Preparation method of tetrachlorohexafluorobutane

Abstract

The invention relates to the technical field of tetrachlorohexafluorobutane, in particular to a preparation method of tetrachlorohexafluorobutane, which comprises the following steps: S1, preparation of zinc potassium monohydrogen dichloride: the preparation method comprises the following steps: A, dissolving potassium chloride in deionized water to obtain a potassium chloride solution with the weight percentage concentration of 20-30%; b, dissolving zinc chloride in deionized water to obtain a zinc chloride solution, wherein the weight percentage concentration of the zinc chloride solution is 50-80%; and C, dropwise adding the zinc chloride solution obtained in the step B into the potassium chloride solution obtained in the step A, reacting to prepare a zinc potassium trichloride solution, and evaporating the zinc potassium trichloride solution to obtain zinc potassium trichloride. The method provided by the invention has the advantages of low cost, high yield and easy realization of industrialization, and overcomes the defects of low yield, more wastes and poor atom economy in the process of preparing tetrachlorohexafluorobutane by coupling chlorotrifluoroethylene and then chloridizing chlorotrifluoroethylene with chlorine; and meanwhile, the high cost restricts the application process of replacing the traditional electronic etching agent carbon tetrafluoride with hexafluorobutadiene in China.

Description

Technical Field

[0001] The invention relates to the technical field of tetrachlorohexafluorobutane, in particular to a method for preparing tetrachlorohexafluorobutane. Background Art

[0002] Tetrachlorohexafluorobutane is an organic compound with the chemical formula C4Cl4F6 and a molecular weight of 303.85. It has a low boiling point and good thermal conductivity, stable chemical properties, and low corrosiveness to metals and plastics. It is mainly used as the main synthetic raw material for hexafluorobutadiene, which is a new type of environmentally friendly electronic etching agent with the advantage of good etching accuracy.

[0003] At present, the invention patent with publication number CN117263769A discloses a method for preparing 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane, comprising: S1, preparing 1,2-dichloro-1,2,2-trifluorobromoethane by addition reaction of trifluorochloroethylene and bromine monochloride; S2, preparing 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane by coupling reaction of 1,2-dichloro-1,2,2-trifluorobromoethane under the action of metallic magnesium. However, the preparation method has the disadvantages of low yield, high waste and poor atom economy in the process of preparing tetrachlorohexafluorobutane by coupling trifluorochloroethylene and then chlorinating with chlorine.

[0004] The invention patent with publication number CN112250541A discloses a method for preparing hexafluorobutadiene, comprising adding isopropanol and aprotic polar solvent in a mass ratio of 1:0.6-1.2 into a reactor and mixing for 8h-12h to obtain a polar base liquid; placing zinc particles with an average particle size of 4mm-5mm in an aqueous solution of HCl with a mass fraction of 8%-15% and soaking for 4h-5h, then washing with distilled water until the pH value is 6.5-7, and then placing at 180°C-220°C and 1.2kPa-1.6kPa for vacuum drying for 8h-10h to obtain activated zinc; placing iodine into a reactor, passing chlorine gas at 32°C-38°C, and distilling the obtained liquid to obtain iodine monochloride; mixing iodine monochloride and chlorotrifluoroethylene and placing them in a reactor, and then adding 6-8 times the mass of the polar base liquid of the iodine monochloride to react. The reaction temperature is -8℃~-5℃, the reaction time is 6h~9h, and then distillation is performed to obtain 1,2-dichloro-2-iodo-1,1,2-trifluoroethane; 1,2-dichloro-2-iodo-1,1,2-trifluoroethane and activated zinc are placed in a reactor, and then a polar base liquid and an ester catalyst are added to react. The reaction time is 5h~15h, and the reaction temperature is 15℃~25℃. After the reaction is completed, it is washed, dried, and distilled to obtain 1,2,3,4-tetrachlorohexafluorobutane. However, the raw material in the preparation process of tetrachlorohexafluorobutane in the preparation method is 1,2-dichloro-1-iodotrifluoroethane, and the existing preparation cost of tetrachlorohexafluorobutane using iodine-containing substances is relatively high, and the high cost restricts the application process of using hexafluorobutadiene to replace traditional electronic etching agent carbon tetrafluoride in my country. For this reason, we propose a preparation method for tetrachlorohexafluorobutane. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing tetrachlorohexafluorobutane, which has the advantages of low cost, high yield and easy industrialization, and solves the disadvantages of low yield, large amount of waste and poor atom economy in the process of preparing tetrachlorohexafluorobutane from chlorotrifluoroethylene coupling and then chlorination with chlorine, and the problem that the high cost restricts the application process of using hexafluorobutadiene to replace traditional electronic etching agent carbon tetrafluoride in my country.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for preparing tetrachlorohexafluorobutane, the reaction equation of which is as follows:

