Equipment for producing 1, 1, 1, 2-tetrafluoroethane

Abstract

The utility model relates to the technical field of fluorine chemical industry, in particular to equipment for producing 1, 1, 1, 2-tetrafluoroethane, which comprises a reactor, the reactor is connected with the top of a first rectifying tower, the top of the reactor is connected with a compressor through a condenser, the compressor is connected with a second rectifying tower, the top of the second rectifying tower is connected with the first rectifying tower, and the first rectifying tower is connected with the first rectifying tower. The bottom of the second rectifying tower is connected with the reactor. According to the device disclosed by the utility model, HCFC-1122 in HFC-134a can be continuously and conveniently removed under the conditions of lower temperature and normal pressure; the method not only solves the problem of impurities in the product in production, but also reduces the production cost of the product, improves the economic benefit, and has wide market demand.

Description

TECHNICAL FIELD

[0001] The utility model relates to fluorine chemical industry technical field especially a kind of equipment for producing 1,1,1,2-tetrafluoroethane. BACKGROUND

[0002] 1,1,1,2-tetrafluoroethane (HFC-134a), normal pressure boiling point-26.5 ℃, ODP value (ozone depletion potential value) is 0, GWP value (greenhouse effect potential value) is 0.26, the main application as automobile air conditioner refrigerant in market at present, also have part in pharmaceutical aerosol.

[0003] There are two mature synthesis routes of HFC-134a, both of which are based on trichloroethylene as raw material, the difference is: one is gas phase two-step synthesis, and the other is liquid phase two-step synthesis. No matter which kind of synthesis method, the reaction of 2-chloro-1,1,1-trifluoroethane (HCFC-133a) removing HF to generate 2-chloro-1,1-difluoroethylene (HCFC-1122) will occur at the same time, the reaction principle is:

[0004] CF3-CH2Cl → CF2=CHCl (HCFC-1122) + HF

[0005] HCFC-1122 is a toxic substance, boiling point-17.7 ℃, can form azeotrope with HFC-134a, and cannot be separated by conventional method. At present, the common method to remove HCFC-1122 in HFC-134a is: one, using special molecular sieve adsorption to remove, molecular sieve adsorption saturation again using hot nitrogen or air to analyze regeneration, repeated use. The disadvantage of this method is that HCFC-1122 still exists after molecular sieve analysis, and cannot be eliminated, and in the analysis process, the adsorbed HFC-134a is not easy to recover due to the existence of a large amount of non-condensable gas, causing loss. Two, using chlorine, hydrogen fluoride, hydrogen and HCFC-1122 addition reaction to saturated alkane and then rectification separation. In the process of chlorine and HCFC-1122 reaction, HFC-134a is also chlorinated by chlorine, causing loss, and the chlorinated material also needs to be treated by alkali washing, water washing and then rectification separation, which is complicated; the addition reaction of hydrogen fluoride and HCFC-1122 also has the problem that the material after reaction needs to be treated by alkali washing, water washing to remove acidity and then rectification separation; part of HFC-134a is also reduced by hydrogen in the addition reaction of hydrogen and HCFC-1122 under the catalysis of hydrogenation catalyst, causing material loss, in addition, the safety risk is high in hydrogenation process. SUMMARY

[0006] The technical problem to be solved by the utility model is to provide a kind of equipment for producing 1,1,1,2-tetrafluoroethane to solve the above problems.

[0007] The technical scheme for solving the above technical problems of the utility model is: a device for producing 1,1,1,2-tetrafluoroethane, comprising a reactor, the reactor is connected with the top of a first rectifying tower, the top of the reactor is connected with a compressor through a condenser, the compressor is connected with a second rectifying tower, the top of the second rectifying tower is connected with the first rectifying tower, and the bottom of the second rectifying tower is connected with the reactor.

[0008] As a preferred technical scheme of the utility model, the reactor is a stainless steel reactor.

[0009] As a preferred technical scheme of the utility model, the volume of the stainless steel reactor is 4-6 cubic meters.

[0010] As a preferred technical scheme of the utility model, the reaction pressure in the stainless steel reactor is normal pressure, and the reaction temperature is 30-90 DEG C.

