A process for the continuous production of difluoromethyl-2,2,2-trifluoroethyl ether

Abstract

This invention discloses a continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether, belonging to the field of chemical production technology. During the start-up phase, trifluoroethanol and an aqueous solution of sodium hydroxide are added to a stirred tank reactor. A stainless steel diaphragm pump is started, and the temperature and pressure are controlled. Difluorochloromethane is dispersed into microbubbles via a gas distributor and introduced into the reaction solution to initiate the reaction. During the continuous and stable operation phase, trifluoroethanol and solid sodium hydroxide are continuously added to maintain the concentration of the reaction solution. The product is collected in a packed distillation column, the bottom liquid is returned to the solid sodium hydroxide container, and the circulating liquid is desalted by a three-in-one filter, and after settling polymer and dehydration by a PTFE organic membrane in a buffer tank, it is returned to the reaction system. The packing material is Hastelloy corrugated packing or fluorosilane modified packing. Compared with existing technologies, this invention achieves high conversion rate of trifluoroethanol, high utilization rate of sodium hydroxide, and near-complete reaction of difluorochloromethane, and the equipment can operate stably for a long period.

Description

Technical Field

[0001] This invention relates to the field of chemical production technology, and in particular to a process for the continuous production of difluoromethyl-2,2,2-trifluoroethyl ether. Background Technology

[0002] Difluoromethyl-2,2,2-trifluoroethyl ether (FE) is a key pharmaceutical intermediate for the production of the anesthetics isoflurane and desflurane. Currently, it is mainly produced industrially by reacting trifluoroethanol with difluorochloromethane under alkaline conditions. Existing synthesis processes are mostly batch reactors, which suffer from problems such as low raw material conversion rate, large consumption of alkali solution, incomplete reaction of fluorinated reagents, and difficulty in recovery, making it difficult to meet the requirements of continuous and stable industrial production.

[0003] Existing technologies have reported methods for the synthesis of fluorinated ether compounds. Chinese Patent Publication No. CN121698728A discloses a continuous synthesis and purification method for tetrafluoroethyl trifluoroethyl ether. This method uses an addition reaction in a reactor, requiring the reaction liquid to be discharged for initial distillation and rectification. This method suffers from drawbacks such as cumbersome reaction and separation steps and limited solvent and catalyst recycling. Chinese Patent Publication No. CN117886677A discloses a method for synthesizing allyl trifluoroethyl ether compounds. This method uses trifluoroethanol as a solvent and performs selective nucleophilic substitution under Lewis acid catalysis. However, the reaction conditions require precise control, and a large amount of acid catalyst is used, resulting in complex post-processing and making it unsuitable for the continuous preparation of difluoromethyl-2,2,2-trifluoroethyl ether. Chinese Patent Publication No. CN110407673A discloses a method for preparing tetrafluoroethyl trifluoroethyl ether. This method involves the reaction in a polyether glycol dialkyl ether solvent. After the reaction, water needs to be added, stirred, filtered, and then rectified. This process involves many steps, high solvent recovery costs, and does not achieve truly continuous production.

[0004] In existing technologies, the preparation of difluoromethyl-2,2,2-trifluoroethyl ether from trifluoroethanol and difluorochloromethane generally suffers from problems such as low trifluoroethanol conversion, low utilization of sodium hydroxide aqueous solution, and incomplete reaction of difluorochloromethane. Since difluorochloromethane is an ozone-depleting substance, incomplete reaction not only wastes raw materials but also leads to difficulties in tail gas treatment. Furthermore, in batch operation mode, product-raw material separation is difficult, energy consumption is high, and trace amounts of organic polymers generated in the reaction system easily adhere and accumulate on the surface of the distillation packing, causing equipment blockage, frequent shutdowns for cleaning, and severely impacting production efficiency and long-term stable operation of the equipment. Therefore, there is an urgent need to develop a continuous production process that can achieve efficient conversion, full utilization of raw materials, continuous separation of by-products, and long-term stable operation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention aims to provide a process for the continuous production of difluoromethyl-2,2,2-trifluoroethyl ether.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] A process for the continuous production of difluoromethyl-2,2,2-trifluoroethyl ether includes the following steps:

