Production process of high-purity 1, 2-dichloroethylene

Abstract

The invention discloses a production process of high-purity 1, 2-dichloroethylene, and relates to the field of production of 1, 2-dichloroethylene. When the 1, 2-dichloroethylene is produced, firstly, a molecular sieve is subjected to acid-base composite treatment, then a silane coupling agent containing allyl is grafted, and then the molecular sieve is polymerized with 1-vinyl-3-octyl imidazole tetrafluoroborate and 1-vinyl-3-ethyl imidazole tetrafluoroborate to obtain a modified molecular sieve; the method comprises the following steps: catalyzing 1, 1, 2-trichloroethane gas phase cracking in a fixed bed reaction device by taking a modified molecular sieve as a catalyst to generate a dichloroethylene mixture, and finally distilling the dichloroethylene mixture to obtain high-purity 1, 2-dichloroethylene.

Description

Technical Field

[0001] The invention relates to the field of 1,2-dichloroethylene production, and in particular to a production process of high-purity 1,2-dichloroethylene. Background Art

[0002] 1,2-Dichloroethylene is an important organic compound with a wide range of applications in multiple industries. It is often used in paints, coatings, adhesives and cleaners as a solvent or diluent, and is also an intermediate in the manufacture of polyvinyl chloride.

[0003] At present, the main methods for preparing 1,2-dichloroethylene in industry are liquid phase method and gas phase cracking method. Among them, gas phase catalytic 1,1,2-trichloroethane dehydrochlorination method is considered to be a very promising method due to its environmental protection and extremely high atomic utilization rate. 1,1,2-trichloroethane dehydrochlorination mainly produces three products, 1,2-dichloroethylene, cis-1,2-dichloroethylene, and trans-1,2-dichloroethylene. At present, there are few research literatures on how to synthesize 1,2-dichloroethylene, and how to synthesize high-purity 1,2-dichloroethylene is a hot topic of research. Therefore, it is necessary to explore a production process for preparing high-purity 1,2-dichloroethylene. Summary of the invention

[0004] The purpose of the present invention is to provide a high-purity 1,2-dichloroethylene production process to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A production process for high-purity 1,2-dichloroethylene comprises the following preparation steps:

[0007] (1) mixing the acid-base composite treated molecular sieve, allyl trimethoxysilane and anhydrous ethanol in a mass ratio of 1: (1.5-2.0): (50-60) evenly, ultrasonically dispersing at 40 Hz for 10-20 min, stirring for 10-12 h, filtering and washing with ethanol for 3-5 times, stirring at 70-80 ° C for 50-60 min, and drying at 60 ° C for 6-8 h to obtain an allyl-containing molecular sieve;

[0008] (2) mixing allyl molecular sieve, 1-vinyl-3-octylimidazole tetrafluoroborate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, benzoyl peroxide and dimethyl sulfoxide evenly, reacting at 80° C. for 4-5 hours, filtering and washing with methanol for 3-4 times, and drying at 60° C. for 6-8 hours to obtain a modified molecular sieve;

[0009] (3) Weighing the modified molecular sieve and 1,1,2-trichloroethane, wherein the mass ratio of 1,1,2-trichloroethane to the molecular sieve is 1:(200-300), placing the modified molecular sieve in a quartz reaction tube of a fixed reaction bed device to form a catalyst bed, and preheating the reaction tube at 300° C. for 1.5-2 h in a nitrogen atmosphere, with a nitrogen flow rate of 30 mL / min; placing the 1,1,2-trichloroethane in a saturator under ice bath conditions, and passing the 1,1,2-trichloroethane into the catalyst bed using nitrogen, with the catalyst bed temperature of 300° C. and the space velocity of 2000 mL / (g*h) to obtain a 1,2-dichloroethylene mixture, condensing the 1,2-dichloroethylene mixture in a condenser to obtain a 1,2-dichloroethylene mixed liquid, with a condensation temperature of 0-10° C., and then distilling the 1,2-dichloroethylene mixed liquid to obtain high-purity 1,2-dichloroethylene.

