 528 g / min.

[0090] (2) The second mixer 8 is cooled to 10°C and the colorless liquid phase generated in step (1) is introduced at a flow rate of 528 g / min. At the same time, sodium hydroxide is fed from the solid feeder 7 at a rate of 37.2 g / min. After 10 min, the intermediate reaction liquid is transported to the second Williamson ether synthesis reactor 10 through the second transfer pump 9 at a flow rate of 565.2 g / min. In the second Williamson ether synthesis reactor 10, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 141.0 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 180°C and the reaction pressure is 5 bar. After 10 min, the reaction liquid is transferred to the second dynamic filter 11 through the differential pressure and the by-product white sodium chloride solid is separated at a rate of 57.4 g / min. Then it is transferred to the sodium chloride storage tank 12 for collection. The colorless liquid phase flows into the third mixer 14 at a flow rate of 555.9 g / min.

[0091] (3) The rest is the same as step (2), except that: the colorless liquid phase feed liquid generated in step (2) is introduced at a flow rate of 555.9 g / min; the intermediate reaction liquid is initially transported to the third Williamson ether synthesis reactor 16 by the third transfer pump 15 at a flow rate of 593.1 g / min; the colorless liquid phase feed liquid filtered by the third dynamic filter 11 flows into the fourth mixer at a flow rate of 583.7 g / min;

[0092] (4) The rest is the same as step (3), except that: the colorless liquid phase feed generated in step (3) is introduced at a flow rate of 583.7 g / min; the intermediate reaction liquid is initially transported to the fourth Williamson ether synthesis reactor 22 by the fourth transfer pump 21 at a flow rate of 620.9 g / min; the liquid phase feed after filtration by the fourth dynamic filter 23 enters the distillation process by the fifth transfer pump 25 at a flow rate of 608.8 g / min, and the purity of the target product diethylene glycol methyl ether is 99.0% as determined by GC. The yield of the target product is 96.1%.

[0093] Comparative Example 1: A detailed description using ethylene glycol dimethyl ether as an example

[0094] A traditional batch reactor two-step method was employed. The first step involved the sodium ether reaction: 482.5 g of ethylene glycol monomethyl ether was added to the reactor and heated to 65°C. NaOH was added in four batches, each batch representing 25% of the total ethylene glycol monomethyl ether. The mixture was stirred for 3 hours, until the reaction system turned a viscous reddish-brown color. The second step was methylation: chloromethane gas was introduced into the reaction system, maintaining a temperature of 65°C and a pressure of 3 bar. Samples were taken every 30 minutes, and the reaction was considered complete when the NaOH concentration in the reaction solution was <0.05 mol / L. The total reaction time was 9 hours.

[0095] After the reaction, a large amount of sodium chloride crystals were found in the system, and the reaction solution was reddish-brown. The resulting reaction solution was filtered, and the filter cake was a reddish-brown byproduct of sodium chloride. The filtrate was post-treated and distilled to obtain 457.7 g of ethylene glycol dimethyl ether. The yield of the target product was 80.1%, and the purity was 99%.

[0096] Comparative Example 2: A detailed description using ethylene glycol dimethyl ether as an example

[0097] A batch-type one-step process was used. 482.5 g of ethylene glycol monomethyl ether was added to the reactor, heated to 65°C, and chloromethane gas was introduced while maintaining a pressure of 3 bar. NaOH was added in four batches, each batch comprising 25% of the total ethylene glycol monomethyl ether. After the first batch of NaOH was added, samples were taken every 30 minutes. The next batch of NaOH was added only when the NaOH concentration in the reaction solution was found to be <0.05 mol / L. The total reaction time was 7 hours.

[0098] After the reaction was completed, a large amount of sodium chloride crystals were present in the system, and the reaction solution was yellow. The resulting reaction solution was filtered, and the filter cake was a yellow byproduct of sodium chloride. The filtrate was then distilled to obtain 497.4 g of ethylene glycol dimethyl ether, with a target product yield of 87.1%.