[0008] Start-up phase: Add trifluoroethanol and sodium hydroxide aqueous solution to the stirred tank reactor, start the stainless steel diaphragm pump, raise the temperature and control the pressure, disperse difluorochloromethane into tiny bubbles and introduce them into the reaction solution to start the reaction;

[0009] During the continuous and stable operation phase: Trifluoroethanol and solid sodium hydroxide are continuously added to the system, and difluorochloromethane is introduced into the reactor to maintain the concentration of the reaction liquid; the product is collected through a packed distillation column, the vapor phase at the top of the column is condensed, difluoromethyl-2,2,2-trifluoroethyl ether is enriched, the condensate is partially refluxed and the finished product is collected, and the bottom liquid is returned to the solid sodium hydroxide container; the circulating liquid is sent to a three-in-one filter for solid-liquid separation, the separated sodium chloride filter cake is washed and vacuum dried in the machine, the by-product sodium chloride is collected as a by-product, and the collected liquid phase is dehydrated by vacuum evaporation and returned to the solid sodium hydroxide container; the circulating liquid flows through a buffer tank, where the trace organic polymers entrained in it settle and separate in the tank, and the sediment is periodically discharged from the bottom of the tank; water is then separated from the reaction system through a PTFE organic membrane, and the remaining substances are returned to the reaction system.

[0010] Preferably, a process for the continuous production of difluoromethyl-2,2,2-trifluoroethyl ether is as follows, in parts by weight:

[0011] Start-up phase: Add 1000-1400 parts of trifluoroethanol and 600-800 parts of 40-60% sodium hydroxide aqueous solution to the stirred tank reactor, and start the stainless steel diaphragm pump; raise the temperature and control the pressure, disperse difluorochloromethane into tiny bubbles and introduce them into the reaction solution to start the reaction. The feed rate of difluorochloromethane is automatically adjusted based on the constant system pressure, with a maximum feed rate of 60-100 parts / h.

[0012] During the continuous and stable operation phase: Trifluoroethanol and solid sodium hydroxide are continuously added to the system, and difluorochloromethane is introduced into the reactor to maintain the concentration of the reaction liquid. The product is collected through a packed distillation column. The vapor phase at the top of the column is condensed, and difluoromethyl-2,2,2-trifluoroethyl ether is enriched. Part of the condensate is refluxed, and the difluoromethyl-2,2,2-trifluoroethyl ether product is collected. The bottom liquid is returned to the solid sodium hydroxide container. The circulating liquid is sent to a three-in-one filter for solid-liquid separation. The separated sodium chloride filter cake is washed and vacuum dried in the filter. The by-product sodium chloride is collected as a by-product. The collected liquid phase is dehydrated by vacuum evaporation and returned to the solid sodium hydroxide container. The circulating liquid flows through a buffer tank, where trace amounts of organic polymers are settled and separated. The settled material is periodically discharged from the bottom of the tank. Water is then separated from the reaction system through a PTFE organic membrane, and the remaining substances are returned to the reaction system.

[0013] The circulating flow rate of the stainless steel diaphragm pump is 15-25 m³ / h. 3 / h, the stirring speed of the stirred tank reactor is 500-700 r / min.

[0014] The temperature rise and pressure control are as follows: the temperature is raised to 100-130℃, and the system pressure is controlled at 0.8-1.2MPa.

[0015] The dispersion into microbubbles involves dispersing difluorochloromethane into microbubbles with an average diameter of 0.3-0.8 mm using a metal sintering gas distributor with a pore size of 20-40 μm.

[0016] The concentration of the maintaining reaction solution is maintained at 5-10% by mass of free sodium hydroxide, 50-70% by mass of trifluoroethanol, and 4-6% by water content.

[0017] The packed distillation column has a theoretical number of 30-40 plates, and the top temperature is controlled at 100-130℃.

[0018] The reflux ratio is 2-4:1.

[0019] The packing material is one of Hastelloy C-276 corrugated packing or modified packing.

