SU979314A1 - Process for producing vinyl chloride - Google Patents

Description

The invention relates to the field of petrochemical synthesis, in particular to an improved method for producing vinyl chloride from dichloroethane, and can be used to obtain a vinyl chloride monomer used to produce polyvinyl chloride and various copolymers.

A known method of producing vinyl chloride from dichloroethane by dehydrochlorination with alcoholic solutions of potassium hydroxide [1]. The yield of vinyl chloride in this method is not high enough (about 90%). In addition, methyl or ethyl alcohols are used in the process.

According to the technical nature and the achieved result, the closest method is to obtain chloralkenes by dehydrochlorination of chloralcanes with an aqueous solution of alkali metal hydroxides at 30-100 ° C in the presence of a quaternary ammonium chloride chloride catalyst, taken in an amount of 1-10% [2 J. Yield of chloralkenes 60- 95% According to this method, dehydrochlorination of dichloroethane can be carried out to obtain vinyl chloride. The disadvantage of this method is the limited (up to 95%) yield of the target product.

The aim of the invention is led away _s chenie vinyl chloride yield.

e object is achieved by a method for producing vinyl chloride by dehydrochlorination of ethylene dichloride in the presence of potassium hydroxide hlo.0 Reed quaternary ammonium base ^υ Nij in an aromatic solvent at the boiling point of the reaction mixture and the volume ratio of dichloroethane ·: aromatic solvent - 1: 1.4-1.6 .

Distinctive features of the method is the process in a medium of aromatic solvent at. the boiling point of the solution and the volume ratio of dichloroethane: aroma 20 -tical solvent -1: 1.4-1.6. As a rule, benzene or toluene is used as an aromatic solvent,

This method allows to obtain vinyl chloride from dichloroethane practically · with a quantitative yield (without the use of an aromatic solvent under comparable conditions, the yield of vinyl chloride does not exceed 80%).

According to the proposed method of dehydrochlorination of dichloroethane into a flask equipped with a stirrer, a thermometer, a dropping funnel and a well-cooled (-10 - -15 ° С) reflux condenser, the upper part of which is connected to a 5-yen receiver trap placed in a Dewar vessel (-50 -40 ° C) pour the aromatic solvent · and catalyst, and with vigorous stirring add caustic potassium. 10 Bring the temperature of the reaction mixture to the boiling point of the solvent with heating. Then dichloroethane was added dropwise slowly over 1 hour. After 10-15 minutes, an energy-15 release of vinyl chloride begins, the main part of which is released within 1-1.5 hours. To complete the dehydrohalogenation process, the reaction mixture is stirred for another 20 to 1-1.5 hours until the complete release of vinyl chloride.

Solid residues consisting of KC1, unreacted, are separated from the reaction mass by filtration.

KOH, water and catalyst. The resulting aromatic solvent filtrate can be sent to the reactor for reuse, and the catalyst can be separated from the solid residue by dissolving in water and subsequent separation, and also

To 30 ml (2.60 g) g of catamine - AB dimethylbenzyl was sent to the reactor.

The following are examples of the process.

Example 1

toluene is poured 1 (53% aqueous solution of ammonium chloride)

CH ₅ - N ⁺ - R

I sn _e - ^e bee ₅ .

gle R - C ₁₂ -C ₁₄

SG was added 16.8 g of KOH, 19.8 g of dichloroethane was added dropwise with stirring at the boiling point of toluene for 1 hour. After 3 hours of operation in a trap after refluxing, 12.8 g of a product consisting of 12.45 g of vinyl chloride and 0.35 g of toluene. After filtration, 25.4 g of a solid residue is obtained, consisting of 14.8 g of KCl, 5.7 KOH,

4.1 g of H ₂ O, 0.3 g of toluene and 0.5 g of catamine. The liquid filtrate (25.5 g) consists of 25.4 toluene, 0.1 g of dichloroethane and contains traces (about 0.3%) of water. The conversion of dichloroethane is 99.6%, the yield of vinyl chloride on the passed dichloroethane is 99.6%, the yield of vinyl chloride on the reacted dichloroethane is 100.0%.

Example 2 (comparative).

2 g of catamine are added to 53.2 ml of water, 22.4 g of KOH are added, and with stirring, 19.8 g of dichloroethane are added dropwise at the boiling point of water for 1 hour. After 3 hours of installation operation, 10.0 g of vinyl chloride was obtained; the yield of vinyl chloride on skipped dichloroethane was 80.0%.

Example 3. To 30 ml of benzene, 1 "g of catamine, 16.8 g of KOH are added dropwise

19.8 g of dichloroethane at the boiling point of benzene. For 3 hours of operation of the vinyl chloride plant, 12.5 g was obtained, the yield of vinyl chloride is 100%.

Example 4. To 30 ml of benzene, 0.5 g of catamine, 16.8 g of KOH, 19.8 g of dichloroethane are added. Under the same conditions as in Example 3, 12 g (96.5%) of vinyl chloride were obtained.

Example 5. To 30 ml of benzene, g of cathinol (di / β-hydroxyethyl / benzylacetyl ammonium chloride

C ₂ H ₄ OH

CfrHs ^- N - C ₁₇ Hj5 s _r n ₄ he

Cl

16.8 g of KOH, 19.8 g of dichloroethane are added dropwise. Under conditions analogous to Example 3, 12 g (96.5%) of vinyl chloride were obtained.

Example 6. Similar to example 3, but instead of catamine, 1 g of cetylpyridinium chloride was used as a catalyst. From 19.8 g of dichloroethane, 12.5 g (100%) of vinyl chloride are obtained.

