Production method and production device of acetic acid-2, 2-difluoroethyl ester

Abstract

The invention provides an acetic acid-2, 2-difluoroethyl ester production method and a production device.The acetic acid-2, 2-difluoroethyl ester production method comprises the following steps that S1, acetic anhydride and 2, 2-difluoroethanol are mixed to obtain a mixture; s2, the mixture is subjected to a heating reaction and then rectified, and acetic acid-2, 2-difluoroethyl ester with a trace amount of acetic acid is obtained; and S3, mixing the acetic acid-2, 2-difluoroethyl ester with trace acetic acid and a saturated sodium carbonate aqueous solution, reacting, and rectifying to obtain an acetic acid-2, 2-difluoroethyl ester product. According to the method, acetic anhydride is used as an acylation reagent and is subjected to an acetic anhydride alcoholysis reaction with 2, 2-difluoroethanol to generate the target product acetic acid-2, 2-difluoroethyl ester. The reaction is high in safety, can be carried out at normal pressure, and is a single liquid phase reaction. The reaction is environment-friendly and efficient, no waste gas or waste residue is generated, the reaction does not need a catalyst, and the reaction yield can reach 98% or above.

Description

Technical Field

[0001] The invention belongs to the field of battery electrolyte additives, and specifically relates to a production method and a production device for 2,2-difluoroethyl acetate. Background Art

[0002] 2,2-Difluoroethyl acetate has a low freezing point and high high-pressure film-forming stability, and can be used as a co-solvent in lithium-ion battery or sodium-ion battery electrolytes. Currently, the raw materials for preparing 2,2-difluoroethyl acetate include acetate and 2,2-difluoro-1-haloethane. In the preparation process, acetate and 2,2-difluoro-1-haloethane are used as raw materials for high-temperature, pressurized and catalytic reactions. In this preparation method, since the raw material 2,2-difluoro-1-haloethane is a low-boiling-point material of 35°C, there are complex processes such as high-temperature pressurized reaction and vacuum discharge in the production process, and the reaction will produce halide salt solid waste, which is very easy to clog equipment and pipelines. Summary of the invention

[0003] In view of this, the present invention provides a method and a production device for 2,2-difluoroethyl acetate, which has high reaction safety, can be carried out under normal pressure, and is a single liquid phase reaction. The reaction is environmentally friendly and efficient, does not generate waste gas or waste residue, does not require a catalyst, and the reaction yield can be as high as 98% or more.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In one aspect, the present invention provides a method for producing 2,2-difluoroethyl acetate, comprising the following steps:

[0006] S1, mixing acetic anhydride and 2,2-difluoroethanol to obtain a mixture;

[0007] S2, the mixture is heated for reaction and then distilled to obtain 2,2-difluoroethyl acetate with a trace amount of acetic acid;

[0008] S3, mixing 2,2-difluoroethyl acetate with a trace amount of acetic acid and a saturated sodium carbonate aqueous solution for reaction and then distilling to obtain 2,2-difluoroethyl acetate.

[0009] Preferably, in step S1, the molar ratio of acetic anhydride to 2,2-difluoroethanol is (1-2):1.

[0010] Preferably, in step S2, the temperature of the mixture heating reaction is 40-150°C; and / or, in step S2, the reaction pressure of the mixture heating reaction is 100-400 kPa; and / or, in step S2, the reaction time of the mixture heating reaction is 10-50 h.

[0011] Preferably, in step S2, the specific steps of distillation are: controlling the temperature to 9-100°C, distilling out the unreacted 2,2-difluoroethanol raw material for recycling, and then controlling the temperature to 102-108°C to produce 2,2-difluoroethyl acetate with a mass purity of ≥99.0%.

[0012] Preferably, in step S3, the mass ratio of the 2,2-difluoroethyl acetate containing a trace amount of acetic acid to the saturated sodium carbonate aqueous solution is (1-10):1.