[0020] The modified filler is prepared as follows:

[0021] Using Hastelloy C-276 corrugated packing as the matrix, the material is subjected to ultrasonic degreasing with acetone for 20-40 minutes, roughening by sandblasting with 50-100 mesh corundum sand, and drying at 50-100℃ for 1-3 hours. Then, it is placed in a PECVD vacuum chamber and evacuated to a vacuum level of 5×10⁻⁶. -3Below Pa, argon gas is introduced to a pressure of 20-50 Pa, and plasma activation treatment is performed for 10-20 min under a radio frequency power of 200-300 W. Subsequently, a mixture of vaporized fluorosilane and argon gas with a volume ratio of 1:5-10 is introduced, and the deposition pressure is controlled at 30-50 Pa, the radio frequency power at 100-200 W, the substrate temperature at 150-180 °C, and the deposition time at 20-40 min, forming a fluorosilane modified layer with a thickness of 1-4 μm on the surface of the filler. After deposition, the filler is cooled in an argon atmosphere to below 60 °C and then removed to obtain the modified filler.

[0022] The fluorosilane is at least one of tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, nonafluorohexyltrimethoxysilane, trifluoropropyltrimethoxysilane, and heptadecafluorodecyltriethoxysilane.

[0023] Preferably, the fluorosilane is composed of heptadecafluorodecyltrimethoxysilane and trifluoropropyltrimethoxysilane in a mass ratio of 0.5-2:0.5-2.

[0024] This invention addresses the problems of low trifluoroethanol conversion rate, low sodium hydroxide aqueous solution utilization rate, and incomplete reaction and difficult recovery of difluorochloromethane in existing batch processes. It adopts a stirred tank reactor for continuous production, achieving rapid reaction by maintaining a high concentration of trifluoroethanol and alkaline solution in the reaction liquid. Difluorochloromethane is dispersed into microbubbles by a gas distributor to enhance gas-liquid mass transfer. The product is continuously collected by a packed distillation column. The circulating liquid is desalted by a three-in-one filter, dehydrated by polymer settling and PTFE organic membrane in a buffer tank, and then returned to the reaction system. Solid sodium hydroxide is mixed with the bottom liquid in a dissolution container and reused, forming a continuous closed loop.

[0025] To address the problem of blockage caused by the adhesion and accumulation of trace organic polymers on the packing surface during continuous operation, this invention uses fluorosilanes to modify the surface of Hastelloy corrugated packing. By combining long and short chain fluorosilanes, a dense low surface energy film layer is formed. The long chain molecules provide the main low surface energy framework, while the short chain molecules fill the microscopic voids, synergistically improving the anti-adhesion performance and extending the continuous operation cycle of the device.

[0026] Compared with the prior art, the present invention has the following beneficial technical effects:

[0027] 1) This invention adopts a stirred tank reactor for continuous production. The system is maintained by a circulating pump, and raw materials and products are continuously added to achieve stable operation, improve production efficiency, and reduce energy consumption.

[0028] 2) In this invention, difluorochloromethane is dispersed into tiny bubbles by a gas distributor and introduced into the reaction liquid. With appropriate stirring speed, gas-liquid mass transfer is enhanced, thereby improving the conversion rate of trifluoroethanol and the utilization rate of difluorochloromethane.

[0029] 3) The circulating liquid of this invention is processed sequentially by a three-in-one filter, a PTFE organic membrane and a buffer tank to continuously remove sodium chloride, water and trace polymers, maintain the stability of the reaction solution concentration and ensure product quality.

[0030] 4) This invention uses fluorosilane-modified packing to reduce the adhesion and accumulation of trace organic polymers on the packing surface, extend the continuous operation cycle of the distillation column, and reduce the frequency of shutdown and cleaning.

[0031] 5) The long- and short-chain fluorosilane compound modified filler of the present invention provides a low surface energy framework with long chains and fills micro voids to form a dense film layer, which synergistically improves the anti-adhesion performance and is superior to single components. Attached Figure Description

[0032] Figure 1 The process flow diagram for the continuous production of difluoromethyl-2,2,2-trifluoroethyl ether of this invention shows a continuous circulation process route with a stirred tank reactor as the core, the product being collected through a packed distillation column, the circulating liquid being desalted by a three-in-one filter, dehydrated by a PTFE membrane module, and polymer being settled in a buffer tank, and solid sodium hydroxide being mixed with the column bottom liquid in a dissolving container and then returned to the reactor. Detailed Implementation

[0033] Some material sources or parameters:

[0034] Hastelloy C-276 corrugated packing: material grade UNS N10276, chemical composition Ni≥57%, Cr 14.5-16.5%, Mo 15-17%, W 3-4.5%, made into corrugated shape by pressing wire mesh (wire diameter 0.1-0.3 mm) according to HG / T 21559.3-2005.