[0007] The first step chemical reaction equation:

[0008] 2C l CF 2 CFC 2 +2KZnHCl 2 →C l CF 2 CFC l CFC l CF 2 C l+2KZnC l 3 +2HCl

[0009] The second step catalyst activation equation:

[0010] 2KV 3 +H 2 →2KZnHCl 2 +2HCl

[0011] The method for preparing tetrachlorohexafluorobutane comprises the following steps:

[0012] S1: Preparation of potassium zinc monohydrogen chloride: The preparation method comprises the following steps:

[0013] A: Potassium chloride solution is obtained by dissolving potassium chloride in deionized water, with a weight percentage concentration of 20-30%;

[0014] B: zinc chloride is dissolved in deionized water to obtain a zinc chloride solution having a weight percentage concentration of 50-80%;

[0015] C: adding the zinc chloride solution obtained in B dropwise to the potassium chloride solution obtained in A to react and prepare a potassium zinc chloride solution, and evaporating the potassium zinc chloride solution to obtain potassium zinc chloride;

[0016] D: Use hydrogen to directly treat the potassium zinc trichloride obtained in C with hydrogen to obtain potassium zinc monohydrogen dichloride;

[0017] S2: 18-26 kg of potassium zinc hydride and 26-35 liters of potassium zinc dichloride catalyst are loaded into 6 40x6000 nickel alloy tubular reactors, and the reactor is heated to 235-260° C.;

[0018] S3: N is introduced at a rate of 8 to 11 L / min. 2 The catalyst is further dried, and after 4 to 6 hours, the temperature is raised to 235 to 260°C, and 1,1,2-trifluoro-1,2,2-trichloroethane is preheated and added from the top of the tubular reactor;

[0019] S4: removing the reaction material from the bottom of the tubular reactor, washing it with water and alkali, drying it with molecular sieves, condensing it, collecting it with rectification, and sampling and analyzing it to obtain tetrachlorohexafluorobutane;

[0020] S5: When the conversion rate and yield of 1,1,2-trifluoro-1,2,2-trichloroethane decrease, stop feeding and switch to hydrogen feeding, keep the temperature of the tubular reactor at 285-315° C., and the hydrogen feeding rate at 340-380 L / min under standard conditions. After 30 minutes, the activation is completed;

[0021] S6: Prepare to switch the feeding, the feeding rate of 1,1,2-trifluoro-1,2,2-trichloroethane is 160-190 L / min under standard conditions, the pressure of the tube reactor is maintained at 0.8 MPa, the reaction materials are removed from the bottom of the tube reactor, directly washed with water alkali, dried with molecular sieves, condensed, distilled, collected and sampled for analysis to obtain tetrachlorohexafluorobutane.

[0022] Preferably, the catalytic reaction temperature of the first step chemical reaction equation is 250-350° C., the reaction pressure is 0.1-1 MPa, and the residence time is 10-20 seconds.

