阅读说明：本技术 一种1，1，2，2-四氟乙烷的制备方法 (Preparation method of 1, 1, 2, 2-tetrafluoroethane ) 是由 段琦 王瑞英 李丕永 孟翔 王永千 崔传博 于 2020-12-01 设计创作，主要内容包括：一种1,1,2,2-四氟乙烷的制备方法,将氟化氢与1,1-二氟-2,2-二氯乙烷作为反应底物,以液相路易斯酸作为催化剂反应得到1,1,2,2-四氟乙烷。本申请提供了一种合成1,1,2,2-四氟乙烷的新路线；原料自身稳定,不受运输距离等限制,且原料作为1,1-二氟-1-氯乙烷的副产物,价格低廉易得；1,1-二氟-2,2-二氯乙烷转化率达到90％以上,R134选择性达到80％以上,该工艺适合工业化生产。(A preparation method of 1, 1, 2, 2-tetrafluoroethane comprises the steps of reacting hydrogen fluoride and 1, 1-difluoro-2, 2-dichloroethane as reaction substrates with liquid-phase Lewis acid as a catalyst to obtain the 1, 1, 2, 2-tetrafluoroethane. The present application provides a new route to 1, 1, 2, 2-tetrafluoroethane; the raw material is stable and is not limited by transportation distance and the like, and the raw material is used as a by-product of the 1, 1-difluoro-1-chloroethane, so that the raw material is low in price and easy to obtain; the conversion rate of the 1, 1-difluoro-2, 2-dichloroethane reaches more than 90 percent, the selectivity of R134 reaches more than 80 percent, and the process is suitable for industrial production.)

1. A preparation method of 1, 1, 2, 2-tetrafluoroethane is characterized by comprising the following steps: hydrogen fluoride and 1, 1-difluoro-2, 2-dichloroethane are used as reaction substrates, and liquid phase Lewis acid is used as a catalyst to react to obtain the 1, 1, 2, 2-tetrafluoroethane.

2. The process according to claim 1 for producing 1, 1, 2, 2-tetrafluoroethane, wherein: the reaction temperature is 60-150 ℃, preferably 80-100 ℃, and the reaction pressure is gauge pressure of 0.6-0.8 MPa.

3. The process according to claim 1 for producing 1, 1, 2, 2-tetrafluoroethane, wherein: the liquid phase Lewis acid is SbCl₅、SnCl₄、TiCl₄、HSO₃Cl、HSO₃F, one or a mixture of several of the F in any proportion.

4. The process according to claim 1 for producing 1, 1, 2, 2-tetrafluoroethane, wherein: the mass of the liquid phase Lewis acid is 5-50%, preferably 5-20% of the mass of the added reaction substrate.

5. The process according to claim 1 for producing 1, 1, 2, 2-tetrafluoroethane, wherein: the mass ratio of the hydrogen fluoride to the 1, 1-difluoro-2, 2-dichloroethane is 1: 3-10, preferably 1: 4-6.

6. The process according to claim 5 for producing 1, 1, 2, 2-tetrafluoroethane, wherein: the liquid phase Lewis acid is activated and then used for catalytic reaction.

7. The process according to claim 6, wherein said process comprises the steps of: the activation treatment was carried out as follows: mixing Lewis acid and hydrogen fluoride, wherein the activation temperature is 70-90 ℃, and the activation time is 4-8 h.

8. The process according to claim 1 for producing 1, 1, 2, 2-tetrafluoroethane, wherein: adding anhydrous hydrogen fluoride into antimony pentachloride put into a reactor for several times through a diaphragm metering pump, heating to a set temperature, and keeping for a set time to ensure that the catalyst is activated completely; then slowly cooling, continuously feeding 1, 1-difluoro-2, 2-dichloroethane and anhydrous hydrogen fluoride for reaction, and washing, alkali washing and rectifying the reaction product to obtain the final product.

9. The process according to claim 1 for producing 1, 1, 2, 2-tetrafluoroethane, wherein: the temperature rise time is controlled to be 2 hours when the catalyst is activated, the temperature is raised to 90 ℃, and the constant temperature is kept for 6 hours.

