TWI610907B - Method of producing vinyl chloride - Google Patents

Abstract

The present invention provides a method for producing vinyl chloride, which may include introducing 1,2-dichloroethane gas into a reactor; and in the above reactor, in the presence of a metal organic skeleton catalyst having a specific structure, The 1,2-dichloroethane gas is subjected to a catalytic cracking step to form vinyl chloride. The catalytic cracking step can be carried out at a cracking temperature of from 200 ° C to 300 ° C. The conversion rate of 60% to 90% of 1,2-dichloroethane can be achieved by the above production method.

Description

Method for producing vinyl chloride

The present invention relates to a method for producing vinyl chloride, and more particularly to a method for producing a vinyl chloride by applying a metal organic skeleton catalyst to a catalytic cracking step. The above manufacturing method can effectively reduce the cracking temperature and increase the conversion rate of 1,2-dichloroethane to produce vinyl chloride.

Poly Vinyl Chloride (PVC) has the advantages of acid and alkali corrosion resistance, heat resistance, etc., and its texture can be soft, elastic or brittle. Therefore, it is widely used in refractory materials, artificial leather and disposable plastic gloves in today's industry. Floor, tablecloth or plastic shoes and other products.

Polyvinyl chloride is obtained by polymerizing vinyl chloride. Therefore, various methods for preparing vinyl chloride have also been developed. In general, a conventional method for producing vinyl chloride can, for example, directly chlorinate ethylene or first form 1,2-dichloroethane (EDC) by oxychlorination, followed by thermal cracking at about 500 ° C. The reaction is carried out to obtain vinyl chloride.

Specifically, the above-mentioned reaction for thermal cracking using 1,2-dichloroethane is carried out industrially using a 1,2-dichloroethane-vinyl chloride thermal cracking furnace (EDC-Vinyl Chloride Monomer (VCM) Furnace). , Among them, the conversion rate of 1,2-dichloroethane is about 55% to 60%. The temperature of the above EDC-VCM pyrolysis furnace is between 490 ° C and 500 ° C. The higher the cracking temperature, the higher the conversion rate of 1,2-dichloroethane, but the higher the reaction temperature makes the energy The consumption is increased, the by-product concentration is increased, and the amount of carbon deposited in the thermal cracking furnace is increased, which in turn increases the manufacturing cost.

In order to solve the above problems, there is currently a method for assisting the cracking reaction of 1,2-dichloroethane by a cracking catalyst, thereby producing vinyl chloride at a lower reaction temperature. The use of cracking catalysts can reduce energy consumption, reduce by-product concentration, and carbon deposits, thereby reducing process hazards and manufacturing costs. In general, common cleavage catalysts comprise a carrier and an active ingredient, wherein the active ingredient is primarily a metal chloride.

However, the aforementioned cracking catalyst having a metal chloride as an active component has a short service life and is often required to be replaced in practical use. Further, the above-mentioned cracking catalyst having a metal chloride as an active component has a low unit yield. For various reasons as described above, the currently known cracking catalysts are still unable to effectively reduce the manufacturing cost of vinyl chloride.

Metal Organic Framework (MOF) is a solid with a permanent pore structure, which is a three-dimensional structure produced by bonding metal ions or nodes between metal clusters and various organic groups. In recent years, metal-organic framework catalysts having crystal properties, high specific surface area, large pore diameter, and low density have been frequently used in various catalytic reactions. For example, metal-organic framework catalysts can be used in the fields of gas storage, purification, molecular sensing, drug delivery, and photocatalysis.

However, as a metal organic skeleton catalyst, the metal species and There are a wide variety of organic groups bonded to it, and its selectivity and stability for specific application areas remains to be explored. Furthermore, there is currently no metal-organic framework catalyst for cracking 1,2-dichloroethane gas to produce a catalytic cracking step of vinyl chloride.

In view of the above advantages and development of the metal-organic framework catalyst, it is urgent to propose a method for producing vinyl chloride, which is to apply a metal-organic framework catalyst to the catalytic cracking step, thereby reducing the cracking temperature and increasing the catalyst unit. The yield and the conversion rate of 1,2-dichloroethane are effectively increased to obtain vinyl chloride.