[0035] Dichlorofluoromethane, CAS No. 75-45-6, purity ≥99.5%, industrial refrigerant, trade name R22.

[0036] Tridecafluorooctyltrimethoxysilane: CAS No. 85857-16-5, purity ≥97%.

[0037] Heptadecafluorodecyltrimethoxysilane: CAS No. 83048-65-1, purity ≥97%.

[0038] Nonafluorohexyltrimethoxysilane: CAS No. 85877-79-8, purity ≥97%.

[0039] Trifluoropropyltrimethoxysilane: CAS No. 429-60-7, purity ≥98%.

[0040] Heptadecafluorodecyltriethoxysilane: CAS No. 101947-16-4, purity ≥97%.

[0041] All raw materials used in the embodiments of this invention are commercially available products.

[0042] Example 1

[0043] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is as follows:

[0044] Start-up phase: Add 1200 kg of trifluoroethanol and 700 kg of 50% sodium hydroxide aqueous solution to the stirred tank reactor, start the stainless steel diaphragm pump, and set the circulation flow rate to 20 m³ / h. 3 / h, the stirring speed of the stirred tank reactor is 600 r / min; the temperature is raised to 120℃, the system pressure is controlled at 1.0 MPa, and dichlorofluoromethane is dispersed into tiny bubbles with an average diameter of 0.5 mm through a metal sintered gas distributor with a pore size of 30 μm and introduced into the reaction liquid to start the reaction. The feed rate of dichlorofluoromethane is automatically adjusted with the system pressure being constant as feedback, and the maximum feed rate is 80 kg / h.

[0045] During the continuous and stable operation phase: Trifluoroethanol and solid sodium hydroxide are continuously added to the system, and difluorochloromethane is introduced into the reactor to maintain the free sodium hydroxide concentration at 8%, the trifluoroethanol concentration at 60%, and the water content at 5% in the reaction solution; the product is collected through a packed distillation column with a theoretical number of 35 plates and a top temperature controlled at 120°C. The vapor phase at the top of the column is condensed, and the difluoromethyl-2,2,2-trifluoroethyl ether enriched condensate is partially refluxed at a reflux ratio of 3:1, and the difluoromethyl-2,2,2-trifluoroethyl ether is collected. The ether product is returned to the solid sodium hydroxide container in the bottom of the tower. The circulating liquid is sent to a three-in-one filter for solid-liquid separation. The separated sodium chloride filter cake is washed and vacuum dried in the machine. The by-product sodium chloride is collected as a by-product. The collected liquid phase is dehydrated by vacuum evaporation and returned to the solid sodium hydroxide container. The circulating liquid flows through a buffer tank, where the trace organic polymers entrained in it settle and separate. The sediment is periodically discharged from the bottom of the tank. The water is then separated from the reaction system through a PTFE organic membrane, and the remaining substances are returned to the reaction system.

[0046] The packing material is Hastelloy C-276 corrugated packing.

[0047] Example 2

[0048] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as that in Example 1, except that the packing material is a modified packing material.

[0049] The modified filler is prepared as follows:

[0050] Using Hastelloy C-276 corrugated packing as the matrix, after ultrasonic degreasing with acetone for 30 minutes, roughening by sandblasting with 80-mesh corundum sand, and drying at 80℃ for 2 hours, it is placed in a PECVD vacuum chamber and evacuated to a vacuum of 5×10⁻⁶. -3 Below Pa, argon gas is introduced to a pressure of 30 Pa, and plasma activation treatment is performed for 15 min under a radio frequency power of 250 W. Subsequently, a mixture of vaporized fluorosilane and argon gas with a volume ratio of 1:8 is introduced, and the deposition pressure is controlled at 40 Pa, the radio frequency power at 120 W, the substrate temperature at 160 °C, and the deposition time at 30 min, forming a 2 μm thick fluorosilane modified layer on the surface of the filler. After deposition, the filler is cooled to below 60 °C in an argon atmosphere and then removed to obtain the modified filler.