[0023] Preferably, the activation reaction temperature of the second step chemical reaction equation is 350-450° C., the reaction pressure is 0.1-1 MPa, and the residence time is 10-20 seconds.

[0024] Preferably, the reaction temperature for preparing the potassium zinc chloride solution in step S1C is 50-80° C., the pressure is normal pressure, and the reaction time is 5-8 hours.

[0025] Preferably, in step S1 D, the molar ratio of potassium zinc chloride to hydrogen is 1:1-1.2, the hydrogenation temperature is 350-450° C., the reaction pressure is 0.1-1 MPa, and the residence time is 10-20 seconds.

[0026] Preferably, the jacket of the tubular reactor in step S2 is heated by heat transfer oil.

[0027] Preferably, the feeding rate of 1,1,2-trifluoro-1,2,2-trichloroethane in step S3 is 160-190 L / min under standard conditions, and the pressure of the tubular reactor is maintained at 0.8 MPa.

[0028] Preferably, the molecular sieve drying temperature in step S4 is 110-130° C., and the drying time is 3-7 hours.

[0029] Preferably, the condensation temperature in step S4 is 40-80°C.

[0030] Preferably, the pressure of the tubular reactor in step S5 is maintained at 0.9 MPa.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The method for preparing tetrachlorohexafluorobutane has low cost, high yield, low waste content, and is easy to industrialize, and can effectively accelerate the application process of hexafluorobutadiene replacing traditional electronic etching agent carbon tetrafluoride.

[0033] 2. The present invention can be repeatedly activated during the production process, which not only ensures the production efficiency of the product, but also facilitates people's use and can reduce the waste of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the steps of the preparation method of the present invention. DETAILED DESCRIPTION

[0035] Embodiment 1

[0036] In this embodiment, tetrachlorohexafluorobutane is prepared by the following method, comprising the following steps:

[0037] S1: Preparation of potassium zinc monohydrogen chloride: The preparation method comprises the following steps:

[0038] A: Potassium chloride solution is obtained by dissolving potassium chloride in deionized water, and the weight percentage concentration is 20%;

[0039] B: zinc chloride is dissolved in deionized water to obtain a zinc chloride solution having a weight percentage concentration of 50%;

[0040] C: adding the zinc chloride solution obtained in B dropwise to the potassium chloride solution obtained in A to react and prepare a potassium zinc chloride solution, the reaction temperature is 50° C., the pressure is normal pressure, the reaction time is 5 hours, and the potassium zinc chloride solution is evaporated to obtain potassium zinc chloride;

[0041] D: directly subjecting the potassium zinc trichloride obtained in C to a hydrogenation reaction with hydrogen, wherein the molar ratio of potassium zinc trichloride to hydrogen is 1:1, the hydrogenation temperature is 350°C, the reaction pressure is 0.1 MPa, and the residence time is 20 seconds to obtain monohydrogen potassium zinc dichloride;

[0042] S2: 21.4 kg of potassium zinc monohydride was filled into 6 40x6000 nickel alloy tubular reactors, and the catalyst potassium zinc dichloride was filled in a volume of 30 liters. The jacket of the tubular reactor was heated by heat transfer oil, and the reactor was heated to 250°C;

[0043] S3: N is introduced at a rate of 10 L / min. 2 After further drying the catalyst, the temperature was raised to 250°C for 5 hours, and 1,1,2-trifluoro-1,2,2-trichloroethane was preheated and added from the top of the tubular reactor. The feeding rate was 180L / min under standard conditions, and the pressure of the tubular reactor was maintained at 0.8Mpa.