[0099] Comparative Example 3

[0100] A method for the continuous production of ethylene glycol dimethyl ether includes the following steps:

[0101] (1) The first mixer 2 is cooled to 0°C and ethylene glycol monomethyl ether is introduced at a flow rate of 482.5 g / min. At the same time, sodium hydroxide is fed from the solid feeder 1 at a rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the first Williamson ether synthesis reactor 4 through the first transfer pump 3 at a flow rate of 545.9 g / min. In the first Williamson ether synthesis reactor 4, monochloromethane gas is introduced from the lower part of the reactor at a flow rate of 240.1 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 80°C and the reaction pressure is 3 bar. After 10 min, the reaction liquid is transferred into the first dynamic filter 5 through the differential pressure and separated into by-product white sodium chloride solid at a rate of 89.5 g / min. Then it is transferred to the first sodium chloride storage tank 6 for collection. The colorless liquid phase flows into the second mixer 8 at a flow rate of 524.8 g / min.

[0102] (2) The temperature of the second mixer 8 is 0℃. The colorless liquid phase generated in step (1) flows into the second mixer 8 at a flow rate of 524.8 g / min. At the same time, sodium hydroxide is fed from the solid feeder 7 at a flow rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the second Williamson ether synthesis reactor 10 through the second transfer pump 9 at a flow rate of 588.2 g / min. In the second Williamson ether synthesis reactor 10, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 240.1 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 80℃ and the reaction pressure is 3 bar. After 10 min, the reaction liquid is transferred into the second dynamic filter 11 through the differential pressure. The by-product white sodium chloride solid is separated at a flow rate of 89.5 g / min and then transferred to the second sodium chloride storage tank 12 for collection. The colorless liquid phase flows into the third mixer 14 at a flow rate of 573.4 g / min.

[0103] (3) The rest is the same as step (2), except that: the colorless liquid phase generated in step (2) flows into the third mixer 14 at a flow rate of 573.4 g / min; the intermediate reaction liquid is initially transported to the third Williamson ether synthesis reactor 16 by the third transfer pump 15 at a flow rate of 636.8 g / min; the colorless liquid phase after being filtered by the third dynamic filter 11 flows into the fourth mixer at a flow rate of 620.7 g / min.

[0104] (4) The rest is the same as step (3), except that: the colorless liquid phase generated in step (3) flows into the fourth mixer at a flow rate of 620.7 g / min; the intermediate reaction liquid is initially transported to the fourth Williamson ether synthesis reactor 22 by the fourth transfer pump 21 at a flow rate of 684.1 g / min, and the liquid phase enters the distillation process at a flow rate of 652.2 g / min. The purity of the target product ethylene glycol dimethyl ether is 99.7% and the yield of the target product is 89.7% as determined by GC.

[0105] If the mixer temperature is too low, the sodium hydroxide reaction will be incomplete within the same residence time, which will lead to a decrease in the yield and production efficiency of ethylene glycol dimethyl ether.

[0106] Comparative Example 4

[0107] A method for the continuous production of ethylene glycol dimethyl ether includes the following steps:

[0108] (1) The first mixer 2 is cooled to 15°C and ethylene glycol monomethyl ether is introduced at a flow rate of 482.5 g / min. At the same time, sodium hydroxide is fed from the solid feeder 1 at a rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the first Williamson ether synthesis reactor 4 through the first transfer pump 3 at a flow rate of 545.9 g / min. In the first Williamson ether synthesis reactor 4, monochloromethane gas is introduced from the lower part of the reactor at a flow rate of 240.1 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 80°C and the reaction pressure is 3 bar. After 10 min, the reaction liquid is transferred into the first dynamic filter 5 through the differential pressure and separated into yellow sodium chloride solid by-product at a rate of 97.8 g / min. Then it is transferred to the first sodium chloride storage tank 6 for collection. The pale yellow liquid phase flows into the second mixer 8 at a flow rate of 525.1 g / min.