[0051] The fluorosilane is tridecafluorooctyltrimethoxysilane.

[0052] Example 3

[0053] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as that in Example 2, except that the fluorosilane is heptadecafluorodecyltrimethoxysilane.

[0054] Example 4

[0055] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as that in Example 2, except that the fluorosilane is nonafluorohexyltrimethoxysilane.

[0056] Example 5

[0057] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as that in Example 2, except that the fluorosilane is trifluoropropyltrimethoxysilane.

[0058] Example 6

[0059] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as that in Example 2, except that the fluorosilane is heptadecafluorodecyltriethoxysilane.

[0060] Example 7

[0061] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as that in Example 2, except that the fluorosilane is composed of heptadecafluorodecyltrimethoxysilane and trifluoropropyltrimethoxysilane in a mass ratio of 1:1.

[0062] Example 8

[0063] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as that in Example 2, except that the fluorosilane is composed of heptadecafluorodecyltrimethoxysilane and heptadecafluorodecyltriethoxysilane in a mass ratio of 1:1.

[0064] Comparative Example 1

[0065] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as in Example 1, except that the difluorochloromethane is directly introduced into the reaction solution without dispersion.

[0066] Comparative Example 2

[0067] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as that in Example 1, except that the stirring speed is 1000 r / min.

[0068] Comparative Example 3

[0069] A continuous process for producing difluoromethyl-2,2,2-trifluoroethyl ether is basically the same as that in Example 1, except that the stirring speed is 200 r / min.

[0070] Test Example 1

[0071] Polymer adhesion test:

[0072] After running stably for 720 hours according to the process methods of each embodiment and comparative example, the machine was shut down. Equal volume packing samples were taken from the same height position in each tower packing section, ultrasonically cleaned with acetone for 30 minutes to remove surface-adhered organic polymers, and then vacuum dried at 80°C to constant weight. The polymer adhesion amount Q (mg / g) per unit mass of packing was weighed and calculated according to the following formula:

[0073] Q=(m0–m1) / m1×1000

[0074] In the formula:

[0075] M0: Mass of the packing sample (including adhering polymer) taken directly after operation, in g;

[0076] M1: Mass of the filler sample after ultrasonic cleaning and drying with acetone (mass of the matrix after removing the polymer), g;

[0077] 1000: Conversion factor (to convert g / g to mg / g).

[0078] For each embodiment or comparative example, three filler samples at the same height were measured separately, and the results were taken as the arithmetic mean. The test results are shown in Table 1.

[0079] Table 1

[0080] Example 1 50.1 Example 2 24.5 Example 3 20.2 Example 4 28.3 Example 5 31.8 Example 6 22.6 Example 7 10.5 Example 8 21.0 Comparative Example 1 58.2 Comparative Example 2 52.4 Comparative Example 3 54.7

[0081] Test Example 2

[0082] Trifluoroethanol conversion test:

[0083] After all examples and comparative examples entered the continuous stable operation phase, the trifluoroethanol mass concentration in the reactor was maintained at 60% for 72 hours of continuous stable operation. The trifluoroethanol feed rate and the product difluoromethyl-2,2,2-trifluoroethyl ether discharge rate were recorded every 24 hours. The trifluoroethanol conversion rate at each time point was calculated using the following formula, and the arithmetic mean of the three measurements was taken as the trifluoroethanol conversion rate:

[0084] X = (F FE ×M TFE / M FE ) / F TFE ×100%

[0085] In the formula:

[0086] X: Trifluoroethanol conversion rate, %

[0087] F FE : The extraction rate of the finished product difluoromethyl-2,2,2-trifluoroethyl ether, kg / h;

[0088] F TFE : Feed rate of trifluoroethanol, kg / h;

[0089] M TFE The molecular weight of trifluoroethanol is 100.04 g / mol.

[0090] M FE The molecular weight of difluoromethyl-2,2,2-trifluoroethyl ether is 150.05 g / mol.

[0091] The relevant test data are summarized in Table 2.