[0013] Preferably, in step S3, during the mixed reaction of 2,2-difluoroethyl acetate with a trace amount of acetic acid and a saturated aqueous sodium carbonate solution, the temperature of the mixed reaction is 20-80° C.; and / or, in step S3, during the mixed reaction of 2,2-difluoroethyl acetate with a trace amount of acetic acid and a saturated aqueous sodium carbonate solution, the reaction time of the mixed reaction is 1-10 h.

[0014] Preferably, in step S3, the specific steps of distillation are: controlling the temperature to 100-105° C., extracting aqueous 2,2-difluoroethyl acetate for recycling purification, and then controlling the temperature to 104-108° C., extracting 2,2-difluoroethyl acetate product with a mass purity of ≥99.9%.

[0015] In another aspect, the present invention provides a production device for producing 2,2-difluoroethyl acetate, wherein the production device is produced using the method described above.

[0016] Preferably, the method comprises a saturated sodium carbonate aqueous solution raw material tank, an acetic anhydride raw material tank, a 2,2-difluoroethanol raw material tank, a first reactor, a first distillation tower, a second reactor and a second distillation tower, wherein the saturated sodium carbonate aqueous solution raw material tank is used to hold a saturated sodium carbonate aqueous solution; the acetic anhydride raw material tank is used to hold acetic anhydride; the 2,2-difluoroethanol raw material tank is used to hold 2,2-difluoroethanol; the first reactor is connected to the acetic anhydride raw material tank and the 2,2-difluoroethanol raw material tank, and acetic anhydride and 2,2-difluoroethanol are heated and reacted in the first reactor; the first distillation tower is connected to the first reactor and the 2,2-difluoroethanol raw material tank, respectively, After the anhydride and 2,2-difluoroethanol are heated and reacted in the first reactor, they are rectified in the first distillation tower, and the 2,2-difluoroethanol that does not participate in the reaction is refluxed into the 2,2-difluoroethanol raw material tank; the second reactor is connected with the first distillation tower and the saturated sodium carbonate aqueous solution raw material tank respectively, and 2,2-difluoroethyl acetate with a trace amount of acetic acid and the saturated sodium carbonate aqueous solution react in the second reactor; the second distillation tower is connected with the second reactor and the outside world, and the rectified 2,2-difluoroethyl acetate with a mass purity of ≥99.9% is transported to the outside world, and the 2,2-difluoroethyl acetate with a trace amount of acetic acid is transported to the second reactor.

[0017] Preferably, it also includes a phase separation tank, which is connected to the second reactor and the second distillation tower respectively. The reaction product enters the phase separation tank through the second reactor, and the phases are statically separated, and the organic phase is transported to the second distillation tower.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The present invention uses acetic anhydride as an acylating agent to carry out alcoholysis of acetic anhydride with 2,2-difluoroethanol to generate the target product, 2,2-difluoroethyl acetate. This reaction is highly safe, can be carried out under normal pressure, and is a single liquid phase reaction. This reaction is environmentally friendly and efficient, does not generate waste gas or waste residue, does not require a catalyst, and the reaction yield can be as high as 98% or more.

[0020] (2) The present invention adopts a high-efficiency extraction reaction coupling process to purify the product, thereby enhancing the separation effect, and the product quality can meet the requirements of battery electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of a production device for producing 2,2-difluoroethyl acetate provided in one embodiment of the present invention.

[0022] Figure numerals: production device 100 for producing 2,2-difluoroethyl acetate, saturated sodium carbonate aqueous solution raw material tank 1, acetic anhydride raw material tank 2, 2,2-difluoroethanol raw material tank 3, first reactor 4, first distillation tower 5, second reactor 6, phase separation tank 7, second distillation tower 8. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can understand the present invention more clearly.

[0024] The present invention provides a method for producing 2,2-difluoroethyl acetate, comprising the following steps:

[0025] S1, mixing acetic anhydride and 2,2-difluoroethanol to obtain a mixture;

[0026] S2, the mixture is heated for reaction and then distilled to obtain 2,2-difluoroethyl acetate with a trace amount of acetic acid;

[0027] S3, mixing 2,2-difluoroethyl acetate with a trace amount of acetic acid and a saturated sodium carbonate aqueous solution for reaction and then distilling to obtain 2,2-difluoroethyl acetate.