[0010] As an optimization, the preparation method of the acid-base composite treated molecular sieve in step (1) is: evenly mix the molecular sieve and 0.3 mol / L sodium hydroxide solution in a mass ratio of 1: (20-25), stir at 70-80°C for 50-60 min, filter and wash with pure water 3-5 times, and then dry at 60°C for 6-8h to obtain an alkali-treated molecular sieve; evenly mix the alkali-treated molecular sieve and 0.1 mol / L hydrochloric acid solution in a mass ratio of 1: (10-15), stir at 70-80°C for 50-60 min, and dry at 60°C for 6-8h to obtain an acid-base composite treated molecular sieve; wherein the molecular sieve model is AS-VZ3.

[0011] As an optimization, the amount of allyl molecular sieve, 1-vinyl-3-octylimidazole tetrafluoroborate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, benzoyl peroxide and dimethyl sulfoxide in step (2) is calculated by mass: 1 part of modified molecular sieve, 0.1-0.3 parts of 1-vinyl-3-octylimidazole tetrafluoroborate, 0.3-0.5 parts of 1-vinyl-3-ethylimidazolium tetrafluoroborate, 0.03-0.05 parts of benzoyl peroxide and 15-20 parts of dimethyl sulfoxide.

[0012] As an optimization, the specific operation steps of the distillation in step (3) are to heat the 1,2-dichloroethylene mixture to 35-40°C for 20-30 minutes, continue heating to 60-65°C, and collect it using a condenser with a condenser temperature of 0-10°C and a heating time of 50-60 minutes to obtain high-purity 1,2-dichloroethylene.

[0013] The present invention also provides 1,2-dichloroethylene produced according to the production process of the high-purity 1,2-dichloroethylene.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0015] When producing high-purity 1,2-dichloroethylene, the present invention firstly performs an acid-base composite treatment on a molecular sieve, then grafts an allyl-containing silane coupling agent, and polymerizes with 1-vinyl-3-octylimidazole tetrafluoroborate and 1-vinyl-3-ethylimidazole tetrafluoroborate to obtain a modified molecular sieve; in a fixed bed reaction device, the modified molecular sieve is used as a catalyst to catalyze gas-phase cracking of 1,1,2-trichloroethane to generate a dichloroethylene mixture, and finally the dichloroethylene mixture is distilled to obtain high-purity 1,2-dichloroethylene.

[0016] First of all, molecular sieve is a kind of crystalline aluminosilicate with various ordered microporous networks and large active surface structures. It has good thermal stability and catalytic performance. It can be used as a catalyst or as a catalyst carrier. The molecular sieve is first treated with alkali to obtain a porous molecular sieve with large pores, which increases the surface area of ​​the molecular sieve and improves the catalytic efficiency. Then, acid treatment can wash away the amorphous aluminum species remaining on the inner and outer pore walls of the molecular sieve after the alkali treatment, making the pore structure more unobstructed, and the pore structure and acid properties can be further adjusted to reduce the inactivation of the catalyst caused by the attachment of carbon deposits; then, a silane coupling agent is used to graft double bonds on the surface of the molecular sieve, which can be used in Under initiator conditions, polymerization is carried out with 1-vinyl-3-octylimidazole tetrafluoroborate and 1-vinyl-3-ethylimidazole tetrafluoroborate. 1-vinyl-3-octylimidazole tetrafluoroborate and 1-vinyl-3-ethylimidazole tetrafluoroborate are a type of borate with high thermal stability. Acidic sites and hydrophobic silane long chains can also be introduced on the surface of the molecular sieve. The introduction of acidic sites can further improve the catalytic activity of the molecular sieve. Then, the modified molecular sieve is used as a catalyst to catalyze the gas-phase cracking of 1,1,2-trichloroethane in a fixed bed reaction device to generate a dichloroethylene mixture. Finally, the dichloroethylene mixture is distilled to obtain high-purity 1,2-dichloroethylene. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] The molecular sieve used in the following examples and comparative examples is of model AS-VZ3.