Example 7. Similar to example 3, but instead of catamine, 1 g of triethylbenzylammonium chloride was used as a catalyst. Received 12.5 g of vinyl chloride (100%) from 19.8 g of dichloroethane.

The process of dehydrohalogenation of dichloroethane is carried out with potassium hydroxide in an aromatic solvent in the presence of a catalyst, which is used as a series of chlorides of quaternary ammonium ·· bases.

This method allows to obtain vinyl chloride from dichloroethane with almost quantitative yield.

The separation of the reaction mass after the process allows you to fully return to the process an aromatic solvent and catalyst.

Claims (2)

According to the proposed method, dehydrochlorination of dichloroethane in a flask equipped with a stirrer, a thermometer, a dropping funnel and well cooled (-10 - -15 ° C) was cooled by a nickname, the upper part of which is connected to a receiver trap placed in a Dewar vessel (- 50 - -40 ° C) the aromatic solvent and catcher are poured, and potassium hydroxide is added with vigorous stirring. The temperature of the reaction mixture is brought to the boiling point of the solvent while heating. Dichloroethane is then slowly added dropwise over 1 hour. After 10-15 minutes, vigorous release of vinyl chloride begins, most of which is released within 1-1.5 hours. To complete the dehydrohalogenation process, the reaction mixture is stirred for an additional 1-1.5 hours to complete vinyl chloride excretion. From the reaction mass, solid residues consisting of KC1, unreacted KOH, water and catalyst are separated by filtration. The resulting aromatic solution filtrate from the phone can be sent to the reactor for reuse, and the catalyst can be separated from the solid residue by dissolving in water and subsequent separation and also sent to the reactor. The following are examples of the process. Example 1. To 30 ml (2.60 g) of toluene, 1 g of catamine - LB (53% aqueous solution of dimethylbenzylammonium chloride) of OH5 CH5-W -R Ci is poured where R is 12 4 CH5-SbHe. 16.8 g of KOH are introduced; 19.8 g of dichloroethane are added dropwise with stirring at the boiling point of toluene. for 1 hour. After 3 hours of operation of the unit, 12.8 g of a product consisting of 12.45 g of vinyl chloride and 0.35 g of toluene was obtained in a trap after refluxing the refrigerator. After filtration, 25.4 g of a solid residue was obtained consisting of 14.8 g of KCl, 5.7 KOH, 4.1 g of HjO, 0.3 g of toluene and 0.5 g of catamine. The liquid filtrate (25.5 g) consists of 25.4 toluene, 0.1 g dichloroethane and contains traces (about 0.3%) of water. Conversion of dichloroethane 99, 6%, the yield of vinyl chloride on the missed dichloroethane was 99.6%, the yield of vinyl chloride on the reacted dichloroethane was 100.0%. Example 2 (comparative). To the 53.2 ml of water, 2 g of catamine are added, 22.4 g of KOH are introduced and 19.8 g of dichloroethane are added dropwise with stirring at the boiling point of water for 1 hour. After 3 hours of operation, 10.0 g of vinyl chloride was obtained, the yield of vinyl chloride to missed dichloroethane was 80.0%. Example 3. To 30 ml of benzene, 1.G of katamine, 16.8 g of KOH, 19.8 g of dichloroethane are added dropwise at the boiling point of benzene. In 3 hours of operation of the vinyl chloride plant, 12.5 g was obtained, the yield of vinyl chloride was 100%. Example 4. To 30 ml of benzene, 0.5 g of catamine, 16.8 g of KOH add 19.8 g of dichloroethane. In analogy to Example 3, 12 g (96.5%) of vinyl chloride was obtained. Example 5. To 30 ml of benzene, 1 g of cathinol (di / fs -oxyethyl / benzyl-acetylammonium chloride CbH-N - C „Hz5 CgHicai 16.8 g of KOH, 19.8 g of dichloroethane were added dropwise. 12 g (96.5%) of vinyl chloride. Example 6: Analogs, example 3, but 1 g of cetylpyridinium chloride was used as a catalyst instead of catamine. From 19.8 g of dichloroethane, 12.5 g (100%) of vinyl chloride was obtained. Similar to example 3, but instead of catamine, 1 g of triethylbenzylammonium chloride was used as a catalyst, 12.5 g of vinyl chloride (100%) were obtained from 19.8 g of dichloroethane. The ester dehydrohalogenation of dichloroethane is carried out with potassium hydroxide in an aromatic solvent in the presence of a catalyst, which uses a series of quaternary ammonium chloride chlorides. This method allows to obtain vinyl chloride from dichloroethane with a quantitative yield. aromatic solvent and catalyst. Claim 1. Method for producing vinyl chloride by dehydrochlorinating dichloroethane with potassium hydroxide using quaternary ammonium chloride as a catalyst, characterized in that, in order to increase the yield of vinyl chloride, the process is carried out in an aromatic solvent at a temperature of 59593146 Neither the reaction mixture "volume sources of information, the ratio of dichloroethane and aroma-taken into account in the examination a cic solvent 1: 1.4-1.6.1. Organochlorine organochlorine 2. The method according to claim 1, whether or not. A. Oshina, M., Himi, 1978, q. 58. i u and with the fact that in quality 5 2. USSR Author's Certificate aromatic solvent used - 771081, cl. C 07 C 21/04, toluene or benzene are synthesized. C 07 C 1/14 1978,. products. Handbook ed.