[0044] S4: The reaction material is removed from the bottom of the tubular reactor, washed directly with water alkali, dried with molecular sieves at a drying temperature of 110°C for 5 hours, condensed at a condensation temperature of 50°C, collected by rectification and sampled for analysis. After 1 hour, 58 kg of tetrachlorohexafluorobutane with a purity of 99% is collected;

[0045] S5: When the conversion rate and yield of 1,1,2-trifluoro-1,2,2-trichloroethane decrease, stop feeding and switch to hydrogen feeding, keep the temperature of the tubular reactor at 300°C, the hydrogen feeding rate at 360L / min under standard conditions, and the pressure of the tubular reactor at 0.9Mpa. After 30min, the activation is completed;

[0046] S6: Prepare to switch the feeding, the feeding rate of 1,1,2-trifluoro-1,2,2-trichloroethane is 180L / min under standard conditions, the pressure of the tube reactor is maintained at 0.8Mpa, the reaction materials are removed from the bottom of the tube reactor, directly washed with water alkali, dried with molecular sieves, condensed, distilled, collected and sampled for analysis, and 55 kg of tetrachlorohexafluorobutane with a purity of 99% is collected after 1 hour.

[0047] Embodiment 2

[0048] In this embodiment, tetrachlorohexafluorobutane is prepared by the following method, comprising the following steps:

[0049] S1: Preparation of potassium zinc monohydrogen chloride: The preparation method comprises the following steps:

[0050] A: Potassium chloride solution is obtained by dissolving potassium chloride in deionized water, with a weight percentage concentration of 25%;

[0051] B: zinc chloride is dissolved in deionized water to obtain a zinc chloride solution having a weight percentage concentration of 60%;

[0052] C: adding the zinc chloride solution obtained in B dropwise to the potassium chloride solution obtained in A to react and prepare a potassium zinc chloride solution, the reaction temperature is 60° C., the pressure is normal pressure, the reaction time is 6.5 hours, and the potassium zinc chloride solution is evaporated to obtain potassium zinc chloride;

[0053] D: directly subjecting the potassium zinc trichloride obtained in C to a hydrogenation reaction with hydrogen, wherein the molar ratio of potassium zinc trichloride to hydrogen is 1:1.1, the hydrogenation temperature is 380°C, the reaction pressure is 0.5 MPa, and the residence time is 15 seconds, to obtain potassium zinc dichloride monohydrogenate;

[0054] S2: 19.2 kg of potassium zinc monohydride was filled into 6 40x6000 nickel alloy tubular reactors, and the catalyst potassium zinc dichloride was filled in a volume of 27 liters. The jacket of the tubular reactor was heated by heat transfer oil, and the reactor was heated to 240°C;

[0055] S3: N2 was introduced at a rate of 9 L / min to further dry the catalyst. After 4 hours, the temperature was raised to 240°C, and 1,1,2-trifluoro-1,2,2-trichloroethane was preheated and added from the top of the tubular reactor. The feeding rate was 160 L / min under standard conditions, and the pressure of the tubular reactor was maintained at 0.8 MPa.

[0056] S4: The reaction material is removed from the bottom of the tubular reactor, washed directly with water alkali, dried with molecular sieves at 120°C for 3 hours, condensed at 40°C, collected by rectification and sampled for analysis. After 1 hour, 50.3 kg of tetrachlorohexafluorobutane with a purity of 99% is collected;

[0057] S5: When the conversion rate and yield of 1,1,2-trifluoro-1,2,2-trichloroethane decrease, stop feeding and switch to hydrogen feeding, keep the temperature of the tubular reactor at 290°C, the hydrogen feeding rate at 340L / min under standard conditions, and the pressure of the tubular reactor at 0.9Mpa. After 30min, the activation is completed;

[0058] S6: Prepare to switch the feeding, the feeding rate of 1,1,2-trifluoro-1,2,2-trichloroethane is 160L / min under standard conditions, the pressure of the tube reactor is maintained at 0.8Mpa, the reaction materials are removed from the bottom of the tube reactor, directly washed with water alkali, dried with molecular sieves, condensed, distilled, collected and sampled for analysis, and 48.9 kg of tetrachlorohexafluorobutane with a purity of 99% is collected after 1 hour.