[0019] Example 1

[0020] A production process for high-purity 1,2-dichloroethylene, comprising the following steps:

[0021] (1) Mix the molecular sieve and 0.3 mol / L sodium hydroxide solution in a mass ratio of 1:20, stir at 80°C for 60 min, filter and wash with pure water 5 times, and dry at 60°C for 8 h to obtain an alkali-treated molecular sieve; mix the alkali-treated molecular sieve and 0.1 mol / L hydrochloric acid solution in a mass ratio of 1:10, stir at 80°C for 60 min, and dry at 60°C for 8 h to obtain an acid-base composite-treated molecular sieve; mix the acid-base composite-treated molecular sieve, allyl trimethoxysilane, and anhydrous ethanol in a mass ratio of 1:1.5:50, ultrasonically disperse at 40 Hz for 20 min, stir for 12 h, filter and wash with ethanol 5 times, stir at 80°C for 60 min, and dry at 60°C for 8 h to obtain an allyl-containing molecular sieve;

[0022] (2) Weigh 1 part of allyl molecular sieve, 0.1 part of 1-vinyl-3-octylimidazole tetrafluoroborate, 0.3 part of 1-vinyl-3-ethylimidazolium tetrafluoroborate, 0.03 part of benzoyl peroxide, and 15 parts of dimethyl sulfoxide; mix allyl molecular sieve, 1-vinyl-3-octylimidazole tetrafluoroborate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, benzoyl peroxide, and dimethyl sulfoxide evenly, react at 80° C. for 5 h, filter, wash with methanol 4 times, and dry at 60° C. for 8 h to obtain a modified molecular sieve;

[0023] (3) Weighing the modified molecular sieve and 1,1,2-trichloroethane, wherein the mass ratio of 1,1,2-trichloroethane to the molecular sieve is 1:200, placing the modified molecular sieve in a quartz reaction tube of a fixed reaction bed device to form a catalyst bed, and preheating the catalyst bed at 300° C. for 2 h in a nitrogen atmosphere with a nitrogen flow rate of 30 mL / min; placing 1,1,2-trichloroethane in a saturator under ice bath conditions, and passing 1,1,2-trichloroethane into the catalyst bed using nitrogen; the catalyst bed temperature is 300° C., and the air is heated to 400° C.; The rate is 2000mL / (g*h) to obtain a 1,2-dichloroethylene mixture, which is condensed in a condenser to obtain a 1,2-dichloroethylene mixed liquid at a condensation temperature of 10°C, and the 1,2-dichloroethylene mixed liquid is distilled, and the 1,2-dichloroethylene mixed liquid is heated to 40°C for 30 minutes, and then heated to 65°C, and collected using a condenser, the condenser temperature is 10°C, and the heating time is 60 minutes to obtain high-purity 1,2-dichloroethylene.

[0024] Example 2

[0025] A production process for high-purity 1,2-dichloroethylene, comprising the following steps:

[0026] (1) Mix the molecular sieve and 0.3 mol / L sodium hydroxide solution in a mass ratio of 1:22, stir at 75°C for 55 minutes, filter and wash with pure water for 4 times, and then dry at 60°C for 7 hours to obtain an alkali-treated molecular sieve; mix the alkali-treated molecular sieve and 0.1 mol / L hydrochloric acid solution in a mass ratio of 1:12, stir at 75°C for 50-60 minutes, and dry at 60°C for 7 hours to obtain an acid-base composite-treated molecular sieve; mix the acid-base composite-treated molecular sieve, allyl trimethoxysilane, and anhydrous ethanol in a mass ratio of 1:1.7:55, ultrasonically disperse at 40 Hz for 15 minutes, stir for 11 hours, filter and wash with ethanol for 4 times, stir at 75°C for 55 minutes, and dry at 60°C for 7 hours to obtain an allyl-containing molecular sieve;

[0027] (2) Weigh 1 part of allyl molecular sieve, 0.2 parts of 1-vinyl-3-octylimidazole tetrafluoroborate, 0.4 parts of 1-vinyl-3-ethylimidazolium tetrafluoroborate, 0.04 parts of benzoyl peroxide, and 16 parts of dimethyl sulfoxide; mix allyl molecular sieve, 1-vinyl-3-octylimidazole tetrafluoroborate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, benzoyl peroxide, and dimethyl sulfoxide evenly, react at 80° C. for 4 h, filter, wash with methanol 4 times, and dry at 60° C. for 7 h to obtain a modified molecular sieve;