[0109] (2) The temperature of the second mixer 8 is 15℃. The pale yellow liquid phase generated in step (1) flows into the second mixer 8 at a flow rate of 525.1 g / min. At the same time, sodium hydroxide is fed from the solid feeder 7 at a flow rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the second Williamson ether synthesis reactor 10 through the second transfer pump 9 at a flow rate of 588.5 g / min. In the second Williamson ether synthesis reactor 10, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 240.1 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 80℃ and the reaction pressure is 3 bar. After 10 min, the reaction liquid is transferred into the second dynamic filter 11 through the differential pressure. The by-product yellow sodium chloride solid is separated at a flow rate of 97.8 g / min and then transferred to the second sodium chloride storage tank 12 for collection. The pale yellow liquid phase flows into the third mixer 14 at a flow rate of 575.1 g / min.

[0110] (3) The rest is the same as step (2), except that: the pale yellow liquid phase generated in step (2) flows into the third mixer 14 at a flow rate of 575.1 g / min; the intermediate reaction liquid is initially transported to the third Williamson ether synthesis reactor 16 by the third transfer pump 15 at a flow rate of 638.5 g / min; the pale yellow liquid phase after being filtered by the third dynamic filter 11 flows into the fourth mixer at a flow rate of 624.2 g / min;

[0111] (4) The rest is the same as step (3), except that: the pale yellow liquid phase generated in step (3) flows into the fourth mixer at a flow rate of 624.2 g / min; the intermediate reaction liquid is initially transported to the fourth Williamson ether synthesis reactor 22 by the fourth feed pump 21 at a flow rate of 687.6 g / min, and the liquid phase enters the distillation process at a flow rate of 656.1 g / min. The purity of the target product ethylene glycol dimethyl ether is 99.4% and the yield of the target product is 91.7% as determined by GC.

[0112] The liquid after the first mixer was slightly yellow, and the liquid after the first reactor was pale yellow. Due to the yellowing, it is presumed that sodium ethylene glycol monomethyl ether has undergone a side reaction.

[0113] Comparative Example 5

[0114] A method for the continuous production of ethylene glycol dimethyl ether includes the following steps:

[0115] (1) The first mixer 2 is cooled to 5°C and ethylene glycol monomethyl ether is introduced at a flow rate of 482.5 g / min. At the same time, sodium hydroxide is fed from the solid feeder 1 at a rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the first Williamson ether synthesis reactor 4 through the first transfer pump 3 at a flow rate of 545.9 g / min. In the first Williamson ether synthesis reactor 4, monochloromethane gas is introduced from the lower part of the reactor at a flow rate of 240.1 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 70°C and the reaction pressure is 3 bar. After 10 min, the reaction liquid is transferred into the first dynamic filter 5 through the differential pressure and separated into by-product white sodium chloride solid at a rate of 96.2 g / min. Then it is transferred to the first sodium chloride storage tank 6 for collection. The colorless liquid phase flows into the second mixer 8 at a flow rate of 528.8 g / min.

[0116] (2) The temperature of the second mixer 8 is 5℃. The colorless liquid phase generated in step (1) flows into the second mixer 8 at a flow rate of 528.8 g / min. At the same time, sodium hydroxide is fed from the solid feeder 7 at a flow rate of 63.4 g / min. After 10 min, the intermediate reaction liquid is transported to the second Williamson ether synthesis reactor 10 through the second transfer pump 9 at a flow rate of 592.2 g / min. In the second Williamson ether synthesis reactor 10, chloromethane gas is introduced from the lower part of the reactor at a flow rate of 240.1 g / min and mixed countercurrently with the intermediate reaction liquid. The reaction temperature is controlled at 70℃ and the reaction pressure is 3 bar. After 10 min, the reaction liquid is transferred into the second dynamic filter 11 through the differential pressure. The by-product white sodium chloride solid is separated at a flow rate of 96.2 g / min and then transferred to the second sodium chloride storage tank 12 for collection. The colorless liquid phase flows into the third mixer 14 at a flow rate of 578.4 g / min.