[0059] Embodiment 3

[0060] In this embodiment, tetrachlorohexafluorobutane is prepared by the following method, comprising the following steps:

[0061] S1: Preparation of potassium zinc monohydrogen chloride: The preparation method comprises the following steps:

[0062] A: Potassium chloride solution is obtained by dissolving potassium chloride in deionized water, and the weight percentage concentration is 30%;

[0063] B: zinc chloride is dissolved in deionized water to obtain a zinc chloride solution having a weight percentage concentration of 80%;

[0064] C: adding the zinc chloride solution obtained in B dropwise to the potassium chloride solution obtained in A to react and prepare a potassium zinc chloride solution, the reaction temperature is 80° C., the pressure is normal pressure, the reaction time is 8 hours, and the potassium zinc chloride solution is evaporated to obtain potassium zinc chloride;

[0065] D: directly subjecting the potassium zinc trichloride obtained in C to a hydrogenation reaction with hydrogen, wherein the molar ratio of potassium zinc trichloride to hydrogen is 1:1.2, the hydrogenation temperature is 450°C, the reaction pressure is 0.9 MPa, and the residence time is 10 seconds, to obtain potassium zinc dichloride monohydrogenate;

[0066] S2: 24.6 kg of potassium zinc monohydride was filled into 6 40x6000 nickel alloy tubular reactors, and the catalyst potassium zinc dichloride was filled in a volume of 36 liters. The jacket of the tubular reactor was heated by heat transfer oil, and the reactor was heated to 260°C;

[0067] S3: N2 was introduced at a rate of 11 L / min to further dry the catalyst. After 6 hours, the temperature was raised to 260°C, and 1,1,2-trifluoro-1,2,2-trichloroethane was preheated and added from the top of the tubular reactor. The feeding rate was 190 L / min under standard conditions, and the pressure of the tubular reactor was maintained at 0.8 MPa.

[0068] S4: The reaction material is removed from the bottom of the tubular reactor, washed directly with water alkali, dried with molecular sieves at a drying temperature of 130°C for 7 hours, condensed at a condensation temperature of 80°C, collected by rectification and sampled for analysis. After 1 hour, 64.3 kg of tetrachlorohexafluorobutane with a purity of 99% is collected;

[0069] S5: When the conversion rate and yield of 1,1,2-trifluoro-1,2,2-trichloroethane decrease, stop feeding and switch to hydrogen feeding, keep the temperature of the tubular reactor at 315°C, the hydrogen feeding rate at 380L / min under standard conditions, and the pressure of the tubular reactor at 0.9Mpa. After 30min, the activation is completed;

[0070] S6: Prepare to switch the feeding, the feeding rate of 1,1,2-trifluoro-1,2,2-trichloroethane is 190L / min under standard conditions, the pressure of the tube reactor is maintained at 0.8Mpa, the reaction materials are removed from the bottom of the tube reactor, directly washed with water alkali, dried with molecular sieves, condensed, distilled, collected and sampled for analysis, and 62.5 kg of tetrachlorohexafluorobutane with a purity of 99% is collected after 1 hour.

[0071] Comparative Example 1

[0072] Compared with Example 1, tetrachlorohexafluorobutane is prepared by coupling chlorotrifluoroethylene and then chlorinating with chlorine.

[0073] The preparation method comprises the following steps:

[0074] S1, the addition reaction of chlorotrifluoroethylene and bromine monochloride to prepare 1,2-dichloro-1,2,2-trifluorobromoethane;

[0075] S2, 1,2-dichloro-1,2,2-trifluorobromoethane undergoes a coupling reaction under the action of metallic magnesium to prepare 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane.

[0076] Comparative Example 2

[0077] Compared with Example 1, 1,2-dichloro-1-iodotrifluoroethane is used to prepare tetrachlorohexafluorobutane.