10. The process according to claim 1 for producing 1, 1, 2, 2-tetrafluoroethane, wherein: during the reaction, the liquid level of the reactor is not higher than 60%, the reaction temperature is 90 ℃, and the reaction pressure is 0.6-0.8 MPa.

Technical Field

The application relates to a preparation method of 1, 1, 2, 2-tetrafluoroethane.

Background

1, 1, 2, 2-tetrafluoroethane (abbreviation HFC-134, R134), the molecular formula is CHF2-CHF2, is an isomer of R134a, has no flammability, no toxicity and no pungent smell, has the boiling point of-23 ℃, has zero ODP (ozone depletion potential) and the GWP value which is far less than R134a, and is a very potential substitute refrigerant. The 1, 1, 2, 2-tetrafluoroethane has high refrigeration coefficient and is superior to other refrigerants in performance on a heat pump.

The earliest reports of R134 synthesis started in 1936, and R134 synthesis was proposed during the study of fluoro derivatives of ethane and ethylene. Song tin gem reported in "New Process for the Synthesis of R134 and R134a, reaction temperature 80-100 ℃ V (C)₂F₄)∶V(H₂) The yield is high when the ratio of 1 to (2-4) is high, and the conversion rate of C2F4 is about 80%. Because the reaction releases heat, heat is difficult to take away in industrial application, temperature control is carried out by means of reactor conduction, the local temperature of the catalyst is greatly increased, the service life of the catalyst is influenced, the reaction selectivity is seriously reduced, and therefore the production cost is increased, and the market competitiveness of products is influenced. The R134 is synthesized by using tetrafluoroethylene and hydrogen as raw materials, the process is simple, but because tetrafluoroethylene has the problem of easy self-polymerization, explosion is easy to cause, long-distance transportation cannot be realized, R134 can be produced only near a tetrafluoroethylene raw material factory, the moisture content and the oxygen content need to be strictly controlled, the reaction temperature for synthesizing R134 is not too high, and the reaction pressure is also suitable to be carried out at low pressure or normal pressure.

The prior art discloses a method for synthesizing R134 by using mixed gas of tetrafluoroethylene and hydrogen and palladium as a catalyst, wherein the reaction pressure is 0.5MPa, the reaction temperature reaches 300 ℃, under the reaction condition, the tetrafluoroethylene is olefin which is extremely easy to self-polymerize, accidents are easily caused by high temperature and high pressure, the reaction process is not easy to control, and the hidden danger of industrial safety production is very large.

Disclosure of Invention

In order to solve the above problems, the present application proposes a process for producing 1, 1, 2, 2-tetrafluoroethane by reacting hydrogen fluoride with 1, 1-difluoro-2, 2-dichloroethane as a reaction substrate and a liquid-phase lewis acid as a catalyst to obtain 1, 1, 2, 2-tetrafluoroethane.

Preferably, the reaction temperature is 60-150 ℃, preferably 80-100 ℃, and the reaction pressure is 0.6-0.8MPa gauge pressure.

It is preferable thatThe liquid phase Lewis acid is SbCl₅、SnCl₄、TiCl₄、HSO₃Cl、HSO₃F, one or a mixture of several of the F in any proportion.

Preferably, the mass of the liquid phase lewis acid is 5 to 50%, preferably 5 to 20% of the mass of the added reaction substrate.

Preferably, the mass ratio of the hydrogen fluoride to the 1, 1-difluoro-2, 2-dichloroethane is 1: 3-10, preferably 1: 4-6.

Preferably, the liquid phase lewis acid is activated before being used for catalytic reaction.

Preferably, the activation treatment is performed as follows: mixing Lewis acid and hydrogen fluoride, wherein the activation temperature is 70-90 ℃, and the activation time is 4-8 h.

Preferably, antimony pentachloride put into the reactor is added with anhydrous hydrogen fluoride into the reactor for a plurality of times through a diaphragm metering pump, and the temperature is raised to a set temperature and kept for a set time to ensure that the activation of the catalyst is finished; then slowly cooling, continuously feeding 1, 1-difluoro-2, 2-dichloroethane and anhydrous hydrogen fluoride for reaction, and washing, alkali washing and rectifying the reaction product to obtain the final product.

Preferably, the temperature rise time during the activation of the catalyst is controlled to be 2 hours, the temperature is raised to 90 ℃, and the temperature is kept constant for 6 hours.