Accordingly, an aspect of the present invention provides a method for producing vinyl chloride which is subjected to a catalytic cracking step using a metal organic skeleton catalyst. In the process of the present invention, the metal-organic framework catalyst has a high catalyst unit yield and can increase the conversion of 1,2-dichloroethane at low temperatures.

According to the above aspect of the invention, a method for producing vinyl chloride is proposed. In one embodiment, the above manufacturing method may comprise the steps of first introducing 1,2-dichloroethane gas into the reactor. Thereafter, in the above reactor, the 1,2-dichloroethane gas is subjected to a catalytic cracking step in the presence of a metal organic skeleton catalyst to form vinyl chloride. Wherein, the catalytic cracking step can be carried out at a cracking temperature of 200 ° C to 300 ° C, and the metal organic skeleton catalyst has a structure represented by the following formula (I): M1 [(M2) x (L1) (L2) y] (I)

In formula (I), M1 and M2 may be selected from the group consisting of zinc ions (Zn ²⁺ ), copper ions (Cu ²⁺ ), cobalt ions (Co ²⁺ ), aluminum ions (Al ³⁺ ), and chromium ions (Cr). ³⁺ ) One of the groups consisting of L1 may be selected from one of a group consisting of a benzoic acid group and a pyridyl group, and L2 may be selected from a nitrate ion, a chloride ion, an ammonia ion (- One of a group consisting of NH ₂ ), a sulfonate ion (-SO ₃ H), and an oxy group, x may be 0 or 1, and y may be an integer from 0 to 3.

According to an embodiment of the present invention, the reaction weight ratio of the metal-organic framework catalyst to the 1,2-dichloroethane gas 毎 hour may be 1:15 to 2:1.

According to an embodiment of the invention, the benzoic acid group may be p-nitrobenzoic acid or sodium 2-sulfonate terephthalate.

According to an embodiment of the present invention, the pyridyl group may be 2,2'-bipyridyl or 4,4'-bipyridyl.

According to an embodiment of the invention, the reactor may be a fixed bed reactor or a fluidized bed reactor.

According to an embodiment of the present invention, in the aforementioned catalytic cracking step, the residence time of the 1,2-dichloroethane gas in the reactor may be from 5 seconds to 100 seconds.

According to an embodiment of the invention, the gas space velocity of the 1,2-dichloroethane gas in the reactor may range from 10/hour to 1000/hour.

According to an embodiment of the invention, the catalytic cracking step can be carried out at a pressure of from 0.1 MPa to 1.5 MPa.

According to an embodiment of the present invention, the conversion of 1,2-dichloroethane gas may be from 60% to 90%.

A method for producing vinyl chloride according to the present invention, which uses gold It is an organic skeleton catalyst for catalytic cracking step, which can increase the conversion rate of 1,2-dichloroethane at a low temperature to obtain vinyl chloride.

One aspect of the present invention is to provide a method for producing vinyl chloride by performing a catalytic cracking step using a metal-organic framework catalyst of a specific structure, wherein the metal-organic framework catalyst and 1,2-dichloroethane gas have Specific reaction weight ratio. By the above production method, the conversion ratio of 1,2-dichloroethane can be increased at a low temperature to obtain vinyl chloride. The method for producing vinyl chloride of the present invention has the advantages of high catalyst unit yield and short residence time, thereby reducing the production cost of vinyl chloride.

The metal organic skeleton catalyst referred to herein may have the structure represented by the following formula (I): M1[(M2)x(L1)(L2)y] Formula (I)

In formula (I), M1 and M2 are selected from the group consisting of zinc ions (Zn ²⁺ ), copper ions (Cu ²⁺ ), cobalt ions (Co ²⁺ ), aluminum ions (Al ³⁺ ), and chromium ions (Cr). ³⁺ ) One of the groups consisting of L1 selected from one of a group consisting of a benzoic acid group and a pyridyl group, and the L2 system is selected from the group consisting of nitrate ions, chloride ions, and ammonia ions (-NH) ₂ ), one of a group consisting of a sulfonate ion (-SO ₃ H) and an oxy group, x is 0 or 1, and y is an integer from 0 to 3.

Preferably, the benzoic acid group described above may be p-nitrobenzoic acid or sodium 2-sulfonate terephthalate. Preferably, the above pyridyl group may be 2,2'-bipyridyl or 4,4'-bipyridyl.

The reaction weight ratio referred to herein as the weight refers to the weight of the metal-organic framework catalyst required to crack a specific weight of 1,2-dichloroethane gas during the catalytic cracking step.