[0028] The invention adopts acetic anhydride as an acylating agent to carry out alcoholysis of acetic anhydride with 2,2-difluoroethanol to generate the target product acetic acid-2,2-difluoroethyl ester. The reaction has high safety, can be carried out under normal pressure, and is a single liquid phase reaction. The reaction is environmentally friendly and efficient, no waste gas or waste residue is generated, no catalyst is required for the reaction, and the reaction yield can be as high as more than 98%.

[0029] Further, in step S1, the molar ratio of acetic anhydride to 2,2-difluoroethanol is (1-2):1, for example, the ratio may be 1:1, 1.5:1, or 2:1.

[0030] Further, in step S2, the temperature of the mixture heating reaction is 40-150°C; and / or, in step S2, the reaction pressure of the mixture heating reaction is 100-400kPa; and / or, in step S2, the reaction time of the mixture heating reaction is 10-50h. Wherein, the temperature of the mixture heating reaction is preferably 60-120°C, and the reaction pressure of the mixture heating reaction is preferably 100-200kPa. In some embodiments, the reaction process is sampled and analyzed, and the heating can be stopped when the conversion rate of 2,2-difluoroethanol is greater than 98%, and the reaction product is transported to the first distillation tower 5.

[0031] Furthermore, in step S2, the specific steps of distillation are: controlling the temperature to 9-100° C., distilling out the unreacted 2,2-difluoroethanol raw material for recycling, and then controlling the temperature to 102-108° C., extracting acetic acid-2,2-difluoroethyl ester with a mass purity of ≥99.0%. In this way, the yield is improved and the prepared product has high purity.

[0032] Further, in step S3, the mass ratio of the acetic acid-2,2-difluoroethyl ester with a trace amount of acetic acid and the saturated sodium carbonate aqueous solution is (1-10): 1. In some embodiments, in step S3, the temperature of the mixed reaction of the acetic acid-2,2-difluoroethyl ester with a trace amount of acetic acid and the saturated sodium carbonate aqueous solution is 20-80°C; and / or, in step S3, the reaction time of the mixed reaction of the acetic acid-2,2-difluoroethyl ester with a trace amount of acetic acid and the saturated sodium carbonate aqueous solution is 1-10h. The temperature of the mixed reaction is preferably 20-50°C.

[0033] Furthermore, in step S3, the specific steps of distillation are: controlling the temperature to 100-105° C., extracting aqueous 2,2-difluoroethyl acetate for recycling purification, and then controlling the temperature to 104-108° C., extracting 2,2-difluoroethyl acetate product with a mass purity of ≥99.9%. In this way, the yield is improved and the prepared product has high purity.

[0034] The present invention also provides a production device 100 for producing 2,2-difluoroethyl acetate, and the production device is produced using the method described above.

[0035] The production method used in the production device provided by the present invention has all the technical features of the above-mentioned production method of 2,2-difluoroethyl acetate, and has all the beneficial effects, which will not be elaborated one by one here.