[0028] (3) Weighing the modified molecular sieve and 1,1,2-trichloroethane, wherein the mass ratio of 1,1,2-trichloroethane to the molecular sieve is 1:250, placing the modified molecular sieve in a quartz reaction tube of a fixed reaction bed device to form a catalyst bed, and preheating the catalyst bed at 300° C. for 1.7 h in a nitrogen atmosphere with a nitrogen flow rate of 30 mL / min; placing 1,1,2-trichloroethane in a saturator under ice bath conditions, and passing 1,1,2-trichloroethane into the catalyst bed using nitrogen, and the catalyst bed temperature is 300° C. , the space velocity is 2000mL / (g*h), and a 1,2-dichloroethylene mixture is obtained. The 1,2-dichloroethylene mixture is condensed in a condenser to obtain a 1,2-dichloroethylene mixed liquid, the condensation temperature is 9°C, and the 1,2-dichloroethylene mixed liquid is distilled. The 1,2-dichloroethylene mixed liquid is heated to 37°C, the heating time is 25min, and it is continued to be heated to 63°C, and collected using a condenser, the condenser temperature is 8°C, and the heating time is 55min, to obtain high-purity 1,2-dichloroethylene.

[0029] Example 3

[0030] A production process for high-purity 1,2-dichloroethylene, comprising the following steps:

[0031] (1) Mix the molecular sieve and 0.3 mol / L sodium hydroxide solution in a mass ratio of 1:25, stir at 70°C for 50 min, filter and wash with pure water for 3 times, and then dry at 60°C for 6 h to obtain an alkali-treated molecular sieve; mix the alkali-treated molecular sieve and 0.1 mol / L hydrochloric acid solution in a mass ratio of 1:15, stir at 70°C for 50 min, and dry at 60°C for 6 h to obtain an acid-base composite-treated molecular sieve; mix the acid-base composite-treated molecular sieve, allyl trimethoxysilane, and anhydrous ethanol in a mass ratio of 1:2.0:60, ultrasonically disperse at 40 Hz for 10 min, stir for 10 h, filter and wash with ethanol for 3 times, stir at 70°C for 50 min, and dry at 60°C for 6 h to obtain an allyl-containing molecular sieve;

[0032] (2) Weigh 1 part of allyl molecular sieve, 0.3 parts of 1-vinyl-3-octylimidazole tetrafluoroborate, 0.5 parts of 1-vinyl-3-ethylimidazolium tetrafluoroborate, 0.05 parts of benzoyl peroxide, and 20 parts of dimethyl sulfoxide; mix allyl molecular sieve, 1-vinyl-3-octylimidazole tetrafluoroborate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, benzoyl peroxide, and dimethyl sulfoxide evenly, react at 80° C. for 4 h, filter, wash with methanol 3 times, and dry at 60° C. for 6 h to obtain a modified molecular sieve;

[0033] (3) Weighing the modified molecular sieve and 1,1,2-trichloroethane, wherein the mass ratio of 1,1,2-trichloroethane to the molecular sieve is 1:300, placing the modified molecular sieve in a quartz reaction tube of a fixed reaction bed device to form a catalyst bed, and preheating the catalyst bed at 300° C. for 1.5 h in a nitrogen atmosphere with a nitrogen flow rate of 30 mL / min; placing 1,1,2-trichloroethane in a saturator under ice bath conditions, and passing 1,1,2-trichloroethane into the catalyst bed using nitrogen, and the catalyst bed temperature is 300° C. , the space velocity is 2000mL / (g*h), and a 1,2-dichloroethylene mixture is obtained. The 1,2-dichloroethylene mixture is condensed in a condenser to obtain a 1,2-dichloroethylene mixed liquid, the condensation temperature is 0°C, and the 1,2-dichloroethylene mixed liquid is distilled. The 1,2-dichloroethylene mixed liquid is heated to 35°C, the heating time is 20min, and it is continued to be heated to 60°C, and collected using a condenser, the condenser temperature is 0°C, and the heating time is 50min, to obtain high-purity 1,2-dichloroethylene.