The catalyst unit yield referred to herein is the amount of 1,2-dichloroethane gas per unit weight of metal-organic framework catalyst cleavable per hour. The smaller the weight ratio of the above reaction per hour, the more unity parts of the metal organic skeleton catalyst cleavable 1,2-dichloroethane gas, so the higher the catalyst unit yield.

The term "low temperature" as used herein means that the catalytic cracking step can be carried out at a temperature of from 200 ° C to 300 ° C.

In one embodiment, the method for producing vinyl chloride of the present invention may comprise the steps of first introducing a 1,2-dichloroethane gas into the reactor. Thereafter, in the above reactor, the 1,2-dichloroethane gas is subjected to a catalytic cracking step in the presence of a metal organic skeleton catalyst represented by the above formula (I) to form vinyl chloride. Wherein, the catalytic cracking step can be carried out at a cracking temperature of 200 ° C to 300 ° C.

If the above metal-organic framework catalyst is not used, the catalytic cracking step cannot be carried out at a cracking temperature of not higher than 300 °C. Further, when a metal organic skeleton catalyst other than the metal organic skeleton catalyst represented by the above formula (I) is used, the catalyst unit yield is low and the conversion effect of 1,2-dichloroethane is not good. Further, if the above-mentioned cracking temperature is higher than 300 ° C, by-products are easily generated after the cracking of 1,2-dichloroethane, but if the cracking temperature is lower than 200 ° C, 1,2-dichloroethane cannot be completely cracked. Therefore, if the cracking temperature of the catalytic cracking step does not fall within the range claimed by the present invention, the conversion rate of 1,2-dichloroethane is lowered. It affects the yield of vinyl chloride.

In one embodiment, the reaction ratio of the metal organic skeleton catalyst to the 1,2-dichloroethane gas per hour may be from 1:15 to 2:1. If the above reaction weight ratio is less than 1:15, the metal organic skeleton catalyst cannot maintain a high cracking rate, and the conversion rate of 1,2-dichloroethane is lowered, thereby affecting the yield of vinyl chloride. If the above reaction weight ratio is higher than 2:1, there is an opportunity to increase the conversion ratio of 1,2-dichloroethane, but the catalyst unit yield and productivity are greatly reduced, thereby increasing the manufacturing cost of vinyl chloride.

In one embodiment, the reactor described above can be a fixed bed reactor or a fluidized bed reactor.

In one embodiment, the residence time of the 1,2-dichloroethane gas in the reactor can range from 5 seconds to 100 seconds. If the residence time is too short, the cracking of 1,2-dichloroethane gas is incomplete, resulting in a decrease in the yield of vinyl chloride and the production of by-products. If the above residence time is too long, it does not benefit from the preparation of vinyl chloride.

In one embodiment, the gas space velocity of the 1,2-dichloroethane gas in the reactor can range from 10/hour to 1000/hour.

In one embodiment, the catalytic cracking step can be carried out at a pressure of from 0.1 MPa to 1.5 MPa.

In one embodiment, the conversion of 1,2-dichloroethane of 60% to 90% can be achieved by the method for producing vinyl chloride of the present invention.

Hereinafter, a method for producing the above-described metal-organic framework catalyst will be described, wherein x of the above formula (I) is 0 (hereinafter referred to as a first type metal organic skeleton catalyst) or x is 1 (hereinafter referred to as second The two cases of the metal-organic framework catalyst are described separately.

Preparation of the first type of metal organic skeleton catalyst

First, a benzoic acid compound of 0.37 millimolar to 37.29 millimolar, a pyridine compound or a salt thereof, and a first metal salt of 1 millimolar to 100 millimolar are added, containing 2.59 millimolar to 259 milligrams. 1 ml of concentrated hydrochloric acid of 12N to 500 ml of deionized water or 1 ml to 500 ml of dimethylformamide. Next, it is heated at 100 ° C to 300 ° C for 1 day to 10 days to obtain a crude product. After the crude product is dried, it is washed and purified to obtain the first type of metal organic skeleton catalyst of the present invention.