[0036] Furthermore, the invention comprises a saturated sodium carbonate aqueous solution raw material tank 1, an acetic anhydride raw material tank 2, a 2,2-difluoroethanol raw material tank 3, a first reactor 4, a first distillation tower 5, a second reactor 6 and a second distillation tower 8, wherein the saturated sodium carbonate aqueous solution raw material tank 1 is used to hold a saturated sodium carbonate aqueous solution; the acetic anhydride raw material tank 2 is used to hold acetic anhydride; the 2,2-difluoroethanol raw material tank 3 is used to hold 2,2-difluoroethanol; the first reactor 4 is connected to the acetic anhydride raw material tank 2 and the 2,2-difluoroethanol raw material tank 3, and acetic anhydride and 2,2-difluoroethanol are heated and reacted in the first reactor 4; the first distillation tower 5 is connected to the first reactor 4 and the 2,2-difluoroethanol raw material tank 3 respectively The first reactor 4 is connected to the second reactor 6, wherein acetic anhydride and 2,2-difluoroethanol are heated and reacted in the first reactor 4, and then distilled in the first distillation tower 5, and the 2,2-difluoroethanol that does not participate in the reaction is refluxed into the 2,2-difluoroethanol raw material tank 3; the second reactor 6 is connected to the first distillation tower 5 and the saturated sodium carbonate aqueous solution raw material tank 1 respectively, and 2,2-difluoroethyl acetate with a trace amount of acetic acid and a saturated sodium carbonate aqueous solution react in the second reactor 6; the second distillation tower 8 is connected to the second reactor 6 and the outside world, and the distilled 2,2-difluoroethyl acetate with a mass purity of ≥99.9% is transported to the outside world, and the 2,2-difluoroethyl acetate with a trace amount of acetic acid is transported to the second reactor 6.

[0037] The above technical solution is as follows Figure 1 As shown, the discharge ports of the acetic anhydride raw material tank 2 and the 2,2-difluoroethanol raw material tank 3 are respectively connected to the feed port of the first reactor 4 through a pump and a pipeline, the discharge port of the first reactor 4 is connected to the feed port of the first distillation tower 5 through a pump and a pipeline, the discharge port of the top reflux tank of the first distillation tower 5 is connected to the feed port of the second reactor 6 through a pump and a pipeline, the discharge port of the second reactor 6 is connected to the feed port of the second distillation tower 8 through a pipeline, the discharge port of the top reflux tank of the second distillation tower 8 is connected to the feed port of the second reactor 6 through a pump and a pipeline, and the discharge port of the top reflux tank of the second distillation tower 8 is connected to the product tank through a pump and a pipeline. The discharge port of the saturated sodium carbonate aqueous solution raw material tank 1 is connected to the feed port of the second reactor 6 through a pump and a pipeline.

[0038] In some embodiments, the first reactor 4 and the second reactor 6 are stirred tank reactors, and the agitator type is a paddle agitator or a turbine agitator. The first reactor 4 is preferably a paddle agitator, and the second reactor 6 is preferably a turbine agitator.

[0039] In some embodiments, the first distillation tower 5 and the second distillation tower 8 are respectively equipped with 2-7 layers of structured packing or bulk packing with a thickness of 2-6 m per layer, preferably CY700 or BX500 structured packing, and a liquid collecting distributor is installed between each layer of packing.

[0040] In some embodiments, a phase separation tank 7 is further included, which is connected to the second reactor 6 and the second distillation tower 8 respectively, and the reaction product enters the phase separation tank 7 through the second reactor 6, and the phases are statically separated, and the organic phase is transported to the second distillation tower 8. The discharge port of the second reactor 6 is connected to the feed port of the phase separation tank 7 through a pipeline, and the discharge port of the phase separation tank 7 is connected to the feed port of the second distillation tower 8 through a pump and a pipeline.

[0041] Example 1

[0042] The present invention provides a device for producing 2,2-difluoroethyl acetate by using acetic anhydride as an acylating agent, comprising a saturated sodium carbonate aqueous solution raw material tank 1, an acetic anhydride raw material tank 2, a 2,2-difluoroethanol raw material tank 3, a first reaction kettle 4, a first distillation tower 5, a second reaction kettle 6, a phase separation tank 7, and a second distillation tower 8.