[0092] Table 2

[0093] Example 1 98.5 Example 2 98.4 Example 3 98.6 Example 4 98.3 Example 5 98.4 Example 6 98.5 Example 7 98.8 Example 8 98.4 Comparative Example 1 78.0 Comparative Example 2 92.0 Comparative Example 3 88.5

[0094] Compared to Comparative Example 1, Example 1 dispersed difluorochloromethane into microbubbles using a gas distributor and introduced them into the reaction liquid, significantly increasing the gas-liquid two-phase contact area and enhancing mass transfer efficiency. This allowed difluorochloromethane and trifluoroethanol to react fully, resulting in a higher conversion rate than Comparative Example 1. Compared to Comparative Examples 2 and 3, Example 1 used a stirring speed of 600 r / min. At this speed, the reaction liquid was in a state of intense turbulence, ensuring uniform dispersion and rapid reaction of difluorochloromethane bubbles in the liquid phase. This prevented bubble coalescence or shortened gas residence time due to excessively high stirring speed, and also avoided uneven mixing and insufficient mass transfer due to excessively low stirring speed. Therefore, Example 1 achieved a higher conversion rate than Comparative Examples 2 and 3.

[0095] Compared to Example 1, the packing materials in Examples 2 to 6, after being modified with fluorosilane, form a low surface energy fluorosilane-modified layer on the packing surface, which effectively reduces the adhesion and accumulation of trace organic polymers on the packing surface. Therefore, the amount of polymer adhesion is lower than that of the unmodified Hastelloy C-276 corrugated packing in Example 1. In Examples 2 to 6, Example 3 uses heptadecafluorodecyltrimethoxysilane as the fluorosilane. Its perfluoroalkyl chain length is moderate, its fluorine content is high, and the methoxy group has better gasification efficiency and plasma pyrolysis activity under PECVD conditions than the ethoxy group, which is conducive to the formation of a more uniform and dense modified layer. Therefore, its anti-organic polymer adhesion effect is better than that of Examples 2, 4, 5, and 6.

[0096] Example 7 uses a combination of heptadecafluorodecyltrimethoxysilane and trifluoropropyltrimethoxysilane. The long-chain molecules provide the main low surface energy framework, while the short-chain molecules, with their small size and strong diffusion ability, can fill the microscopic pits and voids in the matrix that are difficult for the long chains to cover, forming a denser, pinhole-free composite fluorosilane film. Therefore, it has a synergistic effect and better resistance to organic polymer adhesion than when used alone. Example 8 uses a combination of heptadecafluorodecyltrimethoxysilane and heptadecafluorodecyltriethoxysilane. Both have the same perfluoroalkyl chain structure, although their terminal alkoxy groups differ. Under PECVD conditions, the surface chemical composition and surface energy of the film formed tend to be consistent. The complementary filling effect of the long-short chain combination does not exist, and the mixture does not produce a synergistic gain; therefore, it does not have a synergistic effect.

Claims

1. A process for the continuous production of difluoromethyl-2,2,2-trifluoroethyl ether, characterized in that, Includes the following steps: Start-up phase: Add trifluoroethanol and sodium hydroxide aqueous solution to the stirred tank reactor, start the stainless steel diaphragm pump, raise the temperature and control the pressure, disperse difluorochloromethane into tiny bubbles and introduce them into the reaction solution to start the reaction; During the continuous and stable operation phase: Trifluoroethanol and solid sodium hydroxide are continuously added to the system, and difluorochloromethane is introduced into the reactor to maintain the concentration of the reaction liquid; the product is collected through a packed distillation column, the vapor phase at the top of the column is condensed, difluoromethyl-2,2,2-trifluoroethyl ether is enriched, the condensate is partially refluxed and the finished product is collected, and the bottom liquid is returned to the solid sodium hydroxide container; the circulating liquid is sent to a three-in-one filter for solid-liquid separation, the separated sodium chloride filter cake is washed and vacuum dried in the machine, the by-product sodium chloride is collected as a by-product, and the collected liquid phase is dehydrated by vacuum evaporation and returned to the solid sodium hydroxide container; the circulating liquid flows through a buffer tank, where the trace organic polymers entrained in it settle and separate in the tank, and the sediment is periodically discharged from the bottom of the tank; water is then separated from the reaction system through a PTFE organic membrane, and the remaining substances are returned to the reaction system.