In one embodiment, the above cleaning and purification may, for example, wash the crude product with hot deionized water and dry it, and then mix it with 1 ml to 500 ml of ethanol at a pressure of 0.5 MPa to 250 MPa and 100 ° C to 300 ° C. Heat at temperature for 10 to 72 hours. After filtration and drying, refluxing is carried out using 1 ml to 500 ml of ammonium fluoride at 10 ° C to 150 ° C for 5 hours to 50 hours. After washing and drying with deionized water at 20 ° C to 80 ° C, the first type of metal organic skeleton catalyst of the present invention is obtained.

In another embodiment, the above cleaning and purification can be carried out, for example, by a soxhlet extraction method using methanol as a washing liquid for 72 hours to 120 hours, followed by drying to obtain a first type of metal organic skeleton catalyst of the present invention.

The salt of the benzoic acid compound referred to herein may be, for example, a benzene having a functional group such as a nitrate ion, a chloride ion, an ammonia ion (-NH ₂ ), a sulfonate ion (-SO ₃ H) or an oxy group. Sodium formate salt.

The salt of the pyridine compound referred to herein may be, for example, a sodium pyridine having a functional group such as a nitrate ion, a chloride ion, an ammonia ion (-NH ₂ ), a sulfonate ion (-SO ₃ H) or an oxy group. salt.

The first metal salt referred to herein as a metal salt may be, for example, a metal salt of zinc, copper, cobalt, aluminum or chromium.

Preparation of a second type of metal-organic framework catalyst

The second type of metal organic skeleton catalyst is prepared by further reacting the first type of metal organic skeleton catalyst described above. The first type metal organic skeleton catalyst of 0.5 millimolar to 50 millimolar is heated in a vacuum to 50 ° C to 200 ° C for 12 hours to 72 hours to remove pores of the first type metal organic skeleton catalyst The gas in it. Next, mixing the degassed first type metal organic skeleton catalyst, the second metal salt of 0.075 millimolar to 7.5 millimolar, and the anhydrous ethanol of 10 ml to 1000 ml in an oxygen-containing environment (purity greater than 99.5) %) to form a second mixture. The second mixture is heated to 50 ° C to 300 ° C and held at a temperature of 12 hours to 72 hours to obtain a second type of metal organic skeleton catalyst of the present invention.

In one embodiment, the second type metal organic skeleton catalyst can be cleaned by using methanol and deionized water, and the second type metal organic skeleton catalyst is heated under vacuum at 50 ° C to 200 ° C for 12 hours to 72 hours. Hours to further enhance the purity of the prepared second type metal-organic framework catalyst.

The second metal salt referred to herein may be, for example, a metal salt of zinc, copper, cobalt, aluminum or chromium. Further, the aforementioned first metal salt and second metal salt have different metal ions.

In particular, the relative amounts of L1 and L2 in the formula (I) depend on the benzoic acid compound, the pyridine compound and the salt thereof to be used. It depends on the ratio and type of the functional group on the benzoic acid compound, the pyridine compound, and the salt thereof.

Hereinafter, the mode of carrying out the present invention will be specifically described using a plurality of preparation examples and examples.

Preparation Example 1

3.35 grams (12.5 millimoles) of sodium 2-sulfonate p-dibenzoic acid, 1.25 grams (12.5 millimoles) of chromium oxide (CrO ₃ ) and 0.91 grams (25 millimoles) of 12N concentrated hydrochloric acid In 50 ml of deionized water. Next, the above mixed solution was poured into a Teflon-lined stainless steel hydrothermal kettle, and hydrothermal reaction was carried out at 200 ° C for 6 days. Thereafter, it was filtered and washed three times with 400 ml of boiled deionized water, and then dried to form a first purified product. Then, the first purified product and 40 ml of ethanol were mixed and heated at 100 ° C for 20 hours in an autoclave (pressure of about 250 MPa) to form a second purified product. Further, after drying under vacuum at 150 ° C for 6 hours, the second purified product was refluxed with 300 ml of ammonium fluoride (30 mM) at 60 ° C for 10 hours. Thereafter, the washing step was carried out three times with hot deionized water at 60 ° C, and after filtration, drying was carried out to obtain a first type metal organic skeleton catalyst. The metal organic framework catalyst was vacuum heated to 150 ° C for 48 hours to remove gas from its pores. Next, 500 mg of the first type metal organic skeleton catalyst, 300 mg (2.24 mmol) of aluminum chloride, and 100 ml of absolute ethanol (purity 99.5%) were mixed in a nitrogen-filled glove box. Thereafter, the above mixed solution was heated to 90 ° C and held at a temperature for 24 hours to obtain an unpurified metal organic skeleton catalyst of Preparation Example 1. Next, the above-mentioned unpurified metal organic skeleton catalyst of Preparation Example 1 was filtered, and residual aluminum chloride was removed with methanol, and washed with deionized water and methanol. Thereafter, vacuum heating was carried out at 105 ° C for 12 hours to obtain a metal organic skeleton catalyst of Preparation Example 1.