[0078] 1. Add isopropanol and aprotic polar solvent in a mass ratio of 1:0.6-1.2 into a reaction kettle and mix for 8h-12h to prepare a polar base liquid;

[0079] 2. Soak zinc particles with an average particle size of 4 mm to 5 mm in an aqueous solution of HCl with a mass fraction of 8% to 15% for 4 h to 5 h, then wash with distilled water until the pH value is 6.5 to 7, and then place at 180°C to 220°C and 1.2 kPa to 1.6 kPa for vacuum drying for 8 h to 10 h to obtain activated zinc;

[0080] 3. Iodine is placed in a reactor, chlorine gas is introduced at 32°C to 38°C, and the obtained liquid is distilled to obtain iodine monochloride; iodine monochloride and chlorotrifluoroethylene are mixed and placed in a reactor, and then a polar base liquid of 6 to 8 times the mass of iodine monochloride is added to react at a reaction temperature of -8°C to -5°C and a reaction time of 6h to 9h, and then distilled to obtain 1,2-dichloro-2-iodo-1,1,2-trifluoroethane;

[0081] 4. Put 1,2-dichloro-2-iodo-1,1,2-trifluoroethane and activated zinc into a reactor, then add polar base liquid and ester catalyst to react, the reaction time is 5h to 15h, the reaction temperature is 15℃ to 25℃, after the reaction is completed, wash, dry and distill to obtain 1,2,3,4-tetrachlorohexafluorobutane;

[0082] Application performance verification

[0083] The products prepared in Examples 1 to 3 of the present invention and the products prepared in Comparative Examples 1 to 2 were subjected to gas chromatography to detect the finished product content. The measured yield and selectivity of tetrachlorohexafluorobutane are shown in Table 1.

[0084] Table 1 is the yield and selectivity analysis of tetrachlorohexafluorobutane prepared in Examples 1 to 3 and Comparative Examples 1 to 2

[0085]

[0086]

[0087] As can be seen from Table 1, the tetrachlorohexafluorobutane prepared in Examples 1 to 3 has an extremely good yield and selectivity compared with the tetrachlorohexafluorobutane prepared in Comparative Examples 1 to 2.

[0088] The waste content and product cost of the products prepared in Examples 1 to 3 of the present invention were compared with those of the products prepared in Comparative Examples 1 to 2, and the waste content and product cost of the products were divided into ten stages from low to high, and the stages 1 to 10 were replaced by 1 to 10 points, where 1-3 points were low, 4-6 points were average, 7-8 points were relatively high, and 9-10 points were very high. The measured waste content and product cost of tetrachlorohexafluorobutane are shown in Table 2.

[0089] Table 2 is the waste content and product cost analysis of tetrachlorohexafluorobutane prepared in Examples 1 to 3 and Comparative Examples 1 to 2

[0090] Waste content Product Cost Embodiment 1 1 1 Embodiment 2 1 1 Embodiment 3 1 2 Comparative Example 1 8 5 Comparative Example 2 3 9