[0011] As a preferred technical scheme of the utility model, the condenser is a reflux condenser.

[0012] As a preferred technical scheme of the utility model, the boost pressure of the compressor is greater than 0.5MPa.

[0013] As a preferred technical scheme of the utility model, the boost pressure of the compressor is greater than the pressure in the first rectifying tower, and is at least greater than 0.1MPa.

[0014] Due to the structure of the utility model, the following beneficial effects are achieved: HCFC-1122 in HFC-134a can be continuously and conveniently removed under low temperature and normal pressure conditions; the impurity problem of the product in production is solved, the production cost of the product is reduced, the economic benefit is improved, and the utility model has wide market demand. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The utility model relates to a device for producing 1,1,1,2-tetrafluoroethane.

[0016] In the drawing: 1 is a reactor, 2 is a first rectifying tower, 3 is a condenser, 4 is a compressor, and 5 is a second rectifying tower. DETAILED DESCRIPTION

[0017] The utility model will be further explained in detail in combination with the drawings and specific embodiments.

[0018] As Figure 1The utility model discloses a production 1,1,1,2 - tetrafluoroethane equipment, including reactor 1, the reactor 1 is connected with the top of first rectifying column 2, the reactor 1 top is connected with compressor 4 through condenser 3, the compressor 4 is connected with second rectifying column 5, the top of second rectifying column 5 is connected with first rectifying column 2, the bottom of second rectifying column 5 is connected with reactor 1.

[0019] The utility model further, the reactor 1 is stainless steel reaction kettle.

[0020] The utility model further, the volume of stainless steel reaction kettle is 4-6 cubic meters.

[0021] The utility model further, the reaction pressure in stainless steel reaction kettle is normal pressure, and the reaction temperature is 30 ℃ ~ 90 ℃.

[0022] The utility model further, the condenser 3 is reflux condenser.

[0023] The utility model further, the pressure boost pressure of compressor 4 is greater than 0.5MPa.

[0024] The utility model further, the pressure boost pressure of compressor 4 is greater than the pressure in first rectifying column 2, and is at least greater than 0.1MPa.

[0025] Example 1

[0026] 2 tons N-methyl pyrrolidone (NMP) are added to the 5 cubic stainless steel reaction kettle, under the stirring, 1 ton trifluoroethanol, 20 kilograms potassium fluoride are added, after adding, stirring 1 hour while heating to 90 DEG C, the HFC-134a gas that the HFC-134a gas from the stainless steel reaction kettle bottom is rich in HCFC-1122 in HFC-134a rectifying column top is continuously passed into the reaction kettle, controls the air intake speed and is not less than 1 ton HFC-134a per hour, makes the HFC-134a gas of stainless steel reaction kettle discharge HCFC-1122 volume fraction and is less than 50 × 10 -6 , if necessary, can appropriately reduce the air intake speed. The HFC-134a gas of discharge is condensed after passing through the reflux condenser on the reaction kettle and is pressurized to 0.5MPa or more in gas compressor and enters the special rectifying tower rectification, and the HFC-134a gas in the special rectifying tower top enters the middle part of HFC-134a rectifying tower and continues rectification, keeps the HCFC-1122 volume fraction in the HFC-134a in the HFC-134a rectifying tower kettle and is less than 10 × 10 -6HFC-134a is continuously produced. The material in the bottom of the dedicated distillation column is returned to the stainless steel reactor. The pressure boosted by the gas compressor is linked to the pressure of the HFC-134a distillation column, with the gas compressor pressure being at least 0.1 MPa higher than the HFC-134a distillation column pressure.