2. The process method as described in claim 1, characterized in that, Includes the following steps, in parts by weight: Start-up phase: Add 1000-1400 parts of trifluoroethanol and 600-800 parts of 40-60% sodium hydroxide aqueous solution to the stirred tank reactor, and start the stainless steel diaphragm pump; raise the temperature and control the pressure, disperse difluorochloromethane into tiny bubbles and introduce them into the reaction solution to start the reaction. The feed rate of difluorochloromethane is automatically adjusted based on the constant system pressure, with a maximum feed rate of 60-100 parts / h. During the continuous and stable operation phase: Trifluoroethanol and solid sodium hydroxide are continuously added to the system, and difluorochloromethane is introduced into the reactor to maintain the concentration of the reaction liquid. The product is collected through a packed distillation column. The vapor phase at the top of the column is condensed, and difluoromethyl-2,2,2-trifluoroethyl ether is enriched. Part of the condensate is refluxed, and the difluoromethyl-2,2,2-trifluoroethyl ether product is collected. The bottom liquid is returned to the solid sodium hydroxide container. The circulating liquid is sent to a three-in-one filter for solid-liquid separation. The separated sodium chloride filter cake is washed and vacuum dried in the filter. The by-product sodium chloride is collected as a by-product. The collected liquid phase is dehydrated by vacuum evaporation and returned to the solid sodium hydroxide container. The circulating liquid flows through a buffer tank, where trace amounts of organic polymers are settled and separated. The settled material is periodically discharged from the bottom of the tank. Water is then separated from the reaction system through a PTFE organic membrane, and the remaining substances are returned to the reaction system.

3. The process method as described in claim 1 or 2, characterized in that, The circulating flow rate of the stainless steel diaphragm pump is 15-25 m³ / h. 3 / h, the stirring speed of the stirred tank reactor is 500-700 r / min.

4. The process method as described in claim 1 or 2, characterized in that, The temperature rise and pressure control are as follows: the temperature is raised to 100-130℃, and the system pressure is controlled at 0.8-1.2MPa.

5. The process method as described in claim 1 or 2, characterized in that, The dispersion into microbubbles involves dispersing difluorochloromethane into microbubbles with an average diameter of 0.3-0.8 mm using a metal sintering gas distributor with a pore size of 20-40 μm.

6. The process method as described in claim 1 or 2, characterized in that, The concentration of the maintaining reaction solution is maintained at 5-10% by mass of free sodium hydroxide, 50-70% by mass of trifluoroethanol, and 4-6% by water content.

7. The process method as described in claim 1 or 2, characterized in that, The packed distillation column has 30-40 theoretical plates, and the top temperature is controlled at 100-130℃; the reflux ratio is 2-4:

1.

8. The process method as described in claim 1 or 2, characterized in that, The packing material is one of Hastelloy C-276 corrugated packing or modified packing. The modified filler is prepared as follows: Using Hastelloy C-276 corrugated packing as the matrix, the material is subjected to ultrasonic degreasing with acetone for 20-40 minutes, roughening by sandblasting with 50-100 mesh corundum sand, and drying at 50-100℃ for 1-3 hours. Then, it is placed in a PECVD vacuum chamber and evacuated to a vacuum level of 5×10⁻⁶. -3 Below Pa, argon gas is introduced to a pressure of 20-50 Pa, and plasma activation treatment is performed for 10-20 min under a radio frequency power of 200-300 W. Subsequently, a mixture of vaporized fluorosilane and argon gas with a volume ratio of 1:5-10 is introduced, and the deposition pressure is controlled at 30-50 Pa, the radio frequency power at 100-200 W, the substrate temperature at 150-180 °C, and the deposition time at 20-40 min, forming a fluorosilane modified layer with a thickness of 1-4 μm on the surface of the filler. After deposition, the filler is cooled in an argon atmosphere to below 60 °C and then removed to obtain the modified filler.

9. The process method as described in claim 8, characterized in that, The fluorosilane is at least one of tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, nonafluorohexyltrimethoxysilane, trifluoropropyltrimethoxysilane, and heptadecafluorodecyltriethoxysilane.

10. The process method as described in claim 8, characterized in that, The fluorosilane is composed of heptadecafluorodecyltrimethoxysilane and trifluoropropyltrimethoxysilane in a mass ratio of 0.5-2:0.5-2.

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