[0091] As can be seen from Table 2, the waste content and product cost of the tetrachlorohexafluorobutane prepared in Examples 1 to 3 are lower than those of the products prepared in Comparative Examples 1 to 2.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing tetrachlorohexafluorobutane, characterized in that: The reaction equation is as follows: The first step chemical reaction equation: 2ClCF2CFCl2+2KZnHCl2→ClCF2CFClCFClCF2Cl+2KZnCl3+2HCl The second step catalyst activation equation: 2KZnCl3+H2→2KZnHCl2+2HCl The method for preparing tetrachlorohexafluorobutane comprises the following steps: S1: Preparation of potassium zinc monohydrogen chloride: The preparation method comprises the following steps: A: Potassium chloride solution is obtained by dissolving potassium chloride in deionized water, with a weight percentage concentration of 20-30%; B: zinc chloride is dissolved in deionized water to obtain a zinc chloride solution having a weight percentage concentration of 50-80%; C: adding the zinc chloride solution obtained in B dropwise to the potassium chloride solution obtained in A to react and prepare a potassium zinc chloride solution, and evaporating the potassium zinc chloride solution to obtain potassium zinc chloride; D: Use hydrogen to directly treat the potassium zinc trichloride obtained in C with hydrogen to obtain potassium zinc monohydrogen dichloride; S2: 18-26 kg of potassium zinc hydride and 26-35 liters of potassium zinc dichloride catalyst are loaded into 6 40x6000 nickel alloy tubular reactors, and the reactor is heated to 235-260° C.; S3: N2 is introduced at a rate of 8 to 11 L / min to further dry the catalyst. After 4 to 6 hours, the temperature is raised to 235 to 260°C, and 1,1,2-trifluoro-1,2,2-trichloroethane is preheated and added from the top of the tubular reactor; S4: removing the reaction material from the bottom of the tubular reactor, washing it with water and alkali, drying it with molecular sieves, condensing it, collecting it with rectification, and sampling and analyzing it to obtain tetrachlorohexafluorobutane; S5: When the conversion rate and yield of 1,1,2-trifluoro-1,2,2-trichloroethane decrease, stop feeding and switch to hydrogen feeding, keep the temperature of the tubular reactor at 285-315° C., and the hydrogen feeding rate at 340-380 L / min under standard conditions. After 30 minutes, the activation is completed; S6: Prepare to switch the feeding, the feeding rate of 1,1,2-trifluoro-1,2,2-trichloroethane is 160-190 L / min under standard conditions, the pressure of the tube reactor is maintained at 0.8 MPa, the reaction materials are removed from the bottom of the tube reactor, directly washed with water alkali, dried with molecular sieves, condensed, distilled, collected and sampled for analysis to obtain tetrachlorohexafluorobutane.

2. The method for preparing tetrachlorohexafluorobutane according to claim 1, characterized in that: The catalytic reaction temperature of the first step chemical reaction equation is 250-350° C., the reaction pressure is 0.1-1 MPa, and the residence time is 10-20 seconds.

3. The method for preparing tetrachlorohexafluorobutane according to claim 1, characterized in that: The activation reaction temperature of the second step chemical reaction equation is 350-450° C., the reaction pressure is 0.1-1 MPa, and the residence time is 10-20 seconds.

4. The method for preparing tetrachlorohexafluorobutane according to claim 1, characterized in that: The reaction temperature for preparing the potassium zinc trichloride solution in step S1 C is 50-80° C., the pressure is normal pressure, and the reaction time is 5-8 hours.

5. The method for preparing tetrachlorohexafluorobutane according to claim 1, characterized in that: In step S1 D, the molar ratio of potassium zinc chloride to hydrogen is 1:1-1.2, the hydrogenation temperature is 350-450° C., the reaction pressure is 0.1-1 MPa, and the residence time is 10-20 seconds.

6. The method for preparing tetrachlorohexafluorobutane according to claim 1, characterized in that: The jacket of the tubular reactor in step S2 is heated by heat transfer oil.

7. The method for preparing tetrachlorohexafluorobutane according to claim 1, characterized in that: The feeding rate of 1,1,2-trifluoro-1,2,2-trichloroethane in step S3 is 160-190 L / min under standard conditions, and the pressure of the tubular reactor is maintained at 0.8 MPa.

8. The method for preparing tetrachlorohexafluorobutane according to claim 1, characterized in that: The molecular sieve drying temperature in step S4 is 110-130° C., and the drying time is 3-7 hours.

9. The method for preparing tetrachlorohexafluorobutane according to claim 1, characterized in that: The condensation temperature in step S4 is 40-80°C.

10. The method for preparing tetrachlorohexafluorobutane according to claim 1, characterized in that: The pressure of the tube reactor in step S5 is maintained at 0.9 MPa.

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