[0027] Example 2

[0028] 2 tons N , N Dimethylformamide (DMF) is added to a 5 cubic meter stainless steel reactor. While stirring, 1 ton of trifluoroethanol and 60 kg of potassium fluoride are added. After the addition is complete, stirring is continued for 1 hour, and the temperature is raised to 60°C. HFC-134a gas, rich in HCFC-1122, from the top of the HFC-134a distillation column, is continuously introduced into the reactor from the bottom, with the inlet rate controlled to be no less than 1 ton of HFC-134a per hour, ensuring that the volume fraction of HCFC-1122 in the HFC-134a gas discharged from the reactor is below 50 × 10⁻⁶. -6 If necessary, the inlet gas rate can be appropriately reduced or the reaction temperature increased. The discharged HFC-134a gas is condensed by the reflux condenser on the reactor and then pressurized to above 0.5 MPa by the gas compressor before entering a dedicated distillation column for further distillation. The HFC-134a gas at the top of the dedicated distillation column enters the middle section of the column for continued distillation, maintaining the volume fraction of HCFC-1122 in the HFC-134a in the column bottom below 10 × 10⁻⁶. -6 HFC-134a is continuously produced. The material in the bottom of the dedicated distillation column is returned to the stainless steel reactor. The pressure boosted by the gas compressor is linked to the pressure of the HFC-134a distillation column, with the gas compressor pressure being at least 0.1 MPa higher than the HFC-134a distillation column pressure.

[0029] Example 3

[0030] Two tons of 1,3-dimethyl-2-imidazolinone (DMI) were added to a 5 cubic meter stainless steel reactor. One ton of trifluoroethanol and 100 kg of potassium fluoride were added under stirring. After the addition was complete, the mixture was stirred for one hour while maintaining the reaction temperature at 30°C. HFC-134a gas, rich in HCFC-1122, from the top of an HFC-134a distillation column, was continuously introduced into the reactor from the bottom, with the inlet rate controlled to be no less than one ton of HFC-134a per hour, ensuring that the volume fraction of HCFC-1122 in the HFC-134a gas discharged from the reactor was below 50 × 10⁻⁶. -6, the reaction temperature can be appropriately increased if necessary. The discharged HFC-134a gas is condensed by a reflux condenser on the reactor and then pressurized to 0.5 MPa or more by a gas compressor to enter a dedicated rectification column. The HFC-134a gas at the top of the dedicated rectification column enters the middle of an HFC-134a rectification column and is further rectified, and the volume fraction of HCFC-1122 in the HFC-134a in the bottom of the HFC-134a rectification column is kept below 10 x 10 -6 , and HFC-134a is continuously produced. The material in the bottom of the dedicated rectification column is returned to the stainless steel reactor. The pressure of the gas compressor is linked to the pressure of the HFC-134a rectification column, and the pressure of the gas compressor is 0.1 MPa or more higher than the pressure of the HFC-134a rectification column.

[0031] The description and application of the present application are illustrative, and are not intended to limit the scope of the present application to the above-mentioned embodiments. Variations and modifications of the disclosed embodiments are possible, and it is intended that the application encompass such variations and modifications as fall within the scope of the appended claims. It will be apparent to those skilled in the art that the present application can be realized in other forms, structures, arrangements, proportions, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. Other embodiments here disclosed can be made without departing from the spirit or essential characteristics thereof.

Claims

1. An apparatus for producing 1,1,1,2-tetrafluoroethane, characterized by: The reactor (1) is connected with the top of the first rectifying tower (2), the top of the reactor (1) is connected with the compressor (4) through the condenser (3), the compressor (4) is connected with the second rectifying tower (5), the top of the second rectifying tower (5) is connected with the first rectifying tower (2), and the bottom of the second rectifying tower (5) is connected with the reactor (1).

2. An apparatus for producing 1,1,1,2-tetrafluoroethane according to claim 1, characterized by: The reactor (1) is a stainless steel reactor.

3. An apparatus for producing 1,1,1,2-tetrafluoroethane according to claim 2, characterized by: The volume of the stainless steel reactor is 4-6 cubic meters.

4. An apparatus for producing 1,1,1,2-tetrafluoroethane according to claim 2, characterized by: The reaction pressure in the stainless steel reactor is normal pressure, and the reaction temperature is 30-90 DEG C.

5. The apparatus for producing 1,1,1,2-tetrafluoroethane according to claim 1, wherein: The condenser (3) is a reflux condenser.

6. The apparatus for producing 1,1,1,2-tetrafluoroethane according to claim 1, wherein: The boost pressure of the compressor (4) is greater than 0.5 MPa.

7. An apparatus for producing 1,1,1,2-tetrafluoroethane according to claim 6, characterized by: The boost pressure of the compressor (4) is greater than the pressure in the first rectifying tower (2), and is at least greater than 0.1 MPa.

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