Preparation Example 2

3.5 g (21.01 mmol) of terephthalic acid and 4 g (21.1 mmol) of zinc nitrate (Zn(NO ₃ ) ₂ ) were dissolved in 150 ml of dimethylformamide. Next, the above mixed solution was poured into a Teflon-lined stainless steel hydrothermal kettle, and hydrothermal reaction was carried out at 180 ° C for 2 days. Thereafter, the mixture was filtered and washed three times with dimethylformamide, followed by drying. Next, the metal organic skeleton catalyst of Preparation Example 2 was obtained by a soxhlet extraction method using methanol as a washing liquid for 12 hours and then drying.

Preparation Example 3

3.5 g (22.41 mmol) of 2,2'-bipyridine and 3 g (21.07 mmol) of aluminum chloride (AlCl ₃ ) were dissolved in 200 ml of dimethylformamide. Next, the above mixed solution was poured into a Teflon-lined stainless steel hydrothermal kettle, and hydrothermal reaction was carried out at 150 ° C for 3 days. Thereafter, the mixture was filtered and washed three times with dimethylformamide, followed by drying. Next, the metal organic skeleton catalyst of Preparation Example 3 was obtained by a soxhlet extraction method using methanol as a washing liquid for 12 hours and then drying.

Preparation Comparative Example 1

First, the activated carbon is refluxed with 1N hydrochloric acid at 80 ° C. 24 hours for surface treatment. Thereafter, the above activated carbon was washed with pure water and dried in a vacuum oven at 120 °C. The surface treated activated carbon was immersed in a 10 wt.% aqueous solution of ruthenium chloride for 24 hours in a vacuum atmosphere at 30 ° C, and then taken out and allowed to stand. Next, after drying in a vacuum oven at 120 ° C, the metal chloride catalyst of Comparative Example 1 was prepared.

Preparation Comparative Example 2

Preparation Comparative Example 2 was prepared in the same manner as in Preparation Comparative Example 1, except that Comparative Example 2 was prepared by replacing cerium chloride with calcium chloride.

Example 1

Example 1 was carried out using the metal organic skeleton catalyst of Preparation Example 1. First, 50 g of the metal organic skeleton catalyst of Preparation Example 1 was placed in a fluidized bed reactor. Next, 1,2-dichloroethane gas was introduced into a fluidized bed reactor, and 1,2-dichloroethane gas was brought into contact with a metal organic skeleton catalyst, and vinyl chloride was obtained. Among them, the residence time of 1,2-dichloroethane gas is 25 seconds, the gas space velocity is 130/hour, the temperature in the fluidized bed reactor is 220 °C, and the metal organic skeleton catalyst and 1,2-two The reaction weight ratio of ethyl chloride gas per hour is 1:5. The conditions and the evaluation results of Example 1 are shown in Table 1.

Examples 2 to 3 and Comparative Examples 1 to 2

Examples 2 to 3 and Comparative Examples 1 to 2 were carried out in the same manner as in Example 1, except that Examples 2 to 3 and Comparative Examples 1 to 2 were used. The metal-organic framework catalyst or process conditions used are changed. The conditions and evaluation results of Examples 2 to 3 and Comparative Examples 1 to 2 are shown in Table 1, and are not described herein.

Evaluation method

Pyrolysis temperature

The term "cracking temperature" as used herein refers to the temperature required for the cracking of 1,2-dichloroethane to vinyl chloride in the presence of a metal organic skeleton catalyst in the manufacture of vinyl chloride. In general, the lower the pyrolysis temperature of 1,2-dichloroethane, the better the catalytic performance of the metal-organic framework catalyst.

2. 1,2-Dichloroethane conversion rate

The 1,2-dichloroethane (EDC) conversion referred to herein is calculated by the following formula (II).