[0117] (3) The rest is the same as step (2), except that: the colorless liquid phase generated in step (2) flows into the third mixer 14 at a flow rate of 578.4 g / min; the intermediate reaction liquid is initially transported to the third Williamson ether synthesis reactor 16 by the third transfer pump 15 at a flow rate of 641.8 g / min; the colorless liquid phase after being filtered by the third dynamic filter 11 flows into the fourth mixer at a flow rate of 625.9 g / min.

[0118] (4) The rest is the same as step (3), except that: the colorless liquid phase generated in step (3) flows into the fourth mixer at a flow rate of 625.9 g / min; the intermediate reaction liquid is initially transported to the fourth Williamson ether synthesis reactor 22 by the fourth transfer pump 21 at a flow rate of 689.3 g / min, and the liquid phase enters the distillation process at a flow rate of 662.7 g / min. The purity of the target product ethylene glycol dimethyl ether is 99.6% and the yield of the target product is 92.2% as determined by GC.

[0119] If the reactor temperature is too low, the reaction of sodium ethylene glycol monomethyl ether will be incomplete within the same residence time, which will lead to a decrease in the yield and production efficiency of ethylene glycol dimethyl ether.

[0120] Table 1

[0121]

[0122] The reaction time described in Table 1 above is the time taken from when the raw material enters the first-stage reaction unit to when the reaction liquid flows out of the fourth-stage reaction unit after the system has been stably extracted.

[0123] The yields, reaction solution colors, byproduct sodium chloride colors, and reaction times of the dual-terminated ethylene glycol ethers obtained by the methods described in Examples 2-6 and Comparative Examples 1-5 are shown in Table 1.

[0124] As can be seen from Examples 2-6 in Table 1, the preparation method of this invention for preparing double-terminated ethylene glycol ether compounds has the advantages of continuous production, high efficiency, few side reactions, and high product yield. The by-products are all high-quality sodium chloride.

[0125] A comparison of Comparative Examples 1-2 with Example 2 shows that both the traditional batch two-step process and the batch one-step process produce a large amount of byproducts other than sodium chloride, such as methanol, which causes the reaction solution and sodium chloride to be colored. Furthermore, as the amount of sodium hydroxide added increases, the solid content of the system increases, making subsequent stirring difficult, reducing the reaction rate, and significantly affecting the product yield.

Claims

1. An apparatus for the continuous production of dual-terminated glycol ethers, characterized in that, The device includes a four-stage reaction unit, which consists of a first-stage reaction unit, a second-stage reaction unit, a third-stage reaction unit, and a fourth-stage reaction unit connected in sequence. Each stage of the reaction unit consists of a mixer, a reactor, and a dynamic filter connected in sequence through pipelines. The dynamic filter of the previous stage reaction unit is connected to the mixer of the next stage reaction unit. The mixer of the first stage reaction unit is provided with a liquid inlet.

2. The apparatus according to claim 1, characterized in that, A transfer pump is installed on the pipeline connecting the mixer and the reactor.

3. The apparatus according to claim 1, characterized in that, The mixer is equipped with a solid feeder at its top.

4. The apparatus according to claim 2, characterized in that, The reactor is equipped with gas inlets in the lower middle part.

5. The apparatus according to claim 1, characterized in that, The lower outlet of the dynamic filter is connected to a sodium chloride storage tank.

6. The apparatus according to claim 1, characterized in that, The device is also equipped with a distillation system, and the dynamic filter and distillation system of the fourth-stage reaction unit are connected by pipelines.

7. The apparatus according to claim 6, characterized in that, A transfer pump is installed on the pipeline connecting the dynamic filter and the distillation system of the fourth-stage reaction unit.

8. The apparatus according to claim 1, characterized in that, Both the mixer and the reactor are equipped with stirring devices and thermal insulation jackets.

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