[0043] The discharge ports of the acetic anhydride raw material tank 2 and the 2,2-difluoroethanol raw material tank 3 are connected to the feed port of the first reactor 4 through a pump and a pipeline, respectively. The discharge port of the first reactor 4 is connected to the feed port of the first distillation tower 5 through a pump and a pipeline. The discharge port of the top reflux tank of the first distillation tower 5 is connected to the feed port of the second reactor 6 through a pump and a pipeline. The discharge port of the second reactor 6 is connected to the feed port of the phase separation tank 7 through a pipeline. The discharge port of the phase separation tank 7 is connected to the feed port of the second distillation tower 8 through a pump and a pipeline. The discharge port of the top reflux tank of the second distillation tower 8 is connected to the feed port of the second reactor 6 through a pump and a pipeline. The discharge port of the top reflux tank of the second distillation tower 8 is connected to the feed port of the second reactor 6 through a pump and a pipeline. The discharge port of the top reflux tank of the second distillation tower 8 is connected to the product tank through a pump and a pipeline. The first reactor 4 and the second reactor 6 are stirred tank reactors, the first reactor 4 is a paddle stirrer, and the second reactor 6 is a turbine stirrer. The first distillation tower 5 and the second distillation tower 8 are respectively equipped with 3 layers of CY700 structured packing, each layer is 3 meters, and a liquid collecting distributor is installed between each layer of packing.

[0044] The present invention provides a method for producing 2,2-difluoroethyl acetate, comprising the following steps:

[0045] (1) First reactor 4: the molar ratio of acetic anhydride and 2,2-difluoroethanol feed is 1:1, the reaction temperature is 40°C, the reaction pressure is 100 kPa, the reaction time is 10 h, sampling and analysis during the reaction process, when the conversion rate of 2,2-difluoroethanol is greater than 98%, heating can be stopped, and the reaction product is transported to the first distillation tower 5 by a pump.

[0046] (2) First distillation tower 5: intermittent distillation is adopted, and the tower top temperature of the first distillation tower 5 is controlled to be 90°C. The unreacted 2,2-difluoroethanol raw material is taken out from the tower top of the first distillation tower 5 and returned to the 2,2-difluoroethanol raw material tank 3 for recycling. The tower top temperature is controlled to be 102°C, and acetic acid-2,2-difluoroethyl ester with a purity of ≥99.0% is taken out from the tower top and transported to the second reactor 6 by a pump.

[0047] (3) Second reactor 6: adopting extraction reaction coupling process, the mass purity of 2,2-difluoroethyl acetate extracted from the top of the first distillation tower 5 is ≥99.0% and the mass ratio of saturated sodium carbonate aqueous solution is 1:1, the temperature is controlled at 20°C, and the extraction reaction time is 1h. The reaction product enters the phase separation tank 7, static phase separation, the organic phase is sampled to detect the acidity (in terms of HF) ≤50ppm, and the organic phase is transported to the second distillation tower 8 by a pump.

[0048] (4) Second distillation tower 8: intermittent distillation is adopted, and the tower top temperature is controlled at 100° C. The water-containing 2,2-difluoroethyl acetate is produced from the tower top and returned to the second reactor 6 for circulation and purification; the tower top temperature is controlled at 104° C., and the 2,2-difluoroethyl acetate product with a purity of ≥99.9% is produced from the tower top and transported to the 2,2-difluoroethyl acetate product tank by a machine pump.

[0049] Example 2

[0050] The present invention provides a device for producing 2,2-difluoroethyl acetate using acetic anhydride as an acylating agent, and the structure is the same as that of Example 1. The difference is that the first distillation tower 5 and the second distillation tower 8 are respectively equipped with 5 layers of CY700 structured packing with a length of 4 m per layer, and a liquid collecting distributor is installed between each layer of packing.

[0051] The present invention provides a method for producing 2,2-difluoroethyl acetate, comprising the following steps:

[0052] (1) First reactor 4: The molar ratio of acetic anhydride and 2,2-difluoroethanol feed is 1.5:1, the reaction temperature is 100°C, the reaction pressure is 300 kPa, the reaction time is 40 hours, and sampling and analysis during the reaction process. When the conversion rate of 2,2-difluoroethanol is greater than 98%, heating can be stopped, and the reaction product is transported to the first distillation tower 5 by a pump.