，其中

,among them

Table 1

Please refer to Table 1 below. Embodiments 1 to 3 of the present invention can carry out a catalytic cracking step at a low temperature of 200 ° C to 300 ° C in the presence of a metal organic skeleton catalyst, and can reach 60% to 90% of 1,2-dichloroethane. Conversion rate. In addition, the use of a metal-organic framework catalyst can also shorten the residence time, thereby increasing the production efficiency of vinyl chloride per unit time. Further, in the case of cracking the same amount of 1,2-dichloroethane, the amount of the metal organic skeleton catalyst used is low, in other words, the catalyst unit of the metal organic skeleton catalyst of Examples 1 to 3 of the present invention. High yield.

On the other hand, according to Comparative Examples 1 to 2 of Table 1, it was found that if other types of catalysts were used, the catalytic cracking temperature was increased, the residence time was also long, and the conversion ratio of 1,2-dichloroethane was not good. Further, if the amount of 1,2-dichloroethane equivalent to the embodiment of the present invention is to be cleaved, the use amount of the catalyst of Comparative Examples 1 to 2 is high, and the catalyst unit yields of Comparative Examples 1 to 2 are low. .

According to this, the method for producing vinyl chloride of the present invention is applied by The metal organic skeleton catalyst undergoes a catalytic cracking step, which can effectively reduce the catalytic cracking temperature, increase the conversion rate of 1,2-dichloroethane, reduce the residence time of 1,2-dichloroethane, and increase the catalyst unit yield. The pyrolysis temperature of the catalytic cracking step is lowered, which can effectively increase the service life of the metal-organic framework catalyst, slow down the carbon deposition rate in the reactor, and reduce the generation of by-products, thereby improving the production efficiency of vinyl chloride and reducing the production of vinyl chloride. cost.

While the invention has been described above in terms of several embodiments, it is not intended to limit the scope of the invention, and the invention may be practiced in various embodiments without departing from the spirit and scope of the invention. The scope of protection of the present invention is defined by the scope of the appended claims.

Claims (9)

A method for producing vinyl chloride, comprising: introducing a 1,2-dichloroethane gas into a reactor: and in the reactor, in the presence of a metal organic framework (MOF) catalyst, The 1,2-dichloroethane gas is subjected to a catalytic cracking step to form vinyl chloride, and wherein the catalytic cracking step is carried out at a cracking temperature of 200 ° C to 300 ° C, and the metal organic skeleton catalyst has The structure represented by the following formula (I): M1[(M2)x(L1)(L2)y] In the formula (I), the M1 and the M2 are selected from zinc ions (Zn ^{2 ) +} ), one of a group consisting of copper ions (Cu ²⁺ ), cobalt ions (Co ²⁺ ), aluminum ions (Al ³⁺ ), and chromium ions (Cr ³⁺ ) selected from benzene One of a group consisting of a formate group and a pyridyl group selected from the group consisting of a nitrate ion, a chloride ion, an amino ion (-NH ₂ ), a sulfonate ion (-SO ₃ H), and an oxy group. To form one of a group, the x is 0 or 1, and the y is an integer from 0 to 3. The method for producing vinyl chloride according to claim 1, wherein the metal organic skeleton catalyst and the 1,2-dichloroethane gas have a reaction weight ratio of 1:15 to 2:1. The method for producing vinyl chloride according to claim 1, wherein the benzoic acid group is p-nitrobenzoic acid group or sodium 2-sulfonate terephthalic acid group. The method for producing vinyl chloride according to claim 1, wherein the pyridyl group is a 2,2'-bipyridyl group or a 4,4'-bipyridyl group. The method for producing vinyl chloride according to claim 1, wherein the reactor is a fixed bed reactor or a fluidized bed reactor. The method for producing vinyl chloride according to claim 1, wherein in the catalytic cracking step, the 1,2-dichloroethane gas has a residence time of 5 seconds to 100 seconds in the reactor. The method for producing vinyl chloride according to claim 1, wherein the 1,2-dichloroethane gas has a gas space velocity of from 10/hr to 1000/hr in the reactor. The method for producing vinyl chloride according to claim 1, wherein the catalytic cracking step is carried out at a pressure of from 0.1 MPa to 1.5 MPa. The method for producing vinyl chloride according to claim 1, wherein one of the 1,2-dichloroethane gases has a conversion ratio of 60% to 90%.