[0034] Comparative Example 1

[0035] The difference between Comparative Example 1 and Example 2 is that the method does not contain steps (1) and (2), and step (3) is modified to weigh molecular sieve and 1,1,2-trichloroethane, wherein the mass ratio of 1,1,2-trichloroethane to molecular sieve is 1:250, and the modified molecular sieve is placed in a quartz reaction tube of a fixed reaction bed device to form a catalyst bed, and preheated at 300° C. for 1.7 h in a nitrogen atmosphere with a nitrogen flow rate of 30 mL / min; 1,1,2-trichloroethane is placed in a saturator under ice bath conditions, and 1,1,2-trichloroethane is passed into the catalyst using nitrogen. The catalyst bed temperature is 300°C, the space velocity is 2000mL / (g*h), and a 1,2-dichloroethylene mixture is obtained. The 1,2-dichloroethylene mixture is condensed in a condenser to obtain a 1,2-dichloroethylene mixed liquid, the condensation temperature is 9°C, and the 1,2-dichloroethylene mixed liquid is distilled. The 1,2-dichloroethylene mixed liquid is heated to 37°C for 25 minutes, and then heated to 63°C. It is collected using a condenser, the condenser temperature is 8°C, and the heating time is 55 minutes to obtain high-purity 1,2-dichloroethylene.

[0036] Comparative Example 2

[0037] The difference between Comparative Example 2 and Example 2 is that step (2) is not included, and step (1) is modified to mix the molecular sieve and 0.3 mol / L sodium hydroxide solution in a mass ratio of 1:22, stir at 75°C for 55 min, filter and wash with pure water 4 times, and then dry at 60°C for 7 h to obtain an alkali-treated molecular sieve; mix the alkali-treated molecular sieve and 0.1 mol / L hydrochloric acid solution in a mass ratio of 1:12, stir at 75°C for 50-60 min, and dry at 60°C for 7 h to obtain a modified molecular sieve.

[0038] Test Example 1

[0039] Purity test of 1,2-dichloroethylene

[0040] Test method: The purity and yield of 1,2-dichloroethylene in each embodiment and comparative example were calculated by gas chromatography, wherein the gas chromatograph was equipped with a FID detector and a DB-1 capillary column, and the specification of the capillary column was 30m*0.25μm. The results are shown in Table 1.

[0041] Table 1

[0042] Yield (%) purity(%) Example 1 92.3 98.2％ Example 2 91.7 98.1％ Example 3 93.1 97.9％ Comparative Example 1 40.4 90.4％ Comparative Example 2 63.6 91.2％

[0043] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 2 in Table 1, it can be found that the 1,2-dichloroethylene prepared by the present invention has a higher purity and yield, indicating that the molecular sieve is a type of crystalline aluminosilicate with various ordered microporous networks and large active surface structures, which has good thermal stability and catalytic performance, and can be used as a catalyst or a catalyst carrier. The molecular sieve is first treated with an alkali to obtain a porous molecular sieve containing large pores, thereby increasing the surface area of ​​the molecular sieve and improving the catalytic efficiency. The acid treatment can then wash away the amorphous aluminum species remaining on the inner and outer pore walls of the molecular sieve after the alkali treatment, making the pore structure more unobstructed, and the pore structure and acid properties can be further adjusted, thereby reducing the situation where the catalyst is deactivated due to the attachment of carbon deposits. Then, a silane coupling agent is used to graft double bonds on the surface of the molecular sieve, and it can be polymerized with 1-vinyl-3-octylimidazole tetrafluoroborate and 1-vinyl-3-ethylimidazole tetrafluoroborate under initiator conditions. 1-vinyl-3-octylimidazole tetrafluoroborate and 1-vinyl-3-ethylimidazole tetrafluoroborate are a type of borate with high thermal stability. Acidic sites and hydrophobic silane long chains can also be introduced on the surface of the molecular sieve. The introduction of acidic sites can further improve the catalytic activity of the molecular sieve; then, the modified molecular sieve is used as a catalyst in a fixed bed reaction device to catalyze the gas phase cracking of 1,1,2-trichloroethane to generate a dichloroethylene mixture, and finally, the dichloroethylene mixture is distilled to obtain high-purity 1,2-dichloroethylene.