[0053] (2) First distillation tower 5: intermittent distillation is adopted, and the tower top temperature of the first distillation tower 5 is controlled to be 95° C. The unreacted 2,2-difluoroethanol raw material is taken out from the tower top of the first distillation tower 5 and returned to the 2,2-difluoroethanol raw material tank 3 for recycling. The tower top temperature is controlled to be 106° C., and acetic acid-2,2-difluoroethyl ester with a purity of ≥99.0% is taken out from the tower top and transported to the second reactor 6 by a pump.

[0054] (3) Second reactor 6: adopting extraction reaction coupling process, the mass purity of 2,2-difluoroethyl acetate extracted from the top of the first distillation tower 5 is ≥99.0% and the mass ratio of saturated sodium carbonate aqueous solution is 5:1, the temperature is controlled at 60°C, and the extraction reaction time is 5h. The reaction product enters the phase separation tank 7, static phase separation, the organic phase is sampled to detect the acidity (in terms of HF) ≤50ppm, and the organic phase is transported to the second distillation tower 8 by a pump.

[0055] (4) Second distillation tower 8: intermittent distillation is adopted, and the tower top temperature is controlled at 102° C. The water-containing 2,2-difluoroethyl acetate is produced from the tower top and returned to the second reactor 6 for circulation and purification; the tower top temperature is controlled at 106° C., and the 2,2-difluoroethyl acetate product with a purity of ≥99.9% is produced from the tower top and transported to the 2,2-difluoroethyl acetate product tank by a machine pump.

[0056] Example 3

[0057] The present invention provides a device for producing 2,2-difluoroethyl acetate using acetic anhydride as an acylating agent, and the structure is the same as that of Example 1. The difference is that the first distillation tower 5 and the second distillation tower 8 are respectively equipped with 7 layers of BX500 structured packing with a length of 5 m per layer, and a liquid collecting distributor is installed between each layer of packing.

[0058] The present invention provides a method for producing 2,2-difluoroethyl acetate, comprising the following steps:

[0059] (1) First reactor 4: the molar ratio of acetic anhydride and 2,2-difluoroethanol feed is 2:1, the reaction temperature is 150°C, the reaction pressure is 400 kPa, the reaction time is 50 h, and sampling and analysis during the reaction process. When the conversion rate of 2,2-difluoroethanol is greater than 98%, heating can be stopped, and the reaction product is transported to the first distillation tower 5 by a pump.

[0060] (2) First distillation tower 5: intermittent distillation is adopted, and the top temperature of the first distillation tower 5 is controlled to be 100° C. The unreacted 2,2-difluoroethanol raw material is taken out from the top of the first distillation tower 5 and returned to the 2,2-difluoroethanol raw material tank 3 for recycling. The top temperature of the tower is controlled to be 108° C., and acetic acid-2,2-difluoroethyl ester with a purity of ≥99.0% is taken out from the top of the tower and transported to the second reactor 6 by a pump.

[0061] (3) Second reactor 6: adopting extraction reaction coupling process, the mass purity of 2,2-difluoroethyl acetate extracted from the top of the first distillation tower 5 is ≥99.0% and the mass ratio of saturated sodium carbonate aqueous solution is 10:1, the temperature is controlled at 80°C, and the extraction reaction time is 10h. The reaction product enters the phase separation tank 7, static phase separation, the organic phase is sampled to detect the acidity (in terms of HF) ≤50ppm, and the organic phase is transported to the second distillation tower 8 by a pump.

[0062] (4) Second distillation tower 8: intermittent distillation is adopted, and the tower top temperature is controlled at 105° C. The water-containing 2,2-difluoroethyl acetate is produced from the tower top and returned to the second reactor 6 for circulation and purification; the tower top temperature is controlled at 108° C., and the 2,2-difluoroethyl acetate product with a purity of ≥99.9% is produced from the tower top and transported to the 2,2-difluoroethyl acetate product tank by a machine pump.

[0063] The specific raw materials not described in the present invention are all existing materials and can be directly purchased from the market.