Preferably, during the reaction, the liquid level of the reactor is not higher than 60%, the reaction temperature is 90 ℃, and the reaction pressure is 0.6-0.8 MPa.

This application can bring following beneficial effect:

1. the present application provides a new route to 1, 1, 2, 2-tetrafluoroethane;

2. the raw material is stable and is not limited by transportation distance and the like, and the raw material is used as a by-product of the 1, 1-difluoro-1-chloroethane, so that the raw material is low in price and easy to obtain;

the conversion rate of the 1, 1-difluoro-2, 2-dichloroethane reaches more than 90 percent, the selectivity of R134 reaches more than 80 percent, and the process is suitable for industrial production.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a process flow diagram of the present application.

Detailed Description

In order to clearly explain the technical features of the present invention, the present application will be explained in detail by the following embodiments in combination with the accompanying drawings.

As shown in the drawings, the following detailed description is given by way of example in order to more clearly explain the overall concept of the present application.

In addition, in the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on those shown in the drawings, are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present application.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; the connection can be mechanical connection, electrical connection or communication; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Fig. 1 shows a process flow diagram of the present application.

Specific example 1:

1.0Kg of antimony pentachloride catalyst is put into a 10.0L reactor, 6.0Kg of anhydrous hydrogen fluoride is added into the reactor five times by a diaphragm metering pump, the temperature rise time is controlled to be 2 hours, and when the temperature rises to about 90 ℃, the temperature is kept for 6 hours, so that the catalyst is ensured to be activated completely. Then, according to the mass ratio of 1, 1-difluoro-2, 2-dichloroethane: anhydrous hydrogen fluoride ═ 6: 1, 0.7Kg/h, controlling the liquid level of the reactor to be not higher than 60%, controlling the reaction temperature to be about 90 ℃ and the reaction pressure to be 0.6-0.8 Mpa. And (3) washing and alkali washing the reaction product to obtain about 90.0% of R134, and collecting the liquid-phase material after washing for calculating the conversion rate of the 1, 1-difluoro-2, 2-dichloroethane.

Specific example 2:

the continuous feeding ratio of 1, 1-difluoro-2, 2-dichloroethane to anhydrous hydrogen fluoride was changed on the basis of example 1 to 5: 1, 0.7Kg/h, and the reaction conditions were the same as in example 1, and the reaction results are shown in Table 1.

Specific example 3:

the continuous feeding ratio of 1, 1-difluoro-2, 2-dichloroethane to anhydrous hydrogen fluoride was changed on the basis of example 1 to 4: 1, 0.7Kg/h, and the reaction conditions were the same as in example 1, and the reaction results are shown in Table 1.

Specific example 4:

the reaction temperature was changed to 95 ℃ based on example 1, and the reaction results were shown in Table 1, except that the reaction conditions were the same as in example 1.

Specific example 5:

the reaction temperature was changed to 100 ℃ based on example 1, and the reaction conditions were the same as in example 1, and the reaction results are shown in Table 1.

Specific example 6:

the catalyst was changed to SnCl4 based on example 1, and the reaction conditions were the same as in example 1, and the results are shown in Table 1.

Specific example 7:

the catalyst was changed to TiCl4 on the basis of example 1, the remaining reaction conditions were the same as in example 1, and the reaction results are shown in Table 1.

Specific example 8:

the catalyst was changed to HSO3Cl on the basis of example 1, and the reaction conditions were the same as in example 1, and the reaction results are shown in Table 1.

Specific example 9:

the catalyst was changed to HSO3F on the basis of example 1, and the reaction conditions were the same as in example 1, and the reaction results are shown in Table 1.

Specific example 10:

the catalyst was changed to TiCl4 and HSO3Cl (mass ratio 1: 1) on the basis of example 1, and the reaction results were shown in Table 1, except that the reaction conditions were the same as in example 1.

Specific example 11:

the catalyst was changed to TiCl4 and HSO3Cl (mass ratio 2: 1) on the basis of example 1, and the reaction results were shown in Table 1, except that the reaction conditions were the same as in example 1.

TABLE 1

Therefore, the conversion rate of the 1, 1-difluoro-2, 2-dichloroethane reaches more than 90%, the R134 selectivity reaches more than 80%, and the process is suitable for industrial production.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.