[0044] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection 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 scope of protection of the present invention.

Claims

1. A production process for high-purity 1,2-dichloroethylene, characterized in that: The method comprises the following preparation steps: (1) mixing the acid-base composite treated molecular sieve, allyl trimethoxysilane and anhydrous ethanol in a mass ratio of 1: (1.5-2.0): (50-60) evenly, ultrasonically dispersing at 40 Hz for 10-20 min, stirring for 10-12 h, filtering and washing with ethanol for 3-5 times, stirring at 70-80 ° C for 50-60 min, and drying at 60 ° C for 6-8 h to obtain an allyl-containing molecular sieve; (2) mixing allyl molecular sieve, 1-vinyl-3-octylimidazole tetrafluoroborate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, benzoyl peroxide and dimethyl sulfoxide evenly, reacting at 80° C. for 4-5 hours, filtering and washing with methanol for 3-4 times, and drying at 60° C. for 6-8 hours to obtain a modified molecular sieve; (3) Weighing the modified molecular sieve and 1,1,2-trichloroethane, the mass ratio of 1,1,2-trichloroethane to the molecular sieve is 1:(200-300), placing the modified molecular sieve in a quartz reaction tube of a fixed reaction bed device to form a catalyst bed, and preheating the reaction tube at 300° C. for 1.5-2 h in a nitrogen atmosphere, with a nitrogen flow rate of 30 mL / min; placing 1,1,2-trichloroethane in a saturator under ice bath conditions, using nitrogen to pass 1,1,2-trichloroethane into the catalyst bed, the catalyst bed temperature is 300° C., the space velocity is 2000 mL / (g*h), and a 1,2-dichloroethylene mixture is obtained. The 1,2-dichloroethylene mixture is condensed in a condenser to obtain a 1,2-dichloroethylene mixed liquid, the condensation temperature is 0-10° C., and the 1,2-dichloroethylene mixed liquid is distilled to obtain high-purity 1,2-dichloroethylene.

2. A process for producing high-purity 1,2-dichloroethylene according to claim 1, characterized in that: The preparation method of the acid-base composite treated molecular sieve in step (1) is as follows: the molecular sieve and 0.3 mol / L sodium hydroxide solution are mixed uniformly in a mass ratio of 1: (20-25), stirred at 70-80°C for 50-60 min, filtered and washed with pure water for 3-5 times, and then dried at 60°C for 6-8 h to obtain an alkali-treated molecular sieve; the alkali-treated molecular sieve and 0.1 mol / L hydrochloric acid solution are mixed uniformly in a mass ratio of 1: (10-15), stirred at 70-80°C for 50-60 min, and dried at 60°C for 6-8 h to obtain an acid-base composite treated molecular sieve; wherein the molecular sieve model is AS-VZ3.

3. A production process for high-purity 1,2-dichloroethylene according to claim 1, characterized in that: The amounts of the allyl molecular sieve, 1-vinyl-3-octylimidazole tetrafluoroborate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, benzoyl peroxide and dimethyl sulfoxide in step (2) are as follows: 1 part of modified molecular sieve, 0.1-0.3 parts of 1-vinyl-3-octylimidazole tetrafluoroborate, 0.3-0.5 parts of 1-vinyl-3-ethylimidazolium tetrafluoroborate, 0.03-0.05 parts of benzoyl peroxide and 15-20 parts of dimethyl sulfoxide.

4. A process for producing high-purity 1,2-dichloroethylene according to claim 1, characterized in that: The specific operation steps of the distillation in step (3) are to heat the 1,2-dichloroethylene mixture to 35-40°C for 20-30 minutes, continue heating to 60-65°C, and collect it using a condenser with a condenser temperature of 0-10°C and a heating time of 50-60 minutes to obtain high-purity 1,2-dichloroethylene.

5. 1,2-dichloroethylene produced according to the production process of high-purity 1,2-dichloroethylene according to any one of claims 1 to 4.