[0064] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for producing 2,2-difluoroethyl acetate, characterized in that: The following steps are involved: S1, mixing acetic anhydride and 2,2-difluoroethanol to obtain a mixture; S2, the mixture is heated for reaction and then distilled to obtain 2,2-difluoroethyl acetate with a trace amount of acetic acid; S3, mixing 2,2-difluoroethyl acetate with a trace amount of acetic acid and a saturated sodium carbonate aqueous solution for reaction and then distilling to obtain 2,2-difluoroethyl acetate.

2. The method for producing 2,2-difluoroethyl acetate according to claim 1, characterized in that: In step S1, the molar ratio of acetic anhydride to 2,2-difluoroethanol is (1-2):

1.

3. The method according to claim 1, characterized in that: In step S2, the mixture is heated to react at a temperature of 40-150° C.; and / or, In step S2, the reaction pressure of the mixture during heating reaction is 100-400 kPa; and / or, In step S2, the mixture is heated to react for a reaction time of 10-50 hours.

4. The method according to claim 1, characterized in that: In step S2, the specific steps of distillation are: controlling the temperature to 9-100° C., distilling out the unreacted 2,2-difluoroethanol raw material for recycling, and then controlling the temperature to 102-108° C., extracting acetic acid-2,2-difluoroethyl ester with a mass purity of ≥99.0%.

5. The method according to claim 1, characterized in that In step S3, the mass ratio of the 2,2-difluoroethyl acetate containing a trace amount of acetic acid to the saturated sodium carbonate aqueous solution is (1-10):

1.

6. The method according to claim 1, characterized in that In step S3, 2,2-difluoroethyl acetate containing a trace amount of acetic acid and a saturated sodium carbonate aqueous solution are mixed and reacted at a temperature of 20-80° C.; and / or, In step S3, 2,2-difluoroethyl acetate containing a trace amount of acetic acid and a saturated sodium carbonate aqueous solution are mixed for reaction, and the reaction time of the mixed reaction is 1-10 hours.

7. The method according to claim 1, characterized in that In step S3, the specific steps of distillation are: controlling the temperature to 100-105° C., extracting aqueous 2,2-difluoroethyl acetate for recycling purification, and then controlling the temperature to 104-108° C., extracting 2,2-difluoroethyl acetate product with a mass purity of ≥99.9%.

8. A production device for producing 2,2-difluoroethyl acetate, characterized in that: The production device is produced using the method described in any one of claims 1 to 7.

9. The production device according to claim 8, characterized in that: include: A saturated sodium carbonate aqueous solution raw material tank, used to hold the saturated sodium carbonate aqueous solution; Acetic anhydride raw material tank, used to hold acetic anhydride; 2,2-difluoroethanol raw material tank, used to hold 2,2-difluoroethanol; A first reaction kettle is connected to the acetic anhydride raw material tank and the 2,2-difluoroethanol raw material tank, and acetic anhydride and 2,2-difluoroethanol are heated and reacted in the first reaction kettle; A first distillation tower is connected to the first reactor and the 2,2-difluoroethanol raw material tank, respectively. After acetic anhydride and 2,2-difluoroethanol are heated and reacted in the first reactor, they are distilled in the first distillation tower, and the 2,2-difluoroethanol that does not participate in the reaction is refluxed into the 2,2-difluoroethanol raw material tank; A second reactor is connected to the first distillation tower and the saturated sodium carbonate aqueous solution raw material tank respectively, and 2,2-difluoroethyl acetate with a trace amount of acetic acid and the saturated sodium carbonate aqueous solution react in the second reactor; and The second distillation tower is connected to the second reactor and the outside world, and the distilled 2,2-difluoroethyl acetate with a mass purity of ≥99.9% is transported to the outside world, and the 2,2-difluoroethyl acetate with a trace amount of acetic acid is transported to the second reactor.

10. The production device according to claim 9, characterized in that: It also includes a phase separation tank, which is connected to the second reactor and the second distillation tower respectively. The reaction product enters the phase separation tank through the second reactor, and the phases are statically separated, and the organic phase is transported to the second distillation tower.

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